67,493 research outputs found
Self-Organized Criticality in Protein Folding Simulations with AMBER Parameters
AMBER (Assisted Model Building with Energy Refinement) is a force field that allows for the simulation of proteins. Basic proteins were folded by a Monte-Carlo algorithm parameterized by AMBER on MATLAB. Simulations exhibited self-organized critical (SOC) behavior and are shown to be stable throughout the simulations by use of pairwise distance matrixes. Frequency shifting is explored as a possible explanation of the mechanisms behind structure inducing probes (SIPs) in the solid phase synthesis of proteins. This also provides a mechanistic link to many other SOC systems
Experimental study and numerical modelling of woven fabric kenaf fiber composites hybrid adhesively bonded-bolted joints
Couple with natural fiber composite parts, hybrid joints provide better joint strength than using separate joints. There are limited studies on structures response and strength prediction work on hybrid joints that limits its applicability. The aim of present study is to conduct experimental datasets on woven fabric kenaf fiber reinforced polymer (KFRP) and carbon fiber reinforced polymer (CFRP) composite hybrid joints under quasi-static testing and to carry out the strength prediction works subsequently by implementing physically-based traction-separation constitutive law. Testing series investigated includes variation of joint types, normalized W/d = 2 to 5, reinforcing fiber composites, lay-up types, plate thickness and bolt loads. Experimental observations and bearing stress at failures were conducted, the datasets were then used as validation works in FEA modelling. All KFRP hybrid joint series demonstrated net-tension failure mode associated to stress concentration at the vicinity of notch tip. Initially, strength prediction works were attempted by implementing various numerical approaches and fully XFEM techniques was adopted to all series as it provides promising results with better physically representation and less computational time. Good agreements between experimental datasets and predicted bearing stress at failure were found in KFRP hybrid joints with average discrepancy of less than 23%. It was found that combinations of thicker and cross-ply lay-up gives the best prediction of less than 2 % (where experimental datasets and FEA output were given as 201 N/mm2 and 198 N/mm2 respectively) due to better repetitive lay-up with implementation of smeared-out properties. Less significant effects from bolt loads and reinforcing fibers were found for both joint types. It can be concluded that fully XFEM technique able to provide as a unified prediction tools in hybrid joints of most composite materials with reasonable agreements
Mapping approach for examining waste management within construction sites
In light of increased awareness on environmental impacts from construction wastes, waste management has become an important factor in construction project management. Various waste managements have been developed by researchers to manage construction wastes. Nevertheless, less attention is given towards the management of waste handling processes on construction sites such as waste sorting and waste transport. In fact, proper flow of these processes could improve waste management effectiveness. The aim of the study is to examine waste handling process during construction through the mapping of ten project sites in Melaka using the free-flow mapping presentation technique. This will lead to the development of a proposed waste management mapping model (WMMM), which incorporates the good operations embodied in the existing practices and also the outcomes of interviews with the project proponents. The WMMM could serve as a tool assisting in planning waste management procedures as well as a vehicle for comparing waste management practices among construction sites; thus, weaknesses and good practices could be identified and improvement measures may be implemented accordingly. Personal interviews with questionnaires and on site observations were administered for data collection. Analysis was performed on results tabulated in matrix table with interpretation assisted by statistical computations. Qualitative approach was of dominant where comparative evaluation was extensively performed on the waste management practices between these ten sites. Findings revealed that the advantages of waste handling practices outnumbered the weaknesses. The WMMM was proposed based on guidelines derived from the analysis which took into account factors pertaining to cost, environmental protection and time in waste handling management. It was suggested that the proposed WMMM could be incorporated into the Environmental Impact Assessment (EIA) report to assist waste management planning. Overall, the findings of the study have contributed to the basic understanding of the waste management practices within construction sites in Malaysi
Propagation of Actinidia chinensis (Planch.) by stem and root cutting : a thesis presented in partial fulfilment of the requirements for the degree of Master in Horticultural Science at Massey University
Basal wounding, bottom heat, light with IBA treatments were found to be beneficial for rooting of Actinidia chinensis (Planch.). IBA treatment was effective only when there was a high natural ability to initiate root in Summer and Spring. Seasonal fluctuations in rooting ability was pronounced. This seasonal variation seems to be related to the levels of endogenous IAA, ABA and cofactor 2. No correlation between root initiation and bud activity or IAN level was established. IAA seems to be the fundamental physiological promoter of adventitous root formation. IBA plays only a supporting role in promoting root formation, by protecting the endogenous IAA level in the cutting base. Leaf tissue is an important factor for rooting to be successful. The role of leaf tissue is not just to produce auxin or synthesize nutrients but rather some unknown factor in the leaf can produce a synergistic interaction with auxin in root formation processes. Root cuttings of Abbott variety were sequentially harvested and planted over a period from late Autumn (1.4.77) until mid Summer (8.1.78). Root cuttings of different thickness and length were compared to evaluate their effect on regeneration. The effect of various growth regulators was investigated too. Root diameters of 0.5 - 1.5 cm. out performed that of the thinner or thicker ones. Shorter cuttings (5 cm) of equivalent total length were found to be more productive than a single long cutting (15cm). Strong polarity was observed with shoots only arising from the proximal end of the cutting. Regenerative capacity was highest in late Autumn and Winter and lowest in Summer. This seasonal fluctuation can be altered by exogenous application of growth regulators. IBA suppressed shoot regeneration, whereas cytokinin and sucrose promoted it, while GA3 did not have any significant effect. For commercial use, the practical and economic aspects of this techique require further investigation
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