|Publication number||US5215715 A|
|Application number||US 07/727,885|
|Publication date||Jun 1, 1993|
|Filing date||Jul 10, 1991|
|Priority date||Jul 10, 1991|
|Also published as||CA2073201A1, CA2073201C, DE69222368D1, DE69222368T2, EP0522828A1, EP0522828B1|
|Publication number||07727885, 727885, US 5215715 A, US 5215715A, US-A-5215715, US5215715 A, US5215715A|
|Inventors||Stephen J. Haswell, David A. Barclay|
|Original Assignee||Cem Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (3), Non-Patent Citations (12), Referenced by (48), Classifications (24), Legal Events (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to a continuous flow microwave heated digesting system for digesting materials to be analyzed. More particularly, it is of such a system wherein a slug of such a material in a digesting medium is inserted into a carrier liquid, passed through a thin walled tube which is exposed to microwave radiation while a backpressure is maintained on it, and is then cooled, filtered and passed directly to an atomic absorption spectrometer or other suitable instrument for analysis.
Before the present invention microwave radiation had been suggested for use in heating materials to be digested and it had also been suggested that flow injection analysis could be employed wherein a sample to be analyzed could be added as a slug in a digesting fluid, such as an acid, to a carrier stream, such as water, heated by microwave radiation and analyzed by atomic spectrometry. Such disclosures are in 179 Analytica Chimica Acta 351-357 (1986), 5 J. Flow Injection Analysis, No. 2, 121-131, J. Chem. Soc. Chem. Commun. 807-809, and 236 Analytica Chimica Acta 345-350 (1990). However, such references do not describe the present apparatus and process and, in particular they do not describe applicants' use of backpressure regulation, filtration, mechanism (bubbling to promote digestion) and specifics.
In accordance with the present invention a continuous flow microwave heated digesting system comprises a chamber, a source of microwave radiation directed into the chamber, a long, thin bore chemical resistant and microwave transmissive tube in the chamber onto which the microwave radiation impinges so as to heat contents thereof, means for passing through such tube material to be digested, in a slug of a liquid digesting medium therefor, in a carrier liquid, cooling means, to cool the carrier liquid, digesting medium and material digested after such had been microwave heated, and backpressure means to maintain a backpressure on the tube contents, to prevent excessive distribution of the material and digesting medium in the carrier, so that such material is digested in the tube within a time in the range of 5 seconds to 10 minutes. Also within the invention are a process for analyzing a material, in which the described digesting system is employed, and an apparatus or system in which a certain type of filter is present to protect the backpressure regulating means and to prevent insolubles from being transmitted to an analytical apparatus, such as an atomic absorption spectrometer (AAS).
The invention will be readily understood by reference to the appended drawing, in which:
FIG. 1 is a flow diagram of the digestion system of the invention, illustrating continuous flow of carrier liquid that contains a slug of material to be digested in a digesting medium (not specifically shown in this view) being passed through the invented digestion apparatus to an atomic absorption spectrometer, which measures the contents in the sample of various elements.
FIG. 2 is a flow diagram like that of FIG. 1, but with a valving change to insert the FIG. 1 slug of digesting medium, containing material to be digested, into the carrier stream;
FIG. 3 is a flow diagram like that of FIG. 1 illustrating backflushing of a filter that protects the backpressure regulator and prevents insoluble material from entering the AAS;
FIG. 4 is a partially cutaway and sectional elevational view of a filter of this invention joined to tubing through which the carrier and slug of material undergoing digestion pass, illustrating normal flow during digestion, and backflushing of the filter;
FIG. 5 is a schematic illustration of an elongated slug of material to be digested in digesting medium, in a carrier liquid, passing through the microwave heating unit, the cooler and the back-pressure regulator, to the AAS, omitting the filter and the pressure sensor, showing slug expansion and contraction due to controlled bubbling and condensation respectfully; and
FIG. 6 is a plan view, schematically illustrated, of a position in a microwave chamber of the tubing or passage for the carrier and material undergoing heating and digestion.
In FIG. 1 carrier reservoir 11 (which usually contains water, the preferred carrier) is shown communicating with pump 13, which provides the motive force to drive the carrier and the contained slug of material to undergo digestion in the digestion medium through the system. Line or tube 15 connects the reservoir and the pump and line 17 connects the pump to a multi-position Rheodyne® valve 19. In the position of the valve illustrated the carrier passes through line or tubing 21 into microwave chamber 23, wherein the tubing is coiled in a substantially horizontal plane, and the contents thereof are subjected to heating by microwave radiation from a microwave source (not illustrated, but conventional magnetrons or other sources may be employed). The carrier and slug then pass through line 25 into a cooler 27 (preferably of the Peltier type) and then through line 29 to another Rheodyne valve 31, which, as illustrated, directs them via line 33 to filter 35 and then through line 37, valve 31 and line 39 to backpressure regulator 41 and finally to AAS 43 via line 45. Pressure sensor 47 is provided to indicate the pressure in the system. Also shown in FIG. 1 are sample addition means 49, shown as a syringe, a coil 51 of tubing, connecting tubing 53, 55, 57 and 59, valve 19 and waste container 61, the functions of which will be described later. A source of a flushing medium, such as water, which may be used to backflush filter 35, as illustrated in FIG. 3, is shown connected to waste container 63 by line 65, valve 31 and line 67.
In FIG. 2 the various parts of the system are the same as in FIG. 1, with the exception that the FIG. 1 slug of material to be digested, in its digesting medium, which was in coil 51 and lines 55 and 57, has been inserted into the carrier liquid by suitable adjustment of Rheodyne valve 19.
In FIG. 3 the system parts are also the same as those shown in FIG. 1 but in FIG. 3 there is illustrated the backflushing mode, wherein flushing fluid (usually water) is passed through line 65, valve 31 and line 37 in reverse flow to filter 35, to release any solids therefrom, which are carried with the flushing liquid through line 33, valve 31 and line 67 to waste, as represented by waste bottle 63.
FIG. 4 illustrates filter 35, which includes collar means 69 adapted to fit onto tubes 33 and 37, a mesh or fritted filter member 71, of micron sized or somewhat larger openings hand spacings between the tubes and the filter member, designated d1 and d2, with the d1 space being larger than the d2 space and being filled with fine glass wool 73.
FIG. 5 shows a slug 75 of material being digested (including the sample to be analyzed in a digesting medium) in the tubing 21 after being injected into carrier 77 and before entering the microwave heating apparatus chamber 23. During heating in the microwave chamber the slug expands in size and changes in character due to vaporization of some of the digesting medium (such as water and nitric acid), forming bubbles 79, with digesting medium containing digested sample, designated by numeral 81, adjacent to such bubbles. Some undigested particulate material from the sample, designated by numeral 83, trails behind the expanded "slug" of bubbles 79 and medium 81 and after passage through tube 25 and cooler 27 such expanded "slug" contracts to slug 85, trailed by undigested particles 83. Such particles are removed from the carrier by filter 35 (not shown in FIG. 5 but illustrated in FIGS. 1-4), after which the slug passes through backpressure regulator 41 and thence to AAS 43 (not illustrated in FIG. 5) or other analytical means.
In FIG. 6 there is illustrated a preferred form of arrangement (coiling) of the narrow bore tubing, designated 87, in the microwave chamber 23. As illustrated, the tubing is coiled about the interior wall of the chamber in a concentric pattern but other patterns and locations may also be used. The tubing may be stacked, braided, woven, balled, randomly placed or otherwise positioned so long as the contents are satisfactorily heated. In some instances it may be desirable to coil the tubing about a plurality of vertical posts or members in the chamber in the manner that a hose is coiled on a reel. Of course, care will be exercised to avoid having any kinks in the tubing unless such are to be intentionally employed to create desired backpressure on the system (which can also be accomplished with pinch clamps).
The described system may be based on a microwave heating system or apparatus like any of those described in U.S. Pat. Nos. 3,909,598; 4,438,500; 4,565,669; 4,566,312; 4,566,804 or 4,651,285, but in the work reported herein there was employed a CEM Corporation microwave heating system that such company designates as their MDS 81. Such unit has a power rating of 600 watts and in the present work operates at 80 to 100% power, e.g., at 90% power, which is preferred.
Various types of pumps may be employed to force the carrier, digesting medium and sample (mixed in with the digesting medium) through the tubing or lines and the various valves and apparatuses. Peristaltic and gear pumps made of materials not adversely affected by the carrier medium are desirably employed because they are positive flow pumps and can maintain a desirable consistent flow rate through the system and to the nebulizer of the AAS against the backpressure of the system. In the present work there is employed an Ismatec® MV-Z pump.
