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1

Small Volume Dissolution Testing as a Powerful Method during Pharmaceutical Development  

PubMed Central

Standard compendia dissolution apparatus are the first choice for development of new dissolution methods. Nevertheless, limitations coming from the amount of material available, analytical sensitivity, lack of discrimination or biorelevance may warrant the use of non compendial methods. In this regard, the use of small volume dissolution methods offers strong advantages. The present study aims primarily to evaluate the dissolution performance of various drug products having different release mechanisms, using commercially available small volume USP2 dissolution equipment. The present series of tests indicate that the small volume dissolution is a useful tool for the characterization of immediate release drug product. Depending on the release mechanism, different speed factors are proposed to mimic common one liter vessel performance. In addition, by increasing the discriminating power of the dissolution method, it potentially improves know how about formulations and on typical events which are evaluated during pharmaceutical development such as ageing or scale–up. In this regard, small volume dissolution is a method of choice in case of screening for critical quality attributes of rapidly dissolving tablets, where it is often difficult to detect differences using standard working conditions.

Emmanuel, Scheubel; Marc, Lindenberg; Eric, Beyssac; Jean-Michel, Cardot

2010-01-01

2

Automation of dissolution tests  

PubMed Central

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

Rolli, Rolf

2003-01-01

3

Effects of deaeration methods on dissolution testing in aqueous media: a study using a total dissolved gas pressure meter.  

PubMed

Dissolution testing is a critical method for the determination of pharmaceutical product quality and bioequivalence. For some products, dissolved gases in the dissolution medium affect dissolution results thus requiring degassing of the medium prior to use. In this study, we use a total dissolved gas and oxygen meter to measure both oxygen and total gases in dissolution media before and after application of a variety of deaeration methods. Dissolution testing results using a 10 mg Prednisone tablet (NCDA #2) are compared with the percent saturation of oxygen and total gases found in the medium. Reaeration of the medium during different stirring rates was also measured. This study confirms that measurement of total gases and not just oxygen in the medium is necessary to assess adequacy for dissolution testing. For those deaeration techniques that are performed at room temperature, the percent saturation of the total dissolved gases must be well below 100% to prevent outgassing once medium is brought to dissolution test method temperature, typically 37 degrees C. PMID:16732563

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

2006-07-01

4

Standard practice for measurement of the glass dissolution rate using the single-pass flow-through test method  

E-print Network

1.1 This practice describes a single-pass flow-through (SPFT) test method that can be used to measure the dissolution rate of a homogeneous silicate glass, including nuclear waste glasses, in various test solutions at temperatures less than 100°C. Tests may be conducted under conditions in which the effects from dissolved species on the dissolution rate are minimized to measure the forward dissolution rate at specific values of temperature and pH, or to measure the dependence of the dissolution rate on the concentrations of various solute species. 1.2 Tests are conducted by pumping solutions in either a continuous or pulsed flow mode through a reaction cell that contains the test specimen. Tests must be conducted at several solution flow rates to evaluate the effect of the flow rate on the glass dissolution rate. 1.3 This practice excludes static test methods in which flow is simulated by manually removing solution from the reaction cell and replacing it with fresh solution. 1.4 Tests may be conducted wit...

American Society for Testing and Materials. Philadelphia

2010-01-01

5

Bench Scale Saltcake Dissolution Test Report  

SciTech Connect

A potential scenario for retrieving saltcake from single shell tanks is the ''Rainbird{reg_sign} sprinkler'' method. Water is distributed evenly across the surface of the saltcake and allowed to percolate by gravity through the waste. The salt dissolves in the water, forming a saturated solution. The saturated liquid is removed by a saltwell pump situated near the bottom of the tank. By this method, there is never a large inventory of liquid in the tank that could pose a threat of leakage. There are many variables or factors that can influence the hydrodynamics of this retrieval process. They include saltcake porosity; saltwell pumping rate; salt dissolution chemistry; factors that could promote flow channeling (e.g. tank walls, dry wells, inclusions or discontinuities in the saltcake); method of water distribution; plug formation due to crystal formations or accumulation of insoluble solids. A brief literature search indicates that very little experimental data exist on these aspects of saltcake dissolution (Wiersma 1996, 1997). The tests reported here were planned (Herting, 2000) to provide preliminary data and information for planning future, scaled-up tests of the sprinkler method.

BECHTOLD, D.B.; PACQUET, E.A.

2000-12-06

6

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

PubMed

Abstract 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

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

2014-02-12

7

21 CFR 343.90 - Dissolution and drug release testing.  

Code of Federal Regulations, 2013 CFR

...343.90 Dissolution and drug release testing. (a) [Reserved] (b) Aspirin capsules. Aspirin capsules must meet the dissolution standard for aspirin capsules as contained in the United States Pharmacopeia (USP) 23 at page...

2013-04-01

8

21 CFR 343.90 - Dissolution and drug release testing.  

Code of Federal Regulations, 2012 CFR

...343.90 Dissolution and drug release testing. (a) [Reserved] (b) Aspirin capsules. Aspirin capsules must meet the dissolution standard for aspirin capsules as contained in the United States Pharmacopeia (USP) 23 at page...

2012-04-01

9

21 CFR 343.90 - Dissolution and drug release testing.  

Code of Federal Regulations, 2014 CFR

...343.90 Dissolution and drug release testing. (a) [Reserved] (b) Aspirin capsules. Aspirin capsules must meet the dissolution standard for aspirin capsules as contained in the United States Pharmacopeia (USP) 23 at page...

2014-04-01

10

21 CFR 343.90 - Dissolution and drug release testing.  

Code of Federal Regulations, 2011 CFR

...343.90 Dissolution and drug release testing. (a) [Reserved] (b) Aspirin capsules. Aspirin capsules must meet the dissolution standard for aspirin capsules as contained in the United States Pharmacopeia (USP) 23 at page...

2011-04-01

11

Characterization and Dissolution Kinetics Testing of Radioactive H-3 Calcine  

SciTech Connect

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.

Garn, Troy Gerry; Batcheller, Thomas Aquinas

2002-09-01

12

Transfer of drug dissolution testing by statistical approaches: Case study  

PubMed Central

The analytical transfer is a complete process that consists in transferring an analytical procedure from a sending laboratory to a receiving laboratory. After having experimentally demonstrated that also masters the procedure in order to avoid problems in the future. Method of transfers is now commonplace during the life cycle of analytical method in the pharmaceutical industry. No official guideline exists for a transfer methodology in pharmaceutical analysis and the regulatory word of transfer is more ambiguous than for validation. Therefore, in this study, Gauge repeatability and reproducibility (R&R) studies associated with other multivariate statistics appropriates were successfully applied for the transfer of the dissolution test of diclofenac sodium as a case study from a sending laboratory A (accredited laboratory) to a receiving laboratory B. The HPLC method for the determination of the percent release of diclofenac sodium in solid pharmaceutical forms (one is the discovered product and another generic) was validated using accuracy profile (total error) in the sender laboratory A. The results showed that the receiver laboratory B masters the test dissolution process, using the same HPLC analytical procedure developed in laboratory A. In conclusion, if the sender used the total error to validate its analytical method, dissolution test can be successfully transferred without mastering the analytical method validation by receiving laboratory B and the pharmaceutical analysis method state should be maintained to ensure the same reliable results in the receiving laboratory. PMID:24109204

AL-Kamarany, Mohammed Amood; EL Karbane, Miloud; Ridouan, Khadija; Alanazi, Fars K.; Hubert, Philippe; Cherrah, Yahia; Bouklouze, Abdelaziz

2011-01-01

13

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...

14

Pilot-scale tests of HEME and HEPA dissolution process  

SciTech Connect

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.

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

1994-06-01

15

Modeling solid-state transformations occurring in dissolution testing.  

PubMed

Changes in the solid-state form can occur during dissolution testing of drugs. This can often complicate interpretation of results. Additionally, there can be several mechanisms through which such a change proceeds, e.g. solvent-mediated transformation or crystal growth within the drug material itself. Here, a mathematical model was constructed to study the dissolution testing of a material, which undergoes such changes. The model consisted of two processes: the recrystallization of the drug from a supersaturated liquid state caused by the dissolution of the more soluble solid form and the crystal growth of the stable solid form at the surface of the drug formulation. Comparison to experimental data on theophylline dissolution showed that the results obtained with the model matched real solid-state changes and that it was able to distinguish between cases where the transformation was controlled either by solvent-mediated crystallization or solid-state crystal growth. PMID:23506958

Laaksonen, Timo; Aaltonen, Jaakko

2013-04-15

16

Development and Validation of New Discriminative Dissolution Method for Carvedilol Tablets  

PubMed Central

The objective of the present study was to develop and validate a discriminative dissolution method for evaluation of carvedilol tablets. Different conditions such as type of dissolution medium, volume of dissolution medium and rotation speed of paddle were evaluated. The best in vitro dissolution profile was obtained using Apparatus II (paddle), 50 rpm, 900 ml of pH 6.8 phosphate buffer as dissolution medium. The drug release was evaluated by high-performance liquid chromatographic method. The dissolution method was validated according to current ICH and FDA guidelines using parameters such as the specificity, accuracy, precision and stability were evaluated and obtained results were within the acceptable range. The comparison of the obtained dissolution profiles of three different products were investigated using ANOVA-based, model-dependent and model-independent methods, results showed that there is significant difference between the products. The dissolution test developed and validated was adequate for its higher discriminative capacity in differentiating the release characteristics of the products tested and could be applied for development and quality control of carvedilol tablets. PMID:22923865

Raju, V.; Murthy, K. V. R.

2011-01-01

17

Development and Validation of a Dissolution Test for Meloxicam and Pridinol Mesylate from Combined Tablet Formulation  

PubMed Central

The association of meloxicam and pridinol is indicated for treating muscular contractures and low back pain. A dissolution test for the meloxicam-pridinol combined tablet formulation was developed and validated, using a suitable HPLC method for simultaneously quantitating both dissolved drugs. The optimized conditions include the use of USP apparatus 2 at a paddle rotation rate of 75 rpm and 900 ml of 50 mM phosphate buffer (pH= 7.5) as dissolution medium, at 37.0±0.5°. The test, which demonstrated to be robust against small changes in bath temperature, paddle rotation speed and pH of the dissolution medium, was applied to two different brands of tablets; the corresponding dissolution profiles were constructed and both brands showed to dissolve at least 75% of the drugs at the 45 min time point. PMID:20838523

Vignaduzzo, S. E.; Castellano, P. M.; Kaufman, T. S.

2010-01-01

18

In Vitro Dissolution Testing Strategies for Nanoparticulate Drug Delivery Systems: Recent Developments and Challenges  

PubMed Central

Nanoparticulate systems have emerged as prevalent drug delivery systems over the past few decades. These delivery systems (such as liposomes, emulsions, nanocrystals, and polymeric nanocarriers) have been extensively used to improve bioavailability, prolong pharmacological effects, achieve targeted drug delivery, as well as reduce side effects. Considering that any unanticipated change in product performance of such systems may result in toxicity and/or change in vivo efficacy, it is essential to develop suitable in vitro dissolution/release testing methods to ensure product quality and performance, and to assist in product development. The present review provides an overview of the current in vitro dissolution/release testing methods such as dialysis, sample and separate, as well as continuous flow methods. Challenges and future directions in the development of standardized and biorelevant in vitro dissolution/release testing methods for novel nanoparticulate systems are discussed. PMID:24069580

Shen, Jie; Burgess, Diane J.

2013-01-01

19

The differences between the branded and generic medicines using solid dosage forms: In-vitro dissolution testing  

PubMed Central

Introduction Dissolution is the amount of substance that goes into solution per unit time under standardised conditions of liquid/solid interface, solvent composition and temperature. Dissolution is one of the most important tools to predict the in-vivo bioavailability and in some cases to determine bioequivalence and assure interchangeability. Aim To compare the differences in dissolution behaviour of solid dosage forms between innovators (reference products) and their generic counterparts (tested products). Methods Four replicates for each batch of 37 tested medicines was carried out using A PT-DT70 dissolution tester from Pharma Test. A total of 13 branded medicines and 24 generic counterparts were obtained locally and internationally to detect any differences in their dissolution behaviour. They were tested according to the British Pharmacopeia, European Pharmacopeia and the US Pharmacopeia with the rate of dissolution determined by ultra-violet Spectrophotometery. Results Most tested medicines complied with the pharmacopoeial specifications and achieved 85% dissolution in 60 min. However, some generic medicines showed significant differences in dissolution rate at 60 and 120 min. Many generic medicines showed a slower dissolution rate than their branded counterparts such as the generic forms of omeprazole 20 mg. Some showed an incomplete dissolution such as the generic form of nifedipine 10 mg. Other generics showed faster dissolution rate than their branded counterpart such as the generic forms of meloxicam 15 mg. Moreover, some generics from different batches of the same manufacturer showed significant differences in their dissolution rate such as the generic forms of meloxicam 7.5 mg. Nevertheless, some generic medicines violated the EMA and the FDA guidelines for industry when they failed to achieve 85% dissolution at 60 min, such as the generic form of diclofenac sodium 50 mg. Conclusion Most medicines in this study complied with the pharmacopeial limits. However, some generics dissolved differently than their branded counterparts. This can clearly question the interchangeability between the branded and its generic counterpart or even among generics. PMID:25755988

Al Ameri, Mubarak Nasser; Nayuni, Nanda; Anil Kumar, K.G.; Perrett, David; Tucker, Arthur; Johnston, Atholl

2011-01-01

20

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

SciTech Connect

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.

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

21

Test Objectives for the Saltcake Dissolution Retrieval Demonstration  

SciTech Connect

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.

DEFIGH PRICE, C.

2000-09-22

22

Enzymes in the dissolution testing of gelatin capsules.  

PubMed

Gelatin capsules are a widely used dosage form both for pharmaceutical drug products as well as dietary supplements. Gelatin in the presence of certain compounds, mainly aldehydes, or in high humidity and high temperature conditions can cross-link. Cross-linking involves covalent bonding of the amine group of a lysine side chain of one gelatin molecule to a similar amine group on another molecule. The covalent bonding is, for practical purposes, irreversible. Cross-linking results in the formation of a pellicle on the internal or external surface of the gelatin capsule shell that prevents the capsule fill from being released. In vitro dissolution testing of cross-linked gelatin capsules can result in slower release of the drug or no release at all. The data obtained by the Gelatin Capsule Working Group, created in the early 90s to investigate noncompliance of gelatin capsules, was used to establish the type and amounts of enzymes that can be added to the dissolution medium in the case of test failure to the presence of cross-linking in the gelatin. The two-tier dissolution testing was included in the US Pharmacopeia and it recommends the addition of pepsin (pH below 6.8) or pancreatin (pH above 6.8) to the medium depending on its pH. Pepsin shows good protease activity up to pH 4 and pancreatin above pH 6 leaving a gap where neither one has good activity. Possible proteolytic enzymes that could be used for the pH range 4-6.8 could be papain or bromelain. PMID:24942315

Marques, Margareth R C

2014-12-01

23

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

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...

American Society for Testing and Materials. Philadelphia

2003-01-01

24

MRI studies of the hydrodynamics in a USP 4 dissolution testing cell.  

PubMed

We present a detailed study of hydrodynamics inside the flow-through dissolution apparatus when operated according to USP recommendations. The pulsatile flow inside the flow-through cell was measured quantitatively using magnetic resonance imaging (MRI) at a spatial resolution of 234 × 234 ?m(2) and slice thickness of 1 mm. We report the experimental protocols developed for in situ MRI studies and the effect that the operating conditions and tablet orientation have on the hydrodynamics inside commercial flow cells. It was found that the flow field inside the dissolution cells was, at most operating conditions, heterogeneous, rather than fully developed laminar flow, and characterised by re-circulation and backward flow. A model tablet was shown to be contacted by a wide distribution of local velocities as a function of position and orientation in the flow cell. The use of 1 mm beads acted as a distributor of the flow but did not suffice to ensure a fully developed laminar flow profile. These results emphasise the necessity to understand the influence of test conditions on dissolution behaviour in defining robust flow-through dissolution methods. PMID:20949631

Shiko, G; Gladden, L F; Sederman, A J; Connolly, P C; Butler, J M

2011-03-01

25

K Basin Sludge Conditioning Testing: Nitric Acid Dissolution Testing of K East Canister Sludge  

SciTech Connect

This report describes tests performed by Pacific Northwest National Laboratory (PNNL) for Numatec Hanford Corporation (NHC) as part of the overall activities for the development of the K Basin Sludge Treatment System. These tests were conducted to examine the dissolution behavior of a K East Basin canister sludge composite in nitric acid at the following concentrations: 2 M, 4 M, 6 M, 7.8 M and 10 M and temperatures of 25 C and boiling. Assuming that the sludge was 100% uranium metal, a 4X stoichiometric excess of nitric acid was used for all testing, except that conducted at 4 M. In the 4 M nitric acid dissolution test, 50% excess nitric acid was used resulting in a dissolver solution with a significantly higher solids loading. The boiling tests were conducted for 11 hr, the 25 C dissolution tests were conducted from 24 hr to 2 weeks. For the 25 C dissolution testing, the weight percent residual solids was determined, however, chemical and radiochemical analyses were not performed.

Carlson, C.D.; Delegard, C.H.; Burgeson, I.E.: Schmidt, A.J.; Bredt, P.R.; Silvers, K.L.

1999-04-01

26

Screening method to identify preclinical liquid and semi-solid formulations for low solubility compounds: miniaturization and automation of solvent casting and dissolution testing.  

PubMed

We have developed an efficient screening method to identify liquid and semisolid formulations for low-solubility compounds. The method is most suitable for identifying dosing vehicles for compounds in lead optimization, where compound supply is limited and long-term stability is not a requirement. Dilute compound and excipient stock solutions are prepared in organic solvent and then dispensed and mixed in 96-well plates. The solvent is removed in a vacuum centrifuge evaporator, leaving neat formulation (e.g., 10-40 microg compound, 0.4 mg excipient) at the bottom of each well. After an aging step, an aqueous dilution medium is added and the plates are incubated (agitation by orbital shaking). The diluted formulations are then filtered and analyzed by ultraviolet (UV) absorbance or high-performance liquid chromatography (HPLC). To illustrate the method, two compounds (aqueous solubility method to screening compound/surfactant/oil formulations is also presented. PMID:17094139

Mansky, Paul; Dai, Wei-Guo; Li, Shu; Pollock-Dove, Crystal; Daehne, Klaus; Dong, Liang; Eichenbaum, Gary

2007-06-01

27

Calcination/dissolution testing for Hanford Site tank wastes  

SciTech Connect

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.

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

28

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

Microsoft Academic Search

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

Saeed A Qureshi; Iain J McGilveray

1999-01-01

29

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

SciTech Connect

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).

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

30

Silymarin-solid dispersions: characterization and influence of preparation methods on dissolution.  

PubMed

The influence of preparation methodology of silymarin solid dispersions using a hydrophilic polymer on the dissolution performance of silymarin was investigated. Silymarin solid dispersions were prepared using HPMC E 15LV by kneading, spray drying and co-precipitation methods and characterized by FTIR, DSC, XRPD and SEM. Dissolution profiles were compared by statistical and model independent methods. The FTIR and DSC studies revealed weak hydrogen bond formation between the drug and polymer, while XRPD and SEM confirmed the amorphous nature of the drug in co-precipitated solid dispersion. Enhanced dissolution compared to pure drug was found in the following order: co-precipitation > spray drying > kneading methodology (p < 0.05). All preparation methods enhanced silymarin dissolution from solid dispersions of different characteristics. The co-precipitation method proved to be best and provided a stable amorphous solid dispersion with 2.5 improved dissolution compared to the pure drug. PMID:21169135

Sonali, Dalwadi; Tejal, Soni; Vaishali, Thakkar; Tejal, Gandhi

2010-12-01

31

EVALUATION OF ARG-1 SAMPLES PREPARED BY CESIUM CARBONATE DISSOLUTION DURING THE ISOLOK SME ACCEPTABILITY TESTING  

SciTech Connect

Evaluation of Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) recently completed the evaluation of one of these opportunities - the possibility of using an Isolok sampling valve as an alternative to the Hydragard valve for taking DWPF process samples at the Slurry Mix Evaporator (SME). The use of an Isolok for SME sampling has the potential to improve operability, reduce maintenance time, and decrease CPC cycle time. The SME acceptability testing for the Isolok was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 and was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNLRP-2011-00145. RW-0333P QA requirements applied to the task, and the results from the investigation were documented in SRNL-STI-2011-00693. Measurement of the chemical composition of study samples was a critical component of the SME acceptability testing of the Isolok. A sampling and analytical plan supported the investigation with the analytical plan directing that the study samples be prepared by a cesium carbonate (Cs{sub 2}CO{sub 3}) fusion dissolution method and analyzed by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The use of the cesium carbonate preparation method for the Isolok testing provided an opportunity for an additional assessment of this dissolution method, which is being investigated as a potential replacement for the two methods (i.e., sodium peroxide fusion and mixed acid dissolution) that have been used at the DWPF for the analysis of SME samples. Earlier testing of the Cs{sub 2}CO{sub 3} method yielded promising results which led to a TTR from Savannah River Remediation, LLC (SRR) to SRNL for additional support and an associated TTQAP to direct the SRNL efforts. A technical report resulting from this work was issued that recommended that the mixed acid method be replaced by the Cs{sub 2}CO{sub 3} method for the measurement of magnesium (Mg), sodium (Na), and zirconium (Zr) with additional testing of the method by DWPF Laboratory being needed before further implementation of the Cs{sub 2}CO{sub 3} method at that laboratory. While the SME acceptability testing of the Isolok does not address any of the open issues remaining after the publication of the recommendation for the replacement of the mixed acid method by the Cs{sub 2}CO{sub 3} method (since those issues are to be addressed by the DWPF Laboratory), the Cs{sub 2}CO{sub 3} testing associated with the Isolok testing does provide additional insight into the performance of the method as conducted by SRNL. The performance is to be investigated by looking to the composition measurement data generated by the samples of a standard glass, the Analytical Reference Glass - 1 (ARG-1), that were prepared by the Cs{sub 2}CO{sub 3} method and included in the SME acceptability testing of the Isolok. The measurements of these samples were presented as part of the study results, but no statistical analysis of these measurements was conducted as part of those results. It is the purpose of this report to provide that analysis, which was supported using JMP Version 7.0.2.

Edwards, T.; Hera, K.; Coleman, C.

2011-12-05

32

A novel method for measuring dissolution kinetics of pulverized konjac flour.  

PubMed

The aim of the current study was to explore a novel method for measuring hydration and dissolution kinetics of the pulverized konjac flour (PK flour) from Amorphophallus albus using RVA-3D+ Rapid Visco Analyzer (RVA; Newport Scientific Pty Ltd., Australia). The results showed that RVA was a reliable fast technique for determining the hydration curve of PK flour. The test conditions determining the hydration curves were optimized at the concentration of PK flour with 1.0%, test temperature at 30+/-1oC, stirring speed at 160 RPM (Revolution Per Minute), and test time of 16 min. An empirical exponential model has also been established to describe the dis-solution kinetics of PK flour at the concentration of 1.0%: eta= 161.9343.EXP (-2.1522/tau) (R2=0.9762) Where tau is the test time (min); eta is the viscosity of the hydration process (RVU) of PK flour. The results also showed that a significant difference among the hydration curves of 1.0% PK flour when dispersed in distilled water and in different concentrations of sucrose aqueous solution. PMID:17392102

Wu, Yinglong; He, Guoqing; Chen, Xiaohuan; Tan, Steve Q

2007-01-01

33

A validated HPLC method for the determination of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) with fluorescence detection in raw material and pill form: application to an in vitro dissolution test and a content uniformity test.  

PubMed

A simple, sensitive and rapid HPLC method with fluorescence detection for the determination of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) in the raw material and pill form was developed. Liquid chromatography was performed on a C18 column (250 × 4.6 mm i.d., 5 µm particle size), the mobile phase consisted of methanol and 0.05 M sodium dihydrogen phosphate buffer (80 : 20, v/v), and the apparent pH of the mobile phase was adjusted to 3. The fluorescence detector was operated at excitation/emission wavelengths of 275/400 nm. The proposed method allows the determination of DDB within concentration range 0.1-1.5 µg/mL with a limit of detection of 0.032 µg/mL, a limit of quantification of 0.097 µg/mL and a correlation coefficient of 0.9997. The proposed method has been successfully applied for the analysis of DDB in its pills with a percentage recovery of 98.45 ± 0.32. The method was fully validated according to ICH guidelines. Moreover, the high sensitivity of the method permits its use in an in vitro dissolution test for DDB under simulated intestinal conditions. In addition, the proposed method was extended to a content uniformity test according to USP guidelines. PMID:24619600

Walash, Mohamed I; Ibrahim, Fawzia; El Abass, Samah Abo

2014-11-01

34

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

SciTech Connect

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

Zhijie Xu; Hai Huang; Paul Meakin

2012-01-01

35

Validation Testing of the Nitric Acid Dissolution Step Within the K Basin Sludge Pretreatment Process  

SciTech Connect

The work described in this report involved comprehensive bench-scale testing of nitric acid (HNO{sub 3}) dissolution of actual sludge materials from the Hanford K East (KE) Basin to confirm the baseline chemical pretreatment process. In addition, process monitoring and material balance information was collected to support the development and refinement of process flow diagrams. The testing was performed by Pacific Northwest National Laboratory (PNNL)for the US Department of Energy's Office of Spent Fuel Stabilization (EM-67) and Numatec Hanford Corporation (NHC) to assist in the development of the K Basin Sludge Pretreatment Process. The baseline chemical pretreatment process for K Basin sludge is nitric acid dissolution of all particulate material passing a 1/4-in. screen. The acid-insoluble fraction (residual solids) will be stabilized (possibly by chemical leaching/rinsing and grouting), packaged, and transferred to the Hanford Environmental Restoration Disposal Facility (ERDF). The liquid fraction is to be diluted with depleted uranium for uranium criticality safety and iron nitrate for plutonium criticality safety, and neutralized with sodium hydroxide. The liquid fraction and associated precipitates are to be stored in the Hanford Tank Waste Remediation Systems (TWRS) pending vitrification. It is expected that most of the polychlorinated biphenyls (PCBs), associated with some K Basin sludges, will remain with the residual solids for ultimate disposal to ERDF. Filtration and precipitation during the neutralization step will further remove trace quantities of PCBs within the liquid fraction. The purpose of the work discussed in this report was to examine the dissolution behavior of actual KE Basin sludge materials at baseline flowsheet conditions and validate the.dissolution process step through bench-scale testing. The progress of the dissolution was evaluated by measuring the solution electrical conductivity and concentrations of key species in the dissolver solutions as a function of reaction (dissolution) time, by analyzing offgas generation rate and composition, and by analyzing intermittent and final acid-insoluble solids at the end of the dissolution. The testing was conducted in a system designed to assess parameters that can influence sludge dissolution and provide information that can be used to determine operating conditions for the actual system.

AJ Schmidt; CH Delegard; KL Silvers; PR Bredt; CD Carlson; EW Hoppe; JC Hayes; DE Rinehart; SR Gano; BM Thornton

1999-03-24

36

Transfer of drug dissolution testing by statistical approaches: Case study  

Microsoft Academic Search

The analytical transfer is a complete process that consists in transferring an analytical procedure from a sending laboratory to a receiving laboratory. After having experimentally demonstrated that also masters the procedure in order to avoid problems in the future. Method of transfers is now commonplace during the life cycle of analytical method in the pharmaceutical industry. No official guideline exists

Mohammed Amood AL-Kamarany; Miloud EL Karbane; Khadija Ridouan; Fars Kaed Alanazi; Philippe Hubert; Yahia Cherrah; Abdelaziz Bouklouze

37

IntersectionUnion Tests in Dissolution Profile Testing Jorge H. SierraCavazos  

E-print Network

Introduction The dissolution profile of a drug is constructed by plotting the proportion of tablet dissolved dissolution profiles are being measured and denote by X ik the proportion of tablet i of the reference drug dissolved at time t k , for i = 1; : : : ; n. Similarly, Y jk denotes the proportion of tablet j from

38

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method: dissolution behaviour and biological properties after crystallisation.  

PubMed

Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) were synthesised by the sol-gel method as possible implant coating or bone-grafting materials. Calcium nitrate and triethyl phosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride were incorporated for the preparation of the FHA and FA sol-gels. After heating and powdering the sol-gels, dissolution behaviour was assessed using ion chromatography to measure Ca(2+) and PO4 (3-) ion release. Biological behaviour was assessed using cellular proliferation with human osteosarcoma cells and alamarBlue™ assay. Statistical analysis was performed with a two way analysis of variance and post hoc testing with a Bonferroni correction. Increasing fluoride substitution into an apatite structure decreased the dissolution rate. Increasing the firing temperature of the HA, FHA and FA sol-gels up to 1,000 °C decreased the dissolution rate. There was significantly higher cellular proliferation on highly substituted FHA and FA than on HA or Titanium. The properties of an implant coating or bone grafting material can be tailored to meet specific requirements by altering the amount of fluoride that is incorporated into the original apatite structure. The dissolution behaviour can further be altered by the temperature at which the sol-gel is fired. PMID:24052344

Tredwin, Christopher J; Young, Anne M; Abou Neel, Ensanya A; Georgiou, George; Knowles, Jonathan C

2014-01-01

39

Dissolution testing of a metallic waste form in chloride brine  

SciTech Connect

This paper is intended for publication in the peer-reviewed proceedings from the Scientific Basis for Nuclear Waste Management (at the Fall 2006 meeting of the Materials Research Society). The same material was presented in a 15-minute talk. Argonne National Laboratory has developed an electrometallurgical process for conditioning spent sodium-bonded metallic reactor fuel from the Experimental Breeder Reactor II (EBR-II). One waste stream from this process consists of a metal waste form (MWF) whose baseline composition is stainless steel alloyed with 15 wt% Zr (SS-15Zr) and whose microstructure is a eutectic intergrowth of iron solid solutions and Fe-Zr-Cr-Ni intermetallics. This paper reports scanning electron microscope (SEM) observations of corrosion products formed during static immersion tests in which coupons of surrogate MWF containing 10 wt% U (SS-15Zr-10U) were immersed in solutions with nominal pH values of 3 and 4 and 1000 ppm added chloride for 70 days at 50 °C. Although the majority of the surface areas of the coupons appear unchanged, linear areas with localized corrosion products apparently consisting of porous materials overlying corrosion-product-filled channels formed on both coupons, cross-cutting phase boundaries in the original eutectic microstructures. Many of the linear areas intersected the sample edge at notches present before the tests or followed linear flaws visible in pre-test images. Compositions of corrosion products differed significantly from the bulk composition, and the maximum observed concentration of U in corrosion products (~25 at%) slightly exceeded the highest reported values in actinide-bearing phases in uncorroded surrogate MWF samples with comparable concentrations of U (~17-19 at%).

Dawn E Janney

2006-11-01

40

Dissolution enhancement and in vitro performance of clarithromycin nanocrystals produced by precipitation-lyophilization-homogenization method.  

PubMed

The gastroduodenal diseases caused by Helicobacter pylori were commonly treated with antibiotic clarithromycin as a standard regimen. According to the poorly water-soluble of clarithromycin, the nanocrystal formulation was prepared. The aim of this study was to investigate an enhancement effect of clarithromycin nanocrystals produced by precipitation-lyophilization-homogenization (PLH) method on the saturation solubility, dissolution velocity, antibiotic activity, permeability through the gastric mucus and cellular permeability. Poloxamer 407 and sodium lauryl sulfate (SLS) were chosen as combined stabilizers in the nanocrystal system. The obtained clarithromycin nanocrystals were identified as cubic particles by SEM with a bulk population of approximately 400nm existed in crystalline and/or partial amorphous form as investigated by DSC and XRPD. The saturation solubility of the clarithromycin nanocrystals was increased by 1.5- and 6-folds higher than clarithromycin powder in buffer pH 5.0 and 6.8, respectively. The dissolution profiles of clarithromycin nanocrystals at pH 5.0 and 6.8 were significantly different from clarithromycin powder and the marketed product (f1 value >15 and f2 value <50). All dissolution parameters (relative dissolution rate, percent dissolution efficiency and mean dissolution time) showed that clarithromycin nanocrystals had higher dissolution rate when compared with the clarithromycin powder, the lyophilized coarse suspension and the marketed product. The bioassay study by diffusion agar method showed a maintained antibiotic activity of clarithromycin nanocrystals solubilized in buffer solution which was greater potency than the lyophilized coarse suspension and the clarithromycin powder. Additionally, the nanocrystals possessed higher permeability through gastric mucus and cellular monolayer of Caco-2 and NCI-N87 cells as compared to the lyophilized coarse suspension and the clarithromycin powder. The results indicated that, the developed clarithromycin nanocrystals were a potential delivery system that exerts more effectiveness in H. pylori eradication. PMID:25201298

Morakul, Boontida; Suksiriworapong, Jiraphong; Chomnawang, Mullika Traidej; Langguth, Peter; Junyaprasert, Varaporn Burapacheep

2014-11-01

41

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

PubMed Central

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

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

2014-01-01

42

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

SciTech Connect

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.

