Key Issues Influencing the Performance of Near-Field Barriers

1992 ◽  
Vol 294 ◽  
Author(s):  
P.W. Tasker ◽  
S.J. Wisbey ◽  
C.B. Boyle
Keyword(s):  
Near Field ◽  
Performance Assessments ◽  
Gas Generation ◽  
Human Environment ◽  
Factors Affecting ◽  
Control Factors ◽  
Natural Analogues ◽  
Physical Barriers ◽  
Key Issues ◽  
And Control

ABSTRACTIn developing a national strategy for the disposal of radioactive wastes, each country will consider isolation options that are appropriate to the types of waste that are produced. The options are developed in response to specific national regulatory requirements, and thus will focus on different aspects of performance. However, there are a number of technical concerns that are common to all programmes. The major issues concerning the behaviour of the chemical and physical barriers in the near field of a radioactive waste repository are discussed in this paper.The description of key issues has been divided into the following categories: barrier design, barrier evolution, scientific understanding through modelling, and validation of performance. The near-field barriers are selected and designed to provide appropriate radionuclide containment and control. Factors affecting the evolution of these barriers, such as container degradation and gas generation, determine the subsequent release of radionuclides to the human environment. Modelling repository evolution is therefore an integral feature of performance assessments, and issues such as the treatment of inhomogeneities and non-equilibrium chemistry may need to be addressed. However, the use of mathematical and computer models implies a requirement for validation. The use of demonstration experiments and natural analogues builds confidence in the predictions of repository performance models, and provides a degree of validation for otherwise inaccessible timescales.

Identifying the Mental Pattern of Housing Demand by grounded Theory: The Cognitive Science Approach

2019 ◽  
Author(s):  
Sorush Niknamian
Keyword(s):  
Grounded Theory ◽  
Physical Factor ◽  
Housing Demand ◽  
Behavioral Approach ◽  
Structured Interviews ◽  
Factors Affecting ◽  
Control Factors ◽  
Grounded Theory Method ◽  
Axial Coding ◽  
And Control

One of the main challenges of housing demand is the optimal selection of housing that almost everyone faces. A model that can measure the role and impact of all factors affecting the demand for housing is not presented unambiguously and has not been dramatically formulated explicitly. Considering the centrality of budget, behavioral and control factors in housing demand, the present study seeks to explain and design the mental pattern of consumer demand, capital and housing leases with a cognitive and behavioral approach in Tabriz. The present study is based on the qualitative approach and using the grounded theory method. The data collection method was semi-structured interviews. In order to collect information, an interview was carried out using a targeted sampling method with 12 experts in the field of housing. Data analysis was performed in three stages: open coding, axial coding, selective coding, and a qualitative research model has been designed. The results of this study indicate that extraction of more than 250 codes, along with an inventory of more than 20 concepts and 4 categories, are presented in the form of a paradigmatic model including budget constraints as axial categories and causal conditions (as reasons for selection), underlying factors (physical factor) and interventional conditions (control and behavioral factors).

scholarly journals Construction of the Simulation Model of Social Potential of Childhood in a Region

REGIONOLOGY ◽  
2018 ◽  
Vol 26 (4) ◽  
pp. 764-783
Author(s):  
Alexandra G. Filipova ◽  
Alena V. Vysockaya
Keyword(s):  
Simulation Model ◽  
Survival Rates ◽  
Factors Affecting ◽  
Number Of Children ◽  
Correlation And Regression Analysis ◽  
Control Factors ◽  
Regional Systems ◽  
The Social ◽  
Social Potential ◽  
And Control

Introduction. The relevance of the study is determined by the uneven regional conditions for the development of childhood in Russia. Russia’s regions have different resources for preserving children’s health and educating children. The aim of the work is to identify regional factors affecting the social potential of children, and the subsequent construction of the simulation model of Social potential of childhood in a region. Materials and Methods. The study employed the methods of correlation and regression analysis. Statistical data presented in official sources were used as the materials of the study. The calculations were made using the Deductor analytical platform, the construction of the simulation model was implemented using the AnyLogic software. Results. During the study, 12 target and 36 control factors were identified. An analysis of the relationships between the target and control factors made it possible to identify target indicators characterizing children’s education, health and survival rates. The identified control factors were divided into three groups: the constants, factors that can be regulated by the regions, and factors that are difficult to regulate by the regions. The constructed simulation model is part of the assessment of the control factors’ influence on childhood in Russia’s regions. Experiments with the model showed that in addition to influencing the socio-economic situation in a region as a whole, it is important to reduce the number of shifts in schools and at the same time improve the skills of school teachers, increase the number of children involved in summer recreational activities. Discussion and Conclusion. The research materials will be useful in planning for preservation and development of the social potential of childhood in a region. The data obtained are of value both to sociologists and scientists involved in modeling of socio-economic processes. In the study of regional systems.