The tubing used in the microwave heating apparatus may be any such that will transmit microwave radiation through it and will also resist reaction with the digestion medium (and the sample and the carrier, too, of course). While the dimensions of the tubing will often depend on the characteristics of the sample material and the digesting medium, it has been found that the internal diameter (i.d.) of the tubing should usually be in a range like 0.3 or 0.5 to 2 mm preferably being in the range of 0.7 to 1 or 1.5 MM., e.g. about 0.8 MM, and the length thereof should usually be in the range of 5 to 50 meters, preferably 15 to 25 meters, e.g., about 20 meters in the microwave chamber. The overall tubing or line length, through which the sample passes, may be from 8 to 80 meters, preferably 20 to 50 meters, e.g., about 35 meters. Usually it is undesirable to employ tubing of an internal diameter less than 0.5 MM. because of possible blockages caused therein by the sample particles especially in the charging loop or coil. However, for easily digested samples and those which do not block objectionably such thinner bore tubing may be employed but even then it is best for the injection loop tubing to be of at least 0.5 MM. i.d. The preferred material of construction of the tubing is polytetrafluoroethylene (PTFE), such as Teflon®, but glass, borosilicate glass, quartz and resistant plastics, such as polyethylene and polypropylene, may also be employed under the right conditions.
The injection loop of the system should be of appropriate capacity so that the system heats the sample and the digesting medium sufficiently to digest all or substantially all of the materials analyzed for in the digesting medium and it has been found that with a feed rate to the AAS nebulizer in the range of 2 to 10 ml/min., preferably 4 to 6 ml./min., such loop should be of 0.5 to 7.5 or 10 ml capacity, preferably 0.7 to 1.5 ml capacity, e.g., about 1 ml capacity. The greater capacities, such as 7.5 ml allow multiple elemental analyses of a single digested sample to the AAS, which multiple analyses require a longer continuous signal for a longer absorption period (to allow for beam frequency changes) Ideally, the mentioned capacity and bore allow about 1 to 3 minutes for the sample to pass through the system but such period can be varied, being 5 seconds to 10 minutes in some cases, and can be in the range of 10 seconds to 3 minutes. It is normally not preferred for the heating to take more than 3 minutes, since one of the main purposes of the present invention is to speed up the analytical procedure, while retaining accuracy, but for hard to digest material more time may be needed and easily digested samples can be digested more quickly.
The valve mechanism employed to facilitate syringe injection of the analytical sample and digestion medium into the system via the loop or coil 51 may be of other designs than that illustrated in the drawing but it is preferred to employ an Anachem 5020 Rheodyne two-way injection valve or equivalent for both the introduction of the sample and digesting liquid and for facilitating of backwashing. The backpressure regulator, which is important to the invention because it facilitates condensation of the digesting medium after cooling, and prevents excessive gassing of the medium and pumping problems that can be associated with that, may be of any suitable type in the circumstances and desirably maintains the pressure in the system in the range of 30 to 120 lbs./sq. in gauge, preferably 60 to 100 lbs./sq. in. g. e.g., 75 lbs./sq. in. gauge. A suitable regulator is that identified as Anachem P736. The cooler may be of relatively simple or sophisticated design. It is possible to employ a simple ice/water bath through which the tubing may be run after exiting from the microwave chamber. However, it is preferred to utilize thermoelectric heat pump cooling devices that utilize the Peltier effect, such as those available from Melcor, sold under the name Frigichip™. The cooler will normally be effective to cool the liquid stream to a temperature in the range of 5° to 50° C. preferably 20° to 40° C. e.g., room temperature, which is usually in the range of 20° to 30° C.
The filter that is employed has been found to be especially effective in the described applications because it removes undigested particles (from which the digestible materials have been removed) from the digestion medium (containing digested material) without excessive pressure drop due to filter blockages and it does so effectively, allowing virtually no particles of objectionable size to pass through. The glass wool is of a denier like that of normal laboratory glass filter material but other glass wool products can also be utilized, and the material of construction can be changed to borosilicate glass or quartz, when that is desired, and in some cases polymeric plastic materials or mixtures of such with glass or quartz may be useful. The mesh or fritted filter means of the filter assembly will desirably have openings in the 20 to 100 microns range, preferably 40 to 60 microns range, e.g., 50 microns, and the material of construction may be glass or quartz frit or stainless steel (or any other suitable material). The length of the "glass wool section" (d1) will normally be from 1.2 to 5 times that of the spacing downstream of the mesh or fritted filter (d2), preferably 1.5 to 3 times that, e.g., about twice. It has been found that such most preferred proportions result in easier filtration and backflushing, and the glass wool holds its shape and volume and does not pack objectionably during use. Also, the mesh or fritted filter helps to maintain the glass wool filter element in desired position and the d2 spacing facilitates better peripheral filtration and backwashing. The mentioned backflushing may be carried out by injection of backflushing water into the system with a syringe or by other suitable means, in conjunction with operation of the Rheodyne valve.
The pressure sensor or monitor 47 can be a conventional pressure gauge but is preferably an electronic device which digitally displays the pressure continuously. The AAS is one which continuously nebulizes the stream, including carrier and digestible material, with digesting liquid, desirably at a rate of about 4 to 6 ml/min., and reports and records the analyses. Such an AAS may be that sold under the trademark Thermoelectron 357. However, although an AAS is the preferred analytical device employed for analyzing the digested sample, it is possible to utilize the described digesting system to digest samples that are then analyzed with different analytical means, such as colorimeters, chromatographic instruments, infrared instruments, etc. When such other analytical instruments are employed the operations are very preferably continuous and results are computer reported but batch analyses are also feasible. Also, because the feed rates to such other instruments may be different from those to AAS's., it may be desirable for the operating conditions and for the constructions of the system elements to be changed accordingly. Thus, pumping rates, microwave power, tubing internal diameter, backpressure, cooling rate and other factors may be adjusted to compensate for different feed rates of sample to the analytical instrument.
Although it has not been illustrated in the accompanying drawing it is within this invention to utilize temperature control and flow control to regulate the digestion of the analytical sample. For example, a temperature probe may be located at an appropriate place, usually at the downstream end, of the heating tube, and power to the magnetron may be diminished if the temperature becomes too high, or the flow rate can be increased, assuming that such an increase is compatible with the digestion and with the analytical equipment being employed. Alternatively or additionally, the flow rate can be measured and the pump operation may be automatically controlled to maintain it at the desired rate, corresponding to that at which the digested material is being withdrawn for analysis. It is desirable for such control to be computerized and for monitors and printers to be present to display and record the readings, but such is not necessary.
The digestion process of this invention starts with dispersing in digesting medium the analytical sample to be analyzed by means of the AAS or other analytical apparatus. Such dispersion can be accomplished by weighing a sample and adding it to a known weight or volume of digesting medium. The sample to be analyzed may be any material capable of being digested and analyzed by the means at hand but usually the materials to be analyzed are organic materials such as foods, biological tissues and fluids, plants, wastes and environmental samples, or inorganic materials such as water samples, ores, coals, oil shales, sediments and paints or pigments. However, various other materials may also be analyzed and the analyses may be for different elements or compounds, although often the AAS analyses are for elements, such as metals, present in foods or other materials. The digesting medium employed may be any suitable such medium, including acids, bases, salts and solutions of such, with aqueous solutions usually being those of choice, which solutions are very often of strong acids, such as nitric acid, sulfuric acid, hydrochloric acid and perchloric acid, strong oxidizing agents, such as potassium permanganate, or strong reducing agents, such as stannous chloride and formaldehyde. For elemental analyses by AAS the digesting medium of choice is nitric acid and the present inventors have found that the concentration of such acid in water should be at least 5%. Such 5% lower limit is applicable to colorimetric analyses for phosphate and may also be used for some other analyses but for elemental analyses by AAS of various other organic and inorganic samples the desirable lower limit for the acid concentration is 8%. 10% or about 10%,or more, up to 30% is preferred, but about 10% is most preferred because digestion rates are not appreciably improved at higher concentrations, using this digestion system. Mixing of the aqueous nitric acid or other digesting medium and the sample to be analyzed may be effected in normal manner, as by employing a magnetic stirrer in which the stirring magnetic element is coated with PTFE (Teflon) or other protective coating that is non-reactive with the digesting medium. Prior to mixing, the sample is size reduced to particles which are preferably no larger than 180 microns in diameter. After the sample is uniformly mixed in with the digesting medium, usually with the concentration of the sample in the medium being in the range of 0.005 to 0.5%, by weight, or weight (grams) per volume (ml), at which concentration the suspension is non-separating for hours, it is taken up in a syringe which will hold more than the amount needed to fill the system coil or loop. Normally the sample concentration is chosen to contain enough sample, usually at least 25 mg for the analysis, without forming an objectionably thick slurry, which can occur at concentrations greater than 1%. Also, using higher concentrations and/or larger sample particle sizes can cause blockages of the coil or of holes in the Rheodyne valve switching plate, which could result in false analyses. The suspension in the syringe is then injected into the charging loop, which is preferably of about 1 ml capacity. Syringe injection is employed in this procedure but it may be replaced with a pump and auto-sampler combination in a more highly automated embodiment of the invention. The main pump 13 is then activated and the carrier liquid, which is usually water, is pumped through the system as previously described, the 4-way Rheodyne valve is changed its other position (used as a 2-way valve) and the 1 ml slug of sample suspension is inserted into the stream of carrier flowing through the system. The carrier and suspension or thin slurry are both normally at about room temperature when charged to the system but during passage through the microwave chamber in the thin tubing the temperature thereof may be raised to as high as 100° or 110° C. or whatever upper limit can be withstood by the tubing and backpressure regulator, with respect to both pressure and temperature, and it is possible, with resistant tubing and the use of superatmospheric pressure on the suspension, to operate at a temperature as high as 140° C. and at pressures up to 200 lbs./sq. in. g.
