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Showing 1 to 20 of 37 for “"acid digestion"”.
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Optimization of Microwave-Assisted Acid Digestion Method for Determination of Trace Elements in Coal and Coal Fly Ash
… by ICP. Traditionally an open-air hot-plate acid digestion method published as ASTM D6357-04 was used to extract all trace metal elements into solution. Recent development of microwave systems designed for digestions under extreme acidic conditions and high temperatures and pressures shifted …
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Direct determination of cadmium and beryllium in coal and fly ash slurries using graphite furnace atomic absorption spectrometry
… materials and in some cases, comparisons with acid digestion procedures. Data are presented for the analysis of South African coal and fly ash samples. The slurry methods had acceptable accuracy and precision. In comparison with the conventional acid digestion procedures using high pressure …
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Responses of Quercus alba L. seedlings to fertilization with nitrogen and phosphorus
… Soil P tests were made by three methods: dilute acid extractable P (Mehlich), acid flouride extractable P (Bray no. 1), and total P by perchloric acid digestion. Correlation analyses were performed on seedling growth, foliar P content, and soil P tests. Confounding factors, including site …
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Analysis of Kyrock for Leaching of Impurities in Synthetic Rainwater
… presence of organic compounds. Analysis of an acid digestion of the samples using inductively coupled plasma spectroscopy showed inorganic compounds such as titanium oxide, vanadium oxide along with traces of arsenic. Elemental analysis of samples indicates a percent of carbon, and sulfur with …
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The Comparison of Composite Aircraft Field Repair Method (CAFRM) with Traditional Aircraft Repair Technologies
… Specimens were tested with microscopy, acid digestion, short beam shear, and mode I fracture tests. The researcher was able to determine the specimen's void content, fiber volume fraction, shear strength, and opening mode interlaminar fracture toughness for the specimens fabricated using …
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Evaluating the Leachability of Elements from Residuals Generated by Hydraulic Fracturing in Marcellus Shale
… the elements to leach from the landfill. Strong acid digestion using a 3:1 combination of nitric acid to hydrochloric acid in a microwave with closed vessels was used to determine overall elemental composition. Leaching experiments were performed with de-ionized water and acetic acid (0.57%, pH …
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Implementation of Acid/Gas Digestion Approach to Maximize Volatile Fatty Acids Production from Municipal Sludge and a Techno-economic Feasibility Study
<p>Acid digestion, which is the first step of two-phase acid/gas anaerobic digestion process, was studied to identify the optimum operating conditions that would maximize the production of volatile fatty acids (VFAs). Batch and semi-continuous acid digesters were operated using combined primary …
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Mechanisms of Solubilization and Mass Transfer in Oleic Acid/aqueous Surfactant Systems
The dynamics of oleic acid solubilization by aqueous sodium taurodeoxycholate, a model fatty acid digestion system, was studied at 37(DEGREES)C. Steady state stirred experiments provided evidence of enhanced solubilization rates under conditions similar to those present for the physiologic process …
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CO2 sequestration using brine impacted fly fish
… mass spectrometry and ion chromatography. Total acid digestion was carried out to evaluate the differences in the total elemental content in both the fresh ash and the carbonated solid residues. The results suggested that South African FA from Secunda belongs to class F based on the CaO content …
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A Comparative Study of the Anterior Latissimus Dorsi Muscle Following Stretch in the Quail and Chicken
… was determined by direct count after nitric acid digestion of non-muscle tissue. Calculations were then made for individual fiber mass and corrected muscle mass. The other ALD muscle was not stretched, and was used as an intra-animal control. The quail showed a 209-223% increase in muscle …
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The effects of polymeric binders on the processability and properties of composites made by suspension prepregging
… of 21.3 wt% of imidized LaRC TPI polyamic acid binder at a frequency of 1 Hz. The greatest fiber-matrix adhesion was observed for PEEK composites when BisP BTDA polyamic acid was used as a binder. A preliminary, qualitative study on the possibility of using suspension prepregging as means …
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The Development of Analytical Procedures for Analysis of Trace Metals in Pharmaceutical Formulations and the Speciation of Arsenic in Antacids
… involves the use of microwave (MW)-assisted acid digestion step, which is very common for pharmaceutical samples. Sample preparation was performed using a developed MW-assisted acid digestion method with reverse aqua regia. It was found that reaching a temperature of 210°C for sample’s …
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Pollution of soils by lead and its uptake and pathways in the ecosystem.
… industrial activity. A simple reliable and rapid acid digestion procedure was developed and the procedure evaluated through an interlaboratory survey involving 22 laboratories. This demonstrated that analysts should seek to improve analytical performance through achieving better interlaboratory …
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Heavy metals in river sediments
… by Atomic Absorption Spectroscopy after digestion of the dried sample. A rapid hydrochloric acid/hydrogen peroxide digestion was chosen after a brief comparison with the more traditional nitric/perchloric acid digestion.<br/><br/>The results were used in a survey of the heavy metal …
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Trace Evidence Analysis of Forensic Samples Using Inductively Coupled Plasma
… by SN into ICP mass spectrometry (MS) following acid digestion constitutes an even more sensitive approach than ETV-ICP-OES. The concentrations of trace impurities were measured by SN-ICP-MS in lead-tin solder, commonly used in the making of improvised explosive devices, to help to narrow down …
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THE ANALYSIS OF SAMPLES WITH COMPLEX MATRICES FOR ELEMENTAL CONCENTRATION
… analyze these cells without the need for acid digestion or cell pre-treatment. Through utilizing unconventional sample introduction techniques and sample pre-treatment, many problems that plague traditional measurement of these elements in varying matrices can be circumvented.
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Internal Cycling in an Urban Drinking Water Reservoir
… cadmium, copper, lead, and zinc, using a strong acid digestion technique. The samples were also analyzed for iron-bound P (Fe-P), authigenic P (A-P), detrital P (D-P), organic P (O-P), reducible iron, and reducible manganese, using a sequential extraction technique. The results from the study …
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Effect of myofibril length and tissue constituents on acoustic propagation properties of muscle
… (% water), ether extraction (% fat) and nitric acid digestion (% protein). The sarcomere length for individual samples was determined using light microscopy of suitable stained slides. Finally, the effect of the sarcomere structure was determined by homogenizing the tissue samples, and measuring …
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Leaching of metals and metalloids from highway marking glass beads and the potential environmental impact
… were measured using two techniques: hydrofluoric acid digestion followed by inductively coupled plasma mass spectroscopy (HF/ICP-MS), and field portable x-ray fluorescence (FP-XRF) spectroscopy. A number of leaching studies were conducted and included two standard United States Environmental …
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The investigation of potentially toxic elements (PTE) and particulates absorbed on particle filters exposed to vehicle emissions at road level
… set mileages. Different open and closed vessel acid digestion methods were compared to determine which extraction method yields optimum recoveries for a known standard reference material (NIST 1648a Urban Particulate Matter). Analyte concentrations from filter samples were determined using …
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