Spent Nuclear Fuel (SNF) Process Validation Technical Support Plan

International Nuclear Information System (INIS)

SEXTON, R.A.

2000-01-01

The purpose of Process Validation is to confirm that nominal process operations are consistent with the expected process envelope. The Process Validation activities described in this document are not part of the safety basis, but are expected to demonstrate that the process operates well within the safety basis. Some adjustments to the process may be made as a result of information gathered in Process Validation

Towards elucidation of the drug release mechanism from compressed hydrophilic matrices made of cellulose ethers. III. Critical use of thermodynamic parameters of activation for modeling the water penetration and drug release processes.

Science.gov (United States)

Ferrero, Carmen; Massuelle, Danielle; Jeannerat, Damien; Doelker, Eric

2013-09-10

The two main purposes of this work were: (i) to critically consider the use of thermodynamic parameters of activation for elucidating the drug release mechanism from hydroxypropyl methylcellulose (HPMC) matrices, and (ii) to examine the effect of neutral (pH 6) and acidic (pH 2) media on the release mechanism. For this, caffeine was chosen as model drug and various processes were investigated for the effect of temperature and pH: caffeine diffusion in solution and HPMC gels, and drug release from and water penetration into the HPMC tablets. Generally, the kinetics of the processes was not significantly affected by pH. As for the temperature dependence, the activation energy (E(a)) values calculated from caffeine diffusivities were in the range of Fickian transport (20-40 kJ mol⁻¹). Regarding caffeine release from HPMC matrices, fitting the profiles using the Korsmeyer-Peppas model would indicate anomalous transport. However, the low apparent E(a) values obtained were not compatible with a swelling-controlled mechanism and can be assigned to the dimensional change of the system during drug release. Unexpectedly, negative apparent E(a) values were calculated for the water uptake process, which can be ascribed to the exothermic dissolution of water into the initially dry HPMC, the expansion of the matrix and the polymer dissolution. Taking these contributions into account, the true E(a) would fall into the range valid for Fickian diffusion. Consequently, a relaxation-controlled release mechanism can be dismissed. The apparent anomalous drug release from HPMC matrices results from a coupled Fickian diffusion-erosion mechanism, both at pH 6 and 2. Copyright © 2013 Elsevier B.V. All rights reserved.

Validation of radiation sterilization process

International Nuclear Information System (INIS)

Kaluska, I.

2007-01-01

The standards for quality management systems recognize that, for certain processes used in manufacturing, the effectiveness of the process cannot be fully verified by subsequent inspection and testing of the product. Sterilization is an example of such a process. For this reason, sterilization processes are validated for use, the performance of sterilization process is monitored routinely and the equipment is maintained according to ISO 13 485. Different aspects of this norm are presented

Analytical Method Development and Validation for the Quantification of Acetone and Isopropyl Alcohol in the Tartaric Acid Base Pellets of Dipyridamole Modified Release Capsules by Using Headspace Gas Chromatographic Technique

Directory of Open Access Journals (Sweden)

Sriram Valavala

2018-01-01

Full Text Available A simple, sensitive, accurate, robust headspace gas chromatographic method was developed for the quantitative determination of acetone and isopropyl alcohol in tartaric acid-based pellets of dipyridamole modified release capsules. The residual solvents acetone and isopropyl alcohol were used in the manufacturing process of the tartaric acid-based pellets of dipyridamole modified release capsules by considering the solubility of the dipyridamole and excipients in the different manufacturing stages. The method was developed and optimized by using fused silica DB-624 (30 m × 0.32 mm × 1.8 µm column with the flame ionization detector. The method validation was carried out with regard to the guidelines for validation of analytical procedures Q2 demanded by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH. All the validation characteristics were meeting the acceptance criteria. Hence, the developed and validated method can be applied for the intended routine analysis.

A novel technique for die-level post-processing of released optical MEMS

International Nuclear Information System (INIS)

Elsayed, Mohannad Y; Beaulieu, Philippe-Olivier; Briere, Jonathan; Ménard, Michaël; Nabki, Frederic

2016-01-01

This work presents a novel die-level post-processing technique for dies including released movable structures. The procedure was applied to microelectromechanical systems (MEMS) chips that were fabricated in a commercial process, SOIMUMPs from MEMSCAP. It allows the performance of a clean DRIE etch of sidewalls on the diced chips enabling the optical testing of the pre-released MEMS mirrors through the chip edges. The etched patterns are defined by photolithography using photoresist spray coating. The photoresist thickness is tuned to create photoresist bridges over the pre-released gaps, protecting the released structures during subsequent wet processing steps. Then, the chips are subject to a sequence of wet and dry etching steps prior to dry photoresist removal in O 2 plasma. Processed micromirrors were tested and found to rotate similarly to devices without processing, demonstrating that the post-processing procedure does not affect the mechanical performance of the devices significantly. (technical note)

Processing ruminal ingesta to release bacteria attached to feed ...

African Journals Online (AJOL)

A comparison was made of different methods of processing ingesta to release bacteria attached to solid particles, prior to making viable counts. Initially processing was performed under a stream of anaerobic gas and counts were made using the roll tube technique. Later, processing was done in an anaerobic cabinet and ...

Leach resistance properties and release processes for salt-occluded zeolite A

International Nuclear Information System (INIS)

Lewis, M.A.; Fischer, D.F.; Laidler, J.J.

1992-01-01

The pyrometallurgical processing of spent fuel from the Integral Fast Reactor (IFR) results in a waste of LiCl-KCl-NaCl salt containing approximately 10 wt% fission products, primarily CsCl and SrCl 2 . For disposal, this waste must be immobilized in a form that it is leach resistant. A salt-occluded zeolite has been identified as a potential waste form for the salt. Its leach resistance properties were investigated using powdered samples. The results were that strontium was not released and cesium had a low release, 0.056 g/m 2 for the 56 day leach test. The initial release (within 7 days) of alkali metal cations was rapid and subsequent releases were much smaller. The releases of aluminum and silicon were 0.036 and 0.028 g/m 2 , respectively, and were constant. Neither alkali metal cation hydrolysis nor exchange between cations in the leachate and those in the zeolite was significant. Only sodium release followed t 0.5 kinetics. Selected dissolution of the occluded salt was the primary release process. These results confirm that salt-occluded zeolite has promise as the waste form for IFR pyroprocess salt

Hot Experiment on Fission Gas Release Behavior from Voloxidation Process using Spent Fuel

International Nuclear Information System (INIS)

Park, Geun Il; Park, J. J.; Jung, I. H.; Shin, J. M.; Cho, K. H.; Yang, M. S.; Song, K. C.

2007-08-01

Quantitative analysis of the fission gas release characteristics during the voloxidation and OREOX processes of spent PWR fuel was carried out by spent PWR fuel in a hot-cell of the DFDF. The release characteristics of 85 Kr and 14 C fission gases during voloxidation process at 500 .deg. C is closely linked to the degree of conversion efficiency of UO 2 to U 3 O 8 powder, and it can be interpreted that the release from grain-boundary would be dominated during this step. Volatile fission gases of 14 C and 85 Kr were released to near completion during the OREOX process. Both the 14 C and 85 Kr have similar release characteristics under the voloxidation and OREOX process conditions. A higher burn-up spent fuel showed a higher release fraction than that of a low burn-up fuel during the voloxidation step at 500 .deg. C. It was also observed that the release fraction of semi-volatile Cs was about 16% during a reduction at 1,000 .deg. C of the oxidized powder, but over 90% during the voloxidation at 1,250 .deg. C

Integrated Process Modeling-A Process Validation Life Cycle Companion.

Science.gov (United States)

Zahel, Thomas; Hauer, Stefan; Mueller, Eric M; Murphy, Patrick; Abad, Sandra; Vasilieva, Elena; Maurer, Daniel; Brocard, Cécile; Reinisch, Daniela; Sagmeister, Patrick; Herwig, Christoph

2017-10-17

During the regulatory requested process validation of pharmaceutical manufacturing processes, companies aim to identify, control, and continuously monitor process variation and its impact on critical quality attributes (CQAs) of the final product. It is difficult to directly connect the impact of single process parameters (PPs) to final product CQAs, especially in biopharmaceutical process development and production, where multiple unit operations are stacked together and interact with each other. Therefore, we want to present the application of Monte Carlo (MC) simulation using an integrated process model (IPM) that enables estimation of process capability even in early stages of process validation. Once the IPM is established, its capability in risk and criticality assessment is furthermore demonstrated. IPMs can be used to enable holistic production control strategies that take interactions of process parameters of multiple unit operations into account. Moreover, IPMs can be trained with development data, refined with qualification runs, and maintained with routine manufacturing data which underlines the lifecycle concept. These applications will be shown by means of a process characterization study recently conducted at a world-leading contract manufacturing organization (CMO). The new IPM methodology therefore allows anticipation of out of specification (OOS) events, identify critical process parameters, and take risk-based decisions on counteractions that increase process robustness and decrease the likelihood of OOS events.

Study of benzene release from Savannah River in-tank precipitation process slurry simulant

International Nuclear Information System (INIS)

Rappe, K.G.; Gauglitz, P.A.

1998-08-01

At the Savannah River Site, the in-tank precipitation (ITP) process uses sodium tetraphenylborate (NaTPB) to precipitate radioactive cesium from alkaline wastes. During this process, potassium is also precipitated to form 4-wt% KTPB/CsTPB slurry. Residual NaTPB decomposes to form benzene, which is retained by the waste slurry. The retained benzene is also readily released from the waste during subsequent waste processing. While the release of benzene certainly poses flammability and toxicological safety concerns, the magnitude of the hazard depends on the rate of release. Currently, the mechanisms controlling the benzene release rates are not well understood, and predictive models for estimating benzene release rates are not available. The overall purpose of this study is to obtain quantitative measurements of benzene release rates from a series of ITP slurry simulants. This information will become a basis for developing a quantitative mechanistic model of benzene release rates. The transient benzene release rate was measured from the surface of various ITP slurry (solution) samples mixed with benzene. The benzene release rate was determined by continuously purging the headspace of a sealed sample vessel with an inert gas (nitrogen) and analyzing that purged headspace vapor for benzene every minute

Validation of the Vanderbilt Holistic Face Processing Test

OpenAIRE

Wang, Chao-Chih; Ross, David A.; Gauthier, Isabel; Richler, Jennifer J.

2016-01-01

The Vanderbilt Holistic Face Processing Test (VHPT-F) is a new measure of holistic face processing with better psychometric properties relative to prior measures developed for group studies (Richler et al., 2014). In fields where psychologists study individual differences, validation studies are commonplace and the concurrent validity of a new measure is established by comparing it to an older measure with established validity. We follow this approach and test whether the VHPT-F measures the ...

Validation of the Vanderbilt Holistic Face Processing Test.

OpenAIRE

Chao-Chih Wang; Chao-Chih Wang; David Andrew Ross; Isabel Gauthier; Jennifer Joanna Richler

2016-01-01

The Vanderbilt Holistic Face Processing Test (VHPT-F) is a new measure of holistic face processing with better psychometric properties relative to prior measures developed for group studies (Richler et al., 2014). In fields where psychologists study individual differences, validation studies are commonplace and the concurrent validity of a new measure is established by comparing it to an older measure with established validity. We follow this approach and test whether the VHPT-F measures the ...

Validation of the Vanderbilt Holistic Face Processing Test.

Science.gov (United States)

Wang, Chao-Chih; Ross, David A; Gauthier, Isabel; Richler, Jennifer J

2016-01-01

The Vanderbilt Holistic Face Processing Test (VHPT-F) is a new measure of holistic face processing with better psychometric properties relative to prior measures developed for group studies (Richler et al., 2014). In fields where psychologists study individual differences, validation studies are commonplace and the concurrent validity of a new measure is established by comparing it to an older measure with established validity. We follow this approach and test whether the VHPT-F measures the same construct as the composite task, which is group-based measure at the center of the large literature on holistic face processing. In Experiment 1, we found a significant correlation between holistic processing measured in the VHPT-F and the composite task. Although this correlation was small, it was comparable to the correlation between holistic processing measured in the composite task with the same faces, but different target parts (top or bottom), which represents a reasonable upper limit for correlations between the composite task and another measure of holistic processing. These results confirm the validity of the VHPT-F by demonstrating shared variance with another measure of holistic processing based on the same operational definition. These results were replicated in Experiment 2, but only when the demographic profile of our sample matched that of Experiment 1.

Validation of the Vanderbilt Holistic Face Processing Test.

Directory of Open Access Journals (Sweden)

Chao-Chih Wang

2016-11-01

Full Text Available The Vanderbilt Holistic Face Processing Test (VHPT-F is a new measure of holistic face processing with better psychometric properties relative to prior measures developed for group studies (Richler et al., 2014. In fields where psychologists study individual differences, validation studies are commonplace and the concurrent validity of a new measure is established by comparing it to an older measure with established validity. We follow this approach and test whether the VHPT-F measures the same construct as the composite task, which is group-based measure at the center of the large literature on holistic face processing. In Experiment 1, we found a significant correlation between holistic processing measured in the VHPT-F and the composite task. Although this correlation was small, it was comparable to the correlation between holistic processing measured in the composite task with the same faces, but different target parts (top or bottom, which represents a reasonable upper limit for correlations between the composite task and another measure of holistic processing. These results confirm the validity of the VHPT-F by demonstrating shared variance with another measure of holistic processing based on the same operational definition. These results were replicated in Experiment 2, but only when the demographic profile of our sample matched that of Experiment 1.

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

Science.gov (United States)

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

2014-02-01

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.

Development and validation of an in vitro–in vivo correlation (IVIVC model for propranolol hydrochloride extended-release matrix formulations

Directory of Open Access Journals (Sweden)

Chinhwa Cheng

2014-06-01

Full Text Available The objective of this study was to develop an in vitro–in vivo correlation (IVIVC model for hydrophilic matrix extended-release (ER propranolol dosage formulations. The in vitro release characteristics of the drug were determined using USP apparatus I at 100 rpm, in a medium of varying pH (from pH 1.2 to pH 6.8. In vivo plasma concentrations and pharmacokinetic parameters in male beagle dogs were obtained after administering oral, ER formulations and immediate-release (IR commercial products. The similarity factor f2 was used to compare the dissolution data. The IVIVC model was developed using pooled fraction dissolved and fraction absorbed of propranolol ER formulations, ER-F and ER-S, with different release rates. An additional formulation ER-V, with a different release rate of propranolol, was prepared for evaluating the external predictability. The results showed that the percentage prediction error (%PE values of Cmax and AUC0–∞ were 0.86% and 5.95%, respectively, for the external validation study. The observed low prediction errors for Cmax and AUC0–∞ demonstrated that the propranolol IVIVC model was valid.

Release process for non-real property containing residual radioactive material

International Nuclear Information System (INIS)

Ranek, N.L.; Chen, S.Y.; Kamboj, S.; Hensley, J.; Burns, D.; Fleming, R.; Warren, S.; Wallo, A.

1997-01-01

It is DOE's objective to operate its facilities and to conduct its activities so that radiation exposures to members of the public are maintained within acceptable limits and exposures to residual radioactive materials are controlled. To accomplish this, DOE has adopted Order DOE 5400.51 'Radiation Protection of the Public and the Environment', and will be promulgating IO CR Part 834 to codify and clarify the requirements of DOE 5400.5. Under both DOE 5400.5 and 10 CR Part 834, radioactively contaminated DOE property is prohibited from release unless specific actions have been completed prior to the release. This paper outlines a ten-step process that, if followed, will assist DOE Operations and contractor personnel in ensuring that the required actions established by Order DOE 5400.5 and 10 CR Part 834 have been appropriately completed prior to the release for reuse or recycle of non-real property (e.g., office furniture, computers, hand tools, machinery, vehicles and scrap metal). Following the process will assist in ensuring that radiological doses to the public from the released materials will meet applicable regulatory standards and be as low as reasonably achievable (ALARA)

Microsoft Visio 2013 business process diagramming and validation

CERN Document Server

Parker, David

2013-01-01

Microsoft Visio 2013 Business Process Diagramming and Validation provides a comprehensive and practical tutorial including example code and demonstrations for creating validation rules, writing ShapeSheet formulae, and much more.If you are a Microsoft Visio 2013 Professional Edition power user or developer who wants to get to grips with both the essential features of Visio 2013 and the validation rules in this edition, then this book is for you. A working knowledge of Microsoft Visio and optionally .NET for the add-on code is required, though previous knowledge of business process diagramming

Study of the Release Process of Open Source Software: Case Study

OpenAIRE

Eide, Tor Erik

2007-01-01

This report presents the results of a case study focusing on the release process of open source projects initiated with commercial motives. The purpose of the study is to gain an increased understanding of the release process, how a community can be attracted to the project, and how the interaction with the community evolves in commercial open source initiatives. Data has been gathered from four distinct sources to form the basis of this thesis. A thorough review of the open source literatu...

Digital processing method for monitoring the radioactivity of stack releases

International Nuclear Information System (INIS)

Vialettes, H.; Leblanc, P.; Perotin, J.P.; Lazou, J.P.

1978-01-01

The digital processing method proposed is adapted for data supplied by a fixed-filter detector normally used for analogue processing (integrator system). On the basis of the raw data (pulses) from the detector, the technique makes it possible to determine the rate of activity released whereas analogue processing gives only the released activity. Furthermore, the method can be used to develop alarm systems on the basis of a possible exposure rate at the point of fall-out, and by including in the program a coefficient which allows for atmospheric diffusion conditions at any given time one can improve the accuracy of the results. In order to test the digital processing method and demonstrate its advantages over analogue processing, various atmospheric contamination situations were simulated in a glove-box and analysed simultaneously, using both systems, from the pulses transmitted by the same sampling and fixed-filter detection unit. The experimental results confirm the advantages foreseen in the theoretical research. (author)

Validated, Ultra Violet Spectroscopy method for the Dissolution study of Mycophenolate mofetil immediate release 500mg tablets

OpenAIRE

Surajpal P. Verma; Ozair Alam; Pooja Mullick; Nadeem Siddiqui; Suroor A. Khan

2008-01-01

A simple, selective and precise dissolution method was developed and validated for the Mycophenolate mofetil immediate release tablets. The method employed dissolution medium 0.1N HCl (pH1.2) and volume 900ml with USP-II apparatus (Paddle). Detection was made by measuring the absorbance on UV at the [lambda]~max~ 250nm. The method show the linearity in the range of conc. 5[micro]g/ml to 40[micro]g/ml with r^2^=0.999. The method is also validated as per International Conference of Harmonizatio...

AN OVERVIEW OF PHARMACEUTICAL PROCESS VALIDATION AND PROCESS CONTROL VARIABLES OF TABLETS MANUFACTURING PROCESSES IN INDUSTRY

OpenAIRE

Mahesh B. Wazade*, Sheelpriya R. Walde and Abhay M. Ittadwar

2012-01-01

Validation is an integral part of quality assurance; the product quality is derived from careful attention to a number of factors including selection of quality parts and materials, adequate product and manufacturing process design, control of the process variables, in-process and end-product testing. Recently validation has become one of the pharmaceutical industry’s most recognized and discussed subjects. It is a critical success factor in product approval and ongoing commercialization, fac...

Soil Moisture Active Passive Mission L4_SM Data Product Assessment (Version 2 Validated Release)

Science.gov (United States)

Reichle, Rolf Helmut; De Lannoy, Gabrielle J. M.; Liu, Qing; Ardizzone, Joseph V.; Chen, Fan; Colliander, Andreas; Conaty, Austin; Crow, Wade; Jackson, Thomas; Kimball, John;

Prediction and Validation of Heat Release Direct Injection Diesel Engine Using Multi-Zone Model

Science.gov (United States)

Anang Nugroho, Bagus; Sugiarto, Bambang; Prawoto; Shalahuddin, Lukman

2014-04-01

The objective of this study is to develop simulation model which capable to predict heat release of diesel combustion accurately in efficient computation time. A multi-zone packet model has been applied to solve the combustion phenomena inside diesel cylinder. The model formulations are presented first and then the numerical results are validated on a single cylinder direct injection diesel engine at various engine speed and timing injections. The model were found to be promising to fulfill the objective above.

An investigation of effects of modification processes on physical properties and mechanism of drug release for sustaining drug release from modified rice

Energy Technology Data Exchange (ETDEWEB)

Ngo, Vuong Duy; Luu, Thinh Duc; Van Vo, Toi [Pharmaceutical Engineering Laboratory, Biomedical Engineering Department, International University, Vietnam National University, Ho Chi Minh City (Viet Nam); Tran, Van-Thanh [Faculty of Pharmacy, University of Medicine and Pharmacy, Ho Chi Minh City (Viet Nam); Duan, Wei [School of Medicine, Deakin University, Pigdons Road, Waurn Ponds, Victoria (Australia); Tran, Phuong Ha-Lien, E-mail: phuong.tran1@deakin.edu.au [School of Medicine, Deakin University, Pigdons Road, Waurn Ponds, Victoria (Australia); Tran, Thao Truong-Dinh, E-mail: ttdthao@hcmiu.edu.vn [Pharmaceutical Engineering Laboratory, Biomedical Engineering Department, International University, Vietnam National University, Ho Chi Minh City (Viet Nam)

2016-10-01

The aim of this study was to investigate the effect of modification processes on physical properties and explain the mechanism of sustained drug release from modified rice (MR). Various types of Vietnamese rice were introduced in the study as the matrices of sustained release dosage form. Rice was thermally modified in water for a determined temperature at different times with a simple process. Then tablets containing MR and isradipine, the model drug, were prepared to investigate the capability of sustained drug release. Scanning electron microscopy (SEM) was used to determine different morphologies between MR formulations. Flow property of MR was analyzed by Hausner ratio and Carr's indices. The dissolution rate and swelling/erosion behaviors of tablets were evaluated at pH 1.2 and pH 6.8 at 37 ± 0.5 °C. The matrix tablet containing MR showed a sustained release as compared to the control. The SEM analyses and swelling/erosion studies indicated that the morphology as well as swelling/erosion rate of MR were modulated by modification time, drying method and incubation. It was found that the modification process was crucial because it could highly affect the granule morphologies and hence, leading to the change of flowability and swelling/erosion capacity for sustained release of drug. - Highlights: • Modification process affected granule morphologies and flowability of modified rice. • Modification process affected swelling/erosion capacity for drug sustained release. • Freeze-drying could decrease the erosion as well as increase the swelling rate.

An investigation of effects of modification processes on physical properties and mechanism of drug release for sustaining drug release from modified rice

International Nuclear Information System (INIS)

Ngo, Vuong Duy; Luu, Thinh Duc; Van Vo, Toi; Tran, Van-Thanh; Duan, Wei; Tran, Phuong Ha-Lien; Tran, Thao Truong-Dinh

2016-01-01

The aim of this study was to investigate the effect of modification processes on physical properties and explain the mechanism of sustained drug release from modified rice (MR). Various types of Vietnamese rice were introduced in the study as the matrices of sustained release dosage form. Rice was thermally modified in water for a determined temperature at different times with a simple process. Then tablets containing MR and isradipine, the model drug, were prepared to investigate the capability of sustained drug release. Scanning electron microscopy (SEM) was used to determine different morphologies between MR formulations. Flow property of MR was analyzed by Hausner ratio and Carr's indices. The dissolution rate and swelling/erosion behaviors of tablets were evaluated at pH 1.2 and pH 6.8 at 37 ± 0.5 °C. The matrix tablet containing MR showed a sustained release as compared to the control. The SEM analyses and swelling/erosion studies indicated that the morphology as well as swelling/erosion rate of MR were modulated by modification time, drying method and incubation. It was found that the modification process was crucial because it could highly affect the granule morphologies and hence, leading to the change of flowability and swelling/erosion capacity for sustained release of drug. - Highlights: • Modification process affected granule morphologies and flowability of modified rice. • Modification process affected swelling/erosion capacity for drug sustained release. • Freeze-drying could decrease the erosion as well as increase the swelling rate.

Verification and Validation in a Rapid Software Development Process

Science.gov (United States)

Callahan, John R.; Easterbrook, Steve M.

1997-01-01

The high cost of software production is driving development organizations to adopt more automated design and analysis methods such as rapid prototyping, computer-aided software engineering (CASE) tools, and high-level code generators. Even developers of safety-critical software system have adopted many of these new methods while striving to achieve high levels Of quality and reliability. While these new methods may enhance productivity and quality in many cases, we examine some of the risks involved in the use of new methods in safety-critical contexts. We examine a case study involving the use of a CASE tool that automatically generates code from high-level system designs. We show that while high-level testing on the system structure is highly desirable, significant risks exist in the automatically generated code and in re-validating releases of the generated code after subsequent design changes. We identify these risks and suggest process improvements that retain the advantages of rapid, automated development methods within the quality and reliability contexts of safety-critical projects.

Radiochemical verification and validation in the environmental data collection process

International Nuclear Information System (INIS)

Rosano-Reece, D.; Bottrell, D.; Bath, R.J.

1994-01-01

A credible and cost effective environmental data collection process should produce analytical data which meets regulatory and program specific requirements. Analytical data, which support the sampling and analysis activities at hazardous waste sites, undergo verification and independent validation before the data are submitted to regulators. Understanding the difference between verification and validation and their respective roles in the sampling and analysis process is critical to the effectiveness of a program. Verification is deciding whether the measurement data obtained are what was requested. The verification process determines whether all the requirements were met. Validation is more complicated than verification. It attempts to assess the impacts on data use, especially when requirements are not met. Validation becomes part of the decision-making process. Radiochemical data consists of a sample result with an associated error. Therefore, radiochemical validation is different and more quantitative than is currently possible for the validation of hazardous chemical data. Radiochemical data include both results and uncertainty that can be statistically compared to identify significance of differences in a more technically defensible manner. Radiochemical validation makes decisions about analyte identification, detection, and uncertainty for a batch of data. The process focuses on the variability of the data in the context of the decision to be made. The objectives of this paper are to present radiochemical verification and validation for environmental data and to distinguish the differences between the two operations

Flight Dynamic Simulation of Fighter In the Asymmetric External Store Release Process

Science.gov (United States)

Safi’i, Imam; Arifianto, Ony; Nurohman, Chandra

2018-04-01

In the fighter design, it is important to evaluate and analyze the flight dynamic of the aircraft earlier in the development process. One of the case is the dynamics of external store release process. A simulation tool can be used to analyze the fighter/external store system’s dynamics in the preliminary design stage. This paper reports the flight dynamics of Jet Fighter Experiment (JF-1 E) in asymmetric Advance Medium Range Air to Air Missile (AMRAAM) release process through simulations. The JF-1 E and AIM 120 AMRAAAM models are built by using Advanced Aircraft Analysis (AAA) and Missile Datcom software. By using these softwares, the aerodynamic stability and control derivatives can be obtained and used to model the dynamic characteristic of the fighter and the external store. The dynamic system is modeled by using MATLAB/Simulink software. By using this software, both the fighter/external store integration and the external store release process is simulated, and the dynamic of the system can be analyzed.

Release Strategies: The CMS approach for Development and Quality Assurance

International Nuclear Information System (INIS)

Sexton-Kennedy, Elizabeth

2011-01-01

Now that CMS has started data taking there is a balance to be struck between software release stability for operations and the need to improve the physics and technical performance of the code. In addition new code may need to be developed to correct for unforeseen data taking conditions, and has to be integrated into the mainstream releases with a minimum risk. To keep the process under control, CMS uses regular (twice a day) Integration Builds. A complex set of validation steps is used to verify the software at various stages, from the regular Integration Builds to running a full software and physics validation suite on the grid for major releases. CMS has adopted a development model that tries to strike the correct balance between the needs of stability and a constant improvement; this paper will describe our experience with this model, and tell the story of how the commissioning of the CMS offline has proceeded through the perspective of the past year's releases.

Development, validation and routine control of a radiation process

International Nuclear Information System (INIS)

Kishor Mehta

2010-01-01

Today, radiation is used in industrial processing for variety of applications; from low doses for blood irradiation to very high doses for materials modification and even higher for gemstone colour enhancement. At present, radiation is mainly provided by either radionuclides or machine sources; cobalt-60 is the most predominant radionuclide in use. Currently, there are several hundred irradiation facilities worldwide. Similar to other industries, quality management systems can assist radiation processing facilities in enhancing customer satisfaction and maintaining and improving product quality. To help fulfill quality management requirements, several national and international organizations have developed various standards related to radiation processing. They all have requirements and guidelines for development, validation and routine control of the radiation process. For radiation processing, these three phases involve the following activities. Development phase includes selecting the type of radiation source, irradiation facility and the dose required for the process. Validation phase includes conducting activities that give assurance that the process will be successful. Routine control then involves activities that provide evidence that the process has been successfully realized. These standards require documentary evidence that process validation and process control have been followed. Dosimetry information gathered during these processes provides this evidence. (authors)

Experiments to validate the assumptions on Pu release in an aircraft crash

International Nuclear Information System (INIS)

Seehars, H.D.; Hochrainer, D.

1983-01-01

This report describes simulation experiments with the substitute powder CeO 2 to study the release and dispersion of PuO 2 -powder induced by kerosene fires after an aeroplane crash on a Plutonium processing fuel element plant. The release rates of CeO 2 -powder were found to be a nonlinear function of te kerosene combustion rate. The release rates during a ''micro-scale'' fire inside the glovebox (pool area some 20 cm 2 ) were characterized by values of less than 10 μg/s, those during a conflagration (pool area some 200 m 2 ) by values of somewhat more than 25 mg/s. Because of the lack of other weather conditions the dispersion experiments were exclusively realized during weak to moderate winds. Small scale fire induced maximum inhalation hazards from PuO 2 -powder used in production essentially exceeded those of large scale conflagrations. Obviously the activity intake by inhalation exceeded to some extent the admissable threshold of the annual activity intake. (orig.) [de

Analyses of postulated accidental releases of UF6 inside process buildings

International Nuclear Information System (INIS)

Oliveira Neto, Jose Messias de; Nunes, Beatriz Guimaraes; Dias, Cristiane

2009-01-01

Uranium Hexafluoride is a material used in the various processes which comprise the front end of the nuclear fuel cycle (conversion, enrichment and fuel fabrication). Confinement of UF 6 is a very important safety requirement since this material is highly reactive and presents safety hazards to humans. The present paper discusses the safety relevant aspects of accidental releases of UF 6 inside process confinement buildings. Postulated accidental scenarios are analyzed and their consequences evaluated. Implant releases rates are estimated using computer code predictions. A time dependent homogeneous compartment model is used to predict concentrations of UF 6 , hydrogen fluoride and uranyl fluoride inside a confinement building, as well as to evaluate source terms released to the atmosphere. These source terms can be used as input to atmospheric dispersion models to evaluate consequences to the environment. The results can also be used to define adequate protective measures for emergency situations. (author)

Modeling and validating tritium transfer in a grassland ecosystem in response to {sup 3}H releases

Energy Technology Data Exchange (ETDEWEB)

Le Dizes, S.; Maro, D.; Rozet, M.; Hebert, D.; Solier, L.; Nicoulaud, V. [Institut de radioportection et de surete nucleaire - IRSN (France); Vermorel, F.; Aulagnier, C. [Electricite de France - EDF (France)

2014-07-01

Tritium ({sup 3}H) is a major radionuclide released in several forms (HTO, HT) by nuclear facilities under normal operating conditions. In terrestrial ecosystems, tritium can be found under two forms: tritium in tissue free water (TFWT) following absorption of tritiated water by leaves or roots and Organically Bound Tritium (OBT) resulting from TFWT incorporation by the plant organic matter during photosynthesis. In order to study transfers of tritium from atmospheric releases to terrestrial ecosystem such as grasslands, an in-situ laboratory has been set up by IRSN on a ryegrass field plot located 2 km downwind the AREVA NC La Hague nuclear reprocessing plant (North-West of France), as was done in the past for the assessment of transfer of radiocarbon in grasslands. The objectives of this experimental field are: (i) to better understand the OBT formation in plant by photosynthesis, (ii) to evaluate transfer processes of tritium in several forms (HT, HTO) from the atmosphere (air and rainwater) to grass and soil, (iii) to develop a modeling allowing to reproduce the dynamic response of the ecosystem to tritium atmospheric releases depending of variable environmental conditions. For this purpose, tritium activity measurements will be carried out in grass (monthly measurements of HTO, OBT), in air, rainwater, soil (daily measurements of HT, HTO) and CO{sub 2}, H{sub 2}O fluxes between soil and air compartments will be carried out. Then, the TOCATTA-c model previously developed to simulate {sup 14}C transfers to pasture on a hourly time-step basis will be adapted to take account for processes specific to tritium. The model will be tested by a comparison between simulated results and measurements. The objectives of this presentation are (1) to present the organization of the experimental design of the VATO study (Validation of TOCATTA) dedicated to transfers of tritium in a grassland ecosystem, (2) to document the major assumptions, conceptual modelling and

Development of Process Analytical Technology (PAT) methods for controlled release pellet coating.

Science.gov (United States)

Avalle, P; Pollitt, M J; Bradley, K; Cooper, B; Pearce, G; Djemai, A; Fitzpatrick, S

2014-07-01

This work focused on the control of the manufacturing process for a controlled release (CR) pellet product, within a Quality by Design (QbD) framework. The manufacturing process was Wurster coating: firstly layering active pharmaceutical ingredient (API) onto sugar pellet cores and secondly a controlled release (CR) coating. For each of these two steps, development of a Process Analytical Technology (PAT) method is discussed and also a novel application of automated microscopy as the reference method. Ultimately, PAT methods should link to product performance and the two key Critical Quality Attributes (CQAs) for this CR product are assay and release rate, linked to the API and CR coating steps respectively. In this work, the link between near infra-red (NIR) spectra and those attributes was explored by chemometrics over the course of the coating process in a pilot scale industrial environment. Correlations were built between the NIR spectra and coating weight (for API amount), CR coating thickness and dissolution performance. These correlations allow the coating process to be monitored at-line and so better control of the product performance in line with QbD requirements. Copyright © 2014 Elsevier B.V. All rights reserved.

Risk perception and information processing: the development and validation of a questionnaire to assess self-reported information processing.

Science.gov (United States)

Smerecnik, Chris M R; Mesters, Ilse; Candel, Math J J M; De Vries, Hein; De Vries, Nanne K

2012-01-01

The role of information processing in understanding people's responses to risk information has recently received substantial attention. One limitation of this research concerns the unavailability of a validated questionnaire of information processing. This article presents two studies in which we describe the development and validation of the Information-Processing Questionnaire to meet that need. Study 1 describes the development and initial validation of the questionnaire. Participants were randomized to either a systematic processing or a heuristic processing condition after which they completed a manipulation check and the initial 15-item questionnaire and again two weeks later. The questionnaire was subjected to factor reliability and validity analyses on both measurement times for purposes of cross-validation of the results. A two-factor solution was observed representing a systematic processing and a heuristic processing subscale. The resulting scale showed good reliability and validity, with the systematic condition scoring significantly higher on the systematic subscale and the heuristic processing condition significantly higher on the heuristic subscale. Study 2 sought to further validate the questionnaire in a field study. Results of the second study corresponded with those of Study 1 and provided further evidence of the validity of the Information-Processing Questionnaire. The availability of this information-processing scale will be a valuable asset for future research and may provide researchers with new research opportunities. © 2011 Society for Risk Analysis.

Software Process Validation: Quantitatively Measuring the Correspondence of a Process to a Model

National Research Council Canada - National Science Library

Cook, Jonathan E; Wolf, Alexander L

1997-01-01

.... When process models and process executions diverge, something significant is happening. The authors have developed techniques for uncovering and measuring the discrepancies between models and executions, which they call process validation...

Effects of adenosine on renin release from isolated rat glomeruli and kidney slices

DEFF Research Database (Denmark)

Skøtt, O; Baumbach, L

1985-01-01

was used. The specificity of the renin release process was validated by measuring adenylate kinase as a marker for cytoplasmatic leak. Adenosine (10 micrograms/ml) halved basal renin release from incubated KS as compared to controls (P less than 0.001, n = 8, 8). Renin release from LAG stimulated...... by calcium depletion was also inhibited (P less than 0.05, n = 8, 9) whereas basal release was not affected (n = 6, 12). No effect was detected neither on basal nor on calcium stimulated renin release from SAG. We conclude that adenosine inhibits renin release in vitro by a mechanism independent...

Bioactive peptides released during of digestion of processed milk

Science.gov (United States)

Most of the proteins contained in milk consist of alpha-s1-, alpha-s2-, beta- and kappa-casein, and some of the peptides contained in these caseins may impart health benefits. To determine if processing affected release of peptides, samples of raw (R), homogenized (H), homogenized and pasteurized (...

Zero-Release Mixed Waste Process Facility Design and Testing

International Nuclear Information System (INIS)

Richard D. Boardman; John A. Deldebbio; Robert J. Kirkham; Martin K. Clemens; Robert Geosits; Ping Wan

2004-01-01

A zero-release off-gas cleaning system for mixed-waste thermal treatment processes has been evaluated through experimental scoping tests and process modeling. The principles can possibly be adapted to a fluidized-bed calcination or stream reforming process, a waste melter, a rotary kiln process, and possibly other waste treatment thermal processes. The basic concept of a zero-release off-gas cleaning system is to recycle the bulk of the off-gas stream to the thermal treatment process. A slip stream is taken off the off-gas recycle to separate and purge benign constituents that may build up in the gas, such as water vapor, argon, nitrogen, and CO2. Contaminants are separated from the slip stream and returned to the thermal unit for eventual destruction or incorporation into the waste immobilization media. In the current study, a standard packed-bed scrubber, followed by gas separation membranes, is proposed for removal of contaminants from the off-gas recycle slipstream. The scrub solution is continuously regenerated by cooling and precipitating sulfate, nitrate, and other salts that reach a solubility limit in the scrub solution. Mercury is also separated by the scrubber. A miscible chemical oxidizing agent was shown to effectively oxidize mercury and also NO, thus increasing their removal efficiency. The current study indicates that the proposed process is a viable option for reducing off-gas emissions. Consideration of the proposed closed-system off-gas cleaning loop is warranted when emissions limits are stringent, or when a reduction in the total gas emissions volume is desired. Although the current closed-loop appears to be technically feasible, economical considerations must be also be evaluated on a case-by-case basis

SPECIFICITY OF MANIFACTURING PROCESS VALIDATION FOR DIAGNOSTIC SEROLOGICAL DEVICES

Directory of Open Access Journals (Sweden)

O. Yu. Galkin

2018-02-01

Full Text Available The aim of this research was to analyze recent scientific literature, as well as national and international legislature on manifacturing process validation of biopharmaceutical production, in particular devices for serological diagnostics. Technology validation in the field of medical devices for serological diagnostics is most influenced by the Technical Regulation for Medical Devices for in vitro Diagnostics State Standards of Ukraine – SSU EN ISO 13485:2015 “Medical devices. Quality management system. Requirements for regulation”, SSU EN ISO 14971:2015 “Medical devices. Instructions for risk management”, Instruction ST-N of the Ministry of Healthcare of Ukraine 42-4.0:2014 “Medications. Suitable industrial practice”, State Pharmacopoeia of Ukraine and Instruction ICH Q9 on risk management. Current recommendations for validations of drugs manufacturing process, including biotechnological manufacturing, can not be directly applied to medical devices for in vitro diagnostics. It was shown that the specifics of application and raw materials require individual validation parameters and process validations for serological diagnostics devices. Critical parameters to consider in validation plans were provided for every typical stage of production of in vitro diagnostics devices on the example of immunoassay kits, such as obtaining protein antigens, including recombinant ones, preparations of mono- and polyclonal antibodies, immunoenzyme conjugates and immunosorbents, chemical reagents etc. The bottlenecks of technologies for in vitro diagnostics devices were analyzed from the bioethical and biosafety points of view.

How Monte Carlo heuristics aid to identify the physical processes of drug release kinetics.

Science.gov (United States)

Lecca, Paola

2018-01-01

We implement a Monte Carlo heuristic algorithm to model drug release from a solid dosage form. We show that with Monte Carlo simulations it is possible to identify and explain the causes of the unsatisfactory predictive power of current drug release models. It is well known that the power-law, the exponential models, as well as those derived from or inspired by them accurately reproduce only the first 60% of the release curve of a drug from a dosage form. In this study, by using Monte Carlo simulation approaches, we show that these models fit quite accurately almost the entire release profile when the release kinetics is not governed by the coexistence of different physico-chemical mechanisms. We show that the accuracy of the traditional models are comparable with those of Monte Carlo heuristics when these heuristics approximate and oversimply the phenomenology of drug release. This observation suggests to develop and use novel Monte Carlo simulation heuristics able to describe the complexity of the release kinetics, and consequently to generate data more similar to those observed in real experiments. Implementing Monte Carlo simulation heuristics of the drug release phenomenology may be much straightforward and efficient than hypothesizing and implementing from scratch complex mathematical models of the physical processes involved in drug release. Identifying and understanding through simulation heuristics what processes of this phenomenology reproduce the observed data and then formalize them in mathematics may allow avoiding time-consuming, trial-error based regression procedures. Three bullet points, highlighting the customization of the procedure. •An efficient heuristics based on Monte Carlo methods for simulating drug release from solid dosage form encodes is presented. It specifies the model of the physical process in a simple but accurate way in the formula of the Monte Carlo Micro Step (MCS) time interval.•Given the experimentally observed curve of

Production process validation of 2-[18F]-fluoro-2-deoxy-D-glucose

International Nuclear Information System (INIS)

Cantero, Miguel; Iglesias, Rocio; Aguilar, Juan; Sau, Pablo; Tardio, Evaristo; Narrillos, Marcos

2003-01-01

The main of validation of production process of 2-[18F]-fluoro-2-deoxi-D-glucose (FDG) was to check: A) equipment's and services implicated in the production process were correctly installed, well documented, and worked properly, and B) production of FDG was done in a repetitive way according to predefined parameters. The main document was the Validation Master Plan, and steps were: installation qualification, operation qualification, process qualification and validation report. After finalization of all tests established in qualification steps without deviations, we concluded that the production process was validated because is done in a repetitive way according predefined parameters (Au)

Gas release during salt-well pumping: Model predictions and laboratory validation studies for soluble and insoluble gases

International Nuclear Information System (INIS)

Peurrung, L.M.; Caley, S.M.; Gauglitz, P.A.

1997-08-01

The Hanford Site has 149 single-shell tanks (SSTs) containing radioactive wastes that are complex mixes of radioactive and chemical products. Of these, 67 are known or suspected to have leaked liquid from the tanks into the surrounding soil. Salt-well pumping, or interim stabilization, is a well-established operation for removing drainable interstitial liquid from SSTs. The overall objective of this ongoing study is to develop a quantitative understanding of the release rates and cumulative releases of flammable gases from SSTs as a result of salt-well pumping. The current study is an extension of the previous work reported by Peurrung et al. (1996). The first objective of this current study was to conduct laboratory experiments to quantify the release of soluble and insoluble gases. The second was to determine experimentally the role of characteristic waste heterogeneities on the gas release rates. The third objective was to evaluate and validate the computer model STOMP (Subsurface Transport over Multiple Phases) used by Peurrung et al. (1996) to predict the release of both soluble (typically ammonia) and insoluble gases (typically hydrogen) during and after salt-well pumping. The fourth and final objective of the current study was to predict the gas release behavior for a range of typical tank conditions and actual tank geometry. In these models, the authors seek to include all the pertinent salt-well pumping operational parameters and a realistic range of physical properties of the SST wastes. For predicting actual tank behavior, two-dimensional (2-D) simulations were performed with a representative 2-D tank geometry

Development and validation of a dissolution test for diltiazem hydrochloride in immediate release capsules

Directory of Open Access Journals (Sweden)

Taciane Ferreira Mendonça

2011-01-01

Full Text Available This work describes the development and validation of a dissolution test for 60 mg of diltiazem hydrochloride in immediate release capsules. The best dissolution in vitro profile was achieved using potassium phosphate buffer at pH 6.8 as the dissolution medium and paddle as the apparatus at 50 rpm. The drug concentrations in the dissolution media were determined by UV spectrophotometry and HPLC and a statistical analysis revealed that there were significant differences between HPLC and spectrophotometry. This study illustrates the importance of an official method for the dissolution test, since there is no official monograph for diltiazem hydrochloride in capsules.

Interim report: Study of benzene release from Savannah River in-tank precipitation process slurry simulant

International Nuclear Information System (INIS)

Rappe, K.G.; Gauglitz, P.A.

1997-09-01

At the Savannah River Site, the in-tank precipitation (ITP) process uses sodium tetraphenylborate (NaTPB) to precipitate radioactive cesium from alkaline wastes. During this process, potassium is also precipitated to form a 4-wt% KTPB/CsTPB slurry. Residual NaTPB decomposes to form benzene, which is retained by the waste slurry. The retained benzene is also readily released from the waste during subsequent waste processing. While the release of benzene certainly poses both flammability and toxicological safety concerns, the magnitude of the hazard depends on the rate of release. Currently, the mechanisms controlling the benzene release rates are not well understood, and predictive models for estimating benzene release rates are not available. The overall purpose of this study is to obtain quantitative measurements of benzene release rates from a series of ITP slurry stimulants. This information will become a basis for developing a quantitative mechanistic model of benzene release rates. The transient benzene release rate was measured from the surface of various ITP slurry (solution) samples mixed with benzene. The benzene release rate was determined by continuously purging the headspace of a sealed sample vessel with an inert gas (nitrogen) and analyzing that purged headspace vapor for benzene every 3 minutes. The following 75-mL samples were measured for release rates: KTPB slurry with 15,000 ppm freshly added benzene that was gently mixed with the slurry, KTPB slurry homogenized (energetically mixed) with 15,000 ppm and 5,000 ppm benzene, clear and filtered KTPB salt solution saturated with benzene (with and without a pure benzene layer on top of the solution), and a slurry sample from a large demonstration experiment (DEMO slurry) containing-benzene generated in situ

PolyNano M.6.1.1 Process validation state-of-the-art

DEFF Research Database (Denmark)

Tosello, Guido; Hansen, Hans Nørgaard; Calaon, Matteo

2012-01-01

Nano project. Methods for replication process validation are presented and will be further investigated in WP6 “Process Chain Validation” and applied to PolyNano study cases. Based on the available information, effective best practice standard process validation will be defined and implemented...... assessment methods, and presents measuring procedures/techniques suitable for replication fidelity studies. The report reviews state‐of‐the‐art research results regarding replication obtained at different scales, tooling technologies based on surface replication, process validation trough design...

Experimental Study on Ice Forming Process of Cryogenic Liquid Releasing underwater

Science.gov (United States)

Zhang, Bin; Wu, Wanqing; Zhang, Xingdong; Zhang, Yi; Zhang, Chuanlin; Zhang, Haoran; Wang, Peng

2017-11-01

Cryogenic liquid releasing into water would be a process combines hyperactive boiling with ice forming. There are still few researches on the experimental study on the environmental conditions for deciding ice forming speed and liquid surviving state. In this paper, to advance our understanding of ice forming deciding factors in the process of LN2 releasing underwater, a visualization experimental system is built. The results show that the pressure difference significantly influences the ice forming speed and liquid surviving distance, which is observed by the experiment and theoretically analysed by Kelvin-Helmholtz instability. Adding nucleating agent is helpful to provide ice nucleus which can accelerate the ice forming speed. Water flowing has some effect on changing pressure difference, which can affect the ice forming speed and liquid surviving distance.

Validation of a pulsed electric field process to pasteurize strawberry puree

Science.gov (United States)

An inexpensive data acquisition method was developed to validate the exact number and shape of the pulses applied during pulsed electric fields (PEF) processing. The novel validation method was evaluated in conjunction with developing a pasteurization PEF process for strawberry puree. Both buffered...

Release of ultrafine particles from three simulated building processes

International Nuclear Information System (INIS)

Kumar, Prashant; Mulheron, Mike; Som, Claudia

2012-01-01

Building activities are recognised to produce coarse particulate matter but less is known about the release of airborne ultrafine particles (UFPs; those below 100 nm in diameter). For the first time, this study has investigated the release of particles in the 5–560 nm range from three simulated building activities: the crushing of concrete cubes, the demolition of old concrete slabs, and the recycling of concrete debris. A fast response differential mobility spectrometer (Cambustion DMS50) was used to measure particle number concentrations (PNC) and size distributions (PNDs) at a sampling frequency of 10 Hz in a confined laboratory room providing controlled environment and near–steady background PNCs. The sampling point was intentionally kept close to the test samples so that the release of new UFPs during these simulated processes can be quantified. Tri–modal particle size distributions were recorded for all cases, demonstrating different peak diameters in fresh nuclei ( 4 cm −3 . These background modal peaks shifted towards the larger sizes during the work periods (i.e. actual experiments) and the total PNCs increased between 2 and 17 times over the background PNCs for different activities. After adjusting for background concentrations, the net release of PNCs during cube crushing, slab demolition, and ‘dry’ and ‘wet’ recycling events were measured as ∼0.77, 19.1, 22.7 and 1.76 (×10 4 ) cm −3 , respectively. The PNDs were converted into particle mass concentrations (PMCs). While majority of new PNC release was below 100 nm (i.e. UFPs), the bulk of new PMC emissions were constituted by the particles over 100 nm; ∼95, 79, 73 and 90% of total PNCs, and ∼71, 92, 93 and 91% of total PMCs, for cube crushing, slab demolition, dry recycling and wet recycling, respectively. The results of this study firmly elucidate the release of UFPs and raise a need for further detailed studies and designing health and safety related exposure guidelines for

Materials of the Regional Training Course on Validation and Process Control for Electron Beam Radiation Processing

International Nuclear Information System (INIS)

Kaluska, I.; Gluszewski, W.

2007-01-01

Irradiation with electron beams is used in the polymer industry, food, pharmaceutical and medical device industries for sterilization of surfaces. About 20 lectures presented during the Course were devoted to all aspects of control and validation of low energy electron beam processes. They should help the product manufacturers better understand the application of the ANSI/AAMI/ISO 11137 norm, which defines the requirements and standard practices for validation of the irradiation process and the process controls required during routine processing

Electric ignition energy evaluation and the energy distribution structure of energy released in electrostatic discharge process

International Nuclear Information System (INIS)

Liu Qingming; Huang Jinxiang; Shao Huige; Zhang Yunming

2017-01-01

Ignition energy is one of the important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electric spark discharge test system, a series of electric spark discharge experiments were conducted with the capacitor-stored energy in the range of 10 J, 100 J, and 1000 J, respectively. The evaluation method for energy consumed by electric spark, wire, and switch during capacitor discharge process has been studied respectively. The resistance of wire, switch, and plasma between electrodes has been evaluated by different methods and an optimized evaluation method has been obtained. The electric energy consumed by wire, electric switch, and electric spark-induced plasma between electrodes were obtained and the energy structure of capacitor-released energy was analyzed. The dynamic process and the characteristic parameters (the maximum power, duration of discharge process) of electric spark discharge process have been analyzed. Experimental results showed that, electric spark-consumed energy only accounts for 8%–14% of the capacitor-released energy. With the increase of capacitor-released energy, the duration of discharge process becomes longer, and the energy of plasma accounts for more in the capacitor-released energy. The power of electric spark varies with time as a damped sinusoids function and the period and the maximum value increase with the capacitor-released energy. (paper)

Development of In Vitro-In Vivo Correlation for Amorphous Solid Dispersion Immediate-Release Suvorexant Tablets and Application to Clinically Relevant Dissolution Specifications and In-Process Controls.

Science.gov (United States)

Kesisoglou, Filippos; Hermans, Andre; Neu, Colleen; Yee, Ka Lai; Palcza, John; Miller, Jessica

2015-09-01

Although in vitro-in vivo correlations (IVIVCs) are commonly pursued for modified-release products, there are limited reports of successful IVIVCs for immediate-release (IR) formulations. This manuscript details the development of a Multiple Level C IVIVC for the amorphous solid dispersion formulation of suvorexant, a BCS class II compound, and its application to establishing dissolution specifications and in-process controls. Four different 40 mg batches were manufactured at different tablet hardnesses to produce distinct dissolution profiles. These batches were evaluated in a relative bioavailability clinical study in healthy volunteers. Although no differences were observed for the total exposure (AUC) of the different batches, a clear relationship between dissolution and Cmax was observed. A validated Multiple Level C IVIVC against Cmax was developed for the 10, 15, 20, 30, and 45 min dissolution time points and the tablet disintegration time. The relationship established between tablet tensile strength and dissolution was subsequently used to inform suitable tablet hardness ranges within acceptable Cmax limits. This is the first published report for a validated Multiple Level C IVIVC for an IR solid dispersion formulation demonstrating how this approach can facilitate Quality by Design in formulation development and help toward clinically relevant specifications and in-process controls. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Laser Processing of Carbon Fiber Reinforced Plastics - Release of Carbon Fiber Segments During Short-pulsed Laser Processing of CFRP

Science.gov (United States)

Walter, Juergen; Brodesser, Alexander; Hustedt, Michael; Bluemel, Sven; Jaeschke, Peter; Kaierle, Stefan

Cutting and ablation using short-pulsed laser radiation are promising technologies to produce or repair CFRP components with outstanding mechanical properties e.g. for automotive and aircraft industry. Using sophisticated laser processing strategies and avoiding excessive heating of the workpiece, a high processing quality can be achieved. However, the interaction of laser radiation and composite material causes a notable release of hazardous substances from the process zone, amongst others carbon fiber segments or fibrous particles. In this work, amounts and geometries of the released fiber segments are analyzed and discussed in terms of their hazardous potential. Moreover, it is investigated to what extent gaseous organic process emissions are adsorbed at the fiber segments, similar to an adsorption of volatile organic compounds at activated carbon, which is typically used as filter material.