When the digesting system is directly connected to an AAS that nebulizes about 5 ml/min. of digestate (digested sample in digesting medium) the pumping action will be controlled so that the digestate forced through the system is fed at that rate. For a system that includes in the microwave chamber 20 meters of 0.8 MM. inside diameter tubing and the equivalent of an additional 15 meters of such tubing external to such chamber, the stream speed is about 20 m/min. and the time in the system is about 11/2 to 2 minutes, with the time in the heating tubing being about one minute (or 30 seconds to 2 or 3 minutes). The tubing size is chosen so as to carry the slug of digestate (or digesting liquid and sample) through the heating system at the correct feed rate to the analyzer and at a rate at which it will be heated sufficiently in the microwave chamber to digest it completely (or essentially completely). Such tubing size should also be that at which the bubbles of water or digesting medium that form during heating desirably expand to about 2 to 10 times the original slug length, preferably 2 to 5 times such length, at which expansion good digestion results. It is theorized that the improved digestion noted results from the mixing action effected and from new contact surfaces exposed when the bubbles are formed and when they move with respect to the liquid (and solid particle) bounding materials, thereby promoting better contacts between the sample and the digesting medium. However, that theory has not been completely verified so applicants are not bound by it.
When other analytical equipment is being employed or when the digested material is being subjected to batch analysis, so flow rates are not relevant, other velocities through the heating tubing in the microwave chamber may be utilized. However, the AAS analyzer lends itself to ready analyses for a number of different elements in the same slug of digestate, providing that the slug is of sufficient size. Also, continuous analyses, like that described, protect the digestate against contamination, transfer losses, chemical reactions and weighing and measuring errors, and therefore are much preferred.
After passage through the heating passageway in the small bore tubing in the microwave chamber the tubing and contained digestate (and some undissolved parts of the sample, from which the digestible materials [analytes] have been removed) pass through the cooler and are cooled to approximately room temperature or a little above, in most cases. Cooling will normally be to the range of 5 to 50° C. and preferably is to 20° to 30° C. In the cooling operation the bubbles of water vapor and digesting medium, if volatile, will be condensed to liquid and will reform the digesting liquid into an essentially continuous slug of liquid again, in a stream of carrier liquid. Such cooling is important because the presence of bubbles in the slug can interfere with operation of the analytical equipment, such as the nebulizer of the AAS, and can cause false results.
After cooling the slug and carrier to about room temperature and having the slug again become a unified liquid, with no bubbles in it or separating parts of it, it and the carrier stream are passed through the filter, which removes essentially all particles of a diameter (or equivalent diameter) of 50 microns or more. Such removal protects the backpressure regulator and the AAS nebulizer, when employed, and ensures that the absorption pattern of the AAS or the readings of other analytical instruments, when employed, will be consistent and accurate, and will not be affected by false readings caused by the presence of the particulate materials in the digestate. Ideally, the filter will remove particles as small as 5 microns and less from the digested liquid but when the particle sizes are no larger than 50 microns it is found that the AAS and other analytical instruments of the types mentioned previously herein will be accurate (often within about 1% of the amounts of the elements actually present).
The backpressure regulation will be to the ranges previously mentioned, with the main consideration being to coordinate such regulated pressure with the other operating conditions of the system so as to make the flow through the system consistent and at the desired rate and to have the heated slug develop bubbles therein which expand its volume to the extent previously disclosed, while contracting it completely to original size on cooling. Although the operations are controlled as desired there may be noted some particles of samples which are undigested, usually at the trailing interface between the digesting liquid and the carrier, due to the lower concentration of the digesting medium at such location, where it has been mixed to some extent with the carrier, but such particle usually have had enough of their extractable elements removed from them or they are small enough so that their removal from the slug delivered to the analyzer does not adversely affect the results of the analysis. Also, during flow through the tubing the essentially laminar flow, especially of the portion of the cooled slug in contact with the tubing wall, causes a trailing edge effect which changes the absorption curve or reading but such changed reading should be ignored and the reading to be taken should be that for the main section of the slug's atomic absorption pattern (or pattern for other analytical instrument).
It is desirable for the filter to be backwashed after every use of the equipment but in some cases, as when replicates of the same sample material are being analyzed (or prepared) experience may show that less frequent backwashings will suffice without causing any problems. In some instances, as when several such samples are passing through the heating section at the same time, with sufficient carrier between them, it may be difficult to backwash between samples and it may be found to be unnecessary to do so.
The AAS typically takes up the sample to be tested by aspiration into the nebulizer but other means for charging it can also be employed, including positive pump feeding. The AAS preferably includes a display to show the extent of the absorption of the characteristic wavelength that is characteristic of the particular element for which the sample is being analyzed and it is desirable that the results be computer recorded and stored too. Several such elements may be tested for in the same sample slug by utilizing different emitters of such different characteristic wavelengths (for different metals). Alternatively, several replicates can be run and the results can be averaged for a particular element and then a new sample of the same material may be tested for another element, in the same general manner. Instead of running the digestate directly to analytical equipment it may be collected in a manner that separates it from the carrier, and may then be used for batch analyses.
In variations of the invention, temperature, pressure and flow rate controls may be employed to control the system and the digestion processes. A less polar liquid carrier than water may be employed as a carrier provided that it has acceptable mobility and vapor pressure characteristics and does not merge with the digesting medium or react with it or the sample material. A plurality of streams of carriers, digesting media and samples may be passed through the same microwave chamber at the same time, using the same coolers but different filters, backpressure regulators and analyzers. The invention may also be used to promote chemical reactions, with the reactants replacing the sample and digesting medium in a carrier or replacing the carrier, too, in which latter case the reactants are first mixed and then charged to the pump and pumped through the apparatus. In such reactions the backpressure will be controlled as previously described to produce the desirable bubbling on heating and coalescing on cooling. In a further innovation the whole system and process may be computer controlled with respect to coordinating pumping rate, sample injection, magnetron power applied, filtration, backpressure application, AAS or other analyzer operation and reporting of results. Thus, ultimately, the system can involve little operator attention and yields excellent results, as has been proven by comparisons with standard test specimens. Such specimens may be employed to standardize the system initially and periodically the results may be checked against such standards, too.
The advantages of the invented system and processes are significant. It is fast, contamination-free, involves little operator supervision, requires few weighings and transfers, can operate with little sample, can run replicates easily, requires relatively simple and inexpensive equipment, with the exception of the AAS, involves little heating hazard to operators, because the heating chamber is enclosed, releases little noxious fumes, except at the normally hooded AAS, where they are safely removed, and yields accurate analyses, which may be observed on a display or may be computer printed and stored or processed.
Previous flow injection analyzers have not incorporated the backpressure controllers utilized in the present invention and have not included filters like that of this invention so the results obtained by such processes were not as good as those from the present invention. The present results are more accurate and the samples that are tested are digested more rapidly due to the unique bubbling and coalescing actions described, and due to removal of any undigested particulate materials which may be present. Thus, the present invention is superior in speed and accuracy, two of the main objectives of analyses.
The following examples illustrate but do not limit the invention. Unless otherwise indicated all parts are by weight and all temperatures are in °C.
