Sample records for dissolution test method

  1. Vibration effects of lab equipment on dissolution testing with USP paddle method.

    PubMed

    Gao, Zongming; Thies, Andrea; Doub, William

    2010-01-01

    Environmental vibration induced by laboratory equipment, building construction, or even by the analysts themselves is one of the more complicated factors affecting dissolution testing. It is difficult to control and/or calibrate by mechanical means or performance-based methods. In this study, dissolution apparatus vibration levels were measured in the frequency range from 10 to 270 Hz along all three axes using commercially available, single-axis accelerometers. The vibration distribution on the dissolution vessel plate was mapped, and acceleration was subsequently measured during dissolution runs involving NCDA#2 (10 mg prednisone) tablets using the paddle method. Several types of laboratory equipment were used to induce vibration during dissolution testing and vibration levels along the X-, Y-, and Z-axes of the vessel plate were measured in an attempt to establish possible correlation with dissolution results. In the frequency range studied, root mean square (RMS) acceleration values above 0.01 g, in either vertical or horizontal direction, typically affected dissolution results. PMID:19544371

  2. Automation of dissolution tests

    PubMed Central

    Rolli, Rolf

    2003-01-01

    Dissolution testing of drug formulations was introduced in the 1960s and accepted by health regulatory authorities in the 1970s. Since then, the importance of dissolution has grown rapidly as have the number of tests and demands in quality-control laboratories. Recent research works lead to the development of in-vitro dissolution tests as replacements for human and animal bioequivalence studies. For many years, a lot of time and effort has been invested in automation of dissolution tests. There have been a number of in-house solutions from pharmaceutical companies and many have created task forces or even departments to develop automation. Robotic solutions with sequential operation were introduced as well as the simultaneous operation concept developed by SOTAX. Today, pharmaceutical companies focus their resources mainly on the core business and in-house engineering solutions that are very difficult to justify. Therefore, it is important to know the basic considerations in order to plan an automation concept and implement it together with a vendor. PMID:18924885

  3. A discriminating dissolution method for glimepiride polymorphs.

    PubMed

    Bonfilio, Rudy; Pires, Sumaia A; Ferreira, Leonardo M B; de Almeida, Adélia E; Doriguetto, Antônio C; de Araújo, Magali B; Salgado, Hérida R N

    2012-02-01

    Glimepiride, an oral antidiabetic drug, is practically insoluble in water and exists in two polymorphic forms, I and II, of which form II has higher solubility in water. Because the dissolution rate of drugs can depend on the crystal form, there is a need to develop discriminating dissolution methods that are sensitive to changes in polymorphic forms. In this work, a dissolution method for the assessment of 4 mg glimepiride tablets was developed and validated. The optimal dissolution conditions were 1000 mL of phosphate buffer (pH 6.8) containing 0.1% (w/v) of sodium dodecyl sulfate as the dissolution medium and a stirring speed of 50 rpm using a paddle apparatus. The results demonstrated that all the data meet the validation acceptance criteria. Subsequently, tablets containing forms I and II of glimepiride were prepared and subjected to dissolution testing. A significant influence of polymorphism on the dissolution properties of glimepiride tablets was observed. These results suggested that the raw material used to produce glimepiride tablets must be strictly controlled because they may produce undesirable and unpredictable effects. PMID:22052673

  4. Gemifloxacin mesylate (GFM): dissolution test based on in vivo data.

    PubMed

    Paim, Clésio Soldateli; Araújo, Bibiana Verlindo de; Volpato, Nádia Maria; Steppe, Martin; Schapoval, Elfrides Eva Sherman

    2015-04-01

    Gemifloxacin mesylate (GFM) is a synthetic, broad-spectrum, fluoroquinolone antibacterial agent. It is different from other class members because it achieves adequate plasma concentrations to inhibit both topoisomerase IV and gyrase. The aim of this study was to develop and validate a dissolution test for GFM in coated tablets, using a simulated absorption profile based on in vivo data obtained from the literature. The fraction and percentage of the dose absorbed were calculated using model-dependent Loo-Riegelman approach for two compartments. The best in vitro dissolution profile was obtained using 900?mL of pH 6.0 phosphate buffer as a dissolution medium at 37?°C?±?0.5?°C and paddles at 50?rpm. The in vitro dissolution samples were analyzed using a liquid chromatography method, and the validation was performed according to USP 34 (2011). The method showed specificity, precision, accuracy, robustness and linearity. Under these conditions, a level-A in vitro-in vivo correlation was suggested (r?=?0.9926). The prediction errors were calculated to determine the validity and accuracy of the suggested correlation. The dissolution test can be used to evaluate the dissolution profile of GFM-coated tablets and minimize the number of bioavailability studies as part of new formulation development. PMID:24517572

  5. Effects of vessel geometric irregularity on dissolution test results.

    PubMed

    Gao, Zongming; Ahadi, Shafiq; Moore, Terry W; Doub, William H; Westenberger, B J; Buhse, Lucinda F

    2011-03-01

    Dissolution testing of pharmaceutical products is an important technique used extensively for both product development and quality control, but there are many variables that can affect dissolution results. In this study, the effect of the inner shape of standard 1-L dissolution vessels on drug dissolution results was investigated. The geometric dimensions and irregularities of commercially available vessels (obtained from four different manufacturers) were examined using a three-dimensional video-based measuring machine (VMM). The same analyst, dissolution test assembly, and experimental conditions were used for dissolution testing involving 10 mg of prednisone tablets (NCDA #2) with dissolution apparatus 2 (paddle). Mechanical calibration of the dissolution apparatus was performed prior to dissolution testing with each set of vessels. Geometric characteristics varied within and among the sets of vessels, but the overall averages and standard deviations of dissolution results (six vessels) showed no statistical significant differences among the vessel sets. However, some dissolution differences were noted when comparing individual vessels. With these types of comparisons, the vessel concentricity, sphericity, and radius of sphere were found to possibly influence the amount of prednisone dissolved, but flatness of vessel flange, cylindricity, and circularity showed no effect on dissolution results. The study shows that VMM is a technique that could be used to qualify dissolution vessels. PMID:20803604

  6. Automated Dissolution for Enteric-Coated Aspirin Tablets: A Case Study for Method Transfer to a RoboDis II.

    PubMed

    Ibrahim, Sarah A; Martini, Luigi

    2014-01-24

    Dissolution method transfer is a complicated yet common process in the pharmaceutical industry. With increased pharmaceutical product manufacturing and dissolution acceptance requirements, dissolution testing has become one of the most labor-intensive quality control testing methods. There is an increased trend for automation in dissolution testing, particularly for large pharmaceutical companies to reduce variability and increase personnel efficiency. There is no official guideline for dissolution testing method transfer from a manual, semi-automated, to automated dissolution tester. In this study, a manual multipoint dissolution testing procedure for an enteric-coated aspirin tablet was transferred effectively and reproducibly to a fully automated dissolution testing device, RoboDis II. Enteric-coated aspirin samples were used as a model formulation to assess the feasibility and accuracy of media pH change during continuous automated dissolution testing. Several RoboDis II parameters were evaluated to ensure the integrity and equivalency of dissolution method transfer from a manual dissolution tester. This current study provides a systematic outline for the transfer of the manual dissolution testing protocol to an automated dissolution tester. This study further supports that automated dissolution testers compliant with regulatory requirements and similar to manual dissolution testers facilitate method transfer. PMID:24464812

  7. Characterization and Dissolution Kinetics Testing of Radioactive H-3 Calcine

    SciTech Connect

    Garn, Troy Gerry; Batcheller, Thomas Aquinas

    2002-09-01

    Characterization and dissolution kinetics testing were performed with Idaho radioactive H-3 calcine. Calcine dissolution is the key front-end unit operation for the Separations Alternative identified in the Idaho High Level Waste Draft EIS. The impact of the extent of dissolution on the feasibility of Separations must be clearly quantified.

  8. Development and Validation of Discriminating and Biorelevant Dissolution Test for Lornoxicam Tablets

    PubMed Central

    Anumolu, P. D.; Sunitha, G.; Bindu, S. Hima; Satheshbabu, P. R.; Subrahmanyam, C. V. S.

    2015-01-01

    The establishment of biorelevant and discriminating dissolution procedure for drug products with limited water solubility is a useful technique for qualitative forecasting of the in vivo behavior of formulations. It also characterizes the drug product performance in pharmaceutical development. Lornoxicam, a BCS class-II drug is a nonsteroidal antiinflammatory drug of the oxicam class, has no official dissolution media available in the literature. The objective of present work was to develop and validate a discriminating and biorelevant dissolution test for lornoxicam tablet dosage forms. To quantify the lornoxicam in dissolution samples, UV spectrophotometric method was developed using 0.01M sodium hydroxide solution as solvent at ?ma×376 nm. After evaluation of saturation solubility, dissolution, sink conditions and stability of lornoxicam bulk drug in different pH solutions and biorelevant media, the dissolution method was optimized using USP paddle type apparatus at 50 rpm rotation speed and 500 ml simulated intestinal fluid as discriminating and biorelevant dissolution medium. The similarity factor (f2) were investigated for formulations with changes in composition and manufacturing variations, values revealed that dissolution method having discriminating power and method was validated as per standard guidelines. The proposed dissolution method can be effectively applied for routine quality control in vitro dissolution studies of lornoxicam in tablets and helpful to pharmacopoeias. PMID:26180277

  9. ACID DISSOLUTION METHOD FOR THE ANALYSIS OF PLUTONIUM IN SOIL: EVALUATION OF AN INTERLABORATORY COLLABORATIVE TEST AND COMPARISON WITH RESULTS OF A FUSION METHOD TEST

    EPA Science Inventory

    The data from an interlaboratory collaborative test are presented. A statistical analysis of the data is also presented. From that analysis, statements are made of the combined within-laboratory precision, the systematic error between laboratories, the total error between laborat...

  10. New method for characterizing dissolution properties of drug powders.

    PubMed

    Pedersen, P V

    1977-06-01

    Various multiparticulate dissolution models that assume a log-normal particle-size distribution are fitted by nonlinear least-squares regression to data from the dissolution of micronized glyburide. Estimates of parameters describing the effective initial particle-size distribution are obtained, together with estimates of the specific dissolution rate parameter. A dissolution equation based on an ideal, untruncated, log-normal distribution, with the single particles dissolving according to the Hixson-Crowell cube root law, is the best model. The dissolution behavior of glyburide can be well described by this model in terms of the specific dissolution rate parameter and one other parameter accounting for the distribution effect. The estimation of these two parameters represents a more exact way of describing the dissolution characteristics of drug powders than previous approaches. The method should be of interest in the quality control of drugs that may cause bioavailability problems because of dissolution rate-limited absorption. PMID:406380

  11. Online monitoring of dissolution tests using dedicated potentiometric sensors in biorelevant media

    Microsoft Academic Search

    Daniel Juenemann; Hugo Bohets; Mahir Ozdemir; Roy de Maesschalck; Koen Vanhoutte; Karl Peeters; Luc Nagels; Jennifer B. Dressman

    2011-01-01

    The performance of the Ion-Selective Electrode (ISE) for in vitro dissolution testing using biorelevant media was evaluated in this study. In vitro dissolution was carried out using USP apparatus 2 (paddle method) with classical and with updated biorelevant media to simulate the pre- and postprandial states. The ISE was used as an analytical stand-alone system and in combination with a

  12. Pilot-scale tests of HEME and HEPA dissolution process

    SciTech Connect

    Qureshi, Z.H.; Strege, D.K.

    1994-06-01

    A series of pilot-scale demonstration tests for the dissolution of High Efficiency Mist Eliminators (HEME`s) and High Efficiency Particulate Airfilters (HEPA) were performed on a 1/5th linear scale. These fiberglass filters are to be used in the Defense Waste Processing Facility (DWPF) to decontaminate the effluents from the off-gases generated during the feed preparation process and vitrification. When removed, these filters will be dissolved in the Decontamination Waste Treatment Tank (DWTT) using 5 wt% NaOH solution. The contaminated fiberglass is converted to an aqueous stream which will be transferred to the waste tanks. The filter metal structure will be rinsed with process water before its disposal as low-level solid waste. The pilot-scale study reported here successfully demonstrated a simple one step process using 5 wt% NaOH solution. The proposed process requires the installation of a new water spray ring with 30 nozzles. In addition to the reduced waste generated, the total process time is reduced to 48 hours only (66% saving in time). The pilot-scale tests clearly demonstrated that the dissolution process of HEMEs has two stages - chemical digestion of the filter and mechanical erosion of the digested filter. The digestion is achieved by a boiling 5 wt% caustic solutions, whereas the mechanical break down of the digested filter is successfully achieved by spraying process water on the digested filter. An alternate method of breaking down the digested filter by increased air sparging of the solution was found to be marginally successful are best. The pilot-scale tests also demonstrated that the products of dissolution are easily pumpable by a centrifugal pump.

  13. Hydrodynamic investigation of USP dissolution test apparatus II.

    PubMed

    Bai, Ge; Armenante, Piero M; Plank, Russell V; Gentzler, Michael; Ford, Kenneth; Harmon, Paul

    2007-09-01

    The USP Apparatus II is the device commonly used to conduct dissolution testing in the pharmaceutical industry. Despite its widespread use, dissolution testing remains susceptible to significant error and test failures, and limited information is available on the hydrodynamics of this apparatus. In this work, laser-Doppler velocimetry (LDV) and computational fluid dynamics (CFD) were used, respectively, to experimentally map and computationally predict the velocity distribution inside a standard USP Apparatus II under the typical operating conditions mandated by the dissolution test procedure. The flow in the apparatus is strongly dominated by the tangential component of the velocity. Secondary flows consist of an upper and lower recirculation loop in the vertical plane, above and below the impeller, respectively. A low recirculation zone was observed in the lower part of the hemispherical vessel bottom where the tablet dissolution process takes place. The radial and axial velocities in the region just below the impeller were found to be very small. This is the most critical region of the apparatus since the dissolving tablet will likely be at this location during the dissolution test. The velocities in this region change significantly over short distances along the vessel bottom. This implies that small variations in the location of the tablet on the vessel bottom caused by the randomness of the tablet descent through the liquid are likely to result in significantly different velocities and velocity gradients near the tablet. This is likely to introduce variability in the test. PMID:17573698

  14. Dissolution of low burnup Fast Flux Test reactor fuel

    SciTech Connect

    Fellows, R.L.; Campbell, D.O.; Mailen, J.C.

    1984-01-01

    The first Fast-Flux Test Facility reactor fuel (mixed (U,Pu)O/sub 2/ composition) has been used in dissolution tests for fuel reprocessing. The fuel tested here had a peak burnup of 0.22 at. %, with peak centerline temperatures of 1997/sup 0/C. Linear dissolution rates of 0.99 to 1.57 mm/h were determined for dissolver solution and fresh acid, respectively. Insoluble residues from dissolution at 95/sup 0/C ranged from 0.18 to 0.28% of the original fuel. From 2 to 37 wt % of the residue was recoverable plutonium. Dissolution at 29/sup 0/C yielded residues of 0.56 to 0.64% of the original fuel. The major elements present in the HF leached residue included Ru, Mo, and Rh. The recovered cladding from the 95/sup 0/C dissolution contained the equivalent of 198 mg of /sup 239/Pu per 100 g of hulls, while the cladding from the 29/sup 0/c experiments contained only 0.21 mg of /sup 239/Pu per 100 g of hulls. 9 references, 5 figures.

  15. Validation of analytical methods involved in dissolution assays: acceptance limits and decision methodologies.

    PubMed

    Rozet, E; Ziemons, E; Marini, R D; Boulanger, B; Hubert, Ph

    2012-11-01

    Dissolution tests are key elements to ensure continuing product quality and performance. The ultimate goal of these tests is to assure consistent product quality within a defined set of specification criteria. Validation of an analytical method aimed at assessing the dissolution profile of products or at verifying pharmacopoeias compliance should demonstrate that this analytical method is able to correctly declare two dissolution profiles as similar or drug products as compliant with respect to their specifications. It is essential to ensure that these analytical methods are fit for their purpose. Method validation is aimed at providing this guarantee. However, even in the ICHQ2 guideline there is no information explaining how to decide whether the method under validation is valid for its final purpose or not. Are the entire validation criterion needed to ensure that a Quality Control (QC) analytical method for dissolution test is valid? What acceptance limits should be set on these criteria? How to decide about method's validity? These are the questions that this work aims at answering. Focus is made to comply with the current implementation of the Quality by Design (QbD) principles in the pharmaceutical industry in order to allow to correctly defining the Analytical Target Profile (ATP) of analytical methods involved in dissolution tests. Analytical method validation is then the natural demonstration that the developed methods are fit for their intended purpose and is not any more the inconsiderate checklist validation approach still generally performed to complete the filing required to obtain product marketing authorization. PMID:23084050

  16. Development of Alkaline Oxidative Dissolution Methods for Chromium (III) Compounds Present in Hanford Site Tank Sludges

    SciTech Connect

    NN Krot; VP Shilov; AM Fedoseev; NA Budantseva; MV Nikonov; AB Yusov; AYu Garnov; IA Charushnikova; VP Perminov; LN Astafurova; TS Lapitskaya; VI Makarenkov

    1999-07-02

    The high-level radioactive waste sludge in the underground storage tanks at the Hanford Site contains various chromium(III)solid phases. Dissolution and removal of chromium from tank waste sludges is desirable prior to high-level waste vitrification because increased volume is required to incorporate the residual chromium. Unfortunately, dissolution of chromium from the sludge to form Cr(OH){sub 4}{sup {minus}} through treatment with heated NaOH solution (also used to dissolve aluminum phases and metathesize phosphates to sodium salts) generally has been unsuccessful in tests with both simulated and genuine Hanford waste sludges. Oxidative dissolution of the Cr(III) compounds to form soluble chromate has been proposed as an alternative chromium solid phase dissolution method and results of limited prior testing have been reported.

  17. Test Objectives for the Saltcake Dissolution Retrieval Demonstration

    SciTech Connect

    DEFIGH PRICE, C.

    2000-09-22

    This document describes the objectives the Saltcake Dissolution Retrieval Demonstration. The near term strategy for single-shell tank waste retrieval activities has shifted from focusing on maximizing the number of tanks entered for retrieval (regardless of waste volume or content) to a focus on scheduling the retrieval of wastes from those single-shell tanks with a high volume of contaminants of concern. These contaminants are defined as mobile, long-lived radionuclides that have a potential of reaching the groundwater and the Columbia River. This strategy also focuses on the performance of key retrieval technology demonstrations, including the Saltcake Dissolution Retrieval Demonstration, in a variety of waste forms and tank farm locations to establish a technical basis for future work. The work scope will also focus on the performance of risk assessment, retrieval performance evaluations (RPE) and incorporating vadose zone characterization data on a tank-by-tank basis, and on updating tank farm closure/post closure work plans. The deployment of a retrieval technology other than Past-Practice Sluicing (PPS) allows determination of limits of technical capabilities, as well as, providing a solid planning basis for future SST retrievals. This saltcake dissolution technology deployment test will determine if saltcake dissolution is a viable retrieval option for SST retrieval. CH2M Hill Hanford Group (CHG) recognizes the SST retrieval mission is key to the success of the River Protection Project (RPP) and the overall completion of the Hanford Site cleanup. The objectives outlined in this document will be incorporated into and used to develop the test and evaluation plan for saltcake dissolution retrievals. The test and evaluation plan will be developed in fiscal year 2001.

  18. Prediction of coning phenomena for irregular particles in paddle dissolution test.

    PubMed

    Higuchi, Mizuki; Nishida, Shunki; Yoshihashi, Yasuo; Tarada, Katsuhide; Sugano, Kiyohiko

    2015-08-30

    The purpose of the present study was to investigate the applicability of the Zwietering equation to predict the occurrence of coning phenomena for non-spherical, porous, and swell-able particles in the paddle dissolution test. For non-spherical particles, the minimum rotation speed at which the coning phenomena disappear (no coning rpm, NCrpm) was appropriately predicted by using the Stokes diameter or the short side length of the particles. For porous and swell-able particles, NCrpm was appropriately predicted by using the Stokes density of the particles. The accuracy of the Zwietering equation was sufficient to be used for development of a dissolution test method. PMID:25998150

  19. Dissolution rates and activation energy for dissolution of brucite (001) : A new method based on the microtopography of crystal surfaces

    Microsoft Academic Search

    Guntram Jordan; Werner Rammensee

    1996-01-01

    Scanning Force Microscopy (SFM) was used to develop a method which can provide quantitative kinetic data of crystal growth and dissolution. Based on observations of single crystal faces in monolayer resolution, morphology and temperature dependent growth and dissolution rates can be obtained. From these kinetic data activation energies can be calculated and compared with existing theories. The experimental method works

  20. Acid dissolution method for the analysis of plutonium in soil: evaluation of an interlaboratory collaborative test and comparison with results of a fusion method test. Final report, 1 February 1976-1 June 1978

    Microsoft Academic Search

    E. L. Whittaker; G. E. Grothaus

    1979-01-01

    The data from an interlaboratory collaborative test are presented. A statistical analysis of the data is also presented. From that analysis, statements are made of the combined within-laboratory precision, the systematic error between laboratories, the total error between laboratories based on a single analysis, and the method bias. Soil samples used for the test contained plutonium in a highly refractory

  1. Self-reference chemical profiling in the comprehensive dissolution test of herbal medicines.

    PubMed

    Wang, Anqi; Wang, Zhanguo; Yu, Wenjun; Zhong, Ting; Dai, Weiyang; Xu, Liang; Gong, Tao; Lan, Ke

    2012-11-01

    The power of chemical profiling in characterizing the samples' chemical pools has greatly raised the interests of phytomedicine researchers. Unfortunately, the semi-quantitative nature of chemical profiling retards its exploration into the dissolution test of herbal medicines, which is a crucial quantitative measure to evaluate and control the in vitro releasing properties as the prerequisite for biomembrane permeation of herbal constituents. Here, a method integrating chemical profiling approach and self-reference strategy is developed for the purpose of dissolution test of herbal medicines. The chromatographic fingerprints of the self-reference samples are translated by principal component analysis (PCA) into chemical profiles that highly correlate to their nominal gross concentrations in spite of the poor quantitative performances of some individual peaks. Pareto scaling previous to PCA selectively highlights the relative loadings of peaks with good quantitative performances. An example of ginkgo biloba tablets shows that this method is efficient to judge whether the detected constituents are simultaneously released or not, determine both the gross release and the respective dissolution rates of them, and rapidly screen the slowly released ones that may have potential clinical implications. This method has potentials to enable deep insight into the molecular diffusion and dissolution of complex herbal formulations, and open a new window to comprehensively consider the bioavailable properties of herbal medicines. PMID:22748665

  2. Experimental and computational determination of blend time in USP Dissolution Testing Apparatus II.

    PubMed

    Bai, Ge; Armenante, Piero M; Plank, Russell V

    2007-11-01

    Blend time, the time to achieve a predefined level of homogeneity of a tracer in a mixing vessel, is an important parameter to evaluate the mixing efficiency of mixing devices. In this work, the blend time required to homogenize the liquid content of a USP Dissolution Testing Apparatus II under a number of operating conditions was obtained using two different experimental methods (tracer detection via colorimetric and conductivity measurements), a computational approach (computational fluid dynamics (CFD)), and a semi-theoretical analysis of the phenomenon. Under the standard geometric and operating conditions in which the USP Apparatus II is typically used (N = 50 rpm) the experimental blend time to achieve a 92.74% uniformity level was found to be between 27.5 and 33.3 s, depending on the location of the injection point and monitoring point for the tracer. These values were in close agreement with those obtained from CFD simulations. Changing the impeller vertical position (+/-2 mm) had only a limited effect. The CFD predictions also indicated that blend time is inversely proportional to the agitation speed. This conclusion is in agreement with previous reports and equations for blend time in mixing vessels. The blend times obtained in this work appear to be some two orders of magnitude smaller than the time usually required for appreciable tablet dissolution during the typical dissolution test, implying that the liquid contents of the USP Apparatus II can be considered to be relatively well mixed during the typical dissolution test. PMID:17828739

  3. Standard test method for determination of impurities in plutonium: acid dissolution, ion exchange matrix separation, and inductively coupled plasma-atomic emission spectroscopic (ICP/AES) analysis

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This specification covers blended uranium trioxide (UO3), U3O8, or mixtures of the two, powders that are intended for conversion into a sinterable uranium dioxide (UO2) powder by means of a direct reduction process. The UO2 powder product of the reduction process must meet the requirements of Specification C 753 and be suitable for subsequent UO2 pellet fabrication by pressing and sintering methods. This specification applies to uranium oxides with a 235U enrichment less than 5 %. 1.2 This specification includes chemical, physical, and test method requirements for uranium oxide powders as they relate to the suitability of the powder for storage, transportation, and direct reduction to UO2 powder. This specification is applicable to uranium oxide powders for such use from any source. 1.3 The scope of this specification does not comprehensively cover all provisions for preventing criticality accidents, for health and safety, or for shipping. Observance of this specification does not relieve the user of th...

  4. Development and evaluation of methods for starch dissolution using asymmetrical flow field-flow fractionation. Part I: Dissolution of amylopectin.

    PubMed

    Perez-Rea, Daysi; Bergenståhl, Björn; Nilsson, Lars

    2015-06-01

    We have investigated methods of starch dissolution with the aim of finding an optimum method to completely dissolve starch granules to form a molecularly dissolved starch solution without degradation of the polymers. Glycogen was used as a model molecule for amylopectin, to identify the dissolution conditions under which the degradation of the polymers was limited or not present. Dissolution was performed in water with temperatures up to 200 °C, facilitated by the use of heating in an autoclave or a microwave oven, or in dimethyl sulfoxide (DMSO) at 100 °C. Waxy maize starch was chosen due to its high content of amylopectin and very low content of amylose. The degree of starch dissolution under different conditions was determined enzymatically. The effect of different dissolution conditions on the molar mass and root-mean-square radius of the polymers was determined with asymmetrical flow field-flow fractionation coupled to multi-angle light scattering and differential refractive index (AF4-MALS-dRI) detectors under aqueous conditions. The results suggest that reliable and accurate size separation and characterization of amylopectin can be obtained by dissolution of starch granules in an aqueous environment at 140 °C by autoclaving or in DMSO at 100 °C. The results also clearly show an upper limit for heat treatment of starch, above which degradation cannot be avoided. PMID:25925852

  5. In-situ measurement of solid phase transformations during dissolution testing

    E-print Network

    Aaltonen, J.; Strachan, C. J.; Peltonen, L.; Hirvonen, J.; Rantanen, J.

    2006-10-25

    OF THEOPHYLLINE:MCC REFERENCE Aaltonen J et al.: In-situ measurement of solid phase transformations during dissolution testing. J. Pharm. Sci. In Press. doi:10.1002/jps.20725 ACKNOWLEDGEMENTS The Academy of Finland and Finnish Cultural Foundation (Elli Turunen... transformation, but MCC had no effect on the rate of transformation RESULTS ?NF anhydrate (form ?) transformed to NF monohydrate (form II) during the dissolution test. ?The solid phase transformation during dissolution involves several overlapping factors...

  6. Typical variability in drug dissolution testing: study with USP and FDA calibrator tablets and a marketed drug (glibenclamide) product

    Microsoft Academic Search

    Saeed A Qureshi; Iain J McGilveray

    1999-01-01

    To evaluate variability in drug dissolution testing 28 laboratories analyzed USP calibrators, US FDA prednisone tablets and a marketed glibenclamide tablet product. The experiments were conducted using paddle and basket methods at 50 (calibrators) and 75 (glibenclamide) rpm. The media employed were deaerated by equilibrating at 37°C for 24 h and by the USP recommended method. The 95% CI values

  7. Calcination/dissolution testing for Hanford Site tank wastes

    SciTech Connect

    Colby, S.A.; Delegard, C.H. [Westinghouse Hanford Co., Richland, WA (United States); McLaughlin, D.F. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States); Danielson, M.J. [Pacific Northwest Lab., Richland, WA (United States)

    1994-07-01

    Thermal treatment by calcination offers several benefits for the treatment of Hanford Site tank wastes, including the destruction of organics and ferrocyanides and an hydroxide fusion that permits the bulk of the mostly soluble nonradioactive constituents to be easily separated from the insoluble transuranic residue. Critical design parameters were tested, including: (1) calciner equipment design, (2) hydroxide fusion chemistry, and (3) equipment corrosion. A 2 gal/minute pilot plant processed a simulated Tank 101-SY waste and produced a free flowing 700 C molten calcine with an average calciner retention time of 20 minutes and >95% organic, nitrate, and nitrite destruction. Laboratory experiments using actual radioactive tank waste and the simulated waste pilot experiments indicate that 98 wt% of the calcine produced is soluble in water, leaving an insoluble transuranic fraction. All of the Hanford Site tank wastes can benefit from calcination/dissolution processing, contingent upon blending various tank waste types to ensure a target of 70 wt% sodium hydroxide/nitrate/nitrite fluxing agent. Finally, corrosion testing indicates that a jacketed nickel liner cooled to below 400 C would corrode <2 mil/year (0.05 mm/year) from molten calcine attack.

  8. Developing dissolution testing methodologies for extended-release oral dosage forms with supersaturating properties. Case example: Solid dispersion matrix of indomethacin.

    PubMed

    Tajiri, Tomokazu; Morita, Shigeaki; Sakamoto, Ryosaku; Mimura, Hisahi; Ozaki, Yukihiro; Reppas, Christos; Kitamura, Satoshi

    2015-07-25

    The objective of this study was to develop an in vitro dissolution test method with discrimination ability for an extended-release solid dispersion matrix of a lipophilic drug using the United States Pharmacopeia (USP) Apparatus 4, flow-through cell apparatus. In the open-loop configuration, the sink condition was maintained by manipulating the flow rate of the dissolution medium. To evaluate the testing conditions, the drug release mechanism from an extended-release solid dispersion matrix containing hydrophobic and hydrophilic polymers was investigated. As the hydroxypropyl methylcellulose (HPMC) maintained concentrations of indomethacin higher than the solubility in a dissolution medium, the release of HPMC into the dissolution medium was also quantified using size-exclusion chromatography. We concluded that the USP Apparatus 4 is suitable for application to an in vitro dissolution method for orally administered extended-release solid dispersion matrix formulations containing poorly water-soluble drugs. PMID:26022889

  9. Test Objectives for the Saltcake Dissolution Retrieval Demonstration

    Microsoft Academic Search

    DEFIGH PRICE

    2000-01-01

    This document describes the objectives the Saltcake Dissolution Retrieval Demonstration. The near term strategy for single-shell tank waste retrieval activities has shifted from focusing on maximizing the number of tanks entered for retrieval (regardless of waste volume or content) to a focus on scheduling the retrieval of wastes from those single-shell tanks with a high volume of contaminants of concern.

  10. Development of Alkaline Oxidative Dissolution Methods for Chromium (III) Compounds Present in Hanford Site Tank Sludges

    SciTech Connect

    Delegard, Calvin H.; Krot, N N.; Shilov, V P.; Fedoseev, A M.; Budantseva, N A.; Nikonov, M V.; Yusov, A B.; Garnov, A Y.; Charushnikova, I A.; Perminov, V P.; Astafurova, L N.; Lapitskaya, T S.; Makarenkov, V I.

    1999-07-02

    The high-level radioactive waste sludge in the underground storage tanks at the Hanford Site contains various chromium solid phases. Dissolution and removal of chromium from tank waste sludges is desirable prior to high-level waste vitrification because increased volume is required to incorporate the residual chromium. Unfortunately, dissolution of chromium from the sludge to form Cr(OH){sub 4}{sup -} through treatment with heated NaOH solution (also used to dissolve aluminum phases and metathesize phosphates to sodium salts) generally has been unsuccessful in tests with both simulated and genuine Hanford waste sludges. Oxidative dissolution of the Cr(III) compounds to form soluble chromate has been proposed as an alternative chromium solid phase dissolution method and results of limited prior testing have been reported. The present systematic tests investigated oxygen gas, hydrogen peroxide, and sodium persulfate oxidants to dissolve Cr(III) under alkaline conditions to form soluble chromate. Permanganate and ozone also were considered for testing but were thought to be of secondary interest because of the insoluble residue (MnO{sub 2} from permanganate) and complex equipment (necessary to generate ozone) implicit with use of these reagents. The oxygen and hydrogen peroxide reagents leave no condensable residue and sodium persulfate only leaves soluble sodium sulfate. Crystalline Cr(OH){sub 3}, various hydrothermally aged amorphous Cr(III) oxide hydrates, mixed Fe(III)/Cr(III) oxide hydrates, and nickel and iron Cr(III) spinels, all of which have been identified or are likely constituents in Hanford tank wastes, were prepared and characterized for the dissolution tests. The effects of reagent and hydroxide concentrations, reaction temperature, and transition metal catalysts on reaction progress were investigated for each reagent as functions of reaction time. Reaction progress was measured by monitoring chromate concentration. Oxidation of chromium compounds by dissolved oxygen was found to increase linearly with oxygen partial pressure and NaOH concentration. The rate also increased with temperature at low activation energy, 26-36 kJ/mol, reflecting the opposing influences of decreasing oxygen volubility and increasing underlying chemical reaction rate. The reaction apparently proceeds by way of dissolved Cr(III) species, is catalyzed by Ni(II), and is slower for the hydrothermally aged materials. Dissolution rates ranged from about 7 x 10{sup -5} to 2.4 x 10{sup -4} moles Cr(III)/liter-hour in 80 C, 3-M NaOH with one atmosphere pure oxygen for the various Cr(III) compounds tested. These low dissolution rates commend the use of oxygen reagent to waste tank processing where extended residence times maybe practical. Oxidative dissolution of Cr(III) compounds by hydrogen peroxide was hampered in the presence of greater than 0.5 g Fe(III)/liter and other catalysts for H{sub 2}O{sub 2} decomposition and was less effective for materials that had undergone prolonged aging at high temperatures. Leaching was optimized at low excess NaOH and high temperatures (activation energy of {approx}82 kJ/mol). To prevent excessive loss of H{sub 2}O{sub 2} to catalytic decomposition, the peroxide reagent must be added slowly and with intense stirring. Treatment of waste solids with H{sub 2}O{sub 2} may only be attractive for freshly formed Cr(III) hydroxides [formed, for example, by alkaline metathesis of Cr(III)-bearing sludges] in the absence of decomposition catalysts such as Fe(III).

  11. Oral Absorption of Poorly Water-Soluble Drugs: Computer Simulation of Fraction Absorbed in Humans from a Miniscale Dissolution Test

    Microsoft Academic Search

    Ryusuke Takano; Kiyohiko Sugano; Atsuko Higashida; Yoshiki Hayashi; Minoru Machida; Yoshinori Aso; Shinji Yamashita

    2006-01-01

    \\u000a Purpose  The purpose of this study was to develop a new system for computer simulation to predict fraction absorbed (Fa) of Biopharmaceutical Classification System (BCS) class II (low solubility–high permeability) drugs after oral administration\\u000a to humans, from a miniscale dissolution test.\\u000a \\u000a \\u000a \\u000a Methods  Human oral absorption of 12 lipophilic drugs was simulated theoretically by using the dissolution and permeation parameters\\u000a of the drugs.

  12. Phase field and level set methods for modeling solute precipitation and/or dissolution

    SciTech Connect

    Zhijie Xu; Hai Huang; Paul Meakin

    2012-01-01

    The dynamics of solid-liquid interfaces controlled by solute precipitation and/or dissolution due to the chemical reaction at the interface were computed in two dimensions using a phase field models. Sharp-interface asymptotic analysis demonstrated that the phase field solutions should converge to the proper sharp-interface precipitation/dissolution limit. For the purpose of comparison, the numerical solution of the sharp-interface model for solute precipitation/dissolution was directly solved using a level set method. In general, the phase field results are found in good agreement with the level set results for all reaction rates and geometry configurations investigated. Present study supports the applications of both methods to more complicated and realistic reactive systems, including the nuclear waste release and mineral precipitation and dissolution

  13. Field test of a calcite dissolution rate law: Fort's Funnel Cave, Mammoth Cave National Park

    SciTech Connect

    Slunder, J.S. (EMPE Inc., Nashville, TN (United States)); Groves, C.G. (Western Kentucky Univ., Bowling Green, KY (United States). Center for Cave and Karst Studies)

    1994-03-01

    The laboratory-derived calcite dissolution rate law of Plummer et al. (1978) is the most widely used and mechanistically detailed expression currently available for predicting dissolution rates as a function of water chemistry. Such rate expressions are of great use in understanding timescales associated with limestone karst development. Little work has gone into the field testing of the rate law under natural conditions. This work measured dissolution rates by a crystal weight loss experiment in Buffalo Creek within Fort's funnel Cave, which lies within a pristine, forested catchment of Mammoth Cave National Park. Continuous water chemistry sampling over the same period allowed a time-integrated prediction of the dissolution based on the Plummer et al. (1978) expression. Results indicate that the rate law overpredicted dissolution by a factor of about ten. This concurs with earlier laboratory work suggesting that the law tends to overpredict rates in solutions close to equilibrium with respect to calcite, as were the waters within this part of the groundwater flow system.

  14. Observation of the dissolution process of Globigerina bulloides tests (planktic foraminifera) by X-ray microcomputed tomography

    NASA Astrophysics Data System (ADS)

    Iwasaki, Shinya; Kimoto, Katsunori; Sasaki, Osamu; Kano, Harumasa; Honda, Makio C.; Okazaki, Yusuke

    2015-04-01

    We performed a 9 day dissolution experiment with tests of the planktic foraminifer Globigerina bulloides at pH 6.7 ± 0.1 in water undersaturated with respect to calcite. The initial stage of the dissolution process, which is not recognizable from the surface structure of the tests, was quantitatively evaluated by X-ray microcomputed tomography (XMCT). XMCT revealed three distinct test structures: early-developed calcite formed during the juvenile stage of G. bulloides, an inner calcite layer, and an outer calcite layer. The test ultrastructure was observed by scanning electron microscopy, and CT number evaluated the density distribution in the test. The early-developed calcite and inner calcite layer had low CT numbers (500-1300; low density, porous) and were sensitive to dissolution, whereas the outer calcite layer had high CT numbers (<1300 high density) and resisted dissolution. Both the modes and the frequencies of the CT numbers decreased with progress of dissolution. Changes in the CT number histogram with progress of dissolution were quantified in terms of the percentage of calcite volume accounted for by low-density calcite (% Low-CT-number calcite). A clear linear relationship (R2 = 0.87) between % Low-CT-number calcite and % Test weight loss was found. This relationship indicates that the amount of test dissolution can be estimated from the distribution of CT numbers. We propose that XMCT measurements will be useful for quantitatively estimating the amount of carbonate loss from foraminiferal tests by dissolution.

  15. Dissolution testing of isoniazid, rifampicin, pyrazinamide and ethambutol tablets using near-infrared spectroscopy (NIRS) and multivariate calibration.

    PubMed

    de Oliveira Neves, Ana Carolina; Soares, Gustavo Mesquita; de Morais, Stéphanie Cavalcante; da Costa, Fernanda Saadna Lopes; Porto, Dayanne Lopes; de Lima, Kássio Michell Gomes

    2012-01-01

    This work utilized the near-infrared spectroscopy (NIRS) and multivariate calibration to measure the percentage drug dissolution of four active pharmaceutical ingredients (APIs) (isoniazid, rifampicin, pyrazinamide and ethambutol) in finished pharmaceutical products produced in the Federal University of Rio Grande do Norte (Brazil). The conventional analytical method employed in quality control tests of the dissolution by the pharmaceutical industry is high-performance liquid chromatography (HPLC). The NIRS is a reliable method that offers important advantages for the large-scale production of tablets and for non-destructive analysis. NIR spectra of 38 samples (in triplicate) were measured using a Bomen FT-NIR 160 MB in the range 1100-2500nm. Each spectrum was the average of 50 scans obtained in the diffuse reflectance mode. The dissolution test, which was initially carried out in 900mL of 0.1N hydrochloric acid at 37±0.5°C, was used to determine the percentage a drug that dissolved from each tablet measured at the same time interval (45min) at pH 6.8. The measurement of the four API was performed by HPLC (Shimadzu, Japan) in the gradiente mode. The influence of various spectral pretreatments (Savitzky-Golay smoothing, Multiplicative Scatter Correction (MSC), and Savitzky-Golay derivatives) and multivariate analysis using the partial least squares (PLS) regression algorithm was calculated by the Unscrambler 9.8 (Camo) software. The correlation coefficient (R(2)) for the HPLC determination versus predicted values (NIRS) ranged from 0.88 to 0.98. The root-mean-square error of prediction (RMSEP) obtained from PLS models were 9.99%, 8.63%, 8.57% and 9.97% for isoniazid, rifampicin, ethambutol and pyrazinamide, respectively, indicating that the NIR method is an effective and non-destructive tool for measurement of drug dissolution from tablets. PMID:21908131

  16. A description of forsterite dissolution using ab initio methods

    SciTech Connect

    Morrow, Christin [Pennsylvania State University; Kubicki, James D. [Pennsylvania State University; Mueller, Karl [Pennsylvania State University; Cole, David R [ORNL

    2009-01-01

    Molecular clusters representative of protonated, neutral, and deprotonated sites on a forsterite (Mg2SiO4) surface were employed to facilitate examination of Mg Obr bond-breaking via DFT calculations with the B3LYP/6-31+G(d,p) methodology. Hydrolysis reactions of the molecular clusters with a H2O molecule yielded barrier heights of 21, 54, and 39 kJ/mol for protonated, neutral, and deprotonated sites in the gas-phase, respectively, and the rate constants calculated using these barrier heights were 5.7x108, 2.7x104, and 2.2x106 s-1, respectively. Aqueous-phase calculations on the gas-phase structures were also performed, and the barrier heights were 33, 40, and 21 kJ/mol for the protonated, neutral, and deprotonated models. Rate constants were 4.3x106, 6.1x105, and 6.0x108 s-1. For models energy-minimized in the aqueous-phase the barrier heights were 42, 44, and 40 kJ/mol, and the rate constants were 1.4x107, 3.0x104, and 9.9x105 s-1, respectively. These differences highlight the importance of modeling structures with inclusion of solvent effects. Rates of Mg2+ release from the forsterite surface were predicted using these rate constants and models of the reactive site density and the H+ or OH surface speciation. These calculations are consistent with a more rapid rate of Mg2+ release under acidic conditions even though the activation energy barriers are equivalent within computational uncertainty. A comparison of these results to previous data shows that the predicted rates are much faster than experimentally measured dissolution rates, and this suggests that the Mg Obr bond break is a rapid process which is a component of Mg2+ release from the surface consistent with previous experimental observation of preferential Mg2+ leaching from forsterite. A dissolution mechanism involving polymerization and hydrolysis of Si Obr Si linkages is discussed that is consistent with the discrepancy between Mg2+ release rates and dissolution rates of forsterite.

  17. A test for phosphate rock reactivity in which solubility and size are combined in a dissolution rate function

    Microsoft Academic Search

    J. H. Watkinson

    1994-01-01

    A test for phosphate rock (PR) reactivity has been developed based on a representation of certain fundamental properties of the rocks designated the Dissolution Rate Function. The function and properties have been shown to be those important in models of the dissolution rate of PRs in soil. The properties are size or mass distribution with size, solubility product, P content

  18. Development and Characterization of Solid Dispersion for Dissolution Improvement of Furosemide by Cogrinding Method

    PubMed Central

    Siahi-Shadbad, Mohammad Reza; Ghanbarzadeh, Saeed; Barzegar-Jalali, Mohammad; Valizadeh, Hadi; Taherpoor, Alireza; Mohammadi, Ghobad; Barzegar-Jalali, Azim; Adibkia, Khosro

    2014-01-01

    Purpose: The purpose of this study was to prepare and characterize solid dispersion formulation of furosemide to enhance dissolution rate. Methods: Solid dispersions with different drug: carrier ratios were prepared by cogrinding method using crospovidone and microcrystalline cellulose as carrier. The physical state and interactions between the drug and carrier were characterized by Fourier transform infrared spectroscopic (FT-IR) and X ray diffraction (XRD). Results: Solid dispersions (especially with drug: Carrier ratio of 1:2) showed a higher dissolution rate than their respective physical mixture and pure furosemide. Dissolution rate in pH 5.8 was also higher than pH 1.2. The XRD analysis showed that crystalline form was changed to the amorphous state in the solid dispersions. FT-IR analysis did not show any physicochemical interactions in the solid dispersion formulations. Release kinetic of formulations were fitted best to the Weibull and Wagner log probability (linear kinetic) as well as suggested 2 and Gompertz (non-linear kinetic) models. Conclusion: The dissolution properties of furosemide were improved with the use of hydrophilic carriers in solid dispersions due to change in the crystalline form of the drug and more intimate contact between drug and carriers which was dependent on the type and ratio of carrier as well as dissolution medium pH. PMID:25436197

  19. Phase field and level set methods for modeling solute precipitation and/or dissolution

    SciTech Connect

    Xu, Zhijie; Huang, Hai; Li, Xiaoyi; Meakin, Paul

    2012-01-02

    The dynamics of solid-liquid interfaces controlled by solute precipitation and/or dissolution due to the chemical reaction at the interface were computed in two dimensions using a phase field models. Sharp-interface asymptotic analysis demonstrated that the phase field solutions should converge to the proper sharp-interface precipitation/dissolution limit. For the purpose of comparison, the numerical solution of the sharp-interface model for solute precipitation/dissolution was directly solved using a level set method. In general, the phase field results are found in good agreement with the level set results for all reaction rates and geometry configurations. Present study supports the applications of both methods to more complicated and realistic reactive systems.

  20. Gastrointestinal release behaviour of modified-release drug products: dynamic dissolution testing of mesalazine formulations.

    PubMed

    Goyanes, Alvaro; Hatton, Grace B; Merchant, Hamid A; Basit, Abdul W

    2015-04-30

    The aminosalicylate mesalazine (mesalamine) forms the mainstay of treatment in ulcerative colitis (UC), a disease for which many commercial modified-release products have been developed with the aim of providing targeted gastrointestinal release. The release profiles of five of these commercial formulations were evaluated in bicarbonate buffer using a novel dissolution model that mimics the dynamic conditions of the gastrointestinal tract. Monolithic and multi-particulate mesalazine formulations with pH-dependent and/or independent release mechanisms were evaluated (Asacol(®) 800, Octasa(®), Mezavant(®) XL, Salofalk(®), Pentasa(®)), and each of the products displayed a distinctive dissolution profile. The dissolution results for Mezavant(®) XL (Lialda(®)) (lag time 290 min) demonstrated good correlation with previously reported in vivo disintegration times assessed by gamma-scintigraphy in humans. Octasa(®) showed a similar lag time to Mezavant(®) XL. Drug release from Asacol(®) 800 (Asacol(®) HD) showed a wide standard deviation, reflecting the great variability in vivo. Salofalk(®) displayed both delayed release and extended release characteristics. Pentasa(®) released more than 50% of its drug load in the stomach compartment of the model, which is attributed to the absence of a gastro-resistant coating in this product. The new dissolution method provided a realistic and discriminative in vitro assessment of mesalazine release from different formulations. These results demonstrate that this strategy can be used to predict intestinal release behaviour, and potentially aid the rational design of products developed to target different sites of the gut. PMID:25721685

  1. Multiple fiber-optic dual-beam UV\\/Vis system with application to dissolution testing

    Microsoft Academic Search

    Jonas Johansson; Michael Cauchi; Mats Sundgren

    2002-01-01

    A system for fiber-optic probing in dissolution testing of solid pharmaceutical formulations has been constructed. The system is based on an imaging spectrometer and a charged coupled device (CCD) detector and includes 12 fiber-optic probes with a novel dual-path design. UV light was produced by a small arc deuterium lamp illuminating an optical fiber bundle. Twelve fiber-optic dipping probes were

  2. Multiple fiber-optic dual-beam UV/Vis system with application to dissolution testing.

    PubMed

    Johansson, Jonas; Cauchi, Michael; Sundgren, Mats

    2002-07-01

    A system for fiber-optic probing in dissolution testing of solid pharmaceutical formulations has been constructed. The system is based on an imaging spectrometer and a charged coupled device (CCD) detector and includes 12 fiber-optic probes with a novel dual-path design. UV light was produced by a small arc deuterium lamp illuminating an optical fiber bundle. Twelve fiber-optic dipping probes were constructed with a reflection geometry. A 5 mm diameter lens was used to achieve a parallel light beam. The light passed back and forth through the flow-through cuvette defined by a sapphire window and a coated aluminium mirror. The mirror was cut in half and each segment was tilted and set at different distances from the window to obtain two separate paths with different lengths. Two receiver fibers were used for each probe to collect the transmitted light. The 24 receiver fibers from the 12 probes were bunched to a linear bundle and fed to an imaging spectrometer and the corresponding spectra were detected with a 512 x 512 pixel cooled CCD detector. The sampling interval was typically a few seconds for all probes. A software package was developed for data recording and on-line analysis. The program includes tools for multi-component analysis. The system was tested for different tablet formulations. Prednisone 50 mg tablets, normally used for control tests of dissolution baths, were followed for 3 h. Secondly, an extended release low dosage tablet was followed for 7 h resulting in a linear dissolution profile. Finally, a combination tablet containing two active drugs was tested for 60 min profiles. In the latter case, separate dissolution curves for the two active components were obtained. Future work will mainly focus on further development of the multi-component capability of the system. PMID:12062647

  3. Regulatory considerations for the classification of video monitoring in dissolution testing.

    PubMed

    Tieu, Kinh; Salt, Alger; Wirges, James; Grove, Geoffrey N

    2014-12-01

    The goal of this article is to discuss the classification of video recordings and images when applied to dissolution testing in USP apparatus 1 and 2. Three use cases are presented. The first case presents the use and classification of video as RBE (review by exception) data under GAMP 5. The second case presents the use of video in formulation development in a research and development environment. The third case presents a feasibility study using readily available computer vision software to recognize and measure objects in the dissolution vessel, setting the groundwork for the use of image analysis as a quantitative tool. The classification of video as "electronic data", requiring 21 CFR part 11 compliance, versus its classification as a RBE data under GAMP 5, likely depends upon its use case. Another goal of this article is to establish a position on the use of video monitoring technology as a tool for dissolution testing that is fit for purpose and compliant with regulations regarding video data management and information. PMID:25142822

  4. Method for dissolution and stabilization of silica-rich fibers

    DOEpatents

    Jantzen, Carol M. (Aiken, SC)

    1997-01-01

    A method for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters.

  5. Results from Nevada Nuclear Waste Storage Investigations (NNWSI) Series 3 spent fuel dissolution tests

    SciTech Connect

    Wilson, C.N.