Fission product release from nuclear fuel I. Physical modelling in the ASTEC code

International Nuclear Information System (INIS)

Brillant, G.; Marchetto, C.; Plumecocq, W.

2013-01-01

Highlights: • Physical modeling of FP and SM release in ASTEC is presented. • The release is described as solid state diffusion within fuel for high volatile FP. • The release is described as FP vaporisation for semi volatile FP. • The release is described as fuel vaporisation for low volatile FP. • ASTEC validation is presented in the second paper. - Abstract: This article is the first of a series of two articles dedicated to the mechanisms of fission product release from a degraded core as they are modelled in the ASTEC code. The ASTEC code aims at simulating severe accidents in nuclear reactors from the initiating event up to the radiological consequences on the environment. This code is used for several applications such as nuclear plant safety evaluation including probabilistic studies and emergency preparedness. To cope with the requirements of robustness and low calculation time, the code is based on a semi-empirical approach and only the main limiting phenomena that govern the release from intact rods and from debris beds are considered. For solid fuel, fission products are classified into three groups, depending on their degree of volatility. The kinetics of volatile fission products release depend on the rate-limiting process of solid-state diffusion through fuel grains. For semi-volatile fission products, the release from the open fuel porosities is assumed to be governed by vaporisation and mass transfer processes. The key phenomenon for the release of low volatile fission products is supposed to be fuel volatilisation. A similar approach is used for the release of fission products from a rubble bed. An in-depth validation of the code including both analytical and integral experiments is the subject of the second article

Production process validation of 2-[18F]-fluoro-2-deoxy-D-glucose

International Nuclear Information System (INIS)

Cantero, Miguel; Iglesias, Rocio; Aguilar, Juan; Sau, Pablo; Tardio, Evaristo; Narrillos, Marcos

2003-01-01

The aim of production process validation of 2-[18F]-fluoro-2-deoxi-D-glucose (FDG) was to check: A) equipments and services implicated in the production process were correctly installed, well documented, and worked properly, and B) production of FDG was done in a repetitive way according to predefined parameters. The main document was the Validation Master Plan, and steps were: installation qualification, operational qualification, performance qualification and validation final report. After finalization of all tests established in qualification steps without deviations, we concluded that the production process was validated because consistently produced FDG meeting its pre-determined specifications and quality characteristics (Au)

Airborne engineered nanomaterials in the workplace—a review of release and worker exposure during nanomaterial production and handling processes

Energy Technology Data Exchange (ETDEWEB)

Ding, Yaobo [Institute for Work and Health (IST), Universities of Lausanne and Geneva, Route de la Corniche 2, 1066, Epalinges (Switzerland); Kuhlbusch, Thomas A.J. [Institute of Energy and Environmental Technology (IUTA), Air Quality & Sustainable Nanotechnology Unit, Bliersheimer Straße 58-60, 47229 Duisburg (Germany); Centre for Nanointegration (CENIDE), University Duisburg-Essen, Duisburg (Germany); Van Tongeren, Martie; Jiménez, Araceli Sánchez [Centre for Human Exposure Science, Institute of Occupational Medicine (IOM), Research Avenue North, Edinburgh EH14 4AP (United Kingdom); Tuinman, Ilse [TNO, Lange Kleiweg 137, Rijswijk (Netherlands); Chen, Rui [CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Beijing 100190 (China); Alvarez, Iñigo Larraza [ACCIONA Infrastructure, Materials Area, Innovation Division, C/Valportillo II 8, 28108, Alcobendas (Spain); Mikolajczyk, Urszula [Nofer Institute of Occupational Medicine, Lodz (Poland); Nickel, Carmen; Meyer, Jessica; Kaminski, Heinz [Institute of Energy and Environmental Technology (IUTA), Air Quality & Sustainable Nanotechnology Unit, Bliersheimer Straße 58-60, 47229 Duisburg (Germany); Wohlleben, Wendel [Dept. Material Physics, BASF SE, Advanced Materials Research, Ludwigshafen (Germany); Stahlmecke, Burkhard [Institute of Energy and Environmental Technology (IUTA), Air Quality & Sustainable Nanotechnology Unit, Bliersheimer Straße 58-60, 47229 Duisburg (Germany); Clavaguera, Simon [NanoSafety Platform, Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Univ. Grenoble Alpes, Grenoble, 38054 (France); and others

2017-01-15

Highlights: • Release characteristics can be grouped by the type of occupational activities. • Release levels may be linked to process energy. • A better data reporting practice will facilitate exposure assessment. • The results help prioritize industrial processes for human risk assessment. - Abstract: For exposure and risk assessment in occupational settings involving engineered nanomaterials (ENMs), it is important to understand the mechanisms of release and how they are influenced by the ENM, the matrix material, and process characteristics. This review summarizes studies providing ENM release information in occupational settings, during different industrial activities and using various nanomaterials. It also assesses the contextual information — such as the amounts of materials handled, protective measures, and measurement strategies — to understand which release scenarios can result in exposure. High-energy processes such as synthesis, spraying, and machining were associated with the release of large numbers of predominantly small-sized particles. Low-energy processes, including laboratory handling, cleaning, and industrial bagging activities, usually resulted in slight or moderate releases of relatively large agglomerates. The present analysis suggests that process-based release potential can be ranked, thus helping to prioritize release assessments, which is useful for tiered exposure assessment approaches and for guiding the implementation of workplace safety strategies. The contextual information provided in the literature was often insufficient to directly link release to exposure. The studies that did allow an analysis suggested that significant worker exposure might mainly occur when engineering safeguards and personal protection strategies were not carried out as recommended.

Airborne engineered nanomaterials in the workplace—a review of release and worker exposure during nanomaterial production and handling processes

International Nuclear Information System (INIS)

Ding, Yaobo; Kuhlbusch, Thomas A.J.; Van Tongeren, Martie; Jiménez, Araceli Sánchez; Tuinman, Ilse; Chen, Rui; Alvarez, Iñigo Larraza; Mikolajczyk, Urszula; Nickel, Carmen; Meyer, Jessica; Kaminski, Heinz; Wohlleben, Wendel; Stahlmecke, Burkhard; Clavaguera, Simon

2017-01-01

Highlights: • Release characteristics can be grouped by the type of occupational activities. • Release levels may be linked to process energy. • A better data reporting practice will facilitate exposure assessment. • The results help prioritize industrial processes for human risk assessment. - Abstract: For exposure and risk assessment in occupational settings involving engineered nanomaterials (ENMs), it is important to understand the mechanisms of release and how they are influenced by the ENM, the matrix material, and process characteristics. This review summarizes studies providing ENM release information in occupational settings, during different industrial activities and using various nanomaterials. It also assesses the contextual information — such as the amounts of materials handled, protective measures, and measurement strategies — to understand which release scenarios can result in exposure. High-energy processes such as synthesis, spraying, and machining were associated with the release of large numbers of predominantly small-sized particles. Low-energy processes, including laboratory handling, cleaning, and industrial bagging activities, usually resulted in slight or moderate releases of relatively large agglomerates. The present analysis suggests that process-based release potential can be ranked, thus helping to prioritize release assessments, which is useful for tiered exposure assessment approaches and for guiding the implementation of workplace safety strategies. The contextual information provided in the literature was often insufficient to directly link release to exposure. The studies that did allow an analysis suggested that significant worker exposure might mainly occur when engineering safeguards and personal protection strategies were not carried out as recommended.

Nanosized sustained-release pyridostigmine bromide microcapsules: process optimization and evaluation of characteristics

Science.gov (United States)

Tan, Qunyou; Jiang, Rong; Xu, Meiling; Liu, Guodong; Li, Songlin; Zhang, Jingqing

2013-01-01

Background Pyridostigmine bromide (3-[[(dimethylamino)-carbonyl]oxy]-1-methylpyridinium bromide), a reversible inhibitor of cholinesterase, is given orally in tablet form, and a treatment schedule of multiple daily doses is recommended for adult patients. Nanotechnology was used in this study to develop an alternative sustained-release delivery system for pyridostigmine, a synthetic drug with high solubility and poor oral bioavailability, hence a Class III drug according to the Biopharmaceutics Classification System. Novel nanosized pyridostigmine-poly(lactic acid) microcapsules (PPNMCs) were expected to have a longer duration of action than free pyridostigmine and previously reported sustained-release formulations of pyridostigmine. Methods The PPNMCs were prepared using a double emulsion-solvent evaporation method to achieve sustained-release characteristics for pyridostigmine. The preparation process for the PPNMCs was optimized by single-factor experiments. The size distribution, zeta potential, and sustained-release behavior were evaluated in different types of release medium. Results The optimal volume ratio of inner phase to external phase, poly(lactic acid) concentration, polyvinyl alcohol concentration, and amount of pyridostigmine were 1:10, 6%, 3% and 40 mg, respectively. The negatively charged PPNMCs had an average particle size of 937.9 nm. Compared with free pyridostigmine, PPNMCs showed an initial burst release and a subsequent very slow release in vitro. The release profiles for the PPNMCs in four different types of dissolution medium were fitted to the Ritger-Peppas and Weibull models. The similarity between pairs of dissolution profiles for the PPNMCs in different types of medium was statistically significant, and the difference between the release curves for PPNMCs and free pyridostigmine was also statistically significant. Conclusion PPNMCs prepared by the optimized protocol described here were in the nanometer range and had good uniformity

SIMULATION OF VINPOCETINE RELEASE PROCESS FROM MICROCAPSULES WITH HYDROPHOBIC SHELL

Directory of Open Access Journals (Sweden)

Yu. A. Polkovnikova

2017-01-01

Full Text Available Nowadays microcapsules are widely spread in different industries. Microcapsules with vitamins, etheric and fatty oils are included into different cosmetics (creams, gels, serums. Microencapsulated probiotics are used in foods and fodder additives in veterinary. An important field of application of microencapsulation in pharmacy is the combination in the total dosage of drugs that are incompatible when mixed in free form.The aim of work is a comparative analysis of thermodynamic characteristics of vinpocetine release from the melt of beeswax and cacao butter 3:2 into water, solution of hydrochloric acid 0.01 M and ethanol.Materials and methods. For simulation of the process of vinpocetine release from the melt into different environments models component models of the studied systems were built and their atom charges were calculated by quantum-chemical method. Spatial models of the components were built in Hyper Chem 8.01. As an initial state for the thermodynamic characteristics of the calculation of vinpocetine release from the melt, a conformation of «melt-vinpocetine» system was used after thermodynamic equilibration by molecular dynamics simulation in Bioeurica program for 5 ns. For isolated systems a vibrational analysis was performed with the use of unrestricted Hartree-Fock method in STO-3G basis set in Orca 4.0 program.Results and discussion. Vinpocetine release from the melt of beeswax and cacao butter 3:2 into water with different pH values and to ethanol depends on its solubility in these environments, and also on solubility of the melt.Conclusion. The performed study of vinpocetine release from the melt of beeswax and cacao butter 3:2 by molecular dynamics simulation demonstrates the opportunity of vinpocetine release into water with pH=2 and into ethanol. The obtained results make it possible to assume a lower degree of vinpocetine release from the melt into ethanol compared with the solution of hydrochloric acid 0,01 M.

Process behavior and environmental assessment of 14C releases from an HTGR fuel reprocessing facility

International Nuclear Information System (INIS)

Snider, J.W.; Kaye, S.V.

1976-01-01

Large quantities of 14 CO 2 will be evolved when graphite fuel blocks are burned during reprocessing of spent fuel from HTGR reactors. The possible release of some or all of this 14 C to the environment is a matter of concern which is investigated in this paper. Various alternatives are considered in this study for decontaminating and releasing the process off-gas to the environment. Concomitant radiological analyses have been done for the waste process scenarios to supply the necessary feedbacks for process design

Validation and comparison of dispersion models of RTARC DSS

International Nuclear Information System (INIS)

Duran, J.; Pospisil, M.

2004-01-01

RTARC DSS (Real Time Accident Release Consequences - Decision Support System) is a computer code developed at the VUJE Trnava, Inc. (Stubna, M. et al, 1993). The code calculations include atmospheric transport and diffusion, dose assessment, evaluation and displaying of the affected zones, evaluation of the early health effects, concentration and dose rate time dependence in the selected sites etc. The simulation of the protective measures (sheltering, iodine administration) is involved. The aim of this paper is to present the process of validation of the RTARC dispersion models. RTARC includes models for calculations of release for very short (Method Monte Carlo - MEMOC), short (Gaussian Straight-Line Model) and long distances (Puff Trajectory Model - PTM). Validation of the code RTARC was performed using the results of comparisons and experiments summarized in the Table 1.: 1. Experiments and comparisons in the process of validation of the system RTARC - experiments or comparison - distance - model. Wind tunnel experiments (Universitaet der Bundeswehr, Muenchen) - Area of NPP - Method Monte Carlo. INEL (Idaho National Engineering Laboratory) - short/medium - Gaussian model and multi tracer atmospheric experiment - distances - PTM. Model Validation Kit - short distances - Gaussian model. STEP II.b 'Realistic Case Studies' - long distances - PTM. ENSEMBLE comparison - long distances - PTM (orig.)

Designing Process Improvement of Finished Good On Time Release and Performance Indicator Tool in Milk Industry Using Business Process Reengineering Method

Science.gov (United States)

Dachyar, M.; Christy, E.

2014-04-01

To maintain position as a major milk producer, the Indonesian milk industry should do some business development with the purpose of increasing customer service level. One strategy is to create on time release conditions for finished goods which will be distributed to customers and distributors. To achieve this condition, management information systems of finished goods on time release needs to be improved. The focus of this research is to conduct business process improvement using Business Process Reengineering (BPR). The deliverable key of this study is a comprehensive business strategy which is the solution of the root problems. To achieve the goal, evaluation, reengineering, and improvement of the ERP system are conducted. To visualize the predicted implementation, a simulation model is built by Oracle BPM. The output of this simulation showed that the proposed solution could effectively reduce the process lead time and increase the number of quality releases.

Validation of SPARC, a suppression pool aerosol capture model

International Nuclear Information System (INIS)

Owczarski, P.C.; Winegardner, W.K.

1985-09-01

A study of the potential for atmospheric release in hypothetical severe core melt accidents in BWRs with suppression pools was recently completed using a prototype of the SPARC code. The process of validating SPARC using an experimental data base is the concern of this paper

Using process elicitation and validation to understand and improve chemotherapy ordering and delivery.

Science.gov (United States)

Mertens, Wilson C; Christov, Stefan C; Avrunin, George S; Clarke, Lori A; Osterweil, Leon J; Cassells, Lucinda J; Marquard, Jenna L

2012-11-01

Chemotherapy ordering and administration, in which errors have potentially severe consequences, was quantitatively and qualitatively evaluated by employing process formalism (or formal process definition), a technique derived from software engineering, to elicit and rigorously describe the process, after which validation techniques were applied to confirm the accuracy of the described process. The chemotherapy ordering and administration process, including exceptional situations and individuals' recognition of and responses to those situations, was elicited through informal, unstructured interviews with members of an interdisciplinary team. The process description (or process definition), written in a notation developed for software quality assessment purposes, guided process validation (which consisted of direct observations and semistructured interviews to confirm the elicited details for the treatment plan portion of the process). The overall process definition yielded 467 steps; 207 steps (44%) were dedicated to handling 59 exceptional situations. Validation yielded 82 unique process events (35 new expected but not yet described steps, 16 new exceptional situations, and 31 new steps in response to exceptional situations). Process participants actively altered the process as ambiguities and conflicts were discovered by the elicitation and validation components of the study. Chemotherapy error rates declined significantly during and after the project, which was conducted from October 2007 through August 2008. Each elicitation method and the subsequent validation discussions contributed uniquely to understanding the chemotherapy treatment plan review process, supporting rapid adoption of changes, improved communication regarding the process, and ensuing error reduction.

On the improvement of IT process maturity: assessment, recommendation and validation

Directory of Open Access Journals (Sweden)

Dirgahayu Teduh

2018-01-01

Full Text Available The use of information technology (IT in enterprises must be governed and managed appropriately using IT processes. The notion of IT process maturity is useful to measure the actual performance and to define the desired performance of IT processes. Improvements are necessary when there are gaps between the actual and desired performance. Most literatures focus on IT process maturity assessment. They do not address how to improve IT process maturity. This paper proposes an approach to enterprise IT process maturity improvement for COBIT processes. The approach consists of three activities, i.e. IT process maturity assessment, recommendation, and validation. Assessment is to recognise the process’ control objectives maturity. From the assessment results, recommendation identifies control objectives that must be improved and then suggests improvement actions. The prescriptive nature of the control objectives facilitates in suggesting those actions. Recommendations for managements are defined by abstracting similar actions. Validation checks whether the recommendations match with the enterprise needs and capability. It includes a scale for validation, in which enterprise’s capability is categorized into (i not capable, (ii capable with great efforts, and (iii fully capable. The paper illustrates the approach with a case study.

A process improvement model for software verification and validation

Science.gov (United States)

Callahan, John; Sabolish, George

1994-01-01

We describe ongoing work at the NASA Independent Verification and Validation (IV&V) Facility to establish a process improvement model for software verification and validation (V&V) organizations. This model, similar to those used by some software development organizations, uses measurement-based techniques to identify problem areas and introduce incremental improvements. We seek to replicate this model for organizations involved in V&V on large-scale software development projects such as EOS and space station. At the IV&V Facility, a university research group and V&V contractors are working together to collect metrics across projects in order to determine the effectiveness of V&V and improve its application. Since V&V processes are intimately tied to development processes, this paper also examines the repercussions for development organizations in large-scale efforts.

Nifedipine-loaded polymeric nanocapsules: validation of a stability-indicating HPLC method to evaluate the drug entrapment efficiency and in vitro release profiles.

Science.gov (United States)

Granada, Andréa; Tagliari, Monika Piazzon; Soldi, Valdir; Silva, Marcos António Segatto; Zanetti-Ramos, Betina Ghiel; Fernandes, Daniel; Stulzer, Hellen Karine

2013-01-01

A simple stability-indicating analytical method was developed and validated to quantify nifedipine in polymeric nanocapsule suspensions; an in vitro drug release study was then carried out. The analysis was performed using an RP C18 column, UV-Vis detection at 262 nm, and methanol-water (70 + 30, v/v) mobile phase at a flow rate of 1.2 mL/min. The method was validated in terms of specificity, linearity and range, LOQ, accuracy, precision, and robustness. The results obtained were within the acceptable ranges. The nanocapsules, made of poly(epsilon-caprolactone), were prepared by the solvent displacement technique and showed high entrapment efficiency. The entrapment efficiency was 97.6 and 98.2% for the nifedipine-loaded polymeric nanocapsules prepared from polyvinyl alcohol (PVA) and Pluronic F68 (PF68), respectively. The particle size and zeta potential of nanocapsules were found to be influenced by the nature of the stabilizer used. The mean diameter and zeta potential for nanocapsules with PVA and PF68 were 290.9 and 179.9 nm, and -17.7 mV and -32.7 mV, respectively. The two formulations prepared showed a drug release of up to 70% over 4 days. This behavior indicates the viability of this drug delivery system for use as a controlled-release system.

Streamlining Compliance Validation Through Automation Processes

Science.gov (United States)

2014-03-01

INTENTIONALLY LEFT BLANK xv LIST OF ACRONYMS AND ABBREVIATIONS ACAS Assured Compliance Assessment Suite AMP Apache- MySQL -PHP ANSI American...enemy. Of course , a common standard for DoD security personnel to write and share compliance validation content would prevent duplicate work and aid in...process and consume much of the SCAP content available. Finally, it is free and easy to install as part of the Apache/ MySQL /PHP (AMP) [37

Insights into the swelling process and drug release mechanisms from cross-linked pectin/high amylose starch matrices

Directory of Open Access Journals (Sweden)

Fernanda M. Carbinatto

2014-02-01

Full Text Available Cross-linked pectin/high amylose mixtures were evaluated as a new excipient for matrix tablets formulations, since the mixing of polymers and cross-linking reaction represent rational tools to reach materials with modulated and specific properties that meet specific therapeutic needs. Objective: In this work the influence of polymer ratio and cross-linking process on the swelling and the mechanism driving the drug release from swellable matrix tablets prepared with this excipient was investigated. Methods: Cross-linked samples were characterized by their micromeritic properties (size and shape, density, angle of repose and flow rate and liquid uptake ability. Matrix tablets were evaluated according their physical properties and the drug release rates and mechanisms were also investigated. Results: Cross-linked samples demonstrated size homogeneity and irregular shape, with liquid uptake ability insensible to pH. Cross-linking process of samples allowed the control of drug release rates and the drug release mechanism was influenced by both polymer ratio and cross-linking process. The drug release of samples with minor proportion of pectin was driven by an anomalous transport and the increase of the pectin proportion contributed to the erosion of the matrix. Conclusion: The cross-linked mixtures of high amylose and pectin showed a suitable excipient for slowing the drug release rates.

A model system for targeted drug release triggered by biomolecular signals logically processed through enzyme logic networks.

Science.gov (United States)

Mailloux, Shay; Halámek, Jan; Katz, Evgeny

2014-03-07

A new Sense-and-Act system was realized by the integration of a biocomputing system, performing analytical processes, with a signal-responsive electrode. A drug-mimicking release process was triggered by biomolecular signals processed by different logic networks, including three concatenated AND logic gates or a 3-input OR logic gate. Biocatalytically produced NADH, controlled by various combinations of input signals, was used to activate the electrochemical system. A biocatalytic electrode associated with signal-processing "biocomputing" systems was electrically connected to another electrode coated with a polymer film, which was dissolved upon the formation of negative potential releasing entrapped drug-mimicking species, an enzyme-antibody conjugate, operating as a model for targeted immune-delivery and consequent "prodrug" activation. The system offers great versatility for future applications in controlled drug release and personalized medicine.

Validation of the production process of core-equipment HYNIC-Bombesin-Sn; Validacion del proceso de produccion del nucleo-equipo HYNIC-Bombesina-Sn

Energy Technology Data Exchange (ETDEWEB)

Rubio C, N I [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2008-07-01

The validation process is establishing documented evidence that provides a high degree of assurance that a specific process consistently will produce a product that will meet specifications and quality attributes preset and, therefore, ensures the efficiency and effectiveness of a product. The radiopharmaceutical {sup 99m}Tc-HYNlC-Bombesin is part of the gastrin-releasing peptide (GRP) analogues of bombesin that are radiolabelled with technetium 99 metastable for molecular images obtention. Is obtained from freeze-dry formulations kits (core- equipment)) and has reported a very high stability in human serum, specific binding to receptors and rapid internalization. Biodistribution data in mice showed rapid blood clearance with predominant renal excretion and specific binding to tissues with positive response to GRP receptors. According to biokinetics studies performed on patients with breast cancer, breast show a marked asymmetry with increased uptake in neoplastic breast in healthy women and the uptake of radiopharmaceuticals is symmetrical in both breasts. No reported adverse reactions. In this paper, the prospective validation core-equipment HYNlC-Bombesin-Sn, which was shown consistently that the product meets the specifications and quality, attributes to preset from the obtained from the diagnostic radiopharmaceutical third generation: {sup 99m}Tc-HYNlC-Bombesin. The process was successfully validated and thereby ensuring the efficiency and effectiveness of this agent as a preliminary diagnostic for approval to be marketed. (Author)

Model-based verification and validation of the SMAP uplink processes

Science.gov (United States)

Khan, M. O.; Dubos, G. F.; Tirona, J.; Standley, S.

Model-Based Systems Engineering (MBSE) is being used increasingly within the spacecraft design community because of its benefits when compared to document-based approaches. As the complexity of projects expands dramatically with continually increasing computational power and technology infusion, the time and effort needed for verification and validation (V& V) increases geometrically. Using simulation to perform design validation with system-level models earlier in the life cycle stands to bridge the gap between design of the system (based on system-level requirements) and verifying those requirements/validating the system as a whole. This case study stands as an example of how a project can validate a system-level design earlier in the project life cycle than traditional V& V processes by using simulation on a system model. Specifically, this paper describes how simulation was added to a system model of the Soil Moisture Active-Passive (SMAP) mission's uplink process. Also discussed are the advantages and disadvantages of the methods employed and the lessons learned; which are intended to benefit future model-based and simulation-based development efforts.

Analytical models approximating individual processes: a validation method.

Science.gov (United States)

Favier, C; Degallier, N; Menkès, C E

2010-12-01

Upscaling population models from fine to coarse resolutions, in space, time and/or level of description, allows the derivation of fast and tractable models based on a thorough knowledge of individual processes. The validity of such approximations is generally tested only on a limited range of parameter sets. A more general validation test, over a range of parameters, is proposed; this would estimate the error induced by the approximation, using the original model's stochastic variability as a reference. This method is illustrated by three examples taken from the field of epidemics transmitted by vectors that bite in a temporally cyclical pattern, that illustrate the use of the method: to estimate if an approximation over- or under-fits the original model; to invalidate an approximation; to rank possible approximations for their qualities. As a result, the application of the validation method to this field emphasizes the need to account for the vectors' biology in epidemic prediction models and to validate these against finer scale models. Copyright © 2010 Elsevier Inc. All rights reserved.

Capture of Tritium Released from Cladding in the Zirconium Recycle Process

Energy Technology Data Exchange (ETDEWEB)

Spencer, Barry B [ORNL; Bruffey, Stephanie H [ORNL; DelCul, Guillermo Daniel [ORNL; Walker, Trenton Baird [ORNL

2016-08-31

Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-based cladding and could be released from the cladding when the solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using nonradioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.

Capture of Tritium Released from Cladding in the Zirconium Recycle Process

Energy Technology Data Exchange (ETDEWEB)

Bruffey, Stephanie H [ORNL; Spencer, Barry B [ORNL; DelCul, Guillermo Daniel [ORNL

2016-08-31

This report is issued as the first revision to FCRD-MRWFD-2016-000297. Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-based cladding and could be released from the cladding when the solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using non-radioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.

Structure of a low-population intermediate state in the release of an enzyme product.

Science.gov (United States)

De Simone, Alfonso; Aprile, Francesco A; Dhulesia, Anne; Dobson, Christopher M; Vendruscolo, Michele

2015-01-09

Enzymes can increase the rate of biomolecular reactions by several orders of magnitude. Although the steps of substrate capture and product release are essential in the enzymatic process, complete atomic-level descriptions of these steps are difficult to obtain because of the transient nature of the intermediate conformations, which makes them largely inaccessible to standard structure determination methods. We describe here the determination of the structure of a low-population intermediate in the product release process by human lysozyme through a combination of NMR spectroscopy and molecular dynamics simulations. We validate this structure by rationally designing two mutations, the first engineered to destabilise the intermediate and the second to stabilise it, thus slowing down or speeding up, respectively, product release. These results illustrate how product release by an enzyme can be facilitated by the presence of a metastable intermediate with transient weak interactions between the enzyme and product.

Flash release an alternative for releasing complex MEMS devices

NARCIS (Netherlands)

Deladi, S.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

2004-01-01

A novel time-saving and cost-effective release technique has been developed and is described. The physical nature of the process is explained in combination with experimental observations. The results of the flash release process are compared with those of freeze-drying and supercritical CO2

Processing and validation of intermediate energy evaluated data files

International Nuclear Information System (INIS)

2000-01-01

Current accelerator-driven and other intermediate energy technologies require accurate nuclear data to model the performance of the target/blanket assembly, neutron production, activation, heating and damage. In a previous WPEC subgroup, SG13 on intermediate energy nuclear data, various aspects of intermediate energy data, such as nuclear data needs, experiments, model calculations and file formatting issues were investigated and categorized to come to a joint evaluation effort. The successor of SG13, SG14 on the processing and validation of intermediate energy evaluated data files, goes one step further. The nuclear data files that have been created with the aforementioned information need to be processed and validated in order to be applicable in realistic intermediate energy simulations. We emphasize that the work of SG14 excludes the 0-20 MeV data part of the neutron evaluations, which is supposed to be covered elsewhere. This final report contains the following sections: section 2: a survey of the data files above 20 MeV that have been considered for validation in SG14; section 3: a summary of the review of the 150 MeV intermediate energy data files for ENDF/B-VI and, more briefly, the other libraries; section 4: validation of the data library against an integral experiment with MCNPX; section 5: conclusions. (author)

Validation of measured friction by process tests

DEFF Research Database (Denmark)

Eriksen, Morten; Henningsen, Poul; Tan, Xincai

The objective of sub-task 3.3 is to evaluate under actual process conditions the friction formulations determined by simulative testing. As regards task 3.3 the following tests have been used according to the original project plan: 1. standard ring test and 2. double cup extrusion test. The task...... has, however, been extended to include a number of new developed process tests: 3. forward rod extrusion test, 4. special ring test at low normal pressure, 5. spike test (especially developed for warm and hot forging). Validation of the measured friction values in cold forming from sub-task 3.1 has...... been made with forward rod extrusion, and very good agreement was obtained between the measured friction values in simulative testing and process testing....

Process data validation according VDI 2048 in conventional and nuclear power plants

International Nuclear Information System (INIS)

Langenstein, M.; Laipple, B.; Schmid, F.

2004-01-01

Process data validation according VDI 2048 in conventional and nuclear power plants is required for acceptance testing, process and component monitoring, and status-oriented maintenance. Once a validation system like VALI III has been certified according to VDI 2048, power plant owners can use the data obtained for efficiency increase. Further, all control variables can be adjusted so as to ensure maximum plant efficiency. (orig.)

A novel co-processed directly compressible release-retarding polymer: In vitro, solid state and in vivo evaluation

Directory of Open Access Journals (Sweden)

Prashant Kumar Choudhari

2018-06-01

Full Text Available Directly compressible (DC co-processed excipient capable of providing nearly zero order release with improved functionality was developed without any chemical modification by employed various techniques such as physical mixing, high shear mixer granulation and spray drying. Co-processed excipient was developed by using release retarding polymer Eudragit RSPO, separately, in combination with different concentration of hydroxyl propyl methyl cellulose 100 cps (Methocel K100 LV, HPMC, ethyl cellulose (Ethocel N50, EC and hydroxyl propyl cellulose (Klucel EF, HPC. All co-processed excipients were evaluated for their flow properties in terms of angle of repose, bulk density, tapped density, compressibility index and Hausner's ratio. Out of eighteen combinations, the nine co-processed excipients exhibited promising flow properties were found suitable for direct compression and formulated as tablets. Metoprolol succinate, a BCS Class I drug, was selected as a model drug and the formulation was developed employing direct compression approach. The developed tablets were evaluated for physical parameters like uniformity of weight, thickness, hardness, friability and assay. In vitro dissolution study confirms that formulation prepared using co-processed excipient showed sustained drug release. The optimized tablet formulation was characterized by DSC, FTIR and PXRD which confirms the absence of any chemical change during co-processing. The optimized formulation was kept for stability study for six months as per ICH guidelines and found to be stable. In vivo pharmacokinetic study of optimized formulation in rats showed similar pharmacokinetic behaviour as was observed with the marketed brand. Study revealed that co-processed excipient has advantage over polymers with single property and can be utilised for sustained release formulation. Keywords: Co-processed excipient, Metoprolol succinate, Extended-release, Direct compression, Zero-order release

Hanford Environmental Restoration data validation process for chemical and radiochemical analyses

International Nuclear Information System (INIS)

Adams, M.R.; Bechtold, R.A.; Clark, D.E.; Angelos, K.M.; Winter, S.M.

1993-10-01

Detailed procedures for validation of chemical and radiochemical data are used to assure consistent application of validation principles and support a uniform database of quality environmental data. During application of these procedures, it was determined that laboratory data packages were frequently missing certain types of documentation causing subsequent delays in meeting critical milestones in the completion of validation activities. A quality improvement team was assembled to address the problems caused by missing documentation and streamline the entire process. The result was the development of a separate data package verification procedure and revisions to the data validation procedures. This has resulted in a system whereby deficient data packages are immediately identified and corrected prior to validation and revised validation procedures which more closely match the common analytical reporting practices of laboratory service vendors

Uranium geochemistry in estuarine sediments: Controls on removal and release processes

International Nuclear Information System (INIS)

Barnes, C.E.; Cochran, J.K.

1993-01-01

Porewater uranium profiles from Long Island Sound (LIS) and Amazon shelf sediments and LIS sediment incubation experiments indicate that both removal and release processes control U geochemistry in estuarine sediments. Release of U from sediments occurs in association with Fe reduction. A correlation between U and Fe (and Mn) observed in sediment incubation experiments suggests that there is release of U from Fe-Mn-oxides as they are reduced, consistent with data from the Amazon shelf. In both sediment porewater profiles (LIS and Amazon) and sediment incubation experiments (LIS), there is removal of U from porewater under conditions of sulfate reduction. Sediment incubation experiments indicate that the removal rate is first-order with respect to U concentration, and the rate constant is linearly correlated to sulfate reduction rates. The link between U removal and sulfate reduction (a measure of diagenetic microbial activity) is consistent with a microbial mediation of U reduction. The diffusion flux of U into LIS sediments is estimated from porewater profiles. The inclusion of this estuarine removal term in the oceanic U balance increases the importance of the sediment sink. 62 refs., 12 figs., 2 tabs

Development and validation of stability indicating method for the quantitative determination of venlafaxine hydrochloride in extended release formulation using high performance liquid chromatography

Directory of Open Access Journals (Sweden)

Jaspreet Kaur

2010-01-01

Full Text Available Objective : Venlafaxine,hydrochloride is a structurally novel phenethyl bicyclic antidepressant, and is usually categorized as a serotonin-norepinephrine reuptake inhibitor (SNRI but it has been referred to as a serotonin-norepinephrine-dopamine reuptake inhibitor. It inhibits the reuptake of dopamine. Venlafaxine HCL is widely prescribed in the form of sustained release formulations. In the current article we are reporting the development and validation of a fast and simple stability indicating, isocratic high performance liquid chromatographic (HPLC method for the determination of venlafaxine hydrochloride in sustained release formulations. Materials and Methods : The quantitative determination of venlafaxine hydrochloride was performed on a Kromasil C18 analytical column (250 x 4.6 mm i.d., 5 μm particle size with 0.01 M phosphate buffer (pH 4.5: methanol (40: 60 as a mobile phase, at a flow rate of 1.0 ml/min. For HPLC methods, UV detection was made at 225 nm. Results : During method validation, parameters such as precision, linearity, accuracy, stability, limit of quantification and detection and specificity were evaluated, which remained within acceptable limits. Conclusions : The method has been successfully applied for the quantification and dissolution profiling of Venlafaxine HCL in sustained release formulation. The method presents a simple and reliable solution for the routine quantitative analysis of Venlafaxine HCL.

Drug-releasing shape-memory polymers - the role of morphology, processing effects, and matrix degradation.

Science.gov (United States)

Wischke, Christian; Behl, Marc; Lendlein, Andreas

2013-09-01

Shape-memory polymers (SMPs) have gained interest for temporary drug-release systems that should be anchored in the body by self-sufficient active movements of the polymeric matrix. Based on the so far published scientific literature, this review highlights three aspects that require particular attention when combining SMPs with drug molecules: i) the defined polymer morphology as required for the shape-memory function, ii) the strong effects that processing conditions such as drug-loading methodologies can have on the drug-release pattern from SMPs, and iii) the independent control of drug release and degradation by their timely separation. The combination of SMPs with a drug-release functionality leads to multifunctional carriers that are an interesting technology for pharmaceutical sciences and can be further expanded by new materials such as thermoplastic SMPs or temperature-memory polymers. Experimental studies should include relevant molecules as (model) drugs and provide a thermomechanical characterization also in an aqueous environment, report on the potential effect of drug type and loading levels on the shape-memory functionality, and explore the potential correlation of polymer degradation and drug release.

Formulation and evaluation of sustained release matrix tablets of pioglitazone hydrochloride using processed Aloe vera mucilage as release modifier

Directory of Open Access Journals (Sweden)

Manoj Choudhary

2015-01-01

Full Text Available Background: Natural gums and mucilage which hydrates and swells on contact with aqueous media are used as additives in the formulation of hydrophilic drug delivery system. Aim: The purpose of this study was to develop a new monolithic matrix system for complete delivery of Pioglitazone hydrochloride (HCl, in a zero-order manner over an extended time period using processed Aloe vera gel mucilage (PAG as a release modifier. Materials and Methods: The matrices were prepared by dry blending of selected ratios of polymer and ingredients using direct compression technique. Physicochemical properties of dried powdered mucilage of A. vera were studied. Various formulations of pioglitazone HCl and A. vera mucilage were prepared using different drug: Polymer ratios viz., 1:1, 1:2, 1:3, 1:4, 1:5 for PAG by direct compression technique. Results: The formulated matrix tablets were found to have better uniformity of weight and drug content with low statistical deviation. The swelling behavior and in vitro release rate characteristics were also studied. Conclusion: The study proved that the dried A. vera mucilage can be used as a matrix forming material for controlled release of Pioglitazone HCl matrix tablets.

PEANO, a toolbox for real-time process signal validation and estimation

International Nuclear Information System (INIS)

Fantoni, Paolo F.; Figedy, Stefan; Racz, Attila

1998-02-01

PEANO (Process Evaluation and Analysis by Neural Operators), a toolbox for real time process signal validation and condition monitoring has been developed. This system analyses the signals, which are e.g. the readings of process monitoring sensors, computes their expected values and alerts if real values are deviated from the expected ones more than limits allow. The reliability level of the current analysis is also produced. The system is based on neuro-fuzzy techniques. Artificial Neural Networks and Fuzzy Logic models can be combined to exploit learning and generalisation capability of the first technique with the approximate reasoning embedded in the second approach. Real-time process signal validation is an application field where the use of this technique can improve the diagnosis of faulty sensors and the identification of outliers in a robust and reliable way. This study implements a fuzzy and possibilistic clustering algorithm to classify the operating region where the validation process has to be performed. The possibilistic approach (rather than probabilistic) allows a ''don't know'' classification that results in a fast detection of unforeseen plant conditions or outliers. Specialised Artificial Neural Networks are used for the validation process, one for each fuzzy cluster in which the operating map has been divided. There are two main advantages in using this technique: the accuracy and generalisation capability is increased compared to the case of a single network working in the entire operating region, and the ability to identify abnormal conditions, where the system is not capable to operate with a satisfactory accuracy, is improved. This model has been tested in a simulated environment on a French PWR, to monitor safety-related reactor variables over the entire power-flow operating map. (author)

PEANO, a toolbox for real-time process signal validation and estimation

Energy Technology Data Exchange (ETDEWEB)

Fantoni, Paolo F.; Figedy, Stefan; Racz, Attila

1998-02-01

PEANO (Process Evaluation and Analysis by Neural Operators), a toolbox for real time process signal validation and condition monitoring has been developed. This system analyses the signals, which are e.g. the readings of process monitoring sensors, computes their expected values and alerts if real values are deviated from the expected ones more than limits allow. The reliability level of the current analysis is also produced. The system is based on neuro-fuzzy techniques. Artificial Neural Networks and Fuzzy Logic models can be combined to exploit learning and generalisation capability of the first technique with the approximate reasoning embedded in the second approach. Real-time process signal validation is an application field where the use of this technique can improve the diagnosis of faulty sensors and the identification of outliers in a robust and reliable way. This study implements a fuzzy and possibilistic clustering algorithm to classify the operating region where the validation process has to be performed. The possibilistic approach (rather than probabilistic) allows a ''don't know'' classification that results in a fast detection of unforeseen plant conditions or outliers. Specialised Artificial Neural Networks are used for the validation process, one for each fuzzy cluster in which the operating map has been divided. There are two main advantages in using this technique: the accuracy and generalisation capability is increased compared to the case of a single network working in the entire operating region, and the ability to identify abnormal conditions, where the system is not capable to operate with a satisfactory accuracy, is improved. This model has been tested in a simulated environment on a French PWR, to monitor safety-related reactor variables over the entire power-flow operating map. (author)

Effects of process variables on micromeritic properties and drug release of non-degradable microparticles

Directory of Open Access Journals (Sweden)

Mitra Jelvehgari

2011-06-01

Full Text Available Introduction: The purpose of this investigation was to evaluate microencapsulated controlled release preparation of theophylline using Eudragit RS 100 as the retardant material with high entrapment efficiency. Methods: Microspheres were prepared by the emulsion-solvent evaporation method. A mixed solvent system consisting of methanol and acetone and light liquid paraffin as oily phase were chosen. Sucrose stearate was used as the surfactant to stabilize the emulsification process. The prepared microspheres were characterized by drug loading, Fourier-transform infrared spectroscopy (FTIR, differential scanning colorimetry (DSC and scanning electron microscopy (SEM. The in vitro release studies were performed at pH 1.2 and 7.4 aqueous medium. Results: Increasing the concentration of emulsifier, sucrose fatty acid ester F-70, decreased the particle size which contributed to increased drug release rate. The drug loading microparticle Eudragit RS100 (1:6 showed 60-75% of entrapment and mean particle size 205.93-352.76 µm. The results showed that, an increase in the ratio of polymer: drug (F5, 6: 1 resulted in a reduction in the release rate of the drug which may be attributed to the hydrophobic nature of the polymer. Conclusion: The release of theophylline is influenced by the drug to polymer ratio and particle size. Drug release is controlled by diffusion and the best-fit release kinetic is Higuchi model.

Effects of process variables on micromeritic properties and drug release of non-degradable microparticles.

Science.gov (United States)

Jelvehgari, Mitra; Barar, Jaleh; Nokhodchi, Ali; Shadrou, Sanam; Valizadeh, Hadi

2011-01-01

The purpose of this investigation was to evaluate microencapsulated controlled release preparation of theophylline using Eudragit RS 100 as the retardant material with high entrapment efficiency. Microspheres were prepared by the emulsion-solvent evaporation method. A mixed solvent system consisting of methanol and acetone and light liquid paraffin as oily phase were chosen. Sucrose stearate was used as the surfactant to stabilize the emulsification process. The prepared microspheres were characterized by drug loading, Fourier-transform infrared spectroscopy (FTIR), differential scanning colorimetry (DSC) and scanning electron microscopy (SEM). The in vitro release studies were performed at pH 1.2 and 7.4 aqueous medium. Increasing the concentration of emulsifier, sucrose fatty acid ester F-70, decreased the particle size which contributed to increased drug release rate. The drug loading microparticle Eudragit RS100(1:6) showed 60-75% of entrapment and mean particle size 205.93-352.76 μm.The results showed that, an increase in the ratio of polymer: drug (F5, 6: 1) resulted in a reduction in the release rate of the drug which may be attributed to the hydrophobic nature of the polymer. The release of theophylline is influenced by the drug to polymer ratio and particle size. Drug release is controlled by diffusion and the best-fit release kinetic is Higuchi model.

Understanding aroma release from model cheeses by a statistical multiblock approach on oral processing.

Directory of Open Access Journals (Sweden)

Gilles Feron

Full Text Available For human beings, the mouth is the first organ to perceive food and the different signalling events associated to food breakdown. These events are very complex and as such, their description necessitates combining different data sets. This study proposed an integrated approach to understand the relative contribution of main food oral processing events involved in aroma release during cheese consumption. In vivo aroma release was monitored on forty eight subjects who were asked to eat four different model cheeses varying in fat content and firmness and flavoured with ethyl propanoate and nonan-2-one. A multiblock partial least square regression was performed to explain aroma release from the different physiological data sets (masticatory behaviour, bolus rheology, saliva composition and flux, mouth coating and bolus moistening. This statistical approach was relevant to point out that aroma release was mostly explained by masticatory behaviour whatever the cheese and the aroma, with a specific influence of mean amplitude on aroma release after swallowing. Aroma release from the firmer cheeses was explained mainly by bolus rheology. The persistence of hydrophobic compounds in the breath was mainly explained by bolus spreadability, in close relation with bolus moistening. Resting saliva poorly contributed to the analysis whereas the composition of stimulated saliva was negatively correlated with aroma release and mostly for soft cheeses, when significant.

Validation of designing tools as part of nuclear pump development process

International Nuclear Information System (INIS)

Klemm, T.; Sehr, F.; Spenner, P.; Fritz, J.

2010-01-01

Nuclear pumps are characterized by high safety standards, operational reliability as well as long life cycles. For the design process it is of common use to have a down scaled model pump to qualify operating data and simulate exceptional operating conditions. In case of modifications of the pump design compared to existing reactor coolant pumps a model pump is required to develop methods and tools to design the full scale pump. In the presented case it has a geometry scale of 1:2 regarding the full scale pump size. The experimental data of the model pump is basis for validation of methods and tools which are applied in the designing process of the full scale pump. In this paper the selection of qualified tools and the validation process is demonstrated exemplarily on a cooling circuit. The aim is to predict the resulting flow rate. Tools are chosen for different components depending on the benefit to effort ratio. For elementary flow phenomena such as fluid flow in straight pipes or gaps analytic or empirical laws can be used. For more complex flow situations numerical methods are utilized. Main focus is set on the validation process of the applied numerical flow simulation. In this case not only integral data should be compared, it is also necessary to validate local flow structure of numerical flow simulation to avoid systematic errors in CFD Model generation. Due to complex design internal flow measurements are not possible. On that reason simple comparisons of similar flow test cases are used. Results of this study show, that the flow simulation data closely match measured integral pump and test case data. With this validation it is now possible to qualify CFD simulations as a design tool for the full scale pump in similar cooling circuit. (authors)

A Supervised Learning Process to Validate Online Disease Reports for Use in Predictive Models.

Science.gov (United States)

Patching, Helena M M; Hudson, Laurence M; Cooke, Warrick; Garcia, Andres J; Hay, Simon I; Roberts, Mark; Moyes, Catherine L

2015-12-01

Pathogen distribution models that predict spatial variation in disease occurrence require data from a large number of geographic locations to generate disease risk maps. Traditionally, this process has used data from public health reporting systems; however, using online reports of new infections could speed up the process dramatically. Data from both public health systems and online sources must be validated before they can be used, but no mechanisms exist to validate data from online media reports. We have developed a supervised learning process to validate geolocated disease outbreak data in a timely manner. The process uses three input features, the data source and two metrics derived from the location of each disease occurrence. The location of disease occurrence provides information on the probability of disease occurrence at that location based on environmental and socioeconomic factors and the distance within or outside the current known disease extent. The process also uses validation scores, generated by disease experts who review a subset of the data, to build a training data set. The aim of the supervised learning process is to generate validation scores that can be used as weights going into the pathogen distribution model. After analyzing the three input features and testing the performance of alternative processes, we selected a cascade of ensembles comprising logistic regressors. Parameter values for the training data subset size, number of predictors, and number of layers in the cascade were tested before the process was deployed. The final configuration was tested using data for two contrasting diseases (dengue and cholera), and 66%-79% of data points were assigned a validation score. The remaining data points are scored by the experts, and the results inform the training data set for the next set of predictors, as well as going to the pathogen distribution model. The new supervised learning process has been implemented within our live site and is

Sterilization of health care products - Ethylene oxide - Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices

International Nuclear Information System (INIS)

2007-01-01

This part of ISO 11135 describes requirements that, if met, will provide an ethylene oxide sterilization process intended to sterilize medical devices, which has appropriate microbicidal activity. Furthermore, compliance with the requirements ensures that this activity is both reliable and reproducible so that it can be predicted, with reasonable confidence, that there is a low level of probability of there being a viable microorganism present on product after sterilization. Specification of this probability is a matter for regulatory authorities and may vary from country to country. The paper provides information on scope, normative references, terms and definitions, quality management systems, sterilizing agent characterization, process and equipment characterization, product definition, process definition, validation, routine monitoring and control, product release from sterilization and maintaining process effectiveness followed by Annex A (Determination of lethal rate of the sterilization process - Biological indicator/bioburden approach), Annex B (Conservative determination of lethal rate of the sterilization process - Overkill approach, annex C (General guidance) and a bibliography.

Neural processes mediating the preparation and release of focal motor output are suppressed or absent during imagined movement

Science.gov (United States)

Eagles, Jeremy S.; Carlsen, Anthony N.

2016-01-01

Movements that are executed or imagined activate a similar subset of cortical regions, but the extent to which this activity represents functionally equivalent neural processes is unclear. During preparation for an executed movement, presentation of a startling acoustic stimulus (SAS) evokes a premature release of the planned movement with the spatial and temporal features of the tasks essentially intact. If imagined movement incorporates the same preparatory processes as executed movement, then a SAS should release the planned movement during preparation. This hypothesis was tested using an instructed-delay cueing paradigm during which subjects were required to rapidly release a handheld weight while maintaining the posture of the arm or to perform first-person imagery of the same task while holding the weight. In a subset of trials, a SAS was presented at 1500, 500, or 200 ms prior to the release cue. Task-appropriate preparation during executed and imagined movements was confirmed by electroencephalographic recording of a contingent negative variation waveform. During preparation for executed movement, a SAS often resulted in premature release of the weight with the probability of release progressively increasing from 24 % at −1500 ms to 80 % at −200 ms. In contrast, the SAS rarely (movement. However, the SAS frequently evoked the planned postural response (suppression of bicep brachii muscle activity) irrespective of the task or timing of stimulation (even during periods of postural hold without preparation). These findings provide evidence that neural processes mediating the preparation and release of the focal motor task (release of the weight) are markedly attenuated or absent during imagined movement and that postural and focal components of the task are prepared independently. PMID:25744055

Using 'big data' to validate claims made in the pharmaceutical approval process.

Science.gov (United States)

Wasser, Thomas; Haynes, Kevin; Barron, John; Cziraky, Mark

2015-01-01

Big Data in the healthcare setting refers to the storage, assimilation, and analysis of large quantities of information regarding patient care. These data can be collected and stored in a wide variety of ways including electronic medical records collected at the patient bedside, or through medical records that are coded and passed to insurance companies for reimbursement. When these data are processed it is possible to validate claims as a part of the regulatory review process regarding the anticipated performance of medications and devices. In order to analyze properly claims by manufacturers and others, there is a need to express claims in terms that are testable in a timeframe that is useful and meaningful to formulary committees. Claims for the comparative benefits and costs, including budget impact, of products and devices need to be expressed in measurable terms, ideally in the context of submission or validation protocols. Claims should be either consistent with accessible Big Data or able to support observational studies where Big Data identifies target populations. Protocols should identify, in disaggregated terms, key variables that would lead to direct or proxy validation. Once these variables are identified, Big Data can be used to query massive quantities of data in the validation process. Research can be passive or active in nature. Passive, where the data are collected retrospectively; active where the researcher is prospectively looking for indicators of co-morbid conditions, side-effects or adverse events, testing these indicators to determine if claims are within desired ranges set forth by the manufacturer. Additionally, Big Data can be used to assess the effectiveness of therapy through health insurance records. This, for example, could indicate that disease or co-morbid conditions cease to be treated. Understanding the basic strengths and weaknesses of Big Data in the claim validation process provides a glimpse of the value that this research

Evaluation of microplastic release caused by textile washing processes of synthetic fabrics.

Science.gov (United States)

De Falco, Francesca; Gullo, Maria Pia; Gentile, Gennaro; Di Pace, Emilia; Cocca, Mariacristina; Gelabert, Laura; Brouta-Agnésa, Marolda; Rovira, Angels; Escudero, Rosa; Villalba, Raquel; Mossotti, Raffaella; Montarsolo, Alessio; Gavignano, Sara; Tonin, Claudio; Avella, Maurizio

2018-05-01

A new and more alarming source of marine contamination has been recently identified in micro and nanosized plastic fragments. Microplastics are difficult to see with the naked eye and to biodegrade in marine environment, representing a problem since they can be ingested by plankton or other marine organisms, potentially entering the food web. An important source of microplastics appears to be through sewage contaminated by synthetic fibres from washing clothes. Since this phenomenon still lacks of a comprehensive analysis, the objective of this contribution was to investigate the role of washing processes of synthetic textiles on microplastic release. In particular, an analytical protocol was set up, based on the filtration of the washing water of synthetic fabrics and on the analysis of the filters by scanning electron microscopy. The quantification of the microfibre shedding from three different synthetic fabric types, woven polyester, knitted polyester, and woven polypropylene, during washing trials simulating domestic conditions, was achieved and statistically analysed. The highest release of microplastics was recorded for the wash of woven polyester and this phenomenon was correlated to the fabric characteristics. Moreover, the extent of microfibre release from woven polyester fabrics due to different detergents, washing parameters and industrial washes was evaluated. The number of microfibres released from a typical 5 kg wash load of polyester fabrics was estimated to be over 6,000,000 depending on the type of detergent used. The usage of a softener during washes reduces the number of microfibres released of more than 35%. The amount and size of the released microfibres confirm that they could not be totally retained by wastewater treatments plants, and potentially affect the aquatic environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reactive chemicals and process hazards

International Nuclear Information System (INIS)

Surianarayanan, M.

