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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

Reciprocating dialysis tube method: Periodic tapping improved in vitro release\\/dissolution testing of suppositories  

Microsoft Academic Search

The reciprocating dialysis tube (RDT) method can be used for in vitro release\\/dissolution testing of suppositories and has been reported to show good in vitro and in vivo correlation. However, for suppositories with viscous excipients, the result remains variable and generally under-predicts in vivo absorption. The purpose of this study was to assess whether periodic tapping of the closure of

Soichi Itoh; Naomi Teraoka; Toshio Matsuda; Kousuke Okamoto; Tatsuya Takagi; Charles Oo; H. Danny Kao

2006-01-01

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

Development of a new dissolution test method for an oral controlled release preparation, the PVA swelling controlled release system (SCRS).  

PubMed

In vitro dissolution tests of novel controlled release tablets, the poly(vinyl alcohol) (PVA) swelling controlled release system (SCRS), were performed by various methods under different conditions in the sinking state in water. The in vitro release profiles of various tests were almost the same and faster than the in vivo absorption profiles calculated from the plasma drug concentrations of humans. A novel dissolution test method was developed considering the gastrointestinal tract (GI) conditions. PVA particles were used as the filler in a flow-through cell. PVA particles swelled with water were put in the flow-through cell and the tablet was buried in PVA. The test medium was dropped from the top of the cell, and the dissolution medium that dripped from the bottom of the cell was collected and assayed. The in vitro dissolution profile determined by this method was similar to the in vivo absorption profile against other in vitro methods in the sinking state in water. Furthermore, a good correlation between in vitro and in vivo for the two different release rate preparations was obtained using a flow pattern imitating the GI transition. PMID:12767711

Morita, Ryoichi; Honda, Ritsuko; Takahashi, Yoshiteru

2003-06-01

5

Flow Through Diffusion Cell Method: A Better Approach to Study Drug Release Behavior as Compared to Traditional Dissolution Test Method  

Microsoft Academic Search

Co?polymeric hydrogels consisting of N?vinyl?2?pyrrolidone (NVP) and acrylic acid (AAc) were synthesized and evaluated for release of a model drug, i.e., vitamin B12. Release studies in simulated gastric fluid (pH 1.2) and intestinal fluid (pH 7.4), at 37°C, showed the hydrogels to be pH sensitive. An in vitro release study by ‘traditional dissolution test’ (TDT) showed that percent drug released

S. K. Bajpai; Seema Dubey; Sutanjay Saxena

2006-01-01

6

Dissolution test acceptance sampling plans.  

PubMed

The U.S. Pharmacopeia (USP) general monograph provides a standard for dissolution compliance with the requirements as stated in the individual USP monograph for a tablet or capsule dosage form. The acceptance rules recommended by USP have important roles in the quality control process. The USP rules and their modifications are often used as an industrial lot release sampling plan, where a lot is accepted when the tablets or capsules sampled are accepted as proof of compliance with the requirement. In this paper, the operating characteristics of the USP acceptance rules are reviewed and compared to a selected modification. The operating characteristics curves show that the USP acceptance rules are sensitive to the true mean dissolution and do not reject a lot or batch that has a large percentage of tablets that dissolve with less than the dissolution specification. PMID:7581426

Tsong, Y; Hammerstrom, T; Lin, K; Ong, T E

1995-07-01

7

Dissolution test acceptance sampling plans  

Microsoft Academic Search

The U.S. Pharmacopeia (USP) general monograph provides a standard for dissolution compliance with the requirements as stated in the individual USP monograph for a tablet or capsule dosage form. The acceptance rules recommended by USP have important roles in the quality control process. The USP rules and their modifications are often used as an industrial lot release sampling plan, where

Yi Tsong; Thomas Hammerstrom; Karl Lin; Ting Eng Ong

1995-01-01

8

Comparison of UV spectrophotometric method and high performance liquid chromatography for the analysis of flunarizine and its application for the dissolution test.  

PubMed

This study aimed to develop a simple UV spectrophotometric method for the analysis and the dissolution test of flunarizine in capsules. The UV absorbance was both measured directly and by the first derivative measurements at 254 and 268 nm, respectively. The developed methods were validated for their linearity, accuracy, precision, limit of detection (LOD) and limit of quantitation (LOQ) in comparison with the reported HPLC method. The UV spectrophotometric method illustrated excellent linearity (r2 > 0.9999) in the concentration range of 6-24 microg/mL. Precision (%R.S.D. < 1.50) and recoveries were good (%R > 99.62). The LOD of direct UV and first derivative measurements were 0.09 and 0.84 microg/mL, respectively, and the LOQ were 0.26 and 2.55 microg/mL, respectively. Results from the assay of flunarizine in capsules by the UV spectrophotometric methods, both direct and first derivative measurements were not significantly different from those of the HPLC method (P > 0.05). Additionally, the method was successfully used for the dissolution test of flunarizine capsule and was found to be reliable, simple, fast, and inexpensive. PMID:16352415

Busaranon, Kesarin; Suntornsuk, Worapot; Suntornsuk, Leena

2006-04-11

9

In situ dissolution testing using potentiometric sensors.  

PubMed

Potentiometric sensors can be used to determine the amount of API dissolved in the dissolution medium in function of time by measuring directly in the dissolution vessel of a Paddle (USP type 2) and Basket (USP type 1) apparatus. The prototype potentiometric sensor instrumentation showed very promising results for a selection of APIs with different physico-chemical properties. The applicability, benefits and limitations of the prototype were explored. The applicability of the measurement technique strongly depends on the log(P) of the API. Here, it is shown that measurements can easily be performed for APIs with a log(P)>4. Electrode performance however decreases with decreasing logP of the APIs due to decreased drug selectivity in comparison to the excipients and ionic strength of the applied dissolution medium. The potentiometric sensors are shown to be insensitive towards undissolved particles and air bubbles as opposed to UV spectrometric measurement where these can lead to severe light scattering. For the tested APIs, the obtained dissolution profiles are very reproducible and show a low variation compared to the measurements using manual sampling and UV or HPLC analysis. The measurements demonstrate that potentiometric sensors are a very promising technology that can become a standard for in situ dissolution measurements. PMID:18539443

Peeters, Karl; De Maesschalck, Roy; Bohets, Hugo; Vanhoutte, Koen; Nagels, Luc

2008-08-01

10

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

11

21 CFR 343.90 - Dissolution and drug release testing.  

Code of Federal Regulations, 2010 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...

2010-04-01

12

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

13

21 CFR 343.90 - Dissolution and drug release testing.  

...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

14

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

15

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

16

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...

17

Development and validation of a dissolution test for rabeprazole sodium in coated tablets.  

PubMed

The aim of this work is to develop and validate a dissolution test for rabeprazole sodium coated tablets using a reverse-phase liquid chromatographic method. After test sink conditions, dissolution medium and stability of the drug, the best conditions were: paddle at 75 rotations per minute (rpm) stirring speed, HCl 0.1 M and borate buffer pH 9.0 as dissolution medium for acidic and basic steps, respectively, volume of 900 ml for both. The quantitation method was also adapted and validated. Less than 10% of the label amount was released in the acid step, while more than 95% was achieved over 30 min in the basic one. The dissolution profile for tablets was considered satisfactory. The dissolution test developed was adequate for its purpose and could be applied for quality control of rabeprazole tablets, since there is no official monograph. PMID:16513316

Garcia, Cassia V; Paim, Clesio S; Steppe, Martin; Schapoval, Elfrides E S

2006-06-01

18

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

19

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

20

New Dissolution Method for Mesalamine Tablets and Capsules  

Microsoft Academic Search

Dissolution methods are different for extended-release mesalamine capsules (pH 7.5 only) and delayed-release tablets (pH 1.4, 6.0, and 7.2). Mesalamine is used for the treatment of ulcerative colitis. The USP methods have several drawbacks in that they do not mimic gastrointestinal tract environments; tablets are removed from vessels to change dissolution medium; and neither method has been adopted to compare

Monica C. Chuong; J. Mark Christensen; James W. Ayres

21

Comparison of three dissolution apparatuses for testing calcium phosphate pellets used as ibuprofen delivery systems.  

PubMed

Porous calcium phosphate pellets were produced according to two granulation processes (low and high shear wet granulations) and drug loaded with five ibuprofen contents (1.75%, 7%, 12.5%, 22%, and 36%) in order to ensure both bone defect filling and local drug delivery. The drug-release kinetics from the two types of pellets was studied using three dissolution apparatuses: paddle apparatus, reciprocating cylinder, and flow-through cell. The paper compared the three dissolution methods and considered the effect of the granulation process on the ibuprofen-release kinetics. Dissolution data were analyzed using the Weibull function as well as the difference (f1) and similarity (f2) factors. Dissolution kinetics was not influenced by the granulation process, regardless of the dissolution apparatus and of the drug content. The comparison of the three dissolution devices indicated that ibuprofen was released faster from granules loaded with 36% of drug content with the reciprocating apparatus, due to the disintegration of the granules occurring during the dissolution test. For the other drug contents, dissolution profiles were not significantly different from one apparatus to another. However, the flow-through cell seemed to be more suitable for the drug-release study of implantable materials. PMID:19440841

Chevalier, Emilie; Viana, Marylène; Artaud, Aymeric; Chomette, Lisette; Haddouchi, Samir; Devidts, Gille; Chulia, Dominique

2009-01-01

22

Short-end injection technique in capillary electrophoresis for dissolution testing of tablets  

Microsoft Academic Search

A capillary electrophoresis (CE) method using short-end injection technique has been developed for dissolution testing of tablets of calcium acamprosate. After dilution of dissolution bath sample solution (in 0.1M citric acid) in water, the sample (11.5nl) was injected on the detector side in a fused silica capillary 31.2cm long (21cm to the detector)×50?m internal diameter. Acamprosate was separated from sorbate

Marie-Dominique Blanchin; Bassem Baalbaki; Nathalie Bosc; Huguette Fabre

2000-01-01

23

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

PubMed

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

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

2012-11-01

24

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

25

[Dissolution testing combined with computer simulation technology to evaluate the bioequivalence of domestic amoxicillin capsule].  

PubMed

Re-evaluation of bioequivalence of generic drugs is one of the key research focus currently. As a means to ensure consistency of the therapeutic effectiveness of drug products, clinical bioequivalence has been widely accepted as a gold standard test. In vitro dissolution testing based on the theory of the BCS is the best alternative to in vivo bioequivalence study. In this article, the conventional dissolution method and flow-through cell method were used to investigate the dissolution profiles of domestic amoxicillin capsules in different dissolution media, and the absorption behavior of the drugs with different release rates (t85% = 15-180 min) in the gastrointestinal tract was predicted by Gastro Plus. The flow-through cell method was thought better to reflect the release characteristics in vivo, and amoxicillin capsules with regard to the release rates up to 45 min (t85% = 45 min) were having a satisfied bioequivalence with the oral solution according to the C(max) and AUC. Although two different dissolution profiles of domestic amoxicillin capsules were found by flow-through cell methods, prediction results revealed that domestic capsules were probably bioequivalent to each other. PMID:25322558

Pan, Rui-Xue; Gao, Yuan; Chen, Wan-Li; Li, Yu-Lan; Hu, Chang-Qin

2014-08-01

26

Evaluation of floating and sticking extended release delivery systems: an unconventional dissolution test  

Microsoft Academic Search

The extent to which hydrophilic matrix tablets with a propensity to stick to the dissolution apparatus and\\/or float are susceptible to variations in hydrodynamic conditions during dissolution testing was investigated. Furthermore the usefulness of simple alternatives to the current compendial tests is examined. Swellable hydrocolloid (guar) matrix tablets containing verapamil HCl were evaluated using USP dissolution apparatus I and II.

Thomas Dürig; Reza Fassihi

2000-01-01

27

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

28

Characterization Plan and Dissolution Tests for Tank 16H Samples  

SciTech Connect

In support of the closure of Tank 16H, a sample of the solids residue on the bottom of the tank interior and three samples from the tank annulus will be sent to SRTC for analysis. The results of the analysis of the samples from the tank interior and the annulus will define the source term inventory used for fate and transport modeling. In addition, the samples from the tank annulus will be used for dissolution tests to evaluate the effectiveness of various cleaning alternatives.

Davis, P.L.; Hay, M.S.

1998-02-09

29

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

30

Dissolution testing of marketed rifampicin containing fixed dose combination formulations using a new discriminative media: a post marketing retrospective study.  

PubMed

Currently recommended compendial dissolution methods for quality control of orally administered solid dosage forms of rifampicin containing formulations are not found to be able to forecast the in vivo performance. A recently proposed dissolution method of 0.01 N HCl at 50 rpm using paddle apparatus for screening was found to be more appropriate and able to predict the in vivo performance of those formulations. The objective of this investigation was to validate the new method of dissolution testing for solid dosage forms of rifampicin containing formulations using a basket apparatus and to compare it with the frequently recommended pharmacopeial method. In the present study the newly proposed dissolution condition (0.01 N HCl) was validated using six formulations of two, three and four drug combinations from two different manufacturers by basket method and compared with the widely recommended compendial medium. In this investigation, the appropriateness of the proposed methodology was confirmed by the dissolution results of the two FDC formulations (a two-drug and a four-drug combinations) that had previously passed the bioequivalence tests. It was found that the recommended dissolution medium of 0.01 N HCl can be used for screening of rifampicin containing formulations using both paddle and basket dissolution apparatus at 50 rpm and 100 rpm, respectively. PMID:17069424

Panchagnula, R; Kumar Bajpai, A; Agrawal, S; Ashokraj, Y

2006-10-01

31

Development and validation of a discriminative dissolution test for betamethasone sodium phosphate and betamethasone dipropionate intramuscular injectable suspension.  

PubMed

The intramuscular administration of the injectable suspension betamethasone sodium phosphate (BSP) and betamethasone dipropionate (BD) has immediate therapeutic activity due to solubilized BSP and prolonged activity resulting from the slow release of BD micro-crystals. The purpose of this study was to develop and validate a dissolution method for BD in intramuscular injectable suspensions with detection by high-performance liquid chromatography (HPLC) method. Five commercial products presented a distribution of particle sizes, ranging between 7.43 and 40.25 ?m as measured by laser diffraction. It was also found that particle sizes differed between batches of the same product. The different products were tested using the paddle apparatus, with stirring speeds of 25 and 50 rpm in 300 mL of phosphate buffer; simulated body fluid, muscle fluid, and synovial fluid were used as biorelevant dissolution media at 37±0.5°C. It was verified that not only does average particle size affect the dissolution rate, but also the mode and the polydispersity index of the particles. Discriminatory power was obtained using the in vitro dissolution method with 0.1 M sodium phosphate buffer pH 7.4 containing 0.1% sodium lauryl sulfate and a stirring speed of 50 rpm. The HPLC-method is linear, precise, selective, and accurate for the quantification of BSP and BD in dissolution profile testing. This dissolution method can be utilized as a method to control the quality of these injectable suspensions. PMID:23371786

Simon, Alice; de Almeida Borges, Vinícius Raphael; Cabral, Lucio Mendes; de Sousa, Valéria Pereira

2013-03-01

32

A novel method for determining the dissolution kinetics of hydrocolloid powders  

Microsoft Academic Search

Food hydrocolloids are sold as powders so they must be dissolved before use. In modern manufacturing practice, rapid dissolution can be an important specification. However, quantifying dissolution kinetics is a problem, because when lumps form the process becomes irreproducible, partly because lumps tend to stick to the stirrer. This paper presents a simple method for determining the dissolution kinetics of

T. P. Kravtchenko; J. Renoir; A. Parker; G. Brigand

1999-01-01

33

[Study on dissolution test in vitro and bioavailability of oral osmotic pump of verapamil hydrochloride].  

PubMed

This paper deals with the evaluation of osmotic pump of verapamil hydrochloride tablet (C) by measuring in vitro/in vivo test. The results showed that the dissolution behaviors were of zero-order kinetic and release constant in vitro (Kr) of C was 9.9450. The plasma levels of Ver.HCl in eight volunteers following single and multiple oral doses of these dosage forms were determined using HPLC method. The pharmacokinetic parameters were fitted by nonlinear least square method with a computer on the basis of two-compartment model. The pharmacokinetic parameters of Cmax, Tmax, t1/2, Ka, K10 and K21 were calculated. The bioavailability of tablet C relative to B and A was 101.7%, 96.16% respectively. A significant correlation was found between in vitro dissolution and in vivo absorption. PMID:8010021

Guo, J L; Jing, G W; Cao, D S; Li, Y Q; He, H Y; Ling, L X; Li, Z

1993-01-01

34

Measurement of Dissolved Oxygen as a Determination of Media Equilibrium During Dissolution Testing  

Microsoft Academic Search

Scientists have known for years that deaeration of aqueous dissolution media can affect the dissolution rate of solid dosage forms. Several methods have been developed to accomplish deaeration, but the industry stan- dard has been the USP method, using heat, vacuum and filtering. Alternate methods of deaeration may be considered comparable to the USP method by passing the USP Apparatus

Thomas Curley; Richard Forsyth; Susan Sun; Kyle Fliszar; Mitch Colletto; Gregory P. Martin

35

Dating of black gel pen ink using the dissolution-diffusion method.  

PubMed

In many criminal and civil cases in China, the most commonly questioned documents are those written with gel pen ink. An important task for forensic document examiners is to identify whether two or more ink entries in one or more documents were written with the same ink type. The identification of the age of gel ink entries made poses an important and difficult problem for forensic document examiners. In this paper, a dissolution-diffusion method was successfully employed to estimate the relative age of gel ink entries by comparing dissolution-diffusion rates. Using extensive tests, the mixed solution of dimethyl formamide (DMF) and anhydrous ethanol proved to be a suitable solvent and was used to dissolve the dye of gel ink strokes made at different times. As preliminary findings of this study, calibration curves were created to indicate the relationship between the average dissolution-diffusion rate of soluble gel ink components and the age of gel ink entries stored under natural aging conditions. It was also determined that brands of gel inks, types of paper and thickness of gel ink strokes had varying impacts on estimating the dates of gel ink strokes. Experimental results showed that dissolution-diffusion method was applicable for determining the relative age of gel ink entries under certain conditions. PMID:24378312

Li, Biao

2014-01-01

36

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

37

Release of poorly soluble drugs from HPMC tablets studied by FTIR imaging and flow-through dissolution tests.  

PubMed

Spectroscopic imaging and a flow-through dissolution test have been combined to improve the possibilities of investigating the release of a poorly soluble drug (diclofenac) from pharmaceutical tablets. The presented methods aim to overcome the limitations that impede the conventional dissolution test because of its inability to observe precipitates of poorly soluble drug during tablet dissolution. The proposed flow-through set-up allows small drug particles that are being carried along in the water-flow to be analyzed, by adding a dissolution agent to the medium after it left the tablet cell. Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopic imaging provides an insight into the processes inside the tablet and is not hindered by insoluble or recrystallising drug. The techniques have been hyphenated and used to study tablets containing diclofenac sodium and HPMC (hydroxypropyl methylcellulose) in different dissolution media that influence the solubility of the drug. The release profiles obtained by flow-through dissolution test suggest the presence of particles (or precipitates) in the dissolution medium. This is consistent with the results obtained by FTIR imaging, which confirms that both proposed techniques are superior to the ordinary dissolution test when applied to poorly soluble drugs. FTIR imaging data have been analyzed by a classical least squares analysis, corrected for the parts of the tablet outside the field of view, and used to calculate the release profile. The infrared spectra of diclofenac at varying relative humidity were acquired to study the interactions of diclofenac and water, including identification of dissociated diclofenac, thus the chemical specificity of FTIR imaging was fully utilized. PMID:16052556

van der Weerd, Jaap; Kazarian, Sergei G

2005-09-01

38

A new method for alkaline dissolution of uranium metal foil  

Microsoft Academic Search

In order to develop a production process of 99Mo by fission of low-enriched uranium, the first purification step, which consists of dissolution of a uranium metal foil target, was studied. It was found that alkaline NaClO gave good results, reaching the dissolution of up to 300 m of uranium foil. The different conditions for the dissolution were studied and the

A. V. Mondino; M. V. Wilkinson; A. C. Manzini

2001-01-01

39

Solution calorimetry as an alternative approach for dissolution testing of nanosuspensions.  

PubMed

The formulation of poorly soluble drugs as nanocrystals/nanosuspensions has rapidly evolved during the past decade into a mature drug-delivery strategy. The major characteristic of these systems is the high drug dissolution rate, enabling bioavailability enhancement after oral administration. It is therefore of great importance to have access to analytical methodology that is able to accurately monitor the extreme fast dissolution process of such formulations. The aim of the present study was to evaluate solution calorimetry as a novel approach to measure the dissolution rate of nanosuspensions by recording the temperature change in the dissolution vessel during the dissolution process of the nanocrystals. The applicability was tested on different nanosuspensions made up of three model drugs: naproxen, cinnarizine and an investigational API, i.e. compound A. The dissolution process of all nanosuspensions investigated was completed within less than 1 min. During this period, sufficient data points were collected to transform temperature offset data to cumulative heat of solution pointing to the potential of this technique. However, of significant concern is the fact that this technique measures the total heat produced or consumed by all processes that occur during the dissolution, e.g. the heat of mixing when the nanosuspension comes in contact with the dissolution medium. Erroneous conclusions will result if phenomena other than dissolution are not accounted for. PMID:20887787

Kayaert, P; Li, B; Jimidar, I; Rombaut, P; Ahssini, F; Van den Mooter, G

2010-11-01

40

The development of a modified dissolution method suitable for investigating powder mixtures.  

PubMed

A novel dissolution method was developed, suitable for powder mixtures, based on the USP basket apparatus. The baskets were modified such that the powder mixtures were retained within the baskets and not dispersed, a potential difficulty that may arise when using conventional USP basket and paddle apparatus. The advantages of this method were that the components of the mixtures were maintained in close proximity, maximizing any drug: excipient interaction and leading to more linear dissolution profiles. Two weakly acidic model drugs, ibuprofen and acetaminophen, and a selection of pharmaceutical excipients, including potential dissolution-enhancing alkalizing agents, were chosen for investigation. Dissolution profiles were obtained for simple physical mixtures. The f1 fit factor values, calculated using pure drug as the reference material, demonstrated a trend in line with expectations, with several dissolution enhancers apparent for both drugs. Also, the dissolution rates were linear over substantial parts of the profiles. For both drugs, a rank order comparison between the f1 fit factor and calculated dissolution rate, obtained from the linear section of the dissolution profile, demonstrated a correlation using a significance level of P = 0.05. The method was proven to be suitable for discriminating between the effects of excipients on the dissolution of the model drugs. The method design produced dissolution profiles where the dissolution rate was linear for a substantial time, allowing determination of the dissolution rate without mathematical transformation of the data. This method may be suitable as a preliminary excipient-screening tool in the drug formulation development process. PMID:12455473

Shaw, L R; Irwin, W J; Grattan, T J; Conway, B R

2002-10-01

41

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

42

Evaluation of USP apparatus 3 for dissolution testing of immediate-release products  

Microsoft Academic Search

We sought to evaluate whether U.S. Pharmacopeia (USP) apparatus 3 can be used as an alternative to USP apparatus 2 for dissolution\\u000a testing of immediate-release (IR) dosage forms. Highly soluble drugs, metoprolol and ranitidine, and poorly soluble drugs,\\u000a acyclovir and furosemide, were chosen as model drugs. The dissolution profiles of both innovator and generic IR products were\\u000a determined using USP

Lawrence X. Yu; Jin T. Wang; Ajaz S. Hussain

2002-01-01

43

Development and validation of a discriminative dissolution method for atorvastatin calcium tablets using in vivo data by LC and UV methods.  

PubMed

A dissolution method to analyze atorvastatin tablets using in vivo data for RP and test pilot (PB) was developed and validated. The appropriate conditions were determined after solubility tests using different media, and sink conditions were established. The conditions used were equipment paddle at 50 rpm and 900 mL of potassium phosphate buffer pH 6.0 as dissolution medium. In vivo release profiles were obtained from the bioequivalence study of RP and the generic candidate PB. The fraction of dose absorbed was calculated using the Loo-Riegelman method. It was necessary to use a scale factor of time similar to 6.0, to associate the values of absorbed fraction and dissolved fraction, obtaining an in vivo-in vitro correlation level A. The dissolution method to quantify the amount of drug dissolved was validated using high-performance liquid chromatography and ultraviolet spectrophotometry, and validated according to the USP protocol. The discriminative power of dissolution conditions was assessed using two different pilot batches of atorvastatin tablets (PA and PB) and RP. The dissolution test was validated and may be used as a discriminating method in quality control and in the development of the new formulations. PMID:24265014

Machado, J C; Lange, A D; Todeschini, V; Volpato, N M

2014-02-01

44

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. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24619600

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

2014-11-01

45

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

46

Facts, fallacies and future of dissolution testing of polysaccharide based colon-specific drug delivery.  