The apparatus employed in this example is that illustrated in the drawing (all figures) with the pump being an Ismatec MV-Z positive displacement pump, the microwave heating apparatus being A CEM Corporation MDS-81, containing 20 meters of 0.8 mm. inside diameter polytetrafluoroethylene (PTFE) tubing positioned in a horizontal coil in the microwave chamber, the injection loop or coil being of a volume of one ml. and being equipped with a Rheodyne (Anachem 5020) injection valve, the cooling means being a 5 meter length of the PTFE tubing in an ice/water mixture, the filter being of 50 microns stainless steel mesh and being 4 mm. in diameter, with a d1 /d2 ratio of about 2.5, and with the packing in the d1 section being glass wool of about 0.1 mm. in diameter, the pressure sensor being a CEM Corporation sensor, the backpressure regulator being an Anachem P-736, which is set at 75 lbs./sq. in. g., and the AAS being a Thermoelectron 357 unit. The same PTFE tubing was employed throughout the system for all couplings and loops. The analyses by the AAS were recorded by a Linseis LS-52 chart recorder and a magnetic stirrer was employed for initial mixings, prior to entry of the sample and digesting medium into the system, which stirrer had a stirring element that was coated with PTFE.
The digesting medium was nitric acid of analytical reagent grade, supplied by BDH (Poole) and the water was distilled and deionized. Reference samples for digestion and analyses were standards obtained from the National Institute for Environmental Studies (Japan) with the exception of the bovine liver, which was obtained from the National Institute for Standards and Technology (their SRM 1577a). Such samples were employed in amounts of at least 25 mg. and at concentrations in the range of 0.005 to 0.5% w/v (g./ml.) in the digesting medium, e.g., 0.01%,and the sample is of particle sizes that are all below 180 microns in diameter. The concentration of sample in the digesting medium is kept below 1% to avoid occurrence of blockages in the tubing.
Initially, a metal salt of known metal content, in this case a magnesium salt, is mixed with the 10% nitric acid at a concentration of 0.001% and is passed directly to the nebulizer of the Thermoelectron 357 AAS, and the magnesium content is read. Then a 1 ml. portion of the same mixture is passed through the invented system described herein and the magnesium content is read. Correlations are essentially perfect, with the correlation coefficient for the sample passed through the invented system being 0.9999. On the basis of this experiment, and others like it for other metals, such as calcium, zinc and iron, the various samples of materials were analyzed by the invented procedures and results were compared to actual metal contents thereof, as had been established by the agencies which originated the samples, by accepted analytical methods.
A dispersion of about 0.01 g./ml. of Chlorella is made in 10% aqueous nitric acid and is injected into the invented system in the manner previously described, with distilled and deionized water being used as a carrier, with the water, nitric acid and sample being at room temperature (about 25° C.), and with the Chlorella particles being less than 180 microns in diameter. The microwave heating apparatus is operated at 90% of full power, at 540 watts, and heats the digesting medium to 105°-120° C., causing the production of bubbles therein, and the spreading out of the digestate "slug" in the carrier. The digesting medium, being a better coupler of microwave energy than the water carrier, is heated more by the microwaves and therefore can produce bubbling of the analyte without bubbling in the carrier, which carrier will be at a lower temperature. It is normally desirable but it is not essential, to avoid any bubbling of the carrier liquid. After passing through the heating section of the apparatus, which takes about ten seconds, the stream of digestate slug and carrier is cooled in the ice/water mix (but a Peltier cooler or other suitable cooling means may also be used) to about room temperature, is filtered, which removes any 50 micron and greater particles, and is fed through the backpressure regulator to the nebulizer of the AAS, wherein the absorption of relevant magnesium characteristic wavelength radiation is measured and recorded and the percentage of the magnesium is displayed and recorded. Similar runs are made, also with such chlorella sample being digested, and the percentages of calcium, zinc and iron present in it are reported. The described runs were repeated several times, desirably to a total of ten, and the mean values were calculated, together with the relative standard deviations.
The described procedures were repeated with mussel, sargasso, tea leaves, pepper bush and bovine liver samples, with some adjustments of system conditions, such as concentrations in the digesting medium, within the ranges given herein, to promote better heating and flow properties, and the percentages of magnesium, calcium, zinc and iron were recorded. Table 1 gives the concentrations (g./ml.) of test sample in 10% aqueous nitric acid for the various samples employed and for the different metal analyses.
TABLE 1______________________________________ Metal AnalysisSample Magnesium Calcium Zinc Iron______________________________________Chlorella 0.01 0.01 -- 0.2Mussel 0.01 0.01 0.5 0.5Sargasso 0.005 0.005 -- 0.4Tea Leaves 0.01 0.01 -- --Pepper Bush 0.01 0.01 0.2 0.5Bovine Liver 0.01 -- 0.5 0.5______________________________________
In Table 2 are given the analyses and relative standard deviations for analyses of the test samples. The analyses are given on the bases of percentages of known analyses, as reported by the authority from which the test samples originated, which are given in the table as either percentages, by weight, or as micrograms per gram, under the heading Act. (for actual), and it will be apparent which is intended (figures over 10 being for microns/g.).
TABLE 2__________________________________________________________________________MetalMagnesium Calcium Zinc IronSampleAnal. Act. RSD Anal. Act. RSD Anal. Act. RSD Anal. Act. RSD__________________________________________________________________________Chlorella96.3 0.33 2.3 99.0 0.49 3.1 ND 20.5 -- 97.5 0.185 1.5Mussel97.2 0.21 1.4 100.0 0.13 7.6 102 106 7.0 96.8 158 4.0Sargasso102 0.67 0.9 93.8 1.41 1.9 ND 16.4 -- 95.4 187 3.3Tea 101 0.15 2.4 87.0 0.32 3.7 ND 33 -- ND -- --LeavesPepper96.5 0.41 0.8 103 1.38 1.9 93.6 340 0.7 98.0 205 3.0BushBovine94.0 600 4.5 ND 120 -- 95.9 123 0.7 107 194 4.3Liver__________________________________________________________________________ Note RSD = Relative Standard Deviation; ND = Not Determined.
The analyses by the invented method are all considered to be satisfactory and accurate enough to warrant acceptance of the method.
In variations of the experiment of Example 1 digestions of other samples of materials to be analyzed, such as environmental specimens, wastes, ocean floor sediments, paints, pigments, waters and scales deposited from boiler waters, coals, oil shales, ores, plants, body tissues and fluids and various other materials of similar and different sorts, when digested by the process and with the apparatuses of this invention are suitable for analyses, by the AAS or other analytical means, such as colorimetric or chromatographic analytical means.
The processes of Example 1 are repeated but instead of employing the microwave heating apparatus, the CEM MDS-81 at 90% power (540 watts) power settings are changed to 50%, 80% and 100 and the extents of digestions are noted by filterings of the digestates (containing some undigested materials) and comparisons of the amounts undigested. It is found that when 100% of power (600 watts) are employed satisfactory digestion is obtained but it is no better than for the 540 watt experiment of Example 1. When the powers employed are 300 watts (50% power) and 480 watts (80% power) the digestions are measurably less complete, and are generally considered to be unsatisfactory. However, satisfactory digestions can be obtained at such lower power levels by increasing the residence times in the microwave chamber but that lengthens the time needed for digestion, and it is an object of the present invention to speed up the digestion process.
The processes of Example 1 are repeated but instead of employing 10% aqueous nitric acid as the digesting medium other concentrations thereof are substituted, 5%, 20% and 30%. It is found that 5% is unsatisfactory but the 20% and 30% media digest the samples satisfactorily, but not significantly better than the 10% nitric acid. Accordingly, to avoid the need to use the more concentrated acids, which are more corrosive and more dangerous to handle, the 10% acid is that of choice. It is especially preferred when a surfactant is employed with the acid to promote better contact between the sample and the digesting medium. Surfactants such as C12-18 linear alkylbenzene sulfonic acid, Turkey Red oil and Neodol® 25-3 (Shell Chemical Co.) are more stable in the presence of lower concentrations of nitric and other digesting acids than in the presence of more concentrated acids and digesting media.
The apparatus employed in carrying out the process of Example 1 is changed by replacing the 0.8 mm. i.d. tubing with 6.5 meters of 0.3 mm. inside diameter tubing but the injection loop tubing is kept at 0.8 mm. i.d. to prevent blockages therein. The digested materials are then analyzed by colorimetric means directly attached to the exit tubing from the backpressure regulator. Satisfactory analyses are obtained but when the loop is also of 0.3 mm. i.d. tubing the results are unsatisfactory due to blockages of the loop or coil with particulate matter. When the i.d. of the tubing is greater than about 2 mm. the desired type of bubble formation in the digesting medium and contained digestible sample is not obtained so that although the residence time in the system is greater the digestion is not as even and the analyses are not as accurate. Similar unacceptable results are obtained when the backpressure regulator is removed from the system, which allows excessive bubble formation and can even cause "vapor lock" of the pumping means, together with inaccurate analyses.