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

2012-01-02

43

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

PubMed

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 290min) 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

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

2015-04-30

44

Determination of interfacial tension from crystallization and dissolution data: a comparison with other methods  

Microsoft Academic Search

Methods for the determination of interfacial tension between a solid and a liquid are reviewed, including solubility\\/particle size, crystallization and dissolution kinetics. The use of solubility as a function of particle size, originally put forward by Ostwald and later corrected by Freundlich, may be unjustified for determining interfacial tension at solid–liquid interfaces. The interfacial tension values between solutions and sparingly

Wenju Wu; George H. Nancollas

1999-01-01

45

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

PubMed

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

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

2014-12-01

46

Method for dissolution and stabilization of silica-rich fibers  

DOEpatents

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.

Jantzen, Carol M. (Aiken, SC)

1997-01-01

47

Novel silk fibroin films prepared by formic acid/hydroxyapatite dissolution method.  

PubMed

Bombyx mori silk fibroin from the silkworm was firstly found to be soluble in formic acid/hydroxyapatite system. The rheological behavior of silk fibroin solution was significantly influenced by HAp contents in dissolved solution. At the same time, silk fibroin nanofibers were observed in dissolved solution with 103.6±20.4nm in diameter. Moreover, the structure behavior of SF films prepared by formic acid/hydroxyapatite dissolution method was examined. The secondary structure of silk fibroin films was attributed to silk II structure (?-sheet), indicating that the hydroxyapatite contents in dissolved solution were not significantly affected by the structure of silk fibroin. The X-ray diffraction results exhibited obviously hydroxyapatite crystalline nature existing in silk fibroin films; however, when the hydroxyapatite content was 5.0wt.% in dissolved solution, some hydroxyapatite crystals were converted to calcium hydrogen phosphate dehydrate in silk fibroin dissolution process. This result was also confirmed by Fourier transform infrared analysis and DSC measurement. In addition, silk fibroin films prepared by this dissolution method had higher breaking strength and extension at break. Based on these analyses, an understanding of novel SF dissolution method may provide an additional tool for designing and synthesizing advanced materials with more complex structures, which should be helpful in different fields, including biomaterial applications. PMID:24582221

Ming, Jinfa; Liu, Zhi; Bie, Shiyu; Zhang, Feng; Zuo, Baoqi

2014-04-01

48

Method for dissolution and stabilization of silica-rich fibers  

DOEpatents

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.

Jantzen, C.M.

1997-11-11

49

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

SciTech Connect

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.

Wilson, C.N.

1990-06-01

50

CO2CRC's Otway Residual Saturation and Dissolution Test: Using Reactive Ester Tracers to Determine Residual CO2 Saturation  

NASA Astrophysics Data System (ADS)

Residual trapping, that is CO2 held in the rock pore space due to capillarity, is an important storage mechanism in geo-sequestration of over the short to medium term (up to 1000 years). As such residual CO2 saturation is a critical reservoir parameter for assessing the storage capacity and security of carbon capture and storage (CCS). As a component of the CO2CRC's Residual Gas Saturation and Dissolution Test at the CO2CRC Otway Project site in Victoria (Australia), we have recently tested a suite of reactive esters (triacetin, tripropionin and propylene glycol diacetate) in a single well chemical tracer test to determine residual CO2 saturation. The goal of this project was to assess and validate a suite of possible tests that could be implemented to determine residual CO2 saturation. For this test, the chemical tracers were injected with a saturated CO2/water mixture into the formation (that is already at residual CO2 saturation) where they were allowed to 'soak' for approximately 10 days allowing for the partial hydrolysis of the esters to their corresponding carboxylic acids and alcohols. Water containing the tracers was then produced from the well resulting in over 600 tracer samples over a period of 12 hours. A selection of these samples were analysed for tracer content and to establish tracer breakthrough curves. To understand the behaviour of these chemical tracers in the downhole environment containing residually trapped supercritical CO2 and formation water, it is necessary to determine the supercritical CO2/water partition coefficients. We have previously determined these in the laboratory (Myers et al., 2012) and they are used here to model the tracer behaviour and provide an estimate of the residual CO2 saturation. Two different computational simulators were used to analyse the tracer breakthrough profiles. The first is based on simple chromatographic retardation and has been used extensively in single well chemical tracer tests to determine residual oil saturation and the second is based on TOUGH2. The estimates of residual saturation given by these models were similar giving a very low residual CO2 saturation value. We suspect that this low value might be due to CO2 being inadvertently dissolved in the near wellbore region prior to this test. This possible dissolution of CO2 may be attributed to the complexity of the multi-test sequence (including other tracer tests prior to this particular test) used in the overall program at of the Residual Gas Saturation and Dissolution Test. References Myers, M., Stalker, L., Ross, A., Dyt, C., Ho, K.-B., 2012. Method for the determination of residual carbon dioxide saturation using reactive ester tracers. Applied Geochemistry 27, 2148-2156.

Myers, M.; Stalker, L.; LaForce, T.; Pejcic, B.; Dyt, C.; Ho, K.; Ennis-King, J.

2013-12-01

51

Determining the dissolution rates of actinide glasses: A time and temperature Product Consistency Test study  

SciTech Connect

Vitrification has been identified as one potential option for the e materials such as Americium (Am), Curium (Cm), Neptunium (Np), and Plutonium (Pu). A process is being developed at the Savannah River Site to safely vitrify all of the highly radioactive Am/Cm material and a portion of the fissile (Pu) actinide materials stored on site. Vitrification of the Am/Cm will allow the material to be transported and easily stored at the Oak Ridge National Laboratory. The Am/Cm glass has been specifically designed to be (1) highly durable in aqueous environments and (2) selectively attacked by nitric acid to allow recovery of the valuable Am and Cm isotopes. A similar glass composition will allow for safe storage of surplus plutonium. This paper will address the composition, relative durability, and dissolution rate characteristics of the actinide glass, Loeffler Target, that will be used in the Americium/Curium Vitrification Project at Westinghouse Savannah River Company near Aiken, South Carolina. The first part discusses the tests performed on the Loeffler Target Glass concerning instantaneous dissolution rates. The second part presents information concerning pseudo-activation energy for the one week glass dissolution process.

Daniel, W.E.; Best, D.R.

1995-12-01

52

Improved dissolution and chemical separation methods for Lu-Hf garnet chronometry  

Microsoft Academic Search

Garnet-based Lu-Hf geochronology using conventional (HF-HNO3) dissolution methods may be compromised by full or partial digestion of Hf-rich zircon inclusions. This study integrates two complimentary methods to substantially reduce zircon digestion while assuring complete digestion of garnet and sample-spike equilibration. Handpicked garnet fractions are heat treated to >1000°C in an evacuated silica glass ampoule to anneal zircon inclusions and then

J. N. Connelly

2006-01-01

53

Improved dissolution and chemical separation methods for Lu-Hf garnet chronometry  

NASA Astrophysics Data System (ADS)

Garnet-based Lu-Hf geochronology using conventional (HF-HNO3) dissolution methods may be compromised by full or partial digestion of Hf-rich zircon inclusions. This study integrates two complimentary methods to substantially reduce zircon digestion while assuring complete digestion of garnet and sample-spike equilibration. Handpicked garnet fractions are heat treated to >1000°C in an evacuated silica glass ampoule to anneal zircon inclusions and then dissolved with 12 M HCl at 210°C and cold 28 M HF. Analyses of heat-treated garnet (and their high-temperature breakdown products orthopyroxene-spinel-quartz) from Gore Mountain, New York, demonstrate the method is capable of complete dissolution of garnet and routinely achieving sample-spike equilibration. Independent analyses of annealed and unannealed zircons dissolved by HCl - cold HF demonstrate the benefit of heat treatment prior to dissolution. Analyses of zircon-rich garnets from peletic paragneisses of Labrador, Canada, show the potential of this method by returning Lu-Hf ratios commensurate with the degree of heat treatment. Finally, a complementary chemical separation method for Lu and Hf is presented that supports analysis of garnet by MC-ICP-MS.

Connelly, J. N.

2006-04-01

54

FIP\\/AAPS Joint Workshop Report: Dissolution\\/ In Vitro Release Testing of Novel\\/Special Dosage Forms  

Microsoft Academic Search

In 2003, the FIP Dissolution Working group published a position paper on dissolution\\/drug release testing for special\\/novel\\u000a dosage forms that represented the scientific opinions of many experts in the field at that time (1). The position paper has supported activities, programs, and decisions in the scientific, technical, and regulatory community.\\u000a Due to the rapid evolution of new practices and techniques

Cynthia K. Brown; Horst Dieter Friedel; Amy R. Barker; Lucinda F. Buhse; Susanne Keitel; Todd L. Cecil; Johannes Kraemer; J. Michael Morris; Christos Reppas; Mary P. Stickelmeyer; Chikako Yomota; Vinod P. Shah

2011-01-01

55

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

DOEpatents

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.

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

1981-01-01

56

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

DOEpatents

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.

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

1980-01-11

57

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

Microsoft Academic Search

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

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

2011-01-01

58

Predicting the gastrointestinal behaviour of modified-release products: utility of a novel dynamic dissolution test apparatus involving the use of bicarbonate buffers.  

PubMed

The establishment of physiologically relevant in vitro-in vivo correlations (IV-IVCs) is key for any biorelevant dissolution test. Historically, bicarbonate buffers have produced better correlations than compendial phosphate buffered media, though such tests are usually performed at a constant pH experiment, overlooking the notion that the pH of the luminal fluids is variable and fluctuating. In this work, we have devised a dynamic dissolution test method employing a physiological bicarbonate buffer under pH conditions of the proximal gut in order to assess the dissolution behaviour of various enteric polymer-coated (gastro-resistant) prednisolone tablets. The pH of the media is modulated and controlled by an Auto pH System™ which exploits the physiological equilibria between [H2CO3] and [HCO3(-)], to match it to the aboral change in pH with transit of the dosage form through the proximal small intestine (from pH 5.6 up to 6.8). The lag time values for an accelerated release and standard EUDRAGIT(®) L30D-55 coated formulation (25 min and 60 min, respectively) were close to the previously reported initial tablet disintegration time data obtained in-vivo by ?-scintigraphy (28 min and 66 min, respectively). Dissolution of alternative delayed release coated products was also better discriminated in the dynamic buffer system. These data confirm the dynamic dissolution system provides a robust and reliable platform to predict the in vivo fate of oral products in a laboratory setting. PMID:25195730

Merchant, Hamid A; Goyanes, Alvaro; Parashar, Narendra; Basit, Abdul W

2014-11-20

59

Boron determination in biological materials by inductively coupled plasma atomic emission and mass spectrometry: effects of sample dissolution methods  

Microsoft Academic Search

This study compares four sample dissolution methods for Boron determination in two National Institute of Standard and Technology\\u000a (NIST) botanical Standard Reference Materials (SRMs) and three Agriculture Canada\\/NIST RMs, each having a reference (certified\\u000a or best estimate) B concentration. The dissolution treatments consisted of: 1)?dry ashing at 500°?C, 2)?wet digestion with\\u000a HNO3 + H2O2, 3)?extraction with hot HNO3 and 4)?closed

A. M. S. Nyomora; R. N. Sah; P. H. Brown; R. O. Miller

1997-01-01

60

TRANSPORT OF REACTING SOLUTES SUBJECT TO A MOVING DISSOLUTION BOUNDARY: NUMERICAL METHODS AND SOLUTIONS.  

USGS Publications Warehouse

In this paper we consider examples of chemistry-affected transport processes in porous media. A moving boundary problem which arises during transport with precipitation-dissolution reactions is solved by three different numerical methods. Two of these methods (one explicit and one implicit) are based on an integral formulation of mass balance and lead to an approximation of a weak solution. These methods are compared to a front-tracking scheme. Although the two approaches are conceptually different, the numerical solutions showed good agreement. As the ratio of dispersion to convection decreases, the methods based on the integral formulation become computationally more efficient. Specific reactions were modeled to examine the dependence of the system on the physical and chemical parameters.

Willis, Catherine; Rubin, Jacob

1987-01-01

61

The influence of amorphization methods on the apparent solubility and dissolution rate of tadalafil.  

PubMed

This study for the first time investigates the solubility and dissolution rate of amorphous tadalafil (Td)--a poorly water soluble chemical compound which is commonly used for treating the erectile dysfunction. To convert the crystalline form of Td drug to its amorphous counterpart we have employed most of the commercially available amorphization techniques i.e. vitrification, cryogenic grinding, ball milling, spray drying, freeze drying and antisolvent precipitation. Among the mentioned methods only quenched cooling of the molten sample was found to be an inappropriate method of Td amorphization. This is due to the thermal decomposition of Td above 200°C, as proved by the thermogravimetric analysis (TGA). Disordered character of all examined samples was confirmed using differential scanning calorimetry (DSC) and X-ray powder diffraction (PXRD). In the case of most amorphous powders, the largest 3-fold increase of apparent solubility was observed after 5 min, indicating their fast recrystallization in water. On the other hand, the partially amorphous precipitate of Td and hypromellose enhanced the solubility of Td approximately 14 times, as compared with a crystalline substance, which remained constant for half an hour. Finally, disk intrinsic dissolution rate (DIDR) of amorphous forms of Td was also examined. PMID:24907679

Wlodarski, K; Sawicki, W; Paluch, K J; Tajber, L; Grembecka, M; Hawelek, L; Wojnarowska, Z; Grzybowska, K; Talik, E; Paluch, M

2014-10-01

62

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

PubMed

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

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

2014-06-16

63

Study of the effect of temperature on Pt dissolution in polymer electrolyte membrane fuel cells via accelerated stress tests  

NASA Astrophysics Data System (ADS)

Operation of polymer electrolyte membrane fuel cells (PEMFC) at higher cell temperatures accelerates Pt dissolution in the catalyst layer. In this study, a Pt dissolution accelerated stress testing protocol involving the application of a potentiostatic square-wave with 3 s at 0.6 V followed by 3 s at 1.0 V was developed to test fuel cell membrane electrode assemblies (MEAs). The use of this Pt dissolution protocol at three different temperatures (40 °C, 60 °C and 80 °C) was investigated for the same membrane electrode assembly composition. Impedance analysis of the membrane electrode assemblies showed an increase in polarization resistance during the course of the accelerated stress testing. Polarization analysis and electrochemical active surface area (ECSA) loss measurements revealed evidence of increased cathode catalyst layer (CCL) degradation due to Pt dissolution and deposition in the membrane as the cell temperature was raised. Scanning electron microscope (SEM) images confirmed the formation of Pt bands in the membrane. A diagnostic expression was developed to estimate kinetic losses due to oxygen reduction using the effective platinum surface area (EPSA) estimated from cyclic voltammograms. The results indicated that performance degradation occurred mainly due to Pt loss.

Dhanushkodi, S. R.; Kundu, S.; Fowler, M. W.; Pritzker, M. D.

2014-01-01

64

Determination of interfacial tension from crystallization and dissolution data: a comparison with other methods.  

PubMed

Methods for the determination of interfacial tension between a solid and a liquid are reviewed including solubility/particle size, crystallization and dissolution kinetics. The use of solubility as a function of particle size, originally put forward by Ostwald and later corrected by Freundlich, may be unjustified for determining interfacial tension at solid-liquid interfaces. The interfacial tension values between solutions and sparingly soluble minerals such as hydroxyapatite, fluorapatite, brushite, octacalcium phosphate, calcium oxalate monohydrate, barium sulfate, calcium sulfate, calcite, and divalent metal fluorides are discussed. A comparison of these results is made with contact angle or wetting measurements. The interfacial tension values obtained from constant composition reaction kinetics are of the same order of magnitude as those determined using a contact angle method involving thin layer wicking techniques. PMID:10696260

Wu, W; Nancollas, G H

1999-02-01

65

Initial results from dissolution rate testing of N-Reactor spent fuel over a range of potential geologic repository aqueous conditions  

SciTech Connect

Hanford N-Reactor spent nuclear fuel (HSNF) may ultimately be placed in a geologic repository for permanent disposal. To determine whether the engineered barrier system that will be designed for emplacement of light-water-reactor (LWR) spent fuel will also suffice for HSNF, aqueous dissolution rate measurements were conducted on the HSNF. The purpose of these tests was to determine whether HSNF dissolves faster or slower than LWR spent fuel under some limited repository-relevant water chemistry conditions. The tests were conducted using a flowthrough method that allows the dissolution rate of the uranium matrix to be measured without interference by secondary precipitation reactions that would confuse interpretation of the results. Similar tests had been conducted earlier with LWR spent fuel, thereby allowing direct comparisons. Two distinct corrosion modes were observed during the course of these 12 tests. The first, Stage 1, involved no visible corrosion of the test specimen and produced no undissolved corrosion products. The second, Stage 2, resulted in both visible corrosion of the test specimen and left behind undissolved corrosion products. During Stage 1, the rate of dissolution could be readily determined because the dissolved uranium and associated fission products remained in solution where they could be quantitatively analyzed. The measured rates were much faster than has been observed for LWR spent fuel under all conditions tested to date when normalized to the exposed test specimen surface areas. Application of these results to repository conditions, however, requires some comparison of the physical conditions of the different fuels. The surface area of LWR fuel that could potentially be exposed to repository groundwater is estimated to be approximately 100 times greater than HSNF. Therefore, when compared on the basis of mass, which is more relevant to repository conditions, the HSNF and LWR spent fuel dissolve at similar rates.

Gray, W.J.; Einziger, R.E.

1998-04-01

66

Modern Methods of Testing  

NASA Technical Reports Server (NTRS)

After a brief survey of the commonly used single-value test methods, the importance of the determination of the incipient knock for the octane number is discussed and improvements suggested for the knock testing in the CFR engine. The DVL supercharge test method with its superiority of direct determination of fuel knock in each single cylinder of an airplane engine without involving structural changes, is described and the advantages of a multiple-value method enumerated. A diagrammatic presentation of the knock characteristics is presented.

Seeber, F

1939-01-01

67

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

SciTech Connect

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.

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

2012-09-01

68

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 ...

69

Ignitability test method  

NASA Technical Reports Server (NTRS)

To overcome serious weaknesses in determining the performance of initiating devices, a novel 'ignitability test method', representing actual design interfaces and ignition materials, has been developed. Ignition device output consists of heat, light, gas an burning particles. Past research methods have evaluated these parameters individually. This paper describes the development and demonstration of an ignitability test method combining all these parameters, and the quantitative assessment of the ignition performance of two widely used percussion primers, the M42C1-PA101 and the M42C2-793. The ignition materials used for this evaluation were several powder, granule and pellet sizes of black powder and boron-potassium nitrate. This test method should be useful for performance evaluation of all initiator types, quality assurance, evaluation of ignition interfaces, and service life studies of initiators and ignition materials.

Bement, Laurence J.; Schimmel, Morry L.

1989-01-01

70

Rail shear test method  

NASA Technical Reports Server (NTRS)

The results of both an experimental test program and a finite element analysis of selected graphite/polyimide rail shear test specimens are discussed. The two dimensional finite element analysis includes both mechanical and thermal loading (differential expansion) of the specimens and their elastic rails. Parameters in this analysis of unidirectional and symmetric, balanced angle-ply laminates include ply layup angles, the effect of flexible rails, the method of load introduction to the specimen and the effect of uniform heating of the specimen and rails. Two types of tensile rail shear fixtures were investigated experimentally: a uniform thickness, bolted-rail shear fixture loaded diagonally across the specimen test section; and a tapered thickness, bonded-rail shear fixture loaded axially along the center-line of the specimen test section. Test results include room-temperature and 589K strain data taken from the center of the specimen test section during loading.

Garcia, R.; Mcwithey, R. R.

1979-01-01

71

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

PubMed

A simple isocratic reversed-phase HPLC method was developed and validated for the analysis of dissolution samples of gabapentin tablets and capsules. Separation of gabapentin from its major degradation impurity, 3,3-pentamethylene-4-butyrolactam was achieved on a Phenomenex Luna Cyano column using a methanol-acetonitrile-20 mM KH(2)PO(4) (pH 2.2) (5:5:90, v/v/v) mobile phase. The compounds were eluted isocratically at a flow rate of 1.25 mL/min. Both compounds were analyzed with UV detection at 210 nm. The method was validated according to USP Category I requirements for gabapentin. The validation characteristics included accuracy, precision, linearity, range, specificity and limit of quantitation. Robustness testing was also conducted to evaluate the effect of minor changes to the chromatographic system and to establish appropriate system suitability parameters. Validation acceptance criteria were met in all cases. This method was used successfully for the quality assessment of five gabapentin drug products. PMID:17935923

Gupta, Abhay; Ciavarella, Anthony B; Sayeed, Vilayat A; Khan, Mansoor A; Faustino, Patrick J

2008-01-01

72

Test Method Urobilinogen  

E-print Network

Test Method Visual Date Lot # Bilirubin Urobilinogen Ketone AscorbicAcid Glucose Protein Blood p # Ictotest®(Bilirubin): Lot # Protein (Sulfosalicylic Acid): Lot # Specific Gravity - Saline 0.85 Specific # Bilirubin Urobilinogen Ketone AscorbicAcid Glucose Protein Blood pH Nitrite Leukocytes Specific Gravity HCG

Rodriguez, Carlos

73

A Biopharmaceutical Classification System Approach to Dissolution: Mechanisms and Strategies  

Microsoft Academic Search

Dissolution testing is a common characterization method employed by the pharmaceutical industry to design formulations and\\u000a assess product quality. It is a required performance test by many regulatory authorities for solid oral dosage forms, transdermal\\u000a patches, stents, and oral suspensions. Dissolution testing is unique in that it is the only finished product test method in\\u000a routine use that measures the

William E. Bowen; Qingxi Wang; W. Peter Wuelfing; Denise L. Thomas; Eric D. Nelson; Yun Mao; Brian Hill; Mark Thompson; Kimberly Gallagher; Robert Reed

74

Solvent-based dissolution method to sample gas-phase volatile organic compounds for compound-specific isotope analysis.  

PubMed

An investigation was carried out to develop a simple and efficient method to collect vapour samples for compound specific isotope analysis (CSIA) by bubbling vapours through an organic solvent (methanol or ethanol). The compounds tested were benzene and trichloroethylene (TCE). The dissolution efficiency was tested for different air volume injections, using flow rates ranging from 25ml/min to 150ml/min and injection periods varying between 10 and 40min. Based on the results, complete mass recovery for benzene and TCE in both solvents was observed for the flow rates of 25 and 50ml/min. However, small mass loss was observed at increased flow rate. At 150ml/min, recovery was on average 80±17% for benzene and 84±10% for TCE, respectively in methanol and ethanol. The ?(13)C data measured for benzene and TCE dissolved in both solvents were reproducible and were stable independently of the volume of air injected (up to 6L) or the flow rate used. The stability of ?(13)C values hence underlines no isotopic fractionation due to compound-solvent interaction or mass loss. The development of a novel and simple field sampling technique undertaken in this study will facilitate the application of CSIA to diverse gas-phase volatile organic compound studies, such as atmospheric emissions, soil gas or vapour intrusion. PMID:24360256

Bouchard, Daniel; Hunkeler, Daniel

2014-01-17

75

Bio-relevant dissolution testing of hard capsules prepared from different shell materials using the dynamic open flow through test apparatus.  

PubMed

Current compendial dissolution and disintegrating testing is unable to mimic physiological conditions affecting gastric drug release from immediate release dosage forms. In order to obtain more realistic data, a novel test setup was developed that we term a 'dynamic open flow through test apparatus'. It is based on the previously described dissolution stress test device and attempts to simulate the intra-gastric dissolution conditions pertinent to immediate release dosage forms administered under fasting conditions with respect to flow rates, intra-gastric temperature profiles and gastric motility. The concept of the dynamic open flow through test apparatus has been tested using five different types of hard capsules: conventional hard gelatin capsules (HGC), three hypromellose based capsules (Vcaps, Vcaps Plus and DRcaps) and pullulan based capsules (Plantcaps). These were of different sizes but all contained 100mg caffeine in each formulation, adjusted to avoid buoyancy by addition of excipient. When the capsules were stressed in the apparatus under the dynamic flow conditions applying mild pressure simulating gastric motility, release from release from Vcaps Plus, Vcaps and Plantcaps capsules was very well comparable to HGC. Capsules are usually swallowed with cold water and the temperature dependency of release from gelatin was noted as a significant factor, since heat exchange in the stomach is slow. PMID:24021609

Garbacz, Grzegorz; Cadé, Dominique; Benameur, Hassan; Weitschies, Werner

2014-06-16

76

Numerical simulation of dealloying by surface dissolution via the evolving surface finite element method  

E-print Network

, Zeeman Building, Coventry CV4 7AL, United Kingdom a r t i c l e i n f o Article history: Received 28 of silver in an Ag­Au alloy whose surface is immersed in an electrolyte. The dissolution of silver atoms occurs at the alloy/electrolyte interface while the surface gold atoms diffuse on the surface

Elliott, Charles

77

Dissolution behaviour of model basalt fibres studied by surface analysis methods  

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

78

Studies on the dissolution of polycyclic aromatic hydrocarbons from contaminated materials using a novel dialysis tubing experimental method  

SciTech Connect

Assessment of risk and remediation strategies at contaminated sites requires that both the amounts of contaminants present and their potential for release from materials and soils be evaluated. The release, or dissolution, of polycyclic aromatic hydrocarbons (PAHs) from contaminated materials to water was therefore investigated. To facilitate investigations of PAH dissolution from physically disparate materials such as solid coal tars, creosote, oil, and spent oxide, an experimental method for measuring dissolved PAHs was developed employing dialysis tubing in batch-type system. This was validated and compared to aqueous-phase PAH concentrations measured using more traditional techniques and also predicted using Raoult's law. The experimental procedure was successfully used to determine near equilibrium aqueous concentrations of PAHs, but it could only be used to determine relative rates of approach to equilibrium as the dialysis tubing effected the rate constants. It was found that the contaminant materials influenced dissolution, in particular the close to equilibrium concentrations. For materials chemically similar to PAHs, such as nonaqueous-phase liquids (NAPLs), the concentrations could be predicted using Raoult's law. For materials that were chemically dissimilar to PAHs, such as spent oxide, release was more thermodynamically favorable than for NAPLs.

Woolgar, P.J. (Lancaster Univ. (United Kingdom) Scottish Environment Protection Agency, Stirling (United Kingdom)); Jones, K.C. (Lancaster Univ. (United Kingdom))

1999-06-15

79

Modulation of particle size and molecular interactions by sonoprecipitation method for enhancing dissolution rate of poorly water-soluble drug.  

PubMed

Aim of present work was to originally elucidate the roles of ultrasonication method for modulating the size and molecular interactions in controlling release of poorly water-soluble drug. Curcumin was chosen as a model drug. Three types of polymers were investigated as carriers for preparation of polymeric nanoparticles under various ultrasonication conditions and polymer-drug ratios. Changes in drug crystallinity, particle size, and molecular interactions which would be factors enhancing drug dissolution rate were evaluated. Amorphous form of curcumin, size reduction of nanoparticles and interaction between drug and polymer in formulations were attributed to improved drug dissolution rate. Particle size was strongly affected by polymer type, polymer-drug ratio and ultrasonication conditions. Interestingly, control of those factors caused differences in molecular interactions of the hydroxyl groups and then, highly affected particle size of the nanoparticles. It was obvious that there was a reciprocal influence between the drug-polymer interactions and particle size of the nanoparticles. This relation could be modulated by polymers and ultrasonication processes for enhancing drug dissolution rate. PMID:25500098

Tran, Thao Truong-Dinh; Tran, Kiet Anh; Tran, Phuong Ha-Lien

2015-05-01

80

Pore-scale study of the effect of secondary carbonate precipitation on the dissolution of primary minerals using the lattice Boltzmann method  

NASA Astrophysics Data System (ADS)

Reactive transport processes involving dissolution and/or precipitation are pervasive in Earth, energy, and environmental systems. One typical example is geologic sequestration of carbon dioxide. Among these reactive processes, it is commonly encountered that a second phase precipitates while the primary phase dissolves, and the precipitation and dissolution reactions are fully coupled with each other. In the case of mineral trapping of CO2, the primary silicate mineral dissolves due to a decrease of pH caused by the dissolution of CO2 into the solution; meanwhile the dissolved CO2 can react with cations to form a secondary precipitate of carbonate mineral. Although the effect of precipitation of secondary solid phase on the dissolution of the primary solid phase has been studied extensively, the results reported in the literature are often inconclusive and sometimes even contradict one another. The reason is that the coupled dissolution and precipitation processes are controlled by several factors whose contribution is difficult to ascertain, including the dissolution and precipitation reaction kinetics, temperature and pressure, pH and species concentration of the solution, physicochemical properties of the primary and secondary minerals, as well as the nucleation and crystal mechanisms of the precipitates, etc. In this study, a pore-scale (mesoscopic) model based on the lattice Boltzmann method (LBM) is developed to investigate the effects of secondary precipitation on the dissolution of the primary mineral. The model can predict coupled multiple physicochemical processes including fluid flow, mass transport, chemical reaction, dissolution, precipitation consisting of nucleation and crystal growth, as well as dynamical evolution of pore geometries. Effects of dissolution and precipitation reaction kinetics, molar volumes of primary and secondary minerals, initial powder size and surface roughness of the primary mineral, as well as nucleation and crystal growth mechanisms on the dissolution and precipitation processes are investigated in terms of rate and amount of dissolution and precipitation. Several types of dissolution and precipitation processes are identified based on the morphology and structure of the precipitates and on the extent to which the precipitates affect the dissolution of the primary mineral. Simulation results are also compared with existing experimental results. Depending on the conditions, the effect of the precipitates spans the full range of possible behavior from trivial changes to enhanced or reduced dissolution rates of the primary phase.

Kang, Q.; Chen, L.; Carey, J. W.

2013-12-01

81

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

PubMed

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

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

2014-10-01

82

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

PubMed Central

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

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

83

Deeper understanding of solid state phase conversion and influence of excipients on the in-vitro dissolution behavior of carbamazepine disks  

E-print Network

26,000 Da), and polyethylene glycol (PEG) (Mw 6,000 Da). Methods All dissolution tests were performed using USP apparatus 2 (paddle method) at 50 rpm and 37?C. A six-station dissolution apparatus (D800 dissolution tester, Logan Instrument Corp...

Tian, F.; Sandler, N.; Strachan, C. J.; Saville, D. J.; Gordon, K. C.; Rades, T.

2006-10-25

84

Setting dissolution specifications for modified-release dosage forms.  

PubMed

Dissolution specifications are used for quality assurance and may also serve as a surrogate for in vivo bioavailability. These limits can guide formulation development and eliminate the need for bioavailability studies for scale up and post approval changes. Several methods for setting dissolution specifications have been reviewed in this chapter. A summary of the advantages and disadvantages for each method can be found in Table 1. When choosing a method for setting dissolution specifications, it is important to 1) have a discriminating dissolution system, 2) incorporate in vivo data, 3) include intersubject variability, and 4) predict plasma concentration-time profiles. Predicting plasma concentration curves allows one to see how the change in formulation or dissolution limits perform in vivo. Dissolution specifications should be set so that all formulations that have dissolution profiles within the limits of the specifications are bioequivalent. This can be assured if the boundaries are tested for bioequivalence. Minimally, the formulations that have dissolution profiles within the limits of the specifications should be bioequivalent to the pivotal batch. A population prediction of the plasma concentration-time profiles for the upper and lower limit would incorporate the true intersubject variability for the formulation. PMID:9269491

Piscitelli, D A; Young, D

1997-01-01

85

Effects of seafloor and laboratory dissolution on the Mg/Ca composition of Globigerinoides sacculifer and Orbulina universa tests --A laser ablation ICPMS  

E-print Network

sacculifer and Orbulina universa tests -- A laser ablation ICPMS microanalysis perspective Aleksey Yu March 2010 Editor: M.L. Delaney Keywords: Mg/Ca thermometry laser ablation ICPMS planktonic foraminifera laser ablation ICPMS to determine the extent of dissolution-caused changes in Mg/Ca distribution across

86

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

PubMed Central

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

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

2014-01-01

87

Coherent anti-Stokes Raman scattering (CARS) microscopy visualizes pharmaceutical tablets during dissolution.  