    1990-06-01

    The dissolution and radionuclide release behavior of spent fuel in groundwater is being studied by the Yucca Mountain Project (YMP), formerly the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. Specimens prepared from pressurized water reactor fuel rod segments were tested in sealed stainless steel vessels in Nevada Test Site J-13 well water at 85{degree}C and 25{degree}C. The test matrix included three specimens of bare-fuel particles plus cladding hulls, two fuel rod segments with artificially defected cladding and water-tight end fittings, and an undefected fuel rod section with watertight end fittings. Periodic solution samples were taken during test cycles with the sample volumes replenished with fresh J-13 water. Test cycles were periodically terminated and the specimens restarted in fresh J-13 water. The specimens were run for three cycles for a total test duration of 15 months. 22 refs., 32 figs., 26 tabs.

  6. Method for dissolution and stabilization of silica-rich fibers

    DOEpatents

    Jantzen, C.M.

    1997-11-11

    A method is described for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters. 1 fig.

  7. How Do Test Size and Dissolution Modify Stable Isotope Ratios and Mg/Ca in Planktonic Foraminifer Tests? a Quantitative Analysis

    NASA Astrophysics Data System (ADS)

    Mekik, F.

    2014-12-01

    We present new data for stable carbon and oxygen isotope ratios in four test-size ranges for Neogloboquadrina dutertrei from the EEP, and from four foraminifer species on RGR: Globorotalia menardii, Globorotalia truncatulinoides, Globorotalia inflata and Globigerinoides conglobatus. The EEP has a steep gradient to environmental parameters allowing statistical analyses of the effect of habitat and test size on shell chemistry. The RGR permits isolating the effect of sedimentary dissolution on shell chemistry because there is a strong gradient to sedimentary calcite dissolution there while surface environmental parameters remain invariable among core tops. Our statistical analyses include ANOVA, matched pair and independent means t-tests, univariate and multiple linear regression, principle components, and geographic distribution analyses. Calcite dissolution is estimated using the G. menardiiFragmentation Index. Stable isotope data from small N. dutertrei shells (< 350?m) provide more accurate, statistically significant, and consistent estimates of environmental parameters than larger foraminifers. Temperature estimates made from stable oxygen isotopes disagree with those made with Mg/Ca with large and statistically significant differences (up to 4°C) using the same species, in the same core top samples and within the same test-size ranges. Previous studies have shown the strong effect of dissolution in modifying Mg/Ca content of foraminifer tests. While there is no statistically significant evidence on RGR that dissolution modifies stable isotope ratios in foraminifer shells; in EEP core tops we observe a strong and statistically significant relationship between dissolution and shell stable isotope chemistry. Geographic analyses and radiocarbon data suggest that sediments experiencing much dissolution can be as old as 9000 years, and there is a linear and statistically significant relationship between degree of dissolution and core top sediment age. The greater the dissolution, the older the sediment. Therefore, environmental inferences from shell chemistry are not comparable to modern environmental parameters, and dissolution indirectly confounds the accurate interpretation of shell stable isotope data while directly altering the Mg/Ca content of foraminifer shells.

  8. A new method of dissolution in vitro, the "Bio-Dis" apparatus: comparison with the rotating bottle method and in vitro: in vivo correlations.

    PubMed

    Esbelin, B; Beyssac, E; Aiache, J M; Shiu, G K; Skelly, J P

    1991-10-01

    The aim was to study a new method of dissolution in vitro, the "Bio-Dis" apparatus, and to compare it with the classical rotating bottle method. Several theophylline controlled-release drug dosage forms were studied. Dissolution testing was performed in increasing pH in standard conditions and after treatment with peanut oil in order to simulate high fat meals and to correlate the in vitro percent dissolved with the in vivo results obtained. The in vivo study was carried out on three groups of healthy volunteers receiving each dosage form in a randomized order just before a high fat breakfast or in the fasting state. The in vitro percent dissolved obtained was compared with those published results obtained with rotating bottles. A linear relationship was established between these results. From the in vivo absorbed percentages calculated according to the Wagner-Nelson method, a linear relation was found between the in vivo percent absorbed and the in vitro percent dissolved in the different conditions. The relationships observed are similar for all the forms under both conditions. The "Bio-Dis" offers advantages over the rotating bottle method. The study reported allows this dissolution apparatus to be proposed as an alternative to the rotating bottle apparatus. PMID:1784010

  9. Selective chemical dissolution of sulfides: An evaluation of six methods applicable to assaying sulfide-bound nickel

    USGS Publications Warehouse

    Klock, P.R.; Czamanske, G.K.; Foose, M.; Pesek, J.

    1986-01-01

    Six analytical techniques for the selective chemical dissolution of sulfides are compared with the purpose of defining the best method for accurately determining the concentration of sulfide-bound nickel. Synthesized sulfide phases of known elemental content, mixed with well-analyzed silicates, were used to determine the relative and absolute efficiency, based on Ni and Mg recovery, of the techniques. Tested leach-methods purported to dissolve sulfide from silicate phases include: brominated water, brominated water-carbon tetrachloride, nitric-hydrochloric acid, hydrogen peroxide-ammonium citrate, bromine-methanol and hydrogen peroxide-ascorbic acid. Only the hydrogen peroxide-ammonium citrate method did not prove adequate in dissolving the sulfide phases. The remaining five methods dissolved the sulfide phases, but the indicated amount of attack on the silicate portion ranged from 3% to 100%. The bromine-methanol method is recommended for assaying sulfide-Ni deposits when Ni is also present in silicate phases. ?? 1986.

  10. Recovery of waterborne oocysts of Cryptosporidium from water samples by the membrane-filter dissolution method

    Microsoft Academic Search

    T. K. Graczyk; M. R. Cranfield; R. Fayer

    1997-01-01

    The cellulose-acetate membrane (CAM)-filter dissolution method implemented into a Millipore Glass Microanalysis system was used for recovery of Cryptosporidium parvum oocysts seeded into 25 l of drinking water in polyethylene carboy aspirator bottles. CAM-entrapped oocysts were detected by immunofluorescence microscopy. From 65 to 94 oocysts\\/l (mean 75 oocysts\\/l), 34.7% overall of the inoculated oocysts, were unrecovered as determined after the

  11. Method of inhibiting silica dissolution during injection of steam into a reservoir

    SciTech Connect

    Watkins, D. R.; Watanabe, D. J.

    1984-10-09

    A method for inhibiting the dissolution of silica from the matrix around a well during injection of steam into the matrix by adding to the feedwater used to generate the steam or the steam itself an inhibitor comprising an ammonium or substituted ammonium compound selected from the group consisting of ammonium halides, ammonium salts of inorganic acids, ammonium salts of carboxylic acids, quaternary ammonium halides, and amine or substituted amine hydrochlorides.

  12. Method for improving dissolution efficiency in gas-absorption and liquid extraction processes

    DOEpatents

    Kanak, Brant E. (Knoxville, TN); Stephenson, Michael J. (Oak Ridge, TN)

    1981-01-01

    This invention is a method for improving dissolution efficiency in processes in which a feed fluid is introduced to a zone where it is contacted with a liquid solvent for preferentially removing a component of the feed and where part of the solvent so contacted undergoes transfer into the feed fluid to saturate the same. It has been found that such transfer significantly impairs dissolution efficiency. In accordance with the invention, an amount of the above-mentioned solvent is added to the feed fluid being introduced to the contact zone, the solvent being added in an amount sufficient to effect reduction or elimination of the above-mentioned transfer. Preferably, the solvent is added to the feed fluid in an amount saturating or supersaturating the feed fluid under the conditions prevailing in the contact zone.

  13. Method for improving dissolution efficiency in gas-absorption and liquid extraction processes. [Patent application

    DOEpatents

    Kanak, B.E.; Stephenson, M.J.

    1980-01-11

    A method is described for improving dissolution efficiency in processes in which a feed fluid is introduced to a zone where it is contacted with a liquid solvent for preferentially removing a component of the feed and where part of the solvent so contacted undergoes transfer into the feed fluid to saturate the same. It has been found that such transfer significantly impairs dissolution efficiency. In accordance with the invention, an amount of the above-mentioned solvent is added to the feed fluid being introduced to the contact zone, the solvent being added in an amount sufficient to effect reduction or elimination of the above-mentioned transfer. Preferably, the solvent is added to the feed fluid in an amount saturating or supersaturating the feed fluid under the conditions prevailing in the contact zone.

  14. Dating of iron gall ink using the dissolution-diffusion method.

    PubMed

    Li, Biao; Xie, Peng

    2015-03-01

    In many criminal and civil cases, some questioned documents are written with iron gall ink. Determining the date when an iron gall ink entry was written can be important to assess the authenticity of a document. A dissolution-diffusion method was successfully employed to draw aging curves of iron gall ink entries stored in controlled conditions over 40 months. Calibration curves were created to indicate the relationship between the average dissolution-diffusion rate of ink components and the age of ink entries stored under natural aging conditions. As preliminary findings of this study, the mixed solution of dimethyl formamide (DMF) and anhydrous ethanol was suitable to dissolve the dye of iron gall ink strokes made at different time. It was also determined that brands of iron gall inks, types of paper, and thickness of iron gall ink strokes had varying impacts on estimating the dates of iron gall ink strokes. PMID:25677356

  15. In vitro release of ketoprofen suppositories using the USP basket and the flow-through cell dissolution methods.

    PubMed

    Medina, José Raúl; Padilla, Adrián Roberto; Hurtado, Marcela; Cortés, Alma Rosa; Domínguez-Ramírez, Adriana Miriam

    2014-05-01

    In order to study the release characteristics of ketoprofen suppositories under the hydrodynamic environment generated by USP Apparatus 1 and 4, the dissolution profiles of the Mexican reference product (100 mg) were determined. Phosphate buffer pH 8 and 1% sodium lauryl sulfate (SLS) aqueous solutions were proved as dissolution mediums. Baskets were rotated at 100 rpm with USP Apparatus 1 and different flow rates from 16-32 mL/min with USP Apparatus 4 were used. Drug samples were taken and quantified during 60 min by UV analysis at 260 nm. Mean dissolution time (MDT) and dissolution efficiency (DE) were calculated by model-independent methods. Data were also fitted to several kinetic models. Poor dissolution was found in both dissolution mediums when USP basket method was used (< 10% dissolved) while better results were obtained with USP Apparatus 4 when 1% SLS at 24 mL/min was used (43.6% dissolved, MDT of 25.5 min and DE of 25.0%). Kinetics showed a great variability when the USP Apparatus 1 was used, and Gompertz fitted well for data of 1% SLS at 24 mL/min (R(2)(adjusted) > 0.99). The results suggest the need to establish an adequate dissolution method to evaluate the release kinetics of ketoprofen from suppositories. PMID:24811800

  16. Results from NNWSI [Nevada Nuclear Waste Storage Investigations] Series 2 bare fuel dissolution tests

    SciTech Connect

    Wilson, C.N.

    1990-09-01

    The dissolution and radionuclide release behavior of spent fuel in groundwater is being studied by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. Two bare spent fuel specimens plus the empty cladding hulls were tested in NNWSI J-13 well water in unsealed fused silica vessels under ambient hot cell air conditions (25{degree}C) in the currently reported tests. One of the specimens was prepared from a rod irradiated in the H. B. Robinson Unit 2 reactor and the other from a rod irradiated in the Turkey Point Unit 3 reactor. Results indicate that most radionuclides of interest fall into three groups for release modeling. The first group principally includes the actinides (U, Np, Pu, Am, and Cm), all of which reached solubility-limited concentrations that were orders of magnitude below those necessary to meet the NRC 10 CFR 60.113 release limits for any realistic water flux predicted for the Yucca Mountain repository site. The second group is nuclides of soluble elements such as Cs, Tc, and I, for which release rates do not appear to be solubility-limited and may depend on the dissolution rate of fuel. In later test cycles, {sup 137}Cs, {sup 90}Sr, {sup 99}Tc, and {sup 129}I were continuously released at rates between about 5 {times} 10{sup {minus}5} and 1 {times} 10{sup {minus}4} of inventory per year. The third group is radionuclides that may be transported in the vapor phase, of which {sup 14}C is of primary concern. Detailed test results are presented and discussed. 17 refs., 15 figs., 21 tabs.

  17. Development and application of a validated HPLC method for the analysis of dissolution samples of levothyroxine sodium drug products

    Microsoft Academic Search

    J. W. Collier; R. B. Shah; A. R. Bryant; M. J. Habib; M. A. Khan; P. J. Faustino

    2011-01-01

    A rapid, selective, and sensitive gradient HPLC method was developed for the analysis of dissolution samples of levothyroxine sodium tablets. Current USP methodology for levothyroxine (l-T4) was not adequate to resolve co-elutants from a variety of levothyroxine drug product formulations. The USP method for analyzing dissolution samples of the drug product has shown significant intra- and inter-day variability. The sources

  18. Fully-automated system for dissolution rate of solid oral dosage forms according to the paddle method

    PubMed Central

    Lamparter, Erich; Riedl, Dieter

    1993-01-01

    This paper describes a fully-automated system (AUTO DISS®) for the determination of active ingredient release of solid oral dosage forms according to the paddle method of the US Pharmacopoeia (USP) and European Pharmacopoeia. Twenty batches can be tested continuously, with the six individuals (tablets, capsules etc.) of one batch being examined synchronous. The components of the AUTO DISS® system are presented and the operating steps of automatic filling with dissolution medium, dropping in of tablets, sampling and cleaning of vessels are described. Suitability for testing controlled-release drugs by means of automated buffer change from simulated gastric fluid to simulated intestinal fluid according to USP is also demonstrated. On-line determination of active ingredient concentration, as well as evaluation and documentation of measured values, is possible using an integrated automatic sampler in combination with various measuring instruments. The AUTO DISS® system is shown to be both rugged and accurate. PMID:18924973

  19. Dissolution and particle size characterization of radioactive contaminants in Hanford facilities: Criteria for methods of measurement

    SciTech Connect

    Briant, J.K.; James, A.C.

    1990-08-01

    The purpose of this document is to discuss experimental methods that can be applied to evaluate the rate at which an actinide material is likely to dissolve in biological fluids. Criteria are recommended for the design and conduct of meaningful experimental procedures to sample a representative size fraction of the source material, to measure the rate of radionuclide dissolution, and to apply the results to assign the material to an appropriate ICRP Publication-30 lung retention class (or mixture of classes). 26 refs., 3 figs., 3 tabs.

  20. Development of a bio-relevant dissolution test device simulating mechanical aspects present in the fed stomach.

    PubMed

    Koziolek, Mirko; Görke, Kristin; Neumann, Marco; Garbacz, Grzegorz; Weitschies, Werner

    2014-06-16

    A novel bio-relevant in vitro dissolution device was designed to mimic intragastric conditions after food intake paying particular consideration to mechanical aspects: the Fed Stomach Model (FSM). The FSM represents a fully computer-controlled dynamic flow-through system, in which dosage forms are hosted in so-called gastric vessels. Dosage form movement profiles as well as pressures can be simulated in a physiologically relevant manner. This proof-of-concept study aimed at the investigation of the effects of individual parameters and complex test programs on the drug delivery behavior of diclofenac sodium bilayer extended release tablets. Magnetic marker monitoring experiments demonstrated the applicability of the FSM to simulate intragastric movement velocities of solid oral dosage forms equivalent to in vivo data. Dissolution experiments revealed the relevance of all simulated parameters (i.e. pressure, dosage form movement and pump rate). Moreover, three different test scenarios with test programs specific for fundus, antrum and gastric emptying considered the variability of intragastric transit of solid oral dosage forms after food intake and were confirmed to be reasonable. Dissolution rates were low under conditions specific for fundus owing to low shear stresses. In contrast, higher amounts of the drug were released under high stress conditions simulating antral transit and gastric emptying. Concluding, the FSM can be a valuable tool for bio-relevant dissolution testing due to its potential of precise and reproducible simulation of mechanical parameters characteristic for the fed stomach. PMID:24051217

  1. Recovery of waterborne oocysts of Cryptosporidium from water samples by the membrane-filter dissolution method.

    PubMed

    Graczyk, T K; Cranfield, M R; Fayer, R

    1997-01-01

    The cellulose-acetate membrane (CAM)-filter dissolution method implemented into a Millipore Glass Microanalysis system was used for recovery of Cryptosporidium parvum oocysts seeded into 25 l of drinking water in polyethylene carboy aspirator bottles. CAM-entrapped oocysts were detected by immunofluorescence microscopy. From 65 to 94 oocysts/l (mean 75 oocysts/l), 34.7% overall of the inoculated oocysts, were unrecovered as determined after the water had been drained from the bottle, rinsed with 1 l of eluting fluid (EF), and CAM-filtered. Efficiency rates of oocyst recovery ranged from 24.0% to 64.0% (mean 44.1%), without the use of EF and from 72.1% to 82.3% (mean 78.8%) when EF was used. To ensure a high recovery efficiency of Cryptosporidium oocysts from sampled water by the CAM-filter dissolution method, it is recommended that 1 l of EF per 25 l of water be used. PMID:9039693

  2. Development and validation of a HPLC method for dissolution and stability assay of liquid-filled cyclosporine capsule drug products.

    PubMed

    Xu, Xiaoming; Gupta, Abhay; Faustino, Patrick; Sathe, Pradeep M; Sayeed, Vilayat A; Khan, Mansoor A

    2013-09-01

    To assay the dissolution samples of a drug product from several sources, a simple but broadly applicable analytical method is always desired. For the liquid-filled cyclosporine capsules, while analyzing the dissolution samples, the current compendial and literature HPLC methods have been found to be inadequate to provide satisfactory separation of the drug and the excipient peaks. Accordingly, a suitable isocratic reverse-phase HPLC method was developed for the analysis of dissolution samples of liquid-filled cyclosporine capsules. The method successfully separated the cyclosporine peak from the interfering chromatographic peaks of the excipients. The method was validated according to the ICH and FDA guidelines. Specificity, selectivity, linearity, accuracy, precision, and robustness were established over 3 days as part of method validation. Additionally, the degradation kinetics of cyclosporine in dissolution media was determined. Cyclosporine degradation followed a zero-order kinetics in the dissolution media with the respective rate constants of -3.5, -1.5, and -0.3%/h at 37°C, 25°C, and 10°C. PMID:23761263

  3. Method of inhibiting gravel pack and formation sandstone dissolution during steam injection

    SciTech Connect

    Swan, P.G.

    1982-04-06

    A method is claimed of inhibiting dissolution of the gravel pack and/or erosion of the formation standstone in a well bore subject to water or steam injection. The method includes the addition of a material to the surface of the gravel or formation which is capable of adhering to such surfaces and forming a tenacious water-repellent film. The film is monomolecular and hydrophobic. The active ingredient in the chemical treatment is commercial soybean lecithin. The material is added to the surfaces by injecting a liquid solution of the chemical down the annulus of the well during steaming and/or physically precoating the gravel pack by soaking it in a liquid solution of the chemical.

  4. In Vitro Dissolution Tests of Plutonium and Americium Containing Contamination Originating From ZPPR Fuel Plates

    SciTech Connect

    William F. Bauer; Brian K. Schuetz; Gary M. Huestis; Thomas B. Lints; Brian K. Harris; R. Duane Ball; Gracy Elias

    2012-09-01

    Assessing the extent of internal dose is of concern whenever workers are exposed to airborne radionuclides or other contaminants. Internal dose determinations depend upon a reasonable estimate of the expected biological half-life of the contaminants in the respiratory tract. One issue with refractory elements is determining the dissolution rate of the element. Actinides such as plutonium (Pu) and Americium (Am) tend to be very refractory and can have biological half-lives of tens of years. In the event of an exposure, the dissolution rates of the radionuclides of interest needs to be assessed in order to assign the proper internal dose estimates. During the November 2011 incident at the Idaho National Laboratory (INL) involving a ZPPR fuel plate, air filters in a constant air monitor (CAM) and a giraffe filter apparatus captured airborne particulate matter. These filters were used in dissolution rate experiments to determine the apparent dissolution half-life of Pu and Am in simulated biological fluids. This report describes these experiments and the results. The dissolution rates were found to follow a three term exponential decay equation. Differences were noted depending upon the nature of the biological fluid simulant. Overall, greater than 95% of the Pu and 93% of the Am were in a very slow dissolving component with dissolution half-lives of over 10 years.

  5. BEHAVIORAL TEST METHODS WORKSHOP.

    EPA Science Inventory

    This manuscript is the report from a workshop on behavioral testing methods that was held in Philadelphia PA on June 20-21, 2003. The workshop evaluated various aspects of behavioral testing methodology with the overall objective of identifying factors to improve the conduct of ...

  6. Zircon UPb chemical abrasion (bCA-TIMSQ) method: Combined annealing and multi-step partial dissolution analysis

    E-print Network

    Reiners, Peter W.

    Zircon U­Pb chemical abrasion (bCA-TIMSQ) method: Combined annealing and multi-step partial dissolution analysis for improved precision and accuracy of zircon ages James M. Mattinson Department-precision and high-accuracy U­Pb zircon geochronology is the total elimination of discordance caused by Pb loss

  7. Development of Alkaline Oxidative Dissolution Methods for Chromium (III) Compounds Present in Hanford Site Tank Sludges

    Microsoft Academic Search

    Calvin H. Delegard; V. P. Shilov; A. M. Fedoseev; NA Budantseva; M V. Nikonov; AYu Garnov; IA Charushnikova; LN Astafurova; T S. Lapitskaya; V I. Makarenkov

    1999-01-01

    The high-level radioactive waste sludge in the underground storage tanks at the Hanford Site contains various chromium solid phases. Dissolution and removal of chromium from tank waste sludges is desirable prior to high-level waste vitrification because increased volume is required to incorporate the residual chromium. Unfortunately, dissolution of chromium from the sludge to form Cr(OH)â⁻ through treatment with heated NaOH

  8. Bubble size distribution in acoustic droplet vaporization via dissolution using an ultrasound wide-beam method.

    PubMed

    Xu, Shanshan; Zong, Yujin; Li, Wusong; Zhang, Siyuan; Wan, Mingxi

    2014-05-01

    Performance and efficiency of numerous cavitation enhanced applications in a wide range of areas depend on the cavitation bubble size distribution. Therefore, cavitation bubble size estimation would be beneficial for biological and industrial applications that rely on cavitation. In this study, an acoustic method using a wide beam with low pressure is proposed to acquire the time intensity curve of the dissolution process for the cavitation bubble population and then determine the bubble size distribution. Dissolution of the cavitation bubbles in saline and in phase-shift nanodroplet emulsion diluted with undegassed or degassed saline was obtained to quantify the effects of pulse duration (PD) and acoustic power (AP) or peak negative pressure (PNP) of focused ultrasound on the size distribution of induced cavitation bubbles. It was found that an increase of PD will induce large bubbles while AP had only a little effect on the mean bubble size in saline. It was also recognized that longer PD and higher PNP increases the proportions of large and small bubbles, respectively, in suspensions of phase-shift nanodroplet emulsions. Moreover, degassing of the suspension tended to bring about smaller mean bubble size than the undegassed suspension. In addition, condensation of cavitation bubble produced in diluted suspension of phase-shift nanodroplet emulsion was involved in the calculation to discuss the effect of bubble condensation in the bubble size estimation in acoustic droplet vaporization. It was shown that calculation without considering the condensation might underestimate the mean bubble size and the calculation with considering the condensation might have more influence over the size distribution of small bubbles, but less effect on that of large bubbles. Without or with considering bubble condensation, the accessible minimum bubble radius was 0.4 or 1.7 ?m and the step size was 0.3 ?m. This acoustic technique provides an approach to estimate the size distribution of cavitation bubble population in opaque media and might be a promising tool for applications where it is desirable to tune the ultrasound parameters to control the size distribution of cavitation bubbles. PMID:24360840

  9. Validation and Application of a New Reversed Phase HPLC Method for In Vitro Dissolution Studies of Rabeprazole Sodium in Delayed-Release Tablets

    PubMed Central

    Nawaz, Md. Saddam

    2013-01-01

    The purpose of this study was to develop and validate a new reversed phase high performance liquid chromatographic (RP-HPLC) method to quantify in vitro dissolution assay of rabeprazole sodium in pharmaceutical tablet dosage form. Method development was performed on C 18, 100 × 4.6?mm ID, and 10??m particle size column, and injection volume was 20??L using a diode array detector (DAD) to monitor the detection at 280?nm. The mobile phase consisted of buffer: acetonitrile at a ratio of 60?:?40 (v/v), and the flow rate was maintained at 1.0?mL/min. The method was validated in terms of suitability, linearity, specificity, accuracy, precision, stability, and sensitivity. Linearity was observed over the range of concentration 0.05–12.0??g/mL, and the correlation coefficient was found excellent >0.999. The method was specific with respect to rabeprazole sodium, and the peak purity was found 99.99%. The method was precise and had relative standard deviations (RSD) less than 2%. Accuracy was found in the range of 99.9 to 101.9%. The method was robust in different variable conditions and reproducible. This proposed fast, reliable, cost-effective method can be used as quality control tool for the estimation of rabeprazole sodium in routine dissolution test analysis. PMID:24062966

  10. Development and validation of spectrophotometric method for simultaneous estimation of paracetamol and lornoxicam in different dissolution media

    PubMed Central

    Patel, Dasharath M.; Sardhara, Bhavesh M.; Thumbadiya, Diglesh H.; Patel, Chhagan N.

    2012-01-01

    Background: Paracetamol and lornoxicam in combined tablet dosage form are available in the market. This combination is used to treat inflammatory diseases of the joints, osteoarthritis and sciatica. Spectrophotometric and high performance liquid chromatography (HPLC) methods have been reported for their simultaneous estimation in tablet dosage form in specific solvent. This paper presents simple, accurate and reproducible spectrophotometric method for simultaneous determination of paracetamol and lornoxicam in tablet dosage form in different dissolution media. The reported method is helpful in determination of paracetamol and lornoxicam during dissolution study. Materials and Methods: Simple, sensitive, accurate and economical spectrophotometric method based on an absorption correction equation was developed for the estimation of paracetamol and lornoxicam simultaneously in tablet dosage form in different dissolution media at different pH. Results: Paracetamol showed absorption maxima at 243 nm in 0.1N HCland phosphate buffer pH 6.8, while lornoxicam showed absorption maxima at 374 nm in 0.1N HCland phosphate buffer pH 6.8. The linearity was obtained in the concentration range of 4-12 ?g/ml for paracetamol and 4-16 ?g/ ml for lornoxicam. Discussion: The concentrations of the drugs were determined by an absorption correction equation method. The results of analysis have been validated statistically by recovery studies. PMID:23781487

  11. Application of extraction disks in dissolution tests of clenbuterol and levothyroxine tablets by capillary electrophoresis

    Microsoft Academic Search

    C. N. Carducci; S. E. Lucangioli; V. G. Rodríguez; G. C. Fernández Otero

    1996-01-01

    Sample preparation procedures using octadecyl (C18) extraction disks were developed to obtain accurate and reproducible results for determinations of clenbuterol (20 ?g per dose) and levothyroxine (100 ?g per dose) in dissolution media of solid oral dosage forms. Preconcentration of samples allowed final concentrations of 1.1 ?g\\/ml of clenbuterol and 4.0 ?g\\/ml of levothyroxine to be reached prior to CE

  12. Development and application of a validated HPLC method for the analysis of dissolution samples of levothyroxine sodium drug products.

    PubMed

    Collier, J W; Shah, R B; Bryant, A R; Habib, M J; Khan, M A; Faustino, P J

    2011-02-20

    A rapid, selective, and sensitive gradient HPLC method was developed for the analysis of dissolution samples of levothyroxine sodium tablets. Current USP methodology for levothyroxine (L-T(4)) was not adequate to resolve co-elutants from a variety of levothyroxine drug product formulations. The USP method for analyzing dissolution samples of the drug product has shown significant intra- and inter-day variability. The sources of method variability include chromatographic interferences introduced by the dissolution media and the formulation excipients. In the present work, chromatographic separation of levothyroxine was achieved on an Agilent 1100 Series HPLC with a Waters Nova-pak column (250 mm × 3.9 mm) using a 0.01 M phosphate buffer (pH 3.0)-methanol (55:45, v/v) in a gradient elution mobile phase at a flow rate of 1.0 mL/min and detection UV wavelength of 225 nm. The injection volume was 800 ?L and the column temperature was maintained at 28°C. The method was validated according to USP Category I requirements. The validation characteristics included accuracy, precision, specificity, linearity, and analytical range. The standard curve was found to have a linear relationship (r(2)>0.99) over the analytical range of 0.08-0.8 ?g/mL. Accuracy ranged from 90 to 110% for low quality control (QC) standards and 95 to 105% for medium and high QC standards. Precision was <2% at all QC levels. The method was found to be accurate, precise, selective, and linear for L-T(4) over the analytical range. The HPLC method was successfully applied to the analysis of dissolution samples of marketed levothyroxine sodium tablets. PMID:20947276

  13. Investigation of the kinetics of dissolution of metals in metallic melts by the rotating disk method (mechanism of dissolution of iron in aluminum)

    Microsoft Academic Search

    V. N. Eremenko; Ya. V. Natanzon; V. R. Ryabov

    1972-01-01

    Analysis of the mechanism of dissolution of an armco-iron disk rotating at 60–600 rpm in liquid aluminum at 700–800°C showed that, at 700–750° C in the initial stages (first 152–30 min) of the process, the rate of dissolution is reduced due to the formation of a protective T-phase layer. When the disk rotation speed and the reaction time and temperature

  14. Dissolution behaviour of fine-grained magnetite and maghemite in the citrate-bicarbonate-dithionite extraction method

    NASA Astrophysics Data System (ADS)

    van Oorschot, I. H. M.; Dekkers, M. J.

    1999-04-01

    Mineral magnetic properties of soils and sediments are increasingly used as proxy parameters for environmental and palaeoclimate analysis. To investigate which magnetic minerals contribute to the environmental signal in the samples, chemical techniques such as the citrate-bicarbonate-dithionite (CBD) extraction method have been introduced in environmental magnetism studies. This technique is assumed to distinguish lithogenic (magnetite) from pedogenic (maghemite) mineral content in soils and sediments. Unfortunately, interpretation of the CBD extractions is not straightforward because the procedure is sometimes more suitable for distinction between grain size than for distinction between minerals. The procedure of the CBD extraction technique was investigated to determine the influence of extraction temperature and iron oxide concentration on the dissolution behaviour of the samples. Synthetic samples were extracted at three different temperatures (60°, 70° and 80°C) at similar iron oxide concentration (5 wt%), and for three different concentrations (0.1 wt%, 1 wt% and 5 wt%) at the same temperature (60°C). Our results show that a lower extraction temperature reduces the dissolution rate for all samples, while decrease in iron oxide concentration increases the dissolution rate. Thus, the parameters in the CBD procedure have a major influence on the dissolution behaviour of the samples. In practice this means that when natural samples of differing iron oxide concentration are extracted with this technique, the results of the extractions cannot be compared. Therefore, the outcome of this type of extraction experiment can only be accurately interpreted when the effect of the procedure on the dissolution behaviour is taken into account.

  15. Novel application of MRI technique combined with flow-through cell dissolution apparatus as supportive discriminatory test for evaluation of controlled release formulations.

    PubMed

    Dorozy?ski, Przemyslaw P; Kulinowski, Piotr; Mendyk, Aleksander; M?ynarczyk, Anna; Jachowicz, Renata

    2010-06-01

    Dissolution studies cannot distinguish phenomena occurring inside the dosage forms when studying formulation with similar dissolution profiles-such formulations can behave differently when considering their physical changes. The application of flow-through dissolution apparatus integrated with magnetic resonance imaging (MRI) system for discriminative evaluation of controlled release dosage forms with similar dissolution profiles was presented. Hydrodynamically balanced systems (HBS) containing L: -dopa and various grades hydroxypropyl methylcelluloses were prepared. The dissolution studies of L: -dopa were performed at high field (4.7 T) MR system with MR-compatible flow-through cell. MRI was done with 0.14 x 0.14 x 1-mm spatial resolution and temporal resolution of 10 min to record changes of HBS parameters during dissolution in 0.1 M HCl. Structural and geometrical changes were evaluated using the following parameters: total area of HBS cross-section, its Feret's diameter, perimeter and circularity, area of hydrogel layer, and "dry core" area. While the dissolution profiles of L: -dopa were similar, the image analysis revealed differences in the structural and geometrical changes of the HBS. The mechanism of drug release from polymeric matrices is a result of synergy of several different phenomena occurring during dissolution and may differ between formulations, yet giving similar dissolution profiles. A multivariate analysis was performed to create a model taking into account dissolution data, data from MRI, information about chemical structure, and polymer viscosity. It provided a single model for all the formulations which was confirmed to be competent. The presented method has merit as a potential Process Analytical Technology tool. PMID:20352532

  16. Dissolution behaviour of model basalt fibres studied by surface analysis methods

    NASA Astrophysics Data System (ADS)

    Förster, T.; Scheffler, C.; Mäder, E.; Heinrich, G.; Jesson, D. A.; Watts, J. F.

    2014-12-01

    New concepts of surface modifications aimed at the enhancement of alkali resistance of basalt fibres require research work on chemical composition of interacting surface layers as well as knowledge about fundamental processes of basaltic glass dissolution. Therefore, two model basalt fibres manufactured out of subalkaline and alkaline rock material were leached in NaOH solution at a temperature of 80 °C for up to 11 days. The formation of a corrosion shell was observed in both cases and was analyzed by SEM/EDX. The model fibres out of subalkaline rocks show dissolution kinetic, which is two-staged, whereas the more alkaline fibre reflects a linear one. The complex composition of basalt fibre is detected by EDX and XPS. The surface of basalt fibres is rich in Si and Al. XPS high resolution spectra provide information on oxidation state of iron.

  17. Novel Biodegradable Polylactide\\/poly(ethylene glycol) Micelles Prepared by Direct Dissolution Method for Controlled Delivery of Anticancer Drugs

    Microsoft Academic Search

    Liu Yang; Xiaohan Wu; Feng Liu; Yourong Duan; Suming Li

    2009-01-01

    Purpose  The aim of this study is to develop novel polylactide\\/poly(ethylene glycol) (PLA\\/PEG) micelles as carrier of hydrophobic drug\\u000a (paclitaxel) by direct dissolution method without using any organic solvents. The in vitro and in vivo release properties were studied in comparison with micelles prepared by dialysis.\\u000a \\u000a \\u000a \\u000a Methods  Drug encapsulation efficiency (EE) and loading content (LC) of the micelles were evaluated by high-performance

  18. Dissolution-precipitation processes in tank experiments for testing numerical models for reactive transport calculations: Experiments and modelling

    NASA Astrophysics Data System (ADS)

    Poonoosamy, Jenna; Kosakowski, Georg; Van Loon, Luc R.; Mäder, Urs

    2015-06-01

    In the context of testing reactive transport codes and their underlying conceptual models, a simple 2D reactive transport experiment was developed. The aim was to use simple chemistry and design a reproducible and fast to conduct experiment, which is flexible enough to include several process couplings: advective-diffusive transport of solutes, effect of liquid phase density on advective transport, and kinetically controlled dissolution/precipitation reactions causing porosity changes. A small tank was filled with a reactive layer of strontium sulfate (SrSO4) of two different grain sizes, sandwiched between two layers of essentially non-reacting quartz sand (SiO2). A highly concentrated solution of barium chloride was injected to create an asymmetric flow field. Once the barium chloride reached the reactive layer, it forced the transformation of strontium sulfate into barium sulfate (BaSO4). Due to the higher molar volume of barium sulfate, its precipitation caused a decrease of porosity and lowered the permeability. Changes in the flow field were observed with help of dye tracer tests. The experiments were modelled using the reactive transport code OpenGeosys-GEM. Tests with non-reactive tracers performed prior to barium chloride injection, as well as the density-driven flow (due to the high concentration of barium chloride solution), could be well reproduced by the numerical model. To reproduce the mineral bulk transformation with time, two populations of strontium sulfate grains with different kinetic rates of dissolution were applied. However, a default porosity permeability relationship was unable to account for measured pressure changes. Post mortem analysis of the strontium sulfate reactive medium provided useful information on the chemical and structural changes occurring at the pore scale at the interface that were considered in our model to reproduce the pressure evolution with time.

  19. Dissolution-precipitation processes in tank experiments for testing numerical models for reactive transport calculations: Experiments and modelling.

    PubMed

    Poonoosamy, Jenna; Kosakowski, Georg; Van Loon, Luc R; Mäder, Urs

    2015-01-01

    In the context of testing reactive transport codes and their underlying conceptual models, a simple 2D reactive transport experiment was developed. The aim was to use simple chemistry and design a reproducible and fast to conduct experiment, which is flexible enough to include several process couplings: advective-diffusive transport of solutes, effect of liquid phase density on advective transport, and kinetically controlled dissolution/precipitation reactions causing porosity changes. A small tank was filled with a reactive layer of strontium sulfate (SrSO4) of two different grain sizes, sandwiched between two layers of essentially non-reacting quartz sand (SiO2). A highly concentrated solution of barium chloride was injected to create an asymmetric flow field. Once the barium chloride reached the reactive layer, it forced the transformation of strontium sulfate into barium sulfate (BaSO4). Due to the higher molar volume of barium sulfate, its precipitation caused a decrease of porosity and lowered the permeability. Changes in the flow field were observed with help of dye tracer tests. The experiments were modelled using the reactive transport code OpenGeosys-GEM. Tests with non-reactive tracers performed prior to barium chloride injection, as well as the density-driven flow (due to the high concentration of barium chloride solution), could be well reproduced by the numerical model. To reproduce the mineral bulk transformation with time, two populations of strontium sulfate grains with different kinetic rates of dissolution were applied. However, a default porosity permeability relationship was unable to account for measured pressure changes. Post mortem analysis of the strontium sulfate reactive medium provided useful information on the chemical and structural changes occurring at the pore scale at the interface that were considered in our model to reproduce the pressure evolution with time. PMID:25805363

  20. Physical and dissolution characterization of cilostazol solid dispersions prepared by hot melt granulation (HMG) and thermal adhesion granulation (TAG) methods.

    PubMed

    Chen, Ying-Chen; Ho, Hsiu-O; Chiou, Jiun-Da; Sheu, Ming-Thau

    2014-10-01

    A growing number of poorly water-soluble drug have been discovered, but the poor bioavailability is a critical problem. In this study, physical properties and dissolution profiles of cilostazol solid dispersions prepared by hydrophilic/lipophilic excipients (Kollidon(®) VA64, tocopheryl polyethylene glycol succinate (TPGS), vitamine E) with hot-melt and thermal adhesion granulation (TAG) method to adsorb Fujicalin(®) and Microcel(®) were characterized. Results demonstrate the angle of repose in formulations with Fujicalin(®) was improved than those with Microcel(®), but the difference disappeared when more TPGS or vitamin E was added. Compared the formulation made by hot-melt and TAG method, both improved flowability. The hardness decreased with the increased amount of TPGS and vitamin E. The formulations with Microcel(®) had lower hardness than those with Fujicalin(®), because Microcel(®) has weaker adsorption ability and cannot afford much TPGS and vitamin E, leading to lower hardness. Furthermore, the solubility was almost three-fold higher than that of Pletaal(®) (7.68 ± 0.20 ?g/mL) in compositions containing TPGS and vitamin E made by hot-melt or TAG method, in which a controlled drug release pattern was demonstrated. There is no significant difference on dissolution profile between hot-melt and TAG method. However, the procedure of TAG is easier, indicating its potential pharmaceutical use. PMID:25089508

  1. Enhancement of the dissolution rate and bioavailability of fenofibrate by a melt-adsorption method using supercritical carbon dioxide

    PubMed Central

    Cha, Kwang-Ho; Cho, Kyung-Jin; Kim, Min-Soo; Kim, Jeong-Soo; Park, Hee Jun; Park, Junsung; Cho, Wonkyung; Park, Jeong-Sook; Hwang, Sung-Joo

    2012-01-01

    Background: The aim of this study was to enhance the bioavailability of fenofibrate, a poorly water-soluble drug, using a melt-adsorption method with supercritical CO2. Methods: Fenofibrate was loaded onto Neusilin® UFL2 at different weight ratios of fenofibrate to Neusilin UFL2 by melt-adsorption using supercritical CO2. For comparison, fenofibrate-loaded Neusilin UFL2 was prepared by solvent evaporation and hot melt-adsorption methods. The fenofibrate formulations prepared were characterized by differential scanning calorimetry, powder x-ray diffractometry, specific surface area, pore size distribution, scanning electron microscopy, and energy-dispersive x-ray spectrometry. In vitro dissolution and in vivo bioavailability were also investigated. Results: Fenofibrate was distributed into the pores of Neusilin UFL2 and showed reduced crystal formation following adsorption. Supercritical CO2 facilitated the introduction of fenofibrate into the pores of Neusilin UFL2. Compared with raw fenofibrate, fenofibrate from the prepared powders showed a significantly increased dissolution rate and better bioavailability. In particular, the area under the drug concentration-time curve and maximal serum concentration of the powders prepared using supercritical CO2 were 4.62-fold and 4.52-fold greater than the corresponding values for raw fenofibrate. Conclusion: The results of this study highlight the usefulness of the melt-adsorption method using supercritical CO2 for improving the bioavailability of fenofibrate. PMID:23118538

  2. Fabrication of fenofibrate nanocrystals by probe sonication method for enhancement of dissolution rate and oral bioavailability.

    PubMed

    Ige, Pradum Pundlikrao; Baria, Rohan K; Gattani, Surendra G

    2013-08-01

    Fenofibrate (FBT) is lipophillic drug used in hypercholesterolemia and hypertriglyceridemia having logP 5.375, low solubility (practically insoluble in water) and low oral bioavailability (36%). The purpose of work was to develop FBT nanocrystals for the enhancement of solubility and oral bioavailability. Fenofibrate nanosuspension was prepared using probe sonicator and transformed into dry powder using freeze drying and characterized by DSC, FTIR, XRPD, SEM, particle size, polydispersity index (PDI), zeta potential, solubility, in vitro dissolution, in vivo bioavailability and stability studies. Formulation FNS3 and pure drug exhibited the in vitro dissolution about 73.89% and 8.53% in 1% sodium lauryl sulfate (SLS) media, respectively. When the particle size reduced from 80,000±923nm to 460±20nm, saturation solubility was significantly increased. The saturation solubility of formulation FNS3 in 0.5% and 1% of SLS media found to be 67.51±1.5?g/mL and 107±1.9?g/mL, respectively. While, the saturation solubility of pure drug in 0.5% and 1% of SLS was found to be 6.02±1.51?g/ml and 23.54±1.54?g/ml, respectively. The pharmacokinetic study of optimized nanocrystals (FNS3) conducted in New Zealand white rabbits showed 4.73-fold increase in relative bioavailability than that of pure drug. Long term stability studies showed that there was no significant change in the mean particle size and PDI at 5°C±3°C after 180 days. This enhanced dissolution and bioavailability of fenofibrate nanocrystals could be the promising approach for oral delivery. PMID:23602990

  3. Coherent anti-Stokes Raman Scattering (CARS) Microscopy Visualizes Pharmaceutical Tablets During Dissolution

    PubMed Central

    Fussell, Andrew L.; Kleinebudde, Peter; Herek, Jennifer; Strachan, Clare J.; Offerhaus, Herman L.

    2014-01-01

    Traditional pharmaceutical dissolution tests determine the amount of drug dissolved over time by measuring drug content in the dissolution medium. This method provides little direct information about what is happening on the surface of the dissolving tablet. As the tablet surface composition and structure can change during dissolution, it is essential to monitor it during dissolution testing. In this work coherent anti-Stokes Raman scattering microscopy is used to image the surface of tablets during dissolution while UV absorption spectroscopy is simultaneously providing inline analysis of dissolved drug concentration for tablets containing a 50% mixture of theophylline anhydrate and ethyl cellulose. The measurements showed that in situ CARS microscopy is capable of imaging selectively theophylline in the presence of ethyl cellulose. Additionally, the theophylline anhydrate converted to theophylline monohydrate during dissolution, with needle-shaped crystals growing on the tablet surface during dissolution. The conversion of theophylline anhydrate to monohydrate, combined with reduced exposure of the drug to the flowing dissolution medium resulted in decreased dissolution rates. Our results show that in situ CARS microscopy combined with inline UV absorption spectroscopy is capable of monitoring pharmaceutical tablet dissolution and correlating surface changes with changes in dissolution rate. PMID:25045833

  4. The USP Performance Verification Test, Part I: USP Lot P Prednisone Tablets—Quality Attributes and Experimental Variables Contributing to Dissolution Variance

    Microsoft Academic Search

    Gang Deng; Alyssa J. Ashley; William E. Brown; Joseph W. Eaton; Walter W. Hauck; Loice C. Kikwai; Mark R. Liddell; Ronald G. Manning; Jimmy M. Munoz; Pallavi Nithyanandan; Maria J. Glasgow; Erika Stippler; Samir Z. Wahab; Roger L. Williams

    2008-01-01

    Purpose  Beyond instrumental qualification, proficiency testing is not usually a prerequisite for many analytical procedures, given\\u000a reliance on a manufacturer’s assay validation coupled with regulatory review and inspection. Given the special features of\\u000a the dissolution procedure, proficiency testing was put in place initially by pharmaceutical manufacturers and carried on by\\u000a USP. Proficiency testing is designed to help ensure that execution of

  5. Cold dissolution method for the determination of uranium in various geological materials at trace levels by laser fluorimetry.

    PubMed

    Ramdoss, K; Amma, B G; Umashankar, V; Rangaswamy, R

    1997-06-01

    A cold dissolution procedure for the determination of uranium in various geological materials like rocks, minerals, soils etc., has been described. Samples are allowed to react with HF and HNO(3) at room temperature overnight. Boric acid is added to complex excess fluoride ions. From the clear solution thus obtained, uranium is determined directly in laser fluorimeter after the addition of fluorescence enhancing reagents. The results of few standard reference materials analysed by the present method agree with the certified values. This methodology does not require platinum or teflon ware, exhaust system and time consuming solvent extraction step. Hazardous acid vapours are not left in air, so there is no air pollution. Chemicals consumption is minimal. Therefore the method is economical. The method can be employed for high sample throughput which is the prerequisite for exploration geochemists. PMID:18966841

  6. The dissolution of cellulose in NaOH-based aqueous system by two-step process

    Microsoft Academic Search

    Haisong Qi; Quanling Yang; Lina Zhang; Tim Liebert; Thomas Heinze

    2011-01-01

    A new dissolution method, a two-step process, for cellulose in NaOH\\/urea aqueous system was investigated with 13C NMR, wide X-ray diffraction (WXRD), and solubility test. The two steps were as follows: (1) formation and swelling of a\\u000a cellulose–NaOH complex and (2) dissolution of the cellulose–NaOH complex in aqueous urea solution. The dissolution mechanism\\u000a could be described as strong interaction between

  7. HEPA filter dissolution process

    DOEpatents

    Brewer, K.N.; Murphy, J.A.

    1994-02-22

    A process is described for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal. 4 figures.

  8. HEPA filter dissolution process

    SciTech Connect

    Brewer, K.N.; Murphy, J.A.

    1992-12-31

    This invention is comprised of a process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

  9. Hepa filter dissolution process

    DOEpatents

    Brewer, Ken N. (Arco, ID); Murphy, James A. (Idaho Falls, ID)

    1994-01-01

    A process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

  10. Testing methods for large aircraft

    Microsoft Academic Search

    D. L. Moseley

    1961-01-01

    Some unique testing methods in connection with static-load application and associated data acquisition are described. The free-flight method of airplane static testing is covered as it applies to the current test program for the C-133 Cargomaster (300,000 lb gross weight). The loading and safety advantages of the single-pressure concept are discussed. Instrumentation provides for visual readout as well as IBM

  11. Velocity profiles and shear strain rate variability in the USP Dissolution Testing Apparatus 2 at different impeller agitation speeds.

    PubMed

    Bai, Ge; Wang, Yimin; Armenante, Piero M

    2011-01-17

    The fluid velocity profiles at different locations inside a standard USP Dissolution Testing Apparatus 2 were experimentally obtained via Laser Doppler Velocimetry (LDV) at three impeller agitations speeds, namely 50rpm, 75rpm and 100rpm. The experimental results were compared with the predictions obtained with Computational Fluid Dynamics (CFD) where the ?-? model with low Reynolds number correction was used to account for turbulence effects. In general, good agreement was found between the experimental LDV velocity measurements and the CFD simulation predictions. The non-dimensional tangential, axial and radial velocity profiles (scaled with the impeller tip speed) and the flow pattern were found to be nearly independent of the agitation speed in most regions of the vessel, implying that increasing the agitation speed generally produced a corresponding increase in the local values of the velocity. However, the velocity profiles and flow pattern in the inner core region just below the impeller, where the dissolving tablet is usually located, were found to be much less sensitive to agitation speed. In this region, the axial and radial velocities were especially low and were not significantly affected by agitation increases. This inner core region at the center of the vessel bottom persisted irrespective of agitation intensity. The CFD predictions also indicated that increasing the agitation speed resulted in a higher shear strain rate distribution along the vessel bottom, although the strain rate was always very low at the center of the vessel bottom, even when the agitation speed was increased. PMID:20883758

  12. Test methods for textile composites

    NASA Technical Reports Server (NTRS)

    Minguet, Pierre J.; Fedro, Mark J.; Gunther, Christian K.

    1994-01-01

    Various test methods commonly used for measuring properties of tape laminate composites were evaluated to determine their suitability for the testing of textile composites. Three different types of textile composites were utilized in this investigation: two-dimensional (2-D) triaxial braids, stitched uniweave fabric, and three-dimensional (3-D) interlock woven fabric. Four 2-D braid architectures, five stitched laminates, and six 3-D woven architectures were tested. All preforms used AS4 fibers and were resin-transfer-molded with Shell RSL-1895 epoxy resin. Ten categories of material properties were investigated: tension, open-hole tension, compression, open-hole compression, in-plane shear, filled-hole tension, bolt bearing, interlaminar tension, interlaminar shear, and interlaminar fracture toughness. Different test methods and specimen sizes were considered for each category of test. Strength and stiffness properties obtained with each of these methods are documented in this report for all the material systems mentioned above.

  13. Impact of Vibration and Agitation Speed on Dissolution of USP Prednisone Tablets RS and Various IR Tablet Formulations.