The first chlorella experiment of Example 1 is run again ut with the 20 meters of 0.8 mm. tubing being rolled into a ball instead of being looped or coiled. The analysis for magnesium is less accurate than for the previously reported experiment, apparently due to irregular flow of material through the ball, possibly due to kinking therein or due to overly sharp changes of directions therein. From this experiment it is clear that it is desirable for the tubing to be positioned so that the liquid passing through it changes directions gradually and it also appears that it is undesirable for much of the tubing to be shielding other sections thereof from the microwave radiation that is desirably directed onto the analyte within the tubing. To avoid comparatively sharp directional changes in liquid flow, therefore, one usually will avoid tubing patterns of the ball, woven, knitted and crosshatched types, although with easily digested samples of very small particle sizes such may be feasible.
The invention has been described with respect to several illustrations and working embodiments thereof but it is not to be considered as being limited to those, because one of skill in the art, with the present specification before him or her, will be able to utilize substitutes and equivalents without departing from the scope of the invention.
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|U.S. Classification||422/81, 422/186, 204/157.43, 204/158.2, 422/21, 436/177, 436/175, 219/679, 219/693, 436/52|
|International Classification||G01N21/31, G01N1/28, G01N1/00, G01N1/44, G01N35/08|
|Cooperative Classification||G01N35/1097, Y10T436/25125, Y10T436/25375, Y10T436/117497, G01N35/08, G01N21/3103, G01N1/44|
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|Jan 28, 1993||AS||Assignment|
Owner name: CEM CORPORATION, NORTH CAROLINA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:HASWELL, STEPHEN J.;BARCLAY, DAVIDE A.;REEL/FRAME:006408/0489
Effective date: 19910805
|Sep 26, 1996||FPAY||Fee payment|
Year of fee payment: 4
|Jun 9, 2000||AS||Assignment|
Owner name: BANC OF AMERICA COMMERCIAL FINANCE CORPORATION, AS
Free format text: NOTICE OF GRANT OF SECURITY INTEREST;ASSIGNOR:CEM LIMITED, LLC;REEL/FRAME:010892/0430
Effective date: 20000531
|Jun 21, 2000||AS||Assignment|
Owner name: CEM LIMITED, L.L.C., NORTH CAROLINA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CEM CORPORATION;REEL/FRAME:010892/0674
Effective date: 20000531
|Sep 28, 2000||FPAY||Fee payment|
Year of fee payment: 8
|Sep 9, 2002||AS||Assignment|
Owner name: CEM CORPORATION, NORTH CAROLINA
Free format text: MERGER;ASSIGNOR:CEM LIMITED, LLC;REEL/FRAME:013248/0680
Effective date: 20001020
|Sep 27, 2004||FPAY||Fee payment|
Year of fee payment: 12


text:
Sugar House is a project designed by Alter & Company. Shaped like carved blocks of sugar, this family home is a full refurbishment and extension to a 1950’s London suburban house. This scheme places a large contemporary extension wrapping around the existing house over two-storeys. Photography by Alter & Company.
Relocating the staircase centrally to the house with staggered stepped living spaces surrounding the circulation allows for flow and visual connectivity. The built form has been expressed through a refined palette of materials; white stucco, polished white marble, oak and whitewashed complete scheme. Vertical strips of oak have been used to tighten the central staircase bringing warmth to the internal spaces. The facade is playful whilst being controlled, pushing apertures in with key feature seated windows being pulled out with extruded flush framed glazing.

domain: design


Against the backdrop of a pandemic that appears to be declining and inflation at a four-decade high, Amazon on Thursday released its slowest quarterly growth in years and its first quarterly loss since 2015.
The company reported revenue of $ 116.4 billion in the first three months of the year, up 7 percent from a year earlier. This is down from a 44 percent increase in the first quarter of 2021. The number of products that Amazon sold in the quarter was unchanged from a year earlier, and the cost of selling those products also increased.
Amazon lost $ 3.8 billion in the quarter, including a $ 7.6 billion drop in the value of its investments in Rivian Automotive, the maker of electric trucks whose shares fell this year. The loss was also caused by Amazon’s consumer businesses in North America and internationally, though its cloud services division continued to grow and make money.
The results fell far short of Wall Street expectations, causing Amazon shares to fall more than 10 percent in after-hours trading.
“Our teams are uniquely focused on improving productivity and cost-effectiveness in our performance network,” Andy Jassi, the company’s chief executive, said in a statement. “We know how to do it and we have done it before. It may take some time, especially when we are working on pressure on the current inflation and supply chain. “
The company forecasts sales growth of 3 per cent to 7 per cent in the current quarter, indicating that its growth could continue to slow. Amazon said Prime Day, its annual trading event held in June last year, would move into the third quarter of this year, further reducing sales growth in the current quarter.
Amazon took advantage of the corovirus pandemic when people flocked to online shopping. But since vaccines became widespread and inflation reached 8.5 percent in March, behaviors have changed again. Consumer spending on non-durable products that people often buy on Amazon fell 0.6 percent in the first quarter from the last three months of 2021, according to inflation, according to the Commerce Department on Thursday.
Chief Financial Officer Brian Olsawski told reporters that the company was “very pleased” with how often consumers bought on Amazon and that some slowdowns reflected the end of pandemic shopping habits. Consumers made more frequent, low-cost purchases such as masks a year ago and now they are returning to regular purchases, he said.
Amazon also faced rising costs, with operating costs for its consumer business in North America rising 16 percent, while sales in the region rose only 8 percent in the quarter. Inflation costs have added up to $ 2 billion, Mr Olsawski said, adding that “we expect them to be around for a while.”
He said another $ 4 billion in costs were caused by inefficient work. Amazon has spent a lot over the last two years hiring and doubling warehousing infrastructure, including opening delivery warehouses across the country, allowing its network of contractors to quickly deliver packages to people’s doors.
Mr Olsawski said the company was backing down on some expansion plans to increase existing spaces more effectively.
“We now have a lot of space compared to our demand templates,” he said. Without an unpredictable increase in demand for the virus, he said, “we can tighten our capabilities.”
In mid-March, Amazon forced several warehouse workers to take unpaid leave because consumer demand was weak.
In response to rising costs, Amazon has increased prices for consumers and sellers in its market. The price of its Prime membership program increased to $ 139 in February, from $ 119, the first increase since 2018. This month, the company announced additional “fuel and inflation” commission sellers whose inventory it stores and delivers to customers.
The labor deficit has also cost Amazon billions of dollars in recent times as it has responded by raising wages and offering other incentives. The company barely increased its workforce in the quarter, totaling 1.62 million employees.
The company has seen an increase in labor activism. In April, warehouse workers on Staten Island voted to be the first Amazon facility in North America to unite.
Amazon also had bright spots in its business. Amazon Web Services, its cloud computing business, grew 37 percent in the quarter, to $ 18.4 billion in sales.


An ACLU study reveals an increasingly militarized police force across the country that is abusing power and people.
The U.S. Supreme Court dished out a unanimous condemnation of President Obama's dictatorial usurpation of the power of appointment in the June 26 decision of NLRB v. Noel Canning. The court ruled that President Obama exceeded his authority as president when he claimed to exercise his “recess” appointment authority without the consent of the U.S. Senate while the Senate was still in session.
Grassroots Republicans and conservatives across America are furious after the GOP establishment was exposed using dishonest, shameful, and potentially unlawful tactics against its own base in Mississippi. The goal of the dubious establishment operation was to prevent GOP voters from electing Tea Party-backed candidate Chris McDaniel, who was favored to win in a landslide based on surveys of Republican voters. In essence, though, the Republican establishment relied on lies, huge contributions from crony special interests, and deceitful fear-mongering to get Democrats to vote in the Mississippi GOP primary this week — likely in violation of state law, according to critics of the plot. Still, the fight is not over yet.