PubMed

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

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

2014-01-01

88

The biogenic content of process streams from mechanical–biological treatment plants producing solid recovered fuel. Do the manual sorting and selective dissolution determination methods correlate?  

Microsoft Academic Search

The carbon emissions trading market has created a need for standard methods for the determination of biogenic content (?B) in solid recovered fuels (SRF). We compare the manual sorting (MSM) and selective dissolution methods (SDM), as amended by recent research, for a range of process streams from a mechanical–biological treatment (MBT) plant. The two methods provide statistically different biogenic content

Mélanie Séverin; Costas A. Velis; Phil J. Longhurst; Simon J. T. Pollard

2010-01-01

89

Hepa filter dissolution process  

DOEpatents

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.

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

1994-01-01

90

HEPA filter dissolution process  

SciTech Connect

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.

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

1992-12-31

91

HEPA filter dissolution process  

DOEpatents

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.

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

1994-02-22

92

Short-core acoustic resonant bar test and x-ray CT imaging on sandstone samples during super-critical CO2 flooding and dissolution  

NASA Astrophysics Data System (ADS)

Geological sequestration of CO2 requires accurate monitoring of the spatial distribution and pore-level saturation of super-critical (sc-) CO2 for both optimizing reservoir performance and satisfying regulatory requirements. Fortunately, thanks to the high compliance of sc-CO2 compared to brine under in-situ temperatures and pressures, injection of sc-CO2 into initially brine-saturated rock will lead to significant reductions in seismic velocity and increased attenuation of seismic waves. Because of the frequency-dependent nature of this relationship, its determination requires testing at low frequencies (10 Hz-10 kHz) that are not usually employed in the laboratory. In this paper, we present the changes in seismic wave velocities and attenuation in sandstone cores during sc-CO2 core flooding and during subsequent brine re-injection and CO2 removal via convection and dissolution. The experiments were conducted at frequencies near 1 kHz using a variation of the acoustic resonant bar technique, called the Split Hopkinson Resonant Bar (SHRB) method, which allows measurements under elevated temperatures and pressures (up to 120°C, 35 MPa), using a short (several cm long) core. Concurrent x-ray CT scanning reveals sc-CO2 saturation and distribution within the cores. The injection experiments revealed different CO2 patch size distributions within the cores between the injection phase and the convection/dissolution phase of the tests. The difference was reflected particularly in the P-wave velocities and attenuation. Also, compared to seismic responses, which were separately measured during a gas CO2 injection/drainage test, the seismic responses from the sc-CO2 test showed measurable changes over a wider range of brine saturation. Considering the proximity of the frequency band employed by our measurement to the field seismic measurements, this result implies that seismic monitoring of sc-CO2, if constrained by laboratory data and interpreted using a proper petrophysical model, can be conducted with greater accuracy for determining the sc-CO2 saturation and distribution within reservoir rock, than typically predicted by the Gassmann model and/or by a natural gas reservoir analogue.

Nakagawa, S.; Kneafsey, T. J.; Daley, T. M.; Freifeld, B. M.

2010-12-01

93

Use of the reference interaction site model perturbation method to describe the dissolution of nonpolar gases in molecular liquids  

NASA Astrophysics Data System (ADS)

We have used the interaction site model in order to calculate the thermodynamics of dissolution of simple nonpolar gases in molecular liquids. The calculations were carried out for the liquids benzene and n-alkanes, from butane to heptane, and for inert gases, methane, and ethane as solutes using a first-order perturbation method. It is shown that this procedure is much better than the sphericalization of the anisotropic intermolecular potentials since it explicitly incorporates the details of the structure of the different fluids. The proposed procedure is extremely sensitive to the values used for the intermolecular parameters. This feature coupled to the possible inaccuracies of the simple Lorentz-Berthelot combining rule, is a weakness of the calculation procedure when it is used to predict the behavior of real systems. For this purpose it is recommended that the procedure be used semiempirically adjusting the values of the intermolecular parameters with experimental solubility data.

Laria, Daniel; Fernandez-Prini, Roberto

1991-02-01

94

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

PubMed

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

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

2011-01-17

95

Test methods for textile composites  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

96

Spectrophotometric simultaneous determination of Tenofovir disoproxil fumarate and Emtricitabine in combined tablet dosage form by ratio derivative, first order derivative and absorbance corrected methods and its application to dissolution study  

PubMed Central

Three simple, economical, precise, and accurate methods are described for the simultaneous determination of Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM) in combined tablet dosage form. The first method is ratio derivative spectra, second is first-order derivative spectrophotometry and third is absorption corrected method. The amplitudes at 271.07 and 302.17 nm in the ratio derivative method, 224.38 and 306.88 nm in the first order derivative method were selected to determine Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM), respectively, in combined formulation. Beer's law is obeyed in the concentration range of 3-21 ?g/ml for TE and 2-14 ?g/ml for EM for first two methods and range for third method was 6-30 ?g/ml of TE and 4-20 ?g/ml of EM. The percent assay for commercial formulation was found to be in the range 98.91%–101.72% for both the analytes by the proposed three methods. Absorption corrected method was successfully applied to carry out dissolution study of commercial tablet formulation by using USP II dissolution test apparatus. The methods were validated with respect to linearity, precision, and accuracy. Recoveries by proposed methods were found in the range of 99.06 %-101.34 % for both the analytes. PMID:23781430

Choudhari, Vishnu P.; Ingale, Snehal; Gite, Sacchidanand R.; Tajane, Dipali D.; Modak, Vikram G.; Ambekar, Archana

2011-01-01

97

Dissolution point and isolation robustness: Robustness criteria for general cluster analysis methods  

Microsoft Academic Search

Two robustness criteria are presented that are applicable to general clustering methods. Robustness and stability in cluster analysis are not only data dependent, but even cluster dependent. Robustness is in the present paper defined as a property of not only the clustering method, but also of every individual cluster in a data set. The main principles are: (a) dissimilarity measurement

Christian Hennig

2008-01-01

98

Thermal well-test method  

DOEpatents

A well-test method involving injection of hot (or cold) water into a groundwater aquifer, or injecting cold water into a geothermal reservoir. By making temperature measurements at various depths in one or more observation wells, certain properties of the aquifer are determined. These properties, not obtainable from conventional well test procedures, include the permeability anisotropy, and layering in the aquifer, and in-situ thermal properties. The temperature measurements at various depths are obtained from thermistors mounted in the observation wells.

Tsang, Chin-Fu (Albany, CA); Doughty, Christine A. (Berkeley, CA)

1985-01-01

99

In vitro dissolution and physicochemical characterizations of novel PVP-based solid dispersions containing valsartan prepared by a freeze-drying method.  

PubMed

Valsartan (VAL) shows poor oral bioavailability mainly as a result of its low water solubility at low pH. This study is designed to investigate the dissolution properties and physicochemical characteristics of novel PVP-based solid dispersions (SDs) containing VAL. The SDs were prepared with polyvinylpyrrolidone (PVP-K30) as a hydrophilic polymer, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 (F68) as a surfactant, without using any organic solvents by a freeze-drying method. The dissolution study was carried out and the physicochemical properties of SDs were also characterized by using differential scanning calorimetry (DSC), fourier transform-infrared (FT-IR) spectroscopy, X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The dissolution rates of SDs were significantly improved at pH1.2 and pH6.8 compared to that of pure drug. The results of physicochemical properties suggested that some interactions between VAL and carriers had occurred in the molecular level and the drug presented in the SDs was amorphous. It was concluded that the novel PVP-based SDs has been successfully prepared by a freeze-drying method, resulting in significant dissolution improvement of VAL. PMID:25362604

Xu, Wei-Juan; Liu, Yan; Shi, Li-Li; Cui, Jing-Hao; Cao, Qing-Ri

2014-11-01

100

Heuristic Security-Testing Methods  

Microsoft Academic Search

This is the first of two papers that deal with the development of running state requirements for functional testing of security software and hardware systems. It outlines the need to adopt paradigms that reflect typical usage patterns, prevalent infection methods, and proper security tool use and configurations that are grounded in real-world scenarios. This paper outlines a practical set of

John E. Kerivan

2006-01-01

101

Formulation Development and Dissolution Rate Enhancement of Efavirenz by Solid Dispersion Systems  

PubMed Central

The aim of this study was to enhance the dissolution rate of efavirenz using solid dispersion systems (binary and ternary). A comparison between solvent and fusion method was also investigated. Solid dispersions of efavirenz were prepared using polyethylene glycol 8000, polyvinylpyrrolidone K30 alone and combination of both. Tween 80 was incorporated to obtain a ternary solid dispersion system. Dissolution tests were conducted and evaluated on the basis of cumulative percentage drug release and dissolution efficiency. Physicochemical characterizations of the solid dispersions were carried out using differential scanning calorimetric, powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Dissolution was remarkably improved in both systems compared to pure efavirenz (P<0.05). An optimum ratio was identified at a drug:polymer of 1:10. Incorporation of Tween 80 to 1:10 formulations formed using solvent method showed further improvement in the dissolution rate. Physicochemical characterization results suggested that efavirenz existed in the amorphous form in all the solid dispersion systems providing evidence of improvement in dissolution. No statistically significant difference (P>0.05) in dissolution was observed between the two methods. Binary and ternary solid dispersion systems both have showed a significant improvement in the dissolution rate of efavirenz. Formulations with only polyvinylpyrrolidone K30 showed best dissolution profile and 1:10 was identified as an optimum drug-polymer weight ratio. PMID:24082345

Koh, P. T.; Chuah, J. N.; Talekar, Meghna; Gorajana, A.; Garg, S.

2013-01-01

102

Influence of the Efavirenz Micronization on Tableting and Dissolution  

PubMed Central

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

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

103

K Basin Sludge Conditioning Process Testing Fate of PCBs During K Basin Sludge Dissolution in Nitric Acid and with Hydrogen Peroxide Addition  

SciTech Connect

The work described in this report is part of the studies being performed to address the fate of polychlorinated biphenyls (PCBs) in K Basin sludge before the sludge can be transferred to the Tank Waste Remediation System (TWRS) double shell tanks. One set of tests examined the effect of hydrogen peroxide on the disposition of PCBs in a simulated K Basin dissolver solution containing 0.5 M nitric acid/1 M Fe(NO{sub 3}){sub 3}. A second series of tests examined the disposition of PCBs in a much stronger ({approx}10 M) nitric acid solution, similar to that likely to be encountered in the dissolution of the sludge.

GM Mong; AJ Schmidt; EW Hoppe; KH Pool; KL Silvers; BM Thornton

1999-01-04

104

Thermal well-test method  

DOEpatents

A well-test method involving injection of hot (or cold) water into a groundwater aquifer, or injecting cold water into a geothermal reservoir is disclosed. By making temperature measurements at various depths in one or more observation wells, certain properties of the aquifer are determined. These properties, not obtainable from conventional well test procedures, include the permeability anisotropy, and layering in the aquifer, and in-situ thermal properties. The temperature measurements at various depths are obtained from thermistors mounted in the observation wells.

Tsang, C.F.; Doughty, C.A.

1984-02-24

105

Method For Testing Properties Of Corrosive Lubricants  

DOEpatents

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.

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

2006-01-03

106

49 CFR 383.133 - Test methods.  

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

107

Development of a modified - solid dispersion in an uncommon approach of melting method facilitating properties of a swellable polymer to enhance drug dissolution.  

PubMed

The study aimed to develop a modified-solid dispersion method using a swellable hydrophilic polymers accompanied by a conventional carrier to enhance the dissolution of a drug that possesses poor water solubility. Two swellable polymers (hydroxypropyl methylcellulose and polyethylene oxide) were swelled in melted polyethylene glycol 6000 (PEG 6000) in different ratios and under different conditions. The type, amount, and, especially, incorporation method of the swellable polymers were crucial factors affecting the dissolution rate, crystallinity, and molecular interaction of the drug. Interestingly, the method in which the swellable polymer was thoroughly mixed with the melted PEG 6000 as the first step was more effective in increasing drug dissolution than the method in which the drug was introduced to the melted PEG 6000 followed by the addition of the swellable polymer. This system has potential for controlling drug release due to high swelling capabilities of these polymers. Therefore, the current study can be considered to be a promising model for formulations of controlled release systems containing solid dispersions. PMID:25735669

Nguyen, Tuong Ngoc-Gia; Tran, Phuong Ha-Lien; Tran, Thanh Van; Vo, Toi Van; Truong-DinhTran, Thao

2015-04-30

108

Dissolution and spectrophotometric determination of astaxanthin in aqueous solutions.  

PubMed

The poor solubility of astaxanthin in water can cause problems during dissolution tests of dosage forms because they are usually performed in water-based media. The aim of this study was the development of a convenient dissolution medium and a method for a spectrophotometric determination of astaxanthin in an aqueous solution. Three surfactants in different concentrations were tested as solubility-improving substances: sodium lauryl sulfate (SLS), polysorbate 80 (PS 80) and macrogolglycerol hydroxystearate (Cremophor RH 40, CR 40). Optimal conditions were determined. The dissolution of astaxanthin from solid dosage form is performed into 1000 g of a solution of sodium lauryl sulfate with the concentration 1.0% (w/w) at 37 degrees C by paddle method, 100 rotations per minute, dissolution time 30 minutes. The procedure is convenient for solid dosage forms with a content of 4 to 12 mg of astaxanthin. The spectrophotometric determination of astaxanthin in aqueous solution from the dissolution test is measured at 486 nm. The specific absorbance A(1%) 1cm for astaxanthin in water is 2000, a sodium lauryl sulfate solution (1%) was used as a blank. PMID:21901976

Tichý, E; Zabka, M; Gardavská, K; Halenárová, A; Scheerová, Z Kontseková; Potúcková, M

2011-08-01

109

Selective dissolution of magnetic iron oxides in the acidammonium oxalate/ferrous iron extraction method--I. Synthetic samples  

E-print Network

a high magnetic signal com- pared to other magnetic iron oxides (for example, magnetite has a saturationSelective dissolution of magnetic iron oxides in the acid­ammonium oxalate/ferrous iron extraction. Synthetic samples containing a quartz matrix with 0.1 wt per cent of iron oxides were extracted with the AAO

Utrecht, Universiteit

110

A numerical study of mass transfer of ozone dissolution in bubble plumes with an Euler-Lagrange Method  

E-print Network

, as a model problem for a water purification system. The effect of bubble diameter and plume structure on mass are widely observed and exploited in engineering applications, with water purification using ozone bubble the mass transfer process of ozone dissolution in a bubble plume inside a rectangular water tank

Huang, Huaxiong

111

Plutonium dissolution from Rocky Flats Plant incinerator ash  

SciTech Connect

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 values of process parameters were identified. Using the selected process, 99.5% plutonium recovery was achieved, leaving about 12.7 wt % heel residue for an equal weight composite of the three ashes tested. 15 refs., 26 figs.

Delegard, C.H.

1985-06-01

112

Dissolution parameters for sodium diclofenac-containing hypromellose matrix tablet.  

PubMed

Sodium diclofenac (SD) release from dosage forms has been studied under different conditions. However, no dissolution method that is discriminatory enough to reflect slight changes in formulation or manufacturing process, and which could be effectively correlated with the biological properties of the dosage form, has been reported. This study sought to develop three different formulae of SD-containing matrix tablets and to determine the effect of agitation speed in its dissolution profiles. F1, F2 and F3 formulations were developed using hypromellose (10, 20 and 30%, respectively for F1, F2 and F3) and other conventional excipients. Dissolution tests were carried out in phosphate buffer pH 6.8 at 37 degrees C using apparatus II at 50, 75 or 100 rpm. Dissolution efficiency (DE), T(50) and T(90) were determined and plotted as functions of the variables agitation speed and hypromellose concentration. Regarding DE, F2 showed more sensitivity to variations in agitation speed than F1 and F3. Increasing hypromellose concentration reduced DE values, independent of agitation speed. Analysis of T(50) and T(90) suggests that F1 is less sensitive to variations in agitation speed than F2 and F3. Most discriminatory dissolution conditions were observed at 50 rpm. Results suggest that the comparison of dissolution performance of SD matrix tablets should take into account polymer concentration and agitation conditions. PMID:19941944

Mourão, Samanta C; da Silva, Cristiane; Bresolin, Tania M B; Serra, Cristina H R; Porta, Valentina

2010-02-15

113

In vitro release testing of matrices based on starch-methyl methacrylate copolymers: effect of tablet crushing force, dissolution medium pH and stirring rate.  

PubMed

Direct-compressed matrix tablets were obtained from a variety of potato starch-methyl methacrylate copolymers(1) as sustained-release agents, using anhydrous theophylline as a model drug. The aim of this work was to investigate the influence of the copolymer type, the tablet crushing force and dissolution variables such as the pH of the dissolution medium and the agitation intensity on the in vitro drug release behaviour of such matrices. Commercial sustained-release theophylline products (Theo-Dur(®) 100mg, Theolair(®) 175 mg) were used as standards. Test formulations were compacted into tablets at three different crushing force ranges (70-80, 90-100 and 110-120 N) to examine the effect of this factor on the porous network and drug release kinetics. In vitro release experiments were conducted in a pH-changing medium (1.2-7.5) with basket rotation speeds in the range 25-100 r.p.m. to simulate the physiological conditions of the gastrointestinal tract. The release rate of theophylline was practically not affected by pH in the case of Theo-Dur(®) and HSMMA matrices. In contrast, Theolair(®) and CSMMA tablets demonstrated a biphasic drug release pattern, which appeared to be sensitive to the pH of the dissolution medium. An increase in the crushing force of the copolymer matrices was accompanied by a reduction of the matrix porosity, although the porous network depends markedly on the type of copolymer, having a strong influence on the drug release kinetics. Mathematical modelling of release data shows a Fickian diffusion or anomalous transport mechanism. Based on the similarity factor f2, FD-HSMMA, OD-CSMMA and FD-CSMMA at 90-100 N were selected for agitation studies. In general, all formulations showed an agitation speed-dependent release, with Theo-Dur(®) and FD-CSMMA matrices being the less susceptible to this factor. PMID:24333902

Ferrero, C; Jiménez-Castellanos, M R

2014-01-30

114

Pore-scale simulation of coupled reactive transport and dissolution in fractures and porous media using the level set interface tracking method  

SciTech Connect

A level set simulation methodology developed for modeling coupled reactive transport and structure evolution has been applied to dissolution in fracture apertures and porous media. The coupled processes such as fluid flow, reactant transport and dissolution at the solid-liquid interfaces are handled simultaneously. The reaction-induced evolution of solid-liquid interfaces is captured using the level set method, with the advantage of representing the interface with sub-grid scale resolution. The coupled processes are simulated for several geometric models of fractures and porous media under various flow conditions and reaction rates. Quantitative relationships between permeability and porosity are obtained from some of the simulation results and compared with analytical constitutive relations (i.e., the conventional cubic law and the Carman-Kozeny law) based on simplified pore space geometries and reaction induced geometric evolutions. The drastic deviation of the simulation results from these analytical theories is explained by the development of large local concentration gradients of reactants within fracture apertures and individual pores observed in the simulation results and consequently the complex geometric evolution patterns of fracture apertures and pores due to mineral dissolution. The simulation results support the argument that traditional constitutive relations based on simplified geometries and conditions have limited applicability in predicting field scale reactive transport and that incorporation of micro-scale physics is necessary.

Hai Huang; Xiaoyi Li

2011-01-01

115

Error response test system and method using test mask variable  

NASA Technical Reports Server (NTRS)

An error response test system and method with increased functionality and improved performance is provided. The error response test system provides the ability to inject errors into the application under test to test the error response of the application under test in an automated and efficient manner. The error response system injects errors into the application through a test mask variable. The test mask variable is added to the application under test. During normal operation, the test mask variable is set to allow the application under test to operate normally. During testing, the error response test system can change the test mask variable to introduce an error into the application under test. The error response system can then monitor the application under test to determine whether the application has the correct response to the error.

Gender, Thomas K. (Inventor)

2006-01-01

116

Insulator Icing Test Methods and Procedure  

Microsoft Academic Search

This is a position paper prepared by the IEEE Task Force on Insulator Icing Test Methods. Test methods for evaluating flashover voltage of ceramic and nonceramic insulators under ice, snow, and cold-fog conditions are recommended. The paper describes the procedure to be followed at various stages of an evaluation test including preparation of the test object, insulator precontamination, ice, snow,

M. Farzaneh; T. Baker; K. Brown; W. A. Chisholm; C. de Tourreil; J. F. Drapeau; S. Fikke; J. M. George; E. Gnandt; T. Grisham; I. Gutman; R. Hartings; R. Kremer; G. Powell; L. Rolfseng; T. Rosek; D. L. Ruff; D. Shaffner; V. Skienicka; R. Sundararajan; J. Yu

2002-01-01

117

30 CFR 36.41 - Testing methods.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Testing methods. 36.41 Section 36.41 Mineral...ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ...Test Requirements § 36.41 Testing methods. Mobile diesel-powered...

2013-07-01

118

30 CFR 36.41 - Testing methods.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Testing methods. 36.41 Section 36.41 Mineral...ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ...Test Requirements § 36.41 Testing methods. Mobile diesel-powered...

2012-07-01

119

Electrochemical test methods for advanced battery and semiconductor technology  

NASA Astrophysics Data System (ADS)

This dissertation consists of two studies. The first study was the evaluation of metallic materials for advanced lithium ion batteries and the second study was the determination of the dielectric constant k for the low-k materials. The advanced lithium ion battery is miniature for implantable medical devices and capable of being recharged from outside of the body using magnetic induction without physical connections. The stability of metallic materials employed in the lithium ion battery is one of the major safety concerns. Three types of materials---Pt-Ir alloy, Ti alloys, and stainless steels---were evaluated extensively in this study. The electrochemical characteristics of Pt-Ir alloy, Ti alloys, and stainless steels were evaluated in several types of battery electrolytes in order to determine the candidate materials for long-term use in lithium ion batteries. The dissolution behavior of these materials and the decomposition behavior of the battery electrolyte were investigated using the anodic potentiodynamic polarization (APP) technique. Lifetime prediction for metal dissolution was conducted using constant potential polarization (CPP) technique. The electrochemical impedance spectroscopy (EIS) technique was employed to investigate the metal dissolution behavior or the battery electrolyte decomposition at the open circuit potential (OCP). The scanning electron microscope (SEM) was used to observe the morphology changes after these tests. The effects of experimental factors on the corrosion behaviors of the metallic materials and stabilities of the battery electrolytes were also investigated using the 23 factorial design approach. Integration of materials having low dielectric constant k as interlayer dielectrics and/or low-resistivity conductors will partially solve the RC delay problem for the limiting performance of high-speed logic chips. The samples of JSR LKD 5109 material capped by several materials were evaluated by using EIS. The feasibility of using EIS to determine the dielectric constant k of the low-k materials was also evaluated in this study. The test results demonstrated that the EIS technique is a powerful method in the study of low-k materials.

Hsu, Chao-Hung

120

Preparation, Physicochemical Characterization and In-vitro Dissolution Studies of Diosmin-cyclodextrin Inclusion Complexes  

PubMed Central

Diosmin, a vascular-protecting agent, is practically insoluble in water, and its oral absorption is limited by its extremely low dissolution rate. In this study, ?-cyclodextrin (?CD) and 2-hydroxypropyl-?-cyclodextrin (HP?CD) were obtained to improve the solubility and dissolution rate of diosmin. Phase solubility studies of diosmin with ?CD and HP?CD in distilled water were conducted to characterize the complexes in liquid state. The solid-state characterization of the complexes prepared with different methods was performed by fourier transform-infra red spectroscopy (FTIR), optical microscopy analyses, and differential scanning calorimetry (DSC). Dissolution studies were carried out in distilled water using US pharmacopeia dissolution rate testing equipment. The complexation of diosmin with ?CD and HP?CD both indicated an AL type of phase-solubility diagrams, and the apparent stability constants (Kc) was found to be 222.13 and 200.08 M?1, respectively. The Kc values indicated the ?CD and HP?CD showed the similar equal complexation ability with diosmin, HP?CD provided higher solubility for diosmin due to its higher water solubility. The dissolution studies suggest that the inclusion complexes provide higher dissolution rate compared with the physical mixtures and the drug alone. Furthermore, the inclusion complex prepared by freeze drying method presented higher dissolution rate than kneading method. PMID:25587299

Ai, Fengwei; Ma, Yingli; Wang, Jiayu; Li, Yanfeng

2014-01-01

121

Evaluation of a three compartment in vitro gastrointestinal simulator dissolution apparatus to predict in vivo dissolution.  

PubMed

In vitro dissolution tests are performed for new formulations to evaluate in vivo performance, which is affected by the change of gastrointestinal (GI) physiology, in the GI tract. Thus, those environmental changes should be introduced to an in vitro dissolution test. Many studies have successfully shown the improvement of in vitro-in vivo correlations (IVIVC) by introducing those physiological changes into dissolution tests. The gastrointestinal simulator (GIS), a multicompartment in vitro dissolution apparatus, was developed to evaluate in vivo drug dissolution. A gastric-emptying rate along with transit rate are key factors to evaluate in vivo drug dissolution and, hence, drug absorption. Dissolution tests with the GIS were performed with Biopharmaceutical Classification System class I drugs at five different gastric-emptying rates in the fasted state. Computational models were used to determine in vivo gastric-emptying time for propranolol and metoprolol based on the GIS dissolution results. Those were compared with published clinical data to determine the gastric half-emptying time. In conclusion, the GIS is a practical tool to assess dissolution properties and can improve IVIVC. PMID:25251982

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

2014-11-01

122

Tribological test methods and apparatus  

Microsoft Academic Search

Tribology is the term that has been applied since 1966 to the science of friction, wear, lubrication, and the interaction of contacting surfaces when they are displaced relative to each other. Tribology characteristically employs a broad circle of experimental methods. This circle is expanding continuously, and the methods are being improved. Even the prescientific period of development of engineering thought

I. A. Buyanovskii

1994-01-01

123

Electrokinetic remediation prefield test methods  

NASA Technical Reports Server (NTRS)

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.

Hodko, Dalibor (Inventor)

2000-01-01

124

Comparison of X-ray Powder Diffraction and Solid-State Nuclear Magnetic Resonance in Estimating Crystalline Fraction of Tacrolimus in Sustained-Release Amorphous Solid Dispersion and Development of Discriminating Dissolution Method.  

PubMed

The focus of present investigation was to explore X-ray powder diffraction (XRPD) and solid-state nuclear magnetic resonance (ssNMR) techniques for amorphous and crystalline tacrolimus quantification in the sustained-release amorphous solid dispersion (ASD), and to propose discriminating dissolution method that can detect crystalline drug. The ASD and crystalline physical mixture was mixed in various proportions to make sample matrices containing 0%-100% crystalline-amorphous tacrolimus. Partial-least-square regression and principle component regression were applied to the spectral data. Dissolution of the ASD in the US FDA recommended dissolution medium with and without surfactant was performed. R(2) > 0.99 and slope was close to one for all the models. Root-mean-square of prediction, standard error of prediction, and bias were higher in ssNMR-based models when compared with XRPD data models. Dissolution of the ASD decreased with an increase in the crystalline tacrolimus in the formulations. Furthermore, detection of crystalline tacrolimus in the ASD was progressively masked with an increase in the surfactant level in the dissolution medium. XRPD and ssNMR can be used equally to quantitate the crystalline and amorphous fraction of tacrolimus in the ASD with good accuracy; however, ssNMR data collection time is excessively long, and minimum surfactant level in the dissolution medium maximizes detection of crystalline reversion in the formulation. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1777-1786, 2015. PMID:25753829

Rahman, Ziyaur; Bykadi, Srikant; Siddiqui, Akhtar; Khan, Mansoor A

2015-05-01

125

7 CFR 58.644 - Test methods.  

Code of Federal Regulations, 2013 CFR

...Inspection and Grading Service 1 Operations and Operating Procedures § 58.644 Test methods. (a) Microbiological. Microbiological determinations shall be made in accordance with the methods described in the latest edition of...

2013-01-01

126

Ignitability test method and apparatus  

NASA Technical Reports Server (NTRS)

An apparatus for testing ignitability of an initiator includes a body having a central cavity, an initiator holder for holding the initiator over the central cavity of the body, an ignition material holder disposed in the central cavity of the body and having a cavity facing the initiator holder which receives a measured quantity of ignition material to be ignited by the initiator. It contains a chamber in communication with the cavity of the ignition material and the central cavity of the body, and a measuring system for analyzing pressure characteristics generated by ignition of the ignition material by the initiator. The measuring system includes at least one transducer coupled with an oscillograph for recording pressure traces generated by ignition.

Bement, Laurence J. (inventor); Bailey, James W. (inventor); Schimmel, Morry L. (inventor)

1991-01-01

127

Methods for Scaling Icing Test Conditions  

NASA Technical Reports Server (NTRS)

This report presents the results of tests at NASA Lewis to evaluate several methods to establish suitable alternative test conditions when the test facility limits the model size or operating conditions. The first method was proposed by Olsen. It can be applied when full-size models are tested and all the desired test conditions except liquid-water content can be obtained in the facility. The other two methods discussed are: a modification of the French scaling law and the AEDC scaling method. Icing tests were made with cylinders at both reference and scaled conditions representing mixed and glaze ice in the NASA Lewis Icing Research Tunnel. Reference and scale ice shapes were compared to evaluate each method. The Olsen method was tested with liquid-water content varying from 1.3 to .8 g/m(exp3). Over this range, ice shapes produced using the Olsen method were unchanged. The modified French and AEDC methods produced scaled ice shapes which approximated the reference shapes when model size was reduced to half the reference size for the glaze-ice cases tested.

Anderson, David N.

1995-01-01

128

Bootstrap Methods for Testing Homogeneity of Variances  

Microsoft Academic Search

This article describes the use of bootstrap methods for the problem of testing homogeneity of variances when means are not assumed equal or known. The methods are new in this context and allow the use of normal-theory test statistics such as F = s1\\/s2 without the normality assumption that is crucial for validity of critical values obtained from the F

Dennis D. Boos; Cavell Brownie

1989-01-01

129

PE Metrics: Background, Testing Theory, and Methods  

ERIC Educational Resources Information Center

New testing theories, concepts, and psychometric methods (e.g., item response theory, test equating, and item bank) developed during the past several decades have many advantages over previous theories and methods. In spite of their introduction to the field, they have not been fully accepted by physical educators. Further, the manner in which…

Zhu, Weimo; Rink, Judy; Placek, Judith H.; Graber, Kim C.; Fox, Connie; Fisette, Jennifer L.; Dyson, Ben; Park, Youngsik; Avery, Marybell; Franck, Marian; Raynes, De

2011-01-01

130

Relation between acid dissolution time in the vacuum test tube and time required for graphitization for AMS target preparation  

Microsoft Academic Search

Availability of an effective graphitization system is essential for the successful operation of an AMS laboratory for radiocarbon measurements. We have set up a graphitization system consisting of metal vacuum lines for cleaning CO2 sample gas which is then converted to graphite. CO2 gas from a carbonate sample is produced in vacuum in a test tube by injecting concentrated phosphoric

Yusuke Yokoyama; Yousuke Miyairi; Hiroyuki Matsuzaki; Fumiaki Tsunomori

2007-01-01

131

Standard practice for preparation and dissolution of plutonium materials for analysis  

E-print Network

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...

American Society for Testing and Materials. Philadelphia

2008-01-01

132

Development and validation of dissolution study of sustained release dextromethorphan hydrobromide tablets.  