PubMed

Colonic diseases like ulcerative colitis, Crohn's disease, and colon cancer are on rise due to variations in the dietary and lifestyle habits. Increase in prevalence of such diseases has augmented the interest of researchers in colon targeted drug delivery systems. Polysaccharide coating has emerged as one of the most successful approaches in this direction. Evaluation of such systems, however, demands an efficient dissolution method in terms of convenience, economy, relevance and reproducibility. It is problematic to mimic the dynamic and ecologically diverse features of the colon. A number of dissolution approaches were tried which include incorporation of polysaccharide-degrading enzymes, rat caecal contents, human faecal slurries, and multi-stage culture systems. Till date, pursuit for cost-effective and animal-sparing colon-specific bio-relevant dissolution media has been a foremost challenge facing pharmaceutical scientists over many decades. This article reviews various dissolution methods adopted to mimic the in vivo performance of dosage forms that are used for colon targeting. It also highlights limitations of the available methods and conditions that should be taken into account while designing a bio-relevant dissolution method for such systems. PMID:24440665

Kotla, Niranjan Goud; Gulati, Monica; Singh, Sachin Kumar; Shivapooja, Ashwini

2014-03-28

47

Dissolution enhancement of gliclazide using in situ micronization by solvent change method  

Microsoft Academic Search

Gliclazide (GL) is a second-generation sulphonylurea, widely used for the treatment of non-insulin dependent diabetes mellitus. The low water-solubility of GL leads to a low dissolution rate and variable bioavailability. The aim of this study was to enhance the dissolution rate of GL by the preparation of micron-sized particles using a solvent change method. The in situ micronization process was

J. Varshosaz; R. Talari; S. A. Mostafavi; A. Nokhodchi

2008-01-01

48

Optimization and validation of a dissolution test for selegiline hydrochloride tablets by a novel rapid HPLC assay using a monolithic stationary phase.  

PubMed

The present study reports the optimization and validation of a dissolution test for selegiline.HCl tablets using a new high-performance liquid chromatographic (HPLC) method. Rapid separation of the analyte from sample matrix was achieved in less than 60s using a Cromolith RP-18e monolithic column using UV detection at 220 nm. Thorough validation of the assay based on pre-defined criteria included linearity, LOD/LOQ, accuracy, precision, selectivity and ruggedness. The dissolution test was optimized in terms of dissolution medium, basket (type I)/paddle (type II) agitation and rotation speed. Its ruggedness was also validated. The presented analytical and dissolution procedures are currently being applied in the quality and stability control of Cosmopril tablets (5mg/tablet selegiline.HCl, Cosmopharm Ltd., Korinthos, Greece). PMID:18178360

Tzanavaras, Paraskevas D; Themelis, Demetrius G; Zotou, Anastasia; Stratis, John; Karlberg, Bo

2008-03-13

49

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

50

Dissolution profile of 24 levofloxacin (100 mg) tablets.  

PubMed

Although there are 23 generic levofloxacin (100 mg) tablets (LVFX tablets) and 1 brand name LVFX tablet (supply now discontinued) in Japan, there have been no reports that have evaluated and compared the dissolution profiles of LVFX tablets using the same dissolution method. We studied the dissolution profile of LVFX tablets by the Paddle method, a standard dissolution test method. Among 23 generic LVFX tablets, 2 LVFX tablets had lower dissolution rates and 14 had higher dissolution rates than the brand name LVFX tablet. It is suggested that LVFX tablets have different dissolution profiles, which could cause different pharmacokinetic profiles. PMID:23380968

Maezawa, Kayoko; Yajima, Ryo; Terajima, Tomoko; Kizu, Junko; Hori, Seiji

2013-10-01

51

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

52

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

53

Dissolution of HTGR TRISO beads by the alkali fluoride fusion method  

Microsoft Academic Search

The alkali fluoride fusion method for the dissolution of HTGR TRISO fuel beads offers significant time advantage over other commonly used fusion procedures when applied to samples weighing less than three grams. The method is straightforward, utilizes standard analytical laboratory equipment, and yields solutions which may be utilized by customary procedures.

Byster

1980-01-01

54

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.

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

2014-01-01

55

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

56

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

57

IntersectionUnion Tests in Dissolution Profile Testing Jorge H. SierraCavazos  

E-print Network

the proportion of drug dissolved from dosage unit i for the reference drug and for dosage unit j for the test and the IUT given. A method of sample size calculation for the IUT is presented. Keywords: Intersection

58

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

59

Results from Cycles 1 and 2 of NNWSI Series 2 spent fuel dissolution tests  

SciTech Connect

PWR spent fuel rod segments from the H.B. Robinson Unit 2 and Turkey Point Unit 3 reactors were leach tested in Nevada Nuclear Waste Storage Investigations (NNWSI) reference J-13 water under ambient hot cell conditions. The test matrix included bare fuel plus the cladding, rod segments with artificially induced cladding defects, and undefected rod segments. Radionuclide release results are presented and discussed. The actinides Pu, Am, Cm and Np appear to have been released congruently as the UO{sub 2} oxide fuel matrix dissolved. Preferential U release measured in certain tests may be related to dissolution of oxidized UO/sub 2+x/ from the fuel surface, and/or greater solubility (and mobility) of U relative to the other actinides within defected cladding specimens. Uranium solubility measured in the J-13 water was much greater then that measured in deionized water in previous tests. All of the principal fission products analyzed ({sup 137}Cs, {sup 129}I, {sup 99}Tc and {sup 90}Sr) were released preferentially relative to the actinides. Preferential release of activation product {sup 14}C was also measured, with a portion of the {sup 14}C release appearing to originate from the cladding exterior surface. Much greater fractional fuel dissolution appeared to have occurred with bare fuel particles than from fuel contained in defected cladding. Actinide release from test specimens containing small ({similar_to}200 {mu}m) laser-drilled holes through the cladding was not significantly greater than from undefected specimens.

Wilson, C.N.

1987-05-01

60

Asymmetric flow field-flow fractionation (AF4) for the quantification of nanoparticle release from tablets during dissolution testing.  

PubMed

Nanoparticles composed of poly(DL-lactide-co-glycolide) (PLGA) represent promising colloidal drug carriers for improved drug targeting. Although most research activities are focused on intravenous application of these carriers the peroral administration is described to improve bioavailability of poorly soluble drugs. Based on these insights the manuscript describes a model tablet formulation for PLGA-nanoparticles and especially its analytical characterisation with regard to a nanosized drug carrier. Besides physico-chemical tablet characterisation according to pharmacopoeias the main goal of the study was the development of a suitable analytical method for the quantification of nanoparticle release from tablets. An analytical flow field-flow fractionation (AF4) method was established and validated which enables determination of nanoparticle content in solid dosage forms as well as quantification of particle release during dissolution testing. For particle detection a multi-angle light scattering (MALS) detector was coupled to the AF4-system. After dissolution testing, the presence of unaltered PLGA-nanoparticles was successfully proved by dynamic light scattering and scanning electron microscopy. PMID:24296046

Engel, A; Plöger, M; Mulac, D; Langer, K

2014-01-30

61

Effect of hydrodynamic environment on tablet dissolution using flow-through dissolution apparatus.  

PubMed

The main objective of this research is to investigate the principles underlying the dissolution process, study the phenomena of drug release in laminar flow, and better understand the effect of hydrodynamic condition on drug dissolution, in order to predict drug dissolution from a solid dosage form. Two drug models were selected, theophylline (Class I) and naproxen (Class II), and were formulated into conventional tablets containing 105 mg theophylline or 300 mg naproxen using wet granulation method. Additionally theophylline (105 mg) and naproxen (300 mg) matrices containing 30% hydroxypropylmethylcellulose (HPMC) polymer were prepared by direct compression and tested for dissolution using both USP II and IV dissolution apparatus. Tablets were tested for dissolution (USP IV) using different cell diameter, flow rate, and different position of the tablet inside the cell. In general, the drug dissolution at a given time is a direct function of the flow rate, increasing the flow rate increases drug release. The use of a small cell resulted in faster drug dissolution and higher Reynold's Number than using a large cell. Tablet position in the cell, also has an effect on drug dissolution, inserting the tablet in a horizontal position inside the cell gave faster dissolution than a vertical position. The hydrodynamic conditions did not affect the drug dissolution from HPMC controlled release tablets indicating that the drug dissolution is controlled by the matrix. An equation to predict drug dissolution from conventional tablets was established: Sh=-21.36+10.58Re(1/2) where R2=0.98. This study demonstrated that hydrodynamic conditions, and type of dissolution testing apparatus used have an effect on dissolution rate, mass transfer rate, and film thickness underlying dissolution process. PMID:16883682

Wu, Yan; Ghaly, Evone S

2006-03-01

62

Development and validation of dissolution test for lopinavir, a poorly water-soluble drug, in soft gel capsules, based on in vivo data.  

PubMed

The objective of the present study was to develop and validate a dissolution test for lopinavir soft gel capsules (Kaletra), using a simulated absorption profile based on in vivo data. Different conditions such as surfactant concentration, apparatus and rotation speed were evaluated. In vivo release profiles were obtained from the literature. The fraction (and percentage) of dose absorbed (FA) was calculated by using Wagner-Nelson method. The best in vitro dissolution profile was obtained using Apparatus 2 (paddle) at 25 rpm, 1000 ml of medium with 2.3% of sodium lauryl sulfate and pH 6.0. Under these conditions a level-A in vitro-in vivo correlation (IVIVC) was obtained (r = 0.997). The in vitro dissolution samples were analyzed using a HPLC method and the validation was performed according to USP protocol. The method showed accuracy, precision, linearity and specificity within the acceptable range. Both the HPLC method and the in vitro dissolution method were validated and could be used to evaluate the release profile of lopinavir soft gel capsules. PMID:18403160

Donato, Eliane Maria; Martins, Laura Alegria; Fröehlich, Pedro Eduardo; Bergold, Ana Maria

2008-07-15

63

Corrosion tests to determine temperature and pH dependencies of the dissolution rates of sodalite, binder glass, and ceramic waste form.  

SciTech Connect

A glass bonded-sodalite ceramic waste form (CWF) has been developed to immobilize salt wastes from electrometallurgical treatment of sodium-bonded spent nuclear fuel. The CWF is a composite of salt-loaded sodalite and a binder glass formed at high temperature (850-950 C) by hot isostatic pressing (HIP) or pressureless-consolidation (PC) processes. A waste form degradation and radionuclide release model has been developed to support qualification of the CWF for disposal in the proposed repository at Yucca Mountain. Six series of tests were conducted in conjunction with the development of that model. (1) Static tests were conducted to measure the dissolution rate of sodalite, HIP binder glass, and HIP CWF at 40, 70, and 90 C in pH range 4.8-9.8 buffer solution. The parameter values in the degradation model were calculated from the dissolution rates measured by the static tests. (2) Static tests were conducted at 70 C in noncomplexing tertiary amine pH buffers to confirm that the dissolution rate measured with traditional buffers was not affected by the complexation of metal ions. The results showed that the difference between dissolution rate determined with noncomplexing buffer and that determined with traditional buffers was negligible. (3) Static tests were conducted in five buffer solutions in the pH range 4.8-9.8 at 20 C with HIP sodalite, HIP glass, and HIP CWF. The results showed that the model adequately predicts the dissolution rate of these materials at 20 C. (4) Static tests at 20 and 70 C with CWF made by the PC process indicated that the model parameters extracted from the results of tests with HIP CWF could be applied to PC CWF. (5) The dissolution rates of a modified glass made with a composition corresponding to 80 wt% glass and 20 wt% sodalite were measured at 70 C to evaluate the sensitivity of the rate to the composition of binder glass in the CWF. The dissolution rates of the modified binder glass were indistinguishable from the rates of the binder glass. (6) The dissolution rate of a simple five-component glass (CSG) was measured at 70 C using static tests and single-pass flow-through (SPFT) tests. Rates were similar for the two methods; however, the measured rates are about 10X higher than the rates measured previously at Lawrence Livermore National Laboratory (LLNL) for a glass having the same composition using an SPFT test method. Differences are attributed to effects of the solution flow rate on the glass dissolution rate and how the specific surface area of crushed glass is estimated. This comparison indicates the need to standardize the SPFT test procedure.

Jeong, S.-Y.; Fanning, T. H.; Morss, L. R.; Ebert, W. L.

2003-02-12

64

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

SciTech Connect

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

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

1990-08-01

65

Comparison of methods for predicting dissolution and the theoretical implications of particle-size-dependent solubility.  

PubMed

Experimental dissolution data of cilostazol suspensions and hydrocortisone powders were simulated using either the Wang-Flanagan equation (1999. J Pharm Sci 88:731-738; 2002. J Pharm Sci 91:534-542) or the method of Johnson and coworkers (1989. Int J Pharm 51:9-17; 1993. Pharm Res 10:1308-1314; 1996. Pharm Res 13:1795-1798; 2003. Drug Dev Ind Pharm 29:833-842). Both methods were able to simulate experimental data with similar accuracy. For the method of Johnson and coworkers (1989. Int J Pharm 51:9-17; 1993. Pharm Res 10:1308-1314; 1996. Pharm Res 13:1795-1798; 2003. Drug Dev Ind Pharm 29:833-842), a single set of hydrodynamic assumptions was able to simulate both cilostazol and hydrocortisone with similar accuracy. For the Wang-Flanagan equation (1999. J Pharm Sci 88:731-738; 2002. J Pharm Sci 91:534-542), significantly different diffusion layer thicknesses gave the best simulations for cilostazol and hydrocortisone, but a single value of 38 µm provided good overall simulation of dissolution. The general computational method was enhanced to make solubility dependent on particle size, according to the Ostwald-Freundlich equation; it was also able to simulate Ostwald ripening. The enhanced computational method provided no way to explain the large increase in bioavailability of cilostazol in dogs when the drug was dosed as a nanoparticle versus micronized preparation. The method provides a computational tool for exploring theoretical implications and explaining the behavior of nanoparticles. PMID:21989679

Johnson, Kevin C

2012-02-01

66

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

67

Ignitability test method. II  

NASA Technical Reports Server (NTRS)

To determine functional performance of initiating devices, the NASA's Langley Research Center's novel ignitability research on percussion primers has been expanded in 1989 to include measurements of function time, the evaluation of six primer lots (five types), and the determination of the effects of the military cold-temperature requirement of -65 F and primer output closure disks. This test method, a major improvement over the prior primer output test methods, fully met all objectives, while showing a significant amount of ignition variability.

Bement, Laurence J.; Schimmel, Morry L.

1990-01-01

68

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

69

Irregular absorption profiles observed from diclofenac extended release tablets can be predicted using a dissolution test apparatus that mimics in vivo physical stresses  

Microsoft Academic Search

The prediction of the in vivo drug release characteristics of modified release oral dosage forms by in vitro dissolution tests is a prerequisite for successful product development. A novel dissolution test apparatus that mimics the physical conditions experienced by an oral formulation during gastrointestinal transit was developed. This included the simulation of pressure forces exerted by gut wall motility, shear

Grzegorz Garbacz; Ralph-Steven Wedemeyer; Stefan Nagel; Thomas Giessmann; Hubert Mönnikes; Clive G. Wilson; Werner Siegmund; Werner Weitschies

2008-01-01

70

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

71

Simultaneous monitoring of aspirin, phenacetin and caffeine in compound aspirin tablets using a sequential injection drug-dissolution testing system with partial least squares calibration  

Microsoft Academic Search

An automatic system for drug-dissolution studies based on the sequential-injection (SI) technique is described and used for simultaneous monitoring of dissolution profiles of aspirin, phenacetin and caffeine in compound aspirin tablets. The partial least squares calibration technique was used for simultaneous determination of the three components. 300?l test solution in dissolution vessel was aspirated into a PTFE holding coil via

Xue-Zhu Liu; Shu-Sheng Liu; Jin-Feng Wu; Zhao-Lun Fang

1999-01-01

72

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

73

Salt dissolution in oil and gas test holes in central Kansas. Part III. Salt dissolution oil and gas test holes in the Chase-Silica Oilfield, Barton and Rice Counties, central Kansas  

Microsoft Academic Search

In the 135.3 square mile area of the Chase-Silica Oilfield, Barton and Rice Counties, Kansas, all of the 4,845 oil and gas test holes drilled completely through the Hutchinson Salt Member of the Permian Wellington Formation encountered at depths near 900 feet on the east to near 1000 feet on the west. No salt dissolution takes place after drilling ceases

1975-01-01

74

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

75

Dissolution of cellulose in ionic liquids as a way to obtain test materials for metal-ion detection  

Microsoft Academic Search

Cellulose films containing entrapped analytical reagents suitable for metal-ion detection are produced by joint dissolution\\u000a of cellulose and the reagents in ionic liquids then precipitation with water. The conditions of preparation of these test\\u000a materials have been optimized and their properties have been studied. The film obtained by use of the ionic liquid 1-butyl-3-methylimidazolium\\u000a chloride and 1-(2-pyridylazo)-2-naphthol has been used

Vladimir M. Egorov; Svetlana V. Smirnova; Andrey A. Formanovsky; Igor V. Pletnev; Yury A. Zolotov

2007-01-01

76

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

PubMed

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

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

2014-05-01

77

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

78

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

PubMed Central

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

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

2012-01-01

79

Digoxin degradation in acidic dissolution medium.  

PubMed

The release of digoxin and its simultaneous conversion to digoxigenin bisdigitoxoside, digoxigenin monodigitoxoside, and digoxigenin in a USP dissolution test medium were followed by high-pressure liquid chromatography. Two products, Tablets A and B, were manufactured by solvent deposition and simple blending methods, respectively. Tablet A released digoxin faster than Tablet B in distilled water and in artificial intestinal juice, and no decomposition was observed. In the USP dissolution test medium, the rate of hydrolysis to digoxigenin bisdigitoxoside was almost equal to that of hydrolysis to digoxigenin monodigitoxoside, and a comparatively large formation rate of digoxigenin was observed. Concentrations of digoxin and its decomposition products were described by differential equations that included dissolution rates of digoxin (rapidly dissolving digoxin and digoxin crystals) and an apparent hydrolysis rate. In the earlier stage of dissolution, hydrolysis was rate determining; in the later stage, dissolution became the rate-determining step for overall digoxin degradation. To suppress digoxin hydrolysis in the USP dissolution test medium, a developmental formulation study was performed. The incorporation of magnesium oxide and magnesium hydroxide-aluminum hydroxide in the tablet formulations inhibited digoxin hydrolysis by 15.3 and 14.5%, respectively, after dissolution for 30 min without serious delay of drug release. PMID:7373535

Sonobe, T; Hasumi, S; Yoshino, T; Kobayashi, Y; Kawata, H; Nagai, T

1980-04-01

80

Validation and application of a new reversed phase HPLC method for in vitro dissolution studies of rabeprazole sodium in delayed-release tablets.  

PubMed

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

Nawaz, Md Saddam

2013-01-01

81

Comparative in vitro dissolution study of carbamazepine immediate-release products using the USP paddles method and the flow-through cell system  

PubMed Central

Dissolution profiles of four carbamazepine immediate-release generic products (200 mg tablets) and the reference product Tegretol® were evaluated using the USP paddles method and an alternative method with the flow-through cell system, USP Apparatus 4. Under official conditions all products met the Q specification, dissolution profiles of generic products were similar to the dissolution profile of the reference product (f2 > 50) and model-independent parameters showed non significant differences to the reference product except mean dissolution time for product A (p < 0.05). On the other hand, when the flow-through cell system was used, none of the products met the pharmacopeial specification at 15 min and product A did not reach dissolution criteria at 60 min, dissolution profiles of all generic products were not similar to the reference product profile (f2 < 50) and all model-independent parameters showed significant differences compared to the reference product (p < 0.05). Weibull’s model was more useful for adjusting the dissolution data of all products in both USP apparatuses and Td values showed significant differences compared to the reference product (p < 0.05) when USP Apparatus 4 was used. These results indicate that the proposed method, using the flow-through cell system, is more discriminative in evaluating both, rate and extent of carbamazepine dissolution process from immediate-release generic products. PMID:24648826

Medina, Jose Raul; Salazar, Dulce Karina; Hurtado, Marcela; Cortes, Alma Rosa; Dominguez-Ramirez, Adriana Miriam

2013-01-01

82

Dissolution of cellulose in ionic liquids as a way to obtain test materials for metal-ion detection.  

PubMed

Cellulose films containing entrapped analytical reagents suitable for metal-ion detection are produced by joint dissolution of cellulose and the reagents in ionic liquids then precipitation with water. The conditions of preparation of these test materials have been optimized and their properties have been studied. The film obtained by use of the ionic liquid 1-butyl-3-methylimidazolium chloride and 1-(2-pyridylazo)-2-naphthol has been used for colorimetric determination of divalent zinc, manganese, and nickel with detection limits at the 10(-6) mol L-1 level. PMID:17242885

Egorov, Vladimir M; Smirnova, Svetlana V; Formanovsky, Andrey A; Pletnev, Igor V; Zolotov, Yury A

2007-03-01

83

Standard environmental test methods  

Microsoft Academic Search

This guide to uniformity in testing is intended primarily as an aid to persons responsible for designing, developing, and performing environmental tests. It will also be of use to those concerned with production, evaluation, and quality control and assurance. Checklists for preparing the environmental testing portion of product specifications are included, as are copies of Process Standards covering the instrumentation,

1983-01-01

84

Fabrication of quercetin nanoparticles by anti-solvent precipitation method for enhanced dissolution  

Microsoft Academic Search

The aim of this study was to enhance the dissolution rate of a poorly water-soluble drug quercetin by fabricating its nanoparticles with anti-solvent precipitation using the syringe pump and to investigate the effect of drug concentration, solvent to anti-solvent (S\\/AS) ratio, stirring speed and flow rate on the particle size. Characterization of the original quercetin powder and nanoparticles made by

Mitali Kakran; Nanda Gopal Sahoo; Lin Li; Zaher Judeh

85

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

86

Development and validation of a method for simultaneous estimation of ofloxacin and ornidazole in different dissolution media  

PubMed Central

Introduction: Ofloxacin and ornidazole in a combined tablet dosage form is available in the market. This combination has gained increasing acceptance in diarrhea caused due to bacterial and protozoal infections. Ofloxacin and ornidazole are also combined in the capsule dosage form to modify its release pattern in different studies. Spectrophotometric and HPTLC methods have been reported for their simultaneous estimation in the tablet dosage form in specific solvents. This paper presents a simple, accurate, and reproducible spectrophotometric method for simultaneous estimation of ofloxacin and ornidazole in the tablet dosage form in different dissolution media. The reported method is helpful in determination of ofloxacin and ornidazole during a dissolution study. Materials and Methods: A simple, sensitive, accurate, and economical spectrophotometric method based on the simultaneous equation was developed for the estimation of ornidazole and ofloxacin simultaneously in the tablet or capsule dosage form in different dissolution media at different pH values. Results: Ofloxacin showed absorption maxima at 294 nm in 0.1 N HCl and at 287 nm in phosphate buffer pH 6.8 and phosphate buffer pH 7.4 while ornidazole showed absorption maxima at 277 nm in 0.1 N HCl and at 319 nm in two buffers, respectively. The linearity was obtained in the concentration range of 1–8 ?g/ ml for ofloxacin and 4–26 ?g/ml for ornidazole. Discussion: The concentrations of the drugs were determined by the simultaneous equation method. The results of analysis have been validated statistically and by recovery studies. PMID:23781488

Patel, Dasharath M.; Soneji, Jignesh A.; Patel, Parth B.; Patel, Chhagan N.

2012-01-01

87

Column leach study III: Effects of sampling location, sampling methods, and chemical abatement treatments on the dissolution of metals in gold-copper mine tailings  

Microsoft Academic Search

Metal dissolution from tailings collected at a gold-copper mine mill site was examined by researchers from the U.S. Bureau\\u000a of Mines using column leaching procedures and on-site field monitoring wells. The 3-year laboratory study reviewed effects\\u000a of column waste depths, dry cycles, waste sampling locations, and metal dissolution abatement techniques. Results of the laboratory\\u000a testing indicated that the concentrations of

Richard D. Doepker

1994-01-01

88

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

89

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

90

HPLC method with UV detection for evaluation of digoxin tablet dissolution in acidic medium after solid-phase extraction.  