2016-01-01

Exothermic chemical reactions are often accompanied by significant heat release, and therefore, need a thorough investigation before they are taken to a plant scale. Sudden thermal energy releases from exothermic decompositions and runaway reactions have contributed to serious fire and explosions in several chemical process plants. Similarly, thermal runaway had also occurred in storage and transportation of reactive chemicals. The secondary events of thermal runaway reactions can be rupture of process vessel, toxic spills and release of explosive vapor clouds or combination of these also. The explosion hazards are governed by the system thermodynamics and kinetics of the thermal process. Theoretical prediction of limiting temperature is difficult due to process complexities. Further, the kinetic data obtained through classical techniques, at conditions far away from runaway situation, is often not valid for assessing the runaway behavior of exothermic processes. The main focus of this lecture is to discuss the causes and several contributing factors for thermal runaway and instability and present analyses of the methodologies of the new instrumental techniques for assessing the thermal hazards of reactive chemicals during processing, storage and transportation. (author)

Analysis of hazardous substances released during CFRP laser processing

Science.gov (United States)

Hustedt, Michael; Walter, Juergen; Bluemel, Sven; Jaeschke, Peter; Kaierle, Stefan

2017-02-01

Due to their outstanding mechanical properties, in particular their high specific strength parallel to the carbon fibers, carbon fiber reinforced plastics (CFRP) have a high potential regarding resource-efficient lightweight construction. Consequently, these composite materials are increasingly finding application in important industrial branches such as aircraft, automotive and wind energy industry. However, the processing of these materials is highly demanding. On the one hand, mechanical processing methods such as milling or drilling are sometimes rather slow, and they are connected with notable tool wear. On the other hand, thermal processing methods are critical as the two components matrix and reinforcement have widely differing thermophysical properties, possibly leading to damages of the composite structure in terms of pores or delamination. An emerging innovative method for processing of CFRP materials is the laser technology. As principally thermal method, laser processing is connected with the release of potentially hazardous, gaseous and particulate substances. Detailed knowledge of these process emissions is the basis to ensure the protection of man and the environment, according to the existing legal regulations. This knowledge will help to realize adequate protective measures and thus strengthen the development of CFRP laser processing. In this work, selected measurement methods and results of the analysis of the exhaust air and the air at the workplace during different laser processes with CFRP materials are presented. The investigations have been performed in the course of different cooperative projects, funded by the German Federal Ministry of Education and Research (BMBF) in the course of the funding initiative "Photonic Processes and Tools for Resource-Efficient Lightweight Structures".

EQUATIONS FOR GAS RELEASING PROCESS FROM PRESSURIZED VESSELS IN ODH EVALUATION

International Nuclear Information System (INIS)

JIA, L.X.; WANG, L.

2001-01-01

IN THE EVALUATION OF ODH, THE CALCULATION OF THE SPILL RATE FROM THE PRESSURIZED VESSEL IS THE CENTRAL TASK. THE ACCURACY OF THE ENGINEERING ESTIMATION BECOMES ONE OF THE SAFETY DESIGN ISSUES. THIS PAPER SUMMARIZES THE EQUATIONS FOR THE OXYGEN CONCENTRATION CALCULATION IN DIFFERENT CASES, AND DISCUSSES THE EQUATIONS FOR THE GAS RELEASE PROCESS CALCULATION BOTH FOR THE HIGH-PRESSURE GAS TANK AND THE LOW-TEMPERATURE LIQUID CONTAINER

Effect of firing conditions & release height on terminal performance of submunitions and conditions for optimum height of release

Directory of Open Access Journals (Sweden)

L.K. Gite

2017-06-01

Full Text Available Submunitions should exhibit optimum terminal performance at target end when released from certain pre-determined height. Selection of an optimum height of release of the submunitions depends on the terminal parameters like forward throw, remaining velocity, impact angle and flight time. In this paper, the effects of initial firing conditions and height of release on terminal performance of submunitions discussed in detail. For different height of release, the relation between range and forward throw is also established & validated for a number of firing altitude and rocket configurations.

Spent Nuclear Fuel (SNF) Project Design Verification and Validation Process

International Nuclear Information System (INIS)

OLGUIN, L.J.

2000-01-01

This document provides a description of design verification and validation activities implemented by the Spent Nuclear Fuel (SNF) Project. During the execution of early design verification, a management assessment (Bergman, 1999) and external assessments on configuration management (Augustenburg, 1999) and testing (Loscoe, 2000) were conducted and identified potential uncertainties in the verification process. This led the SNF Chief Engineer to implement corrective actions to improve process and design products. This included Design Verification Reports (DVRs) for each subproject, validation assessments for testing, and verification of the safety function of systems and components identified in the Safety Equipment List to ensure that the design outputs were compliant with the SNF Technical Requirements. Although some activities are still in progress, the results of the DVR and associated validation assessments indicate that Project requirements for design verification are being effectively implemented. These results have been documented in subproject-specific technical documents (Table 2). Identified punch-list items are being dispositioned by the Project. As these remaining items are closed, the technical reports (Table 2) will be revised and reissued to document the results of this work

Development and preliminary validation of flux map processing code MAPLE

International Nuclear Information System (INIS)

Li Wenhuai; Zhang Xiangju; Dang Zhen; Chen Ming'an; Lu Haoliang; Li Jinggang; Wu Yuanbao

2013-01-01

The self-reliant flux map processing code MAPLE was developed by China General Nuclear Power Corporation (CGN). Weight coefficient method (WCM), polynomial expand method (PEM) and thin plane spline (TPS) method were applied to fit the deviation between measured and predicted detector signal results for two-dimensional radial plane, to interpolate or extrapolate the non-instrumented location deviation. Comparison of results in the test cases shows that the TPS method can better capture the information of curved fitting lines than the other methods. The measured flux map data of the Lingao Nuclear Power Plant were processed using MAPLE as validation test cases, combined with SMART code. Validation results show that the calculation results of MAPLE are reasonable and satisfied. (authors)

Dose estimation models for environmental tritium released from fusion facilities

International Nuclear Information System (INIS)

Murata, Mikio

1993-01-01

Various mathematical models are being developed to predict the behavior of HT released to the natural environment and their consequent impact. This report outlines models and the major findings of HT field release studies in France and Canada. The models are constructed to incorporate the key processes thought to be responsible for the formation of atmospheric HTO from a release of HT. It has been established from the experiments that HT oxidized in surface soil is incorporated almost entirely into soil water as HTO. This tritium may be reemitted to the atmosphere in the form of HTO through exchange of soil and atmospheric moisture as well as through the bulk water mass flux from the soil the atmosphere due to evaporation and transpiration. The direct conversion of HT to HTO in air and direct uptake of HT by vegetation are expected to be negligible for the time and space scales of interest in considering short duration releases. HTO emitted to the atmosphere is can further exchange with soil and vegetation water. Validation of these models against experimental data is conducted to demonstrate their credibility. It may be concluded that further laboratory and field works are needed in order to develop a sufficiently good understanding of the dependence of the key processes on environmental factors (including diurnal cycling and seasonality) to allow the rates of the processes to be predicted from a knowledge of environmental conditions. (author)

Thermal effects from the release of selenium from a coal combustion during high-temperature processing: a review.

Science.gov (United States)

Hu, Jianjun; Sun, Qiang; He, Huan

2018-04-11

The release of selenium (Se) during coal combustion can have serious impacts on the ecological environment and human health. Therefore, it is very important to study the factors that concern the release of Se from coal combustion. In this paper, the characteristics of the release of Se from coal combustion, pyrolysis, and gasification of different coal species under different conditions are studied. The results show that the amount of released Se increases at higher combustion temperatures. There are obvious increases in the amount of released Se especially in the temperature range of 300 to 800 °C. In addition, more Se is released from the coal gasification than coal combustion process, but more Se is released from coal combustion than pyrolysis. The type of coal, rate of heating, type of mineral ions, and combustion atmosphere have different effects on the released percentage of Se. Therefore, having a good understanding of the factors that surround the release of Se during coal combustion, and then establishing the combustion conditions can reduce the impacts of this toxic element to humans and the environment.

Dynamic modeling and experimental validation for direct contact membrane distillation (DCMD) process

KAUST Repository

Eleiwi, Fadi

2016-02-01

This work proposes a mathematical dynamic model for the direct contact membrane distillation (DCMD) process. The model is based on a 2D Advection–Diffusion Equation (ADE), which describes the heat and mass transfer mechanisms that take place inside the DCMD module. The model studies the behavior of the process in the time varying and the steady state phases, contributing to understanding the process performance, especially when it is driven by intermittent energy supply, such as the solar energy. The model is experimentally validated in the steady state phase, where the permeate flux is measured for different feed inlet temperatures and the maximum absolute error recorded is 2.78 °C. Moreover, experimental validation includes the time variation phase, where the feed inlet temperature ranges from 30 °C to 75 °C with 0.1 °C increment every 2min. The validation marks relative error to be less than 5%, which leads to a strong correlation between the model predictions and the experiments.

Dynamic modeling and experimental validation for direct contact membrane distillation (DCMD) process

KAUST Repository

Eleiwi, Fadi; Ghaffour, NorEddine; Alsaadi, Ahmad Salem; Francis, Lijo; Laleg-Kirati, Taous-Meriem

2016-01-01

This work proposes a mathematical dynamic model for the direct contact membrane distillation (DCMD) process. The model is based on a 2D Advection–Diffusion Equation (ADE), which describes the heat and mass transfer mechanisms that take place inside the DCMD module. The model studies the behavior of the process in the time varying and the steady state phases, contributing to understanding the process performance, especially when it is driven by intermittent energy supply, such as the solar energy. The model is experimentally validated in the steady state phase, where the permeate flux is measured for different feed inlet temperatures and the maximum absolute error recorded is 2.78 °C. Moreover, experimental validation includes the time variation phase, where the feed inlet temperature ranges from 30 °C to 75 °C with 0.1 °C increment every 2min. The validation marks relative error to be less than 5%, which leads to a strong correlation between the model predictions and the experiments.

Adequate Measuring Technology and System of Fission Gas release Behavior from Voloxidation Process

International Nuclear Information System (INIS)

Park, Geun Il; Park, J. J.; Jung, I. H.; Shin, J. M.; Yang, M. S.; Song, K. C.

2006-09-01

Based on the published literature and an understanding of available hot cell technologies, more accurate measuring methods for each volatile fission product released from voloxidation process were reviewed and selected. The conceptual design of an apparatus for measuring volatile and/or semi-volatile fission products released from spent fuel was prepared. It was identified that on-line measurement techniques can be applied for gamma-emitting fission products, and off-line measurement such as chemical/or neutron activation analysis can applied for analyzing beta-emitting fission gases. Collection methods using appropriate material or solutions were selected to measure the release fraction of beta-emitting gaseous fission products at IMEF M6 hot cell. Especially, the on-line gamma-ray counting system for monitoring of 85Kr and the off-line measuring system of 14C was established. On-line measuring system for obtaining removal ratios of the semi-volatile fission products, mainly gamma-emitting fission products such as Cs, Ru etc., was also developed at IMEF M6 hot cell which was based on by measuring fuel inventory before and after the voloxidation test through gamma measuring technique. The development of this measurement system may enable basic information to be obtained to support design of the off-gas treatment system for the voloxidation process at INL, USA

Recommendations for elaboration, transcultural adaptation and validation process of tests in Speech, Hearing and Language Pathology.

Science.gov (United States)

Pernambuco, Leandro; Espelt, Albert; Magalhães, Hipólito Virgílio; Lima, Kenio Costa de

2017-06-08

to present a guide with recommendations for translation, adaptation, elaboration and process of validation of tests in Speech and Language Pathology. the recommendations were based on international guidelines with a focus on the elaboration, translation, cross-cultural adaptation and validation process of tests. the recommendations were grouped into two Charts, one of them with procedures for translation and transcultural adaptation and the other for obtaining evidence of validity, reliability and measures of accuracy of the tests. a guide with norms for the organization and systematization of the process of elaboration, translation, cross-cultural adaptation and validation process of tests in Speech and Language Pathology was created.

Validation and computing and performance studies for the ATLAS simulation

CERN Document Server

Marshall, Z; The ATLAS collaboration

2009-01-01

We present the validation of the ATLAS simulation software pro ject. Software development is controlled by nightly builds and several levels of automatic tests to ensure stability. Computing validation, including CPU time, memory, and disk space required per event, is benchmarked for all software releases. Several different physics processes and event types are checked to thoroughly test all aspects of the detector simulation. The robustness of the simulation software is demonstrated by the production of 500 million events on the World-wide LHC Computing Grid in the last year.

Validation of Structures in the Protein Data Bank.

Science.gov (United States)

Gore, Swanand; Sanz García, Eduardo; Hendrickx, Pieter M S; Gutmanas, Aleksandras; Westbrook, John D; Yang, Huanwang; Feng, Zukang; Baskaran, Kumaran; Berrisford, John M; Hudson, Brian P; Ikegawa, Yasuyo; Kobayashi, Naohiro; Lawson, Catherine L; Mading, Steve; Mak, Lora; Mukhopadhyay, Abhik; Oldfield, Thomas J; Patwardhan, Ardan; Peisach, Ezra; Sahni, Gaurav; Sekharan, Monica R; Sen, Sanchayita; Shao, Chenghua; Smart, Oliver S; Ulrich, Eldon L; Yamashita, Reiko; Quesada, Martha; Young, Jasmine Y; Nakamura, Haruki; Markley, John L; Berman, Helen M; Burley, Stephen K; Velankar, Sameer; Kleywegt, Gerard J

2017-12-05

The Worldwide PDB recently launched a deposition, biocuration, and validation tool: OneDep. At various stages of OneDep data processing, validation reports for three-dimensional structures of biological macromolecules are produced. These reports are based on recommendations of expert task forces representing crystallography, nuclear magnetic resonance, and cryoelectron microscopy communities. The reports provide useful metrics with which depositors can evaluate the quality of the experimental data, the structural model, and the fit between them. The validation module is also available as a stand-alone web server and as a programmatically accessible web service. A growing number of journals require the official wwPDB validation reports (produced at biocuration) to accompany manuscripts describing macromolecular structures. Upon public release of the structure, the validation report becomes part of the public PDB archive. Geometric quality scores for proteins in the PDB archive have improved over the past decade. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Quantitative Analysis of Kr-85 Fission Gas Release from Dry Process for the Treatment of Spent PWR Fuel

International Nuclear Information System (INIS)

Park, Geun Il; Cho, Kwang Hun; Lee, Dou Youn; Lee, Jung Won; Park, Jang Jin; Song, Kee Chan

2007-01-01

As spent UO 2 fuel oxidizes to U 3 O 8 by air oxidation, a corresponding volume expansion separate grains, releasing the grain-boundary inventory of fission gases. Fission products in spent UO 2 fuel can be distributed in three major regions : the inventory in fuel-sheath gap, the inventory on grain boundaries and the inventory in UO 2 matrix. Release characteristic of fission gases depends on its distribution amount in three regions as well as spent fuel burn-up. Oxidation experiments of spent fuel at 500 .deg. C gives the information of fission gases inventory in spent fuel, and further annealing experiments at higher temperature produces matrix inventory of fission gases on segregated grain. In previous study, fractional release characteristics of Kr- 85 during OREOX (Oxidation and REduction of Oxide fuel) treatment as principal key process for recycling spent PWR fuel via DUPIC cycle have already evaluated as a function of fuel burn-up with 27.3, 35 and 65 MWd/tU. In this paper, new release experiment results of Kr-85 using spent fuel with burn- up of 58 GWd/tU are included to evaluate the fission gas release behavior. As a point of summary in fission gases release behavior, the quantitative analysis of Kr- 85 release characteristics from various spent fuels with different burn-up during voloxidation and OREOX process were reviewed

Dynamics of nanomaterials released from polymer composites in the pelletizing process

International Nuclear Information System (INIS)

Kato, Nobuyuki; Yoneda, Minoru; Matsui, Yasuto

2017-01-01

Measures against exposure to carbon nanotubes (CNT) are necessary, especially in workplaces that handle nanomaterials, because adverse health effects are a concern. This study focuses on the dynamics of CNT released from CNT/polymer composites during the pelletizing process at a pilot factory. It is difficult to identify CNT and the base resin. By characterizing the possibility of separating CNT from the composite with a kinetic weighting coefficient, estimation can be carried out using a Computational Fluid Dynamics (CFD) simulation. The mass concentration of black carbon and the particle number concentration by diameter were measured using two different measurement apparatuses. The simulation results were then compared to the measured data. The model was verified by the correlation between the simulation and measured results. The model provided a strong correlation, indicating that the dynamics of CNT and the base resin released from the polymer composite can be simulated. It is expected that the model using the CFD simulation can be applied to the occupational health field. (paper)

Process-generated nanoparticles from ceramic tile sintering: Emissions, exposure and environmental release.

Science.gov (United States)

Fonseca, A S; Maragkidou, A; Viana, M; Querol, X; Hämeri, K; de Francisco, I; Estepa, C; Borrell, C; Lennikov, V; de la Fuente, G F

2016-09-15

The ceramic industry is an industrial sector in need of significant process changes, which may benefit from innovative technologies such as laser sintering of ceramic tiles. Such innovations result in a considerable research gap within exposure assessment studies for process-generated ultrafine and nanoparticles. This study addresses this issue aiming to characterise particle formation, release mechanisms and their impact on personal exposure during a tile sintering activity in an industrial-scale pilot plant, as a follow-up of a previous study in a laboratory-scale plant. In addition, possible particle transformations in the exhaust system, the potential for particle release to the outdoor environment, and the effectiveness of the filtration system were also assessed. For this purpose, a tiered measurement strategy was conducted. The main findings evidence that nanoparticle emission patterns were strongly linked to temperature and tile chemical composition, and mainly independent of the laser treatment. Also, new particle formation (from gaseous precursors) events were detected, with nanoparticles efficiency of the filtration system was successfully tested and evidenced a >87% efficiency in particle number concentrations removal. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Determination of the radionuclide release factor for an evaporator process using nondestructive assay

International Nuclear Information System (INIS)

Johnson, R.E.

1998-01-01

The 242-A Evaporator is the primary waste evaporator for the Hanford Site radioactive liquid waste stored in underground double-shell tanks. Low pressure evaporation is used to remove water from the waste, thus reducing the amount of tank space required for storage. The process produces a concentrated slurry, a process condensate, and an offgas. The offgas exhausts through two stages of high-efficiency particulate air (HEPA) filters before being discharged to the atmosphere 40 CFR 61 Subpart H requires assessment of the unfiltered exhaust to determine if continuous compliant sampling is required. Because potential (unfiltered) emissions are not measured, methods have been developed to estimate these emissions. One of the methods accepted by the Environmental Protection Agency is the measurement of the accumulation of radionuclides on the HEPA filters. Nondestructive assay (NDA) was selected for determining the accumulation on the HEPA filters. NDA was performed on the HEPA filters before and after a campaign in 1997. NDA results indicate that 2.1 E+4 becquerels of cesium-137 were accumulated on the primary HEPA 1700 filter during the campaign. The feed material processed in the campaign contained a total of 1.4 E+l6 Bq of cesium-137. The release factor for the evaporator process is 1.5 E-12. Based on this release factor, continuous compliant sampling is not required

Mechanistic modelling of drug release from polymer-coated and swelling and dissolving polymer matrix systems.

Science.gov (United States)

Kaunisto, Erik; Marucci, Mariagrazia; Borgquist, Per; Axelsson, Anders

2011-10-10

The time required for the design of a new delivery device can be sensibly reduced if the release mechanism is understood and an appropriate mathematical model is used to characterize the system. Once all the model parameters are obtained, in silico experiments can be performed, to provide estimates of the release from devices with different geometries and compositions. In this review coated and matrix systems are considered. For coated formulations, models describing the diffusional drug release, the osmotic pumping drug release, and the lag phase of pellets undergoing cracking in the coating due to the build-up of a hydrostatic pressure are reviewed. For matrix systems, models describing pure polymer dissolution, diffusion in the polymer and drug release from swelling and eroding polymer matrix formulations are reviewed. Importantly, the experiments used to characterize the processes occurring during the release and to validate the models are presented and discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Validation Process for LEWICE by Use of a Navier-Stokes Solver

Science.gov (United States)

Wright, William B.; Porter, Christopher E.

2017-01-01

A research project is underway at NASA Glenn to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. This report will present results from the latest LEWICE release, version 3.5. This program differs from previous releases in its ability to model mixed phase and ice crystal conditions such as those encountered inside an engine. It also has expanded capability to use structured grids and a new capability to use results from unstructured grid flow solvers. A quantitative comparison of the results against a database of ice shapes that have been generated in the NASA Glenn Icing Research Tunnel (IRT) has also been performed. This paper will extend the comparison of ice shapes between LEWICE 3.5 and experimental data from a previous paper. Comparisons of lift and drag are made between experimentally collected data from experimentally obtained ice shapes and simulated (CFD) data on simulated (LEWICE) ice shapes. Comparisons are also made between experimentally collected and simulated performance data on select experimental ice shapes to ensure the CFD solver, FUN3D, is valid within the flight regime. The results show that the predicted results are within the accuracy limits of the experimental data for the majority of cases.

Development and Validation of a Dissolution Test Method for ...

African Journals Online (AJOL)

Purpose: To develop and validate a dissolution test method for dissolution release of artemether and lumefantrine from tablets. Methods: A single dissolution method for evaluating the in vitro release of artemether and lumefantrine from tablets was developed and validated. The method comprised of a dissolution medium of ...

Kinetics of corrosion products release from nickel-base alloys corroding in primary water conditions. A new modeling of release

International Nuclear Information System (INIS)

Carrette, F.; Guinard, L.; Pieraggi, B.

2002-01-01

The radioactivity in the primary circuit arises mainly from the activation of corrosion products in the core of pressurised water reactors; corrosion products dissolve from the oxide scales developed on steam generator tubes of alloy 690. The controlling and modelling of this process require a detailed knowledge of the microstructure and chemical composition of oxide scales as well as the kinetics of their corrosion and dissolution. Alloy 690 was studied as tubes and sheets, with three various surface states (as-received, cold-worked, electropolished). Corrosion tests were performed at 325 C and 155 bar in primary water conditions (B/Li - 1000/2 ppm, [H 2 ] 30 cm 3 .kg -1 TPN, [O 2 ] < 5 ppb); test durations ranged between 24 and 2160 hours. Corrosion tests in the TITANE loop provided mainly corrosion and oxidation kinetics, and tests in the BOREAL loop yielded release kinetics. This study revealed asymptotic type kinetics. Characterisation of the oxide scales grown in representative conditions of the primary circuit was performed by several techniques (SEM, TEM, SIMS, XPS, GIXRD). These analyses revealed the essential role of the fine grained cold-worked scale present on as-received and cold-worked materials. This scale controls the corrosion and release phenomena. The kinetic study and the characterisation of the oxide scales contributed to the modelling of the corrosion/release process. A growth/dissolution model was proposed for corrosion product scales grown in non-saturated dynamic fluid. This model provided the temporal evolution of oxide scales and release kinetics for different species (Fe, Ni, Cr). The model was validated for several surface states and several alloys. (authors)

QA/QC Reflected in ISO 11137; The Role of Dosimetry in the Validation Process

International Nuclear Information System (INIS)

Kovacs, A.

2007-01-01

Standardized dosimetry (ISO/ASTM standards) - as a tool of QC - has got key role for the validation of the sterilization and ford irradiation processes, as well as to control the radiation processing of polymer products. In radiation processing, validation and process control (e.g. sterilization, food irradiation) depend on the measurement of absorbed dose. These measurements shall be performed using a dosimetric system or systems having a known level of accuracy and precision (European standard EN552:1994). In presented lecture different aspects of the operational qualification during the radiation processing of polymer products are described

Sustained-release microsphere formulation containing an agrochemical by polyurethane polymerization during an agitation granulation process.

Science.gov (United States)

Terada, Takatoshi; Tagami, Manabu; Ohtsubo, Toshiro; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

2016-07-25

In this report, a new solventless microencapsulation method by synthesizing polyurethane (PU) from polyol and isocyanate during an agglomeration process in a high-speed mixing apparatus was developed. Clothianidin (CTD), which is a neonicotinoid insecticide and highly effective against a wide variety of insect pests, was used as the model compound. The microencapsulated samples covered with PU (CTD microspheres) had a median diameter of <75μm and sustained-release properties. The CTD microspheres were analyzed by synchrotron X-ray computed tomography measurements. Multiple cores of CTD and other solid excipient were dispersed in PU. Although voids appeared in the CTD microspheres after CTD release, the spherical shape of the microspheres remained stable and no change in its framework was observed. The experimental release data were highly consistent with the Baker-Lonsdale model derived from drug release of spherical monolithic dispersions and consistent with the computed tomography measurements. Copyright © 2016 Elsevier B.V. All rights reserved.

Modulation of drug release kinetics of shellac-based matrix tablets by in-situ polymerization through annealing process.

Science.gov (United States)

Limmatvapirat, Sontaya; Limmatvapirat, Chutima; Puttipipatkhachorn, Satit; Nunthanid, Jurairat; Luangtana-anan, Manee; Sriamornsak, Pornsak

2008-08-01

A new oral-controlled release matrix tablet based on shellac polymer was designed and developed, using metronidazole (MZ) as a model drug. The shellac-based matrix tablets were prepared by wet granulation using different amounts of shellac and lactose. The effect of annealing temperature and pH of medium on drug release from matrix tablets was investigated. The increased amount of shellac and increased annealing temperature significantly affected the physical properties (i.e., tablet hardness and tablet disintegration) and MZ release from the matrix tablets. The in-situ polymerization played a major role on the changes in shellac properties during annealing process. Though the shellac did not dissolve in acid medium, the MZ release in 0.1N HCl was faster than in pH 7.3 buffer, resulting from a higher solubility of MZ in acid medium. The modulation of MZ release kinetics from shellac-based matrix tablets could be accomplished by varying the amount of shellac or annealing temperature. The release kinetics was shifted from relaxation-controlled release to diffusion-controlled release when the amount of shellac or the annealing temperature was increased.

SmartWeld/SmartProcess - intelligent model based system for the design and validation of welding processes

Energy Technology Data Exchange (ETDEWEB)

Mitchner, J.

1996-04-01

Diagrams are presented on an intelligent model based system for the design and validation of welding processes. Key capabilities identified include `right the first time` manufacturing, continuous improvement, and on-line quality assurance.

Fast Running Urban Dispersion Model for Radiological Dispersal Device (RDD) Releases: Model Description and Validation

Energy Technology Data Exchange (ETDEWEB)

Gowardhan, Akshay [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Neuscamman, Stephanie [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Donetti, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Walker, Hoyt [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Belles, Rich [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Eme, Bill [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Homann, Steven [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Simpson, Matthew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC); Nasstrom, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Atmospheric Release Advisory Center (NARAC)

2017-05-24

Aeolus is an efficient three-dimensional computational fluid dynamics code based on finite volume method developed for predicting transport and dispersion of contaminants in a complex urban area. It solves the time dependent incompressible Navier-Stokes equation on a regular Cartesian staggered grid using a fractional step method. It also solves a scalar transport equation for temperature and using the Boussinesq approximation. The model also includes a Lagrangian dispersion model for predicting the transport and dispersion of atmospheric contaminants. The model can be run in an efficient Reynolds Average Navier-Stokes (RANS) mode with a run time of several minutes, or a more detailed Large Eddy Simulation (LES) mode with run time of hours for a typical simulation. This report describes the model components, including details on the physics models used in the code, as well as several model validation efforts. Aeolus wind and dispersion predictions are compared to field data from the Joint Urban Field Trials 2003 conducted in Oklahoma City (Allwine et al 2004) including both continuous and instantaneous releases. Newly implemented Aeolus capabilities include a decay chain model and an explosive Radiological Dispersal Device (RDD) source term; these capabilities are described. Aeolus predictions using the buoyant explosive RDD source are validated against two experimental data sets: the Green Field explosive cloud rise experiments conducted in Israel (Sharon et al 2012) and the Full-Scale RDD Field Trials conducted in Canada (Green et al 2016).

SMAP RADAR Calibration and Validation

Science.gov (United States)

West, R. D.; Jaruwatanadilok, S.; Chaubel, M. J.; Spencer, M.; Chan, S. F.; Chen, C. W.; Fore, A.

2015-12-01

The Soil Moisture Active Passive (SMAP) mission launched on Jan 31, 2015. The mission employs L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Immediately following launch, there was a three month instrument checkout period, followed by six months of level 1 (L1) calibration and validation. In this presentation, we will discuss the calibration and validation activities and results for the L1 radar data. Early SMAP radar data were used to check commanded timing parameters, and to work out issues in the low- and high-resolution radar processors. From April 3-13 the radar collected receive only mode data to conduct a survey of RFI sources. Analysis of the RFI environment led to a preferred operating frequency. The RFI survey data were also used to validate noise subtraction and scaling operations in the radar processors. Normal radar operations resumed on April 13. All radar data were examined closely for image quality and calibration issues which led to improvements in the radar data products for the beta release at the end of July. Radar data were used to determine and correct for small biases in the reported spacecraft attitude. Geo-location was validated against coastline positions and the known positions of corner reflectors. Residual errors at the time of the beta release are about 350 m. Intra-swath biases in the high-resolution backscatter images are reduced to less than 0.3 dB for all polarizations. Radiometric cross-calibration with Aquarius was performed using areas of the Amazon rain forest. Cross-calibration was also examined using ocean data from the low-resolution processor and comparing with the Aquarius wind model function. Using all a-priori calibration constants provided good results with co-polarized measurements matching to better than 1 dB, and cross-polarized measurements matching to about 1 dB in the beta release. During the

Validation of the process control system of an automated large scale manufacturing plant.

Science.gov (United States)

Neuhaus, H; Kremers, H; Karrer, T; Traut, R H

1998-02-01

The validation procedure for the process control system of a plant for the large scale production of human albumin from plasma fractions is described. A validation master plan is developed, defining the system and elements to be validated, the interfaces with other systems with the validation limits, a general validation concept and supporting documentation. Based on this master plan, the validation protocols are developed. For the validation, the system is subdivided into a field level, which is the equipment part, and an automation level. The automation level is further subdivided into sections according to the different software modules. Based on a risk categorization of the modules, the qualification activities are defined. The test scripts for the different qualification levels (installation, operational and performance qualification) are developed according to a previously performed risk analysis.

Technical Report Series on Global Modeling and Data Assimilation. Volume 42; Soil Moisture Active Passive (SMAP) Project Calibration and Validation for the L4_C Beta-Release Data Product

Science.gov (United States)

Koster, Randal D. (Editor); Kimball, John S.; Jones, Lucas A.; Glassy, Joseph; Stavros, E. Natasha; Madani, Nima (Editor); Reichle, Rolf H.; Jackson, Thomas; Colliander, Andreas

2015-01-01

During the post-launch Cal/Val Phase of SMAP there are two objectives for each science product team: 1) calibrate, verify, and improve the performance of the science algorithms, and 2) validate accuracies of the science data products as specified in the L1 science requirements according to the Cal/Val timeline. This report provides analysis and assessment of the SMAP Level 4 Carbon (L4_C) product specifically for the beta release. The beta-release version of the SMAP L4_C algorithms utilizes a terrestrial carbon flux model informed by SMAP soil moisture inputs along with optical remote sensing (e.g. MODIS) vegetation indices and other ancillary biophysical data to estimate global daily NEE and component carbon fluxes, particularly vegetation gross primary production (GPP) and ecosystem respiration (Reco). Other L4_C product elements include surface (<10 cm depth) soil organic carbon (SOC) stocks and associated environmental constraints to these processes, including soil moisture and landscape FT controls on GPP and Reco (Kimball et al. 2012). The L4_C product encapsulates SMAP carbon cycle science objectives by: 1) providing a direct link between terrestrial carbon fluxes and underlying freeze/thaw and soil moisture constraints to these processes, 2) documenting primary connections between terrestrial water, energy and carbon cycles, and 3) improving understanding of terrestrial carbon sink activity in northern ecosystems.

Development of a mechanistic model for release of radionuclides from spent fuel in brines: Salt Repository Project

International Nuclear Information System (INIS)

Reimus, P.W.; Windisch, C.F.

1988-03-01

At present there are no comprehensive mechanistic models describing the release of radionuclides from spent fuel in brine environments. This report provides a comprehensive review of the various factors that can affect radionuclide release from spent fuel, suggests a modeling approach, and discusses proposed experiments for obtaining a better mechanistic understanding of the radionuclide release processes. Factors affecting radionuclide release include the amount, location, and disposition of radionuclides in the fuel and environmental factors such as redox potential, pH, the presence of complexing anions, temperature, and radiolysis. It is concluded that a model describing the release of radionuclides from spent fuel should contain separate terms for release from the gap, grain boundaries, and grains of the fuel. Possible functional forms for these terms are discussed in the report. Experiments for assessing their validity and obtaining key model parameters are proposed. 71 refs., 4 figs., 6 tabs

Use of fuzzy logic in signal processing and validation

International Nuclear Information System (INIS)

Heger, A.S.; Alang-Rashid, N.K.; Holbert, K.E.

1993-01-01

The advent of fuzzy logic technology has afforded another opportunity to reexamine the signal processing and validation process (SPV). The features offered by fuzzy logic can lend themselves to a more reliable and perhaps fault-tolerant approach to SPV. This is particularly attractive to complex system operations, where optimal control for safe operation depends on reliable input data. The reason for the use of fuzzy logic as the tool for SPV is its ability to transform information from the linguistic domain to a mathematical domain for processing and then transformation of its result back into the linguistic domain for presentation. To ensure the safe and optimal operation of a nuclear plant, for example, reliable and valid data must be available to the human and computer operators. Based on these input data, the operators determine the current state of the power plant and project corrective actions for future states. This determination is based on available data and the conceptual and mathematical models for the plant. A fault-tolerant SPV based on fuzzy logic can help the operators meet the objective of effective, efficient, and safe operation of the nuclear power plant. The ultimate product of this project will be a code that will assist plant operators in making informed decisions under uncertain conditions when conflicting signals may be present

The development and validation of a new collision processor for MONK

International Nuclear Information System (INIS)

Connolly, Simon; Grimstone, Malcolm

2003-01-01

This paper summarises the progress with a major development project for the MONK Monte Carlo criticality code, namely the development of a new collision processing modelling package and nuclear data library. The development has now reached the final validation stage and further results will become available over the coming months in the period leading up the release of MONK9. (J.P.N.)

Validation process of simulation model

International Nuclear Information System (INIS)

San Isidro, M. J.

1998-01-01

It is presented a methodology on empirical validation about any detailed simulation model. This king of validation it is always related with an experimental case. The empirical validation has a residual sense, because the conclusions are based on comparisons between simulated outputs and experimental measurements. This methodology will guide us to detect the fails of the simulation model. Furthermore, it can be used a guide in the design of posterior experiments. Three steps can be well differentiated: Sensitivity analysis. It can be made with a DSA, differential sensitivity analysis, and with a MCSA, Monte-Carlo sensitivity analysis. Looking the optimal domains of the input parameters. It has been developed a procedure based on the Monte-Carlo methods and Cluster techniques, to find the optimal domains of these parameters. Residual analysis. This analysis has been made on the time domain and on the frequency domain, it has been used the correlation analysis and spectral analysis. As application of this methodology, it is presented the validation carried out on a thermal simulation model on buildings, Esp., studying the behavior of building components on a Test Cell of LECE of CIEMAT. (Author) 17 refs

Requirements for the workflow-based support of release management processes in the automotive sector

NARCIS (Netherlands)

Bestfleisch, U.; Herbst, J.; Reichert, M.U.; Abdelmalek, B.

One of the challenges the automotive industry currently has to master is the complexity of the electrical/elctronic system of a car. One key factor for reaching short product development cycles and high quality in this area are well-defined, properly executed test and release processes. In this

Additive advantage in characteristics of MIMCAPs on flexible silicon (100) fabric with release-first process

KAUST Repository

Ghoneim, Mohamed T.; Rojas, Jhonathan Prieto; Hussain, Aftab M.; Hussain, Muhammad Mustafa

2013-01-01

We report the inherent increase in capacitance per unit planar area of state-of-the art high-κ integrated metal/insulator/metal capacitors (MIMCAPs) fabricated on flexible silicon fabric with release-first process. We methodically study and show

Analysis of accidental UF6 releases

International Nuclear Information System (INIS)

Fan Yumao; Tan Rui; Gao Qifa

2012-01-01

As interim substance in the nuclear fuel enrichment process, Uranium Hexafluoride (UF 6 ) is widely applied in nuclear processing, enrichment and fuel fabrication plants. Because of its vivid chemical characteristics and special radiological hazard and chemical toxicity, great attention must be paid to accident of UF 6 leakage. The chemical reactions involved in UF 6 release processes were introduced, therewith potential release styles, pathways and characteristics of diffusion were analyzed. The results indicated that the accidental release process of UF 6 is not a simple passive diffusion. So, specific atmospheric diffusion model related to UF 6 releases need be used in order to analyze and evaluate accurately the accidental consequences. (authors)

Quality Control Assays for Clinical-Grade Human Mesenchymal Stromal Cells: Validation Strategy.

Science.gov (United States)

Radrizzani, Marina; Soncin, Sabrina; Bolis, Sara; Lo Cicero, Viviana; Andriolo, Gabriella; Turchetto, Lucia

2016-01-01

The present chapter focuses on the validation of the following analytical methods for the control of mesenchymal stromal cells (MSC) for cell therapy clinical trials: Microbiological control for cellular product Endotoxin assay Mycoplasma assay Cell count and viability Immunophenotype Clonogenic potential (CFU-F assay) In our lab, these methods are in use for product release, process control or control of the biological starting materials. They are described in detail in the accompanying Chapter 19.For each method, validation goals and strategy are presented, and a detailed experimental scheme is proposed.

A Mathematical Model for Scheduling a Batch Processing Machine with Multiple Incompatible Job Families, Non-identical Job dimensions, Non-identical Job sizes, Non-agreeable release times and due dates

International Nuclear Information System (INIS)

Ramasubramaniam, M; Mathirajan, M

2013-01-01

The paper addresses the problem scheduling a batch processing machine with multiple incompatible job families, non-identical job dimensions, non-identical job sizes and non-agreeable release dates to minimize makespan. The research problem is solved by proposing a mixed integer programming model that appropriately takes into account the parameters considered in the problem. The proposed is validated using a numerical example. The experiment conducted show that the model can pose significant difficulties in solving the large scale instances. The paper concludes by giving the scope for future work and some alternative approaches one can use for solving these class of problems.

IV&V Project Assessment Process Validation

Science.gov (United States)

Driskell, Stephen

2012-01-01

The Space Launch System (SLS) will launch NASA's Multi-Purpose Crew Vehicle (MPCV). This launch vehicle will provide American launch capability for human exploration and travelling beyond Earth orbit. SLS is designed to be flexible for crew or cargo missions. The first test flight is scheduled for December 2017. The SLS SRR/SDR provided insight into the project development life cycle. NASA IV&V ran the standard Risk Based Assessment and Portfolio Based Risk Assessment to identify analysis tasking for the SLS program. This presentation examines the SLS System Requirements Review/System Definition Review (SRR/SDR), IV&V findings for IV&V process validation correlation to/from the selected IV&V tasking and capabilities. It also provides a reusable IEEE 1012 scorecard for programmatic completeness across the software development life cycle.

Analysis of Wigner energy release process in graphite stack of shut-down uranium-graphite reactor

OpenAIRE

Bespala, E. V.; Pavliuk, A. O.; Kotlyarevskiy, S. G.

2015-01-01

Data, which finding during thermal differential analysis of sampled irradiated graphite are presented. Results of computational modeling of Winger energy release process from irradiated graphite staking are demonstrated. It's shown, that spontaneous combustion of graphite possible only in adiabatic case.

Natural and industrial analogues for release of CO2 from storagereservoirs: Identification of features, events, and processes and lessonslearned

Energy Technology Data Exchange (ETDEWEB)

Lewicki, Jennifer L.; Birkholzer, Jens; Tsang, Chin-Fu

2006-03-03

The injection and storage of anthropogenic CO{sub 2} in deep geologic formations is a potentially feasible strategy to reduce CO{sub 2} emissions and atmospheric concentrations. While the purpose of geologic carbon storage is to trap CO{sub 2} underground, CO{sub 2} could migrate away from the storage site into the shallow subsurface and atmosphere if permeable pathways such as well bores or faults are present. Large-magnitude releases of CO{sub 2} have occurred naturally from geologic reservoirs in numerous volcanic, geothermal, and sedimentary basin settings. Carbon dioxide and natural gas have also been released from geologic CO{sub 2} reservoirs and natural gas storage facilities, respectively, due to influences such as well defects and injection/withdrawal processes. These systems serve as natural and industrial analogues for the potential release of CO{sub 2} from geologic storage reservoirs and provide important information about the key features, events, and processes (FEPs) that are associated with releases, as well as the health, safety, and environmental consequences of releases and mitigation efforts that can be applied. We describe a range of natural releases of CO{sub 2} and industrial releases of CO{sub 2} and natural gas in the context of these characteristics. Based on this analysis, several key conclusions can be drawn, and lessons can be learned for geologic carbon storage. First, CO{sub 2} can both accumulate beneath, and be released from, primary and secondary reservoirs with capping units located at a wide range of depths. Both primary and secondary reservoir entrapments for CO{sub 2} should therefore be well characterized at storage sites. Second, many natural releases of CO{sub 2} have been correlated with a specific event that triggered the release, such as magmatic fluid intrusion or seismic activity. The potential for processes that could cause geomechanical damage to sealing cap rocks and trigger the release of CO{sub 2} from a storage

The role of surface charge in the desolvation process of gelatin: implications in nanoparticle synthesis and modulation of drug release

Directory of Open Access Journals (Sweden)

Ahsan SM

2017-01-01

Full Text Available Saad M Ahsan, Chintalagiri Mohan Rao Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, Telangana, India Abstract: The process of moving hydrophobic amino acids into the core of a protein by desolvation is important in protein folding. However, a rapid and forced desolvation can lead to precipitation of proteins. Desolvation of proteins under controlled conditions generates nanoparticles – homogeneous aggregates with a narrow size distribution. The protein nanoparticles, under physiological conditions, undergo surface erosion due to the action of proteases, releasing the entrapped drug/gene. The packing density of protein nanoparticles significantly influences the release kinetics. We have investigated the desolvation process of gelatin, exploring the role of pH and desolvating agent in nanoparticle synthesis. Our results show that the desolvation process, initiated by the addition of acetone, follows distinct pathways for gelatin incubated at different pH values and results in the generation of nanoparticles with varying matrix densities. The nanoparticles synthesized with varying matrix densities show variations in drug loading and protease-dependent extra- and intracellular drug release. These results will be useful in fine-tuning the synthesis of nanoparticles with desirable drug release profiles. Keywords: protein desolvation, nanoparticle assembly, gelatin nanoparticle synthesis, protease susceptibility, intracellular drug release

Identification and validation of multiple cell surface markers of clinical-grade adipose-derived mesenchymal stromal cells as novel release criteria for good manufacturing practice-compliant production.

Science.gov (United States)

Camilleri, Emily T; Gustafson, Michael P; Dudakovic, Amel; Riester, Scott M; Garces, Catalina Galeano; Paradise, Christopher R; Takai, Hideki; Karperien, Marcel; Cool, Simon; Sampen, Hee-Jeong Im; Larson, A Noelle; Qu, Wenchun; Smith, Jay; Dietz, Allan B; van Wijnen, Andre J

2016-08-11

Clinical translation of mesenchymal stromal cells (MSCs) necessitates basic characterization of the cell product since variability in biological source and processing of MSCs may impact therapeutic outcomes. Although expression of classical cell surface markers (e.g., CD90, CD73, CD105, and CD44) is used to define MSCs, identification of functionally relevant cell surface markers would provide more robust release criteria and options for quality control. In addition, cell surface expression may distinguish between MSCs from different sources, including bone marrow-derived MSCs and clinical-grade adipose-derived MSCs (AMSCs) grown in human platelet lysate (hPL). In this work we utilized quantitative PCR, flow cytometry, and RNA-sequencing to characterize AMSCs grown in hPL and validated non-classical markers in 15 clinical-grade donors. We characterized the surface marker transcriptome of AMSCs, validated the expression of classical markers, and identified nine non-classical markers (i.e., CD36, CD163, CD271, CD200, CD273, CD274, CD146, CD248, and CD140B) that may potentially discriminate AMSCs from other cell types. More importantly, these markers exhibit variability in cell surface expression among different cell isolates from a diverse cohort of donors, including freshly prepared, previously frozen, or proliferative state AMSCs and may be informative when manufacturing cells. Our study establishes that clinical-grade AMSCs expanded in hPL represent a homogeneous cell culture population according to classical markers,. Additionally, we validated new biomarkers for further AMSC characterization that may provide novel information guiding the development of new release criteria. Use of Autologous Bone Marrow Aspirate Concentrate in Painful Knee Osteoarthritis (BMAC): Clinicaltrials.gov NCT01931007 . Registered August 26, 2013. MSC for Occlusive Disease of the Kidney: Clinicaltrials.gov NCT01840540 . Registered April 23, 2013. Mesenchymal Stem Cell Therapy in Multiple

Investigating the feasibility of temperature-controlled accelerated drug release testing for an intravaginal ring.

Science.gov (United States)

Externbrink, Anna; Clark, Meredith R; Friend, David R; Klein, Sandra

2013-11-01

The objective of the present study was to investigate if temperature can be utilized to accelerate drug release from Nuvaring®, a reservoir type intravaginal ring based on polyethylene vinyl acetate copolymer that releases a constant dose of contraceptive steroids over a duration of 3 weeks. The reciprocating holder apparatus (USP 7) was utilized to determine real-time and accelerated etonogestrel release from ring segments. It was demonstrated that drug release increased with increasing temperature which can be attributed to enhanced drug diffusion. An Arrhenius relationship of the zero-order release constants was established, indicating that temperature is a valid parameter to accelerate drug release from this dosage form and that the release mechanism is maintained under these accelerated test conditions. Accelerated release tests are particularly useful for routine quality control to assist during batch release of extended release formulations that typically release the active over several weeks, months or even years, since they can increase the product shelf life. The accelerated method should therefore be able to discriminate between formulations with different release characteristics that can result from normal manufacturing variance. In the case of Nuvaring®, it is well known that the process parameters during the extrusion process strongly influence the polymeric structure. These changes in the polymeric structure can affect the permeability which, in turn, is reflected in the release properties. Results from this study indicate that changes in the polymeric structure can lead to a different temperature dependence of the release rate, and as a consequence, the accelerated method can become less sensitive to detect changes in the release properties. When the accelerated method is utilized during batch release, it is therefore important to take this possible restriction into account and to evaluate the accelerated method with samples from non

Validation of the vault computer model 'VERMIN' for post-closure behaviour of repositories in geological formations

International Nuclear Information System (INIS)

Laurens, J.-M.

1987-10-01

A validation methodology is proposed and applied to the computer model VERMIN, which is used to simulate radionuclide release from repositories for solid radioactive wastes. The processes included in the validation exercise are leaching from the waste matrix, diffusive transport and advective transport combined with sorption. Suggestions are made for new experimental studies relevant to VERMIN validation. In addition, VERMIN was used to simulate the behaviour of a repository in a clay formation and thus provide input for the geosphere model being used in the PACOMA study. Results from these simulations are reported. (author)

The Second Data Release of the Sloan Digital Sky Survey

CERN Document Server

Abazajian, Kevork; ̈ueros, Marcel A. Ag; Allam, Sahar S.; Anderson, KurtS. J.; Anderson, Scott F.; Annis, James; Bahcall, Neta A.; Baldry, Ivan K.; StevenBastian; Berlind, Andreas; Bernardi, Mariangela; Blanton, Michael R.; BochanskiJr., John J.; Boroski, William N.; Briggs, John W.; Brinkmann, J.; Brunner, Robert J.; ́ari, Tam ́asBudav; Carey, Larry N.; Carliles, Samuel; Castander, Francisco J.; Connolly, A. J.; Csabai, Istvan; Doi, Mamoru; Dong, Feng; Eisenstein, Daniel J.; Evans, Michael L.; Fan, Xiaohui; Finkbeiner, Douglas P.; Friedman, Scott D.; Frieman, Joshua A.; Fukugita, Masataka; Gal, RoyR.; Gillespie, Bruce; Glazebrook, Karl; Gray, Jim; Grebel, Eva K.; Gunn, James E.; Gurbani, Vijay K.; Hall, Patrick B.; Hamabe, Masaru; Harris, Frederick H.; C.Harris, Hugh; Harvanek, Michael; Heckman, Timothy M.; Hendry, John S.; Hennessy, Gregory S.; Hindsley, Robert B.; Hogan, Craig J.; Hogg, David W.; Holmgren, Donald J.; Ichikawa, Shin-ichi; Ichikawa, Takashi; Ivezic, Zeljko; Jester, Sebastian; Johnston, David E.; Jorgensen, AndersM.; Kent, Stephen M.; Kleinman, S. J.; Knapp, G. R.; Kniazev, Alexei Yu.; Kron, Richard G.; Krzesinski, Jurek; Kunszt, Peter Z.; Kuropatkin, Nickolai; Q.Lamb, Donald; Lampeitl, Hubert; Lee, Brian C.; Leger, R. French; Li, Nolan; Lin, Huan; Loh, Yeong-Shang; Long, Daniel C.; Loveday, Jon; Lupton, Robert H.; Malik, Tanu; BruceMargon; Matsubara, Takahiko; McGehee, Peregrine M.; McKay, Timothy A.; AveryMeiksin; Munn, Jeffrey A.; Nakajima, Reiko; Nash, Thomas; Neilsen, Eric H. Jr.; JoNewberg, Heidi; Newman, Peter R.; Nichol, Robert C.; Nicinski, Tom; Nieto-Santisteban, Maria; Nitta, Atsuko; Okamura, Sadanori; O'Mullane, William; Ostriker, Jeremiah P.; Owen, Russell; Padmanabhan, Nikhil; Peoples, John; Pier, Jeffrey R.; Pope, Adrian C.; Quinn, Thomas R.; Richards, Gordon T.; Richmond, Michael W.; Rix, Hans-Walter; Rockosi, Constance M.; Schlegel, David J.; Schneider, Donald P.; Scranton, Ryan; Sekiguchi, Maki; Seljak, Uros; Sergey, Gary; Sesar, Branimir; Sheldon, Erin; Shimasaku, Kazu; Siegmund, Walter A.; Silvestri, Nicole M.; Smith, J. Allyn; ́c, Vernesa Smolči; Snedden, Stephanie A.; AlbertStebbins; Stoughton, Chris; Strauss, Michael A.; SubbaRao, Mark; Szalay, Alexander S.; Szapudi, Istv ́an; Szkody, Paula; Szokoly, Gyula P.; Tegmark, Max; Teodoro, Luis; Thakar, AniruddhaR.; Tremonti, Christy; Tucker, Douglas L.; Uomoto, Alan; Vanden Berk, Daniel E.; Vandenberg, Jan; Vogeley, Michael S.; Voges, Wolfgang; Vogt, Nicole P.; M.Walkowicz, Lucianne; Wang, Shu-i; Weinberg, David H.; West, Andrew A.; White, Simon D.M.; Wilhite, BrianC.; Xu, Yongzhong; Yanny, Brian; Yasuda, Naoki; Yip, Ching-Wa; Yocum, D. R.; York, Donald G.; Zehavi, Idit; Zibetti, Stefano; Zucker, Daniel B.

2004-01-01

The Sloan Digital Sky Survey has validated and made publicly available its Second Data Release. This data release consists of 3324 square degrees of five-band (u g r i z) imaging data with photometry for over 88 million unique objects, 367,360 spectra of galaxies, quasars, stars and calibrating blank sky patches selected over 2627 degrees of this area, and tables of measured parameters from these data. The imaging data reach a depth of r ~ 22.2 (95% completeness limit for point sources) and are photometrically and astrometrically calibrated to 2% rms and 100 milli-arcsec rms per coordinate, respectively. The imaging data have all been processed through a new version of the SDSS imaging pipeline, in which the most important improvement since the last data release is fixing an error in the model fits to each object. The result is that model magnitudes are now a good proxy for point spread function (PSF) magnitudes for point sources, and Petrosian magnitudes for extended sources. The spectroscopy extends from 38...

A2A-D2 receptor-receptor interaction modulates gliotransmitter release from striatal astrocyte processes.

Science.gov (United States)

Cervetto, Chiara; Venturini, Arianna; Passalacqua, Mario; Guidolin, Diego; Genedani, Susanna; Fuxe, Kjell; Borroto-Esquela, Dasiel O; Cortelli, Pietro; Woods, Amina; Maura, Guido; Marcoli, Manuela; Agnati, Luigi F

2017-01-01

Evidence for striatal A2A-D2 heterodimers has led to a new perspective on molecular mechanisms involved in schizophrenia and Parkinson's disease. Despite the increasing recognition of astrocytes' participation in neuropsychiatric disease vulnerability, involvement of striatal astrocytes in A2A and D2 receptor signal transmission has never been explored. Here, we investigated the presence of D2 and A2A receptors in isolated astrocyte processes prepared from adult rat striatum by confocal imaging; the effects of receptor activation were measured on the 4-aminopyridine-evoked release of glutamate from the processes. Confocal analysis showed that A2A and D2 receptors were co-expressed on the same astrocyte processes. Evidence for A2A-D2 receptor-receptor interactions was obtained by measuring the release of the gliotransmitter glutamate: D2 receptors inhibited the glutamate release, while activation of A2A receptors, per se ineffective, abolished the effect of D2 receptor activation. The synthetic D2 peptide VLRRRRKRVN corresponding to the receptor region involved in electrostatic interaction underlying A2A-D2 heteromerization abolished the ability of the A2A receptor to antagonize the D2 receptor-mediated effect. Together, the findings are consistent with heteromerization of native striatal astrocytic A2A-D2 receptors that via allosteric receptor-receptor interactions could play a role in the control of striatal glutamatergic transmission. These new findings suggest possible new pathogenic mechanisms and/or therapeutic approaches to neuropsychiatric disorders. © 2016 International Society for Neurochemistry.

Validation of the VTT's reactor physics code system

International Nuclear Information System (INIS)

Tanskanen, A.

