Design and Development of EPICS Based RF Conditioning System for the High Power RF Components of Charged Particle Accelerators

Charged particle accelerators use various vacuum windows on their accelerating RF cavities to pass very high RF power through for the acceleration of particles. The accelerating cavities and the windows should be cleaned, baked and fully RF conditioned to eliminate poor vacuum caused by outgassing and other contamination. The linear accelerator (Linac) in the Spallation Neutron Source (SNS) contains various accelerating cavity structures and RF conditioning of their high power vacuum windows is necessary for present work as well as future upgrade and development. An example is the coaxial fundamental power coupler (FPC) with an annular alumina ceramic window for each of the 81 superconducting RF cavities in the SNS Linac. The FPC’s need to be tested up to 650 kW peak in traveling wave and 2.6 MW in standing wave in 1.3 microsecond 60 pulses per second RF. 805 MHz, 550-kW klystrons (700 kW maximum) are the main power source of the superconducting Linac and the conditioning power source of the FPC’s. The conditioning process has to be controlled very carefully not to damage the window; with the high power RF the initial vacuum is unpredictable and any unsafe vacuum level can damage the high quality ceramic windows. In this thesis, an Experimental Physics and Industrial Control System (EPICS) controlled RF conditioning system for the SNS RF Test Facility (RFTF) has been presented. Various RF and control instruments are integrated through the EPICS system on Linux platform to measure and to control the vacuum and the RF power while monitoring electron emission and unwanted arcing during the conditioning. Monitoring arcing at the window and flow and temperature of cooling water in high power RF load and ceramic window is necessary to interlock the RF not to have any kind of undesirable operation condition. The interlock system has been designed by using the Programmable Logic Controller (PLC) and an RF switch with microseconds response time. Usually the whole conditioning process takes several days, so it is necessary to get the flexibility to control, monitor, and archive the system operation remotely along with good upgradeability. To get these advantages in EPICS, VXI/VME based Input and Output Controller (IOC)s are used for controlling and monitoring the RF conditioning system. This thesis summarizes all the hardware and software design strategies, provides the results obtained so far at room temperature and describes the future research scope

Investigation of CNTFET Performance with Gate Control Coefficient Effect

For the first time, a deep study of gate control coefficient (αG) effect on CNTFET performance has done in this research. A new, analytical CNTFET simulation along with multiple parameter approach has executed with 3D output in MATLAB and that used it to examine device performance. It is found that, drain current and transconductance increases with high gate control coefficient. On the other hand, total capacitance decreases with high αG value resulting improved charging energy. Likewise, drain induced barrier lowering (DIBL) decreases with αG that provides less deviation from ideal device performance. Finally, subthreshold swing comes very close to the theoretical limit at high αG which is desired for low threshold voltage and low-power operation for FETs scaled down to small sizes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3598

Performance of socially responsible investment funds in China: A comparison with traditional funds

This paper empirically examines and compares social responsibility investment funds to traditional funds, and explores the performance of the existing social responsibility investment funds in China. Based on 64 social responsibility investment funds (SRI Funds) and 64 traditional funds, this paper extracts the data of the sample fund from the fourth quarter of 2016 to the fourth quarter of 2019 as sample data to conduct a comparative analysis of the difference between the SRI fund and the traditional fund in terms of return and risk, and to then empirically study the performance of the funds. The results show that the difference between the return of China’s socially responsible investment funds and the traditional funds is insignificant, and the risk of socially responsible investment funds is significantly lower than that of traditional funds. The regression analysis is also carried out on a model of social responsibility as a factor affecting the performance of the funds. Subsequently, the results show that social responsibility has a significant positive impact on the fund’s return in the Chinese market

Effects of stocking density on growth and production of GIFT (Oreochromis niloticus)