PubMed

A simple and reliable method for the evaluation of dissolution of digoxin tablets in 0.01 M hydrochloric acid was developed. Digoxin and its degradation products after solid-phase extraction using C18 Sep-Pak cartridges were evaluated. Analyses were performed on C18 column (LiChrospher RP-18e, 5 microm, 125 x 4.0 mm), as mobile phase water and acetonitrile (72:28, v/v) were used. Detection wavelength was 218 nm. Identity of digoxin degradation products was confirmed by HPLC-MS. PMID:12946537

Jedlicka, A; Grafnetterová, T; Miller, V

2003-09-15

91

Regulatory status on the role of in vitro dissolution testing in quality control and biopharmaceutics in Europe.  

PubMed

An overview is provided regarding the different use of in vitro dissolution and particular related regulatory aspects. The overview attempts to clarify the regulatory requirements in all contexts in which in vitro dissolution data are employed. The different areas comprise the development of new and generic products as well as bioequivalence between different formulations. In vitro dissolution is no longer one issue among others in terms of specifications and batch release only, but is aimed to be a relevant tool for describing biopharmaceutic product characteristics for different purposes in the regulatory environment. Accordingly, the extent of the experiments will depend on the purpose of the in vitro dissolution data. PMID:23585295

Limberg, Jobst; Potthast, Henrike

2013-07-01

92

Enhanced dissolution rate of felodipine using spherical agglomeration with Inutec SP1 by quasi emulsion solvent diffusion method.  

PubMed

Felodipine is a second generation calcium channel blocker widely used as antihypertensive and antianginal drug which belongs to BCS class II category. Hence, its low water solubility limits the pharmacological effect. The aim of this study was to improve the dissolution rate of felodipine using spherical agglomeration technique with acetone, water and dichloromethane as good solvent, poor solvent and bridging liquid, respectively. The quasi emulsion solvent diffusion technique was used as a method for spherical agglomeration. Inutec SP1 was used as an emulsion stabilizer and as hydrophilic polymer in agglomeration process. The FTIR and DSC results showed no change in the drug after crystallization process. PXRD studies showed sharp peaks in the diffractograms of spherical agglomerates with minor reduction in height of the peaks. The particle size of spherical agglomerates (FI-2) was about 134.33 ± 13.57 µm, n=3 and the dissolution efficiency of felodipine up to 120 min increased to about 4-fold in phosphate buffer containing 1.8% Tween 80 (pH 6.8). Spherical agglomerates showed enhanced solubility compared to untreated powder possibly due to the partial conversion to amorphous form. PMID:21589802

Tapas, A R; Kawtikwar, P S; Sakarkar, D M

2009-07-01

93

Testing methods for large aircraft  

Microsoft Academic Search

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

D. L. Moseley

1961-01-01

94

Development and validation of a dissolution test for a once-a-day combination tablet of immediate-release cetirizine dihydrochloride and extended-release pseudoephedrine hydrochloride  

Microsoft Academic Search

A dissolution test for a once daily combination tablet containing 10mg of cetirizine dihydrochloride (cetirizine HCl) for immediate release and 240mg of pseudoephedrine hydrochloride (pseudoephedrine HCl) for extended release was developed and validated according to current ICH and FDA guidelines. The cetirizine HCl is contained within an outer layer of the tablet while a semipermeable membrane of cellulose acetate and

Michael D. Likar; Hany L. Mansour; Jeffrey W. Harwood

2005-01-01

95

Development and validation of dissolution test for lopinavir, a poorly water-soluble drug, in soft gel capsules, based on in vivo data  

Microsoft Academic Search

The objective of the present study was to develop and validate a dissolution test for lopinavir soft gel capsules (Kaletra®), using a simulated absorption profile based on in vivo data. Different conditions such as surfactant concentration, apparatus and rotation speed were evaluated. In vivo release profiles were obtained from the literature. The fraction (and percentage) of dose absorbed (FA) was

Eliane Maria Donato; Laura Alegria Martins; Pedro Eduardo Fröehlich; Ana Maria Bergold

2008-01-01

96

Standard Test Method for Sandwich Corrosion Test  

E-print Network

1.1 This test method defines the procedure for evaluating the corrosivity of aircraft maintenance chemicals, when present between faying surfaces (sandwich) of aluminum alloys commonly used for aircraft structures. This test method is intended to be used in the qualification and approval of compounds employed in aircraft maintenance operations. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information. 1.3 This standard may involve hazardous materials, operations, and equipment. 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. Specific hazard statements appear in Section 9.

American Society for Testing and Materials. Philadelphia

2009-01-01

97

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

98

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

99

Evaluation of in vitro dissolution profile comparison methods of sustained release tramadol hydrochloride liquisolid compact formulations with marketed sustained release tablets.  

PubMed

The aim of the present work was to prepare and evaluate sustained release liquisolid compact formulations of tramadol hydrochloride. The dissolution profile of the prepared compacts was also compared to that of a marketed preparation. Liquisolid sustained release formulations were prepared by using HPMC K4M as a sustained release agent. Precompression studies of characteristics such as flow properties were also carried out. Liquisolid compacts were evaluated by hardness, friability, and in vitro dissolution studies. Comparison of dissolution profiles was carried out by using a modelindependent, model-dependent, and statistical approach. The prepared liquisolid compacts are new dosage forms with better sustained release behavior compared to a marketed sustained formulation. The dissolution profile followed the Peppas model as "best fit" model. Two-way ANOVA results revealed a significant difference in dissolution profiles. This systematic approach to producing a formulation was found to help with analyzing the sustained release of tramadol hydrochloride. The use and evaluation of model-dependent methods is more complicated. These methods provide an acceptable model approach that indicates the true relationship between percent drug release and time variables, including statistical assumptions. PMID:22491149

Karmarkar, A B; Gonjari, I D; Hosmani, A H; Dhabale, P N

2010-02-01

100

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

101

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

102

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

103

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

Microsoft Academic Search

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,

Paula J. Woolgar; Kevin C. Jones

1999-01-01

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. 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

105

Test methods for optical fiber  

NASA Astrophysics Data System (ADS)

This paper proposes a simplified method for measuring the transmission and attenuation of optical fiber used for illumination. Use of an integrating sphere, in combination with the traditional fiber optic cut-back measurement approach, is described. Use of color filters to measure specific sets of wavelengths is also proposed. A `blue filter' method of measuring yellow color shift is described. Tests run using a lumen meter and a blue filter are summarized.

Poppendieck, Mary

1998-10-01

106

A Simplified Method for Measuring the Entropy Change of Urea Dissolution. An Experiment for the Introductory Chemistry Lab  

NASA Astrophysics Data System (ADS)

The enthalpy change, equilibrium constant, Gibbs free energy change, and entropy change of the dissolution of urea in water were determined in a guided-inquiry lab experiment. Introductory-level students were able to obtain quite satisfactory thermodynamic values for the dissolution of urea using minimal equipment and a very simple procedure. The enthalpy change of dissolution was determined with a simple coffee-cup calorimeter. Students then directly determined the concentration of a saturated solution of urea simply by measuring the amount of urea used and the total volume of the solution as prepared in a graduated cylinder. The equilibrium expression for the dissolution of urea can be simplified to K = [urea]. With the enthalpy change and the equilibrium constant determined experimentally, the free energy change and enthalpy change for the process are readily calculated.

Liberko, Charles A.; Terry, Stephanie

2001-08-01

107

Salt dissolution in oil and gas test holes in central Kansas. Part I. Salt beds in the subsurface in Russell, Lincoln, Ellsworth, Barton, and Rice Counties, central Kansas  

Microsoft Academic Search

The Hutchinson Salt Member of the Permian Wellington Formation is described in a five-county study area of 4,000 square miles. Most of the 22,200 oil and gas test holes in the study area were drilled with fresh water, causing dissolution of the salt during drilling, commonly resulting in borehole enlargement to three times the diameter of the drill bit (some

1975-01-01

108

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

109

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

110

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

111

Use of the co-grinding method to enhance the dissolution behavior of a poorly water-soluble drug: generation of solvent-free drug-polymer solid dispersions.  

PubMed

The solid dispersion (SD) technique is the most effective method for improving the dissolution rate of poorly water-soluble drugs. In the present work, SDs of the Ca2+ channel blocker dipfluzine (DF) with polyvinylpyrrolidone K30 (PVP) and poloxamer 188 (PLXM) were prepared by the powder solid co-grinding method under a solvent-free condition. The properties of all SDs and physical mixtures were investigated by X-ray diffraction, Fourier-transform infrared, differential scanning calorimetry, scanning electron microscopy, dissolution test, and particles size determination. Eutectic compounds were produced between the DF and PLXM matrix during the co-grinding process, whereas glass suspension formed in the SDs with PVP carrier. Hydrogen bond formation was not observed between DF and carriers and DF was microcrystalline state in the PVP and PLXM matrices. The solubility of DF in different concentration of carriers at 25, 31, and 37°C was investigated; the values obtained were used to calculate the thermodynamic parameters of interaction between DF and carriers. The Gibbs free energy (?rG?) values were negative, indicating the spontaneous nature of dispersing DF into the carriers. Moreover, entropy is the drive force when DF disperses into the matrix of PVP, while, enthalpy-driven dispersing encounters in the PLXM carrier. All the SDs of DF/carriers showed a considerably higher dissolution rate than pure DF and the corresponding physical mixtures. The cumulative dissolution rate at 10?min of the SD with a 1?:?3 DF/carrier ratio increased 5.1-fold for PVP and 5.5-fold for PLXM. PMID:22790815

Yang, Caiqin; Xu, Xiujuan; Wang, Jing; An, Zhiqian

2012-01-01

112

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

113

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

114

Solubility and dissolution improvement of Rofecoxib using solid dispersion technique.  

PubMed

Rofecoxib (RXB) is a potent and selective cyclo-oxygenase-2 (COX-2) inhibitor, highly effective in the treatment of various pains, inflammatory condition, post-operative pain, rheumatoid arthritis, other musculo-skeletal and joint disorders. Although they are completely absorbed upon oral administration, the peak plasma concentration is reached 2-3 hours after oral ingestion. The reason for delay being slow rate of absorption due to poor aqueous solubility. An attempt has been made to enhance solubility and dissolution of rofecoxib by solid dispersion(SD) technique using various hydrophilic excipients like PEG 4000, PEG 6000, PVP at different ratios by melting method and solvent evaporation method. The prepared SD of RXB were characterized to various physico-chemical properties and in vitro drug dissolution studies in 0.1N HCl with 0.25% SLS (pH 1.1) media for a period of 90 min using USP XXIII electro lab 8 basket tab dissolution test apparatus using paddle. The result of study indicated that there was no drug-polymer interaction found. The drug dissolution was found to enhance percent in PEG 4000, PEG 6000 and PVP, after 90 mins of dissolution study 79.02%, 88.02%, 98.57% respectively. On comparison of various polymers used at varied concentrations PVP at 75:25 ratio by fusion method was found to be best suitable for the enhancement of dissolution and solubility of RXB. PMID:18930854

Rahamathulla, Mohamed; Hv, Gangadharappa; Rathod, Neelkant

2008-10-01

115

30 CFR 27.31 - Testing methods.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.31 Testing methods. A methane-monitoring system shall be tested by MSHA to determine its functional...

2013-07-01

116

30 CFR 27.31 - Testing methods.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.31 Testing methods. A methane-monitoring system shall be tested by MSHA to determine its functional...

2011-07-01

117

30 CFR 27.31 - Testing methods.  

...DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.31 Testing methods. A methane-monitoring system shall be tested by MSHA to determine its functional...

2014-07-01

118

30 CFR 27.31 - Testing methods.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.31 Testing methods. A methane-monitoring system shall be tested by MSHA to determine its functional...

2012-07-01

119

Applications of a Biorelevant In Vitro Dissolution Method Using USP Apparatus 4 in Early Phase Formulation Development  

E-print Network

to the patient. Using the commonly used over-the-counter drug Tylenol®, which is used to treat a headache or fever as an example, the drug absorption from the Tylenol® tablets after oral administration depends on several factors including: (1) the release... over the last two decades (2). And because of the important nature of the first two steps of oral administration described above (release of the drug substance from the drug product and dissolution or solubilization of the drug under physiological...

Robertson, Vivian Ku

2013-08-31

120

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

121

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

122

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

123

DATE: __________________ NVLAP LAB CODE: _________________ Test Method  

E-print Network

DATE: __________________ NVLAP LAB CODE: _________________ Test Method Designation Short Title _____ 30/DISC00A ANSI/INCITS 423.1 (2008) Information Technology - Conformance Testing Methodology Standard for Biometric Data Interchange Format Standards - Part 1: Generalized Conformance Testing Methodology _____ 30

124

Advanced methods for cascade testing  

Microsoft Academic Search

Considerable advances have been achieved over the last decennia in the field of cascade testing, but they were generally not reported in sufficient detail. As an example, details of transonic\\/supersonic cascade testing procedures were scarcely documented in literature. Many other aspects evolved considerably, originally from the progress of experimental techniques as well as from the interaction with computer data. New

Charles Hirsch

1993-01-01

125

A novel method of non-violent dissolution of sodium metal in a concentrated aqueous solution of Epsom salt  

NASA Astrophysics Data System (ADS)

A new technique of non-violent and fast dissolution of sodium metal in a concentrated aqueous solution of Epsom salt (MgSO 4.7H 2O) at room temperature (RT) has been developed. The dissolution process is mildly exothermic but could be carried out even in a glass beaker in air under swift stirring condition. The reaction products consist of mixed salts of MgSO 4 and Na 2SO 4 as well as Mg(OH) 2 which are only mildly alkaline and hence are non-corrosive and non-hazardous unlike NaOH. A 50 mL solution having Epsom salt concentration of 2 M was found to give the optimal composition for disposal of 1 g of sodium. Supersaturated (>2.7 M), as well as dilute (<1.1 M) solutions, however, cause violent reactions and hence should be avoided. Repeated sodium dissolution in Epsom solution produced a solid waste of 4.7 g per g of sodium dissolved which is comparable with the waste (4 g) produced in 8 M NaOH solution. A 1.4 M Epsom solution sprayed with a high-pressure jet cleaner at RT in air easily removed the sodium blocked inside a metal pipe made of mild steel. The above jet also dissolved peacefully residual sodium collected on the metal tray after a sodium fire experiment. No sodium fire or explosion was observed during this campaign. The Epsom solution spray effectively neutralized the minor quantity of sodium aerosol produced during this campaign. This novel technique would hence be quite useful for draining sodium from fast breeder reactor components and bulk processing of sodium as well as for sodium fire fighting.

Lakshmanan, A. R.; Prasad, M. V. R.; Ponraju, D.; Krishnan, H.

2004-10-01

126

A process analytical technology approach based on near infrared spectroscopy: tablet hardness, content uniformity, and dissolution test measurements of intact tablets.  

PubMed

Near infrared spectroscopy (NIRS) is a nondestructive analytical technique that enables simultaneous measurements of chemical composition (viz. the content in active pharmaceutical ingredient, API) and various physical properties (viz. tablet hardness and dissolution profile) in pharmaceutical tablets. In this work, partial least squares (PLS) calibration models and discriminant partial least squares (DPLS) classification models were constructed by using calibration sets consisting of laboratory samples alone. The laboratory samples were mixtures of the API and excipients that were pressed into tablets. API content, tablet hardness, and dissolution measurements of intact tablets were made by using three different calibration models that are fast--results can be obtained within a few seconds--, simple and robust--they involve minimal analyst intervention--, and clean--they use no toxic reagent and produce no toxic waste. Based on the results, the proposed NIR method is an effective alternative to current reference methods for the intended purpose. The advantages provided by NIR spectroscopy in this context confirm its potential for inclusion in process analytical technologies in the pharmaceutical industry. PMID:16883562

Blanco, Marcelo; Alcalá, Manel; González, Josep M; Torras, Ester

2006-10-01

127

Applying Formal Methods to Software Testing  

Microsoft Academic Search

This thesis examines applying formal methods to software testing. Software testingis a critical phase of the software life-cycle which can be very effective if performedrigorously. Formal specifications offer the bases for rigorous testing practices. Notsurprisingly, the most immediate use of formal specifications in software testing isas sources of black-box test suites. However, formal specifications have more usesin software testing than

Philip Alan Stocks

1993-01-01

128

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

129

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

130

$t$ Tests, $F$ Tests and Otsu's Methods for Image Thresholding  

Microsoft Academic Search

Otsu's binarization method is one of the most popular image- thresholding methods; Student's -test is one of the most widely-used sta- tistical tests to compare two groups. This paper aims to stress the equiv- alence between Otsu's binarization method and the search for an optimal threshold that provides the largest absolute Student's -statistic. It is then naturally demonstrated that the

Jing-Hao Xue; D. Michael Titterington

2011-01-01

131

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

132

Multipoint dissolution specification and acceptance sampling rule based on profile modeling and principal component analysis  

Microsoft Academic Search

In dissolution testing multiple dissolution measurements at specific time points are needed in quality control when the compliance of the product requires controlled dissolution throughout the time course. The dissolution specification based on general multivariate confidence region was proposed by Chen and Tsong (8). This paper presents two alternative procedures when the dissolution profile consists of important measurements at more

Yi Tsong; Thomas Hammerstrom; James J. Chen

1997-01-01

133

Silica Gel as a Surrogate for Biogenic Silica in Batch Dissolution Experiments at pH 9.2: Further Testing of the Shrinking Object Model and a Novel Approach to the Dissolution of a Population of Particles  

Microsoft Academic Search

Recently, the increase in dissolved concentration in the batch dissolution of various salts or sucrose has been successfully\\u000a modelled with three equations, one a cubic in time. However, from three separate earlier investigations with ocean sediments\\u000a and phytoplankton frustules, there is residual suspicion that biogenic silica does not follow this behaviour. This paper shows\\u000a that the Shrinking Object Model applies

Victor W. Truesdale

2010-01-01

134

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. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3416-3422, 2014. PMID:25251982

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

2014-11-01

135

Salt dissolution in oil and gas test holes in central Kansas. Part III. Salt dissolution in oil and gas test holes in the Chase-Silica Oilfield, Barton and Rice Counties, central Kansas  

Microsoft Academic Search

In the Chase-Silica Oilfield (135.3 square miles), all of the 4845 oil and gas test holes drilled completely through the Hutchinson Salt Member of the Permian Wellington Formation (depths of 900 ft on east to 1000 ft on west). The salt is 250 ft thick in the structurally highest areas above buried Precambrian quartzite hills; 300 ft over most of

1975-01-01

136

Integrating drug permeability with dissolution profile to develop IVIVC.  

PubMed

In this review article, three different approaches to predict in vivo oral absorption based on the in vitro data of drug permeability, solubility and dissolution were introduced. At the drug discovery stage, the absorption potential of each candidate is most important to select better compounds for further development. The concept of maximum absorbable dose is applied widely, not only to evaluate the absorption potential but also to elucidate the rate-limiting process of oral absorption that helps us to understand the cause of poor absorption. To integrate the permeability of the drug with its dissolution profile, two different approaches, in vitro dissolution/permeation system (D/P system) and in silico model and simulation method, are proposed. In the D/P system, by mimicking the in vivo process of drug absorption, the permeated amount of drugs, that is the total output of dissolution and permeation processes, are correlated with the fraction absorbed in human (F(a)). This system is powerful for evaluating the improved absorption by various formulations and the effect of food intake. On the other hand, in the model and simulation approach, an intrinsic dissolution parameter of drug particle, z, was extracted from the small scale in vitro test and the process of intestinal absorption was re-constructed in silico by incorporating the physiological parameters in human. The effective use of these approaches for the development of oral drug products is discussed through various case studies. PMID:22581486

Takano, Ryusuke; Kataoka, Makoto; Yamashita, Shinji

2012-10-01

137

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

138

Methods in Scaling the Basic Competence Test  

ERIC Educational Resources Information Center

This study evaluates the effects of employing the linear, normalizing, and arcsine transformation methods for constructing scale scores on the Basic Competence Test (BCTEST). Tests in three subject areas (Chinese, English, and Mathematics) were studied using the data of test administrations from 2001 to 2003. The resulting scale scores for each…

Chang, Shun-Wen

2006-01-01

139

EVALUATING TEST METHODS USED TO CHARACTERIZE SOFTBALLS  

E-print Network

of baseball and softball bats can depend strongly on the properties of the ball. Standard test methods exist in a quasi- static compression test and the COR is measured by impacting the ball against a rigid plate testing (which is not controlled in any standard) was observed to affect the ball's measured response

Smith, Lloyd V.

140

FIP position paper on qualification of paddle and basket dissolution apparatus.  

PubMed

The qualification process for ensuring that a paddle or basket apparatus is suitable for its intended use is a highly debated and controversial topic. Different instrument qualification and suitability methods have been proposed by the pharmacopeias and regulatory bodies. In an effort to internationally harmonize dissolution apparatus suitability requirements, the International Pharmaceutical Federation's (FIP) Dissolution/Drug Release Special Interest Group (SIG) reviewed current instrument suitability requirements listed in the US, European, and Japanese pharmacopeias and the International Conference on Harmonization (ICH) Topic Q4B on harmonization of pharmacopoeial methods, in its Annex 7, Dissolution Test General. In addition, the SIG reviewed the Food and Drug Administration (FDA) Draft Guidance for Industry, "The Use of Mechanical Calibration of Dissolution Apparatus 1 and 2-Current Good Manufacturing Practice (CGMP)" and the related ASTM Standard E2503-07. Based on this review and several in-depth discussions, the FIP Dissolution/Drug Release SIG recommends that the qualification of a dissolution test instrument should be performed following the calibration requirements as indicated in the FDA (draft) guidance. If additional system performance information is desired, a performance verification test using US Pharmacopeia Reference Standard tablet or an established in-house reference product can be conducted. Any strict requirement on the use of a specific performance verification test tablet is not recommended at this time. PMID:19609681

Brown, Cynthia K; Buhse, Lucinda; Friedel, Horst-Dieter; Keitel, Susanne; Kraemer, Johannes; Morris, J Michael; Stickelmeyer, Mary; Yomota, Chikako; Shah, Vinod P

2009-01-01

141

Effect of inorganic ligands and hydrogen peroxide on ThO2 dissolution. Behaviour of Th0.87Pu0.13O2 during leaching test.  

PubMed

The dissolution of ThO2 powdered samples was examined in various conditions of pH and concentration of anions in the leachate. The first part of this paper describes the influence of pH on the dissolution of ThO2 in both nitric and hydrochloric media. The partial order relative to the proton concentration and the apparent normalized dissolution rate constants were determined. The second part of the paper describes the influence of other ligands such as perchlorate, chloride, sulfate, and hydrogen peroxide on the dissolution kinetics (at pH 1). An increase of RL was observed correlatively with the increase of complexing affinity of the ligand with Th. While nitric and hydrochloric media, which are weakly complexing, lead to RL values with the same order of magnitude as those for perchlorate media, the presence of sulfate or peroxide in the leachate significantly enhances the dissolution of ThO2. Consequently, the dissolution mechanism can be explained by the weakening of Th-O bonds through the formation of surface complexes at the solid/liquid interface, which enhance the detachment and thus accelerate the global dissolution. In addition, the dissolution of Th 0.87Pu 0.13O2 solid solution was also examined. The increase of the dissolution kinetics of Th 0.87Pu 0.13O 2, in comparison with that of ThO2, is considered to be caused by the presence of hydrogen peroxide formed by radiolysis of the leachate. Moreover, the redox properties of plutonium in acidic media, like disproportionation of Pu(IV) and Pu(V) and reduction of Pu(VI) and Pu(IV) in Pu(III) by H2O2, probably increase the dissolution of plutonium. PMID:18260624

Hubert, Solange; Heisbourg, Guillaume; Dacheux, Nicolas; Moisy, Philippe

2008-03-17

142

Methods of Testing Thermal Insulation and Associated Test Apparatus  

NASA Technical Reports Server (NTRS)

The system and method for testing thermal insulation uses a cryostatic insulation tester having a vacuum chamber and a cold mass including a test chamber and upper and lower guard chambers adjacent thereto. The thermal insulation is positioned within the vacuum chamber and adjacent the cold mass. Cryogenic liquid is supplied to the test chamber, upper guard and lower guard to create a first gas layer in an upper portion of the lower guard chamber and a second gas layer in an upper portion of the test chamber. Temperature are sensed within the vacuum chamber to test the thermal insulation.