    PubMed

    Seeger, Nicole; Lange, Sigrid; Klein, Sandra

    2015-08-01

    Dissolution testing is an in vitro procedure which is widely used in quality control (QC) of solid oral dosage forms and, given that real biorelevant test conditions are applied, can also be used as a predictive tool for the in vivo performance of such formulations. However, if a dissolution method is intended to be used for such purposes, it has to deliver results that are only determined by the quality of the test product, but not by other variables. In the recent past, more and more questions were arising on how to address the effects of vibration on dissolution test results. The present study was performed to screen for the correlation of prednisone dissolution of USP Prednisone Tablets RS with vibration caused by a commercially available vibration source as well as to investigate how drug release from a range of immediate release formulations containing class 1-4 drugs of the biopharmaceutical classification scheme is affected by vibration when performing dissolution experiments at different agitation rates. Results of the present study show that the dissolution process of oral drug formulations can be affected by vibration. However, it also becomes clear that the degree of which a certain level of vibration impacts dissolution is strongly dependent on several factors such as drug properties, formulation parameters, and the design of the dissolution method. To ensure the establishment of robust and predictive dissolution test methods, the impact of variation should thus be considered in method design and validation. PMID:26104919

  14. Measurement of pseudoephedrine hydrochloride dissolution using chloride-ion electrode.

    PubMed

    Chen, S T; Thompson, R C; Poust, R I

    1981-11-01

    Experiments were performed to determine the suitability of using a chloride-ion electrode for the measurement of pseudoephedrine hydrochloride dissolution from commercially available compressed tablets. Dissolution experiments were carried out in 500 ml of distilled water using the USP paddle method at 100 rpm. Both chloride ion and pseudoephedrine (UV spectrophotometry) were measured at six different sampling times. Percent dissolved versus time values were linearized on a log-normal probability basis. The slopes of individual lines obtained from the chloride and pseudoephedrine measurements were compared using a Student t test and did not differ significantly (t = 0.415, df = 5, p greater than 0.05). In addition to providing an efficient, inexpensive, and simple method for measuring pseudoephedrine hydrochloride dissolution rates, the chloride-ion electrode could be used in the measurement of dissolution rates for a wide variety of drugs available as hydrochloride salts. PMID:7299681

  15. Effects of the Preparation Method on the Formation of True Nimodipine SBE-?-CD/HP-?-CD Inclusion Complexes and Their Dissolution Rates Enhancement.

    PubMed

    Semcheddine, Farouk; Guissi, Nida El Islem; Liu, XueYin; Wu, ZuoMin; Wang, Bo

    2015-06-01

    The aims of this study were to enhance the solubility and dissolution rate of nimodipine (ND) by preparing the inclusion complexes of ND with sulfobutylether-b-cyclodextrin (SBE-?-CD) and 2-hydroxypropyl-b-cyclodextrin (HP-?-CD) and to study the effect of the preparation method on the in vitro dissolution profile in different media (0.1 N HCl pH 1.2, phosphate buffer pH 7.4, and distilled water). Thus, the inclusion complexes were prepared by kneading, coprecipitation, and freeze-drying methods. Phase solubility studies were conducted to characterize the complexes in the liquid state. The inclusion complexes in the solid state were investigated with differential scanning calorimetry (DSC), X-ray diffractometry (X-RD), and Fourier transform infrared spectroscopy (FT-IR). Stable complexes of ND/SBE-?-CD and ND/HP-?-CD were formed in distilled water in a 1:1 stoichiometric inclusion complex as indicated by an AL-type diagram. The apparent stability constants (Ks) were 1334.4 and 464.1 M(-1) for ND/SBE-?-CD and ND/HP-?-CD, respectively. The water-solubility of ND was significantly increased in an average of 22- and 8-fold for SBE-?-CD and HP-?-CD, respectively. DSC results showed the formation of true inclusion complexes between the drug and both SBE-?-CD and HP-?-CD prepared by the kneading method. In contrast, crystalline drug was detectable in all other products. The dissolution studies showed that all the products exhibited higher dissolution rate than those of the physical mixtures and ND alone, in all mediums. However, the kneading complexes displayed the maximum dissolution rate in comparison with drug and other complexes, confirming the influence of the preparation method on the physicochemical properties of the products. PMID:25511809

  16. Influence of the Efavirenz Micronization on Tableting and Dissolution

    PubMed Central

    Pinto, Eduardo Costa; do Carmo, Flávia Almada; da Silva Honório, Thiago; da Silva Ascenção Barros, Rita de Cássia; Castro, Helena Carla Rangel; Rodrigues, Carlos Rangel; Esteves, Valéria Sant'Anna Dantas; Rocha, Helvécio Vinícius Antunes; de Sousa, Valeria Pereira; Cabral, Lucio Mendes

    2012-01-01

    The purpose of this study was to propose an analytical procedure that provides the effects of particle size and surface area on dissolution of efavirenz. Five different batches obtained by different micronization processes and with different particle size distribution and surface area were studied. The preformulation studies and dissolution curves were used to confirm the particle size distribution effect on drug solubility. No polymorphic variety or amorphization was observed in the tested batches and the particle size distribution was determined as directly responsible for the improvement of drug dissolution. The influence of the preparation process on the tablets derived from efavirenz was observed in the final dissolution result in which agglomeration, usually seen in non-lipophilic micronized material, was avoided through the use of an appropriate wet granulation method. For these reasons, micronization may represent one viable alternative for the formulation of brick dust drugs. PMID:24300301

  17. Intro Temporal Tests Declustering Methods Tests on SCEC data Spatiotemporal Test Discussion Testing for Poisson Behavior

    E-print Network

    Stark, Philip B.

    Intro Temporal Tests Declustering Methods Tests on SCEC data Spatiotemporal Test Discussion Testing Seismological Society of America Annual Meeting San Diego, CA #12;Intro Temporal Tests Declustering Methods Tests on SCEC data Spatiotemporal Test Discussion Quake Physics versus Quake Statistics · Distribution

  18. A level set method for three dimensional vector Stefan problems: Dissolution of stoichiometric particles

    E-print Network

    Vuik, Kees

    -cell method; Velocity extension 1. Introduction In the thermal processing of both ferrous and non killed construction steels, HSLA steels, all engineering steels, as well as in processing aluminum properties is necessary. Dumont et al. [9,10] carry out an experimental study to link the volume fraction

  19. 49 CFR 383.133 - Test methods.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 5 2012-10-01 2012-10-01 false Test methods. 383.133 Section 383.133 Transportation...DRIVER'S LICENSE STANDARDS; REQUIREMENTS AND PENALTIES Tests § 383.133 Test methods. (a) All tests must be...

  20. 49 CFR 383.133 - Test methods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 5 2013-10-01 2013-10-01 false Test methods. 383.133 Section 383.133 Transportation...DRIVER'S LICENSE STANDARDS; REQUIREMENTS AND PENALTIES Tests § 383.133 Test methods. (a) All tests must be...

  1. 49 CFR 383.133 - Test methods.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 5 2011-10-01 2011-10-01 false Test methods. 383.133 Section 383.133 Transportation...DRIVER'S LICENSE STANDARDS; REQUIREMENTS AND PENALTIES Tests § 383.133 Test methods. (a) All tests must be...

  2. 49 CFR 383.133 - Test methods.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 5 2014-10-01 2014-10-01 false Test methods. 383.133 Section 383.133 Transportation...DRIVER'S LICENSE STANDARDS; REQUIREMENTS AND PENALTIES Tests § 383.133 Test methods. (a) All tests must be...

  3. Method For Testing Properties Of Corrosive Lubricants

    DOEpatents

    Ohi, James (Denver, CO); De La Cruz, Jose L. (San Antonio, TX); Lacey, Paul I. (Wexford, IE)

    2006-01-03

    A method of testing corrosive lubricating media using a wear testing apparatus without a mechanical seal. The wear testing apparatus and methods are effective for testing volatile corrosive lubricating media under pressure and at high temperatures.

  4. Test methods for acceptance testing of telescopes

    NASA Astrophysics Data System (ADS)

    1993-07-01

    This guide will provide government organizations who are responsible for the procurement of long focal-length optical systems (telescopes) with a general knowledge of what tests can, and generally should, be performed on these systems to ensure compliance with the required specifications. General test procedures are also included. Since test facilities and test equipment available vary considerably among organizations, it is impractical to write a 'cookbook' type of guide to be followed rigorously by all. It is also true that some procured systems may possess special features not generally found in the normal imaging telescope system such as beam splitters, special filters, and reticles.

  5. Development and Validation of an RP?HPLC Method for the Determination of Valacyclovir in Tablets and Human Serum and Its Application to Drug Dissolution Studies

    Microsoft Academic Search

    Ayhan Sava?er; Cansel K. Özkan; Yalç?n Özkan; Bengi Uslu; Sibel A. Özkan

    2003-01-01

    A specific, sensitive, simple, and rapid HPLC method has been developed for the determination of valacyclovir (VACL) in raw material, pharmaceutical dosage forms, and human serum, in order to carry out drug dissolution studies from tablets. The chromatographic separation was achieved with acetonitrile:methanol:0.067 M KH2PO4 (27:20:53, v\\/v\\/v) adjusted to pH 6.5 with 3 M NaOH as mobile phase, a Waters Spherisorb C18

  6. Nanotechnology versus other techniques in improving drug dissolution.

    PubMed

    Kwok, Philip Chi Lip; Chan, Hak-Kim

    2014-01-01

    Many newly discovered drug molecules have low aqueous solubility, which results in low bioavailability. One way to improve their dissolution is to formulate them as nanoparticles, which have high specific surface areas, consequently increasing the dissolution rate and solubility. Nanoparticles can be produced via top-down or bottom-up methods. Top-down techniques such as wet milling and high pressure homogenisation involve reducing large particles to nano-sizes. Some pharmaceutical products made by these processes have been marketed. Bottom-up methods such as precipitation and controlled droplet evaporation form nanoparticles from molecules in solution. To minimise aggregation upon drying and promote redispersion of the nanoparticles upon reconstitution or administration, hydrophilic matrix formers are added to the formulation. However, the nanoparticles will eventually agglomerate together after dispersing in the liquid and hinders dissolution. Currently there is no pharmacopoeial method specified for nanoparticles. Amongst the current dissolution apparatus available for powders, the flow-through cell has been shown to be the most suitable. Regulatory and pharmacopoeial standards should be established in the future to standardise the dissolution testing of nanoparticles. More nanoparticle formulations of new hydrophobic drugs are expected to be developed in the future with the advancement of nanotechnology. However, the agglomeration problem is inherent and difficult to overcome. Thus the benefit of dissolution enhancement often cannot be fully realised. On the other hand, chemical strategies such as modifying the parent drug molecule to form a more soluble salt form, prodrug, or cyclodextrin complexation are well established and have been shown to be effective in enhancing dissolution. Thus the value of nanoformulations needs to be interpreted in the light of their limitations. Chemical approaches should also be considered in new product development. PMID:23651399

  7. Estimating rock and slag wool fiber dissolution rate from composition.

    PubMed

    Eastes, W; Potter, R M; Hadley, J G

    2000-12-01

    A method was tested for calculating the dissolution rate constant in the lung for a wide variety of synthetic vitreous silicate fibers from the oxide composition in weight percent. It is based upon expressing the logarithm of the dissolution rate as a linear function of the composition and using a different set of coefficients for different types of fibers. The method was applied to 29 fiber compositions including rock and slag fibers as well as refractory ceramic and special-purpose, thin E-glass fibers and borosilicate glass fibers for which in vivo measurements have been carried out. These fibers had dissolution rates that ranged over a factor of about 400, and the calculated dissolution rates agreed with the in vivo values typically within a factor of 4. The method presented here is similar to one developed previously for borosilicate glass fibers that was accurate to a factor of 1.25. The present coefficients work over a much broader range of composition than the borosilicate ones but with less accuracy. The dissolution rate constant of a fiber may be used to estimate whether disease would occur in animal inhalation or intraperitoneal injection studies of that fiber. PMID:11114785

  8. Protocol Testing: Review of Methods and Relevance

    E-print Network

    von Bochmann, Gregor

    for testing computer hardware and software have also evolved. Since protocols are implemented in software andProtocol Testing: Review of Methods and Relevance for Software Testing G. v. Bochmann and Alexandre Juin 1994 #12; Protocol Testing: Review of Methods and Relevance for Software Testing Gregor v

  9. A versatile pore-scale multicomponent reactive transport approach based on lattice Boltzmann method: Application to portlandite dissolution

    NASA Astrophysics Data System (ADS)

    Patel, Ravi A.; Perko, Janez; Jacques, Diederik; De Schutter, Geert; Van Breugel, Klaas; Ye, Guang

    A versatile lattice Boltzmann (LB) based pore-scale multicomponent reactive transport approach is presented in this paper. This approach is intended to capture mineral phase and pore structure evolution resulting from geochemical interactions applicable, for example to model microstructural evolution of hardened cement paste during chemical degradation. In the proposed approach heterogeneous reactions are conceptualized as pseudo-homogenous (volumetric) reactions by introducing an additional source term in the fluid node located at the interface adjacent to a solid node, and not as flux boundaries as used in previously proposed approaches. This allows a complete decoupling of transport and reaction computations, thus different reaction systems can be introduced within the LB framework through coupling with external geochemical codes. A systematic framework for coupling an external geochemical code with the LB including pore geometry evolution is presented, with the generic geochemical code PHREEQC as an example. The developed approach is validated with a set of benchmarks. A first example demonstrates the ability of the developed approach to capture the influence of pH on average portlandite dissolution rate and surface evolution. This example is further extended to illustrate the influence of reactive surface area and spatial arrangement of mineral grains on average dissolution rate. It was demonstrated that both location of mineral grains and surface area play a crucial role in determining average dissolution rate and pore structure evolution.

  10. Dissolution of metallic uranium and its alloys

    Microsoft Academic Search

    C. A. Laue; D. Gates-Anderson; T. E. Fitch

    2004-01-01

    This review focuses on dissolution\\/reaction systems capable of treating uranium metal waste to remove its pyrophoric properties.\\u000a The primary emphasis is the review of literature describing analytical and production-scale dissolution methods applied to\\u000a either uranium metal or uranium alloys. A brief summary of uranium's corrosion behavior is included since the corrosion resistance\\u000a of metals and alloys affects their dissolution behavior.

  11. 30 CFR 27.31 - Testing methods.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Testing methods. 27.31 Section 27...EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS...Requirements § 27.31 Testing methods. A methane-monitoring...characteristics. Since all possible designs, arrangements, or...

  12. 30 CFR 27.31 - Testing methods.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Testing methods. 27.31 Section 27...EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS...Requirements § 27.31 Testing methods. A methane-monitoring...characteristics. Since all possible designs, arrangements, or...

  13. 30 CFR 27.31 - Testing methods.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Testing methods. 27.31 Section 27...EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS...Requirements § 27.31 Testing methods. A methane-monitoring...characteristics. Since all possible designs, arrangements, or...

  14. 30 CFR 27.31 - Testing methods.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Testing methods. 27.31 Section 27...EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS...Requirements § 27.31 Testing methods. A methane-monitoring...characteristics. Since all possible designs, arrangements, or...

  15. 30 CFR 27.31 - Testing methods.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Testing methods. 27.31 Section 27...EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS...Requirements § 27.31 Testing methods. A methane-monitoring...characteristics. Since all possible designs, arrangements, or...

  16. Dissolution processes: Stuffed structures

    NASA Astrophysics Data System (ADS)

    Fenter, Paul

    2012-03-01

    Understanding oxide dissolution processes on the molecular scale remains a challenge. A study on nanoscale oxides suggests a mechanism for dissolution that proceeds through the formation of oxygen-stuffed metastable structures.

  17. Accelerated testing method of LED luminaries

    Microsoft Academic Search

    M. Cai; D. G. Yang; S. Koh; C. A. Yuan; W. B. Chen; B. Y. Wu; G. Q. Zhang

    2012-01-01

    With rapid development of lighting emitting diode (LED) market, more people are focusing on reliability testing method of LED luminaries system. However, it is difficult to use traditional reliability testing method for electronic products to assess LED luminaries with high reliability and long life. In this paper, reliability testing methods applied on LED, LED luminaries and other fields are reviewed

  18. Simulation of surface dynamics during dissolution as a function of the surface orientation: Implications for non-constant dissolution rates

    NASA Astrophysics Data System (ADS)

    Godinho, J. R. A.; Piazolo, S.; Evans, L.

    2014-12-01

    An important problem in geochemistry is the understanding of how changes occurring on a surface during dissolution affect the variability of measured dissolution rates. In this study a new approach to study the effect of surface dynamics on dissolution rates is tested by coupling experimental data with a numerical model that simulates the retreat of surface profiles during dissolution. We present specific results from the simulation of dissolution of fluorite surfaces. The equations that determine the retreat of a surface are based on experimentally obtained equations that relate the retreat rate of a surface to a single variable, the crystallographic orientation of the surface. Our results show that depending on the starting orientation, different types of topography are developed, similar to those observed experimentally. During the initial dissolution phase, changes of topography are rapid and associated with fast dissolution rates. The progressively slower dissolution rates are coupled with the development of surface segments with orientations that dissolve at a slower rate. Consequently, the overall retreat rate of a profile decreases during the simulation, and tends to a near-constant value. The results show a close relationship between dissolution rates, surface orientation and surface dynamics, which suggests that the dissolution rate of a specific mineral phase is not constant but varies with dissolution time and surface structure. This variability needs to be considered in the evaluation of experimentally derived dissolution rates, future dissolution experiments, and predictive kinetic models of dissolution.

  19. Electrokinetic remediation prefield test methods

    NASA Technical Reports Server (NTRS)

    Hodko, Dalibor (Inventor)

    2000-01-01

    Methods for determining the parameters critical in designing an electrokinetic soil remediation process including electrode well spacing, operating current/voltage, electroosmotic flow rate, electrode well wall design, and amount of buffering or neutralizing solution needed in the electrode wells at operating conditions are disclosed These methods are preferably performed prior to initiating a full scale electrokinetic remediation process in order to obtain efficient remediation of the contaminants.

  20. Standard practice for preparation and dissolution of plutonium materials for analysis

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice is a compilation of dissolution techniques for plutonium materials that are applicable to the test methods used for characterizing these materials. Dissolution treatments for the major plutonium materials assayed for plutonium or analyzed for other components are listed. Aliquants of the dissolved samples are dispensed on a weight basis when one of the analyses must be highly reliable, such as plutonium assay; otherwise they are dispensed on a volume basis. 1.2 The treatments, in order of presentation, are as follows: Procedure Title Section Dissolution of Plutonium Metal with Hydrochloric Acid 9.1 Dissolution of Plutonium Metal with Sulfuric Acid 9.2 Dissolution of Plutonium Oxide and Uranium-Plutonium Mixed Oxide by the Sealed-Reflux Technique 9.3 Dissolution of Plutonium Oxide and Uranium-Plutonium Mixed Oxides by Sodium Bisulfate Fusion 9.4 Dissolution of Uranium-Plutonium Mixed Oxides and Low-Fired Plutonium Oxide in Beakers 9.5 1.3 The values stated in SI units are to be re...

  1. Interferometric test method for testing convex aspheric mirror surfaces

    NASA Astrophysics Data System (ADS)

    McKechnie, T. Stewart

    2010-07-01

    An interferometric null Test Method is described for testing convex aspheric surfaces, such as found in secondary mirrors of Cassegrain telescopes or variations thereof such as Mersenne and Ritchey-Chrétien. A family of test designs is described covering a wide range of mirror diameters, radii of curvature, and aspheric shapes as described by conic constants and/or polynomials. The Test Method has been used successfully for testing the convex hyperboloid surface of the 244-mm diameter secondary mirror of the NASA 3-meter IRTF telescope. The Test Method is currently being used to test the 120-mm diameter, convex paraboloid secondary mirrors of the Magdalena Ridge Observatory Interferometer (MROI). Test designs exist on paper for both Keck secondary mirrors (0.53-m and 1.4-m diameter), the HST secondary (0.3-meter diameter), and secondary mirrors of some of the extremely large telescopes of the future, such as the TMT secondary (3.2-m diameter). In typical test embodiments, the simplicity of the Test enables rapid implementation at a fraction of the cost of comparable Hindle-Sphere or Hindle-Simpson tests.

  2. Dissolution enthalpies of cellulose in ionic liquids.

    PubMed

    Parviainen, Helena; Parviainen, Arno; Virtanen, Tommi; Kilpeläinen, Ilkka; Ahvenainen, Patrik; Serimaa, Ritva; Grönqvist, Stina; Maloney, Thaddeus; Maunu, Sirkka Liisa

    2014-11-26

    In this work, interactions between cellulose and ionic liquids were studied calorimetrically and by optical microscopy. Two novel ionic liquids (1,5-Diazabicyclo[4.3.0]non-5-enium propionate and N-methyl-1,5-diazabicyclo[4.3.0]non-5-enium dimethyl phosphate) and 1-ethyl-3-methylimidazolium acetate-water mixtures were used as solvents. Optical microscopy served in finding the extent of dissolution and identifying the dissolution pattern of the cellulose sample. Calorimetric studies identified a peak relating to dissolution of cellulose in solvent. The transition did, however, not indicate complete dissolution, but rather dissolution inside fibre or fibrils. This method was used to study differences between four cellulose samples with different pretreatment or origins. PMID:25256460

  3. Drug-Testing Methods and Reliability

    Microsoft Academic Search

    David W. Fretthold

    1990-01-01

    The methods used by laboratories to analyze urine collected from employees are described. Federally designed procedures designed for analyzing government employee samples have become the highest standard for performing such tests, although at present there are no guidelines that specifically address drug testing in the private sector. Samples and analysis should be handled in a manner that ensures that test

  4. Dissolution properties and physical characterization of telmisartan-chitosan solid dispersions prepared by mechanochemical activation.

    PubMed

    Zhong, Lin; Zhu, Xingyi; Luo, Xiaofang; Su, Weike

    2013-06-01

    Solid dispersion systems of telmisartan (a poorly water-soluble antihypertension drug) with biopolymer carrier chitosan have been investigated in this study. The mechanism of solubilization of chitosan for drug has been studied. In addition, the influence of several factors was carefully examined, including the preparation methods, the drug/carrier weight ratios, and the milling time. Drug dissolution and physical characterization of different binary systems were studied by in vitro dissolution test, particle size distribution, Fourier transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffractometry, and scanning electron microscopy. The results presented that the weak basic property of chitosan appeared as the main driving force for the drug dissolution enhancement. Other effects such as decreased drug crystallinity and size played a positive contributory role. Among the preparation methods, cogrinding was the best method showing strong drug amorphization, reduced particle size, and enhanced dissolution. The drug dissolution markedly improved with increasing the amount of chitosan in solid mixtures. As a result, a significant effect of chitosan increasing telmisartan dissolution has been demonstrated, and cogrinding in a roll ball mill was the best way to prepare solid dispersions, which had high degree of uniformity in drug content and had a practical application in manufacturing. PMID:23430728

  5. Dissolution of Globular Clusters

    E-print Network

    Holger Baumgardt

    2006-05-04

    Globular clusters are among the oldest objects in galaxies, and understanding the details of their formation and evolution can bring valuable insight into the early history of galaxies. This review summarises the current knowledge about the dissolution of star clusters and discusses the implications of star cluster dissolution for the evolution of the mass function of star cluster systems in galaxies.

  6. [Process monitoring of dissolution of valsartan and hydrochlorothiazide tablets by fiber-chemical sensor assisted by mathematical separation model of linear equations].

    PubMed

    Ding, Hai-Yan; Li, Gai-Ru; Yu, Ying-Ge; Guo, Wei; Zhi, Ling; Li, Xin-Xia

    2014-04-01

    A method for on-line monitoring the dissolution of Valsartan and hydrochlorothiazide tablets assisted by mathematical separation model of linear equations was established. UV spectrums of valsartan and hydrochlorothiazide were overlapping completely at the maximum absorption wavelength respectively. According to the Beer-Lambert principle of absorbance additivity, the absorptivity of Valsartan and hydrochlorothiazide was determined at the maximum absorption wavelength, and the dissolubility of Valsartan and hydrochlorothiazide tablets was detected by fiber-optic dissolution test (FODT) assisted by the mathematical separation model of linear equations and compared with the HPLC method. Results show that two ingredients were real-time determined simultaneously in given medium. There was no significant difference for FODT compared with HPLC (p > 0.05). Due to the dissolution behavior consistency, the preparation process of different batches was stable and with good uniformity. The dissolution curves of valsartan were faster and higher than hydrochlorothiazide. The dissolutions at 30 min of Valsartan and hydrochlorothiazide were concordant with US Pharmacopoeia. It was concluded that fiber-optic dissolution test system assisted by the mathematical separation model of linear equations that can detect the dissolubility of Valsartan and hydrochlorothiazide simultaneously, and get dissolution profiles and overall data, which can directly reflect the dissolution speed at each time. It can provide the basis for establishing standards of the drug. Compared to HPLC method with one-point data, there are obvious advantages to evaluate and analyze quality of sampling drug by FODT. PMID:25007628

  7. On the factors affecting the dissolution of copper in molten lead-free solders and development of a method to assess the soldering parameters

    Microsoft Academic Search

    D. Di Maio; C. P. Hunt

    2009-01-01

    Purpose – The purpose of this paper is to investigate the various factors that influence the dissolution of copper in molten solder, paying particular attention to important parameters: temperature, solder composition and flow rate. Design\\/methodology\\/approach – To determine the dissolution rate of copper in lead-free solders, a simple and automated technique is developed. This methodology provides repeatable measurements that allow

  8. Method and apparatus for testing microfilaments

    DOEpatents

    Schleitweiler, Patrick M. (Dayton, OH); Merten, Jr., Charles W. (West Carrollton, OH)

    1995-08-01

    A method and apparatus are disclosed for testing tensile strength of microfilaments. Fibers as small as 0.001 inch in diameter and 0.04 inches in length have been tested, although the method and apparatus of the invention are capable of testing fibers of smaller diameter and length. The invention utilizes a method wherein one or both ends of a microfilament is gripped using resin which is softened sufficiently to accept an end of the microfilament and then allowed to harden. The invention also employs the use of a translation stage capable of controlled three-dimensional movement suited to facilitating gripping of the microfilament.

  9. Method and apparatus for testing microfilaments

    DOEpatents

    Schleitweiler, P.M.; Merten, C.W. Jr.

    1995-08-01

    A method and apparatus are disclosed for testing tensile strength of microfilaments. Fibers as small as 0.001 inch in diameter and 0.04 inches in length have been tested, although the method and apparatus of the invention are capable of testing fibers of smaller diameter and length. The invention utilizes a method wherein one or both ends of a microfilament is gripped using resin which is softened sufficiently to accept an end of the microfilament and then allowed to harden. The invention also employs the use of a translation stage capable of controlled three-dimensional movement suited to facilitating gripping of the microfilament. 2 figs.

  10. Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

    SciTech Connect

    Arianie, Lucy, E-mail: lucy205@yahoo.com [Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Tanjungpura, Jl. A.Yani, 73 Pontianak 78124 (Indonesia); Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id; Nurrachman, Zeily, E-mail: deana@chem.itb.ac.id; Natalia, Dessy, E-mail: deana@chem.itb.ac.id [Department of Chemistry, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung 40132 (Indonesia)

    2014-03-24

    The decrease of cellulose crystallinity index of palm empty fruit bunch is crucial for the next application of cellulose as raw material for various biofuel and its derivatives. The aim of this research is to decrease the cellulose crystallinity index of palm empty fruit bunch using 1-butyl-3-methylimidazoliumbromide or [BMIM] bromide which has been synthesized using Microwave-Assisted Organic Synthesis (MAOS) method. Conventional reaction method has also been carried out to synthesize [BMIM]bromide for comparison as well. The characterization of synthesized product using FTIR, {sup 1}H-NMR, {sup 13}C-NMR and LC-MS showed that these reactions have been carried out successfully. The results showed that MAOS method is up to 90% faster in producing [BMIM]bromide compare to the conventional method. The application of [BMIM]bromide for dissolution of palm empty fruit bunch showed that cellulose and lignin could be extracted using stirring process for 20 hours. The decrease of cellulose crystallinity index and its morphology changes were identified using FTIR and Scanning Electron Microscope.

  11. Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

    NASA Astrophysics Data System (ADS)

    Arianie, Lucy; Wahyuningrum, Deana; Nurrachman, Zeily; Natalia, Dessy

    2014-03-01

    The decrease of cellulose crystallinity index of palm empty fruit bunch is crucial for the next application of cellulose as raw material for various biofuel and its derivatives. The aim of this research is to decrease the cellulose crystallinity index of palm empty fruit bunch using 1-butyl-3-methylimidazoliumbromide or [BMIM] bromide which has been synthesized using Microwave-Assisted Organic Synthesis (MAOS) method. Conventional reaction method has also been carried out to synthesize [BMIM]bromide for comparison as well. The characterization of synthesized product using FTIR, 1H-NMR, 13C-NMR and LC-MS showed that these reactions have been carried out successfully. The results showed that MAOS method is up to 90% faster in producing [BMIM]bromide compare to the conventional method. The application of [BMIM]bromide for dissolution of palm empty fruit bunch showed that cellulose and lignin could be extracted using stirring process for 20 hours. The decrease of cellulose crystallinity index and its morphology changes were identified using FTIR and Scanning Electron Microscope.

  12. In Silico Toxicology – Non-Testing Methods

    PubMed Central

    Raunio, Hannu

    2011-01-01

    In silico toxicology in its broadest sense means “anything that we can do with a computer in toxicology.” Many different types of in silico methods have been developed to characterize and predict toxic outcomes in humans and environment. The term non-testing methods denote grouping approaches, structure–activity relationship, and expert systems. These methods are already used for regulatory purposes and it is anticipated that their role will be much more prominent in the near future. This Perspective will delineate the basic principles of non-testing methods and evaluate their role in current and future risk assessment of chemical compounds. PMID:21772821

  13. New combined shear and compression test method

    SciTech Connect

    Fabian, P.E. [Composite Technology Development, Inc., Boulder, CO (United States); Reed, R.P. [Cryogenic Materials, Inc., Boulder, CO (United States)

    1997-06-01

    A new test method was developed to determine shear/compression properties of composite insulation systems used in superconducting magnets. It was developed specifically to enable in-situ testing (without warm-up) of insulation systems in a high flux neutron radiation and cryogenic (4 K) temperature environment at the Munich Research Reactor (FRM - Forschungsreaktor Munchen). The new shear/compression specimen consists of two sections of composite insulation bonded at a specific angle between three pieces of 316 stainless steel. During the test, the specimen is compressed between two loading platens. By varying the angle of the test specimen, different shear/compression ratios can be evaluated and a shear/compression envelope for various materials can be produced. This test method produces the same shear and compressive strengths found in other shear/compression tests, but the test fixture is smaller, and multiple test specimens are not required. The composite insulation systems were tested at 45{degrees} to demonstrate the feasibility of the test. Specimens were produced from a vacuum pressure impregnation (VPI) resin system and a prepreg resin system. Design and fabrication of the test specimens and their shear and compressive properties are presented.

  14. Interpretation and optimization of the dissolution specifications for a modified release product with an in vivo-in vitro correlation (IVIVC).

    PubMed

    Hayes, Siobhán; Dunne, Adrian; Smart, Trevor; Davis, John

    2004-03-01

    This article considers the in vivo significance attached to in vitro dissolution testing. Almost invariably, the in vitro dissolution test is interpreted in terms of bioequivalence. The literature that describes methods for setting in vitro dissolution specifications is reviewed. The most common interpretation of these specifications is a deterministic one, that is, those batches passing the dissolution specifications would be bioequivalent with the reference if tested in vivo and those failing the dissolution specifications would not be bioequivalent if tested in vivo. Due to random variation, the deterministic interpretation is not appropriate. Instead, we need to consider the conditional probability that a batch that has passed the in vitro dissolution test would demonstrate bioequivalence if tested in vivo, and that a batch known to have failed the in vitro dissolution test would demonstrate bioinequivalence if tested in vivo. One way to estimate these probabilities is by means of a simulated experiment in which the production and testing (in vivo and in vitro) of a large number of batches is computer simulated. Such a simulation can only be performed if the relationship between the in vitro dissolution characteristics and the in vivo performance of the product has been modeled. These models are generally referred to as in vivo-in vitro correlations (IVIVC). The results of one such experiment are described. The above-mentioned conditional probabilities are shown to depend on the choice of dissolution specifications. This result leads to the notion of optimal dissolution specifications. However, both of the conditional probabilities cannot be maximized simultaneously. The probability of making a correct decision on the basis of the in vitro dissolution test is introduced as a possible optimality criterion. This probability is a linear combination of the two conditional probabilities of interest. Using this criterion, the optimal dissolution specifications can be found by searching over the multidimensional space defined by the half width of each interval used in the specifications to find the combination that maximizes this probability. This process is demonstrated using the Nelder-Mead search routine. The choice of dissolution specifications has profound implications for the routine production of the product because if the specifications were very narrow the probability of a batch passing would be low, resulting in a low hit rate. The same computer program used to perform the simulation experiment can be used to estimate the hit rate. Furthermore, it can be used to explore the magnitude of changes required in the parameters describing the test product (particularly variability) to increase a low hit rate to an acceptable level. PMID:14762896

  15. Standard test methods of tension testing of metallic foil

    E-print Network

    American Society for Testing and Materials. Philadelphia

    1993-01-01

    1.1 These test methods cover the tension testing of metallic foil at room temperature in thicknesses less than 0.006 in. (0.150 mm). Note 1—Exception to these methods may be necessary in individual specifications or test methods for a particular material. 1.2 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Standard test method for dynamic tear testing of metallic materials

    E-print Network

    American Society for Testing and Materials. Philadelphia

    1983-01-01

    1.1 This test method covers the dynamic tear (DT) test using specimens that are 3/16 in. to 5/8 in. (5 mm to 16 mm) inclusive in thickness. 1.2 This test method is applicable to materials with a minimum thickness of 3/16 in. (5 mm). 1.3 The pressed-knife procedure described for sharpening the notch tip generally limits this test method to materials with a hardness level less than 36 HRC. Note 1—The designation 36 HRC is a Rockwell hardness number of 36 on Rockwell C scale as defined in Test Methods E 18. 1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. ASTM Validates Air Pollution Test Methods

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1973

    1973-01-01

    The American Society for Testing and Materials (ASTM) has validated six basic methods for measuring pollutants in ambient air as the first part of its Project Threshold. Aim of the project is to establish nationwide consistency in measuring pollutants; determining precision, accuracy and reproducibility of 35 standard measuring methods. (BL)

  18. Test Driven Development and the Scientific Method

    Microsoft Academic Search

    Rick Mugridge

    2003-01-01

    The scientific method serves as a good metaphor for several practices in Extreme Programming (XP). We explore the commonalities and differences and show that the scientific method, by analogy, can be used to better understand Test Driven Development (and vice versa).

  19. Alternative Test Methods for Electronic Parts

    NASA Technical Reports Server (NTRS)

    Plante, Jeannette

    2004-01-01

    It is common practice within NASA to test electronic parts at the manufacturing lot level to demonstrate, statistically, that parts from the lot tested will not fail in service using generic application conditions. The test methods and the generic application conditions used have been developed over the years through cooperation between NASA, DoD, and industry in order to establish a common set of standard practices. These common practices, found in MIL-STD-883, MIL-STD-750, military part specifications, EEE-INST-002, and other guidelines are preferred because they are considered to be effective and repeatable and their results are usually straightforward to interpret. These practices can sometimes be unavailable to some NASA projects due to special application conditions that must be addressed, such as schedule constraints, cost constraints, logistical constraints, or advances in the technology that make the historical standards an inappropriate choice for establishing part performance and reliability. Alternate methods have begun to emerge and to be used by NASA programs to test parts individually or as part of a system, especially when standard lot tests cannot be applied. Four alternate screening methods will be discussed in this paper: Highly accelerated life test (HALT), forward voltage drop tests for evaluating wire-bond integrity, burn-in options during or after highly accelerated stress test (HAST), and board-level qualification.

  20. Current status of antifungal susceptibility testing methods.

    PubMed

    Arikan, Sevtap

    2007-11-01

    Antifungal susceptibility testing is a very dynamic field of medical mycology. Standardization of in vitro susceptibility tests by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST), and current availability of reference methods constituted the major remarkable steps in the field. Based on the established minimum inhibitory concentration (MIC) breakpoints, it is now possible to determine the susceptibilities of Candida strains to fluconazole, itraconazole, voriconazole, and flucytosine. Moreover, utility of fluconazole antifungal susceptibility tests as an adjunct in optimizing treatment of candidiasis has now been validated. While the MIC breakpoints and clinical significance of susceptibility testing for the remaining fungi and antifungal drugs remain yet unclear, modifications of the available methods as well as other methodologies are being intensively studied to overcome the present drawbacks and limitations. Among the other methods under investigation are Etest, colorimetric microdilution, agar dilution, determination of fungicidal activity, flow cytometry, and ergosterol quantitation. Etest offers the advantage of practical application and favorable agreement rates with the reference methods that are frequently above acceptable limits. However, MIC breakpoints for Etest remain to be evaluated and established. Development of commercially available, standardized colorimetric panels that are based on CLSI method parameters has added more to the antifungal susceptibility testing armamentarium. Flow cytometry, on the other hand, appears to offer rapid susceptibility testing but requires specified equipment and further evaluation for reproducibility and standardization. Ergosterol quantitation is another novel approach, which appears potentially beneficial particularly in discrimination of azole-resistant isolates from heavy trailers. The method is yet investigational and requires to be further studied. Developments in methodology and applications of antifungal susceptibility testing will hopefully provide enhanced utility in clinical guidance of antifungal therapy. However, and particularly in immunosuppressed host, in vitro susceptibility is and will remain only one of several factors that influence clinical outcome. PMID:17885947

  1. Adoption Disruption and Dissolution

    MedlinePLUS

    ... who began adoptive placements between 1995 and 2000, Smith, Howard, Garnier, and Ryan (2006) found that approximately ... 1988; Rosenthal et al., 1988, Berry & Barth, 1990, Smith & Howard, 1991) Adoption Disruption and Dissolution https://www. ...

  2. Thermal Insulation Testing Method and Apparatus

    NASA Technical Reports Server (NTRS)

    Fesmire, James E. (Inventor); Augustynowicz, Stanislaw D. (Inventor)

    2004-01-01

    A test apparatus and method of its use for evaluating various performance aspects of a test specimen is disclosed. A chamber within a housing contains a cold mass tank with a contact surface in contact with a first surface of a test specimen. The first surface of the test specimen is spaced from the second surface of the test specimen by a thickness. The second surface of the test specimen is maintained at a a constant temperature by a liquid disposed within the cold mass tank. A boil-off flow rate of the gas is monitored and provided to a processor along with the temperature of the first and second surfaces of the test specimen. The processor calculates thermal insulation values of the test specimen including comparative values for heat flux and apparent thermal conductivity k-value). The test specimen may be placed in any vacuum pressure level ranging from about 0.01 millitorr to 1,000,000 millitorr with different residual gases as desired. The test specimen may be placed under a mechanical load with the cold mass tank and another factors may be imposed upon the test specimen so as to simulate the actual use conditions.

  3. Thermal insulation testing method and apparatus

    NASA Technical Reports Server (NTRS)

    Fesmire, James E. (Inventor); Augustynowicz, Stanislaw D. (Inventor)

    2004-01-01

    A test apparatus and method of its use for evaluating various performance aspects of a test specimen is disclosed. A chamber within a housing contains a cold mass tank with a contact surface in contact with a first surface of a test specimen. The first surface of the test specimen is spaced from the second surface of the test specimen by a thickness. The second surface of the test specimen is maintained at a desired warm temperature. The first surface is maintained at a constant temperature by a liquid disposed within the cold mass tank. A boil-off flow rate of the gas is monitored and provided to a processor along with the temperature of the first and second surfaces of the test specimen. The processor calculates thermal insulation values of the test specimen including comparative values for heat flux and apparent thermal conductivity (k-value). The test specimen may be placed in any vacuum pressure level ranging from about 0.01 millitorr to 1,000,000 millitorr with different residual gases as desired. The test specimen may be placed under a mechanical load with the cold mass tank and another factors may be imposed upon the test specimen so as to simulate the actual use conditions.

  4. Standard Test Methods for Textile Composites

    NASA Technical Reports Server (NTRS)

    Masters, John E.; Portanova, Marc A.

    1996-01-01

    Standard testing methods for composite laminates reinforced with continuous networks of braided, woven, or stitched fibers have been evaluated. The microstructure of these textile' composite materials differs significantly from that of tape laminates. Consequently, specimen dimensions and loading methods developed for tape type composites may not be applicable to textile composites. To this end, a series of evaluations were made comparing testing practices currently used in the composite industry. Information was gathered from a variety of sources and analyzed to establish a series of recommended test methods for textile composites. The current practices established for laminated composite materials by ASTM and the MIL-HDBK-17 Committee were considered. This document provides recommended test methods for determining both in-plane and out-of-plane properties. Specifically, test methods are suggested for: unnotched tension and compression; open and filled hole tension; open hole compression; bolt bearing; and interlaminar tension. A detailed description of the material architectures evaluated is also provided, as is a recommended instrumentation practice.

  5. Development of test methods for textile composites

    NASA Technical Reports Server (NTRS)

    Masters, John E.; Ifju, Peter G.; Fedro, Mark J.

    1993-01-01

    NASA's Advanced Composite Technology (ACT) Program was initiated in 1990 with the purpose of developing less costly composite aircraft structures. A number of innovative materials and processes were evaluated as a part of this effort. Chief among them are composite materials reinforced with textile preforms. These new forms of composite materials bring with them potential testing problems. Methods currently in practice were developed over the years for composite materials made from prepreg tape or simple 2-D woven fabrics. A wide variety of 2-D and 3-D braided, woven, stitched, and knit preforms were suggested for application in the ACT program. The applicability of existing test methods to the wide range of emerging materials bears investigation. The overriding concern is that the values measured are accurate representations of the true material response. The ultimate objective of this work is to establish a set of test methods to evaluate the textile composites developed for the ACT Program.

  6. Validation of handset antenna test methods

    Microsoft Academic Search

    Mikael B. Knudsen; Gert F. Pedersen; Bo G. H. Olsson; Kim Olesen; Stig-he A. Larsson

    2000-01-01

    In this work an investigation of a test method for validating the transmitted power by a mobile handset proposed by Olsson and Larsson (see COST 259 WG2.2, 1998) and by Olsson (see COST 259 WG2.2, Leidschendam, Netherlands, 1999) has been made for 1800 MHz GSM handsets. Test results of 8 commercially available GSM1800 handsets measured in the setup has been

  7. Direct Measurement of Lipase Inhibition by Orlistat Using a Dissolution Linked In Vitro Assay

    PubMed Central

    Lewis, Daniel R; Liu, Dongzhou J

    2014-01-01

    Purpose To develop a bio-assay that would be able to directly test gastrointestinal and/or dissolution samples to determine lipase activity and inhibition by Orlistat. Methods Enzyme assays were performed with porcine pancreatic lipase and para-Nitrophenyl Palmitate (pNPP) in pH 8.0 reaction buffer at 37°C. Substrate hydrolysis was monitored by absorbance changes at 410 nm. The dissolution of two Orlistat formulations was tested with a USP II apparatus. Samples were HPLC analyzed to determine release profile in addition to being diluted and directly assayed for inhibitory effect. Results The lipase-pNPP system demonstrates linearity and Michalis-Menten kinetics with a Km=2.7 ± 0.2 ?M and Kcat = 0.019 s?1. Orlistat showed highly potent and time dependent inhibition with 5 ng/ml effecting 50% activity after 5 minutes in the Lipase-pNPP system. Dissolution studies showed a correlation of the drug release profile to the inhibitory effect of dissolution samples in the assay. Conclusions The lipase-pNPP method can be used as an in vitro assay to monitor orlistat inhibition from drug release or dissolution samples. PMID:25419492

  8. Simple, low-cost method for the dissolution of metal and mineral samples in plastic pressure vessels

    Microsoft Academic Search

    R. F. Farrell; S. A. Matthes; A. J. Mackie

    1980-01-01

    A goal of the US Department of the Interior, Bureau of Mines, is the advancement of minerals technology through the development of improved metals and minerals processing. In support of this goal, the Bureau of Mines has developed a general method for preparing solutions from a wide range of metal and mineral samples for chemical analysis. The development of the

  9. Transport Test Problems for Hybrid Methods Development

    SciTech Connect

    Shaver, Mark W.; Miller, Erin A.; Wittman, Richard S.; McDonald, Benjamin S.

    2011-12-28

    This report presents 9 test problems to guide testing and development of hybrid calculations for the ADVANTG code at ORNL. These test cases can be used for comparing different types of radiation transport calculations, as well as for guiding the development of variance reduction methods. Cases are drawn primarily from existing or previous calculations with a preference for cases which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22.

  10. SCC behavior and anodic dissolution of Inconel 600 in low concentration thiosulfate

    NASA Astrophysics Data System (ADS)

    Hsu, S. S.; Tsai, S. C.; Kai, J. J.; Tsai, C. H.

    1991-09-01

    The anodic dissolution behavior and the resistance to stress corrosion cracking of Inconel 600 in low concentration thiosulfate were studied utilizing the potentiodynamic polarization and constant load test methods under potential control. It was found that sensitized Inconel 600 was susceptible to IGSCC in thiosulfate solution only when pH was lower than 3. There existed an optimum combination of dissolution/repassivation rates that shortest failure time occured, which corresponded well with the maximum potentiostatic current at onset of abrupt current increase. The constant load test results for samples of different heat treatment also showed that the grain boundary chromium concentration and the crack tip electrochemical potential control the anodic dissolution behavior and thereby determine the stress corrosion resistance of Inconel 600.

  11. Development and validation of an inductively coupled plasma mass spectrometry method for quantification of levothyroxine in dissolution studies

    Microsoft Academic Search

    Dimple Pabla; Fatemeh Akhlaghi; Aftab Ahmed; Hossein Zia

    2008-01-01

    A simple, sensitive and reproducible inductively coupled plasma mass spectrometry (ICP-MS) method for the direct determination of levothyroxine (T4), based on the analysis of iodide content, in aqueous media was developed. The sample preparation consisted of addition of antimony, as the internal standard, and dilution with a 0.5% ammonia solution. The analytes were quantified at m\\/z126.90 and 120.90 for iodide

  12. The effect of calcination temperature on the microstructure and photocatalytic activity of TiO2-based composite nanotubes prepared by an in situ template dissolution method

    NASA Astrophysics Data System (ADS)

    Fan, Jiajie; Zhao, Li; Yu, Jiaguo; Liu, Gang

    2012-09-01

    TiO2-based composite nanotubes, based on an in situ template dissolution method, were one-step fabricated in a mixed aqueous solution of ammonium hexafluorotitanate and boric acid using ZnO nanorods as templates, and then the samples were calcined at different temperatures. The photocatalytic activity of the samples was evaluated by photocatalytic decoloration of Methyl Orange (MO) aqueous solution at ambient temperature under UV light. The results showed that the prepared sample possessed nanoscale tubular morphology with a wall thickness of ca. 30-50 nm, inner diameters of ca. 50-150 nm and lengths of ca. 400-2000 nm. The calcined samples exhibited excellent stabilization of the anatase phase in a wide temperature range of 300-800 °C. The un-calcined and calcined samples possessed hierarchically macro-mesoporous structures. The sample calcined at 600 °C exhibited the highest photocatalytic activity, corresponding to the maximal formation rate of \\z.rad OH on the photocatalyst. This is attributed to the improvement of anatase TiO2 crystallization, the formation of multi-phase structures including anatase, cubic Zn2TiO4, hexagonal ZnTiO3 and cubic ZnTiO3, and the presence of hierarchically macro-mesoporous structures.

  13. Development of In Vitro-In Vivo Correlation/Relationship Modeling Approaches for Immediate Release Formulations Using Compartmental Dynamic Dissolution Data from "Golem": A Novel Apparatus.

    PubMed

    ?ulen, Martin; Tuszy?ski, Pawe? K; Polak, Sebastian; Jachowicz, Renata; Mendyk, Aleksander; Dohnal, Ji?í

    2015-01-01

    Different batches of atorvastatin, represented by two immediate release formulation designs, were studied using a novel dynamic dissolution apparatus, simulating stomach and small intestine. A universal dissolution method was employed which simulated the physiology of human gastrointestinal tract, including the precise chyme transit behavior and biorelevant conditions. The multicompartmental dissolution data allowed direct observation and qualitative discrimination of the differences resulting from highly pH dependent dissolution behavior of the tested batches. Further evaluation of results was performed using IVIVC/IVIVR development. While satisfactory correlation could not be achieved using a conventional deconvolution based-model, promising results were obtained through the use of a nonconventional approach exploiting the complex compartmental dissolution data. PMID:26120580

  14. Development of In Vitro-In Vivo Correlation/Relationship Modeling Approaches for Immediate Release Formulations Using Compartmental Dynamic Dissolution Data from “Golem”: A Novel Apparatus

    PubMed Central

    ?ulen, Martin; Tuszy?ski, Pawe? K.; Polak, Sebastian; Jachowicz, Renata; Mendyk, Aleksander; Dohnal, Ji?í

    2015-01-01

    Different batches of atorvastatin, represented by two immediate release formulation designs, were studied using a novel dynamic dissolution apparatus, simulating stomach and small intestine. A universal dissolution method was employed which simulated the physiology of human gastrointestinal tract, including the precise chyme transit behavior and biorelevant conditions. The multicompartmental dissolution data allowed direct observation and qualitative discrimination of the differences resulting from highly pH dependent dissolution behavior of the tested batches. Further evaluation of results was performed using IVIVC/IVIVR development. While satisfactory correlation could not be achieved using a conventional deconvolution based-model, promising results were obtained through the use of a nonconventional approach exploiting the complex compartmental dissolution data. PMID:26120580

  15. Method for non-destructive testing

    DOEpatents

    Akers, Douglas W. (Idaho Falls, ID)

    2011-08-30

    Non-destructive testing method may include providing a source material that emits positrons in response to bombardment of the source material with photons. The source material is exposed to photons. The source material is positioned adjacent the specimen, the specimen being exposed to at least some of the positrons emitted by the source material. Annihilation gamma rays emitted by the specimen are detected.

  16. Testing alleged mediumship: methods and results.

    PubMed

    O'keeffe, Ciarán; Wiseman, Richard

    2005-05-01

    Mediums claim to be able to communicate with the deceased. Such claims attract a considerable amount of public interest and, if valid, have important implications for many areas of psychology. For over 100 years, researchers have tested alleged mediums. This work has obtained mixed results and provoked a considerable amount of methodological debate. This paper reviews the key issues in this debate, describes how the authors devised a method of testing that aimed to prevent the many problems that have hindered past research, and how they then used this method to test several professional mediums. The results of this work did not support the existence of genuine mediumistic ability. Competing interpretations of these results are discussed, along with ways in which the methodology presented in the paper could be used to assess conceptually similar, but non-paranormal, claims made in clinical, occupational and forensic contexts. PMID:15969829

  17. ``Retests'': A better method of test corrections

    NASA Astrophysics Data System (ADS)

    McManus, Jeff

    2011-02-01

    Physics instructors at all levels employ a variety of techniques to encourage students to reflect on and correct mistakes made on quizzes, unit tests, or exams. A thorough analysis of several methods was recently published in these pages that compared several variations of quiz corrections in college courses. One common method is to have students rewrite the solutions to the questions or problems that they missed, with the goal of earning some part of the missed points. While this method is helpful for some students, it often discourages students with already decent grades to reflect on their work. I use a method called "retesting" with my AP® Physics C students that I learned from my high school geometry teacher, Bill Kramer. I feel his clever method offers significant advantages over more traditional approaches.

  18. 78 FR 68076 - Request for Information on Alternative Skin Sensitization Test Methods and Testing Strategies and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ...alternative safety testing methods and integrated testing...works to promote the scientific validation and regulatory...acceptance of testing methods that more accurately...Federal agency test method review, and optimize utilization of scientific expertise...

