The Engineering of Polymers for Mechanical Behavior

1969 ◽  
Vol 42 (4) ◽  
pp. 1175-1185 ◽  
Author(s):  
F. N. Kelley ◽  
M. L. Williams
Keyword(s):  
Relaxation Modulus ◽  
Engineering Properties ◽  
Stress Fields ◽  
Interaction Matrix ◽  
Systematic Analysis ◽  
Bulk Compressibility ◽  
Starting Point ◽  
Engineering Parameters ◽  
Broad Subject ◽  
Rupture Properties

Abstract The broad subject matter in this paper is treated in only cursory fashion. Our intent was to present an approach to the systematic analysis of the relationships between engineering properties and molecular variables for viscoelastic materials. Literature omissions will undoubtedly be numerous, but the basic concept of the Interaction Matrix allows for continual upgrading and refinement. The examples chosen were based on the stress relaxation modulus which provided an ideal starting point due to the wide use of this property in viscoelastic stress analysis and fracture mechanics. Other important engineering parameters which might be selected for similar examination include bulk compressibility and dilation for example; and, of course, the rupture properties under various imposed stress fields.

scholarly journals Fields Connected with Particles in Terms of Complex-Riemannian Geometry

1990 ◽  
Vol 45 (2) ◽  
pp. 81-94
Author(s):  
Julian Ławrynowicz ◽  
Katarzyna Kędzia ◽  
Leszek Wojtczak
Keyword(s):  
Field Potential ◽  
Riemannian Metrics ◽  
Interaction Matrix ◽  
Explicit Calculation ◽  
Maxwell System ◽  
Curved Space ◽  
Starting Point ◽  
Autocorrelation Time ◽  
The Fourier Transform ◽  
Convolution Equations

AbstractA complex analytical method of solving the generalised Dirac-Maxwell system has recently been proposed by two of us for a certain class of complex Riemannian metrics. The Dirac equation without the field potential in such a metric appeared to be equivalent to the Dirac-Maxwell system including the field potentials produced by the currents of a particle in question. The method proposed is connected with applying the Fourier transform with respect to the electric charge treated as a variable, with the consideration of the mass as an eigenvalue, and with solving suitable convolution equations. In the present research an explicit calculation based on linearization of the spinor connections is given. The conditions for the motion are interpreted as a starting point to seek selection rules for curved space-times corresponding to actually existing particles. Then the same method is applied to solids. Namely, by a suitable transformation of the configuration space in terms of elements of the interaction matrix corresponding to the Coulomb, exchange, and dipole integrals, the interaction term in the hamiltonian becomes zero, thus leading to experimentally verificable formulae for the autocorrelation time

scholarly journals Physical modelling of failure in composites

2016 ◽  
Vol 374 (2071) ◽  
pp. 20150280 ◽  
Author(s):  
Ramesh Talreja
Keyword(s):  
Composite Materials ◽  
Failure Modes ◽  
Structural Integrity ◽  
Failure Mechanisms ◽  
Local Stress ◽  
Physical Modelling ◽  
Stress Fields ◽  
Systematic Analysis ◽  
Composite Failure ◽  
Failure Theories

Structural integrity of composite materials is governed by failure mechanisms that initiate at the scale of the microstructure. The local stress fields evolve with the progression of the failure mechanisms. Within the full span from initiation to criticality of the failure mechanisms, the governing length scales in a fibre-reinforced composite change from the fibre size to the characteristic fibre-architecture sizes, and eventually to a structural size, depending on the composite configuration and structural geometry as well as the imposed loading environment. Thus, a physical modelling of failure in composites must necessarily be of multi-scale nature, although not always with the same hierarchy for each failure mode. With this background, the paper examines the currently available main composite failure theories to assess their ability to capture the essential features of failure. A case is made for an alternative in the form of physical modelling and its skeleton is constructed based on physical observations and systematic analysis of the basic failure modes and associated stress fields and energy balances. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’.

