223 research outputs found
ANALYSIS AND OPTIMIZING CONNECTING ROD FOR WEIGHT AND COST REDUCTION
The objective of this work is to explore weight and cost reduction opportunities, in the design and production of connecting rod. The study has been dealt with two steps. First part of the study analysis includes the determination of loads acting on connecting rod as a function of time. This is done in order to find out the minimum stress area and to remove the material in those areas. The relationship between the load and acceleration of connecting rod for a given constant speed of the crankshaft are also determined. Finite element analysis was performed at several crank angles. The connecting rod can be designed and optimized under the loads ranging from tensile load, corresponding with 360º crank angle at the maximum engine speed as one extreme load and compressive load corresponding with the peak gas pressure as the other extreme load. Modal analysis is performed to find out the natural frequencies
DESIGN AND FABIRCATION OF HYBRID TWO WHEELER
The progress of automobiles for transportation has been intimately associated with the progress of civilization. The automobile of today is the result of the accumulation of many years of pioneering research development. In the modern trend automobiles have certain disadvantages soon as fuel cost relative to mileage, pollution and less efficiency.To improve efficiencyTo decrease the fuel cost relative to mileageTo control the pollution is to be effectThen our “HYBRID TWO WHEELER†is an aspect. The goal of this project was to implement the most efficient and less polluting vehicle. In our project the hybrid electric vehicle model combines the internal combustion engine of a conventional vehicle with the battery and electric motor of an electric vehicle, resulting in twice the fuel economy of conventional vehicle. We implement this hybrid electric vehicle concept for two wheeler
Surface Kinetics and Generation of Different Terms in a Conservative Growth Equation
A method based on the kinetics of adatoms on a growing surface under
epitaxial growth at low temperature in (1+1) dimensions is proposed to obtain a
closed form of local growth equation. It can be generalized to any growth
problem as long as diffusion of adatoms govern the surface morphology. The
method can be easily extended to higher dimensions. The kinetic processes
contributing to various terms in the growth equation (GE) are identified from
the analysis of in-plane and downward hops. In particular, processes
corresponding to the (h -> -h) symmetry breaking term and curvature dependent
term are discussed. Consequence of these terms on the stable and unstable
transition in (1+1) dimensions is analyzed. In (2+1) dimensions it is shown
that an additional (h -> -h) symmetry breaking term is generated due to the
in-plane curvature associated with the mound like structures. This term is
independent of any diffusion barrier differences between in-plane and out
of-plane migration. It is argued that terms generated in the presence of
downward hops are the relevant terms in a GE. Growth equation in the closed
form is obtained for various growth models introduced to capture most of the
processes in experimental Molecular Beam Epitaxial growth. Effect of
dissociation is also considered and is seen to have stabilizing effect on the
growth. It is shown that for uphill current the GE approach fails to describe
the growth since a given GE is not valid over the entire substrate.Comment: 14 pages, 7 figure
E7(7) formulation of N=2 backgrounds
In this paper we reformulate N=2 supergravity backgrounds arising in type II
string theory in terms of quantities transforming under the U-duality group
E7(7). In particular we combine the Ramond--Ramond scalar degrees of freedom
together with the O(6,6) pure spinors which govern the Neveu-Schwarz sector by
considering an extended version of generalised geometry. We give
E7(7)-invariant expressions for the Kahler and hyperkahler potentials
describing the moduli space of vector and hypermultiplets, demonstrating that
both correspond to standard E7(7) coset spaces. We also find E7(7) expressions
for the Killing prepotentials defining the scalar potential, and discuss the
equations governing N=1 vacua in this formalism.Comment: 40 pages, final version to appear in JHE
Power and knowledge-building in teacher inquiry: negotiating interpersonal and ideational difference
Professional collaboration in schools features prominently in contemporary approaches to educational change. Advocates highlight the importance of situated knowledge to continuous teacher learning, sustained school reform and improved student learning. Critics portray collaboration as an invisible and coercive means of official control. The framework presented in this paper aims to treat these perspectives not as ideological positions but as starting points for empirical investigation into the dynamics of power in professional collaboration. The framework draws on social semiotic theories of language and functional linguistics to portray the ways in which the development of ideas and the development of social relations ideational and interpersonal meaning move in concert. Excerpts from an in-depth study of interaction among science teachers and teacher-leaders in a secondary school undergoing broad reform illustrate the application of this framework. Attention to the dynamics of support and challenge in the most generative of these interactions reveals distinctive patterns of the negotiation of interpersonal and ideational meaning. These patterns of control provide a means of connecting the microprocesses of building knowledge with the broader dynamics of power at play in educational change
Genome-wide association and Mendelian randomisation analysis provide insights into the pathogenesis of heart failure
Heart failure (HF) is a leading cause of morbidity and mortality worldwide. A small proportion of HF cases are attributable to monogenic cardiomyopathies and existing genome-wide association studies (GWAS) have yielded only limited insights, leaving the observed heritability of HF largely unexplained. We report results from a GWAS meta-analysis of HF comprising 47,309 cases and 930,014 controls. Twelve independent variants at 11 genomic loci are associated with HF, all of which demonstrate one or more associations with coronary artery disease (CAD), atrial fibrillation, or reduced left ventricular function, suggesting shared genetic aetiology. Functional analysis of non-CAD-associated loci implicate genes involved in cardiac development (MYOZ1, SYNPO2L), protein homoeostasis (BAG3), and cellular senescence (CDKN1A). Mendelian randomisation analysis supports causal roles for several HF risk factors, and demonstrates CAD-independent effects for atrial fibrillation, body mass index, and hypertension. These findings extend our knowledge of the pathways underlying HF and may inform new therapeutic strategies
Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.
INTRODUCTION: The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI) is low. Comparative effectiveness research (CER) has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. METHODS: We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions. RESULTS: All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%), designated as a level I trauma center (n = 48, 68%) and situated in an urban location (n = 70, 99%). The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57%) had a dedicated neuro-intensive care unit (ICU), 36 (51%) had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45) of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers. CONCLUSION: Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches
Glycosylation of immunoglobulin G is regulated by a large network of genes pleiotropic with inflammatory diseases
Effector functions of immunoglobulin G (IgG) are regulated by the composition of a glycan moiety, thus affecting activity of the immune system. Aberrant glycosylation of IgG has been observed in many diseases, but little is understood about the underlying mechanisms. We performed a genome-wide association study of IgG N-glycosylation (N = 8090) and, using a data-driven network approach, suggested how associated loci form a functional network. We confirmed in vitro that knockdown of IKZF1 decreases the expression of fucosyltransferase FUT8, resulting in increased levels of fucosylated glycans, and suggest that RUNX1 and RUNX3, together with SMARCB1, regulate expression of glycosyltransferase MGAT3. We also show that variants affecting the expression of genes involved in the regulation of glycoenzymes colocalize with variants affecting risk for inflammatory diseases. This study provides new evidence that variation in key transcription factors coupled with regulatory variation in glycogenes modifies IgG glycosylation and has influence on inflammatory diseases.Molecular Epidemiolog
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