Pravin Hindurao Yadav and Dillip kumar Mohanty
This paper aims to analyze the effect of fin geometry on mechanisms of flow induced vibration. Finned tube arrays are used in a heat exchanger to increase its efficiency…
Abstract
Purpose
This paper aims to analyze the effect of fin geometry on mechanisms of flow induced vibration. Finned tube arrays are used in a heat exchanger to increase its efficiency. Therefore, it is necessary to investigate the effect of geometric parameters of the fin fluid elastic instability and vortex shedding. In this paper, the effect of fin height, fin density and tube pitch ratio for parallel triangular tube array on fluid elastic instability and vortex shedding is analyzed.
Design/methodology/approach
Experimental analysis was carried out on a parallel triangular finned tube array with a pitch ratio of 1.79 subjected to water crossflow. The experimentation aims to study fluid elastic instability and vortex-induced vibration mechanism responsible for flow induced vibration for finned tube array. A fully flexible finned tube array of the copper tube was used with its base diameter of 19.05 mm and thickness of 2 mm. Over the tube surface, crimped fins of height 6 mm and the same material are welded spirally with fin density 8.47 mm and 2.82 mm. Experimental analysis was carried out on a test setup developed for the same. The results obtained for the finned tube array were compared with those for the plain tube array with the same base tube diameter.
Findings
For parallel triangular tube array of copper material, test results show that critical velocity increases with an increase in fin pitch density for low pitch tube array. Before the occurrence of instability, the rate of growth in tube vibrations is high for plain tubes compared to that with fin tubes. The results based on Owen’s hypothesis show vortex shedding before the occurrence of fluid elastic instability. The effect of fin geometry on vortex-induced forces is analyzed. For the tube array pattern understudy, the values of Conner’s constant K for coarse fin-tube and fine fin tube array are obtained, respectively, 6.14 and 7.25.
Originality/value
This paper fulfills the need for research on the effect of fin geometry on fluid elastic instability and Vortex shedding on a tube array subjected to water cross flow when the pitch ratio is less than two, i.e. with a low pitch ratio.
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Eric Rosenblum, Martina Davis, Marianna Grossman, Drew Clark, Jim Davis and Jeff Risberg
South Bay Water Recycling (SBWR) is a regional recycled water distribution system serving industrial and commercial customers in the area of northern California (USA) known as…
Abstract
South Bay Water Recycling (SBWR) is a regional recycled water distribution system serving industrial and commercial customers in the area of northern California (USA) known as "Silicon Valley." In early 2008 the City of San José, as administering agency of the San José/Santa Clara Water Pollution Control Plant, implemented a Cooling Tower Initiative to encourage recycled water use by commercial and industrial facilities. In 2009, Sustainable Silicon Valley, a non-profit organization dedicated to a sustainable future, convened a meeting of utilities, high-tech and academics to discuss how local stakeholders might collaborate to improve the sustainable use of water in Silicon Valley. Out of these discussions emerged the concept of the EcoCloud™, a coalition of private companies, public utilities, environmental organizations and academic researchers who encourage each other to adopt sustainable practices, supported by the latest social networking and data analysis tools. While the initial focus of the EcoCloud™ is to help industrial facilities use water sustainably—especially by using recycled water for cooling—its long-term goal is to support all aspects of sustainability, including energy reduction, materials management and land use. The EcoCloud™ allowed the City of San José to move from a serial marketing to a group marketing model, reaching more potential customers and connecting more facilities to the recycled water system.
Inspired by the concept of industrial ecology, the EcoCloud™ is designed to be a "virtual" industrial ecosystem where industry, government and educational institutions can work together to share information about all aspects of sustainability. Although industries in the EcoCloud™ are not located next to each other, they share a common interest in reducing energy usage, conserving resources, eliminating waste, and cutting costs to improve their bottom line. Just as "cloud computing" uses the distributed power of the internet for more efficient data processing, the EcoCloud™ harnesses the power of web-based social networking tools so local business leaders and facility managers can work with industry experts, technology innovators, university researchers and government agencies to make their enterprises more sustainable and more profitable.
Felicita Davis, Manoj Britto Francis Gnanasekar and Satyanarayana Parayitam
The present study is aimed at examining the antecedents of online shopping user behavior and customer satisfaction. More specifically, (1) the effect of social influence, variety…
Abstract
Purpose
The present study is aimed at examining the antecedents of online shopping user behavior and customer satisfaction. More specifically, (1) the effect of social influence, variety seeking behavior, advertising and convenience on user behavior, and (2) the effect of user behavior on customer satisfaction are examined.