Military Necessity and the Cultures of Military Law

2013 ◽  
Vol 26 (2) ◽  
pp. 315-349 ◽  
Author(s):  
DAVID LUBAN
Keyword(s):  
Human Rights ◽  
Human Dignity ◽  
Legal Regulation ◽  
Systematic Analysis ◽  
Law Of War ◽  
Military Necessity ◽  
Starting Point ◽  
Military Law ◽  
Interpretive Communities ◽  
The Military

AbstractMilitary and humanitarian lawyers approach the laws of war in different ways. For military lawyers, the starting point is military necessity, and the reigning assumption is that legal regulation of war must accommodate military necessity. For humanitarian lawyers, the starting point is human dignity and human rights. The result is two interpretive communities that systematically disagree not only over the meaning of particular law-of-war norms, but also over the sources and methods of law that could be used to resolve the disagreements. That raises the question whether military lawyers’ advice should acknowledge any validity to the contrary views of the ‘humanitarian’ community. The article offers a systematic analysis of the concept of military necessity, showing that civilian interests must figure in assessing military necessity itself. Even on its own terms, the military version of the law of war should seek to accommodate the civilian perspectives featured in the humanitarian version.

scholarly journals WATCHING THE WATCHDOG: ONLINE DISCOURSES ABOUT MEDIA FRAUDS

2020 ◽  
Author(s):  
Tobias Eberwein
Keyword(s):  
Professional Identity ◽  
Fake News ◽  
Systematic Analysis ◽  
Web Based ◽  
International Media ◽  
News Magazine ◽  
The Public ◽  
Starting Point ◽  
German Speaking

Media frauds often lead to lively public discussions about journalism’s professional identity and its social mandate. The paper uses the so-called Relotius case as a starting point for a systematic analysis of the responsibility of narrative journalists in an age of “fake news” and post-truth politics – and the question of how they can be held to account in the online realm. Claas Relotius counted as one of the most talented journalistic storytellers in the German-speaking world. In December 2018, however, the news magazine Der Spiegel revealed that he had fabricated many of his texts, either completely or partly. This revelation developed into one of the biggest German media scandals of the recent years and triggered a massive outcry, also in international media. A multi-method research design allows for a differentiated assessment of the Relotius case in particular and web-based media accountability processes in general: A literature review and problem-centered interviews with senior reporters demonstrate that stylistic devices of fiction have a long history in German narrative journalism – also in Spiegel magazine. A discourse analysis focusing on the public debate following the revelation of the scandal points out that many journalistic commenters, including Spiegel’s editorial board, displayed a clear lack of self-criticism in their discussion of the case, while non-professional watchbloggers broadened the scope of the analysis. The paper reflects the empirical results from a normative perspective, in order to illustrate the potentials and shortcomings of professional journalistic self-observation as opposed to external public control in online discourses.

Analysis on Coupling of Temperature Field and Stress Field for Tunnel Surrounding Rock in Cold Region

2012 ◽  
Vol 594-597 ◽  
pp. 2578-2581
Author(s):  
Hui Mei Zhang ◽  
Yuan Liang ◽  
Chuan Gao Chen ◽  
Hai Bo Cao
Keyword(s):  
Theoretical Model ◽  
Theoretical Basis ◽  
Mutual Influence ◽  
Surrounding Rock ◽  
Stress Fields ◽  
Cold Region ◽  
Rock Body ◽  
Volume Load ◽  
Engineering Parameters ◽  
Mountain Tunnel

Based on the theory of mass and energy transfer, the coupling theoretical model of temperature and stress fields in the process of rock freeze-thaw was established considering the volume load caused by temperature change within the rock body. Taking Daban mountain tunnel surrounding rock at its exit as example, the heat--stress coupling process was numerically calculated, and the mutual influence and varied laws of temperature and stress fields were researched. The simulating result is similar to the current results and engineering experience, which can verify the correctness of the theoretical model and the reliability of calculation method, and also provide some theoretical basis for determining the engineering parameters scientifically, optimizing the lining and supporting scheme and ensuring the safety of design and construction.

