scholarly journals Room Closure Response to Gas Generation and Mechanical Strength of Different Waste Forms in a Bedded Salt Repository

1993 ◽  
Vol 333 ◽  
Author(s):  
F. T. Mendenhall ◽  
C.M. Stone
Keyword(s):  
Constitutive Models ◽  
Creep Model ◽  
Secondary Creep ◽  
Salt Formation ◽  
Gas Generation ◽  
Waste Forms ◽  
Time Period ◽  
Finite Element Calculations ◽  
Consolidation Model ◽  
History Of

ABSTRACTFinite element calculations of the porosity history of a nuclear waste disposal room for transuranic (TRU) waste in a bedded salt formation have been completed. The analyses include a reduced elastic/secondary creep model for the host halite and a nonlinear consolidation model for the crushed salt backfill. Separate gas generation and constitutive models were used for three distinct hypothetical waste forms: 1) unaltered defense-related, contact-handled transuranic (CH-TRU) waste, 2) shredded and cemented CH-TRU waste, and 3) incinerated and vitrified CH-TRU waste. Histories were determined for a 2000 year time period starting from the emplacement of room seals. The resulting final room porosities varied from roughly 55% to less than 10%, according to waste forms.

Mechanical Analyses of Wipp Disposal Rooms Backfilled with Either Crushed Salt or Crushed Salt-Bentonite

1990 ◽  
Vol 207 ◽  
Author(s):  
Ralph A. Wagner ◽  
G. D. Callahan ◽  
B. M. Butcher
Keyword(s):  
Finite Element ◽  
Constitutive Models ◽  
Creep Model ◽  
Finite Element Program ◽  
Waste Isolation Pilot Plant ◽  
Modeling Methodology ◽  
Salt Creep ◽  
Consolidation Model ◽  
Element Program ◽  
Nonlinear Elastic

AbstractNumerical calculations of disposal room configurations at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM are presented. Specifically, the behavior of either crushed salt or a crushed salt-bentonite mixture, when used as a backfill material in disposal rooms, is modeled in conjunction with the creep behavior of the surrounding intact salt. The backfill consolidation model developed at Sandia National Laboratories was implemented into the SPECTROM-32 finite element program. This model includes nonlinear elastic as well as deviatoric and volumetric creep components. Parameters for the models were determined from laboratory tests with deviatoric and hydrostatic loadings. The performance of the intact salt creep model previously implemented into SPECTROM-32 is well documented.Results from the SPECTROM-32 analyses were compared to a similar study conducted by Sandia National Laboratories using the SANCHO finite element program. The calculated deformations and stresses from the SPECTROM-32 and SANCHO analyses agree reasonably well despite differences in constitutive models and modeling methodology. These results provide estimates of the backfill consolidation through time. The trends in the backfill consolidation can then be used to estimate the permeability of the backfill and subsequent radionuclide transport.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

A Very Brief History of Internet Jurisdiction

2017 ◽  
Author(s):  
Dan Jerker B. Svantesson
Keyword(s):  
Academic Community ◽  
Court Decisions ◽  
Time Period ◽  
Technological Developments ◽  
History Of

This chapter provides a brief history of Internet jurisdiction taking account of key court decisions, legislation as well as developments in the academic thinking on the topic. In doing so, it divides the history of Internet jurisdiction into four relatively distinct phases. The discussion in the chapter highlights facts such as that: (1) law has largely been reactive, responding to technological developments; (2) the level of creativity applied in the search for workable solutions was seemingly higher in the earlier stages than in more recent times; and (3) unsurprisingly, the attitudes of courts, legislators, and the academic community have varied considerably over the time period examined.