The study was carried out to assess the effects of stocking density on growth and production of GIFT for a period of 100 days. Three stocking densities were used 150, 200 and 250 fish/decimal; designated as treatment T1, T2 and T3 respectively having two replicates for each. Commercial pellet feeds were fed at the rate of 30% body weight up to first 10 days and then gradually it was readjusted to 22%, 18%, 15%, 12%, 10%, 8%, 6%, 5% and 4% respectively after every 10 days interval. The result showed that the fish in the treatment T1 stocked with the lowest stocking density (150 fish/dec) resulted in best individual weight gain (148.65g) followed by those in treatment T2 and T3 respectively. The specific growth rates (SGR) at every 10 days were ranged from 6.59 to 1.11 in different treatments during the experimental period. The food conversion ratio (FCR) values ranged between 1.82 to 2.03 with treatment T1 showing the lowest FCR. The survival rate ranged between 84 to 92%. Treatment T1 and treatment T2 showed significantly higher survival than Treatment T3. The fish production rate in treatment T1, T2 and T3 were 18.58, 23.87 and 26.78 kg/decimal respectively

Removal of Arsenic (III) from groundwater applying a reusable Mg-Fe-Cl layered double hydroxide

BACKGROUND: Layered double hydroxide compounds (LDHs) have been applied for the removal of oxyanions including arsenate (As(V)). However, the aim of this present research is to develop a LDH to treat arsenite (As(III)). Both batch and column sorption studies were conducted to assess the effect of LDH dosage, contact time, solution pH and initial As(III) concentrations on the As(III) removal performance. The potential re-use of this sorbent was also investigated.<p></p> RESULTS: For 2 g L−1 of Mg-Fe-Cl LDH, As(III) in test solution can be reduced from 400 µg L−1 to <10 µg L−1 after a contact time of 2 h. High As(III) concentration in Bangladesh groundwater can be reduced to meet the national drinking water standards (<50 µg L−1). The maximum adsorption capacity of As(III) by Mg-Fe-Cl LDH is 14.6 mg g−1-LDH. Further, reusability of this sorbent was at least 20 cycles of regeneration with effective As(III) removal between 93.0 and 98.5%. Moreover, As(III) removal was unaffected by the solution pH but affected by the co-existing competing anions and concentration of As(III). Finally, the main mechanism of As(III) removal by Mg-Fe-Cl LDH was suggested to be chemical sorption together with anion and ligand exchange with interlayer Cl− and OH− ions.<p></p> CONCLUSION: High efficiency of sorption of As(III) by the developed Mg-Fe-Cl LDH was demonstrated in this study which is generally not the case for most other sorbent materials. Pilot-scale trials are needed to explore the suitability of full application of the developed Mg-Fe-Cl LDH for the removal of As(III).<p></p&gt

MHD Peristaltic Flow of a Couple Stress Fluids with Heat and Mass Transfer through a Porous Medium

In the present article, we have studied the effects of heat and mass transfer on the MHD flow of an incompressible, electrically conducting couple stress fluid through a porous medium in an asymmetric flexible channel over which a traveling wave of contraction and expansion is produced, resulting in a peristaltic motion. The flow is examined in a wave frame of reference moving with the velocity of the wave. Formulas of dimensionless velocity, temperature and concentration are obtained analytically under assumptions of long wavelength and low Reynolds number. The effects of various parameters of interest such as the couple stress fluid parameter, Darcy number, Hartmann number and Schmidt number on these formulas were discussed and illustrated graphically through a set of figures. Key words: peristalsis,  Couple stress fluid,  Porous medium,  MHD flow, Heat transfer,  Mass transfer

Food Insecurity and Conflict Events in Africa

The aim of this paper is to examine the relationship between food insecurity and conflict events short of war in Africa, taking account of a host of mediating factors, including the degree of inequality, the level of development, democratic quality, quality of governance and the degree of government expenditure, which we incorporate into our analysis. Our results suggest that food price volatility does contribute significantly to conflict events measured by political events in Africa (ACLED). Greater democracy can engender more conflict, but in a non-linear fashion. The broader V-DEM participatory index of democracy also encourages more protest. Our governance variables are significant, emphasising the salience of state capacity in this regard. An innovation of our study is the inclusion of inequality. We deploy two metrics of vertical inequality: the GINI coefficient and the broader V-DEM egalitarian index. The GINI index of income inequality has a counter-intuitive statistically insignificant sign, suggesting that greater income equality or middle-class share of income results in greater political unrest. We also utilise political measures of inter-group horizontal inequality which significantly engender conflict risk

