A new effective viscosity model for nanofluids

2018 ◽  
Vol 28 (3) ◽  
pp. 571-583 ◽  
Author(s):  
Saleh Etaig ◽  
Reaz Hasan ◽  
Noel Perera
Keyword(s):  
Nusselt Number ◽  
Regression Analysis ◽  
Effective Viscosity ◽  
Design Methodology ◽  
Viscosity Model ◽  
Horizontal Pipe ◽  
Content Type ◽  
Proposed Model ◽  
Novel Model ◽  
Good Agreement

Purpose The purpose of this paper is to present a novel model for predicting the effective viscosity of nanofluids. At present, no unified model exists for the same. Design/methodology/approach The present effective viscosity model draws upon the regression analysis of carefully selected published papers covering experimental, numerical and theoretical findings. Findings Unlike some other models, this one is reliable and has a good level of accuracy. This model has been assessed in a numerical investigation using a 3D horizontal pipe, and the results are presented. Originality/value This is a new model for predicting the effective viscosity of nanofluids. The proposed model has been tested in a 3D horizontal pipe, and the predicted results for viscosity and Nusselt number show good agreement with the available data.

LBM simulation of piezo fan in square enclosure

2019 ◽  
Vol 30 (1) ◽  
pp. 401-426 ◽  
Author(s):  
Mohammad Yaghoub Abdollahzadeh Jamalabadi
Keyword(s):  
Prandtl Number ◽  
Design Methodology ◽  
Heat Removal ◽  
Constant Wall Temperature ◽  
Content Type ◽  
Square Enclosure ◽  
Proposed Model ◽  
Prandtl Numbers ◽  
Boltzmann Method ◽  
Good Agreement

Purpose This paper aims to investigate the use of a piezo fan in an enclosure on wall heat transfer and thermal boundary layer profile in constant wall temperature situation. Design/methodology/approach The governing partial differential equations of mass, momentum and energy in addition to boundary conditions are solved by lattice Boltzmann method. The problem is solved numerically using D2Q9 population's model and Bhatnagar–Gross–Krook collision model with a code written in MATLAB. Findings The effects of Prandtl number (Pr) and the frequency of piezo fan vibrations are critically investigated on the hydrothermal characteristics of the square cavity. The mesh independency study and the validation of the proposed model are accomplished with numerical results of Ghia et al. (1982) and analytical solution of pure conduction very good agreement is found between present results and benchmark findings. Generally, with increasing beam frequency, the heat removal from heat source increased. It is found that, for all Prandtl numbers, wall Nusselt number will increase with the increase of the beam frequency. This enhancement is more intense in higher Prandtl number. Originality/value Based on these results, the use of piezo fan in an enclosure can be classified as standalone as well as heat sink integrated cooling solution.

The socio-demographic determinants of workplace loneliness in India

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mantasha Firoz ◽  
Richa Chaudhary ◽  
Madhu Lata
Keyword(s):  
Regression Analysis ◽  
Marital Status ◽  
Design Methodology ◽  
Demographic Characteristics ◽  
Average Level ◽  
Hypotheses Testing ◽  
Business Organizations ◽  
Organizational Hierarchy ◽  
Content Type ◽  
Service Sectors

PurposeThis study was conducted with two main objectives: (1) to examine the prevalence of workplace loneliness in the Indian manufacturing and service sectors (2) to examine the influence of socio-demographic characteristics (age, gender, marital status, nature of the organization, tenure, number of friends at the workplace, and position in the organizational hierarchy) on the feeling of loneliness in the workplace.Design/methodology/approachData were collected from 934 employees working in manufacturing and service sectors across India. Regression analysis was used for hypotheses testing.FindingsFindings indicated below average level of loneliness in Indian workplace. Significant differences were found in workplace loneliness with respect to age, marital status and number of friends at the workplace. In contrast, gender, nature of organization, position and tenure had no effect on the feeling of workplace loneliness.Originality/valueThis study advances the limited literature on workplace loneliness by identifying its prevalence and socio-demographic determinants in Indian business organizations. It would help HR practitioners in comprehending and dealing with the emerging challenges associated with workplace loneliness.

The presence of academic journals on Twitter and its relationship with dissemination (tweets) and research impact (citations)

2017 ◽  
Vol 69 (6) ◽  
pp. 674-687 ◽  
Author(s):  
Jose Luis Ortega
Keyword(s):  
Regression Analysis ◽  
Design Methodology ◽  
Research Impact ◽  
Research Papers ◽  
Content Type ◽  
Paired Samples ◽  
Dissemination Of Research ◽  
Twitter Account ◽  
The Relationship ◽  
Plum Analytics

Purpose The purpose of this paper is to analyze the relationship between dissemination of research papers on Twitter and its influence on research impact. Design/methodology/approach Four types of journal Twitter accounts (journal, owner, publisher and no Twitter account) were defined to observe differences in the number of tweets and citations. In total, 4,176 articles from 350 journals were extracted from Plum Analytics. This altmetric provider tracks the number of tweets and citations for each paper. Student’s t-test for two-paired samples was used to detect significant differences between each group of journals. Regression analysis was performed to detect which variables may influence the getting of tweets and citations. Findings The results show that journals with their own Twitter account obtain more tweets (46 percent) and citations (34 percent) than journals without a Twitter account. Followers is the variable that attracts more tweets (ß=0.47) and citations (ß=0.28) but the effect is small and the fit is not good for tweets (R2=0.46) and insignificant for citations (R2=0.18). Originality/value This is the first study that tests the performance of research journals on Twitter according to their handles, observing how the dissemination of content in this microblogging network influences the citation of their papers.

