Development of a Comprehensive Simulation Platform to Investigate System Interactions Among Solid-Oxide Fuel Cell, Power-Conditioning Systems, and Application Loads

2003 ◽  
Author(s):  
S. K. Mazumder ◽  
R. Burra ◽  
K. Acharya ◽  
M. R. von Spakovsky ◽  
D. Nelson ◽  
...  
Keyword(s):  
System Level ◽  
Power Conditioning ◽  
Load Variations ◽  
Load Following ◽  
Balance Of Plant ◽  
Local Current ◽  
Critical Issues ◽  
Increasing Demand ◽  
And Performance ◽  
The Impact

SOFC stacks respond quickly to changes in load and exhibit high part- and full-load efficiencies (due to rapid electrochemistry), which is not true for the balance of plant (BOP), where load-following time constants are several orders of magnitude higher. This dichotomy diminishes the reliability and performance of the electrode with increasing demand of load. Because these unwanted phenomena are not well understood, the manufacturers of SOFC use conservative schemes to control stack responses to load variations, which limit the applicability of SOFC systems from a cost standpoint. Thus, a need exists for the synthesis of component- and system-level models of SOFC power-conditioning systems and the development of methodologies for investigating the system-interaction issues (which reduce the lifetime and efficiency of a SOFC) and optimizing the responses of each subsystem. Equally important are “multiresolution” finite-element modeling and simulation studies that can predict the impact of changes in system-level variables (e.g., current ripple and load-transients) on the local current densities, voltages, and temperature (these parameters are very difficult or cumbersome, if not impossible to obtain) within a SOFC cell. Towards that end, this paper presents a design methodology (with illustrations) for a simulation tool that will enable comprehensive analyses of above (critical) issues.

scholarly journals THE IMPACT ANALYSIS OF MOTIVATION, TRAINING, AND WORK ENVIRONMENT TO NURSES PERFORMANCE IN PATIENT SAFETY

2019 ◽  
Vol 2 (1) ◽  
pp. 54
Author(s):  
Fushen Fushen ◽  
Meylona Verawaty Zendrato
Keyword(s):  
Patient Safety ◽  
Work Environment ◽  
Public Hospital ◽  
Impact Analysis ◽  
Working Environment ◽  
Cross Sectional ◽  
The Public ◽  
Increasing Demand ◽  
And Performance ◽  
The Impact

The development of hospitals in health industry as economic institutions and the establishment of many new hospitals increase the number of nurses needed while the number of nurses produced cannot keep pace with the increasing demand. In hospital services, nurse is the most frequently interacted person with patients and are fully responsible for patient care, including in terms of patient safety. This study aims to obtain empirical evidence about the effect of motivation, training and work environment on the performance of nurses in patient safety in the Public Hospital. Expected output from this study can be used as a reference to determine the policy for nurse management at the hospital. This is a correlational analytic study with a cross-sectional approach and descriptive method of verification. The research was conducted in a Public Hospital in Jakarta. The research sample are 90 nurses working in inpatient wards. The hypothesis of this study were analyzed with path analysis methods. The results of this study showed a significant positive effect between motivation and performance (20.7%), training and performance (21.8%), working environment and performance (20.7%), and the simultaneous influence from motivation, training, and working environment on the performance (63.2% ).

Thermal Interface Materials and Cooling Technologies in Microelectronic Packaging—A Critical Review

2018 ◽  
Vol 15 (2) ◽  
pp. 63-74
Author(s):  
Dinesh P. R. Thanu ◽  
Boxi Liu ◽  
Marco Aurelio Cartas
Keyword(s):  
Integrated Circuit ◽  
Semiconductor Industry ◽  
Thermal Dissipation ◽  
System Level ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Field Programmable ◽  
Increasing Demand ◽  
And Performance ◽  
Interface Materials

