Electrets and their application in contamination studies

Data are presented on the surface charge of many different types of electrets formed by several different techniques. Results are presented on the investigation of electrets as pollution control devices for their possible use in the control of a spacecraft environment

Impact of dietary changes on hepatic homocysteine metabolism in young broilers

Information regarding the impact of sulfur amino acids (SAA) on hepatic homocysteine (Hcy) flux through the various metabolic pathways competing for Hcy in young broilers is lacking. An experiment was conducted to evaluate the impact of varying levels of dietary methionine (Met), choline, and betaine on hepatic Hcy flux in young broiler chickens. A standard starter basal diet was fed to chicks until 8 d of age; 12 experimental diets were given from 8-22 d. The experimental basal diet contained deficient levels of Met and cysteine (Cys); supplemental Met (0, 0.08, 0.16, and 0.24%) was added to the basal diet in combination with isomethyl levels of choline (0 or 0.25%) or betaine (0 or 0.28%). The 12 dietary treatments were replicated with three pens containing five chicks each (15 birds per treatment). Weight gain and feed efficiency increased (P \u3c 0.05) with Met addition and were maximized with the addition of 0.16% digestible Met. No significant interactions (P \u3e 0.05) with choline or betaine addition were noted for weight gain, feed intake, or feed efficiency, but numerical improvements for these variables were observed with the addition of choline and betaine to the Met-deficient basal diet. Analysis of liver tissue indicated that folate-dependent remethylation of Hcy predominated over betaine-dependent remethylation. Further, folate-dependent remethylation of Hcy appeared to be impacted by dietary choline and betaine levels, whereas betaine-dependent remethylation appeared to be more impacted by dietary SAA levels

Cloudlet-based just-in-time indexing of IoT video

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Hawks and Doves: Evaluating Presidential Powers and Duties Against Congress\u27s Power to Declare War

What would happen if Congress declared war against the president’s wishes? Would the president be forced to prosecute the war? Or are there mechanisms, whether through the system of checks and balances or the president’s own delegated, independent powers, that give the president the authority to disregard Congress’s declaration? This Note argues that a declaration of war must go through the process of bicameralism and presentment to be valid. Thus, the president has the authority to veto a declaration of war. If Congress overcomes the president’s veto, this Note concludes that the president must prosecute the war. The president does not have the independent authority under the commander-in-chief power to overcome Congress’s declare-war power. Further, the president has a separate duty under the Take Care Clause to faithfully execute the law, which includes a declaration of war

Plasticization and Aging Effect on Polysulfone (PsF) Based Mixed Matrix Membrane in Carbon Dioxide Permeation

Polysulfone (PsF) membranes which undergo plasticization during gas separation involving CO2 is a rising issue that has to be dealt with. Plasticization which is an irreversible process causes the disentanglement of polymer chains at high pressure observed by the depression of the glass transition temperature, Tg. Another problem faced by the polymeric membranes such as PsF aging which is the deterioration of the membranes performance with time. Mixed matrix membranes which contains the mixture of polymeric membranes and inorganic particles makes use of the advantages of both the components, making it the new approach in the membrane separation technology. In the present work, PsF/ZIF-8 mixed matrix membrane was fabricated and their structural properties was characterized using analytical tools such as scanning electron microscope and energy dispersive X-ray. The resultant membranes underwent plasticization and aging test in CO2 permeation. The resultant data showed that the membranes fabricated using different loadings of ZIF-8 improved the aging duration of the membrane. Pure PsF membrane showed a 49.97% permeation reduction due to aging after 30 days. The MMM with 5 wt% ZIF-8 showed a 47.54% permeation reduction while the 20 wt% ZIF-8 MMM showed a 5.99% permeation reduction. The membranes shows and increase in resistance towards aging effect with the increase in the amount of loading of ZIF-8.The resultant mixed matrix membrane also showed improvements in permeation towards CO2. However, no significant improvements towards plasticization was discovered from the mixed matrix membrane fabricated in the present work

Simplified CFD based Approach for Estimation of Heat Flux over Wedge Models in High Speed Plasma Flows

Analysis of plasma flows at hypersonic velocity over blunt bodies is quite complex and challenging as it involves complex flow physics and carries several uncertainties. Simultaneous simulation of all the parameters as existing in re-entry flight puts constraints on most of the ground based experiments. Numerical simulations, on the other hand, require modelling of ionisation and real gas effects and prove to be computationally costly. This paper highlights the development of unstructured, cell centred second order accurate parallel version of in-house computational fluid dynamics (CFD) solver where high temperature equivalent properties used from Hansen’s 7 species model and establishment of a simplified procedure for estimation of heat flux over wedge models tested in Plasma Wind Tunnel facility, Vikram Sarabhai Space Centre. Numerical simulations were carried out for Plasma tunnel initially to get the flow properties inside the tunnel when operated without any model. A simplified CFD based approach is established for computing the heat flux over the bodies tested inside the tunnel and compared with the measured data. The comparison of numerical and measured values shows that the proposed methodology captures the flow physics and various parameters with acceptable levels of accuracy