1998-01-01

At VTT Energy several international reactor physics codes and nuclear data libraries are used in a variety of applications. The codes and libraries are under constant development and every now and then new updated versions are released, which are taken in use as soon as they have been validated at VTT Energy. The primary aim of the validation is to ensure that the code works properly, and that it can be used correctly. Moreover, the applicability of the codes and libraries are studied in order to establish their advantages and weak points. The capability of generating program-specific nuclear data for different reactor physics codes starting from the same evaluated data is sometimes of great benefit. VTT Energy has acquired a nuclear data processing system based on the NJOY-94.105 and TRANSX-2.15 processing codes. The validity of the processing system has been demonstrated by generating pointwise (MCNP) and groupwise (ANISN) temperature-dependent cross section sets for the benchmark calculations of the Doppler coefficient of reactivity. At VTT Energy the KENO-VI three-dimensional Monte Carlo code is used in criticality safety analyses. The KENO-VI code and the 44GROUPNDF5 data library have been validated at VTT Energy against the ZR-6 and LR-0 critical experiments. Burnup Credit refers to the reduction in reactivity of burned nuclear fuel due to the change in composition during irradiation. VTT Energy has participated in the calculational VVER-440 burnup credit benchmark in order to validate criticality safety calculation tools. (orig.)

A Process Analytical Technology (PAT) approach to control a new API manufacturing process: development, validation and implementation.

Science.gov (United States)

Schaefer, Cédric; Clicq, David; Lecomte, Clémence; Merschaert, Alain; Norrant, Edith; Fotiadu, Frédéric

2014-03-01

Pharmaceutical companies are progressively adopting and introducing Process Analytical Technology (PAT) and Quality-by-Design (QbD) concepts promoted by the regulatory agencies, aiming the building of the quality directly into the product by combining thorough scientific understanding and quality risk management. An analytical method based on near infrared (NIR) spectroscopy was developed as a PAT tool to control on-line an API (active pharmaceutical ingredient) manufacturing crystallization step during which the API and residual solvent contents need to be precisely determined to reach the predefined seeding point. An original methodology based on the QbD principles was designed to conduct the development and validation of the NIR method and to ensure that it is fitted for its intended use. On this basis, Partial least squares (PLS) models were developed and optimized using chemometrics methods. The method was fully validated according to the ICH Q2(R1) guideline and using the accuracy profile approach. The dosing ranges were evaluated to 9.0-12.0% w/w for the API and 0.18-1.50% w/w for the residual methanol. As by nature the variability of the sampling method and the reference method are included in the variability obtained for the NIR method during the validation phase, a real-time process monitoring exercise was performed to prove its fit for purpose. The implementation of this in-process control (IPC) method on the industrial plant from the launch of the new API synthesis process will enable automatic control of the final crystallization step in order to ensure a predefined quality level of the API. In addition, several valuable benefits are expected including reduction of the process time, suppression of a rather difficult sampling and tedious off-line analyses. © 2013 Published by Elsevier B.V.

Benchmarking and validation activities within JEFF project

Directory of Open Access Journals (Sweden)

Cabellos O.

2017-01-01

Full Text Available The challenge for any nuclear data evaluation project is to periodically release a revised, fully consistent and complete library, with all needed data and covariances, and ensure that it is robust and reliable for a variety of applications. Within an evaluation effort, benchmarking activities play an important role in validating proposed libraries. The Joint Evaluated Fission and Fusion (JEFF Project aims to provide such a nuclear data library, and thus, requires a coherent and efficient benchmarking process. The aim of this paper is to present the activities carried out by the new JEFF Benchmarking and Validation Working Group, and to describe the role of the NEA Data Bank in this context. The paper will also review the status of preliminary benchmarking for the next JEFF-3.3 candidate cross-section files.

Benchmarking and validation activities within JEFF project

Science.gov (United States)

Cabellos, O.; Alvarez-Velarde, F.; Angelone, M.; Diez, C. J.; Dyrda, J.; Fiorito, L.; Fischer, U.; Fleming, M.; Haeck, W.; Hill, I.; Ichou, R.; Kim, D. H.; Klix, A.; Kodeli, I.; Leconte, P.; Michel-Sendis, F.; Nunnenmann, E.; Pecchia, M.; Peneliau, Y.; Plompen, A.; Rochman, D.; Romojaro, P.; Stankovskiy, A.; Sublet, J. Ch.; Tamagno, P.; Marck, S. van der

2017-09-01

The challenge for any nuclear data evaluation project is to periodically release a revised, fully consistent and complete library, with all needed data and covariances, and ensure that it is robust and reliable for a variety of applications. Within an evaluation effort, benchmarking activities play an important role in validating proposed libraries. The Joint Evaluated Fission and Fusion (JEFF) Project aims to provide such a nuclear data library, and thus, requires a coherent and efficient benchmarking process. The aim of this paper is to present the activities carried out by the new JEFF Benchmarking and Validation Working Group, and to describe the role of the NEA Data Bank in this context. The paper will also review the status of preliminary benchmarking for the next JEFF-3.3 candidate cross-section files.

Important processes affecting the release and migration of radionuclides from a deep geological repository

International Nuclear Information System (INIS)

Barátová, Dana; Nečas, Vladimír

2017-01-01

The processes that affect significantly the transport of contaminants through the near field and far field of a deep geological repository of spent nuclear fuel were studied. The processes can be generally divided into (i) processes related to the release of radionuclides from the spent nuclear fuel; (ii) processes related to the radionuclide transport mechanisms (such as advection and diffusion); and (iii) processes affecting the rate of radionuclide migration through the multi-barrier repository system. A near-field and geosphere model of an unspecified geological repository sited in a crystalline rock is also described. Focus of the treatment is on the effects of the different processes on the activity flow of the major safety-relevant radionuclides. The activity flow was simulated for one spent fuel cask by using the GoldSim simulation tool. (orig.)

Mechanisms of within- and across- channel processing in comodulation masking release

DEFF Research Database (Denmark)

Piechowiak, Tobias

2007-01-01

The audibility of a target sound embedded in another masking sound can be improved by adding sound energy that is remote in frequency from both the masker and the target. This effect is known as comodulation masking release (CMR) and is observed when the remote sound and the masker share coherent...... role in our ability to deal with natural complex acoustic environments. While a large body of data has been presented, the mechanisms underlying CMR are not clear. This study proposes an auditory processing model that accounts for various aspects of CMR. The model includes an equalization...

The Release of Trace Elements in the Process of Coal Coking

Directory of Open Access Journals (Sweden)

Jan Konieczyński

2012-01-01

Full Text Available In order to assess the penetration of individual trace elements into the air through their release in the coal coking process, it is necessary to determine the loss of these elements by comparing their contents in the charge coal and in coke obtained. The present research covered four coke oven batteries differing in age, technology, and technical equipment. By using mercury analyzer MA-2 and the method of ICP MS As, Be, Cd, Co, Hg, Mn, Ni, Se, Sr, Tl, V, and Zn were determined in samples of charge coal and yielded coke. Basing on the analyses results, the release coefficients of selected elements were determined. Their values ranged from 0.5 to 94%. High volatility of cadmium, mercury, and thallium was confirmed. The tests have shown that although the results refer to the selected case studies, it may be concluded that the air purity is affected by controlled emission occurring when coke oven batteries are fired by crude coke oven gas. Fugitive emission of the trace elements investigated, occurring due to coke oven leaks and openings, is small and, is not a real threat to the environment except mercury.

Relative Release-to-Birth Indicators for Investigating TRISO Fuel Fission Gas Release Models

International Nuclear Information System (INIS)

Harp, Jason M.; Hawari, Ayman I.

2008-01-01

TRISO microsphere fuel is the fundamental fuel unit for Very High Temperature Reactors (VHTR). A single TRISO particle consists of an inner kernel of uranium dioxide or uranium oxycarbide surrounded by layers of pyrolytic carbon and silicon carbide. If the silicon carbide layer fails, fission products, especially the noble fission gases Kr and Xe, will begin to escape the failed particle. The release of fission gas is usually quantified by measuring the ratio of the released activity (R) to the original birth activity (B), which is designated as the R/B ratio. In this work, relative Release-to-Birth indicators (I) are proposed as a technique for interpreting the results of TRISO irradiation experiments. By implementing a relative metric, it is possible to reduce the sensitivity of the indicators to instrumental uncertainties and variations in experimental conditions. As an example, relative R/B indicators are applied to the interpretation of representative data from the Advanced Gas Reactor-1 TRISO fuel experiment that is currently taking place at the Advanced Test Reactor of Idaho National Laboratory. It is shown that the comparison of measured to predicted relative R/B indicators (I) gives insight into the physics of release and helps validate release models. Different trends displayed by the indicators are related to the mechanisms of fission gas release such as diffusion and recoil. The current analysis shows evidence for separate diffusion coefficients for Kr and Xe and supports the need to account for recoil release. (authors)

On-line validation of linear process models using generalized likelihood ratios

International Nuclear Information System (INIS)

Tylee, J.L.

1981-12-01

A real-time method for testing the validity of linear models of nonlinear processes is described and evaluated. Using generalized likelihood ratios, the model dynamics are continually monitored to see if the process has moved far enough away from the nominal linear model operating point to justify generation of a new linear model. The method is demonstrated using a seventh-order model of a natural circulation steam generator

NHPoisson: An R Package for Fitting and Validating Nonhomogeneous Poisson Processes

Directory of Open Access Journals (Sweden)

Ana C. Cebrián

2015-03-01

Full Text Available NHPoisson is an R package for the modeling of nonhomogeneous Poisson processes in one dimension. It includes functions for data preparation, maximum likelihood estimation, covariate selection and inference based on asymptotic distributions and simulation methods. It also provides specific methods for the estimation of Poisson processes resulting from a peak over threshold approach. In addition, the package supports a wide range of model validation tools and functions for generating nonhomogenous Poisson process trajectories. This paper is a description of the package and aims to help those interested in modeling data using nonhomogeneous Poisson processes.

Validation of Alternative In Vitro Methods to Animal Testing: Concepts, Challenges, Processes and Tools.

Science.gov (United States)

Griesinger, Claudius; Desprez, Bertrand; Coecke, Sandra; Casey, Warren; Zuang, Valérie

This chapter explores the concepts, processes, tools and challenges relating to the validation of alternative methods for toxicity and safety testing. In general terms, validation is the process of assessing the appropriateness and usefulness of a tool for its intended purpose. Validation is routinely used in various contexts in science, technology, the manufacturing and services sectors. It serves to assess the fitness-for-purpose of devices, systems, software up to entire methodologies. In the area of toxicity testing, validation plays an indispensable role: "alternative approaches" are increasingly replacing animal models as predictive tools and it needs to be demonstrated that these novel methods are fit for purpose. Alternative approaches include in vitro test methods, non-testing approaches such as predictive computer models up to entire testing and assessment strategies composed of method suites, data sources and decision-aiding tools. Data generated with alternative approaches are ultimately used for decision-making on public health and the protection of the environment. It is therefore essential that the underlying methods and methodologies are thoroughly characterised, assessed and transparently documented through validation studies involving impartial actors. Importantly, validation serves as a filter to ensure that only test methods able to produce data that help to address legislative requirements (e.g. EU's REACH legislation) are accepted as official testing tools and, owing to the globalisation of markets, recognised on international level (e.g. through inclusion in OECD test guidelines). Since validation creates a credible and transparent evidence base on test methods, it provides a quality stamp, supporting companies developing and marketing alternative methods and creating considerable business opportunities. Validation of alternative methods is conducted through scientific studies assessing two key hypotheses, reliability and relevance of the

Applying the Mixed Methods Instrument Development and Construct Validation Process: the Transformative Experience Questionnaire

Science.gov (United States)

Koskey, Kristin L. K.; Sondergeld, Toni A.; Stewart, Victoria C.; Pugh, Kevin J.

2018-01-01

Onwuegbuzie and colleagues proposed the Instrument Development and Construct Validation (IDCV) process as a mixed methods framework for creating and validating measures. Examples applying IDCV are lacking. We provide an illustrative case integrating the Rasch model and cognitive interviews applied to the development of the Transformative…

[Spectral characteristics of dissolved organic matter released during the metabolic process of small medusa].

Science.gov (United States)

Guo, Dong-Hui; Yi, Yue-Yuan; Zhao, Lei; Guo, Wei-Dong

2012-06-01

The metabolic processes of jellyfish can produce dissolved organic matter (DOM) which will influence the functioning of the aquatic ecosystems, yet the optical properties of DOM released by jellyfish are unknown. Here we report the absorption and fluorescence properties of DOM released by a medusa species Black fordia virginica during a 24 h incubation experiment. Compared with the control group, an obvious increase in the concentrations of dissolved organic carbon (DOC), absorption coefficient (a280) and total dissolved nitrogen (TDN) was observed in incubation group. This clearly demonstrated the release of DOM, chromophoric DOM (CDOM) and dissolved nutrients by B. virginica which feed on enough of Artemia sp. before the experiment. The increase in spectral slope ratio (SR) and decrease in humification index (HIX) indicated that the released DOM was less-humified and had relatively lower molecular weight. Parallel factor analysis (PARAFAC) decomposed the fluorescence matrices of DOM into three humic-like components (C1-C3) and one protein-like component (C4). The Fmax of two components (C2: 400 nm showed little changes. Thus, we suggested a zooplankton index (ZIX) to trace and characterize the DOM excreted by metabolic activity of zooplankton, which is calculated as the ratio of the sum of Fmax of all fluorescence components with the emission wavelength 400 nm.

Verification and validation of ACE-format library created from ENDF/B-VII.0

International Nuclear Information System (INIS)

Chen Chaobin; Hu Zehua; Zhang Benai; Chen Yixue; Wu Jun

2009-01-01

ENDF/B-VII.0, released by the USA Cross Section Evaluation Working Group(CSEWG) in December 2006, was developed in five years since the previous release of ENDF/B-VI.8 and was demonstrated to contain much better physical representations of the data and to perform much better than previus ENDF evaluations over a broad range of applications. We generated ACE-format pointwise cross section library from the ENDF/B-VII.0 neutron reaction sublibrary with the processing code NJOY. The paper provides an overview of ENDF/B-VII.0, a summary of the ACE-format files producing process and a detail description of the validation of the ACE-format library. The conclusion is that the ACE-format library produced is correct. (authors)

Challenges in validating the sterilisation dose for processed human amniotic membranes

International Nuclear Information System (INIS)

Yusof, Norimah; Hassan, Asnah; Firdaus Abd Rahman, M.N.; Hamid, Suzina A.

2007-01-01

Most of the tissue banks in the Asia Pacific region have been using ionising radiation at 25 kGy to sterilise human tissues for save clinical usage. Under tissue banking quality system, any dose employed for sterilisation has to be validated and the validation exercise has to be a part of quality document. Tissue grafts, unlike medical items, are not produced in large number per each processing batch and tissues relatively have a different microbial population. A Code of Practice established by the International Atomic Energy Agency (IAEA) in 2004 offers several validation methods using smaller number of samples compared to ISO 11137 (1995), which is meant for medical products. The methods emphasise on bioburden determination, followed by sterility test on samples after they were exposed to verification dose for attaining of sterility assurance level (SAL) of 10 -1 . This paper describes our experience in using the IAEA Code of Practice in conducting the validation exercise for substantiating 25 kGy as sterilisation dose for both air-dried amnion and those preserved in 99% glycerol

Challenges in validating the sterilisation dose for processed human amniotic membranes

Energy Technology Data Exchange (ETDEWEB)

Yusof, Norimah [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)], E-mail: norimah@mint.gov.my; Hassan, Asnah [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Firdaus Abd Rahman, M.N.; Hamid, Suzina A. [National Tissue Bank, Hospital Universiti Sains Malaysia, Kubang Kerian, 16130 Kelantan (Malaysia)

2007-11-15

Most of the tissue banks in the Asia Pacific region have been using ionising radiation at 25 kGy to sterilise human tissues for save clinical usage. Under tissue banking quality system, any dose employed for sterilisation has to be validated and the validation exercise has to be a part of quality document. Tissue grafts, unlike medical items, are not produced in large number per each processing batch and tissues relatively have a different microbial population. A Code of Practice established by the International Atomic Energy Agency (IAEA) in 2004 offers several validation methods using smaller number of samples compared to ISO 11137 (1995), which is meant for medical products. The methods emphasise on bioburden determination, followed by sterility test on samples after they were exposed to verification dose for attaining of sterility assurance level (SAL) of 10{sup -1}. This paper describes our experience in using the IAEA Code of Practice in conducting the validation exercise for substantiating 25 kGy as sterilisation dose for both air-dried amnion and those preserved in 99% glycerol.

Validation of new CFD release by Ground-Coupled Heat Transfer Test Cases

Directory of Open Access Journals (Sweden)

Sehnalek Stanislav

2017-01-01

Full Text Available In this article is presented validation of ANSYS Fluent with IEA BESTEST Task 34. Article stars with outlook to the topic, afterward are described steady-state cases used for validation. Thereafter is mentioned implementation of these cases on CFD. Article is concluded with presentation of the simulated results with a comparison of those from already validated simulation software by IEA. These validation shows high correlation with an older version of tested ANSYS as well as with other main software. The paper ends by discussion with an outline of future research.

Opportunities and challenges of real-time release testing in biopharmaceutical manufacturing.

Science.gov (United States)

Jiang, Mo; Severson, Kristen A; Love, John Christopher; Madden, Helena; Swann, Patrick; Zang, Li; Braatz, Richard D

2017-11-01

Real-time release testing (RTRT) is defined as "the ability to evaluate and ensure the quality of in-process and/or final drug product based on process data, which typically includes a valid combination of measured material attributes and process controls" (ICH Q8[R2]). This article discusses sensors (process analytical technology, PAT) and control strategies that enable RTRT for the spectrum of critical quality attributes (CQAs) in biopharmaceutical manufacturing. Case studies from the small-molecule and biologic pharmaceutical industry are described to demonstrate how RTRT can be facilitated by integrated manufacturing and multivariable control strategies to ensure the quality of products. RTRT can enable increased assurance of product safety, efficacy, and quality-with improved productivity including faster release and potentially decreased costs-all of which improve the value to patients. To implement a complete RTRT solution, biologic drug manufacturers need to consider the special attributes of their industry, particularly sterility and the measurement of viral and microbial contamination. Continued advances in on-line and in-line sensor technologies are key for the biopharmaceutical manufacturing industry to achieve the potential of RTRT. Related article: http://onlinelibrary.wiley.com/doi/10.1002/bit.26378/full. © 2017 Wiley Periodicals, Inc.

Improving the quality of EMI Releases by leveraging the EMI Testing Infrastructure

International Nuclear Information System (INIS)

Aiftimiei, C; Ceccanti, A; Dongiovanni, D; Giacomini, F; Meglio, A Di

2012-01-01

What is an EMI Release? What is its life cycle? How is its quality assured through a continuous integration and large scale acceptance testing? These are the main questions that this article will answer, by presenting the EMI release management process with emphasis on the role played by the Testing Infrastructure in improving the quality of the middleware provided by the project. The European Middleware Initiative (EMI) is a close collaboration of four major European technology providers: ARC, gLite, UNICORE and dCache. Its main objective is to deliver a consolidated set of components for deployment in EGI (as part of the Unified Middleware Distribution, UMD), PRACE and other DCIs. The harmonized set of EMI components thus enables the interoperability and integration between Grids. EMI aims at creating an effective environment that satisfies the requirements of the scientific communities relying on it. The EMI distribution is organized in periodic major releases whose development and maintenance follow a 5-phase yearly cycle: i) requirements collection and analysis; ii) development and test planning; iii) software development, testing and certification; iv) release certification and validation and v) release and maintenance. In this article we present in detail the implementation of operational and infrastructural resources supporting the certification and validation phase of the release. The main goal of this phase is to harmonize into a single release the strongly inter-dependent products coming from various development teams through parallel certification paths. To achieve this goal the continuous integration and large scale acceptance testing performed on the EMI Testing Infrastructure plays a key role. The purpose of this infrastructure is to provide a system where both the production and the release candidate product versions are deployed. On this system inter-component testing by different product team testers can concurrently take place. The Testing

Drug release from non-aqueous suspensions. II. The release of methylxanthines from paraffin suspensions

NARCIS (Netherlands)

Blaey, C.J. de; Fokkens, J.G.

1984-01-01

The release of 3 methylxanthines, i.e. caffeine, theobromine and theophylline, from suspensions in liquid paraffin to an aqueous phase was determined in an in vitro apparatus. The release rates were determined as a function of the pH of the aqueous phase. It was proved that the release process was

The Chernobyl I-131 Release: Model Validation and Assessment of the Countermeasure Effectiveness. Report of the Chernobyl 131I Release Working Group of EMRAS Theme 1

International Nuclear Information System (INIS)

2012-01-01

The Chernobyl 131 I Release Working Group (IWG) which was established within the framework of the EMRAS Programme continues some of the more traditional work of previous international programmes that were aimed at increasing confidence in methods and models for the assessment of radiation exposure related to the environmental releases. There is still very little information regarding the quantitative relationship between radiation dose to the thyroid from Chernobyl and the risk of thyroid cancer. The uncertainty combined with individual estimates of radiation dose constitutes a crucial point in establishing this relationship, since, any release of radioiodine into environment creates wide range of uncertainty for internal dose assessments. The 131 I scenarios provide an excellent opportunity to compare a number of modelling approaches to a single assessment problem, in a dose reconstruction context. Nine experts in environmental modelling participated in the Plavsk Scenario dealing with areas of assessment modelling for which the capabilities are not yet well established. One could observes the remarkably improvement in models performance comparing with previous radioiodine scenarios. Predictions of the various models were within a factor of three of the observations, discrepancies between the estimates of average doses to thyroid produced by most participant not exceeded a factor of ten. The process of testing independent model calculations against independent data set also provided useful information to the originators of the test data.

Effect of WOW process parameters on morphology and burst release of FITC-dextran loaded PLGA microspheres.

Science.gov (United States)

Mao, Shirui; Xu, Jing; Cai, Cuifang; Germershaus, Oliver; Schaper, Andreas; Kissel, Thomas

2007-04-04

Using fluorescein isothiocyanate labeled dextran (FITC-dextran 40, FD40) as a hydrophilic model compound, microspheres were prepared by a WOW double emulsion technique. Influence of process parameters on microsphere morphology and burst release of FD40 from PLGA microspheres was studied. Internal morphology of microspheres was investigated by stereological method via cryo-cutting technique and scanning electron microscopy (SEM). Drug distribution in microspheres was observed with confocal laser scanning microscopy (CLSM). Polymer nature (RG503 and RG503H) had significant influence on the micro-morphology of microspheres. Increase in continuous water phase volume (W2) led to increased surface porosity but decreased internal porosity. By increasing PVA concentration in the continuous phase from 0.1 to 1%, particle size changed marginally but burst release decreased from 12.2 to 5.9%. Internal porosity of microspheres decreased considerably with increasing polymer concentration. Increase in homogenization speed during the primary emulsion preparation led to decreased internal porosity. Burst release decreased with increasing drug loading but increased with drug molecular weight. Drug distribution in microspheres depended on preparation method. The porosity of microspheres decreased with time in the diffusion stage, but internal morphology had no influence on the release behavior in the bioerosion stage. In summary, surface porosity and internal morphology play a significant role in the release of hydrophilic macromolecules from biodegradable microspheres in the initial release phase characterized by pore diffusion.

Validation of the sterilization process for radiopharmaceuticals and materials with humid heat

International Nuclear Information System (INIS)

Robles, Anita; Moore, Mariel; Morote, Mario; Guevara, Buenaventura; Castro, Delcy; Paragulla, Wilson; Martinez, Ramos; Ocana, Elias; Novoa, Carlos

2014-01-01

A validation protocol has been designed and applied for the sterilization process of radiopharmaceuticals and materials, with humid heat for sodium pertechnetate Tc-99m injection solution (placebo) and materials, in compliance with good manufacturing practices for pharmaceutical products. The sterilization cycle set for each load is developed, according to the following parameters: 121 o C ± 1 o C (temperature), 15 ± 0.5 psi (pressure) and an exposure time of 20 and 15 minutes, respectively. The results in the penetration test with load, F0 values were higher than 20 minutes at 121 o C and for the biological challenge by biological indicators (Bacillus stearothermophilus) was negative in colder spots, in three consecutive runs. The sterilization process for each load and equipment has been validated to meet the established acceptance criteria. (authors).

Precooking as a Control for Histamine Formation during the Processing of Tuna: An Industrial Process Validation.

Science.gov (United States)

Adams, Farzana; Nolte, Fred; Colton, James; De Beer, John; Weddig, Lisa

2018-02-23

An experiment to validate the precooking of tuna as a control for histamine formation was carried out at a commercial tuna factory in Fiji. Albacore tuna ( Thunnus alalunga) were brought on board long-line catcher vessels alive, immediately chilled but never frozen, and delivered to an on-shore facility within 3 to 13 days. These fish were then allowed to spoil at 25 to 30°C for 21 to 25 h to induce high levels of histamine (>50 ppm), as a simulation of "worst-case" postharvest conditions, and subsequently frozen. These spoiled fish later were thawed normally and then precooked at a commercial tuna processing facility to a target maximum core temperature of 60°C. These tuna were then held at ambient temperatures of 19 to 37°C for up to 30 h, and samples were collected every 6 h for histamine analysis. After precooking, no further histamine formation was observed for 12 to 18 h, indicating that a conservative minimum core temperature of 60°C pauses subsequent histamine formation for 12 to 18 h. Using the maximum core temperature of 60°C provided a challenge study to validate a recommended minimum core temperature of 60°C, and 12 to 18 h was sufficient to convert precooked tuna into frozen loins or canned tuna. This industrial-scale process validation study provides support at a high confidence level for the preventive histamine control associated with precooking. This study was conducted with tuna deliberately allowed to spoil to induce high concentrations of histamine and histamine-forming capacity and to fail standard organoleptic evaluations, and the critical limits for precooking were validated. Thus, these limits can be used in a hazard analysis critical control point plan in which precooking is identified as a critical control point.

On the Load-Unload (L-U) and Force-Release (F-R) Algorithms for Simulating Brittle Fracture Processes via Lattice Models

KAUST Repository

Liu, Jinxing

2011-11-11

General summaries on the load-unload and force-release methods indicate that the two methods are efficient for different-charactered quasi-static failures; therefore, it is important to choose the right one for different applications. Then we take, as an example, the case where the release of the ruptured element\\'s internal force is infinitely slower than the relaxation of the lattice system and analyze why the force-release method works better than the load-unload method in this particular case. Different trial deformation fields are used by them to track the next equilibrium state. Force-release method ensures that the deformation throughout the whole failure process coincides exactly with the controlled-displacement boundary conditions and we utilize the \\'left modulus\\' concept to prove that this method satisfies the energetic evolution in the force-displacement diagram; both of which are not satisfied by the load-unload method. To illustrate that the force-release method is not just another form of the load-unload method, a tensile test on a specifically designed system is analyzed to further compare the above two methods, showing that their predicted sequences of elemental failures can be different. In closing, we simulate the uniaxial tensile test on a beam lattice system by the load-unload and force-release methods and exploit the details of the resulting fracture processes. © The Author(s), 2011.

Notification: Preliminary Research on EPA's Decision Making Process to Release Information Under the Freedom of Information Act

Science.gov (United States)

July 19, 2013. The Office of Inspector General plans to begin preliminary research on the U.S. Environmental Protection Agency’s process for deciding to release information requested under the Freedom of Information Act.

Design for validation: An approach to systems validation

Science.gov (United States)

Carter, William C.; Dunham, Janet R.; Laprie, Jean-Claude; Williams, Thomas; Howden, William; Smith, Brian; Lewis, Carl M. (Editor)

1989-01-01

Every complex system built is validated in some manner. Computer validation begins with review of the system design. As systems became too complicated for one person to review, validation began to rely on the application of adhoc methods by many individuals. As the cost of the changes mounted and the expense of failure increased, more organized procedures became essential. Attempts at devising and carrying out those procedures showed that validation is indeed a difficult technical problem. The successful transformation of the validation process into a systematic series of formally sound, integrated steps is necessary if the liability inherent in the future digita-system-based avionic and space systems is to be minimized. A suggested framework and timetable for the transformtion are presented. Basic working definitions of two pivotal ideas (validation and system life-cyle) are provided and show how the two concepts interact. Many examples are given of past and present validation activities by NASA and others. A conceptual framework is presented for the validation process. Finally, important areas are listed for ongoing development of the validation process at NASA Langley Research Center.

Development of Maltodextrin-Based Immediate-Release Tablets Using an Integrated Twin-Screw Hot-Melt Extrusion and Injection-Molding Continuous Manufacturing Process.

Science.gov (United States)

Puri, Vibha; Brancazio, Dave; Desai, Parind M; Jensen, Keith D; Chun, Jung-Hoon; Myerson, Allan S; Trout, Bernhardt L

2017-11-01

The combination of hot-melt extrusion and injection molding (HME-IM) is a promising process technology for continuous manufacturing of tablets. However, there has been limited research on its application to formulate crystalline drug-containing immediate-release tablets. Furthermore, studies that have applied the HME-IM process to molded tablets have used a noncontinuous 2-step approach. The present study develops maltodextrin (MDX)-based extrusion-molded immediate-release tablets for a crystalline drug (griseofulvin) using an integrated twin-screw HME-IM continuous process. At 10% w/w drug loading, MDX was selected as the tablet matrix former based on a preliminary screen. Furthermore, liquid and solid polyols were evaluated for melt processing of MDX and for impact on tablet performance. Smooth-surfaced tablets, comprising crystalline griseofulvin solid suspension in the amorphous MDX-xylitol matrix, were produced by a continuous process on a twin-screw extruder coupled to a horizontally opening IM machine. Real-time HME process profiles were used to develop automated HME-IM cycles. Formulation adjustments overcame process challenges and improved tablet strength. The developed MDX tablets exhibited adequate strength and a fast-dissolving matrix (85% drug release in 20 min), and maintained performance on accelerated stability conditions. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Halogenation processes of secondary organic aerosol and implications on halogen release mechanisms

Directory of Open Access Journals (Sweden)

J. Ofner

2012-07-01

Full Text Available Reactive halogen species (RHS, such as X·, X₂ and HOX containing X = chlorine and/or bromine, are released by various sources like photo-activated sea-salt aerosol or from salt pans, and salt lakes. Despite many studies of RHS reactions, the potential of RHS reacting with secondary organic aerosol (SOA and organic aerosol derived from biomass-burning (BBOA has been neglected. Such reactions can constitute sources of gaseous organohalogen compounds or halogenated organic matter in the tropospheric boundary layer and can influence physicochemical properties of atmospheric aerosols.

Model SOA from α-pinene, catechol, and guaiacol was used to study heterogeneous interactions with RHS. Particles were exposed to molecular chlorine and bromine in an aerosol smog-chamber in the presence of UV/VIS irradiation and to RHS, released from simulated natural halogen sources like salt pans. Subsequently, the aerosol was characterized in detail using a variety of physicochemical and spectroscopic methods. Fundamental features were correlated with heterogeneous halogenation, which results in new functional groups (FTIR spectroscopy, changes UV/VIS absorption, chemical composition (ultrahigh resolution mass spectroscopy (ICR-FT/MS, or aerosol size distribution. However, the halogen release mechanisms were also found to be affected by the presence of organic aerosol. Those interaction processes, changing chemical and physical properties of the aerosol are likely to influence e.g. the ability of the aerosol to act as cloud condensation nuclei, its potential to adsorb other gases with low-volatility, or its contribution to radiative forcing and ultimately the Earth's radiation balance.

Disruption of Brewers' yeast by hydrodynamic cavitation: Process variables and their influence on selective release.

Science.gov (United States)

Balasundaram, B; Harrison, S T L

2006-06-05

Intracellular products, not secreted from the microbial cell, are released by breaking the cell envelope consisting of cytoplasmic membrane and an outer cell wall. Hydrodynamic cavitation has been reported to cause microbial cell disruption. By manipulating the operating variables involved, a wide range of intensity of cavitation can be achieved resulting in a varying extent of disruption. The effect of the process variables including cavitation number, initial cell concentration of the suspension and the number of passes across the cavitation zone on the release of enzymes from various locations of the Brewers' yeast was studied. The release profile of the enzymes studied include alpha-glucosidase (periplasmic), invertase (cell wall bound), alcohol dehydrogenase (ADH; cytoplasmic) and glucose-6-phosphate dehydrogenase (G6PDH; cytoplasmic). An optimum cavitation number Cv of 0.13 for maximum disruption was observed across the range Cv 0.09-0.99. The optimum cell concentration was found to be 0.5% (w/v, wet wt) when varying over the range 0.1%-5%. The sustained effect of cavitation on the yeast cell wall when re-circulating the suspension across the cavitation zone was found to release the cell wall bound enzyme invertase (86%) to a greater extent than the enzymes from other locations of the cell (e.g. periplasmic alpha-glucosidase at 17%). Localised damage to the cell wall could be observed using transmission electron microscopy (TEM) of cells subjected to less intense cavitation conditions. Absence of the release of cytoplasmic enzymes to a significant extent, absence of micronisation as observed by TEM and presence of a lower number of proteins bands in the culture supernatant on SDS-PAGE analysis following hydrodynamic cavitation compared to disruption by high-pressure homogenisation confirmed the selective release offered by hydrodynamic cavitation. Copyright 2006 Wiley Periodicals, Inc.

Applicability of near-infrared spectroscopy in the monitoring of film coating and curing process of the prolonged release coated pellets.

Science.gov (United States)

Korasa, Klemen; Hudovornik, Grega; Vrečer, Franc

2016-10-10

Although process analytical technology (PAT) guidance has been introduced to the pharmaceutical industry just a decade ago, this innovative approach has already become an important part of efficient pharmaceutical development, manufacturing, and quality assurance. PAT tools are especially important in technologically complex operations which require strict control of critical process parameters and have significant effect on final product quality. Manufacturing of prolonged release film coated pellets is definitely one of such processes. The aim of the present work was to study the applicability of the at-line near-infrared spectroscopy (NIR) approach in the monitoring of pellet film coating and curing steps. Film coated pellets were manufactured by coating the active ingredient containing pellets with film coating based on polymethacrylate polymers (Eudragit® RS/RL). The NIR proved as a useful tool for the monitoring of the curing process since it was able to determine the extent of the curing and hence predict drug release rate by using partial least square (PLS) model. However, such approach also showed a number of limitations, such as low reliability and high susceptibility to pellet moisture content, and was thus not able to predict drug release from pellets with high moisture content. On the other hand, the at-line NIR was capable to predict the thickness of Eudragit® RS/RL film coating in a wide range (up to 40μm) with good accuracy even in the pellets with high moisture content. To sum up, high applicability of the at-line NIR in the monitoring of the prolonged release pellets production was demonstrated in the present study. The present findings may contribute to more efficient and reliable PAT solutions in the manufacturing of prolonged release dosage forms. Copyright © 2016 Elsevier B.V. All rights reserved.

Additive advantage in characteristics of MIMCAPs on flexible silicon (100) fabric with release-first process

KAUST Repository

Ghoneim, Mohamed T.

2013-11-20

We report the inherent increase in capacitance per unit planar area of state-of-the art high-κ integrated metal/insulator/metal capacitors (MIMCAPs) fabricated on flexible silicon fabric with release-first process. We methodically study and show that our approach to transform bulk silicon (100) into a flexible fabric adds an inherent advantage of enabling higher integration density dynamic random access memory (DRAM) on the same chip area. Our approach is to release an ultra-thin silicon (100) fabric (25 μm thick) from the bulk silicon wafer, then build MIMCAPs using sputtered aluminium electrodes and successive atomic layer depositions (ALD) without break-ing the vacuum of a high-κ aluminium oxide sandwiched between two tantalum nitride layers. This result shows that we can obtain flexible electronics on silicon without sacrificing the high density integration aspects and also utilize the non-planar geometry associated with fabrication process to obtain a higher integration density compared to bulk silicon integration due to an increased normalized capacitance per unit planar area. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Guidelines for the Development, Validation and Routine Control of Industrial Radiation Processes

DEFF Research Database (Denmark)

Safrany, A.; Miller, Arne; Kovacs, A.

Radiation processing has become a well accepted technology on the global market, with uses ranging from the sterilization of medical devices to polymer cross-linking and curing to the irradiation of selected food items. Besides these well established uses, new radiation technology applications...... are emerging for environmental remediation and the synthesis of advanced materials and products. Quality assurance is vital for the success of these technologies and requires the development of standardized procedures as well as the harmonization of process validation and process control. It is recognized...

Best practice strategies for validation of micro moulding process simulation

DEFF Research Database (Denmark)

Costa, Franco; Tosello, Guido; Whiteside, Ben

2009-01-01

The use of simulation for injection moulding design is a powerful tool which can be used up-front to avoid costly tooling modifications and reduce the number of mould trials. However, the accuracy of the simulation results depends on many component technologies and information, some of which can...... be easily controlled or known by the simulation analyst and others which are not easily known. For this reason, experimental validation studies are an important tool for establishing best practice methodologies for use during analysis set up on all future design projects. During the validation studies......, detailed information about the moulding process is gathered and used to establish these methodologies. Whereas in routine design projects, these methodologies are then relied on to provide efficient but reliable working practices. Data analysis and simulations on preliminary micro-moulding experiments have...

Funding for the 2ND IAEA technical meeting on fusion data processing, validation and analysis

Energy Technology Data Exchange (ETDEWEB)

Greenwald, Martin

2017-06-02

The International Atomic Energy Agency (IAEA) will organize the second Technical Meeting on Fusion Da Processing, Validation and Analysis from 30 May to 02 June, 2017, in Cambridge, MA USA. The meeting w be hosted by the MIT Plasma Science and Fusion Center (PSFC). The objective of the meeting is to provide a platform where a set of topics relevant to fusion data processing, validation and analysis are discussed with the view of extrapolation needs to next step fusion devices such as ITER. The validation and analysis of experimental data obtained from diagnostics used to characterize fusion plasmas are crucial for a knowledge based understanding of the physical processes governing the dynamics of these plasmas. The meeting will aim at fostering, in particular, discussions of research and development results that set out or underline trends observed in the current major fusion confinement devices. General information on the IAEA, including its mission and organization, can be found at the IAEA websit Uncertainty quantification (UQ) Model selection, validation, and verification (V&V) Probability theory and statistical analysis Inverse problems & equilibrium reconstru ction Integrated data analysis Real time data analysis Machine learning Signal/image proc essing & pattern recognition Experimental design and synthetic diagnostics Data management

Experimental validation of thermo-chemical algorithm for a simulation of pultrusion processes

Science.gov (United States)

Barkanov, E.; Akishin, P.; Miazza, N. L.; Galvez, S.; Pantelelis, N.

2018-04-01

To provide better understanding of the pultrusion processes without or with temperature control and to support the pultrusion tooling design, an algorithm based on the mixed time integration scheme and nodal control volumes method has been developed. At present study its experimental validation is carried out by the developed cure sensors measuring the electrical resistivity and temperature on the profile surface. By this verification process the set of initial data used for a simulation of the pultrusion process with rod profile has been successfully corrected and finally defined.

Identification, detection, and validation of vibrating structures: a signal processing approach

International Nuclear Information System (INIS)

Candy, J.V.; Lager, D.L.

1979-01-01

This report discusses the application of modern signal processing techniques to characterize parameters governing the vibrational response of a structure. Simulated response data is used to explore the feasibility of applying these techniques to various structural problems. On-line estimator/indentifiers are used to estimate structural parameters, validate designed structures, and detect structural failure when used with a detector

Modifying an Active Compound’s Release Kinetic Using a Supercritical Impregnation Process to Incorporate an Active Agent into PLA Electrospun Mats

Directory of Open Access Journals (Sweden)

Carol López de Dicastillo

2018-04-01

Full Text Available The main objective of this work was to study the release of cinnamaldehyde (CIN from electrospun poly lactic acid (e-PLA mats obtained through two techniques: (i direct incorporation of active compound during the electrospinning process (e-PLA-CIN; and (ii supercritical carbon dioxide (scCO2 impregnation of CIN within electrospun PLA mats (e-PLA/CINimp. The development and characterization of both of these active electrospun mats were investigated with the main purpose of modifying the release kinetic of this active compound. Morphological, structural, and thermal properties of these materials were also studied, and control mats e-PLA and e- PLA CO 2 were developed in order to understand the effect of electrospinning and scCO2 impregnation, respectively, on PLA properties. Both strategies of incorporation of this active compound into PLA matrix resulted in different morphologies that influenced chemical and physical properties of these composites and in different release kinetics of CIN. The electrospinning and scCO2 impregnation processes and the presence of CIN altered PLA thermal and structural properties when compared to an extruded PLA material. The incorporation of CIN through scCO2 impregnation resulted in higher release rate and lower diffusion coefficients when compared to active electrospun mats with CIN incorporated during the electrospinning process.

Donabedian's structure-process-outcome quality of care model: Validation in an integrated trauma system.

Science.gov (United States)

Moore, Lynne; Lavoie, André; Bourgeois, Gilles; Lapointe, Jean

2015-06-01

According to Donabedian's health care quality model, improvements in the structure of care should lead to improvements in clinical processes that should in turn improve patient outcome. This model has been widely adopted by the trauma community but has not yet been validated in a trauma system. The objective of this study was to assess the performance of an integrated trauma system in terms of structure, process, and outcome and evaluate the correlation between quality domains. Quality of care was evaluated for patients treated in a Canadian provincial trauma system (2005-2010; 57 centers, n = 63,971) using quality indicators (QIs) developed and validated previously. Structural performance was measured by transposing on-site accreditation visit reports onto an evaluation grid according to American College of Surgeons criteria. The composite process QI was calculated as the average sum of proportions of conformity to 15 process QIs derived from literature review and expert opinion. Outcome performance was measured using risk-adjusted rates of mortality, complications, and readmission as well as hospital length of stay (LOS). Correlation was assessed with Pearson's correlation coefficients. Statistically significant correlations were observed between structure and process QIs (r = 0.33), and process and outcome QIs (r = -0.33 for readmission, r = -0.27 for LOS). Significant positive correlations were also observed between outcome QIs (r = 0.37 for mortality-readmission; r = 0.39 for mortality-LOS and readmission-LOS; r = 0.45 for mortality-complications; r = 0.34 for readmission-complications; 0.63 for complications-LOS). Significant correlations between quality domains observed in this study suggest that Donabedian's structure-process-outcome model is a valid model for evaluating trauma care. Trauma centers that perform well in terms of structure also tend to perform well in terms of clinical processes, which in turn has a favorable influence on patient outcomes

Field studies of the atmospheric processing of radionuclides released at Chernobyl

International Nuclear Information System (INIS)

Slinn, W.G.N.; Brodzinski, R.L.; Busness, K.M.

1987-01-01

This report gives a summary description of the goals and execution of field studies to characterize the radionuclides released from Chernobyl and to examine their long-range atmospheric transport and processing. Starting on April 28, 1986, an intensive planning and preparation effort was mounted over a very short time intercept and characterize the Chernobyl plume on its arrival over the western US. During the execution of these studies, they had very little firm information (beyond their own measurements and trajectory estimates) to confirm the location of the Chernobyl plume. On May 20, 1986, the studies were terminated, after extensive airborne sampling of air, cloud water, precipitation, soil, and vegetation as the plume traversed the western and central US and moved into Canada

Analysis of drug effects on neurotransmitter release

International Nuclear Information System (INIS)

Rowell, P.; Garner, A.

1986-01-01

The release of neurotransmitter is routinely studied in a superfusion system in which serial samples are collected and the effects of drugs or other treatments on the amount of material in the superfusate is determined. With frequent sampling interval, this procedure provides a mechanism for dynamically characterizing the release process itself. Using automated data collection in conjunction with polyexponential computer analysis, the equation which describes the release process in each experiment is determined. Analysis of the data during the nontreated phase of the experiment allows an internal control to be used for accurately assessing any changes in neurotransmitter release which may occur during a subsequent treatment phase. The use of internal controls greatly improves the signal to noise ratio and allows determinations of very low concentrations of drugs on small amounts of tissue to be made. In this presentation, the effects of 10 μM nicotine on 3 H-dopamine release in rat nucleus accumbens is described. The time course, potency and efficacy of the drug treatment is characterized using this system. Determinations of the exponential order of the release as well as the rate constants allow one to study the mechanism of the release process. A description of 3 H-dopamine release in normal as well as Ca ++ -free medium is presented

Management of the General Process of Parenteral Nutrition Using mHealth Technologies: Evaluation and Validation Study.

Science.gov (United States)

Cervera Peris, Mercedes; Alonso Rorís, Víctor Manuel; Santos Gago, Juan Manuel; Álvarez Sabucedo, Luis; Wanden-Berghe, Carmina; Sanz-Valero, Javier

2018-04-03

Any system applied to the control of parenteral nutrition (PN) ought to prove that the process meets the established requirements and include a repository of records to allow evaluation of the information about PN processes at any time. The goal of the research was to evaluate the mobile health (mHealth) app and validate its effectiveness in monitoring the management of the PN process. We studied the evaluation and validation of the general process of PN using an mHealth app. The units of analysis were the PN bags prepared and administered at the Son Espases University Hospital, Palma, Spain, from June 1 to September 6, 2016. For the evaluation of the app, we used the Poststudy System Usability Questionnaire and subsequent analysis with the Cronbach alpha coefficient. Validation was performed by checking the compliance of control for all operations on each of the stages (validation and transcription of the prescription, preparation, conservation, and administration) and by monitoring the operative control points and critical control points. The results obtained from 387 bags were analyzed, with 30 interruptions of administration. The fulfillment of stages was 100%, including noncritical nonconformities in the storage control. The average deviation in the weight of the bags was less than 5%, and the infusion time did not present deviations greater than 1 hour. The developed app successfully passed the evaluation and validation tests and was implemented to perform the monitoring procedures for the overall PN process. A new mobile solution to manage the quality and traceability of sensitive medicines such as blood-derivative drugs and hazardous drugs derived from this project is currently being deployed. ©Mercedes Cervera Peris, Víctor Manuel Alonso Rorís, Juan Manuel Santos Gago, Luis Álvarez Sabucedo, Carmina Wanden-Berghe, Javier Sanz-Valero. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 03.04.2018.

The Influence of Polyethylene Glycol Solution on the Dissolution Rate of Sustained Release Morphine.

Science.gov (United States)

Hodgman, Michael; Holland, Michael G; Englich, Ulrich; Wojcik, Susan M; Grant, William D; Leitner, Erich

2016-12-01

Whole bowel irrigation (WBI) is a management option for overdose of medications poorly adsorbed to activated charcoal, with modified release properties, or for body packers. Polyethylene glycol (PEG) is a mixture of ethylene oxide polymers of varying molecular weight. PEG with an average molecular weight of 3350 g/mol is used for WBI. PEG electrolyte lavage solution has been shown in vitro to hasten the dissolution of acetaminophen. The impact of PEG on the pharmacokinetics of extended release pharmaceuticals is unknown. Lower average molecular weight PEG mixtures are used as solvents and excipients. We sought to investigate the impact of PEG on the release of morphine from several extended release morphine formulations. An in vitro gastric model was developed. To test the validity of our model, we first investigated the previously described interaction of ethanol and Avinza®. Once demonstrated, we then investigated the effect of PEG with several extended release morphine formulations. In the validation portion of our study, we confirmed an ethanol Avinza® interaction. Subsequently, we did not observe accelerated release of morphine from Avinza® or generic extended release morphine in the presence of PEG. The use of PEG for gastric decontamination following ingestion of these extended release morphine formulations is unlikely to accelerate morphine release and aggravate intoxication.

Sludge thermal oxidation processes: mineral recycling, energy impact, and greenhouse effect gases release

Energy Technology Data Exchange (ETDEWEB)

Guibelin, Eric

2003-07-01

Different treatment routes have been studied for a mixed sludge: the conventional agricultural use is compared with the thermal oxidation processes, including incineration (in gaseous phase) and wet air oxidation (in liquid phase). The interest of a sludge digestion prior to the final treatment has been also considered according to the two major criteria, which are the fossil energy utilisation and the greenhouse effect gases (CO{sub 2}, CH{sub 4}, N{sub 2}O) release. Thermal energy has to be recovered on thermal processes to make these processes environmentally friendly, otherwise their main interest is to extract or destroy micropollutants and pathogens from the carbon cycle. In case of continuous energy recovery, incineration can produce more energy than it consumes. Digestion is especially interesting for agriculture: according to these two schemes, the energy final balance can also be in excess. As to wet air oxidation, it is probably one of the best way to minimize greenhouse effect gases emission. (author)

Release Notes for Whisper-1.1

Energy Technology Data Exchange (ETDEWEB)

Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-04-27

Whisper is a statistical analysis package developed in 2014 to support nuclear criticality safety (NCS) validation [1-3]. It uses the sensitivity profile data for an application as computed by MCNP6 [4-6] along with covariance files [7,8] for the nuclear data to determine a baseline upper-subcritical-limit (USL) for the application. Whisper version 1.0 was first developed and used at LANL in 2014 [3]. During 2015-2016, Whisper was updated to version 1.1 [9] and is to be included with the upcoming release of MCNP6.2. This document describes the Whisper-1.1 package that will be included with the MCNP6.2 release during 2017. Specific details are provided on the computer systems supported, the software quality assurance (SQA) procedures, installation, and testing. This document does not address other important topics, such as the importance of sensitivity-uncertainty (SU) methods to NCS validation, the theory underlying SU methodology, tutorials on the usage of MCNP-Whisper, practical approaches to using SU methodology to support and extend traditional validation, etc. There are over 50 documents included with Whisper-1.1 and available in the MCNP Reference Collection on the MCNP website (mcnp.lanl.gov) that address all of those topics and more. In this document, however, a complete bibliography of relevant MCNP-Whisper references is provided.

A mathematical model for hydrogen evolution in an electrochemical cell and experimental validation

International Nuclear Information System (INIS)

Mahmut D Mat; Yuksel Kaplan; Beycan Ibrahimoglu; Nejat Veziroglu; Rafig Alibeyli; Sadiq Kuliyev

2006-01-01

Electrochemical reaction is largely employed in various industrial areas such as hydrogen production, chlorate process, electroplating, metal purification etc. Most of these processes often take place with gas evaluation on the electrodes. Presence of gas phase in the liquid phase makes the problem two-phase flow which is much knowledge available from heat transfer and fluid mechanics studies. The motivation of this study is to investigate hydrogen release in an electrolysis processes from two-phase flow point of view and investigate effect of gas release on the electrolysis process. Hydrogen evolution, flow field and current density distribution in an electrochemical cell are investigated with a two-phase flow model. The mathematical model involves solutions of transport equations for the variables of each phase with allowance for inter phase transfer of mass and momentum. An experimental set-up is established to collect data to validate and improve the mathematical model. Void fraction is determined from measurement of resistivity changes in the system due to the presence of bubbles. A good agreement is obtained between numerical results and experimental data. (authors)

Respiratory symptoms and ex vivo cytokine release are associated in workers processing herring

DEFF Research Database (Denmark)

Bønløkke, Jakob Hjort; Thomassen, Mads; Viskum, Sven

2004-01-01

in the plasma by chemiluminescence ELISA. RESULTS: Among smoking fish-factory workers the forced vital capacity (FVC) was higher (per cent predicted 92.0 vs 85.0; P=0.028) than among municipal workers. Fish rinsing water induced WBA IL-8 release to higher levels than LPS and glucan. Among non-smokers...... the induced IL-1beta release for rinsing water ( P=0.007) and the IL-8 release for skin ( P=0.001) and meat ( P=0.003) were higher in fish-factory workers than in municipal workers. The IL-1beta release for rinsing water ( P=0.028) and skin ( P=0.041) was higher among non-smokers than among smokers, and so...... was the IL-8 release for rinsing water ( P=0.008). CONCLUSIONS: Assessing the cytokine release by use of the WBA we identified substances in the occupational environment with a pro-inflammatory potential comparable to that of LPS. The cytokine release for fish constituents was highest among non-smoking fish...

Preparation and Optimization of Immediate Release/Sustained Release Bilayered Tablets of Loxoprofen Using Box-Behnken Design.

Science.gov (United States)

Tak, Jin Wook; Gupta, Biki; Thapa, Raj Kumar; Woo, Kyu Bong; Kim, Sung Yub; Go, Toe Gyeong; Choi, Yongjoo; Choi, Ju Yeon; Jeong, Jee-Heon; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

2017-05-01

The aim of our current study was to characterize and optimize loxoprofen immediate release (IR)/sustained release (SR) tablet utilizing a three-factor, three-level Box-Behnken design (BBD) combined with a desirability function. The independent factors included ratio of drug in the IR layer to total drug (X 1 ), ratio of HPMC to drug in the SR layer (X 2 ), and ratio of Eudragit RL PO to drug in the SR layer (X 3 ). The dependent variables assessed were % drug released in distilled water at 30 min (Y 1 ), % drug released in pH 1.2 at 2 h (Y 2 ), and % drug released in pH 6.8 at 12 h (Y 3 ). The responses were fitted to suitable models and statistical validation was performed using analysis of variance. In addition, response surface graphs and contour plots were constructed to determine the effects of different factor level combinations on the responses. The optimized loxoprofen IR/SR tablets were successfully prepared with the determined amounts of ingredients that showed close agreement in the predicted and experimental values of tablet characterization and drug dissolution profile. Therefore, BBD can be utilized for successful optimization of loxoprofen IR/SR tablet, which can be regarded as a suitable substitute for the current marketed formulations.