scholarly journals Pengaruh Pemeliharaan Dan Pengendalian Kualitas Terhadap Tingkat Produk Gagal Di PT.Granesia (Studi Kasus Pada Divisi Produksi Buku Percetakan)

2020 ◽  
Vol 21 (2) ◽  
pp. 166-175
Author(s):  
Dudi Haryadi
Keyword(s):  
Quality Control ◽  
Validity And Reliability ◽  
Sale Price ◽  
Factors Affecting ◽  
Product Level ◽  
Descriptive Research ◽  
Control Factors ◽  
The Subject ◽  
And Control

The product fails to be a product that cannot be categorized as a final product and is economically or technically irreversible so that it should be discarded or sold below the sale price of the final product, due to the factors affecting the failure Products are the maintenance and quality control factors to minimize product failure rates. Through this research the author intends to further analyze the maintenance and control of quality that affect the failure of failed products in PT. Granesia. The effectiveness of resources is crucial to face the various challenges of the company both internally and externally to maintain the quality of the product. Through increased ability employees are expected to obtain a competent workforce that will reduce the failure rate of products produced by the company. Therefore, the descriptive and Vericular methods become the author's choice with the subject of production division employees. The instrument is used through the validity and reliability test first. Data collection is carried out using a questionnaire distributed with 70 questionnaires. The statistical method uses the analysis path. The results of the descriptive research on the production division of PT. Granesia showed that maintenance is already good, the quality control assessed is good and the product level fail to be assessed low. The results of the verificative studies indicate that there is an influence on the maintenance and quality control of the production division of PT. Granesia. Based on the results The study showed that PT. Granesia maintenance significantly affects the product's level of failure. Quality control has significant effect on the failing product level. Quality maintenance and control are simultaneously influential.

Pyruvate Metabolism and Control: Factors Affecting Pyruvic Carboxylase Activity

Science ◽  
1964 ◽  
Vol 145 (3627) ◽  
pp. 58-60 ◽  
Author(s):  
A. D. Freedman ◽  
L. Kohn
Keyword(s):  
Pyruvate Metabolism ◽  
Carboxylase Activity ◽  
Factors Affecting ◽  
Control Factors ◽  
And Control

Green peach aphid and potato leafroll virus: transmission and control

2020 ◽  
Author(s):  
R.A. Bagrov ◽  
◽  
V.I. Leunov
Keyword(s):  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Virus Transmission ◽  
Potato Leafroll Virus ◽  
Factors Affecting ◽  
Potato Viruses ◽  
Tuber Necrosis ◽  
Aphid Vectors ◽  
Leafroll Virus ◽  
And Control

The mechanisms of transmission of potato viruses from plants to aphid vectors and from aphids to uninfected plants are described, including the example of the green peach aphid (Myzus persicae, GPA). Factors affecting the spreading of tuber necrosis and its manifestation on plants infected with potato leafroll virus (PLRV) are discussed. Recommendations for PLRV and GPA control in the field are given.

MODEL OF SOCIAL POTENTIAL OF CHILDHOOD IN THE RUSSIAN REGIONS: THE RESULTS OF EXPERIMENTS

2019 ◽  
pp. 152-162
Author(s):  
A.G. Filipova ◽  
A.V. Vysotskaya
Keyword(s):  
Third Wave ◽  
Russian Regions ◽  
The Third ◽  
Control Factors ◽  
Social Potential ◽  
System Input ◽  
Optimal Values ◽  
Fixed Ideal ◽  
And Control ◽  
Selection Of

The article presents the results of mathematical experiments with the system «Social potential of childhood in the Russian regions». In the structure of system divided into three subsystems – the «Reproduction of children in the region», «Children’s health» and «Education of children», for each defined its target factor (output parameter). The groups of infrastructure factors (education, health, culture and sport, transport), socio-economic, territorial-settlement, demographic and en-vironmental factors are designated as the factors that control the system (input parameters). The aim of the study is to build a model îf «Social potential of childhood in the Russian regions», as well as to conduct experiments to find the optimal ratio of the values of target and control factors. Three waves of experiments were conducted. The first wave is related to the analysis of the dynam-ics of indicators for 6 years. The second – with the selection of optimal values of control factors at fixed ideal values of target factors. The third wave allowed us to calculate the values of the target factors based on the selected optimal values of the control factors of the previous wave.

scholarly journals Interactive effects between travel behaviour and COVID-19: a questionnaire study

2021 ◽  
Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee
Keyword(s):  
Early Stage ◽  
Travel Behaviour ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Individual Level ◽  
Passenger Volume ◽  
Spatial Autoregressive ◽  
Railway Passenger ◽  
The Individual ◽  
And Control

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.