Multi-Objective Optimization of Mooring Systems for Offshore Renewable Energy

This is the author accepted manuscript. The final version is available from EWTEC via the link in this record.This paper presents a method for the optimization of mooring systems in offshore renewable energy systems. This methodology considers the location of anchors as well as the length, material, and diameter of the mooring lines in order to simultaneously minimize the tension in the lines, the cost of the mooring system, and the fatigue damage in the system. By considering these three objectives using a multi-objective approach rather than reduction to a single objective optimization problem allows a Pareto hull of solutions to be obtained representing a range of solutions which balance the three objectives. From this, a system designer can select the design which appropriately balances the trade-off between the competing objectives. In this work, a set of mooring designs that represent efficient solutions for the constraints are found and presented considering the OC4 DeepCWind semi-submersible at Wave Hub. This reliability-based design optimization approach will be applicable to other offshore technology subsystems allowing reliability to be considered in a multi-objective optimization from the design phase.This work is funded by the EPSRC (UK) grant for the United Kingdom Centre for Marine Energy Research (UKCMER) [grant number: EP/P008682/1]

Development of a Multi-Objective Genetic Algorithm for the Design of Offshore Renewable Energy Systems

This is the author accepted manuscript. The final version is available from the publisher via the URL in this record.Optimization algorithms have been deployed for a range of renewable energy problems and can successfully be applied to aid in the design of devices, farms, control strategies, and operations and maintenance strategies. Building on this, the present work makes use of a multi-objective genetic algorithm (GA) in order to develop a framework that can further aid in the design and development of offshore renewable energy systems by explicitly taking into account reliability considerations. Though the reliability-based design optimization approach has previously been used in offshore renewable energy applications and multi-objective optimization applications, it has not previously been applied to multi-objective offshore renewable energy design optimization. As the offshore renewable energy sectors grows it is important for the industry to explore more sophisticated methods of designing devices in order to ensure that the device reliability and lifetime can be maximized while downtime and cost are minimized. This paper describes the development of a framework using a GA in order to aid in the design of a mooring system for offshore renewable energy devices. This framework couples numerical models of the mooring system and structural response to both stress-life cumulative damage models and cost models in order for the GA to effectively operate considering the multiple objectives. The use of this multi-objective optimization approach allows multiple design objectives such as system lifetime and cost to be satisfied simultaneously using an automated mathematical approach. From the outputs of this approach, a designer can then select a solution which appropriately balances the different objectives. The developed framework will be applicable to any offshore technology subsystem allowing multi-objective optimization and reliability to be considered from the design stage in order to improve the design efficiency and aid the industry in using more systematic design approaches.This work is funded by the EPSRC (UK) grant for the SuperGen United Kingdom Centre for Marine Energy Research (UKCMER) [grant number: EP/P008682/1]

Mooring System Design Optimization Using a Surrogate Assisted Multi-Objective Genetic Algorithm

This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this record.This article presents a novel framework for the multi-objective optimization of o shore re- newable energy mooring systems using a random forest based surrogate model coupled to a genetic algorithm. This framework is demonstrated for the optimization of the mooring system for a oating o shore wind turbine highlighting how this approach can aid in the strategic design decision making for real-world problems faced by the o shore renewable energy sector. This framework utilizes validated numerical models of the mooring system to train a surrogate model, which leads to a computationally e cient optimization routine, allowing the search space to be more thoroughly searched. Minimizing both the cost and cumulative fatigue damage of the mooring system, this framework presents a range of op- timal solutions characterizing how design changes impact the trade-o between these two competing objectives.This work is funded by the EPSRC (UK) grant for the SuperGen Marine United Kingdom Centre for Marine Energy Research (UKCMER) [grant number: EP/P008682/1]. The authors would also like to thank Jason Jonkman at NREL who provided the hydrodynamic data for the OC4 semi-submersible and Orcina Ltd. for providing OrcaFlex

Examining The Role Of Social-Cultural Capital In Youth Entrepreneurship : A Comparative Study Between Malaysia And Laos

This comparative study explores the role of social-cultural capital in youth entrepreneurship through social network between the efficiency-based economy of Malaysia and the factor based economy of Laos/Lao PDR.Two non-homogenous sovereign contexts are compared to unveil the potent role of social-cultural capital in youth entrepreneurship through social network dynamics.Central to this discussion is the Theory of Social Network with its emphasis on network structure,type and ties coupled with social context within the theoretical frameworks of Bourdieu,Coleman and Putnam etc.A qualitative case study research approach was employed through the strategy inquiry tools of in-depth interviews and focus groups studies in analysing youth entrepreneurship contexts and contents.This preferred approach is focused on garnering in-depth information: thematically rich with meaningful interpretation and significant application.Furthermore, case study method encapsulates,demarcates and facilitates diverse cases for comparison between two sovereign contexts through a comprehensive case study protocol.Key findings emerging from thematic pattern at synthesis level include:the emergence of two tier prominent categories,with the first tier codes such as family members and entrepreneurial ecosystem governing the stimulating or stifling factor of social-cultural capital on youth entrepreneurship,both in Malaysia and Laos.The second tier codes unveil the role of value system, acquaintance,informal groups,culture and community in supporting first tier codes in the actualization of youth entrepreneurship.The ancillary codes such as technology and social media equally affect the governing and second tier codes in influencing youth entrepreneurship.Three types of primary network system are unveiled through the collaboration of these prominent codes and categories including privileged,preferred and laissez faire networks,which dynamically intermingle with four types of social context network ties.The outcome of this study contributes theoretically in asserting the likelihood of comparing two non homogenous socio-economic contexts in determining the role of social-cultural capital through social network in youth entrepreneurship,at micro-,meso- and macro- level.From practical perspective,this study reveals the capability of social-cultural capital in opening up pathways to the avenues of financial,physical, human and knowledge capitals,making it applicable to the broader regional context of ASEAN which is made up of factor-,efficiency and innovation- based economies. Further research study is recommended in exploring the possibility of two different sovereign socio-economic contexts sharing the capability of social network system in influencing youth entrepreneurship beyond the pursuit of uniformity in economic status or development