PWR-GALE, Radioactive Gaseous Release and Liquid Release from PWR

International Nuclear Information System (INIS)

Chandrasekaran, T.; Lee, J.Y.; Willis, C.A.

1988-01-01

1 - Description of program or function: The PWR-GALE (Boiling Water Reactor Gaseous and Liquid Effluents) Code is a computerized mathematical model for calculating the release of radioactive material in gaseous and liquid effluents from pressurized water reactors (PWRs). The calculations are based on data generated from operating reactors, field tests, laboratory tests, and plant-specific design considerations incorporated to reduce the quantity of radioactive materials that may be released to the environment. 2 - Method of solution: GALE calculates expected releases based on 1) standardized coolant activities derived from ANS Standards 18.1 Working Group recommendations, 2) release and transport mechanisms that result in the appearance of radioactive material in liquid and gaseous waste streams, 3) plant-specific design features used to reduce the quantities of radioactive materials ultimately released to the environs, and 4) information received on the operation of nuclear power plants. 3 - Restrictions on the complexity of the problem: The liquid release portion of GALE uses subroutines taken from the ORIGEN (CCC-217) to calculate radionuclide buildup and decay during collection, processing, and storage of liquid radwaste. Memory requirements for this part of the program are determined by the large nuclear data base accessed by these subroutines

Overview of the independent ASTEC V2.0 validation by SARNET partners

International Nuclear Information System (INIS)

Chatelard, Patrick; Arndt, Siegfried; Atanasova, Boryana; Bandini, Giacomino; Bleyer, Alexandre; Brähler, Thimo; Buck, Michael; Kljenak, Ivo; Kujal, Bohumir

2014-01-01

Significant efforts are put into the assessment of the severe accident integral code ASTEC, jointly developed since several years by IRSN and GRS, either through comparison with results of the most important international experiments or through benchmarks with other severe accident simulation codes on plant applications. These efforts are done in first priority by the code developers’ organisations, IRSN and GRS, and also by numerous partners, in particular in the frame of the SARNET European network. The first version of the new series ASTEC V2 had been released in July 2009 to SARNET partners. Two subsequent V2.0 code revisions, including several modelling improvements, have been then released to the same partners, respectively in 2010 and 2011. This paper summarises first the approach of ASTEC validation vs. experiments, along with a description of the validation matrix, and presents then a few examples of applications of the ASTEC V2.0-rev1 version carried out in 2011 by the SARNET users. These calculation examples are selected in a way to cover diverse aspects of severe accident phenomenology, i.e. to cover both in-vessel and ex-vessel processes, in order to provide a good picture of the current ASTEC V2 capabilities. Finally, the main lessons drawn from this joint validation task are summarised, along with an evaluation of the current physical modelling relevance and thus an identification of the ASTEC V2.0 validity domain

Development of safety analysis codes and experimental validation for a very high temperature gas-cooled reactor Final report

Energy Technology Data Exchange (ETDEWEB)

Chang Oh

2006-03-01

The very high-temperature gas-cooled reactor (VHTR) is envisioned as a single- or dual-purpose reactor for electricity and hydrogen generation. The concept has average coolant temperatures above 9000C and operational fuel temperatures above 12500C. The concept provides the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperature to support process heat applications, such as coal gasification, desalination or cogenerative processes, the VHTR’s higher temperatures allow broader applications, including thermochemical hydrogen production. However, the very high temperatures of this reactor concept can be detrimental to safety if a loss-of-coolant accident (LOCA) occurs. Following the loss of coolant through the break and coolant depressurization, air will enter the core through the break by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heatup of the reactor core and the release of toxic gasses (CO and CO2) and fission products. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. Prior to the start of this Korean/United States collaboration, no computer codes were available that had been sufficiently developed and validated to reliably simulate a LOCA in the VHTR. Therefore, we have worked for the past three years on developing and validating advanced computational methods for simulating LOCAs in a VHTR. Research Objectives As described above, a pipe break may lead to significant fuel damage and fission product release in the VHTR. The objectives of this Korean/United States collaboration were to develop and validate advanced computational methods for VHTR safety analysis. The methods that have been developed are now

Development of safety analysis codes and experimental validation for a very high temperature gas-cooled reactor Final report

International Nuclear Information System (INIS)

Chang Oh

2006-01-01

The very high-temperature gas-cooled reactor (VHTR) is envisioned as a single- or dual-purpose reactor for electricity and hydrogen generation. The concept has average coolant temperatures above 900 C and operational fuel temperatures above 1250 C. The concept provides the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperature to support process heat applications, such as coal gasification, desalination or cogenerative processes, the VHTR's higher temperatures allow broader applications, including thermochemical hydrogen production. However, the very high temperatures of this reactor concept can be detrimental to safety if a loss-of-coolant accident (LOCA) occurs. Following the loss of coolant through the break and coolant depressurization, air will enter the core through the break by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heatup of the reactor core and the release of toxic gases (CO and CO2) and fission products. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. Prior to the start of this Korean/United States collaboration, no computer codes were available that had been sufficiently developed and validated to reliably simulate a LOCA in the VHTR. Therefore, we have worked for the past three years on developing and validating advanced computational methods for simulating LOCAs in a VHTR. Research Objectives As described above, a pipe break may lead to significant fuel damage and fission product release in the VHTR. The objectives of this Korean/United States collaboration were to develop and validate advanced computational methods for VHTR safety analysis. The methods that have been developed are now

Validation of the TTM processes of change measure for physical activity in an adult French sample.

Science.gov (United States)

Bernard, Paquito; Romain, Ahmed-Jérôme; Trouillet, Raphael; Gernigon, Christophe; Nigg, Claudio; Ninot, Gregory

2014-04-01

Processes of change (POC) are constructs from the transtheoretical model that propose to examine how people engage in a behavior. However, there is no consensus about a leading model explaining POC and there is no validated French POC scale in physical activity This study aimed to compare the different existing models to validate a French POC scale. Three studies, with 748 subjects included, were carried out to translate the items and evaluate their clarity (study 1, n = 77), to assess the factorial validity (n = 200) and invariance/equivalence (study 2, n = 471), and to analyze the concurrent validity by stage × process analyses (study 3, n = 671). Two models displayed adequate fit to the data; however, based on the Akaike information criterion, the fully correlated five-factor model appeared as the most appropriate to measure POC in physical activity. The invariance/equivalence was also confirmed across genders and student status. Four of the five existing factors discriminated pre-action and post-action stages. These data support the validation of the POC questionnaire in physical activity among a French sample. More research is needed to explore the longitudinal properties of this scale.

Examining the Validity of Self-Reports on Scales Measuring Students' Strategic Processing

Science.gov (United States)

Samuelstuen, Marit S.; Braten, Ivar

2007-01-01

Background: Self-report inventories trying to measure strategic processing at a global level have been much used in both basic and applied research. However, the validity of global strategy scores is open to question because such inventories assess strategy perceptions outside the context of specific task performance. Aims: The primary aim was to…

Analysis of in-pile tritium release experiments

International Nuclear Information System (INIS)

Kopasz, J.P.; Tam, S.W.; Johnson, C.E.

1992-01-01

The objective of this work is to characterize tritium release behavior from lithium ceramics and develop insight into the underlying tritium release mechanisms. Analysis of tritium release data from recent laboratory experiments with lithium aluminate has identified physical processes which were previously unaccounted for in tritium release models. A new model that incorporates the recent data and provides for release from multiple sites rather than only one site was developed. Calculations of tritium release using this model are in excellent agreement with the tritium release behavior reported for the MOZART experiment

Verification and Validation of the Tritium Transport Code TMAP7

International Nuclear Information System (INIS)

Longhurst, Glen R.; Ambrosek, James

2005-01-01

The TMAP code has been upgraded to version 7, which includes radioactive decay along with many features implemented in prior versions. Pursuant to acceptance and release for distribution, the code was exercised in a variety of problem types to demonstrate that it provides results in agreement with theoretical results for cases where those are available. It has also been used to model certain experimental results. In this paper, the capabilities of the TMAP7 code are demonstrated by presenting some of the results from the verification and validation process

Validation of the manufacturing process used to produce long-acting recombinant factor IX Fc fusion protein.

Science.gov (United States)

McCue, J; Osborne, D; Dumont, J; Peters, R; Mei, B; Pierce, G F; Kobayashi, K; Euwart, D

2014-07-01

Recombinant factor IX Fc (rFIXFc) fusion protein is the first of a new class of bioengineered long-acting factors approved for the treatment and prevention of bleeding episodes in haemophilia B. The aim of this work was to describe the manufacturing process for rFIXFc, to assess product quality and to evaluate the capacity of the process to remove impurities and viruses. This manufacturing process utilized a transferable and scalable platform approach established for therapeutic antibody manufacturing and adapted for production of the rFIXFc molecule. rFIXFc was produced using a process free of human- and animal-derived raw materials and a host cell line derived from human embryonic kidney (HEK) 293H cells. The process employed multi-step purification and viral clearance processing, including use of a protein A affinity capture chromatography step, which binds to the Fc portion of the rFIXFc molecule with high affinity and specificity, and a 15 nm pore size virus removal nanofilter. Process validation studies were performed to evaluate identity, purity, activity and safety. The manufacturing process produced rFIXFc with consistent product quality and high purity. Impurity clearance validation studies demonstrated robust and reproducible removal of process-related impurities and adventitious viruses. The rFIXFc manufacturing process produces a highly pure product, free of non-human glycan structures. Validation studies demonstrate that this product is produced with consistent quality and purity. In addition, the scalability and transferability of this process are key attributes to ensure consistent and continuous supply of rFIXFc. © 2014 The Authors. Haemophilia Published by John Wiley & Sons Ltd.

Real-time process signal validation based on neuro-fuzzy and possibilistic approach

International Nuclear Information System (INIS)

Figedy, S.; Fantoni, P.F.; Hoffmann, M.

2001-01-01

Real-time process signal validation is an application field where the use of fuzzy logic and Artificial Neural Networks can improve the diagnostics of faulty sensors and the identification of outliers in a robust and reliable way. This study implements a fuzzy and possibilistic clustering algorithm to classify the operating region where the validation process is to be performed. The possibilistic approach allows a fast detection of unforeseen plant conditions. Specialized Artificial Neural Networks are used, one for each fuzzy cluster. This offers two main advantages: the accuracy and generalization capability is increased compared to the case of a single network working in the entire operating region, and the ability to identify abnormal conditions, where the system is not capable to operate with a satisfactory accuracy, is improved. This system analyzes the signals, which are e.g. the readings of process monitoring sensors, computes their expected values and alerts if real values are deviated from the expected ones more than limits allow. The reliability level of the current analysis is also produced. This model has been tested on a simulated data from the PWR type of a nuclear power plant, to monitor safety-related reactor variables over the entire power-flow operating map and were installed in real conditions of BWR nuclear reactor. (Authors)

Investigating the in vitro drug release kinetics from controlled release diclofenac potassium-ethocel matrix tablets and the influence of co-excipients on drug release patterns.

Science.gov (United States)

Shah, Shefaat Ullah; Shah, Kifayat Ullah; Rehman, Asimur; Khan, Gul Majid

2011-04-01

The objective of the study was to formulate and evaluate controlled release polymeric tablets of Diclofenac Potassium for the release rate, release patterns and the mechanism involved in the release process of the drug. Formulations with different types and grades of Ethyl Cellulose Ether derivatives in several drug-to-polymer ratios (D:P) were compressed into tablets using the direct compression method. In vitro drug release studies were performed in phosphate buffer (pH 7.4) as dissolution medium by using USP Method-1 (Rotating Basket Method). Similarity factor f2 and dissimilarity factor f1 were applied for checking the similarities and dissimilarities of the release profiles of different formulations. For the determination of the release mechanism and drug release kinetics various mathematical/kinetic models were employed. It was found that all of the Ethocel polymers could significantly slow down the drug release rate with Ethocel FP polymers being the most efficient, especially at D:P ratios of 10:03 which lead towards the achievement of zero or near zero order release kinetics.

Validation of EAF-2005 data

International Nuclear Information System (INIS)

Kopecky, J.

2005-01-01

Full text: Validation procedures applied on EAF-2003 starter file, which lead to the production of EAF-2005 library, are described. The results in terms of reactions with assigned quality scores in EAF-20005 are given. Further the extensive validation against the recent integral data is discussed together with the status of the final report 'Validation of EASY-2005 using integral measurements'. Finally, the novel 'cross section trend analysis' is presented with some examples of its use. This action will lead to the release of improved library EAF-2005.1 at the end of 2005, which shall be used as the starter file for EAF-2007. (author)

Validation of a functional model for integration of safety into process system design

DEFF Research Database (Denmark)

Wu, J.; Lind, M.; Zhang, X.

2015-01-01

with the process system functionalities as required for the intended safety applications. To provide the scientific rigor and facilitate the acceptance of qualitative modelling, this contribution focuses on developing a scientifically based validation method for functional models. The Multilevel Flow Modeling (MFM...

Pharmaceutical Product Lead Optimization for Better In vivo Bioequivalence Performance: A case study of Diclofenac Sodium Extended Release Matrix Tablets.

Science.gov (United States)

Shahiwala, Aliasgar; Zarar, Aisha

2018-01-01

In order to prove the validity of a new formulation, a considerable amount of effort is required to study bioequivalence, which not only increases the burden of carrying out a number of bioequivalence studies but also eventually increases the cost of the optimization process. The aim of the present study was to develop sustained release matrix tablets containing diclofenac sodium using natural polymers and to demonstrate step by step process of product development till the prediction of in vivo marketed product equivalence of the developed product. Different batches of tablets were prepared by direct compression. In vitro drug release studies were performed as per USP. The drug release data were assessed using model-dependent, modelindependent and convolution approaches. Drug release profiles showed that extended release action were in the following order: Gum Tragacanth > Sodium Alginate > Gum Acacia. Amongst the different batches prepared, only F1 and F8 passed the USP criteria of drug release. Developed formulas were found to fit Higuchi kinetics model with Fickian (case I) diffusion-mediated release mechanism. Model- independent kinetics confirmed that total of four batches were passed depending on the similarity factors based on the comparison with the marketed Diclofenac. The results of in vivo predictive convolution model indicated that predicted AUC, Cmax and Tmax values for batch F8 were similar to that of marketed product. This study provides simple yet effective outline of pharmaceutical product development process that will minimize the formulation development trials and maximize the product success in bioequivalence studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1

International Nuclear Information System (INIS)

Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

2015-01-01

In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by 137 Cesium ( 137 Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as 132 Te- 132 I, 131 I, 134 Cs and 137 Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h −1 per initial 137 Cs deposition of 1000 kBq m −2 , whereas it was 100 μGy h −1 around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m −2 for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums ( 134 Cs + 137 Cs) around Chernobyl and Fukushima-1, respectively

Review of processes for the release of DOE real and non-real property for reuse and recycle

International Nuclear Information System (INIS)

Ranek, N.L.; Kamboj, S.; Hensley, J.; Chen, S.Y.; Blunt, D.

1997-11-01

This report summarizes the underlying historical and regulatory framework supporting the concept of authorizing release for restricted or unrestricted reuse or recycle of real and non-real U.S. Department of Energy (DOE) properties containing residual radioactive material. Basic radiation protection principles as recommended by the International Commission on Radiological Protection are reviewed, and international initiatives to investigate radiological clearance criteria are reported. Applicable requirements of the U.S. Nuclear Regulatory Commission, the Environmental Protection Agency, DOE, and the State of Washington are discussed. Several processes that have been developed for establishing cleanup and release criteria for real and non-real DOE property containing residual radioactive material are presented. Examples of DOE real property for which radiological cleanup criteria were established to support unrestricted release are provided. Properties discussed include Formerly Utilized Sites Remedial Action Project sites, Uranium Mill Tailings Remedial Action Project sites, the Shippingport decommissioning project, the south-middle and south-east vaults in the 317 area at Argonne National Laboratory, the Heavy Water Components Test Reactor at DOE's Savannah River Site, the Experimental Boiling Water Reactor at Argonne National Laboratory, and the Weldon Spring site. Some examples of non-real property for which DOE sites have established criteria to support unrestricted release are also furnished. 10 figs., 4 tabs

Validation of King's transaction process for healthcare provider-patient communication in pharmaceutical context: One cross-sectional study.

Science.gov (United States)

Wang, Dan; Liu, Chenxi; Zhang, Zinan; Ye, Liping; Zhang, Xinping

2018-03-27

With the impressive advantages of patient-pharmacist communication being advocated and poor pharmacist-patient communication in different settings, it is of great significance and urgency to explore the mechanism of the pharmacist-patient communicative relationship. The King's theory of goal attainment is proposed as one of the most promising models to be applied, because it takes into consideration both improving the patient-pharmacist relationship and attaining patients' health outcomes. This study aimed to validate the King's transaction process and build the linkage between the transaction process and patient satisfaction in a pharmaceutical context. A cross-sectional study was conducted in four tertiary hospitals in two provincial cities (Wuhan and Shanghai) in central and east China in July 2017. Patients over 18 were investigated in the pharmacies of the hospitals. The instrument for the transaction process was revised and tested. Path analysis was conducted for the King's transaction process and its relationship with patient satisfaction. Five hundred eighty-nine participants were investigated for main study. Prior to the addition of covariates, the hypothesised model of the King's transaction process was validated, in which all paths of the transaction process were statistically significant (p process had direct effects on patient satisfaction (p process was established as one valid theoretical framework of healthcare provider-patient communication in a pharmaceutical context. Copyright © 2018 Elsevier Inc. All rights reserved.

Validating the extract, transform, load process used to populate a large clinical research database.

Science.gov (United States)

Denney, Michael J; Long, Dustin M; Armistead, Matthew G; Anderson, Jamie L; Conway, Baqiyyah N

2016-10-01

Informaticians at any institution that are developing clinical research support infrastructure are tasked with populating research databases with data extracted and transformed from their institution's operational databases, such as electronic health records (EHRs). These data must be properly extracted from these source systems, transformed into a standard data structure, and then loaded into the data warehouse while maintaining the integrity of these data. We validated the correctness of the extract, load, and transform (ETL) process of the extracted data of West Virginia Clinical and Translational Science Institute's Integrated Data Repository, a clinical data warehouse that includes data extracted from two EHR systems. Four hundred ninety-eight observations were randomly selected from the integrated data repository and compared with the two source EHR systems. Of the 498 observations, there were 479 concordant and 19 discordant observations. The discordant observations fell into three general categories: a) design decision differences between the IDR and source EHRs, b) timing differences, and c) user interface settings. After resolving apparent discordances, our integrated data repository was found to be 100% accurate relative to its source EHR systems. Any institution that uses a clinical data warehouse that is developed based on extraction processes from operational databases, such as EHRs, employs some form of an ETL process. As secondary use of EHR data begins to transform the research landscape, the importance of the basic validation of the extracted EHR data cannot be underestimated and should start with the validation of the extraction process itself. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Can gamma irradiation during radiotherapy influence the metal release process for biomedical CoCrMo and 316L alloys?

Science.gov (United States)

Wei, Zheng; Edin, Jonathan; Karlsson, Anna Emelie; Petrovic, Katarina; Soroka, Inna L; Odnevall Wallinder, Inger; Hedberg, Yolanda

2018-02-09

The extent of metal release from implant materials that are irradiated during radiotherapy may be influenced by irradiation-formed radicals. The influence of gamma irradiation, with a total dose of relevance for radiotherapy (e.g., for cancer treatments) on the extent of metal release from biomedical stainless steel AISI 316L and a cobalt-chromium alloy (CoCrMo) was investigated in physiological relevant solutions (phosphate buffered saline with and without 10 g/L bovine serum albumin) at pH 7.3. Directly after irradiation, the released amounts of metals were significantly higher for irradiated CoCrMo as compared to nonirradiated CoCrMo, resulting in an increased surface passivation (enhanced passive conditions) that hindered further release. A similar effect was observed for 316L showing lower nickel release after 1 h of initially irradiated samples as compared to nonirradiated samples. However, the effect of irradiation (total dose of 16.5 Gy) on metal release and surface oxide composition and thickness was generally small. Most metals were released initially (within seconds) upon immersion from CoCrMo but not from 316L. Albumin induced an increased amount of released metals from AISI 316L but not from CoCrMo. Albumin was not found to aggregate to any greater extent either upon gamma irradiation or in the presence of trace metal ions, as determined using different light scattering techniques. Further studies should elucidate the effect of repeated friction and fractionated low irradiation doses on the short- and long term metal release process of biomedical materials. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

Testing the behaviour of different kinetic models for uptake/release of radionuclides between water and sediments when implemented in a marine dispersion model

International Nuclear Information System (INIS)

Perianez, R.

2004-01-01

Three kinetic models for adsorption/release of 137 Cs between water and sediments have been tested when they are included in a previously validated dispersion model of the English Channel. Radionuclides are released to the Channel from La Hague nuclear fuel reprocessing plant (France). The kinetic models are a 1-step model consisting of a single reversible reaction, a 2-step model consisting of two consecutive reversible reactions and an irreversible model consisting of three parallel reactions: two reversible and one irreversible. The models have been tested under three typical situations that correspond to the source terms that can generally be found: instantaneous release, continuous release and redissolution of radionuclides from contaminated sediments. Differences between the models become more evident when contact times between water and sediments are larger (continuous release) and in the case of redissolution from sediments. Time scales for the redissolution process are rather different between the three models. The 1-step model produces a redissolution that is too fast when compared with experimental evidence. The irreversible model requires that saturation effects of the irreversible phase are included. Probably, the 2-step model represents the best compromise between ease and level of detail of the description of sorption/release processes

RAVEN Beta Release

International Nuclear Information System (INIS)

Rabiti, Cristian; Alfonsi, Andrea; Cogliati, Joshua Joseph; Mandelli, Diego; Kinoshita, Robert Arthur; Wang, Congjian; Maljovec, Daniel Patrick; Talbot, Paul William

2016-01-01

This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

RAVEN Beta Release

Energy Technology Data Exchange (ETDEWEB)

Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-02-01

This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

Process validation for the manufacturing of Tc-99m generator at Nuclear Malaysia

International Nuclear Information System (INIS)

Noriah Jamal; Rehir Dahlan; Wan Anuar Wan Awang; Zakaria Ibrahim; Shaaban Kassim; Wan Firdaus Wan Ishak; Nelly Bo Nai Lee; Noraisyah Yusof; Siti Selina Abdul Hamid; Ng Yen; Rahimah Abdul Rahim; Muhammad Hanafi Mohamad Mokhtar; Azahari Kasbollah; Abd Jalil Abd Hamid; Yahya Talib; Shafii Khamis; Zulkifli Mohamed Hashim

2007-01-01

Process validation provides the best platform in identifying potential problems in the actual radiopharmaceuticals manufacturing work. The purpose of this paper is to present experience in performing process validation for the manufacturing of Tc-99m generator at Nuclear Malaysia. Process validation for the manufacturing of Tc-99m generator was done by performing four try runs, between October 2006 to April 2007. It was done using saline instead of the actual product. Each try run took four days to complete. On day 1, clean room was cleaned and disinfected. On day 2, activity of washing and sterilization of utensils, columns, rubber stoppers and aluminium caps was carried out. On day 3, preparation of white top, alumina packed column and mixing solutions was performed. Apparatus was also sent for sterilizing test. On day 4, the actual production day of the try run by impregnating column with sterile saline was performed. Prior to the manufacturing activities, particle counts measurement and area clearance were performed to ensure that the temperature and humidity of the clean room are suitable for the production work. Settle plates were placed at the identified positions including in the Hot Cell. Personnel's finger print was performed before and after production work by using touch plates. After completion of try run, elution from the generators that been manufactured, settle and touch plates were sent to quality control unit for the microbiological test. It took fourteen days to get the test results. The first try run was failed, which may be due to insufficient of proper arrangement/preparation of work. It may also due to problem of cleaning/disinfection of clean room, which may not be done properly. The further three consecutive try runs meet all the specifications including the sterility test, endotoxin test and finger prints. It shows that the manufacturing of Tc-99m generator at Nuclear Malaysia is validated and ready for the active run. (Author)

Food and Drug Administration process validation activities to support 99Mo production at Sandia National Laboratories

International Nuclear Information System (INIS)

McDonald, M.J.; Bourcier, S.C.; Talley, D.G.

1997-01-01

Prior to 1989 99 Mo was produced in the US by a single supplier, Cintichem Inc., Tuxedo, NY. Because of problems associated with operating its facility, in 1989 Cintichem elected to decommission the facility rather than incur the costs for repair. The demise of the 99 Mo capability at Cintichem left the US totally reliant upon a single foreign source, Nordion International, located in Ottawa Canada. In 1992 the DOE purchased the Cintichem 99 Mo Production Process and Drug Master File (DMF). In 1994 the DOE funded Sandia National Laboratories (SNL) to produce 99 Mo. Although Cintichem produced 99 Mo and 99m Tc generators for many years, there was no requirement for process validation which is now required by the Food and Drug Administration (FDA). In addition to the validation requirement, the requirements for current Good manufacturing Practices were codified into law. The purpose of this paper is to describe the process validation being conducted at SNL for the qualification of SNL as a supplier of 99 Mo to US pharmaceutical companies

Validation of a DNA IQ-based extraction method for TECAN robotic liquid handling workstations for processing casework.

Science.gov (United States)

Frégeau, Chantal J; Lett, C Marc; Fourney, Ron M

2010-10-01

A semi-automated DNA extraction process for casework samples based on the Promega DNA IQ™ system was optimized and validated on TECAN Genesis 150/8 and Freedom EVO robotic liquid handling stations configured with fixed tips and a TECAN TE-Shake™ unit. The use of an orbital shaker during the extraction process promoted efficiency with respect to DNA capture, magnetic bead/DNA complex washes and DNA elution. Validation studies determined the reliability and limitations of this shaker-based process. Reproducibility with regards to DNA yields for the tested robotic workstations proved to be excellent and not significantly different than that offered by the manual phenol/chloroform extraction. DNA extraction of animal:human blood mixtures contaminated with soil demonstrated that a human profile was detectable even in the presence of abundant animal blood. For exhibits containing small amounts of biological material, concordance studies confirmed that DNA yields for this shaker-based extraction process are equivalent or greater to those observed with phenol/chloroform extraction as well as our original validated automated magnetic bead percolation-based extraction process. Our data further supports the increasing use of robotics for the processing of casework samples. Crown Copyright © 2009. Published by Elsevier Ireland Ltd. All rights reserved.

A self-referential HOWTO on release engineering

Energy Technology Data Exchange (ETDEWEB)

Galassi, Mark C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-01-31

Release engineering is a fundamental part of the software development cycle: it is the point at which quality control is exercised and bug fixes are integrated. The way in which software is released also gives the end user her first experience of a software package, while in scientific computing release engineering can guarantee reproducibility. For these reasons and others, the release process is a good indicator of the maturity and organization of a development team. Software teams often do not put in place a release process at the beginning. This is unfortunate because the team does not have early and continuous execution of test suites, and it does not exercise the software in the same conditions as the end users. I describe an approach to release engineering based on the software tools developed and used by the GNU project, together with several specific proposals related to packaging and distribution. I do this in a step-by-step manner, demonstrating how this very paper is written and built using proper release engineering methods. Because many aspects of release engineering are not exercised in the building of the paper, the accompanying software repository also contains examples of software libraries.

Quality-by-design III: application of near-infrared spectroscopy to monitor roller compaction in-process and product quality attributes of immediate release tablets.

Science.gov (United States)

Kona, Ravikanth; Fahmy, Raafat M; Claycamp, Gregg; Polli, James E; Martinez, Marilyn; Hoag, Stephen W

2015-02-01

The objective of this study is to use near-infrared spectroscopy (NIRS) coupled with multivariate chemometric models to monitor granule and tablet quality attributes in the formulation development and manufacturing of ciprofloxacin hydrochloride (CIP) immediate release tablets. Critical roller compaction process parameters, compression force (CFt), and formulation variables identified from our earlier studies were evaluated in more detail. Multivariate principal component analysis (PCA) and partial least square (PLS) models were developed during the development stage and used as a control tool to predict the quality of granules and tablets. Validated models were used to monitor and control batches manufactured at different sites to assess their robustness to change. The results showed that roll pressure (RP) and CFt played a critical role in the quality of the granules and the finished product within the range tested. Replacing binder source did not statistically influence the quality attributes of the granules and tablets. However, lubricant type has significantly impacted the granule size. Blend uniformity, crushing force, disintegration time during the manufacturing was predicted using validated PLS regression models with acceptable standard error of prediction (SEP) values, whereas the models resulted in higher SEP for batches obtained from different manufacturing site. From this study, we were able to identify critical factors which could impact the quality attributes of the CIP IR tablets. In summary, we demonstrated the ability of near-infrared spectroscopy coupled with chemometrics as a powerful tool to monitor critical quality attributes (CQA) identified during formulation development.

Mitigation of release of volatile iodine species during severe reactor accidents - a novel reliable process of safety technology

International Nuclear Information System (INIS)

Guentay, S.; Bruchertseifer, H.

2010-01-01

In severe accidents, a significant risk for public health may be generated as a result of release of the gaseous iodine species into the environment through the containment leaks or containment venting filter systems with low retention efficiency. The elemental iodine and volatile organic iodides are the main gaseous iodine species in the containment. Potential release of large quantities of gaseous elemental iodine from the reactor coolant system or its radiolytic generation in the containment sump constitute the key source of gaseous elemental iodine in containment atmosphere. Iodine paint reactions as well as the reaction of iodine with organic residuals in sump water are the main mechanisms for the generation of high volatile organic iodides in the containment. Although very much desired, significant research activities conducted in 70's unfortunately did not create any technically feasible solution to mitigate iodine release into the environment under prevailing conditions. Development of a process leading to a fast, comprehensive and reliable retention of volatile iodine species in aqueous solution with an aim to implement for the severe accident management applications has been subject of a research project in the recent years at Paul Scherrer Institut. The process developed utilizes simultaneous use of two customary technical chemical additives in an aqueous solution. The results of the experimental program have demonstrated a fast and reliable destruction of high volatile organic iodine species and fast reduction of elemental iodine into iodide ions in aqueous solutions and an efficient mitigation of the re-formation of gaseous iodine from iodide ions. Investigations covered a broad range of anticipated severe accident conditions in the containment. The project additionally focused on possible application of the process to existing containment venting filter systems, specifically as a passive add-on for back-fitting. This paper describes the process

40 CFR 68.25 - Worst-case release scenario analysis.

Science.gov (United States)

2010-07-01

... PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Hazard Assessment § 68.25 Worst-case release... processes, one worst-case release scenario for each Program 1 process; (2) For Program 2 and 3 processes: (i... toxic substances from covered processes under worst-case conditions defined in § 68.22; (ii) One worst...

Gravitational vacuum and energy release in microworld

International Nuclear Information System (INIS)

Mel'nikov, V.N.; Nikolaev, Yu.M.; Stanyukovich, K.P.

1981-01-01

It is shown that gravitati.onal interaction can be connected with the processes of energy release in microworld. Suggested is a planckeon model within the frames of which gradual production of the observed substance of the Universe during the whole evolution is explained. Burst processes in nuclei of the Galaxy are explained. It is concluded that the theory of gravitational vacuum creates preconditions for developing the general theory of the field explaining the basic peculiarities of the micro- and macroworld, reveals significant applications in the physics of elementary particles and atomic nucleus. The process of 235 U fission is considered for testing the hypothesis that the coefficient of energy release depends on the nature of the reaction in different processes of energy release in the micro- and macroworld [ru

Validation of cleaning method for various parts fabricated at a Beryllium facility

Energy Technology Data Exchange (ETDEWEB)

Davis, Cynthia M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-12-15

This study evaluated and documented a cleaning process that is used to clean parts that are fabricated at a beryllium facility at Los Alamos National Laboratory. The purpose of evaluating this cleaning process was to validate and approve it for future use to assure beryllium surface levels are below the Department of Energy’s release limits without the need to sample all parts leaving the facility. Inhaling or coming in contact with beryllium can cause an immune response that can result in an individual becoming sensitized to beryllium, which can then lead to a disease of the lungs called chronic beryllium disease, and possibly lung cancer. Thirty aluminum and thirty stainless steel parts were fabricated on a lathe in the beryllium facility, as well as thirty-two beryllium parts, for the purpose of testing a parts cleaning method that involved the use of ultrasonic cleaners. A cleaning method was created, documented, validated, and approved, to reduce beryllium contamination.

Risk-Based Tailoring of the Verification, Validation, and Accreditation/Acceptance Processes (Adaptation fondee sur le risque, des processus de verification, de validation, et d’accreditation/d’acceptation)

Science.gov (United States)

2012-04-01

AGARD doivent comporter la dénomination « RTO » ou « AGARD » selon le cas, suivi du numéro de série. Des informations analogues, telles que le titre ...MSG-054 Risk-Based Tailoring of the Verification, Validation, and Accreditation/ Acceptance Processes (Adaptation fondée sur le risque, des...MSG-054 Risk-Based Tailoring of the Verification, Validation, and Accreditation/ Acceptance Processes (Adaptation fondée sur le risque, des

Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.

Science.gov (United States)

Zou, Jinte; Zhang, Lili; Wang, Lin; Li, Yongmei

2017-03-01

The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigation of delayed fission gas release

International Nuclear Information System (INIS)

Cayet, Nicolas

1996-05-01

The study of the fission gas release process in the high burnup rig IFA-562 has revealed a particular fuel behaviour: a delay in the fission gas release process. It appeared that an important release of gas was measured by the pressure transducers once the power had decreased, whereas, during steady-state operation, the pressure did not increase very much. After examinations, the gap size has been concluded to be the main parameter involving this delay. However the burnup could have been a potential factor, its role is mainly to close the gap by swelling. The observations of low burnup rods have shown the same delayed fission gas release, the gap being small by design and closed essentially by thermal expansion. The study of the kinetics has demonstrated the time-independency of the phenomenon. Thus the proposed mechanism driving this delayed fission gas release would involve three consecutives stages. During steady-state, the gas is released into the interlinkage network of grain boundary bubbles and cracks. Due to the closed gap, the gas is trapped in some void volumes, unable to escape the pellet. During power reduction, the gap and some old/new cracks open, immediately providing a path for the gas to the pressure transducers and explaining this delay in the fission gas release. (author)

Understanding Drug Release Data through Thermodynamic Analysis.

Science.gov (United States)

Freire, Marjorie Caroline Liberato Cavalcanti; Alexandrino, Francisco; Marcelino, Henrique Rodrigues; Picciani, Paulo Henrique de Souza; Silva, Kattya Gyselle de Holanda E; Genre, Julieta; Oliveira, Anselmo Gomes de; Egito, Eryvaldo Sócrates Tabosa do

2017-06-13

Understanding the factors that can modify the drug release profile of a drug from a Drug-Delivery-System (DDS) is a mandatory step to determine the effectiveness of new therapies. The aim of this study was to assess the Amphotericin-B (AmB) kinetic release profiles from polymeric systems with different compositions and geometries and to correlate these profiles with the thermodynamic parameters through mathematical modeling. Film casting and electrospinning techniques were used to compare behavior of films and fibers, respectively. Release profiles from the DDSs were performed, and the mathematical modeling of the data was carried out. Activation energy, enthalpy, entropy and Gibbs free energy of the drug release process were determined. AmB release profiles showed that the relationship to overcome the enthalpic barrier was PVA-fiber > PVA-film > PLA-fiber > PLA-film. Drug release kinetics from the fibers and the films were better fitted on the Peppas-Sahlin and Higuchi models, respectively. The thermodynamic parameters corroborate these findings, revealing that the AmB release from the evaluated systems was an endothermic and non-spontaneous process. Thermodynamic parameters can be used to explain the drug kinetic release profiles. Such an approach is of utmost importance for DDS containing insoluble compounds, such as AmB, which is associated with an erratic bioavailability.

Understanding Drug Release Data through Thermodynamic Analysis

Science.gov (United States)

Freire, Marjorie Caroline Liberato Cavalcanti; Alexandrino, Francisco; Marcelino, Henrique Rodrigues; Picciani, Paulo Henrique de Souza; Silva, Kattya Gyselle de Holanda e; Genre, Julieta; de Oliveira, Anselmo Gomes; do Egito, Eryvaldo Sócrates Tabosa

2017-01-01

Understanding the factors that can modify the drug release profile of a drug from a Drug-Delivery-System (DDS) is a mandatory step to determine the effectiveness of new therapies. The aim of this study was to assess the Amphotericin-B (AmB) kinetic release profiles from polymeric systems with different compositions and geometries and to correlate these profiles with the thermodynamic parameters through mathematical modeling. Film casting and electrospinning techniques were used to compare behavior of films and fibers, respectively. Release profiles from the DDSs were performed, and the mathematical modeling of the data was carried out. Activation energy, enthalpy, entropy and Gibbs free energy of the drug release process were determined. AmB release profiles showed that the relationship to overcome the enthalpic barrier was PVA-fiber > PVA-film > PLA-fiber > PLA-film. Drug release kinetics from the fibers and the films were better fitted on the Peppas–Sahlin and Higuchi models, respectively. The thermodynamic parameters corroborate these findings, revealing that the AmB release from the evaluated systems was an endothermic and non-spontaneous process. Thermodynamic parameters can be used to explain the drug kinetic release profiles. Such an approach is of utmost importance for DDS containing insoluble compounds, such as AmB, which is associated with an erratic bioavailability. PMID:28773009

[Support of the nursing process through electronic nursing documentation systems (UEPD) – Initial validation of an instrument].

Science.gov (United States)

Hediger, Hannele; Müller-Staub, Maria; Petry, Heidi

2016-01-01

Electronic nursing documentation systems, with standardized nursing terminology, are IT-based systems for recording the nursing processes. These systems have the potential to improve the documentation of the nursing process and to support nurses in care delivery. This article describes the development and initial validation of an instrument (known by its German acronym UEPD) to measure the subjectively-perceived benefits of an electronic nursing documentation system in care delivery. The validity of the UEPD was examined by means of an evaluation study carried out in an acute care hospital (n = 94 nurses) in German-speaking Switzerland. Construct validity was analyzed by principal components analysis. Initial references of validity of the UEPD could be verified. The analysis showed a stable four factor model (FS = 0.89) scoring in 25 items. All factors loaded ≥ 0.50 and the scales demonstrated high internal consistency (Cronbach's α = 0.73 – 0.90). Principal component analysis revealed four dimensions of support: establishing nursing diagnosis and goals; recording a case history/an assessment and documenting the nursing process; implementation and evaluation as well as information exchange. Further testing with larger control samples and with different electronic documentation systems are needed. Another potential direction would be to employ the UEPD in a comparison of various electronic documentation systems.

Screening tool for oropharyngeal dysphagia in stroke - Part I: evidence of validity based on the content and response processes.

Science.gov (United States)

Almeida, Tatiana Magalhães de; Cola, Paula Cristina; Pernambuco, Leandro de Araújo; Magalhães, Hipólito Virgílio; Magnoni, Carlos Daniel; Silva, Roberta Gonçalves da

2017-08-17

The aim of the present study was to identify the evidence of validity based on the content and response process of the Rastreamento de Disfagia Orofaríngea no Acidente Vascular Encefálico (RADAVE; "Screening Tool for Oropharyngeal Dysphagia in Stroke"). The criteria used to elaborate the questions were based on a literature review. A group of judges consisting of 19 different health professionals evaluated the relevance and representativeness of the questions, and the results were analyzed using the Content Validity Index. In order to evidence validity based on the response processes, 23 health professionals administered the screening tool and analyzed the questions using a structured scale and cognitive interview. The RADAVE structured to be applied in two stages. The first version consisted of 18 questions in stage I and 11 questions in stage II. Eight questions in stage I and four in stage II did not reach the minimum Content Validity Index, requiring reformulation by the authors. The cognitive interview demonstrated some misconceptions. New adjustments were made and the final version was produced with 12 questions in stage I and six questions in stage II. It was possible to develop a screening tool for dysphagia in stroke with adequate evidence of validity based on content and response processes. Both validity evidences obtained so far allowed to adjust the screening tool in relation to its construct. The next studies will analyze the other evidences of validity and the measures of accuracy.

Development and Validation of a National System for Routine Monitoring of Mortality in People Recently Released from Prison.

Directory of Open Access Journals (Sweden)

Stuart A Kinner

Full Text Available People released from prison are at increased risk of death. However, no country has established a system for routine monitoring of mortality in this population. The aims of this study were to (a evaluate a system for routine monitoring of deaths after release from prison in Australia and (b estimate the number of deaths annually within 28 and 365 days of prison release from 2000 to 2013.Persons released from prison and deaths were identified in records held by Centrelink, Australia's national provider of unemployment benefits. Estimates generated in this manner were compared with those from a study that probabilistically linked correctional records with the National Death Index (NDI, for each calendar year 2000 to 2007. Using Centrelink data, national estimates of mortality within 28 and 365 days of release were produced for each calendar year 2000 to 2013.Compared with estimates based on linkage with the NDI, the estimated crude mortality rate based on Centrelink records was on average 52% lower for deaths within 28 days of release and 24% lower for deaths within 365 days of release. Nationally, over the period 2000 to 2013, we identified an average of 32 deaths per year within 28 days of release and 188 deaths per year within 365 days of release. The crude mortality rate for deaths within both 28 and 365 days of release increased over this time.Using routinely collected unemployment benefits data we detected the majority of deaths in people recently released from prison in Australia. These data may be sufficient for routine monitoring purposes and it may be possible to adopt a similar approach in other countries. Routine surveillance of mortality in ex-prisoners serves to highlight their extreme vulnerability and provides a basis for evaluating policy reforms designed to reduce preventable deaths.

Command Leadership DEOCS 4.1 Construct Validity Summary

Science.gov (United States)

2017-08-01

Command Leadership DEOCS 4.1 Construct Validity Summary DEFENSE EQUAL OPPORTUNITY MANAGEMENT INSTITUTE...Report #15-18 1 Command Leadership DEOCS 4.1 Construct Validity Summary Background In 2014, DEOMI released DEOCS 4.0 for Department of Defense...individual items on the DEOCS. The following paper details the work conducted to modify the factor of Leadership Cohesion so that it focuses more

Chitosan microparticles: influence of the gelation process on the release profile and oral bioavailability of albendazole, a class II compound.

Science.gov (United States)

Piccirilli, Gisela N; García, Agustina; Leonardi, Darío; Mamprin, María E; Bolmaro, Raúl E; Salomón, Claudio J; Lamas, María C

2014-11-01

Encapsulation of albendazole, a class II compound, into polymeric microparticles based on chitosan-sodium lauryl sulfate was investigated as a strategy to improve drug dissolution and oral bioavailability. The microparticles were prepared by spray drying technique and further characterized by means of X-ray powder diffractometry, infrared spectroscopy and scanning electron microscopy. The formation of a novel polymeric structure between chitosan and sodium lauryl sulfate, after the internal or external gelation process, was observed by infrared spectroscopy. The efficiency of encapsulation was found to be between 60 and 85% depending on the internal or external gelation process. Almost spherically spray dried microparticles were observed using scanning electron microscopy. In vitro dissolution results indicated that the microparticles prepared by internal gelation released 8% of the drug within 30 min, while the microparticles prepared by external gelation released 67% within 30 min. It was observed that the AUC and Cmax values of ABZ from microparticles were greatly improved, in comparison with the non-encapsulated drug. In conclusion, the release properties and oral bioavailability of albendazole were greatly improved by using spraydried chitosan-sodium lauryl sulphate microparticles.

Heat release rate from the combustion of uranium

International Nuclear Information System (INIS)

Solbrig, C.W.

1995-01-01

Fuel treatment is planned at the Argonne National Laboratory on EBR-II spent fuel. The electrochemical treatment process is carried out in a cell with an argon atmosphere to prevent any reaction. The amount of fuel processed at any time is limited by the amount of energy which could be released by metal combustion if air is inadvertently allowed into the cell since the heat release would increase the cell pressure. The cell pressure is required to be below atmospheric even if combustion occurs to ensure no cell gas/aerosol is released to the environment. Metal fires can release large amounts of heat. In certain configurations such as fine particulate, metal can be pyrophoric at room temperature. When the metal is a nuclear fuel, it is important to be able to predict the reaction/heat release rate if the metal is inadvertently exposed to air. A realistic combustion model is needed to predict heat release rates for the many different flow and transport configurations which exist in the various fuel processing steps. A model for the combustion of uranium is developed here which compares satisfactorily to experimental data

Tech-X Corporation releases simulation code for solving complex problems in plasma physics : VORPAL code provides a robust environment for simulating plasma processes in high-energy physics, IC fabrications and material processing applications

CERN Multimedia

2005-01-01

Tech-X Corporation releases simulation code for solving complex problems in plasma physics : VORPAL code provides a robust environment for simulating plasma processes in high-energy physics, IC fabrications and material processing applications

Numerical Validation of Chemical Compositional Model for Wettability Alteration Processes

Science.gov (United States)

Bekbauov, Bakhbergen; Berdyshev, Abdumauvlen; Baishemirov, Zharasbek; Bau, Domenico

2017-12-01

Chemical compositional simulation of enhanced oil recovery and surfactant enhanced aquifer remediation processes is a complex task that involves solving dozens of equations for all grid blocks representing a reservoir. In the present work, we perform a numerical validation of the newly developed mathematical formulation which satisfies the conservation laws of mass and energy and allows applying a sequential solution approach to solve the governing equations separately and implicitly. Through its application to the numerical experiment using a wettability alteration model and comparisons with existing chemical compositional model's numerical results, the new model has proven to be practical, reliable and stable.

Construct Validity in TOEFL iBT Speaking Tasks: Insights from Natural Language Processing

Science.gov (United States)

Kyle, Kristopher; Crossley, Scott A.; McNamara, Danielle S.

2016-01-01

This study explores the construct validity of speaking tasks included in the TOEFL iBT (e.g., integrated and independent speaking tasks). Specifically, advanced natural language processing (NLP) tools, MANOVA difference statistics, and discriminant function analyses (DFA) are used to assess the degree to which and in what ways responses to these…

Obtaining Valid Safety Data for Software Safety Measurement and Process Improvement

Science.gov (United States)

Basili, Victor r.; Zelkowitz, Marvin V.; Layman, Lucas; Dangle, Kathleen; Diep, Madeline

2010-01-01

We report on a preliminary case study to examine software safety risk in the early design phase of the NASA Constellation spaceflight program. Our goal is to provide NASA quality assurance managers with information regarding the ongoing state of software safety across the program. We examined 154 hazard reports created during the preliminary design phase of three major flight hardware systems within the Constellation program. Our purpose was two-fold: 1) to quantify the relative importance of software with respect to system safety; and 2) to identify potential risks due to incorrect application of the safety process, deficiencies in the safety process, or the lack of a defined process. One early outcome of this work was to show that there are structural deficiencies in collecting valid safety data that make software safety different from hardware safety. In our conclusions we present some of these deficiencies.

Detection of Overreported Psychopathology with the MMPI-2 RF Form Validity Scales

Science.gov (United States)

Sellbom, Martin; Bagby, R. Michael

2010-01-01

We examined the utility of the validity scales on the recently released Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2 RF; Ben-Porath & Tellegen, 2008) to detect overreported psychopathology. This set of validity scales includes a newly developed scale and revised versions of the original MMPI-2 validity scales. We…

76 FR 4360 - Guidance for Industry on Process Validation: General Principles and Practices; Availability

Science.gov (United States)

2011-01-25

... and Development (HFM-40), Center for Biologics Evaluation and Research (CBER), Food and Drug...] Guidance for Industry on Process Validation: General Principles and Practices; Availability AGENCY: Food... of Drug Information, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New...

Evaluating the Release, Delivery, and Deployment Processes of Eight Large Product Software Vendors applying the Customer Configuration Update Model

NARCIS (Netherlands)

Jansen, S.R.L.; Brinkkemper, S.

2006-01-01

For software vendors the processes of release, delivery, and deployment to customers are inherently complex. However, software vendors can greatly improve their product quality and quality of service by applying a model that focuses on customer interaction if such a model were available. This

Enhancement of ASTEC and COCOSYS regarding fission product release during MCCI

Energy Technology Data Exchange (ETDEWEB)

Agethen, Kathrin [Bochum Univ. (Germany). Reactor Simulation and Safety Group

2016-10-15

The focus in this paper is on the enhancement of the fission product release model during molten core concrete interaction in the severe accident analysis codes ASTEC and COCOSYS. After both codes are harmonised and the model interaction as well as the input parameters are adapted, extended model approaches are implemented. These lead to an improvement of the release rates for selected semi-volatile species validated against the ACE tests under ex-vessel conditions.

Release modes and processes relevant to source-term calculations at Yucca Mountain

International Nuclear Information System (INIS)

Apted, M.J.

1994-01-01

The feasibility of permanent disposal of radioactive high-level waste (HLW) in repositories located in deep geologic formations is being studied world-wide. The most credible release pathway is interaction between groundwater and nuclear waste forms, followed by migration of radionuclide-bearing groundwater to the accessible environment. Under hydrologically unsaturated conditions, vapor transport of volatile radionuclides is also possible. The near-field encompasses the waste packages composed of engineered barriers (e.g. man-made materials, such as vitrified waste forms, corrosion-resistant containers), while the far-field includes the natural barriers (e.g. host rock, hydrologic setting). Taken together, these two subsystems define a series of multiple, redundant barriers that act to assure the safe isolation of nuclear waste. In the U.S., the Department of energy (DOE) is investigating the feasibility of safe, long-term disposal of high-level nuclear waste at the Yucca Mountain site in Nevada. The proposed repository horizon is located in non-welded tuffs within the unsaturated zone (i.e. above the water table) at Yucca Mountain. The purpose of this paper is to describe the source-term models for radionuclide release from waste packages at Yucca Mountain site. The first section describes the conceptual release modes that are relevant for this site and waste package design, based on a consideration of the performance of currently proposed engineered barriers under expected and unexpected conditions. No attempt is made to asses the reasonableness nor probability of occurrence for any specific release mode. The following section reviews the waste-form characteristics that are required to model and constrain the release of radionuclides from the waste package. The next section present mathematical models for the conceptual release modes, selected from those that have been implemented into a probabilistic total system assessment code developed for the Electric Power

A validated stability-indicating RP-HPLC method for levofloxacin in the presence of degradation products, its process related impurities and identification of oxidative degradant.

Science.gov (United States)

Lalitha Devi, M; Chandrasekhar, K B

2009-12-05

The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of levofloxacin as well as its related substances determination in bulk samples, pharmaceutical dosage forms in the presence of degradation products and its process related impurities. Forced degradation studies were performed on bulk sample of levofloxacin as per ICH prescribed stress conditions using acid, base, oxidative, water hydrolysis, thermal stress and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed during oxidative stress and the degradation product formed was identified by LCMS/MS, slight degradation in acidic stress and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies and the impurity spiked solution. Good resolution between the peaks corresponds to process related impurities and degradation products from the analyte were achieved on ACE C18 column using the mobile phase consists a mixture of 0.5% (v/v) triethyl amine in sodium dihydrogen orthophosphate dihydrate (25 mM; pH 6.0) and methanol using a simple linear gradient. The detection was carried out at 294 nm. The limit of detection and the limit of quantitation for the levofloxacin and its process related impurities were established. The stressed test solutions were assayed against the qualified working standard of levofloxacin and the mass balance in each case was in between 99.4 and 99.8% indicating that the developed LC method was stability indicating. Validation of the developed LC method was carried out as per ICH requirements. The developed LC method was found to be suitable to check the quality of bulk samples of levofloxacin at the time of batch release and also during its stability studies (long term and accelerated stability).

Understanding Drug Release Data through Thermodynamic Analysis

Directory of Open Access Journals (Sweden)

Marjorie Caroline Liberato Cavalcanti Freire

2017-06-01

Full Text Available Understanding the factors that can modify the drug release profile of a drug from a Drug-Delivery-System (DDS is a mandatory step to determine the effectiveness of new therapies. The aim of this study was to assess the Amphotericin-B (AmB kinetic release profiles from polymeric systems with different compositions and geometries and to correlate these profiles with the thermodynamic parameters through mathematical modeling. Film casting and electrospinning techniques were used to compare behavior of films and fibers, respectively. Release profiles from the DDSs were performed, and the mathematical modeling of the data was carried out. Activation energy, enthalpy, entropy and Gibbs free energy of the drug release process were determined. AmB release profiles showed that the relationship to overcome the enthalpic barrier was PVA-fiber > PVA-film > PLA-fiber > PLA-film. Drug release kinetics from the fibers and the films were better fitted on the Peppas–Sahlin and Higuchi models, respectively. The thermodynamic parameters corroborate these findings, revealing that the AmB release from the evaluated systems was an endothermic and non-spontaneous process. Thermodynamic parameters can be used to explain the drug kinetic release profiles. Such an approach is of utmost importance for DDS containing insoluble compounds, such as AmB, which is associated with an erratic bioavailability.

The process of processing: exploring the validity of Neisser's perceptual cycle model with accounts from critical decision-making in the cockpit.

Science.gov (United States)

Plant, Katherine L; Stanton, Neville A

2015-01-01

The perceptual cycle model (PCM) has been widely applied in ergonomics research in domains including road, rail and aviation. The PCM assumes that information processing occurs in a cyclical manner drawing on top-down and bottom-up influences to produce perceptual exploration and actions. However, the validity of the model has not been addressed. This paper explores the construct validity of the PCM in the context of aeronautical decision-making. The critical decision method was used to interview 20 helicopter pilots about critical decision-making. The data were qualitatively analysed using an established coding scheme, and composite PCMs for incident phases were constructed. It was found that the PCM provided a mutually exclusive and exhaustive classification of the information-processing cycles for dealing with critical incidents. However, a counter-cycle was also discovered which has been attributed to skill-based behaviour, characteristic of experts. The practical applications and future research questions are discussed. Practitioner Summary: This paper explores whether information processing, when dealing with critical incidents, occurs in the manner anticipated by the perceptual cycle model. In addition to the traditional processing cycle, a reciprocal counter-cycle was found. This research can be utilised by those who use the model as an accident analysis framework.