  19. Standard Method For Radiation Tests Of Liquids

    NASA Technical Reports Server (NTRS)

    Bouquet, Frank L.; Somoano, Robert B.

    1989-01-01

    Simple procedure provides standard method for radiation tests of liquids. Assures identical handling and dosage so data from different test laboratories compared reliably. Pair of glass vials, joined by frangible neck and equipped with valves, used. Third vial also used. Filled with control specimen and not irradiated. Developed for measuring properties of liquids for use in radiation-resistant liquid-dielectric capacitors, procedure used for any of variety of liquids proposed for use in high-radiation environment - in x-ray and particle-accelerating machines and nuclear reactors, for example.

  20. Standard test method for plutonium assay by plutonium (III) diode array spectrophotometry

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This test method describes the determination of total plutonium as plutonium(III) in nitrate and chloride solutions. The technique is applicable to solutions of plutonium dioxide powders and pellets (Test Methods C 697), nuclear grade mixed oxides (Test Methods C 698), plutonium metal (Test Methods C 758), and plutonium nitrate solutions (Test Methods C 759). Solid samples are dissolved using the appropriate dissolution techniques described in Practice C 1168. The use of this technique for other plutonium-bearing materials has been reported (1-5), but final determination of applicability must be made by the user. The applicable concentration range for plutonium sample solutions is 10–200 g Pu/L. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropria...

  1. Evolution of a physiological pH 6.8 bicarbonate buffer system: application to the dissolution testing of enteric coated products.

    PubMed

    Liu, Fang; Merchant, Hamid A; Kulkarni, Rucha P; Alkademi, Maram; Basit, Abdul W

    2011-05-01

    The use of compendial pH 6.8 phosphate buffer to assess dissolution of enteric coated products gives rise to poor in vitro-in vivo correlations because of the inadequacy of the buffer to resemble small intestinal fluids. A more representative and physiological medium, pH 6.8 bicarbonate buffer, was developed to evaluate the dissolution behaviour of enteric coatings. The bicarbonate system was evolved from pH7.4 Hanks balanced salt solution to produce a pH 6.8 bicarbonate buffer (modified Hanks buffer, mHanks), which resembles the ionic composition and buffer capacity of intestinal milieu. Prednisolone tablets were coated with a range of enteric polymers: hypromellose phthalate (HP-50 and HP-55), cellulose acetate phthalate (CAP), hypromellose acetate succinate (HPMCAS-LF and HPMCAS-MF), methacrylic acid copolymers (EUDRAGIT® L100-55, EUDRAGIT® L30D-55 and EUDRAGIT® L100) and polyvinyl acetate phthalate (PVAP). Dissolution of coated tablets was carried out using USP-II apparatus in 0.1M HCl for 2h followed by pH 6.8 phosphate buffer or pH 6.8 mHanks bicarbonate buffer. In pH 6.8 phosphate buffer, the various enteric polymer coated products displayed rapid and comparable dissolution profiles. In pH 6.8 mHanks buffer, drug release was delayed and marked differences were observed between the various coated tablets, which is comparable to the delayed disintegration times reported in the literature for enteric coated products in the human small intestine. In summary, the use of pH 6.8 physiological bicarbonate buffer (mHanks) provides more realistic and discriminative in vitro release assessment of enteric coated formulations compared to compendial phosphate buffer. PMID:21255647

  2. Calcination/dissolution residue treatment

    SciTech Connect

    Knight, R.C.; Creed, R.F. [Westinghouse Hanford Co., Richland, WA (United States); Patello, G.K.; Hollenberg, G.W.; Buehler, M.F.; O`Rourke, S.M. [Pacific Northwest Lab., Richland, WA (United States); Visnapuu, A. [Bureau of Mines, Rolla, MO (United States); McLaughlin, D.F. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

    1994-09-01

    Currently, high-level wastes are stored underground in steel-lined tanks at the Hanford site. Current plans call for the chemical pretreatment of these wastes before their immobilization in stable glass waste forms. One candidate pretreatment approach, calcination/dissolution, performs an alkaline fusion of the waste and creates a high-level/low-level partition based on the aqueous solubilities of the components of the product calcine. Literature and laboratory studies were conducted with the goal of finding a residue treatment technology that would decrease the quantity of high-level waste glass required following calcination/dissolution waste processing. Four elements, Fe, Ni, Bi, and U, postulated to be present in the high-level residue fraction were identified as being key to the quantity of high-level glass formed. Laboratory tests of the candidate technologies with simulant high-level residues showed reductive roasting followed by carbonyl volatilization to be successful in removing Fe, Ni, and Bi. Subsequent bench-scale tests on residues from calcination/dissolution processing of genuine Hanford Site tank waste showed Fe was separated with radioelement decontamination factors of 70 to 1,000 times with respect to total alpha activity. Thermodynamic analyses of the calcination of five typical Hanford Site tank waste compositions also were performed. The analyses showed sodium hydroxide to be the sole molten component in the waste calcine and emphasized the requirement for waste blending if fluid calcines are to be achieved. Other calcine phases identified in the thermodynamic analysis indicate the significant thermal reconstitution accomplished in calcination.

  3. 16 CFR 1500.40 - Method of testing toxic substances.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Method of testing toxic substances. 1500.40 Section 1500.40...REGULATIONS § 1500.40 Method of testing toxic substances. The method of testing the toxic substances referred to in §...

  4. Methods and instruments for materials testing

    NASA Technical Reports Server (NTRS)

    Hansma, Paul (Inventor); Drake, Barney (Inventor); Rehn, Douglas (Inventor); Adams, Jonathan (Inventor); Lulejian, Jason (Inventor)

    2011-01-01

    Methods and instruments for characterizing a material, such as the properties of bone in a living human subject, using a test probe constructed for insertion into the material and a reference probe aligned with the test probe in a housing. The housing is hand held or placed so that the reference probe contacts the surface of the material under pressure applied either by hand or by the weight of the housing. The test probe is inserted into the material to indent the material while maintaining the reference probe substantially under the hand pressure or weight of the housing allowing evaluation of a property of the material related to indentation of the material by the probe. Force can be generated by a voice coil in a magnet structure to the end of which the test probe is connected and supported in the magnet structure by a flexure, opposing flexures, a linear translation stage, or a linear bearing. Optionally, a measurement unit containing the test probe and reference probe is connected to a base unit with a wireless connection, allowing in the field material testing.

  5. Plutonium dissolution from Rocky Flats Plant incinerator ash

    Microsoft Academic Search

    Delegard

    1985-01-01

    Rockwell Hanford Operations (Rockwell) soon will commence recovery of plutonium from Rocky Flats Plant incinerator ash. In preparation for this processing, Rockwell undertook literature and laboratory studies to identify, select and optimize plutonium dissolution methods for treating the ash. Ash reburning, followed by dissolution in nitric acid containing calcium fluoride, was selected as the processing method for the ash. Recommended

  6. High temperature pressurized high frequency testing rig and test method

    DOEpatents

    De La Cruz, Jose; Lacey, Paul

    2003-04-15

    An apparatus is described which permits the lubricity of fuel compositions at or near temperatures and pressures experienced by compression ignition fuel injector components during operation in a running engine. The apparatus consists of means to apply a measured force between two surfaces and oscillate them at high frequency while wetted with a sample of the fuel composition heated to an operator selected temperature. Provision is made to permit operation at or near the flash point of the fuel compositions. Additionally a method of using the subject apparatus to simulate ASTM Testing Method D6079 is disclosed, said method involving using the disclosed apparatus to contact the faces of prepared workpieces under a measured load, sealing the workface contact point into the disclosed apparatus while immersing said contact point between said workfaces in a lubricating media to be tested, pressurizing and heating the chamber and thereby the fluid and workfaces therewithin, using the disclosed apparatus to impart a differential linear motion between the workpieces at their contact point until a measurable scar is imparted to at least one workpiece workface, and then evaluating the workface scar.

  7. Characterization methods for ultrasonic test systems

    SciTech Connect

    Busse, L.J.; Becker, F.L.; Bowey, R.E.; Doctor, S.R.; Gribble, R.P.; Posakony, G.J.

    1982-07-01

    Methods for the characterization of ultrasonic transducers (search units) and instruments are presented. The instrument system is considered as three separate components consisting of a transducer, a receiver-display, and a pulser. The operation of each component is assessed independently. The methods presented were chosen because they provide the greatest amount of information about component operation and were not chosen based upon such conditions as cost, ease of operation, field implementation, etc. The results of evaluating a number of commercially available ultrasonic test instruments are presented.

  8. Explosive materials equivalency, test methods and evaluation

    NASA Technical Reports Server (NTRS)

    Koger, D. M.; Mcintyre, F. L.

    1980-01-01

    Attention is given to concepts of explosive equivalency of energetic materials based on specific airblast parameters. A description is provided of a wide bandwidth high accuracy instrumentation system which has been used extensively in obtaining pressure time profiles of energetic materials. The object of the considered test method is to determine the maximum output from the detonation of explosive materials in terms of airblast overpressure and positive impulse. The measured pressure and impulse values are compared with known characteristics of hemispherical TNT data to determine the equivalency of the test material in relation to TNT. An investigation shows that meaningful comparisons between various explosives and a standard reference material such as TNT should be based upon the same parameters. The tests should be conducted under the same conditions.

  9. Non-Parametric Methods Non-Parametric Tests

    E-print Network

    Masci, Frank

    Non-Parametric Methods Contents Non-Parametric Tests Wilcoxon Mann-Whitney Test Wilcoxon Signed Ranks Test Sign Test Runs Test Kolmogorov-Smirnov Test Kruskal-Wallis Test Back to Main Contents Page 1.1/nonparam.html #12;Non-Parametric Tests Non-Parametric tests are often used in place of their parametric

  10. Studies on the applicability of tamarind kernel powder as a carrier in the dissolution enhancement of poorly water soluble drug, celecoxib.

    PubMed

    Babu, G V Murali Mohan; Gowrisankar, V; Himasankar, K; Murthy, K V Ramana

    2003-01-01

    In the present investigation, tamarind kernel powder (TP) was evaluated for its suitability as a carrier to improve the dissolution rate of poorly water-soluble drug, celecoxib (CC). The influence of polysaccharide concentration and method of preparation of solid mixtures on dissolution rate was investigated. Solid mixtures of CC and TP were prepared in different ratios (1:1, 1:4 & 1:9 w/w, CC:TP) using co-grinding technique to test the effect of polysac-charide concentration. Four different methods namely (i) physical mixing method (ii) co-grinding method (iii) kneading method and (iv) solvent deposition method were used to assess the effect of method of preparation. Solid mixtures were characterized by Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) studies and solubility studies. Dissolution rate of CC was increased as the TP concentration increased and optimum weight ratio was found to be 1:4 (CC:TP). It was found that method of preparation of solid mixtures significantly effected the dissolution rate of CC from solid mixtures. The order of products basing on dissolution efficency is solvent deposition > co-grinding > kneading > physical mixing > pure CC. Among all the methods, though the solvent deposition technique improved the dissolution rate to maximum, co-grinding technique was found to be suitable from practical point of view and commercialization. PMID:12705095

  11. Plutonium oxide dissolution

    SciTech Connect

    Gray, J.H.

    1992-09-30

    Several processing options for dissolving plutonium oxide (PuO{sub 2}) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO{sub 2} typically generated by burning plutonium metal and PuO{sub 2} produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuO{sub 2} in canyon dissolvers. The options involve solid solution formation of PuO{sub 2} With uranium oxide (UO{sub 2}) and alloying incinerator ash with aluminum. An oxidative dissolution process involving nitric acid solutions containing a strong oxidizing agent, such as cerium (IV), was neither proven nor rejected. This uncertainty was due to difficulty in regenerating cerium (IV) ions during dissolution. However, recent work on silver-catalyzed dissolution of PuO{sub 2} with persulfate has demonstrated that persulfate ions regenerate silver (II). Use of persulfate to regenerate cerium (IV) or bismuth (V) ions during dissolution of PuO{sub 2} materials may warrant further study.

  12. Plutonium oxide dissolution

    SciTech Connect

    Gray, J.H.

    1992-09-30

    Several processing options for dissolving plutonium oxide (PuO[sub 2]) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO[sub 2] typically generated by burning plutonium metal and PuO[sub 2] produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuO[sub 2] in canyon dissolvers. The options involve solid solution formation of PuO[sub 2] With uranium oxide (UO[sub 2]) and alloying incinerator ash with aluminum. An oxidative dissolution process involving nitric acid solutions containing a strong oxidizing agent, such as cerium (IV), was neither proven nor rejected. This uncertainty was due to difficulty in regenerating cerium (IV) ions during dissolution. However, recent work on silver-catalyzed dissolution of PuO[sub 2] with persulfate has demonstrated that persulfate ions regenerate silver (II). Use of persulfate to regenerate cerium (IV) or bismuth (V) ions during dissolution of PuO[sub 2] materials may warrant further study.

  13. Testing methods and techniques: A compilation

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Mechanical testing techniques, electrical and electronics testing techniques, thermal testing techniques, and optical testing techniques are the subject of the compilation which provides technical information and illustrations of advanced testing devices. Patent information is included where applicable.

  14. Evaluating dissolution profiles of an anti-HIV agent using ANOVA and non-linear regression models in JMP software.

    PubMed

    Qazi, Sanjive; Samuel, N K Peter; Venkatachalam, T K; Uckun, Fatih M

    2003-02-18

    A powerful statistical method was designed using JMP software to detect factors contributing to differences in the dissolution process of an antiviral drug delivered in an oral dosage form. Due to the large number of dissolution media available for solid dosage forms, a statistical method to choose the appropriate medium is critical for testing solid dosage forms. We have developed an analysis of variance model to analyze the overall dissolution profile obtained from the various media. In vitro tests were performed using a standard USP basket apparatus (Vankel Inc., Cary, NC), and the analysis used the restricted/residual maximum likelihood method (JMP software) to partition the variance due to media (pH 1.2 and 6.8, +SDS, water alone and at pH 1.2 with pepsin), time (repeated measure) and capsule (random effect). This allowed correct standard error estimates to be used to compare dissolution in different media using planned linear contrasts. The model provided us with statistically powerful criteria to identify significant differences in capsule dissolution across time and to quantify capsule-to-capsule population variance estimate. The time specific linear contrasts showed the largest sum of square values (SS) occurred at 180 min (SS=0.268) for the simulated SIF (pH 6.8) versus SGF (pH 1.2) comparison (DF=166, MSE=3.92 x 10(-3)). The dissolution processes were further characterized using a non-linear regression fit of a power law function to the data for each capsule. This resulted in a method to statistically differentiate between the dissolution processes of the capsules in different media. PMID:12550778

  15. Sodium sulfate - Deposition and dissolution of silica

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.

    1989-01-01

    The hot-corrosion process for SiO2-protected materials involves deposition of Na2SO4 and dissolution of the protective SiO2 scale. Dew points for Na2SO4 deposition are calculated as a function of pressure, sodium content, and sulfur content. Expected dissolution regimes for SiO2 are calculated as a function of Na2SO4 basicity. Controlled-condition burner-rig tests on quartz verify some of these predicted dissolution regimes. The basicity of Na2SO4 is not always a simple function of P(SO3). Electrochemical measurements of an (Na2O) show that carbon creates basic conditions in Na2SO4, which explains the extensive corrosion of SiO2-protected materials containing carbon, such as SiC.

  16. Experimental test of airplane boarding methods

    DOE PAGESBeta

    Steffen, Jason H.; Hotchkiss, Jon

    2012-01-01

    We report the results of an experimental comparison of different airplane boarding methods. This test was conducted in a mock 757 fuselage, located on a Southern California soundstage, with 12 rows of six seats and a single aisle. Five methods were tested using 72 passengers of various ages. We found a significant reduction in the boarding times of optimized methods over traditional methods. These improved methods, if properly implemented, could result in a significant savings to airline companies. The process of boarding an airplane is of interest to a variety of groups. The public is interested both as a curiosity,more »as it is something that they may regularly experience, and as a consumer, as their experiences good or bad can affect their loyalties. Airline companies and their employees also have a stake in an efficient boarding procedure as time saved in the boarding process may result is monetary savings, in the quality of interactions with passengers, and in the application of human resources to the general process of preparing an airplane for departure. A recent study (Nyquist and McFadden, 2008) indicates that the average cost to an airline company for each minute of time spent at the terminal is roughly $30. Thus, each minute saved in the turn-around time of a flight has the potential to generate over $16,000,000 in annual savings (assuming an average of 1500 flights per day). While the boarding process may not be the primary source of delay in returning an airplane to the skies, reducing the boarding time may effectively eliminate passenger boarding as a contributor in any meaningful measure. Consequently, subsequent efforts to streamline the other necessary tasks, such as refueling and maintenance, would be rewarded with a material reduction in time at the gate for each flight.« less

  17. Veriflow Campylobacter. Performance tested method 101201.

    PubMed

    Joelsson, Adam C; Brown, Ashley S; Puri, Amrita; Keough, Martin P; Pascal, Benjamin J; Gaudioso, Zara E

    2014-01-01

    Veriflow Campylobacter is a molecular based assay for the presumptive and qualitative detection of the most common occurring foodborne Campylobacter species: C. jejuni and C. coli. The assay utilizes a PCR detection method coupled with a rapid, visual, flow-based assay that develops in 3 min post PCR amplification and requires only 24 h of non-specialized enrichment for maximum sensitivity. The Veriflow Campylobacter system eliminates the need for microaerobic chambers, gel electrophoresis or fluorophore based detection of target amplification, and does not require complex data analysis. This Performance Tested Method validation study demonstrated the ability of the Veriflow method to detect naturally occurring Campylobacterfrom chicken carcass rinsates. In the reference comparison study, Chi-square and probability of detection analyses of two unpaired studies indicated that there was no significant difference between the Veriflow Campylobacter method and the U.S. Department of Agriculture (USDA)/Food Safety and Inspection Service (FSIS) reference method. There was no indication of false positive or false negative detection in the reference comparison study, and all 50 C. jejuni and C. coli strains were detected, while 35 nonspecific organisms were undetected in the exclusivity/ inclusivity study. The study results show that Veriflow Campylobacter is a sensitive, selective and robust assay for the detection of C. jejuni and C. coli in chicken carcass rinsates. PMID:25051630

  18. Standardization of fretting fatigue test methods and equipment

    Microsoft Academic Search

    M. H. Attia; R. B. Waterhouse

    1992-01-01

    Papers contained in this book are grouped under the topics of the fundamental aspects of fretting fatigue testing (conceptual framework and mechanics of contact), methods and equipment for fretting fatigue testing, environmental and surface conditions, and nonconventional materials and test methods. Papers are presented on the problems of fretting fatigue testing, a critical appraisal of testing methods in fretting fatigue,

  19. Standard test method for radiochemical determination of uranium isotopes in soil by alpha spectrometry

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers the determination of alpha-emitting uranium isotopes in soil. This test method describes one acceptable approach to the determination of uranium isotopes in soil. 1.2 The test method is designed to analyze 10 g of soil; however, the sample size may be varied to 50 g depending on the activity level. This test method may not be able to completely dissolve all forms of uranium in the soil matrix. Studies have indicated that the use of hydrofluoric acid to dissolve soil has resulted in lower values than results using total dissolution by fusion. 1.3 The lower limit of detection is dependent on count time, sample size, detector, background, and tracer yield. The chemical yield averaged 78 % in a single laboratory evaluation, and 66 % in an interlaboratory collaborative study. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, ass...

  20. Test methods for evaluating reformulated fuels

    SciTech Connect

    Croudace, M.C. [PetroSpec, Inc., Newton, MA (United States)

    1994-12-31

    The US Environmental Protection Agency (EPA) introduced regulations in the 1989 Clean Air Act Amendment governing the reformulation of gasoline and diesel fuels to improve air quality. These statutes drove the need for a fast and accurate method for analyzing product composition, especially aromatic and oxygenate content. The current method, gas chromatography, is slow, expensive, non portable, and requires a trained chemist to perform the analysis. The new mid-infrared spectroscopic method uses light to identify and quantify the different components in fuels. Each individual fuel component absorbs a specific wavelength of light depending on the molecule`s unique chemical structure. The quantity of light absorbed is proportional to the concentration of that fuel component in the mixture. The mid-infrared instrument has significant advantages; it is easy to use, rugged, portable, fully automated and cost effective. It can be used to measure multiple oxygenate or aromatic components in unknown fuel mixtures. Regulatory agencies have begun using this method in field compliance testing; petroleum refiners and marketers use it to monitor compliance, product quality and blending accuracy.

  1. Dissolution of tonalitic enclaves in ascending hydrous granitic magmas: An experimental study

    Microsoft Academic Search

    O. García-Moreno; A. Castro; L. G. Corretgé; H. El-Hmidi

    2006-01-01

    Dissolution of natural mafic magmatic enclaves in a hydrous leucogranitic synthetic melt has been tested experimentally. Results suggest that the mechanism of enclave dissolution is a potential hybridization process in granitic systems. Experiments performed in decompression, simulating ascending magmas, show interesting results: from 10 kbar to 4 kbar, for a given temperature, enhanced dissolution of the tonalitic enclave into the

  2. DISSOLUTION OF PLUTONIUM METAL IN 8-10 M NITRIC ACID

    SciTech Connect

    Rudisill, T.; Pierce, R.

    2012-02-21

    The H-Canyon facility will be used to dissolve Pu metal for subsequent purification and conversion to plutonium dioxide (PuO{sub 2}) using Phase II of HB-Line. To support the new mission, the development of a Pu metal dissolution flowsheet which utilizes concentrated (8-10 M) nitric acid (HNO{sub 3}) solutions containing potassium fluoride (KF) is required. Dissolution of Pu metal in concentrated HNO{sub 3} is desired to eliminate the need to adjust the solution acidity prior to purification by anion exchange. The preferred flowsheet would use 8-10 M HNO{sub 3}, 0.015-0.07 M KF, and 0.5-1.0 g/L Gd to dissolve the Pu up to 6.75 g/L. An alternate flowsheet would use 8-10 M HNO{sub 3}, 0.1-0.2 M KF, and 1-2 g/L B to dissolve the Pu. The targeted average Pu metal dissolution rate is 20 mg/min-cm{sup 2}, which is sufficient to dissolve a 'standard' 2250-g Pu metal button in 24 h. Plutonium metal dissolution rate measurements showed that if Gd is used as the nuclear poison, the optimum dissolution conditions occur in 10 M HNO{sub 3}, 0.04-0.05 M KF, and 0.5-1.0 g/L Gd at 112 to 116 C (boiling). These conditions will result in an estimated Pu metal dissolution rate of {approx}11-15 mg/min-cm{sup 2} and will result in dissolution times of 36-48 h for standard buttons. The recommended minimum and maximum KF concentrations are 0.03 M and 0.07 M, respectively. The maximum KF concentration is dictated by a potential room-temperature Pu-Gd-F precipitation issue at low Pu concentrations. The purpose of the experimental work described in this report was two-fold. Initially a series of screening experiments was performed to measure the dissolution rate of Pu metal as functions of the HNO{sub 3}, KF, and Gd or B concentrations. The objective of the screening tests was to propose optimized conditions for subsequent flowsheet demonstration tests. Based on the rate measurements, this study found that optimal dissolution conditions in solutions containing 0.5-1.0 g/L Gd occurred in 8-10 M HNO{sub 3} with 0.04-0.05 M KF at 112 to 116 C (boiling). The testing also showed that solutions containing 8-10 M HNO{sub 3}, 0.1-0.2 M KF, and 1-2 g/L B achieved acceptable dissolution rates in the same temperature range. To confirm that conditions identified by the dissolution rate measurements for solutions containing Gd or B can be used to dissolve Pu metal up to 6.75 g/L in the presence of Fe, demonstration experiments were performed using concentrations in the optimal ranges. In two of the demonstration experiments using Gd and in one experiment using B, the offgas generation during the dissolution was measured and samples were analyzed for H{sub 2}. The experimental methods used to perform the dissolution rate measurements and flowsheet demonstrations and a discussion of the results are presented.

  3. The use of modified microwave digestion\\/dissolution for the quantitattve determination of aluminum, silicon, and iron in biological materials by inductively coupled plasma spectrometry

    Microsoft Academic Search

    S. Fridlund; S. Littlefield; J. Rivers

    1994-01-01

    A method is described to quantitatively determine Aluminum (Al), Silicon (Si), and Iron (Fe) in biological materials by Inductively Coupled Plasma (ICP) spectrometry using Hydrofluoric Acid (HF) to modify the microwave digestion\\/dissolution method. This method was tested using five plant tissues: NIST 1547 (peach), UCD 155 (Avocado), UCD 176 (Citrus), UCD 124 (Barley Hulls), and UCD 190 (Rice Straw). Values

  4. Fatigue testing a plurality of test specimens and method

    NASA Technical Reports Server (NTRS)

    Hodo, James D. (inventor); Moore, Dennis R. (inventor); Morris, Thomas F. (inventor); Tiller, Newton G. (inventor)

    1987-01-01

    Described is a fatigue testing apparatus for simultaneously subjecting a plurality of material test specimens to cyclical tension loading to determine the fatigue strength of the material. The fatigue testing apparatus includes a pulling head having cylinders defined therein which carry reciprocating pistons. The reciprocation of the pistons is determined by cyclical supplies of pressurized fluid to the cylinders. Piston rods extend from the pistons through the pulling head and are attachable to one end of the test specimens, the other end of the test specimens being attachable to a fixed base, causing test specimens attached between the piston rods and the base to be subjected to cyclical tension loading. Because all the cylinders share a common pressurized fluid supply, the breaking of a test specimen does not substantially affect the pressure of the fluid supplied to the other cylinders nor the tension applied to the other test specimens.

  5. An Accelerated Method for Soldering Testing

    SciTech Connect

    Han, Qingyou [ORNL; Xu, Hanbing [University of Tennessee, Knoxville (UTK); Ried, Paul [Ried, Engineering; Olson, Paul [Balzers, Inc.

    2007-01-01

    An accelerated method for testing die soldering has been developed. High intensity ultrasonic vibrations have been applied to simulate the die casting conditions such as high pressure and high molten metal velocity on the pin. The soldering tendency of steels and coated pins has been examined. The results suggest that in the low carbon steel/Al system, the onset of soldering is 60 times faster with ultrasonic vibration than that without ultrasonic vibration. In the H13/A380 system, the onset of soldering reaction is accelerated to between 30-60 times. Coatings significantly reduce the soldering tendency. For purposes of this study, several commercial coatings from Balzers demonstrated the potential for increasing the service life of core pins between 15 and 180 times.

  6. Overview of chemical modeling of nuclear waste glass dissolution

    SciTech Connect

    Bourcier, W.L.

    1991-02-01

    Glass dissolution takes place through metal leaching and hydration of the glass surface accompanied by development of alternation layers of varying crystallinity. The reaction which controls the long-term glass dissolution rate appears to be surface layer dissolution. This reaction is reversible because the buildup of dissolved species in solution slows the dissolution rate due to a decreased dissolution affinity. Glass dissolution rates are therefore highly dependent on silica concentrations in solution because silica is the major component of the alteration layer. Chemical modeling of glass dissolution using reaction path computer codes has successfully been applied to short term experimental tests and used to predict long-term repository performance. Current problems and limitations of the models include a poorly defined long-term glass dissolution mechanism, the use of model parameters determined from the same experiments that the model is used to predict, and the lack of sufficient validation of key assumptions in the modeling approach. Work is in progress that addresses these issues. 41 refs., 7 figs., 2 tabs.

  7. A stochastic differential equation model for drug dissolution and its parameters

    Microsoft Academic Search

    Petr Lánský; Vera Lánská; Michael Weiss

    2004-01-01

    A stochastic differential equation describing the process of drug dissolution is presented. This approach generalizes the classical deterministic first-order model. Instead of assuming a constant fractional dissolution rate, it is considered here that the rate is corrupted by a white noise. The half-dissolution time is investigated for the model. The maximum likelihood and Bayes methods for the estimation of the

  8. 7 CFR 58.644 - Test methods.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...the methods described in the latest edition of Official Methods of Analysis of the Association of Official Analytical Chemists, the latest edition of Standard Methods, or by other methods giving equivalent...

  9. Testing Generalized Linear Models Using Smoothing Spline Methods

    E-print Network

    Meiring, Wendy

    Testing Generalized Linear Models Using Smoothing Spline Methods Anna Liu, Wendy Meiring and Yuedong Wang University of California, Santa Barbara Abstract This article considers testing exponential families. The tests developed are based on the connection between the smoothing spline models

  10. Efavirenz Dissolution Enhancement I: Co-Micronization

    PubMed Central

    da Costa, Maíra Assis; Seiceira, Rafael Cardoso; Rodrigues, Carlos Rangel; Hoffmeister, Cristiane Rodrigues Drago; Cabral, Lucio Mendes; Rocha, Helvécio Vinícius Antunes

    2012-01-01

    AIDS constitutes one of the most serious infectious diseases, representing a major public health priority. Efavirenz (EFV), one of the most widely used drugs for this pathology, belongs to the Class II of the Biopharmaceutics Classification System for drugs with very poor water solubility. To improve EFV’s dissolution profile, changes can be made to the physical properties of the drug that do not lead to any accompanying molecular modifications. Therefore, the study objective was to develop and characterize systems with efavirenz able to improve its dissolution, which were co-processed with sodium lauryl sulfate (SLS) and polyvinylpyrrolidone (PVP). The technique used was co-micronization. Three different drug:excipient ratios were tested for each of the two carriers. The drug dispersion dissolution results showed significant improvement for all the co-processed samples in comparison to non-processed material and corresponding physical mixtures. The dissolution profiles obtained for dispersion with co-micronized SLS samples proved superior to those of co-micronized PVP, with the proportion (1:0.25) proving the optimal mixture. The improvements may be explained by the hypothesis that formation of a hydrophilic layer on the surface of the micronized drug increases the wettability of the system formed, corroborated by characterization results indicating no loss of crystallinity and an absence of interaction at the molecular level. PMID:24300394

  11. Myasthenia Gravis: Tests and Diagnostic Methods

    MedlinePLUS

    ... of response that is characteristic of MG. Single Fiber EMG — studies can provide support for the diagnosis ... MG when characteristic patterns are present. The single fiber EMG and AChR antibody test are primary tests ...

  12. Current methods of testing for human papillomavirus

    Microsoft Academic Search

    Philip Davies; Janet Kornegay; Thomas Iftner

    2001-01-01

    Human papillomavirus DNA testing is gaining wider acceptance, yet the majority of testing is still undertaken in the research setting using protocols that are unsuitable for clinical diagnostic laboratories. Large-scale clinical human papillomavirus DNA testing is likely to be introduced as an adjunct to cervical cytology, so the cytology laboratory is an appropriate place for it to be undertaken. This

  13. Formal Methods in Testing Software Architectures

    Microsoft Academic Search

    Antonia Bertolino; Henry Muccini

    2003-01-01

    SAs provide a high-level model of large, complex systems using suitable abstractions of the system components and their interac- tions. SA dynamic descriptions can be usefully employed in testing and analysis. We describe here an approach for SA-based conformance test- ing: architectural tests are selected from a Labelled Transition System (LTS) representing the SA behavior and are then refined into

  14. FORCE-VIBRATION TESTING OF BUILDINGS USING THE LINEAR SHAKER SEISMIC SIMULATION (LSSS) TESTING METHOD

    Microsoft Academic Search

    Eunjong YU; Daniel H. WHANG; Ravi VENUGOPAL; Jonathan P. STEWART

    SUMMARY This paper describes the development and numerical verification of a test method to realistically simulate the seismic structural response of full-scale buildings. The result is a new field testing procedure referred to as the linear shaker seismic simulation (LSSS) testing method. This test method uses a linear shaker system in which a mass mounted on the structure is commanded

  15. Basic Concepts in Modern Methods of Test Equating.

    ERIC Educational Resources Information Center

    Woldbeck, Tanya

    This paper summarizes some of the basic concepts in test equating. Various types of equating methods, as well as data collection designs, are outlined, with attempts to provide insight into preferred methods and techniques. Test equating describes a group of methods that enable test constructors and users to compare scores from two different forms…

  16. All-cellulose nanocomposites by surface selective dissolution of bacterial cellulose

    Microsoft Academic Search

    Nattakan Soykeabkaew; Chandeep Sian; Saharman Gea; Takashi Nishino; Ton Peijs

    2009-01-01

    All-cellulose nanocomposites using bacterial cellulose (BC) as a single raw material were prepared by a surface selective\\u000a dissolution method. The effect of the immersion time of BC in the solvent (lithium chloride\\/N,N-dimethylacetamide) during preparation on the nanocomposite properties was investigated. The structure, morphology and mechanical\\u000a properties of the nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, and tensile testing.

  17. The role of force measurements in advanced vibration test methods

    SciTech Connect

    Smallwood, D.O.

    1994-10-01

    The role of force measurements in vibration testing is discussed. The rational for a vibration test based on the extremal control of force and acceleration is developed. The differences between force measurements in vibration testing and modal testing is discussed. Several methods for estimating the input force in a vibration test are outlined.

  18. The Influence of Pressure on the Intrinsic Dissolution Rate of Amorphous Indomethacin

    PubMed Central

    Löbmann, Korbinian; Flouda, Konstantina; Qiu, Danwen; Tsolakou, Theodosia; Wang, Wenbo; Rades, Thomas

    2014-01-01

    New drug candidates increasingly tend to be poorly water soluble. One approach to increase their solubility is to convert the crystalline form of a drug into the amorphous form. Intrinsic dissolution testing is an efficient standard method to determine the intrinsic dissolution rate (IDR) of a drug and to test the potential dissolution advantage of the amorphous form. However, neither the United States Pharmacopeia (USP) nor the European Pharmacopeia (Ph.Eur) state specific limitations for the compression pressure in order to obtain compacts for the IDR determination. In this study, the influence of different compression pressures on the IDR was determined from powder compacts of amorphous (ball-milling) indomethacin (IND), a glass solution of IND and poly(vinylpyrrolidone) (PVP) and crystalline IND. Solid state properties were analyzed with X-ray powder diffraction (XRPD) and the final compacts were visually observed to study the effects of compaction pressure on their surface properties. It was found that there is no significant correlation between IDR and compression pressure for crystalline IND and IND–PVP. This was in line with the observation of similar surface properties of the compacts. However, compression pressure had an impact on the IDR of pure amorphous IND compacts. Above a critical compression pressure, amorphous particles sintered to form a single compact with dissolution properties similar to quench-cooled disc and crystalline IND compacts. In such a case, the apparent dissolution advantage of the amorphous form might be underestimated. It is thus suggested that for a reasonable interpretation of the IDR, surface properties of the different analyzed samples should be investigated and for amorphous samples the IDR should be measured also as a function of the compression pressure used to prepare the solid sample for IDR testing. PMID:25140536

  19. A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

    SciTech Connect

    Chen Zhu; William E. Seyfried

    2005-01-01

    Currently, DOE is conducting pilot CO{sub 2} injection tests to evaluate the concept of geological sequestration. One strategy that potentially enhances CO{sub 2} solubility and reduces the risk of CO{sub 2} leak back to the surface is dissolution of indigenous minerals in the geological formation and precipitation of secondary carbonate phases, which increases the brine pH and immobilizes CO{sub 2}. Clearly, the rates at which these dissolution and precipitation reactions occur directly determine the efficiency of this strategy. However, one of the fundamental problems in modern geochemistry is the persistent two to five orders of magnitude discrepancy between laboratory-measured and field derived feldspar dissolution rates. To date, there is no real guidance as to how to predict silicate reaction rates for use in quantitative models. Current models for assessment of geological carbon sequestration have generally opted to use laboratory rates, in spite of the dearth of such data for compositionally complex systems, and the persistent disconnect between lab and field applications. Therefore, a firm scientific basis for predicting silicate reaction kinetics in CO{sub 2} injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation to measure silicate dissolution rates and iron carbonate precipitation rates at conditions pertinent to geological carbon sequestration. In the first year of the project, we have successfully developed a sample preparation method and completed three batch feldspar dissolution experiments at 200 C and 300 bars. The changes of solution chemistry as dissolution experiments progressed were monitored with on-line sampling of the aqueous phase at the constant temperature and pressure. These data allow calculating overall apparent feldspar dissolution rates and secondary mineral precipitation rates as a function of saturation states. State-of-the-art atomic resolution transmission electron microscopy (TEM), scanning electron microscopy, and electron microprobe was used to characterize the reactants (feldspars before experiments). We experimented with different sample preparation methods for TEM study, and found excellent images and chemical resolution with reactants, which shows promise of the technology and establishes the baseline for comparison with products (feldspars after the experiments). Preliminary electron microscopic characterization shows that the reacted feldspars have etch pits and are covered with secondary sheet silicate phases. Reaction-path geochemical modeling is used to interpret the experimental results. We have established the software and database, and are making great progress. Also during the first year, our education goal of graduate student training has been achieved. A Ph. D. student at Indiana University is progressing well in the degree program and has taken geochemical modeling, SEM, and TEM courses, which will facilitate research in the second and third year. A Ph. D. student at University of Minnesota is progressing well in conducting the experiments, and is near graduation. With the success of training of graduate students and excellent experimental data in the first year, we anticipate a more fruitful year in the second year.

  20. Plutonium dissolution process

    DOEpatents

    Vest, M.A.; Fink, S.D.; Karraker, D.G.; Moore, E.N.; Holcomb, H.P.

    1994-01-01

    A two-step process for dissolving Pu metal is disclosed in which two steps can be carried out sequentially or simultaneously. Pu metal is exposed to a first mixture of 1.0-1.67 M sulfamic acid and 0.0025-0.1 M fluoride, the mixture having been heated to 45-70 C. The mixture will dissolve a first portion of the Pu metal but leave a portion of the Pu in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alternatively, nitric acid between 0.05 and 0.067 M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution is diluted with nitrogen.

  1. Plutonium dissolution process

    DOEpatents

    Vest, Michael A. (Oak Park, IL); Fink, Samuel D. (Aiken, SC); Karraker, David G. (Aiken, SC); Moore, Edwin N. (Aiken, SC); Holcomb, H. Perry (North Augusta, SC)

    1996-01-01

    A two-step process for dissolving plutonium metal, which two steps can be carried out sequentially or simultaneously. Plutonium metal is exposed to a first mixture containing approximately 1.0M-1.67M sulfamic acid and 0.0025M-0.1M fluoride, the mixture having been heated to a temperature between 45.degree. C. and 70.degree. C. The mixture will dissolve a first portion of the plutonium metal but leave a portion of the plutonium in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alteratively, nitric acid in a concentration between approximately 0.05M and 0.067M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution process is diluted with nitrogen.

  2. In situ dissolution analysis using coherent anti-Stokes Raman scattering (CARS) and hyperspectral CARS microscopy.

    PubMed

    Fussell, Andrew; Garbacik, Erik; Offerhaus, Herman; Kleinebudde, Peter; Strachan, Clare

    2013-11-01

    The solid-state form of an active pharmaceutical ingredient (API) in an oral dosage form plays an important role in determining the dissolution rate of the API. As the solid-state form can change during dissolution, there is a need to monitor the oral dosage form during dissolution testing. Coherent anti-Stokes Raman scattering (CARS) microscopy provides rapid, spectrally selective imaging to monitor the oral dosage form during dissolution. In this study, in situ CARS microscopy was combined with inline UV absorption spectroscopy to monitor the solid-state change in oral dosage forms containing theophylline anhydrate undergoing dissolution and to correlate the solid-state change with a change in dissolution rate. The results from in situ CARS microscopy showed that theophylline anhydrate converted to theophylline monohydrate during dissolution resulting in a reduction in the dissolution rate. The addition of methyl cellulose to the dissolution medium was found to delay the theophylline monohydrate growth and changed the morphology of the monohydrate. The net effect was an increased dissolution rate for theophylline anhydrate. Our results show that in situ CARS microscopy combined with inline UV absorption spectroscopy is capable of monitoring oral dosage forms undergoing dissolution and correlating changes in solid-state form with changes in dissolution rate. PMID:23994672

  3. Multicomponent Analysis of Liquids by Test Methods

    Microsoft Academic Search

    V. G. Amelin

    2002-01-01

    Test strips were proposed for the simultaneous determination of the sum of heavy metals, iron(III), copper, zinc, total alkalinity, hardness, chlorides, sulfates, nitrates, nitrites, and fluorides, and composite test strips were proposed for the determination of copper, iron(III), and cobalt. Determination is based on the dependence of the length of colored zones of indicator papers sealed in a polymer film

  4. Implementing and Testing Upstream Corner Balance Methods in PDT 

    E-print Network

    Seager, Robert John

    2013-10-01

    coarser mesh is significant. Upstream corner balance (UCB) methods are a specific family of spatial discretization methods that have some advantages over other methods. This research assesses the strengths and weaknesses of UCB by implementing, testing...

  5. Mechanized Indexing Methods and Their Testing

    Microsoft Academic Search

    John O'Connor

    1964-01-01

    Methods of mechanized indexing (subject indexing by computer) which have been proposed are systematically summarized. Every suggested method consists of some document preparation process (mostly or wholly mechanical) followed by the application of indexing rules to the prepared document. A comprehensive document preparation is described from which proposed methods can be derived by selection. It includes full text input, document

  6. 40 CFR 63.865 - Performance test requirements and test methods.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Chemical Recovery Combustion Sources at Kraft... Performance test requirements...kiln, using the test methods and procedures...furnace, sulfite combustion unit, smelt...Washington facility (Emission...the performance test. (2) If...semichemical combustion unit has...

  7. 40 CFR 63.865 - Performance test requirements and test methods.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Chemical Recovery Combustion Sources at Kraft... Performance test requirements...kiln, using the test methods and procedures...furnace, sulfite combustion unit, smelt...Washington facility (Emission...the performance test. (2) If...semichemical combustion unit has...

  8. 40 CFR 63.865 - Performance test requirements and test methods.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Chemical Recovery Combustion Sources at Kraft... Performance test requirements...kiln, using the test methods and procedures...furnace, sulfite combustion unit, smelt...Washington facility (Emission...the performance test. (2) If...semichemical combustion unit has...

  9. 40 CFR 63.865 - Performance test requirements and test methods.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Chemical Recovery Combustion Sources at Kraft... Performance test requirements...kiln, using the test methods and procedures...furnace, sulfite combustion unit, smelt...Washington facility (Emission...the performance test. (2) If...semichemical combustion unit has...

  10. 40 CFR 63.865 - Performance test requirements and test methods.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Chemical Recovery Combustion Sources at Kraft... Performance test requirements...kiln, using the test methods and procedures...furnace, sulfite combustion unit, smelt...Washington facility (Emission...the performance test. (2) If...semichemical combustion unit has...

  11. A Residual Mass Ballistic Testing Method to Compare Armor Materials or Components (Residual Mass Ballistic Testing Method)

    SciTech Connect

    Benjamin Langhorst; Thomas M Lillo; Henry S Chu

    2014-05-01

    A statistics based ballistic test method is presented for use when comparing multiple groups of test articles of unknown relative ballistic perforation resistance. The method is intended to be more efficient than many traditional methods for research and development testing. To establish the validity of the method, it is employed in this study to compare test groups of known relative ballistic performance. Multiple groups of test articles were perforated using consistent projectiles and impact conditions. Test groups were made of rolled homogeneous armor (RHA) plates and differed in thickness. After perforation, each residual projectile was captured behind the target and its mass was measured. The residual masses measured for each test group were analyzed to provide ballistic performance rankings with associated confidence levels. When compared to traditional V50 methods, the residual mass (RM) method was found to require fewer test events and be more tolerant of variations in impact conditions.

  12. PERFORMANCE TESTING OF METHOD 1312-QA SUPPORT FOR RCRA TESTING

    EPA Science Inventory

    The question of how to access the risks associated with ground water contamination from soils containing toxic substances is a critical issue for the Agency. A major limitation of using Method 1310 and 1311 for this purpose is the fact that the sanitary landfill codisposal scenar...

  13. 40 CFR 60.374 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Test methods and procedures. 60...of Performance for Lead-Acid Battery Manufacturing Plants § 60.374 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  14. 40 CFR 60.374 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Test methods and procedures. 60...of Performance for Lead-Acid Battery Manufacturing Plants § 60.374 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  15. 40 CFR 60.374 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Test methods and procedures. 60...of Performance for Lead-Acid Battery Manufacturing Plants § 60.374 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  16. 40 CFR 60.374 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Test methods and procedures. 60...of Performance for Lead-Acid Battery Manufacturing Plants § 60.374 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  17. A new test method for young age strength of shotcrete

    SciTech Connect

    Teramoto, Shozo [Construction Technology Dept., Tokyo (Japan)

    1995-12-31

    As a method for testing the young-age strength of shotcrete used as tunnel supports, use of the Parotester, which is designed to measure the hardness of paper rolls at printing factories, has been considered. This paper reports the results of laboratory tests conducted to establish this method as a means of strength testing.

  18. Standard Test Method for Testing Nonmetallic Seal Materials by Immersion in a Simulated Geothermal Test Fluid

    E-print Network

    American Society for Testing and Materials. Philadelphia

    1985-01-01

    1.1 This test method covers a procedure for a laboratory test for performing an initial evaluation (screening) of nonmetallic seal materials by immersion in a simulated geothermal test fluid. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Section 6 and 11.7.

  19. Kinetics of gold dissolution in thiosulfate electrolytes

    Microsoft Academic Search

    R. Yu. Bek; O. N. Shevtsova

    2010-01-01

    The kinetics of gold dissolution in solutions containing Na2S2O3 with the concentration c from 0.025 to 0.2 M and different supporting electrolytes is studied by the voltammetric method on renewable electrodes and\\u000a the quartz crystal microbalance. It is shown that in the range from the steady-state potential to E = 0.3 V (from hereon, the potentials are related to the

  20. Methods of Assessing Bias and Fairness in Tests.

    ERIC Educational Resources Information Center

    Merz, William R.

    Several methods of assessing test item bias are described, and the concept of fair use of tests is examined. A test item is biased if individuals of equal ability have different probabilities of attaining the item correct. The following seven general procedures used to examine test items for bias are summarized and discussed: (1) analysis of…

  1. Investigation into physical-chemical variables affecting the manufacture and dissolution of wet-milled clarithromycin nanoparticles.

    PubMed

    Shahbazi Niaz, Maliheh; Traini, Daniela; Young, Paul M; Ghadiri, Maliheh; Rohanizadeh, Ramin

    2014-12-01

    A critical problem associated with poor water-soluble drugs is their low and variable bioavailability, which is derived from the slow dissolution and erratic absorption. Nano-formulation has been identified as one approach to enhance the rate and extent of drug absorption for compounds that demonstrate limited water solubility. This study aimed to investigate the physico-chemical variables that affect the manufacture, dissolution and consequent bioavailability of wet-milled clarithromycin (CLA) nanoparticles, a macrolide antibiotic. CLA nanoparticles were prepared using wet milling method followed by freeze-drying. Different stabilizer systems, consisting of surfactants and polymers alone or their combinations were studied to determine the optimum conditions for producing nano-sized CLA particles. In vitro characterizations of the CLA nanoparticles were performed using dynamic light scattering, X-ray powder diffraction, differential scanning calorimetry and dissolution efficiency test. Results showed that in general the wet milling process did not modify the crystallinity of the CLA nanoparticles. The poloxamers and polyvinyl alcohol (PVA) stabilizers resulted in nanoparticles with the smallest particle size and best dissolution rates. Furthermore, poloxamers F68 and F127, and PVA stabilizers demonstrated the best performance in increasing dissolution efficacy. PMID:24093825

  2. Change in pore structure and composition of hardened cement paste during the process of dissolution

    SciTech Connect

    Haga, Kazuko; Shibata, Masahito; Hironaga, Michihiko; Tanaka, Satoru; Nagasaki, Shinya

    2005-05-01

    An understanding about the dissolution phenomena of cement hydrates is important to assess changes in the long-term performance of radioactive waste disposal facilities. To investigate the alteration associated with dissolution, dissolution tests of ordinary Portland cement (OPC) hydrates were performed. Through observation of the samples after leaching, it was confirmed that ettringite precipitation increased as the dissolution of the portlandite and the C-S-H gel progressed. EPMA performed on cross-sections of the solid phase showed a clear difference between the altered and unaltered parts. The boundary between the two parts was termed the portlandite (CH) dissolution front. As the leaching period became longer, the CH dissolution front shifted toward the inner part of the sample. A linear relationship was derived by plotting the distance moved by the CH dissolution front against the square root of the leaching time. This indicated Ca ion movement by diffusion.

  3. DEVELOPMENT AND VALIDATION OF A TEST METHOD FOR FORMALDEHYDE EMSSION

    EPA Science Inventory

    This document details the field validation of a test method for the sampling and analysis of formaldehyde emissions from stationary sources. hree potential source methods were evaluated. ield testing of the methods were conducted at two different sites. t formaldehyde manufacturi...

  4. 40 CFR Table 3 of Subpart Aaaaaaa... - Test Methods

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...appendix A to part 60. 5. Measuring the PM emissions EPA test method 5A in appendix A to part 60. 6. Measuring the PAH emissions EPA test method 23 b with analysis by SW-846 Method 8270D. a The sampling locations must be located...

  5. 40 CFR Table 3 of Subpart Aaaaaaa... - Test Methods

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...appendix A to part 60. 5. Measuring the PM emissions EPA test method 5A in appendix A to part 60. 6. Measuring the PAH emissions EPA test method 23 b with analysis by SW-846 Method 8270D. a The sampling locations must be located...

  6. 40 CFR Table 3 of Subpart Aaaaaaa... - Test Methods

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...appendix A to part 60. 5. Measuring the PM emissions EPA test method 5A in appendix A to part 60. 6. Measuring the PAH emissions EPA test method 23 b with analysis by SW-846 Method 8270D. a The sampling locations must be located...

  7. 40 CFR Table 3 of Subpart Aaaaaaa... - Test Methods

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...appendix A to part 60. 5. Measuring the PM emissions EPA test method 5A in appendix A to part 60. 6. Measuring the PAH emissions EPA test method 23 b with analysis by SW-846 Method 8270D. a The sampling locations must be located...

  8. Comparison of two methods of fatigue testing bone cement

    Microsoft Academic Search

    K. E. Tanner; Jian-Sheng Wang; Fred Kjellson; Lars Lidgren

    2010-01-01

    Two different methods have been used to fatigue test four bone cements. Each method has been used previously, but the results have not been compared. The ISO 527-based method tests a minimum of 10 samples over a single stress range in tension only and uses Weibull analysis to calculate the median number of cycles to failure and the Weibull modulus.

  9. Test Oracles Using Statistical Methods Johannes Mayer, Ralph Guderlei

    E-print Network

    Pfeifer, Holger

    Test Oracles Using Statistical Methods Johannes Mayer, Ralph Guderlei Abteilung Angewandte of random- ized software. The presented Statistical Oracle is a Heuristic Oracle using statistical methods, of characteristics computable from the test results are available. A Statistical Oracle using statistical methods

  10. 40 CFR 63.1257 - Test methods and compliance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...or greater. (D) Combustion treatment processes...applies to performance tests that are conducted to...demonstrate compliance of a combustion treatment process with...Alternatively, any other test method validated according...gas stream exiting the combustion treatment...