The ever increasing demand for fast computing has led to heterogeneous integration of packages as can be seen in the latest Xeon family segments in the market. Microprocessors are now adjacent to memory chips, transceivers, field-programmable gate arrays, and even other microprocessors within a single substrate. These complex designs have instigated an increase in cooling demand for microprocessors, and hence, there has been an increased focus within the semiconductor industry on developing advance thermal solutions. From the packaging level, thermal interface materials (TIMs) play a key role in thermally connecting various components within the package and helps reduce the thermal resistance between the die surfaces and integrated heat spreaders. From the system level, cooling technology is critical to attain the desired overall thermal dissipation and performance. In this review, progress made in the area of TIMs and system cooling solutions are presented. The focus is on the evolution of TIMs and cooling technologies and their challenges in the integrated circuit packaging. Merits and demerits of various TIM materials available in the commercial market are also discussed. The article will be concluded with some directions for the future that would be potentially very beneficial.

A Multidisciplinary Design Optimization Approach to Relating Affordability and Performance in a Conceptual Submarine Design

2010 ◽  
Vol 26 (04) ◽  
pp. 273-289 ◽  
Author(s):  
N. Vlahopoulos ◽  
C. G. Hart
Keyword(s):  
Design Optimization ◽  
Multidisciplinary Design Optimization ◽  
Geometric Model ◽  
Multidisciplinary Optimization ◽  
System Level ◽  
Multidisciplinary Design ◽  
Manufacturing Cost ◽  
Optimization Approach ◽  
And Performance ◽  
The Impact

A multidisciplinary design optimization (MDO) framework is used for a conceptual submarine design study. Four discipline-level performances—internal deck area, powering, maneuvering, and structural analysis—are optimized simultaneously. The four discipline-level optimizations are driven by a system level optimization that minimizes the manufacturing cost while at the same time coordinates the exchange of information and the interaction among the discipline-level optimizations. Thus, the interaction among individual optimizations is captured along with the impact of the physical characteristics of the design on the manufacturing cost. A geometric model for the internal deck area of a submarine is created, and resistance, structural design, and maneuvering models are adapted from theoretical information available in the literature. These models are employed as simulation drivers in the discipline-level optimizations. Commercial cost-estimating software is leveraged to create a sophisticated, automated affordability model for the fabrication of a submarine pressure hull at the system level. First, each one of the four discipline optimizations and also the cost-related top level optimization are performed independently. As expected, five different design configurations result, one from each analysis. These results represent the "best" solution from each individual discipline optimization, and they are used as reference for comparison with the MDO solution. The deck area, resistance, structural, maneuvering, and affordability models are then synthesized into a multidisciplinary optimization statement reflecting a conceptual submarine design problem. The results from this coordinated MDO capture the interaction among disciplines and demonstrate the value that the MDO system offers in consolidating the results to a single design that improves the discipline-level objective functions while at the same time produces the highest possible improvement at the system level.

scholarly journals Performance Evaluation of a Maisotsenko Cycle Cooling Tower with Uneven Length of Dry and Wet Channels in Hot and Humid Conditions

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8249
Author(s):  
Xuchen Fan ◽  
Xiaofeng Lu ◽  
Jiping Wang ◽  
Zilong Li ◽  
Quanhai Wang ◽  
...  
Keyword(s):  
Cooling Tower ◽  
Cooling Water ◽  
Experimental System ◽  
Cooling Capacity ◽  
Pressure Drops ◽  
Industrial Sectors ◽  
Optimal Value ◽  
Increasing Demand ◽  
And Performance ◽  
The Impact

The use of the Maisotsenko cycle (M-Cycle) in traditional wet cooling towers (TWCTs) has the potential to reduce the costs of electricity generation by cooling water below the inlet air’s wet-bulb temperature. TWCTs cannot provide sufficient cooling capacity for the increasing demand for cooling energy in the power and industrial sectors—especially in hot and wet climates. Due to this fact, an experimental system of an M-Cycle cooling tower (MCT) with parallel counter-flow arrangement fills was constructed in order to provide perspective on the optimal length of dry channels (ldry), thermal performance under different conditions, and pressure drops of the MCT. Results showed that the optimal value of ldry was 2.4 m, and the maximum wet-bulb effectiveness was up to 180%. In addition, the impact of air velocity in wet channels on the pressure drops of the novel fills was also summarized. This study confirms the great potential of using the M-Cycle in TWCTs, and provides a guideline for the industrial application and performance improvement of MCTs.