2004-01-01

143

Concentration profile for the dissolution of drug tablets undergoing simultaneous degradation.  

PubMed

An empirical approach to the concentration-time history of a dissolving drug has resulted in a cube-root equation in which the characteristic constant of the equation embodies the important physical variables of the system. This expression has been used to study the dissolution of a drug that degrades simultaneously in the test solution. An alternative representation of the dissolution process is first-order kinetics. These two approaches are compared by fitting the experimental data of the dissolution of digoxin and melphalan tablets in various media, and a new method for the proper analysis of data for the dissolution of tablets that simultaneously degrade in the test solution is presented. PMID:7229912

Chen, H S; Chang, S Y; Evans, T L; Gross, J F

1980-12-01

144

Protocol testing: review of methods and relevance for software testing  

Microsoft Academic Search

Communication protocols are the rules that govern the communication between the different components within a distributed computer system. Since protocols are implemented in software and\\/or hardware, the question arises whether the existing hardware and software testing methods would be adequate for the testing of communication protocols. The purpose of this paper is to explain in which way the problem of

Gregor von Bochmann; Alexandre Petrenko

1994-01-01

145

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.

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

1995-08-01

146

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

147

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

E-print Network

method--I. Synthetic samples Ingeborg H. M. van Oorschot and Mark J. Dekkers Utrecht University. The AAO-Fe(II) method preferentially dissolved the smaller iron oxides from the samples. For samples of magnetite and maghemite in the acid­ammonium oxalate method to see whether the method is suitable

Utrecht, Universiteit

148

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

149

In Silico Toxicology - Non-Testing Methods  

PubMed Central

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

Raunio, Hannu

2011-01-01

150

30 CFR 36.41 - Testing methods.  

Code of Federal Regulations, 2013 CFR

... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT...Requirements § 36.41 Testing methods. Mobile diesel-powered transportation...

2013-07-01

151

30 CFR 36.41 - Testing methods.  

Code of Federal Regulations, 2012 CFR

... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT...Requirements § 36.41 Testing methods. Mobile diesel-powered transportation...

2012-07-01

152

30 CFR 36.41 - Testing methods.  

Code of Federal Regulations, 2011 CFR

... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT...Requirements § 36.41 Testing methods. Mobile diesel-powered transportation...

2011-07-01

153

30 CFR 36.41 - Testing methods.  

... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT...Requirements § 36.41 Testing methods. Mobile diesel-powered transportation...

2014-07-01

154

30 CFR 36.41 - Testing methods.  

Code of Federal Regulations, 2010 CFR

... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT...Requirements § 36.41 Testing methods. Mobile diesel-powered transportation...

2010-07-01

155

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

156

Chemical imaging of oral solid dosage forms and changes upon dissolution using coherent anti-Stokes Raman scattering microscopy.  

PubMed

Dissolution testing is a crucial part of pharmaceutical dosage form investigations and is generally performed by analyzing the concentration of the released drug in a defined volume of flowing dissolution medium. As solid-state properties of the components affect dissolution behavior to a large and sometimes even unpredictable extent there is a strong need for monitoring and especially visualizing solid-state properties during dissolution testing. In this study coherent anti-Stokes Raman scattering (CARS) microscopy was used to visualize the solid-state properties of lipid-based oral dosage forms containing the model drug theophylline anhydrate during dissolution in real time. The drug release from the dosage form matrix was monitored with a spatial resolution of about 1.5 microm. In addition, as theophylline anhydrate tends to form the less soluble monohydrate during dissolution, CARS microscopy allowed the solid-state transformation of the drug to be spatially visualized. The results obtained by CARS microscopy revealed that the method used to combine lipid and active ingredient into a sustained release dosage form can influence the physicochemical behavior of the drug during dissolution. In this case, formation of theophylline monohydrate on the surface was visualized during dissolution with tablets compressed from powdered mixtures but not with solid lipid extrudates. PMID:19209888

Windbergs, Maike; Jurna, Martin; Offerhaus, Herman L; Herek, Jennifer L; Kleinebudde, Peter; Strachan, Clare J

2009-03-15

157

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

158

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

159

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

160

Alternative Test Methods for Electronic Parts  

NASA Technical Reports Server (NTRS)

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

Plante, Jeannette

2004-01-01

161

Chlorhexidine gel associated with papain in pulp tissue dissolution  

PubMed Central

Objectives This study aimed to evaluate the capacity of 2% chlorhexidine gel associated with 8% papain gel in comparison with 5.25% sodium hypochlorite in bovine pulp tissue dissolution. Materials and Methods Ninety bovine pulps of standardized sizes were used and fragmented into 5-mm sizes. The fragments were removed from the root middle third region. They were divided into 6 experimental groups (n = 15), 1) 8% papain; 2) 2% chlorhexidine; 3) 2% chlorhexidine associated with 8% papain; 4) 0.9% saline solution; 5) 2.5% sodium hypochlorite; and 6) 5.25% sodium hypochlorite. The pulp fragments were weighed and put into immobile test tubes for dissolution for time intervals of 30, 60, 90, and 120 min. Results The 5.25% sodium hypochlorite had greater dissolution potential than the pure papain, and when associated with chlorhexidine, both promoted greater dissolution than did the saline solution and 2% chlorhexidine groups (p < 0.05). The 2.5% sodium hypochlorite promoted dissolution to a lesser extent than the groups with papain within a period of 30 min (p < 0.05), but, was comparable to the saline solution and chlorhexidine. After 120 min, the 2.5% and 5.25% sodium hypochlorite promoted dissolution of 100% of the pulp fragments, and papain, 61%, while chlorhexidine associated with papain and chlorhexidine alone dissolved only 55% and 3%, respectively. Conclusions The 8% papain in gel, both alone and in association with chlorhexidine, was able to dissolve bovine pulp tissue, but to a lesser extent than did 5.25% sodium hypochlorite. PMID:24303355

Couto De Oliveira, Gabriel; Ferraz, Caio Souza; Andrade Junior, Carlos Vieira

2013-01-01

162

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

163

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

164

Formal methods for test case generation  

NASA Technical Reports Server (NTRS)

The invention relates to the use of model checkers to generate efficient test sets for hardware and software systems. The method provides for extending existing tests to reach new coverage targets; searching *to* some or all of the uncovered targets in parallel; searching in parallel *from* some or all of the states reached in previous tests; and slicing the model relative to the current set of coverage targets. The invention provides efficient test case generation and test set formation. Deep regions of the state space can be reached within allotted time and memory. The approach has been applied to use of the model checkers of SRI's SAL system and to model-based designs developed in Stateflow. Stateflow models achieving complete state and transition coverage in a single test case are reported.

Rushby, John (Inventor); De Moura, Leonardo Mendonga (Inventor); Hamon, Gregoire (Inventor)

2011-01-01

165

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

166

[A method for Rhesus box test].  

PubMed

To study the method for Rhesus box test and its significance, the sequence specific primers of upstream, downstream and hybrid Rhesus boxes were designed according to RhD gene sequence; the upstream, downstream and hybrid Rhesus boxes were determined by PCP-SSP and mismatched PCR. The results showed that this method was confirmed by DNA Standard test. It was shown that in unrelative RhD positive individuals RHD(+)/RHD(-), RHD(+)/RHD(+) genotype accounted for 9.00%, 91.00% respectively, and in RhD negative individuals RHD(+)/RHD(-), RHD(+)/RHD(+), RHD(-)/RHD(-) genotype were 26.14%, 3.92%, 69.94% respectively. It is concluded that the method of Rhesus box test was confirmed to be reliable and can be used for the identification of RhD haplotype gene structure, as well as for study on inheritance, clinical transfusion and neonatal hemolytic diseases. PMID:16403290

Lan, Jiong-Cai; Zhou, Hua-You; Xia, Rong; Cao, Qiong; Xing, Yan-Chao; Pang, Gui-Zhi; Wu, Can; Yang, Quan-Ke

2005-12-01

167

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

168

CHROMagar Salmonella Detection Test Kit. Performance Tested Method 020502.  

PubMed

BBL CHROMagar Salmonella was evaluated by an external food testing laboratory for the recovery of Salmonella in peanut butter using the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) procedure. The peanut butter was found to be negative for the presence of Salmonella and, therefore, was seeded with heat-stressed Salmonella at target concentrations of 0.2 and 2 CFU/25 g. The Salmonella-seeded samples remained at room temperature for 14 days before analysis to stabilize the Salmonella in the food environment. Twenty 25 g test portions from each seeded level and five 25 g samples of uninoculated control samples were processed using enrichment broths as outlined in the FDA-BAM procedure. BBL CHROMagar Salmonella-prepared plates were evaluated with the FDA reference method media (bismuth sulfite, xylose lysine desoxycholate, and Hektoen enteric agars). Fractionally positive results were obtained from the lower inoculum level of peanut butter samples. Five positive cultures were recovered from both the BBL CHROMagar Salmonella and reference methods. The two methods gave identical results for all cultures resulting in a method agreement of 100%. McNemar's chi2 test, which assesses the evidence for difference in marginal proportions between two methods, could not be evaluated because it requires one or more discrepant cultures. However, because there were no discrepant cultures, the marginal proportions for the two methods were identical; therefore, there is no evidence of a difference between the methods. This study demonstrates that the results from BBL CHROMagar Salmonella are comparable to the three reference method media for the detection of Salmonella in peanut butter using the FDA-BAM procedures. PMID:20166616

Webb, Katana; Ritter, Vicki

2009-01-01

169

Uranium dioxide dissolution under acidic aqueous conditions  

SciTech Connect

Understanding of the long-term dissolution of waste forms in groundwater is required for the safe disposal of high level nuclear waste in a geologic repository, because waste-form radionuclides could be released by dissolution and transported in groundwater. The dissolution of the uranium dioxide (UO{sub 2}) matrix in spent nuclear fuel is considered the rate-limiting step for release of radioactive fission products. The intrinsic UO{sub 2} dissolution rate sets an upper limit on the aqueous radionuclide release rate. Unsaturated spent fuel tests have shown that pH`s of leachates have decreased to a range of 4 to 6, presumably due to air radiolysis that oxidizes nitrogen, producing nitric acid. Dissolution rates under such acidic conditions may be different than those previously reported for alkaline groundwater conditions. No dissolution rate measurements of UO{sub 2} or spent fuel have been reported for acidic conditions possibly relevant to a geologic repository. The purpose of our work has been to measure the intrinsic dissolution rates of uranium dioxide under acidic conditions that are relevant to a repository and allow for modeling. Experiments have been completed at room-temperature and 75 C, pH`s of 4 and 6, and air and oxygen saturated aqueous solutions. These are compared with earlier work on spent fuel and UO{sub 2} using alkaline solutions.

Steward, S.A.; Mones, E.T.

1995-11-20

170

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

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

2011-07-01

171

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

172

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

173

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

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

2014-07-01

174

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

175

Integrating Formal Methods and Testing 2002  

NASA Technical Reports Server (NTRS)

Traditionally, qualitative program verification methodologies and program testing are studied in separate research communities. None of them alone is powerful and practical enough to provide sufficient confidence in ultra-high reliability assessment when used exclusively. Significant advances can be made by accounting not only tho formal verification and program testing. but also the impact of many other standard V&V techniques, in a unified software reliability assessment framework. The first year of this research resulted in the statistical framework that, given the assumptions on the success of the qualitative V&V and QA procedures, significantly reduces the amount of testing needed to confidently assess reliability at so-called high and ultra-high levels (10-4 or higher). The coming years shall address the methodologies to realistically estimate the impacts of various V&V techniques to system reliability and include the impact of operational risk to reliability assessment. Combine formal correctness verification, process and product metrics, and other standard qualitative software assurance methods with statistical testing with the aim of gaining higher confidence in software reliability assessment for high-assurance applications. B) Quantify the impact of these methods on software reliability. C) Demonstrate that accounting for the effectiveness of these methods reduces the number of tests needed to attain certain confidence level. D) Quantify and justify the reliability estimate for systems developed using various methods.

Cukic, Bojan

2002-01-01

176

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

177

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

178

Real-time dissolution behavior of furosemide in biorelevant media as determined by UV imaging.  

PubMed

The potential of UV imaging as a new small scale flow-through dissolution testing platform and its ability to incorporate biorelevant media was tested. Furosemide was utilized as a model poorly soluble drug, and dissolution media simulating conditions in the small intestine (5/1.25?mM and 40/10?mM bile salt/phospholipid, pH 6.5) together with corresponding blank buffer were employed. Dissolution rates as a function of flow rate (0.2-1.0?mL/min) were determined directly from UV images, and by analysis of collected effluent using UV spectrophotometry. A good agreement in dissolution rates was observed, however repeatability of data based on measurement of collected effluent was superior to that obtained by UV imaging in the utilized prototypic flow cell. Both methods indicated that biorelevant media did not markedly increase the dissolution rate of furosemide as compared to buffer. Qualitatively, UV images indicated that uncontrolled swelling/precipitation of furosemide on the compact surface was occurring in some samples. In situ Raman spectroscopy together with X-ray diffraction analysis confirmed that the observations were not due to a solid form transformation of furosemide. The presented results highlight the complementary features of the utilized techniques and, in particular, the detailed information related to dissolution behavior which can be achieved by UV imaging. PMID:23136844

Gordon, Sarah; Naelapää, Kaisa; Rantanen, Jukka; Selen, Arzu; Müllertz, Anette; Østergaard, Jesper

2013-01-01

179

Comparing various techniques to produce micro/nanoparticles for enhancing the dissolution of celecoxib containing PVP.  

PubMed

One of the major challenges in pharmaceutical development is the poor dissolution performance of drugs. Celecoxib (CLX) is a poorly water soluble drug with its bioavailability being limited by its poor dissolution. In this study several particle engineering methods were employed on CLX using various ratios of CLX:PVP-K30. Micro/nanoparticles of CLX:PVP were prepared by using spray drying (SD), antisolvent crystallization followed by freeze drying (CRS-FD) and spray drying (CRS-SD) techniques. The suspension obtained through antisolvent crystallization was also subjected to high pressure homogenization followed by freeze drying (HPH-FD). Particle size measurements, saturation solubility, optical and scanning electron microscopy, DSC, XRPD, FT-IR and dissolution test were performed to characterize the physicochemical and pharmaceutical properties of the samples. The results showed that spray dried samples in the presence of (50%) PVP produced spherical particles and exhibited a high dissolution rate. Interestingly in the antisolvent crystallization technique, spherical nanoparticles of drug-PVP were obtained in the range of 291-442 nm. The average particle size was dependent on the concentration of the PVP used during the crystallization process. Solid state analysis showed that these particles were completely amorphous in nature. Also interesting to note was that at concentration of 5% PVP, when the suspension of nanoparticles was subjected to the high pressure homogenization process, the crystallinity of CLX increased. Despite the partial crystallinity of particles produced, they showed excellent dissolution behavior. It can thus be concluded that the method of preparation of CLX micro/nanoparticles had a big impact on the dissolution rate when the concentration of PVP was low (e.g., 5%). At high PVP concentration (e.g., 50%) all methods used to prepare engineered CLX particles showed better dissolution with no significant differences in their dissolution efficiency. PMID:24952357

Homayouni, Alireza; Sadeghi, Fatemeh; Varshosaz, Jaleh; Garekani, Hadi Afrasiabi; Nokhodchi, Ali

2014-09-01

180

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

181

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

182

Chemical Protective Clothing Standard Test Method Development: Part II. Degradation Test Method  

Microsoft Academic Search

A “round-robin” interlaboratory evaluation of a proposed American Society for Testing and Materials (ASTM) standard test method was conducted for measuring the resistance of chemical protective clothing materials to degradation by liquid chemicals. The objective of this project was to determine the relative precision of the method and, where appropriate, recommend modifications that would improve reliability. In the round-robin format,

GERARD C. COLETTA; S. Z. MANSDORF; S. P. BERARDINELLI

1988-01-01

183

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

184

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

185

Standard test method for static leaching of monolithic waste forms for disposal of radioactive waste  

E-print Network

1.1 This test method provides a measure of the chemical durability of a simulated or radioactive monolithic waste form, such as a glass, ceramic, cement (grout), or cermet, in a test solution at temperatures <100°C under low specimen surface- area-to-leachant volume (S/V) ratio conditions. 1.2 This test method can be used to characterize the dissolution or leaching behaviors of various simulated or radioactive waste forms in various leachants under the specific conditions of the test based on analysis of the test solution. Data from this test are used to calculate normalized elemental mass loss values from specimens exposed to aqueous solutions at temperatures <100°C. 1.3 The test is conducted under static conditions in a constant solution volume and at a constant temperature. The reactivity of the test specimen is determined from the amounts of components released and accumulated in the solution over the test duration. A wide range of test conditions can be used to study material behavior, includin...

American Society for Testing and Materials. Philadelphia

2010-01-01

186

Testing Photometric Methods in the Euclid Testbed  

NASA Astrophysics Data System (ADS)

The Euclid satellite will investigate the distance-redshift relationship and the evolution of cosmic structures by measuring shapes and redshifts of galaxies and clusters of galaxies. The various Euclid experiments require very accurate object photometry in order to achieve its science goals. Building upon our experience in the Dark Energy Survey data management, we have developed the Euclid Testbed which allows one to compare different methods for various data processing steps such as object detection and object photometry. Our first target is testing photometric methods that are based on measurements taken on the ensemble of single images and not on co-added images. In this contribution we present and discuss the structure of the Euclid Testbed. We introduce our own single image photometry software FitPhot, and give a detailed comparison of its accuracy with other photometric methods/software.

Kümmel, M.; Mohr, J.; Desai, S.; Henderson, R.; Koppenhoefer, J.; Paech, K.; Wetzstein, M.

2014-05-01

187

Maximum Parsimony and Maximum Likelihood Methods Comparisons and Bootstrap Tests  

E-print Network

Maximum Parsimony and Maximum Likelihood Methods Comparisons and Bootstrap Tests Character Likelihood Methods Comparisons and Bootstrap Tests Character Reconstruction PHYLIP and T-REX Exercises Outline 1 Maximum Parsimony and Maximum Likelihood 2 Methods Comparisons and Bootstrap Tests 3 Character

Qiu, Weigang

188

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

189

Statistical assessment of dissolution and drug release profile similarity using a model-dependent approach  

Microsoft Academic Search

A general multivariate procedure for assessing the similarity of dissolution and drug release profiles was developed. A mathematical model is fit to the data, and Hotelling's T2 test is used to calculate the joint confidence region around the vector of differences between least-squares estimates of the parameters in the model. The method of Lagrange multipliers is used to determine if

Mark R. Berry; Michael D. Likar

2007-01-01

190

[Comparison in dissolution behavior of ethical and over-the counter scopolamine butylbromide].  

PubMed

Marketing authorization holders do not disclose any information on the pharmaceutical properties of over-the-counter drugs (OTC). When a drug is switched from a prescription drug to OTC, pharmacists can acquire that information from the corresponding ethical drug (ED) through the package insert, interview form, and so on. However, the pharmaceutical equivalence between ED and OTC is unclear. In this study, we examined the drug dissolution behavior of both ED and OTCs containing scopolamine butylbromide. Dissolution tests were performed by the paddle method using Japanese Pharmacopeia (JP) XV test fluids at pH 1.2, 4.0 and 6.8 and water based on the guidelines for bioequivalence studies of generic products. The dissolution profiles of OTCs differed significantly from ED showing a similarity factor (f2) value ranging from 8.9 to 42.9. Time until 85% dissolution ranged from 23 to 95 min and from 17 to 174 min at pH 1.2 and pH 6.8, respectively. Then JP XV disintegration tests were conducted to investigate differences in the disintegration process. The disintegration time of preparations showing delayed dissolution was prolonged compared to that of others, suggesting that the disintegration of the tablet or capsule is one of the important factors affecting the drug dissolution. These differences in the disintegration and drug dissolution might cause differences in the bioavailability of the drug. For patient safety, more detailed product information of OTCs should be supplied by the manufacturer, and not be assumed from that of corresponding ED. PMID:22041704

Suzuki, Ichie; Miyazaki, Yasunori; Uchino, Tomonobu; Kagawa, Yoshiyuki

2011-01-01

191

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

192

Experimental test of airplane boarding methods  

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

193

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

PubMed Central

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

Lewis, Daniel R; Liu, Dongzhou J

2014-01-01

194

Chemical Protective Clothing Standard Test Method Development Part 1. Penetration Test Method  

Microsoft Academic Search

A “round-robin” interlaboratory study was conducted to validate the relative precision of the American Society for Testing and Materials (ASTM) F-903 test method for measuring the resistance of protective materials to penetration by liquids. The study utilized seven independent laboratories performing three trials of five protective clothing materials challenged by five widely used commercial liquids. The level of overall agreement

S. Z. MANSDORF; S. P. BERARDINELLI

1988-01-01

195

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

196

Effect of particle size on solubility, dissolution rate, and oral bioavailability: evaluation using coenzyme Q?? as naked nanocrystals.  

PubMed

In this paper work, four naked nanocrystals (size range 80-700 nm) were prepared without any surfactant or polymer using the solvent/nonsolvent method. The effects of particle size on their solubility, dissolution, and oral bioavailability were investigated. Solubility and dissolution testing were performed in three types of dissolution medium, and the studies demonstrated that the equilibrium solubilities of coenzyme Q?? nanocrystals and bulk drugs were not affected by the dissolution media but the kinetic solubilities were. Kinetic solubility curves and changes in particle size distribution were determined and well explained by the proposed solubilization model for the nanocrystals and bulk drugs. The particle size effect on dissolution was clearly influenced by the diffusion coefficients of the various dissolution media, and the dissolution velocity of coenzyme Q?? increased as particle size decreased. The bioavailability of coenzyme Q?? after oral administration in beagle dogs was improved by reducing the particle size. For 700 nm nanocrystals, the AUC???? was 4.4-fold greater than that for the coarse suspensions, but a further decrease in particle size from 700 nm to 120 nm did not contribute to improvement in bioavailability until the particle size was reduced to 80 nm, when bioavailability was increased by 7.3-fold. PMID:23166438

Sun, Jiao; Wang, Fan; Sui, Yue; She, Zhennan; Zhai, Wenjun; Wang, Chunling; Deng, Yihui

2012-01-01

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

Dissolution Studies With Pilot Plant and Actual INTEC Calcines  

SciTech Connect

The dissolution of Idaho Nuclear Technology and Engineering Center (INTEC) pilot plant calcines was examined to determine solubility of calcine matrix components in acidic media. Two representatives pilot plant calcine types were studied: Zirconia calcine and Zirconia/ Sodium calcine. Dissolution of these calcines was evaluated using lower initial concentrations of nitric acid than used in previous tests to decrease the [H+] concentration in the final solutions. Lower [H+] concentrations contribute to more favorable TRUEX/SREX solvent extraction flowsheet performance. Dissolution and analytical results were also obtained for radioactive calcines produced using high sodium feeds blended with non-radioactive A1(NO3)3 solutions to dilute the sodium concentration and prevent bed agglomeration during the calcination process. Dissolution tests indicated >95 wt. % of the initial calcine mass can be dissolved using the baseline dissolution procedure, with the exception that higher initial nitric acid concentrations are required. The higher initial acid concentration is required for stoichiometric dissolution of the oxides, primarily aluminum oxide. Statistically designed experiments using pilot plant calcine were performed to determine the effect of mixing rate on dissolution efficiency. Mixing rate was determined to provide minimal effects on wt. % dissolution. The acid/calcine ratio and temperature were the predominate variables affecting the wt. % dissolution, a result consistent with previous studies using other similar types of pilot plant calcines.

Herbst, Ronald Scott; Garn, Troy Gerry

1999-04-01

199

Dissolution studies with pilot plant and actual INTEC calcines  

SciTech Connect

The dissolution of Idaho Nuclear Technology and Engineering Center (INTEC) pilot plant calcines was examined to determine solubility of calcine matrix components in acidic media. Two representatives pilot plant calcine types were studied: Zirconia calcine and Zirconia/Sodium calcine. Dissolution of these calcines was evaluated using lower initial concentrations of nitric acid than used in previous tests to decrease the [H+] concentration in the final solutions. Lower [H+] concentrations contribute to more favorable TRUEX/SREX solvent extraction flowsheet performance. Dissolution and analytical results were also obtained for radioactive calcines produced using high sodium feeds blended with non-radioactive Al(NO{sub 3}){sub 3} solutions to dilute the sodium concentration and prevent bed agglomeration during the calcination process. Dissolution tests indicated {gt}95 wt.% of the initial calcine mass can be dissolved using the baseline dissolution procedure, with the exception that higher initial nitric acid concentrations are required. The higher initial acid concentration is required for stoichiometric dissolution of the oxides, primarily aluminum oxide. Statistically designed experiments using pilot plant calcine were performed to determine the effect of mixing rate on dissolution efficiency. Mixing rate was determined to provide minimal effects on wt.% dissolution. The acid/calcine ratio and temperature were the predominate variables affecting the wt.% dissolution, a result consistent with previous studies using other similar types of pilot plant calcines.