text:
tv BBC News at Ten BBC News May 21, 2019 10:00pm-10:31pm BST
tonight at ten — despite theresa may offering what she calls a "new deal" over brexit, labour and some conservative mps, labour and some conservative mps say they won't back her proposals for leaving the eu. she says parliament has one last chance to deliver brexit and offered concessions including a vote on another referendum. to every mp of every party — i have compromised. now, i ask you to compromise, too. we can't support this bill because it's basically a rehash of what was discussed before. mps are due to vote on mrs may's brexit plans, early next month. also tonight... the government is asked to step in again to bail out british steel to prevent a company collapse.
simple food but made with love. come in and see us. he says he exhausted every option to save his business, but jamie oliver's restaurant group goes into administration. hungary's far right populists leading the charge against immigration, as the eu chooses a new parliament. voters are being bombarded with this message to stop migration. and this is a country where last year, there were fewer than 700 asylum seekers. and — he endured a horrific crash but was back racing just weeks later. now, the world pays tribute to niki lauda, who's died at the age of 70. and coming up on sportsday on bbc news — as arsenal's mkhitaryan decides not to play in the europa league final over security fears, the azerbaijan fa tells us politics and sport should stay separate.
good evening. despite offering what she calls a "new deal" over brexit, labour and several conservative mps say they won't be backing theresa may's proposals for leaving the european union, with the commons due to vote on her plans early next month. theresa may warned today that mps have "one last chance" to deliver a negotiated exit from the eu, and in an effort to win support, she promised mps that if it passes, they'll get a vote on whether to hold a referendum on the final deal. there was also the promise of a vote on future customs arrangements. and new guarantees on workers' rights. butjeremy corbyn says labour won't support the bill because it doesn't go far enough, while some conservatives say they‘ re unhappy because they believe mrs may's gone too far in making concessions. here's our political editor, laura kuenssburg.
a strange—looking world... any sign of progress? a tory cabinet, cloistered for hours... any agreement, secretary of state, on what you will offer the labour party? chewing over how much to offer labour to get them on side... foreign secretary, do you think you have concessions that will tempt labour mps to vote for the deal? to try and breath life into an exhausted plan and an exhausted administration... dr fox, are you still in the cabinet? to take us out of the eu by summer. after nearly three years, it is oh, so late in the day. always fascinating. win or lose, few in the political goldfish bowl, or perhaps the audience at this london business, or maybe among you, believe it is anything other than her last shot. the majority of mps say they want to deliver the result of the referendum. so i think we need to help them find a way and i believe there is now one
last chance to do that. today, i am making a serious offer to mps across parliament — a new brexit deal. newly packaged up together, but familiar promises. extra protection for workers' rights and the environment, giving mps the say on the fraught issue of customs and acknowledging many of them want a chance at least to vote on another referendum. i do not believe this is a route we should take, but i recognise the genuine and sincere strength of feeling across the house on this important issue. the government will therefore include in the withdrawal agreement bill, at introduction, a requirement to vote on whether to hold a second referendum. the prime minister, though, cannot pretend. she might never be able to keep her promise of taking us out of the eu. i have compromised. now i ask you to compromise, too. we've been given a clear instruction by the people we are supposed to represent. so, help me find a way
to honour that instruction. move our country and our politics forward and build the better future that all of us want to see. thank you. you've had nearly three years. but the opposition parties have already said they will not vote for this deal. isn't it simply too late for you to be offering a compromise? many mps simply do not want to listen. wait and look at the details of the bill and think about the importance of delivering brexit, because this is the way that we can ratify an agreement and ensure that we leave the european union. theresa may's last efforts to win over parliament feel a parallel universe to what is playing out around the country. the european elections in a matter of days. only happening because the government has failed. tories and labour both jangling with nerves as smaller parties,
pushing clarity, not compromise, stand to gain. voters will give a verdict with parliament's meltdown the back drop. parliament's meltdown the backdrop. labour won't give number ten a way out. we can't support this bill because it's basically a rehash of what was discussed before and it does not make any fundamental moves on market alignment or the customs union or protection of rights. the commitment to give mps another vote on a referendum is not enough for those on that side. well, the deal agreed by the cabinet would take scotland and the uk out of the european union but also out of the single market and the snp will not vote for a deal that does that. we will be voting against this. what we want is people to be able to stop brexit by having a people's vote. but it's a compromise too far for those on the other. it's a hodgepodge of proposals, but the fundamental flaws in the withdrawal treaty remain.
we've got a remain prime minister saying to leavers that we should make compromises towards a remain parliament. it's a brexit in name only trap, and is something i will not be supporting. the vote is still more than a week away. the prime minister won't give up and minds could still change, but rejection of this bundle of new measures may already have taken root. given the concessions and compromises mrs may says she has made to her deal, and given the response to it so far, is it dead before it even gets to the house this time next month?” before it even gets to the house this time next month? i inside no 10, you have to be an optimist of herculean proportions to think that somehow they've made a case which is going to deliver them victory as an when this comes to the commons, probably at the end of this week. and i think today, really, we've seen more and i think today, really, we've seen more evidence of a theme that we have seen so seen more evidence of a theme that we have seen so many seen more evidence of a theme that we have seen so many times during
theresa may's leadership, that by trying to please everyone, this time including the official opposition and other smaller parties, she's ended up pleasing no—one. and several ministers have said to me tonight, and plenty of other mps have said, that actually this speech today, this package of proposals, makes things worse rather than better. but for numeral, they believe that while it be difficult, this is still the right thing to do. and unless you are someone who is trying to stop brexit, like the protester down behind me, or you are someone protester down behind me, or you are someone who protester down behind me, or you are someone who wants protester down behind me, or you are someone who wants to leave without a deal, well, this is the only way that they see in front of them to do it. it is right that if this bill falls, if it doesn't even get to the later stages of legislation, there is simplya later stages of legislation, there is simply a big question about what would happen next. but i think right now, the risk of more uncertainty does not mean that mps are suddenly going to fall in line. and it would
bea going to fall in line. and it would be a political achievement of death—defying success for no 10 actually to get their way. laura kuenssberg, thank you for that. thousands of british steel workers, are waiting to hear if the company can secure a £30 million rescue deal from the government. the business, which employs more than 3,000 people in scunthorpe, and around 800 on teesside, is on the brink of collapse unless it receives emergency funding to weather what the company calls brexit related issues. our business correspondent colleta smith is in scunthorpe for us tonight. clive, pressure is only increasing on british steel tonight. we understand they‘ re still on british steel tonight. we understand they're still in discussions with the government in the hope of another bailout. they have already had a cash injection a couple of weeks ago here at this plant. now they want more, to cover a drop in orders that they say is caused by brexit uncertainty. it's impossible to overemphasise just how
significant this plant is to the town. scunthorpe significant this plant is to the town. scu nthorpe orbits significant this plant is to the town. scunthorpe orbits around these steelworks, and that means for the thousands impacted, no news today means another sleepless night. alan's got a day off from the blast furnaces today, but work is still the only thing on his mind. we were being told one minute people were losing theirjobs, then the next minute, it's not happening. it's just frustrating, obviously not knowing your future, and obviously if it happens here, what do you have to do? do you have to look to move elsewhere, to try and get a job elsewhere, or do you try and stay here and find a job and just struggle on and survive? i don't know. you've got kids, then, in schools here? yeah. that are settled. yeah, i've got a seven—year—old, she's got a six—year—old, and obviously we've got a nine—year—old as well. that's a big impact on the family and all of them, isn't it? it is, it's a massive upheaval for everybody. but then the other thing is, do you look at working away and not see your kids? i don't know. the town's just going to shut down because nobody's going to be in work
and it's going to be like a ghost town. what are we going to do with the steelworks? turn it into a theme park? companies like yourselves, then, are brought in to do other work... it's a massive knock—on effect for us. we don't even know whether we'll get paid for the job we're doing now, and we've got a lot more work up and coming there. the company had plans to extend their production lines this autumn, but now, that future is far from certain. they've already had one loan from the government, and today they were asking for another. it will buy us some time but it's not a long—term solution. personally, i think the right solution would be a temporary nationalisation. we're not talking forever, but it would give us that period of calm and certainty where we could rebuild the business, get it back on an even keel, make it sustainable and get back to where we were, well, pre—2008 crash, because we've yet to come out of that recession. the government say they've ruled out nationalisation but are still working to try
and save the company. subject to strict legal bounds, the government will leave no stone unturned in its support for the steel industry. the business say they need the cash to keep the furnaces burning until there's a brexit deal, but that staff will get this month's pay cheque — a small relief to the thousands of families depending on those wages. coletta smith, bbc news, in scu nthorpe. our business editor simon jack is here. simon, given all this, does british steelmaking still have a future? 0bviously, steelmaking still have a future? obviously, there is a hugely proud tradition of steelmaking in this country and scu nthorpe tradition of steelmaking in this country and scunthorpe has been a big part of that. but the truth is, it has been in long—term serious decline. if you look at this graph, it will show you how many people used to be employed in the steel industry in the 19705, and how many are now. it is now 10% of what it was are now. it is now 10% of what it wa5 a0 yea r5 are now. it is now 10% of what it wa5 a0 years ago. part of that is deindustriali5ation over the last
few yea r5, deindustriali5ation over the last few years, the other reason is very stiff international competition. thi5 stiff international competition. this particular graph will show you china dwarfing... this particular graph will show you china dwarfing. .. thi5 this particular graph will show you china dwarfing... this was 2016. in the last two years, china has produced more steel than the uk has in its entire history. so, that's what you're up against, and it is against that kind of backdrop that the government has a very difficult decision, do you either give taxpayer money, which many people think would be equivalent to chucking it in the furnace, it will burn through in a second... do you let it go bust two days before a european election? 0r let it go bust two days before a european election? or do you nationalise it? i was talking to trea5ury nationalise it? i was talking to treasury officials in the last hour and they said to nationalise it even temporarily, you would have to think you would have a buyer who could ta ke you would have a buyer who could take it on. and given tho5e you would have a buyer who could take it on. and given those kind of statistics, that is very difficult to see. so i'm afraid the future for this plant look5 incredibly precariou5 tonight. this plant look5 incredibly precarious tonight. simon jack, thank you very much. the restaurant group setup
by the celebrity chef jamie oliver has gone into administration, with the loss of around 1,000 jobs. just three of his 25 restaurants is still operating, after failure to find a buyer. jamie oliver says he exhausted every option to try to save the business, and is deeply saddened. here's our business correspondent, emma simp5on. so, what you get... from the cheeky new chef on the block... look at that! ..to campaigner, tv star and books, jamie oliver has built an empire a5 britain's most successful chef. and he opened dozens of restaurants, too. come in and see us at jamie's italian. nothing was being served up today, though. his restaurant business collapsed, 22 outlets clo5ed with immediate effect. around 1,000 jobs lo5t. in a statement, jamie oliver said... "i'm devastated that our much—loved uk restaurants have gone into administration. i am deeply saddened by this outcome and would like to thank all of the people who have put their hearts and souls into this business over the years." so, what went wrong? itju5t got a bit too chain...