  11. 40 CFR 63.1257 - Test methods and compliance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...or greater. (D) Combustion treatment processes...applies to performance tests that are conducted to...demonstrate compliance of a combustion treatment process with...Alternatively, any other test method validated according...gas stream exiting the combustion treatment...

  12. 40 CFR 63.1257 - Test methods and compliance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...or greater. (D) Combustion treatment processes...applies to performance tests that are conducted to...demonstrate compliance of a combustion treatment process with...Alternatively, any other test method validated according...gas stream exiting the combustion treatment...

  13. 40 CFR 63.1257 - Test methods and compliance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...or greater. (D) Combustion treatment processes...applies to performance tests that are conducted to...demonstrate compliance of a combustion treatment process with...Alternatively, any other test method validated according...gas stream exiting the combustion treatment...

  14. 40 CFR 60.583 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Flexible Vinyl and Urethane Coating and Printing § 60.583 Test methods and procedures...minutes and shall continue until the printing operation is interrupted or until 180...each test run, the print line shall be printing continuously and operating...

  15. 40 CFR 60.583 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Flexible Vinyl and Urethane Coating and Printing § 60.583 Test methods and procedures...minutes and shall continue until the printing operation is interrupted or until 180...each test run, the print line shall be printing continuously and operating...

  16. 40 CFR 60.583 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Flexible Vinyl and Urethane Coating and Printing § 60.583 Test methods and procedures...minutes and shall continue until the printing operation is interrupted or until 180...each test run, the print line shall be printing continuously and operating...

  17. 40 CFR 60.583 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Flexible Vinyl and Urethane Coating and Printing § 60.583 Test methods and procedures...minutes and shall continue until the printing operation is interrupted or until 180...each test run, the print line shall be printing continuously and operating...

  18. 40 CFR 60.583 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Flexible Vinyl and Urethane Coating and Printing § 60.583 Test methods and procedures...minutes and shall continue until the printing operation is interrupted or until 180...each test run, the print line shall be printing continuously and operating...

  19. 40 CFR 60.303 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Grain Elevators § 60.303 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  20. 40 CFR 60.303 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Grain Elevators § 60.303 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  1. 40 CFR 60.303 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Grain Elevators § 60.303 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  2. 40 CFR 60.303 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Grain Elevators § 60.303 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  3. 40 CFR 60.303 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Grain Elevators § 60.303 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

  4. ASTM test methods for composite characterization and evaluation

    NASA Technical Reports Server (NTRS)

    Masters, John E.

    1994-01-01

    A discussion of the American Society for Testing and Materials is given. Under the topic of composite materials characterization and evaluation, general industry practice and test methods for textile composites are presented.

  5. 40 CFR 60.266 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Ferroalloy Production Facilities § 60.266 Test methods and procedures. (a) During any performance test required...

  6. 40 CFR 60.93 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.93 Test methods and procedures. (a) In conducting the performance tests required...

  7. 40 CFR 60.93 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.93 Test methods and procedures. (a) In conducting the performance tests required...

  8. 40 CFR 60.93 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.93 Test methods and procedures. (a) In conducting the performance tests required...

  9. 40 CFR 60.93 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.93 Test methods and procedures. (a) In conducting the performance tests required...

  10. 40 CFR 60.93 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.93 Test methods and procedures. (a) In conducting the performance tests required...

  11. Parallel methods for absolute irreducibility testing

    Microsoft Academic Search

    Fatima K. Abu Salem; Laurence Tianruo Yang

    2008-01-01

    A heuristic algorithm for testing absolute irreducibility of multivariate polynomials over arbitrary elds using Newton Polytopes was proposed in (8). A preliminary implementa- tion by S. Gao and A. Lauder (2003) established a wide range of families of low degree and sparse polynomials for which the algorithm works ecien tly and with a high success rate. In this paper, we

  12. Tracer Test Interpretation Methods for Reservior Properties

    SciTech Connect

    Shook, George Michael

    2001-08-01

    The purpose of this project is to develop tools that can be used to interpret tracer tests and obtain estimates of reservoir and operational parameters. These tools (mostly in the form of spreadsheet applications) can be used to optimize geothermal resource management.

  13. Optical metrology of nano-scale mineral dissolutions using a phase-shift interference microscope

    NASA Astrophysics Data System (ADS)

    Satoh, H.; Nishimura, Y.; Tsukamoto, K.; Ueda, A.; Ueta, S.; Kato, K.

    2005-12-01

    Solid materials are greater or less soluble on the Earth's surface environment in nano-scale. Dissolution is critical issue for weathering and geo-environmental assessment. Recent advances in nanoscopy are derived from novel topographic method with scanning probe microscopes (AFM, STM, LCM). As another classical but precise method, interferometry is still useful optical tool and enables quick and easy survey of vertical surface topography by utilizing computer processing. We have newly designed a white-light phase-shift interference microscope (PSI-M) for detecting ultra-slow dissolution and precipitation to validate the endurance of artificial barrier system for radioactive waste repository (Ueda et al., 2005) and assess the geologic CO2 storage system. The measurement system is comprised of Maki-type (modified Michelson) phase-shift interferometer, white light source, computer camera, and Ti reaction cell with syringe pump. Minimum resolutions are calculated to be about 0.7 nm for surface-reflection mode and 6.6 nm for back-reflection mode. It takes only 2 s to obtain a phase-shift interferogram. After sequential image acquisitions, we can measure the rates of advance and retreat in real-time at the surface of the specimen in the view field by image-processing. As a benchmark test of surface reflection mode, we carried out a dissolution experiment on BK7 glass in pure H2O flowing at 105 um/s. Result showed 8.7E-5 nm/s of dissolution velocity, corresponding to a rate of ~3um/yr . Measurement at etch pits on calcite (10-14) in pure H2O showed an acceptable dissolution rate of 2.9E-10 mol/cm2/s (Ueda et al., 2005). Another measurement on anorthite (010) in 0.5M of NaCl-NaOH-HCl solutions at 105 um/s flow showed consistent rates of 2.4E-13 to 2.3E-11 mol/cm2/s at pH = 3-12.4 with the previous data (Blum and Stillings, 1995). These results sufficiently confirmed precision of the rate determination with PSI-M. We have further carried out the dissolution measurement on ~100x100x2 um3 smectite (Na-montmorillonite) in NaCl-NaOH solution (pH = 7-14) by back-reflection mode. The obtained rates at (001) were three-order faster (6.9E-10 to 3.6E-8 mol/m2/s) than the data previously reported (e.g., Cama et al., 2000; Yokoyama et al., 2005: ~1E-10 to 1E-12 mol/m2/s) and showed inhomogeneity. It has further been found that dissolution rate at etch-pit is three times accelerated than that at grain edge even at pH = 8. Flow-rate dependency on dissolution rates recognized in NaOH 1.0M solution but in the presence of Na2SiO3 (0.05 to 5.00 mM) suggests that the dissolution of smectite is strongly limited by Si release probably enhanced by flow. Thus, our established PSI-M system can be used to consider the mechanism concerning the dissolution and precipitation by controlling conditions of temperature, pressure, composition, and flow as present in natural system with 2D recognizing the dissolution step and pit.

  14. Electrochemical polishing of thread fastener test specimens of nickel-chromium iron alloys

    DOEpatents

    Kephart, Alan R. (Scotia, NY)

    1991-01-01

    An electrochemical polishing device and method for selective anodic dissolution of the surface of test specimens comprised, for example, of nickel-chromium-iron alloys, which provides for uniform dissolution at the localized sites to remove metal through the use of a coiled wire electrode (cathode) placed in the immediate proximity of the working, surface resulting in a polished and uniform grain boundary.

  15. Optical non-destructive testing methods of cultural heritage artefacts

    NASA Astrophysics Data System (ADS)

    Hain, Miroslav; Bartl, Ján; Jacko, Vlado

    2005-08-01

    Optical methods are very powerful tools for non-destructive testing of works of art. There are several tasks connected with testing of works of art, which can be solved by use of optical methods, for example revealing of underdrawings in pictures, visualisation of artefacts that are due to degradation process invisible by naked eye, distinguishing between authentic and retouched parts of work of art, testing of degradation and ageing of works of art and many other tasks. In the contribution several selected optical testing methods will be described, among them ultraviolet fluorescence, infrared reflectography and laser scattering method.

  16. A Novel Method for Strain Controlled Tests

    Microsoft Academic Search

    G. Olmi

    The present paper aims at providing a contribution to the testing strategies in the field of mechanics of materials, with\\u000a particular reference to low cycle fatigue in the strain control mode. After a detailed analysis of the state of the art on\\u000a possible techniques for strain controlling, the paper points out the difficulties that could be encountered when a conventional

  17. Public transfers and marital dissolution

    Microsoft Academic Search

    Sigve Tjøtta; Kjell Vaage

    2008-01-01

    In this paper, we analyze determinants of marital dissolution, focusing on the alleged influences from public transfers, child\\u000a allowance, and child support awards. We use a Norwegian panel of 2,806 couples with information on public and private transfers\\u000a in cases of divorce. The sample was observed over a 5-year period, with the purpose of registering marital dissolution. We\\u000a find that

  18. A method to assess the ranking importance of uncertainties of residual and dissolution trapping of CO2 on a large-scale storage site

    NASA Astrophysics Data System (ADS)

    Audigane, P.; Rohmer, J.; Manceau, J. C.

    2014-12-01

    The long term fate of mobile CO2 remaining after the injection period is a crucial issue for regulators and operators. There are needs to evaluate properly the amount of gas free to migrate and to estimate the fluid movements at long time scales. Often the difficulty is to manage the computational time to assess the large time and dimension scale of the problem. The second limitation is the large level of uncertainty associated to the computation prediction. A variance-based global sensitivity analysis is proposed to assess the importance ranking of uncertainty sources, with regards to the behavior of the mobile CO2 during the post-injection period. We consider three output parameters which characterize the location and the quantity of mobile CO2, considering residual and dissolution trapping. To circumvent both (i) the large number of computationally intensive reservoir-scale flow simulations and (ii) the different nature of uncertainties whether linked to parameters (continuous variables) or to modeling assumptions (scenario-like variables) we propose to use advanced meta-modeling techniques of ACOSSO-type. The feasibility of the approach is demonstrated using a potential site for CO2 storage in the Paris basin (France), for which the amount, nature and quality of the data available at disposal and the associated uncertainties can be seen as representative to those of a storage project at the post-screening stage. A special attention has been paid to confront the results of the sensitivity analysis with the physical interpretation of the processes.

  19. The Method of Manufactured Universes for Testing Uncertainty Quantification Methods 

    E-print Network

    Stripling, Hayes Franklin

    2011-02-22

    The Method of Manufactured Universes is presented as a validation framework for uncertainty quantification (UQ) methodologies and as a tool for exploring the effects of statistical and modeling assumptions embedded in ...

  20. Correlation between in vitro dissolution profiles from enteric-coated dosage forms and in vivo absorption in rats for high-solubility and high-permeability model drugs.

    PubMed

    Sakuma, Shinji; Ogura, Ryoko; Masaoka, Yoshie; Kataoka, Makoto; Tanno, Fumié K; Kokubo, Hiroyasu; Yamashita, Shinji

    2009-11-01

    We examined the in vitro dissolution-in vivo absorption correlation (IVIVC) for enteric-coated granules containing theophylline, antipyrine or acetaminophen as model drugs with high solubility and high permeability. More than 85% of each drug was released from granules coated with hypromellose acetate succinate (HPMCAS) (AS-LG grade, which dissolves at pH above 5.5) at a mean dissolution rate of more than 5 %/min after a lag time of less than 4 min in simulated intestinal fluid of pH 6.8. The lag time and the dissolution rate were significantly extended and reduced, respectively, when AS-LG was replaced with AS-HG (a grade of HPMCAS that dissolves at pH above 6.8). Enteric-coated granules were administered intraduodenally to anesthetized rats. Statistical significances of differences of in vitro lag time between AS-LG- and AS-HG-coated granules were consistent with those in vivo, for all drugs. Significant differences in dissolution rates between granules also corresponded to those in absorption rates calculated using a deconvolution method, and both parameters had comparable absolute values, except in the case of antipyrine-containing granules with relatively fast dissolution rates. Thus, a good IVIVC was generally obtained; however, the exception suggests the importance of developing a dissolution test that fully reflects the in vivo situation. PMID:19283766

  1. Test methods and design allowables for fibrous composites. Volume 2

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C. (editor)

    1989-01-01

    Topics discussed include extreme/hostile environment testing, establishing design allowables, and property/behavior specific testing. Papers are presented on environmental effects on the high strain rate properties of graphite/epoxy composite, the low-temperature performance of short-fiber reinforced thermoplastics, the abrasive wear behavior of unidirectional and woven graphite fiber/PEEK, test methods for determining design allowables for fiber reinforced composites, and statistical methods for calculating material allowables for MIL-HDBK-17. Attention is also given to a test method to measure the response of composite materials under reversed cyclic loads, a through-the-thickness strength specimen for composites, the use of torsion tubes to measure in-plane shear properties of filament-wound composites, the influlence of test fixture design on the Iosipescu shear test for fiber composite materials, and a method for monitoring in-plane shear modulus in fatigue testing of composites.

  2. Recommendations for Developing Alternative Test Methods for Developmental Neurotoxicity

    EPA Science Inventory

    There is great interest in developing alternative methods for developmental neurotoxicity testing (DNT) that are cost-efficient, use fewer animals and are based on current scientific knowledge of the developing nervous system. Alternative methods will require demonstration of the...

  3. COMPILATION AND EVALUATION OF LEACHING TEST METHODS

    EPA Science Inventory

    Under the Resource Recovery and Conservation Act of 1976, EPA is required to promulgate criteria for identification of hazardous wastes. One method of identification is to characterize the leachability of the waste. This study evaluates those factors important to the design of su...

  4. Harmonization of standard toxicity test methods used in North America

    SciTech Connect

    Ingersoll, C.G.; Dwyer, F.J. [NBS, Columbia, MO (United States); Ankley, G.T. [Environmental Protection Agency, Duluth, MN (United States)] [and others

    1995-12-31

    Over the past two years, Environment Canada (EC) and the US Environmental Protection Agency (EPA) have developed standard methods for conducting toxicity and bioaccumulation tests with freshwater, estuarine, and marine sediments. Existing ASTM methods were used as a basis to harmonize these methods for conducting testing with either field-collected or laboratory-spiked sediments. For freshwater toxicity tests, methods are described by EC and EPA for the amphipod Hyalella azteca and the midges Chironomus tentans and C. riparius. Endpoints include 10- to 14-d survival of growth. Methods are also described by EPA for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus. For estuarine and marine toxicity tests, methods are described for several amphipods (i.e., Rhepoxynius abronius, Ampelisca abdita, Eohaustorius estuarius, Leptocheirus plumulosus). Endpoints include 10-d survival and reburial. EC is also developing methods for conducting toxicity tests with Atlantic, Pacific, and Arctic Canadian species of polychaetes. Methods are described by EPA for conducting 28-d bioaccumulation tests with a variety of mollusks (i.e., Macoma spp.) and polychaetes (i.e., Nereis spp.). Slight inconsistencies in methods between freshwater and estuarine/marine testing or between EC and EPA testing include: (1) static vs. flow-through conditions, (2) sieving of sediment, (3) types and quantity of food, (4) age of test organisms, or (4) duration of the test and required endpoints. Additional research is in progress to: (1) develop chronic toxicity tests with amphipods and midges measuring survival, growth, or reproduction, (2) develop whole-sediment toxicity identification evaluation (TIE) procedures, (3) refine sediment spiking procedures, and (4) field-validate laboratory tests.

  5. Method and apparatus for container leakage testing

    DOEpatents

    Kronberg, James W. (Aiken, SC)

    1995-01-01

    An apparatus for use in one-hundred percent leak testing of food containers used in conjunction with a tracer gas. The apparatus includes a shell with entrance and exit air locks to create a controlled atmosphere through which a series of containers is conveyed by a conveyor belt. The pressure in the shell is kept lower than the pressure in the containers and the atmosphere is made to flow with the containers so that a tracer gas placed in the packages before sealing them will leak more readily, but the leaked tracer gas will remain associated with the leaking package as it moves through the shell. The leaks are detected with a sniffer probe in fluid communication with a gas chromatograph. The gas chromatograph issues a signal when it detects a leak to an ejector that will eject the leaking container from the conveyor. The system is timed so that the series of containers can move continuously into and out of the shell, past the probe and the ejector, without stopping, yet each package is tested for leaks and removed if leaking.

  6. Method and apparatus for container leakage testing

    SciTech Connect

    Kronberg, J.W.

    1993-10-18

    This invention is an apparatus for use in 100% leak testing of food containers used in conjunction with a tracer gas. It includes a shell with entrance and exit air locks to create a controlled atmosphere through which a series of containers is conveyed by a conveyor belt. Pressure in the shell is kept lower than that in the containers and the atmosphere is made to flow with the containers so that a tracer gas placed in the packages before sealing them will leak more readily, but the leaked tracer gas will remain associated with the leaking package as it moves through the shell. The leaks are detected with a sniffer probe in fluid communication with a gas chromatograph (GC). The GC issues a signal when it detects a leak to an ejector that eject the leaking container from the conveyor. The system is timed so that the series of containers can move continuously into and out of the shell, past the probe and the ejector, without stopping, yet each package is tested for leaks and removed if leaking.

  7. 40 CFR 62.15245 - What test methods must I use to stack test?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false What test methods must I use to stack test? 62.15245 Section...PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal...Small Municipal Waste Combustion Units Constructed on...62.15245 What test methods must I...

  8. 40 CFR 62.15245 - What test methods must I use to stack test?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false What test methods must I use to stack test? 62.15245 Section...PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal...Small Municipal Waste Combustion Units Constructed on...62.15245 What test methods must I...

  9. 40 CFR 62.15245 - What test methods must I use to stack test?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false What test methods must I use to stack test? 62.15245 Section...PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal...Small Municipal Waste Combustion Units Constructed on...62.15245 What test methods must I...

  10. 40 CFR 62.15245 - What test methods must I use to stack test?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false What test methods must I use to stack test? 62.15245 Section...PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal...Small Municipal Waste Combustion Units Constructed on...62.15245 What test methods must I...

  11. 40 CFR 62.15245 - What test methods must I use to stack test?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false What test methods must I use to stack test? 62.15245 Section...PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal...Small Municipal Waste Combustion Units Constructed on...62.15245 What test methods must I...

  12. The Improvement of the Dissolution Rate of Ziprasidone Free Base from Solid Oral Formulations.

    PubMed

    Zakowiecki, Daniel; Cal, Krzysztof; Kaminski, Kamil; Adrjanowicz, Karolina; Swinder, Lech; Kaminska, Ewa; Garbacz, Grzegorz

    2015-08-01

    This work aims at increasing solubility and dissolution rate of ziprasidone free base-Biopharmaceutics Classifaction System (BCS) class II compound. The authors describe a practical approach to amorphization and highlight problems that may occur during the development of formulations containing amorphous ziprasidone, which was obtained by grinding in high-energy planetary ball mills or cryogenic mills. The release of ziprasidone free base from the developed formulations was compared to the reference drug product containing crystalline ziprasidone hydrochloride-Zeldox® hard gelatin capsules. All preparations were investigated using compendial tests (USP apparatuses II and IV) as well as novel, biorelevant dissolution tests. The novel test methods simulate additional elements of mechanical and hydrodynamic stresses, which have an impact on solid oral dosage forms, especially during gastric emptying. This step may prove to be particularly important for many formulations of BCS class II drugs that are often characterized by narrow absorption window, such as ziprasidone. The dissolution rate of the developed ziprasidone free base preparations was found to be comparable or even higher than in the case of the reference formulation containing ziprasidone hydrochloride, whose water solubility is about 400 times higher than its free base. PMID:25588366

  13. Template occluded SBA-15: An effective dissolution enhancer for poorly water-soluble drug

    NASA Astrophysics Data System (ADS)

    Tingming, Fu; Liwei, Guo; Kang, Le; Tianyao, Wang; Jin, Lu

    2010-09-01

    The aim of the present work was to improve the dissolution rate of piroxicam by inclusion into template occluded SBA-15. Our strategy involves directly introducing piroxicam into as-prepared SBA-15 occluded with P123 (EO 20PO 70EO 20) by self assembling method in acetonitrile/methylene chloride mixture solution. Ultraviolet spectrometry experiment and thermogravimetric analysis-differential scanning calorimetry (TG-DSC) profiles show that the piroxicam and P123 contents in the inclusion compound are 12 wt% and 28 wt%, respectively. X-ray powder diffraction and DSC analysis reveal that the included piroxicam is arranged in amorphous form. N 2 adsorption-desorption experiment indicates that the piroxicam has been introduced to the mesopores instead of precipitating at the outside of the silica material. The inclusion compound was submitted to in vitro dissolution tests, the results show that the piroxicam dissolve from template occluded inclusion compound more rapidly, than these from the piroxicam crystalline and template removed samples in all tested conditions. Thus a facile method to improve the dissolution rate of poorly water-soluble drug was established, and this discovery opens a new avenue for the utilization of templates used for the synthesis of mesoporous materials.

  14. Investigating Item Exposure Control Methods in Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Ozturk, Nagihan Boztunc; Dogan, Nuri

    2015-01-01

    This study aims to investigate the effects of item exposure control methods on measurement precision and on test security under various item selection methods and item pool characteristics. In this study, the Randomesque (with item group sizes of 5 and 10), Sympson-Hetter, and Fade-Away methods were used as item exposure control methods. Moreover,…

  15. State-recycling method for testing contextuality

    E-print Network

    Marek Wajs; Su-Yong Lee; Pawel Kurzynski; Dagomir Kaszlikowski

    2015-05-08

    Quantum nonlocality and contextuality are two phenomena stemming from nonclassical correlations. Whereas the former requires entanglement that is consumed in the measurement process the latter can occur for any state if one chooses a proper set of measurements. Despite this stark differences experimental tests of both phenomena were similar so far. For each run of the experiment one had to use a different copy of a physical system prepared according to the same procedure, or the system had to be brought to its initial state. Here we show that this is not necessary and that the state-independent contextuality can be manifested in a scenario in which each measurement round is done on an output state from the previous round.

  16. Non-destructive testing method and apparatus

    DOEpatents

    Akers, Douglas W. (Idaho Falls, ID)

    2011-10-04

    Non-destructive testing apparatus may comprise a photon source and a source material that emits positrons in response to bombardment of the source material with photons. The source material is positionable adjacent the photon source and a specimen so that when the source material is positioned adjacent the photon source it is exposed to photons produced thereby. When the source material is positioned adjacent the specimen, the specimen is exposed to at least some of the positrons emitted by the source material. A detector system positioned adjacent the specimen detects annihilation gamma rays emitted by the specimen. Another embodiment comprises a neutron source and a source material that emits positrons in response to neutron bombardment.

  17. Eddy Current Method for Fatigue Testing

    NASA Technical Reports Server (NTRS)

    Simpson, John W. (Inventor); Fulton, James P. (Inventor); Wincheski, Russell A. (Inventor); Todhunter, Ronald G. (Inventor); Namkung, Min (Inventor); Nath, Shridhar C. (Inventor)

    1997-01-01

    Flux-focusing electromagnetic sensor using a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks and material loss in high conductivity material. A ferrous shield isolates a high-turn pick-up coil from an excitation coil. Use of the magnetic shield produces a null voltage output across the receiving coil in presence of an unflawed sample. Redistribution of the current flow in the sample caused by the presence of flaws. eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. Maximum sensor output is obtained when positioned symmetrically above the crack. By obtaining position of maximum sensor output, it is possible to track the fault and locate the area surrounding its tip. Accuracy of tip location is enhanced by two unique features of the sensor; a very high signal-to-noise ratio of the probe's output resulting in an extremely smooth signal peak across the fault, and a rapidly decaying sensor output outside a small area surrounding the crack tip enabling the search region to be clearly defined. Under low frequency operation, material thinning due to corrosion causes incomplete shielding of the pick-up coil. Low frequency output voltage of the probe is therefore a direct indicator of thickness of the test sample. Fatigue testing a conductive material is accomplished by applying load to the material, applying current to the sensor, scanning the material with the sensor, monitoring the sensor output signal, adjusting material load based on the sensor output signal of the sensor, and adjusting position of the sensor based on its output signal.

  18. An efficient BIST method for testing of embedded SRAMs

    Microsoft Academic Search

    Mohammad H. Tehranipour; Zainalabedin Navabi; Seid Mehdi Fakhraie

    2001-01-01

    We have developed an algorithm by which to enable conventional microprocessors to test their on-chip SRAM using their existing hardware and software resources. This test method utilizes a mixture of existing memory testing techniques, which cover all important memory faults. This i; achieved by writing a routine called BIST Program by which only uses the existing ROM and creates no

  19. Bayesian Methods for Accelerated Destructive Degradation Test Planning

    E-print Network

    Bayesian Methods for Accelerated Destructive Degradation Test Planning Ying Shi Dept. of Statistics University Ames, IA 50011 wqmeeker@iastate.edu Abstract Accelerated Destructive Degradation Tests (ADDTs destructive degradation tests (ADDTs) are sometimes used in manufac- turing industries to obtain reliability

  20. Improved method for minimum inhibitory concentration testing of flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple and reliable microdilution method has been developed to test the susceptibility of Flavobacterium columnare to antibiotics in vitro. The method has been used to determine the minimum inhibitory concentration (MIC) of 23 F. columnare isolates. The tests were conducted at 28 °C using a stan...

  1. Identifying test methods for breeder reactor core materials

    SciTech Connect

    Not Available

    1981-01-01

    The practice covers the test methods that may be used for measuring physical and mechanical properties for solid metallic materials for use in the design and evaluation of fast breeder reactor core materials. The test methods referenced are applicable to the in-core portion of ducts, cladding (both end caps and tubing), wire wrap, spacer grids, wear pads, and welded structures. (JMT)

  2. PREDICTIVE TEST METHODS: PERMEATION OF POLYMERIC MEMBRANES BY ORGANIC SOLVENTS

    EPA Science Inventory

    As the result of screening elastomeric materials that may be suitable for formulating chemical-protective clothing, a simple test method has been developed that allows the prediction of the permeation of an organic solvent through a polymeric membrane. The test method, based on l...

  3. Statistical Tests for Evaluating Earthquake Prediction Methods Kurt S. Riedel

    E-print Network

    Statistical Tests for Evaluating Earthquake Prediction Methods Kurt S. Riedel Courant Institute methodology fails to forecast the earthquakes. We formulate a statistical test for this possibil­ ity cited as VAN]. The central argument is whether the VEVL method predicts better than random chance

  4. Improved method of HIPOT testing of advanced ignition system product

    SciTech Connect

    Baker, P.C.

    1992-04-01

    A new method of high potential (HIPOT) testing of advanced ignition system (AIS) product was developed. The new incorporated using a silver-filled RTV silicone as the electrodes of the HIPOT tester instead of the preformed, semi-rigid aluminum electrodes of the current tester. Initial results indicate that the developed method was more sensitive to the testing requirements of the HIPOT test. A patent for the combination of the material used and the method of testing developed was attempted but was withdrawn following a patent search by the US Patent Office.

  5. Nondestructive testing methods for 55-gallon, waste storage drums

    SciTech Connect

    Ferris, R.H.; Hildebrand, B.P.; Hockey, R.L.; Riechers, D.M.; Spanner, J.C. [Pacific Northwest Lab., Richland, WA (United States); Duncan, D.R. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-06-01

    The Westinghouse Hanford Company (WHC) authorized Pacific Northwest Laboratory (PNL) to conduct a feasibility study to identify promising nondestructive testing (NDT) methods for detecting general and localized (both pitting and pinhole) corrosion in the 55-gal drums that are used to store solid waste materials at the Hanford Site. This document presents results obtained during a literature survey, identifies the relevant reference materials that were reviewed, provides a technical description of the methods that were evaluated, describes the laboratory tests that were conducted and their results, identifies the most promising candidate methods along with the rationale for these selections, and includes a work plan for recommended follow-on activities. This report contains a brief overview and technical description for each of the following NDT methods: magnetic testing techniques; eddy current testing; shearography; ultrasonic testing; radiographic computed tomography; thermography; and leak testing with acoustic detection.

  6. Environment-sensitive fracture: Evaluation and comparison of test methods

    SciTech Connect

    Dean, S.W.; Pugh, E.N.; Ugiansky, G.M

    1984-01-01

    These proceedings collect papers on metal fracture mechanics. Titles include: A Fracture Mechanics Model for Iodine Stress Corrosion Crack Propagation in Zircaloy Tubing; Evaluation of SCC Test Methods for Inconel 600 in Low-temperature Aqueous Solutions; Automated Corrosion Fatigue Crack Growth Testing in Pressurized Water Environments; and use of a constant /Delta//kappa/ test method in the investigation of fatigue crack growth in 288/sup 0/C water environments.

  7. Boehmite Dissolution Studies Supporting High Level Waste Pretreatment - 9383

    SciTech Connect

    Peterson, Reid A.; Russell, Renee L.; Snow, Lanee A.

    2009-03-01

    Boehmite is present in significant quantities in several of the Hanford waste tanks. It has been proposed that the boehmite will be dissolved through caustic leaching in the Hanford Waste Treatment Plant currently under construction. Therefore, it is important to fully understand the nature of this dissolution so that the process can be deployed. This research determined the impact of primary control parameters on the boehmite dissolution rate. The impact of aluminate ion on the dissolution kinetics was determined. In addition, other parameters that impact boehmite dissolution, such as free hydroxide concentration and reaction temperature, were also assessed and used to develop a semi-empirical model of the boehmite dissolution process. The understanding derived from this work will be used as the basis to evaluate and improve the planned performance of the Hanford Waste Treatment plant. This work is the first in a series of programs aimed at demonstrating the Waste Treatment Plant dissolution process. This work will be used to develop a simulant of the boehmite-containing Hanford waste. That simulant will then be used in laboratory- and pilot-scale testing to demonstrate the Waste Treatment Plant pretreatment process in an integrated fashion.

  8. Fracture mechanics life analytical methods verification testing

    NASA Technical Reports Server (NTRS)

    Favenesi, J. A.; Clemmons, T. G.; Lambert, T. J.

    1994-01-01

    Verification and validation of the basic information capabilities in NASCRAC has been completed. The basic information includes computation of K versus a, J versus a, and crack opening area versus a. These quantities represent building blocks which NASCRAC uses in its other computations such as fatigue crack life and tearing instability. Several methods were used to verify and validate the basic information capabilities. The simple configurations such as the compact tension specimen and a crack in a finite plate were verified and validated versus handbook solutions for simple loads. For general loads using weight functions, offline integration using standard FORTRAN routines was performed. For more complicated configurations such as corner cracks and semielliptical cracks, NASCRAC solutions were verified and validated versus published results and finite element analyses. A few minor problems were identified in the basic information capabilities of the simple configurations. In the more complicated configurations, significant differences between NASCRAC and reference solutions were observed because NASCRAC calculates its solutions as averaged values across the entire crack front whereas the reference solutions were computed for a single point.

  9. Methods for testing the strength of cancellous bone and tested method effects on cortical bone in the ovariectomized rat 

    E-print Network

    Ruhmann, Sean Phillip

    1998-01-01

    In this study, two mechanical testing procedures were developed to test the strength of cancellous bone from the proximal tibia of the rat, the "punch method" and the "whole slice method". These were used to quantify the effect of ovariectomy on rat...

  10. Methods for testing the strength of cancellous bone and tested method effects on cortical bone in the ovariectomized rat

    E-print Network

    Ruhmann, Sean Phillip

    1998-01-01

    In this study, two mechanical testing procedures were developed to test the strength of cancellous bone from the proximal tibia of the rat, the "punch method" and the "whole slice method". These were used to quantify the effect of ovariectomy on rat...

  11. Testing prediction methods: Earthquake clustering versus the Poisson model

    USGS Publications Warehouse

    Michael, A.J.

    1997-01-01

    Testing earthquake prediction methods requires statistical techniques that compare observed success to random chance. One technique is to produce simulated earthquake catalogs and measure the relative success of predicting real and simulated earthquakes. The accuracy of these tests depends on the validity of the statistical model used to simulate the earthquakes. This study tests the effect of clustering in the statistical earthquake model on the results. Three simulation models were used to produce significance levels for a VLF earthquake prediction method. As the degree of simulated clustering increases, the statistical significance drops. Hence, the use of a seismicity model with insufficient clustering can lead to overly optimistic results. A successful method must pass the statistical tests with a model that fully replicates the observed clustering. However, a method can be rejected based on tests with a model that contains insufficient clustering. U.S. copyright. Published in 1997 by the American Geophysical Union.

  12. Flight-Test Evaluation of Flutter-Prediction Methods

    NASA Technical Reports Server (NTRS)

    Lind, RIck; Brenner, Marty

    2003-01-01

    The flight-test community routinely spends considerable time and money to determine a range of flight conditions, called a flight envelope, within which an aircraft is safe to fly. The cost of determining a flight envelope could be greatly reduced if there were a method of safely and accurately predicting the speed associated with the onset of an instability called flutter. Several methods have been developed with the goal of predicting flutter speeds to improve the efficiency of flight testing. These methods include (1) data-based methods, in which one relies entirely on information obtained from the flight tests and (2) model-based approaches, in which one relies on a combination of flight data and theoretical models. The data-driven methods include one based on extrapolation of damping trends, one that involves an envelope function, one that involves the Zimmerman-Weissenburger flutter margin, and one that involves a discrete-time auto-regressive model. An example of a model-based approach is that of the flutterometer. These methods have all been shown to be theoretically valid and have been demonstrated on simple test cases; however, until now, they have not been thoroughly evaluated in flight tests. An experimental apparatus called the Aerostructures Test Wing (ATW) was developed to test these prediction methods.

  13. Ergodicity test of the eddy correlation method

    NASA Astrophysics Data System (ADS)

    Chen, J.; Hu, Y.; Yu, Y.; Lü, S.

    2014-07-01

    The turbulent flux observation in the near-surface layer is a scientific issue which researchers in the fields of atmospheric science, ecology, geography science, etc. are commonly interested in. For eddy correlation measurement in the atmospheric surface layer, the ergodicity of turbulence is a basic assumption of the Monin-Obukhov (M-O) similarity theory, which is confined to steady turbulent flow and homogenous surface; this conflicts with turbulent flow under the conditions of complex terrain and unsteady, long observational period, which the study of modern turbulent flux tends to focus on. In this paper, two sets of data from the Nagqu Station of Plateau Climate and Environment (NaPlaCE) and the cooperative atmosphere-surface exchange study 1999 (CASE99) were used to analyze and verify the ergodicity of turbulence measured by the eddy covariance system. Through verification by observational data, the vortex of atmospheric turbulence, which is smaller than the scale of the atmospheric boundary layer (i.e., its spatial scale is less than 1000 m and temporal scale is shorter than 10 min) can effectively meet the conditions of the average ergodic theorem, and belong to a wide sense stationary random processes. Meanwhile, the vortex, of which the spatial scale is larger than the scale of the boundary layer, cannot meet the conditions of the average ergodic theorem, and thus it involves non-ergodic stationary random processes. Therefore, if the finite time average is used to substitute for the ensemble average to calculate the average random variable of the atmospheric turbulence, then the stationary random process of the vortex, of which spatial scale was less than 1000 m and thus below the scale of the boundary layer, was possibly captured. However, the non-ergodic random process of the vortex, of which the spatial scale was larger than that of the boundary layer, could not be completely captured. Consequently, when the finite time average was used to substitute for the ensemble average, a large rate of error would occur with use of the eddy correction method due to losing the low frequency component information of the larger vortex. When the multi-station observation was compared with the single-station observation, the wide sense of stationary random process originating from the multi-station observation expanded from a vortex which was about 1000 m smaller than a boundary layer scale to the turbulent vortex, which was larger than the boundary layer scale of 2000 m. Therefore, the calculation of the turbulence average or variance and turbulent flux could effectively meet the ergodic assumption, and the results would be approximate to the actual values. Regardless of vertical velocity and temperature, if the ergodic stationary random processes could be met, then the variance of the vortexes in the different temporal scales could follow M-O similarity theory; in the case of the non-ergodic random process, its vortex variance deviated from the M-O similarity relations. The exploration of ergodicity in the atmospheric turbulence measurements is doubtlessly helpful to understanding the issues in atmospheric turbulent flux observation, and provides a theoretical basis for overcoming related difficulties.

  14. Rate-Limiting Steps of Oral Absorption for Poorly Water-Soluble Drugs in Dogs; Prediction from a Miniscale Dissolution Test and a Physiologically-Based Computer Simulation

    Microsoft Academic Search

    Ryusuke Takano; Kentaro Furumoto; Koji Shiraki; Noriyuki Takata; Yoshiki Hayashi; Yoshinori Aso; Shinji Yamashita

    2008-01-01

    Purpose  Nonlinear oral absorption due to poor solubility often impedes drug development. The purpose of this study was to elucidate\\u000a the rate-limiting process in oral absorption of Biopharmaceutical Classification System (BCS) class II (low solubility–high\\u000a permeability) drugs in order to predict nonlinear absorption of dose caused by solubility-limited absorption.\\u000a \\u000a \\u000a \\u000a Methods  Oral absorption of danazol, griseofulvin, and aprepitant was predicted from a miniscale

  15. Test report for cesium powder and pellets inner container decontamination method determination test

    SciTech Connect

    Kelly, D.L.

    1998-08-17

    This report documents the decontamination method determination testing that was performed on three cesium powder and pellets inner container test specimens The test specimens were provided by B and W Hanford Company (BVMC). The tests were conducted by the Numatec Hanford Company (NHC), in the 305 Building. Photographic evidence was also provided by NHC. The Test Plan and Test Report were provided by Waste Management Federal Services, Inc., Northwest Operations. Witnesses to testing included a test engineer, a BC project engineer, and a BC Quality Assurance (QA) representative. The Test Plan was modified with the mutual decision of the test engineer, the BWHC project engineer, and the BVMC QA representative. The results of this decision were written in red (permanent type) ink on the official copy of the test procedure, Due to the extent of the changes, a summary of the test results are provided in Section 3.0 of this Test Report. In addition, a copy of the official copy field documentation obtained during testing is included in Appendix A. The original Test Plan (HNF-2945) will be revised to indicate that extensive changes were required in the field during testing, however, the test documentation will stand as is (i.e., it will not be retyped, text shaded, etc.) due to the inclusion of the test parameters and results into this Test Report.

  16. [Preparation of two poor water soluble drugs - nanoporous ZnO solid dispersions and the mechanism of drug dissolution improvement].

    PubMed

    Gao, Bei; Sun, Chang-shan; Zhi, Zhuang-zhi; Wang, Yan; Chang, Di; Wang, Si-ling; Jiang, Tong-ying

    2011-11-01

    Nanoporous ZnO was used as a carrier to prepare drug solid dispersion, the mechanism of which to improve the drug dissolution was also studied. Nanoporous ZnO, obtained through chemical deposition method, was used as a carrier to prepare indomethacin and cilostazol solid dispersions by melt-quenching method, separately. The results of scanning electron microscope, surface area analyzer, fourier transform infra-red spectroscopy, differential scanning calorimeter and X-ray diffraction showed that drugs were implanted into nanopores of ZnO by physical adsorption effect and highly dispersed into nanopores of ZnO in amorphous form, moreover, these nanopores strongly inhibited amorphous recrystallization in the condition of 45 degrees C and 75% RH. In addition, the results of the dissolution tested in vitro exhibited that the accumulated dissolutions of indomethacin and cilostazol solid dispersions achieved about 90% within 5 min and approximately 80% within 30 min. It was indicated in this study that the mechanism of drug dissolution improvement was associated with the effects of nanoporous ZnO carrier on increasing drug dispersion, controlling drug in nanopores as amorphous form and inhibiting amorphous recrystallization. PMID:22260037

  17. Synergistic Effect of Hydrotrope and Surfactant on Solubility and Dissolution of Atorvastatin Calcium: Screening Factorial Design Followed by Ratio Optimization

    PubMed Central

    Patel, V. F.; Sarai, J.

    2014-01-01

    The present study was aimed at investigating the effect of hydrotrope and surfactant on poor solubility of atorvastatin calcium. Excipients screening followed by factorial design was performed to study effect of excipients and manufacturing methods on solubility of drug. Three independent factors (carrier, surfactant and manufacturing method) were evaluated at two levels using solubility as a dependant variable. Solid-state characterisation was performed using Fourier transform infrared spectroscopy and differential scanning calorimetry. Optimised complex were incorporated into orally disintegrating micro tablets and in vitro dissolution test was performed. Nicotinamide, Plasdone and sodium dodecyl sulphate were emerged as promising excipients from excipient screening. General regression analysis revealed only the type of carrier has significantly enhanced (P<0.05) the solubility of drug while other factors were found to be nonsignificant. Ratio optimisation trial revealed that drug to nicotinamide ratio is more critical in enhancing the solubility of drug (40 fold increases in solubility compared to pure drug) in comparison to drug-surfactant ratio; however the presence of surfactant deemed essential. Significantly higher rate and extent of dissolution was observed from solid dispersion complex and tablets compared to dissolution of pure drug (P<0.05). Study revealed hydrotrope and surfactant have synergistic effect on solubility and dissolution of atorvastatin calcium and this can be explored further. PMID:25593381

  18. High Level Waste System Impacts from Acid Dissolution of Sludge

    SciTech Connect

    KETUSKY, EDWARD

    2006-04-20

    This research evaluates the ability of OLI{copyright} equilibrium based software to forecast Savannah River Site High Level Waste system impacts from oxalic acid dissolution of Tank 1-15 sludge heels. Without further laboratory and field testing, only the use of oxalic acid can be considered plausible to support sludge heel dissolution on multiple tanks. Using OLI{copyright} and available test results, a dissolution model is constructed and validated. Material and energy balances, coupled with the model, identify potential safety concerns. Overpressurization and overheating are shown to be unlikely. Corrosion induced hydrogen could, however, overwhelm the tank ventilation. While pH adjustment can restore the minimal hydrogen generation, resultant precipitates will notably increase the sludge volume. OLI{copyright} is used to develop a flowsheet such that additional sludge vitrification canisters and other negative system impacts are minimized. Sensitivity analyses are used to assess the processability impacts from variations in the sludge/quantities of acids.

  19. ON SCIENTIFIC METHOD AS A METHOD FOR TESTING THE LEGITIMACY OF CONCEPTS

    E-print Network

    Stone, Abraham

    13 ON SCIENTIFIC METHOD AS A METHOD FOR TESTING THE LEGITIMACY OF CONCEPTS ABRAHAM D. STONE research (Carnap). I argue that scientific method aims precisely at empirical testing of concepts, and that even the simplest scientific ex- periment or observation results in conceptual change. There are two

  20. A study of short test and charge retention test methods for nickel-cadmium spacecraft cells

    NASA Technical Reports Server (NTRS)

    Scott, W. R.

    1975-01-01

    Methods for testing nickel-cadmium cells for internal shorts and charge retention were studied. Included were (a) open circuit voltage decay after a brief charge, (b) open circuit voltage recovery after shorting, and (c) open circuit voltage decay and capacity loss after a full charge. The investigation included consideration of the effects of prior history, of conditioning cells prior to testing, and of various test method variables on the results of the tests. Sensitivity of the tests was calibrated in terms of equivalent external resistance. The results were correlated. It was shown that a large number of variables may affect the results of these tests. It is concluded that the voltage decay after a brief charge and the voltage recovery methods are more sensitive than the charged stand method, and can detect an internal short equivalent to a resistance of about (10,000/C)ohms where "C' is the numerical value of the capacity of the cell in ampere hours.

  1. The role of soil pH in the dissolution of phosphate rock fertilizers

    Microsoft Academic Search

    I. A. K. Kanabo; R. J. Gilkes

    1987-01-01

    The influence of soil pH on the dissolution of phosphate rock fertilizers was investigated in laboratory experiments with reactive North Carolina phosphate rock (PR) in a lateritic soil adjusted to several pH values. Increased soil pH resulted in decreased dissolution as estimated by the increase in exchangeable calcium (?Ca) method. The extent of PR dissolution was related to soil pH

  2. Standardization of fretting fatigue test methods and equipment

    SciTech Connect

    Attia, M.H.; Waterhouse, R.B.

    1992-01-01

    Papers contained in this book are grouped under the topics of the fundamental aspects of fretting fatigue testing (conceptual framework and mechanics of contact), methods and equipment for fretting fatigue testing, environmental and surface conditions, and nonconventional materials and test methods. Papers are presented on the problems of fretting fatigue testing, a critical appraisal of testing methods in fretting fatigue, the determination and control of contact pressure distribution in fretting fatigue, and fretting fatigue analysis of strength improvement models with grooving or knurling on a contact surface. Other papers include a critical review of fretting fatigue investigations at the Royal Aerospace Establishment, techniques for the characterization of fretting fatigue damage, improving fretting fatigue strength at elevated temperatures by shot peening in steam turbine steel, the fretting fatigue properties of a blade steel in air and vapor environments, and fretting fatigue of carbon-fiber-reinforced epoxy laminates.

  3. From the Kirsch-Kress potential method via the range test to the singular sources method

    NASA Astrophysics Data System (ADS)

    Potthast, R.; Schulz, J.

    2005-01-01

    We review three reconstruction methods for inverse obstacle scattering problems. We will analyse the relation between the Kirsch-Kress potential method 1986, the range test of Kusiak, Potthast and Sylvester (2003) and the singular sources method of Potthast (2000). In particular, we show that the range test is a logical extension of the Kirsch-Kress method into the category of sampling methods employing the tool of domain sampling. Then we will show how a multi-wave version of the range test can be set up and we will work out its relation to the singular sources method. Numerical examples and demonstrations will be provided.

  4. 40 CFR 62.14354 - Procedures, test methods, and monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    Federal Plan Requirements for Municipal Solid Waste Landfills That Commenced Construction Prior to May 30, 1991 and Have Not Been Modified or Reconstructed Since May 30, 1991 § 62.14354 Procedures, test methods, and...

  5. 40 CFR 60.176 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.176 Test methods and procedures. ...operator shall determine compliance with the particulate matter, sulfur dioxide (SO2 ), and visible emission standards in §§...

  6. 40 CFR 60.435 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Graphic Arts Industry: Publication Rotogravure Printing § 60.435 Test methods and procedures. (a) The owner or operator of any affected facility using...

  7. 16 CFR 1509.6 - Component-spacing test method.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR NON-FULL-SIZE BABY CRIBS § 1509.6 Component-spacing test method. The apex of the wedge (see § 1509.5(a)) shall be placed...

  8. 16 CFR 1509.6 - Component-spacing test method.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR NON-FULL-SIZE BABY CRIBS § 1509.6 Component-spacing test method. The apex of the wedge (see § 1509.5(a)) shall be placed...

  9. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Standard for Inorganic Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures...effective date of this subpart in the case of an existing copper converter or a copper converter that has an initial startup date...

  10. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Standard for Inorganic Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures...effective date of this subpart in the case of an existing copper converter or a copper converter that has an initial startup date...

  11. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Standard for Inorganic Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures...effective date of this subpart in the case of an existing copper converter or a copper converter that has an initial startup date...

  12. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Standard for Inorganic Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures...effective date of this subpart in the case of an existing copper converter or a copper converter that has an initial startup date...

  13. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Standard for Inorganic Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures...effective date of this subpart in the case of an existing copper converter or a copper converter that has an initial startup date...

  14. Comparison of bulk sediment and sediment elutriate toxicity testing methods

    EPA Science Inventory

    Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

  15. 40 CFR 60.224 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry: Diammonium Phosphate Plants § 60.224 Test methods and procedures. (a) In conducting the...

  16. 40 CFR 76.15 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Section 76.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.15 Test methods and procedures. (a) The owner or...

  17. 40 CFR 76.15 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Section 76.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.15 Test methods and procedures. (a) The owner or...

  18. 40 CFR 76.15 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Section 76.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.15 Test methods and procedures. (a) The owner or...

  19. 40 CFR 76.15 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Section 76.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.15 Test methods and procedures. (a) The owner or...

  20. 40 CFR 76.15 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Section 76.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.15 Test methods and procedures. (a) The owner or...

  1. 40 CFR 60.614 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...SOURCES Standards of Performance for Volatile Organic Compound (VOC) Emissions From the Synthetic Organic Chemical Manufacturing Industry (SOCMI) Air Oxidation Unit Processes § 60.614 Test methods and procedures. (a) For the...

  2. 40 CFR 60.664 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...SOURCES Standards of Performance for Volatile Organic Compound (VOC) Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Distillation Operations § 60.664 Test methods and procedures. (a) For the...

  3. Moisture distribution in sludges based on different testing methods.

    PubMed

    Deng, Wenyi; Li, Xiaodong; Yan, Jianhua; Wang, Fei; Chi, Yong; Cen, Kefa

    2011-01-01

    Moisture distributions in municipal sewage sludge, printing and dyeing sludge and paper mill sludge were experimentally studied based on four different methods, i.e., drying test, thermogravimetric-differential thermal analysis (TG-DTA) test, thermogravimetric-differential scanning calorimetry (TG-DSC) test and water activity test. The results indicated that the moistures in the mechanically dewatered sludges were interstitial water, surface water and bound water. The interstitial water accounted for more than 50% wet basis (wb) of the total moisture content. The bond strength of sludge moisture increased with decreasing moisture content, especially when the moisture content was lower than 50% wb. Furthermore, the comparison among the four different testing methods was presented. The drying test was advantaged by its ability to quantify free water, interstitial water, surface water and bound water; while TG-DSC test, TG-DTA test and water activity test were capable of determining the bond strength of moisture in sludge. It was found that the results from TG-DSC and TG-DTA test are more persuasive than water activity test. PMID:21790063

  4. Automated test methods for fracture and fatigue crack growth

    SciTech Connect

    Cullen, W.H.; Kaisand, L.R.; Underwood, J.H.; Landgraf, R.W.

    1985-01-01

    The topics of fatigue and fatigue crack growth testing systems and of fracture testing systems are presented, including papers on new developments in automated materials testing systems, development of an automated fatigue crack propagation test, crack shape monitoring using ac field measurements, a low-cost microprocessor-based data acquisition and control system for fatigue crack growth testing, and an automatic fatigue crack monitoring system and its application to corrosion fatigue. Consideration is given to potential-drop monitoring of cracks in surface-flawed specimens, a microprocessor-based system for determining near-threshold fatigue crack growth rates, Krak-gages for automated fatigue crack growth rate testing, automated test methods for fatigue crack growth and fracture toughness tests on irradiated stainless steels at high temperature. Additional papers include an automated method of computer-controlled low-cycle fatigue crack growth testing using the elastic-plastic parameter, automated technique for R-curve testing and analysis, a computer-interactive system for elastic-plastic fracture toughness testing, and computerized single-specimen J-R curve determination for compact tension and three-point bend specimens.