Herbst, R.S.; Garn, T.G.

1999-04-01

200

Towards a universal dissolution medium for carbamazepine.  

PubMed

The aim of this study was to develop a dissolution medium for assessment of various carbamazepine (CBZ) formulations with different strengths. The design of a system inhibiting transformation of the anhydrous CBZ (CBZ A) to the dihydrate form (CBZ D), with minimum surface-active properties and suitable sink was investigated. The effect of pH, different concentrations of sodium lauryl sulphate (SLS), polyvinylpyrrolidone (PVP), and methyl cellulose (MC) on dissolution rate, solubility, dissolution solubility, and polymorphic transformation of CBZ was assessed. Solution-mediated transformation of CBZ A into CBZ D was monitored using optical microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. Results showed that different strengths (100, 200, 400 mg) of the same CBZ tablet formulation exhibited different dissolution patterns, in 1% SLS (USP system). Such differences were reduced in 0.5% SLS solution which provided sufficient sink for up to 200 mg CBZ. It was also shown that solubility of CBZ A could not be detected in the media under study (water, SGF, SIF, and SLS solutions) due to its rapid transformation into CBZ D. The use of 3% PVP solution protected CBZ A from conversion for 75 min, while 0.01% MC completely inhibited the transformation up to 24 h. Therefore, a medium consisting of 0.5% SLS and 0.01% MC was selected. The medium provided: a) protection against transformation of CBZ A to CBZ D, b) increased solubility of CBZ A (204 mg % compared to 128 mg % of CBZ D in 0.5% SLS), c) suitable sink for up to 400 mg CBZ and d) overlapping dissolution profiles of various strengths of the same CBZ formulation. The suggested system may be a step in the way of solving CBZ dissolution problems that forced the USP to specify two similar dissolution tests with two different limits for conventional 200 mg CBZ tablets. PMID:16908426

El-Massik, M A; Abdallah, O Y; Galal, S; Daabis, N A

2006-08-01

201

An Accelerated Method for Soldering Testing  

SciTech Connect

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

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

2007-01-01

202

Disk Pressure Test a Sensitive Test Method of Material Embrittlement.  

National Technical Information Service (NTIS)

A mechanical test for characterizing embrittlement of materials under stress and non-homogeneous deformation is described. In this test a disk, fixed at the periphery, is broken by an increasing gas pressure, pressures obtained are compared in standard co...

R. Arnould-Laurent, J. P. Fidelle

1980-01-01

203

Proposed testing method for foam padding  

E-print Network

One very basic necessity for foam padding testing technology is the ability to test two different padding samples and compare the results. The current standard for testing is to use a steel anvil backing for the padding, ...

Hyatt, Daniel (Daniel Elliot)

2011-01-01

204

Myasthenia Gravis: Tests and Diagnostic Methods  

MedlinePLUS

... of patients with SNMG test positive for the anti-MuSK antibody. The remaining patients have unidentified antibodies causing their MG. OfficeTests —Sleep, Ice Pack and Edrophonium tests are examinations performed by ...

205

Automated testing assistant to enforce method coverage in testing OOP  

Microsoft Academic Search

(337) 482-6206 Abstract - Re-implementation testing is performed to capture software errors, reduce unnecessary post- implementation testing, and prevent error recurrence. Rigorous pre-implementation testing is never sufficient to eliminate all probability of error occurrence and generally is cost-prohibitive; however, a minimum level of testing is necessary to reduce the probability of serious errors. Regardless of the importance that this minimum

Ihssan Alkadi; Ghassan Alkadi; Harlan Etheridge

2003-01-01

206

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

207

Using Formal Methods To Derive Test Frames In Category-Partition Testing  

E-print Network

Mason University, Fairfax, VA 22030 Abstract Testing is a standard method of assuring that softwareUsing Formal Methods To Derive Test Frames In Category-Partition Testing Paul Ammann Je O utt y- based testing method. An important aspect of category- partition testing is the construction of test

Offutt, Jeff

208

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

209

16 CFR 1500.40 - Method of testing toxic substances.  

...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

210

40 CFR 75.22 - Reference test methods.  

Code of Federal Regulations, 2010 CFR

...stratification testing is part of the test protocol, follow the procedures... (5) ASTM D6784-02, Standard Test Method for Elemental, Oxidized...appendix A to this part. Otherwise, performance tests shall be conducted and data...

2010-07-01

211

Spousal Dissimilarity, Race, and Marital Dissolution  

ERIC Educational Resources Information Center

I test the claims that spousal differences in ideational, behavioral, and other traits contribute to elevated rates of marital dissolution among African Americans. Using data from 3 waves of the National Survey of Families and Households (N = 5,424), I find that African American spouses experience high levels of dissimilarity in traits that may…

Clarkwest, Andrew

2007-01-01

212

Corrosivity Test Methods for Polymeric Materials. Part 3- Modified DIN Test Method  

Microsoft Academic Search

This is the third in a series of papers to investigate corrosivity test methods published by the Polyolefins Fire Performance Council, an operating unit of The Society of the Plastics Industry, Inc. In the first paper, 24 polymeric materials were evaluated for smoke corrosivity following the \\

James G. Bennett; Stephen L. Kessel; Charles E. Rogers

1994-01-01

213

Monitoring lidocaine single-crystal dissolution by ultraviolet imaging.  

PubMed

Dissolution critically affects the bioavailability of Biopharmaceutics Classification System class 2 compounds. When unexpected dissolution behaviour occurs, detailed studies using high information content technologies are warranted. In the present study, an evaluation of real-time ultraviolet (UV) imaging for conducting single-crystal dissolution studies was performed. Using lidocaine as a model compound, the aim was to develop a setup capable of monitoring and quantifying the dissolution of lidocaine into a phosphate buffer, pH 7.4, under stagnant conditions. A single crystal of lidocaine was placed in the quartz dissolution cell and UV imaging was performed at 254 nm. Spatially and temporally resolved mapping of lidocaine concentration during the dissolution process was achieved from the recorded images. UV imaging facilitated the monitoring of lidocaine concentrations in the dissolution media adjacent to the single crystals. The concentration maps revealed the effects of natural convection due to density gradients on the dissolution process of lidocaine. UV imaging has great potential for in vitro drug dissolution testing. PMID:21387316

Østergaard, Jesper; Ye, Fengbin; Rantanen, Jukka; Yaghmur, Anan; Larsen, Susan Weng; Larsen, Claus; Jensen, Henrik

2011-08-01

214

49 CFR 383.133 - Testing methods.  

Code of Federal Regulations, 2010 CFR

...the required knowledge and skills contained in subpart G of...scoring the knowledge and skills tests. (d) Passing scores...135. (e) Knowledge and skills tests shall be based solely on the information contained in the driver...

2010-10-01

215

Using biochemical system to improve cinnabar dissolution.  

PubMed

In order to evaluate the leaching of cinnabar, a chemobiological reactor system with Acidithiobacillus ferrooxidans for cinnabar dissolution was investigated. The results demonstrated cinnabar dissolution had relation to bioprocess of A. ferrooxidans and iron concentration tightly. The optimal dilution rate and iron concentration were 0.4/h and 2-3 g/L in chemobiological reactor. The process may be contributed to the indirect catalyzing of ferric iron generated with A. ferrooxidans and direct adherence oxidation function. This research shows the new microbiological technique may be a feasible and economical method in application. PMID:23384822

Wang, Y J; Li, H Y; Hu, H F; Li, D P; Yang, Y J; Liu, C

2013-03-01

216

Using Formal Methods To Derive Test Frames In CategoryPartition Testing  

E-print Network

Using Formal Methods To Derive Test Frames In Category­Partition Testing Paul Ammann \\Lambda Jeff Engineering George Mason University, Fairfax, VA 22030 Abstract Testing is a standard method of assuring is a specification­ based testing method. An important aspect of category­ partition testing is the construction

Offutt, Jeff

217

40 CFR 63.1161 - Performance testing and test methods.  

...performance tests. (b) Establishment of scrubber operating parameters. During the...device, the owner or operator using a wet scrubber to achieve compliance shall establish...operating parameter values for the minimum scrubber makeup water flow rate...

2014-07-01

218

40 CFR 63.1161 - Performance testing and test methods.  

Code of Federal Regulations, 2013 CFR

...Process Facilities and Hydrochloric Acid Regeneration Plants § 63.1161 Performance...Establishment of hydrochloric acid regeneration plant operating parameters. ...performance test for hydrochloric acid regeneration plants, the owner or...

2013-07-01

219

In vitro\\/in vivo correlations of dissolution data of carbamazepine immediate release tablets with pharmacokinetic data obtained in healthy volunteers  

Microsoft Academic Search

The aim of the study was to select a dissolution test method for carbamazepine (CBZ) immediate release tablets, giving the best in vitro\\/in vivo correlations (IVIVC) and to determine the potential of this method as an estimate for bioequivalence testing. Four 200 mg CBZ products which are sold on the Dutch market, covering the innovator and three generic products, were

O. A. Lake; M. Olling; D. M. Barends

1999-01-01

220

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

221

Development of standard testing methods for nuclear-waste forms  

SciTech Connect

Standard test methods for waste package component development and design, safety analyses, and licensing are being developed for the Nuclear Waste Materials Handbook. This paper describes mainly the testing methods for obtaining waste form materials data. (DLC)

Mendel, J.E.; Nelson, R.D.

1981-11-01

222

40 CFR 75.22 - Reference test methods.  

Code of Federal Regulations, 2012 CFR

...assurance and quality control tests: (1) Methods 1 or 1A are...used when relative accuracy test audits of continuous moisture monitoring systems...A to this part. Otherwise, performance tests shall be conducted and...

2012-07-01

223

40 CFR 75.22 - Reference test methods.  

Code of Federal Regulations, 2011 CFR

...assurance and quality control tests: (1) Methods 1 or 1A are...used when relative accuracy test audits of continuous moisture monitoring systems...A to this part. Otherwise, performance tests shall be conducted and...

2011-07-01

224

Quick test methods for marine antifouling paints  

Microsoft Academic Search

Antifouling paints are used to protect ship and boat hulls from fouling settlement and to improve craft speed by reducing water friction. All this, in shipping economics, translates into several advantages obtained through faster craft speed and fuel saving. In this paper, laboratory tests are described that have been developed and tested in pilot plants with a view to speeding

Ilva Trentin; Vittorio Romairone; Giuseppe Marcenaro; Giorgio De Carolis

2001-01-01

225

40 CFR 63.547 - Test methods.  

Code of Federal Regulations, 2012 CFR

...to select the sampling port location... (2) EPA Method 2 at 40 CFR part...Point Integrated Sampling and Analytical Procedure of Method 3B to measure...to select the sampling port location... (2) EPA Method 2 at 40 CFR...

2012-07-01

226

40 CFR 63.547 - Test methods.  

Code of Federal Regulations, 2013 CFR

...to select the sampling port location... (2) EPA Method 2 at 40 CFR part...Point Integrated Sampling and Analytical Procedure of Method 3B to measure...to select the sampling port location... (2) EPA Method 2 at 40 CFR...

2013-07-01

227

Dissolution Kinetics of Zirconia Calcine  

SciTech Connect

Liquid radioactive raffinates from nuclear fuel reprocessing at the Idaho National Engineering and Environmental Laboratory were solidified, or calcines, in a fluidized bed reactor at approximately 500 C to form a dry granular material. This calcine has been provisionally stored near-surface in concrete-encased stainless steel bins at the Idaho Nuclear Technology Engineering Center. Research addressing the permanent immobilization of radioactive waste has been ongoing. One option is to separate the radioactive constituents from the calcine, thereby reducing the radioactive waste volume to be ultimately stored at a national nuclear waste repository. Nitric acid dissolution of the calcine is a key front-end unit operation in the separations option. In order to design calcine dissolution equipment, quantification of dissolution reaction rate parameters is required. A pilot-plant-produced, non-radioactive calcine was utilized to study the dissolution kinetics of a zirconia-type calcine. A heterogeneous overall calcine dissolution rate expression has been developed from the dissolution kinetics experimental data. This modeling work indicates that internal diffusion is the predominate controlling mechanism during dissolution of zirconia-type calcine. A shrinking core model with an exponentially decreasing internal diffusion as dissolution progresses fits that data best. However, this simple heterogeneous reaction model is not adequate to completely describe calcine dissolution.

T. A. Batcheller

1999-06-01

228

Basic Concepts in Modern Methods of Test Equating.  

ERIC Educational Resources Information Center

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

Woldbeck, Tanya

229

Sexually transmitted disease testing: evaluation of diagnostic tests and methods.  

PubMed

Most STIs in adolescents are asymptomatic. Recent studies in adolescents have documented relatively short periods of time until reinfection occurs (median times 4.7-7.6 months), suggesting that sexually active adolescents should be screened for STI every 6 months. Evidence-based practice is exceedingly helpful in deciding when to test, whom to test, and which methodology to use. In a recent critical analysis regarding screening women for chlamydia, screening all women for chlamydia was more cost-effective than testing only symptomatic women. With the proliferation of highly sensitive and specific assays, and the usefulness of different specimen sources (such as urine or self-swabs), health care providers of adolescents should screen all patients at risk for STIs. Although these screening and diagnostic techniques provide greater accuracy than previously attainable, screening should be part of a comprehensive methodology designed to promote good health care decisions, such as encouraging abstinence, promoting safer sexual practices, and using the most appropriate methodology to detect and treat STIs. PMID:15449846

Spigarelli, Michael G; Biro, Frank M

2004-06-01

230

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

231

30 CFR 27.31 - Testing methods.  

Code of Federal Regulations, 2010 CFR

...explosion-proof and other safety characteristics. Since all possible designs, arrangements, or combinations cannot be foreseen, MSHA reserves the right to make any tests or to place any limitations on equipment, or components or subassemblies...

2010-07-01

232

40 CFR 63.547 - Test methods.  

Code of Federal Regulations, 2010 CFR

...test. (d) Compliance with the face velocity requirements under § 63.544(b...Owners and operators shall calculate face velocity using the procedures in paragraphs...operating conditions. (iv) Face velocity shall be determined by dividing...

2010-07-01

233

40 CFR 63.547 - Test methods.  

Code of Federal Regulations, 2011 CFR

...test. (d) Compliance with the face velocity requirements under § 63.544(b...Owners and operators shall calculate face velocity using the procedures in paragraphs...operating conditions. (iv) Face velocity shall be determined by dividing...

2011-07-01

234

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

235

Overview of chemical modeling of nuclear waste glass dissolution  

SciTech Connect

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

Bourcier, W.L.

1991-02-01

236

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

237

Prediction of dissolution profiles of acetaminophen beads using artificial neural networks.  

PubMed

Immediate release acetaminophen (APAP) beads with 40% drug loading were prepared using the extrusion-spheronization process. Eighteen batches of beads were prepared based on a full factorial design by varying process variables such as extruder type, extruder screw speed, spheronization speed, and spheronization time. An in vitro dissolution test was carried out using the USP 27 Apparatus II (paddle) method. Artificial Neural Network (ANN) models were developed based on the aforementioned process variables and dissolution data. The trained ANN models were used to predict the dissolution profiles of APAP from the beads, which were prepared with various processing conditions. For training the ANN models, process variables were used as inputs, and percent drug released from APAP beads was used as the output. The dissolution data from one out of 18 batches of APAP beads was selected as the validation data set. The dissolution data of other 17 batches were used to train the ANN models using the ANN software (AI Trilogy) with two different training strategies, namely, neural and genetic. The validation results showed that the ANN model trained with the genetic strategy had better predictability than the one trained with the neural strategy. The ANN model trained with the genetic strategy was then used to predict the drug release profiles of two new batches of APAP beads, which were prepared with process variables that were not used during the ANN model training process. However, the process variables used to prepare the two new batches of APAP beads were within the confines of the process variables used to prepare the 18 batches. The actual drug release profile of these two batches of APAP beads was similar to the ones predicted by the trained and validated ANN model, as indicated by the high f2 values. Furthermore, the ANN model trained with genetic strategy was also used to optimize process variables to achieve the desired dissolution profiles. These batches of APAP beads were then actually prepared using the process variables predicted by the trained and validated ANN model. The dissolution results showed that the actual dissolution profiles of the APAP beads prepared from the predicted process variables were similar to the desired dissolution profiles. PMID:16895844

Peng, Yingxu; Geraldrajan, Maria; Chen, Quanmin; Sun, Yichun; Johnson, James R; Shukla, Atul J

2006-01-01

238

40 CFR 63.1208 - What are the test methods?  

Code of Federal Regulations, 2010 CFR

...furans, you must use: (A) Method 0023A, Sampling Method for Polychlorinated Dibenzo-p...testing, and whether previous Method 0023 analyses detected low levels...furan in the front half of the sampling train. (3 )...

2010-07-01

239

40 CFR 63.694 - Testing methods and procedures.  

Code of Federal Regulations, 2012 CFR

...document the test method, sampling protocol, and the...air, integrated sampling and analysis procedures of Method 3B of 40 CFR part...selection of the sampling site. (2) No...traverse site selection method is needed for...

2012-07-01

240

40 CFR 63.694 - Testing methods and procedures.  

Code of Federal Regulations, 2010 CFR

...document the test method, sampling protocol, and the...air, integrated sampling and analysis procedures of Method 3B of 40 CFR part...selection of the sampling site. (2) No...traverse site selection method is needed for...

2010-07-01

241

40 CFR 63.1208 - What are the test methods?  

Code of Federal Regulations, 2011 CFR

...furans, you must use: (A) Method 0023A, Sampling Method for Polychlorinated Dibenzo-p...testing, and whether previous Method 0023 analyses detected low levels...furan in the front half of the sampling train. (3 )...

2011-07-01

242

40 CFR 63.1208 - What are the test methods?  

Code of Federal Regulations, 2012 CFR

...furans, you must use: (A) Method 0023A, Sampling Method for Polychlorinated Dibenzo-p...testing, and whether previous Method 0023 analyses detected low levels...furan in the front half of the sampling train. (3 )...

2012-07-01

243

40 CFR 63.694 - Testing methods and procedures.  

Code of Federal Regulations, 2011 CFR

...document the test method, sampling protocol, and the...air, integrated sampling and analysis procedures of Method 3B of 40 CFR part...selection of the sampling site. (2) No...traverse site selection method is needed for...

2011-07-01

244

40 CFR 63.1208 - What are the test methods?  

...furans, you must use: (A) Method 0023A, Sampling Method for Polychlorinated Dibenzo-p...testing, and whether previous Method 0023 analyses detected low levels...furan in the front half of the sampling train. (3 )...

2014-07-01

245

40 CFR 63.694 - Testing methods and procedures.  

Code of Federal Regulations, 2013 CFR

...document the test method, sampling protocol, and the...air, integrated sampling and analysis procedures of Method 3B of 40 CFR part...selection of the sampling site. (2) No...traverse site selection method is needed for...

2013-07-01

246

40 CFR 63.1208 - What are the test methods?  

Code of Federal Regulations, 2013 CFR

...furans, you must use: (A) Method 0023A, Sampling Method for Polychlorinated Dibenzo-p...testing, and whether previous Method 0023 analyses detected low levels...furan in the front half of the sampling train. (3 )...

2013-07-01

247

Slow dissolution behaviour of amorphous capecitabine.  

PubMed

In this article, we report the anomalous dissolution behaviour of amorphous capecitabine. In contrast to what is expected from thermodynamic theory, amorphous capecitabine dissolves significantly slower compared to its crystalline counterpart. Our experiments show that this is due to the "gelling" properties of amorphous capecitabine in an aqueous environment. The "gel", which is immediately formed upon contact with water, entraps the capecitabine and significantly slows down its dissolution. This "gelling" property is hypothesized to be related to the low glass transition temperature (Tg 19°C) of amorphous capecitabine, resulting in an instant collapse ("gelling") in an aqueous environment. From IR and DSC analysis it is shown that this collapsed capecitabine is remarkably stable and does not recrystallize upon an increased water content or temperature. This highly reproducible dissolution behaviour can be applied in the development of a sustained release dosage form as substantially less sustained release excipient is required in order to attain the desired release profile. As capecitabine is a high-dosed drug, this is highly favourable in view of the size and thus clinical feasibility of the final dosage form. Currently, we are developing and clinically testing a sustained release formulation making use of amorphous capecitabine and its remarkable dissolution behaviour. PMID:23219704

Meulenaar, Jelte; Beijnen, Jos H; Schellens, Jan H M; Nuijen, Bastiaan

2013-01-30

248

Tracer Test Interpretation Methods for Reservior Properties  

SciTech Connect

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

Shook, George Michael

2001-08-01

249

Methods for planning repeated measures degradation tests  

Microsoft Academic Search

The failure mechanism of an item often can be linked directly to some sort of degradation process. This degradation process eventually weakens the item which then induces a failure. As system components have become highly reliable, traditional life tests, where the response is time to failure, provide few or no failures during the life of a study. For such situations,

Brian Phillip Weaver

2011-01-01

250

40 CFR 63.547 - Test methods.  

40 Protection of Environment 10 2014-07-01 2014-07-01...Section 63.547 Protection of Environment ENVIRONMENTAL PROTECTION...Air Pollutants From Secondary Lead Smelting § 63.547 Test...the emissions standards for lead compounds specified in §...

2014-07-01

251

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

252

Multiple Testing with Modified Bonferroni Methods.  

ERIC Educational Resources Information Center

This paper discusses the issue of multiple testing and overall Type I error rates in contexts other than multiple comparisons of means. It demonstrates, using a 5 x 5 correlation matrix, the application of 5 recently developed modified Bonferroni procedures developed by the following authors: (1) Y. Hochberg (1988); (2) B. S. Holland and M. D.…

Li, Jianmin; And Others

253

Plutonium dissolution process  

SciTech Connect

A two-step process is described 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 C and 70 C. The mixture will dissolve a first portion of the plutonium metal but leave a portion of the plutonium in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alteratively, nitric acid in a concentration between approximately 0.05M and 0.067M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution process is diluted with nitrogen. 2 figs.

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

1996-01-09

254

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

255

Robotic dissolution station  

SciTech Connect

This invention is comprised of a robotic station for dissolving active metals in acid in an automated fashion. A vessel with cap, containing the active metal is placed onto a shuttle which retracts to a point at which it is directly beneath a cap removing and retaining mechanism. After the cap is removed, a tube carrying an appropriate acid is inserted into the vessel, and the acid is introduced. The structure of the station forms an open hood which is swept of gases generated by the dissolution and the air removed to a remote location for scrubbing. After the reaction is complete, the shuttle extends and the vessel may be removed by a robot arm.

Beugelsdijk, T.J.; Hollen, R.M.; Temer, D.J.; Haggart, R.J.; Erkkila, T.H.

1991-12-31

256

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

257

Dissolution of nickel hydroxide in ammoniacal aqueous solutions  

NASA Astrophysics Data System (ADS)

The dissolution of nickel hydroxide in ammoniacal solutions was investigated to develop a new recycling process for nickel-metal hydride batteries. The effects of temperature, total ammonia concentration, and pH of the solution were examined in the range of 30 °C to 60 °C, 3.0 to 5.0 M, and 9.0 to 10.7, respectively. All dissolution-time curves showed sigmoidal shapes, which could be approximately expressed by the Johnson-Mehl-Avrami-Yerofeev-Kolmogrov (JMAYK) equation. The hydroxide particles were pitted, and some of them were broken into fragments in the course of the dissolution. An increase in the surface area of the hydroxide particles due to the formation of pits and fragmentation seemed to be the reason for the acceleration of dissolution in the early stage. The surface area of the hydroxide was measured by the Brunauer-Emmett-Teller (BET) method, and the dissolution rate per surface area was determined. The activation energy for the dissolution was obtained as 100±10 kJ mol-1, which confirmed that the dissolution was controlled by chemical reactions at the hydroxide/liquid interface. The dissolution rate was increased by the increase in ammonia concentration, and the highest rate was observed at pH ca. 10.