Detection of Pavement Maintenance Treatments using Deep-Learning Network

2021 ◽  
pp. 036119812110078
Author(s):  
Lu Gao ◽  
Yao Yu ◽  
Yi Hao Ren ◽  
Pan Lu
Keyword(s):  
Deep Learning ◽  
Measurement Errors ◽  
Short Term Memory ◽  
Learning Networks ◽  
Pavement Maintenance ◽  
Time Period ◽  
Learning Techniques ◽  
Maintenance And Rehabilitation ◽  
History Of ◽  
Deep Learning Network

Pavement maintenance and rehabilitation (M&R) records are important as they provide documentation that M&R treatment is being performed and completed appropriately. Moreover, the development of pavement performance models relies heavily on the quality of the condition data collected and on the M&R records. However, the history of pavement M&R activities is often missing or unavailable to highway agencies for many reasons. Without accurate M&R records, it is difficult to determine if a condition change between two consecutive inspections is the result of M&R intervention, deterioration, or measurement errors. In this paper, we employed deep-learning networks of a convolutional neural network (CNN) model, a long short-term memory (LSTM) model, and a CNN-LSTM combination model to automatically detect if an M&R treatment was applied to a pavement section during a given time period. Unlike conventional analysis methods so far followed, deep-learning techniques do not require any feature extraction. The maximum accuracy obtained for test data is 87.5% using CNN-LSTM.

Naval Service Cohort Study of Occupational Stress: Background to the research and a review of the latest findings

2008 ◽  
Vol 94 (1) ◽  
pp. 22-30
Author(s):  
R S Bridger
Keyword(s):  
Occupational Stress ◽  
Psychological Health ◽  
Prevalence Rate ◽  
Pathological Process ◽  
Work Demands ◽  
Cross Sectional ◽  
Time Period ◽  
History Of ◽  
Made In ◽  
Naval Service

AbstractThe Naval Service has been actively involved in research on occupational stress for almost 10 years. Three cross-sectional studies have been completed during this time period. It has been shown that the prevalence rate of psychological strain amongst personnel is relatively constant at 31-34%. Several smaller studies, of personnel at sea and of the availability of support services have also been completed. In general, the research has shown that the prevalence rate of strain is higher in the NS than in the general population and is comparable to that found in similar uniformed service organisations, such as the Police.Recognising the limitations of crosssectional research methods, the decision was made, in 2006, to follow a cohort of personnel over a 6-year period in order to gain better understanding of the processes by which work demands impact on psychological health and to determine whether psychological ill-health has an adverse impact on factors such as premature voluntary retirement and medical downgrading.The paper presents the history of the research and some of the work in progress.‘Disease is a pathological process that, at least in theory, is amenable to objective, external verification. Illness, on the other hand, is by definition, a subjective state’. D. Coggan 2006(1).

scholarly journals The history of introduction of the African baobab ( Adansonia digitata , Malvaceae: Bombacoideae) in the Indian subcontinent

2015 ◽  
Vol 2 (9) ◽  
pp. 150370 ◽  
Author(s):  
Karen L. Bell ◽  
Haripriya Rangan ◽  
Christian A. Kull ◽  
Daniel J. Murphy
Keyword(s):  
West Africa ◽  
Indian Subcontinent ◽  
Central India ◽  
Adansonia Digitata ◽  
Multiple Introductions ◽  
Human Interactions ◽  
Time Period ◽  
History Of ◽  
Genetic Clusters ◽  
Southeast India

To investigate the pathways of introduction of the African baobab, Adansonia digitata , to the Indian subcontinent, we examined 10 microsatellite loci in individuals from Africa, India, the Mascarenes and Malaysia, and matched this with historical evidence of human interactions between source and destination regions. Genetic analysis showed broad congruence of African clusters with biogeographic regions except along the Zambezi (Mozambique) and Kilwa (Tanzania), where populations included a mixture of individuals assigned to at least two different clusters. Individuals from West Africa, the Mascarenes, southeast India and Malaysia shared a cluster. Baobabs from western and central India clustered separately from Africa. Genetic diversity was lower in populations from the Indian subcontinent than in African populations, but the former contained private alleles. Phylogenetic analysis showed Indian populations were closest to those from the Mombasa-Dar es Salaam coast. The genetic results provide evidence of multiple introductions of African baobabs to the Indian subcontinent over a longer time period than previously assumed. Individuals belonging to different genetic clusters in Zambezi and Kilwa may reflect the history of trafficking captives from inland areas to supply the slave trade between the fifteenth and nineteenth centuries. Baobabs in the Mascarenes, southeast India and Malaysia indicate introduction from West Africa through eighteenth and nineteenth century European colonial networks.