  5. Nondestructive spot test method for magnesium and magnesium alloys

    NASA Technical Reports Server (NTRS)

    Wilson, M. L. (inventor)

    1973-01-01

    A method for spot test identification of magnesium and various magnesium alloys commonly used in aerospace applications is described. The spot test identification involves color codes obtained when several drops of 3 M hydrochloric acid are placed on the surface to be tested. After approximately thirty seconds, two drops of this reacted acid is transferred to each of two depressions in a spot plate for additions of other chemicals with subsequent color changes indicating magnesium or its alloy.

  6. Impetus of composite mechanics on test methods for fiber composites

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1978-01-01

    The impetus of composite mechanics on composite test methods and/or on interpreting test results is described by using examples from composite micromechanics, composite macromechanics and laminate theory. The specific examples included contributions such as criteria for selecting resin matrices for improved composite strength, the 10 deg off-axis tensile test, criteria for configuring hybrids and superhybrids for improved impact resistance and the reduced bending rigidities concept for buckling and vibration analyses.

  7. Economic reliability test methods of new soldering materials

    Microsoft Academic Search

    Wojciech Niedzwiedz; Marcin Szwech; Jacek Chmielewski; Zdzislaw Drozd

    2010-01-01

    According to RoHS directive, many new electronic products are manufactured by using of new technology and lead-free soldering materials. For reduction of the risks concerning quality and reliability of such products are necessary accurate investigations. Reliability tests of electronic interconnections are time consuming and expensive. In Reliability Laboratory of Warsaw University of Technology (WUT) are studied different test methods and

  8. A Conditional Exposure Control Method for Multidimensional Adaptive Testing

    ERIC Educational Resources Information Center

    Finkelman, Matthew; Nering, Michael L.; Roussos, Louis A.

    2009-01-01

    In computerized adaptive testing (CAT), ensuring the security of test items is a crucial practical consideration. A common approach to reducing item theft is to define maximum item exposure rates, i.e., to limit the proportion of examinees to whom a given item can be administered. Numerous methods for controlling exposure rates have been proposed…

  9. Comparison of two methods of fatigue testing bone cement.

    PubMed

    Tanner, K E; Wang, Jian-Sheng; Kjellson, Fred; Lidgren, Lars

    2010-03-01

    Two different methods have been used to fatigue test four bone cements. Each method has been used previously, but the results have not been compared. The ISO 527-based method tests a minimum of 10 samples over a single stress range in tension only and uses Weibull analysis to calculate the median number of cycles to failure and the Weibull modulus. The ASTM F2118 test regime uses fewer specimens at various stress levels tested in fully reversed tension-compression, and generates a stress vs. number of cycles to failure (S-N) or Wöhler curve. Data from specimens with pores greater than 1mm across is rejected. The ISO 527-based test while quicker to perform, provides only tensile fatigue data, but the material tested includes pores, thus the cement is closer to cement in clinical application. The ASTM regime uses tension and compression loading and multiple stress levels, thus is closer to physiological loading, but excludes specimens with defects obviously greater than 1mm, so is less representative of cement in vivo. The fatigue lives between the cements were up to a factor 15 different for the single stress level tension only tests, while they were only a factor of 2 different in the fully reversed tension-compression testing. The ISO 527-based results are more sensitive to surface flaws, thus the differences found using ASTM F2118 are more indicative of differences in the fatigue lives. However, ISO 527-based tests are quicker, so are useful for initial screening. PMID:19766742

  10. Sensitivity test method for the characterization of laser damage behavior

    NASA Astrophysics Data System (ADS)

    Arenberg, Jonathan W.; Thomas, Michael D.

    2014-12-01

    This paper introduces a sensitivity test for characterizing the laser damage behavior of a sample. A sensitivity test analyzes unbinned laser damage test data to estimate the damage probability curve. The means of estimation is by employing a parametric model of the probability of damage and identifying the parameters most likely to produce the observed results using the maximum-likelihood (ML) method. The ML method applied to laser damage measurements is reviewed. The sensitivity test is analyzed for its performance using Monte Carlo methods. A series of laser damage tests are simulated on a test of a hypothetical test optic. A Weibull distribution is selected for the damage probability model, while the virtual test optic was chosen to have a non-Weibull shaped damage probability curve. Damage measurements for varying the number of sites exposed are modeled to show the convergence of the Weibull parameters. This paper concludes by showing how the underlying defect distribution is calculated from results of the sensitivity test.

  11. Formulations for iron oxides dissolution

    DOEpatents

    Horwitz, Earl P. (Argonne, IL); Chiarizia, Renato (Argonne, IL)

    1992-01-01

    A mixture of a di- or polyphosphonic acid and a reductant wherein each is present in a sufficient amount to provide a synergistic effect with respect to the dissolution of metal oxides and optionally containing corrosion inhibitors and pH adjusting agents.

  12. An evaluation of the whole effluent toxicity test method

    SciTech Connect

    Osteen, D.V.

    1999-12-17

    Whole effluent toxicity (WET) testing has become increasingly more important to the Environmental Protection Agency (EPA) and the States in the permitting of wastewater discharges from industry and municipalities. The primary purpose of the WET test is to protect aquatic life by predicting the effect of an effluent on the receiving stream. However, there are both scientific and regulatory concerns that using WET tests to regulate industrial effluents may result in either false positives and/or false negatives. In order to realistically predict the effect of an effluent on the receiving stream, the test should be as representative as possible of the conditions in the receiving stream. Studies (Rand and Petrocelli 1985) suggested several criteria for an ideal aquatic toxicity test organism, one of which is that the organism be indigenous to, or representative of, the ecosystem receiving the effluent. The other component needed in the development of a predictive test is the use of the receiving stream water or similar synthetic water as the control and dilution water in the test method. Use of an indigenous species and receiving water in the test should help reduce the variability in the method and allow the test to predict the effect of the effluent on the receiving stream. The experience with toxicity testing at the Savannah River Site (SRS) has yielded inconclusive data because of the inconsistency and unreliability of the results. The SRS contention is that the WET method in its present form does not adequately mimic actual biological/chemical conditions of the receiving streams and is neither reasonable nor accurate. This paper discusses the rationale for such a position by SRS on toxicity testing in terms of historical permitting requirements, outfall effluent test results, standard test method evaluation, scientific review of alternate test species, and concerns over the test method expressed by other organizations. This paper presents the Savannah River Site position that the EPA test is neither reasonable nor accurate and thus cannot adequately establish the impact of NPDES outfall discharges on receiving streams.

  13. Comparison of the effect of chitosan and polyvinylpyrrolidone on dissolution properties and analgesic effect of naproxen

    Microsoft Academic Search

    Naima Zerrouk; Natascia Mennini; Francesca Maestrelli; Chantal Chemtob; Paola Mura

    2004-01-01

    The solubilizing and absorption enhancer properties towards naproxen of chitosan and polyvinylpyrrolidone (PVP) have been investigated. Solid binary systems prepared at various drug–polymer ratios by mixing, cogrinding or kneading, were characterized by differential scanning calorimetry, X-ray diffractometry, Fourier transform infrared spectroscopy, and scanning electron microscopy, and tested for dissolution behavior. Both carriers improved drug dissolution and their performance depended on

  14. Test Results for Entry Guidance Methods for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Hanson, John M.; Jones, Robert E.

    2003-01-01

    There are a number of approaches to advanced guidance and control (AG&C) that have the potential for achieving the goals of significantly increasing reusable launch vehicle (RLV) safety and reliability, and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies (ITAGCT) has recently completed a rigorous testing phase where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. Results show a significant improvement over previous guidance approaches. The two best-scoring algorithm approaches show roughly equivalent results and are ready to be applied to future reusable vehicle concepts.

  15. Test Results for Entry Guidance Methods for Space Vehicles

    NASA Technical Reports Server (NTRS)

    Hanson, John M.; Jones, Robert E.

    2004-01-01

    There are a number of approaches to advanced guidance and control that have the potential for achieving the goals of significantly increasing reusable launch vehicle (or any space vehicle that enters an atmosphere) safety and reliability, and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies has recently completed a rigorous testing phase where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. Results show a significant improvement over previous guidance approaches. The two best-scoring algorithm approaches show roughly equivalent results and are ready to be applied to future vehicle concepts.

  16. Method and apparatus for tensile testing of metal foil

    NASA Technical Reports Server (NTRS)

    Wade, O. W. (inventor)

    1976-01-01

    A method for obtaining accurate and reproducible results in the tensile testing of metal foils in tensile testing machines is described. Before the test specimen are placed in the machine, foil side edges are worked until they are parallel and flaw free. The specimen are also aligned between and secured to grip end members. An aligning apparatus employed in the method is comprised of an alignment box with a longitudinal bottom wall and two upright side walls, first and second removable grip end members at each end of the box, and a means for securing the grip end members within the box.

  17. Test Method Extensional viscosity of a thermotropic liquid crystalline polymer

    E-print Network

    Feng, James J.

    Test Method Extensional viscosity of a thermotropic liquid crystalline polymer measured by thread disintegration method Ruobing Yua , Wei Yua , Chixing Zhoua,*, J.J. Fengb a Department of Polymer Science the extensional viscosity of thermotropic liquid crystalline polymer: disintegration of liquid crystalline polymer

  18. Testing and Validation of the Dynamic Inertia Measurement Method

    NASA Technical Reports Server (NTRS)

    Chin, Alexander W.; Herrera, Claudia Y.; Spivey, Natalie D.; Fladung, William A.; Cloutier, David

    2015-01-01

    The Dynamic Inertia Measurement (DIM) method uses a ground vibration test setup to determine the mass properties of an object using information from frequency response functions. Most conventional mass properties testing involves using spin tables or pendulum-based swing tests, which for large aerospace vehicles becomes increasingly difficult and time-consuming, and therefore expensive, to perform. The DIM method has been validated on small test articles but has not been successfully proven on large aerospace vehicles. In response, the National Aeronautics and Space Administration Armstrong Flight Research Center (Edwards, California) conducted mass properties testing on an "iron bird" test article that is comparable in mass and scale to a fighter-type aircraft. The simple two-I-beam design of the "iron bird" was selected to ensure accurate analytical mass properties. Traditional swing testing was also performed to compare the level of effort, amount of resources, and quality of data with the DIM method. The DIM test showed favorable results for the center of gravity and moments of inertia; however, the products of inertia showed disagreement with analytical predictions.

  19. NNWSI waste form test method for unsaturated disposal conditions

    SciTech Connect

    Bates, J.K.; Gerding, T.J.

    1985-03-01

    A test method has been developed to measure the release of radionuclides from the waste package under simulated NNWSI repository conditions, and to provide information concerning materials interactions that may occur in the repository. Data are presented from Unsaturated testing of simulated Savannah River Laboratory 165 glass completed through 26 weeks. The relationship between these results and those from parametric and analog testing are described. The data indicate that the waste form test is capable of producing consistent, reproducible results that will be useful in evaluating the role of the waste package in the long-term performance of the repository. 6 refs., 7 figs., 5 tabs.

  20. Inductive method for AC and DC testing; Creation and testing of installations

    SciTech Connect

    Dolgosheev, P.I.; Sytnikov, V.E.; Radchenko, I.P.; Vahtinski, N.A. (All-Union Research and Development Inst. of Cable Industry, Moscow (SU))

    1991-03-01

    High value of critical current multiwire superconducting cables makes unsuitable and sometime impossible the utilization of the galvanic current input method for sample testing. It necessitates the development the inductive method. This report presents the possibility of utilization of the method for the critical-, quench-, recovery currents and the obtained results.

  1. Process of Dissolution of Polydisperse Materials in a Unit with a Rotary Pulsation Apparatus

    NASA Astrophysics Data System (ADS)

    Kukhlenko, A. A.; Orlov, S. E.; Ivanova, D. B.; Vasilishin, M. S.

    2015-01-01

    In this article, the authors have presented a mathematical model of the process of dissolution of polydisperse materials in a unit with a rotary pulsation apparatus; the model takes account of the mechanical grinding of dissolved particles. Experimental work on substantiation of the efficiency of the mathematical dissolution model has been performed. Data on dissolution in the unit with a pulsation apparatus and with a bulk-capacity tank have been compared. Methods for raising the efficiency of units with rotary-type pulsation apparatuses when the dissolution of dispersed materials is carried out in them have been proposed.

  2. In vitro dissolution methodology, mini-Gastrointestinal Simulator (mGIS), predicts better in vivo dissolution of a weak base drug, dasatinib.

    PubMed

    Tsume, Yasuhiro; Takeuchi, Susumu; Matsui, Kazuki; Amidon, Gregory E; Amidon, Gordon L

    2015-08-30

    USP apparatus I and II are gold standard methodologies for determining the in vitro dissolution profiles of test drugs. However, it is difficult to use in vitro dissolution results to predict in vivo dissolution, particularly the pH-dependent solubility of weak acid and base drugs, because the USP apparatus contains one vessel with a fixed pH for the test drug, limiting insight into in vivo drug dissolution of weak acid and weak base drugs. This discrepancy underscores the need to develop new in vitro dissolution methodology that better predicts in vivo response to assure the therapeutic efficacy and safety of oral drug products. Thus, the development of the in vivo predictive dissolution (IPD) methodology is necessitated. The major goals of in vitro dissolution are to ensure the performance of oral drug products and the support of drug formulation design, including bioequivalence (BE). Orally administered anticancer drugs, such as dasatinib and erlotinib (tyrosine kinase inhibitors), are used to treat various types of cancer. These drugs are weak bases that exhibit pH-dependent and high solubility in the acidic stomach and low solubility in the small intestine (>pH 6.0). Therefore, these drugs supersaturate and/or precipitate when they move from the stomach to the small intestine. Also of importance, gastric acidity for cancer patients may be altered with aging (reduction of gastric fluid secretion) and/or co-administration of acid-reducing agents. These may result in changes to the dissolution profiles of weak base and the reduction of drug absorption and efficacy. In vitro dissolution methodologies that assess the impact of these physiological changes in the GI condition are expected to better predict in vivo dissolution of oral medications for patients and, hence, better assess efficacy, toxicity and safety concerns. The objective of this present study is to determine the initial conditions for a mini-Gastrointestinal Simulator (mGIS) to assess in vivo dissolution of BCS class IIb drugs, dasatinib as a model drug, including the different gastric condition. The maximum dissolution of dasatinib with USP dissolution apparatus II was less than 1% in pH 6.5 SIF, while the one with mGIS (pH 1.2 SGF/pH 6.5 SIF) reached almost 100%. The supersaturation and precipitation of dasatinib were observed in the in vitro dissolution studies with mGIS but not with USP apparatus II. Additionally, dasatinib dissolution with mGIS was reduced to less than 10% when the gastric pH was elevated, suggesting the co-administration of acid reducing agents will decrease the oral bioavailability of dasatinib. Accurate prediction of in vivo drug dissolution would be beneficial for assuring product safety and efficacy for patients. To this end, we have created a new in vitro dissolution system, mGIS, to predict the in vivo dissolution phenomena of a weak base drug, dasatinib. The experimental results when combined with in silico simulation suggest that the mGIS predicted the in vivo dissolution well due to the elevation of gastric pH. Thus, mGIS might be suitable to predict in vivo dissolution of weak basic drugs. This mGIS methodology is expected to significantly advance the prediction of in vivo drug dissolution. It is also expected to assist in optimizing product development and drug formulation design in support of Quality by Design (QbD) initiatives. PMID:25978875

  3. Field tests of carbon monitoring methods in forestry projects

    SciTech Connect

    NONE

    1999-07-01

    In response to the emerging scientific consensus on the facts of global climate change, the international Joint Implementation (JI) program provided a pilot phase in which utilities and other industries could finance, among other activities, international efforts to sequester carbon dioxide, a major greenhouse gas. To make JI and its successor mechanisms workable, however, cost-effective methods are needed for monitoring progress in the reduction of greenhouse gas emissions. The papers in this volume describe field test experiences with methods for measuring carbon storage by three types of land use: natural forest, plantation forest, and agroforestry. Each test, in a slightly different land-use situation, contributes to the knowledge of carbon-monitoring methods as experienced in the field. The field tests of the agroforestry guidelines in Guatemala and the Philippines, for example, suggested adaptations in terms of plot size and method of delineating the total area for sampling.

  4. Thermal testing methods in determination of characterization of charcoals

    Microsoft Academic Search

    Liu Shouxin; zhang Shirun; Li Boning; Zhu Wenhong

    2000-01-01

    Thermal analysis testing methods were used in determination of the characterization of charcoals. Thermogravimetry (TG) method\\u000a was adopted to determine the composition of charcoals, which include moisture, volatiles, fixed carbon and ash contents. The\\u000a result showed that this method could detect the subtle change of charcoal composition, even the variation of different parts\\u000a of material. Differential Thermal analysis (DTA) and

  5. A Simple Method for Determining Specific Yield from Pumping Tests

    USGS Publications Warehouse

    Ramsahoye, L.E.; Lang, Solomon Max

    1961-01-01

    A simpler solution which greatly reduces the time necessary to compute the specific yield by the pumping-test method of Remson and Lang (1955) is presented. The method consists of computing the volume of dewatered material in the cone of depression and comparing it with the total volume of discharged water. The original method entails the use of a slowly converging series to compute the volume of dewatered material. The solution given herein is derived directly from Darcy's law.

  6. Uncertainty in dissolution test of drug release

    Microsoft Academic Search

    M. Paakkunainen; S. Matero; J. Ketolainen; M. Lahtela-Kakkonen; A. Poso; S.-P. Reinikainen

    2009-01-01

    The uncertainty estimation of measurements in pharmaceutical manufacturing is often neglected in process optimization. For instance, tablet manufacturing consists of several process steps called unit operations where many measurements on the process conditions and quality are carried out. These measurements are assumed to be error-free and the possibility of the cumulative error throughout the process stages that only goes up

  7. Spent fuel dissolution studies FY 1991 to 1994

    SciTech Connect

    Gray, W.J.; Wilson, C.N.

    1995-12-01

    Dissolution and transport as a result of groundwater flow are generally accepted as the primary mechanisms by which radionuclides from spent fuel placed in a geologic repository could be released to the biosphere. To help provide a source term for performance assessment calculations, dissolution studies on spent fuel and unirradiated uranium oxides have been conducted over the past few years at Pacific Northwest National Laboratory (PNNL) in support of the Yucca Mountain Site Characterization Project. This report describes work for fiscal years 1991 through 1994. The objectives of these studies and the associated conclusions, which were based on the limited number of tests conducted so far, are described in the following subsections.

  8. Method - Pressure drop tests for fuel system components

    NASA Astrophysics Data System (ADS)

    1990-12-01

    Techniques are presented for testing components and improving the accuracy of such tests to meet the requirements of MIL-F-8615 or equivalent specifications. Pressure-drop tests for individual components are described generally including the single and double piezometer-tube methods, and many of the suggested improvements apply to these techniques. The test setup is presented graphically, and the procedural conditions are described. The suggestions for improving the test results include notes regarding air bubbles, pumping-source pulsations, attachment fittings, overshooting the flow rate, and the importance of precise calibration. Diagrams are given for the double piezometer-tube, the mercury-manometer, and the fuel-manometer tests, and the arithmetic computation is described for the data-reduction equation.

  9. Dissolution and depolymerization of barley starch in selected ionic liquids.

    PubMed

    Lappalainen, Katja; Kärkkäinen, Johanna; Lajunen, Marja

    2013-03-01

    Polysaccharides like starch are poorly soluble in common solvents. However, certain ionic liquids (ILs) have been found to dissolve them, although some depolymerization happens during the dissolution. Dissolution and depolymerization of barley starch in ten ionic liquids have been studied with p-TsOH as a catalyst under controlled microwave heating. Dissolution time and the extent of the depolymerization of starch, determined by using HPLC-ELSD, were specific to each IL. Dialkylimidazolium halide ILs dissolved starch fast and depolymerized it substantially producing 79-100% water-soluble starch oligomers with the average molecular weight of 1000-2000Da. 1-Ethyl-3-methylimidazolium phosphate ([EMIM][Me2PO4]) and 2-hydroxyethylammonium formate ([NH3CH2CH2OH][HCOO]) dissolved starch slowly and depolymerized it least among the tested ILs. For the slow depolymerization of starch these ILs can be considered as suitable solvents for starch modifications where its depolymerization should be avoided. PMID:23465905

  10. L2 READING COMPREHENSION TEST IN THE PERSIAN CONTEXT: LANGUAGE OF PRESENTATION AS A TEST METHOD FACET

    Microsoft Academic Search

    Mohammad Rahimi

    2007-01-01

    Test method facet has been considered as an important factor affecting the testee's performance on a test. That is, a test used to assess a particular ability would yield different results when different test methods are used to gauge the same trait. The language of presentation is an aspect of test method conceived of as affecting the performance of the

  11. L2 Reading Comprehension Test in the Persian Context: Language of Presentation as a Test Method Facet

    ERIC Educational Resources Information Center

    Rahimi, Mohammad

    2007-01-01

    Test method facet has been considered as an important factor affecting the testee's performance on a test. That is, a test used to assess a particular ability would yield different results when different test methods are used to gauge the same trait. The language of presentation is an aspect of test method conceived of as affecting the performance…

  12. Dissolution of a 316L stainless steel vessel by a pool of molten aluminum

    SciTech Connect

    Tutu, N.K.; Finfrock, C.C.; Lara, J.D.; Schwarz, C.E.; Greene, G.A.

    1993-01-01

    Two experiments to study the dissolution of a torospherical stainless steel vessel by an isothermal pool of molten aluminum have been performed. The test vessels consisted of 24 inch diameter 316L stainless steel ``ASME Flanged and Dished Heads.`` The nominal values of the average melt temperatures for the two tests were: 977{degree}C and 1007{degree}C. The measurements of the dissolution depth as a function of the position along the vessel surface showed the dissolution to be spatially highly non-uniform. Large variations in the dissolution depth with respect to the azimuthal coordinate were also observed. The maximum value of the measured time averaged dissolution rate was found to be 5.05 mm/hr, and this occurred near the edge of the molten pool. The concentration measurements indicated that the molten pool was highly stratified with respect to the concentration of stainless steel in the melt (molten aluminum-stainless steel solution).

  13. Mass exchange during simultaneous grinding and dissolution

    SciTech Connect

    Aksel'rud, G.A.; Semenishin, E.M.; Kopyt, S.Ya.; Trotskii, V.I.

    1988-03-20

    Extraction of ore components of interest has a number of disadvantages, one of which being low efficiency. Combining the grinding and dissolution steps in one apparatus makes the process more efficient. Adoption of this technology, however, requires theoretical and mathematical studies. This paper reports the kinetics of simultaneous grinding and dissolution of copper-containing minerals. Simultaneous grinding and dissolution accelerated several fold the mass transfer of components of interest in the interaction of malachite and azurite with sulfuric acid solutions. The complete dissolution time was determined by adding the experimental rates of dissolution and abrasion.

  14. Standard Methods for Bolt-Bearing Testing of Textile Composites

    NASA Technical Reports Server (NTRS)

    Portanova, M. A.; Masters, J. E.

    1995-01-01

    The response of three 2-D braided materials to bolt bearing loading was evaluated using data generated by Boeing Defense and Space Group in Philadelphia, PA. Three test methods, stabilized single shear, unstabilized single shear, and double shear, were compared. In general, these textile composites were found to be sensitive to bolt bearing test methods. The stabilized single shear method yielded higher strengths than the unstabilized single shear method in all cases. The double shear test method always produced the highest strengths but these results may be somewhat misleading. It is therefore recommended that standard material comparisons be made using the stabilized single shear test method. The effects of two geometric parameters, W/D and e/D, were also studied. An evaluation of the effect of the specimen width (W) to hole diameter (D) ratio concluded that bolt bearing responses were consistent with open hole tension results. A W/D ratio of 6 or greater should be maintained. The proximity of the hole to the specimen edge significantly affected strength. In all cases, strength was improved by increasing the ratio of the distance from the hole center to the specimen edge (e) to the hole diameter (D) above 2. An e/D ratio of 3 or greater is recommended.

  15. Standard Test Methods for Constituent Content of Composite Materials

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 These test methods determine the constituent content of composite materials by one of two approaches. Method I physically removes the matrix by digestion or ignition by one of seven procedures, leaving the reinforcement essentially unaffected and thus allowing calculation of reinforcement or matrix content (by weight or volume) as well as percent void volume. Method II, applicable only to laminate materials of known fiber areal weight, calculates reinforcement or matrix content (by weight or volume), and the cured ply thickness, based on the measured thickness of the laminate. Method II is not applicable to the measurement of void volume. 1.1.1 These test methods are primarily intended for two-part composite material systems. However, special provisions can be made to extend these test methods to filled material systems with more than two constituents, though not all test results can be determined in every case. 1.1.2 The procedures contained within have been designed to be particularly effective for ce...

  16. Development of fire test methods for airplane interior materials

    NASA Technical Reports Server (NTRS)

    Tustin, E. A.

    1978-01-01

    Fire tests were conducted in a 737 airplane fuselage at NASA-JSC to characterize jet fuel fires in open steel pans (simulating post-crash fire sources and a ruptured airplane fuselage) and to characterize fires in some common combustibles (simulating in-flight fire sources). Design post-crash and in-flight fire source selections were based on these data. Large panels of airplane interior materials were exposed to closely-controlled large scale heating simulations of the two design fire sources in a Boeing fire test facility utilizing a surplused 707 fuselage section. Small samples of the same airplane materials were tested by several laboratory fire test methods. Large scale and laboratory scale data were examined for correlative factors. Published data for dangerous hazard levels in a fire environment were used as the basis for developing a method to select the most desirable material where trade-offs in heat, smoke and gaseous toxicant evolution must be considered.

  17. Automatic Test Case Generation Using Multi-protocol Test Method Soo-in Lee, Yongbum Park, and Myungchul Kim

    E-print Network

    Lee, Ben

    Automatic Test Case Generation Using Multi-protocol Test Method Soo-in Lee, Yongbum Park, mckim}@icu.ac.kr Abstract - A method for testing multi-protocol implementation under test (IUT) with a single test suite has been proposed in the literature. It tests a multi-protocol IUT in an integrated way

  18. Dissolution Kinetics of Alumina Calcine

    SciTech Connect

    Batcheller, Thomas Aquinas

    2001-09-01

    Dissolution kinetics of alumina type non-radioactive calcine was investigated as part of ongoing research that addresses permanent disposal of Idaho High Level Waste (HLW). Calcine waste was produced from the processing of nuclear fuel at the Idaho Nuclear Technology and Engineering Center (INTEC). Acidic radioactive raffinates were solidified at ~500°C in a fluidized bed reactor to form the dry granular calcine material. Several Waste Management alternatives for the calcine are presented in the Idaho High Level Waste Draft EIS. The Separations Alternative addresses the processing of the calcine so that the HLW is ready for removal to a national geological repository by the year 2035. Calcine dissolution is the key front-end unit operation for the separations alternative.

  19. A Model Based Security Testing Method for Protocol Implementation

    PubMed Central

    Fu, Yu Long; Xin, Xiao Long

    2014-01-01

    The security of protocol implementation is important and hard to be verified. Since the penetration testing is usually based on the experience of the security tester and the specific protocol specifications, a formal and automatic verification method is always required. In this paper, we propose an extended model of IOLTS to describe the legal roles and intruders of security protocol implementations, and then combine them together to generate the suitable test cases to verify the security of protocol implementation. PMID:25105163

  20. Experimental hydrothermal dissolution of forsterite, enstatite, diopside, and labradorite

    SciTech Connect

    Ponader, H.B.

    1989-01-01

    Natural hydrothermal water/rock interactions such as those which occur during mineral dissolution and serpentinization were experimentally duplicated using a flow-through apparatus. Labradorite, forsterite, enstatite, diopside, and lherzolite powders were reached with flowing aqueous fluids ({approximately} 10 ml/day) at 300 C and 300 bars for up to 58 days in order to quantify mineral stabilities and dissolution rates, and to characterize dissolution textures and mechanisms. The principal methods for characterization of the solids included surface sensitive spectroscopies (SAM and SPS), SEM, and XRD; reacted fluids were analyzed for major element chemistry and pH. Chapters 1 and 2 investigate labradorite dissolution by deionized water. The labradorite powder dissolved extensively while boehmite and halloysite precipitated. The SAM results show that, in general, the reacted surfaces are enriched in Al and depleted in Si, Na, and Ca. Chapter 3 describes the experiments that reacted deionized water with diopside, enstatite, forsterite, and lherzolite, from which lizardite {plus minus} chrysotile {plus minus} Fe-oxides precipitated. The reacted diopside and enstatite surfaces appeared highly corroded; their crystal structures, in part, control the mechanisms by which they dissolve. The stabilities of the minerals decrease in the order: lherzolite > diopside > enstatite > forsterite. At near neutral pH, the degree to which total surface areas influence dissolution rates appears greater that the effect of mineral composition and interaction of the primary minerals within the lherzolite.

  1. Evaluation of 3 dental unit waterline contamination testing methods

    PubMed Central

    Porteous, Nuala; Sun, Yuyu; Schoolfield, John

    2015-01-01

    Previous studies have found inconsistent results from testing methods used to measure heterotrophic plate count (HPC) bacteria in dental unit waterline (DUWL) samples. This study used 63 samples to compare the results obtained from an in-office chairside method and 2 currently used commercial laboratory HPC methods (Standard Methods 9215C and 9215E). The results suggest that the Standard Method 9215E is not suitable for application to DUWL quality monitoring, due to the detection of limited numbers of heterotrophic organisms at the required 35°C incubation temperature. The results also confirm that while the in-office chairside method is useful for DUWL quality monitoring, the Standard Method 9215C provided the most accurate results. PMID:25574718

  2. Recent development in novolak dissolution

    SciTech Connect

    Dammel, R. [Hoechst Celanese Corp., Coventry, RI (United States); Reiser, A. [Polytechnic Univ., Brooklyn, NY (United States)

    1993-12-31

    Two different lines of research have recently considerably increased understanding of the phenomena involved in the dissolution of novolak matrix polymers and photoresists. Taking the physical chemistry approach, investigations of the diffusion processes occurring in the penetration zone of a dissolving novolak resin have led to the picture of novalak as a hydrophobic resin into which the developer penetrates along a network of hydrophilic sites. The dissolution rate is limited by the speed of diffusion of the developer`s counter-cations through the penetration zone and into the polymer bulk. Subsequent application of percolation theory has led to a general scaling law for the dissolution rate, which can be used to generate a dimensionless master curve for all percolative diffusion. The curvature of this master curve effortlessly explains the difference in inhibition properties of, say, a lithographic novolak resin and polyhydroxystyrene. The second approach, which seems inspired more by organic chemistry, has focused on the nature of the chemical interactions between developer and phenolic resin. Some surprising differences have been observed for alkali-metal containing and metal ion free (TMAH) developers. Spectroscopic and kinetic evidence (i.e. negative apparent activation energies) points at strong complex formation between TMAH and both model compounds and actual matrix resins. The nature of these interactions casts a new light such diverse phenomena such as the incompatibility of TMAH and inorganic developers, the effect of cationic surfactant additives, or the dissolution inhibition by onium salt photosensitizers. This paper will attempt to investigate to which extent these different approaches can be combined into a coherent view of the development process.

  3. Method and apparatus for testing surface characteristics of a material

    NASA Technical Reports Server (NTRS)

    Johnson, David L. (Inventor); Kersker, Karl D. (Inventor); Richardson, David E. (Inventor); Stratton, Troy C. (Inventor)

    2006-01-01

    A method, apparatus and system for testing characteristics of a material sample is provided. The system includes an apparatus configured to house the material test sample while defining a sealed volume against a surface of the material test sample. A source of pressurized fluid is in communication with, and configured to pressurize, the sealed volume. A load applying apparatus is configured to apply a defined load to the material sample while the sealed volume is monitored for leakage of the pressurized fluid. Thus, the inducement of surface defects such as microcracking and crazing may be detected and their effects analyzed for a given material. The material test samples may include laminar structures formed of, for example, carbon cloth phenolic, glass cloth phenolic, silica cloth phenolic materials or carbon-carbon materials. In one embodiment the system may be configured to analyze the material test sample while an across-ply loading is applied thereto.

  4. Apparatus and method for defect testing of integrated circuits

    DOEpatents

    Cole, Jr., Edward I. (Albuquerque, NM); Soden, Jerry M. (Placitas, NM)

    2000-01-01

    An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V.sub.DD, to an IC under test and measures a transient voltage component, V.sub.DDT, signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V.sub.DDT signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V.sub.DDT signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.

  5. Apparatus and method for defect testing of integrated circuits

    SciTech Connect

    Cole, E.I. Jr.; Soden, J.M.

    2000-02-29

    An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V(DD), to an IC under test and measures a transient voltage component, V(DDT), signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V(DDT) signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V(DDT) signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.

  6. Truncated Product Methods for Panel Unit Root Tests*

    PubMed Central

    SHENG, XUGUANG; YANG, JINGYUN

    2012-01-01

    This paper proposes two new panel unit root tests based on Zaykin et al. (2002)’s truncated product method. The first one assumes constant correlation between p-values and the second one uses sieve bootstrap to allow for general forms of cross-section dependence in the panel units. Monte Carlo simulation shows that both tests have reasonably good size and are powerful in cases of some very large p-values. The proposed tests are applied to a panel of real GDP and inflation density forecasts, resulting in evidence that professional forecasters may not update their forecast precision in an optimal Bayesian way. PMID:23869116

  7. Fatigue Testing of Wing Beam by the Resonance Method

    NASA Technical Reports Server (NTRS)

    Bleakney, William M

    1938-01-01

    Preliminary fatigue tests on two aluminum-alloy wing-beam specimens subjected to reversed axial loading are described. The motion used consists in incorporating one or two reciprocating motors in a resonance system of which the specimen is the spring element. A description is given of the reciprocating motors, and of the method of assembling and adjusting the vibrating system. The results indicate that the method is well adapted to fatigue tests of not only uniform wing beams but also wing beams with asymmetrical local reinforcements.

  8. Bar Dissolution in Prolate Halos.

    PubMed

    Ideta; Hozumi

    2000-06-01

    The time evolution of barred structures is examined under the influence of the external forces exerted by a spherical halo and by prolate halos. In particular, galaxy disks are placed in the plane including the major axis of prolate halos, whose configuration is often found in cosmological simulations. N-body disks in fixed external halo fields are simulated, so that bars are formed via dynamical instability. In the subsequent evolution, the bars in prolate halos dissolve gradually with time, while the bar pattern in a spherical halo remains almost unchanged to the end of the simulation. The decay times of the bars suggest that they can be destroyed in a time smaller than a Hubble time. Our results indicate that this dissolution process could occur in real barred galaxies, if they are surrounded by massive dark prolate halos, and the configuration adopted here is not unusual from the viewpoint of galaxy formation. For a prolate halo model, an additional simulation that is restricted to two-dimensional in-plane motions has also ended up with similar bar dissolution. This means that the vertical motions of disk stars do not play an essential role in the bar dissolution demonstrated here. PMID:10835306

  9. Dissolution and condensation kinetics of silica in alkaline solution

    SciTech Connect

    Thornton, S.D.; Radke, C.J.

    1985-03-01

    This paper addresses the viability of soluble silicates reducing hydroxide consumption by siliceous rock reactions. By utilizing a convenient differential rate method, new experimental kinetic data is obtained for the dissolution/condensation rates of quartz at 23 degrees C over the pH range from 11 to 12 and in one molar sodium chloride. The role of added silicates is studied from zero solution concentration to considerably above the solubility limit. A molecular dissolution/condensation reaction scheme is proposed, based on equilibrium absorption of unionized silicic acid. A mathematical model is developed which agrees quite well with the measured kinetic rate data.

  10. NON-DESTRUCTIVE TESTING METHODS FOR GEOTHERMAL PIPING.

    SciTech Connect

    BERNDT,M.L.

    2001-03-23

    Non-destructive testing is a key component of optimized plant inspection and maintenance programs. Risk based inspection, condition based maintenance and reliability centered maintenance systems all require detection, location and sizing of defects or flaws by non-destructive methods. Internal damage of geothermal piping by corrosion and erosion-corrosion is an ongoing problem requiring inspection and subsequent maintenance decisions to ensure safe and reliable performance. Conventional manual ultrasonic testing to determine remaining wall thickness has major limitations, particularly when damage is of a random and localized nature. Therefore, it is necessary to explore alternative non-destructive methods that offer potential benefits in terms of accurate quantification of size, shape and location of damage, probability of detection, ability to use on-line over long ranges, and economics. A review of non-destructive methods and their applicability to geothermal piping was performed. Based on this, ongoing research will concentrate on long range guided wave and dynamic methods.

  11. Detection of fatigue cracks by nondestructive testing methods

    NASA Technical Reports Server (NTRS)

    Anderson, R. T.; Delacy, T. J.; Stewart, R. C.

    1973-01-01

    The effectiveness was assessed of various NDT methods to detect small tight cracks by randomly introducing fatigue cracks into aluminum sheets. The study included optimizing NDT methods calibrating NDT equipment with fatigue cracked standards, and evaluating a number of cracked specimens by the optimized NDT methods. The evaluations were conducted by highly trained personnel, provided with detailed procedures, in order to minimize the effects of human variability. These personnel performed the NDT on the test specimens without knowledge of the flaw locations and reported on the flaws detected. The performance of these tests was measured by comparing the flaws detected against the flaws present. The principal NDT methods utilized were radiographic, ultrasonic, penetrant, and eddy current. Holographic interferometry, acoustic emission monitoring, and replication methods were also applied on a reduced number of specimens. Generally, the best performance was shown by eddy current, ultrasonic, penetrant and holographic tests. Etching provided no measurable improvement, while proof loading improved flaw detectability. Data are shown that quantify the performances of the NDT methods applied.

  12. Self potential observations during DNAPL dissolution

    NASA Astrophysics Data System (ADS)

    Ntarlagiannis, D.; Slater, L.; Kulessa, B.; Russell, C.; Kalin, R.; Ferguson, A.; Graber, J.

    2006-05-01

    Dense non aqueous phase liquids (DNAPLs) are a major environmental problem and are considered to be long term heavy contaminant sources in the subsurface. Accurate monitoring of DNAPL breakdown is required to monitor remediation efforts. We aim to evaluate the efficiency of geophysical methods to monitor DNAPL remediation. Toward this goal we performed self potential (SP) measurements on laboratory columns packed with DNAPL contaminated sand undergoing (a) biodegradation, and (b) abiotic DNAPL dissolution. Geochemical monitoring showed higher concentration of dissolved DNAPL byproducts in the abiotic columns; the use of HgCl2 as a biocide probably increased the rates of DNAPL dissolution in the abiotic columns. The concentration of DNAPL byproducts is significantly lower in the biotic columns due to microbial activity since DNAPL degrading bacteria within the column consume the breakdown products. SP responses are significantly higher (~ 90 mV) in the abiotic columns; in the microbial active columns SP values remain steady with a value ~ 10 mV. High SP signals (up to 110 mV) are associated with DNAPL byproduct concentration gradients within the abiotic columns and exhibit a temporal behavior that mimics total organic carbon concentrations. Although microbial activity in organic rich contaminated areas has been associated with strong negative SP anomalies our results show that positive SP anomalies can also be generated in contaminated areas in the absence of any microbial activity. We discuss a possible SP source mechanism and the implications in geophysical monitoring of DNAPL remedial processes.

  13. Reproduction of natural corrosion by accelerated laboratory testing methods

    SciTech Connect

    Luo, J.S.; Wronkiewicz, D.J.; Mazer, J.J.; Bates, J.K.

    1996-05-01

    Various laboratory corrosion tests have been developed to study the behavior of glass waste forms under conditions similar to those expected in an engineered repository. The data generated by laboratory experiments are useful for understanding corrosion mechanisms and for developing chemical models to predict the long-term behavior of glass. However, it is challenging to demonstrate that these test methods produce results that can be directly related to projecting the behavior of glass waste forms over time periods of thousands of years. One method to build confidence in the applicability of the test methods is to study the natural processes that have been taking place over very long periods in environments similar to those of the repository. In this paper, we discuss whether accelerated testing methods alter the fundamental mechanisms of glass corrosion by comparing the alteration patterns that occur in naturally altered glasses with those that occur in accelerated laboratory environments. This comparison is done by (1) describing the alteration of glasses reacted in nature over long periods of time and in accelerated laboratory environments and (2) establishing the reaction kinetics of naturally altered glass and laboratory reacted glass waste forms.

  14. 40 CFR Appendix A to Part 63 - Test Methods

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...specifications (e.g.,equipment and supplies) and procedures (e.g., sampling...this test method.6.0Equipment and Supplies 6.1Stalagmometer. Any commercially...and inhalation. 6.0Equipment and Supplies6.1Sample Collection. The...

  15. 40 CFR 60.335 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Standards of Performance for Stationary Gas Turbines § 60.335 Test methods and procedures...for: Lean premix stationary combustion turbines; units used in association with heat...the normal operating range of the gas turbine, including the minimum point in...

  16. 40 CFR 60.335 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Standards of Performance for Stationary Gas Turbines § 60.335 Test methods and procedures...for: Lean premix stationary combustion turbines; units used in association with heat...the normal operating range of the gas turbine, including the minimum point in...

  17. 40 CFR 60.335 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Standards of Performance for Stationary Gas Turbines § 60.335 Test methods and procedures...for: Lean premix stationary combustion turbines; units used in association with heat...the normal operating range of the gas turbine, including the minimum point in...

  18. 40 CFR 60.335 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Standards of Performance for Stationary Gas Turbines § 60.335 Test methods and procedures...for: Lean premix stationary combustion turbines; units used in association with heat...the normal operating range of the gas turbine, including the minimum point in...

  19. 16 CFR 1610.3 - Summary of test method.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES The Standard § 1610.3 Summary...methods of testing the flammability of textiles from or intended to be used for apparel...forth the requirements for classifying textiles; and prohibits the use of single...

  20. 40 CFR 60.404 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.404 Test methods and...matter, kg/Mg (lb/ton) of phosphate rock feed. cs = concentration of particulate...dscm/hr (dscf/hr). P=phosphate rock feed rate, Mg/hr (ton/hr)....

  1. 40 CFR 60.404 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.404 Test methods and...matter, kg/Mg (lb/ton) of phosphate rock feed. cs =concentration of particulate...dscm/hr (dscf/hr). P=phosphate rock feed rate, Mg/hr (ton/hr)....

  2. 40 CFR 60.404 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.404 Test methods and...matter, kg/Mg (lb/ton) of phosphate rock feed. cs =concentration of particulate...dscm/hr (dscf/hr). P=phosphate rock feed rate, Mg/hr (ton/hr)....

  3. 40 CFR 60.404 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.404 Test methods and...matter, kg/Mg (lb/ton) of phosphate rock feed. cs =concentration of particulate...dscm/hr (dscf/hr). P=phosphate rock feed rate, Mg/hr (ton/hr)....

  4. TBA test by an extractive method applied to ‘paté’

    Microsoft Academic Search

    M. R. Rosmini; F. Perlo; J. A. Pérez-Alvarez; M. J. Pagán-Moreno; A. Gago-Gago; F. López-Santoveña; V. Aranda-Catalá

    1996-01-01

    The aim of this work was to study the influence of different conditions on the thiobarbituric acid (TBA) test, determined by the extractive method, as a measure of lipid oxidation in ‘paté’.Different extracting agents (trichloroacetic acid and trichloroacetic acid in 2 M phosphoric acid), different concentrations of these acids (10, 15 and 20%), different reaction times and temperatures (35 min

  5. TROPICAL COLLECTOR URCHIN, TRIPNEUSTES GRATILLA, FERTILIZATION TEST METHOD

    EPA Science Inventory

    This document describes a fertilization method to estimate the chronic toxicity of effluents and receiving waters to the gametes of the tropical sea urchin (Tripneustes gratilla). This toxicity test measures the fertilizing capacity of sperm following a static, non-renewal 60-mi...

  6. Laboratory methods for testing the performance of acoustic rail dampers

    E-print Network

    Paris-Sud XI, Université de

    Laboratory methods for testing the performance of acoustic rail dampers M. Towarda and D. J@soton.ac.uk Proceedings of the Acoustics 2012 Nantes Conference 23-27 April 2012, Nantes, France 3739 #12;Rail dampers with distance of vibration transmitted along the rail (decay rate). These dampers, attached to the rail between

  7. Some Exploratory Indices for Selection of a Test Equating Method.

    ERIC Educational Resources Information Center

    Jaeger, Richard M.

    Five statistical indices are developed and described which may be used for determining (1) when linear equating of two approximately parallel tests is adequate, and (2) whan a more complex method such as equipercentile equating must be used. The indices were based on: (1) similarity of cumulative score distributions; (2) shape of the raw-score to…

  8. 40 CFR Table 3 of Subpart Bbbbbbb... - Test Methods

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Subpt. BBBBBBB, Table 3 Table 3 of Subpart BBBBBBB of Part 63...in appendix A to part 60. 3. Determining the gas molecular...determination EPA test method 3, 3A, 3B, as appropriate, in appendix A to part 60. 4. Measuring the moisture content of the...

  9. Computer Controlled Oral Test Administration: A Method and Example.

    ERIC Educational Resources Information Center

    Milligan, W. Lloyd

    1978-01-01

    A computer/tape recorder interface was designed, which permits automatic oral adminstration of "true-false" or "multiple-choice" type tests. This paper describes the hardware and control program software, which were developed to implement the method on a DEC PDP 11 computer. (Author/JKS)

  10. Impetus of composite mechanics on test methods for fiber composites

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1978-01-01

    Significant contributions of the three major areas of composite mechanics to the development of test methods are illustrated with selected examples. The areas of composite mechanics include composite micromechanics, composite macromechanics, and laminate theory. The examples can be considered to be representative of the contribution of composite mechanics to the development of composite test methods. The specific examples describe contributions such as criteria for selecting resin matrices for improved composite strength, the 10 deg off-axis tensile test, procedures for configuring hybrids, and the concept of 'reduced bending rigidities'. The pertinent composite mechanics equations associated with each contribution are given and supplemented by tabular and/or graphical data which illustrate the significance of the contribution.

  11. The Use of Artificial Neural Network for Prediction of Dissolution Kinetics

    PubMed Central

    Elçiçek, H.; Akdo?an, E.; Karagöz, S.

    2014-01-01

    Colemanite is a preferred boron mineral in industry, such as boric acid production, fabrication of heat resistant glass, and cleaning agents. Dissolution of the mineral is one of the most important processes for these industries. In this study, dissolution of colemanite was examined in water saturated with carbon dioxide solutions. Also, prediction of dissolution rate was determined using artificial neural networks (ANNs) which are based on the multilayered perceptron. Reaction temperature, total pressure, stirring speed, solid/liquid ratio, particle size, and reaction time were selected as input parameters to predict the dissolution rate. Experimental dataset was used to train multilayer perceptron (MLP) networks to allow for prediction of dissolution kinetics. Developing ANNs has provided highly accurate predictions in comparison with an obtained mathematical model used through regression method. We conclude that ANNs may be a preferred alternative approach instead of conventional statistical methods for prediction of boron minerals. PMID:25028674

  12. The use of artificial neural network for prediction of dissolution kinetics.

    PubMed

    Elçiçek, H; Akdo?an, E; Karagöz, S

    2014-01-01

    Colemanite is a preferred boron mineral in industry, such as boric acid production, fabrication of heat resistant glass, and cleaning agents. Dissolution of the mineral is one of the most important processes for these industries. In this study, dissolution of colemanite was examined in water saturated with carbon dioxide solutions. Also, prediction of dissolution rate was determined using artificial neural networks (ANNs) which are based on the multilayered perceptron. Reaction temperature, total pressure, stirring speed, solid/liquid ratio, particle size, and reaction time were selected as input parameters to predict the dissolution rate. Experimental dataset was used to train multilayer perceptron (MLP) networks to allow for prediction of dissolution kinetics. Developing ANNs has provided highly accurate predictions in comparison with an obtained mathematical model used through regression method. We conclude that ANNs may be a preferred alternative approach instead of conventional statistical methods for prediction of boron minerals. PMID:25028674

  13. IMPACT OF NUCLEAR MATERIAL DISSOLUTION ON VESSEL CORROSION

    SciTech Connect

    Mickalonis, J.; Dunn, K.; Clifton, B.

    2012-10-01

    Different nuclear materials require different processing conditions. In order to maximize the dissolver vessel lifetime, corrosion testing was conducted for a range of chemistries and temperature used in fuel dissolution. Compositional ranges of elements regularly in the dissolver were evaluated for corrosion of 304L, the material of construction. Corrosion rates of AISI Type 304 stainless steel coupons, both welded and non-welded coupons, were calculated from measured weight losses and post-test concentrations of soluble Fe, Cr and Ni.

  14. Analog and mixed-signal test methods using on-chip embedded test cores

    NASA Astrophysics Data System (ADS)

    Hafed, Mohamed M.

    2002-08-01

    A robust method has been developed for the test and characterization of analog and mixed-signal integrated circuits. The method relies on a compact, robust, and easily synthesized integrated test core capable of emulating the function of external automatic test equipment. The core consists of a 2 x N memory whose contents are periodically circulated, a coarse analog filter, and a voltage comparator. One half of the circular memory is used to generate analog signals without the need for multi-bit digital-to-analog converters. The second half is used to generate extremely accurate DC levels, the latter being programmed using a clever software encoding technique that relies on some form of sigma-delta modulation. The DC levels, in combination with the comparator, enable multi-bit digitization using a progressive multiple conversion pass procedure. In order to accommodate broadband circuit phenomena, a delayed-clock sub-sampling mechanism is also employed, in which the digitizer sample clock is consistently delayed over multiple runs of the periodic test signal. One method of delaying the clock is to use a voltage-controlled delay line tuned by a delay-locked loop. The timing resolution of this approach is determined by the value of the consistent clock delay and not its period. A divide-and-conquer approach to the test of deeply embedded analog integrated circuits using the proposed test core is described. Multiple test configurations are presented that can span a wide range of phenomena to be tested both internally to the integrated circuit and externally through I/O interfaces. The applicability of these configurations to increasing test parallelism both at the core and die levels is investigated. Performance limits of the proposed test core are also derived by drawing a comparison to conventional circuits used for data-conversion applications. The same fundamental limitations on integrated circuit performance are shown to affect the test core electronics, although test-specific requirements, such as forcing periodicity and the reliance on software signal processing, help further enhance on-chip measurement accuracy and repeatability. Finally, several successful experimental prototypes that demonstrate the viability of the proposed approach are presented. The prototypes range from concept proving test core integrated circuits to ones containing multiple simultaneously operated test cores and completely embedded circuits under test. In total, several hundred different test cores have been demonstrated, which is further testimony to the practicality of the proposed techniques.