HC and financial performance with two HRM strategies

2017 ◽  
Vol 66 (4) ◽  
pp. 459-478 ◽  
Author(s):  
Nopadol Rompho
Keyword(s):  
Human Capital ◽  
Regression Analysis ◽  
Financial Performance ◽  
Lead Time ◽  
Design Methodology ◽  
Strategy Choice ◽  
Content Type ◽  
The Relationship ◽  
Practical Implications

Purpose The purpose of this paper is to examine the relationship between levels of human capital and financial performance of firms that use two distinct human resource management (HRM) strategies. Design/methodology/approach A survey of 128 HRM managers was conducted to assess differences in human capital between firms using different HRM strategies. A multiple regression analysis was used to investigate the relationship between firms’ human capital and financial performance. Findings The results show that companies employing a make-organic strategy have a higher level of human capital than companies employing a buy-bureaucratic strategy. There was no relationship between the level of human capital and long term financial performance of firms with both make-organic and buy-bureaucratic strategies. Research limitations/implications This research contributes toward understanding the effect of HRM strategy and facilitates an optimal strategy choice depending on the organization. However, this study did not consider the lead time between changes in human capital and the effect on financial performance. Practical implications The research encourages firm managers to understand the value of human capital, preparing them for changes in the future. Originality/value This study is among the first to investigate the relationship between human capital and financial performance considering different HRM strategies.

Investigating the effects of operators on warranty cost under sales delay conditions

2018 ◽  
Vol 24 (2) ◽  
pp. 244-259
Author(s):  
Sepideh Eskandari Dorabati ◽  
Ali Zeinal Hamadani ◽  
Hamed Fazlollahtabar
Keyword(s):  
Data Analysis ◽  
Design Methodology ◽  
Claims Data ◽  
Time Interval ◽  
Content Type ◽  
Proposed Model ◽  
Warranty Cost ◽  
Warranty Costs ◽  
Warranty Claims ◽  
Claims Data Analysis

Purpose Due to the fact that the non-standard products, being used by customers, may cause failures in products with sales delays, which naturally affect the warranty policy. Thus, it seems to be necessary to study these two concepts simultaneously. The paper aims to discuss these issues. Design/methodology/approach In this paper, a model is developed for estimating the expected warranty costs under sales delay conditions when two operator costs (failing but not reported and non-failing but reported) are included. Findings The proposed model is validated using a numerical example for a two types of intermittent and fatal failures occur under a non-renewing warranty policy. Originality/value Sales delay is the time interval between the date of production and the date of sale. Most reported literature on warranty claims data analysis related to sales delay have mainly focussed on estimating the probability distribution of the sales delay.

Proposing micro-macro HRM strategies to overcome challenges of workforce diversity and deviance in ASEAN

2018 ◽  
Vol 37 (1) ◽  
pp. 6-26 ◽  
Author(s):  
Pooja Malik ◽  
Usha Lenka ◽  
Debashish Kumar Sahoo
Keyword(s):  
Systematic Review ◽  
Conceptual Framework ◽  
Design Methodology ◽  
Southeast Asian ◽  
Workplace Deviance ◽  
Workforce Diversity ◽  
Review Of Literature ◽  
Content Type ◽  
Proposed Model ◽  
Key Word

Purpose The purpose of this paper is to propose a conceptual framework associating globalization, workforce diversity, and deviance and suggest micro-macro HRM strategies to overcome challenges associated with the workforce diversity and workplace deviance. Design/methodology/approach A systematic review of literature of past 25 years was carried out with the key word “globalization, workforce diversity, and deviance” from several electronic databases. Findings Findings propose micro-macro HRM strategies to be adopted by HR practitioners in Association of Southeast Asian Nations (ASEAN) organizations to manage workforce diversity and deviance in the age of globalization. Research limitations/implications The challenges due to workforce diversity may get worse because ASEAN is more incongruent in terms of phases of economic, social, cultural, and political advancement. Therefore, proposed model can be tested and compared in different ASEAN organizations. Originality/value There is a dearth of literature associating globalization, workforce diversity, and deviance. This paper bridges this gap by proposing a conceptual framework in the ASEAN context and suggests micro-macro HRM strategies to be adopted by HRM practitioners to overcome associated challenges with workforce diversity and deviance.

scholarly journals Actionable threat intelligence for digital forensics readiness