PubMed

This study describes the development and validation of dissolution tests for sustained release Dextromethorphan hydrobromide tablets using an HPLC method. Chromatographic separation was achieved on a C18 column utilizing 0.5% triethylamine (pH 7.5) and acetonitrile in the ratio of 50:50. The detection wavelength was 280 nm. The method was validated and response was found to be linear in the drug concentration range of 10-80 microg mL(-1). The suitable conditions were clearly decided after testing sink conditions, dissolution medium and agitation intensity. The most excellent dissolution conditions tested, for the Dextromethorphan hydrobromide was applied to appraise the dissolution profiles. The method was validated and response was found to be linear in the drug concentration range of 10-80 microg mL(-1). The method was established to have sufficient intermediate precision as similar separation was achieved on another instrument handled by different operators. Mean Recovery was 101.82%. Intra precisions for three different concentrations were 1.23, 1.10 0.72 and 1.57, 1.69, 0.95 and inter run precisions were % RSD 0.83, 1.36 and 1.57%, respectively. The method was successfully applied for dissolution study of the developed Dextromethorphan hydrobromide tablets. PMID:24897800

Rajan, Sekar; Colaco, Socorrina; Ramesh, N; Meyyanathan, Subramania Nainar; Elango, K

2014-02-01

133

Dissolution enthalpies of cellulose in ionic liquids.  

PubMed

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

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

2014-11-26

134

Boehmite Actual Waste Dissolutions Studies  

SciTech Connect

The U.S. Department of Energy plans to vitrify approximately 60,000 metric tons of high-level waste (HLW) sludge from underground storage tanks at the Hanford Nuclear Reservation. To reduce the volume of HLW requiring treatment, a goal has been set to remove a significant quantity of the aluminum, which comprises nearly 70 percent of the sludge. Aluminum is found in the form of gibbsite, sodium aluminate and boehmite. Gibbsite and sodium aluminate can be easily dissolved by washing the waste stream with caustic. Boehmite, which comprises nearly half of the total aluminum, is more resistant to caustic dissolution and requires higher treatment temperatures and hydroxide concentrations. Samples were taken from four Hanford tanks and homogenized in order to give a sample that is representative of REDOX (Reduction Oxidation process for Pu recovery) sludge solids. Bench scale testing was performed on the homogenized waste to study the dissolution of boehmite. Dissolution was studied at three different hydroxide concentrations, with each concentration being run at three different temperatures. Samples were taken periodically over the 170 hour runs in order to determine leaching kinetics. Results of the dissolution studies and implications for the proposed processing of these wastes will be discussed.

Snow, Lanee A.; Lumetta, Gregg J.; Fiskum, Sandra K.; Peterson, Reid A.

2008-07-15

135

Fabrication of carvedilol nanosuspensions through the anti-solvent precipitation-ultrasonication method for the improvement of dissolution rate and oral bioavailability.  

PubMed

The present study aims to prepare carvedilol (CAR) nanosuspensions using the anti-solvent precipitation-ultrasonication technique to improve its dissolution rate and oral bioavailability. Alpha-tocopherol succinate (VES) was first used as a co-stabilizer to enhance the stability of the nanosuspensions. The effects of the process parameters on particle size of the nanosuspensions were investigated. The optimal values of the precipitation temperature, power inputs, and the time length of ultrasonication were selected as 10°C, 400 W, and 15 min, respectively. Response surface methodology based on central composite design was utilized to evaluate the formulation factors that affect the size of nanosuspensions, i.e., the concentration of CAR and VES in the organic solution, and the level of sodium dodecyl sulfate in the anti-solvent phase, respectively. The optimized formulation showed a mean size of 212 ± 12 nm and a zeta potential of -42 ± 3 mV. Scanning electron microscopy revealed that the nanosuspensions were flaky-shaped. Powder X-ray diffraction and differential scanning calorimetry analysis confirmed that the nanoparticles were in the amorphous state. Fourier transform infrared analysis demonstrated that the reaction between CAR and VES is probably due to hydrogen bonding. The nanosuspension was physically stable at 25°C for 1 week, which allows it to be further processing such as drying. The dissolution rate of the nanosuspensions was markedly enhanced by reducing the size. The in vivo test demonstrated that the C(max) and AUC(0-36) values of nanosuspensions were approximately 3.3- and 2.9-fold greater than that of the commercial tablets, respectively. PMID:22246736

Liu, Dandan; Xu, Heming; Tian, Baocheng; Yuan, Kun; Pan, Hao; Ma, Shilin; Yang, Xinggang; Pan, Weisan

2012-03-01

136

Testing variance components by two jackknife methods  

Technology Transfer Automated Retrieval System (TEKTRAN)

The jacknife method, a resampling technique, has been widely used for statistical tests for years. The pseudo value based jacknife method (defined as pseudo jackknife method) is commonly used to reduce the bias for an estimate; however, sometimes it could result in large variaion for an estmimate a...

137

Dissolution of Globular Clusters  

E-print Network

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.

Holger Baumgardt

2006-05-04

138

SAS molecular tests Salmonella detection kit. Performance tested method 021202.  

PubMed

The SAS Molecular tests Salmonella Detection method, a Loop-mediated Isothermal Amplification method, performed as well as or better than the U.S. Department of Agriculture-Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. The ground beef (30% fat, 25 g test portion), poultry matrixes and leafy greens were validated in a 6-7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16-20 h enrichment. The method performance for meat and leafy green matrixes was shown to be acceptable under conditions of co-enrichment with Escherichia coli 0157. Thus, after a short 6-7 h co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non-Salmonella species examined. The method was shown to be robust when enrichment time, DNA extract hold time, and DNA volume were varied. PMID:25051629

Bapanpally, Chandra; Montier, Laura; Khan, Shah; Kasra, Akif; Brunelle, Sharon L

2014-01-01

139

The dilemma of disappearing diatoms: Incorporating diatom dissolution data into palaeoenvironmental modelling and reconstruction  

NASA Astrophysics Data System (ADS)

Taphonomic issues pose fundamental challenges for Quaternary scientists to recover environmental signals from biological proxies and make accurate inferences of past environments. The problem of microfossil preservation, specifically diatom dissolution, remains an important, but often overlooked, source of error in both qualitative and quantitative reconstructions of key variables from fossil samples, especially those using relative abundance data. A first step to tackling this complex issue is establishing an objective method of assessing preservation (here, diatom dissolution) that can be applied by different analysts and incorporated into routine counting strategies. Here, we establish a methodology for assessment of diatom dissolution under standard light microscopy (LM) illustrated with morphological criteria for a range of major diatom valve shapes. Dissolution data can be applied to numerical models (transfer functions) from contemporary samples, and to fossil material to aid interpretation of stratigraphic profiles and taphonomic pathways of individual taxa. Using a surface sediment diatom-salinity training set from the Northern Great Plains (NGP) as an example, we explore a variety of approaches to include dissolution data in salinity inference models indirectly and directly. Results show that dissolution data can improve models, with apparent dissolution-adjusted error (RMSE) up to 15% lower than their unadjusted counterparts. Internal validation suggests improvements are more modest, with bootstrapped prediction errors (RMSEP) up to 10% lower. When tested on a short core from Devils Lake, North Dakota, which has a historical record of salinity, dissolution-adjusted models infer higher values compared to unadjusted models during peak salinity of the 1930s-1940s Dust Bowl but nonetheless significantly underestimate peak values. Site-specific factors at Devils Lake associated with effects of lake level change on taphonomy (preservation and re-working, implied by dissolution data) may override model improvements incorporating dissolution. Dissolution-adjusted salinity models are also applied to a 150-year sediment record from Spiritwood Lake, North Dakota, which suggests that this lake has a damped and lagged response to major regional climate forcing of salinity during the Dust Bowl. At this site, dissolution data also suggest different taphonomic behaviour of taxa related to their seasonal patterns of growth and sedimentation. Thus, dissolution data can improve models, and aid interpretation of sedimentary profiles as records of limnological, ecological and environmental change, filtered by taphonomy.

Ryves, David B.; Battarbee, Richard W.; Fritz, Sherilyn C.

2009-01-01

140

Method and apparatus for testing microfilaments  

DOEpatents

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.

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

1995-08-01

141

Experiment analysis of freeform testing based on absolute testing method  

NASA Astrophysics Data System (ADS)

Requirements for the measurement resolution in the sub-nanometer range have become quite common which includes not only the repeatability or reproducibility but also the absolute measurement accuracy. The freeform lens for wavefront compensating contains some medium spatial frequency terms. The wavefront error of lithographic object lens is very small. One method to reduce the wavefront error of lithographic object lens is to use the freeform lens. The freeform lens for compensation needs more accuracy than the object lens. We can also use freeform lens of sphere or aspheric for compensation. The testing accuracy of sphere and aspheric lens are hard to achieve 1nm. The sphere and aspheric will contain the power term and are hard to find the cat-eye. The ion beam figure system (IBF) is the best polishing machine for nanometer manufacture which will polish the PV of 2um for several weeks even months. Usually we use the PV 200nm lens for compensation. So the freeform for compensation looks like a flat. In this paper we will show the testing experiment of the freeform and the testing problem. The freeform surface is created by 66 Zernike polynomials which are based on the flat lens. The freeform flat is polished by the ion figuring machine of NTG. The environment such as temperature, vibration, humidity is controlled well. The Zygo's interferometer Verifire Ashpere with absolute testing method is used to test the freeform. Position Accuracy is a problem in optical testing and manufacture. The high accuracy testing can't be determined by one method, we need the different method to compare the result especially these method will contain some defects. The defects of the recently absolute testing method are discussed.

Jia, Xin; Xu, Fuchao; Xing, Tingwen

2014-07-01

142

[Seed quality test methods of Paeonia suffruticosa].  

PubMed

In order to optimize the testing methods for Paeonia suffruticosa seed quality, and provide basis for establishing seed testing rules and seed quality standard of P. suffruticosa. The seed quality of P. suffruticosa from different producing areas was measured based on the related seed testing regulations. The seed testing methods for quality items of P. suffruticosa was established preliminarily. The samples weight of P. suffruticosa was at least 7 000 g for purity analysis and was at least 700 g for test. The phenotypic observation and size measurement were used for authenticity testing. The 1 000-seed weight was determined by 100-seed method, and the water content was carried out by low temperature drying method (10 hours). After soaking in distilled water for 24 h, the seeds was treated with different temperature stratifications of day and night (25 degrees C/20 degrees C, day/night) in the dark for 60 d. After soaking in the liquor of GA3 300 mg x L(-1) for 24 h, the P. suffruticos seeds were cultured in wet sand at 15 degrees C for 12-60 days for germination testing. Seed viability was tested by TlC method. PMID:25775790

Cao, Ya-Yue; Zhu, Zai-Biao; Guo, Qiao-Sheng; Liu, Li; Wang, Chang-Lin

2014-11-01

143

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

PubMed

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

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

2013-06-01

144

Modeling dissolution in aluminum alloys  

NASA Astrophysics Data System (ADS)

Aluminum and its alloys are used in many aspects of modern life, from soda cans and household foil to the automobiles and aircraft in which we travel. Aluminum alloy systems are characterized by good workability that enables these alloys to be economically rolled, extruded, or forged into useful shapes. Mechanical properties such as strength are altered significantly with cold working, annealing, precipitation-hardening, and/or heat-treatments. Heat-treatable aluminum alloys contain one or more soluble constituents such as copper, lithium, magnesium, silicon and zinc that individually, or with other elements, can form phases that strengthen the alloy. Microstructure development is highly dependent on all of the processing steps the alloy experiences. Ultimately, the macroscopic properties of the alloy depend strongly on the microstructure. Therefore, a quantitative understanding of the microstructural changes that occur during thermal and mechanical processing is fundamental to predicting alloy properties. In particular, the microstructure becomes more homogeneous and secondary phases are dissolved during thermal treatments. Robust physical models for the kinetics of particle dissolution are necessary to predict the most efficient thermal treatment. A general dissolution model for multi-component alloys has been developed using the front-tracking method to study the dissolution of precipitates in an aluminum alloy matrix. This technique is applicable to any alloy system, provided thermodynamic and diffusion data are available. Treatment of the precipitate interface is explored using two techniques: the immersed-boundary method and a new technique, termed here the "sharp-interface" method. The sharp-interface technique is based on a variation of the ghost fluid method and eliminates the need for corrective source terms in the characteristic equations. In addition, the sharp-interface method is shown to predict the dissolution behavior of precipitates in aluminum alloys when compared with published experimental results. The influence of inter-particle spacing is examined and shown to have a significant effect on dissolution kinetics. Finally, the impact of multiple particles of various sizes interacting in an aluminum matrix is investigated. It is shown that smaller particles dissolve faster, as expected, but influence the dissolution of larger particles through soft-impingement, even after the smaller particles have disappeared.

Durbin, Tracie Lee

2005-07-01

145

Calorimetric Investigation of Kinetics of Solid Phase Dissolution: Calcium Carbonate Dissolution in Aqueous EDTA Solution  

Microsoft Academic Search

The calorimetric method for examination of the kinetics of solid phase dissolution is presented. The thermograms are interpreted by considering the heat evolution due to the reaction as well as the heat transfer in the calorimeter. The kinetic interpretation is based on the change of particle surface area during the dissolution process. The experimental results confirm the applicability of the

Nikola Kallay; Vlasta Tomaši?; Suzana Žalac; Ljerka Bre?evi?

1997-01-01

146

Dimensionality reduction, and function approximation of poly(lactic-co-glycolic acid) micro- and nanoparticle dissolution rate  

PubMed Central

Prediction of poly(lactic-co-glycolic acid) (PLGA) micro- and nanoparticles’ dissolution rates plays a significant role in pharmaceutical and medical industries. The prediction of PLGA dissolution rate is crucial for drug manufacturing. Therefore, a model that predicts the PLGA dissolution rate could be beneficial. PLGA dissolution is influenced by numerous factors (features), and counting the known features leads to a dataset with 300 features. This large number of features and high redundancy within the dataset makes the prediction task very difficult and inaccurate. In this study, dimensionality reduction techniques were applied in order to simplify the task and eliminate irrelevant and redundant features. A heterogeneous pool of several regression algorithms were independently tested and evaluated. In addition, several ensemble methods were tested in order to improve the accuracy of prediction. The empirical results revealed that the proposed evolutionary weighted ensemble method offered the lowest margin of error and significantly outperformed the individual algorithms and the other ensemble techniques. PMID:25709436

Ojha, Varun Kumar; Jackowski, Konrad; Abraham, Ajith; Snášel, Václav

2015-01-01

147

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)

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.

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

2014-03-01

148

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

SciTech Connect

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.

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

149

40 CFR 63.1656 - Performance testing, test methods, and compliance demonstrations.  

Code of Federal Regulations, 2010 CFR

...Performance testing, test methods, and compliance demonstrations...using the applicable test methods. (3) Each run must...representative of normal process operations. ...dscf). (b) Test methods. The following test...the number of traverse points. (2) Method 2...

2010-07-01

150

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

PubMed

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

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

2014-04-01

151

The chronic toxicity of ZnO nanoparticles and ZnCl2 to Daphnia magna and the use of different methods to assess nanoparticle aggregation and dissolution.  

PubMed

In this study, the effect of ZnO nanoparticles and ZnCl2 on growth, reproduction and accumulation of zinc in Daphnia magna was determined in a 21-day chronic toxicity test. A variety of techniques were used to distinguish the free zinc ion, dissolved, nanoparticle and aggregated zinc fraction in the Daphnia test medium. The results showed similar chronic effects on growth, reproduction and accumulation for the ZnO nanoparticles (EC10, 20, 50 reproduction: 0.030, 0.049, 0.112 mg Zn/l) and the ZnCl2 (EC10, 20, 50 reproduction: 0.014, 0.027, 0.082 mg Zn/l). A large fraction of the nanoparticles rapidly dissolved after introduction in the exposure medium. Aggregation of nanoparticles was also observed but within 48 h of exposure most of these ZnO aggregates were dissolved. Based on the combined dissolution kinetics and toxicity results, it can be concluded that the toxicological effects of ZnO nanoparticles at the chronic level can be largely attributed to the dissolved fraction rather than the nanoparticles or initially formed aggregates. PMID:23837602

Adam, Nathalie; Schmitt, Claudia; Galceran, Josep; Companys, Encarna; Vakurov, Alexander; Wallace, Rachel; Knapen, Dries; Blust, Ronny

2014-11-01

152

Testing the methods of sound signal compression  

Microsoft Academic Search

Three sound signal compression methods are being offered allowing (depending on the application aim) finding the best trade-off between the compression efficiency and the realization complexity. The testing of the methods proposed was done on a half-nature simulation system including personal computers 10 Mbit\\/sec Ethernet LAN and the sound signal input\\/output means.

Valery Zagursky; Aigars Riekstinch; Ivars Zarumba

2003-01-01

153

ASTM Validates Air Pollution Test Methods  

ERIC Educational Resources Information Center

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)

Chemical and Engineering News, 1973

1973-01-01

154

Test Driven Development and the Scientific Method  

Microsoft Academic Search

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).

Rick Mugridge

2003-01-01

155

Validation of qualitative microbiological test methods.  

PubMed

This paper considers a statistical model for the detection mechanism of qualitative microbiological test methods with a parameter for the detection proportion (the probability to detect a single organism) and a parameter for the false positive rate. It is demonstrated that the detection proportion and the bacterial density cannot be estimated separately, not even in a multiple dilution experiment. Only the product can be estimated, changing the interpretation of the most probable number estimator. The asymptotic power of the likelihood ratio statistic for comparing an alternative method with the compendial method, is optimal for a single dilution experiment. The bacterial density should either be close to two CFUs per test unit or equal to zero, depending on differences in the model parameters between the two test methods. The proposed strategy for method validation is to use these two dilutions and test for differences in the two model parameters, addressing the validation parameters specificity and accuracy. Robustness of these two parameters might still be required, but all other validation parameters can be omitted. A confidence interval-based approach for the ratio of the detection proportions for the two methods is recommended, since it is most informative and close to the power of the likelihood ratio test. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25412584

IJzerman-Boon, Pieta C; van den Heuvel, Edwin R

2015-03-01

156

40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)  

Code of Federal Regulations, 2011 CFR

...false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part...268—Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) Note: The EP...

2011-07-01

157

40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B...IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method...

2010-07-01

158

Thermal insulation testing method and apparatus  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

159

Thermal Insulation Testing Method and Apparatus  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

160

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. ...

161

Standard Test Methods for Textile Composites  

NASA Technical Reports Server (NTRS)

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.

Masters, John E.; Portanova, Marc A.

1996-01-01

162

Development of test methods for textile composites  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

163

Enhanced dissolution and stability of Tanshinone IIA base by solid dispersion system with nano-hydroxyapatite  

PubMed Central

Background: Tanshinone IIA (TSIIA) exhibits a variety of cardiovascular effects; however, it has low solubility in water. The preparation of poorly soluble drugs for oral delivery is one of the greatest challenges in the field of formulation research. Among the approaches available, solid dispersion (SD) technique has proven to be one of the most commonly used these methods for improving dissolution and bioavailability of drugs, because of its relative simplicity and economy in terms of both preparation and evaluation. Objective: This study was aimed at investigating the dissolution behavior and physical stability of SDs of TSIIA by employing nano-hydroxyapatite (n-HAp). Materials and Methods: The TSIIA SDs was prepared to use a spray-drying method. First, an in vitro dissolution test was performed to assess dissolution characteristics. Next, a set of complementary techniques (differential scanning calorimetry, scanning electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy) was used to monitor the physicochemical properties of the SDs. The SDs was stored at 40°C/75% relative humidity for 6 months, after which their stability was assessed. Results: TSIIA dissolution remarkably improved because of the formulation of the SDs with n-HAp particles. Comparisons with the corresponding physical mixtures revealed changes in the SDs and explained the formation of the amorphous phase. In the stability test, virtually no time-dependent decrease was observed in either in vitro drug dissolution or drug content. Conclusion: SD formulation with n-HAp may be a promising approach for enhancing the dissolution and stability of TSIIA. PMID:25210322

Jiang, Yan-rong; Zhang, Zhen-hai; Huang, Sai-yan; Lu, Yan; Ma, Tian-tian; Jia, Xiao-bin

2014-01-01

164

A polyexponential deconvolution method. Evaluation of the “gastrointestinal bioavailability” and mean in vivo dissolution time of some ibuprofen dosage forms  

Microsoft Academic Search

A new deconvolution algorithm (DCON) suitable for pharmacokinetic applications is presented. It requires that both the impulse and input responses, typically systemic drug levels, be well described by polyexponential equations. DCON has a wider range of applications than an earlier method (DECONV) from which it is derived. A FORTRAN program is provided, making implementation of the technique a simple matter.

William R. Gillespie; Peter Veng-Pedersen

1985-01-01

165

Transport Test Problems for Hybrid Methods Development  

SciTech Connect

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.

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

2011-12-28

166

Factorial interlaboratory tests for microbiological measurement methods  

Microsoft Academic Search

\\u000a Abstract  This paper presents a validation approach for microbiological methods based on a combination of interlaboratory tests and\\u000a factorial experiments. It requires not more than 4 participants but is achieving comparable statistical confidence as in method\\u000a validation studies with 8–12 participants, if properly designed. The approach is illustrated by a comprehensive validation\\u000a of the Arxula adeninivorans yeast estrogen screen (A-YES) assay

Steffen Uhlig; Petra Gowik

2010-01-01

167

Classical Nucleation Theory Explains Mineral Growth and Dissolution Within a Mechanistic and Quantitative Framework  

NASA Astrophysics Data System (ADS)

The dissolution and precipitation of silicate minerals exert strong controls on the spatio-temporal evolution of geothermal and faulted subsurface systems. Geochemical principles dictate that these processes must be dependent upon thermodynamic driving force (extent of fluid undersaturation or supersaturation), however this dependence is not well understood. A complete physical picture that explains widely observed variations in dissolution behavior is lacking and some data show ongoing inconsistencies that cannot be explained by the largely-empirical kinetic `laws'. Here we show that the dissolution of silica and silicate minerals can be understood across broad conditions through the same nucleation rate theory that was originally developed for crystal growth. This theory should, in principle, also apply to dissolution but, before now, has never been tested. Methods: Kinetic measurements were conducted at 200°C using quartz sand (Destin, FL) using established flow-through reactor methods for measuring H4SiO4 production rate at steady state. Undersaturated solutions were prepared with and without reagent grade NaCl or CaCl2·2H2O and additions of silicic acid. All solutions had circumneutral pH and calculated pHT,200 = 5.7. Parallel experiments exposed natural (100) surfaces of a euhedral quartz crystal to four experimental conditions that, according to theory, should give distinct dissolution mechanisms. Durations of each treatment were determined from measured rates to calculate reaction time necessary to give equal silica production at 200°C. Thus, etching times ranged from 28 days to four hours. Resulting nanoscale structures were examined under a drop of water using atomic force microscopy. Findings: By generalizing nucleation theory across the potential energy continuum of growth to include dissolution, we present a quantitative and mechanistic model that explains how quartz dissolution processes change with increasing undersaturation from simple step edge retreat, to dislocation and defect-driven pit nucleation. We further show that the origin of the so-called salt effect that was recognized almost 100 years ago arises from increases in surface energy to activate dissolution by two-dimensional nucleation of vacancy islands, to greatly increase site density. This process has not been heretofore recognized as possible for oxide or silicate minerals. Nucleation rate theory also describes the dependence of dissolution kinetics on undersaturation and supersaturation for the dominant aluminosilicates, kaolinite and K-feldspar. In doing so, it resolves discrepancies between data sets reported for kaolinite at 80° and 200°C by revealing the existence of a temperature-activated transition in the dissolution and growth processes. Nucleation theory may be the missing link to unifying mineral growth and dissolution into a mechanistic and quantitative framework across the continuum of driving force.

Dove, P. M.; Han, N.; de Yoreo, J. J.

2005-12-01

168

Method for non-destructive testing  

DOEpatents

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.

Akers, Douglas W. (Idaho Falls, ID)

2011-08-30

169

IMPROVED TEST METHODS FOR ELECTRONIC AIR CLEANERS  

EPA Science Inventory

The objective of this project was to develop a fractional filtration efficiency test protocol for residential electrostatic precipitators (ESPs) that avoids the limitations of the ASHRAE 52.2 method. Specifically, the objectives were to a) determine the change in efficiency that ...

170

Item selection methods for increasing test homogeneity  

Microsoft Academic Search

A number of methods for increasing test homogeneity by item selection are discussed. Exact selection conditions which will maximize obtained homogeneity as measured by KR - 20 and KR - 21 are derived, and an application is given. Since they require only item count data, the selection conditions are economical to apply.

Harold Webster

1957-01-01

171

Method for testing vapor recovery lines  

Microsoft Academic Search

A method for testing the integrity of the vapor recovery unit of a gasoline station dispensing station where the vapor recovery unit has phase 11 capability is described, comprising the steps of: sealing the vapor recovery unit from the dispensing station at the point most proximal to the dispensing station; sealing the vapor recovery unit from the gasoline reservoir; installing

Tuma

1993-01-01

172

Standard test method for creep-fatigue crack growth testing  

E-print Network

1.1 This test method covers the determination of creep-fatigue crack growth properties of nominally homogeneous materials by use of pre-cracked compact type, C(T), test specimens subjected to uniaxial cyclic forces. It concerns fatigue cycling with sufficiently long loading/unloading rates or hold-times, or both, to cause creep deformation at the crack tip and the creep deformation be responsible for enhanced crack growth per loading cycle. It is intended as a guide for creep-fatigue testing performed in support of such activities as materials research and development, mechanical design, process and quality control, product performance, and failure analysis. Therefore, this method requires testing of at least two specimens that yield overlapping crack growth rate data. The cyclic conditions responsible for creep-fatigue deformation and enhanced crack growth vary with material and with temperature for a given material. The effects of environment such as time-dependent oxidation in enhancing the crack growth ra...

American Society for Testing and Materials. Philadelphia

2010-01-01

173

Methods and instruments for materials testing  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

174

Singlepath Salmonella. Performance Tested Method 060401.  

PubMed

Singlepath Salmonella is an immunochromatographic (lateral flow) assay for the presumptive qualitative detection of Salmonella spp. in food. A previous AOAC Performance Tested Method study evaluated Singlepath Salmonella as an effective method for the detection of Salmonella spp. in the following selected foods: dried skimmed milk, black pepper, dried pet food, desiccated coconut, cooked peeled frozen prawns, raw ground beef, and raw ground turkey. In this Emergency Response Validation extension, creamy peanut butter was inoculated with S. enterica. ser. Typhimurium. For low contamination level (1.08 CFU/25 g), a Chi-square value of 0.5 indicated that there was no significant difference between Singlepath Salmonella and the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) reference method. For high-level and uninoculated control there was 100% agreement between the methods. PMID:20166612

Lindhardt, Charlotte; Schönenbrücher, Holger; Slaghuis, Jörg; Bubert, Andreas; Ossmer, Rolf

2009-01-01

175

A comprehensive test method for reprogammable field programmable gate arrays  

E-print Network

the logic and interconnection resources are tested by the proposed method in a hierarchical manner. The proposed test method is divided into three parts of several programming steps each. Parts I and II of the proposed method test the interconnection...

Ashen, David Glen

1996-01-01

176

Crystal growth of calcite from calcium bicarbonate solutions at constant PCO2 and 25??C: a test of a calcite dissolution model  

USGS Publications Warehouse

A highly reproducible seeded growth technique was used to study calcite crystallization from calcium bicarbonate solutions at 25??C and fixed carbon dioxide partial pressures between 0.03 and 0.3 atm. The results are not consistent with empirical crystallization models that have successfully described calcite growth at low PCO2 (< 10-3 atm). Good agreement was found between observed crystallization rates and those calculated from the calcite dissolution rate law and mechanism proposed by Plummer et al. (1978). ?? 1981.

Reddy, M.M.; Plummer, L.N.; Busenberg, E.

1981-01-01

177

Characterization methods for ultrasonic test systems  

SciTech Connect

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.

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

1982-07-01

178

Calcination/dissolution residue treatment  

SciTech Connect

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.

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

179

Intracellular particle dissolution in alveolar macrophages.  

PubMed Central

Aerosol particles deposited in the lungs that are not readily soluble in the epithelial lining fluid will be phagocytized by alveolar macrophages (AM). Inside the phagolysosomal vacuole, the constituents of the plasma allow dissolution of a variety of compounds at a higher rate than dissolution in extracellular lung fluids. Chelator concentration and a pH value of about 5 were found to control intracellular particle dissolution (IPD). Hence, IPD is the initial step of translocation of dissolved material to blood, which is an important lung clearance mechanism for particles retained long term. IPD rates of uniform test particles determined in human, baboon, and canine AM cultures were similar to initial translocation rates determined in lung clearance studies of the same species after inhalation of the same test particles. IPD rate in cultured AM proved to be a sensitive functional parameter of AM, which was used to identify changes in the clearance mechanism of translocation during different exposure conditions. PMID:1396446

Kreyling, W G

1992-01-01

180

Dissolution Rate Behavior of Hydroxyapatite-Fluorapatite Mixtures  

Microsoft Academic Search

Studies were conducted to gain insights into how remineralization by fluorapatite (FAP) deposition onto hydroxyapatite (HAP) crystals might influence dissolution rate behavior and acid resistance. Dissolution rate behavior of compressed pellets was studied in 0.1 M acetate buffer, pH 4.5, ionic strength 0.5, using the rotating disk method. Attempts were made to determine the dissolution rate controlling phase by addition

D. J. Crommelin; W. I. Higuchi; J. L. Fox; P. J. Spooner; A. V. Katdare

1983-01-01

181

Mergers, Annexations, Dissolutions  

ERIC Educational Resources Information Center

Consolidations come in all shapes and sizes, including mergers, annexations and dissolutions. They do not all take place under state mandate, however. A handful of districts consolidate every year in some states like Illinois that have large numbers of small districts, many of them dual districts that serve K-8 or 9-12 in the same geographic area.…

Russo, Alexander

2006-01-01

182

Plutonium oxide dissolution  

SciTech Connect

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.

Gray, J.H.

1992-09-30

183

Plutonium oxide dissolution  

SciTech Connect

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.

Gray, J.H.

1992-09-30

184

Control system health test system and method  

DOEpatents

A method is provided for testing multiple elements of a work machine, including a control system, a component, a sub-component that is influenced by operations of the component, and a sensor that monitors a characteristic of the sub-component. In one embodiment, the method is performed by the control system and includes sending a command to the component to adjust a first parameter associated with an operation of the component. Also, the method includes detecting a sensor signal from the sensor reflecting a second parameter associated with a characteristic of the sub-component and determining whether the second parameter is acceptable based on the command. The control system may diagnose at least one of the elements of the work machine when the second parameter of the sub-component is not acceptable.

Hoff, Brian D.; Johnson, Kris W.; Akasam, Sivaprasad; Baker, Thomas M.

2006-08-15

185

Improved dissolution and anti-inflammatory effect of ibuprofen by solid dispersion.  

PubMed

The purpose of this study was to improve the dissolution rate and anti-inflammatory effect of ibuprofen by a solid dispersion (SD) method. Initial screening was developed based on drug solubility in carriers in the liquid state to select a suitable water-soluble carrier system for the preparation of SDs. The dissolution of ibuprofen in urea was higher than in PEG4000 or mannitol. Thus, urea was selected as the carrier for the preparation of SDs. SDs were characterized in terms of dissolution, differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. Solid dispersion-based (SDBT) and conventional (CT) tablets were prepared by the wet granulation method. The anti-inflammatory effect of SDBT was evaluated using the mouse ear edema test with xylene. In vitro release results indicated that the ibuprofen dissolution rate was improved by the SD. SD characterization results suggested that ibuprofen partly precipitates in crystalline and amorphous forms after SD preparation and that ibuprofen and urea do not interact. SDBT displayed more significant anti-inflammatory effects than CT. The dissolution rate and anti-inflammatory effect of ibuprofen were significantly enhanced by the ibuprofen-urea SD. PMID:22573218

Chen, Liyuan; Dang, Qifeng; Liu, Chengsheng; Chen, Jun; Song, Lei; Chen, Xiguang

2012-06-01

186

Using noble gas tracers to estimate residual CO2 saturation in the field: results from the CO2CRC Otway residual saturation and dissolution test  

NASA Astrophysics Data System (ADS)

Residual CO2 saturation is a critically important parameter in CO2 storage as it can have a large impact on the available secure storage volume and post-injection CO2 migration. A suite of single-well tests to measure residual trapping was conducted at the Otway test site in Victoria, Australia during 2011. One or more of these tests could be conducted at a prospective CO2 storage site before large-scale injection. The test involved injection of 150 tonnes of pure carbon dioxide followed by 454 tonnes of CO2-saturated formation water to drive the carbon dioxide to residual saturation. This work presents a brief overview of the full test sequence, followed by the analysis and interpretation of the tests using noble gas tracers. Prior to CO2 injection krypton (Kr) and xenon (Xe) tracers were injected and back-produced to characterise the aquifer under single-phase conditions. After CO2 had been driven to residual the two tracers were injected and produced again. The noble gases act as non-partitioning aqueous-phase tracers in the undisturbed aquifer and as partitioning tracers in the presence of residual CO2. To estimate residual saturation from the tracer test data a one-dimensional radial model of the near-well region is used. In the model there are only two independent parameters: the apparent dispersivity of each tracer and the residual CO2 saturation. Independent analysis of the Kr and Xe tracer production curves gives the same estimate of residual saturation to within the accuracy of the method. Furthermore the residual from the noble gas tracer tests is consistent with other measurements in the sequence of tests.