chainy. chainy. yeah. whereas just around here, there are so many quirky little re5taura nt5, and just one—offs that you can go to. today's news isn't a total surpri5e. thi5 chain almost went bu5t a couple of years ago. jamie oliver put in £13 million of his own money to save it. 12 outlets already clo5ed last year in a restructuring plan. but it's clear that turnaround hasn't worked. it's been tough for lots of other casual dining chains, too. prezzo, byron, carluccio'5, just some of the brands that have had to close outlets, counting the cost of overexpansion. mid—market restaurants are being squeezed at both ends. they are finding it quite hard to make money at this time. if they're not offering exactly what consumers want, then they find they can't make money because the cost of wages, the cost of business rate5 and the cost of running promotions to get people through the door are simply too much. we are going to fry that off... his other businesses may be
thriving, but it seems jamie 0liver‘5 restaurants weren't able to keep up with changing tastes in what's become an increasingly crowded market. emma simp5on, bbc news. nigel farage has accused the electoral commission, officials from the electoral commission, have visited brexit party headquarters, to review it's online fundraising. no evidence of electoral offences were found, but the commission said there had been significant public concern. the european parliament has confirmed it's investigating donations mr farage received, shortly after the eu referendum in 2016. 0ur deputy political editor john pienaar is at the brexit party hq in central london. what more can you tell us? well, when i spoke to nigel farage early on today, he described the current criticism of the donations and support for him and his party as 5mear5, collusion. yet, as you say, a new front has opened up. the valuable support from arron banks,
which nigel farage de5cribes valuable support from arron banks, which nigel farage describes as a purely personal, has been referred toa purely personal, has been referred to a scrutiny and discipline committee of the european parliament, where he is a member. he went to provide a driver, a home in london, travel and parties in the usa. if they recommend to the president of the parliament that there was a breach of the rules, potential sanctions are there, from a reprimand to the withdrawal of privileges. meanwhile, at brexit headquarters in central london, cro55 headquarters in central london, cross the road, the electoral commi55ion went in today. they say it was as part of a review, not an investigation into the handling of donations. mr farr raj say5 investigation into the handling of donations. mr farr raj says it is all part of collusion between the commission under party enemie5. will it stay the party or damage the party, or view all part of collusion between the commission under party enemie5. will it 5tain between the commission under party enemie5. will it stain the party or damage the party, orfuel the i5 enemie5. will it stain the party or damage the party, orfuel the is the 5ugge5tion damage the party, orfuel the is the suggestion that nigel farage i5 damage the party, orfuel the is the suggestion that nigel farage is keen to promote this evening.
the inquests into the london bridge attacks in 2017 has heard how a football fan threw glasses and bottles at the attackers, as he tried to save people's lives. giving evidence at the old bailey gerard vowl5 said he started throwing makeshift weapons at them and shouting to warn as many people as possible of the danger. a man who was infected with contaminated blood a5 a child in the 19705 has been speaking of the devastating effects on his life. the public inquiry into what's been called "the worst treatment scandal in the history of the nhs" heard evidence in belfast today. contaminated blood is thought to have caused the deaths of at least 3,000 people across the uk in the 19705 and 805. 0ur health editor, hugh pym, has more. paul says he and his family have always lived under a cloud. a haemophiliac, he got hepatitis c after treatment with infected blood products. he lives in fear of other conditions developing. his brother, also a haemophiliac, died with liver cancer. still cloud5 coming and still a lot
of unknowns, and it is a fear that will live with me. deep down, i remember saying to my wife, my first objective in life was to outlive my brother. he died at 51. the inquiry‘s come to belfast to hear stories like paul's. it will move on to other cities around the uk. he says he's been mocked about his condition, so speaking out today was a big step. it reinforced the fact you have to be so private about your health and this major decision for me here, do i go...? it's the first time i've told my story publicly. that has been ma55ive. i've worked with good people for 30 years and most of them don't know yet. campaigners say there are still big differences in the financial support available to victims around the uk, and that's unfair and must be urgently addre55ed. the government at westminster made more money available to bring england in line with scotland,
but northern ireland and wales are still lagging behind. it's an issue that the judge chairing the inquiry wants to see resolved. he and his team will continue hearing personal stories here over the next three days. hugh pym, bbc news, belfast. this week's elections for the european parliament will be a test of the popularity of several nationalist movements across europe, for whom a key issue is immigration. the model for many of these groups has been hungary, where the prime minister, victor 0rban, has enforced a strong anti—immigrant policy, in defiance of eu criticism. at the height of the migrant crisis in 2015, he ordered the construction of a fence along the southern border with serbia and croatia, to prevent migrants getting in. jean mackenzie reports. the gabor family have two passion5, swimming and their prime minister.
viktor 0rban has won popular support here in hungary, partly by giving financial help to large families. an ardent nationalist, 0rban has waged war on migrant5. hungary wa5 hungary was at the forefront of the refugee cri5i5. although most people we re refugee cri5i5. although most people were just passing through, within week5 were just passing through, within weeks he had built a fence to keep them out. now giant eu election billboards tell people to support the prime minister's plan to end immigration. the5e posters are absolutely everywhere. voter5 are being bombarded with this message to stop migration. and this is a country where la5t year there were fewer than 700 asylum seekers.