scholarly journals THE IMPACT ANALYSIS OF MOTIVATION, TRAINING, AND WORK ENVIRONMENT TO NURSES PERFORMANCE IN PATIENT SAFETY

2019 ◽  
Vol 2 (1) ◽  
pp. 54
Author(s):  
Fushen Fushen ◽  
Meylona Verawaty Zendrato
Keyword(s):  
Patient Safety ◽  
Work Environment ◽  
Public Hospital ◽  
Impact Analysis ◽  
Working Environment ◽  
Cross Sectional ◽  
The Public ◽  
Increasing Demand ◽  
And Performance ◽  
The Impact

The development of hospitals in health industry as economic institutions and the establishment of many new hospitals increase the number of nurses needed while the number of nurses produced cannot keep pace with the increasing demand. In hospital services, nurse is the most frequently interacted person with patients and are fully responsible for patient care, including in terms of patient safety. This study aims to obtain empirical evidence about the effect of motivation, training and work environment on the performance of nurses in patient safety in the Public Hospital. Expected output from this study can be used as a reference to determine the policy for nurse management at the hospital. This is a correlational analytic study with a cross-sectional approach and descriptive method of verification. The research was conducted in a Public Hospital in Jakarta. The research sample are 90 nurses working in inpatient wards. The hypothesis of this study were analyzed with path analysis methods. The results of this study showed a significant positive effect between motivation and performance (20.7%), training and performance (21.8%), working environment and performance (20.7%), and the simultaneous influence from motivation, training, and working environment on the performance (63.2% ).

Dynamic Modeling of SOFC Cogeneration Systems for Light Commercial Applications

2014 ◽  
Author(s):  
Kevin J. Albrecht ◽  
Robert J. Braun
Keyword(s):  
Steady State ◽  
Waste Heat ◽  
System Level ◽  
System Component ◽  
Part Load ◽  
Load Following ◽  
Balance Of Plant ◽  
Level Model ◽  
Commercial Applications ◽  
Component Models

One potentially attractive application of solid oxide fuel cells (SOFCs) is for combined heat and power (CHP) in light commercial buildings. An SOFC-based CHP system can be employed to efficiently serve building thermal and electric loads, thereby lowering utility bills and offering many distributed generation benefits. It is often desirable to operate SOFCs in a predominately base load manner from a hardware viewpoint. However, systems in practice will experience some load dynamics during their lifetime and furthermore, optimal economic dispatch of CHP systems frequently recommends a load-following strategy. Thus, the present work is motivated by the need to understand the dynamic response capabilities of SOFC-CHP systems. Part-load performance and dynamic load-following capabilities of a 24 kW planar SOFC system for light commercial applications was investigated through computational modeling. The SOFC and balance-of-plant component models were implemented in gPROMS modeling software. The modeling strategy of each system component and associated transients are discussed. A dynamic SOFC channel-level model, which has been verified against experimental cell data, was integrated with additional balance-of-plant (BOP) component models consisting of a fuel reformer, tail gas combustor, turbomachinery, heat exchangers, and bypass valves. The performance of the system at part-load operation displays increases in electrical efficiency and decreases in CHP efficiency, as well as a more uniform PEN temperature profile. Modeling comparisons between the responses of systems consisting of either dynamic or steady-state BOP component models are reported. A fully dynamic system-level model displays anodic fuel depletion effects and waste heat recovery transients not captured by the steady-state models. The dynamics influence the ability of an SOFC system to load follow indicating when thermal and electric storage may be necessary.