Real world treatment patterns in chronic myeloid leukemia patients newly initiated on tyrosine kinase inhibitors in an U.S. integrated healthcare system

2017 ◽  
Vol 24 (4) ◽  
pp. 253-263
Author(s):  
Nazia Rashid ◽  
Han A Koh ◽  
Kathy J Lin ◽  
Brian Stwalley ◽  
Eugene Felber
Keyword(s):  
Chronic Myelogenous Leukemia ◽  
Index Date ◽  
Stem Cell Transplant ◽  
Study Time ◽  
Myelogenous Leukemia ◽  
Prior History ◽  
Cell Transplant ◽  
Time Period ◽  
History Of

Purpose To evaluate treatment patterns in patients diagnosed with incident chronic myelogenous leukemia (CML) newly initiating therapy with imatinib, dasatinib, or nilotinib. Patients were followed to determine switching and discontinuation rates. Factors associated with switching or discontinuation from index TKI therapy, reasons for discontinuation based on electronic chart notes, and frequency of laboratory monitoring were assessed during the follow-up period. Methods A retrospective cohort study was conducted in chronic myelogenous leukemia patients aged ≥ 18 years who were identified from the Kaiser Permanente Southern California (KPSC) Cancer Registry database during the study time period of 1 January 2007 to 12 December 2013. The index date was defined as the date of the first TKI prescription (imatinib, dasatinib, or nilotinib) identified during the study time period with no prior history of TKI use within 12 months. Patients had to have continuous membership with drug benefit eligibility and no prior history of stem cell transplant (SCT) or other cancers during the 12 months prior to the index date. Baseline characteristics were identified during 12 months prior to the index date and outcomes were identified during the follow-up period after the index date. All patients were followed from index TKI therapy until end of study time period (12 December 2014), death, stem cell transplant, or disenrollment from the health plan unless one of the following occurred first: a patient switched their index therapy, or a patient discontinued their index therapy. Forward stepwise selection multivariable logistic regression models were used to evaluate factors associated with patients who continued therapy compared to those who switched or discontinued therapy with the index TKI. Chart notes were reviewed 30 days prior and 30 days post index TKI discontinuation to evaluate reasons for discontinuation. Molecular and cytogenetic testing frequency was also assessed during the follow-up period among the different patient groups. Results Two hundred sixteen patients were identified with incident chronic myelogenous leukemia and use of TKI therapy: 189 (87.5%) received imatinib, 19 (8.8%) received dasatinib, and 8 (3.7%) received nilotinib. The mean age on index date was 53 years and 63% were male; 103 patients (48%) continued on their index therapy, while 62 patients (28%) switched, and 51 patients (24%) discontinued.

scholarly journals The works of Leningrad popular science film studio “Lennauchfilm” in the 1970s – 1980s

2021 ◽  
pp. 19-29
Author(s):  
Mariya Vladimirovna Kalenichenko
Keyword(s):  
Social Life ◽  
Popular Science ◽  
Time Period ◽  
Film Directors ◽  
Archival Documents ◽  
Art And Culture ◽  
History Of ◽  
Film Texts ◽  
Scientific Achievements