Molecularly Imprinted Polymers for 5-Fluorouracil Release in Biological Fluids

Directory of Open Access Journals (Sweden)

Franco Alhaique

2007-04-01

Full Text Available The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs as a controlled release device for 5-fluorouracil (5-FU in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs. MIPs were synthesized using methacrylic acid (MAA as functional monomer and ethylene glycol dimethacrylate (EGDMA as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

Dual-controlled release system of drugs for bone regeneration.

Science.gov (United States)

Kim, Yang-Hee; Tabata, Yasuhiko

2015-11-01

Controlled release systems have been noted to allow drugs to enhance their ability for bone regeneration. To this end, various biomaterials have been used as the release carriers of drugs, such as low-molecular-weight drugs, growth factors, and others. The drugs are released from the release carriers in a controlled fashion to maintain their actions for a long time period. Most research has been focused on the controlled release of single drugs to demonstrate the therapeutic feasibility. Controlled release of two combined drugs, so-called dual release systems, are promising and important for tissue regeneration. This is because the tissue regeneration process of bone formation is generally achieved by multiple bioactive molecules, which are produced from cells by other molecules. If two types of bioactive molecules, (i.e., drugs), are supplied in an appropriate fashion, the regeneration process of living bodies will be efficiently promoted. This review focuses on the bone regeneration induced by dual-controlled release of drugs. In this paper, various dual-controlled release systems of drugs aiming at bone regeneration are overviewed explaining the type of drugs and their release materials. Copyright © 2015 Elsevier B.V. All rights reserved.

Interpretation and modelling of fission product Ba and Mo releases from fuel

Science.gov (United States)

Brillant, G.

2010-02-01

The release mechanisms of two fission products (namely barium and molybdenum) in severe accident conditions are studied using the VERCORS experimental observations. Barium is observed to be mostly released under reducing conditions while molybdenum release is most observed under oxidizing conditions. As well, the volatility of some precipitates in fuel is evaluated by thermodynamic equilibrium calculations. The polymeric species (MoO 3) n are calculated to largely contribute to molybdenum partial pressure and barium volatility is greatly enhanced if the gas atmosphere is reducing. Analytical models of fission product release from fuel are proposed for barium and molybdenum. Finally, these models have been integrated in the ASTEC/ELSA code and validation calculations have been performed on several experimental tests.

Validity of Scientific Based Chemistry Android Module to Empower Science Process Skills (SPS) in Solubility Equilibrium

Science.gov (United States)

Antrakusuma, B.; Masykuri, M.; Ulfa, M.

2018-04-01

Evolution of Android technology can be applied to chemistry learning, one of the complex chemistry concept was solubility equilibrium. this concept required the science process skills (SPS). This study aims to: 1) Characteristic scientific based chemistry Android module to empowering SPS, and 2) Validity of the module based on content validity and feasibility test. This research uses a Research and Development approach (RnD). Research subjects were 135 s1tudents and three teachers at three high schools in Boyolali, Central of Java. Content validity of the module was tested by seven experts using Aiken’s V technique, and the module feasibility was tested to students and teachers in each school. Characteristics of chemistry module can be accessed using the Android device. The result of validation of the module contents got V = 0.89 (Valid), and the results of the feasibility test Obtained 81.63% (by the student) and 73.98% (by the teacher) indicates this module got good criteria.

Precision Departure Release Capability (PDRC): NASA to FAA Research Transition

Science.gov (United States)

Engelland, Shawn; Davis, Thomas J.

2013-01-01

After takeoff, aircraft must merge into en route (Center) airspace traffic flows which may be subject to constraints that create localized demand-capacity imbalances. When demand exceeds capacity, Traffic Management Coordinators (TMCs) and Frontline Managers (FLMs) often use tactical departure scheduling to manage the flow of departures into the constrained Center traffic flow. Tactical departure scheduling usually involves use of a Call for Release (CFR) procedure wherein the Tower must call the Center to coordinate a release time prior to allowing the flight to depart. In present-day operations release times are computed by the Center Traffic Management Advisor (TMA) decision support tool based upon manual estimates of aircraft ready time verbally communicated from the Tower to the Center. The TMA-computed release time is verbally communicated from the Center back to the Tower where it is relayed to the Local controller as a release window that is typically three minutes wide. The Local controller will manage the departure to meet the coordinated release time window. Manual ready time prediction and verbal release time coordination are labor intensive and prone to inaccuracy. Also, use of release time windows adds uncertainty to the tactical departure process. Analysis of more than one million flights from January 2011 indicates that a significant number of tactically scheduled aircraft missed their en route slot due to ready time prediction uncertainty. Uncertainty in ready time estimates may result in missed opportunities to merge into constrained en route flows and lead to lost throughput. Next Generation Air Transportation System plans call for development of Tower automation systems capable of computing surface trajectory-based ready time estimates. NASA has developed the Precision Departure Release Capability (PDRC) concept that improves tactical departure scheduling by automatically communicating surface trajectory-based ready time predictions and

Inhibition of basophil histamine release by gangliosides. Further studies on the significance of cell membrane sialic acid in the histamine release process

DEFF Research Database (Denmark)

Jensen, C; Norn, S; Thastrup, Ole

1987-01-01

with the glucolipid mixture increased the sialic acid content of the cells, and this increase was attributed to an insertion of gangliosides into the cell membrane. The inhibition of histamine release was abolished by increasing the calcium concentration, which substantiates our previous findings that cell membrane......Histamine release from human basophils was inhibited by preincubation of the cells with a glucolipid mixture containing sialic acid-containing gangliosides. This was true for histamine release induced by anti-IgE, Concanavalin A and the calcium ionophore A23187, whereas the release induced by S....... aureus Wood 46 was not affected. It was demonstrated that the inhibitory capacity of the glucolipid mixture could be attributed to the content of gangliosides, since no inhibition was obtained with cerebrosides or with gangliosides from which sialic acid was removed. Preincubation of the cells...

In situ detection of the Zn(2+) release process of ZnO NPs in tumour cells by confocal laser scanning fluorescence microscopy.

Science.gov (United States)

Song, Wenshuang; Tang, Xiaoling; Li, Yong; Sun, Yang; Kong, Jilie; Qingguang, Ren

2016-08-01

The use of zinc oxide (ZnO) nanoparticles (NPs) for cancer is not yet clear for human clinical applications, which is primarily due to the lack of a better understanding of the action mechanisms and cellular consequences of the direct exposure of cells to these NPs. In this work, the authors have selected zinquin ethyl ester, a Zn(2+)-specific fluorescent molecular probe, to efficiently differentiate ZnO NPs and Zn(2+), and combined with confocal laser scanning microscopy (CLSM) to in situ study the Zn(2+) release process of ZnO NPs in cancer cell system through detecting the change of Zn(2+) level over time. During the experiments, the authors have designed the test group ZnO-2 in addition to assess the influence of a long-term storage on the characteristics of ZnO NPs in aqueous solution, and the Zn(2+) release process of ZnO NPs in cancer cell system. After three-month storage at room temperature, the release process became earlier and faster, which was consistent with previous results of transmission electron microscope, UV-Vis and PL spectra. It is a good detection method that combination of Zn(2+)-specific fluorescent molecular probe and CLSM, which will be helpful for ZnO NPs using in clinical research.

Improved Methodology of MSLB M/E Release Analysis for OPR1000

International Nuclear Information System (INIS)

Park, Seok Jeong; Kim, Cheol Woo; Seo, Jong Tae

2006-01-01

A new mass and energy (M/E) release analysis methodology for the equipment environmental qualification (EEQ) on loss-of-coolant accident (LOCA) has been recently developed and adopted on small break LOCA EEQ. The new methodology for the M/E release analysis is extended to the M/E release analysis for the containment design for large break LOCA and the main steam line break (MSLB) accident, and named KIMERA (KOPEC Improved Mass and Energy Release Analysis) methodology. The computer code systems used in this methodology is RELAP5K/CONTEMPT4 (or RELAP5-ME) which couples RELAP5/MOD3.1/K with enhanced M/E model and LOCA long term model, and CONTEMPT4/ MOD5. This KIMERA methodology is applied to the MSLB M/E release analysis to evaluate the validation of KIMERA methodology for MSLB in containment design. The results are compared with the OPR 1000 FSAR

Trust in Leadership DEOCS 4.1 Construct Validity Summary

Science.gov (United States)

2017-08-01

Trust in Leadership DEOCS 4.1 Construct Validity Summary DEFENSE EQUAL OPPORTUNITY MANAGEMENT INSTITUTE...Report #04-18 1 Trust in Leadership DEOCS 4.1 Construct Validity Summary Background In 2014, DEOMI released DEOCS 4.0 for Department of Defense...and individual items on the DEOCS. The following details the efforts directed toward updating the factor of Trust in Leadership . Included is a review

Aerosol release factor for Pu as a consequence of an ion exchange resin fire in the process cell of a fuel reprocessing plant

Energy Technology Data Exchange (ETDEWEB)

Bhanti, D.P.; Malvankar, S.V.; Kotrappa, P.; Somasundaram, S.; Raghunath, B.; Curtay, A.M.

1988-12-01

One of the upper limit accidents usually considered in the safety analysis of a fuel reprocessing plant is an accidental explosion, followed by a fire, of an ion exchange column containing resin loaded with large quantities of plutonium. In such accidents, a certain fraction (release factor) of Pu is released in the form of an aerosol into the ventilation system, and finally to the environment through HEPA filters and the stack. The present study was undertaken to determine the aerosol release factor for Pu in the process cell of a typical fuel reprocessing plant. Geometrically similar scaled-down models of three different sizes were built, and suitably scaled-down quantities of resin loaded with thorium in nitric acid medium were burnt in these model cells. Thorium was used in place of Pu because of its physical and chemical similarities with Pu. The release factor was obtained by comparing the amount of Th in air with the total. The study also dealt with aerosol characteristics and kinematics of process of fire. The aerosol release factors for the three models were found to lie in the range 0.01-0.07%, and varied non-monotonically with model size. The analysis of scaled down results in conjunction with simplified aerosol modelling yielded the release factor for the actual cell conditions as 0.012% with an upper limit value of 0.1%. The particle size analysis based on Th-radioactivity and particle-mass indicated nonuniform tagging of Th to aerosol particles. These particles were irregularly shaped, but not as long chain-like aggregates. The study proposes, with a reasonable degree of conservatism, the release factor of 0.1% for such fires, and aerosol parameters, AMAD and sigma/sub g/, as 2 m and 2 respectively. However, for situations significantly different from the present one, the release factor of 1% recommended by the American National Standards Institute may be used with a greater degree of confidence in the light of the present work.

Groundwater Model Validation

Energy Technology Data Exchange (ETDEWEB)

Ahmed E. Hassan

2006-01-24

Models have an inherent uncertainty. The difficulty in fully characterizing the subsurface environment makes uncertainty an integral component of groundwater flow and transport models, which dictates the need for continuous monitoring and improvement. Building and sustaining confidence in closure decisions and monitoring networks based on models of subsurface conditions require developing confidence in the models through an iterative process. The definition of model validation is postulated as a confidence building and long-term iterative process (Hassan, 2004a). Model validation should be viewed as a process not an end result. Following Hassan (2004b), an approach is proposed for the validation process of stochastic groundwater models. The approach is briefly summarized herein and detailed analyses of acceptance criteria for stochastic realizations and of using validation data to reduce input parameter uncertainty are presented and applied to two case studies. During the validation process for stochastic models, a question arises as to the sufficiency of the number of acceptable model realizations (in terms of conformity with validation data). Using a hierarchical approach to make this determination is proposed. This approach is based on computing five measures or metrics and following a decision tree to determine if a sufficient number of realizations attain satisfactory scores regarding how they represent the field data used for calibration (old) and used for validation (new). The first two of these measures are applied to hypothetical scenarios using the first case study and assuming field data consistent with the model or significantly different from the model results. In both cases it is shown how the two measures would lead to the appropriate decision about the model performance. Standard statistical tests are used to evaluate these measures with the results indicating they are appropriate measures for evaluating model realizations. The use of validation

Development, Validation and Integration of the ATLAS Trigger System Software in Run 2

CERN Document Server

Keyes, Robert; The ATLAS collaboration

2016-01-01

The trigger system of the ATLAS detector at the LHC is a combination of hardware, firmware and software, associated to various sub-detectors that must seamlessly cooperate in order to select 1 collision of interest out of every 40,000 delivered by the LHC every millisecond. This talk will discuss the challenges, workflow and organization of the ongoing trigger software development, validation and deployment. This development, from the top level integration and configuration to the individual components responsible for each sub system, is done to ensure that the most up to date algorithms are used to optimize the performance of the experiment. This optimization hinges on the reliability and predictability of the software performance, which is why validation is of the utmost importance. The software adheres to a hierarchical release structure, with newly validated releases propagating upwards. Integration tests are carried out on a daily basis to ensure that the releases deployed to the online trigger farm duri...

Controlled release of tocopherols from polymer blend films

Science.gov (United States)

Obinata, Noe

Controlled release packaging has great potential to increase storage stability of foods by releasing active compounds into foods continuously over time. However, a major limitation in development of this technology is the inability to control the release and provide rates useful for long term storage of foods. Better understanding of the factors affecting active compound release is needed to overcome this limitation. The objective of this research was to investigate the relationship between polymer composition, polymer processing method, polymer morphology, and release properties of active compounds, and to provide proof of principle that compound release is controlled by film morphology. A natural antioxidant, tocopherol was used as a model active compound because it is natural, effective, heat stable, and soluble in most packaging polymers. Polymer blend films were produced from combination of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) with 3000 ppm mixed tocopherols using conventional blending method and innovative blending method, smart blending with a novel mixer using chaotic advection. Film morphologies were visualized with scanning electron microscopy (SEM). Release of tocopherols into 95% ethanol as a food simulant was measured by UV/Visible spectrophotometry or HPLC, and diffusivity of tocopherols in the polymers was estimated from this data. Polymer composition (blend proportions) and processing methods have major effects on film morphology. Four different types of morphologies, dispersed, co-continuous, fiber, and multilayer structures were developed by either conventional extrusion or smart blending. With smart blending of fixed polymer compositions, different morphologies were progressively developed with fixed polymer composition as the number of rod rotations increased, providing a way to separate effects of polymer composition and morphology. The different morphologies

Release enhancement of tritium from graphite by addition of hydrogen

International Nuclear Information System (INIS)

Saeki, Masakatsu; Masaki, N.M.

1989-01-01

The release behavior of tritium from graphite was studied in pure He and He + H 2 atmosphere. The release from powdered graphite was significantly enhanced in hydrogen environment. Apparent diffusion coefficients of tritium in graphite also became much higher in an atmosphere containing hydrogen than values obtained in pure helium atmosphere. A careful investigation of the release processes resulted in the conclusion that the most important process of tritium behaviour in graphite was diffusion, but the desorption process of tritium from the surface played a significant role. The enhancement of the desorption process was controlled by atomic hydrogen. (orig.)

3-D loaded scaffolds obtained by supercritical CO2 assisted process

Science.gov (United States)

Cardea, S.; Reverchon, E.

2014-08-01

In this work, a supercritical CO2 (SC-CO2) drying process for the formation of 3-D PVDF-HFP loaded scaffolds was tested. Experiments at pressures ranging between 150 and 250 bar and at temperatures ranging between 35 and 55°C were performed. The PVDF-HFP- acetone-ethanol solution at 15% w/w polymer was selected as the base case. The drug (amoxicillin) concentration was varied from 20 to 30% w/w with respect to PVDF-HFP. SC- CO2 drying process was confirmed to be a valid alternative to generate loaded structures; indeed, scaffolds characterized by nanometric networks (with mean pore diameter of about 300 nm) with a homogeneous drug distribution were obtained. Drug controlled release experiments were also performed and a quasi-zero order release kinetic was observed.

Nodal Stub-Release in All-Optical Networks

DEFF Research Database (Denmark)

Ruepp, Sarah Renée; Buron, Jakob Due; Andriolli, Nicola

2008-01-01

In wavelength-routed networks, the scarcity of wavelength-converters severely impacts successful connection recovery. This can be mitigated by releasing the connection’s stubs (i.e. the surviving upstream and downstream span and node resources) prior to the restoration process. Releasing span...

Session 3, Measurement systems and signal validation/processing: Rapporteur's report

International Nuclear Information System (INIS)

Shepard, R.L.

1991-01-01

Eight papers scheduled for presentation dealt with in-core flux and temperature detectors and the interpretation of their signals. Our theme discussed was how core models could be used to validate in-core detector signals, and conversely, how the detector signals could validate the core models. Methods were proposed for distinguishing between detector malfunction (invalid signals) and actual changes in core conditions. It it necessary to reconcile these conflicting possibilities so that accurate and timely assessments of the present and future state of the core may be made during reactor operation, particularly during upset conditions. A second theme addressed the advantages and disadvantages of fixed vs movable in-core detectors -- their characteristics, employment, and signal interpretation. The economic and operating tradeoffs of fixed and movable detectors were addressed. A third theme was the use of signal processing to distinguish between gamma noise and neutron flux signals and how to improve the response times of in-core detectors. The discussion in this session relates to a broader discussion of the relative merits of self-powered neutron detectors and gamma thermometers for in-core flux monitoring which took place at the Cadarache meeting in 1988, and which was continued in Session 1 of this meeting

Development and evaluation of diltiazem hydrochloride controlled-release pellets by fluid bed coating process

Directory of Open Access Journals (Sweden)

Mikkilineni Bhanu Prasad

2013-01-01

Full Text Available The aim of the present study was to develop controlled-release pellets of diltiazem HCl with ethyl cellulose and hydroxylpropyl methylcellulose phthalate as the release rate retarding polymers by fluid bed coating technique. The prepared pellets were evaluated for drug content, particle size, subjected to Scanning Electron Microscopy (SEM and Differential Scanning Calori metry (DSC, and evaluated for in vitro release. Stability studies were carried out on the optimized formulations for a period of 3 months. The drug content was in the range of 97%-101%. The mean particle size of the drug-loaded pellets was in the range 700-785 μm. The drug release rate decreased as the concentration of ethyl cellulose increased in the pellet formulations. Among the prepared formulations, FDL10 and FDL11 showed 80% drug release in 16 h, matching with USP dissolution test 6 for diltiazem HCl extended-release capsules. SEM photographs confirmed that the prepared formulations were spherical in nature with a smooth surface. The compatibility between drug and polymers in the drug-loaded pellets was confirmed by DSC studies. Stability studies indicated that the pellets were stable.

Release and attenuation of fluorocarbons in landfills

DEFF Research Database (Denmark)

Kjeldsen, Peter; Scheutz, Charlotte

2003-01-01

Several halocarbons with very high global warming and ozone depleting potentials have been used as blowing agent for insulation foam in refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam...... blown with CFC-11, HCFC-141b, HFC- 134a, and HFC-245fa revealed that most of the blowing agent is not released to the atmosphere during a six-week period following the shredding process. The fraction which is released in the six-week period is highly dependent on how fine the foam is shredded....... The residual blowing agent remaining after the six-week period may be very slowly released if the integrity of the foam particles with respect to diffusional properties is kept after disposal of the foam waste in landfills. Laboratory experiments simulating attenuation processes in the landfilled waste...

Modeling of container failure and radionuclide release from a geologic nuclear waste repository

International Nuclear Information System (INIS)

Kim, Chang Lak; Kim, Jhin Wung; Choi, Kwang Sub; Cho, Chan Hee

1989-02-01

Generally, two processes are involved in leaching and dissolution; (1) chemical reactions and (2) mass transfer by diffusion. The chemical reaction controls the dissolution rates only during the early stage of exposure to groundwater. The exterior-field mass transfer may control the long-term dissolution rates from the waste solid in a geologic repository. Masstransfer analyses rely on detailed and careful application of the governing equations that describe the mechanistic processes of transport of material between and within phases. We develop analytical models to predict the radionuclide release rate into the groundwater with five different approaches: a measurement-based model, a diffusion model, a kinetics model, a diffusion-and-kinetics model, and a modified diffusion model. We also collected experimental leaching data for a partial validation of the radionuclide release model based on the mass transfer theory. Among various types of corrosions, pitting is the most significant because of its rapid growth. The failure time of the waste container, which also can be interpreted as the containment time, is a milestone of the performance of a repository. We develop analytical models to predict the pit growth rate on the container surface with three different approaches: an experimental method, a statistical method, and a mathematical method based on the diffusion theory. (Author)

THE PROCESS OF MASS TRANSFER ON THE SOLID-LIQUID BOUNDARY LAYER DURING THE RELEASE OF DICLOFENAC SODIUM AND PAPAVERINE HYDROCHLORIDE FROM TABLETS IN A PADDLE APPARATUS.

Science.gov (United States)

Kasperek, Regina; Zimmer, Lukasz; Poleszak, Ewa

2016-01-01

The release study of diclofenac sodium (DIC) and papaverine hydrochloride (PAP) from two formulations of the tablets in the paddle apparatus using different rotation speeds to characterize the process of mass transfer on the solid-liquid boundary layer was carried out. The dissolution process of active substances was described by values of mass transfer coefficients, the diffusion boundary layer thickness and dimensionless numbers (Sh and Re). The values of calculated parameters showed that the release of DIC and PAP from tablets comprising potato starch proceeded faster than from tablets containing HPMC and microcrystalline cellulose. They were obtained by direct dependencies between Sh and Re in the range from 75 rpm to 125 rpm for both substances from all tablets. The description of the dissolution process with the dimensionless numbers make it possible to plan the drug with the required release profile under given in vitro conditions.

Workflow for Criticality Assessment Applied in Biopharmaceutical Process Validation Stage 1

Directory of Open Access Journals (Sweden)

Thomas Zahel

2017-10-01

Full Text Available Identification of critical process parameters that impact product quality is a central task during regulatory requested process validation. Commonly, this is done via design of experiments and identification of parameters significantly impacting product quality (rejection of the null hypothesis that the effect equals 0. However, parameters which show a large uncertainty and might result in an undesirable product quality limit critical to the product, may be missed. This might occur during the evaluation of experiments since residual/un-modelled variance in the experiments is larger than expected a priori. Estimation of such a risk is the task of the presented novel retrospective power analysis permutation test. This is evaluated using a data set for two unit operations established during characterization of a biopharmaceutical process in industry. The results show that, for one unit operation, the observed variance in the experiments is much larger than expected a priori, resulting in low power levels for all non-significant parameters. Moreover, we present a workflow of how to mitigate the risk associated with overlooked parameter effects. This enables a statistically sound identification of critical process parameters. The developed workflow will substantially support industry in delivering constant product quality, reduce process variance and increase patient safety.

[Sediment-water flux and processes of nutrients and gaseous nitrogen release in a China River Reservoir].

Science.gov (United States)

Chen, Zhu-hong; Chen, Neng-wang; Wu, Yin-qi; Mo, Qiong-li; Zhou, Xing-peng; Lu, Ting; Tian, Yun

2014-09-01

The key processes and fluxes of nutrients (N and P) and gaseous N (N2 and N2O) across the sediment-water interface in a river reservoir (Xipi) of the Jiulong River watershed in southeast China were studied. Intact core sediment incubation of nutrients exchange, in-situ observation and lab incubation of excess dissolved N2 and N2O (products of nitrification, denitrification and Anammox), and determination of physiochemical and microbe parameters were carried out in 2013 for three representative sites along the lacustrine zone of the reservoir. Results showed that ammonium and phosphate were generally released from sediment to overlying water [with averaged fluxes of N (479.8 ± 675.4) mg. (m2. d)-1 and P (4. 56 ± 0.54) mg. (m2 d) -1] , while nitrate and nitrite diffused into the sediment. Flood events in the wet season could introduce a large amount of particulate organic matter that would be trapped by the dam reservoir, resulting in the high release fluxes of ammonium and phosphate observed in the following low-flow season. No clear spatial variation of sediment nutrient release was found in the lacustrine zone of the reservoir. Gaseous N release was dominated by excess dissolved N2 (98% of total), and the N2 flux from sediment was (15.8 ± 12. 5) mg (m2. d) -1. There was a longitudinal and vertical variation of excess dissolved N2, reflecting the combined results of denitrification and Anammox occurring in anoxic sediment and fluvial transport. Nitrification mainly occurred in the lower lacustrine zone, and the enrichment of N2O was likely regulated by the ratio of ammonium to DIN in water.

Disruption of Pseudomonas putida by high pressure homogenization: a comparison of the predictive capacity of three process models for the efficient release of arginine deiminase.

Science.gov (United States)

Patil, Mahesh D; Patel, Gopal; Surywanshi, Balaji; Shaikh, Naeem; Garg, Prabha; Chisti, Yusuf; Banerjee, Uttam Chand

2016-12-01

Disruption of Pseudomonas putida KT2440 by high-pressure homogenization in a French press is discussed for the release of arginine deiminase (ADI). The enzyme release response of the disruption process was modelled for the experimental factors of biomass concentration in the broth being disrupted, the homogenization pressure and the number of passes of the cell slurry through the homogenizer. For the same data, the response surface method (RSM), the artificial neural network (ANN) and the support vector machine (SVM) models were compared for their ability to predict the performance parameters of the cell disruption. The ANN model proved to be best for predicting the ADI release. The fractional disruption of the cells was best modelled by the RSM. The fraction of the cells disrupted depended mainly on the operating pressure of the homogenizer. The concentration of the biomass in the slurry was the most influential factor in determining the total protein release. Nearly 27 U/mL of ADI was released within a single pass from slurry with a biomass concentration of 260 g/L at an operating pressure of 510 bar. Using a biomass concentration of 100 g/L, the ADI release by French press was 2.7-fold greater than in a conventional high-speed bead mill. In the French press, the total protein release was 5.8-fold more than in the bead mill. The statistical analysis of the completely unseen data exhibited ANN and SVM modelling as proficient alternatives to RSM for the prediction and generalization of the cell disruption process in French press.

PCDD/PCDF release inventories

Energy Technology Data Exchange (ETDEWEB)

Fiedler, H. [UNEP Chemicals, Chatelaine (Switzerland)

2004-09-15

The Stockholm Convention on Persistent Organic Pollutants (POPs) entered into force on 17 May 2004 with 50 Parties. In May 2004, 59 countries had ratified or acceded the Convention. The objective of the Convention is ''to protect human health and the environment from persistent organic pollutants''. For intentionally produced POPs, e.g., pesticides and industrial chemicals such as hexachlorobenzene and polychlorinated biphenyls, this will be achieved by stop of production and use. For unintentionally generated POPs, such as polychlorinated dibenzo-pdioxins (PCDD) and polychlorinated dibenzofurans (PCDF), measures have to be taken to ''reduce the total releases derived from anthropogenic sources''; the final goal is ultimate elimination, where feasible. Under the Convention, Parties have to establish and maintain release inventories to prove the continuous release reduction. Since many countries do not have the technical and financial capacity to measure all releases from all potential PCDD/PCDF sources, UNEP Chemicals has developed the ''Standardized Toolkit for the Identification of Quantification of Dioxin and Furan Releases'' (''Toolkit'' for short), a methodology to estimate annual releases from a number of sources. With this methodology, annual releases can be estimated by multiplying process-specific default emission factors provided in the Toolkit with national activity data. At the seventh session of the Intergovernmental Negotiating Committee, the Toolkit was recommended to be used by countries when reporting national release data to the Conference of the Parties. The Toolkit is especially used by developing countries and countries with economies in transition where no measured data are available. Results from Uruguay, Thailand, Jordan, Philippines, and Brunei Darussalam have been published.

Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

Science.gov (United States)

2012-01-01

Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg) from Pichia pastoris expression cells were optimized using response surface methodology (RSM) based on the central composite design (CCD). The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW) and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR) and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing. PMID:23039947

A Decision Support System to Choose Optimal Release Cycle Length in Incremental Software Development Environments

OpenAIRE

Suman, Avnish Chandra; Mishra, Saraswati; Anand, Abhinav

2016-01-01

In the last few years it has been seen that many software vendors have started delivering projects incrementally with very short release cycles. Best examples of success of this approach has been Ubuntu Operating system that has a 6 months release cycle and popular web browsers such as Google Chrome, Opera, Mozilla Firefox. However there is very little knowledge available to the project managers to validate the chosen release cycle length. We propose a decision support system that...

Modeling Drug-Carrier Interaction in the Drug Release from Nanocarriers

Directory of Open Access Journals (Sweden)

Like Zeng

2011-01-01

Full Text Available Numerous nanocarriers of various compositions and geometries have been developed for the delivery and release of therapeutic and imaging agents. Due to the high specific surface areas of nanocarriers, different mechanisms such as ion pairing and hydrophobic interaction need to be explored for achieving sustained release. Recently, we developed a three-parameter model that considers reversible drug-carrier interaction and first-order drug release from liposomes. A closed-form analytical solution was obtained. Here, we further explore the ability of the model to capture the release of bioactive molecules such as drugs and growth factors from various nanocarriers. A parameter study demonstrates that the model is capable of resembling major categories of drug release kinetics. We further fit the model to 60 sets of experimental data from various drug release systems, including nanoparticles, hollow particles, fibers, and hollow fibers. Additionally, bootstrapping is used to evaluate the accuracy of parameter determination and validate the model in selected cases. The simplicity and universality of the model and the clear physical meanings of each model parameter render the model useful for the design and development of new drug delivery systems.

International Heart Valve Bank Survey: A Review of Processing Practices and Activity Outcomes

Science.gov (United States)

Albrecht, Helmi; Lim, Yeong Phang; Manning, Linda

2013-01-01

A survey of 24 international heart valve banks was conducted to acquire information on heart valve processing techniques used and outcomes achieved. The objective was to provide an overview of heart valve banking activities for tissue bankers, tissue banking associations, and regulatory bodies worldwide. Despite similarities found for basic manufacturing processes, distinct differences in procedural details were also identified. The similarities included (1) use of sterile culture media for procedures, (2) antibiotic decontamination, (3) use of dimethyl sulfoxide (DMSO) as a cryoprotectant, (4) controlled rate freezing for cryopreservation, and (5) storage at ultralow temperatures of below −135°C. Differences in procedures included (1) type of sterile media used, (2) antibiotics combination, (3) temperature and duration used for bioburden reduction, (4) concentration of DMSO used for cryopreservation, and (5) storage duration for released allografts. For most banks, the primary reasons why allografts failed to meet release criteria were positive microbiological culture and abnormal morphology. On average, 85% of allografts meeting release criteria were implanted, with valve size and type being the main reasons why released allografts were not used clinically. The wide variation in percentage of allografts meeting release requirements, despite undergoing validated manufacturing procedures, justifies the need for regular review of important outcomes as cited in this paper, in order to encourage comparison and improvements in the HVBs' processes. PMID:24163756

[Preventable drug-related morbidity: determining valid indicators for primary care in Portugal].

Science.gov (United States)

Guerreiro, Mara Pereira; Cantrill, Judith A; Martins, Ana Paula

2007-01-01

Preventable drug-related morbidity (PDRM) indicators are operational measures of therapeutic risk management. These clinical indicators, which cover a wide range of drugs, combine process and outcome in the same instrument. They were developed in the US and have been validated for primary care settings in the US, UK and Canada. This study is part of a research programme; it aimed to determine a valid set of PDRM indicators for adult patients in primary care in Portugal. Face validity of 61 US and UK-derived indicators translated to Portuguese was preliminarily determined by means of a postal questionnaire using a purposive sample of four Portuguese pharmacists with different backgrounds. Preliminary content validity of indicators approved in the previous stage was determined by cross-checking each definition of PDRM with standard drug information sources in Portugal. Face and content validity of indicators yielded by preliminary work were then established by a 37 expert panel (20 community pharmacists and 17 general practitioners) using a two-round Delphi survey. Data were analysed using SPSS release 11.5. Nineteen indicators were ruled out in preliminary validation. Changes were made in the content of eight of the remaining 42 indicators; these were related to differences in the drugs being marketed and patterns of drug monitoring between countries. Thirty-five indicators were consensus approved as PDRM for adult patients in Portuguese primary care by the Delphi panel.

A Self-Peeling Vat for Improved Release Capabilities During DLP Materials Processing

DEFF Research Database (Denmark)

Pedersen, David Bue; Zhang, Yang; Nielsen, Jakob Skov

2016-01-01

for an eased release of the manufactured part from the vat by means of a flexible membrane system. A membrane of fluorinated ethylene polymer will through elastic deformation automatically peel off the part as the part is lifted during layer changes. Peeling has been qualified by means of a truncated inverted...... cone as test geometry. As the cross-sectional diameter of the cone increase throughout the build-job, the geometry will release from the glass based build platform at the point where the peeling force exceed the adhesion force between platform and part. At failure point the lateral surface area...... of the top and bottom of the truncated cone is used as a measure of the performance of the vat with respect to release-capability. This has been tested at increasing manufacturing rates. The new self-peeling vat outperformed industrial state-of-the-art vats by 814% percent....

Carbon nanotube release from polymers into a food simulant

International Nuclear Information System (INIS)

Xia, Yining; Uysal Unalan, Ilke; Rubino, Maria; Auras, Rafael

2017-01-01

The release assessment of multi-walled carbon nanotubes (CNTs) was performed on two types of polymer-CNT nanocomposites: polypropylene (PP) and polyamide 6 (PA6) containing 3 wt% CNT. Nanocomposite films were prepared and then exposed to ethanol as a fatty-food simulant at 40 °C, and the amount of CNT release into ethanol was determined by ultraviolet-visible spectroscopy (UV-Vis) and graphite furnace atomic absorption spectrometry (GFAAS). The CNTs released into ethanol were visualized by transmission electron microscopy (TEM) and verified by Raman spectroscopy. UV-Vis analysis showed a very small amount of CNT release from the nanocomposite films into ethanol over 60 d: maximum CNT concentrations in ethanol were 1.3 mg/L for the PP-CNT film and 1.2 mg/L for the PA6-CNT film. GFAAS results indicated that the amount of CNTs released into ethanol after 12 d was over 20-fold higher than the results obtained by UV-Vis. Overestimation of CNT release by GFAAS suggested aggregation and poor dispersion of CNTs in the solvent. This assumption was verified by TEM images exhibiting the embedded CNTs in the polymer flakes, which could be poorly dispersed in the solvent. In general, CNT release from the nanocomposite films was considered a surface phenomenon, as indicated by detachment of CNT-containing polymer flakes from the film surface. - Highlights: • Release of CNT from polypropylene and polyamide nanocomposites were quantified and validated with TEM and Raman. • Spectroscopy and silane-labeled CNT were used for tracking the release of CNT. • The release behavior of CNT from nanocomposites was mostly generated from the polymer surfaces.

Sustained release biodegradable solid lipid microparticles: Formulation, evaluation and statistical optimization by response surface methodology.

Science.gov (United States)

Hanif, Muhammad; Khan, Hafeez Ullah; Afzal, Samina; Mahmood, Asif; Maheen, Safirah; Afzal, Khurram; Iqbal, Nabila; Andleeb, Mehwish; Abbas, Nazar

2017-12-20

For preparing nebivolol loaded solid lipid microparticles (SLMs) by the solvent evaporation microencapsulation process from carnauba wax and glyceryl monostearate, central composite design was used to study the impact of independent variables on yield (Y1), entrapment efficiency (Y2) and drug release (Y3). SLMs having a 10-40 μm size range, with good rheological behavior and spherical smooth surfaces, were produced. Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry pointed to compatibility between formulation components and the zeta-potential study confirmed better stability due to the presence of negative charge (-20 to -40 mV). The obtained outcomes for Y1 (29-86 %), Y2 (45-83 %) and Y3 (49-86 %) were analyzed by polynomial equations and the suggested quadratic model were validated. Nebivolol release from SLMs at pH 1.2 and 6.8 was significantly (p 0.85 value (Korsmeyer- Peppas) suggested slow erosion along with diffusion. The optimized SLMs have the potential to improve nebivolol oral bioavailability.

Decontamination for free release

Energy Technology Data Exchange (ETDEWEB)

Simpson, K A; Elder, G R [Bradtec Ltd., Bristol (United Kingdom)

1997-02-01

Many countries are seeking to treat radioactive waste in ways which meet the local regulatory requirements, but yet are cost effective when all contributing factors are assessed. In some countries there are increasing amounts of waste, arising from nuclear plant decommissioning, which are categorized as low level waste: however with suitable treatment a large part of such wastes might become beyond regulatory control and be able to be released as non-radioactive. The benefits and disadvantages of additional treatment before disposal need to be considered. Several processes falling within the overall description of decontamination for free release have been developed and applied, and these are outlined. In one instance the process seeks to take advantage of techniques and equipment used for decontaminating water reactor circuits intermittently through reactor life. (author). 9 refs, 1 fig., 3 tabs.

The Signal Validation method of Digital Process Instrumentation System on signal conditioner for SMART

International Nuclear Information System (INIS)

Moon, Hee Gun; Park, Sang Min; Kim, Jung Seon; Shon, Chang Ho; Park, Heui Youn; Koo, In Soo

2005-01-01

The function of PIS(Process Instrumentation System) for SMART is to acquire the process data from sensor or transmitter. The PIS consists of signal conditioner, A/D converter, DSP(Digital Signal Process) and NIC(Network Interface Card). So, It is fully digital system after A/D converter. The PI cabinet and PDAS(Plant Data Acquisition System) in commercial plant is responsible for data acquisition of the sensor or transmitter include RTD, TC, level, flow, pressure and so on. The PDAS has the software that processes each sensor data and PI cabinet has the signal conditioner, which is need for maintenance and test. The signal conditioner has the potentiometer to adjust the span and zero for test and maintenance. The PIS of SMART also has the signal conditioner which has the span and zero adjust same as the commercial plant because the signal conditioner perform the signal condition for AD converter such as 0∼10Vdc. But, To adjust span and zero is manual test and calibration. So, This paper presents the method of signal validation and calibration, which is used by digital feature in SMART. There are I/E(current to voltage), R/E(resistor to voltage), F/E(frequency to voltage), V/V(voltage to voltage). Etc. In this paper show only the signal validation and calibration about I/E converter that convert level, pressure, flow such as 4∼20mA into signal for AD conversion such as 0∼10Vdc

The Metacognitive Anger Processing (MAP) Scale - Validation in a Mixed Clinical and a Forensic In-Patient Sample

DEFF Research Database (Denmark)

Moeller, Stine Bjerrum; Bech, Per

2018-01-01

BACKGROUND: The metacognitive approach by Wells and colleagues has gained empirical support with a broad range of symptoms. The Metacognitive Anger Processing (MAP) scale was developed to provide a metacognitive measure on anger (Moeller, 2016). In the preliminary validation, three components were...... identified (positive beliefs, negative beliefs and rumination) to be positively correlated with the anger. AIMS: To validate the MAP in a sample of mixed clinical patients (n = 88) and a sample of male forensic patients (n = 54). METHOD: The MAP was administered together with measures of metacognition, anger......, rumination, anxiety and depressive symptoms. RESULTS: The MAP showed acceptable scalability and excellent reliability. Convergent validity was evidenced using the general metacognitive measure (MCQ-30), and concurrent validity was supported using two different anger measures (STAXI-2 and NAS). CONCLUSIONS...

The release code package REVOLS/RENONS for fission product release from a liquid sodium pool into an inert gas atmosphere

International Nuclear Information System (INIS)

Starflinger, J.; Scholtyssek, W.; Unger, H.

1994-12-01

For aerosol source term considerations in the field of nuclear safety, the investigation of the release of volatile and non-volatile species from liquid surfaces into a gas atmosphere is important. In case of a hypothetical liquid metal fast breeder reactor accident with tank failure, primary coolant sodium with suspended or solved fuel particles and fission products may be released into the containment. The computer code package REVOLS/RENONS, based on a theoretical mechanistic model with a modular structure, has been developed for the prediction of sodium release as well as volatile and non-volatile radionuclide release from a liquid pool surface into the inert gas atmosphere of the inner containment. Hereby the release of sodium and volatile fission products, like cesium and sodium iodide, is calculated using a theoretical model in a mass transfer coefficient formulation. This model has been transposed into the code version REVOLS.MOD1.1, which is discussed here. It enables parameter analysis under highly variable user-defined boundary conditions. Whereas the evaporative release of the volatile components is governed by diffusive and convective transport processes, the release of the non-volatile ones may be governed by mechanical processes which lead to droplet entrainment from the wavy pool surface under conditions of natural or forced convection into the atmosphere. The mechanistic model calculates the liquid entrainment rate of the non-volatile species, like the fission product strontium oxide and the fuel (uranium dioxide) from a liquid pool surface into a parallel gas flow. The mechanistic model has been transposed into the computer code package REVOLS/RENONS, which is discussed here. Hereby the module REVOLS (RElease of VOLatile Species) calculates the evaporative release of the volatile species, while the module RENONS (RElease of NON-Volatile Species) computes the entrainment release of the non-volatile radionuclides. (orig./HP) [de

THE RADIAL VELOCITY EXPERIMENT (RAVE): THIRD DATA RELEASE

International Nuclear Information System (INIS)

Siebert, A.; Williams, M. E. K.; Siviero, A.; Boeche, C.; Steinmetz, M.; De Jong, R. S.; Enke, H.; Anguiano, B.; Reid, W.; Ritter, A.; Fulbright, J.; Wyse, R. F. G.; Munari, U.; Zwitter, T.; Watson, F. G.; Burton, D.; Cass, C. J. P.; Fiegert, K.; Hartley, M.; Russel, K. S.

2011-01-01

We present the third data release of the RAdial Velocity Experiment (RAVE) which is the first milestone of the RAVE project, releasing the full pilot survey. The catalog contains 83,072 radial velocity measurements for 77,461 stars in the southern celestial hemisphere, as well as stellar parameters for 39,833 stars. This paper describes the content of the new release, the new processing pipeline, as well as an updated calibration for the metallicity based upon the observation of additional standard stars. Spectra will be made available in a future release. The data release can be accessed via the RAVE Web site.

Enhancement of the use of digital mock-ups in the verification and validation process for ITER remote handling systems

Energy Technology Data Exchange (ETDEWEB)

Sibois, R., E-mail: romain.sibois@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1300, 33101 Tampere (Finland); Salminen, K.; Siuko, M. [VTT Technical Research Centre of Finland, P.O. Box 1300, 33101 Tampere (Finland); Mattila, J. [Tampere University of Technology, Korkeakoulunkatu 6, 33720 Tampere (Finland); Määttä, T. [VTT Technical Research Centre of Finland, P.O. Box 1300, 33101 Tampere (Finland)

2013-10-15

Highlights: • Verification and validation process for ITER remote handling system. • Verification and validation framework for complex engineering systems. • Verification and validation roadmap for digital modelling phase. • Importance of the product life-cycle management in the verification and validation framework. -- Abstract: The paper is part of the EFDA's programme of European Goal Oriented Training programme on remote handling (RH) “GOT-RH”. The programme aims to train engineers for activities supporting the ITER project and the long-term fusion programme. This paper is written based on the results of a project “verification and validation (V and V) of ITER RH system using digital mock-ups (DMUs)”. The purpose of this project is to study efficient approach of using DMU for the V and V of the ITER RH system design utilizing a system engineering (SE) framework. This paper reviews the definitions of DMU and virtual prototype and overviews the current trends of using virtual prototyping in the industry during the early design phase. Based on the survey of best industrial practices, this paper proposes ways to improve the V and V process for ITER RH system utilizing DMUs.

Poly(dimethylsiloxane) coatings for controlled drug release--polymer modifications.

Science.gov (United States)

Schulze Nahrup, J; Gao, Z M; Mark, J E; Sakr, A

2004-02-11

Modifications of endhydroxylated poly(dimethylsiloxane) (PDMS) formulations were studied for their ability to be applied onto tablet cores in a spray-coating process and to control drug release in zero-order fashion. Modifications of the crosslinker from the most commonly used tetraethylorthosilicate (TEOS) to the trifunctional 3-(2,3-epoxypropoxy)propyltrimethoxysilane (SIG) and a 1:1 mixture of the two were undertaken. Addition of methylpolysiloxane-copolymers were studied. Lactose, microcrystalline cellulose (MCC) and polyethylene glycol 8000 (PEG) were the channeling agents applied. The effects on dispersion properties were characterized by particle size distribution and viscosity. Mechanical properties of resulting free films were studied to determine applicability in a pan-coating process. Release of hydrochlorothiazide (marker drug) was studied from tablets coated in a lab-size conventional coating pan. All dispersions were found suitable for a spray-coating process. Preparation of free films showed that copolymer addition was not possible due to great decline in mechanical properties. Tablets coated with formulations containing PEG were most suitable to control drug release, at only 5% coating weight. Constant release rates could be achieved for formulations with up to 25% PEG; higher amounts resulted in a non-linear release pattern. Upon adding 50% PEG, a drug release of 63% over 24 h could be achieved.

Preparation of temperature responsive fragrance release membranes by UV curing

International Nuclear Information System (INIS)

Nakayama, Hiroshi; Kaetsu, Isao; Uchida, Kumao; Okuda, Jyunya; Kitami, Toshiaki; Matsubara, Yoshio

2003-01-01

The authors have studied the preparation and the function of intelligent drug release membranes by UV curing. Temperature responsive fragrance release membranes were prepared by UV curing process and the release functions were investigated as the function of thickness and composition of membrane. Microscopic observations were used to prove the postulated release mechanism

Controlled release of biofunctional substances by radiation-induced polymerization

International Nuclear Information System (INIS)

Yoshida, M.; Kumakura, M.; Kaetsu, I.

1978-01-01

The release behaviour of a drug from flat circular capsules obtained by radiation-induced polymerization at low temperatures and with different hydrophilic properties has been studied. The effect of various factors on release property was investigated. The release process could be divided into three parts, an initial quick release stage, stationary state release stage and a retarded release stage. Release behaviour in the stationary state was examined using Noyes-Whitney and Higuchi equations. It was shown that the hydrophilic property of polymer matrix expressed by water content was the most important effect on diffusion and release rate. Rigidity of the polymer may also affect diffusivity. The first quick release step could be attributed to rapid dissolution of drug in the matrix surface due to polymer swelling. (author)

FACTAR validation

International Nuclear Information System (INIS)

Middleton, P.B.; Wadsworth, S.L.; Rock, R.C.; Sills, H.E.; Langman, V.J.

1995-01-01

A detailed strategy to validate fuel channel thermal mechanical behaviour codes for use of current power reactor safety analysis is presented. The strategy is derived from a validation process that has been recently adopted industry wide. Focus of the discussion is on the validation plan for a code, FACTAR, for application in assessing fuel channel integrity safety concerns during a large break loss of coolant accident (LOCA). (author)

HEPA filter leaching concept validation trials at the Idaho Chemical Processing Plant

International Nuclear Information System (INIS)

Chakravartty, A.C.

1995-04-01

The enclosed report documents six New Waste Calcining Facility (NWCF) HEPA filter leaching trials conducted at the Idaho Chemical Processing Plant using a filter leaching system to validate the filter leaching treatment concept. The test results show that a modified filter leaching system will be able to successfully remove both hazardous and radiological constituents to RCRA disposal levels. Based on the success of the filter leach trials, the existing leaching system will be modified to provide a safe, simple, effective, and operationally flexible filter leaching system

Correlation of recent fission product release data

International Nuclear Information System (INIS)

Kress, T.S.; Lorenz, R.A.; Nakamura, T.; Osborne, M.F.

1989-01-01

For the calculation of source terms associated with severe accidents, it is necessary to model the release of fission products from fuel as it heats and melts. Perhaps the most definitive model for fission product release is that of the FASTGRASS computer code developed at Argonne National Laboratory. There is persuasive evidence that these processes, as well as additional chemical and gas phase mass transport processes, are important in the release of fission products from fuel. Nevertheless, it has been found convenient to have simplified fission product release correlations that may not be as definitive as models like FASTGRASS but which attempt in some simple way to capture the essence of the mechanisms. One of the most widely used such correlation is called CORSOR-M which is the present fission product/aerosol release model used in the NRC Source Term Code Package. CORSOR has been criticized as having too much uncertainty in the calculated releases and as not accurately reproducing some experimental data. It is currently believed that these discrepancies between CORSOR and the more recent data have resulted because of the better time resolution of the more recent data compared to the data base that went into the CORSOR correlation. This document discusses a simple correlational model for use in connection with NUREG risk uncertainty exercises. 8 refs., 4 figs., 1 tab

Electrosprayed nanoparticle delivery system for controlled release

Energy Technology Data Exchange (ETDEWEB)

Eltayeb, Megdi, E-mail: megdi.eltayeb@sustech.edu [Department of Biomedical Engineering, Sudan University of Science and Technology, PO Box 407, Khartoum (Sudan); Stride, Eleanor, E-mail: eleanor.stride@eng.ox.ac.uk [Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Old Road Campus Research Building, Headington OX3 7DQ (United Kingdom); Edirisinghe, Mohan, E-mail: m.edirisinghe@ucl.ac.uk [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Harker, Anthony, E-mail: a.harker@ucl.ac.uk [London Centre for Nanotechnology, Gordon Street, London WC1H 0AH (United Kingdom); Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2016-09-01

This study utilises an electrohydrodynamic technique to prepare core-shell lipid nanoparticles with a tunable size and high active ingredient loading capacity, encapsulation efficiency and controlled release. Using stearic acid and ethylvanillin as model shell and active ingredients respectively, we identify the processing conditions and ratios of lipid:ethylvanillin required to form nanoparticles. Nanoparticles with a mean size ranging from 60 to 70 nm at the rate of 1.37 × 10{sup 9} nanoparticles per minute were prepared with different lipid:ethylvanillin ratios. The polydispersity index was ≈ 21% and the encapsulation efficiency ≈ 70%. It was found that the rate of ethylvanillin release was a function of the nanoparticle size, and lipid:ethylvanillin ratio. The internal structure of the lipid nanoparticles was studied by transmission electron microscopy which confirmed that the ethylvanillin was encapsulated within a stearic acid shell. Fourier transform infrared spectroscopy analysis indicated that the ethylvanillin had not been affected. Extensive analysis of the release of ethylvanillin was performed using several existing models and a new diffusive release model incorporating a tanh function. The results were consistent with a core-shell structure. - Highlights: • Electrohydrodynamic spraying is used to produce lipid-coated nanoparticles. • A new model is proposed for the release rates of active components from nanoparticles. • The technique has potential applications in food science and medicine. • Electrohydrodynamic processing controlled release lipid nanoparticles.

Development and application of the PBMR fission product release calculation model

International Nuclear Information System (INIS)

Merwe, J.J. van der; Clifford, I.

2008-01-01

At PBMR, long-lived fission product release from spherical fuel spheres is calculated using the German legacy software product GETTER. GETTER is a good tool when performing calculations for fuel spheres under controlled operating conditions, including irradiation tests and post-irradiation heat-up experiments. It has proved itself as a versatile reactor analysis tool, but is rather cumbersome when used for accident and sensitivity analysis. Developments in depressurized loss of forced cooling (DLOFC) accident analysis using GETTER led to the creation of FIssion Product RElease under accident (X) conditions (FIPREX), and later FIPREX-GETTER. FIPREX-GETTER is designed as a wrapper around GETTER so that calculations can be carried out for large numbers of fuel spheres with design and operating parameters that can be stochastically varied. This allows full Monte Carlo sensitivity analyses to be performed for representative cores containing many fuel spheres. The development process and application of FIPREX-GETTER in reactor analysis at PBMR is explained and the requirements for future developments of the code are discussed. Results are presented for a sample PBMR core design under normal operating conditions as well as a suite of design-base accident events, illustrating the functionality of FIPREX-GETTER. Monte Carlo sensitivity analysis principles are explained and presented for each calculation type. The plan and current status of verification and validation (V and V) is described. This is an important and necessary process for all software and calculation model development at PBMR

Once daily, extended release ciprofloxacin for complicated urinary tract infections and acute uncomplicated pyelonephritis.

Science.gov (United States)

Talan, David A; Klimberg, Ira W; Nicolle, Lindsay E; Song, James; Kowalsky, Steven F; Church, Deborah A

2004-02-01

We assessed the efficacy and safety of 1,000 mg extended release ciprofloxacin orally once daily vs conventional 500 mg ciprofloxacin orally twice daily, each for 7 to 14 days, in patients with a complicated urinary tract infection (cUTI) or acute uncomplicated pyelonephritis (AUP). In this prospective, randomized, double-blind, North American multicenter clinical trial adults were stratified based on clinical presentation of cUTI or AUP and randomized to extended release ciprofloxacin or ciprofloxacin twice daily. Efficacy valid patients had positive pretherapy urine cultures (105 or greater cFU/ml) and pyuria within 48 hours of study entry. Bacteriological and clinical outcomes were assessed at the test of cure visit (5 to 11 days after therapy) and the late followup visit (28 to 42 days after therapy). The intent to treat population comprised 1,035 patients (extended release ciprofloxacin in 517 and twice daily in 518), of whom 435 were efficacy valid (cUTI in 343 and AUP in 92). For efficacy valid patients (cUTI and AUP combined) bacteriological eradication rates at test of cure were 89% (183 of 206) vs 85% (195 of 229) (95% CI -2.4%, 10.3%) and clinical cure rates were 97% (198 of 205) vs 94% (211 of 225) (95% CI -1.2%, 6.9%) for extended release vs twice daily ciprofloxacin. Late followup outcomes were consistent with test of cure findings. Eradication rates for Escherichia coli, which accounted for 58% of pathogens, were 97% or greater per group. Drug related adverse event rates were similar for extended release and twice daily ciprofloxacin (13% and 14%, respectively). Extended release ciprofloxacin at a dose of 1,000 mg once daily was as safe and effective as conventional treatment with 500 mg ciprofloxacin twice daily, each given orally for 7 to 14 days in adults with cUTI or AUP. It provides a convenient, once daily, empirical treatment option.