Surveys in business process management – a literature review

2015 ◽  
Vol 21 (3) ◽  
pp. 692-718 ◽  
Author(s):  
Tobias Roeser ◽  
Eva-Maria Kern
Keyword(s):  
Literature Review ◽  
Survey Research ◽  
Business Process ◽  
Business Process Management ◽  
Process Management ◽  
Research Field ◽  
Analysis Framework ◽  
Systematic Analysis ◽  
Content Type ◽  
Starting Point

Purpose – The purpose of this paper is to conduct a literature review to provide an overview of surveys focussing on business process management (BPM)/business process orientation (BPO) or on BPM-related topics in order to describe the status quo, uncover trends, classify survey contributions and assess the possible further development of survey research. Design/methodology/approach – In order to achieve the research goals, the authors conduct a literature review. The authors analyze the retrieved literature by means of a developed analysis framework which allows the authors to examine the surveys from the meta-perspective and content-based perspective. Findings – A lot of surveys focussing on BPM/BPO or on BPM-related topics have been published in German- and English-speaking literature over the last years. Nevertheless, the authors find out that while some topics, countries/regions and industries are well explored others were neglected in the past. Moreover, the authors provide first evidence that companies have a different BPM demand. Finally, the authors conclude that although the implications of the incorporated surveys provide a good starting point for practitioners they seem to be too abstract to be helpful for them. Thus, the authors recommend the conduction of qualitative research endeavors to develop adaptable theories for practitioners. Research limitations/implications – This literature review focusses on survey research in BPM. It could be repeated in order to verify the findings and moreover to track progress. However, although the authors followed the steps proposed for a literature review, the selection of relevant articles might be a limitation of this paper. Originality/value – The literature review provides an overview of surveys focussing on BPM/BPO or on BPM-related topics that have been published so far. The developed and strictly applied analysis framework supports a systematic analysis of survey research and could therefore provide a detailed picture of the current state of this research field. To the best of the authors’ knowledge, no comparable literature review has been undertaken until now.

scholarly journals Systematic Analysis of FASTK Gene Family Alterations in Cancer

2021 ◽  
Vol 22 (21) ◽  
pp. 11337
Author(s):  
Lorena Magraner-Pardo ◽  
Dino Gobelli ◽  
Miguel A. de la Fuente ◽  
Tirso Pons ◽  
María Simarro
Keyword(s):  
Mitochondrial Gene ◽  
Interaction Network ◽  
Genetic Alterations ◽  
Future Research ◽  
Mrna Levels ◽  
Systematic Analysis ◽  
Lung Cancers ◽  
Protein Protein Interaction ◽  
Starting Point ◽  
Post Transcriptional Regulation

The FASTK family of proteins have been recently reported to play a key role in the post-transcriptional regulation of mitochondrial gene expression, including mRNA stability and translation. Accumulated studies have provided evidence that the expression of some FASTK genes is altered in certain types of cancer, in agreement with the central role of mitochondria in cancer development. Here, we obtained a pan-cancer overview of the genomic and transcriptomic alterations of FASTK genes. FASTK, FASTKD1, FASTKD3 and FASTKD5 showed the highest rates of genetic alterations. FASTK and FASTKD3 alterations consisted mainly of amplifications that were seen in more than 8% of ovarian and lung cancers, respectively. FASTKD1 and FASTKD5 were the most frequently mutated FASTK genes, and the mutations were identified in 5–7% of uterine cancers, as well as in 4% of melanomas. Our results also showed that the mRNA levels of all FASTK members were strongly upregulated in esophageal, stomach, liver and lung cancers. Finally, the protein-protein interaction network for FASTK proteins uncovers the interaction of FASTK, FASTKD2, FASTKD4 and FASTKD5 with cancer signaling pathways. These results serve as a starting point for future research into the potential of the FASTK family members as diagnostic and therapeutic targets for certain types of cancer.

scholarly journals Investigation of the Anisotropic Structure of Travertine in Terms of Geological and Physico-Mechanical Properties: Sarıhıdır (Avanos-Nevşehir) Travertine Quarry

2022 ◽  
Author(s):  
Ersin Kolay ◽  
Gökhan Karakoç ◽  
Uğur Temiz
Keyword(s):  
Mechanical Properties ◽  
Engineering Properties ◽  
Economic Losses ◽  
Ultramafic Rocks ◽  
Anisotropic Structure ◽  
Engineering Parameters ◽  
Cutting Direction ◽  
Physical Index ◽  
Better Than