LaForce, T.; Ennis-King, J.; Paterson, L.

2013-12-01

187

Dissolution kinetics during localized corrosion  

SciTech Connect

The dissolution kinetics of iron and cobalt have been measured under one-dimensional diffusional boundary conditions. Experimental results obtained in aggressive neutral electrolytes show features resulting from transient supersaturation, salt film precipitation and diffusion controlled dissolution. A mathematical model incorporating these features has been applied to metal dissolution in neutral chloride solutions. The effects of sulfur-containing ions on localized dissolution of iron are descirbed with reference to the stress-corrosion cracking of sensitized stainless steels. 12 figures.

Isaacs, H.S.; Newman, R.C.

1981-01-01

188

Testing methods and techniques: A compilation  

NASA Technical Reports Server (NTRS)

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.

1974-01-01

189

A new method of field MRTD test  

NASA Astrophysics Data System (ADS)

MRTD is an important indicator to measure the imaging performance of infrared camera. In the traditional laboratory test, blackbody is used as simulated heat source which is not only expensive and bulky but also difficult to meet field testing requirements of online automatic infrared camera MRTD. To solve this problem, this paper introduces a new detection device for MRTD, which uses LED as a simulation heat source and branded plated zinc sulfide glass carved four-bar target as a simulation target. By using high temperature adaptability cassegrain collimation system, the target is simulated to be distance-infinite so that it can be observed by the human eyes to complete the subjective test, or collected to complete objective measurement by image processing. This method will use LED to replace blackbody. The color temperature of LED is calibrated by thermal imager, thereby, the relation curve between the LED temperature controlling current and the blackbody simulation temperature difference is established, accurately achieved the temperature control of the infrared target. Experimental results show that the accuracy of the device in field testing of thermal imager MRTD can be limited within 0.1K, which greatly reduces the cost to meet the project requirements with a wide application value.

Chen, Zhibin; Song, Yan; Liu, Xianhong; Xiao, Wenjian

2014-09-01

190

Experimental test of airplane boarding methods  

DOE PAGESBeta

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, 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.

Steffen, Jason H. [Fermilab; Hotchkiss, Jon [Hotchkiss Industries, Sherman Oaks

2012-01-01

191

Extension of Pack Method for Compressive Tests  

NASA Technical Reports Server (NTRS)

The pack method for determining compressive stress-strain graphs described in NACA Report No. 649 has been modified to extend it's application to thinner gages and stronger materials. The principal modifications consisted in the provision of additional support against instability cementing the specimens of the pack together with fused shellac and the provision of special clamps to hold the specimens together while the test is in progress. The shellac was found to increase the buckling load of the pack without any appreciable effect on the compressive stress-strain graph of the material. The extended pack method described in this note has made possible the application of stresses in excess of 220 kips per square inch to sheet material having a thickness of only 0.02 inch.

Aitchison, C S

1940-01-01

192

Measurement of the pure dissolution rate constant of a mineral in water  

E-print Network

We present here a methodology, using holographic interferometry, enabling to measure the pure surface reaction rate constant of the dissolution of a mineral in water, unambiguously free from the influence of mass transport. We use that technique to access to this value for gypsum and we demonstrate that it was never measured before but could be deduced a posteriori from the literature results if hydrodynamics is taken into account with accuracy. It is found to be much smaller than expected. This method enables to provide reliable rate constants for the test of dissolution models and the interpretation of in situ measurements, and gives clues to explain the inconsistency between dissolution rates of calcite and aragonite, for instance, in the literature.

Jean Colombani

2009-11-26

193

40 CFR 60.46 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...8, and subsequent performance tests as requested by the EPA Administrator...reference methods and procedures the test methods in appendix A of this...each fuel burned during each test period, and a material balance over the steam generating...

2014-07-01

194

40 CFR 60.46 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...8, and subsequent performance tests as requested by the EPA Administrator...reference methods and procedures the test methods in appendix A of this...each fuel burned during each test period, and a material balance over the steam generating...

2013-07-01

195

40 CFR 60.46 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...and subsequent performance tests as requested by the EPA Administrator...reference methods and procedures the test methods in appendix A of this...each fuel burned during each test period, and a material balance over the steam generating...

2011-07-01

196

40 CFR 60.46 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...8, and subsequent performance tests as requested by the EPA Administrator...reference methods and procedures the test methods in appendix A of this...each fuel burned during each test period, and a material balance over the steam generating...

2012-07-01

197

Mesh deployable antenna mechanics testing method  

NASA Astrophysics Data System (ADS)

Rapid development in spatial technologies and continuous expansion of astronautics applications require stricter and stricter standards in spatial structure. Deployable space structure as a newly invented structural form is being extensively adopted because of its characteristic (i.e. deployability). Deployable mesh reflector antenna is a kind of common deployable antennas. Its reflector consists in a kind of metal mesh. Its electrical properties are highly dependent on its mechanics parameters (including surface accuracy, angle, and position). Therefore, these mechanics parameters have to be calibrated. This paper presents a mesh antenna mechanics testing method that employs both an electronic theodolite and a laser tracker. The laser tracker is firstly used to measure the shape of radial rib deployable antenna. The measurement data are then fitted to a paraboloid by means of error compensation. Accordingly, the focus and the focal axis of the paraboloid are obtained. The following step is to synchronize the coordinate systems of the electronic theodolite and the measured antenna. Finally, in a microwave anechoic chamber environment, the electromechanical axis is calibrated. Testing results verify the effectiveness of the presented method.

Jiang, Li

198

16 CFR 1500.40 - Method of testing toxic substances.  

Code of Federal Regulations, 2013 CFR

...toxicity of substances, including testing that does not require animals, are presented in the CPSC's animal testing policy set forth in 16 CFR 1500...to reduce the number of test animals. The method of testing the toxic substances...

2013-01-01

199

16 CFR 1500.40 - Method of testing toxic substances.  

Code of Federal Regulations, 2014 CFR

...toxicity of substances, including testing that does not require animals, are presented in the CPSC's animal testing policy set forth in 16 CFR...to reduce the number of test animals. The method of testing the toxic substances...

2014-01-01

200

40 CFR 60.745 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...any inconsistency between a Method 24 test and a facility's formulation data, the Method 24 test will govern. For Method 24, the coating sample...1-liter container at a point in the process where the sample will...

2010-07-01

201

Incongruent dissolution and surface area of kaolinite  

NASA Astrophysics Data System (ADS)

The surface of kaolinite is modeled as a combination of Al and Si surface sites in order to understand its aqueous dissolution behavior. The pH dependence of the initial nonstoichiometric dissolution of kaolinite at 25°C can be related to the pH dependence of protonation and deprotonation of the surface Si and Al sites. The analysis indicates Al dissolution rates are greater than Si at pH < 4 with Si dissolution rate greater than Al at 4 < pH < 11 and initial stoichiometric dissolution at pH > 11. An analysis of the surface site density of kaolinite from surface potentiometric titration data is presented. This indicates that the surface area of kaolinite and possibly other clay minerals available for forming surface complexes and sites for cation detachment is significantly larger than that measured by standard gas adsorption methods. It is believed that H + and OH - can penetrate between layers in the sheet silicates which is not possible for the gas, Kr, used in the BET analysis.

Xie, Zhixin; Walther, John V.

1992-09-01

202

Fracture mechanics life analytical methods verification testing  

NASA Technical Reports Server (NTRS)

The objective was to evaluate NASCRAC (trademark) version 2.0, a second generation fracture analysis code, for verification and validity. NASCRAC was evaluated using a combination of comparisons to the literature, closed-form solutions, numerical analyses, and tests. Several limitations and minor errors were detected. Additionally, a number of major flaws were discovered. These major flaws were generally due to application of a specific method or theory, not due to programming logic. Results are presented for the following program capabilities: K versus a, J versus a, crack opening area, life calculation due to fatigue crack growth, tolerable crack size, proof test logic, tearing instability, creep crack growth, crack transitioning, crack retardation due to overloads, and elastic-plastic stress redistribution. It is concluded that the code is an acceptable fracture tool for K solutions of simplified geometries, for a limited number of J and crack opening area solutions, and for fatigue crack propagation with the Paris equation and constant amplitude loads when the Paris equation is applicable.

Favenesi, J. A.; Clemons, T. G.; Riddell, W. T.; Ingraffea, A. R.; Wawrzynek, P. A.

1994-01-01

203

DISSOLUTION OF PLUTONIUM METAL IN 8-10 M NITRIC ACID  

SciTech Connect

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.

Rudisill, T.; Pierce, R.

2012-02-21

204

Understanding the dissolution of zeolites.  

PubMed

Scientific knowledge of how zeolites, a unique classification of microporous aluminosilicates, undergo dissolution in aqueous hydrochloric acid solutions is limited. Understanding the dissolution of zeolites is fundamental to a number of processes occurring in nature and throughout industry. To better understand the dissolution process, experiments were carried out establishing that the Si-to-Al ratio controls zeolite framework dissolution, by which the selective removal of aluminum constrains the removal of silicon. Stoichiometric dissolution is observed for Type 4A zeolite in HCl where the Si-to-Al ratio is equal to 1.0. Framework silicon dissolves completely during Type 4A dissolution and is followed by silicate precipitation. However, for the zeolite analcime which has a Si-to-Al ratio of 2.0 dissolves non-stoichiometrically as the selective removal of aluminum results in partially dissolved silicate particles followed by silicate precipitation. In Type Y zeolite, exhibiting a Si-to-Al ratio of 3.0, there is insufficient aluminum to weaken the structure and cause silicon to dissolve in HCl. Thus, little or no precipitation is observed, and amorphous undissolvable silicate particles remain intact. The initial dissolution rates of Type Y and 4A zeolites demonstrate that dissolution is constrained by the number of available reaction sites, and a selective removal rate parameter is applied to delineate the mechanism of particle dissolution by demonstrating the kinetic influence of the Si-to-Al ratio. Zeolite framework models are constructed and used to undergird the basic dissolution mechanism. The framework models, scanning electron micrographs of partially dissolved crystals, and experimentally measured dissolution rates all demonstrate that a zeolite's Si-to-Al framework ratio plays a universal role in the dissolution mechanism, independent of framework type. Consequently, the unique mechanism of zeolite dissolution has general implications on how petroleum reservoir stimulation treatments should be designed. PMID:17429989

Hartman, Ryan L; Fogler, H Scott

2007-05-01

205

Diverter system test tool and method  

SciTech Connect

A method is described for testing a diverter system on an offshore drilling rig of a type having a marine riser assembly extending to a subsea well, the diverter system having a packer element and at least one port located below the packer element for the passage of drilling fluid flowing upward from the marine riser assembly during drilling. The method consists of connecting a tubular member to the upper end of a packer having an elastomeric expansive seal element; placing the packer in an upper portion of the marine riser assembly below the diverter system and expanding the seal element against the interior of the upper portion; closing the packer element of the diverter system around the tubular member; and finally applying fluid pressure in the space between the packer element of the diverter system and the seal element of the packer to determine if any leakage in the diverter system exists. The patent also describes an offshore drilling rig linked to a subsea well by a marine riser assembly extending upward from the subsea well.

Funderburg, R.R. Jr.; Kattner, M.E.; Milberger, L.J.; Slaughter, L.D.

1989-04-04

206

Analysis of Formation and Interfacial WC Dissolution Behavior of WC-Co/Invar Laser-TIG Welded Joints  

NASA Astrophysics Data System (ADS)

During the valve fabrication, hard metal is welded to stainless steel or invar alloy for sealing purposes because of its good heat resistance operating at 500 °C. However, WC (tungsten carbide) dissolution in weld pool softens the hard metal and decreases mechanical properties near the hard metal/weld interface. In order to analyze the WC dissolution in welded joint, joining of hard metal and invar alloy was carried out using laser-tungsten inert gas hybrid welding method. Microstructures of the weld region, chemical composition were investigated using optical microscope, scanning electron microscopy, and EDAX, respectively. Mechanical properties such as microhardness and four-point bend strength test were performed. Larger and smaller WC dissolution and WC dissolution through transition layer based on thermo-dynamics were discussed. The results thus indicate that WC dissolution led to cellular microstructure, columnar crystal, and transition layer under the effect of laser beam and tungsten arc. WC dissolution was affected by metal ions Fe+, Ni+, Co+ exchange in W-M-C system, and WC grain growth was driven by forces caused by laser beam and tungsten arc in larger WC, smaller WC, and liquid Fe, Ni systems.

Xu, P. Q.; Ren, J. W.; Zhang, P. L.; Gong, H. Y.; Yang, S. L.

2013-02-01

207

Evaluation of the test method activated sludge, respiration inhibition test proposed by the OECD  

SciTech Connect

The test method of activated sludge, respiration inhibition test proposed by the OECD was critically carried out and compared with other test methods. Investigation of test conditions showed that the moderate deviation from the test conditions defined by the OECD Test Guidelines did not have much effect on the result, and some modifications were proposed to improve the method. This method had a poor detection limit compared with the LC50 test with Oryzias latipes and EC50 of the growth inhibition test with Tetrahymena pyriformis. The susceptivity of the method was particularly poor for the chemicals which were highly toxic in the other two tests.

Yoshioka, Y.; Nagase, H.; Ose, Y.; Sato, T.

1986-12-01

208

Evaluating Testing Methods by Delivered Reliability  

Microsoft Academic Search

There are two main goals in testing software: (1) To achieve adequate quality (debug testing);the objective is to probe the software for defects so that these can be removed. (2) To assessexisting quality (operational testing); the objective is to gain confidence that the softwareis reliable. The names are arbitrary, and most testing techniques address both goals tosome degree. However, debug

Phyllis G. Frankl; Richard G. Hamlet; Bev Littlewood; Lorenzo Strigini

1998-01-01

209

Testing methods and techniques: Environmental testing: A compilation  

NASA Technical Reports Server (NTRS)

Various devices and techniques are described for testing hardware and components in four special environments: low temperature, high temperature, high pressure, and vibration. Items ranging from an automatic calibrator for pressure transducers to a fixture for testing the susceptibility of materials to ignition by electric spark are included.

1971-01-01

210

40 CFR 63.827 - Performance test methods.  

Code of Federal Regulations, 2011 CFR

...the conditions of performance tests. (a) An owner or operator...conduct an initial performance test to demonstrate compliance if...monthly liquid-liquid material balance. (b) Determination...operator must submit an alternative test method for determining...

2011-07-01

211

Anodic dissolution of the copper-nickel alloy under transient conditions  

Microsoft Academic Search

Anodic dissolution of an electrolytic copper-nickel alloy in 1 M HCl was studied by nonequilibrium electrochemical methods.\\u000a The dissolution of the alloy began with selective ionization of nickel. Then the rate of the anodic dissolution was limited\\u000a by nonsteady-state bulk diffusion.

V. N. Tseluikin

2008-01-01

212

Calcination/dissolution treatment of Hanford site tank waste  

SciTech Connect

Calcination/dissolution (C/D) is a candidate pretreatment method for achieving separation of low-level and high-level fractions of Hanford Site tank waste prior to their separate immobilization in waste forms for long-term disposal. The C/D process destroys nitrate and nitrite to form hydroxide and N{sub 2} and O{sub 2} offgas and converts organic carbon to carbonate. The resulting powerfully oxidizing sodium hydroxide fusion converts insoluble AlOOH, Al(OH){sub 3}, Cr(OH){sub 3}, and (Fe,Bi)PO{sub 4} waste components to soluble sodium salts which can be partitioned to the LLW fraction. Lab tests with waste simulants and genuine tank wastes were used to determine the disposition of the bulk waste components (e.g., Na, Al, Cr, Fe, Mn, Bi, Si, U, NO{sub 3}{sup -}, N{sub 2}{sup -}, CO{sub 3}{sup 2-}, PO{sub 4}{sup 3-}, and SO{sub 4}{sup 2-}) and the important radioactive isotopes (e.g., {sup 90}Sr, {sup 99}Tc, {sup 137}Cs, {sup 237}Np, {sup 239,240}Pu, and {sup 241}Am) during C/D processing. Unwanted dissolution of Np and Pu by formation of soluble hydroxide and peroxide complexes was discovered. Methods to remove Np and Pu from solution following their solubilization by C/D were developed and tested.

Delegard, C.H. [Westinghouse Hanford Co., Richland, WA (United States)

1996-10-01

213

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Test Methods 3 Table 3 of Subpart...BBBBBBB of Part 63—Test Methods For * * * You must...the number of traverse points EPA test method 1 or 1A in appendix A...at the outlet of the process equipment (or...

2010-07-01

214

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Test Methods 3 Table 3 of Subpart...AAAAAAA of Part 63—Test Methods For * * * You must...the number of traverse points EPA test method 1 or 1A in appendix A...at the outlet of the process equipment (or...

2010-07-01

215

Phase-Field Modeling of Solute Precipitation and Dissolution  

SciTech Connect

A phase-field approach to the dynamics of liquid-solid interfaces that evolve due to precipitation and/or dissolution is presented. For the purpose of illustration and comparison with other methods, phase field simulations were carried out assuming first order reaction (dissolution/precipitation) kinetics. In contrast to solidification processes controlled by a temperature field that is continuous across the solid/liquid interface (with a discontinuous temperature gradient) precipitation/dissolution is controlled by a solute concentration field that is discontinuous at the solid/liquid interface. The sharp-interface asymptotic analysis of the phase-field equations for solidification [Karma and Rappel, Phys. Rev. E57 (1998) 4342] has been modified for precipitation/dissolution processes to demonstrate that the phase-field equations converge to the proper sharp-interface limit. The mathematical model has been validated for a one-dimensional precipitation/dissolution problem by comparison with the analytical solution.

Zhijie Xu; Paul Meakin

2008-07-01

216

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

Microsoft Academic Search

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

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

217

Efavirenz Dissolution Enhancement I: Co-Micronization  

PubMed Central

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

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

2012-01-01

218

Dissolution inhibitors for 157-nm photolithography  

NASA Astrophysics Data System (ADS)

The focus of 157 nm lithographic research is shifting from materials research to process development. Poly (2-(3,3,3-trifluoro-2-trifuoromethyl-2-hydroxypropyl) bicyclo[2.2.1]heptane-5-ene) (PNBHFA) has received a great deal of attention as a possible base resin for 157 nm lithography. The Asahi Glass RS001 polymer, which was introduced at SPIE in 2002, has also shown promise as a 157 nm base resin due to its low absorbance. Partial protection of either polymer with an acid labile protecting group is a common design for functional photoresists. We previously reported the blending of the carbon monoxide copolymers with PNBHFA copolymers to achieve the critical number of protected sites for optimum imaging performance and contrast. Our group has since studied the use of the unprotected base resin with an additive monomeric dissolution inhibitors (DIs) and a photoacid generator (PAG) to form a three component resist. Surprisingly unprotected PNBHFA was discovered to have dissolution inhibition properties that are far superior to the dissolution inhibition properties of novolac. Several DIs were prepared and tested in PNBHFA to take advantage of the resins dissolution inhibition properties. We have also recently explored the performance of a two-component resist using PAGs that also function as DIs.

Chambers, Charles R.; Kusumoto, Shiro; Lee, Guen Su; Vasudev, Alok; Walthal, Leonidas; Osborn, Brian P.; Zimmerman, Paul; Conley, Will; Willson, C. Grant

2003-06-01

219

Acid dissolution of cupric oxide  

NASA Astrophysics Data System (ADS)

The rates of dissolution of synthetic cupric oxide in solutions containing perchloric, sulfuric, nitric or hydrochloric acid were studied using sintered disks. In each case, the dissolution rate increased with elapsed retention time until an essentially constant value was reached. This phenomenon can be attributed to an increase in the disk’s effective surface area. The dissolution rate is of the first order with respect to aH + for perchloric, nitric, and hydrochloric acids, while it is of a half order for sulfuric acid. High activation energies, ranging from 12.4 to 20.5 kcal/mol, and the independence of agitation speed on cupric oxide dissolution reaction rate suggest that chemical reactions are the major determinants of dissolution rates. The addition of electrolytes having anions common with the acids resulted in an acceleration of the dissolution rate due to increases in aH + values. However, the addition of electrolytes of noncommon anions revealed a quite different effect on dissolution rate. This suggests that the adsorption and/ or complexing of anions on the cupric oxide surface may have had a significant role in the determination of the dissolution rates. The type of acid used determined the identity of the adsorbed anion.

Majima, H.; Awakura, Y.; Yazaki, T.; Chikamori, Y.

1980-06-01

220

Acid dissolution hydrodynamic force analysis  

Microsoft Academic Search

The purpose of this calculation is to analyze the hydrodynamic forces associated with the in-tank piping feeding the tank fluid agitation eductor (sparger), as well as eductor induced forces. These forces will be used as input to the structural analysis of the support structure used for the acid dissolution assembly, and the acid dissolution assembly itself.

2003-01-01

221

Acid dissolution hydrodynamic force analysis  

SciTech Connect

The purpose of this calculation is to analyze the hydrodynamic forces associated with the in-tank piping feeding the tank fluid agitation eductor (sparger), as well as eductor induced forces. These forces will be used as input to the structural analysis of the support structure used for the acid dissolution assembly, and the acid dissolution assembly itself.

WHITE, M.A.

2003-05-21

222

77 FR 1129 - Revisions to Test Methods and Testing Regulations  

Federal Register 2010, 2011, 2012, 2013, 2014

...Interface Gas Chromatography/Mass Spectrometry as an alternative to EPA Method...but potentially detected by mass spectrometry, the additional system continuing...not amenable to detection by mass spectrometry, ASTM D6420-99...

2012-01-09

223

40 CFR 63.1161 - Performance testing and test methods.  

Code of Federal Regulations, 2010 CFR

...National Emission Standards for Hazardous Air Pollutants for Steel Pickling-HCl Process Facilities and Hydrochloric Acid Regeneration...b) of this subpart: (i) Method 1, to determine the number and location of sampling points, with the exception that...

2010-07-01

224

Plutonium dissolution process  

DOEpatents

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.

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

225

Plutonium dissolution process  

DOEpatents

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.

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

1994-01-01

226

Low level accelerometer test methods are investigated  

NASA Technical Reports Server (NTRS)

Problems associated with testing accelerometers to an accuracy where the standard error is less than .0000001 g are centered around the elimination of uncertainties in the acceleration input to the accelerometer. By placing a test rig in free fall, the uncertainty in the earths gravity field can be eliminated.

Nelson, R. H., Jr.; Plourde, H. S.

1966-01-01

227

Multicomponent Analysis of Liquids by Test Methods  

Microsoft Academic Search

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

V. G. Amelin

2002-01-01

228

A Survey of Methods for Planning and Analyzing Accelerated Tests  

Microsoft Academic Search

This paper surveys methods for planning and analyzing accelerated life tests. Many of these methods are new and providemore informative results for less time and cost than do previous methods. These methods are of value to all who plan and analyze accelerated tests on any product or material.

Wayne Nelson

1974-01-01

229

In vivo dissolution measurement with indium-111 summation peak ratios  

SciTech Connect

Dissolution of (/sup 111/In)labeled tablets was measured in vivo in a totally noninvasive manner by using a modification of the perturbed angular correlation technique known as the summation peak ratio method. This method, which requires the incorporation of only 10-12 microCi into the dosage form, provided reliable dissolution data after oral administration of (/sup 111/In)lactose tablets. These results were supported by in vitro experiments which demonstrated that the dissolution rate as measured by the summation peak ratio method was in close agreement with the dissolution rate of salicylic acid in a (/sup 111/In)salicylic acid tablet. The method has the advantages of using only one detector, thereby avoiding the need for complex coincidence counting systems, requiring less radioactivity, and being potentially applicable to a gamma camera imaging system.

Jay, M.; Woodward, M.A.; Brouwer, K.R.

1985-10-01

230

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

PubMed Central

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

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

2014-01-01

231

Subscale Test Methods for Combustion Devices  

NASA Technical Reports Server (NTRS)

Stated goals for long-life LRE s have been between 100 and 500 cycles: 1) Inherent technical difficulty of accurately defining the transient and steady state thermochemical environments and structural response (strain); 2) Limited statistical basis on failure mechanisms and effects of design and operational variability; and 3) Very high test costs and budget-driven need to protect test hardware (aversion to test-to-failure). Ambitious goals will require development of new databases: a) Advanced materials, e.g., tailored composites with virtually unlimited property variations; b) Innovative functional designs to exploit full capabilities of advanced materials; and c) Different cycles/operations. Subscale testing is one way to address technical and budget challenges: 1) Prototype subscale combustors exposed to controlled simulated conditions; 2) Complementary to conventional laboratory specimen database development; 3) Instrumented with sensors to measure thermostructural response; and 4) Coupled with analysis

Anderson, W. E.; Sisco, J. C.; Long, M. R.; Sung, I.-K.

2005-01-01

232

Design of a dissolution system for the evaluation of the release rate characteristics of artemether and dihydroartemisinin from tablets.  

PubMed

As none of the pharmacopoeial dissolution methods are suitable to evaluate the release rate of artemether and dihydroartemisinin from tablets, a 'two-phase partition-dissolution' method, based on the one of [J. Pharm. Sci. 85 (1996) 1060] was developed. It consists of an organic solvent in the upper part and the aqueous phase, in which the dissolution test was executed. The main requirements for the selection of the solvent are: the density should be lower than 1; the analyte should dissolve in the organic part as much as required for 'sink' conditions; if possible, the cut off should be near 200 nm, which allows direct HPLC measurement at 215 nm. The most suitable solvent for artemether is isooctane in a ratio of 100/150 ml aqueous phase. Samples could be analysed without further treatment. For dihydroartemisinin, chlorobutane was selected in a ratio 150/150 ml water. In the latter method, the solvent disturbed in the HPLC analysis and therefore samples were evaporated and then reconstituted in methanol. Repeatability of the test was satisfactory and discrimination ability tests on Artenam tablet batches and self-made dihydroartemisinin tablets, respectively, showed good results, confirmed via calculation of the similarity factor f2 (value <50). Dissolution determination of Cotecxin tablets was proven not to be conform as immediate-release tablet. PMID:15072800

Gabriëls, M; Plaizier-Vercammen, J

2004-04-15

233

Economical test methods for developmental neurobehavioral toxicity.  

PubMed Central

The assessment of behavioral changes produced by prenatal or early postnatal exposure to potentially noxious agents requires both the designing of ad hoc tests and the adaptation of tests for adult animals to the characteristics of successive developmental stages. The experience in designing tests is still more limited than in the adaptation of tests, but several tests have already proven their usefulness; some examples are the suckling test, the homing test, and evaluations of dam-pup and pup-pup interactions. Functional observational batteries can exploit the development at specified postnatal ages of several reflexes and responses that are absent at birth in altricial rodent species with a short pregnancy such as the rat and the mouse. In neonates, the assessment of early treatment effects can rely not only on deviations from normal responding but also on changes in the time of appearance of otherwise normal response patterns. The same applies to other end points such as responses to pain and various types of spontaneous motor/exploratory activities, including reactivity to a variety of drug challenges that can provide information on the regulatory systems whose development may be affected by early treatments. In particular, the analysis of ontogenetic dissociations (i.e., differential early treatment effects depending jointly on developmental stage at the time of exposure, age of testing, and response end point) can be of considerable value in the study of treatments' mechanisms of action. Overall, it appears that behavioral teratological assessments can be effectively used both proactively, i.e., in risk assessment prior to any human exposure, and reactively. In the latter case, these assessments could have special value in the face of agents suspected to produce borderline changes in developing humans, whose innocuousness or noxiousness can be difficult to establish in the absence of hard evidence of teratogenicity. PMID:9182035

Bignami, G

1996-01-01

234

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...

235

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

SciTech Connect

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.

Benjamin Langhorst; Thomas M Lillo; Henry S Chu

2014-05-01

236

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

E-print Network

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.

American Society for Testing and Materials. Philadelphia

1985-01-01

237

DATE: ____________________ NVLAP LAB CODE: __________________ Test Method  

E-print Network

______ 23/G05 ASTM D2718 Structural Panels in Planar Shear (Rolling Shear) ______ 23/G06 ASTM D2719 (Method C) Structural Panels in Shear Through-the-Thickness, Method C: Two-Rail Shear ______ 23/G07 ASTM D for Shear Resistance of Framed Walls for Buildings ______ 23/G13 ASTM E695 Measuring Relative Resistance

238

Hydrogeologic and hydrochemical properties of salt-dissolution zones, Palo Duro Basin, Texas Panhandle - Preliminary assessment  

SciTech Connect

In this Department of Energy-funded study, data were collected from six test wells: four were drilled for hydrologic testing and geochemical sampling of salt-dissolution zones in the Panhandle, and drill-stem tests at the two other wells were conducted to measure permeability and hydraulic head. Chemical composition of ground waters sampled from two test wells along the perimeter of the Southern High Plains clearly reflects dissolution of halite, gypsum, calcite, and dolomite by circulating ground water. Halite dissolution accounts for most of the salinity of Na-Cl ground water in salt-dissolution zones. At present, ground water in salt-dissolution zones is undersaturated with respect to halite. Presence of /sup 14/C in the ground water and the large concentration of dissolved solids discharging into streams draining the area indicate that the salt-dissolution process has taken place throughout the Holocene and is ongoing.

Dutton, A.R.

1987-01-01

239

Phase II of a Six sigma Initiative to Study DWPF SME Analytical Turnaround Times: SRNL's Evaluation of Carbonate-Based Dissolution Methods  

SciTech Connect

The Analytical Development Section (ADS) and the Statistical Consulting Section (SCS) of the Savannah River National Laboratory (SRNL) are participating in a Six Sigma initiative to improve the Defense Waste Processing Facility (DWPF) Laboratory. The Six Sigma initiative has focused on reducing the analytical turnaround time of samples from the Slurry Mix Evaporator (SME) by developing streamlined sampling and analytical methods [1]. The objective of Phase I was to evaluate the sub-sampling of a larger sample bottle and the performance of a cesium carbonate (Cs{sub 2}CO{sub 3}) digestion method. Successful implementation of the Cs{sub 2}CO{sub 3} fusion method in the DWPF would have important time savings and convenience benefits because this single digestion would replace the dual digestion scheme now used. A single digestion scheme would result in more efficient operations in both the DWPF shielded cells and the inductively coupled plasma--atomic emission spectroscopy (ICP-AES) laboratory. By taking a small aliquot of SME slurry from a large sample bottle and dissolving the vitrified SME sample with carbonate fusion methods, an analytical turnaround time reduction from 27 hours to 9 hours could be realized in the DWPF. This analytical scheme has the potential for not only dramatically reducing turnaround times, but also streamlining operations to minimize wear and tear on critical shielded cell components that are prone to fail, including the Hydragard{trademark} sampling valves and manipulators. Favorable results from the Phase I tests [2] led to the recommendation for a Phase II effort as outlined in the DWPF Technical Task Request (TTR) [3]. There were three major tasks outlined in the TTR, and SRNL issued a Task Technical and QA Plan [4] with a corresponding set of three major task activities: (1) Compare weight percent (wt%) total solids measurements of large volume samples versus peanut vial samples. (2) Evaluate Cs{sub 2}CO{sub 3} and K{sub 2}CO{sub 3} fusion methods using DWPF simulated glass (part 1) and (to the extent possible) using DWPF radioactive glass (part 2). (3) Recommend specific equipment to implement the new methods and work with SRNL's Equipment Engineering Section (EES) to ensure compatibility of the equipment with the DWPF shielded cells. The focus of this report is major task activity No.2 (parts 1 and 2). The other two major task activities are to be addressed separately. The measurements supporting task activity No.1 are being conducted at the DWPF. EES is currently designing and fabricating the DWPF cell equipment needed for the new method as part of major task activity No.3.