Miyake, Masao; Maeda, Masafumi

2006-04-01

258

A NON-MARITAL, ROMANTIC RELATIONSHIP DISSOLUTION STUDY.  

E-print Network

??The present study examines three non-marital, romantic relationship dissolution types: (1) normal dyadic dissolution, (2) fatal attraction dissolution, and (3) social allergen dissolution among a… (more)

Stork-Hestad, Nicole B.

2010-01-01

259

Method and apparatus for gripping test specimens  

NASA Astrophysics Data System (ADS)

A pair of solid-teeth wedges are employed in an improved gripping system. The wedges fit inside a pair of plates having an angled cavity to accommodate them. As stress is applied to the specimen, the wedges are urged toward the specimen by the angled cavity to increase the gripping force. An alignment fixturing device is used to properly position the grips on the test specimen. This device not only axially aligns the grips but also locates them at the proper spacing.

Mackay, Rebecca A.; Nathal, Michael V.

1992-05-01

260

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

261

A Tale of Two Paradigms: Formal Methods and Software Testing  

Microsoft Academic Search

There are two camps of software developers: formal methods advocates battling against traditionalist supporters of software testing and assessment metrics. Surely, as Turing observed, we will (must) never do away with testing in some form. But clearly, formal methods cannot be ignored, and must be the basis of quality assurance in some form. Important impacts of specifications on testing are

David A. Carrington; Phil Stocks

1994-01-01

262

Low-cycle fatigue testing methods  

NASA Technical Reports Server (NTRS)

The good design of highly stressed mechanical components requires accurate knowledge of the service behavior of materials. The main methods for solving the problems of designers are: determination of the mechanical properties of the material after cyclic stabilization; plotting of resistance to plastic deformation curves; effect of temperature on the life on low cycle fatigue; and simulation of notched parts behavior.

Lieurade, H. P.

1978-01-01

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

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

Federal Register 2010, 2011, 2012, 2013

...to replace the use of animals in skin sensitization testing for hazard and potency...Laboratory for Alternatives to Animal Testing (EURL ECVAM), and by...Alternative (non- animal) methods for cosmetics testing: current status and...

2013-11-13

265

Dissolution rate of alpha-doped UO2 in natural groundwater  

NASA Astrophysics Data System (ADS)

The objective of this work is to determine whether the presence of trace elements in natural groundwaters affects the dissolution rate of uranium dioxide in the presence of alpha radiation that causes radiolysis of water. The study is a part of the project Reducing Uncertainty in Performance Prediction (REDUPP) under the Seventh Framework Programme of the European Atomic Energy Community (EURATOM). The project aims to reduce uncertainties related to the extrapolation of the results of laboratory experiments to the conditions expected under geologic disposal. Thus far, synthetic groundwater has been normally used in the experiments. The synthetic groundwaters used do not contain all of the chemical elements that occur in natural groundwaters. Three natural groundwaters were chosen for the dissolution experiments with 0%, 5%, and 10% 233U-doped UO2 samples. These include a brackish groundwater, a saline groundwater and a low ionic strength groundwater. At the time of writing this paper, the dissolution experiments have been finished in the first groundwater, which was a moderately saline, brackish groundwater. The groundwater samples for the experiments were taken from a borehole in the Olkiluoto site in Finland. The measurements for dissolution rates were conducted under reducing conditions established using metallic iron in solution and an argon atmosphere in the glove box. The isotope dilution method was used to decrease uncertainties due to precipitation and sorption effects. The resulting dissolution rates in OL-KR6 natural groundwater were generally somewhat higher than the rates measured previously in synthetic groundwaters under similar redox conditions. No clear effect of alpha radiolysis could be seen for tests with lower SA/V, while those for higher SA/V indicated that the dissolution rate was higher for the 10% 233U-doped UO2, suggesting the effect of alpha radiolysis under these conditions.

Ollila, Kaija; Myllykylä, Emmi; Tanhua-Tyrkkö, Merja; Lavonen, Tiina

2013-11-01

266

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

267

Field testing method for photovaltaic modules  

NASA Astrophysics Data System (ADS)

For remote areas, where solar photovoltaic modules are the only source of power, it is essential to perform preventive maintenance to insure that the PV system works properly; unfortunately, prices for PV testers range from 1,700 to 8,000. To address this issue, a portable inexpensive tester and analysis methodology have been developed. Assembling a simple tester, which costs $530 and weighs about 5 pounds, and using the Four-Parameters PV Model, we characterized the current-voltage (I-V) curve at environmental testing conditions; and then employing radiation, temperature, and age degradation sensitivity equations, we extrapolated the I-V curve to standard testing conditions. After applying the methodology to three kinds of silicon modules (mono-crystalline, multi-crystalline, and thin-film), we obtained maximum power points up to 97% of the manufacturer's specifications. Therefore, based on these results, it is reasonably accurate and affordable to verify the performance of solar modules in the field.

Ramos, Gerber N.

268

SQUID method of lung contamination testing  

NASA Astrophysics Data System (ADS)

We are reporting on the development of a SQUID magnetometric method of ferromagnetic dust quantification in the human lungs. In order to solve this problem we utilize a forward method of magnetized ferromagnetic particle (dipole) distribution 3D modeling in human lung torso and in an arc welder’s lungs. We also solve the inverse problem, by which the amount of dust in the lungs is estimated using the results of the remanent magnetic induction Br measurement upon the human chest. We state the formula for SQUID measured output voltage U to Br conversion for the second order gradiometer, which is in a highly dipole position and density dependent. We utilize a low- Tc second order rf SQUID gradiometer with the sensitivity of 10 -14 T in the unit frequency range.

Martinická, F.; Šimá?ek, I.; Jurdák, P.; Cigá?, A.; Ma?ka, J.

2006-03-01

269

Methods of Assessing Bias and Fairness in Tests.  

ERIC Educational Resources Information Center

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

Merz, William R.

270

Development of an oxygen impact-testing method  

NASA Technical Reports Server (NTRS)

The development of a gaseous oxygen impact test method to aid in the selection of materials for high pressure oxygen systems is discussed. The objectives of the tests and the test equipment used are described. It is concluded that the impact test procedures are adequate for present purposes, but cannot be depended upon for establishing future standards.

Jamison, H. H.

1971-01-01

271

Testing a variational method for fluctuations  

NASA Astrophysics Data System (ADS)

A variational approach for many-body systems due to Balian and Vénéroni, which goes beyond the Harrtree-Fock mean field, has been implemented in the case of nuclear Skyrme effective interactions used in examining large amplitude collective motion. An evaluation of the numerical issues involved with the method is presented, in which it is found that the effect of model parameters is generally under control, but long-time running leads to unphysical results.

Stevenson, P. D.; Broomfield, J. M. A.

2010-01-01

272

Results of Ocular Dominance Testing Depend on Assessment Method  

PubMed Central

Purpose We developed a near ocular dominance test modeled after the distance hole-in-the card test, and assessed both test-retest reliability of four tests of ocular dominance and agreement between tests. Methods 46 subjects ages 18 to 78 years with visual acuity 20/40 or better in each eye were enrolled from a primary care practice. All subjects had normal eye examinations, with the exception of refractive error, and were examined in their habitual correction. Subjects were tested twice each with the distance hole-in-the-card test, new near hole- in-the-card test, near convergence test, and the Pediatric Eye Disease Investigator Group (PEDIG) fixation preference test. Test-retest reliability and agreement between tests were evaluated with the Kappa statistic. Results There was substantial to almost perfect test-retest reliability for the distance hole-in-the-card test, new near hole-in-the-card test, convergence test, and PEDIG fixation preference test (Kappa, k=0.77, 0.62, 0.84, 0.77, respectively). In contrast, the agreement between the new near hole in the card test and the other three tests – distance hole in the card, near convergence, and PEDIG fixation preference– was moderate to slight (k=0.41, 0.19, 0.11, respectively). Agreement was moderate to fair (k=0.47, 0.32) between the distance hole in the card test and the near convergence test, and between the distance-hole-in-the-card test and the PEDIG fixation preference test. Agreement was fair (k=0.27) between the near convergence test and the PEDIG fixation preference test. Conclusions Although there was excellent test-retest reliability of each ocular dominance test, there was only moderate to slight agreement between tests. Results of ocular dominance tests seem to vary depending on both the testing distance and the specific activity performed as part of the testing procedure. PMID:18455935

Rice, Melissa L.; Leske, David A.; Smestad, Christina E.; Holmes, Jonathan M.

2008-01-01

273

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

274

Dissolution kinetics of quicklime in various organic solvents and solutions.  

PubMed

The rate of the dissolution of quicklime was measured in different organic solvents and solutions of methanol, ethylene glycol, glycerol and sucrose. It was found that the rate of dissolution in methanol, glycerol and sucrose was dramatically reduced compared with that in deionized water. However, little difference was measured in a solution of ethylene glycol compared with aqueous solutions. The presence of chloride ions increases the rate of dissolution in all solvents and solutions, except for ethylene glycol, where a decrease was actually observed. It was also found that the presence of sulphate ions decreases the rate in all organic solvents and solutions tested. PMID:22856289

Potgieter, J H; Gregory, H

2012-06-01

275

Standard test method for liquid impingement erosion using rotating apparatus  

E-print Network

1.1 This test method covers tests in which solid specimens are eroded or otherwise damaged by repeated discrete impacts of liquid drops or jets. Among the collateral forms of damage considered are degradation of optical properties of window materials, and penetration, separation, or destruction of coatings. The objective of the tests may be to determine the resistance to erosion or other damage of the materials or coatings under test, or to investigate the damage mechanisms and the effect of test variables. Because of the specialized nature of these tests and the desire in many cases to simulate to some degree the expected service environment, the specification of a standard apparatus is not deemed practicable. This test method gives guidance in setting up a test, and specifies test and analysis procedures and reporting requirements that can be followed even with quite widely differing materials, test facilities, and test conditions. It also provides a standardized scale of erosion resistance numbers applicab...

American Society for Testing and Materials. Philadelphia

2010-01-01

276

A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics  

SciTech Connect

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

Chen Zhu; William E. Seyfried

2005-01-01

277

Efficient Methods for Interoperability Testing Using Event Sequences.  

National Technical Information Service (NTIS)

Many software testing problems involve sequences of events. The methods described in this paper were motivated by testing needs of mission critical systems that may accept multiple communication or sensor inputs and generate output to several communicatio...

D. R. Kuhn, J. F. Lawrence, J. M. Higdon, R. N. Kacker, Y. Lei

2012-01-01

278

40 CFR 60.133 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.133 Test methods and procedures. (a) In conducting performance tests...

2011-07-01

279

40 CFR 60.133 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.133 Test methods and procedures. (a) In conducting performance tests...

2010-07-01

280

40 CFR 60.133 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.133 Test methods and procedures. (a) In conducting performance tests...

2013-07-01

281

40 CFR 60.133 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.133 Test methods and procedures. (a) In conducting performance tests...

2012-07-01

282

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

283

40 CFR 63.425 - Test methods and procedures.  

... After 4 minutes 112 (4.4) After 5 minutes 140 (5.5) (h) Continuous performance pressure decay test. The continuous performance pressure decay test shall be performed using Method 27, appendix A, 40 CFR Part 60....

2014-07-01

284

40 CFR 60.303 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

285

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

286

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

287

Disintegration of highly soluble immediate release tablets: a surrogate for dissolution.  

PubMed

The purpose of the work was to investigate correlation between disintegration and dissolution for immediate release tablets containing a high solubility drug and to identify formulations where disintegration test, instead of the dissolution test, may be used as the acceptance criteria based on International Conference on Harmonization Q6A guidelines. A statistical design of experiments was used to study the effect of filler, binder, disintegrating agent, and tablet hardness on the disintegration and dissolution of verapamil hydrochloride tablets. All formulation variables, i.e., filler, binder, and disintegrating agent, were found to influence tablet dissolution and disintegration, with the filler and disintegrating agent exerting the most significant influence. Slower dissolution was observed with increasing disintegration time when either the filler or the disintegrating agent was kept constant. However, no direct corelationship was observed between the disintegration and dissolution across all formulations due to the interactions between different formulation components. Although all tablets containing sodium carboxymethyl cellulose as the disintegrating agent, disintegrated in less than 3 min, half of them failed to meet the US Pharmacopeia 30 dissolution criteria for the verapamil hydrochloride tablets highlighting the dependence of dissolution process on the formulation components other than the disintegrating agent. The results identified only one formulation as suitable for using the disintegration test, instead of the dissolution test, as drug product acceptance criteria and highlight the need for systematic studies before using the disintegration test, instead of the dissolution test as the drug acceptance criteria. PMID:19387843

Gupta, Abhay; Hunt, Robert L; Shah, Rakhi B; Sayeed, Vilayat A; Khan, Mansoor A

2009-01-01

288

Overview of Non-Volatile Testing and Screening Methods  

NASA Technical Reports Server (NTRS)

Testing methods for memories and non-volatile memories have become increasingly sophisticated as they become denser and more complex. High frequency and faster rewrite times as well as smaller feature sizes have led to many testing challenges. This paper outlines several testing issues posed by novel memories and approaches to testing for radiation and reliability effects. We discuss methods for measurements of Total Ionizing Dose (TID).

Irom, Farokh

2001-01-01

289

Status and applications of echinoid (phylum echinodermata) toxicity test methods  

SciTech Connect

The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). The status and relative sensitivity of various test methods are described. The most frequently used test methods consist of short-term exposures of sea urchin sperm or embryos; these tests can be easily conducted at all times of the year by using species with complementary spawning cycles or laboratory conditioned populations of a single species. Data from reference toxicant and effluent toxicity tests are summarized. Information on the precision and sensitivity of echinoid test methods are limited and preclude rigorous comparisons with other test methods. The available data indicate that the sensitivity and precision of these methods are comparable to short-term chronic methods for other marine invertebrates and fish. Recent application of the sperm test in toxicity identification evaluations (TIEs) and studies of effluent toxicity decay and sediment toxicity illustrate the versatility of this rapid (10 to 60 min exposure) test method. Embryo tests typically use a 48 to 96 h exposure period and measure the occurrence of embryo malformations. Most recent applications of the embryo test have been for the assessment of sediment elutriate toxicity. Adult echinoderms are not frequently used to assess effluent or receiving water toxicity. Recent studies have had success in using the adult life stage of urchins and sand dollars to assess the effects of contaminated sediment on growth, behavior, and bioaccumulation.

Bay, S.; Burgess, R.; Nacci, D.

1993-01-01

290

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

291

Mathematical modeling of drug dissolution.  

PubMed

The dissolution of a drug administered in the solid state is a pre-requisite for efficient subsequent transport within the human body. This is because only dissolved drug molecules/ions/atoms are able to diffuse, e.g. through living tissue. Thus, generally major barriers, including the mucosa of the gastro intestinal tract, can only be crossed after dissolution. Consequently, the process of dissolution is of fundamental importance for the bioavailability and, hence, therapeutic efficacy of various pharmaco-treatments. Poor aqueous solubility and/or very low dissolution rates potentially lead to insufficient availability at the site of action and, hence, failure of the treatment in vivo, despite a potentially ideal chemical structure of the drug to interact with its target site. Different physical phenomena are involved in the process of drug dissolution in an aqueous body fluid, namely the wetting of the particle's surface, breakdown of solid state bonds, solvation, diffusion through the liquid unstirred boundary layer surrounding the particle as well as convection in the surrounding bulk fluid. Appropriate mathematical equations can be used to quantify these mass transport steps, and more or less complex theories can be developed to describe the resulting drug dissolution kinetics. This article gives an overview on the current state of the art of modeling drug dissolution and points out the assumptions the different theories are based on. Various practical examples are given in order to illustrate the benefits of such models. This review is not restricted to mathematical theories considering drugs exhibiting poor aqueous solubility and/or low dissolution rates, but also addresses models quantifying drug release from controlled release dosage forms, in which the process of drug dissolution plays a major role. PMID:23618956

Siepmann, J; Siepmann, F

2013-08-30

292

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

293

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

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

2014-01-01

294

Experimental results of calcine dissolution studies performed during FY-94,95  

SciTech Connect

Calcine dissolution studies were performed in FY-94,95 in order to extend the knowledge of dissolution and to obtain information necessary for scale-up design and operation. Experiments reported in this document were performed with non-radioactive and actual calcines to generate qualitative data regarding: (a) calcine dissolution rates, (b) undissolved solids settling characteristics, (c) undissolved solids heel formation, and (d) chemical treatments for undissolved solids heel dissolution. The goal of this work was to achieve complete calcine dissolution, or to determine conditions that would result in the maximum calcine dissolution. Small scale laboratory experiments (test-tube dissolutions) and a bench scale dissolver set-up were used in the effort. Results from this work show the bulk of the undissolved solids to settle at a rate of >9 inches per second when the baseline dissolution parameters are used. Baseline dissolution parameters were 100 grams of calcine being dissolved in 1 L of 5 M HNO{sub 3} at > 90 C while the solution is being vigorously and constantly mixed. This work also verified that dissolution is most complete when performed with aggressive mixing. Sequential dissolutions performed with non-radioactive and actual calcine indicate that little undissolved solids heel build-up is expected, and this small heel can be further dissolved by increasing the dissolution time or by adding fresh nitric acid.

Brewer, K.N.; Olson, A.L.; Roesener, W.S.; Tonso, J.L.

1997-09-01

295

40 CFR 63.786 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...Standard Test Methods for Aromatics in Mineral Spirits by Gas Chromatography (incorporation by reference—see § 63.14). In determining...ASTM Method E260-91 or 96: Standard Practice for Gas Chromatography [incorporation by reference—see §...

2012-07-01

296

40 CFR 63.805 - Performance test methods.  

... NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Wood Furniture Manufacturing Operations § 63.805 Performance test methods. (a)(1) The EPA Method 311...

2014-07-01

297

40 CFR 60.715 - Test methods and procedures.  

Code of Federal Regulations, 2012 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...

2012-07-01

298

40 CFR 60.715 - Test methods and procedures.  

Code of Federal Regulations, 2013 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...

2013-07-01

299

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

300

40 CFR 63.786 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...Standard Test Methods for Aromatics in Mineral Spirits by Gas Chromatography (incorporation by reference—see § 63.14). In determining...ASTM Method E260-91 or 96: Standard Practice for Gas Chromatography [incorporation by reference—see §...

2013-07-01

301

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...

302

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

303

Chlorpheniramine dissolution and relative urinary excretion from commercial products.  

PubMed

Dissolution profiles were determined for seven commercially available nonprescription solid dosage forms containing chlorpheniramine (four sustained release and three immediate release). An in vitro pH change method used to simulate GI transit produced dissolution profiles for some similarly labeled products which were significantly nonequivalent. One product failed to release its chlorpheniramine even when ground in a mortar and pestle in HCl solution, but did release drug in H3PO4 solution. A small (four subjects) relative bioavailability study based on average cumulative excretion of intact drug in urine gave results in parallel with substantially nonequivalent dissolution data for three products. PMID:2600791

Hsu, H Y; Ayres, J W

1989-10-01

304

Investigating the effect of solubility and density gradients on local hydrodynamics and drug dissolution in the USP 4 dissolution apparatus.  

PubMed

The aim of this investigation was to evaluate the effect of solubility and related solution density gradients, on hydrodynamics and dissolution rate in a low velocity pulsing flow, in the USP 4 flow-through dissolution apparatus. The paddle apparatus, flow-through apparatus and a free convection system were used in dissolution testing, using benzoic acid (BA) and lactose monohydrate (LM), representing slightly and freely soluble model compounds, respectively. A flow rate of 8 ml min(-1) (22.6 mm diameter cell) was used in the flow-through apparatus. Computational fluid dynamics (CFD) simulations were used to analyze the effect of the dissolved compounds on local hydrodynamics. A higher dissolution rate of both BA and LM was obtained in the free convection system compared to the flow-through apparatus, with highest dissolution rate from both compounds in the paddle apparatus. The effect of downward flow arising from natural convection had a significant effect for the more soluble compound, LM, on local fluid velocities, whereas flow reversal induced by the forced convection environment was a significant feature impacting on the hydrodynamics in the BA species transfer simulation. The effect of solution density on local hydrodynamics needs to be considered when selecting dissolution conditions in the USP 4 dissolution apparatus. PMID:21843609

D'Arcy, Deirdre M; Liu, Bo; Corrigan, Owen I

2011-10-31

305

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...

306

Comparison of three standardized disc susceptibility testing methods for colistin  

Microsoft Academic Search

Methods: A total of 228 clinical isolates of Acinetobacter spp., Pseudomonas aeruginosa and Entero- bacteriaceae were included in the study. Isolates were tested by agar dilution for susceptibility to colistin, and results were compared with those obtained by three disc susceptibility testing methods (product insert based on CLSI methodology, British BSAC and French SFM). Results: Colistin displayed good activity against

Thean Yen Tan; Lily Siew; Yong Ng

2006-01-01

307

ENERGY EFFICIENT LIGHTING PRODUCTS TEST METHOD SELECTION LIST  

E-print Network

ENERGY EFFICIENT LIGHTING PRODUCTS TEST METHOD SELECTION LIST NOTICE TO APPLICANTS FOR SOLID STATE of IES LM-79. ENERGY EFFICIENT LIGHTING PRODUCTS NOTICE (2013-08-30) i #12;DATE: __________________ NVLAP: _________________ _________________________________________________________________________________________________________________ NVLAP ENERGY EFFICIENT LIGHTING APPLICATION (REV. 2014-03-07) PAGE 1 OF 6 Test Method Designation Short

308

Applicability of the Accelerated Switching Test Method - A Comprehensive Survey  

Microsoft Academic Search

The enhanced degradation exhibited at low dose rates by many bipolar-technology components is a major reliability issue for spacecraft electronics. As an accelerated ELDRS test method an approach has been suggested that makes use of sequenced high dose rate and low dose rate exposures - the so called accelerated switching test method. In this paper we describe the results of

M. Wind; P. Beck; J. Boch; L. Dusseau; M. Latocha; M. Poizat; A. Zadeh

2011-01-01

309

Methods for Studying Bias in Psychological and Educational Tests.  

ERIC Educational Resources Information Center

This article defines test bias and reviews research methods most aptly applied postpublication to educational and psychological tests. Best methods for estimating bias in criterion-related or predictive validity and determining bias in construct validity across groups are explained. (Author/JDD)

Reynolds, Cecil R.

1991-01-01

310

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

311

A Test Characteristic Curve Linking Method for the Testlet Model  

ERIC Educational Resources Information Center

When tests are made up of testlets, a testlet-based item response theory (IRT) model may be used to account for local dependence among items from a common testlet. This study presents a new test characteristic curve method to link calibrations based on the Bradlow, Wainer, and Wang (1999) testlet model. Procedures for calculating the test

Li, Yanmei; Bolt, Daniel M.; Fu, Jianbin

2005-01-01

312

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

313

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

314

Test Methods in the Development of Sports Equipment  

Microsoft Academic Search

\\u000a The advancement and diversification of sports is closely linked to the enhancement, new development and increasing testing\\u000a of sports equipment, which can be implemented by using a variety of test methods and procedures. The presentation outlines\\u000a these test methods for specific examples and demonstrates the significance, possibilities and limitations of the development\\u000a of sports equipment. The focus is to show

Stephan Odenwald

315

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

316

Dissolution of plutonium dioxide in nitric acid  

SciTech Connect

Two alternative procedures of the electrochemical dissolution of plasmothermal plutonium dioxide in nitric acid were studied: reductive dissolution in the presence of U(IV) stabilized by hydrazine and dissolution in hot nitric acid at the alternating current supply. The current field accelerates dissolution of PuO{sub 2}.

Nikitina, G.P.; Zhukova, I.N.; Egorova, V.P. [Khlopin Radium Inst., St. Petersburg (Russian Federation)

1995-07-01

317

Routing engine, method of routing a test probe and testing system employing the same  

US Patent & Trademark Office Database

Embodiments of the present disclosure provide a routing engine, a method of routing a test probe and a testing system employing the router or the method. In one embodiment, the routing engine is for use with a test unit having at least one test probe and includes an analysis unit configured to analyze alternative test probe routing sequences that employ representative circuit chips of a semiconductor wafer to be tested by the test unit. The routing engine also includes a selection unit configured to select at least one of the test probe routing sequences as a test probe path for testing the semiconductor wafer based on a total cost of travel for the test probe path.