Abstract Travertine is a sedimentary rock with generally layered structure, mainly comprising carbonate. They are used for different purposes in interior and exterior spaces by cutting parallel or perpendicular to the bedding according to use. Travertine may contain several facies linked to variations in conditions during formation. With these features, travertine is one of the rocks with anisotropy most commonly observed. In this study, the anisotropic structure due to facies and layering in travertine was investigated considering geological and engineering properties. The Sarıhıdır travertine quarry face was divided into four different zones with different features. Chemical, mineralogic, physical, index and mechanical properties of the samples taken from these zones were determined. During determination of engineering parameters, samples were prepared parallel and perpendicular to bedding. The source of the travertine is a mixture of limestone, dolomite, evaporite and ultramafic rocks and they have epigean character, though they were affected by the hypogean environment. It appeared there were textural differences between the zones, rather than differences in chemical and mineralogic composition. When travertine was cut parallel to layering, all zones were suitable for decoration and facing. Only T-4 zone samples cut parallel were useable for flooring and load-bearing elements. In terms of compression and abrasion resistance, T-4 zone was better than the other zones. The cut direction of the travertine samples is an important factor for physical and mechanical behavior. Samples cut parallel to layering were observed to provide better results. According to the results, it is recommended to use products from the same travertine zone side-by-side in structures and to consider the cutting direction for long life of the building and to prevent economic losses.

scholarly journals A systematic analysis of metabolic pathways in the human gut microbiota

2021 ◽  
Author(s):  
Victoria Pascal Andreu ◽  
Hannah E Augustijn ◽  
Lianmin Chen ◽  
Alexandra Zhernakova ◽  
Jingyuan Fu ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Gut Microbiome ◽  
Gene Clusters ◽  
Population Based ◽  
Specific Gene ◽  
Biosynthetic Genes ◽  
Fatty Acid Production ◽  
Systematic Analysis ◽  
Energy Capture ◽  
Starting Point

The gut microbiota produce hundreds of small molecules, many of which modulate host physiology. Although efforts have been made to identify biosynthetic genes for secondary metabolites, the chemical output of the gut microbiome consists predominantly of primary metabolites. Here, we systematically profile primary metabolic genes from the gut microbiome, identifying 19,885 gene clusters in 4,240 high-quality microbial genomes. We find marked differences in pathway distribution among phyla, reflecting distinct strategies for energy capture. These data explain taxonomic differences in short-chain fatty acid production and suggest a characteristic metabolic niche for each taxon. Analysis of 1,135 subjects from a Dutch population-based cohort shows that the level of 14 microbiome-derived metabolites in plasma is almost completely uncorrelated with the metagenomic abundance of the corresponding biosynthetic genes, revealing a crucial role for pathway-specific gene regulation and metabolite flux. This work is a starting point for understanding differences in how bacterial taxa contribute to the chemistry of the microbiome.

Using some of Microsoft Office Excel Functions to Compute Soil Engineering Parameters Based on Raw Results of Laboratory Tests

2020 ◽  
Vol 857 ◽  
pp. 273-282
Author(s):  
Azhar Sadiq Yasun ◽  
Sultan A. Daud
Keyword(s):  
Soil Classification ◽  
Engineering Properties ◽  
Soil Parameters ◽  
Algebraic Equations ◽  
Microsoft Excel ◽  
Unconfined Compression Test ◽  
Engineering Parameters ◽  
Parameter Test ◽  
Microsoft Office ◽  
Engineering Soil

The main aim of this research can be represented as a trail to computerize the most soil engineering properties to compute them automatically using many simple Microsoft Excel functions based on raw soil test experimental data. This work will be shortening the time and effort of the geotechnical engineers calculating different soil parameters with acceptable accurate values. Nine different Microsoft Excel formulas, some of the techniques by certain Excel expressions and normal designed algebraic equations were used to present the final spreadsheet. The main computed soil parameters were (ω, LL, PL, PI, ρd,max, ωopt, k) soil classification AASHTO, (qu and cu) for unconfined compression test, (ø and c') for the direct shear test finally (Cc and Cs) for consolidation tests. To get a better understanding on how most of the programmed tools and to Microsoft Excel sheets work, the user should have knowledge about basic concepts of the certain soil parameter test and experimental steps and also the guidelines of the theory that depends to compute the parameter. Also, the user should have enough background about engineering soil properties laboratory experiments computation.

Sign in / Sign up

Export Citation Format

Share Document