  15. Comparison of the results of short-term static tests and single-pass flow-through tests with LRM glass.

    SciTech Connect

    Ebert, W. L.; Chemical Engineering

    2007-01-29

    Static dissolution tests were conducted to measure the forward dissolution rate of LRM glass at 70 C and pH(RT) 11.7 {+-} 0.1 for comparison with the rate measured with single-pass flow-through (SPFT) tests in an interlaboratory study (ILS). The static tests were conducted with monolithic specimens having known geometric surface areas, whereas the SPFT tests were conducted with crushed glass that had an uncertain specific surface area. The error in the specific surface area of the crushed glass used in the SPFT tests, which was calculated by modeling the particles as spheres, was assessed based on the difference in the forward dissolution rates measured with the two test methods. Three series of static tests were conducted at 70 C following ASTM standard test method C1220 using specimens with surfaces polished to 600, 800, and 1200 grit and a leachant solution having the same composition as that used in the ILS. Regression of the combined results of the static tests to the affinity-based glass dissolution model gives a forward rate of 1.67 g/(m{sup 2}d). The mean value of the forward rate from the SPFT tests was 1.64 g/(m{sup 2}d) with an extended uncertainty of 1.90 g/(m{sup 2}d). This indicates that the calculated surface area for the crushed glass used in the SPFT tests is less than 2% higher than the actual surface area, which is well within the experimental uncertainties of measuring the forward dissolution rate using each test method. These results indicate that the geometric surface area of crushed glass calculated based on the size of the sieves used to isolate the fraction used in a test is reliable. In addition, the C1220 test method provides a means for measuring the forward dissolution rate of borosilicate glasses that is faster, easier, and more economical than the SPFT test method.

  16. Dissolution methodology for taste masked oral dosage forms.

    PubMed

    Gittings, Sally; Turnbull, Neil; Roberts, Clive J; Gershkovich, Pavel

    2014-01-10

    Conventional adult dosage forms are often not suitable for the paediatric and geriatric populations due to either swallowing difficulties or patient repulsion and a requirement for tailored dosing to individual compliance or physiological needs. Alternative formulations are available; however these often require the incorporation of more complex taste masking techniques. One approach to taste masking is to reduce contact between the bitter Active Pharmaceutical Ingredient (API) and oral cavity taste bud regions. This is achieved by hindering release in the oral cavity, or including competitive inhibition of bitter sensation for example by using flavours or sweeteners. There may also be other sensational complications from the API such as residual burning, reflux or metallic taste sensations to deal with. In vitro dissolution testing is employed to elucidate taste masking capability by quantifying release of the drug in simulated oral cavity conditions. Dissolution testing approaches may also be used to potentially predict or quantify the effect of the taste masking technique on the resultant pharmacokinetic profile. The present review investigates the anatomy and physiology of the oral cavity and current approaches to taste masking. In vitro dissolution methodologies adopted in the evaluation of taste masked formulations are discussed for their relative merits and drawbacks. A vast array of methodologies has been employed, with little agreement between approaches, and a lack of biorelevance. Future directions in dissolution methodology such as TNO Intestinal Model (TIM) and the Artificial Stomach and Duodenum model (ASD) are also discussed. PMID:24184344

  17. Method and device for spin-testing of turbocharger rotor

    SciTech Connect

    Kawasaki, K.

    1987-09-22

    This patent describes a method for spin-testing a turbocharger rotor. The rotor includes a shaft portion which is fixed to an assembly of component parts which include a thrust bearing, a spacer, at least one of a sleeve portion and compressor rotor portion, and a lock nut. The improvement comprises: preparing an integral composite member consisting of at least two of the component parts; dynamically balancing the turbocharger rotor, without the shaft portion fixed to the assembly; placing the turbocharger rotor and the integral composite member in a testing device, such that the shaft portion and the assembly are fixed to each other by the lock nut, and are rotatable as a unit; and rotating the turbocharger rotor and the assembly in the testing device, to effect the spin-testing.

  18. Improved dissolution and absorption of ketoconazole in the presence of organic acids as pH-modifiers.

    PubMed

    Adachi, Masashi; Hinatsu, Yuta; Kusamori, Kosuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Nakatani, Manabu; Wada, Koichi; Yamamoto, Akira

    2015-08-30

    Formulation development of poorly water-soluble compounds can be challenging because of incomplete dissolution that causes low and variable bioavailability. Enhancing compound solubility is important and many techniques have been investigated to that end, but they require specific materials and machinery. This study investigates the incorporation of a pH-modifier as a method to increase compound solubility and uses ketoconazole (KZ), which is weakly basic (pKa: 6.5), as a model compound. Organic acids are effective pH-modifiers and are generally used in pharmaceutical industries. We successfully obtained granules containing variable organic acids (KZ/acid granule) using a high-shear mixer. Dissolution tests of the KZ/acid granule resulted in highly enhanced solubility under non-sink conditions. Adding water-soluble acids, such as citric acid (CA) and tartaric acid, resulted in more than 8-fold higher dissolution at pH 6.0 compared to that of KZ only. The granules containing citric acid (KZ/CA granule) improved the dissolution of KZ after oral administration to rats under low gastric acid conditions, where the bioavailability of the KZ/CA granules at elevated gastric pH was comparable with that of KZ only at gastric acidic pH. The incorporation of organic acids would result in effective therapeutic outcomes independent of gastric pH in patients. In addition, higher bioavailability of KZ was observed after oral administration of KZ/CA granules under gastric acidic pH conditions than that of KZ alone. Thus, CA improved the dissolution and absorption rate of KZ after oral administration. PMID:25988287

  19. OECD test strategies and methods for endocrine disruptors.

    PubMed

    Gelbke, H P; Kayser, M; Poole, A

    2004-12-01

    The question whether (man-made or natural) chemical substances may have an adverse effect on the endocrine system has gained high visibility in the public as well as in the scientific community. This relates to possible effects on the environment as well as on human health for chemicals with (anti)estrogenic, (anti)androgenic or (anti)thyroid activity. Taking into account the broad universe of chemicals to which humans or the environment may be exposed, a sound testing strategy and robust test methods are urgently needed. Both subjects have been addressed by a specific OECD working group (EDTA-Endocrine Disruptor Testing and Assessment Task Force) involving regulatory agencies, the scientific community, chemical industry and NGOs. Like other organizations the OECD has adopted a tiered-testing strategy with the first tier using screening assays as quick and inexpensive tools, providing a way of generating alerts to potential endocrine activity that can be used to prioritize substances for definitive tests that then can determine the toxicological consequences of endocrine toxicity. The efforts of the OECD have therefore concentrated on the validation of specific screening and testing guidelines, like the uterotrophic, the Hershberger, and the "enhanced TG 407" test. The experimental testing necessary for this validation procedure is completed for the uterotrophic and the "enhanced TG 407" tests and near completion for the Hershberger assay. The data obtained so far have been published (for the uterotrophic assay) or will be submitted to the EDTA working group for final evaluation. Overall, the validation program has been very successful and should be sufficient for setting up OECD test guidelines for these experimental procedures. This will add substantially to the "tool-box" of OECD test methods that is available internationally to regulatory agencies and chemical industry for the identification and assessment of possible endocrine disruptors. Despite this success it is well recognized that the methodological "tool-box" should be supplemented by further screening and testing procedures related to effects on human health and the environment. PMID:15458786

  20. Dissolution behavior of ?-cyclodextrin molecular inclusion complexes of aceclofenac

    PubMed Central

    Dua, Kamal; Pabreja, Kavita; Ramana, M. V.; Lather, Vinny

    2011-01-01

    The objective of the present investigation was to study the effect of ?-cyclodextrin (?-CD) on the in vitro dissolution of aceclofenac (AF) from molecular inclusion complexes. Aceclofenac molecular inclusion complexes in 1:1 and 1:2 M ratio were prepared using a kneading method. The in vitro dissolution of pure drug, physical mixtures, and cyclodextrin inclusion complexes was carried out. Molecular inclusion complexes of AF with ?-CD showed a considerable increase in the dissolution rate in comparison with the physical mixture and pure drug in 0.1 N HCl, pH 1.2, and phosphate buffer, pH 7.4. Inclusion complexes with a 1:2 M ratio showed the maximum dissolution rate in comparison to other ratios. Fourier transform infrared spectroscopy and differential scanning calorimetry studies indicated no interaction between AF and ?-CD in complexes in solid state. Molecular modeling results indicated the relative energetic stability of the ?-CD dimer-AF complex as compared to ?-CD monomer-AF. Dissolution enhancement was attributed to the formation of water soluble inclusion complexes with ?-CD. The in vitro release from all the formulations was best described by first-order kinetics (R2 = 0.9826 and 0.9938 in 0.1 N HCl and phosphate buffer, respectively) followed by the Higuchi release model (R2 = 0.9542 and 0.9686 in 0.1 N HCl and phosphate buffer, respectively). In conclusion, the dissolution of AF can be enhanced by the use of a hydrophilic carrier like ?-CD. PMID:21966164

  1. Dissolution behavior of ?-cyclodextrin molecular inclusion complexes of aceclofenac.

    PubMed

    Dua, Kamal; Pabreja, Kavita; Ramana, M V; Lather, Vinny

    2011-07-01

    The objective of the present investigation was to study the effect of ?-cyclodextrin (?-CD) on the in vitro dissolution of aceclofenac (AF) from molecular inclusion complexes. Aceclofenac molecular inclusion complexes in 1:1 and 1:2 M ratio were prepared using a kneading method. The in vitro dissolution of pure drug, physical mixtures, and cyclodextrin inclusion complexes was carried out. Molecular inclusion complexes of AF with ?-CD showed a considerable increase in the dissolution rate in comparison with the physical mixture and pure drug in 0.1 N HCl, pH 1.2, and phosphate buffer, pH 7.4. Inclusion complexes with a 1:2 M ratio showed the maximum dissolution rate in comparison to other ratios. Fourier transform infrared spectroscopy and differential scanning calorimetry studies indicated no interaction between AF and ?-CD in complexes in solid state. Molecular modeling results indicated the relative energetic stability of the ?-CD dimer-AF complex as compared to ?-CD monomer-AF. Dissolution enhancement was attributed to the formation of water soluble inclusion complexes with ?-CD. The in vitro release from all the formulations was best described by first-order kinetics (R(2) = 0.9826 and 0.9938 in 0.1 N HCl and phosphate buffer, respectively) followed by the Higuchi release model (R(2) = 0.9542 and 0.9686 in 0.1 N HCl and phosphate buffer, respectively). In conclusion, the dissolution of AF can be enhanced by the use of a hydrophilic carrier like ?-CD. PMID:21966164

  2. Comparative Performance Tests and Validation of NDT Methods for Concrete Testing

    Microsoft Academic Search

    Ralf Beutel; Hans-Wolf Reinhardt; Christian U. Grosse; André Glaubitt; Martin Krause; Christiane Maierhofer; Daniel Algernon; Herbert Wiggenhauser; Martin Schickert

    2008-01-01

    Validation of non-destructive testing methods is necessary to create a common basis where different systems can be compared\\u000a and their applications and limitations be identified. This can be achieved through comparing the measurements taken by several\\u000a systems used for a common diagnostic purpose under practical but controlled testing conditions. Well-designed small and large\\u000a laboratory or field specimens promise such conditions.

  3. CPV solar receiver ageing tests: The enhanced electroluminescence method

    NASA Astrophysics Data System (ADS)

    Mabille, Loïc; Mangeant, Christophe; Baudrit, Mathieu

    2013-09-01

    For two years now, CEA INES is involved in the development of insulated metal substrates (IMS) for CPV receivers. In an effort for establishing the reliability of such a new design compared to state-of-the-art direct bonded copper (DBC) design, accelerated ageing test have been carried out. During these tests, several characterization tools were used including current voltage measurements, X-ray tomography and electroluminescence. A new method for the characterization of thermal inhomogeneities has been developed, the so-called Enhanced Electroluminescence (EEL) which is described in this paper.

  4. Fracture Test Methods for Plastically Responding COPV Liners

    NASA Technical Reports Server (NTRS)

    Dawicke, David S.; Lewis, Joseph C.

    2009-01-01

    An experimental procedure for evaluating the validity of using uniaxial tests to provide a conservative bound on the fatigue crack growth rate behavior small cracks in bi-axially loaded Composite Overwrapped Pressure Vessel (COPV) liners is described. The experimental procedure included the use of a laser notch to quickly generate small surface fatigue cracks with the desired size and aspect ratios. An out-of-plane constraint system was designed to allow fully reversed, fully plastic testing of thin sheet uniaxial coupons. Finally, a method was developed to determine to initiate small cracks in the liner of COPVs.

  5. Cartridge output testing - Methods to overcome closed-bomb shortcomings

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1991-01-01

    Although the closed-bomb test has achieved virtually universal acceptance for measuring the output performance of pyrotechnic cartridges, there are serious shortcomings in its ability to quantify the performance of cartridges used as energy sources for pyrotechnic-activated mechanical devices. This paper presents several examples of cartridges (including the NASA Standard Initiator NSI) that successfully met closed-bomb performance requirements, but resulted in functional failures in mechanisms. To resolve these failures, test methods were developed to demonstrate a functional margin, based on comparing energy required to accomplish the function to energy deliverable by the cartridge.

  6. Physicochemical Hydrodynamics of NAPL Dissolution

    NASA Astrophysics Data System (ADS)

    Doss, S. K.; Ezzedine, S.; Ziagos, J. P.; Hoffman, F.; Gelinas, R. J.

    2001-05-01

    Determining the continually changing interface between the non-aqueous phase liquid (NAPL) and aqueous phase liquid (APL) phases, and the physical and chemical processes by which mass is transferred across the interface is critical to the understanding of NAPL dissolution. Most researchers, however, address only the flux of mass from NAPL into the aqueous phase and the subsequent migration of the dissolved contaminants; little effort has been made to track the NAPL/APL interface. While it is crucial to have an accurate account of mass flux from NAPL to APL in order to design successful remediation strategies, the absence of rigor in tracking the NAPL/APL boundary interface makes such mass flux estimates less reliable. Our studies account for the moving NAPL/APL boundary interface. We introduce a new approach in developing non-linearly coupled flow and transport equations in order to include specific description of chemical dissolution processes.The governing NAPL/APL evolution equations were formulated along principles similar to the Stefan Problem of moving interfaces. Essentially, the diffusion coefficient is allowed to vary in unison with the concentration but with a near discontinuity at the threshold of the NAPL solubility limit. Below the solubility limit, the diffusion takes on its customary value throughout the aqueous phase. Meanwhile, very small values are assigned to the diffusion coefficient within the non-aqueous phase. Along the NAPL/APL interface, the diffusion coefficient is given some transition shape function, which is ultimately determined by calibration to laboratory experiments. In addition to accounting for the continuous erosion of NAPL/APL interface due to the dissolution, blobs of NAPL are allowed to diffuse and move, rather freely, under the influence of prevailing physical forces. Our numerical simulations were obtained using Adaptive Grid, Galerkin Finite Elements technique to solve the coupled flow and transport equations simultaneously. Various synthetic heterogeneous porous medium and initial TCE populations were generated in order to gain a more quantitative understanding of the spatial and temporal evolution of aqueous phase contaminants in distal plumes under different aquifer conditions. Results show the dissolution of single and multiple blobs of TCE in saturated porous media. The simulations were conducted at both the pore-scale and the porous medium scale. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

  7. Standard test method for analysis of isotopic composition of uranium in nuclear-grade fuel material by quadrupole inductively coupled plasma-mass spectrometry

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described i...

  8. Suggested methods for swelling tests - a critical review

    NASA Astrophysics Data System (ADS)

    Pimentel, Erich

    2015-04-01

    Argillaceous and anhydritic rocks as well as rocks containing pyrite are prone to swelling, i.e. to adsorb water, which either increases their volume or, in the case of deformation constriction, causes an external pressure. The swelling process can also lead to a significant reduction of shear strength and stiffness. In tunneling, swelling rock can lead to big deformations or to excessive stress on the lining, thus leading to severe damages. Until now, the only adequate way to quantify the swelling potential of rocks is via swelling tests on undisturbed rock samples. The testing technique has been developed since the 1970's. The first suggested methods for swelling tests were published by the International Society of Rock Mechanics (ISRM) in 1979. Updates of these recommendations were published in 1989 and 1999. In Germany recommendations were published by the DGGT (now DGEG) in 1986. The Swiss recommendations published by VSS in 2006 are based on the ISRM recommendations from 1999. Some of the testing procedures described in the recommendations mentioned above can lead to an overestimation of the swelling potential. This is particularly the case for weak argillaceous rock. For rocks associated with high swelling pressures the proposed apparatuses can lead to an underestimation of the swelling potential. In general, a main flaw of the above mentioned recommendations is that they only propose the apparatus which should be used instead of the requirements which need be satisfied by the apparatus. However, several tests are being run with newer, improved apparatuses over the past decade; i.e. the recommendations are often being ignored. Furthermore, the suggested methods according to the recommendations are completely inadequate for evaluating the swelling potential of rock containing pyrite. This is due to the fact that the knowledge on swelling of rock containing pyrite was insufficient at that time. . This contribution will give an insight into the most important aspects concerning the testing technique of swelling rocks, which need to be modified for future testing.

  9. Standard test methods for bend testing of metallic flat materials for spring applications involving static loading

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This standard describes three test methods for determining the modulus of elasticity in bending and the bending strength of metallic strips or sheets intended for the use in flat springs: 1.1.1 Test Method A—a cantilever beam, 1.1.2 Test Method B—a three-point loaded beam (that is, a beam resting on two supports and centrally loaded), and 1.1.3 Test Method C—a four-point loaded beam (that is, a beam resting on two supports and loaded at two points equally spaced from each support). 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 6.1 This test me...

  10. 40 CFR 260.21 - Petitions for equivalent testing or analytical methods.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Petitions for equivalent testing or analytical methods. 260.21 Section 260...Petitions for equivalent testing or analytical methods. (a) Any person seeking to add a testing or analytical method to part 261, 264,...

  11. 40 CFR 260.21 - Petitions for equivalent testing or analytical methods.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Petitions for equivalent testing or analytical methods. 260.21 Section 260...Petitions for equivalent testing or analytical methods. (a) Any person seeking to add a testing or analytical method to part 261, 264,...

  12. 40 CFR 260.21 - Petitions for equivalent testing or analytical methods.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Petitions for equivalent testing or analytical methods. 260.21 Section 260...Petitions for equivalent testing or analytical methods. (a) Any person seeking to add a testing or analytical method to part 261, 264,...

  13. Standard test method for measuring pH of soil for use in corrosion testing

    E-print Network

    American Society for Testing and Materials. Philadelphia

    1995-01-01

    1.1 This test method covers a procedure for determining the pH of a soil in corrosion testing. The principle use of the test is to supplement soil resistivity measurements and thereby identify conditions under which the corrosion of metals in soil may be accentuated (see G 57 - 78 (1984)). 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. Recommended Minimum Test Requirements and Test Methods for Assessing Durability of Random-Glass-Fiber Composites

    SciTech Connect

    Battiste, R.L.; Corum, J.M.; Ren, W.; Ruggles, M.B.

    1999-06-01

    This report provides recommended minimum test requirements are suggested test methods for establishing the durability properties and characteristics of candidate random-glass-fiber polymeric composites for automotive structural applications. The recommendations and suggestions are based on experience and results developed at Oak Ridge National Laboratory (ORNL) under a US Department of Energy Advanced Automotive Materials project entitled ''Durability of Lightweight Composite Structures,'' which is closely coordinated with the Automotive Composites Consortium. The report is intended as an aid to suppliers offering new structural composites for automotive applications and to testing organizations that are called on to characterize the composites.

  15. Standard methods for open hole tension testing of textile composites

    NASA Technical Reports Server (NTRS)

    Portanova, M. A.; Masters, J. E.

    1995-01-01

    Sizing effects have been investigated by comparing the open hole failure strengths of each of the four different braided architectures as a function of specimen thickness, hole diameter, and the ratio of specimen width to hole diameter. The data used to make these comparisons was primarily generated by Boeing. Direct comparisons of Boeing's results were made with experiments conducted at West Virginia University whenever possible. Indirect comparisons were made with test results for other 2-D braids and 3-D weaves tested by Boeing and Lockheed. In general, failure strength was found to decrease with increasing plate thickness, increase with decreasing hole size, and decreasing with decreasing width to diameter ratio. The interpretation of the sensitive to each of these geometrical parameters was complicated by scatter in the test data. For open hole tension testing of textile composites, the use of standard testing practices employed by industry, such as ASTM D5766 - Standard Test Method for Open Hole Tensile Strength of Polymer Matrix Composite Laminates should provide adequate results for material comparisons studies.

  16. Solar collector test procedures: development of a method to refer measured efficiencies to standardized test conditions

    SciTech Connect

    Thomas, W.C.

    1984-02-01

    An analytical procedure has been developed for referring collector efficiency measurements, obtained under different test conditions, to a common, or standard set of conditions. The procedure applies to flat-plate liquid-type collectors of conventional tube-in-sheet design. The basic Hottel-Whillier-Bliss theory is used with appropriate extensions to account for serpentine flow configurations and glazing materials with high infrared transmittance. The procedure includes a systematic method for deriving two invariant collector parameters directly from ASHRAE Standard 93-77 test results. The two parameters selected are the plate absorptance and back loss coefficient. A set of standard conditions is recommended which corresponds to favorable test conditions. Experiments were conducted, to evaluate the analytical procedure, on two collectors curves. The results were more consistent for the carefully-controlled research experiments than for routine ASHRAE Standard 93-77 tests at a commercial laboratory. The analytical model provides an effective basis for identifying questionable test data. The analytical correction procedure also applies to alternate test methods for generating flat-plate collector efficiency curves. Experiences and results are described where the test procedure consisted of measuring optical efficiencies and heat losses separately.

  17. Dissolution Dynamic Nuclear Polarization of Polypeptides 

    E-print Network

    Ragavan, Mukundan

    2014-06-27

    Nuclear Magnetic Resonance (NMR) spectroscopy provides remarkable site resolution, but often requires signal averaging because of low sensitivity. Dissolution dynamic nuclear polarization (DNP), which offers large signal ...

  18. Siderite dissolution in the presence of chromate

    NASA Astrophysics Data System (ADS)

    Tang, Yuanzhi; Martin, Scot T.

    2011-09-01

    Siderite (FeCO 3) is an important reduced phase iron mineral and end product of bacteria anaerobic respiration. This study addresses its dissolution behavior in the presence of the oxidant chromate, which is a common environmental contaminant. Macroscopic dissolution experiments combined with microscopic observations by atomic force microscopy show that at pH < 4.5 the dissolution rate with chromate is slower than that in control solution without chromate. Isolated deep dissolution pits and clustered shallow pits occur simultaneously with surface precipitation. The implication is that the surface precipitate inhibits further dissolution. For 5 < pH < 9.5, the slowest dissolution and the fastest precipitation rates are observed, both at edge steps and on terraces. For pH > 10, the dissolution rate in the presence of chromate exceeds that of the control, plausibly due to electron transfer facilitated by Fe(OH)4-. Dissolution and re-precipitation of round hillocks are observed. X-ray photoelectron spectroscopy indicates the presence of Cr(III) as well as reaction products in a hydroxide form. Based on the redox reaction mechanism, macroscopic dissolution behavior, and previous studies on the reaction products of Fe(II) with Cr(VI), we propose the formation of a low solubility nano-sized Cr(III)-Fe(III)-hydroxide as the surface precipitate. Results from this study provide a basis for understanding and quantifying the interactions between reduced-iron minerals and aqueous-phase oxidants.

  19. GROUNDWATER MONITORING: Statistical Methods for Testing Special Background Conditions

    SciTech Connect

    Chou, Charissa J.

    2004-04-28

    This chapter illustrates application of a powerful intra-well testing method referred as the combined Shewhart-CUSUM control chart approach, which can detect abrupt and gradual changes in groundwater parameter concentrations. This method is broadly applicable to groundwater monitoring situations where there is no clearly defined upgradient well or wells, where spatial variability exists in parameter concentrations, or when groundwater flow rate is extremely slow. Procedures for determining the minimum time needed to acquire independent groundwater samples and useful transformations for obtaining normally distributed data are also provided. The control chart method will be insensitive to detect real changes if a preexisting trend is observed in the background data set. A method and a case study describing how a trend observed in a background data set can be removed using a transformation suggested by Gibbons (1994) are presented to illustrate treatment of a preexisting trend.

  20. Kinetics of gibbsite dissolution under low ionic strength conditions

    NASA Astrophysics Data System (ADS)

    Ganor, Jiwchar; Mogollón, Jose Luis; Lasaga, Antonio C.

    1999-06-01

    Experiments measuring synthetic gibbsite dissolution rates were carried out using both a stirred-flow-through reactor and a column reactor at 25°C, and pH range of 2.5-4.1. All experiments were conducted under far from equilibrium conditions (? G < -1.1 kcal/mole). The experiments were performed with perchloric acid under relatively low (and variable) ionic strength conditions. An excellent agreement was found between the results of the well-mixed flow-through experiments and those of the (nonmixed) column experiments. This agreement shows that the gibbsite dissolution rate is independent of the stirring rate and therefore supports the conclusion of Bloom and Erich (1987) that gibbsite dissolution reaction is surface controlled and not diffusion controlled. The Brunauer-Emmett-Teller (BET) surface area of the gibbsite increased during the flow-through experiments, while in the column experiments no significant change in surface area was observed. The agreement between the dissolution rates of the mixed flow-through experiments that were normalized to the final surface area, with these of the column experiments, supports the assumption that the changes in surface area occurred early in the experiment, before the first steady state was approached. The significant differences in the BET surface area between the column experiments and the flow-through experiments, and the excellent agreement between the rates obtained by both methods, enable us to justify the substitution of the BET surface area for the reactive surface area. The dissolution rate of gibbsite varied as a function of the perchloric acid concentration. At pH > 3.5 the dissolution rate increased as a function of acid concentration, while at pH < 3.5 it decreased with acid concentration. We interpret the gibbsite dissolution rate as a result of a combined effect of proton catalysis and perchlorate inhibition. Following the theoretical study of Ganor and Lasaga (1998) we propose specific reaction mechanisms for the gibbsite dissolution in the presence of perchloric acid. The mathematical predictions of two of these reaction mechanisms adequately describe the experimental data.

  1. A method for testing handgun bullets in deer

    E-print Network

    Courtney, M; Courtney, Amy; Courtney, Michael

    2007-01-01

    Using service handguns to test bullets in deer is problematic because of velocity loss with range and accuracy giving sub-optimal shot placement. An alternate method is presented using a scoped muzzleloader shooting saboted handgun bullets to allow precise (within 2" in many cases) shot placement for studying terminal ballistics in a living target. Deer are baited to a known range and path obstructions are used to place the deer broadside to the shooter. Muzzleloading powder charges provide a combination of muzzle velocity and velocity loss due to air resistance for a given ballistic coefficient that produce impact velocities corresponding to typical pistol velocities. With readily available sabots, this approach allows for testing of terminal ballistics of .355, .357, .40, .429, .45, and .458 caliber bullets with two muzzleloaders (.45 and .50 caliber). Examples are described demonstrating the usefulness of testing handgun bullets in deer for acoustic shooting event reconstruction, understanding tissue damag...

  2. A method for testing handgun bullets in deer

    E-print Network

    Michael Courtney; Amy Courtney

    2007-08-01

    Using service handguns to test bullets in deer is problematic because of velocity loss with range and accuracy giving sub-optimal shot placement. An alternate method is presented using a scoped muzzleloader shooting saboted handgun bullets to allow precise (within 2" in many cases) shot placement for studying terminal ballistics in a living target. Deer are baited to a known range and path obstructions are used to place the deer broadside to the shooter. Muzzleloading powder charges provide a combination of muzzle velocity and velocity loss due to air resistance for a given ballistic coefficient that produce impact velocities corresponding to typical pistol velocities. With readily available sabots, this approach allows for testing of terminal ballistics of .355, .357, .40, .429, .45, and .458 caliber bullets with two muzzleloaders (.45 and .50 caliber). Examples are described demonstrating the usefulness of testing handgun bullets in deer for acoustic shooting event reconstruction, understanding tissue damage effects, and comparing relative incapacitation of different loads.

  3. Filtration method efficiently desalts crude in commercial test

    SciTech Connect

    Not Available

    1993-05-17

    During 3 months of industrial testing of a filtration crude oil desalting method, a total of 120,500 metric tons (mt), or 1,475 mt/d (almost 11,000 b/d) of crude was processed. Rongxi Du, Kai Peng, and Li Wang, engineers at Wuhan Petrochemical Works, Wuhan, China, in an unpublished report, indicate that they determined unit operating parameters and performed statistical analyses of desalting-efficiency data from the test run. The engineers also determined relationships between desalting efficiency and flow velocity, relative density, mixing pressure drop (MPD), filtration-tank pressure drop, and temperature. The desalting and dewatering level of single-stage filtrations desalting was found to be equal to that of two-stage electrostatic desalting with remarkable benefits resulting from reduced power, water, and demulsifier requirements. This paper describes the filtration desalting, test parameters, performance results, and filter revivification.

  4. Fluorescence And Alternative Methods In Urine Drug Testing

    NASA Astrophysics Data System (ADS)

    Jain, Naresh C.

    1988-04-01

    Drug abuse has become-one of the most compelling realities _ ot contemporary society. It has penetrated every segment ot our population: trom schools to sports and trom organized crime to board rooms . Drugs in tie w9rkplace allegedly cost government agencies and business millions ot dollars each year in increased absenteeism,. poor work performance, thefts,accidents andwastedtime. The President's Commission on Organized Crime and the federal government are in tavor ot urine drug testing. In fact many employers are now resorting to urine drug testing on current and prospective employees. This presep.tation discusses different laboratory methods used in urine drug.testing, including immunoassays, fluorescence polarization, thin layer chromatography, high pressure liquid chromatography, gas chromatography and gas-chromatography-mass spectrometry.

  5. An improved brine shrimp larvae lethality microwell test method.

    PubMed

    Zhang, Yi; Mu, Jun; Han, Jinyuan; Gu, Xiaojie

    2012-01-01

    This article described an improved brine shrimp larvae lethality microwell test method. A simply designed connecting vessel with alternative photoperiod was used to culture and collect high yield of active Artemia parthenogenetica nauplii for brine shrimp larvae lethality microwell test. Using this method, pure A. parthenogenetica nauplii suspension was easily cultured and harvested with high density about 100-150 larvae per milliliter and the natural mortality was reduced to near zero by elimination of unnecessary artificial disturbance. And its sensitivity was validated by determination of LC(50)-24 h of different reference toxicants including five antitumor agents, two pesticides, three organic pollutants, and four heavy metals salts, most of which exhibited LC(50)-24 h between 0.07 and 58.43 mg/L except for bleomycin and mitomycin C with LC(50)-24 h over 300 mg/L. PMID:21859360

  6. Cost-effective test methods for Shuttle payloads

    NASA Technical Reports Server (NTRS)

    Tinker, Michael L.

    1993-01-01

    Techniques are discussed for deriving constrained vibration mode shapes for Space Shuttle payloads using unconstrained or free-boundary dynamic properties. Application of the residual flexibility method requires measurement of a set of free-boundary modes plus the residual flexibility of the payload-to-orbiter interfaces. The mass-additive approach involves the measurement of unconstrained modes and frequencies of a payload with large masses attached to the interfaces. In either case, the orbiter interfaces of the test-verified payload model are analytically constrained to provide the mode shapes for the Shuttle-constrained configuration. Use of these methods or a hybrid combination of them for structures to which they are applicable allows the difficult and expense associated with development and verification of fixed-base test fixtures to be avoided.

  7. Cost-effective test methods for Shuttle payloads

    NASA Technical Reports Server (NTRS)

    Tinker, Michael L.

    1993-01-01

    Techniques are discussed for deriving constrained vibration mode shapes for space shuttle payloads using unconstrained or free-boundary dynamic properties. Application of the residual flexibility method requires measurement of a set of free boundary modes plus the residual flexibility of the payload-to-orbiter interfaces. The mass-additive approach involves the measurement of unconstrained modes and frequencies of a payload with large masses attached to the interfaces. In either case, the orbiter interfaces of the test-verified payload model are analytically constrained to provide the mode shapes for the shuttle-constrained configuration. Use of these methods or a hybrid combination of them for structures to which they are applicable allows the difficulty and expense associated with development and verification of fixed-base test fixtures to be avoided.

  8. Alternative test methods in inhalation toxicology: challenges and opportunities.

    PubMed

    Costa, Daniel L

    2008-06-01

    Requirements under the new European Union rules regarding Registration, Evaluation & Authorization of Chemicals (REACH) necessitate widespread toxicological safety testing of existing and new chemicals. Given the enormity of new and already in-service chemicals that fall under this new rule, obtaining inhalation toxicity testing data has unique challenges when compared to most biotesting regimes due to the complexity, time and expense involved in conducting standardized inhalation assessments of whole animals. A number of in vitro approaches have been used to obtain respiratory system-related information, but there is no universal or accepted test system to replace inhalation exposure studies. There are many considerations that must be satisfied before adopting any single in vitro bioassay or battery of such assays to substitute for whole animal inhalation data. These considerations relate mostly to the relevance of the bioassay(s) regarding selection of bioassay cell type(s), dose, and fundamental study procedures. There are data in the literature although these have not been well-assessed for such applications, and there exist perhaps more relevant unpublished data in the private sector that could provide guidance on this issue. The formation of a coalition of scientists to assess current knowledge and perhaps to consider a basic comparative study where consensus approaches (with frank discussions of their strengths and weaknesses) would be invaluable to the testing community and to the ultimate protection of human health. In May 2007, a Congress of government, industry, and academic scientists met at the Federal Institute for Risk Assessment (BfR), Berlin, on the subject of Alternative Test Methods in Inhalation Toxicology. The stimulus for the meeting arose from the European Union's (EU) recent implementation of the new REACH safety testing requirements for commercial chemicals and products. Attendees at the meeting presented a panoply of data and perspectives on the state of the science on alternative testing methods and how these might aid safety assessments of inhaled materials. The focus of many presentations was on the fundamental attributes of inhalation toxicology and how these are translated or otherwise addressed in alternative in vitro test methods. There was recognition of the needs and the potential for progress through collaboration, but there remains a clear need for continued discussion and proactive support to a broad-based comparative study. The present discussion provides one perspective of this complex issue and how the science community might collaborate to develop acceptable alternative approaches based in science that have utility in inhalation toxicological assessments. PMID:18486462

  9. Homopolymer Dissolution in a Hydrophilic Ionic Liquid

    NASA Astrophysics Data System (ADS)

    Hoagland, David; Harner, John

    2010-03-01

    Dissolution, structure, and dynamics of both neutral and charged polymers dissolved in a hydrophilic room temperature ionic liquid (IL), ethylmethylimidazolium ethyl sulfate [EMIM][EtSO4], have been studied by classical physicochemical methods (static and dynamic light scattering, intrinsic viscosity, refractometry) to determine differences in solution behavior from conventional aqueous and organic solvents. This IL is water miscible. Many neutral polymers and charged polymer salts molecularly dissolve, although solubility doesn't correlate with polymer hydrophilicity. Model neutral soluble polymers are polyvinylpyrrolidone and hydroroxyethyl cellulose while sodium poly(styrene sulfonate) and the iodo salt of methyl-quaternized poly(vinyl pyridine) fill the same role for charged polymers. The latter display none of the polyelectrolyte effects found in low ionic strength water, consistent with strong electrostatic screening in IL. In virial coefficient and coil size, the IL acts for these neutral and charged polymers as a classical good solvent. (Support: UMass MRSEC)

  10. Applications of Automation Methods for Nonlinear Fracture Test Analysis

    NASA Technical Reports Server (NTRS)

    Allen, Phillip A.; Wells, Douglas N.

    2013-01-01

    Using automated and standardized computer tools to calculate the pertinent test result values has several advantages such as: 1. allowing high-fidelity solutions to complex nonlinear phenomena that would be impractical to express in written equation form, 2. eliminating errors associated with the interpretation and programing of analysis procedures from the text of test standards, 3. lessening the need for expertise in the areas of solid mechanics, fracture mechanics, numerical methods, and/or finite element modeling, to achieve sound results, 4. and providing one computer tool and/or one set of solutions for all users for a more "standardized" answer. In summary, this approach allows a non-expert with rudimentary training to get the best practical solution based on the latest understanding with minimum difficulty.Other existing ASTM standards that cover complicated phenomena use standard computer programs: 1. ASTM C1340/C1340M-10- Standard Practice for Estimation of Heat Gain or Loss Through Ceilings Under Attics Containing Radiant Barriers by Use of a Computer Program 2. ASTM F 2815 - Standard Practice for Chemical Permeation through Protective Clothing Materials: Testing Data Analysis by Use of a Computer Program 3. ASTM E2807 - Standard Specification for 3D Imaging Data Exchange, Version 1.0 The verification, validation, and round-robin processes required of a computer tool closely parallel the methods that are used to ensure the solution validity for equations included in test standard. The use of automated analysis tools allows the creation and practical implementation of advanced fracture mechanics test standards that capture the physics of a nonlinear fracture mechanics problem without adding undue burden or expense to the user. The presented approach forms a bridge between the equation-based fracture testing standards of today and the next generation of standards solving complex problems through analysis automation.

  11. Problems with outlier test methods in flood frequency analysis

    NASA Astrophysics Data System (ADS)

    Hu, Siyi

    1987-12-01

    In flood frequency analysis, the term "outlier" is commonly used to denote large floods in the systematic record or historical floods which lie far above the majority of the floods in the sample. The mere existence of these outliers complicates the frequency analysis procedure. In order to avoid any subjectivity in the detection and treatment of outliers, the U.S. Water Resources Council (WRC) recommended a method based on the principles of hypotheses testing. In spite of the fact that it has been extensively applied in the United States, there are some theoretical and practical aspects which require further consideration. A study of principles reveals that outlier tests in a statistical context postulate an assumption that outliers have a unique distribution which is different from that of the remaining sample observations. Thus, the theory underlying the outlier test is in conflict with the phenomenon of outliers in flood data because it is generally accepted that both historical floods and extraordinary floods in systematic records all come from a common unknown population including all floods. Consequently it would not be reasonable to introduce outlier tests into a flood frequency analysis. In addition, the so-called "masking effect" encountered in the practical use of the outlier test method in U.S. Water Resources Council (1981) is analytically discussed. Observed flood records at several stations are used to illustrate that the test in WRC Bulletin 17B does not guarantee the detection of outliers if more than one is present in the sample due to this "masking effect".

  12. Lidar Tracking of Multiple Fluorescent Tracers: Method and Field Test

    NASA Technical Reports Server (NTRS)

    Eberhard, Wynn L.; Willis, Ron J.

    1992-01-01

    Past research and applications have demonstrated the advantages and usefulness of lidar detection of a single fluorescent tracer to track air motions. Earlier researchers performed an analytical study that showed good potential for lidar discrimination and tracking of two or three different fluorescent tracers at the same time. The present paper summarizes the multiple fluorescent tracer method, discusses its expected advantages and problems, and describes our field test of this new technique.

  13. Impact friction test method by applying stress wave

    Microsoft Academic Search

    K. Ogawa

    1997-01-01

    To understand the dynamic response of two bodies in contact, kinetic friction during impact presently is focused on. A new\\u000a testing technique, which provides the normal and the tangential impact force independently, is developed by modifying the\\u000a split Hopkinson pressure bar method. Normal and torsional stress wave propagation in a one-dimensional framework of an axial\\u000a impact of an input tube

  14. Standard Test Method for Hot Spot Protection Testing of Photovoltaic Modules

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method provides a procedure to determine the ability of a photovoltaic (PV) module to endure the long-term effects of periodic “hot spot” heating associated with common fault conditions such as severely cracked or mismatched cells, single-point open circuit failures (for example, interconnect failures), partial (or non-uniform) shadowing or soiling. Such effects typically include solder melting or deterioration of the encapsulation, but in severe cases could progress to combustion of the PV module and surrounding materials. 1.2 There are two ways that cells can cause a hot spot problem; either by having a high resistance so that there is a large resistance in the circuit, or by having a low resistance area (shunt) such that there is a high-current flow in a localized region. This test method selects cells of both types to be stressed. 1.3 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of this test method....

  15. In vitro dissolution and in vivo bioavailability of six brands of ciprofloxacin tablets administered in rabbits and their pharmacokinetic modeling.

    PubMed

    Fahmy, Sahar; Abu-Gharbieh, Eman

    2014-01-01

    This study was undertaken to assess the in vitro dissolution and in vivo bioavailability of six brands of ciprofloxacin oral tablets available in the UAE market using rabbits. The in vitro dissolution profiles of the six ciprofloxacin products were determined using the USP dissolution paddle method. Pharmacokinetic modeling using compartmental and noncompartmental analysis was done to determine the pharmacokinetic parameters of ciprofloxacin after single-dose oral administration. In vitro release study revealed that the amount of ciprofloxacin released in 20 minutes was not less than 80% of the labeled amount which is in accordance with the pharmacopoeial requirements. All tested products are considered to be very rapid dissolving except for formulae A and D. Ciprofloxacin plasma concentration in rabbits was best fitted to a two-compartment open model. The lowest bioavailability was determined to be for product A (93.24%) while the highest bioavailability was determined to be for product E (108.01%). Postmarketing surveillance is very crucial to ensure product quality and eliminating substandard products to be distributed and, consequently, ensure better patient clinical outcome. The tested ciprofloxacin generic products distributed in the UAE market were proven to be of good quality and could be used interchangeably with the branded ciprofloxacin product. PMID:24995312

  16. A comparison of three shear test methods for composite materials

    NASA Technical Reports Server (NTRS)

    Ho, H.; Tsai, M. Y.; Morton, J.; Farley, G. L.

    1991-01-01

    A graphite-epoxy composite material system is used to evaluate the performance of three popular shear tests - the 10-deg off-axis, the +/-45-deg tension, and the Iosipescu specimen tested in the modified Wyoming fixture. A comparison of the shear stress-strain response for each test method is made using a conventional strain gage instrument and moire interferometry. The uniformity and purity of the strain fields in the test sections of the specimens are discussed, and the shear responses obtained from each test are presented and compared. It is shown that the shear stress-strain responses obtained by instrumenting only one face of the 90-deg Iosipescu specimen could give erroneous results. The +/-45-deg tensile and 0-deg Iosipescu specimens were not affected by front-to-back face shear strain variations. Correction factors could be applied to bring all responses together, within the limits of the material uniformity, which was itself documented in the moire fringe patterns.

  17. Standard methods for filled hole tension testing of textile composites

    NASA Technical Reports Server (NTRS)

    Portanova, M. A.; Masters, J. E.

    1995-01-01

    The effects of two test specimen geometry parameters, the specimen width and W/D ratio, on filled-hole tensile strength were determined for textile composite materials. Test data generated by Boeing and Lockheed on 2-D and 3-D braids, and 3-D weaves were used to make these evaluations. The investigation indicated that filled-hole tensile-strength showed little sensitivity to either parameter. Test specimen configurations used in open-hole tension tests, such as those suggested by ASTM D5766 - Standard Test Method for Open Hole Tensile Strength of Polymer Matrix Composite Laminates or those proposed by MIL-HDBK-17-lD should provide adequate results for material comparisons studies. Comparisons of the materials' open-hole and filled-hole tensile strengths indicated that the latter were generally lower than the former. The 3-D braids were the exception; their filled-hole strengths were unexpected larger than their open-hole strengths. However, these increases were small compared to the scatter in the data. Thus, filled hole tension may be a critical design consideration for textile composite materials.

  18. Standard Methods for Unnotched Tension Testing of Textile Composites

    NASA Technical Reports Server (NTRS)

    Portanova, M. A.

    1995-01-01

    An investigation was conducted by researchers at the Boeing Defense & Space Group to investigate the effects of specimen sizing on several braided textile materials. Test results from this and other test programs were compared in an effort to determine what effect, if any, specimen size has on elastic property measurements of unnotched tension test. In general, the unnotched tensile strength of 2-D braids was found to be insensitive to specimen width, length, or thickness effects. The results from this study suggest that standard testing methods used for tape materials may be sufficient for tension testing of textile composite materials. Specifically, the straight sided specimen geometry described in ASTM 3034, and used by Boeing, should provide acceptable results. Further experiments performed at Boeing and by other investigators on other textile architectures suggest similar results. Although specimen size studies were not conducted, failing stresses varied on the same order as those obtained with the 2-D materials. This suggests that the accuracy of the results were consistent with those obtained with the 2-D materials.

  19. Efficient Method for Calculating Hydraulic Conductivity from Pneumatic Slug Tests

    NASA Astrophysics Data System (ADS)

    Peng, X.; Cheung, B.; Knappett, P. S.; Zhan, H.

    2014-12-01

    Pneumatic slug tests are widely used in characterizing the hydraulic conductivity of aquifers. In comparison to a manual slug test wherein the water level is measured using a water level tape, pneumatic slug tests are especially useful when the water level recovery is very fast (<10 sec) in a high hydraulic conductivity (K) aquifer (>10-4 m/s) and when the recovery is very slow (<10-7 m/s). The submerged pressure transducer monitors pressure changes at intervals of fractions of a second and for longer recoveries no personnel are required to make repeated measurements. A pneumatic slug test begins with pressurizing the well at the well head using an air pump followed by several minutes waiting for the pressure in the well to equalize with the pressure outside the well screen. In semi-confined settings this equalization may take >5 minutes. In lower K media it's not always feasible to wait until the well fully recovers before making the next replicate measurement. Therefore, it would greatly reduce the time needed to make replicate measurements if these waiting times could be reduced. Here we present a method using non-linear least squares regression on a portion of the recovery curve to simultaneously fit 3 parameters used to determine K from a slug tests using the Hvorslev method. The advantage of this approach is that waiting for the well to reach static head between replicate measurements is not required. This is because the regression fits static head (H) from the shape of only part the recovery curve. We compare the resulting K values from this new method to values obtained from manually measured static heads for triplicate measurements on 50 wells. The well's settings ranged from unconfined to semi-confined and K ranged from 10-3 to 10-5 m/s. The new method gave identical results. We performed the same comparison on a subset 16 wells using data collected in half the time, where only part of the recovery curves were measured before starting the next replicate. This also resulted in near identical K values. Sensitivity analyses indicated that only about 30% of the recovery curve needs to be measured to accurately determine K. This method saves time in investigations where large numbers of monitoring wells are involved and/or where wells are placed in low K media.

  20. Light water reactor fuel reprocessing: dissolution studies of voloxidized and nonvoloxidized fuel

    SciTech Connect

    Johnson, D.R.; Stone, J.A.

    1980-04-01

    Small-scale tests with irradiated Zircaloy-clad fuels from Robinson, Oconee, Saxton, and Point Beach reactors with burnups from about 200 to 28,000 MWD/MTHM have been made to determine the dissolution behavior of both voloxidized (U{sub 3}O{sub 8}) and nonvoloxidized (UO{sub 2}) fuel. No significant technical problems were encountered in batch-dissolving of either form. Dissolution rates were well-controlled in all tests. Significant characteristics of U{sub 3}O{sub 8} dissolution that differed from UO{sub 2} dissolution included: (1) reduced tritium and ruthenium ({sup 106}Ru) concentrations in product solutions, (2) increased insoluble noble metal fission product residue (about 2.2X greater), and (3) increased insoluble plutonium in the fission product residue. The insoluble plutonium is easily leached from the residue by 10M HNO{sub 3}. The weight of the fission product residue collected from both U{sub 3}O{sub 8} and UO{sub 2} fuels increased aproximately linearly with fuel burnup. A major fraction (>83%) of the {sup 85}Kr was evolved from U{sub 3}O{sub 8} fuel during dissolution rather than voloxidation. The {sup 85}Kr evolution rate was an appropriate monitor of fuel dissolution rate. Virtually all of the {sup 129}I was evolved by air sparging of the dissolver solution during dissolution. 30 tables, 18 figures.

  1. Hydrodynamic Enhancements of Dissolution from Drug Particles: In vivo vs. In vitro

    NASA Astrophysics Data System (ADS)

    Brasseur, James; Wang, Yanxing

    2013-11-01

    Absorption of drug molecules into the blood stream is generally limited by dissolution-rate in the intestines. Dissolution occurs via diffusion enhanced by a response to the hydrodynamic flow environment, a process that is very different in the human intestine than in a USP-II dissolution apparatus, commonly used by drug companies to validate new drug formulations. Whereas in vivo hydrodynamics are driven by the motility of intestinal wall muscles, the USP-II apparatus is a rotating paddle to mix drug particles during dissolution testing. These differences are of current interest to agencies that regulate drug product development. Through lattice-Boltzmann-based computer simulation of point particles transported through human intestine, we analyze the hydrodynamic parameters associated with convection that quantify the extent to which in vitro dissolution tests are or are not relevant to in vivo hydrodynamics. . We show that for drug particles less that ~100-200 microns, effects of convection are negligible in the intestines. However, we discover a previously unappreciated phenomenon that significantly enhances dissolution-rate and that distinguishes in vitro from in vivo dissolution: the fluid shear rate at the particle. Supported by NSF and AstraZeneca.

  2. Dissolution and compaction instabilities in geomaterials

    NASA Astrophysics Data System (ADS)

    Stefanou, I.; Sulem, J.; de Sauvage, J.

    2014-12-01

    Compaction bands play an important role in reservoir engineering and geological storage. Their presence in geological formations may also provide useful information on various geological processes. Several mechanisms can be involved at different scales and may be responsible for compaction band instabilities [1]. Compaction bands can be seen as a particular instability of the governing mathematical system leading to localization of deformation [2-4]. In a saturated porous rock, the progressive mechanical damage of the solid skeleton during compaction, results in the increase of the interface area of the reactants and consequently in the acceleration of the dissolution rate of the solid phase [2,5]. Thus, the solid skeleton is degraded more rapidly (mass removal because of dissolution), the overall mechanical properties of the system diminish (contraction of the elastic domain - chemical softening), deformations increase and the solid skeleton is further damaged (intergranular fractures, debonding, breakage of the porous network etc.). The stability of this positive feedback process is investigated analytically through linear stability analysis by considering the strong chemo-poro-mechanical coupling due to chemical dissolution. The post bifurcation behavior is then studied analytically and numerically revealing the compaction band thickness and periodicity. The effect of various parameters is studied as for instance the influence of the hydraulic diffusivity on the compaction band thickness. [1] P. Baud, S. Vinciguerra, C. David, A. Cavallo, E. Walker and T. Reuschlé (2009), Pure Appl. Geophys., 166(5-7), 869-898 [2] I. Stefanou and J. Sulem (2014), JGR: Solid Earth, 119(2), 880-899. doi:10.1002/2013JB010342I [3] J.W. Rudnicki and J.R. Rice (1975), Journal of the Mechanics and Physics of Solids 23(6),: 371-394 [4] K.A. Issen and J.W. Rudnicki (2000), JGR, 105(B9), 21529. doi:10.1029/2000JB900185 [5] R. Nova, R. Castellanza and C. Tamagnini (2003), International Journal for Numerical and Analytical Methods in Geomechanics, 27(9): 705-732

  3. Phototoxicity: Its Mechanism and Animal Alternative Test Methods

    PubMed Central

    Park, Hyeonji; Lim, Kyung-Min

    2015-01-01

    The skin exposure to solar irradiation and photoreactive xenobiotics may produce abnormal skin reaction, phototoxicity. Phototoxicity is an acute light-induced response, which occurs when photoreacive chemicals are activated by solar lights and transformed into products cytotoxic against the skin cells. Multifarious symptoms of phototoxicity are identified, skin irritation, erythema, pruritis, and edema that are similar to those of the exaggerated sunburn. Diverse organic chemicals, especially drugs, are known to induce phototoxicity, which is probably from the common possession of UV-absorbing benzene or heterocyclic rings in their molecular structures. Both UVB (290~320 nm) and UVA (320~400 nm) are responsible for the manifestation of phototoxicity. Absorption of photons and absorbed energy (hv) by photoactive chemicals results in molecular changes or generates reactive oxygen species and depending on the way how endogenous molecules are affected by phototoxicants, mechanisms of phototoxcity is categorized into two modes of action: Direct when unstable species from excited state directly react with the endogenous molecules, and indirect when endogeneous molecules react with secondary photoproducts. In order to identify phototoxic potential of a chemical, various test methods have been introduced. Focus is given to animal alternative test methods, i.e., in vitro, and in chemico assays as well as in vivo. 3T3 neutral red uptake assay, erythrocyte photohemolysis test, and phototoxicity test using human 3-dimensional (3D) epidermis model are examples of in vitro assays. In chemico methods evaluate the generation of reactive oxygen species or DNA strand break activity employing plasmid for chemicals, or drugs with phototoxic potential.