Signal validation with control-room information-processing computers

International Nuclear Information System (INIS)

Belblidia, L.A.; Carlson, R.W.; Russell, J.L. Jr.

1985-01-01

One of the 'lessons learned' from the Three Mile Island accident focuses upon the need for a validated source of plant-status information in the control room. The utilization of computer-generated graphics to display the readings of the major plant instrumentation has introduced the capability of validating signals prior to their presentation to the reactor operations staff. The current operations philosophies allow the operator a quick look at the gauges to form an impression of the fraction of full scale as the basis for knowledge of the current plant conditions. After the introduction of a computer-based information-display system such as the Safety Parameter Display System (SPDS), operational decisions can be based upon precise knowledge of the parameters that define the operation of the reactor and auxiliary systems. The principal impact of this system on the operator will be to remove the continuing concern for the validity of the instruments which provide the information that governs the operator's decisions. (author)

Measurement of Nanoparticles Release during Drilling of Polymer Nanocomposites

Science.gov (United States)

Gendre, L.; Marchante Rodriguez, V.; Abhyankar, H.; Blackburn, K.; Brighton, J. L.

2015-05-01

Nanomaterials are one of the promising technologies of this century. The Project on Emerging Nanotechnologies [1] reports more than 1600 consumer products based on nanotechnology that are currently on the market and advantages link to the reinforcement of polymeric materials using nano-fillers are not to demonstrate anymore. However, the concerns about safety and its consumer perception can slow down the acceptance of nanocomposites. Indeed, during its life-cycle, a nanotechnology-based product can release nano-sized particles exposing workers, consumers and environment and the risk involved in the use and disposal of such particles is not well known. The current legislation concerning chemicals and environment protection doesn't explicitly cover nanomaterials and changes undergone by nanoparticles during the products’ life cycle. Also, the possible physio-chemical changes that the nanoparticles may undergo during its life cycle are unknown. Industries need a standard method to evaluate nanoparticles release during products’ life cycle in order to improve the knowledge in nanomaterials risk assessment and the legislation, and to inform customers about the safety of nanomaterials and nanoproducts. This work aims to propose a replicable method in order to assess the release of nanoparticles during the machining of nanocomposites in a controlled environment. For this purpose, a new experimental set-up was implemented and issues observed in previous methods (background noise due to uncontrolled ambient environment and the process itself, unrepeatable machining parameters) were solved. A characterisation and validation of the chamber used is presented in this paper. Also, preliminary testing on drilling of polymer-based nanocomposites (Polyamide-6/Glass Fibre reinforced with nano-SiO2) manufactured by extrusion and injection moulding were achieved.

Sterile insect supply, emergence, and release

International Nuclear Information System (INIS)

Dowell, R.V.; Worley, J.; Gomes, P.J.

2005-01-01

Insect mass-rearing for a sterile insect technique (SIT) programme is designed to move beyond the large-scale rearing of insects in a laboratory to the industrial production of consistently high-quality insects for sterilization and release. Each facility reflects the unique biology of the insect reared within it, but there are some generalities for all rearing facilities. Rearing insects in self-contained modules offers flexibility, and increased safety from catastrophic occurrences, compared with using a single building which houses all facets of the rearing process. Although mechanizing certain aspects of the rearing steps helps provide a consistently high-quality insect, successful mass-rearing and delivery depends largely upon the human component. Besides production in centralized facilities, insects can be produced from purchased eggs, or nowadays, adult insects are often obtained from specialized satellite emergence/collection facilities. Interest in commercializing insect production and release is increasing. Shipping sterile insects, sometimes over long distances, is now common practice. Procedures for handling and chilling adult insects, and providing food and water prior to release, are continually being improved. Sterile insects are released via static-release receptacles, ground-release systems, or most commonly from the air. The aerial release of chilled sterile insects is the most efficient method of release, especially when aircraft flight paths are guided by a Global Positioning System (GPS) linked to a computer-controlled release mechanism. (author)

IT release management a hands-on guide

CERN Document Server

Howard, Dave

2011-01-01

When implemented correctly, release management can help ensure that quality is integrated throughout the development, implementation, and delivery of services, applications, and infrastructure. This holistic, total cost of ownership approach allows for higher levels of system availability, is more cost effective to maintain, and increases overall stability, maintainability, and reliability. Filled with practical insights, IT Release Management: A Hands-on Guide clearly illustrates the effective implementation of a release process in the real world. It examines the similarities and differences

First do no harm: developing an ethical process of consent and release for digital storytelling in healthcare

Directory of Open Access Journals (Sweden)

Pip Hardy

2015-11-01

Full Text Available Opportunities to disseminate the stories of patients and those who care for them via the internet create new dilemmas with respect to ethical processes of consent and release. The possibility of utilising images as well as words further complicates this issue. Balancing the need to protect the safety and security of those who share their stories with their own desire for their stories to be widely heard presents a complex blend of ethical issues.The Patient Voices programme has been helping people create and share digital stories of healthcare since 2003. During that time, careful thought has been given to the development of a respectful process that both empowers and protects storytellers, affording time at every stage of the process to reflect and make informed decisions about consent, sharing and dissemination. This paper describes how that process has been developed and explores the issues that it was designed to address.

CMS Partial Releases Model, Tools, and Applications. Online and Framework-Light Releases

CERN Document Server

Jones, Christopher D; Meschi, Emilio; Shahzad Muzaffar; Andreas Pfeiffer; Ratnikova, Natalia; Sexton-Kennedy, Elizabeth

2009-01-01

The CMS Software project CMSSW embraces more than a thousand packages organized in subsystems for analysis, event display, reconstruction, simulation, detector description, data formats, framework, utilities and tools. The release integration process is highly automated by using tools developed or adopted by CMS. Packaging in rpm format is a built-in step in the software build process. For several well-defined applications it is highly desirable to have only a subset of the CMSSW full package bundle. For example, High Level Trigger algorithms that run on the Online farm, and need to be rebuilt in a special way, require no simulation, event display, or analysis packages. Physics analysis applications in Root environment require only a few core libraries and the description of CMS specific data formats. We present a model of CMS Partial Releases, used for preparation of the customized CMS software builds, including description of the tools used, the implementation, and how we deal with technical challenges, suc...

Preparation and properties of a drug sustained-release hydrogel film

International Nuclear Information System (INIS)

Yue Ling; Yang Zhanshan; Yang Shuqin; Li Qinghua

2009-01-01

A hydrogel film of drug sustained-release was prepared to accelerate wound healing. The hydrogel films containing drug or not were prepared by the freezing and thawing process. Their properties such as the physicochemical property and the drug release behavior in vitro were studied. Effect of the freezing and thawing process on antimicrobial efficacy of the gentamicin was evaluated by diffusion method. The results indicate that swelling ratio of the hydrogel films freezed for 4h is 841.21% and their gel fraction, tensile strength and elongation at break is 96.10%, 0.222 MPa and 673.50% respectively. The antimicrobial efficacy of the gentamicin has no change. The hydrogel film contained gentamicin releases the antibiotic to peak during 6 h with the cumulative drug release rate of 59.57%. The drug releases continually up to the 5th day. The drug delivery conforms to Higuchi kinetic equation, and mechanism of the drug release is matrix diffusion. The results show that the hydrogel film prepared by the freezing and thawing process display satisfactory physicochemical properties and can be used as a drug delivery system. (authors)

Resveratrol immobilization and release in polymeric hydrogels

International Nuclear Information System (INIS)

Momesso, Roberta Grazzielli Ramos Alves Passarelli

2010-01-01

Resveratrol (3, 4', 5-trihydroxystilbene) is a polyphenolic produced by a wide variety of plants in response to injury and found predominantly in grape skins. This active ingredient has been shown to possess benefits for the health, such as the antioxidant capacity which is related to the prevention of several types of cancer and skin aging. However, the oral bioavailability of resveratrol is poor and makes its topical application interesting. The purpose of this study was to immobilize resveratrol in polymeric hydrogels to obtain a release device for topical use. The polymeric matrices composed of poli(N-vinyl-2-pyrrolidone) (PVP), poly(ethyleneglycol) (PEG) and agar or PVP and glycerol irradiated at 20 kGy dose were physical-chemically characterized by gel fraction and swelling tests and its preliminary biocompatibility by in vitro test of cytotoxicity using the technique of neutral red uptake. Due to low solubility of resveratrol in water, the addition of 2% ethanol to the matrices was verified. All matrices showed a high crosslinking degree, capacity of swelling and the preliminary cytotoxicity test showed nontoxicity effect. The devices were obtained by resveratrol immobilization in polymeric matrices, carried out in a one-or-two-steps process, that is, before or after irradiation, respectively. The one step resveratrol devices were characterized by gel fraction, swelling tests and preliminary biocompatibility, and their properties were maintained even after the resveratrol incorporation. The devices containing 0,05% of resveratrol obtained by one-step process and 0,1% of resveratrol obtained by two-steps process were submitted to the release test during 24 h. Resveratrol quantification was done by high performance liquid chromatography (HPLC). The results obtained in the kinetics of release showed that only the devices obtained by two-step process release the resveratrol, which demonstrate antioxidant capacity after the release. (author)

Idaho National Engineering Laboratory release criteria for decontamination and decommissioning

International Nuclear Information System (INIS)

Dolenc, M.R.; Case, M.J.

1986-01-01

Criteria have been developed for release of Idaho National Engineering Laboratory (INEL) facilities and land areas following decontamination and decommissioning (D and D). Decommissioning release criteria in the form of dose guidelines were proposed by the US Nuclear Regulatory Commission as early as 1980. These criteria were used on an interim basis for INEL D and D projects. However, dose guidelines alone do not adequately cover the criteria necessary to release sites for unrestricted use. In actual practice, other parameters such as pathways analyses, sampling and instrumentation techniques, and implementation procedures are required to develop the basis for unrestricted release of a site. Thus, a rigorous approach for evaluating these other parameters is needed to develop acceptable D and D release criteria. Because of the complex and sensitive nature of the dose and pathways analyses work, a thorough review by experts in those respective fields was desired. Input and support in preparing or reviewing each part of the criteria development task was solicited from several DOE field offices. Experts were identified and contracted to assist in preparing portions of the release criteria, or to serve on a peer-review committee. Thus, the entire release criteria development task was thoroughly reviewed by recognized experts from each DOE field office, to validate technical content of the INEL site-specific document

Development of controlled release spheroids using Buchananiacochinchinesis gum

Directory of Open Access Journals (Sweden)

Narayan Babulal Gaikwad

2013-03-01

Full Text Available Chirauli nut gum was isolated from the bark of Buchanania cochinchinesis (fam. Anacadiacea and was used as a release modifier for the preparation of Diclofenac sodium spheroids using the extrusion spheronization technique. The process was studied for the effects on variables when making spheroids with satisfactory particle shape, size and size distribution. The prepared spheroids were characterized for surface morphology, qualitative surface porosity, friability, bulk density and flow properties. In vitro studies demonstrated that the release exhibited Fickian diffusion kinetics which was confirmed by the Higuchi and the Korsmeyer-Peppas models. The physico-chemical parameters of the gum could be correlated to the in vitro dissolution profile of the spheroids. The spheroids were not able to sustain the drug releases over 12 hours. A greater concentration of Chirauli nut gum and a process that can accommodate such greater concentrations may produce a formulation capable of significant sustained release.

A new mechanistic and engineering fission gas release model for a uranium dioxide fuel

International Nuclear Information System (INIS)

Lee, Chan Bock; Yang, Yong Sik; Kim, Dae Ho; Kim, Sun Ki; Bang, Je Geun

2008-01-01

A mechanistic and engineering fission gas release model (MEGA) for uranium dioxide (UO 2 ) fuel was developed. It was based upon the diffusional release of fission gases from inside the grain to the grain boundary and the release of fission gases from the grain boundary to the external surface by the interconnection of the fission gas bubbles in the grain boundary. The capability of the MEGA model was validated by a comparison with the fission gas release data base and the sensitivity analyses of the parameters. It was found that the MEGA model correctly predicts the fission gas release in the broad range of fuel burnups up to 98 MWd/kgU. Especially, the enhancement of fission gas release in a high-burnup fuel, and the reduction of fission gas release at a high burnup by increasing the UO 2 grain size were found to be correctly predicted by the MEGA model without using any artificial factor. (author)

Savannah River Site offsite hazardous waste shipment data validation report. Revision 1

International Nuclear Information System (INIS)

Casey, C.; Kudera, D.E.; Page, L.A.; Rohe, M.J.

1995-05-01

The objective of this data validation is to verify that waste shipments reported in response to the US Department of Energy Headquarters data request are properly categorized according to DOE-HQ definitions. This report documents all findings and actions resulting from the independent review of the Savannah River Site data submittal, and provides a summary of the SRS data submittal and data validation strategy. The overall hazardous waste management and offsite release process from 1987--1991 is documented, along with an identification and description of the hazardous waste generation facilities. SRS did not ship any hazardous waste offsite before 1987. Sampling and analysis and surface surveying procedures and techniques used in determining offsite releasability of the shipments are also described in this report. SRS reported 150 manifested waste shipments from 1984 to 1991 that included 4,755 drums or lab packs and 13 tankers. Of these waste items, this report categorizes 4,251 as clean (including 12 tankers), 326 as likely clean, 138 as likely radioactive, and 55 as radioactive (including one tanker). Although outside the original scope of this report, 14 manifests from 1992 and 1993 are included, covering 393 drums or lab packs and seven tankers. From the 1992--1993 shipments, 58 drums or lab packs are categorized as radioactive and 16 drums are categorized as likely radioactive. The remainder are categorized as clean

Savannah River Site offsite hazardous waste shipment data validation report. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Casey, C.; Kudera, D.E.; Page, L.A.; Rohe, M.J.

1995-05-01

The objective of this data validation is to verify that waste shipments reported in response to the US Department of Energy Headquarters data request are properly categorized according to DOE-HQ definitions. This report documents all findings and actions resulting from the independent review of the Savannah River Site data submittal, and provides a summary of the SRS data submittal and data validation strategy. The overall hazardous waste management and offsite release process from 1987--1991 is documented, along with an identification and description of the hazardous waste generation facilities. SRS did not ship any hazardous waste offsite before 1987. Sampling and analysis and surface surveying procedures and techniques used in determining offsite releasability of the shipments are also described in this report. SRS reported 150 manifested waste shipments from 1984 to 1991 that included 4,755 drums or lab packs and 13 tankers. Of these waste items, this report categorizes 4,251 as clean (including 12 tankers), 326 as likely clean, 138 as likely radioactive, and 55 as radioactive (including one tanker). Although outside the original scope of this report, 14 manifests from 1992 and 1993 are included, covering 393 drums or lab packs and seven tankers. From the 1992--1993 shipments, 58 drums or lab packs are categorized as radioactive and 16 drums are categorized as likely radioactive. The remainder are categorized as clean.

Bcl-2 and Bcl-xL overexpression inhibits cytochrome c release, activation of multiple caspases, and virus release following coxsackievirus B3 infection

International Nuclear Information System (INIS)

Carthy, Christopher M.; Yanagawa, Bobby; Luo Honglin; Granville, David J.; Yang, Decheng; Cheung, Paul; Cheung, Caroline; Esfandiarei, Mitra; Rudin, Charles M.; Thompson, Craig B.; Hunt, David W.C.; McManus, Bruce M.

2003-01-01

Coxsackievirus B3, a cytopathic virus in the family Picornaviridae, induces degenerative changes in host cell morphology. Here we demonstrate cytochrome c release and caspases-2, -3, -6, -7, -8, and -9 processing. Enforced Bcl-2 and Bcl-xL expression markedly reduced release of cytochrome c, presentation of the mitochondrial epitope 7A6, and depressed caspase activation following infection. In comparison, cell death using TRAIL ligand caused caspase-8 processing prior to cytochrome c release and executioner caspases and cell death was only partially rescued by Bcl-2 and Bcl-xL overexpression. Disruption of the mitochondrial inner membrane potential following CVB3 infection was not inhibited by zVAD.fmk treatment. Bcl-2 or Bcl-xL overexpression or zVAD.fmk treatment delayed the loss of host cell viability and decreased progeny virus release following infection. Our data suggest that mitochondrial release of cytochrome c may be an important early event in caspase activation in CVB3 infection, and, as such, may contribute to the loss of host-cell viability and progeny virus release

Review of specific effects in atmospheric dispersion calculations. The impact of source-term characteristics -and the processes that modify them post release- on dry and wet deposition rates

International Nuclear Information System (INIS)

Cooper, P.J.; Underwood, B.Y.; Brearley, I.

1985-01-01

In the first half of the work the source-term characteristics potentially influencing behaviour were identified and examined. It was concluded that a number of source characteristics, in addition to those conventionally provided for consequence assessment, could significantly influence deposition behaviour. Linking with this, a review was undertaken of past reactor-accident risk assessment and more recent source-term studies to pick out information, if any, on the parameters of interest. The second half of the study resulted in a list of processes capable of transforming the released material vis-a-vis deposition characteristics, including processes occurring in the near field associated with the initial release transient and also those occurring over a longer time span as the plume travels downwind. Scoping calculations were performed for some of the processes in the context of idealized accident scenarios, leading to the conclusions that in some circumstances post-release mechanisms could have an important impact on the deposition behaviour of released material. Statistical theory was used to describe the behaviour of a plume both before and after detachment, and the limitations of the theory were discussed. A review of the lateral wind velocity spectra was undertaken so that simplified spectra could be constructed and used to predict the plume behaviour as a function of travel time, stability category and release duration. It was found that commonly used methods of allowing for release duration overpredicted the dependence, in general, upon release duration. For example the adoption of a stability-independent meandering term would lead to the underprediction of threshold effects such as early death and land/crop interdiction. In addition, theory indicated that the 'Y' curves for different stability categories would converge gradually with increasing travel time

GEWEX SRB Shortwave Release 4

Science.gov (United States)

Cox, S. J.; Stackhouse, P. W., Jr.; Mikovitz, J. C.; Zhang, T.

2017-12-01

The NASA/GEWEX Surface Radiation Budget (SRB) project produces shortwave and longwave surface and top of atmosphere radiative fluxes for the 1983-near present time period. Spatial resolution is 1 degree. The new Release 4 uses the newly processed ISCCP HXS product as its primary input for cloud and radiance data. The ninefold increase in pixel number compared to the previous ISCCP DX allows finer gradations in cloud fraction in each grid box. It will also allow higher spatial resolutions (0.5 degree) in future releases. In addition to the input data improvements, several important algorithm improvements have been made since Release 3. These include recalculated atmospheric transmissivities and reflectivities yielding a less transmissive atmosphere. The calculations also include variable aerosol composition, allowing for the use of a detailed aerosol history from the Max Planck Institut Aerosol Climatology (MAC). Ocean albedo and snow/ice albedo are also improved from Release 3. Total solar irradiance is now variable, averaging 1361 Wm-2. Water vapor is taken from ISCCP's nnHIRS product. Results from GSW Release 4 are presented and analyzed. Early comparison to surface measurements show improved agreement.

Conceptualization of Approaches and Thought Processes Emerging in Validating of Model in Mathematical Modeling in Technology Aided Environment

Science.gov (United States)

Hidiroglu, Çaglar Naci; Bukova Güzel, Esra

2013-01-01

The aim of the present study is to conceptualize the approaches displayed for validation of model and thought processes provided in mathematical modeling process performed in technology-aided learning environment. The participants of this grounded theory study were nineteen secondary school mathematics student teachers. The data gathered from the…

Site release in the decommissioning of nuclear installations

International Nuclear Information System (INIS)

Revilla, Jose Luis; Sanz, Maria Teresa; Marugan, Inmaculada; Simon, Inmaculada; Martin, Manuel; Solis, Susana; Sterling, Agustina

2008-01-01

Spanish regulatory framework for the decommissioning process of a nuclear facility ends up with a decommission statement, which releases the licence-holder of the facility from its responsibilities as an operator. It also establishes -where a restricted site release applies- the appropriate future use restrictions, and the responsible of both maintaining such restrictions and ensuring their compliance. Releasing a site implies eliminating all radiological monitoring. The Regulations, however, did not specify either the radiological conditions to be met for the site to be released, or the possibility of a partial release -with or without restrictions-. In case of restricted site release, the Regulations did not specify either the required criteria for such a release. This paper presents the main features of the Safety Instruction IS-13 'Radiological criteria for the release of nuclear facilities sites' issued recently by the Spanish Nuclear Safety Council as a new specific regulation. This Safety Instruction establishes the requirements and conditions for the release of nuclear facility sites, that is, radiological criteria on the effective dose to the public, partial release of nuclear facility sites and restricted release of nuclear facility sites. (author).

Improving the residency admissions process by integrating a professionalism assessment: a validity and feasibility study.

Science.gov (United States)

Bajwa, Nadia M; Yudkowsky, Rachel; Belli, Dominique; Vu, Nu Viet; Park, Yoon Soo

2017-03-01

The purpose of this study was to provide validity and feasibility evidence in measuring professionalism using the Professionalism Mini-Evaluation Exercise (P-MEX) scores as part of a residency admissions process. In 2012 and 2013, three standardized-patient-based P-MEX encounters were administered to applicants invited for an interview at the University of Geneva Pediatrics Residency Program. Validity evidence was gathered for P-MEX content (item analysis); response process (qualitative feedback); internal structure (inter-rater reliability with intraclass correlation and Generalizability); relations to other variables (correlations); and consequences (logistic regression to predict admission). To improve reliability, Kane's formula was used to create an applicant composite score using P-MEX, structured letter of recommendation (SLR), and structured interview (SI) scores. Applicant rank lists using composite scores versus faculty global ratings were compared using the Wilcoxon signed-rank test. Seventy applicants were assessed. Moderate associations were found between pairwise correlations of P-MEX scores and SLR (r = 0.25, P = .036), SI (r = 0.34, P = .004), and global ratings (r = 0.48, P applicants using composite score versus global rating differed significantly (z = 5.41, P improve the reliability of the residency admissions process by improving applicant composite score reliability.

19 CFR 142.50 - Line Release data base corrections or changes.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Line Release data base corrections or changes. 142...; DEPARTMENT OF THE TREASURY (CONTINUED) ENTRY PROCESS Line Release § 142.50 Line Release data base corrections... numbers or bond information on a Line Release Data Loading Sheet as soon as possible. Notification shall...

Double-layer Tablets of Lornoxicam: Validation of Quantification ...

African Journals Online (AJOL)

Double-layer Tablets of Lornoxicam: Validation of Quantification Method, In vitro Dissolution and Kinetic Modelling. ... Satisfactory results were obtained from all the tablet formulations met compendial requirements. The slowest drug release rate was obtained with tablet cores based on PVP K90 (1.21 mg%.h-1).

Temperature-regulated guest admission and release in microporous materials

Science.gov (United States)

Li, Gang (Kevin); Shang, Jin; Gu, Qinfen; Awati, Rohan V.; Jensen, Nathan; Grant, Andrew; Zhang, Xueying; Sholl, David S.; Liu, Jefferson Z.; Webley, Paul A.; May, Eric F.

2017-06-01

While it has long been known that some highly adsorbing microporous materials suddenly become inaccessible to guest molecules below certain temperatures, previous attempts to explain this phenomenon have failed. Here we show that this anomalous sorption behaviour is a temperature-regulated guest admission process, where the pore-keeping group's thermal fluctuations are influenced by interactions with guest molecules. A physical model is presented to explain the atomic-level chemistry and structure of these thermally regulated micropores, which is crucial to systematic engineering of new functional materials such as tunable molecular sieves, gated membranes and controlled-release nanocontainers. The model was validated experimentally with H2, N2, Ar and CH4 on three classes of microporous materials: trapdoor zeolites, supramolecular host calixarenes and metal-organic frameworks. We demonstrate how temperature can be exploited to achieve appreciable hydrogen and methane storage in such materials without sustained pressure. These findings also open new avenues for gas sensing and isotope separation.

Preliminary Process Theory does not validate the Comparison Question Test: A comment on Palmatier and Rovner

NARCIS (Netherlands)

Ben-Shakar, G.; Gamer, M.; Iacono, W.; Meijer, E.; Verschuere, B.

2015-01-01

Palmatier and Rovner (2015) attempt to establish the construct validity of the Comparison Question Test (CQT) by citing extensive research ranging from modern neuroscience to memory and psychophysiology. In this comment we argue that merely citing studies on the preliminary process theory (PPT) of

Validity of High School Physic Module With Character Values Using Process Skill Approach In STKIP PGRI West Sumatera

Science.gov (United States)

Anaperta, M.; Helendra, H.; Zulva, R.

2018-04-01

This study aims to describe the validity of physics module with Character Oriented Values Using Process Approach Skills at Dynamic Electrical Material in high school physics / MA and SMK. The type of research is development research. The module development model uses the development model proposed by Plomp which consists of (1) preliminary research phase, (2) the prototyping phase, and (3) assessment phase. In this research is done is initial investigation phase and designing. Data collecting technique to know validation is observation and questionnaire. In the initial investigative phase, curriculum analysis, student analysis, and concept analysis were conducted. In the design phase and the realization of module design for SMA / MA and SMK subjects in dynamic electrical materials. After that, the formative evaluation which include self evaluation, prototyping (expert reviews, one-to-one, and small group. At this stage validity is performed. This research data is obtained through the module validation sheet, which then generates a valid module.

Statistical sampling method for releasing decontaminated vehicles

International Nuclear Information System (INIS)

Lively, J.W.; Ware, J.A.

1996-01-01

Earth moving vehicles (e.g., dump trucks, belly dumps) commonly haul radiologically contaminated materials from a site being remediated to a disposal site. Traditionally, each vehicle must be surveyed before being released. The logistical difficulties of implementing the traditional approach on a large scale demand that an alternative be devised. A statistical method (MIL-STD-105E, open-quotes Sampling Procedures and Tables for Inspection by Attributesclose quotes) for assessing product quality from a continuous process was adapted to the vehicle decontamination process. This method produced a sampling scheme that automatically compensates and accommodates fluctuating batch sizes and changing conditions without the need to modify or rectify the sampling scheme in the field. Vehicles are randomly selected (sampled) upon completion of the decontamination process to be surveyed for residual radioactive surface contamination. The frequency of sampling is based on the expected number of vehicles passing through the decontamination process in a given period and the confidence level desired. This process has been successfully used for 1 year at the former uranium mill site in Monticello, Utah (a CERCLA regulated clean-up site). The method forces improvement in the quality of the decontamination process and results in a lower likelihood that vehicles exceeding the surface contamination standards are offered for survey. Implementation of this statistical sampling method on Monticello Projects has resulted in more efficient processing of vehicles through decontamination and radiological release, saved hundreds of hours of processing time, provided a high level of confidence that release limits are met, and improved the radiological cleanliness of vehicles leaving the controlled site

Using Healthcare Failure Mode and Effect Analysis to reduce medication errors in the process of drug prescription, validation and dispensing in hospitalised patients.

Science.gov (United States)

Vélez-Díaz-Pallarés, Manuel; Delgado-Silveira, Eva; Carretero-Accame, María Emilia; Bermejo-Vicedo, Teresa

2013-01-01

To identify actions to reduce medication errors in the process of drug prescription, validation and dispensing, and to evaluate the impact of their implementation. A Health Care Failure Mode and Effect Analysis (HFMEA) was supported by a before-and-after medication error study to measure the actual impact on error rate after the implementation of corrective actions in the process of drug prescription, validation and dispensing in wards equipped with computerised physician order entry (CPOE) and unit-dose distribution system (788 beds out of 1080) in a Spanish university hospital. The error study was carried out by two observers who reviewed medication orders on a daily basis to register prescription errors by physicians and validation errors by pharmacists. Drugs dispensed in the unit-dose trolleys were reviewed for dispensing errors. Error rates were expressed as the number of errors for each process divided by the total opportunities for error in that process times 100. A reduction in prescription errors was achieved by providing training for prescribers on CPOE, updating prescription procedures, improving clinical decision support and automating the software connection to the hospital census (relative risk reduction (RRR), 22.0%; 95% CI 12.1% to 31.8%). Validation errors were reduced after optimising time spent in educating pharmacy residents on patient safety, developing standardised validation procedures and improving aspects of the software's database (RRR, 19.4%; 95% CI 2.3% to 36.5%). Two actions reduced dispensing errors: reorganising the process of filling trolleys and drawing up a protocol for drug pharmacy checking before delivery (RRR, 38.5%; 95% CI 14.1% to 62.9%). HFMEA facilitated the identification of actions aimed at reducing medication errors in a healthcare setting, as the implementation of several of these led to a reduction in errors in the process of drug prescription, validation and dispensing.

Verification and validation of RADMODL Version 1.0

International Nuclear Information System (INIS)

Kimball, K.D.

1993-03-01

RADMODL is a system of linked computer codes designed to calculate the radiation environment following an accident in which nuclear materials are released. The RADMODL code and the corresponding Verification and Validation (V ampersand V) calculations (Appendix A), were developed for Westinghouse Savannah River Company (WSRC) by EGS Corporation (EGS). Each module of RADMODL is an independent code and was verified separately. The full system was validated by comparing the output of the various modules with the corresponding output of a previously verified version of the modules. The results of the verification and validation tests show that RADMODL correctly calculates the transport of radionuclides and radiation doses. As a result of this verification and validation effort, RADMODL Version 1.0 is certified for use in calculating the radiation environment following an accident

Verification and validation of RADMODL Version 1.0

Energy Technology Data Exchange (ETDEWEB)

Kimball, K.D.

1993-03-01

RADMODL is a system of linked computer codes designed to calculate the radiation environment following an accident in which nuclear materials are released. The RADMODL code and the corresponding Verification and Validation (V&V) calculations (Appendix A), were developed for Westinghouse Savannah River Company (WSRC) by EGS Corporation (EGS). Each module of RADMODL is an independent code and was verified separately. The full system was validated by comparing the output of the various modules with the corresponding output of a previously verified version of the modules. The results of the verification and validation tests show that RADMODL correctly calculates the transport of radionuclides and radiation doses. As a result of this verification and validation effort, RADMODL Version 1.0 is certified for use in calculating the radiation environment following an accident.

Chromium(VI) release from leather and metals can be detected with a diphenylcarbazide spot test.

Science.gov (United States)

Bregnbak, David; Johansen, Jeanne D; Jellesen, Morten S; Zachariae, Claus; Thyssen, Jacob P

2015-11-01

Along with chromium, nickel and cobalt are the clinically most important metal allergens. However, unlike for nickel and cobalt, there is no validated colorimetric spot test that detects chromium. Such a test could help both clinicians and their patients with chromium dermatitis to identify culprit exposures. To evaluate the use of diphenylcarbazide (DPC) as a spot test reagent for the identification of chromium(VI) release. A colorimetric chromium(VI) spot test based on DPC was prepared and used on different items from small market surveys. The DPC spot test was able to identify chromium(VI) release at 0.5 ppm without interference from other pure metals, alloys, or leather. A market survey using the test showed no chromium(VI) release from work tools (0/100). However, chromium(VI) release from metal screws (7/60), one earring (1/50), leather shoes (4/100) and leather gloves (6/11) was observed. We found no false-positive test reactions. Confirmatory testing was performed with X-ray fluorescence (XRF) and spectrophotometrically on extraction fluids. The use of DPC as a colorimetric spot test reagent appears to be a good and valid test method for detecting the release of chromium(VI) ions from leather and metal articles. The spot test has the potential to become a valuable screening tool. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

EQCM verification of the concept of drug immobilization and release from conducting polymer matrix

International Nuclear Information System (INIS)

Krukiewicz, Katarzyna; Bednarczyk-Cwynar, Barbara; Turczyn, Roman; Zak, Jerzy K.

2016-01-01

Highlights: • Disuccinyl derivative of anti-cancer drug, betulin, was immobilized in PEDOT matrix. • EQCM was used to monitor the processes of drug immobilization and release. • SEM, EDS and IR confirmed the presence of drug in polymer matrix. • The release of drug was performed with and without application of external potential. • Potentiodynamic stimulation was more efficient that potentiostatic release. - Abstract: Local drug delivery based on conducting polymer carriers is an innovative approach of medical treatment joining the concept of regional release of biomolecules with ion-exchange properties of conjugated polymers. In this study, we have applied electrochemical quartz crystal microbalance (EQCM) to monitor the process of three-step immobilization and release of anti-cancer drug, disuccinyl derivative of betulin, in PEDOT matrix. Each step of this process has been carefully investigated, i.e. electrochemical polymerization of monomer in the absence of drug, removal of primary dopant during the process of matrix reduction and drug incorporation during the process of matrix oxidation. The release of drug from PEDOT matrix has been performed via three paths, i.e. spontaneous release with no application of external potential, active release under potentiostatic conditions and active release under potentiodynamic conditions. EDS elemental analysis, scanning electron microscopy, IR and Raman spectroscopies, have been used to analyze structural and surface properties of drug-loaded PEDOT matrices.

Flavor release measurement by atmospheric pressure chemical ionization ion trap mass spectrometry, construction of interface and mathematical modeling of release profiles

DEFF Research Database (Denmark)

Haahr, Anne-Mette; Madsen, Henrik; Smedsgaard, Jørn

2003-01-01

and the method can be used to measure breath from the nose. A mathematical model of the data was developed to give a quantitative method for description and characterization of the release of flavor compounds. The release profiles consisted of two sequences, one for a chewing period, and one for a phasing out...... process. The proposed method for modeling provided a reasonable description of the release process. In addition to flavor compounds, this new interface and mathematical application could provide information on chemicals in the human breath which could be interesting, for example, within medical diagnosis....... with that of the flavor detection threshold. An application study on the release of menthone and menthol from chewing gum by a group of six test persons was performed. Flavored chewing gum was used as a model matrix because of the long chewing periods and the simplicity of the system. It is concluded that the interface...

Drug kinetics release from Eudragit – Tenofovir@SiOC tablets

Energy Technology Data Exchange (ETDEWEB)

Tamayo, A., E-mail: aitanath@icv.csic.es [Ceramics and Glass Institute, CSIC, Madrid (Spain); Mazo, M.A. [Ceramics and Glass Institute, CSIC, Madrid (Spain); Veiga, M.D.; Ruiz-Caro, R.; Notario-Pérez, F. [Dpt. Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid (Spain); Rubio, J. [Ceramics and Glass Institute, CSIC, Madrid (Spain)

2017-06-01

A novel drug release system has been obtained in form of tablets from Eudragit® RS and tenofovir loaded on porous silicon oxycarbide glasses (SiOC). Active carbon (AC) and mesoporous silica (MCM-41) have also been used for comparative purposes. The porous silicon oxycarbide presents a bimodal mesopore size distribution that is maintained after functionalization with amino groups. We have studied the adsorption kinetics and adsorption equilibrium when the materials are loaded with tenofovir and, in all cases, pseudo-second order kinetics and Langmuir isotherm have been revealed as the most representative models describing the kinetic and thermodynamic parameters. Besides, the tenofovir adsorption on these materials turns out to be a favorable process. In vitro release of tenofovir has been studied in simulated vaginal medium by applying different release models. Continuous tenofovir release for > 20 days has been obtained for the SiOC material functionalized with amine groups. We concluded that the drug release occurs in two steps that involve a drug diffusion step through the material pores and diffusion through the swollen polymer. The interactions between the tenofovir drug and de amine groups of the functionalized silicon oxycarbide also play an important role in the release process. - Highlights: • Kinetic and thermodinamic parameters of the adsorption of tenofovir on porous substrates have been obtained. • Sustained release of TFV for > 20 days in SVF when it is supported on SiOC and manufactured as Eudragit®RS-containing tablets. • Release described by a two-step process involving diffusion through SiOC matrix and subsequent diffusion through the polymer.

Release of Streptomyces albus propagules from contaminated surfaces

International Nuclear Information System (INIS)

Gorny, R.L.; Mainelis, Gediminas; Grinshpun, Sergey A.; Willeke, Klaus; Dutkiewicz, Jacek; Reponen, Tiina

2003-01-01

The release of Streptomyces albus propagules from contaminated agar an ceiling tile surfaces was studied under controlled environmental condition in a newly developed aerosolization chamber. The experiments revealed tha both spores and cell fragments can be simultaneously released from the colonized surface by relatively gentle air currents of 0.3 m s -1 . A 100x increase of the air velocity can result in a 50-fold increase in the number of released propagules. The aerosolization rate depends strongly on the typ and roughness of the contaminated surface. Up to 90% of available actinomycete propagules can become airborne during the first 10 min of th release process. Application of vibration to the surface did not reveal an influence on the aerosolization process of S. albus propagules under th tested conditions. This study has shown that propagules in the fine particle size range can be released in large amounts from contaminated surfaces Measurement of the number of S. albus fragments in the vicinity of contaminated area, as an alternative to conventional air or surface sampling appears to be a promising approach for quantitative exposure assessment

Comprehensive validation scheme for in situ fiber optics dissolution method for pharmaceutical drug product testing.

Science.gov (United States)

Mirza, Tahseen; Liu, Qian Julie; Vivilecchia, Richard; Joshi, Yatindra

2009-03-01

There has been a growing interest during the past decade in the use of fiber optics dissolution testing. Use of this novel technology is mainly confined to research and development laboratories. It has not yet emerged as a tool for end product release testing despite its ability to generate in situ results and efficiency improvement. One potential reason may be the lack of clear validation guidelines that can be applied for the assessment of suitability of fiber optics. This article describes a comprehensive validation scheme and development of a reliable, robust, reproducible and cost-effective dissolution test using fiber optics technology. The test was successfully applied for characterizing the dissolution behavior of a 40-mg immediate-release tablet dosage form that is under development at Novartis Pharmaceuticals, East Hanover, New Jersey. The method was validated for the following parameters: linearity, precision, accuracy, specificity, and robustness. In particular, robustness was evaluated in terms of probe sampling depth and probe orientation. The in situ fiber optic method was found to be comparable to the existing manual sampling dissolution method. Finally, the fiber optic dissolution test was successfully performed by different operators on different days, to further enhance the validity of the method. The results demonstrate that the fiber optics technology can be successfully validated for end product dissolution/release testing. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

Validation of precision powder injection molding process simulations using a spiral test geometry

DEFF Research Database (Denmark)

Marhöfer, Maximilian; Müller, Tobias; Tosello, Guido

2015-01-01

Like in many other areas of engineering, process simulations find application in precision injection molding to assist and optimize the quality and design of precise products and the molding process. Injection molding comprises mainly the manufacturing of plastic components. However, the variant ....... The necessary data and the implementation procedure of the new material models are outlined. In order to validate the simulation studies and evaluate their accuracy, the simulation results are compared with experiments performed using a spiral test geometry...... for powder injection molding. This characterization includes measurements of rheological, thermal, and pvT behavior of the powder-binder-mixes. The acquired material data was used to generate new material models for the database of the commercially available Autodesk Moldflow® simulation software...

On the release of cppxfel for processing X-ray free-electron laser images.

Science.gov (United States)

Ginn, Helen Mary; Evans, Gwyndaf; Sauter, Nicholas K; Stuart, David Ian

2016-06-01

As serial femtosecond crystallography expands towards a variety of delivery methods, including chip-based methods, and smaller collected data sets, the requirement to optimize the data analysis to produce maximum structure quality is becoming increasingly pressing. Here cppxfel , a software package primarily written in C++, which showcases several data analysis techniques, is released. This software package presently indexes images using DIALS (diffraction integration for advanced light sources) and performs an initial orientation matrix refinement, followed by post-refinement of individual images against a reference data set. Cppxfel is released with the hope that the unique and useful elements of this package can be repurposed for existing software packages. However, as released, it produces high-quality crystal structures and is therefore likely to be also useful to experienced users of X-ray free-electron laser (XFEL) software who wish to maximize the information extracted from a limited number of XFEL images.

Modelling isothermal fission gas release

International Nuclear Information System (INIS)

Uffelen, P. van

2002-01-01

The present paper presents a new fission gas release model consisting of two coupled modules. The first module treats the behaviour of the fission gas atoms in spherical grains with a distribution of grain sizes. This module considers single atom diffusion, trapping and fission induced re-solution of gas atoms associated with intragranular bubbles, and re-solution from the grain boundary into a few layers adjacent to the grain face. The second module considers the transport of the fission gas atoms along the grain boundaries. Four mechanisms are incorporated: diffusion controlled precipitation of gas atoms into bubbles, grain boundary bubble sweeping, re-solution of gas atoms into the adjacent grains and gas flow through open porosity when grain boundary bubbles are interconnected. The interconnection of the intergranular bubbles is affected both by the fraction of the grain face occupied by the cavities and by the balance between the bubble internal pressure and the hydrostatic pressure surrounding the bubbles. The model is under validation. In a first step, some numerical routines have been tested by means of analytic solutions. In a second step, the fission gas release model has been coupled with the FTEMP2 code of the Halden Reactor Project for the temperature distribution in the pellets. A parametric study of some steady-state irradiations and one power ramp have been simulated successfully. In particular, the Halden threshold for fission gas release and two simplified FUMEX cases have been computed and are summarised. (author)

Trigger release mechanism for release of mine water to Magela Creek

International Nuclear Information System (INIS)

McQuade, C.V.; McGill, R.A.

1988-01-01

The Ranger Uranium Mine is surrounded by a World Heritage National Park. The strict environmental controls under which the mine operates are based on scientific and social requirements. Release of non-process storm runoff water to the Magela Creek during flood discharge and under controlled conditions has been identified as best practicable technology for the operation of the water management system. Social and political factors have limited this release to a wet season with an annual exceedance probability of one in ten. The first-generation trigger mechanism was based on a percentile analysis of monthly rainfall. The second-generation trigger is based on cumulative monthly volume increase in the retention ponds and is considered to be more applicable to the operation of the mine water management system. 6 figs., 2 tabs

Releases of radioactivity at the Savannah River Plant, 1954--1985

International Nuclear Information System (INIS)

Zeigler, C.C.; Lawrimore, I.B.

1988-07-01

Radioactive releases from Savannah River Plant (SRP) facilities to air, water and earthen seepage basins have been monitored and tabulated throughout the history of the site. The purpose of this report is to provide a source of data on routine releases of radioactivity to air, water and seepage basins that can be used for analyses of trends, environmental impact, etc. As used in this report, routine radioactive releases means radioactive materials that are released through established effluents from process facilities. This report provides a summary of radioactive releases that inflects the release values contained m records and documents from startup through 1985

Fission-product release modelling in the ASTEC integral code: the status of the ELSA module

International Nuclear Information System (INIS)

Plumecocq, W.; Kissane, M.P.; Manenc, H.; Giordano, P.

2003-01-01

Safety assessment of water-cooled nuclear reactors encompasses potential severe accidents where, in particular, the release of fission products (FPs) and actinides into the reactor coolant system (RCS) is evaluated. The ELSA module is used in the ASTEC integral code to model all releases into the RCS. A wide variety of experiments is used for validation: small-scale CRL, ORNL and VERCORS tests; large-scale Phebus-FP tests; etc. Being a tool that covers intact fuel and degraded states, ELSA is being improved maximizing the use of information from degradation modelling. Short-term improvements will include some treatment of initial FP release due to intergranular inventories and implementing models for release of additional structural materials (Sn, Fe, etc.). (author)

Electron sterilization validation techniques using the controlled depth of sterilization process

International Nuclear Information System (INIS)

Cleghorn, D.A.; Nablo, S.V.

1990-01-01

Many pharmaceutical products, especially parenteral drugs, cannot be sterilized with gamma rays or high energy electrons due to the concomitant product degradation. In view of the well-controlled electron energy spectrum available in modern electron processors, it is practical to deliver sterilizing doses over depths considerably less than those defining the thickness of blister-pack constructions or pharmaceutical containers. Because bremsstrahlung and X-ray production are minimized at these low electron energies and in these low Z materials, very high electron: penetrating X-ray dose ratios are possible for the application of the technique. Thin film dosimetric techniques have been developed utilizing radiochromic film in the 10-60 g/m 2 range for determining the surface dose distribution in occluded surface areas where direct electron illumination is not possible. Procedures for validation of the process using dried spore inoculum on the product as well as in good geometry are employed to determine the process lethality and its dependence on product surface geometry. Applications of the process to labile pharmaceuticals in glass and polystyrene syringes are reviewed. It has been applied to the sterilization of commercial sterile products since 1987, and the advantages and the natural limitations of the technique are discussed. (author)

Computational modeling and analysis of iron release from macrophages.

Directory of Open Access Journals (Sweden)

Alka A Potdar

2014-07-01

Full Text Available A major process of iron homeostasis in whole-body iron metabolism is the release of iron from the macrophages of the reticuloendothelial system. Macrophages recognize and phagocytose senescent or damaged erythrocytes. Then, they process the heme iron, which is returned to the circulation for reutilization by red blood cell precursors during erythropoiesis. The amount of iron released, compared to the amount shunted for storage as ferritin, is greater during iron deficiency. A currently accepted model of iron release assumes a passive-gradient with free diffusion of intracellular labile iron (Fe2+ through ferroportin (FPN, the transporter on the plasma membrane. Outside the cell, a multi-copper ferroxidase, ceruloplasmin (Cp, oxidizes ferrous to ferric ion. Apo-transferrin (Tf, the primary carrier of soluble iron in the plasma, binds ferric ion to form mono-ferric and di-ferric transferrin. According to the passive-gradient model, the removal of ferrous ion from the site of release sustains the gradient that maintains the iron release. Subcellular localization of FPN, however, indicates that the role of FPN may be more complex. By experiments and mathematical modeling, we have investigated the detailed mechanism of iron release from macrophages focusing on the roles of the Cp, FPN and apo-Tf. The passive-gradient model is quantitatively analyzed using a mathematical model for the first time. A comparison of experimental data with model simulations shows that the passive-gradient model cannot explain macrophage iron release. However, a facilitated-transport model associated with FPN can explain the iron release mechanism. According to the facilitated-transport model, intracellular FPN carries labile iron to the macrophage membrane. Extracellular Cp accelerates the oxidation of ferrous ion bound to FPN. Apo-Tf in the extracellular environment binds to the oxidized ferrous ion, completing the release process. Facilitated-transport model can

Helium release from radioisotope heat sources

Energy Technology Data Exchange (ETDEWEB)

Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

1984-05-01

Diffusion of helium in /sup 238/PuO/sub 2/ fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel.

Helium release from radioisotope heat sources

International Nuclear Information System (INIS)

Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

1984-05-01

Diffusion of helium in 238 PuO 2 fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel

Development of Safety Analysis Codes and Experimental Validation for a Very High Temperature Gas-Cooled Reactor

Energy Technology Data Exchange (ETDEWEB)

Chang, H. Oh, PhD; Cliff Davis; Richard Moore

2004-11-01

The very high temperature gas-cooled reactors (VHTGRs) are those concepts that have average coolant temperatures above 900 degrees C or operational fuel temperatures above 1250 degrees C. These concepts provide the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation and nuclear hydrogen generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperatures to support process heat applications, such as desalination and cogeneration, the VHTGR's higher temperatures are suitable for particular applications such as thermochemical hydrogen production. However, the high temperature operation can be detrimental to safety following a loss-of-coolant accident (LOCA) initiated by pipe breaks caused by seismic or other events. Following the loss of coolant through the break and coolant depressurization, air from the containment will enter the core by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structures and fuel. The oxidation will release heat and accelerate the heatup of the reactor core. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. The Idaho National Engineering and Environmental Laboratory (INEEL) has investigated this event for the past three years for the HTGR. However, the computer codes used, and in fact none of the world's computer codes, have been sufficiently developed and validated to reliably predict this event. New code development, improvement of the existing codes, and experimental validation are imperative to narrow the uncertaninty in the predictions of this type of accident. The objectives of this Korean/United States collaboration are to develop advanced computational methods for VHTGR safety analysis codes and to validate these computer codes.

Release of the 2008 Evaluated Nuclear Data Library (ENDL2008)

Energy Technology Data Exchange (ETDEWEB)

Brown, D A; Descalle, M; Hoffman, R; Kelley, K; Navratil, P; Pruet, J; Summers, N; Thompson, I; Vogt, R

2009-05-08

use in neutronics simulations. There is an ongoing effort to provide all of these radiochemical evaluations, including isomers, in the next major ENDL release. The new library has undergone extensive unclassified testing. All isotopes were required to pass a set of simple tests with both deterministic and Monte Carlo codes to ensure that, at a minimum, they do not cause problems for the transport codes. As well, the data was validated through simulations of historical integral experiments. Calculations for k eigenvalues for a broad array of bare and reflected critical assemblies show a marked improvement over ENDL99 and performance comparable to or better than any other currently available library. In particular, there is now excellent agreement with results for the bare plutonium Jezebel assembly (k=1.0007). Similarly, simulations of photon production and neutron time of flight show, with some exceptions, excellent agreement with the LLNL pulsed sphere experiments. Our intention with this initial release is to engage the programmatic community to begin the process of testing with more complicated unclassified and classified problems. We would greatly appreciate recommendations and any reports of problems or oddities. These will be included in the final release of this database in 2009.

Release of the 2008 Evaluated Nuclear Data Library (ENDL2008)

International Nuclear Information System (INIS)

Brown, D.A.; Descalle, M.; Hoffman, R.; Kelley, K.; Navratil, P.; Pruet, J.; Summers, N.; Thompson, I.; Vogt, R.

2009-01-01

neutronics simulations. There is an ongoing effort to provide all of these radiochemical evaluations, including isomers, in the next major ENDL release. The new library has undergone extensive unclassified testing. All isotopes were required to pass a set of simple tests with both deterministic and Monte Carlo codes to ensure that, at a minimum, they do not cause problems for the transport codes. As well, the data was validated through simulations of historical integral experiments. Calculations for k eigenvalues for a broad array of bare and reflected critical assemblies show a marked improvement over ENDL99 and performance comparable to or better than any other currently available library. In particular, there is now excellent agreement with results for the bare plutonium Jezebel assembly (k=1.0007). Similarly, simulations of photon production and neutron time of flight show, with some exceptions, excellent agreement with the LLNL pulsed sphere experiments. Our intention with this initial release is to engage the programmatic community to begin the process of testing with more complicated unclassified and classified problems. We would greatly appreciate recommendations and any reports of problems or oddities. These will be included in the final release of this database in 2009.

Sustained release biodegradable solid lipid microparticles: Formulation, evaluation and statistical optimization by response surface methodology

Directory of Open Access Journals (Sweden)

Hanif Muhammad

2017-12-01

Full Text Available For preparing nebivolol loaded solid lipid microparticles (SLMs by the solvent evaporation microencapsulation process from carnauba wax and glyceryl monostearate, central composite design was used to study the impact of independent variables on yield (Y1, entrapment efficiency (Y2 and drug release (Y3. SLMs having a 10-40 μm size range, with good rheological behavior and spherical smooth surfaces, were produced. Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry pointed to compatibility between formulation components and the zeta-potential study confirmed better stability due to the presence of negative charge (-20 to -40 mV. The obtained outcomes for Y1 (29-86 %, Y2 (45-83 % and Y3 (49-86 % were analyzed by polynomial equations and the suggested quadratic model were validated. Nebivolol release from SLMs at pH 1.2 and 6.8 was significantly (p 0.85 value (Korsmeyer- Peppas suggested slow erosion along with diffusion. The optimized SLMs have the potential to improve nebivolol oral bioavailability.

Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956)- An Assessment of Quantities released, Off-Site Radiation Doses, and Potential Excess Risks of Thyroid Cancer, Volume 1

International Nuclear Information System (INIS)

Apostoaei, A.I.; Burns, R.E.; Hoffman, F.O.; Ijaz, T.; Lewis, C.J.; Nair, S.K.; Widner, T.E.

1999-01-01

In the early 1990s, concern about the Oak Ridge Reservation's past releases of contaminants to the environment prompted Tennessee's public health officials to pursue an in-depth study of potential off-site health effects at Oak Ridge. This study, the Oak Ridge dose reconstruction, was supported by an agreement between the U.S. Department of Energy (DOE) and the State of Tennessee, and was overseen by a 12-member panel appointed by Tennessee's Commissioner of Health. One of the major contaminants studied in the dose reconstruction was radioactive iodine, which was released to the air by X-10 (now called Oak Ridge National Laboratory) as it processed spent nuclear reactor fuel from 1944 through 1956. The process recovered radioactive lanthanum for use in weapons development. Iodine concentrates in the thyroid gland so health concerns include various diseases of the thyroid, such as thyroid cancer. The large report, ''Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956) - An Assessment of Quantities Released, Off-site Radiation Doses, and Potential Excess Risks of Thyroid Cancer,'' is in two volumes. Volume 1 is the main body of the report, and Volume 1A, which has the same title, consists of 22 supporting appendices. Together, these reports serve the following purposes: (1) describe the methodologies used to estimate the amount of iodine-131 (I-131) released; (2) evaluate I-131's pathway from air to vegetation to food to humans; (3) estimate doses received by human thyroids; (4) estimate excess risk of acquiring a thyroid cancer during ones lifetime; and (5) provide equations, examples of historical documents used, and tables of calculated values. Results indicate that females born in 1952 who consumed milk from a goat pastured a few miles east of X-10 received the highest doses from I-131 and would have had the highest risks of contracting thyroid cancer. Doses from cow's milk are considerably less . Detailed

Role of fission gas release in reactor licensing

International Nuclear Information System (INIS)

1975-11-01

The release of fission gases from oxide pellets to the fuel rod internal voidage (gap) is reviewed with regard to the required safety analysis in reactor licensing. Significant analyzed effects are described, prominent gas release models are reviewed, and various methods used in the licensing process are summarized. The report thus serves as a guide to a large body of literature including company reports and government documents. A discussion of the state of the art of gas release analysis is presented

Processing of thyrotropin-releasing hormone prohormone (pro-TRH) generates a biologically active peptide, prepro-TRH-(160-169), which regulates TRH-induced thyrotropin secretion

International Nuclear Information System (INIS)

Bulant, M.; Vaudry, H.; Roussel, J.P.; Astier, H.; Nicolas, P.