2009-10-06

318

Development and Evaluation of the Quadrant Ring Test Method  

Microsoft Academic Search

Testing of ring-shaped specimens often is required for determining the hoop-direction mechanical properties of cylindrical\\u000a composite structures. A quadrant ring test method was developed in an effort to produce a relatively uniform stress distribution\\u000a in the ring specimen using a conventional tensile testing machine. Finite element analysis results indicated that the four-sector\\u000a quadrant test is capable of producing a more

E. J. Walsh; D. O. Adams

2008-01-01

319

Methods for speeding up radiated and conducted immunity tests  

Microsoft Academic Search

Different methods for reducing test time in immunity tests similar to IEC 61000-4-6 or IEC 61000-4-3 are compared. One option is to apply multiple signals at the same time. Hardware and software methods to create those signals are explained, limits and possible amplitude errors are discussed. Mode stirred chambers and methods which aim at substituting sinusoidal excitation by strong pulsed

D. Pommerenke

2000-01-01

320

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

Code of Federal Regulations, 2011 CFR

...HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants for Wet-Formed Fiberglass Mat Production Testing and Initial Compliance Requirements § 63.2993 What test methods must I use in conducting...

2011-07-01

321

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

...POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Wet-Formed Fiberglass Mat Production Testing and Initial Compliance Requirements § 63.2993 What test methods must I use in conducting...

2014-07-01

322

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

Code of Federal Regulations, 2012 CFR

...POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Wet-Formed Fiberglass Mat Production Testing and Initial Compliance Requirements § 63.2993 What test methods must I use in conducting...

2012-07-01

323

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

Code of Federal Regulations, 2013 CFR

...POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Wet-Formed Fiberglass Mat Production Testing and Initial Compliance Requirements § 63.2993 What test methods must I use in conducting...

2013-07-01

324

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

325

Insulator icing test methods and procedures: a position paper prepared by the IEEE task force on insulator icing test methods  

Microsoft Academic Search

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, and cold-fog deposits as well as voltage applications and flashover voltage evaluation. Some relevant parameters for

M. Farzaneh; T. Baker; A. Bernstorf; 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. Rozek; D. L. Ruff; D. Shaffner; V. Sklenicka; R. Sundararajan; J. Yu

2003-01-01

326

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

327

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

328

Residual flexibility test method for verification of constrained structural models  

NASA Technical Reports Server (NTRS)

A method is presented for deriving constrained modes and frequencies from a model correlated to a set of free-free test modes and a set of measured residual flexibilities. The method involves a simple modification of the MacNeal and Rubin component mode representation to allow verification of a constrained structural model. Results for two spaceflight structures show quick convergence of constrained modes using an easily measurable set of free-free modes plus the residual flexibility matrix or its boundary partition. This paper further validates the residual flexibility approach as an alternative test/analysis method when fixed-base testing proves impractical.

Admire, John R.; Tinker, Michael L.; Ivey, Edward W.

1992-01-01

329

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 accidental 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 Ohio State University 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

330

Dissolution kinetics and etch pit studies of potassium aluminium sulphate  

NASA Astrophysics Data System (ADS)

The dissolution process of the {111} faces of potash alum is studied, both by microtopographic examinations of the etch pit patterns and by measurement of the dissolution kinetics in a rotating disc crystallizer. Both methods showed that the Cabrera-Levine dissolution theory holds for the two most common dislocation types ending on the {111} faces of potash alum. On the basis of the rotating disc experiments, the interfacial supersaturation of the etch pit experiments was roughly estimated. Using this, it was found that at interfacial supersaturations below -0.6% (dislocations with <110> Burgers vector) or below -0.85% (dislocations with <100> Burgers vector) numerous etch pits related to those dislocation types appeared. Below those undersaturations the dissolution process is mainly determined by volume diffusion. From the critical undersaturation, determined in the rotating disc crystallizer, the value of the edge free energy of a step was found to be approximately 0.01 J/m 2.

van der Hoek, B.; Van Enckevort, W. J. P.; Van Der Linden, W. H.

1983-03-01

331

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

E-print Network

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

Stone, Abraham

332

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

333

40 CFR 63.805 - Performance test methods.  

Code of Federal Regulations, 2012 CFR

...iii) Use any alternative protocol and test method provided they meet either the requirements of the data quality objective (DQO) approach or the lower confidence level (LCL) approach (see § 63.801); (iv) Shut down all nonaffected HAP...

2012-07-01

334

40 CFR 63.805 - Performance test methods.  

Code of Federal Regulations, 2011 CFR

...iii) Use any alternative protocol and test method provided they meet either the requirements of the data quality objective (DQO) approach or the lower confidence level (LCL) approach (see § 63.801); (iv) Shut down all nonaffected HAP...

2011-07-01

335

40 CFR 63.805 - Performance test methods.  

Code of Federal Regulations, 2013 CFR

...iii) Use any alternative protocol and test method provided they meet either the requirements of the data quality objective (DQO) approach or the lower confidence level (LCL) approach (see § 63.801); (iv) Shut down all nonaffected HAP...

2013-07-01

336

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

337

40 CFR 76.15 - Test methods and procedures.  

...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

338

40 CFR 60.214 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid Plants § 60.214 Test methods and procedures. (a) In conducting the...

2013-07-01

339

40 CFR 60.204 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate Fertilizer Industry: Wet-Process Phosphoric Acid Plants § 60.204 Test methods and procedures. (a) In conducting...

2013-07-01

340

40 CFR 60.204 - 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: Wet-Process Phosphoric Acid Plants § 60.204 Test methods and procedures. (a) In conducting...

2012-07-01

341

40 CFR 60.224 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

342

40 CFR 60.214 - 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: Superphosphoric Acid Plants § 60.214 Test methods and procedures. (a) In conducting the...

2012-07-01

343

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...

344

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

345

40 CFR 60.736 - 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 Calciners and Dryers in Mineral Industries § 60.736 Test methods and procedures. (a) In conducting the performance...

2010-07-01

346

40 CFR 60.736 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Calciners and Dryers in Mineral Industries § 60.736 Test methods and procedures. (a) In conducting the performance...

2012-07-01

347

40 CFR 60.736 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Calciners and Dryers in Mineral Industries § 60.736 Test methods and procedures. (a) In conducting the performance...

2013-07-01

348

40 CFR 60.736 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Calciners and Dryers in Mineral Industries § 60.736 Test methods and procedures. (a) In conducting the performance...

2011-07-01

349

40 CFR 60.685 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standard of Performance for Wool Fiberglass Insulation Manufacturing Plants § 60.685 Test methods and procedures. (a) In conducting the performance...

2013-07-01

350

40 CFR 60.685 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standard of Performance for Wool Fiberglass Insulation Manufacturing Plants § 60.685 Test methods and procedures. (a) In conducting the performance...

2012-07-01

351

40 CFR 60.685 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standard of Performance for Wool Fiberglass Insulation Manufacturing Plants § 60.685 Test methods and procedures. (a) In conducting the performance...

2010-07-01

352

40 CFR 60.685 - Test methods and procedures.  

Code of Federal Regulations, 2011 CFR

...PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standard of Performance for Wool Fiberglass Insulation Manufacturing Plants § 60.685 Test methods and procedures. (a) In conducting the performance...

2011-07-01

353

40 CFR 60.46 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...STATIONARY SOURCES Standards of Performance for Fossil-Fuel-Fired Steam Generators § 60.46 Test methods...pairs of samples. (c) When combinations of fossil fuels or fossil fuel and wood residue are fired, the owner or...

2012-07-01

354

40 CFR 60.46 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...STATIONARY SOURCES Standards of Performance for Fossil-Fuel-Fired Steam Generators § 60.46 Test methods...pairs of samples. (c) When combinations of fossil fuels or fossil fuel and wood residue are fired, the owner or...

2013-07-01

355

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

356

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

357

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

358

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

359

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

360

Multipoint dissolution specification and acceptance sampling rule based on profile modeling and principal component analysis.  

PubMed

In dissolution testing, multiple dissolution measurements at specific time points are needed in quality control when the compliance of the product requires controlled dissolution throughout the time course. The dissolution specification based on general multivariate confidence region was proposed by Chen and Tsong (8). This paper presents two alternative procedures when the dissolution profile consists of important measurements at more than 4 time points. In the first procedure, when the dissolution profile can be described by a physical curve through modeling, the dissolution specification is developed based on the confidence region of the parameters of the physical curve. In the second procedure, the principal components (PCS) as the linear combinations of the dissolution measurements are identified and dissolution specification is set based by the confidence intervals of the values of principal components. In both approaches the specification can be set at lower dimensions than the general multivariate confidence region approach. A single-stage acceptance rule can be used in both approaches by first projecting the dissolution values of each tablet in the new testing batch onto the determined parameters axes (through modeling in modeling approach and through projection on the selected PCS in principal component approach). Then check if the projections of the new tablet fall within the specifications. Finally, count the number of tablets that fall outside the specification limits and reject the batch if the proportion of out-of-specification tablet is high and accept the lot for release if the proportion is low. PMID:9252835

Tsong, Y; Hammerstrom, T; Chen, J J

1997-07-01

361

Modeling the Trans-Varestraint test with finite element method  

Microsoft Academic Search

The Trans-Varestraint test is modeled as three dimensional contact problem with finite element method (FEM). The local strains at the trailing of weld molten pool of samples with the Trans-Varestraint test are calculated under different bending strains. The calculated local strains are in good agreement with the experimental measurements. Meanwhile, the simulated results show that the maximum local strain on

Yanhong Wei; Zhibo Dong; Renpei Liu; Zhujue Dong

2006-01-01

362

Method for Smoke Spread Testing of Large Premises  

Microsoft Academic Search

A method for performing non-destructive smoke spread tests has been developed, tested and applied to several existing buildings. Burning methanol in different size steel trays cooled by water generates the heat source. Several tray sizes are available to cover fire sources up to nearly 1MW. The smoke is supplied by means of a suitable number of smoke generators that produce

P. Walmerdahl; P. Werling

2001-01-01

363

A Conditional Exposure Control Method for Multidimensional Adaptive Testing  

ERIC Educational Resources Information Center

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

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

2009-01-01

364

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

365

Experimental test results from an environmental protection agency test method for determination of vapor suppressant effectiveness  

Microsoft Academic Search

The results obtained from laboratory experiments conducted using Environmental Protection Agency (EPA) subpart WWWW of 40 Code of Federal Regulations (CFR) part 63 (1)-test method are discussed in this article. The original test method was developed to measure the effectiveness of wax suppressants used to reduce hazardous air pollutant (HAP) emissions from unsaturated polyester (UP)\\/vinyl ester resins. Wax additions of

Richard W. Tock; Daniel W. Ahern

2005-01-01

366

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

367

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

368

Method for Smoke Spread Testing of Large Premises  

NASA Astrophysics Data System (ADS)

A method for performing non-destructive smoke spread tests has been developed, tested and applied to several existing buildings. Burning methanol in different size steel trays cooled by water generates the heat source. Several tray sizes are available to cover fire sources up to nearly 1MW. The smoke is supplied by means of a suitable number of smoke generators that produce a smoke, which can be described as a non-toxic aerosol. The advantage of the method is that it provides a means for performing non-destructive tests in already existing buildings and other installations for the purpose of evaluating the functionality and design of the active fire protection measures such as smoke extraction systems, etc. In the report, the method is described in detail and experimental data from the try-out of the method are also presented in addition to a discussion on applicability and flexibility of the method.

Walmerdahl, P.; Werling, P.

2001-11-01

369

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

370

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

371

Method and apparatus for tensile testing of metal foil  

NASA Technical Reports Server (NTRS)

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

Wade, O. W. (inventor)

1976-01-01

372

Antimycobacterial susceptibility testing methods for natural products research  

Microsoft Academic Search

The emergence of multidrug-resistant strains of Mycobacterium tuberculosis underscores the need of continuous developments on new and efficient methods to determine the susceptibility of isolates of M. tuberculosis in the search for novel antimicrobial agents. Natural products constitute an important source of new drugs, but design and implementation of antimycobacterial susceptibility testing methods are necessary for evaluate the different extracts

Juan Gabriel Bueno Sánchez; Vladimir V. Kouznetsov

2010-01-01

373

40 CFR 60.534 - Test methods and procedures.  

Code of Federal Regulations, 2012 CFR

...Standards of Performance for New Residential Wood Heaters § 60.534 Test methods and procedures...Method 28A shall be used to determine that a wood combustion unit qualifies under the definition of wood heater in § 60.531(a). If such a...

2012-07-01

374

40 CFR 60.534 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...Standards of Performance for New Residential Wood Heaters § 60.534 Test methods and procedures...Method 28A shall be used to determine that a wood combustion unit qualifies under the definition of wood heater in § 60.531(a). If such a...

2010-07-01

375

40 CFR 60.534 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...Standards of Performance for New Residential Wood Heaters § 60.534 Test methods and procedures...Method 28A shall be used to determine that a wood combustion unit qualifies under the definition of wood heater in § 60.531(a). If such a...

2013-07-01

376

Transient method for testing flat-plate solar collectors  

Microsoft Academic Search

A transient test method has been developed to characterize the dynamic behavior of flat-plate solar collectors. It is based on a one-node model in which the heat capacity of the plate, the tubes and the fluid are lumped together in one node referred to the mean temperature of the working fluid. The method is simple and less time consuming. It

E. H. Amer; J. K. Nayak; G. K. Sharma

1998-01-01

377

40 CFR 60.547 - Test methods and procedures.  

Code of Federal Regulations, 2010 CFR

...Standards of Performance for the Rubber Tire Manufacturing Industry § 60.547 Test methods and...VOC content of cements or green tire spray materials. In the event...Method 24, the cement or green tire spray sample shall be a...

2010-07-01

378

A method of estimating accuracy of test scoring  

Microsoft Academic Search

When errors of test scoring obey a Poisson frequency law (theoretical considerations suggest that they do), the method described may be used for finding the upper fiducial limits of scoring errors per paper. A criterion is suggested for establishing tolerance limits on scoring errors, and a method is given (1) for finding the probability of being wrong in the statement

Walter L. Deemer

1942-01-01

379

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

380

Comparison of the "method of limits" and "alternate choice" methods in vibrometry testing  

E-print Network

COMPARISON OF THE "METHOD OF LIMITS" AND "ALTERNATE CHOICEST' METHODS IN VIBROMETRY TESTING A Thesis by ELOISE CARLTON HAYES Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requhements... for the degree of MASTER OF SCIENCE December 1992 Major Subject: Industrial Engineerhtg COMPARISON OF THE "METHOD OF LIMITS" AND "ALTERNATE CHOICE" METHODS IN VIBROMETRY TESTING A Thesis by ELOISE CARLTON HAYES Approved as to style and content by: Jeto...

Hayes, Eloise Carlton

2012-06-07

381

Standard test methods for forming superplastic metallic sheet  

E-print Network

1.1 These test methods describe procedures for determining the biaxial formability of a superplastic metallic sheet in a circular die. 1.2 The intent of these test methods are primarily to be used as tests of superplasticity as measured by the ability to form to a prescribed depth in a die cavity without rupturing. These test methods can also be used to generate material for the measurement of cavitation in the formed part. These can be used as go/no go criteria for qualification to a specification. 1.3 These test methods have been used successfully with aluminum alloys. The use of these test methods on other metals should be verified. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of ...

American Society for Testing and Materials. Philadelphia

2009-01-01

382

Survey of aircraft subcritical flight flutter testing methods  

NASA Technical Reports Server (NTRS)

The results of a survey of U. S., British and French subcritical aircraft flight flutter testing methods are presented and evaluation of the applicability of these methods to the testing of the space shuttle are discussed. Ten U. S. aircraft programs covering the large civil transport aircraft and a variety of military aircraft are reviewed. In addition, three major French and British programs are covered by the survey. The significant differences between the U. S., French and British practices in the areas of methods of excitation, data acquisition, transmission and analysis are reviewed. The effect of integrating the digital computer into the flight flutter test program is discussed. Significant saving in analysis and flight test time are shown to result from the use of special digital computer routines and digital filters.

Rosenbaum, R.

1974-01-01

383

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

384

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

385

In vitro dissolution studies of sodium diclofenac granules coated with Eudragit L-30D-55 by fluidized-bed system.  

PubMed

The objective of this work was to study the dissolution process of sodium diclofenac granules coated with a polymeric suspension of Eudragit L-30D-55 by fluidized bed. Methacrylic acid-methylmetacrylate copolymer, also known as Eudragit, has been used as a pH sensitive coating material to protect drug substances prior to delivery to the human intestines. The sodium diclofenac granules were prepared by wet granulation technology using microcrystalline cellulose (MICROCEL), sodium diclofenac, and polivinilpirrolidone K-30. The granules coating operation was carried out in a fluidized bed with top spraying by a double-fluid nozzle. The dissolutions studies of the coated granules were performed in triplicate in a dissolution test station according to USP XXIII (1995) "in vitro testing requirements" Method A (paddle method, rotation of 100 RPM and temperature fixed at 37 degrees C). The dissolution mediums were 0.1N HCl solution and a pH 6.8 phosphate buffer solution, following the pH change dissolution procedure specified in USP for enteric-coated articles: 2 h of exposure to 750 mL of 0.1N HCl followed by testing in 1000 mL of pH 6.8 phosphate buffer, the pH being adjusted with 250 mL of 0.2 M tribasic sodium phosphate solution. The released amount of sodium diclofenac was periodically determined by UV spectrophotometry at wavelength of 276 nm, using a spectrophotometer UV-VIS HP 8453. The coated product showed gastric resistance properties confirming the feasibility of the fluidized bed for applying enteric coating in granules and pharmaceutical powders. PMID:16885121

Silva, O S; Souza, C R F; Oliveira, W P; Rocha, S C S

2006-07-01

386

Validated stability indicating RP-HPLC method for simultaneous determination and in vitro dissolution studies of thiocolchicoside and diclofenac potassium from tablet dosage form  

Microsoft Academic Search

A simple, rapid, and robust stability indicating RP-HPLC method has been developed and validated to measure thiocolchicoside (TH) and diclofenac potassium (DP) at single wavelength (258nm) in order to assess assay and in vitro drug release profile of drug from tablet formulation. A gradient elution of samples performed on Zorbax SB CN 250mm×4.6mm, 5?m column with buffered mobile phase consisting

Suraj D. Jadhav; S. R. Butle; Sachin D. Patil; P. K. Jagtap

387

Precision of skin prick and puncture tests with nine methods.  

PubMed

New devices for puncture tests have been proposed recently, but their precision by comparison to the prick test method is poorly known. Seven puncture tests (Allerprick, Morrow Brown standardized needle, Phazer, Pricker, Stallerpointe, Stallerkit, and Wyeth bifucated needle) were compared with the modified prick test performed with hypodermic or intradermal needles in eight carefully selected normal volunteers. Skin tests with histamine hydrochloride (10 mg/ml) were only performed when there was no factor that might interfere with their interpretation. The site of skin tests on the forearm was demonstrated not to significantly influence the reaction size. The coefficient of variation of the tests ranged from 8.4% to 21.7%. Modified skin prick tests are satisfactory since they are highly reproducible (coefficient of variation: 13.4% and 16.5%) and there is no subject effect. Phazet was found to be more reproducible without subject effect. Pricker is satisfactory since it has no subject effect and a reproducibility similar to that of modified prick tests. Other tests are less reproducible (Stallerkit or Morrow Brown) or vary between subjects (Allerkit, Stallerkit, Stallerpointe, and Wyeth Needle). PMID:1955634

Demoly, P; Bousquet, J; Manderscheid, J C; Dreborg, S; Dhivert, H; Michel, F B

1991-11-01

388

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

389

[Comparative diagnostic value of Helicobacter pylori infection testing methods].  

PubMed

In 213 patients with gastric and duodenal pathology, including received surgery, comparative estimation of results of Helicobacter pylori (Hp) infection testing with invasive and noninvasive methods, were performed. Material for invasive endoscopic biopsy test (EBT), including rapid urease test (RUT) for rapid Hp identification by determination of urease activity, smear cytology and histology was extracted on endoscopy or intraoperationally. RUT was carried out with the help of URE-HP test kit. Serological test for Hp antibodies IgG and IgA class was performed by IFA using kit ELISA. 13? urea breath test (UBT) was made by determination of 13/12CO2 in breath samples on infrared spectroscope. Based on 5 different methods of Hp infection testing Hp positivity in 172 (80,8%) and Hp negativity in 41 (19,2%) from 213 examined patients was revealed. 13?-UBT revealed the highest diagnostic value (accuracy-97,5%, sensibility-97,0%, specificity-100%) in Hp infection diagnostics. In treatment efficiency control this parameters of 13?-UBT are also much high (96,7%, 90,0% and 100% respectively). In spite of high sensitivity of serological test (100%), it had comparative low specificity (71,0%) with high probability of false positive results in treated patients (antibodies titer to Hp after eradication retains for a long time). Thought, this test may be successfully used only in primary patients and in epidemiological studies. Among three methods of EBT, Hp infection detection with RUT revealed the best results (accuracy-94,8%, sensibility-95,0%, specificity-100%). Correlation of RUT and UBT results and much higher diagnostic value of UBT, necessitate RUT with histological study of stomach body mucosa to perform in patients over 45 year, with prolonged anamnesis and dangerous symptoms of disease. In Hp positive patients correlation of index DOB‰ of breath test with results of RUT was revealed. This can serve the index DOB‰ of 13?-UBT as a marker of Hp infection rate. The (accuracy, sensibility and specificity of breath test with local made 13?-urea (98,7%, 98,5% and 100% respectively) are the same as those for BT with standard 13?-urea (96,7%, 96,2% and 100% respectively). Above mentioned, 13?-UBT advantages (noninvasiveness, simplicity, rapidity, safety) and high diagnostic value exceeding same of other applied tests, give us opportunity to offer 13?-UBT as screening method of Hp infection diagnosis and a method of choise in control of Hp infection treatment efficiency. PMID:24423677

Girdalidze, A M; Elisabedashvili, G V; Sharvadze, L G; Dzhorbenadze, T A

2013-12-01

390

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...

391

Laboratory simulation of salt dissolution during waste removal  

SciTech Connect

Laboratory experiments were performed to support the field demonstration of improved techniques for salt dissolution in waste tanks at the Savannah River Site. The tests were designed to investigate three density driven techniques for salt dissolution: (1) Drain-Add-Sit-Remove, (2) Modified Density Gradient, and (3) Continuous Salt Mining. Salt dissolution was observed to be a very rapid process as salt solutions with densities between 1.38-1.4 were frequently removed. Slower addition and removal rates and locating the outlet line at deeper levels below the top of the saltcake provided the best contact between the dissolution water and the saltcake. It was observed that dissolution with 1 M sodium hydroxide solution resulted in salt solutions that were within the current inhibitor requirements for the prevention of stress corrosion cracking. This result was independent of the density driven technique. However, if inhibited water (0.01 M sodium hydroxide and 0.011 M sodium nitrite) was utilized, the salt solutions were frequently outside the inhibitor requirements. Corrosion testing at conditions similar to the environments expected during waste removal was recommended.

Wiersma, B.J.; Parish, W.R.

1997-01-01

392

Alternative methods in toxicology tests: in vitro toxicity.  

PubMed

Toxicity testing is required for new chemicals being introduced onto the market. The use of animals in evaluating chemical safety is costly and time consuming. Furthermore, there is the ethical need to develop alternative methods to reduce the required number of animals. The new in vitro assays offer numerous advantages such as speed, reproducibility and control of test conditions, and increased sensitivity. Although the dermal irritation assays might be substituted by the in vitro tests in the near future (Duffy, 1989), much work is required to evaluate organ toxicity with in vitro methods. We present data regarding the use of Balb/3T3 mice fibroblasts and primary rat hepatocytes as test systems for in vitro toxicity. The end-points we have analysed are total protein content, dye accumulation in lysosomes, reductase mitochondrial activity, intracellular content and leakage of enzymes into the medium. PMID:1367120

Cinelli, S; Falezza, A; Meli, C; Ciliutti, P; Vericat, J A

1991-01-01

393

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

394

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

395

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

396

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

397

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

398

Experimental test results from an environmental protection agency test method for determination of vapor suppressant effectiveness  

Microsoft Academic Search

The results obtained from laboratory experiments conducted using Environmental Protection Agency (EPA) subpart WWWW of 40\\u000a Code of Federal Regulations (CFR) part 63 (1)-test method are discussed in this article. The original test method was developed\\u000a to measure the effectiveness of wax suppressants used to reduce hazardous air pollutant (HAP) emissions from unsaturated polyester\\u000a (UP)\\/vinyl ester resins. Wax additions of

Richard W. Tock; Daniel W. Ahern

2005-01-01

399

Sulfate scale dissolution  

SciTech Connect

This patent describes a method for removing barium sulfate scale. It comprises contacting the scale with an aqueous solution having a pH of about 8 to about 14 and consisting essentially of a chelating agent comprising a polyaminopolycarboxylic acid or salt of such an acid in a concentration of 0.1 to 1.0 M, and anions of a monocarboxylic acid selected form mercaptoacetic acid, hydroxyacetic acid, aminoacetic acid, or salicyclic acid in a concentration of 0.1 to 1.0 M and which is soluble in the solution under the selected pH conditions, to dissolve the scale.