Edwards, Thomas

2005-09-01

240

49 CFR 383.133 - Test methods.  

Code of Federal Regulations, 2014 CFR

...and can be administered in a foreign language, provided no interpreter is used in administering the test. (4) A State must...combination of on-street and off-street conditions. (5) Interpreters are prohibited during the administration of skills...

2014-10-01

241

49 CFR 383.133 - Test methods.  

Code of Federal Regulations, 2012 CFR

...and can be administered in a foreign language, provided no interpreter is used in administering the test. (4) A State must...combination of on-street and off-street conditions. (5) Interpreters are prohibited during the administration of skills...

2012-10-01

242

49 CFR 383.133 - Test methods.  

Code of Federal Regulations, 2013 CFR

...and can be administered in a foreign language, provided no interpreter is used in administering the test. (4) A State must...combination of on-street and off-street conditions. (5) Interpreters are prohibited during the administration of skills...

2013-10-01

243

A Test of the Experimental Method  

Microsoft Academic Search

Do the insights into human behavior generated by laboratory experiments hold outside the lab? This is the crucial question of external validity that naturally troubles both experimentalists and their critics. We address this question by adopting Popper's injunction that hypotheses should be tested, not by seeking instances of confirmation, but through exposure to conditions where falsification is a serious possibility.

Shaun P. Hargreaves Heap; Arjan Verschoor; Daniel John Zizzo

244

Testing alleged mediumship: Methods and results  

Microsoft Academic Search

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

Ciarán O'Keeffe; Richard Wiseman

2005-01-01

245

Evaluation of SSME test data reduction methods  

NASA Technical Reports Server (NTRS)

Accurate prediction of hardware and flow characteristics within the Space Shuttle Main Engine (SSME) during transient and main-stage operation requires a significant integration of ground test data, flight experience, and computational models. The process of integrating SSME test measurements with physical model predictions is commonly referred to as data reduction. Uncertainties within both test measurements and simplified models of the SSME flow environment compound the data integration problem. The first objective of this effort was to establish an acceptability criterion for data reduction solutions. The second objective of this effort was to investigate the data reduction potential of the ROCETS (Rocket Engine Transient Simulation) simulation platform. A simplified ROCETS model of the SSME was obtained from the MSFC Performance Analysis Branch . This model was examined and tested for physical consistency. Two modules were constructed and added to the ROCETS library to independently check the mass and energy balances of selected engine subsystems including the low pressure fuel turbopump, the high pressure fuel turbopump, the low pressure oxidizer turbopump, the high pressure oxidizer turbopump, the fuel preburner, the oxidizer preburner, the main combustion chamber coolant circuit, and the nozzle coolant circuit. A sensitivity study was then conducted to determine the individual influences of forty-two hardware characteristics on fourteen high pressure region prediction variables as returned by the SSME ROCETS model.

Santi, L. Michael

1994-01-01

246

40 CFR 60.204 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Test methods and procedures...Industry: Wet-Process Phosphoric Acid Plants § 60.204 Test methods and procedures...fluorides from emission point “i,” mg/dscm...lb). (2) Method 13A or 13B shall...each of the emission points. The...

2010-07-01

247

Test Oracles Using Statistical Methods Johannes Mayer, Ralph Guderlei  

E-print Network

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

Pfeifer, Holger

248

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...

249

40 CFR 60.344 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Lime Manufacturing Plants § 60.344 Test methods and procedures. (a) In conducting the performance tests required in §...

2012-07-01

250

40 CFR 60.344 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Lime Manufacturing Plants § 60.344 Test methods and procedures. (a) In conducting the performance tests required in §...

2013-07-01

251

40 CFR 60.344 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Lime Manufacturing Plants § 60.344 Test methods and procedures. (a) In conducting the performance tests required in §...

2011-07-01

252

40 CFR 60.344 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Lime Manufacturing Plants § 60.344 Test methods and procedures. (a) In conducting the performance tests required in §...

2010-07-01

253

40 CFR 60.344 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Lime Manufacturing Plants § 60.344 Test methods and procedures. (a) In conducting the performance tests required in §...

2014-07-01

254

40 CFR 60.64 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Portland Cement Plants § 60.64 Test methods and procedures. (a) In conducting the performance tests required in § 60.8,...

2010-07-01

255

40 CFR 60.64 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Portland Cement Plants § 60.64 Test methods and procedures. (a) In conducting the performance tests and relative accuracy...

2014-07-01

256

40 CFR 60.64 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Portland Cement Plants § 60.64 Test methods and procedures. (a) In conducting the performance tests and relative accuracy...

2013-07-01

257

STATUS AND APPLICATIONS OF ECHINOID (PHYLUM ECHINODERMATA) TOXICITY TEST METHODS  

EPA Science Inventory

The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrolus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). he status and relative sensitivity of various test methods are descri...

258

ASTM test methods for composite characterization and evaluation  

NASA Technical Reports Server (NTRS)

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.

Masters, John E.

1994-01-01

259

Standard test methods for arsenic in uranium hexafluoride  

E-print Network

1.1 These test methods are applicable to the determination of total arsenic in uranium hexafluoride (UF6) by atomic absorption spectrometry. Two test methods are given: Test Method A—Arsine Generation-Atomic Absorption (Sections 5-10), and Test Method B—Graphite Furnace Atomic Absorption (Appendix X1). 1.2 The test methods are equivalent. The limit of detection for each test method is 0.1 ?g As/g U when using a sample containing 0.5 to 1.0 g U. Test Method B does not have the complete collection details for precision and bias data thus the method appears as an appendix. 1.3 Test Method A covers the measurement of arsenic in uranyl fluoride (UO2F2) solutions by converting arsenic to arsine and measuring the arsine vapor by flame atomic absorption spectrometry. 1.4 Test Method B utilizes a solvent extraction to remove the uranium from the UO2F2 solution prior to measurement of the arsenic by graphite furnace atomic absorption spectrometry. 1.5 Both insoluble and soluble arsenic are measured when UF6 is...

American Society for Testing and Materials. Philadelphia

2005-01-01

260

A Method of Partly Automated Testing of Software  

NASA Technical Reports Server (NTRS)

A method of automated testing of software has been developed that provides an alternative to the conventional mostly manual approach for software testing. The method combines (1) automated generation of test cases on the basis of systematic exploration of the input domain of the software to be tested with (2) run-time analysis in which execution traces are monitored, verified against temporal-logic specifications, and analyzed by concurrency-error-detection algorithms. In this new method, the user only needs to provide the temporal logic specifications against which the software will be tested and the abstract description of the input domain.

Lowry, Mike; Visser, Willem; Washington, Rich; Artho, Cyrille; Goldberg, Allen; Haveland, Klaus; Pasareanu, Corina; Khurshid, Sarfraz; Roflu, Grigore

2007-01-01

261

On the effects of subsurface parameters on evaporite dissolution (Switzerland)  

NASA Astrophysics Data System (ADS)

Uncontrolled subsurface evaporite dissolution could lead to hazards such as land subsidence. Observed subsidences in a study area of Northwestern Switzerland were mainly due to subsurface dissolution (subrosion) of evaporites such as halite and gypsum. A set of 2D density driven flow simulations were evaluated along 1000 m long and 150 m deep 2D cross sections within the study area that is characterized by tectonic horst and graben structures. The simulations were conducted to study the effect of the different subsurface parameters that could affect the dissolution process. The heterogeneity of normal faults and its impact on the dissolution of evaporites is studied by considering several permeable faults that include non-permeable areas. The mixed finite element method (MFE) is used to solve the flow equation, coupled with the multipoint flux approximation (MPFA) and the discontinuous Galerkin method (DG) to solve the diffusion and the advection parts of the transport equation.

Zidane, Ali; Zechner, Eric; Huggenberger, Peter; Younes, Anis

2014-05-01

262

Do Assessment Methods Matter? A Sensitivity Test  

ERIC Educational Resources Information Center

A good assessment method should be able to distinguish between deep learners and surface learners in a way so the former are rewarded while the later are punished. Using data of a survey conducted at the Institute of Contemporary Chinese Studies, University of Nottingham, the study finds strong evidence that assignment essays serve to reward deep…

Tian, Xiaowen

2007-01-01

263

Test Method Clinitek 10, 50, 100  

E-print Network

Bilirubin Ketone Specific Gravity Blood pH Protein Urobilinogen Nitrite Leukocytes hCG: Method Lot # Acetest® (Ketone): Lot # Clinitest® (Glucose): Lot # Ictotest®(Bilirubin): Lot # Protein (Sulfosalicylic Acid): Lot are registered trademarks of Siemens Corporation. MS.QPDLII Rev. 08/09/13 Date Lot # Glucose Bilirubin Ketone

Rodriguez, Carlos

264

SEA URCHIN (STRONGYLOCENTROTUS PURPURATUS) FERTILIZATION TEST METHOD  

EPA Science Inventory

This method measures the toxicity of effluents and receiving water to the gametes of a sea urchin, Strongylocentrotus purpuratus, during a 1 h sperm exposure and a subsequent 20 min exposure period following the addition of eggs for measuring the fertilizing capacity of the sperm...

265

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

PubMed

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

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

2014-12-01

266

Test methods and design allowables for fibrous composites. Volume 2  

NASA Technical Reports Server (NTRS)

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.

Chamis, Christos C. (editor)

1989-01-01

267

An Improved Method for Students' Flame Tests in Qualitative Analysis  

Microsoft Academic Search

A new method for flame tests to be performed by students is presented. The method involves the use of a hot wire to vaporize the sample,which is subsequently drawn into the flame via the burner air vent.

William D. Bare; Tom Bradley; Elizabeth Pulliam

1998-01-01

268

Evaluation criteria and test methods for electrochromic windows  

SciTech Connect

Report summarizes the test methods used for evaluating electrochromic (EC) windows, and summarizes what is known about degradation of their performance, and recommends methods and procedures for advancing EC windows for buildings applications. 77 refs., 13 figs., 6 tabs.

Czanderna, A.W. (Solar Energy Research Inst., Golden, CO (USA)); Lampert, C.M. (Lawrence Berkeley Lab., CA (USA))

1990-07-01

269

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...

270

40 CFR 60.715 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Magnetic Tape Coating Facilities § 60.715 Test methods and procedures. Methods in appendix A of this part, except as...

2010-07-01

271

Method and apparatus for container leakage testing  

DOEpatents

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.

Kronberg, James W. (Aiken, SC)

1995-01-01

272

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

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

273

Harmonization of standard toxicity test methods used in North America  

SciTech Connect

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.

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

274

[Comparative study on decoction and dissolution of crude and processed corni fructus].  

PubMed

To compare and study the decoction and dissolution of active constituents in crude and processed Corni Fructus. HPLC, the traditional Chinese medicine (TCM) decoction method and the dissolution methods were adopted to compare and study the decoction yield and dissolution rate of loganin and morroniside, active constituents in crude and processed Corni Fructus. The results showed that the content of active constituents loganin and morroniside in crude and processed Corni Fructus did not change significantly; compared with crude Corni Fructus, processed Corni Fructus (decoction) contained much higher loganin, with no obvious change in morroniside; compared with crude Corni Fructus, processed Corni Fructus (extracts) showed no significant difference in loganin dissolution, but notable increase in morroniside dissolution in intestinal fluid; in gastric fluid, processed Corni Fructus showed significant increase in loganin and morroniside dissolutions. However, in comprehensive consideration of the decoction dose in clinical administration, and calculated on the basis of the formula of the decoction yield x dissolution rate = decoction-dissolution product, it showed increase in the decoction-dissolution products of both of the active constituents loganin and morroniside, with significant difference. This suggested that processed Corni Fructus is superior to crude Corni Fructus in clinical application. In this article, we proposed to compare the changes in decoction and dissolution of active constituents in crude and processed Corni Fructus, study the decoction-dissolution product, and then apply it in the quality evaluation of crude and processed Corni Fructus. PMID:24558870

Zhou, Han-Yu; Yang, Pei-Pei; Cong, Xiao-Dong; Zhang, Cheng-Rong; Cai, Bao-Chang

2013-11-01

275

Non-destructive testing method and apparatus  

DOEpatents

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.

Akers, Douglas W. (Idaho Falls, ID)

2011-10-04

276

Eddy Current Method for Fatigue Testing  

NASA Technical Reports Server (NTRS)

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.

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

277

Electric vehicle chassis dynamometer test methods at JPL and their correlation to track tests  

NASA Technical Reports Server (NTRS)

Early in its electric vehicle (EV) test program, JPL recognized that EV test procedures were too vague and too loosely defined to permit much meaningful data to be obtained from the testing. Therefore, JPL adopted more stringent test procedures and chose the chassis dynamometer rather than the track as its principal test technique. Through the years, test procedures continued to evolve towards a methodology based on chassis dynamometers which would exhibit good correlation with track testing. Based on comparative dynamometer and track test results on the ETV-1 vehicle, the test methods discussed in this report demonstrate a means by which excellent track-to-dynamometer correlation can be obtained.

Marte, J.; Bryant, J.

1983-01-01

278

Standardization of methods of accelerated tests of stainless steels for resistance to pitting corrosion. electrochemical tests  

Microsoft Academic Search

Earlier (1) the problems and features of standardization of accelerated chemical and electrochemical tests of stainless steels for resistance to pitting corrosion (or pitting resistance) were presented and on the basis of collective experimental data a method of testing in a ferric chloride solution was proposed for standardization. A method of electrochemical tests is substantiated and recommended for standardization.

L. I. Freiman; R. Bartonichek; Flis Y; Garts I; B. Narovska; M. Prazhak

1986-01-01

279

Unravelling the relationship between degree of disorder and the dissolution behavior of milled glibenclamide.  

PubMed

Milling is an attractive method to prepare amorphous formulations as it does not require the use of solvents and is suitable for thermolabile drugs. One of the key critical quality attributes of milled amorphous formulations is their dissolution behavior. However, there are limited studies that have investigated the relationship between degree of disorder induced by milling and dissolution behavior. The main aim of this study was to identify the analytical technique used to characterize degree of disorder that correlates best with the recrystallization behavior during dissolution of milled glibenclamide samples. Solid state and surface changes during dissolution of milled glibenclamide samples were monitored in order to elucidate the processes that influence the dissolution behavior of milled glibenclamide samples. Glibenclamide was ball milled for different durations and analyzed using X-ray powder diffractometry (XRPD), Raman spectroscopy and differential scanning calorimetry (DSC). Recrystallization during dissolution of the milled amorphous materials was investigated using an in situ Raman setup. SEM was used to monitor the surfaces of the compacts during dissolution. XRPD, Raman spectroscopy and DSC indicated that glibenclamide was fully amorphous after milling for 30, 60, and 120 min, respectively. 'DSC amorphous' (i.e. fully amorphous according to the onset of crystallization obtained from DSC) glibenclamide samples experienced negligible recrystallization which had no effect on the dissolution profiles. Samples that were not 'DSC amorphous' experienced recrystallization which resulted in a decrease in dissolution rate. Unexpected elevated dissolution rate was observed initially during dissolution for samples milled for 15 to 45 min, and this was related to particle loss from surfaces of the disks during dissolution. In conclusion, the onset of crystallization obtained from DSC best predicts the recrystallization of glibenclamide during dissolution. Recrystallization and particle loss from the surface of the dissolution should be considered when interpreting the dissolution data of milled glibenclamide samples. PMID:24224572

Mah, Pei T; Laaksonen, Timo; Rades, Thomas; Aaltonen, Jaakko; Peltonen, Leena; Strachan, Clare J

2014-01-01

280

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

DOEpatents

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.

Kephart, Alan R. (Scotia, NY)

1991-01-01

281

Kinetics of dissolution of copper-nickel alloys. Anodic dissolution of alloy Cu30Ni under steady-state conditions  

Microsoft Academic Search

A radiometric method employing a Co⁵⁸ tracer and double neutron irradiation was developed to determine the partial rates of dissolution of the components of copper-nickel alloys. The applicability of the ..gamma..-isotope of Co⁵⁸ as a foreign tracer for nickel is demonstrated in the anodic dissolution and corrosion of alloy Cu30Ni by comparative measurements with isotopes Ni⁶⁵ and Co⁵⁸. The isotopes

E. I. Zolotarev; A. P. Pchelnikov; Ya. B. Shuratnik; M. A. Dembrovskii; N. I. Khokhlov; V. V. Losev

1988-01-01

282

Method and apparatus for sound testing mufflers  

SciTech Connect

An apparatus is described for producing operating conditions and measuring sound of an operable vehicle during a stationary simulated drive-by test. The apparatus comprises: an actual vehicle including wheels and means for driving the wheels. The driving means includes an engine with means for exhausting gases including a muffler with driving means disconnected with respect to driving wheels; a dynamometer; means attached to the actual vehicle for connecting the dynamometer to the driving means; means for controlling the dynamometer to simulate operational loading of the engine; means for measuring sound, the measuring means including: regularly spaced microphones along a first line parallel to and spaced from a second line in an imaginary direction of travel; and means for at least partially shielding sound, the muffler unshields means with respect to the microphones. The shielding means shields much of the sound from the driving means, except from the muffler, so that the sound means measures primarily muffler sound in the operational environment even though vehicle is not moving. The dynamometer and controlling means simulates operational loading of the engine.

Wagner, W.M.; Bethke, T.A.

1987-06-30

283

40 CFR 63.365 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...Sterilization Facilities § 63.365 Test methods and procedures. ...weight percent of compound in the balance of the mixture MWx = molecular weight of compound in the balance gas mixture (ii) The...40 CFR part 60, appendix A, Test Methods 2, 2A, 2C,...

2014-07-01

284

40 CFR 63.365 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...Sterilization Facilities § 63.365 Test methods and procedures. ...weight percent of compound in the balance of the mixture MWx =molecular weight of compound in the balance gas mixture (ii) The...40 CFR part 60, appendix A, Test Methods 2, 2A, 2C,...

2013-07-01

285

40 CFR 63.365 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...Sterilization Facilities § 63.365 Test methods and procedures. ...weight percent of compound in the balance of the mixture MWx =molecular weight of compound in the balance gas mixture (ii) The...40 CFR part 60, appendix A, Test Methods 2, 2A, 2C,...

2011-07-01

286

40 CFR 63.365 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...Sterilization Facilities § 63.365 Test methods and procedures. ...weight percent of compound in the balance of the mixture MWx =molecular weight of compound in the balance gas mixture (ii) The...40 CFR part 60, appendix A, Test Methods 2, 2A, 2C,...

2012-07-01

287

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...

288

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

289

Optimization of HPLC method for stability testing of bacitracin  

Microsoft Academic Search

A stability indicating HPLC assay for bacitracin has been developed and validated. The assay is based on a gradient elution, reversed phase column and UV diode array detection. On the basis of our previous analytical work several additional systematic HPLC tests for optimization of analytical method were performed. In order to achieve the highest selectivity of HPLC method, tests were

Viljem Pavli; Vojko Kmetec

2001-01-01

290

Bayesian Methods for Accelerated Destructive Degradation Test Planning  

E-print Network

Bayesian Methods for Accelerated Destructive Degradation Test Planning Ying Shi Dept. of Statistics methods for ADDT planning under a class of nonlinear degradation models with one accelerating variable. We quantile at use conditions to find optimum test plans. A large-sample approximation for the posterior

291

40 CFR 75.22 - Reference test methods.  

Code of Federal Regulations, 2011 CFR

...NOX emission tests of...and quality control tests: (1) Methods 1 or 1A are...concentrations in the emissions. (4...SO2 and NOX pollutant...boilers and combustion turbines...4 of the method allowing...performing the post-run system...determining NOX and diluent emissions from...

2011-07-01

292

40 CFR 75.22 - Reference test methods.  

Code of Federal Regulations, 2014 CFR

...NOX emission tests of...and quality control tests: (1) Methods 1 or 1A are...concentrations in the emissions. (4...SO2 and NOX pollutant...boilers and combustion turbines...4 of the method allowing...performing the post-run system...determining NOX and diluent emissions from...

2014-07-01

293

40 CFR 75.22 - Reference test methods.  

Code of Federal Regulations, 2013 CFR

...NOX emission tests of...and quality control tests: (1) Methods 1 or 1A are...concentrations in the emissions. (4...SO2 and NOX pollutant...boilers and combustion turbines...4 of the method allowing...performing the post-run system...determining NOX and diluent emissions from...

2013-07-01

294

40 CFR 75.22 - Reference test methods.  

Code of Federal Regulations, 2012 CFR

...NOX emission tests of...and quality control tests: (1) Methods 1 or 1A are...concentrations in the emissions. (4...SO2 and NOX pollutant...boilers and combustion turbines...4 of the method allowing...performing the post-run system...determining NOX and diluent emissions from...

2012-07-01

295

Development of a test machine and method for galling studies  

Microsoft Academic Search

A test method for evaluating galling resistance in tubular connections by using the established evaluation technique known as the up and down or Bruceton method was studied. A unique test machine that would closely simulate the actual field conditions was designed and constructed. By using the Taguchi technique, the relative effects of rotational speed, roughness, and axial load on the

A. Ertas; H. J. Carper; W. R. Blackstone

1992-01-01

296

New method for an occupational dust challenge test  

Microsoft Academic Search

OBJECTIVES--Specific challenge tests with a suspected allergen in the workplace are standard to confirm the diagnosis of asthma. Facilities for sophisticated exposure tests are available only in a few institutions. A pilot study was carried out that used a novel approach for an occupational dust challenge test with a rotahaler. METHODS--Nine consecutive patients were enrolled in this study. Six of

F J Lin; H Chen; M Chan-Yeung

1995-01-01

297

Interval Methods in NonDestructive Testing of Material Structures  

E-print Network

Interval Methods in Non­Destructive Testing of Material Structures Keith Worden 1 ; Roberto at the early stage, when it is still possible to cure it. Several non­destructive testing techniques situations, e.g., in aerospace applications and in mammography, it is important to test the structural

Kreinovich, Vladik

298

Methods of testing parameterizations: Vertical ocean mixing  

NASA Technical Reports Server (NTRS)

The ocean's velocity field is characterized by an exceptional variety of scales. While the small-scale oceanic turbulence responsible for the vertical mixing in the ocean is of scales a few centimeters and smaller, the oceanic general circulation is characterized by horizontal scales of thousands of kilometers. In oceanic general circulation models that are typically run today, the vertical structure of the ocean is represented by a few tens of discrete grid points. Such models cannot explicitly model the small-scale mixing processes, and must, therefore, find ways to parameterize them in terms of the larger-scale fields. Finding a parameterization that is both reliable and plausible to use in ocean models is not a simple task. Vertical mixing in the ocean is the combined result of many complex processes, and, in fact, mixing is one of the less known and less understood aspects of the oceanic circulation. In present models of the oceanic circulation, the many complex processes responsible for vertical mixing are often parameterized in an oversimplified manner. Yet, finding an adequate parameterization of vertical ocean mixing is crucial to the successful application of ocean models to climate studies. The results of general circulation models for quantities that are of particular interest to climate studies, such as the meridional heat flux carried by the ocean, are quite sensitive to the strength of the vertical mixing. We try to examine the difficulties in choosing an appropriate vertical mixing parameterization, and the methods that are available for validating different parameterizations by comparing model results to oceanographic data. First, some of the physical processes responsible for vertically mixing the ocean are briefly mentioned, and some possible approaches to the parameterization of these processes in oceanographic general circulation models are described in the following section. We then discuss the role of the vertical mixing in the physics of the large-scale ocean circulation, and examine methods of validating mixing parameterizations using large-scale ocean models.

Tziperman, Eli

1992-01-01

299

Alloy dissolution in argon stirred steel  

NASA Astrophysics Data System (ADS)

Alloying is required for the production of all steel products from small castings to large beams. Addition of large quantities of bulk alloys can result in alloy segregation and inconsistent alloy recovery. The objective of this research was to better understand alloy dissolution in liquid steel especially as it relates to Missouri S&Ts' patented continuous steelmaking process. A 45-kilogram capacity ladle with a single porous plug was used to evaluate the effect of four experimental factors on alloy dissolution: alloy species, alloy size or form, argon flow rate, and furnace tap temperature. Four alloys were tested experimentally including Class I low carbon ferromanganese, nickel and tin (as a surrogate for low melting alloys) and Class II ferroniobium. The alloys ranged in size and form from granular to 30 mm diameter lumps. Experimental results were evaluated using a theoretically based numerical model for the steel shell period, alloy mixing (Class I) and alloy dissolution (Class II). A CFD model of the experimental ladle was used to understand steel motion in the ladle and to provide steel velocity magnitudes for the numerical steel shell model. Experiments and modeling confirmed that smaller sized alloys have shorter steel shell periods and homogenize faster than larger particles. Increasing the argon flow rate shortened mixing times and reduced the delay between alloy addition and the first appearance of alloy in the melt. In addition, for every five degree increase in steel bath temperature the steel shell period was shortened by approximately four percent. Class II ferroniobium alloy dissolution was an order of magnitude slower than Class I alloy mixing.

Webber, Darryl Scott

300

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

Federal Register 2010, 2011, 2012, 2013, 2014

...in vitro methods (the direct peptide reactivity assay, human cell line activation test, KeratinoSens\\SM\\, and myeloid U937 skin sensitization test), which cover key events in the AOP for skin sensitization (Adler et al., 2011)....

2013-11-13

301

40 CFR 63.865 - Performance test requirements and test methods.  

Code of Federal Regulations, 2012 CFR

...Emission Standards for Hazardous Air Pollutants for Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills § 63.865 Performance test requirements and test methods. The owner or operator of...

2012-07-01

302

40 CFR 63.865 - Performance test requirements and test methods.  

Code of Federal Regulations, 2013 CFR

...Emission Standards for Hazardous Air Pollutants for Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills § 63.865 Performance test requirements and test methods. The owner or operator of...

2013-07-01

303

40 CFR 63.865 - Performance test requirements and test methods.  

Code of Federal Regulations, 2014 CFR

...Emission Standards for Hazardous Air Pollutants for Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills § 63.865 Performance test requirements and test methods. The owner or operator of...

2014-07-01

304

Fracture mechanics life analytical methods verification testing  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

305

Development of a simulated bird-strike test method  

NASA Astrophysics Data System (ADS)

An inexpensive test method has been developed to predict the dynamic impact response (bird-strike resistance) of aircraft turbine engine fan blade materials. The test utilizes an instrumented pendulum to transfer energy to a machined fan blade cross section. To validate the test, the relative performance of one wrought and four cast Ti-6Al-4V materials subjected to the simulated bird-strike test was compared to that of the same materials tested at Wright-Patterson Air Force Base by conventional bird-strike testing. The relative ranking of crack initiation loads determined from the simulated test corresponded to fan blade failure velocities determined by the Air Force test, thereby validating the simulated method as a screening tool for fan blade material development.

Colvin, G. N.; Falls, J. R.

1990-05-01

306

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

NASA Astrophysics Data System (ADS)

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.

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

2010-09-01

307

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

E-print Network

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...

Ruhmann, Sean Phillip

1998-01-01

308

Ergodicity test of the eddy correlation method  

NASA Astrophysics Data System (ADS)

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.

Chen, J.; Hu, Y.; Yu, Y.; Lü, S.

2014-07-01

309

Alginic Acid Accelerates Calcite Dissolution  

NASA Astrophysics Data System (ADS)

Accelerated carbonate weathering through biological activity affects both geochemical cycling and the local pH and alkalinity of terrestrial and marine waters. Microbes affect carbonate dissolution through metabolic activity, production of acidic or chelating exudates, and cation binding by cell walls. Dissolution occurs within microbial biofilms - communities of microorganisms attached to stone in an exopolymer matrix. We investigated the effect of alginic acid, a common biological polymer produced by bacteria and algae, on calcite dissolution using a paired atomic force microscopy/flow-through reactor apparatus. The alginic acid caused up to an order of magnitude increase in dissolution rate at 3 < pH < 12. Additionally, the polymer preferentially binds to the obtuse pit steps and increases step velocity. We propose that the polymer is actively chelating surficial cations reducing the activation energy and increasing dissolution rate. The role of biologically produced polymers in mineral weathering is important in the protection of cultural heritage materials and understanding of marine and terrestrial systems.

Perry, T. D.; Duckworth, O. W.; McNamara, C. J.; Martin, S. T.; Mitchell, R.

2003-12-01

310

Testing prediction methods: Earthquake clustering versus the Poisson model  

USGS Publications Warehouse

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.

Michael, A.J.

1997-01-01

311

Simulation of In Vitro Dissolution Behavior Using DDDPlus™.  

PubMed

Dissolution testing is a performance test for many dosage forms including tablets and capsules. The objective of this study was to evaluate if computer simulations can predict the in vitro dissolution of two model drugs for which different dissolution data were available. Published montelukast sodium and glyburide dissolution data was used for the simulations. Different pharmacopeial and biorelevant buffers, volumes, and rotations speeds were evaluated. Additionally, a pH change protocol was evaluated using these buffers. DDDPlus™ 3, Beta version (Simulation Plus, Inc.), was used to simulate the in vitro dissolution data. The simulated data were compared with the in vitro data. A regression coefficient between predicted and observed data was used to assess the simulations. The statistical analysis of Montelukast sodium showed that there was a significant correlation between the in vitro release data and the predicted data for all cases except for one buffer. For glyburide, there was also a significant correlation between the experimental data and the predicted data using single pH conditions. Using the dynamic pH protocol, a correlation was significant for one biorelevant media. The simulations showed that both in vitro drug releases were sensitive to solubility effects which confirmed their BCS class II category. Computer simulations of the in vitro release using DDDPlus™ have the potential to estimate the in vivo dissolution at an early stage in the drug development process. This might be used to choose the most appropriate dissolution condition to establish IVIVC and to develop biorelevant in vitro performance tests to capture critical product attributes for quality control procedures in quality by design environments. PMID:25409918

Almukainzi, May; Okumu, Arthur; Wei, Hai; Löbenberg, Raimar

2015-02-01

312

Flight-Test Evaluation of Flutter-Prediction Methods  

NASA Technical Reports Server (NTRS)

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.

Lind, RIck; Brenner, Marty

2003-01-01

313

40 CFR 63.457 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...NCASI Method DI/MEOH-94.02, Methanol in Process Liquids by GC/FID, August 1998, Methods Manual, NCASI, Research Triangle Park, NC. This test method is incorporated by reference in § 63.14(f) of subpart A of this part. (iii) Any...

2011-07-01

314

Applicability of ultrasonic testing for the determination of volume fraction of particulates in alumina-reinforced aluminum matrix composites  

SciTech Connect

An ultrasonic testing technique was employed to determine the volume fraction of alumina particulate reinforcement in 6061 aluminum matrix composites. this study was performed on various composites with Al{sub 2}O{sub 3} nominal volume fractions of 10, 15, and 20%. For comparison, other techniques were employed as well, including the Archimedes method, metallographic image analysis, X-ray diffraction, and acid dissolution. Observations indicated that ultrasonic testing and acid dissolution methods are more reliable than the other techniques, while ultrasonic testing is faster than the acid dissolution method.

Fang, C.K.; Fang, R.L.; Weng, W.P.; Chuang, T.H.

1999-10-01

315

Fire test method for graphite fiber reinforced plastics  

NASA Technical Reports Server (NTRS)

A potential problem in the use of graphite fiber reinforced resin matrix composites is the dispersal of graphite fibers during accidential fires. Airborne, electrically conductive fibers originating from the burning composites could enter and cause shorting in electrical equipment located in surrounding areas. A test method for assessing the burning characteristics of graphite fiber reinforced composites and the effectiveness of the composites in retaining the graphite fibers has been developed. The method utilizes a modified rate of heat release apparatus. The equipment and the testing procedure are described. The application of the test method to the assessment of composite materials is illustrated for two resin matrix/graphite composite systems.

Bowles, K. J.

1980-01-01

316

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

SciTech Connect

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.

Kelly, D.L.