1990-01-01

Rat thyrotropin-releasing hormone (TRH) prohormone contains five copies of the TRH progenitor sequence Gln-His-Pro-Gly linked together by connecting sequences whose biological activity is unknown. Both the predicted connecting peptide prepro-TRH-(160-169) (Ps4) and TRH are predominant storage forms of TRH precursor-related peptides in the hypothalamus. To determine whether Ps4 is co-released with TRH, rat median eminence slices were perfused in vitro. Infusion of depolarizing concentrations of KCl induced stimulation of release of Ps4- and TRH-like immunoreactivity. The possible effect of Ps4 on thyrotropin release was investigated in vitro using quartered anterior pituitaries. Infusion of Ps4 alone had no effect on thyrotropin secretion but potentiated TRH-induced thyrotropin release in a dose-dependent manner. In addition, the occurrence of specific binding sites for 125 I-labeled Tyr-Ps4 in the distal lobe of the pituitary was demonstrated by binding analysis and autoradiographic localization. These findings indicate that these two peptides that arise from a single multifunctional precursor, the TRH prohormone, act in a coordinate manner on the same target cells to promote hormonal secretion. These data suggest that differential processing of the TRH prohormone may have the potential to modulate the biological activity of TRH

FEBEX. Investigations on gas generation, release and migration

International Nuclear Information System (INIS)

Jockwer, Norbert; Wieczorek, Klaus

2008-06-01

The FEBEX project is based on the Spanish reference concept for the disposal of radioactive waste in crystalline rock, which considers the emplacement of the canisters enclosing the conditioned waste surrounded by clay barriers constructed of high-compacted bentonite blocks in horizontal drifts /ENR 957. The whole project consisted of an experimental and a modelling part. The experimental part itself was divided into the in-situ test, a mock-up test performed at the CIEMAT laboratory, and various small-scale laboratory tests. In the modelling part it was expected to develop and validate the thermo-hydro-mechanical (THM) and the thermo-hydro-chemical (THC) processes for the performance assessment of the near-field behaviour. GRS was only involved in the in-situ test and some additional laboratory work with regard to gas generation, gas migration, and pore pressure build-up in the buffer constructed of high-compacted bentonite blocks around the electrical heaters simulating the waste containers. The following topics are covered: installation and dismantling of the heater pipes; methods of gas generation and release measurement, summary of results and discussion

Tunable controlled release of molecular species from Halloysite nanotubes

Science.gov (United States)

Elumalai, Divya Narayan

Encouraged by potential applications in rust coatings, self-healing composites, selective delivery of drugs, and catalysis, the transport of molecular species through Halloysite nanotubes (HNTs), specifically the storage and controlled release of these molecules, has attracted strong interest in recent years. HNTs are a naturally occurring biocompatible nanomaterial that are abundantly and readily available. They are alumosilicate based tubular clay nanotubes with an inner lumen of 15 nm and a length of 600-900 nm. The size of the inner lumen of HNTs may be adjusted by etching. The lumen can be loaded with functional agents like antioxidants, anticorrosion agents, flame-retardant agents, drugs, or proteins, allowing for a sustained release of these agents for hours. The release times can be further tuned for days and months by the addition of tube end-stoppers. In this work a three-dimensional, time-quantified Monte Carlo model that efficiently describes diffusion through and from nanotubes is implemented. Controlled delivery from Halloysite Nanotubes (HNT) is modeled based on interactions between the HNT's inner wall and the nanoparticles (NP) and among NPs themselves. The model was validated using experimental data published in the literature. The validated model is then used to study the effect of multiple parameters like HNT diameter and length, particle charge, ambient temperature and the creation of smart caps at the tube ends on the release of encapsulated NPs. The results show that release profiles depend on the size distribution of the HNT batch used for the experiment, as delivery is sensitive to HNT lumen and length. The effect of the addition of end-caps to the HNTs, on the rate of release of encapsulated NPs is also studied here. The results show that the release profiles are significantly affected by the addition of end caps to the HNTs and is sensitive to the end-cap pore lumen. A very good agreement with the experiment is observed when a weight

Validation of a Process-Based Agro-Ecosystem Model (Agro-IBIS for Maize in Xinjiang, Northwest China

Directory of Open Access Journals (Sweden)

Tureniguli Amuti

2018-03-01

Full Text Available Agricultural oasis expansion and intensive management practices have occurred in arid and semiarid regions of China during the last few decades. Accordingly, regional carbon and water budgets have been profoundly impacted by agroecosystems in these regions. Therefore, study on the methods used to accurately estimate energy, water, and carbon exchanges is becoming increasingly important. Process-based models can represent the complex processes between land and atmosphere among agricultural ecosystems. However, before the models can be applied they must be validated under different environmental and climatic conditions. In this study, a process-based agricultural ecosystem model (Agro-IBIS was validated for maize crops using 3 years of soil and biometric measurements at Wulanwusu agrometeorological site (WAS located in the Shihezi oasis in Xinjiang, northwest China. The model satisfactorily represented leaf area index (LAI during the growing season, simulating its peak values within the magnitude of 0–10%. The total biomass carbon was overestimated by 15%, 8%, and 16% in 2004, 2005, and 2006, respectively. The model satisfactorily simulated the soil temperature (0–10 cm and volumetric water content (VWC (0–25 cm of farmland during the growing season. However, it overestimated soil temperature approximately by 4 °C and VWC by 15–30% during the winter, coinciding with the period of no vegetation cover in Xinjiang. Overall, the results indicate that the model could represent crop growth, and seems to be applicable in multiple sites in arid oases agroecosystems of Xinjiang. Future application of the model will impose more comprehensive validation using eddy covariance flux data, and consider including dynamics of crop residue and improving characterization of the final stage of leaf development.

H2S release rate assessment guidelines and audit forms

International Nuclear Information System (INIS)

Johnson, S.; Wilson, T.; Long, R.; Shewan, K.; Nchkalo, H.; Nelson, R.; Morand, M.

1998-01-01

Development of a process to evaluate and calculate potential hydrogen sulfide release has been recommended by the Canadian Association of Petroleum Producers' Drilling and Completion Committee, and the Alberta Energy and Utilities Board. To facilitate the process, CAPP has released guidelines describing a methodology and standard for the industry to calculate the potential hydrogen sulfide release rates of a well, and a standardized format for the documentation and retention of data. The Guidelines describe a four-step process, with each step having an increasing degree of complexity. Step One describes the zone hydrogen sulfide exclusion area maps, defining when reporting is to be used (based on well location and distance from inhabited areas). Step Two provides details of the recommended method for determining hydrogen sulfide release through a data search process. Step Three consists of a series of instructions in the use of geologic analogs, data editing and wellbore design to further refine the cumulative hydrogen sulfide release rate. Step Four contains information designed to assist in detailed geological and reservoir modeling. It is not necessary to use all four steps in all cases. The user, however, is advised to use sound engineering judgement and due diligence in the calculation decisions. Sample calculations are provided for a variety of different situations. Measurement techniques are described in an appendix. A completed example of an audit form is attached. 10 + 6 refs., tabs

Noble Gas Release Signal as a Precursor to Fracture

Science.gov (United States)

Bauer, S. J.; Lee, H.; Gardner, W. P.

2017-12-01

We present empirical results of rock strain, microfracturing, acoustic emissions, and noble gas release from laboratory triaxial experiments for a granite, basalt, shale and bedded rock salt. Noble gases are released and measured real-time during deformation using mass spectrometry. The gas release represents a precursive signal to macrofracture. Gas release is associated with increased acoustic emissions indicating that microfracturing is required to release gas and create pathways for the gas to be sensed. The gas released depends on initial gas content, pore structure and its evolution during deformation, the deformation amount, matrix permeability, deformation style and the stress/strain history. Gases are released from inter and intracrystalline sites; release rate increases as strain and microfracturing increases. The gas composition depends on lithology, geologic history and age, fluids present, and radioisotope concentrations that affect radiogenic noble gas isotope (e.g. 4He,40Ar) production. Noble gas emission and its relationship to crustal processes such as seismicity and volcanism, tectonic velocities, qualitative estimates of deep permeability, age dating of groundwater, and a signature of nuclear weapon detonation. Our result show that mechanical deformation of crustal materials is an important process controlling gas release from rocks and minerals, and should be considered in techniques which utilize gas release and/or accumulation. We propose using noble gas release to signal rock deformation in boreholes, mines and waste repositories. We postulate each rock exhibits a gas release signature which is microstructure, stress, strain, and/or permanent deformation dependent. Calibration of such relationships, for example relating gas release per rock unit volume to strain may be used to quantify rock deformation and develop predictive models.Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and

Radionuclide releases from natural analogues of spent nuclear fuel

International Nuclear Information System (INIS)

Curtis, D.B.; Fabryka-Martin, J.; Dixon, P.; Aguilar, R.; Rokop, D.; Cramer, J.

1993-01-01

Measures of 99 Tc, 129 I, 239 Pu and U concentrations in rock samples from uranium deposits at Cigar Lake and Koongarra have been used to study processes of radionuclide release from uranium minerals. Rates of release have been immeasurably slow at Cigar Lake. At Koongarra release rates appear to have been faster, producing small deficiencies of 99 Tc, and larger ones of 129 I. The inferred differences in radionuclide release rates are consistent with expected differences in uranium mineral degradation rates produced by the differing hydrogeochemical environments at the two sites

Preparation and scale up of extended-release tablets of bromopride

Directory of Open Access Journals (Sweden)

Guilherme Neves Ferreira

2014-04-01

Full Text Available Reproducibility of the tablet manufacturing process and control of its pharmaceutics properties depends on the optimization of formulation aspects and process parameters. Computer simulation such as Design of Experiments (DOE can be used to scale up the production of this formulation, in particular for obtaining sustained-release tablets. Bromopride formulations are marketed in the form of extended-release pellets, which makes the product more expensive and difficult to manufacture. The aim of this study was to formulate new bromopride sustained release formulations as tablets, and to develop mathematical models to standardize the scale up of this formulation, controlling weight and hardness of the tablets during manufacture according to the USP 34th edition. DOE studies were conducted using Minitab(tm software. Different excipient combinations were evaluated in order to produce bromopride sustained-release matrix tablets. In the scale-up study, data were collected and variations in tableting machine parameters were measured. Data were processed by Minitab(tm software, generating mathematical equations used for prediction of powder compaction behavior, according to the settings of the tableting machine suitable for scale-up purposes. Bromopride matrix tablets with appropriate characteristics for sustained release were developed. The scale-up of the formulation with the most suitable sustained release profile was established by using mathematical models, indicating that the formulation can be a substitute for the pellets currently marketed.

Border cell release

DEFF Research Database (Denmark)

Mravec, Jozef

2017-01-01

Plant border cells are specialised cells derived from the root cap with roles in the biomechanics of root growth and in forming a barrier against pathogens. The mechanism of highly localised cell separation which is essential for their release to the environment is little understood. Here I present...... in situ analysis of Brachypodium distachyon, a model organism for grasses which possess type II primary cell walls poor in pectin content. Results suggest similarity in spatial dynamics of pectic homogalacturonan during dicot and monocot border cell release. Integration of observations from different...... species leads to the hypothesis that this process most likely does not involve degradation of cell wall material but rather employs unique cell wall structural and compositional means enabling both the rigidity of the root cap as well as detachability of given cells on its surface....

Predicting patient exposure to nickel released from cardiovascular devices using multi-scale modeling.

Science.gov (United States)

Saylor, David M; Craven, Brent A; Chandrasekar, Vaishnavi; Simon, David D; Brown, Ronald P; Sussman, Eric M

2018-04-01

Many cardiovascular device alloys contain nickel, which if released in sufficient quantities, can lead to adverse health effects. However, in-vivo nickel release from implanted devices and subsequent biodistribution of nickel ions to local tissues and systemic circulation are not well understood. To address this uncertainty, we have developed a multi-scale (material, tissue, and system) biokinetic model. The model links nickel release from an implanted cardiovascular device to concentrations in peri-implant tissue, as well as in serum and urine, which can be readily monitored. The model was parameterized for a specific cardiovascular implant, nitinol septal occluders, using in-vitro nickel release test results, studies of ex-vivo uptake into heart tissue, and in-vivo and clinical measurements from the literature. Our results show that the model accurately predicts nickel concentrations in peri-implant tissue in an animal model and in serum and urine of septal occluder patients. The congruity of the model with these data suggests it may provide useful insight to establish nickel exposure limits and interpret biomonitoring data. Finally, we use the model to predict local and systemic nickel exposure due to passive release from nitinol devices produced using a wide range of manufacturing processes, as well as general relationships between release rate and exposure. These relationships suggest that peri-implant tissue and serum levels of nickel will remain below 5 μg/g and 10 μg/l, respectively, in patients who have received implanted nitinol cardiovascular devices provided the rate of nickel release per device surface area does not exceed 0.074 μg/(cm 2  d) and is less than 32 μg/d in total. The uncertainty in whether in-vitro tests used to evaluate metal ion release from medical products are representative of clinical environments is one of the largest roadblocks to establishing the associated patient risk. We have developed and validated a multi

Validation of an in vitro digestive system for studying macronutrient decomposition in humans.

Science.gov (United States)

Kopf-Bolanz, Katrin A; Schwander, Flurina; Gijs, Martin; Vergères, Guy; Portmann, Reto; Egger, Lotti

2012-02-01

The digestive process transforms nutrients and bioactive compounds contained in food to physiologically active compounds. In vitro digestion systems have proven to be powerful tools for understanding and monitoring the complex transformation processes that take place during digestion. Moreover, the investigation of the physiological effects of certain nutrients demands an in vitro digestive process that is close to human physiology. In this study, human digestion was simulated with a 3-step in vitro process that was validated in depth by choosing pasteurized milk as an example of a complex food matrix. The evolution and decomposition of the macronutrients was followed over the entire digestive process to the level of intestinal enterocyte action, using protein and peptide analysis by SDS-PAGE, reversed-phase HPLC, size exclusion HPLC, and liquid chromatography-MS. The mean peptide size after in vitro digestion of pasteurized milk was 5-6 amino acids (AA). Interestingly, mostly essential AA (93.6%) were released during in vitro milk digestion, a significantly different relative distribution compared to the total essential AA concentration of bovine milk (44.5%). All TG were degraded to FFA and monoacylglycerols. Herein, we present a human in vitro digestion model validated for its ability to degrade the macronutrients of dairy products comparable to physiological ranges. It is suited to be used in combination with a human intestinal cell culture system, allowing ex vivo bioavailability measurements and assessment of the bioactive properties of food components.

Barrier and operational risk analysis of hydrocarbon releases (BORA-Release)

International Nuclear Information System (INIS)

Sklet, Snorre; Vinnem, Jan Erik; Aven, Terje

2006-01-01

This paper presents results from a case study carried out on an offshore oil and gas production platform with the purpose to apply and test BORA-Release, a method for barrier and operational risk analysis of hydrocarbon releases. A description of the BORA-Release method is given in Part I of the paper. BORA-Release is applied to express the platform specific hydrocarbon release frequencies for three release scenarios for selected systems and activities on the platform. The case study demonstrated that the BORA-Release method is a useful tool for analysing the effect on the release frequency of safety barriers introduced to prevent hydrocarbon releases, and to study the effect on the barrier performance of platform specific conditions of technical, human, operational, and organisational risk influencing factors (RIFs). BORA-Release may also be used to analyse the effect on the release frequency of risk reducing measures

Controlled release system for ametryn using polymer microspheres: Preparation, characterization and release kinetics in water

International Nuclear Information System (INIS)

Grillo, Renato; Pereira, Anderson do Espirito Santo; Ferreira Silva de Melo, Nathalie; Porto, Raquel Martins; Feitosa, Leandro Oliveira; Tonello, Paulo Sergio; Dias Filho, Newton L.; Rosa, Andre Henrique; Lima, Renata; Fraceto, Leonardo Fernandes

2011-01-01

The purpose of this work was to develop a modified release system for the herbicide ametryn by encapsulating the active substance in biodegradable polymer microparticles produced using the polymers poly(hydroxybutyrate) (PHB) or poly(hydroxybutyrate-valerate) (PHBV), in order to both improve the herbicidal action and reduce environmental toxicity. PHB or PHBV microparticles containing ametryn were prepared and the efficiencies of herbicide association and loading were evaluated, presenting similar values of approximately 40%. The microparticles were characterized by scanning electron microscopy (SEM), which showed that the average sizes of the PHB and PHBV microparticles were 5.92 ± 0.74 μm and 5.63 ± 0.68 μm, respectively. The ametryn release profile was modified when it was encapsulated in the microparticles, with slower and more sustained release compared to the release profile of pure ametryn. When ametryn was associated with the PHB and PHBV microparticles, the amount of herbicide released in the same period of time was significantly reduced, declining to 75% and 87%, respectively. For both types of microparticle (PHB and PHBV) the release of ametryn was by diffusion processes due to anomalous transport (governed by diffusion and relaxation of the polymer chains), which did not follow Fick's laws of diffusion. The results presented in this paper are promising, in view of the successful encapsulation of ametryn in PHB or PHBV polymer microparticles, and indications that this system may help reduce the impacts caused by the herbicide, making it an environmentally safer alternative.

Gaseous release of radioactive iodine from decaying plants. I. Release following foliar and root uptake

International Nuclear Information System (INIS)

Saas, Arsene; Grauby, Andre

1975-12-01

Iodine uptake by plants is a significant link in the contamination of the food chain. Long half-live iodine was studied considering foliar and root uptake, loss by rain scavenging, residue decay or outgassing in order to assess two aspects of the problem: the importance of outgassing and the effect of the route of transfer on iodine losses. It appeared that iodine release was a function of the vegetal type, there were differences according to the pattern of absorption (via leaf or root) and the processes of iodine release were usually related to biochemical mechanisms [fr

Environmental Release Prevention and Control Plan

International Nuclear Information System (INIS)

Mamatey, A.; Arnett, M.

1997-01-01

During the history of SRS, continual improvements in facilities, process, and operations, and changes in the site''s mission have reduced the amount of radioactive liquid releases. In the early years of SRS (1958 to 1965), the amount of tritium discharged to the Savannah River averaged approximately 61,000 curies a year. During the mid-1980''s (1983 to 1988), liquid releases of tritium averaged 27,000 curies a year. By 1996, liquid releases of tritium are projected to be just 3000 curies for the year. This large projected decrease is the result of the planned shut-down of all reactors and the anticipated significant decline in the amount of tritium migrating from the site seepage basins and the Solid Waste Disposal Facility

39 CFR 762.28 - Release of original disbursement postal money orders.

Science.gov (United States)

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Release of original disbursement postal money... and Processing of Disbursement Postal Money Orders § 762.28 Release of original disbursement postal money orders. An original Disbursement Postal Money Order may be released to a responsible endorser only...

Herwig++ 2.5 release note

International Nuclear Information System (INIS)

Gieseke, S.; Roehr, C.A.; Siodmok, A.

2011-02-01

A new release of the Monte Carlo program Herwig++ (version 2.5) is now available. This version comes with a number of improvements including: new next-to-leading order matrix elements, including weak boson pair production; a colour reconnection model; diffractive processes; additional models of physics beyond the Standard Model; new leading-order matrix elements for hadron-hadron and lepton-lepton collisions as well as photon-initiated processes. (orig.)

Herwig++ 2.5 release note

Energy Technology Data Exchange (ETDEWEB)

Gieseke, S.; Roehr, C.A.; Siodmok, A. [Karlsruher Institut fuer Technologie, Karlsruhe (DE). Inst. fuer Theoretische Physik] (and others)

2011-02-15

A new release of the Monte Carlo program Herwig++ (version 2.5) is now available. This version comes with a number of improvements including: new next-to-leading order matrix elements, including weak boson pair production; a colour reconnection model; diffractive processes; additional models of physics beyond the Standard Model; new leading-order matrix elements for hadron-hadron and lepton-lepton collisions as well as photon-initiated processes. (orig.)

The influence of spray-drying parameters on phase behavior, drug distribution, and in vitro release of injectable microspheres for sustained release.

Science.gov (United States)

Meeus, Joke; Lenaerts, Maité; Scurr, David J; Amssoms, Katie; Davies, Martyn C; Roberts, Clive J; Van Den Mooter, Guy

2015-04-01

For ternary solid dispersions, it is indispensable to characterize their structure, phase behavior, and the spatial distribution of the dispersed drug as this might influence the release profile and/or stability of these formulations. This study shows how formulation (feed concentration) and process (feed rate, inlet air temperature, and atomizing air pressure) parameters can influence the characteristics of ternary spray-dried solid dispersions. The microspheres considered here consist of a poly(lactic-co-glycolic acid) (PLGA) surface layer and an underlying polyvinylpyrrolidone (PVP) phase. A poorly soluble active pharmaceutical ingredient (API) was molecularly dispersed in this matrix. Differences were observed in component miscibility, phase heterogeneity, particle size, morphology, as well as API surface coverage for selected spray-drying parameters. Observed differences are likely because of changes in the droplet generation, evaporation, and thus particle formation processes. However, varying particle characteristics did not influence the drug release of the formulations studied, indicating the robustness of this approach to produce particles of consistent drug release characteristics. This is likely because of the fact that the release is dominated by diffusion from the PVP layer through pores in the PLGA surface layer and that observed differences in the latter have no influence on the release. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Validation of basophil histamine release against the autologous serum skin test and outcome of serum-induced basophil histamine release studies in a large population of chronic urticaria patients

DEFF Research Database (Denmark)

Platzer, M H; Grattan, C E H; Poulsen, Lars K.

2005-01-01

the immunoglobulin E (IgE) or the high affinity IgE receptor (FcepsilonRI) and serum-induced histamine release (HR) from basophils and mast cells. We have examined the correlation between the ASST and a new basophil histamine-releasing assay (the HR-Urtikaria test) in a group of well-characterized CU patients...... and subsequently determined the frequency of HR-Urticaria-positive sera from a larger population of CU patients....

Lesson 6: Signature Validation

Science.gov (United States)

Checklist items 13 through 17 are grouped under the Signature Validation Process, and represent CROMERR requirements that the system must satisfy as part of ensuring that electronic signatures it receives are valid.

Predictive Simulation of Material Failure Using Peridynamics -- Advanced Constitutive Modeling, Verification and Validation

Science.gov (United States)

2016-03-31

AFRL-AFOSR-VA-TR-2016-0309 Predictive simulation of material failure using peridynamics- advanced constitutive modeling, verification , and validation... Self -explanatory. 8. PERFORMING ORGANIZATION REPORT NUMBER. Enter all unique alphanumeric report numbers assigned by the performing organization, e.g...for public release. Predictive simulation of material failure using peridynamics-advanced constitutive modeling, verification , and validation John T

Validation of the FEA of a deep drawing process with additional force transmission

Science.gov (United States)

Behrens, B.-A.; Bouguecha, A.; Bonk, C.; Grbic, N.; Vucetic, M.

2017-10-01

In order to meet requirements by automotive industry like decreasing the CO2 emissions, which reflects in reducing vehicles mass in the car body, the chassis and the powertrain, the continuous innovation and further development of existing production processes are required. In sheet metal forming processes the process limits and components characteristics are defined through the process specific loads. While exceeding the load limits, a failure in the material occurs, which can be avoided by additional force transmission activated in the deep drawing process before the process limit is achieved. This contribution deals with experimental investigations of a forming process with additional force transmission regarding the extension of the process limits. Based on FEA a tool system is designed and developed by IFUM. For this purpose, the steel material HCT600 is analyzed numerically. Within the experimental investigations, the deep drawing processes, with and without the additional force transmission are carried out. Here, a comparison of the produced rectangle cups is done. Subsequently, the identical deep drawing processes are investigated numerically. Thereby, the values of the punch reaction force and displacement are estimated and compared with experimental results. Thus, the validation of material model is successfully carried out on process scale. For further quantitative verification of the FEA results the experimental determined geometry of the rectangular cup is measured optically with ATOS system of the company GOM mbH and digitally compared with external software Geomagic®QualifyTM. The goal of this paper is the verification of the transferability of the FEA model for a conventional deep drawing process to a deep drawing process with additional force transmission with a counter punch.

Human Factors methods concerning integrated validation of nuclear power plant control rooms; Metodutveckling foer integrerad validering

Energy Technology Data Exchange (ETDEWEB)

Oskarsson, Per-Anders; Johansson, Bjoern J.E.; Gonzalez, Natalia (Swedish Defence Research Agency, Information Systems, Linkoeping (Sweden))

2010-02-15

The frame of reference for this work was existing recommendations and instructions from the NPP area, experiences from the review of the Turbic Validation and experiences from system validations performed at the Swedish Armed Forces, e.g. concerning military control rooms and fighter pilots. These enterprises are characterized by complex systems in extreme environments, often with high risks, where human error can lead to serious consequences. A focus group has been performed with representatives responsible for Human Factors issues from all Swedish NPP:s. The questions that were discussed were, among other things, for whom an integrated validation (IV) is performed and its purpose, what should be included in an IV, the comparison with baseline measures, the design process, the role of SSM, which methods of measurement should be used, and how the methods are affected of changes in the control room. The report brings different questions to discussion concerning the validation process. Supplementary methods of measurement for integrated validation are discussed, e.g. dynamic, psychophysiological, and qualitative methods for identification of problems. Supplementary methods for statistical analysis are presented. The study points out a number of deficiencies in the validation process, e.g. the need of common guidelines for validation and design, criteria for different types of measurements, clarification of the role of SSM, and recommendations for the responsibility of external participants in the validation process. The authors propose 12 measures for taking care of the identified problems

ASTER Global Digital Elevation Model Version 2 - summary of validation results

Science.gov (United States)

Tachikawa, Tetushi; Kaku, Manabu; Iwasaki, Akira; Gesch, Dean B.; Oimoen, Michael J.; Zhang, Z.; Danielson, Jeffrey J.; Krieger, Tabatha; Curtis, Bill; Haase, Jeff; Abrams, Michael; Carabajal, C.; Meyer, Dave

2011-01-01

On June 29, 2009, NASA and the Ministry of Economy, Trade and Industry (METI) of Japan released a Global Digital Elevation Model (GDEM) to users worldwide at no charge as a contribution to the Global Earth Observing System of Systems (GEOSS). This “version 1” ASTER GDEM (GDEM1) was compiled from over 1.2 million scenebased DEMs covering land surfaces between 83°N and 83°S latitudes. A joint U.S.-Japan validation team assessed the accuracy of the GDEM1, augmented by a team of 20 cooperators. The GDEM1 was found to have an overall accuracy of around 20 meters at the 95% confidence level. The team also noted several artifacts associated with poor stereo coverage at high latitudes, cloud contamination, water masking issues and the stacking process used to produce the GDEM1 from individual scene-based DEMs (ASTER GDEM Validation Team, 2009). Two independent horizontal resolution studies estimated the effective spatial resolution of the GDEM1 to be on the order of 120 meters.

Three phase heat and mass transfer model for unsaturated soil freezing process: Part 2 - model validation

Science.gov (United States)

Zhang, Yaning; Xu, Fei; Li, Bingxi; Kim, Yong-Song; Zhao, Wenke; Xie, Gongnan; Fu, Zhongbin

2018-04-01

This study aims to validate the three-phase heat and mass transfer model developed in the first part (Three phase heat and mass transfer model for unsaturated soil freezing process: Part 1 - model development). Experimental results from studies and experiments were used for the validation. The results showed that the correlation coefficients for the simulated and experimental water contents at different soil depths were between 0.83 and 0.92. The correlation coefficients for the simulated and experimental liquid water contents at different soil temperatures were between 0.95 and 0.99. With these high accuracies, the developed model can be well used to predict the water contents at different soil depths and temperatures.

Oxaliplatin loaded PLAGA microspheres: design of specific release profiles.

Science.gov (United States)

Lagarce, F; Cruaud, O; Deuschel, C; Bayssas, M; Griffon-Etienne, G; Benoit, J

2002-08-21

Oxaliplatin loaded PLAGA microspheres have been prepared by solvent extraction process. Parameters affecting the release kinetics in vitro have been studied in order to design specific release profiles suitable for direct intra-tumoral injection. By varying the nature and the relative proportions of different polymers we managed to prepare microspheres with good encapsulation efficiency (75-90%) and four different release profiles: zero order kinetics (type II) and the classical sigmoïd release profile with three different sizes of plateau and burst. These results, if correlated with in vivo activity, are promising to enhance effectiveness of local tumor treatment.

Validating the BISON fuel performance code to integral LWR experiments

Energy Technology Data Exchange (ETDEWEB)

Williamson, R.L., E-mail: Richard.Williamson@inl.gov [Fuel Modeling and Simulation, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Gamble, K.A., E-mail: Kyle.Gamble@inl.gov [Fuel Modeling and Simulation, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Perez, D.M., E-mail: Danielle.Perez@inl.gov [Fuel Modeling and Simulation, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Novascone, S.R., E-mail: Stephen.Novascone@inl.gov [Fuel Modeling and Simulation, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Pastore, G., E-mail: Giovanni.Pastore@inl.gov [Fuel Modeling and Simulation, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Gardner, R.J., E-mail: Russell.Gardner@inl.gov [Fuel Modeling and Simulation, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Hales, J.D., E-mail: Jason.Hales@inl.gov [Fuel Modeling and Simulation, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Liu, W., E-mail: Wenfeng.Liu@anatech.com [ANATECH Corporation, 5435 Oberlin Dr., San Diego, CA 92121 (United States); Mai, A., E-mail: Anh.Mai@anatech.com [ANATECH Corporation, 5435 Oberlin Dr., San Diego, CA 92121 (United States)

2016-05-15

Highlights: • The BISON multidimensional fuel performance code is being validated to integral LWR experiments. • Code and solution verification are necessary prerequisites to validation. • Fuel centerline temperature comparisons through all phases of fuel life are very reasonable. • Accuracy in predicting fission gas release is consistent with state-of-the-art modeling and the involved uncertainties. • Rod diameter comparisons are not satisfactory and further investigation is underway. - Abstract: BISON is a modern finite element-based nuclear fuel performance code that has been under development at Idaho National Laboratory (INL) since 2009. The code is applicable to both steady and transient fuel behavior and has been used to analyze a variety of fuel forms in 1D spherical, 2D axisymmetric, or 3D geometries. Code validation is underway and is the subject of this study. A brief overview of BISON's computational framework, governing equations, and general material and behavioral models is provided. BISON code and solution verification procedures are described, followed by a summary of the experimental data used to date for validation of Light Water Reactor (LWR) fuel. Validation comparisons focus on fuel centerline temperature, fission gas release, and rod diameter both before and following fuel-clad mechanical contact. Comparisons for 35 LWR rods are consolidated to provide an overall view of how the code is predicting physical behavior, with a few select validation cases discussed in greater detail. Results demonstrate that (1) fuel centerline temperature comparisons through all phases of fuel life are very reasonable with deviations between predictions and experimental data within ±10% for early life through high burnup fuel and only slightly out of these bounds for power ramp experiments, (2) accuracy in predicting fission gas release appears to be consistent with state-of-the-art modeling and with the involved uncertainties and (3) comparison

Dry washing: the solution for contaminated liquid effluent releases

International Nuclear Information System (INIS)

L'homme, D.; Trambouze, P.

1998-01-01

The release of wash water used for contaminated garments poses an ever-increasing problem on nuclear sites. Even though the radioactivity is low, it mixes with organic compounds, thus polluting a large quantity of liquid effluents. In many cases, several thousands of m 3 /year per nuclear site are produced, which at times represents more than 30% of the volume of total releases. The conventional dry cleaning process is not a viable option, given that repeated washing cause clothes to fade and the odors are rot removed completely. In order to eliminate releases, STMI has developed, after several years of research with the Technological University of Compiegne, France, a solvent dry washing process for garments used in the nuclear industry. (author)

A comparison between endogenous acetylcholiner release and (3H) choline outflow from guinea-pig brain slices

International Nuclear Information System (INIS)

Beani, L.; Bianchi, C.; Siniscalchi, A.; Sivilotti, L.; Tanganelli, S.; Veratti, E.

1986-01-01

The measure of tritium-choline efflux from preloaded brain slices is considered a valid method for studying cholinergic functiton. At variance with th say of endogenous acetylcholine this procedure gives andindex of the release process in the absence of esterase inhibition, thus excluding the dampening of the autoreceptor-mediated negative feedback. In order to establish the equivalence of these approaches the tow methods have been compared on electrically=stimulated guinea-pig brain slices, kept under the ame experimental conditions. The results show that only a partial equivalence of the two methods can be recognized. A drawback of the tritium-choline approach is the exhaustion or dilution of tritium stores, so that drug-induced increases of evoked efflux are minimized

Processes subject to integrated pollution control. Petroleum processes: oil refining and associated processes

International Nuclear Information System (INIS)

1995-01-01

This document, part of a series offering guidance on pollution control regulations issued by Her Majesty's Inspectorate of Pollution, (HMIP) focuses on petroleum processes such as oil refining and other associated processes. The various industrial processes used, their associated pollution release routes into the environment and techniques for controlling these releases are all discussed. Environmental quality standards are related to national and international agreements on pollution control and abatement. HMIP's work on air, water and land pollution monitoring is also reported. (UK)

Design of sustained release fine particles using two-step mechanical powder processing: particle shape modification of drug crystals and dry particle coating with polymer nanoparticle agglomerate.

Science.gov (United States)

Kondo, Keita; Ito, Natsuki; Niwa, Toshiyuki; Danjo, Kazumi

2013-09-10

We attempted to prepare sustained release fine particles using a two-step mechanical powder processing method; particle-shape modification and dry particle coating. First, particle shape of bulk drug was modified by mechanical treatment to yield drug crystals suitable for the coating process. Drug crystals became more rounded with increasing rotation speed, which demonstrates that powerful mechanical stress yields spherical drug crystals with narrow size distribution. This process is the result of destruction, granulation and refinement of drug crystals. Second, the modified drug particles and polymer coating powder were mechanically treated to prepare composite particles. Polymer nanoparticle agglomerate obtained by drying poly(meth)acrylate aqueous dispersion was used as a coating powder. The porous nanoparticle agglomerate has superior coating performance, because it is completely deagglomerated under mechanical stress to form fine fragments that act as guest particles. As a result, spherical drug crystals treated with porous agglomerate were effectively coated by poly(meth)acrylate powder, showing sustained release after curing. From these findings, particle-shape modification of drug crystals and dry particle coating with nanoparticle agglomerate using a mechanical powder processor is expected as an innovative technique for preparing controlled-release coated particles having high drug content and size smaller than 100 μm. Copyright © 2013 Elsevier B.V. All rights reserved.

Development and evaluation of accelerated drug release testing methods for a matrix-type intravaginal ring.

Science.gov (United States)

Externbrink, Anna; Eggenreich, Karin; Eder, Simone; Mohr, Stefan; Nickisch, Klaus; Klein, Sandra

2017-01-01

Accelerated drug release testing is a valuable quality control tool for long-acting non-oral extended release formulations. Currently, several intravaginal ring candidates designed for the long-term delivery of steroids or anti-infective drugs are being in the developing pipeline. The present article addresses the demand for accelerated drug release methods for these formulations. We describe the development and evaluation of accelerated release methods for a steroid releasing matrix-type intravaginal ring. The drug release properties of the formulation were evaluated under real-time and accelerated test conditions. Under real-time test conditions drug release from the intravaginal ring was strongly affected by the steroid solubility in the release medium. Under sufficient sink conditions that were provided in release media containing surfactants drug release was Fickian diffusion driven. Both temperature and hydro-organic dissolution media were successfully employed to accelerate drug release from the formulation. Drug release could be further increased by combining the temperature effect with the application of a hydro-organic release medium. The formulation continued to exhibit a diffusion controlled release kinetic under the investigated accelerated conditions. Moreover, the accelerated methods were able to differentiate between different prototypes of the intravaginal ring that exhibited different release profiles under real-time test conditions. Overall, the results of the present study indicate that both temperature and hydro-organic release media are valid parameters for accelerating drug release from the intravaginal ring. Variation of either a single or both parameters yielded release profiles that correlated well with real-time release. Copyright © 2016 Elsevier B.V. All rights reserved.

Modification and Validation of an Automotive Data Processing Unit, Compessed Video System, and Communications Equipment

Energy Technology Data Exchange (ETDEWEB)

Carter, R.J.

1997-04-01

The primary purpose of the "modification and validation of an automotive data processing unit (DPU), compressed video system, and communications equipment" cooperative research and development agreement (CRADA) was to modify and validate both hardware and software, developed by Scientific Atlanta, Incorporated (S-A) for defense applications (e.g., rotary-wing airplanes), for the commercial sector surface transportation domain (i.e., automobiles and trucks). S-A also furnished a state-of-the-art compressed video digital storage and retrieval system (CVDSRS), and off-the-shelf data storage and transmission equipment to support the data acquisition system for crash avoidance research (DASCAR) project conducted by Oak Ridge National Laboratory (ORNL). In turn, S-A received access to hardware and technology related to DASCAR. DASCAR was subsequently removed completely and installation was repeated a number of times to gain an accurate idea of complete installation, operation, and removal of DASCAR. Upon satisfactory completion of the DASCAR construction and preliminary shakedown, ORNL provided NHTSA with an operational demonstration of DASCAR at their East Liberty, OH test facility. The demonstration included an on-the-road demonstration of the entire data acquisition system using NHTSA'S test track. In addition, the demonstration also consisted of a briefing, containing the following: ORNL generated a plan for validating the prototype data acquisition system with regard to: removal of DASCAR from an existing vehicle, and installation and calibration in other vehicles; reliability of the sensors and systems; data collection and transmission process (data integrity); impact on the drivability of the vehicle and obtrusiveness of the system to the driver; data analysis procedures; conspicuousness of the vehicle to other drivers; and DASCAR installation and removal training and documentation. In order to identify any operational problems not captured by the systems

21 CFR 1316.92 - Petition for expedited release in an administrative forfeiture action.

Science.gov (United States)

2010-04-01

... for expedited release shall establish the following: (1) The owner has a valid, good faith interest in..., which would be subject to seizure for administrative forfeiture for a violation of law involving... in the property, which shall be supported by title documentation, bills of sale, contracts, mortgages...

Validation of a numerical release model (REPCOM) for the Finnish reactor waste disposal systems: Pt.1

International Nuclear Information System (INIS)

Nykyri, Mikko

1987-05-01

The aim of the work is to model experimentally the inner structures and materials of two reactor waste repositories and to use the results for the validation work of a numerical near field release model, REPCOM. The experimental modelling of the multibarrier systems is conducted on a laboratory scale by using the same principal materials as are employed in the Finnish reactor waste disposal concepts. The migration of radionuclides is studied in two or more consecutive material layers. The laboratory arrangements include the following test materials: bituminized resin, cemented resin, concrete, crushed rock, and water. The materials correspond to the local materials in the planned disposal systems. Cs-137, Co-60, Sr-85, and Sr-90 are used as tracers, with which the resin, water, and crushed rock are labeled depending on the specimen type. The basic specimen geometries are cylindrical and cubic. In the cylindrical geometry the test materials were placed into PVC-tubes. The corresponding numerical model is one-dimensional. In the cubic geometry the materials were placed inside each other. The boundaries form cubes, and the numerical model is three-dimensional. Altogether 12 test system types were produced. The gamma active nuclides in the cylindrical samples were measured nondestructively with a scanner in order to determine the activity profiles in the specimens. The gamma active nuclides in the cubic samples and the beta emeitting Sr-90 in separate samples will be measured after splitting the samples. One to five activity profiles were determined for each cylindrical gamma-active sample. There are already clear diffusion profiles to be had for strontium in crushed rock, and for cesium in crushed rock and in concrete. Cobalt indicated no diffusion. No activity profiles were measured for the cubic samples or for the beta active, Sr-90-doped samples

Assessment of chromium(VI) release from 848 jewellery items by use of a diphenylcarbazide spot test

DEFF Research Database (Denmark)

Bregnbak, David; Johansen, Jeanne D.; Hamann, Dathan

2016-01-01

We recently evaluated and validated a diphenylcarbazide(DPC)-based screening spot test that can detect the release of chromium(VI) ions (≥0.5 ppm) from various metallic items and leather goods (1). We then screened a selection of metal screws, leather shoes, and gloves, as well as 50 earrings......, and identified chromium(VI) release from one earring. In the present study, we used the DPC spot test to assess chromium(VI) release in a much larger sample of jewellery items (n=848), 160 (19%) of which had previously be shown to contain chromium when analysed with X-ray fluorescence spectroscopy (2)....

Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956)- An Assessment of Quantities released, Off-Site Radiation Doses, and Potential Excess Risks of Thyroid Cancer, Volume 1

Energy Technology Data Exchange (ETDEWEB)

Apostoaei, A.I.; Burns, R.E.; Hoffman, F.O.; Ijaz, T.; Lewis, C.J.; Nair, S.K.; Widner, T.E.

1999-07-01

In the early 1990s, concern about the Oak Ridge Reservation's past releases of contaminants to the environment prompted Tennessee's public health officials to pursue an in-depth study of potential off-site health effects at Oak Ridge. This study, the Oak Ridge dose reconstruction, was supported by an agreement between the U.S. Department of Energy (DOE) and the State of Tennessee, and was overseen by a 12-member panel appointed by Tennessee's Commissioner of Health. One of the major contaminants studied in the dose reconstruction was radioactive iodine, which was released to the air by X-10 (now called Oak Ridge National Laboratory) as it processed spent nuclear reactor fuel from 1944 through 1956. The process recovered radioactive lanthanum for use in weapons development. Iodine concentrates in the thyroid gland so health concerns include various diseases of the thyroid, such as thyroid cancer. The large report, ''Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956) - An Assessment of Quantities Released, Off-site Radiation Doses, and Potential Excess Risks of Thyroid Cancer,'' is in two volumes. Volume 1 is the main body of the report, and Volume 1A, which has the same title, consists of 22 supporting appendices. Together, these reports serve the following purposes: (1) describe the methodologies used to estimate the amount of iodine-131 (I-131) released; (2) evaluate I-131's pathway from air to vegetation to food to humans; (3) estimate doses received by human thyroids; (4) estimate excess risk of acquiring a thyroid cancer during ones lifetime; and (5) provide equations, examples of historical documents used, and tables of calculated values. Results indicate that females born in 1952 who consumed milk from a goat pastured a few miles east of X-10 received the highest doses from I-131 and would have had the highest risks of contracting thyroid cancer. Doses from cow

Nuclear energy release from fragmentation

Energy Technology Data Exchange (ETDEWEB)

Li, Cheng [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Souza, S.R. [Instituto de Física, Universidade Federal do Rio de Janeiro Cidade Universitária, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Tsang, M.B. [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); National Superconducting Cyclotron Laboratory and Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824 (United States); Zhang, Feng-Shou, E-mail: fszhang@bnu.edu.cn [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 730000 (China)

2016-08-15

It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting {sup 230,232}Th and {sup 235,238}U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for {sup 230,232}Th and {sup 235,238}U are around 0.7–0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.

Simulation of tritium behavior after intended tritium release in ventilated room

International Nuclear Information System (INIS)

Iwai, Yasunori; Hayashi, Takumi; Yamanishi, Toshihiko; Kobayashi, Kazuhiro; Nishi, Masataka

2001-01-01

At the Tritium Process Laboratory (TPL) at the Japan Atomic Energy Research Institute (JAERI), Caisson Assembly for Tritium Safety study (CATS) with 12 m 3 of large airtight vessel (Caisson) was fabricated for confirmation and enhancement of fusion reactor safety to estimate tritium behavior in the case where a tritium leak event should happen. One of the principal objectives of the present studies is the establishment of simulation method to predict the tritium behavior after the tritium leak event should happen in a ventilated room. The RNG model was found to be valid for eddy flow calculation in the 50 m 3 /h ventilated Caisson with acceptable engineering precision. The calculated initial and removal tritium concentration histories after intended tritium release were consistent with the experimental observations in the 50 m 3 /h ventilated Caisson. It is found that the flow near a wall plays an important role for the tritium transport in the ventilated room. On the other hand, tritium behavior intentionally released in the 3,000 m 3 of tritium handling room was investigated experimentally under a US-Japan collaboration. The tritium concentration history calculated with the same method was consistent with the experimental observations, which proves that the present developed method can be applied to the actual scale of tritium handling room. (author)

Analysis of an LPG accidental release

Energy Technology Data Exchange (ETDEWEB)

Demichela, M.; Piccinini, N.; Poggio, A.

2004-03-01

An industrial LPG storage accident due to the release of propane from a tanker is described in this paper and the sequence of events that led to the collapse of a storage tank is examined using simulation software. A model taking both released flows into account as a radiant thermal contribution in the presence of flames is presented. The progression of the accident is assessed through digitalization and processing of the film of the fireball produced by about 500 L of LPG, whose diameter was calculated as approximately 50 m. (author)

The role of performance assessment in validation, regulation and public acceptance

International Nuclear Information System (INIS)

Pigford, T.H.

1992-01-01

This paper reports that regulation of public health and safety for a geologic repository for radioactive waste requires that performance assessment show that radioactive releases will not violate a safety limit. Accurate predictions of actual performance are not required. Because of the long times in the future when radioactivity can be released, performance predictions must be based on sound hypothesis of the mechanisms that control and mitigate releases. Such hypotheses are useful only if they lead to clear mathematical formulations, specify clearly the parameters that are expected to control the releases, and specify means of accelerated testing or other means for validating the hypotheses. useful hypotheses usually lead to conservative and bounding analyses that can be more reliable for this purpose than efforts to predict actual repository performance

Nutrient-induced glucagon like peptide-1 release is modulated by serotonin.

Science.gov (United States)

Ripken, Dina; van der Wielen, Nikkie; Wortelboer, Heleen M; Meijerink, Jocelijn; Witkamp, Renger F; Hendriks, Henk F J

2016-06-01

Glucagon like peptide-1 (GLP-1) and serotonin are both involved in food intake regulation. GLP-1 release is stimulated upon nutrient interaction with G-protein coupled receptors by enteroendocrine cells (EEC), whereas serotonin is released from enterochromaffin cells (ECC). The central hypothesis for the current study was that nutrient-induced GLP-1 release from EECs is modulated by serotonin through a process involving serotonin receptor interaction. This was studied by assessing the effects of serotonin reuptake inhibition by fluoxetine on nutrient-induced GLP-1, PYY and CCK release from isolated pig intestinal segments. Next, serotonin-induced GLP-1 release was studied in enteroendocrine STC-1 cells, where effects of serotonin receptor inhibition were studied using specific and non-specific antagonists. Casein (1% w/v), safflower oil (3.35% w/v), sucrose (50mM) and rebaudioside A (12.5mM) stimulated GLP-1 release from intestinal segments, whereas casein only stimulated PYY and CCK release. Combining nutrients with fluoxetine further increased nutrient-induced GLP-1, PYY and CCK release. Serotonin release from intestinal tissue segments was stimulated by casein and safflower oil while sucrose and rebaudioside A had no effect. The combination with fluoxetine (0.155μM) further enhanced casein and safflower oil induced-serotonin release. Exposure of ileal tissue segments to serotonin (30μM) stimulated GLP-1 release whereas it did not induce PYY and CCK release. Serotonin (30 and 100μM) also stimulated GLP-1 release from STC-1 cells, which was inhibited by the non-specific 5HT receptor antagonist asenapine (1 and 10μM). These data suggest that nutrient-induced GLP-1 release is modulated by serotonin through a receptor mediated process. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Factors controlling alkalisalt deposition in recovery boiler- release mechanisms

Energy Technology Data Exchange (ETDEWEB)

McKeough, P.; Kylloenen, H.; Kurkela, M. [VTT Energy, Espoo (Finland). Process Technology Group

1996-12-01

As part of a cooperative effort to develop a model to describe the behaviour of inorganic compounds in kraft recovery boilers, an experimental investigation of the release of sulphur during black liquor pyrolysis has been undertaken. Previous to these studies, the mechanisms of sulphur release and the reasons for the observed effects of process conditions on sulphur release were very poorly understood. On the basis of the experimental results, the main reactions leading to sulphur release have been elucidated with a fair degree of certainty. Logical explanations for the variations of sulphur release with temperature and with liquor solids content have been proposed. The influence of pressure has been investigated in order to gain insights into the effects of mass transfer on the sulphur-release rate. In the near future, the research will be aimed at generating the kinetic data necessary for modelling the release of sulphur in the recovery furnace. (author)

Description and validation of ERAD: An atmospheric dispersion model for high explosive detonations

Energy Technology Data Exchange (ETDEWEB)

Boughton, B.A.; DeLaurentis, J.M.

1992-10-01

The Explosive Release Atmospheric Dispersion (ERAD) model is a three-dimensional numerical simulation of turbulent atmospheric transport and diffusion. An integral plume rise technique is used to provide a description of the physical and thermodynamic properties of the cloud of warm gases formed when the explosive detonates. Particle dispersion is treated as a stochastic process which is simulated using a discrete time Lagrangian Monte Carlo method. The stochastic process approach permits a more fundamental treatment of buoyancy effects, calm winds and spatial variations in meteorological conditions. Computational requirements of the three-dimensional simulation are substantially reduced by using a conceptualization in which each Monte Carlo particle represents a small puff that spreads according to a Gaussian law in the horizontal directions. ERAD was evaluated against dosage and deposition measurements obtained during Operation Roller Coaster. The predicted contour areas average within about 50% of the observations. The validation results confirm the model`s representation of the physical processes.

Fission product release from defected nuclear reactor fuel elements

International Nuclear Information System (INIS)

Lewis, B.J.

1983-01-01

The release of gaseous (krypton and xenon) and iodine radioactive fission products from defective fuel elements is described with a semi-empirical model. The model assumes precursor-corrected 'Booth diffusional release' in the UO 2 and subsequent holdup in the fuel-to-sheath gap. Transport in the gap is separately modelled with a phenomenological rate constant (assuming release from the gap is a first order rate process), and a diffusivity constant (assuming transport in the gap is dominated by a diffusional process). Measured release data from possessing various states of defection are use in this analysis. One element (irradiated in an earlier experiment by MacDonald) was defected with a small drilled hole. A second element was machined with 23 slits while a third element (fabricated with a porous end plug) displayed through-wall sheath hydriding. Comparison of measured release data with calculated values from the model yields estimates of empirical diffusion coefficients for the radioactive species in the UO 2 (1.56 x 10 -10 to 7.30 x 10 -9 s -1 ), as well as escape rate constants (7.85 x 10 -7 to 3.44 x 10 -5 s -1 ) and diffusion coefficients (3.39 x 10 -5 to 4.88 x 10 -2 cm 2 /s) for these in the fuel-to-sheath gap. Analyses also enable identification of the various rate-controlling processes operative in each element. For the noble gas and iodine species, the rate-determining process in the multi-slit element is 'Booth diffusion'; however, for the hydrided element an additional delay results from diffusional transport in the fuel-to-heath gap. Furthermore, the iodine species exhibit an additional holdup in the drilled element because of significant trapping on the fuel and/or sheath surfaces. Using experimental release data and applying the theoretical results of this work, a systematic procedure is proposed to characterize fuel failures in commercial power reactors (i.e., the number of fuel failures and average leak size)

Understanding the drug release mechanism from a montmorillonite matrix and its binary mixture with a hydrophilic polymer using a compartmental modelling approach

Science.gov (United States)

Choiri, S.; Ainurofiq, A.

2018-03-01

Drug release from a montmorillonite (MMT) matrix is a complex mechanism controlled by swelling mechanism of MMT and an interaction of drug and MMT. The aim of this research was to explain a suitable model of the drug release mechanism from MMT and its binary mixture with a hydrophilic polymer in the controlled release formulation based on a compartmental modelling approach. Theophylline was used as a drug model and incorporated into MMT and a binary mixture with hydroxyl propyl methyl cellulose (HPMC) as a hydrophilic polymer, by a kneading method. The dissolution test was performed and the modelling of drug release was assisted by a WinSAAM software. A 2 model was purposed based on the swelling capability and basal spacing of MMT compartments. The model evaluation was carried out to goodness of fit and statistical parameters and models were validated by a cross-validation technique. The drug release from MMT matrix regulated by a burst release mechanism of unloaded drug, swelling ability, basal spacing of MMT compartment, and equilibrium between basal spacing and swelling compartments. Furthermore, the addition of HPMC in MMT system altered the presence of swelling compartment and equilibrium between swelling and basal spacing compartment systems. In addition, a hydrophilic polymer reduced the burst release mechanism of unloaded drug.

Overview of SCIAMACHY validation: 2002 2004

Science.gov (United States)