Morris, R.L.; Paul, J.M.

1992-01-28

400

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

401

Dissolution of hematite in acidic oxalate solutions  

Microsoft Academic Search

The dissolution of hematite in acidic oxalate solutions has been studied under various experimental conditions. The effect of temperature, oxalate concentration and pH on hematite dissolution were studied. In order to study the effect of atmospheric oxygen and light on the dissolution reaction, experiments were carried out in an inert atmosphere (purging with argon), in an ‘oxidising atmosphere’ (without purging),

M. Taxiarchou; D. Panias; I. Douni; I. Paspaliaris; A. Kontopoulos

1997-01-01

402

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...

403

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

404

Modification of proportion sensitivity testing method for ethionamide.  

PubMed

Standardized methodology for drug susceptibility testing of second line drugs is vital for treatment of multi/extensively drug resistant tuberculosis. Discrepancy between laboratory methods and clinical interpretation is well established for bacteriostatic drugs such as ethionamide. Optimization of the standard proportion sensitivity testing (PST) method for ethionamide was under taken in 235 Mycobacterium tuberculosis isolates from new and previously treated pulmonary tuberculosis patients. An additional higher concentration of 57 ?g/ml was evaluated against at the standard 40 ?g/ml concentration in PST method. Performance parameters and agreement between the two drug concentrations was higher indicating the efficiency of PST method at its present format at 40 ?g/ml and additional higher concentration of 57 ?g/ml as an alternative when required. PMID:23315266

Lakshmi, Rajagopalan; Ramachandran, Ranjani; Devika, K; Radhika, G; Syam Sundar, A; Rahman, Fathima; Selvakumar, N; Kumar, Vanaja

2013-06-01

405

In vitro dissolution of uranium oxide by baboon alveolar macrophages.  

PubMed Central

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 functional 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 (U3O8) particles in alginate beads linked with Ca2+. 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 microns(sigma 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 U3O8 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. PMID:1396447

Poncy, J L; Metivier, H; Dhilly, M; Verry, M; Masse, R

1992-01-01

406

Detection of fatigue cracks by nondestructive testing methods  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

407

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

408

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

409

Web accessibility testing: when the method is the culprit  

E-print Network

to determine usability of the web site with respect to disabled users. More confusion exists regarding successful. And when the property depends on human cognitive processes, then also the testing method may of effectiveness; now and then it is defined in terms of usability; but unfortunately there are too often claims

Brajnik, Giorgio

410

16 CFR 1610.3 - Summary of test method.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

411

16 CFR 1610.3 - Summary of test method.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

412

16 CFR 1610.3 - Summary of test method.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

413

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

414

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

415

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

416

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

417

An Analytical Method of Identifying Biased Test Items.  

ERIC Educational Resources Information Center

A follow-up technique is needed to identify items contributing to items-by-groups interaction when using an ANOVA procedure to examine a test for biased items. The method described includes distribution theory for assessing level of significance and is sensitive to items at all difficulty levels. (Author/GSK)

Plake, Barbara S.; Hoover, H. D.

1979-01-01

418

Alternative methods for eye and skin irritation tests: an overview.  

PubMed

The evaluation of eye and skin irritation potential is essential to ensuring the safety of individuals in contact with a wide variety of substances designed for industrial, pharmaceutical or cosmetic use. The Draize rabbit eye and skin irritancy tests have been used for 60 years to attempt to predict the human ocular and dermal irritation of such products. The Draize test has been the standard for ocular and dermal safety assessments for decades. However, several aspects of the test have been criticised. These include: the subjectivity of the method; the overestimation of human responses; and the method's cruelty. The inadequacies of the Draize test have led to several laboratories over the last 20 years making efforts to develop in vitro assays to replace it. Protocols that use different types of cell cultures and other methods have been devised to study eye and skin irritation. Different commercial kits have also been developed to study eye and skin irritation, based on the action of chemicals on these tissues. This article presents a review of the main alternatives developed to replace the use of animals in the study of chemical irritation. Particular attention is paid to the reproducibility of each method. PMID:17701961

Vinardell, M P; Mitjans, M

2008-01-01

419

Check valve test method using truncated accumulator blowdown  

Microsoft Academic Search

A method is described for testing a normally closed check valve connected in series with an isolation valve at an outlet of an accumulator tank in a passive injection system for supplying liquid to a reactor cooling system in a pressurized light water nuclear power system. The passive injection system is connected to a low pressure system and supplies liquid

Gerlowski

1987-01-01

420

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.

2008-12-26

421

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

422

40 CFR Appendix B to Part 61 - Test Methods  

Code of Federal Regulations, 2013 CFR

...1Select a nozzle size based on the range of velocity heads to assure that it is not necessary...11, respectively. 12.2Stack Gas Velocity. Using the data from this test and Equation...Method 2, calculate the average stack gas velocity vs. 12.3Total...

2013-07-01

423

40 CFR Appendix B to Part 61 - Test Methods  

Code of Federal Regulations, 2010 CFR

...1Select a nozzle size based on the range of velocity heads to assure that it is not necessary...11, respectively. 12.2Stack Gas Velocity. Using the data from this test and Equation...Method 2, calculate the average stack gas velocity vs. 12.3Total...

2010-07-01

424

40 CFR Appendix B to Part 61 - Test Methods  

Code of Federal Regulations, 2012 CFR

...1Select a nozzle size based on the range of velocity heads to assure that it is not necessary...11, respectively. 12.2Stack Gas Velocity. Using the data from this test and Equation...Method 2, calculate the average stack gas velocity vs. 12.3Total...

2012-07-01

425

40 CFR Appendix B to Part 61 - Test Methods  

Code of Federal Regulations, 2011 CFR

...1Select a nozzle size based on the range of velocity heads to assure that it is not necessary...11, respectively. 12.2Stack Gas Velocity. Using the data from this test and Equation...Method 2, calculate the average stack gas velocity vs. 12.3Total...

2011-07-01

426

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

E-print Network

(EMF), Energy to the Max Force; (EFF), Energy to Fracture Force, (EMF to EFF), Energy from the maximum force to the fracture force for the OVX and Sham groups. . . 84 Figure 57 "Punch method" compression testing on slices removed from the proximal.../mm) for the OVX and Sham operated groups. 91 Figure 5 15. "Whole slice method" compression testing on slices removed from the proximal portion of the tibia (EMF), Energy to the Max Force; (EFF), Energy to Fracture Force, (EMF to EFF), Energy from the maximum...

Ruhmann, Sean Phillip

2012-06-07

427

Dissolution Kinetics of Alumina Calcine  

SciTech Connect

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

Batcheller, Thomas Aquinas

2001-09-01

428

Marital Dissolution Among Interracial Couples  

PubMed Central

Increases in interracial marriage have been interpreted as reflecting reduced social distance among racial and ethnic groups, but little is known about the stability of interracial marriages. Using six panels of Survey of Income and Program Participation (N = 23,139 married couples), we found that interracial marriages are less stable than endogamous marriages, but these findings did not hold up consistently. After controlling for couple characteristics, the risk of divorce or separation among interracial couples was similar to the more-divorce-prone origin group. Although marital dissolution was found to be strongly associated with race/ethnicity, the results failed to provide evidence that interracial marriage is associated with an elevated risk of marital dissolution.

Zhang, Yuanting; Van Hook, Jennifer

2014-01-01

429

Atomic force microscopy of atomic-scale ledges and etch pits formed during dissolution of quartz  

NASA Technical Reports Server (NTRS)

The processes involved in the dissolution and growth of crystals are closely related. Atomic force microscopy (AFM) of faceted pits (called negative crystals) formed during quartz dissolution reveals subtle details of these underlying physical mechanisms for silicates. In imaging these surfaces, the AFM detected ledges less than 1 nm high that were spaced 10 to 90 nm apart. A dislocation pit, invisible to optical and scanning electron microscopy measurements and serving as a ledge source, was also imaged. These observations confirm the applicability of ledge-motion models to dissolution and growth of silicates; coupled with measurements of dissolution rate on facets, these methods provide a powerful tool for probing mineral surface kinetics.

Gratz, A. J.; Manne, S.; Hansma, P. K.

1991-01-01

430

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

431

Preliminary test method for the determination of surface firmness.  

PubMed

The Americans with Disabilities Act Accessibility Guidelines (ADAAG) specify that ground and floor surfaces should be firm, stable, and slip-resistant. These specifications are subjective; objective methods for assessing surface firmness and stability are lacking. Objective measures are needed to assess the accessibility of walking and wheeling surfaces and to improve accessibility for people with mobility limitations. This research study focused only on the development of an objective wheelchair work measurement method to assess surface firmness. Firmness was quantified in terms of the work per meter required to propel a wheelchair across the surface. Work was determined by using a SMARTwheel to measure the forces applied to the pushrim. This measurement method was evaluated on carpet, hard trail surfaces, and various playground surfacing materials. Measurements were also taken on an adjustable ramp set at different grades, cross slopes, and grade/cross slope combinations. Reliable results were obtained on all test surfaces except two (sand and pea gravel) which could not be negotiated by the test wheelchair rider according to the test protocol. The test method was capable of measuring a wide range of surface types, produced repeatable results on nearly all test surfaces, and was sensitive enough to measure 1% changes in grade and differences in surfacing materials. Comparisons between the measurements made on level surfaces and on various ramp angles demonstrated the feasibility of using the work per meter value for a specific ramp grade as pass/fail performance criteria for short distances of accessible surfaces. For outdoor recreational environments, this work measurement method would provide an objective measure of firmness which could be used to classify surfaces into categories (e.g., hard, firm, soft). PMID:8800221

Chesney, D A; Axelson, P W

1996-09-01

432

Film coated pellets containing verapamil hydrochloride: enhanced dissolution into neutral medium.  

PubMed

Weakly basic drugs, such as verapamil hydrochloride, that are poorly soluble in neutral/alkaline medium may have poor oral bioavailability due to reduced solubility in the small intestine and colon. Film coated pellets were prepared using two strategies to enhance drug release at high pH values. Firstly, pellets were coated with Eudragit RS/hydroxypropyl methylcellulose acetate succinate (HMAS) mixtures in proportions of 10:1 and 10:3, respectively. The enteric polymer, HMAS, would dissolve in medium at pH > 6 creating pores through the insoluble Eudragit RS membrane to increase drug release. Secondly, an acidic environment was created within the core by the inclusion of fumaric acid at concentrations of 5 and 10% in order to increase drug solubility. Both strategies enhanced drug release into neutral medium in dissolution studies using the pH change method to simulate GIT transit. Dissolution profiles of samples tested in pH 1.2 for 12 hr were compared with those using the pH change method (pH 1.2 for first 1.5 hr, pH raised to 6.8 for remaining 10.5 hr) using the area under the dissolution curve (AUC), the dissolution half-life (t50%), and the amount of drug released in 3 hr (A3hr) values. Both strategies enhanced drug release into neutral medium although the strategy using HMAS in the film was more effective. The formulation least affected by pH change was a combination of the two strategies, i.e., pellets containing 5% fumaric acid coated with Eudragit RS 12% w/w and HMAS 1.2% w/w. PMID:12779287

Munday, Dale L

2003-05-01

433

Residual flexibility test method for verification of constrained structural models  

NASA Technical Reports Server (NTRS)

A method is described for deriving constrained modes and frequencies from a reduced model based on a subset of the free-free modes plus the residual effects of neglected modes. The method involves a simple modification of the MacNeal and Rubin component mode representation to allow development of a verified constrained (fixed-base) structural model. Results for two spaceflight structures having translational boundary degrees of freedom show quick convergence of constrained modes using a measureable number of free-free modes plus the boundary partition of the residual flexibility matrix. This paper presents the free-free residual flexibility approach as an alternative test/analysis method when fixed-base testing proves impractical.

Admire, John R.; Tinker, Michael L.; Ivey, Edward W.

1994-01-01

434

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

435

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

436

A novel approach to dissolution correction of Mg/Ca-based paleothermometry in the tropical Pacific  

NASA Astrophysics Data System (ADS)

Mg/Ca in planktonic foraminifers carries two main signals: calcification temperature and postdepositional test dissolution. Shell dissolution thus distorts water temperature reconstructions made with Mg/Ca in foraminifers. This problem could be resolved by quantifying the impact of carbonate dissolution on Mg/Ca with an independent, temperature-insensitive deep-sea calcite dissolution proxy, such as the Globorotalia menardii fragmentation index (MFI). To test the validity of this approach, we measured Mg/Ca in the tests of several planktonic foraminifers and MFI in core tops collected over a wide geographic region of the tropical Pacific and covering a wide range of deep-sea calcite dissolution and seawater temperature. We confirm that Mg/Ca from different species have different susceptibility to temperature and dissolution. Mg/Ca in surface-dwelling Globigerina bulloides is controlled by calcification temperature and is largely unaffected by carbonate dissolution estimated from MFI. In contrast, Mg/Ca in deeper dwelling G. menardii is minimally sensitive to temperature and dominantly affected by dissolution. Mg/Ca in Neogloboquadrina dutertrei and Pulleniatina obliquiloculata are significantly affected by both temperature and dissolution, and MFI can be effectively used to correct temperature estimates from these species for calcite dissolution. Additional variables besides temperature and dissolution appear to control Mg/Ca in Globorotalia tumida, and their identification is a prerequisite for interpreting elemental shell composition in this species. Combining down-core measurements of Mg/Ca in multiple foraminifer species with MFI provides a powerful tool for reconstructing past changes in the upper water column temperature structure in the tropical Pacific.

Mekik, Figen; FrançOis, Roger; Soon, Maureen

2007-09-01

437

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

NASA Astrophysics Data System (ADS)

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

Hafed, Mohamed M.

2002-08-01

438

BSAC standardized disc susceptibility testing method (version 10).  

PubMed

The BSAC standardized disc susceptibility testing method remains unchanged, but there are considerable changes to the interpretative criteria due to continuing harmonization with the European Committee on Antimicrobial Susceptibility Testing (EUCAST) MIC breakpoints. There are a number of agents for which interpretative criteria have been removed. These MIC and/or zone diameter breakpoints will be published on the BSAC web site as a 'Legacy' table; they may be used for research or comparative purposes, but are not recommended for clinical management. Notably, testing of staphylococci for susceptibility to glycopeptides by disc diffusion has been removed because this method has been found to be unreliable, particularly for the detection of low-level resistance; low-level vancomycin resistance in staphylococci is increasingly deemed to be of clinical relevance. The tables for anaerobes have been expanded to include MIC breakpoints that have been determined by EUCAST. There are currently no zone diameter breakpoints for these organisms and an MIC method is recommended if susceptibility testing is required. PMID:21921076

Andrews, J M; Howe, R A

2011-12-01

439

[Clinical application of testing methods on acid-fast bacteria].  

PubMed

Clinical bacteriology pertaining to acid-fast bacteria has made marked advances over the past decade, initiated by the development of a DNA probe kit for identification of acid-fast bacteria. Wide-spread use of nucleic acid amplification for rapid detection of tubercle bacillus contributed more greatly than any other factor to such advances in this field. At present, 90% of all kits used for nucleic acid amplification in the world are consumed in Japan. Unfortunately, not a few clinicians in Japan have a false idea that the smear method and nucleic acid amplification are necessary but culture is not. In any event nucleic acid amplification has exerted significant impacts on the routine works at bacteriology laboratories. Among others, collecting bacteria by pretreatment with NALC-NaOH has simplified the introduction of the collective mode smear method and liquid media. Furthermore, as clinicians have become increasingly more experienced with various methods of molecular biology, it now seems possible to apply these techniques for detection of genes encoding drug resistance and for utilization of molecular epidemiology in routine laboratory works. Meanwhile, attempts to diagnose acid-fast bacteriosis by checking blood for antibody have also been made, primarily in Japan. At present, two kits for detecting antibodies to glycolipids (LAM, TDM, etc.) are covered by national health insurance in Japan. We have an impression that in Japan clinicians do not have adequate knowledge and skill to make full use of these new testing methods clinically. We, as the chairmen of this symposium, hope that this symposium will help clinicians increase their skill related to new testing methods, eventually leading to stimulation of advances in clinical practices related to acid-fast bacteria in Japan. 1. Smear microscopy by concentration method and broth culture system: Kazunari TSUYUGUCHI (Clinical Research Center, National Hospital Organization Kinki-chuo Chest Medical Center) Smear microscopy and culture still remain the cornerstone to diagnose tuberculosis. However, the classical methods in Japan using direct microscopy and Ogawa solid media were not sufficient for clinical use. In recent years substantial advance has been made in these fields. Concentration of clinical samples by centrifugation improves the sensitivity of smear microscopy with excellent reproducibility. The Mycobacteria Growth Indicator Tube (MGIT) system using liquid media yields high sensitivity and rapidity. Using these methods, more and more tuberculosis cases would be correctly diagnosed and treated adequately based on drug susceptibility testing. 2. New technologies for anti-tuberculosis drug susceptibility testing: Satoshi MITARAI (Bacteriology Division, Reference Centre for Mycobacterium, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association) Several new technologies have been developed to obtain anti-tuberculosis drug susceptibility testing (AST) results rapidly, utilising liquid culture and molecular technologies. Mycobacterium Growth Indicator Tube (MGIT), as a popular liquid culturing and AST system, was evaluated for its accuracy and usefulness. As for isoniazid, MGIT showed 12.6% of discordant result comparing with standard method. These MGIT resistant and Ogawa susceptible strains had relatively high MICs ranging 0.13 to 2.0 microg/ml. The molecular detection of resistant gene mutation is also a useful method to estimate drug resistance rapidly. The rpoB mutation detection is reliable with high sensitivity and specificity. 3. Nucleic acid amplification and novel diagnostic methods: Shunji TAKAKURA (Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine) Sensitivities of nucleic acid amplification tests (NAATs) for the diagnosis of tuberculosis meet clinical requirement that patients with high-risk of transmission should be identified within a day. Comparison of the performance of various NAATs is difficult because of the difference in sample processing and in samples tested among methods and reports. Con

Ichiyama, Satoshi; Suzuki, Katsuhiro

2005-02-01

440

[Testing methods for the characterization of catheter balloons and lumina].  

PubMed

The present paper reports on the characterization of catheter balloons and lumina on the basis of such known parameters as residual volume, compliance, burst pressure and flow rate, with the aim of developing standards, test methods and testing equipment as well as standards. These are becoming ever more important with the coming into force of the EC directive on medical products [7] and the law governing medical products in Germany [13], which requires manufacturers to specify the properties of their products. Our testing concept is based on a commercially available machine that subjects materials to alternating extension and compression forces over the long-term, to which we added a special hydraulic module. Using the multimedia technology we achieved a real time superimposition of the volume-diameter curve on the balloon. The function of the testing device and method is demonstrated on dilatation catheters. Our initial results reveal compatibility with the requirements of the 1% accuracy class. Use of this methodology for comparative testing of catheters and quality evaluation is recommended. PMID:8527639

Werner, C; Rössler, K; Deckert, F

1995-10-01

441

Fracture Test Methods for Plastically Responding COPV Liners  

NASA Technical Reports Server (NTRS)

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

Dawicke, David S.; Lewis, Joseph C.

2009-01-01

442

Cartridge output testing - Methods to overcome closed-bomb shortcomings  

NASA Technical Reports Server (NTRS)

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

Bement, Laurence J.; Schimmel, Morry L.

1991-01-01

443

Method of and apparatus for testing the integrity of filters  

DOEpatents

A method of and apparatus are disclosed for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstream upstream and downstream of such filter stage. Samples of the particle concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage. 5 figs.

Herman, R.L.

1985-05-07

444

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

PubMed

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 the drug-polymer ratio and the system preparation method. Chitosan was more effective than PVP, despite the greater amorphizing power of PVP as revealed by solid state analyses. The 3/7 (w/w) drug-carrier coground systems with chitosan and PVP were the best products enabling, respectively, an improvement of 4.8 and 3.6 times of drug dissolution efficiency. In vivo experiments in mice demonstrated that administration of 45 mg/kg of drug coground with PVP or chitosan resulted, respectively, in a 25 and 60% reduction of acetic acid-induced writhings in comparison to pure drug, which, instead, was statistically ineffective as compared to the control group. Moreover, the 3/7 (w/w) drug-chitosan coground product demonstrated an antiwrithing potency 2.4 times higher than the coground with PVP. Thus, the direct-compression properties and antiulcerogenic activity, combined with the demonstrated solubilizing power and analgesic effect enhancer ability towards the drug, make chitosan particularly suitable for developing a reduced-dose fast-release solid oral dosage form of naproxen. PMID:14729084

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

2004-01-01

445

Methods of interpreting structural incompatibility in bored pier uplift test  

SciTech Connect

This paper presents two methods of analysis of data obtained from an uplift loading test on an instrumented bored pier reinforced only by a central steel angle to which the uplift load was applied. The objective of the analyses was to estimate the unit shaft resistance profile along the length of the pier at pull-out. The analysis methods consisted of a load-movement matching technique to obtain the unit shaft resistance profile down the pier in conjunction with a stability plot to determine pier integrity, and an iterative method to determine the mobilized unit shaft resistance down the pier from measured strains. Iteration was required because the uplift load caused cracking in the concrete of the pier, resulting in a loss of structural compatibility between the concrete and the steel angle. The two methods of analysis resulted in unit shaft resistance profiles that were in good agreement, giving confidence in the results.

Wong, K.Y; Williams, D.J. [Univ. of Queensland, (Australia). Dept. of Civil Engineering

1993-12-01

446

Biopharmaceutical characterization of oral theophylline and aminophylline tablets. Quantitative correlation between dissolution and bioavailability studies.  

PubMed

Considering the narrow therapeutic index of theophylline and the low range between the safe and toxic serum concentrations of this drug, the study of its pharmacokinetic properties is necessary. However, considering the time consuming and expensive in vivo tests, quantitative correlation between in vivo bioavailability and in vitro dissolution tests can be used routinely in quality control tests of these drug products to predict the in vivo pharmacokinetic parameters. For this reason healthy human volunteers were used for in vivo studies and serum samples were analyzed by a fluorescence polarization immunoassay analysis (FPIA) method. The results showed that an open one compartmental model could best describe the pharmacokinetic properties of orally administered theophylline and aminophylline tablets. Linear regression analysis by least-square method showed a good correlation between some in vivo and in vitro parameters obtained from dissolution studies by rotating basket and paddle methods. D(30)% (percentage of drug dissolved in vitro after 30 min) and F(0.5)% (drug absorbed in vivo after half an hour calculated by Wagner-Nelson equation) showed best correlation (r=0. 99036). C(max) (maximum serum concentration) of this drug also correlates well with t(25%) (time required to dissolve 25% of the drug). The calculated correlation coefficients could best predict the actual values of some pharmacokinetic parameters; AUC(0-->infinity), AUC(0-->1), F(0.5)% and C(max). PMID:10962242

Varshosaz, J; Ghafghazi, T; Raisi, A; Falamarzian, M

2000-09-01

447

A quantum method to test the existence of consciousness  

E-print Network

As we know, "Who can be said to be a conscious being?" is one of the hard problems in present science, and no method has been found to strictly differentiate the conscious being from the being without consciousness or usual matter. In this short paper, we present a strict physical method based on revised quantum dynamics to test the existence of consciousness, and the principle is to use the distinguishability of nonorthogonal single states. We demonstrate that although the dynamical collapse time can't be measured by a physical measuring device, a conscious being can perceive it under the assumed QSC condition, thus can distinguish the nonorthogonal single states in the framework of revised quantum dynamics This in principle provides a quantum method to differentiate man and machine, or to test the existence of consciousness. We further discuss the rationality of the assumed QSC condition, and denote that some experimental evidences have indicated that our human being can satisfy the condition. This not only provides some confirmation of our method, but also indicates that the method is a practical proposal, which can be implemented in the near future experiments.

Rui Qi

2002-09-06

448

Self potential observations during DNAPL dissolution  

NASA Astrophysics Data System (ADS)

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

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