1998-08-17

317

WASHING AND DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS USING POST ALUMINUM DISSOLUTION TANK 51 SLUDGE SLURRY  

SciTech Connect

The remaining contents of Tank 51 from Sludge Batch 4 will be blended with Purex sludge from Tank 7 to constitute Sludge Batch 5 (SB5). The Savannah River Site (SRS) Liquid Waste Organization (LWO) has completed caustic addition to Tank 51 to perform low temperature Al dissolution on the H-Modified (HM) sludge material to reduce the total mass of sludge solids and Al being fed to the Defense Waste Processing Facility (DWPF). The Savannah River National Lab (SRNL) has also completed aluminum dissolution tests using a 3-L sample of Tank 51 sludge slurry through funding by DOE EM-21. This report documents assessment of downstream impacts of the aluminum dissolved sludge, which were investigated so technical issues could be identified before the start of SB5 processing. This assessment included washing the aluminum dissolved sludge to a Tank Farm projected sodium concentration and weight percent insoluble solids content and DWPF Chemical Process Cell (CPC) processing using the washed sludge. Based on the limited testing, the impact of aluminum dissolution on sludge settling is not clear. Settling was not predictable for the 3-L sample. Compared to the post aluminum dissolution sample, settling after the first wash was slower, but settling after the second wash was faster. For example, post aluminum dissolution sludge took six days to settle to 60% of the original sludge slurry height, while Wash 1 took nearly eight days, and Wash 2 only took two days. Aluminum dissolution did impact sludge rheology. A comparison between the as-received, post aluminum dissolution and washed samples indicate that the downstream materials were more viscous and the concentration of insoluble solids less than that of the starting material. This increase in viscosity may impact Tank 51 transfers to Tank 40. The impact of aluminum dissolution on DWPF CPC processing cannot be determined because acid addition for the Sludge Receipt and Adjustment Tank (SRAT) cycle was under-calculated and thus under-added. Although the sludge was rheologically thick throughout the SRAT and Slurry Mix Evaporator (SME) cycles, this may have been due to the under addition of acid. Aluminum dissolution did, however, impact analyses of the SRAT receipt material. Two methods for determining total base yielded significantly different results. The high hydroxide content and the relatively high soluble aluminum content of the washed post aluminum dissolution sludge likely contributed to this difference and the ultimate under addition of acid. It should be noted that the simulant used to provide input for the SRAT cycle was an inadequate representation of the waste in terms of acid demand, likely due to the differences in the form of aluminum and hydroxide in the simulant and actual waste. Based on the results of this task, it is recommended that: (1) Sludge settling and rheology during washing of the forthcoming Sludge Batch 5 qualification sample be monitored closely and communicated to the Tank Farm. (2) SRNL receive a sample of Tank 51 after all chemical additions have been made and prior to the final Sludge Batch 5 decant for rheological assessment. Rheology versus wt% insoluble solids will be performed to determine the maximum amount of decant prior to the Tank 51 to Tank 40 transfer. (3) As a result of the problem with measuring total base and subsequently under-calculating acid for the DWPF CPC processing of the post aluminum dissolution sludge; (4) Studies to develop understanding of how the sludge titrates (i.e., why different titration methods yield different results) should be performed. (5) Simulants that better match the properties of post aluminum dissolution sludge should be developed. (6) Work on developing an acid calculation less dependant on the total base measurement should be continued.

Pareizs, J; Cj Bannochie, C; Damon Click, D; Erich Hansen, E; Dan Lambert, D; Michael Stone, M

2008-04-28

318

Bioequivalence of tacrolimus formulations with different dynamic solubility and in-vitro dissolution profiles.  

PubMed

This study was to evaluate the pharmacokinetics and bioequivalence of two tacrolimus formulations which had different in vitro drug release profiles. Dynamic solubility, in vitro dissolution profiles of the two formulations, and their influence on pharmacokinetics were examined. The male volunteers were randomly assigned to receive a single 1-mg capsule of the test or reference formulation and pharmacokinetic parameters were determined using a noncompartmental method. The two formulations released >85 % of tacrolimus in water within 30 min, which passed the criterion of evaluating the test formulation. However, the test formulation produced a faster initial release rate and plateaued in about 15 min, while the reference showed almost zero order initial release profiles. The AUC0-? values were 145.92 (reference) and 140.49 ng h/mL (test). The mean Cmax was 15.70 (reference) and 16.08 ng/mL (test) with Tmax values of 1.63 and 1.60 h, respectively. The t1/2 for the reference and test formulations was 29.12 and 27.85 h, respectively. Relative bioavailability was calculated to be 96.28 %. The point estimates for the mean ratio of the test to reference for the AUC0-t and Cmax were 0.969 and 1.026, respectively, satisfying the criterion for bioequivalence. The results suggest that the test formulation is pharmacokinetically equivalent to the reference in terms of both rate and extent of absorption. Even though the in vitro dissolution profiles of the formulations might not be equivalent, the pharmacokinetics indicated bioequivalence. Therefore, when developing poorly soluble drugs, it might be beneficial to pay attention to the dynamic solubility as well as dissolution profiles. PMID:24627339

Kwon, Minchang; Yeom, Daeil; Kim, Nam Ah; Choi, Du Hyung; Park, Junsang; Wang, Hunsik; Yoo, Sun Dong; Jeong, Seong Hoon

2015-01-01

319

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

NASA Technical Reports Server (NTRS)

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.

Scott, W. R.

1975-01-01

320

40 CFR 61.304 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...AIR POLLUTANTS National Emission Standard for Benzene Emissions From Benzene Transfer Operations § 61.304 Test methods...hours, during which at least 300,000 liters of benzene are loaded. If the throughput criterion is...

2012-07-01

321

40 CFR 61.304 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...AIR POLLUTANTS National Emission Standard for Benzene Emissions From Benzene Transfer Operations § 61.304 Test methods...hours, during which at least 300,000 liters of benzene are loaded. If the throughput criterion is...

2010-07-01

322

40 CFR 61.304 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...AIR POLLUTANTS National Emission Standard for Benzene Emissions From Benzene Transfer Operations § 61.304 Test methods...hours, during which at least 300,000 liters of benzene are loaded. If the throughput criterion is...

2014-07-01

323

40 CFR 61.304 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...AIR POLLUTANTS National Emission Standard for Benzene Emissions From Benzene Transfer Operations § 61.304 Test methods...hours, during which at least 300,000 liters of benzene are loaded. If the throughput criterion is...

2013-07-01

324

40 CFR 61.304 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...AIR POLLUTANTS National Emission Standard for Benzene Emissions From Benzene Transfer Operations § 61.304 Test methods...hours, during which at least 300,000 liters of benzene are loaded. If the throughput criterion is...

2011-07-01

325

40 CFR 76.15 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

326

40 CFR 76.15 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

327

40 CFR 76.15 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

328

40 CFR 76.15 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

329

40 CFR 76.15 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

330

40 CFR 63.1385 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Wool Fiberglass Manufacturing § 63.1385 Test methods and procedures. (a) The owner or operator shall use the...

2013-07-01

331

8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND BETA BACKSCATTERING. (7/13/56) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

332

40 CFR 60.485a - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...SOURCES Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 § 60.485a Test methods and...

2013-07-01

333

40 CFR 60.485a - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...SOURCES Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 § 60.485a Test methods and...

2014-07-01

334

40 CFR 60.485a - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...SOURCES Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 § 60.485a Test methods and...

2011-07-01

335

40 CFR 60.485a - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...SOURCES Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 § 60.485a Test methods and...

2012-07-01

336

40 CFR 60.485a - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...SOURCES Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 § 60.485a Test methods and...

2010-07-01

337

40 CFR 60.144a - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Emissions from Basic Oxygen Process Steelmaking Facilities for Which Construction is Commenced After January 20, 1983 § 60.144a Test methods...

2013-07-01

338

40 CFR 60.144a - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Emissions from Basic Oxygen Process Steelmaking Facilities for Which Construction is Commenced After January 20, 1983 § 60.144a Test methods...

2014-07-01

339

40 CFR 60.144a - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Emissions from Basic Oxygen Process Steelmaking Facilities for Which Construction is Commenced After January 20, 1983 § 60.144a Test methods...

2012-07-01

340

40 CFR 60.144a - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Emissions from Basic Oxygen Process Steelmaking Facilities for Which Construction is Commenced After January 20, 1983 § 60.144a Test methods...

2011-07-01

341

40 CFR 60.244 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry: Granular Triple Superphosphate Storage Facilities § 60.244 Test methods and procedures. (a) The...

2012-07-01

342

40 CFR 60.244 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry: Granular Triple Superphosphate Storage Facilities § 60.244 Test methods and procedures. (a) The...

2010-07-01

343

40 CFR 60.244 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry: Granular Triple Superphosphate Storage Facilities § 60.244 Test methods and procedures. (a) The...

2011-07-01

344

40 CFR 60.244 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry: Granular Triple Superphosphate Storage Facilities § 60.244 Test methods and procedures. (a) The...

2014-07-01

345

40 CFR 60.275a - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

... STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Steel Plants: Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels Constructed After August 17, 1983 § 60.275a Test methods and procedures....

2013-07-01

346

40 CFR 60.275a - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

... STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Steel Plants: Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels Constructed After August 17, 1983 § 60.275a Test methods and procedures....

2011-07-01

347

40 CFR 60.275a - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

... STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Steel Plants: Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels Constructed After August 17, 1983 § 60.275a Test methods and procedures....

2012-07-01

348

40 CFR 60.275a - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

... STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Steel Plants: Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels Constructed After August 17, 1983 § 60.275a Test methods and procedures....

2014-07-01

349

40 CFR 60.664 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...Manufacturing Industry (SOCMI) Distillation Operations § 60.664 Test methods...control device, prior to any post-distillation dilution of the stream with air, and prior to any post-distillation introduction of halogenated...

2012-07-01

350

40 CFR 60.664 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...Manufacturing Industry (SOCMI) Distillation Operations § 60.664 Test methods...control device, prior to any post-distillation dilution of the stream with air, and prior to any post-distillation introduction of halogenated...

2014-07-01

351

40 CFR 60.664 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...Manufacturing Industry (SOCMI) Distillation Operations § 60.664 Test methods...control device, prior to any post-distillation dilution of the stream with air, and prior to any post-distillation introduction of halogenated...

2011-07-01

352

40 CFR 60.664 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...Manufacturing Industry (SOCMI) Distillation Operations § 60.664 Test methods...control device, prior to any post-distillation dilution of the stream with air, and prior to any post-distillation introduction of halogenated...

2013-07-01

353

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...

354

40 CFR 60.614 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...the Synthetic Organic Chemical Manufacturing Industry (SOCMI) Air Oxidation Unit Processes § 60.614 Test methods...rate correction factor, integrated sampling and analysis...c) When a boiler or process heater with a...

2010-07-01

355

40 CFR 60.85 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...SOURCES Standards of Performance for Sulfuric Acid Plants § 60.85 Test methods...determine compliance with the SO2 acid mist, and visible emission standards... (1) The emission rate (E) of acid mist or SO2 shall be...

2011-07-01

356

40 CFR 60.85 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...SOURCES Standards of Performance for Sulfuric Acid Plants § 60.85 Test methods...determine compliance with the SO2 acid mist, and visible emission standards... (1) The emission rate (E) of acid mist or SO2 shall be...

2014-07-01

357

40 CFR 60.85 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...SOURCES Standards of Performance for Sulfuric Acid Plants § 60.85 Test methods...determine compliance with the SO2 acid mist, and visible emission standards... (1) The emission rate (E) of acid mist or SO2 shall be...

2012-07-01

358

40 CFR 60.85 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...SOURCES Standards of Performance for Sulfuric Acid Plants § 60.85 Test methods...determine compliance with the SO2 acid mist, and visible emission standards... (1) The emission rate (E) of acid mist or SO2 shall be...

2010-07-01

359

40 CFR 60.85 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...SOURCES Standards of Performance for Sulfuric Acid Plants § 60.85 Test methods...determine compliance with the SO2 acid mist, and visible emission standards... (1) The emission rate (E) of acid mist or SO2 shall be...

2013-07-01

360

40 CFR 63.750 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

...National Emission Standards for Aerospace Manufacturing and Rework Facilities...manufacturer's data, standard engineering reference texts, or other...specification(s) for the aerospace vehicle or component being...method test period for similar aerospace vehicles or...

2014-07-01

361

40 CFR 63.750 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...National Emission Standards for Aerospace Manufacturing and Rework Facilities...manufacturer's data, standard engineering reference texts, or other...specification(s) for the aerospace vehicle or component being...method test period for similar aerospace vehicles or...

2012-07-01

362

40 CFR 63.750 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...National Emission Standards for Aerospace Manufacturing and Rework Facilities...manufacturer's data, standard engineering reference texts, or other...specification(s) for the aerospace vehicle or component being...method test period for similar aerospace vehicles or...

2013-07-01

363

40 CFR 63.750 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...National Emission Standards for Aerospace Manufacturing and Rework Facilities...manufacturer's data, standard engineering reference texts, or other...specification(s) for the aerospace vehicle or component being...method test period for similar aerospace vehicles or...

2011-07-01

364

40 CFR 60.496 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...Performance for the Beverage Can Surface Coating Industry § 60.496 Test methods and...from which the VOC content of the coatings used for each affected facility...When VOC content of water-borne coatings, determined from data...

2010-07-01

365

An Alternative Method Of Specifying Shock Test Criteria  

NASA Technical Reports Server (NTRS)

Shock testing of aerospace vehicle hardware has presented many challenges over the years due to the high magnitude and short duration of the specifications. Recently, component structural failures have occurred during testing that have not manifested themselves on over 200 Space Shuttle solid rocket booster (SRB) flights (two boosters per flight). It is suspected that the method of specifying shock test criteria may be leaving important information out of the test process. The traditional test criteria specification, the shock response spectrum, can be duplicated by any number of waveforms that may not resemble the actual flight test recorded time history. One method of overcoming this limitation is described herein, which may prove useful for qualifying hardware for the upcoming Constellation Program.

Ferebee, R. C.; Clayton, J.; Alldredge, D.; Irvine, T.

2008-01-01

366

The effect of additives on lime dissolution rates. Final report  

SciTech Connect

Based on the previous years` studies concerning the efficiency of SO{sub 2} removal by spray dryers with high sulfur coal flue gas, the work for year five included investigations of lime dissolution rates at different slaking conditions and with the effect of additives. The prominent additives that have significant effects on lime dissolution rates were tested with the mini pilot spray drying absorber to see their effects on spray drying desulfurization applications. The mechanisms of these additive effects along with the properties of hygroscopic additives have been discussed and incorporated into the spray drying desulfurization model ``SPRAYMOD-M.`` Slaking conditions are very important factors in producing high quality lime slurry in spray drying desulfurization processes. At optimal slaking conditions, the slaked lime particles are very fine (3-5{mu}m) and the slaked lime has high BET surface areas which are beneficial to the desulfurization. The slaked lime dissolution rate experiments in our study are designed to determine how much lime can dissolve in a unit time if the initial lime surface area is kept constant. The purpose of the dissolution rate study for different additives is to find those effective additives that can enhance lime dissolution rates and to investigate the mechanisms of the dissolution rate enhancement properties for these additives. The applications of these additives on spray drying desulfurization are to further verify the theory that dissolution rate is a rate limiting step in the whole spray drying desulfurization process as well as to test the feasibility of these additives on enhancing SO{sub 2} removal in spray dryers.

Khang, S.J.

1996-07-31

367

A High Order Test Discretization for Unsymmetric Meshless Methods  

E-print Network

We introduce a high order test discretization for unsymmetric meshless methods, which samples the residual's derivatives in addition to the residual itself. When modified to use this new test discretization, unsymmetric meshless methods can exploit arbitrarily high smoothness in the solution to obtain arbitrarily high convergence orders or convergence in arbitrarily strong Sobolev norms, assuming a previously conjectured inverse inequality. This is justified using a new sampling inequality within the context of Schaback's framework.

Corrigan, Andrew; Wanner, Thomas

2008-01-01

368

Primer Stepper Motor Nomenclature, Definition, Performance and Recommended Test Methods  

NASA Technical Reports Server (NTRS)

There has been an unfortunate lack of standardization of the terms and components of stepper motor performance, requirements definition, application of torque margin and implementation of test methods. This paper will address these inconsistencies and discuss in detail the implications of performance parameters, affects of load inertia, control electronics, operational resonances and recommended test methods. Additionally, this paper will recommend parameters for defining and specifying stepper motor actuators. A useful description of terms as well as consolidated equations and recommended requirements is included.

Starin, Scott; Shea, Cutter

2014-01-01

369

Nondestructive spot test method for magnesium and magnesium alloys  

NASA Technical Reports Server (NTRS)

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.

Wilson, M. L. (inventor)

1973-01-01

370

A method for testing association patterns of social animals  

Microsoft Academic Search

Association indices were originally developed to describe species co-occurrences, but have been used increasingly to measure associations between individuals. However, no statistical method has been published that allows one to test the extent to which the observed association index values differ from those of a randomly associating population. Here, we describe an adaptation of a test developed by Manly (1995,Ecology,76,

LARS BEJDER; DAVID FLETCHER; STEFAN BRÄGER

1998-01-01

371

40 CFR 60.303 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) 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...concentration and the volumetric flow rate of the effluent gas. The sampling time and sample volume for each run shall be at least 60 minutes and 1.70......

2010-07-01

372

Method of Creating Database for Test System Based on MCU  

Microsoft Academic Search

In this paper the method of creating database for test system based on MCU was introduced. Firstly, a database which could save the data transmitted through the serial bus connecting PC with a test system based on MCU, was created on PC. Then a serving application on PC was programmed with the technologies of serial interface and ODBC. When the

Chen Buyue; Wang Yinkun; Zhang Jin

2007-01-01

373

Evaluation of methods for nondestructive testing of brazed joints  

NASA Technical Reports Server (NTRS)

Evaluation of nondestructive methods of testing brazed joints reveals that ultrasonic testing is effective in the detection of nonbonds in diffusion bonded samples. Radiography provides excellent resolutions of void or inclusion defects, and the neutron radiographic technique shows particular advantage for brazing materials containing cadmium.

Kanno, A.

1968-01-01

374

Prediction of the in vivo performance of enteric coated pellets in the fasted state under selected biorelevant dissolution conditions.  

PubMed

The purpose of this research was to predict the in vivo dissolution of lansoprazole from enteric coated pellets in the fasted state using a biorelevant flow-through dissolution method with low flow rates and volumes close to those in vivo. Additionally, a novel rotating stirring element, composed from magnet inserted in a silicone tube, was used to produce the movement of the pellets and expose them to slightly increased physical stress. Obtained dissolution results were compared to the dissolution results of our previous work using the USP IV with higher flow rate (11 ml/min). As drug release from enteric coated pellets usually starts in the small intestine, the influence of pellets' residence time in the gastric medium and additionally the effect of different media on drug release was studied. Prolongation of residence time in an acidic medium had only minor effect on the release rate after initial lag time, but significantly reduced the total amount of the drug released from both tested formulations, which was attributed to the drug's degradation in an acidic medium. The increased physical load on the pellets induced by the rotating stirring element compensated for the decrease of flow rate from 11 ml/min using the USP IV to 3 ml/min using the non-compendial system. Considering also gastric emptying kinetics good prediction of the in vivo release was achieved compared to in vivo absorption data obtained from a pharmacokinetic study under fasting conditions. Thus, using more physiologically relevant dissolution conditions, expressed through low volume and lower flow rate, and in combination with increased mechanical stress we obtained equally good in vitro/in vivo correlation as using USP IV and higher flow rates. Comparison of the dissolution results obtained with two different systems provided additional insight into product behaviour and improved prediction of in vivo performance. PMID:24844699

Stefani?, M; Vre?er, F; Rizmal, P; Mrhar, A; Bogataj, M

2014-10-01

375

Sensitivity test method for the characterization of laser damage behavior  

NASA Astrophysics Data System (ADS)

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.

Arenberg, Jonathan W.; Thomas, Michael D.

2014-12-01

376

High Level Waste System Impacts from Acid Dissolution of Sludge  

SciTech Connect

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.

KETUSKY, EDWARD

2006-04-20

377

Testing methods and techniques: Testing electrical and electronic devices: A compilation  

NASA Technical Reports Server (NTRS)

The methods, techniques, and devices used in testing various electrical and electronic apparatus are presented. The items described range from semiconductor package leak detectors to automatic circuit analyzer and antenna simulators for system checkout. In many cases the approaches can result in considerable cost savings and improved quality control. The testing of various electronic components, assemblies, and systems; the testing of various electrical devices; and the testing of cables and connectors are explained.

1972-01-01

378

Dissolution criticality in developing solid oral formulations: from inception to perception.  

PubMed

Currently, dissolution testing has become a vital tool for accessing product performance, especially in the hierarchy of solid oral dosage forms. With advances in complicated, expensive, and sophisticated analytical instruments, characterization of formulations has become easier, but simple dissolution assembly is gradually gaining momentum from industrial environs as well as regulatory agencies. As such, simple dissolution testing involves many complexities which must be properly understood to reach correct conclusions. The appropriate selection of multiple parameters (e.g., apparatus, medium, agitation, etc.) involved in dissolution testing and understanding their impact on analysis require thorough subject knowledge. In the words of regulatory provisions, in vitro dissolution testing can become a surrogate for expensive and tedious bioequivalence studies in special cases (i.e., when a biowaiver is recommended). As a consequence, reduced human testing as well as lower product development cost ultimately benefit patients and society. Therefore, the dissolution science has recently become one of the keys for success for formulation scientists, especially generic manufacturers. While designing dissolution methodologies, generic manufacturers need to follow the respective regulatory guidelines at the product development stage; concomitant data are required for the approval process. This comprehensive review is an earnest attempt to acquaint readers with the history, contemporary practices, and relevant issues regarding dissolution which may become a guiding tool for overcoming challenges and opening better prospects in product development. PMID:24099398

Patadia, Riddhish; Vora, Chintan; Mittal, Karan; Mashru, Rajashree

2013-01-01

379

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

PubMed Central

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

Patel, V. F.; Sarai, J.

2014-01-01

380

An evaluation of the whole effluent toxicity test method  

SciTech Connect

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.

Osteen, D.V.

1999-12-17

381

Test Results for Entry Guidance Methods for Space Vehicles  

NASA Technical Reports Server (NTRS)

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.

Hanson, John M.; Jones, Robert E.

2004-01-01

382

Test Results for Entry Guidance Methods for Reusable Launch Vehicles  

NASA Technical Reports Server (NTRS)

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.

Hanson, John M.; Jones, Robert E.

2003-01-01

383

Dissolution behavior of alumina in mold fluxes for steel continuous casting  

Microsoft Academic Search

Dissolution of alumina in various mold fluxes for steel continuous casting has been investigated by employing the rotating\\u000a cylinder method. The weight loss of the rod, the dipping area and the immersed time were measured to determine dissolution\\u000a rate of Al2O3. The dissolution rate increased with temperature of molten fluxes, the rotating speed of the rod and the addition of

Anh-Hoa Bui; Hyun-Mo Ha; Youn-Bae Kang; In-Sang Chung; Hae-Geon Lee

2005-01-01

384

Experimental determination of calcite dissolution rates and equilibrium concentrations in deionized water approaching calcite equilibrium  

Microsoft Academic Search

The calcite dissolution rates at 50–250 °C and 20 MPa in deionized water with flow rate varying from 0.2 to 5 mL\\/min were\\u000a experimentally measured in a continuous flow column pressure vessel reactor. Equilibrium concentration (c\\u000a eq) of calcite dissolution in deionized water at 20 MPa was determined using dissolution data according to the iterative method\\u000a presented by Jeschke and

Qingjie Gong; Jun Deng; Qingfei Wang; Liqiang Yang; Min She

2010-01-01

385

Formulations for iron oxides dissolution  

DOEpatents

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.

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

1992-01-01

386

The Rocketdyne Multifunction Tester. Part 1: Test Method  

NASA Technical Reports Server (NTRS)

The Rocketdyne Multifunction Tester is a general purpose test apparatus which utilizes axial and radial magnetic bearings as shaft excitation devices. The tester is modular in design so that different seal and bearing packages can be tested on the same test stand. The tester will be used for rotordynamic coefficient extraction, as well as life and fluid/material compatibility evaluations. Use of a magnetic bearing as a shaft excitation device opens up many possibilities for shaft excitation and rotordynamic coefficient extraction. In addition to describing the basic apparatus, some of the excitation and extraction methods are described. Some of the excitation methods to be discussed include random, aperiodic, harmonic, impulse and chirp.

Murphy, Brian T.; Scharrer, Joseph K.; Sutton, Robert F.

1991-01-01

387

Review of Standard Test methods for Moisture in Lint Cotton  

Technology Transfer Automated Retrieval System (TEKTRAN)

Almost all of the standard test methods for moisture in lint cotton utilize the oven-drying technique. The loss in weight is taken as the amount of water and is expressed as a percentage of the mass of either the moist or dried material. There is a need to review the standard methods and compare t...

388

Testing Generalized Linear Models Using Smoothing Spline Methods  

E-print Network

Testing Generalized Linear Models Using Smoothing Spline Methods Anna Liu, Wendy Meiring to data from the Wisconsin Epidemiology Study of Diabetic Retinopathy, the results of which con#12;rm tools are especially important in practice. In this pa- per, we propose and compare three methods

Meiring, Wendy

389

40 CFR 63.786 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) National Emission Standards for Shipbuilding and Ship Repair (Surface Coating) § 63.786 Test methods and procedures...original sample. The sensitivity is defined as ten times the noise level as specified in ASTM Method D3257-93: Standard...

2011-07-01

390

40 CFR 63.786 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) National Emission Standards for Shipbuilding and Ship Repair (Surface Coating) § 63.786 Test methods and procedures...original sample. The sensitivity is defined as ten times the noise level as specified in ASTM Method D3257-93: Standard...

2010-07-01

391

40 CFR 63.786 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) National Emission Standards for Shipbuilding and Ship Repair (Surface Coating) § 63.786 Test methods and procedures...original sample. The sensitivity is defined as ten times the noise level as specified in ASTM Method D3257-93: Standard...

2012-07-01

392

40 CFR 63.786 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) National Emission Standards for Shipbuilding and Ship Repair (Surface Coating) § 63.786 Test methods and procedures...original sample. The sensitivity is defined as ten times the noise level as specified in ASTM Method D3257-93: Standard...

2013-07-01

393

DISSOLUTION AND CRYSTALLIZATION OF CALCIUM SULFITE PLATELETS  

EPA Science Inventory

The paper discusses the dissolution and crystallization of calcium sulfite platelets. The rates of calcium sulfite dissolution and crystallization are important in slurry scrubbing processes for flue gas desulfurization. The rates affect the scrubber solution composition, SO2 abs...

394

25 CFR 11.606 - Dissolution proceedings.  

Code of Federal Regulations, 2010 CFR

... (a) Either or both parties to the marriage may initiate dissolution proceedings...petition in a proceeding for dissolution of marriage or legal separation shall allege that the marriage is irretrievably broken and shall set...

2010-04-01

395

Gas hydrate dissolution rates quantified with laboratory and seafloor experiments  

NASA Astrophysics Data System (ADS)

Methane hydrates are stable at high pressure, low temperature, and saturated methane concentrations. However, natural hydrates exist at the seafloor where methane concentrations are well below saturation. Under such conditions, hydrate outcrops should shrink rapidly as they dissolve into the surrounding seawater. However, some natural hydrate outcrops have been observed for years undergoing little to no visible signs of change. Further, hydrate dissolution rates vary greatly among sites where changes have been observed. In this study, we perforated a natural hydrate outcrop on the seafloor of the Gulf of Mexico and measured the expansion of the hole after 30 days. From the rate of volume loss, we calculated a dissolution rate of 15 cm y-1. This rate is nearly an order of magnitude slower than hydrate dissolution rates observed in the Northern Cascadia Margin. We hypothesized that crystal structure influences hydrate dissolution rates and that the variability observed in in situ hydrate dissolution is caused by different hydrate structures. To test this hypothesis, we measured methane hydrate (structure I) and propane hydrate (structure II) dissolution rates in a series of laboratory experiments. Hydrates were formed in a pressure vessel and maintained at pressure and temperature conditions conducive to hydrate stability. After formation, the gas source was removed. Dissolution rates were calculated by measuring the increase in the dissolved gas concentration over time. Structure I (methane) hydrate dissolved at an average rate of 5.2 ± 2.5 mM CH4 d-1. Structure II (propane) hydrate dissolved at an average rate of 0.3 ± 0.2 mM C3H8 d-1. The ratio of these dissolution rates was proportional to the ratio of methane and propane solubilities under the experimental conditions. This suggests that dissolution rates in our experiments were diffusion-controlled and not influenced by differences in the crystal structure. We propose that natural contaminants such as oils or biofilms may have slowed the dissolution rate of the hydrate we observed in the Gulf of Mexico.

Lapham, Laura L.; Wilson, Rachel M.; MacDonald, Ian R.; Chanton, Jeffrey P.

2014-01-01

396

Testing and Validation of the Dynamic Inertia Measurement Method  

NASA Technical Reports Server (NTRS)

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.

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

2015-01-01

397

Testing for trends when there are changes in methods  

SciTech Connect

Data from monitoring projects often include sampling or analytical changes that preclude trend analysis on the entire period of record. A modification of the nonparametric Kendall's test for monotonic trends, which accounts for such changes in the period of record, is described here. This approach blocks the data so that only data collected or analyzed under similar circumstances are compared. Alternatively, when appropriate data exist, data collected using the old method may be calibrated to values expected from the new method. Traditional trend tests may then be applied to resulting data sets. Results from simulations assessing both the power of the blocked test and the standard test performed on calibrated data are presented. The power of the blocked test exceeded the power of the calibration approach only when the calibration error was extremely large. Both the blocking and calibration approaches were applied to and compared for chemical data from Vermont lakes. (Copyright (c) 1993 Kluwer Academic Publishers.)

Newell, A.D.; Blick, D.J.; Hjort, R.C.

1993-01-01

398

Methodical aspects of text testing in a driving simulator.  

PubMed

A test with 30 test persons was conducted in a driving simulator. The test was a concept exploration and comparison of existing user interaction technologies for text message handling with focus on traffic safety and experience (technology familiarity and learning effects). Focus was put on methodical aspects how to measure and how to analyze the data. Results show difficulties with the eye tracking system (calibration etc.) per se, and also include the subsequent raw data preparation. The physical setup in the car where found important for the test completion. PMID:22317503

Sundin, A; Patten, C J D; Bergmark, M; Hedberg, A; Iraeus, I-M; Pettersson, I

2012-01-01

399

NNWSI waste form test method for unsaturated disposal conditions  

SciTech Connect

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.

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

1985-03-01

400

A Simple Method for Determining Specific Yield from Pumping Tests  

USGS Publications Warehouse

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.

Ramsahoye, L.E.; Lang, Solomon Max

1961-01-01

401

In vitro dissolution of uranium oxide by baboon alveolar macrophages  

SciTech Connect

In vitro cellular dissolution tests for insoluble forms of uranium oxide are technically difficult with conventional methodology using adherent alveolar macrophages. The limited number of cells per flask and the slow dissolution rate in a large volume of nutritive medium are obvious restricting factors. macrophages in suspension cannot be substituted because they represent different and poorly reproducible functional subtypes with regard to activation and enzyme secretion. Preliminary results on the dissolution of uranium oxide using immobilized alveolar macrophages are promising because large numbers of highly function macrophages can be cultured in a limited volume. Cells were obtained by bronchoalveolar lavages performed on baboons (Papio papio) and then immobilized after the phagocytosis of uranium octoxide (U[sub 3]O[sub 8]) particles in alginate beads linked with Ca[sup 2+]. The dissolution rate expressed as percentage of initial uranium content in cells was 0.039 [+-] 0.016%/day for particles with a count median geometric diameter of 3.84 [mu]m([sigma][sub g] = 1.84). A 2-fold increase in the dissolution rate was observed when the same number of particles was immobilized without macrophages. These results, obtained in vitro, suggest that the U[sub 3]O[sub g] preparation investigated should be assigned to inhalation class Y as recommended by the International Commission on Radiological Protection. Future experiments are intended to clarify this preliminary work and to examine the dissolution characteristics of other particles such as uranium dioxide. It is recommended that the dissolution rate should be measured over an interval of 3 weeks, which is compatible with the survival time of immobilized cells in culture and may reveal transformation states occurring with aging of the particles. 23 refs., 3 figs.