The Impact of Property Characteristics on Economic Performance of Russian Industrial Enterprises

2005 ◽  
pp. 53-68 ◽  
Author(s):  
R. Kapeliushnikov ◽  
N. Demina
Keyword(s):  
Detailed Analysis ◽  
Economic Performance ◽  
Ownership Concentration ◽  
Corporate Sector ◽  
Concentrated Ownership ◽  
Industrial Enterprises ◽  
Russian Industry ◽  
Control Premium ◽  
And Performance ◽  
The Impact

The paper provides new survey evidence on effects of concentrated ownership upon investment and performance in Russian industrial enterprises. Authors trace major changes in their ownership profile, assess pace of post-privatization redistribution of shareholdings and provide evidence on ownership concentration in the Russian industry. The major econometric findings are that the first largest shareholding is negatively associated with the firm’s investment and performance but surprisingly the second largest shareholding is positively associated with them. Moreover, these relationships do not depend on identity of majority shareholders. These results are consistent with the assumption that the entrenched controlling owners are engaged in extracting "control premium" but sizable shareholdings accumulated by other blockholders may put brakes on their expropriating behavior and thus be conductive for efficiency enhancing. The most interesting topic for further more detailed analysis is formation, stability and roles of coalitions of large blockholders in the corporate sector of post-socialist countries.

The Impact of Women’s Employment on Marital Stability in Qatar Society

2019 ◽  
Vol 10 (2) ◽  
pp. 144-151
Author(s):  
Noora Ahmed Lari ◽  
Keyword(s):  
Work Motivation ◽  
Marital Stability ◽  
Female Employment ◽  
Social Constraints ◽  
Primary Data ◽  
Family Policies ◽  
Insufficient Time ◽  
And Performance ◽  
The Impact ◽  
The Relationship

The State of Qatar has implemented several family policies in order to improve the wellbeing of Qatari families and ensure fair distribution of development benefits for both men and women. However, there is a linkage between female employment outside the home and instability in the marriages of Qatari families. This paper investigates the impact of female employment on marital stability, based on the results of primary data collected in Qatar, a questionnaire that consisted of several sections such as challenges in the workplace, supervisor, family and spouse relations, work motivation and performance. Of the 824 questionnaires that were returned, 807 were completed and valid for analysis. Regression analysis and an ANOVA test have been used to test the relationship between the variables. The results of the research have produced mixed findings about how wives’ employment increases marital instability and have yielded few significant differences on mean scores of discuss on work demands, insufficient time together, housework, financial matters, communication, relatives and rearing children. The results indicates that in general Qatar working women face several challenges in relation to their marital life as part of cultural and social constraints.

THE IMPACT OF UKRAINE'S EXCISE DUTY POLICY ON THE TRANSFORMATION PROCESSES OF THE TOBACCO MARKET

2020 ◽  
Vol 2020 (10) ◽  
pp. 19-33
Author(s):  
Nadiia NOVYTSKA ◽  
◽  
Inna KHLIEBNIKOVA ◽  
Keyword(s):  
Structural Changes ◽  
Tax Avoidance ◽  
Transformation Process ◽  
State Regulation ◽  
Tobacco Products ◽  
Excise Duty ◽  
Increasing Demand ◽  
High Level ◽  
The Impact ◽  
Transformation Processes

The market of tobacco products in Ukraine is one of the most dynamic and competitive. It develops under the influence of certain factors that cause structural changes, therefore, the aim of the article is to conduct a comprehensive analysis of transformation processes in the market of tobacco and their alternatives in Ukraine and identify the factors that cause them. The high level of tax burden and the proliferation of alternative products with a potentially lower risk to human health, including heating tobacco products and e-cigarettes, are key factors in the market’s transformation process. Their presence leads to an increase in illicit turnover of tobacco products, which accounts for 6.37% of the market, and the gradual replacement of cigarettes with alternative products, which account for 12.95%. The presence on the market of products that are not taxed or taxed at lower rates is one of the reasons for the reduction of excise duty revenues. According to the results of 2019, the planned indicators of revenues were not met by 23.5%. Other reasons for non-fulfillment of excise duty revenues include: declining dynamics of the tobacco products market; reduction in the number of smokers; reorientation of «cheap whites» cigarette flows from Ukraine to neighboring countries; tax avoidance. Prospects for further research are identified, namely the need to develop measures for state regulation and optimization of excise duty taxation of tobacco products and their alternatives, taking into account the risks to public health and increasing demand of illegal products.

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