scholarly journals Phytolith and Calcitic Spherulite Indicators from Modern Reference Animal Dung from Mediterranean Island Ecosystems: Menorca, Balearic Islands

2021 ◽  
Vol 11 (16) ◽  
pp. 7202
Author(s):  
Marta Portillo ◽  
Kate Dudgeon ◽  
Montserrat Anglada ◽  
Damià Ramis ◽  
Yolanda Llergo ◽  
...  
Keyword(s):  
Biosphere Reserve ◽  
Balearic Islands ◽  
Island Ecosystems ◽  
Human Environment ◽  
Factors Affecting ◽  
Faecal Pellets ◽  
Fundamental Information ◽  
Animal Dung ◽  
Interdisciplinary Approaches ◽  
Mediterranean Island

This study illustrates the contribution of plant and faecal microfossil records to interdisciplinary approaches on the identification, composition, taphonomy and seasonality of livestock dung materials. The focus is on the taphonomy of opal phytoliths and calcitic dung spherulites embedded within modern faecal pellets collected from pasture grounds and pens from a range of animals, including cattle, sheep and pigs from three different farms and seasons of the year in Menorca (Balearic Islands, Spain) declared a Biosphere Reserve by UNESCO. Modern reference materials provide comparative plant and dung microfossil indicators on factors affecting the formation, composition, preservation and decay of animal faeces, as well as on the diverse environmental and anthropogenic aspects influencing these. The reported results show relevant changes in phytolith and spherulite composition according to animal species and age, livestock management, seasonality, and grazing and foddering regimes. Both microfossil records provide fundamental information on taphonomic issues that are understudied, such as the variation in the digestibility among different species, including under investigated animals such as pigs, as well on the seasonality of plant and faecal microfossils that are excreted with dung as an important material for reconstructing human-environment interactions which is commonly overlooked in archaeology.

Improving the Strength of Abrasive Wheels and Optimizing the Control over the Strength of Composite Abrasive Materials

2019 ◽  
Vol 946 ◽  
pp. 380-385
Author(s):  
Boris A. Chaplygin ◽  
Viacheslav V. Shirokov ◽  
Tat'yana A. Lisovskaya ◽  
Roman A. Lisovskiy
Keyword(s):  
Mechanical Properties ◽  
Test Results ◽  
Key Factors ◽  
Special Equipment ◽  
Material Density ◽  
Factors Affecting ◽  
Control Factors ◽  
Reinforcing Material ◽  
Special Studies ◽  
First Time

The strength of abrasive wheels is one of the key factors affecting the performance of abrasive machining. The paper discusses ways to improve the strength of abrasive wheels. The stress-state mathematical model presented herein is a generalization of the existing models. It is used herein to find for the first time that there are numerous optimal combinations of the elastic modulus and reinforcing material density, which result in the same minimum value of the objective function. It is found out that increasing the radius of the reinforcing component while also optimizing the mechanical properties of its material may increase the permissible breaking speed of the wheel several times. We herein present a regression equation and a nomogram for finding the optimal combination of control factors. Conventional methods for testing the mechanical properties of materials, which have been proven reliable for testing metals and alloys, are not as reliable for testing abrasive materials, as the test results they generate are not sufficiently stable or accurate. We therefore propose an alternative method that does not require any special equipment or special studies.

Some Important Mechanisms and Processes in the Near Field of the Swedish Repository for Spent Nuclear Fuel

1992 ◽  
Vol 294 ◽  
Author(s):  
Ivars Neretnieks
Keyword(s):  
Molecular Diffusion ◽  
Spent Nuclear Fuel ◽  
Dominant Role ◽  
Near Field ◽  
Water Flow Rate ◽  
Crystalline Rock ◽  
Diffusive Transport ◽  
Actual Design ◽  
Natural Analogues ◽  
And Performance

ABSTRACTIn repositories for nuclear waste there are many processes that will be instrumental in damaging the canisters and releasing the nuclides. Based on experiences from studies of the performance of repositories and of an actual design, the major mechanisms influencing the integrity and performance of a repository are described and discussed. The paper addresses only conditions in crystalline rock repositories. The low water flow rate in fractures and channels plays a dominant role in limiting the interaction between water and waste. Molecular diffusion in the backfill and rock matrix, as well as in the mobile water, is an important transport process, but actually limits the exchange rate because diffusive transport is slow. Solubility limits of both waste matrix and of individual nuclides are also important. Complicating processes include alpha-radiolysis, which may change the water chemistry in the near-field. The sizes and locations of water flowpaths and damages in the canisters considerably influence the release rates. Uncertainties in data are large. Nevertheless the system is very robust in the sense that practically no reasonably conceivable assumptions or data will lead to large nuclide releases. Several natural analogues have been found to exhibit similarities with a waste repository and help to validate concepts and to increase our confidence that all major issues have been considered.

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