Design/methodology/approach
A conceptual model is developed and tested after verifying the psychometric properties of the survey instrument. Data were collected from 556 respondents from three major cities (Hyderabad, Chennai and Bangalore) in the southern part of India using structured instrument. Hierarchical regression is performed. Measurement model was checked using structural equation modeling (Lisrel package).
Findings
The results reveal that (1) social influence, (2) variety seeking, (3) advertising, (4) convenience, (5) trust and (6) product factors were positively related to online user behavior. Results also show that user behavior is significantly and positively related to customer satisfaction. The hierarchical regression results also showed moderating effects of (1) trust in the relationship between social influence, variety seeking and user behavior, and (2) product factors in the relationship between advertising, convenience and user behavior. Finally, results suggest that user behavior is partially mediating the relationship between trust and customer satisfaction, i.e. trust has both direct and indirect effect on customer satisfaction.
Research limitations/implications
As with any survey-based research, the present study suffers from the problems associated with self-report measures viz., common method bias and social desirability bias. However, the authors attempted to minimize these limitations by following appropriate statistical techniques.
Practical implications
This study contributes to both practicing managers and the literature on advertising. The study suggests that trust and product play a major role in strengthening the relationship between antecedents and user behavior.
Originality/value
This study provides new insights about the importance of gaining trust in influencing consumer behavior. The conceptual model the authors developed is novel in the sense not many studies are available in India to empirically examine the moderating relationships of trust and product in consumer behavior.
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The TUC calls them ‘pseudo‐unions’. The men who have broken away to form their own negotiating groups say they are guided by professional codes—and firms are caught up in the…
The Summer 1972 issue of Personnel Review contained an article by Enid Mumford setting out a framework for analysing job satisfaction. This article presented a theoretical and…
Abstract
The Summer 1972 issue of Personnel Review contained an article by Enid Mumford setting out a framework for analysing job satisfaction. This article presented a theoretical and practical approach for evaluating and measuring job satisfaction, together with a definition which equated job satisfaction with the fit between what an employee was seeking from work and what he was receiving or, in other words, the fit between job needs and expectations and the requirements of the job. This analytical framework has since been used extensively in industrial and commercial organizations as a means for assisting the design of the human part of computer systems. The method has been used in the following way.
The microprocessor and digital technologies have spawned an economic revolution enabling the global customization of mass production and services in close synchronization with the…
Abstract
The microprocessor and digital technologies have spawned an economic revolution enabling the global customization of mass production and services in close synchronization with the automation of consumer processes. An important outcome of this revolution is the embedding of educational processes within commercial transactions before the sale and following delivery, before which the transaction is not complete. These new processes demand that business and education work collaboratively in a new digital environment potentiating a global diaspora of highly interactive entrepreneurial and intrapreneurial commerce. The new methods of telecommunications will be so powerful and ubiquitous as to become the ESL of the new millennium. People will need to learn the methods and processes of digital work to participate in the new economy. Explores the belief that these trends have serious implications for the processes by which education prepares students for the world of work, how education and business work together, and how society prepares citizens for roles in the new economy.
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Abstract
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Increases in urbanization and mobility, as well as local government fiscal crises have altered the financing of local government expenditures. Intergovernmental transfer of funds…
Abstract
Increases in urbanization and mobility, as well as local government fiscal crises have altered the financing of local government expenditures. Intergovernmental transfer of funds has evolved as a major source of revenue for local government units. Intergovernmental transfers to subordinate governments are enacted by various fsical instruments: (1) direct transfer of funds through loans, categorical grants, and unrestricted grants; (2) sharing of the tax base through tax supplements, tax deducations, and tax credits; and (3) intergovernmental coordination of activities. Federal grants to state and local governments have rapidly increased: federal aid as a percentage of state and local sources of general revenue was 8 percent in 1942, 11 percent in 1948, 15 percent in 1965, and 20 percent in 1967. During this same period, the amount of annual state payments to local governments increased from 3.2 billion dollars to 19.1 billion dollars (although throughout the period the payments were a consistent fraction of the national total of states' expenditures). Local government finances for 1972–73 substantiate the importance of intergovernmental funding directed to the local public sector. The total intergovernmental revenue received by all local governments in the United States was 28.6 billion in 1972–73 with 23.3 billion emanating from state governments and 5.3 billion from the federal government. In 1972 Texas state government expenditure in transfers totaled 1.2 billion dollars.