2019 ◽  
Vol 27 (2) ◽  
pp. 273-291 ◽  
Author(s):  
Nikolaos Serketzis ◽  
Vasilios Katos ◽  
Christos Ilioudis ◽  
Dimitrios Baltatzis ◽  
George J. Pangalos
Keyword(s):  
Digital Forensics ◽  
Quantitative Methodology ◽  
Content Type ◽  
Proposed Model ◽  
Threat Intelligence ◽  
Cyber Threat ◽  
Cyber Threat Intelligence ◽  
Security Incidents ◽  
Novel Model ◽  
Forensic Value

PurposeThe purpose of this paper is to formulate a novel model for enhancing the effectiveness of existing digital forensic readiness (DFR) schemes by leveraging the capabilities of cyber threat information sharing.Design/methodology/approachThis paper uses a quantitative methodology to identify the most popular cyber threat intelligence (CTI) elements and introduces a lightweight approach to correlate those with potential forensic value, resulting in the quick and accurate triaging and identification of patterns of malicious activities.FindingsWhile threat intelligence exchange steadily becomes a common practice for the prevention or detection of security incidents, the proposed approach highlights its usefulness for the digital forensics (DF) domain.Originality/valueThe proposed model can help organizations to improve their DFR posture, and thus minimize the time and cost of cybercrime incidents.

Increases of suicide rates in Kansas: results from 2009-2018

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jason D. Lloyd ◽  
David W. Oakley
Keyword(s):  
Regression Analysis ◽  
Design Methodology ◽  
Percentage Change ◽  
Sex Characteristics ◽  
Annual Percentage Change ◽  
Joinpoint Regression ◽  
Content Type ◽  
Suicide Rates ◽  
Joinpoint Regression Analysis ◽  
The Difference

Purpose The purpose of this study is to evaluate the increase in suicide rates for Kansas residents, as well as quantify the difference in suicide rates between men and women across the State of Kansas. Design/methodology/approach To evaluate increases in suicide rates, a joinpoint regression analysis was conducted to calculate the annual percentage change in suicide rates. To evaluate differences between sex characteristics, a one-way analysis of variance was conducted. Findings Results of a joinpoint regression analysis found that the annual percentage change in the suicide rates of Kansas did increase significantly between 2009 and 2018. Furthermore, the rate of suicide increase among women was greater than the suicide rate increases of men. Originality/value The value of this study provides context to the suicide literature that could allow for better local and statewide policy decisions.

An areal openness model (AOM) for quantifying the “openness” of floor plans

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zoraya Roldán Rockow ◽  
Brandon E. Ross
Keyword(s):  
Real World ◽  
Design Methodology ◽  
Floor Plan ◽  
Existing Buildings ◽  
Content Type ◽  
Alternative Plan ◽  
Proposed Model ◽  
Reasonable Approach ◽  
Floor Plans

PurposeThis paper aims to describe and demonstrate a quantitative areal openness model (AOM) for measuring the openness of floor plans. Creation of the model was motivated by the widely reported but rarely quantified link between openness and adaptability.Design/methodology/approachThe model calculates values for three indicators: openness score (OS), weighted OS (WOS) and openness potential (OP). OS measures the absence of obstructions (walls, chases, columns) that separate areas in a floor plan. WOS measures the number of obstructions while also accounting for the difficulty of removing them. OP measures the potential of a floor plan to become more open. Indicators were calculated for three demolished case study buildings and for three adapted buildings. The case study buildings were selected because openness – or lack thereof – contributed to the owners' decisions to demolish or adapt.FindingsOpenness indicators were consistent with the real-world outcomes (adaptation or demolition) of the case study buildings. This encouraging result suggests that the proposed model is a reasonable approach for comparing the openness of floor plans and evaluating them for possible adaptation or demolition.Originality/valueThe AOM is presented as a tool for facility managers to evaluate inventories of existing buildings, designers to compare alternative plan layouts and researchers to measure openness of case studies. It is intended to be sufficiently complex as to produce meaningful results, relatively simple to apply and readily modifiable to suit different situations. The model is the first to calculate floor plan openness within the context of adaptability.

A numerical method for solving the physics-based model of IGBT with all free-carrier injection conditions in the base region

2017 ◽  
Vol 36 (6) ◽  
pp. 1653-1662 ◽  
Author(s):  
Jiajia Chen ◽  
Yuhan Ma ◽  
Shiyou Yang
Keyword(s):  
Mathematical Model ◽  
Numerical Model ◽  
Design Methodology ◽  
Free Carrier ◽  
Carrier Injection ◽  
Base Region ◽  
Content Type ◽  
Insulated Gate Bipolar Transistor ◽  
Proposed Model ◽  
Solution Methodology

Purpose The purpose of this paper is to provide an accurate model and method to simulate the transient performances of an insulated gate bipolar transistor (IGBT) in an arbitrary free-carrier injection condition. Design/methodology/approach A numerical model and method for solving the physics-based model, an ambipolar diffusion equation-based model, of an IGBT is proposed. Findings The results of the proposed model are very close to the tested ones. Originality/value A mathematical model for an IGBT considering all free-carrier injection conditions is introduced, and a numerical solution methodology is proposed.

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