in the border town of kubekhaza, the mayor is one of 0rban's most vocal critics. propaganda tv. this is propaganda tv. this is state tv? yes, yes. most of hungary's media now has some link to the government. and migrant storie5 are constantly in the news. what do you hear on the news about what is happening in western europe? we have asked many times to speak to
somebody from viktor 0rban's party, fidesz, but they have refused. so we head to one of their campaign eve nts. why is your eu electoral campaign focused on migration when migrants have virtually stopped coming to hungary in recent years? well, it's not a question whether in this timeframe they are coming or not. this is mobili5ing our efforts. that's the reason. that's what we are expected to talk about. concerned by the direction hungary i5 concerned by the direction hungary is heading, a new young opposition party is fighting back. we decided to do party is fighting back. we decided todoa party is fighting back. we decided to do a march, 5tanding party is fighting back. we decided to do a march, standing up for the value5, to do a march, standing up for the values, the european values. how do you feel about the relationship that so no you feel about the relationship that so no viktor 0rban i5 forging with the eu at the moment? well, i think it is the eu at the moment? well, i think it i5a the eu at the moment? well, i think it is a dangerous game. so far he is
a single freedom fighter, a5 it is a dangerous game. so far he is a single freedom fighter, as he calls himself. however, if his allies get more power as well, he can start a domino effect, which is dangerous. a5 nationalist parties across europe seek to capitalise on migration, for many, viktor 0rban is their hero. hungary their inspiration. jean mackenzie, bbc news. the first female newsreader on bbc televi5ion, nan winton, has died, at the age of 93. born nancy wigginton, she was an experienced journalist who worked on several programmes including panorama. the bbc‘s director of news and current affairs fran un5worth today, called her a "trailblazer". tribute5 have been paid throughout the day to niki lauda — the veteran motor racing driver, who's died aged 70. a three—time formula one world champion, he made an astonishing recovery from a near fatal crash in 1976 — going on to become a successful businessman. 0ur sports editor dan roan looks back on his life and his achievements. niki lauda will forever be remembered as one of sport's
bravest figures and for one of its most compelling comeback5. having pursued a career in racing against the wishes of his wealthy family and with the help of a bank loan, the steely austrian won his first world championship with ferrari in 1975. he was on course to retain it, but then at the german grand prix, during formula 1's mo5t dangerous era, lauda suffered the terrible crash that almost claimed his life. trapped inside an inferno for over a minute, other drivers had to rescue him from the wreckage. i knelt down and rested his head on my lap. and we were able to talk. he was lucid. he'd suffered severe inhalation of toxic and superheated air from the burning bodywork of his car. and it was that, 2a hours later, put his life into jeopardy. read his last rite5 in hospital, lauda wa5 scarred for life. but in an act of unimaginable courage, ju5t a0 days later, he was back behind the wheel. when that feeling came, you get a big fright. you know, you're really
worried and frightened that you're going to die. and that means you start everything possible to keep you going. you can't start your body, because the body doesn't react. you only can start the brain. if the brain works, the body 5tarts to work sooner or later. lauda's defiance wa5 fuelled by his great rivalry with british driverjame5 hunt, transforming f1‘5 global appeal and depicted in a hollywood film. speaking from his home in brazil tonight, the man who ran the sport for decades paid this tribute. niki was liked all over the world. i don't think he's done anything bad to anybody. certainly i've known him for many, many years, and all that i heard is people saying what a nice guy he is. he was a super guy. lauda regained the world championship the year after his accident, claiming it again in 198a. an astute busine55man, he launched his own airline and became chairman of mercedes, helping to recruit lewis hamilton, who tonight tweeted. .. "i'm struggling to believe you're
gone, thank you for being a bright light in my life." decade5 on from his crash, lauda continued to suffer the consequences, undergoing a double lung transplant last year. but he'll always be known a5 f1‘5 legendary 5urvivor. niki lauda, who's died, at the age of 70. that's it. now on bbc one, time for the news where you are. goodbye.
hello and welcome to sport5day. he's got the magic — jofra archer's england team mates welcome the all rounder‘s inclu5ion in the world cup squad. "politics and sport should stay separate". the azerbaijan fa tells the bbc it's disappointed in mhykitarian's decision to miss the europa league final. and more tributes to two time formula 1 champion niki lauda, who5e died at the age of 70.
hello and welcome to sport5day. just over a week to go until the cricket world cup gets under way — and today the 15 man squad has been confirmed. while there was heartbreak for both david willey and joe denly, the inclusion of barbados born jofra archer came as no surprise to many following his performances in the 0dis with pakistan. england are the favourites this year and number the batsmanjoe root say5 they're embracing that position. it excites me and it's a complement to the group because we worked really ha rd in to the group because we worked really hard in the past four years to get into this position and we played big cricket along the way, especially the last few years. and i feel like we are peaking at the right time, so it's about making 5ure right time, so it's about making sure that we carry forward and we enjoy the fact that we are
favourites and home conditions and we keep going about cricketju5t a5 we keep going about cricketju5t a5 we have done don't take a backward step and change too much, just trying to adapt to conditions in front of us and continue to be positive and how we do things. he is seen positive and how we do things. he is seen when he plays and domestic tournaments are on the road, he has ability to change game on his own he has magic and other plays may not be able to do that he help5 has magic and other plays may not be able to do that he helps and he has more games down the bad they are all good qualities to have and i think he is good qualities to have and i think he i5a good qualities to have and i think he is a brilliant addition to the squad he has earned that through performing under pressure and high profile tournaments and it's a great chance for him now what to say she 5ta rted chance for him now what to say she 5tarted career on. for details of the full 15 man squad you can head over to the bbc website bbc.co.uk/5port where you can also check out the new england kit if you want to as well.

domain: news


About Mattress Toppers
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The extra advantages you get from using mattress toppers will benefit you over a longer period of time, it permits your sleeping cushion or the mattress to stay new and in fresh condition for much longer time and gives you an expanded solace. At the point when the mattress topper has taken everything it can, after the daily exercises on the bed, it is advisable to change the mattress topper before the time when you have to replace the whole of the mattress. The mattress toppers act as an additional covering for the beds, they save the mattress from the extra damage. Instead of damaging and replacing the mattresses you can easily purchase a topper for a mattress. The toppers are waterproof and provide an efficient water absorbing method. Which does not lets your bedding mattress and other bedding materials to be damaged because of the liquid spill. \the mattress toppers are very useful and are much trendy these days.
The mattress toppers are easily available in the cloth market. Asking for the mattress toppers you will be immediately shown a variety of mattress toppers. There is a wide range of mattress toppers, which are accessible in the market. People tend to buy the water proof mattress toppers as they save the bed from any liquid spills. The toppers are very easy to lay down over the mattresses. The mattress, duvets, cushions, bed sheets, mattress sheets and the mattress toppers are also considered as the bedding materials. These are accessible easily.


text:
Amazon parrots for sale are beautiful and friendly companions – however, breeding them is another matter entirely and can be quite difficult as they are often slow to do so. If you want your pet Amazon parrots to breed with one another you will need: at least two of them (obviously!) and a lot of patience.
Make sure you purchase young and healthy Amazon parrots or else there is almost no point trying to breed them. Amazon parrots cannot be visually sexed so you need proof of a DNA test – any reputable breeder will offer this so you know you are buying a male and a female. House your breeding pair in a suitable cage. Most breeders use aviaries at least 10 feet long, 4 feet wide and 4 feet high. The walls should be made of 1 inch by half-inch 1.2 to 1.3 mm gauge wire. The nesting box should be roughly 9 to 10 inches square and 30 to 40 inches deep, depending on the size of the parrots, obviously. Line the nest box with sawdust, newspaper shreddings, grass or straw. Don’t use any toxic wood shavings such as pine or cedar.
To prevent boredom (which will lead to depression which will in itself lead to a distinct unwillingness to breed), make sure to stock the cage full of parrot toys and perches. Parrots need a certain amount of natural light every day, as well as a high-quality, healthy diet – including seed mixture, apples, bananas, carrots and pears. To keep your female healthy give her calcium supplements or put a calcium-rich cuttlebone in the cage.
Check on the nest at least once a day. Once the female lays her eggs, you can remove them for incubation (most breeders recommend doing this) or wait until the eggs hatch and them remove the chicks so you can hand rear them. Female Amazon parrots typically lay about two or three eggs, in springtime.

domain: pet


Via Boston Globe we’ve discovered RainDance Technologies, Inc., a Lexington, Massachusetts company that is developing high throughput microfluidic technology to deliver, sort, and analyze individual liquid droplets at 3,000 units per minute.
From the company:
RainStorm technology creates an island of simplicity in the controlled chaos of the laboratory. It utilizes simplicity and speed to inspire scientists to design experiments in ways previously unaffordable or unimaginable. The platform is aligned with current applications to accelerate workflow and throughput. This approach has generated quantifiable benefits:
Individualized reactions based on proven methods with minimal opportunity for process induced bias or error, while avoiding the disadvantages and limitations of multiplexed assay formats Full control of the discrete droplets with our microfluidic elements and advanced signal processing, providing operators simple and streamlined workflows Picoliter reaction volumes providing favorable reaction kinetics and efficient utilization of precious samples Physical characteristics that allow the flexibility to meet the needs of a variety of applications The speed and higher precision of millions of reactions per hour in a compact instrument footprint, avoiding the need for large automation solutions Increased statistical confidence provided by large numbers of replicate measurements The ability to easily capture the output of on-chip processes, empowering the technology with both preparative and analytical capabilities
By deflecting the costs inherent in large automation solutions and circumventing the complexities of multiplex assays, the RainStorm droplet-based technology platform easily adapts to applications in high-growth life science markets.
Here’s a video, slowed down by a factor of 1,000, showing RainDance’s droplet sorting system:
RainDance technology page…
More from Boston Globe…


There is a pulse, a rhythm unfolding before me and I feel the flow.
There is a harmony, a tune and I can hear the song.
The song of the “I am”, the song of “So ham” the song of the eternal.
I am swept up by the melody and my soul dances away.
A dear friend sends me messages of pain and death.
The pain resonates with my own brokenness and longing.
I can feel the sorrow and in the tension between life and death,
the music is swirls with a wild beauty.
I am sitting in a small cafe looking out over a busy street.
And life sings to me…