Organizational culture and participation in local governance: a study on infrastructure projects under LGSP in Bangladesh

This thesis is submitted in partial fulfillment of the requirements for the degree of Masters of Arts in Governance and Development, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (page 50 - 55).The study reveals that most of the respondents (53%) do not know the functions of Union Parishad. Even most of them did not hear about LGSP and its concerned committees as well as TOR of these committees. So it is unthinkable for them to attend the meetings of the committees. Participation in project planning is very low. Even those who have knowledge (23% of total respondents) about LGSP do not participate in the committee meetings. Only 35% of the knowledgeable respondents participated in the committee meetings and of them only 33% were entertained with opinions. In the implementation phase, participation is also very low, almost as like as in the planning phase. Only 32% of the knowledgeable xi respondents participated in implementation of the projects under LGSP. It has also been found that participation male respondents are higher than that of the female. It was taken as a truth that there was centralized control over decision making of UP as a politico- organizational culture especially by the local MP or other political elites. But, in case LGSP, neither most of UP members nor of the mass are with the notion. This is, in truth, a good sign of improving quality of participation in decision making process in project planning and implementation.Though there has been change in terms of politicoorganizational culture of UP, little change has been found in terms of people’s participation. The reason behind this is supposed to be unawareness of the mass, patron-client relationship between UP bodies and the mass, manipulation in committee formation with the chosen few in terms of personal relationship and a hidden paper-based adjustment of balance of payment of the fund for LGSP. The UP representatives still try to hide information about LGSP and they are completely reluctant to place Sign Board at each of the project area as per the guidelines of LGSP and UP manual mentioning amount of money allotted for. Amazingly, not a single sign-board was found among the five projects and being inquired about it the representatives came with common answers that those were broken up or stolen away. It seems to be true that the culture of adjusting election cost through projects’ implementation still affects the participation of common people in project planning and implementation under LGSP. Most of the UP representatives appreciated the local political elites. It leaves a room for doubt that they, with the aid of ignorance of the common people, bring the most socially and politically influential people in manipulating participation. This long existing unholy alliance between the UP representatives and local elites seems still to be practiced in case of LGSP. This culture of UP is persisting as common do not understand or never try to understand the nitty-gritty of project management. Major policy initiatives are required to avert the situation. Along with bringing transparency in the whole process, improving literacy rate, imparting training to UP members, raising awareness among the beneficiaries through GO, NGOs, print and electronic media are of great significance. Evaluation of the projects must also be done by both competent public and private project teams.S.M. Mehedi HasanM. Governance and Developmen

Capacity building for transnationalisation of higher education: Knowledge management for organisational efficacy

Purpose – Transnationalism and transnational concept are extensively researched in many social science areas; however, transnational management and transnational marketing is relatively a less explored research domain. Also, knowledge management for transnational education (TNE) marketing is not well-researched. Capacity building is an established research-stream, with a key focus on socio-economic and ecological development; however, prior research on capacity building from the context of TNE’s knowledge management and marketing is scarce. The purpose of this study is to analyse TNE marketing mix, to understand the influence of transnational stakeholders’ causal scope(s) on knowledge management in TNE to uphold their transnatioalisation processes through capacity building in TNEs’ marketing management. Design/methodology/approach – An inductive constructivist method is followed. Findings – Organisational learning from the context of transnational market and socio-economic competitive factors, based on analysing the transnational stakeholders’ causal scope(s) is imperative for proactive knowledge management capacity in TNE marketing. Following the analysis of transnational stakeholders’ causal scope(s) to learn about the cause and consequence of the transnational stakeholders’ relationships and interactions, an initial conceptual framework of knowledge management for TNE marketing is proposed. Practical insights from different TNE markets are developed in support of this novel knowledge management capacity building framework of TNE, and its generalisation perspectives and future research areas are discussed. Practical implications – These insights will be useful for TNE administrators to better align their knowledge management perspectives and propositions with their transnational stakeholders to underpin TNE marketing. Academics will be able to use these insights as a basis for future research. Originality/value – This study proposes a novel conceptual stakeholder-centred capacity building framework for TNE’s knowledge management to uphold TNE marketing and supports the framework, based on practical insights from three different transnational market