  4. Novel Trends in Optical Non-Destructive Testing Methods

    NASA Astrophysics Data System (ADS)

    Huke, P.; Klattenhoff, R.; von Kopylow, C.; Bergmann, R. B.

    2013-07-01

    Non-destructive testing (NDT) describes a wide range of methods for measuring and comparing physical quantities against a nominal condition. In this paper we describe and compare different optical NdT (ONDT)-methods with respect to their characteristics and capability for different measurement tasks. ONDT may be specified in two categories, passive and active. The NDT principles of the first category just use a measurement method like view inspection, elipsometry or reflectometry to detect defects which are easily accessible. The principles of the second category use an excitation force, such as heat or mechanical vibration introduced by transducers to detect hidden defects. This category can be specified into two subcategories. The first subcategory "time-/depth-resolved" includes measurement methods delivering detailed information of the geometric features of a hidden defect. Therefore the excitation of the material and the detection of the reaction have to provide a ti! me step which enables depth-solved measurements. Phase-resolved thermography and laser ultrasound are examples for this category. The second subcategory "Integrating" includes measurement technique coupled with an excitation that enables detection of defects but not evaluation of their geometric features. Examples for these measurement techniques are shearography, reflectometry, vibrometry and thermography coupled with excitation method like simple heating or loading with a constant force. We demonstrate experimental results obtained using methods developed in our institute and highlight directions of further development.

  5. Simulation of rock salt dissolution and its impact on land subsidence

    NASA Astrophysics Data System (ADS)

    Zidane, A.; Zechner, E.; Huggenberger, P.; Younes, A.

    2014-06-01

    Extensive land subsidence can occur due to subsurface dissolution of evaporites such as halite and gypsum. This paper explores techniques to simulate the salt dissolution forming an intrastratal karst, which is embedded in a sequence of carbonates, marls, anhydrite and gypsum. A numerical model is developed to simulate laminar flow in a subhorizontal void, which corresponds to an opening intrastratal karst. The numerical model is based on the laminar steady-state Stokes flow equation, and the advection dispersion transport equation coupled with the dissolution equation. The flow equation is solved using the nonconforming Crouzeix-Raviart (CR) finite element approximation for the Stokes equation. For the transport equation, a combination between discontinuous Galerkin method and multipoint flux approximation method is proposed. The numerical effect of the dissolution is considered by using a dynamic mesh variation that increases the size of the mesh based on the amount of dissolved salt. The numerical method is applied to a 2-D geological cross section representing a Horst and Graben structure in the Tabular Jura of northwestern Switzerland. The model simulates salt dissolution within the geological section and predicts the amount of vertical dissolution as an indicator of potential subsidence that could occur. Simulation results showed that the highest dissolution amount is observed near the normal fault zones, and, therefore, the highest subsidence rates are expected above normal fault zones.

  6. Simulation of rock salt dissolution and its impact on land subsidence

    NASA Astrophysics Data System (ADS)

    Zidane, A.; Zechner, E.; Huggenberger, P.; Younes, A.

    2013-10-01

    Extensive land subsidence can occur due to subsurface dissolution of evaporites such as halite and gypsum. This paper explores techniques to simulate the salt dissolution forming an intrastratal karst, which is embedded in a sequence of carbonates, marls, anhydrite and gypsum. A numerical model is developed to simulate laminar flow in reactive fractures. The numerical model is based on the laminar steady state Stokes flow equation, and the advection dispersion transport equation coupled with the dissolution equation. The flow equation is solved using the nonconforming Crouzeix-Raviart (CR) finite element approximation for the Stokes equation. For the transport equation, a combination between Discontinuous Galerkin Method and Multipoint Flux Approximation Method is proposed. The numerical effect of the dissolution is considered by using a dynamic mesh variation that increases the size of the mesh based on the amount of dissolved salt. The numerical method is applied to a 2-D geological cross section representing a Horst and Graben structure in the Tabular Jura of north-western Switzerland. It simulates salt dissolution within the geological section and predicts the amount of vertical dissolution as an indicator of subsidence that could occur. Simulation results showed that the highest dissolution amount is observed near the normal fault zones, and therefore the highest subsidence rates are expected above fault zones.

  7. CALCIUM CARBONATE DISSOLUTION RATE IN LIMESTONE CONTRACTORS

    EPA Science Inventory

    The rate of carbonate mineral dissolution from limestone was studied using a rotating disk apparatus and samples of limestone of varied composition. he purpose of this study was to determine the effect of limestone composition on the kinetics of carbonate mineral dissolution. he ...

  8. Stirring effect on kaolinite dissolution rate

    NASA Astrophysics Data System (ADS)

    Metz, Volker; Ganor, Jiwchar

    2001-10-01

    Experiments were carried out measuring kaolinite dissolution rates using stirred and nonstirred flow-through reactors at pHs 2 to 4 and temperatures of 25°C, 50°C, and 70°C. The results show an increase of kaolinite dissolution rate with increasing stirring speed. The stirring effect is reversible, i.e., as the stirring slows down the dissolution rate decreases. The effect of stirring speed on kaolinite dissolution rate is higher at 25°C than at 50°C and 70°C and at pH 4 than at pHs 2 and 3. It is suggested that fine kaolinite particles are formed as a result of stirring-induced spalling or abrasion of kaolinite. These very fine particles have an increased ratio of reactive surface area to specific surface area, which results in enhancement of kaolinite dissolution rate. A balance between production and dissolution of the fine particles explains both the reversibility and the temperature and pH dependence of the stirring effect. Since the stirring effect on kaolinite dissolution rate varies with temperature and pH, measurement of kinetic parameters such as activation energy may be influenced by stirring. Therefore, standard use of nonagitated reaction vessels for kinetic experiments of mineral dissolution and precipitation is recommended, at least for slow reactions that are surface controlled.

  9. Thermal dissolution of solid fossil fuels

    SciTech Connect

    E.G. Gorlov [Institute for Fossil Fuels, Moscow (Russian Federation)

    2007-10-15

    The use of oil shales and coals in the processes of thermal dissolution is considered. It is shown that thermal dissolution is a mode of liquefaction of solid fossil fuels and can be used both independently and in combination with liquefaction of coals and processing of heavy petroleum residues.

  10. Test method for the microbial barrier properties of packaging for medical devices ; RIVM method

    Microsoft Academic Search

    Bruijn ACP de; Asten JAAM van

    2007-01-01

    One of the most important qualities of packaging for medical devices is\\u000athe ability to keep the contents sterile. The quality of the packaging\\u000ais determined by the quality of the material and the quality of the\\u000aseals. The former is usually tested with test methods using\\u000amicro-organisms. In hospitals many packages are formed by wrapping\\u000ainstrument trays in sheet

  11. Triboelectrification and dissolution property enhancements of solid dispersions.

    PubMed

    Asare-Addo, Kofi; Šupuk, Enes; Al-Hamidi, Hiba; Owusu-Ware, Samuel; Nokhodchi, Ali; Conway, Barbara R

    2015-05-15

    The use of solid dispersion techniques to modify physicochemical properties and improve solubility and dissolution rate may result in alteration to electrostatic properties of particles. Particle triboelectrification plays an important part in powder processing, affecting end product quality due to particle deposition and powder loss. This study investigates the use of glucosamine hydrochloride (GLU) in solid dispersions with indomethacin. Solvents selected for the preparation of the dispersions were acetone, acetone-water, ethanol and ethanol-water. Solid state characterizations (DSC, FTIR and XRPD) and dissolution were conducted. Dispersions were subjected to charge using a custom built device based on a shaking concept, consisting of a Faraday cup connected to an electrometer. All dispersions improved the dissolution rate of indomethacin. Analysis showed the method of preparation of the dispersion induced polymorphic forms of the drug. Indomethacin had a high propensity for charging (-411nC/g). GLU had a very low charge (-1nC/g). All dispersions had low charges (-1 to 14nC/g). Acetone as a solvent, or in combination with water, produced samples with an electronegative charge in polarity. The same approach with ethanol produced electropositive charging. The results show the selection of solvents can influence powder charge thereby improving powder handling as well as dissolution properties. PMID:25772415

  12. Verification and application of the Iosipescu shear test method

    NASA Technical Reports Server (NTRS)

    Walrath, D. E.; Adams, D. F.

    1984-01-01

    Finite element models were used to study the effects of notch angle variations on the stress state within an Iosipescu shear test speciment. These analytical results were also studied to determine the feasibility of using strain gage rosettes and a modified extensometer to measure shear strains in this test specimen. Analytical results indicate that notch angle variations produced only small differences in simulated shear properties. Both strain gage rosettes and the modified extensometer were shown to be feasible shear strain transducers for the test method. The Iosipoescu shear test fixture was redesigned to incorporate several improvements. These improvements include accommodation of a 50 percent larger specimen for easier measurement of shear train, a clamping mechanism to relax strict tolerances on specimen width, and a self contained alignment tool for use during specimen installation. A set of in-plane and interlaminar shear properties were measured for three graphite fabric/epoxy composites of T300/934 composite material. The three weave patterns were Oxford, 5-harness satin, and 8-harness satin.

  13. Simulation Method for Wind Tunnel Based Virtual Flight Testing

    NASA Astrophysics Data System (ADS)

    Li, Hao; Zhao, Zhong-Liang; Fan, Zhao-Lin

    The Wind Tunnel Based Virtual Flight Testing (WTBVFT) could replicate the actual free flight and explore the aerodynamics/flight dynamics nonlinear coupling mechanism during the maneuver in the wind tunnel. The basic WTBVFT concept is to mount the test model on a specialized support system which allows for the model freely rotational motion, and the aerodynamic loading and motion parameters are measured simultaneously during the model motion. The simulations of the 3-DOF pitching motion of a typical missile in the vertical plane are performed with the openloop and closed-loop control methods. The objective is to analyze the effect of the main differences between the WTBVFT and the actual free flight, and study the simulation method for the WTBVFT. Preliminary simulation analyses have been conducted with positive results. These results indicate that the WTBVFT that uses closed-loop autopilot control method with the pitch angular rate feedback signal is able to replicate the actual free flight behavior within acceptable differences.

  14. METHOD TO TEST ISOTOPIC SEPARATION EFFICIENCY OF PALLADIUM PACKED COLUMNS

    SciTech Connect

    Heung, L; Gregory Staack, G; James Klein, J; William Jacobs, W

    2007-06-27

    The isotopic effect of palladium has been applied in different ways to separate hydrogen isotopes for many years. At Savannah River Site palladium deposited on kieselguhr (Pd/k) is used in a thermal cycling absorption process (TCAP) to purify tritium for over ten years. The need to design columns for different throughputs and the desire to advance the performance of TCAP created the need to evaluate different column designs and packing materials for their separation efficiency. In this work, columns with variations in length, diameter and metal foam use, were tested using an isotope displacement method. A simple computer model was also developed to calculate the number of theoretical separation stages using the test results. The effects of column diameter, metal foam and gas flow rate were identified.

  15. Test images for the maximum entropy image restoration method

    NASA Technical Reports Server (NTRS)

    Mackey, James E.

    1990-01-01

    One of the major activities of any experimentalist is data analysis and reduction. In solar physics, remote observations are made of the sun in a variety of wavelengths and circumstances. In no case is the data collected free from the influence of the design and operation of the data gathering instrument as well as the ever present problem of noise. The presence of significant noise invalidates the simple inversion procedure regardless of the range of known correlation functions. The Maximum Entropy Method (MEM) attempts to perform this inversion by making minimal assumptions about the data. To provide a means of testing the MEM and characterizing its sensitivity to noise, choice of point spread function, type of data, etc., one would like to have test images of known characteristics that can represent the type of data being analyzed. A means of reconstructing these images is presented.

  16. Evaluation of Cleanliness Test Methods for Spacecraft PCB Assemblies

    NASA Astrophysics Data System (ADS)

    Tegehall, P.-E.; Dunn, B. D.

    2006-10-01

    Ionic contamination on printed-circuit-board assemblies may cause current leakage and short-circuits. The present cleanliness requirement in ECSS-Q-70-08, "The manual soldering of high-reliability electrical connections", is that the ionic contamination shall be less than 1.56 fl-glcm2 NaCI equivalents. The relevance of the method used for measurement of the ionic contamination level, resistivity of solvent extract, has been questioned. Alternative methods are ion chromatography and measurement of surface insulation resistance, but these methods also have their drawbacks. These methods are first described and their advantages and drawbacks are discussed. This is followed by an experimental evaluation of the three methods. This was done by soldering test vehicles at four manufacturers of space electronics using their ordinary processes for soldering and cleaning printed board assemblies. The experimental evaluation showed that the ionic contamination added by the four assemblers was very small and well below the acceptance criterion in ECSS-Q-70-80. Ion-chromatography analysis showed that most of the ionic contamination on the cleaned assembled boards originated from the hot-oil fusing of the printed circuit boards. Also, the surface insulation resistance was higher on the assembled boards compared to the bare printed circuit boards. Since strongly activated fluxes are normally used when printed circuit boards are hot-oil fused, it is essential that they are thoroughly cleaned in order to achieve low contamination levels on the final printed-board assemblies.

  17. Attenuated total reflection infrared spectroscopy (ATR-IR) as an in s itu technique for dissolution studies

    Microsoft Academic Search

    Abe Kassis; Vrushali M. Bhawtankar; John R. Sowa Jr.

    2010-01-01

    Dissolution studies are critical tests for measuring the performance of a drug product. We have developed a novel technique using in situ ATR-IR spectroscopy to monitor dissolutions of pharmaceutical drug products. The accuracy of this technique is ±3% relative to HPLC using salicylic acid calibrator tablets and acetaminophen OTC tablets. This novel approach also gives the research laboratory the capability

  18. Assessment of Dissolution Profile of Marketed Aceclofenac Formulations

    PubMed Central

    Soni, T; Chotai, N

    2010-01-01

    Statistical comparison of dissolution profiles under a variety of conditions relating to formulation characteristics, lot-to-lot, and brand-to-brand variation attracts interest of pharmaceutical scientist. The objective of this work is to apply several profile comparison approaches to the dissolution data of five-marketed aceclofenac tablet formulations. Model-independent approaches including ANOVA-based procedures, ratio test procedure, and pair wise procedure. The ratio test includes percentage, area under the curve, mean dissolution time, while the pair wise procedure includes difference factor (f1), similarity factor (f2), and Rescigno index. In the model-dependent approach, zero order, first order, Hixson-Crowell, Higuchi, and Weibull models were applied to the utilization of fit factors. All the approaches were applicable and useful. ANOVA with multiple comparison tests was found to be sensitive and discriminating for comparing the profiles. Weibull parameters were more sensitive to the difference between two release kinetic data in terms of curve shape and level. PMID:21331186

  19. Assessment of dissolution profile of marketed aceclofenac formulations.

    PubMed

    Soni, T; Chotai, N

    2010-01-01

    Statistical comparison of dissolution profiles under a variety of conditions relating to formulation characteristics, lot-to-lot, and brand-to-brand variation attracts interest of pharmaceutical scientist. The objective of this work is to apply several profile comparison approaches to the dissolution data of five-marketed aceclofenac tablet formulations. Model-independent approaches including ANOVA-based procedures, ratio test procedure, and pair wise procedure. The ratio test includes percentage, area under the curve, mean dissolution time, while the pair wise procedure includes difference factor (f(1)), similarity factor (f(2)), and Rescigno index. In the model-dependent approach, zero order, first order, Hixson-Crowell, Higuchi, and Weibull models were applied to the utilization of fit factors. All the approaches were applicable and useful. ANOVA with multiple comparison tests was found to be sensitive and discriminating for comparing the profiles. Weibull parameters were more sensitive to the difference between two release kinetic data in terms of curve shape and level. PMID:21331186

  20. Comparison of the "method of limits" and "alternate choice" methods in vibrometry testing 

    E-print Network

    Hayes, Eloise Carlton

    1992-01-01

    ) Eloise Carlton Hayes, B. S. , Texas ASM University Chair of Advisory Committee: Dr. Jerome J. Congleton Vibrometry, a diagnostic tool used to screen for early Carpal Tunnel Syndrome (CTS) cases, utilizes two testing techniques. These two methods... finger when data was compared to previous studies using the alternate choice method. ACKNOWLEDGEMENTS The work presented in this thesis could not have been completed without the help and encouragement of many persons. I would like to thank Dr. Jerome...

  1. Comparison of the "method of limits" and "alternate choice" methods in vibrometry testing

    E-print Network

    Hayes, Eloise Carlton

    1992-01-01

    ) Eloise Carlton Hayes, B. S. , Texas ASM University Chair of Advisory Committee: Dr. Jerome J. Congleton Vibrometry, a diagnostic tool used to screen for early Carpal Tunnel Syndrome (CTS) cases, utilizes two testing techniques. These two methods... the Vibratron II to measure vibration thresholds. Each group consisted of 25 subjects. All subjects were screened and found to be "healthy" (i. e. non-symptomatic for CTS). The method of limits technique was preferted by 70% of the subjects over...

  2. Standard Test Method for Measured Speed of Oil Diffusion Pumps

    E-print Network

    American Society for Testing and Materials. Philadelphia

    1982-01-01

    1.1 This test method covers the determination of the measured speed (volumetric flow rate) of oil diffusion pumps. 1.2 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  3. An Accelerated Method for Testing Soldering Tendency of Core Pins

    SciTech Connect

    Han, Qingyou [ORNL; Xu, Hanbing [ORNL; Ried, Paul [Ried, Engineering; Olson, Paul [Balzers, Inc.

    2010-01-01

    An accelerated method for testing die soldering has been developed. High intensity ultrasonic vibrations has been used to simulate the die casting conditions such as high pressure and high impingement speed of molten metal on the pin. Soldering tendency of steels and coated pins has been examined. The results indicate that in the low carbon steel/Al system, the onset of soldering is 60 times faster with ultrasonic vibration than that without ultrasonic vibration. In the H13/A380 system, the onset of soldering reaction is accelerated to 30-60 times. Coating significantly reduces the soldering tendency of the core pins.

  4. Standard Test Method for Abrasive Wear Resistance of Cemented

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the determination of abrasive wear resistance of cemented carbides. 1.2 The values stated in inch-pound units are to be regarded as the standard. The SI equivalents of inch-pound units are in parentheses and may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  5. Asymmetric collapse by dissolution or melting in a uniform flow

    E-print Network

    Rycroft, Chris H

    2015-01-01

    An advection--diffusion-limited dissolution model of an object being eroded by a two-dimensional potential flow is presented. By taking advantage of the conformal invariance of the model, a numerical method is introduced that tracks the evolution of the object boundary in terms of a time-dependent Laurent series. Simulations of a variety of dissolving objects are shown, which shrink and then collapse to a single point in finite time. The simulations reveal a surprising exact relationship whereby the collapse point is the root of a non-analytic function given in terms of the flow velocity and the Laurent series coefficients describing the initial shape. This result is subsequently derived using residue calculus. The structure of the non-analytic function is examined for three different test cases, and a practical approach to determine the collapse point using a generalized Newton--Raphson root-finding algorithm is outlined. These examples also illustrate the possibility that the model breaks down in finite tim...

  6. Dissolution characteristics of mixed UO{sub 2} powders in J-13 water under saturated conditions

    SciTech Connect

    Veleckis, E.; Hoh, J.C.

    1991-03-01

    The Yucca Mountain Project/Spent Fuel program at Argonne National Laboratory is designed to determine radionuclide release rates by exposing high-level waste to repository-relevant groundwater. To gain experience for the tests with spent fuel, a scoping experiment was conducted at room temperature to determine the uranium release rate from an unirradiated UO{sub 2} powder mixture (14.3 wt % enrichment in {sup 235}U) to J-13 water under saturated conditions. Another goal set for the experiment was to develop a method for utilizing isotope dilution techniques to determine whether the dissolution rate of UO{sub 2} matrix is in accordance with an existing kinetic model. Results of these analyses revealed unequal uranium dissolution rates from the enriched and depleted portions of the powder mixture because of undisclosed differences between them. Although the presence of this inhomogeneity has precluded the application of the kinetic model, it also provided an opportunity to elaborate on the utilization of isotope dilution data in recognizing and quantifying such conditions. Detailed listings of uranium release and solution chemistry data are presented. Other problems commonly associated with spent fuel, such as the effectiveness of filtering media, the existence of uranium concentration peaks during early stages of the leach tests, the need for concentration corrections due to water replenishments of sample volumes, and experience derived from isotope dilution data are discussed in the context of the present results. 10 refs., 5 figs., 7 tabs.

  7. Appropriate In Vitro Methods for Genotoxicity Testing of Silver Nanoparticles

    PubMed Central

    Kim, Ha Ryong; Park, Yong Joo; Shin, Da Young; Oh, Seung Min

    2013-01-01

    Objectives We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. Methods Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration (0.2 µm pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. Results Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from 0.01 µg/mL to 10 µg/mL). In particular, MN induction was affected by cytoB. Conclusions All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles. PMID:23440978

  8. 40 CFR 63.772 - Test methods, compliance procedures, and compliance demonstrations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Test methods, compliance...Natural Gas Production Facilities § 63.772 Test methods, compliance...section. The performance test results shall be submitted...compliance with the enclosed combustion device total HAP...

  9. 40 CFR 63.772 - Test methods, compliance procedures, and compliance demonstrations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Test methods, compliance...Natural Gas Production Facilities § 63.772 Test methods, compliance...section. The performance test results shall be submitted...compliance with the enclosed combustion device total HAP...

  10. The application of biotechnological methods in authenticity testing.

    PubMed

    Popping, Bert

    2002-09-11

    By counterfeiting brand names in the food and drink industry as well as fraudulently labelling and selling low quality products as premium products, this sector of the industry has lost significant amounts of money and the consumer has been deceived. While it was difficult to establish certain types of fraud before the advent of modern biotechnology, DNA-based methods make an important contribution to protect high-quality brand names and protect the consumer. Several years ago, DNA technologies were considered as methods used in universities, primarily for research purpose, not so much for 'real-life' applications. However, this has changed and a number of laboratories have specialised in offering such services to the industry. This article will review DNA-based techniques commonly used for authenticity testing. PMID:12126809

  11. Dissolution of Functional Materials and Rare Earth Oxides into Pseudo Alveolar Fluid

    Microsoft Academic Search

    Mitsutoshi TAKAYA; Yasushi SHINOHARA; Fumio SERITA; Mariko ONO-OGASAWARA; Noriko OTAKI; Tadao TOYA; Ayako TAKATA; Katsumi YOSHIDA; Norihiko KOHYAMA

    2006-01-01

    The dissolution rates of rare earth oxides and two types of rare earth containing functional materials into water, saline solution, and Gamble's fluid were measured in order to evaluate the biological effects of rare earth-containing functional materials. The tested materials were yttrium, lanthanum, cerium and neodymium oxides, and neodymium-boron-iron magnet alloy (NdBFe) and lanthanum-mish-metal-nickel-cobalt (LmNiCo) hydrogen-containing alloy. The dissolution rates

  12. Kinetic and Thermodynamic Implications of some Commonly Used Rate Laws for Glass Dissolution

    SciTech Connect

    Grant, M.W.

    2001-03-28

    This report discusses the results of the examination of three rate laws for glass dissolution. These three are: SLDF, LDF/LDF and ZO/LDF. All three models can fit the results of static powder leach tests reasonably well. The existence of a fundamental relationship between the thermodynamics and the kinetics of glass dissolution/leaching has been demonstrated for the three rate models.

  13. 40 CFR Appendix A to Part 63 - Test Methods Pollutant Measurement Methods From Various Waste Media

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...specifications (e.g.,equipment and supplies) and procedures (e.g.,sampling...this test method.6.0Equipment and Supplies6.1Stalagmometer. Any commercially...and inhalation.6.0Equipment and Supplies 6.1Sample Collection. The...

  14. High-Temperature Studies of Glass Dissolution Rates Close to Saturation

    SciTech Connect

    Zavarin, M; Roberts, S; Zhao, P; Williams, R; Rose, T; Rainer, A; Pawloski, G

    2004-06-14

    Most long-lived radionuclides associated with an underground nuclear test are incorporated into a melt glass and are released by glass dissolution to become part of the hydrologic source term (HST) (Pawloski et al., 2001). Although the rates of rhyolite glass dissolution are well known under conditions where the fluid is far from saturation with respect to glass, the rates are not well known under conditions where the fluid approaches saturation. These rates are commonly much lower than the far-fromsaturation rates, often by a factor greater than 100. In recent HST simulations (Pawloski et al., 2001; Pawloski et al., 2000; Tompson et al., 1999), we conservatively estimated steady-state release rates based on a far-from-saturation fluid conditions. In recent CHESHIRE near-field simulations (Pawloski et al., 2001), it was predicted that {approx}30% of the nuclear melt glass dissolved over 1000 years. Although the ''far-from-saturation rate'' approach provides a conservative estimate of glass dissolution, it may greatly overestimate the rates of melt glass dissolution. At CHESHIRE, less conservative estimates suggest that only {approx}1% of the nuclear melt glass will dissolve in 1000 years. Lower glass dissolution rates result in lower radionuclide release rates from nuclear melt glass. The following report documents glass dissolution experiments performed to measure glass dissolution rates close to saturation.

  15. Data processing device test apparatus and method therefor

    DOEpatents

    Wilcox, Richard Jacob (Austin, TX); Mulig, Jason D. (Austin, TX); Eppes, David (Austin, TX); Bruce, Michael R. (Austin, TX); Bruce, Victoria J. (Austin, TX); Ring, Rosalinda M. (Austin, TX); Cole, Jr., Edward I. (New Bernalillo, NM); Tangyunyong, Paiboon (Bernalillo, NM); Hawkins, Charles F. (Bernalillo, NM); Louie, Arnold Y. (Santa Clara, CA)

    2003-04-08

    A method and apparatus mechanism for testing data processing devices are implemented. The test mechanism isolates critical paths by correlating a scanning microscope image with a selected speed path failure. A trigger signal having a preselected value is generated at the start of each pattern vector. The sweep of the scanning microscope is controlled by a computer, which also receives and processes the image signals returned from the microscope. The value of the trigger signal is correlated with a set of pattern lines being driven on the DUT. The trigger is either asserted or negated depending the detection of a pattern line failure and the particular line that failed. In response to the detection of the particular speed path failure being characterized, and the trigger signal, the control computer overlays a mask on the image of the device under test (DUT). The overlaid image provides a visual correlation of the failure with the structural elements of the DUT at the level of resolution of the microscope itself.

  16. Novel Method for Pairing Wood Samples in Choice Tests

    PubMed Central

    Oberst, Sebastian; Evans, Theodore A.; Lai, Joseph C. S.

    2014-01-01

    Choice tests are a standard method to determine preferences in bio-assays, e.g. for food types and food additives such as bait attractants and toxicants. Choice between food additives can be determined only when the food substrate is sufficiently homogeneous. This is difficult to achieve for wood eating organisms as wood is a highly variable biological material, even within a tree species due to the age of the tree (e.g. sapwood vs. heartwood), and components therein (sugar, starch, cellulose and lignin). The current practice to minimise variation is to use wood from the same tree, yet the variation can still be large and the quantity of wood from one tree may be insufficient. We used wood samples of identical volume from multiple sources, measured three physical properties (dry weight, moisture absorption and reflected light intensity), then ranked and clustered the samples using fuzzy c-means clustering. A reverse analysis of the clustered samples found a high correlation between their physical properties and their source of origin. This suggested approach allows a quantifiable, consistent, repeatable, simple and quick method to maximize control over similarity of wood used in choice tests. PMID:24551173

  17. Expedient methods of respiratory protection. II. Leakage tests. Final report

    SciTech Connect

    Cooper, D.W.; Hinds, W.C.; Price, J.M.; Weker, R.; Yee, H.S.

    1983-07-01

    The following readily-available materials were tested on a manikin connected to a breathing simulator to determine the fraction of an approximately 2-..mu..m-diameter aerosol that would leak around the seal of the materials to the manikin's face: cotton/polyester shirt material, cotton handkerchief material, toweling (a wash cloth), a surgical mask (Johnson and Johnson Co., model HRI 8137), and a NIOSH-approved disposable face mask (3M, model number 8710). The leakage tests were performed to supplement the measurements of penetration through the materials, conducted as the first phase of this investigation. The leakage tests were performed with the materials held on to the face by three methods, leakage fractions being determined from comparisons with the penetration of the same aerosol for the materials fully taped to the face. At a breathing rate of 37 liters per minute, mean leakages ranged from 0.0 percent to 63 percent. Mean penetrations exclusive of leakage ranged from 0.6 percent to 39 percent. Use of nylon hosiery material (panty hose) to hold the handkerchief material or the disposable face mask to the face was found to be very effective in preventing leakage. Such a combination could be expected to reduce leakage around the handkerchief to about ten percent or less in practice, and around the mask to less than one percent, offering substantial protection from accidentally generated aerosols. The reduction in leakage around the mask provided by the hosiery material suggests the adaptation and use of such an approach in regular industrial hygiene practice. The third and final phase of this investigation is underway, in which the penetration of the materials by particles with diameters between 0.05 and 0.5 ..mu..m is being measured and the effectiveness of the methods for dose reduction in the presence of radioactive aerosols is being modeled.

  18. Parents' Union Dissolution and Adolescents' School Performance: Comparing Methodological Approaches.

    PubMed

    Frisco, Michelle L; Muller, Chandra; Frank, Kenneth

    2007-08-01

    We use data from the National Longitudinal Study of Adolescent Health and the Adolescent Health and Academic Achievement Study to estimate how parents' union dissolution influences changes in adolescents' mathematics course work gains, overall grade point average, and course failure rates during a window of approximately 1 year (N = 2,629). A primary purpose of this study is demonstrating the utility of propensity score matching techniques for studying topics such as ours that pose methodological challenges such as dealing with endogeneity and selection bias. We compare propensity score matching techniques to ordinary least squares (OLS) regression methods to show and discuss comparability of results obtained using these different procedures. Findings suggest that associations between parents' union dissolution and achievement may be causal, regardless of method used. PMID:20300482

  19. Comparison of different test methods for the measurement of fabric or garment moisture transfer properties

    NASA Astrophysics Data System (ADS)

    Kar, F.; Fan, J.; Yu, W.

    2007-07-01

    Several test methods exist for determining the water vapour permeability or resistance of textile fabrics or garments. The differences and interrelationships between these methods are not always clear, which presents a problem in comparing results from different test methods. This study is aimed at investigating the relationships between the test results from four typical test methods, including the moisture transmission test (Model CS-141), ASTM E96 cup method, sweating guarded hot plate method (ISO11092) and the sweating fabric manikin (Walter). For the range of air permeable knitted fabrics tested, it was found that good interrelationships exist between the results from the four types of test methods, although some discrepancies exist between different tests due to differences in testing conditions. Test results from different moisture transfer test methods can therefore be convertible with due consideration.

  20. Dissolution Rates and Mineral Lifetimes of Phosphate Containing Minerals and Implications for Mars

    NASA Astrophysics Data System (ADS)

    Adcock, C. T.; Hausrath, E.

    2011-12-01

    The objectives of NASA's Mars Exploration Program include exploring the planet's habitability and the possibility of past, present, or future life. This includes investigating "possible supplies of bioessential elements" [1]. Phosphate is one such bioessential element for life as we understand it. Phosphate is also abundant on Mars [2], and the phosphate rich minerals chlorapatite, fluorapatite, and merrillite have been observed in Martian meteorites [3]. Surface rock analyses from the MER Spirit also show the loss of a phosphate rich mineral from the rocks Wishstone and Watchtower at Gusev Crater [4,5], implying mineral dissolution. Dissolution rates of phosphate containing minerals are therefore important for characterizing phosphate mobility and bioavailability on Mars. Previous studies have measured dissolution rates of fluorapatite [6-8]. However, chlorapatite and merrillite (a non-terrestrial mineral similar to whitlockite) are more common phosphate minerals found in Martian meteorites [3], and few dissolution data exist for these minerals. We have begun batch dissolution experiments on chlorapatite, synthesized using methods of [9], and whitlockite, synthesized using a method modified from [10]. Additionally, we are dissolving Durango fluorapatite to compare to dissolution rates in literature, and natural Palermo whitlockite to compare to dissolution rates of our synthesized whitlockite. Batch dissolution experiments were performed after [8], using a 0.01 molar KNO3 solution with 0.1500g-0.3000g mineral powders and starting solution volumes of 180ml in LDPE reaction vessels. HNO3 or KOH were used to adjust initial pH as required. Dissolution rates are calculated from the rate of change of elemental concentration in solution as a function of time, and normalized to the mineral surface area as measured by BET. Resulting rates will be used to calculate mineral lifetimes for the different phosphate minerals under potential Mars-like aqueous conditions, and in future reactive transport modeling.

  1. Testing for Additivity at Select Mixture Groups of Interest Based on Statistical Equivalence Testing Methods

    SciTech Connect

    Stork, LeAnna M.; Gennings, Chris; Carchman, Richard; Carter, Jr., Walter H.; Pounds, Joel G.; Mumtaz, Moiz

    2006-12-01

    Several assumptions, defined and undefined, are used in the toxicity assessment of chemical mixtures. In scientific practice mixture components in the low-dose region, particularly subthreshold doses, are often assumed to behave additively (i.e., zero interaction) based on heuristic arguments. This assumption has important implications in the practice of risk assessment, but has not been experimentally tested. We have developed methodology to test for additivity in the sense of Berenbaum (Advances in Cancer Research, 1981), based on the statistical equivalence testing literature where the null hypothesis of interaction is rejected for the alternative hypothesis of additivity when data support the claim. The implication of this approach is that conclusions of additivity are made with a false positive rate controlled by the experimenter. The claim of additivity is based on prespecified additivity margins, which are chosen using expert biological judgment such that small deviations from additivity, which are not considered to be biologically important, are not statistically significant. This approach is in contrast to the usual hypothesis-testing framework that assumes additivity in the null hypothesis and rejects when there is significant evidence of interaction. In this scenario, failure to reject may be due to lack of statistical power making the claim of additivity problematic. The proposed method is illustrated in a mixture of five organophosphorus pesticides that were experimentally evaluated alone and at relevant mixing ratios. Motor activity was assessed in adult male rats following acute exposure. Four low-dose mixture groups were evaluated. Evidence of additivity is found in three of the four low-dose mixture groups.The proposed method tests for additivity of the whole mixture and does not take into account subset interactions (e.g., synergistic, antagonistic) that may have occurred and cancelled each other out.

  2. Radiocarbon age modeling: dissolution, bioturbation and sediment redistribution

    NASA Astrophysics Data System (ADS)

    Mekik, F.

    2012-12-01

    We generated radiocarbon dates for whole and fragmented planktonic foraminifer tests (by several species) from a series of core tops which have experienced little dissolution from two depth transects (Rio Grande Rise - RIO and Ontong Java Plateau - OJP) and from down core records from three tropical Pacific cores with significantly different sediment accumulation rates. We also generated new radiocarbon data from both whole Globorotalia menardii shells and its fragments within the same sediments in order to test the robustness of a calcite dissolution proxy, the G. menardii Fragmentation Index (MFI). Our data reveal that the ages of all sediment components increase with increasing dissolution. This is most easily observable on RIO where the age offset between the shallowest samples and deepest samples is ~5 ka, while the mixing ages of the cores are ~1.9ka. This result is new and significant because previous work has always been in the tropical Pacific where bioturbation and mixing ages are high. Furthermore, two of the 7 core top samples from RIO revealed whole G. menardii shells of Glacial age. This is surprising because G. menardiis have not been reported in sediments from the Atlantic Ocean older than 13,000 years. Lastly, we found that the higher the sediment accumulation rate, the closer the age offset between G. menradii whole shells and its fragments in the same sediments both on RIO and OJP. This is important for the interpretation of down core work with MFI.

  3. In situ Characterization of Photoresist Dissolution

    NASA Astrophysics Data System (ADS)

    Itani, Toshiro; Santillan, Julius Joseph

    2010-06-01

    The dissolution process plays an important role in optimizing photoresist materials and processes for next-generation lithographic technologies. In this paper, we describe the application of high-speed atomic force microscopy for in situ analysis and characterization of photoresist dissolution. In particular, the physical changes in an exposed extreme ultraviolet (EUV) photoresist film are analyzed in real time - before, during, and after the development process. In this initial work, we report the dissolution characteristics of an EUV-exposed poly(4-hyrdroxystyrene)-based polymer resist processed with a tetramethylammonium hydroxide developer solution.

  4. Bubble dissolution physics and the treatment of decompression sickness

    SciTech Connect

    Kunkle, T.D.; Beckman, E.L.

    1983-03-01

    The treatment of decompression sickness often involves both recompressing the victim and administering hyperbaric oxygen in the hope of more rapidly dissolving the bubbles which cause this malady. Although many hundreds of such treatments are conducted each year in the United States alone, the underlying physical principles governing the dissolution of such bubbles are not well understood and only empirically tested. In this paper, we present a mathematical theory of bubble dissolution that is verified by comparison with laboratory experiments. This theory suggests that the commonly employed treatment techniques would be only marginally effective, and that in many situations the bubbles that cause the disease cannot be adequately dissolved using existing techniques and facilities.

  5. Contamination of nanoparticles by endotoxin: evaluation of different test methods

    PubMed Central

    2012-01-01

    Background Nanomaterials can be contaminated with endotoxin (lipopolysaccharides, LPS) during production or handling. In this study, we searched for a convenient in vitro method to evaluate endotoxin contamination in nanoparticle samples. We assessed the reliability of the commonly used limulus amebocyte lysate (LAL) assay and an alternative method based on toll-like receptor (TLR) 4 reporter cells when applied with particles (TiO2, Ag, CaCO3 and SiO2), or after extraction of the endotoxin as described in the ISO norm 29701. Results Our results indicate that the gel clot LAL assay is easily disturbed in the presence of nanoparticles; and that the endotoxin extraction protocol is not suitable at high particle concentrations. The chromogenic-based LAL endotoxin detection systems (chromogenic LAL assay and Endosafe-PTS), and the TLR4 reporter cells were not significantly perturbed. Conclusion We demonstrated that nanoparticles can interfere with endotoxin detection systems indicating that a convenient test method must be chosen before assessing endotoxin contamination in nanoparticle samples. PMID:23140310

  6. Application of laser scanning microscopy for the analysis of oral biofilm dissolution by different endodontic irrigants

    PubMed Central

    del Carpio-Perochena, Aldo; Bramante, Clovis Monteiro; Hungaro Duarte, Marco Antonio; de Andrade, Flaviana Bombarda; Cavenago, Bruno Cavalini; Villas-Bôas, Marcelo Haas; Ordinola-Zapata, Ronald; Amoroso-Silva, Pablo

    2014-01-01

    Background: Multi-specie biofilms are highly resistant to antimicrobials due to cellular interactions found in them. The purpose of this study was to evaluate, by confocal laser scanning microscopy, the biofilm dissolution effectiveness of different irrigant solutions on biofilms developed on infected dentin in situ. Materials and Methods: A total of 120 bovine dentin specimens infected intraorally (30/group) were treated by the following solutions: 2% of chlorhexidine digluconate, 1%, 2.5% and 5.25% of sodium hypochlorite (NaOCl). The solutions were utilized for 5, 15 and 30 min with 2 experimental volumes 500 ?L and 1 mL. All the samples were stained using an acridine orange and the biofilm thickness before (control group) and after the experiments were evaluated, utilizing a confocal microscope at ×40. The Mann-Whitney U and the nom-parametric Kruskal-Wallis Dunns tests were utilized to determine the influence of the volume and to perform the comparisons among the groups respectively. The significance level was set at P < 0.05. Results: Statistical differences were not found among the control and the 2% chlorhexidine digluconate groups at any experimental period (P > 0.05). The biofilm dissolution treated with 1% NaOCl was directly proportional to the exposure time (P < 0.05). The higher values of biofilm dissolution were found in 2.5% and 5.25% NaOCl groups (P > 0.05). Conclusion: The higher exposure times and concentrations of NaOCl were not sufficient to dissolve 100% of the biofilm. However, all NaOCl solutions were more effective than 2% chlorhexidine digluconate to dissolve organic matter. PMID:25225556

  7. Establishing New Acceptance Limits for Dissolution Performance Verification of USPC Apparatus 1 and 2 Using USPC Prednisone Tablets Reference Standard

    Microsoft Academic Search

    Anthony J. DeStefano; Walter W. Hauck; Erika S. Stippler; William E. Brown; Chensheng Li; Gloria G. Huang; Barbara J. Jones; Kevin O’Hool; William F. Koch; Roger L. Williams

    2011-01-01

    Purpose  On 1 March 2010, the US Pharmacopeial Convention released into commerce Lot P1I300 of its Prednisone Tablets Reference Standard\\u000a for use in periodic performance verification testing (PVT) of dissolution Apparatus 1 and 2. This report presents the collaborative\\u000a study data, development of the acceptance limits, and results from supporting work for this Lot.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  The collaborative study involved 25 collaborators who

  8. Using Response Surface Methods to Correlate the Modal Test of an Inflatable Test Article

    NASA Technical Reports Server (NTRS)

    Gupta, Anju

    2013-01-01

    This paper presents a practical application of response surface methods (RSM) to correlate a finite element model of a structural modal test. The test article is a quasi-cylindrical inflatable structure which primarily consists of a fabric weave, with an internal bladder and metallic bulkheads on either end. To mitigate model size, the fabric weave was simplified by representing it with shell elements. The task at hand is to represent the material behavior of the weave. The success of the model correlation is measured by comparing the four major modal frequencies of the analysis model to the four major modal frequencies of the test article. Given that only individual strap material properties were provided and material properties of the overall weave were not available, defining the material properties of the finite element model became very complex. First it was necessary to determine which material properties (modulus of elasticity in the hoop and longitudinal directions, shear modulus, Poisson's ratio, etc.) affected the modal frequencies. Then a Latin Hypercube of the parameter space was created to form an efficiently distributed finite case set. Each case was then analyzed with the results input into RSM. In the resulting response surface it was possible to see how each material parameter affected the modal frequencies of the analysis model. If the modal frequencies of the analysis model and its corresponding parameters match the test with acceptable accuracy, it can be said that the model correlation is successful.

  9. Time Triggered Ethernet System Testing Means and Method

    NASA Technical Reports Server (NTRS)

    Smithgall, William Todd (Inventor); Hall, Brendan (Inventor); Varadarajan, Srivatsan (Inventor)

    2014-01-01

    Methods and apparatus are provided for evaluating the performance of a Time Triggered Ethernet (TTE) system employing Time Triggered (TT) communication. A real TTE system under test (SUT) having real input elements communicating using TT messages with output elements via one or more first TTE switches during a first time interval schedule established for the SUT. A simulation system is also provided having input simulators that communicate using TT messages via one or more second TTE switches with the same output elements during a second time interval schedule established for the simulation system. The first and second time interval schedules are off-set slightly so that messages from the input simulators, when present, arrive at the output elements prior to messages from the analogous real inputs, thereby having priority over messages from the real inputs and causing the system to operate based on the simulated inputs when present.

  10. Comparison of disc diffusion & E test methods with agar dilution for antimicrobial susceptibility testing of Haemophilus influenzae

    Microsoft Academic Search

    Anand Manoharan; Rekha Pai; V. Shankar; Kurien Thomas; M. K. Lalitha

    2003-01-01

    Methods: A total of 46 isolates of H. influenzae from various invasive sites were included as test strains. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method for ampicillin, chloramphenicol, trimethoprim-sulphamethoxazole (TMP-SMZ) and cefotaxime. Minimum Inhibitory Concentration (MIC) determination was performed by E test and agar dilution for the same set of antimicrobials. All tests were performed on Haemophilus

  11. Latency in Visionic Systems: Test Methods and Requirements

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Arthur, J. J., III; Williams, Steven P.; Kramer, Lynda J.

    2005-01-01

    A visionics device creates a pictorial representation of the external scene for the pilot. The ultimate objective of these systems may be to electronically generate a form of Visual Meteorological Conditions (VMC) to eliminate weather or time-of-day as an operational constraint and provide enhancement over actual visual conditions where eye-limiting resolution may be a limiting factor. Empirical evidence has shown that the total system delays or latencies including the imaging sensors and display systems, can critically degrade their utility, usability, and acceptability. Definitions and measurement techniques are offered herein as common test and evaluation methods for latency testing in visionics device applications. Based upon available data, very different latency requirements are indicated based upon the piloting task, the role in which the visionics device is used in this task, and the characteristics of the visionics cockpit display device including its resolution, field-of-regard, and field-of-view. The least stringent latency requirements will involve Head-Up Display (HUD) applications, where the visionics imagery provides situational information as a supplement to symbology guidance and command information. Conversely, the visionics system latency requirement for a large field-of-view Head-Worn Display application, providing a Virtual-VMC capability from which the pilot will derive visual guidance, will be the most stringent, having a value as low as 20 msec.

  12. Detection of silica-mediated dissolution of magnetic grains in sediments using FORC diagrams

    NASA Astrophysics Data System (ADS)

    Wetter, Laura; Verosub, Ken; Russell, James

    2007-06-01

    Recently silica-mediated dissolution has been recognized as a potentially important factor influencing magnetic studies of marine and lacustrine sediments. Although direct evidence for the dissolution of magnetic particles in silica-rich environments is lacking, the process is expected to produce changes in the magnetic grain-size distribution, a hypothesis that is tested in this study on sediments from Lake Tanganyika, East Africa, using First Order Reversal Curves (FORCs). Results from different magnetic intensity zones within the studied samples clearly show changes in the grain-size distribution of magnetic minerals. In particular, zones with high biogenic silica content (BSi) correlated with depletion in fine-grained magnetic material, whereas zones with lower BSi showed no depletion. These results are consistent with the idea that silica-mediated dissolution results in the preferential removal of fine-grained magnetic material, and indicate that FORC diagrams are effective in characterizing silica-mediated dissolution in sediments.

  13. Aqueous Dissolution of Silver Iodide and Associated Iodine Release Under Reducing Conditions with Sulfide

    SciTech Connect

    Yaohiro Inagaki; Toshitaka Imamura; Kazuya Idemitsu; Tatsumi Arima [Kyushu University, Fukuoka, 819-0395 (Japan); Osamu Kato [Kobe Steel Inc., Kobe, 657-0845 (Japan); Hidekazu Asano; Tsutomu Nishimura [RWMC, Tokyo, 105-0001 (Japan)

    2007-07-01

    Aqueous dissolution tests of silver iodide (AgI) were performed in Na{sub 2}S solutions in order to evaluate, empirically, dissolution of AgI to release iodine under reducing conditions with sulfide. The results indicated that AgI dissolves to release iodine being controlled by mainly precipitation of Ag{sub 2}S. However, the dissolution of AgI can be depressed to proceed, and the thermodynamic equilibrium cannot be attained easily. Solid phase analysis for the reacted AgI suggested that a thin layer of solid silver forming at AgI surface may evolve to be protective against transportation of reactant species, which can lead to the depression in the dissolution of AgI. (authors)

  14. Effect of Physiochemical Properties and Bath Chemistry on Alumina Dissolution Rate in Cryolite Electrolyte

    NASA Astrophysics Data System (ADS)

    Yang, Youjian; Gao, Bingliang; Wang, Zhaowen; Shi, Zhongning; Hu, Xianwei

    2015-05-01

    The relationships of dissolution rate to alumina specifications and bath chemistry including electrolyte composition, operating temperature and superheat were investigated. The key physiochemical properties of industrial alumina samples were tested including moisture content, loss on ignition, surface area and phase composition. The dissolution of these samples in several bath compositions was observed through a quartz crucible equipped with a visual recording system. The dissolution rate increased with increasing loss on ignition and surface area. The operating temperatures and existing alumina concentration in the electrolyte had a greater impact on the alumina dissolution rate than the minor change of the bath compositions and superheat. Same trends were also obtained for the lab-calcined alumina samples.

  15. Swelling and dissolution of cellulose. Part IV: Free floating cotton and wood fibres in ionic liquids

    Microsoft Academic Search

    Céline Cuissinat; Patrick Navard; Thomas Heinze

    2008-01-01

    The objective of this paper is to investigate if the swelling and dissolution mechanisms found for aqueous solvents are valid for non-aqueous ones. Three different ionic liquids were used and the swelling and dissolution mechanisms were investigated by optical methods. Native and enzymatically treated cellulose fibres (cotton and wood fibres) are dipped into three ionic liquids (1-N-butyl-3-methylimidazolium chloride ([C4mim]+Cl?)\\/DMSO, allylmethylimidazolium

  16. 40 CFR 60.564 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...14-day rolling average used in test results to justify implementing...the initial 14-day performance test during which the facility is shown to be in compliance...parameter constitutes a performance test. [55 FR 51035, Dec....

  17. 40 CFR 60.564 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...14-day rolling average used in test results to justify implementing...the initial 14-day performance test during which the facility is shown to be in compliance...parameter constitutes a performance test. [55 FR 51035, Dec....

  18. 40 CFR 60.564 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...14-day rolling average used in test results to justify implementing...the initial 14-day performance test during which the facility is shown to be in compliance...parameter constitutes a performance test. [55 FR 51035, Dec....

  19. 40 CFR 60.564 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...14-day rolling average used in test results to justify implementing...the initial 14-day performance test during which the facility is shown to be in compliance...parameter constitutes a performance test. [55 FR 51035, Dec....

  20. 40 CFR 60.564 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...14-day rolling average used in test results to justify implementing...the initial 14-day performance test during which the facility is shown to be in compliance...parameter constitutes a performance test. [55 FR 51035, Dec....