This article is dedicated to examination of works of the film directors of the Leningrad popular science film studio “Lennauchfilm” in the 1970s – 1980s. Based on the archival documents presented in the Central Archive of Literature and Art of Saint Petersburg, the author analyzes the work of the film studio: carries out classification of filmography by formal-semantic criterion, as well as determines the key processes typical to this time period. The following main trends are highlighted: natural science, technical-propagandistic, historical-revolutionary, military-patriotic, social life, history of art and culture. Special attention is given to the films that cover the topics, which have not previously been included in the field of popular science cinematography. The novelty of this research lies in classification of the thematic trends of the Leningrad film studio as an integral artistic system, as well as in comparison of the plots of popular science film texts by each direction over the two decades. As a result, the author identified the main trends, which broadened the thematic field in the work of the studio, as well as fundamentally changed the representations on the goals and tasks of popular science cinematography. The key object of popular science cinematography is being shifted during the Perestroika period. Emphasis is place not on science and technological achievements, but human and society. Film directors through their works conveyed the attitude of society towards science, raising the questions of transformation of ethics and morality in the context of scientific and technological revolution. The idea of the harm of scientific achievements and responsibility of the scholars before society is being advanced. Without any doubt, the works of the Leningrad film directors broadened the ideological-artistic range by offering the own vision of specificity of the Soviet popular science cinematography.

scholarly journals History of earthquake studies in Russia

2009 ◽  
Vol 47 (2-3) ◽  
Author(s):  
R. Tatevossian
Keyword(s):  
Seismic Hazard Assessment ◽  
Historical Seismicity ◽  
Primary Sources ◽  
Original Form ◽  
Correct Identification ◽  
Tectonic Earthquake ◽  
Time Period ◽  
Long Time ◽  
History Of ◽  
Modern Knowledge

To evaluate the completeness of modern knowledge on historical seismicity it is necessary to know the general geopolitical and socio-cultural background in the country. It determines the possibility to record the evidence of an earthquake and conserve the record in original form for a long time-period. The potential duration of historical earthquake study in Russia is assessed based on these considerations. Certain stages of earthquake study in Russia have been detected. Specific problems of seismicity studies of low active areas are discussed as an example of Russian platform. The value of each (even moderate magnitude) event becomes crucial for seismic hazard assessment in such territories. A correct identification of event nature (tectonic earthquake or exogenous phenomena - landslides, karsts, etc.) is practically impossible without using primary sources with detailed descriptions. Occurrence of modern earthquakes can be used to assess the accuracy of historical seismicity knowledge.

scholarly journals Effect of brimonidine on central corneal thickness in normal tension glaucoma patients

2019 ◽  
Vol 7 (6) ◽  
pp. 2216
Author(s):  
Neethu K. V. ◽  
Latha N. V. ◽  
Praveena K. K.
Keyword(s):  
Intraocular Pressure ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Topical Administration ◽  
Normal Tension Glaucoma ◽  
Thickness Measurement ◽  
Applanation Tonometry ◽  
Time Period ◽  
Field Assessment ◽  
History Of

Background: Brimonidine is a potent ocular hypotensive agent widely used in glaucoma treatment. A reduction in central corneal thickness can lead to an underestimation of intraocular pressure by Goldmann applanation tonometry and vice versa. The aim of this study is to determine whether brimonidine has an effect on central corneal thickness.Methods: 30 eyes of patients who attended the Ophthalmology OPD between the time period October 2017 and June 2018 who were newly diagnosed with normal tension glaucoma with no history of any systemic illness or not on any medication were included. Each patient underwent a complete ophthalmic evaluation including fundus examination, visual field assessment, intraocular pressure, central corneal thickness measurement by pachymetry before as well as 1 month and 6 months after starting treatment with 0.2% topical brimonidine twice daily.Results: Administration of brimonidine 0.2% resulted in an increase in central corneal thickness from 525±21 µm before starting brimonidine to 528±21 µm (p<0.05) after 1 month and 535±20 µm (p<0.001) after 6 months. It also resulted in a reduction in intraocular pressure from an initial value of 16±2 mmHg before starting brimonidine to 14±2 mmHg (p<0.05) and 13±2 mmHg (p<0.05), 1month and 6 months after starting treatment, respectively.Conclusions: The data presented in this study show that topical administration of 0.2% brimonidine twice daily results in a significant increase in central corneal thickness in patients with normal tension glaucoma.

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