Poncy, J.L.; Dhilly, M.; Verry, M. (CEA/DSV/DPTE/LRT, Bruyeres le Chatel (France)); Metivier, H. (CEA/IPSN/DRSN, Fontenay aux Roses (France)); Masse, R. (CEA/DSV/DPTE, Fontenay aux Roses (France))

1992-07-01

402

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

Microsoft Academic Search

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

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

2004-01-01

403

Silicate Anion Structural Change in Calcium Silicate Hydrate Gel on Dissolution of Hydrated Cement  

Microsoft Academic Search

High pH conditions of aqueous solutions in a radioactive waste repository can be brought about by dissolution of cementitious materials. In order to clarify the mechanisms involved in maintaining this high pH for long time, we investigated the dissolution phenomena of OPC hydrate. In the present research, leaching tests on powdered cement hydrates were conducted by changing the ratio of

Kazuko HAGA; Masahito SHIBATA; Michihiko HIRONAGA; Satoru TANAKA; Shinya NAGASAKI

2002-01-01

404

On the effects of subsurface parameters on evaporite dissolution (Switzerland).  

PubMed

Uncontrolled subsurface evaporite dissolution could lead to hazards such as land subsidence. Observed subsidences in a study area of Northwestern Switzerland were mainly due to subsurface dissolution (subrosion) of evaporites such as halite and gypsum. A set of 2D density driven flow simulations were evaluated along 1000 m long and 150 m deep 2D cross sections within the study area that is characterized by tectonic horst and graben structures. The simulations were conducted to study the effect of the different subsurface parameters that could affect the dissolution process. The heterogeneity of normal faults and its impact on the dissolution of evaporites is studied by considering several permeable faults that include non-permeable areas. The mixed finite element method (MFE) is used to solve the flow equation, coupled with the multipoint flux approximation (MPFA) and the discontinuous Galerkin method (DG) to solve the diffusion and the advection parts of the transport equation. Results show that the number of faults above the lower aquifer that contains the salt layer is considered as the most important factor that affects the dissolution compared to the other investigated parameters of thickness of the zone above the halite formation, a dynamic conductivity of the lower aquifer, and varying boundary conditions in the upper aquifer. PMID:24650646

Zidane, Ali; Zechner, Eric; Huggenberger, Peter; Younes, Anis

2014-05-01

405

Standard Methods for Bolt-Bearing Testing of Textile Composites  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

406

40 CFR 63.2993 - What test methods must I use in conducting performance tests?  

Code of Federal Regulations, 2011 CFR

...Wet-Formed Fiberglass Mat Production Testing and Initial Compliance...measuring the concentration of formaldehyde. (d) Use the method...for determining the free-formaldehyde content in the urea-formaldehyde resin. (e) Use...

2011-07-01

407

40 CFR 63.2993 - What test methods must I use in conducting performance tests?  

Code of Federal Regulations, 2010 CFR

...Wet-Formed Fiberglass Mat Production Testing and Initial Compliance...measuring the concentration of formaldehyde. (d) Use the method...for determining the free-formaldehyde content in the urea-formaldehyde resin. (e) Use...

2010-07-01

408

Spent fuel dissolution studies FY 1991 to 1994  

SciTech Connect

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.

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

1995-12-01

409

Premarital Cohabitation and Marital Dissolution: An Examination of Recent Marriages  

ERIC Educational Resources Information Center

An ongoing question remains for family researchers: Why does a positive association between cohabitation and marital dissolution exist when one of the primary reasons to cohabit is to test relationship compatibility? Drawing on recently collected data from the 2006-2008 National Survey of Family Growth, the authors examined whether premarital…

Manning, Wendy D.; Cohen, Jessica A.

2012-01-01

410

SAS molecular tests Escherichia coli O157 detection kit. Performance tested method 031203.  

PubMed

The SAS Molecular tests Escherichia coli O157 Detection method, a loop-mediated isothermal amplification method, performed as well as or better than the U.S. Department of Agriculture, Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, bagged mixed lettuce, and fresh spinach. Ground beef (30% fat, 25 g test portion) was validated for 7-8 h enrichment, leafy greens were validated in a 6-7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16-20 h enrichment. The method performance for meat and leafy green matrixes was also shown to be acceptable under conditions of co-enrichment with Salmonella. Thus, after a short co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. The SAS Molecular tests Salmonella Detection Kit was validated using the same test portions as for the SAS Molecular tests E. coli O157 Detection Kit and those results are presented in a separate report. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 E. coli 0157 strains, including H7 and non-motile strains, and 30 non-E. coli O157 strains examined. Finally, the method was shown to be robust when variations to DNA extract hold time and DNA volume were varied. The method comparison and robustness data suggest a full 7 h enrichment time should be used for 25 g ground beef test portions. PMID:25051628

Bapanpally, Chandra; Montier, Laura; Khan, Shah; Kasra, Akif; Brunelle, Sharon L

2014-01-01

411

Mechanism of single-layer 193-nm dissolution inhibition resist  

NASA Astrophysics Data System (ADS)

We have found that the progress of developer base into films of terpolymers of norbornene (NB)-maleic anhydride (MA) and acrylic acid (AA) is a percolation process with a critical site concentration of x(c) equals 0.084 which suggests that every acrylic acid site in the terpolymer of norbornene-maleic anhydride-acrylic acid can make 12 monomer units of the polymer water compatible. In practice these systems are being used with various tert-butyl esters of cholic acid as dissolution inhibitors. The cholates differ very much in their dissolution inhibition factors (lowest t-butyl cholate (1.3) to highest t-butyl lithocholate glutarate dimer (7.4). The change in these factors corrected for molarity follow the hydrophobic character of the dissolution as measured by log(p). A quick screening method has also been established to evaluate dissolution inhibitors based on our observation that the cloud point (the volume % acetone in a water/acetone which gives persistent cloudiness) parallels the dissolution inhibiting power as measured by the dissolution inhibition factor. For dissolution promotion, optimal results are obtained with t-butyl 1,3,5-cyclohexanetricarboxylate (f equals -6.3) and poorest results with t-butyl lithocholate (f equals -2.8); this appears to track with the number of carboxyl groups and the hydrophobicity of the carboxylic acids. The Rmax found for resist formulations tracks well with these findings. Another factor in determining the ultimate achievable contrast is the degree of acidolytic deprotection achieved by the material. It appears that acidolyticaly cleaveable carboxylate esters with a higher concentration of electron withdrawing groups such as t-butyl 1,3,5-cyclohexanetricarboxylate are more effective.

Yan, Zhenglin; Houlihan, Francis M.; Reichmanis, Elsa; Nalamasu, Omkaram; Reiser, Arnost; Dabbagh, Gary; Hutton, Richard S.; Osei, Dan; Sousa, Jose; Bolan, Kevin J.

2000-06-01

412

Development of fire test methods for airplane interior materials  

NASA Technical Reports Server (NTRS)

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.

Tustin, E. A.

1978-01-01

413

Comparison of the E Test and Agar Dilution Method for Antimicrobial Suceptibility Testing of Helicobacter pylori  

Microsoft Academic Search

.  A multicentre study was carried out in order to validate the E test in comparison with the reference agar dilution method\\u000a for testing the susceptibility of Helicobacter pylori to amoxicillin, clarithromycin, and metronidazole. Ten clinical isolates and one control collection isolate (Helicobacter pylori ATCC 43504) were tes\\u000a \\u000a ted blindly at four centres according to a uniform methodology. The E test

Y. Glupczynski; N. Broutet; A. Cantagrel; L. Andersen; T. Alarcon; M. López-Brea; F. Mégraud

2002-01-01

414

An integrated test method for high-temperature liquid lubricants: Dynamic test  

NASA Astrophysics Data System (ADS)

A three-ball-on-disk (TBOD) bench test has been developed to evaluate high-temperature liquid lubricants such as the polyphenyl ethers. The TBOD test method is capable of generating an integrated set of tribo-measurements including friction, wear, lubricant consumption, and lubricant tribochemistry. Unlike the four-ball wear test, well-defined wear scars of circular and elliptical shapes are exclusively produced, which is critical for precise wear volume calculation.

Chao, Kenneth K.; Toth, Douglas K.; Saba, Costandy S.

1994-04-01

415

A Model Based Security Testing Method for Protocol Implementation  

PubMed Central

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

Fu, Yu Long; Xin, Xiao Long

2014-01-01

416

The split-method of ultrasonic nondestructive testing  

Microsoft Academic Search

This article describes a new method of echo-impulse ultrasonic testing based on a new “split-algorithm” for signal formation and processing. Application of a split-algorithm can significantly raise the sensitivity of testing devices (by two–three or more orders) while avoiding the loss of resolving capacity. Experimental results prove the practical importance of split-algorithms. Due to its high sensitivity, the proposed flaw

Igor V. Sokolov

2003-01-01

417

COMPARATIVE TOXICITY OF SIX TEST CHEMICALS TO LETTUCE USING TWO ROOT ELONGATION TEST METHODS (JOURNAL VERSION)  

EPA Science Inventory

Lettuce (Lactuca sativa L., cv buttercrunch) was used to evaluate and compare the results from two different root elongation phytotoxicity test methods with the same six test substances. Seeds were either germinated in the dark on an inclined filter paper substrate with one end i...

418

Low Temperature Aluminum Dissolution Of Sludge Waste  

SciTech Connect

High Level Waste (HLW) at the Savannah River Site (SRS) is currently stored in aging underground storage tanks. This waste is a complex mixture of insoluble solids, referred to as sludge, and soluble salts. Continued long-term storage of these radioactive wastes poses an environmental risk. The sludge is currently being stabilized in the Defense Waste Processing Facility (DWPF) through a vitrification process immobilizing the waste in a borosilicate glass matrix for long-term storage in a federal repository. Without additional treatment, the existing volume of sludge would produce nearly 8000 canisters of vitrified waste. Aluminum compounds, along with other non-radioactive components, represent a significant portion of the sludge mass currently planned for vitrification processing in DWPF. Removing the aluminum from the waste stream reduces the volume of sludge requiring vitrification and improves production rates. Treating the sludge with a concentrated sodium hydroxide (caustic) solution at elevated temperatures (>90 deg. C) to remove aluminum is part of an overall sludge mass reduction effort to reduce the number of vitrified canisters, shorten the life cycle for the HLW system, and reduce the risk associated with the long term storage of radioactive wastes at SRS. A projected reduction of nearly 900 canisters will be achieved by performing aluminum dissolution on six targeted sludge batches; however, a project to develop and install equipment will not be ready for operation until 2013. The associated upgrades necessary to implement a high temperature process in existing facilities are costly and present many technical challenges. Efforts to better understand the characteristics of the sludge mass and dissolution kinetics are warranted to overcome these challenges. Opportunities to further reduce the amount of vitrified waste and increase production rates should also be pursued. Sludge staged in Tank 51 as the next sludge batch for feed to DWPF consisted primarily of radioactive wastes containing a very high aluminum concentration. Based on initial laboratory testing and previous sludge characterization, aluminum in this sludge could be dissolved at low temperature (no more than 65 deg. C) in a concentrated caustic solution. The amount of aluminum predicted to dissolve under these conditions ranged from 25% to 80%. An opportunity existed to remove a significant amount of aluminum prior to vitrification in DWPF and increase the level of understanding of the effects of caustic dissolution of aluminum at lower temperatures. This paper presents the results of a real waste laboratory demonstration and full-scale implementation of a low temperature aluminum dissolution process which should be considered as a viable means to reduce radioactive sludge mass and reduce the amount of waste to be vitrified. (authors)

Keefer, M.T.; Hamm, B.A.; Pike, J.A. [Washington Savannah River Company, Aiken, SC (United States)

2008-07-01

419

Mass exchange during simultaneous grinding and dissolution  

SciTech Connect

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.

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

1988-03-20

420

A method for testing association patterns of social animals.  

PubMed

Association indices were originally developed to describe species co-occurrences, but have been used increasingly to measure associations between individuals. However, no statistical method has been published that allows one to test the extent to which the observed association index values differ from those of a randomly associating population. Here, we describe an adaptation of a test developed by Manly (1995, Ecology, 76, 1109-1115), which uses the observed association data as a basis for a computer-generated randomization. The observed pattern of association is tested against a randomly created one while retaining important features of the original data, for example group size and sighting frequency. We applied this new method to test four data sets of associations from two populations of Hector's dolphin, Cephalorhynchus hectori, using the Half-Weight Index (HWI) as an example of a measure of association. The test demonstrated that populations with similar median HWI values showed clear differences in association patterns, that is, some were associating nonrandomly whereas others were not. These results highlight the benefits of using this new testing method in order to validate the analysis of association indices. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9784222

Bejder; Fletcher; BrÄger

1998-09-01

421

Topology testing of phylogenies using least squares methods  

PubMed Central

Background The least squares (LS) method for constructing confidence sets of trees is closely related to LS tree building methods, in which the goodness of fit of the distances measured on the tree (patristic distances) to the observed distances between taxa is the criterion used for selecting the best topology. The generalized LS (GLS) method for topology testing is often frustrated by the computational difficulties in calculating the covariance matrix and its inverse, which in practice requires approximations. The weighted LS (WLS) allows for a more efficient albeit approximate calculation of the test statistic by ignoring the covariances between the distances. Results The goal of this paper is to assess the applicability of the LS approach for constructing confidence sets of trees. We show that the approximations inherent to the WLS method did not affect negatively the accuracy and reliability of the test both in the analysis of biological sequences and DNA-DNA hybridization data (for which character-based testing methods cannot be used). On the other hand, we report several problems for the GLS method, at least for the available implementation. For many data sets of biological sequences, the GLS statistic could not be calculated. For some data sets for which it could, the GLS method included all the possible trees in the confidence set despite a strong phylogenetic signal in the data. Finally, contrary to WLS, for simulated sequences GLS showed undercoverage (frequent non-inclusion of the true tree in the confidence set). Conclusion The WLS method provides a computationally efficient approximation to the GLS useful especially in exploratory analyses of confidence sets of trees, when assessing the phylogenetic signal in the data, and when other methods are not available. PMID:17150093

Czarna, Aleksandra; Sanjuán, Rafael; González-Candelas, Fernando; Wróbel, Borys

2006-01-01

422

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

E-print Network

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

Lee, Ben

423

[Modification of the Photobacterium phosphoreum toxicity test method].  

PubMed

In order to reduce the variation of Photobacterium phosphoreum luminous intensity during testing, the Photobacterium phosphoreum toxicity test was modified by a correction factor, PIacetone, in this paper. The effects of magnetic stirring time, culture time, culture generation and culture temperature on the measured results were discussed. The modified method had good laboratory repeatability and the relative standard deviation (RSD) was between 2.1% and 13.1%. Reliable data could be obtained using the modified method. It would be beneficial to the development of the quantitative structure-activity relationships on multicomponent organic compounds. PMID:11432056

Lin, Z; Yu, H; Xu, S; Wang, L

2001-03-01

424

Method and apparatus for testing surface characteristics of a material  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

425

Apparatus and method for defect testing of integrated circuits  

SciTech Connect

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.

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

2000-02-29

426

Apparatus and method for defect testing of integrated circuits  

DOEpatents

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.

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

2000-01-01

427

Truncated Product Methods for Panel Unit Root Tests*  

PubMed Central

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

SHENG, XUGUANG; YANG, JINGYUN

2012-01-01

428

High power battery test methods for hybrid vehicle applications  

SciTech Connect

Commonly used EV battery tests are not very suitable for testing hybrid vehicle batteries, which may be primarily intended to supply vehicle acceleration power. The capacity of hybrid vehicle batteries will be relatively small, they will typically operate over a restricted range of states-of-charge, and they may seldom if ever be fully recharged. Further, hybrid propulsion system designs will commonly impose a higher regeneration content than is typical for electric vehicles. New test methods have been developed for use in characterizing battery performance and life for hybrid vehicle use. The procedures described in this paper were developed from the requirements of the government-industry cooperative Partnership for A New Generation of Vehicles (PNGV) program; however, they are expected to have broad application to the testing of energy storage devices for hybrid vehicles. The most important performance measure for a high power battery is its pulse power capability as a function of state-of-charge for both discharge and regeneration pulses. It is also important to characterize cycle life, although the {open_quote}cycles{close_quote} involved are quite different from the conventional full-discharge, full-recharge cycle commonly used for EV batteries, This paper illustrates in detail several test profiles which have been selected for PNGV battery testing, along with some sample results and lessons learned to date from the use of these test profiles. The relationship between the PNGV energy storage requirements and these tests is described so that application of the test methods can be made to other hybrid vehicle performance requirements as well. The resulting test procedures can be used to characterize the pulse power capability of high power energy storage devices including batteries and ultracapacitors, as well as the life expectancy of such devices, for either power assist or dual mode hybrid propulsion system designs.

Hunt, G.L.; Haskins, H.; Heinrich, B.; Sutula, R.

1997-11-01

429

NON-DESTRUCTIVE TESTING METHODS FOR GEOTHERMAL PIPING.  

SciTech Connect

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.

BERNDT,M.L.

2001-03-23

430

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

SciTech Connect

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).

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

1993-01-01

431

Characterisation of human saliva as a platform for oral dissolution medium development.  

PubMed

Human saliva is a biological fluid of great importance in the field of dissolution testing. However, until now, no consensus has been reached on its key characteristics relevant to dissolution testing. As a result, it is difficult to select or develop an in vitro dissolution medium to best represent human saliva. In this study, the pH, buffer capacity, surface tension, viscosity and flow rate of both unstimulated (US) and stimulated (SS) human saliva were investigated in order to provide a platform of reference for future dissolution studies using simulated salivary fluids. Age and gender related differences in a sample size of 30 participants for each parameter were investigated. Significant differences were established between US and SS for all characteristics except surface tension. Therefore, the requirement for using two simulated salivary fluids should be considered when developing an oral dissolution model. PMID:25603197

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

2015-04-01

432

40 CFR 80.47 - Performance-based Analytical Test Method Approach.  

Code of Federal Regulations, 2014 CFR

...method results from the applicable method-defined alternative test method. (11) Statistical quality control (SQC) means...and precision values, all test method documentation, and any statistical quality control testing and...

2014-07-01

433

Proposal for a Brazilian centre on alternative test methods.  

PubMed

Several initiatives have recently taken place in Brazil in order to foster the creation of centers dedicated to alternatives to animal testing. In 2008, Vanessa Sá-Rocha organized a meeting with Brazilian regulatory authorities and the major stakeholders in the field of testing to foster discussions on the process of funding, development, and validation of alternative methods in Brazil. Octavio Presgrave published a scientific article on "The Need for the Establishment of a Brazilian Centre for the Validation of Alternative Methods." Also in 2008, Jadir Nunes, together with Dermeval de Carvalho, prepared and presented a proposal to the Brazilian National Agency of Health Surveillance (ANVISA) for the creation of a Centre for the Validation of Alternative Methods. ECVAM and other European stakeholders have been involved in the initiatives. Furthermore, also in 2008, a new legislation has been adopted in Brazil regarding the use of animals for scientific purposes ("lei Arouca"). The legislation establishes, among other provisions, the task of monitoring and evaluating the introduction of alternative methods. However, the legislation does not provide for promotion of or information about, existing alternative methods to the larger Brazilian scientific community. In order to streamline the different activities, Chantra Eskes acted as a facilitator by establishing a new joint proposal with the current Brazilian stakeholders, aimed at setting up a Brazilian Center on Alternative Test Methods. PMID:20383476

Eskes, Chantra; Sá-Rocha, Vanessa de Moura; Nunes, Jadir; Presgrave, Octavio; de Carvalho, Dermeval; Masson, Philippe; Rivera, Ekaterina; Coecke, Sandra; Kreysa, Joachim; Hartung, Thomas

2009-01-01

434

Asteroid Dynamical Families: a Reliability Test for Two Identification Methods  

NASA Astrophysics Data System (ADS)

Since a couple of years the asteroid families are under the light of a renewed interest. This is due to the simultaneous improvement of the techniques of proper elements computation and of the methods of classification. Recently, two different cluster analysis methods (Zappalà et al. 1990; Bendjoya et al. 1991) have provided two very similar lists of asteroid families. This has brought a renewed confidence on the reliability of asteroid families classification. Since a new set of improved proper elements is now available (Milani & Kneževi? 1992), the idea of the present work is to test the two identification methods by means of artificially generated families in order to gain an insight into their limitations and to possibly develop improved strategies for future analyses. Different cases have been envisaged in order to study the effectiveness of the methods as a function of increasing background densities and of the spread of the families. The ability of the methods to detect peculiar features such as filaments or to separate two close families has also been tested. The number of interlopers has been determined in each case in order to evaluate their relative amount. While some improvements to the adopted procedures are suggested by the numerical tests, the results presented in the present paper are encouraging and allow us to be confident about the reliability of our previous family lists, as well as about the expected performances of the methods in future applications.

Bendjoya, P.; Cellino, A.; Froeschle, C.; Zappala, V.

1993-05-01

435

Method for testing and characterization of analog-digital systems  

Microsoft Academic Search

The author proposes a method of testing of analog-digital systems (ADS). A linear inertial heteroscedastic ADS model, that takes account of nonlinear and inertial conversion effects is developed. The validity of the model is verified by actual measurements of the dynamic responses of an analog-digital converter (ADC)

V. Zagursky

2001-01-01

436

Method for testing and characterization of analog-digital system  

Microsoft Academic Search

The authors propose a method of testing of analog-digital systems (ADS). It is developed linear inertial heteroscedastic ADS model that takes account of nonlinear and inertial conversion effects. The validity of the model is verified by actual measurements of the dynamic responses of analog-digital converter (ADC)

V. Zagursky

2001-01-01

437

Prismatic ray cells versus tetrahedra numerical tests of interpolation methods  

E-print Network

Prismatic ray cells versus tetrahedra ­ numerical tests of interpolation methods Petr Bulant to divide ray tubes into ray cells formed by four points (tetrahedra) and gain from the simplification tetrahedra, see figure 1. The sides of tetrahedra for two neighbouring ray tubes must coincide

Cerveny, Vlastislav

438

40 CFR 60.64 - Test methods and procedures  

Code of Federal Regulations, 2011 CFR

...NEW STATIONARY SOURCES Standards of Performance for Portland Cement Plants § 60.64 Test methods and procedures (a... and SO2 as the total of all hourly emissions data for a cement kiln in the preceding 30 days, divided by the total tons...

2011-07-01

439

40 CFR 60.64 - Test methods and procedures  

Code of Federal Regulations, 2012 CFR

...NEW STATIONARY SOURCES Standards of Performance for Portland Cement Plants § 60.64 Test methods and procedures (a... and SO2 as the total of all hourly emissions data for a cement kiln in the preceding 30 days, divided by the total tons...

2012-07-01

440

Youden test application in robustness assays during method validation.  

PubMed

Analytical method validation is a vital step following method development for ensuring reliable and accurate method performance. Among examined figures of merit, robustness/ruggedness study allows us to test performance characteristics of the analytical process when operating conditions are altered either deliberately or not. This study yields useful information, being a fundamental part of method validation. Since many experiments are required, this step is high demanding in time and consumables. In order to avoid the difficult task of performing too many experiments the Youden test which makes use of fractional factorial designs and has been proved to be a very effective approach. The main advantage of Youden test is the fact that it keeps the required time and effort to a minimum, since only a limited number of determinations have to be made, using combinations of the chosen investigated factors. Typical applications of this robustness test found in literature covering a wide variety of sample matrices are briefly discussed in this review. PMID:24508395

Karageorgou, Eftichia; Samanidou, Victoria

2014-08-01

441

ENVIRONMENTAL METHODS TESTING SITE PROJECT: PROJECT MANAGEMENT PLAN  

EPA Science Inventory

The Environmental Methods Testing Site Project is being conducted by the Environmental Protection Agency with the cooperation of the state of Georgia, the state of Tennessee, Hamilton County, Tennessee, and the city of Chattanooga. The concept is to establish one well-characteriz...

442

Laboratory methods for testing the performance of acoustic rail dampers  

E-print Network

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

Paris-Sud XI, Université de

443

Test method Evaluating the influence of contacting fluids on polyethylene  

E-print Network

Test method Evaluating the influence of contacting fluids on polyethylene using acoustic emissions emissions Polyethylene Penetrant Toluene Aqueous detergent a b s t r a c t Identifying microstructural) on the structure of a semi-crystalline polymer (high density polyethylene, HDPE) over different periods of exposure

Thompson, Michael

444

Heart rate-based lactate minimum test: a reproducible method  

Microsoft Academic Search

OBJECTIVE: To find the individual intensity for aerobic endurance training, the lactate minimum test (LMT) seems to be a promising method. LMTs described in the literature consist of speed or work rate-based protocols, but for training prescription in daily practice mostly heart rate is used. The aim of the present study was to investigate the reproducibility of a new heart

M. Strupler; G Mueller; C. Perret

2009-01-01

445

A New Method of Assessing Bias in Test Items.  

ERIC Educational Resources Information Center

In order to screen out items which may be biased against some ethnic group prior to the final selection of items in test construction, a statistical technique for assessing item bias was developed. Based on a theoretical formulation of R. B. Darlington, the method compares the performance of individuals who belong to different ethnic groups, but…

Scheuneman, Janice

446

40 CFR 60.404 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

... 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)....

2012-07-01

447

40 CFR 60.404 - Test methods and procedures.  

Code of Federal Regulations, 2014 CFR

... 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)....

2014-07-01

448

40 CFR 60.404 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

... 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)....

2010-07-01

449

40 CFR 60.404 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

... 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)....

2011-07-01

450

40 CFR 60.404 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

... 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)....

2013-07-01

451

Improving Dementia Screening Tests with Machine Learning Methods  

E-print Network

Improving Dementia Screening Tests with Machine Learning Methods William Rodman Shankle Department improve dementia screening. DSM-IV criteria for dementia were used to categorize patients into normal their accuracy in detecting cognitive impairment and dementia, and to implement their combined use in a simple

Pazzani, Michael J.

452

Improving Dementia Screening Tests with Machine Learning Methods  

E-print Network

Improving Dementia Screening Tests with Machine Learning Methods William Rodman Shankle Department improve dementia screening. DSM­IV criteria for dementia were used to categorize patients into normal their accuracy in detecting cognitive impairment and dementia, and to implement their combined use in a simple

Pazzani, Michael J.

453

Reproduction of natural corrosion by accelerated laboratory testing methods  

SciTech Connect

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.

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

1996-05-01

454

Research Methods Knowledge Base : The t-Test  

NSDL National Science Digital Library

This particular textbook lesson, presented by Cornell University's Research Methods Knowledge Base, addresses the independent t-test. It presents to the user how to compute the t statistic and then how to interpret the results. The site uses graphs and charts along with the text to enhance the presentation. Overall, this is a useful resource for any mathematics classroom.

Trochim, William M.K.

455

ENVIRONMENTAL METHODS TESTING SITE PROJECT: DATA MANAGEMENT PROCEDURES PLAN  

EPA Science Inventory

The Environmental Methods Testing Site (EMTS) Data Management Procedures Plan identifies the computer hardware and software resources used in the EMTS project. It identifies the major software packages that are available for use by principal investigators for the analysis of data...

456

40 CFR 60.335 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

457

Nondestructive testing method of concrete using impact acoustics  

Microsoft Academic Search

A new nondestructive testing method for concrete using impact acoustics is investigated. Impact acoustics, which has a strong relation with the vibration of a concrete surface, can offer important information about the physical properties of concrete structures such as shapes, material properties and defects. In this paper, the relation between impact acoustics and vibration at the same surface of the

Y. Ito; T. Uomoto

1997-01-01

458

Hydrocode Simulation of Wedge Tests to Determine How the Test Method Affects the Pop Plot  

NASA Astrophysics Data System (ADS)

Most of the available shock reactivity data for explosives comes from either wedge tests or from embedded gauge data obtained from flyer plate tests. A question arises, what effect does the test method have on the Pop Plot obtained? A flyer plate test will impart a constant input pressure whereas wedge testing using a plane wave lens (PWL) system will not. To gauge this effect, explicit numerical simulations were performed for 4'' and 8'' diameter wedge tests using a PWL system and for flyer plate impact tests. For the flyer plate tests, the simulations modeled the flyer plate and explosive sample. For the PWL system, the simulations modeled the PWL, the booster explosive, the attenuator and the explosive sample. The simulations resulted in distance-time curves of the shock or detonation wave traveling into the sample. These curves, when differentiated, resulted in shock velocity versus distance and shock velocity versus time plots. Inspection of these plots for various input pressures allowed for prediction of pop plots (log of run distance versus log of time and log of run distance versus log of input pressure). Comparison of the Pop Plots indicated the effect of the test method on Pop Plot slope and intercept. Simulations were performed for both an ideal and a non-ideal explosive.

Sutherland, Gerrit

2011-06-01

459

Dissolution of nepheline, jadeite and albite glasses: toward better models for aluminosilicate dissolution  

NASA Astrophysics Data System (ADS)

SLB acknowledges many educational and entertaining conversations with Hal Helgeson (ranging from kinetics to bent head morphologies) over the last 17 years. To investigate the effects of changing the Al/Si ratio on plagioclase dissolution without complications of varying Na/Ca content or exsolution, three glasses with varying Al/Si ratios (albite, jadeite, and nepheline glasses) were synthesized and dissolved. Many similarities in dissolution behavior between plagioclase crystals and this suite of glasses were observed: 1) dissolution was slowest at near-neutral pH and increased under acid and basic conditions; 2) dissolution rate at all pH values increased with increasing Al/Si ratio; 3) the pH dependence of dissolution was higher for the phase with Al/Si = 1 than the phase with Al/Si = 0.3; 4) after acid leaching, the extent of Al depletion of the altered surface increased with increasing bulk Al/Si ratio from Al/Si = 0.3 (albite glass) to 0.5 (jadeite glass), but then decreased in nepheline glass (Al/Si = 1.0), which dissolved stoichiometrically with respect to Al; and 5) little to no Al depletion of the surface of any glass occurred at pH > 7. In contrast with some observations for plagioclase dissolution, however, log (rate) increased linearly with Al content, and n, the slope of the log (rate) - pH curve at low pH, varied smoothly from albite glass to jadeite glass to nepheline glass ( n = -0.3, -0.6, and -1.0, respectively). These results, plus the observation that the slope calculated at high pH, m, did not differ between glasses ( m = 0.4 ± 0.1), may be consistent with an identical mechanism controlling dissolution of albite, jadeite, and nepheline glasses, although no Si-rich layer can develop on nepheline because of the lack of SiOSi linkages. Such a conclusion is consistent with a transition state for these aluminosilicates at high pH consisting of a deprotonated Q3Si hydroxyl group (where Qvx refers to an x atom in a tetrahedral site with v bridging oxygens) or a five-coordinate Si site after nucleophilic attack by OH-. At low pH, bridging oxygens between Q4Si and Q4Al may be rate limiting if they are slower to hydrolyze than QvSiQwSi linkages ( v,w? 3). According to this mechanism, dissolution rate increases from albite to jadeite to nepheline glass because hydrolysis of AlOSi bonds become more energetically favorable as the number of Al atoms per Si tetrahedron increases, a phenomenon documented here by geometry optimizations by use of ab initio methods. A model wherein Q4AlQ4Si linkages are faster to hydrolyze than lower connectivity linkages between Si atoms ( QvSiQwSi, v,w? 3) may also explain aspects of this data. Further computational and experimental measurements are needed to distinguish the models.

Hamilton, James P.; Brantley, Susan L.; Pantano, Carlo G.; Criscenti, Louise J.; Kubicki, James D.

2001-11-01

460

Mode-Stirred Method Implementation for HIRF Susceptibility Testing and Results Comparison with Anechoic Method  

NASA Technical Reports Server (NTRS)

This paper describes the implementation of mode-stirred method for susceptibility testing according to the current DO-160D standard. Test results on an Engine Data Processor using the implemented procedure and the comparisons with the standard anechoic test results are presented. The comparison experimentally shows that the susceptibility thresholds found in mode-stirred method are consistently higher than anechoic. This is consistent with the recent statistical analysis finding by NIST that the current calibration procedure overstates field strength by a fixed amount. Once the test results are adjusted for this value, the comparisons with the anechoic results are excellent. The results also show that test method has excellent chamber to chamber repeatability. Several areas for improvements to the current procedure are also identified and implemented.

Nguyen, Truong X.; Ely, Jay J.; Koppen, Sandra V.

2001-01-01