Search results

This study aims to apply some concepts of actuarial statistics to the authorship of Iranian ISI papers in the field of chemistry based on Price’s model. The study determines scientific birth rate, death rate, infant mortality rate, natural increase rate and life expectancy.

Price maintained that authors in each given period in any field fall into four categories including newcomers, transients, continuants and terminators. He suggested that actuarial statistics could be applied to authorship to calculate death rate and birth rate in scientific fields. A total 25,573 papers written by 59,661 Iranian chemistry authors between 1973 and 2012 were downloaded from Web of Science (WoS) and were subjected to statistical analysis.

The average birth rate was 66.7 per cent, the average death rate was 19.4 per cent, infant mortality rate was 51.2 per cent, average natural increase was 47.3 per cent, the average life expectancy was 1.98 years and the longest scientific age was 22 years. The results show that although a large number of people start their scientific activity, the number of those who terminate their activity in the same year as they start (infant mortality rate) is also large and little continuity exists in the publishing activities of Iranian chemists.

The findings have implications for the planning of human resources in science. They could help maintain a stable scientific labor force and decide for instance whether a larger number of scientists should be trained and hired, or the barriers should be removed so the existing scientists can work for more years. The limitation is that the study is restricted to ISI articles, although they are not the only kind of scientific output.

This is the first study of its kind on Iranian scientific output. It shows that the overall labor force in the field of chemistry in Iran was not satisfactory, as the majority of authors in each period are transients. There is a need for better planning for the labor force.

The mischievous nodes that defy the standard corrupt the exhibition of good nodes considerably. Therefore, an intrusion discovery mechanism should be included to the mobile ad-hoc network (MANET). In this paper, worm-hole and other destructive malignant attacks are propelled in MANET.

A wireless ad-hoc network also called as mobile ad-hoc network (MANET) is a gathering of hubs that utilizes a wireless channel to exchange information and coordinate together to establish information exchange among any pair of hubs, without any centralized structure. The security issue is a major difficulty while employing MANETs.

Consequently, the attacks due to the malicious node activity are detected using Hybrid Reactive Search and Bat (HRSB) mechanism to prevent the mischievous nodes from entering the network beneath the untruthful information. Moreover, the attack detection rate and node energy are predicted for determining the lifetime of the node.

The simulation outcomes of the proposed HRSB technique are evaluated with the prevailing methods. The comparison studies have proven the efficacy of the current research model by attaining high attack detection rate and achieving more network lifetime.

Raise in temperatures due to climate change is likely to increase the heat stress in occupations that are physically exerting and performed outdoors which might potentially have adverse health and productivity consequences. The purpose of this paper is to estimate the productivities in construction work under the influence of heat stress using the predicted mean vote (PMV) index.

Field studies were conducted during May 2014 which is summer time in Chennai. Continuous heart rate of workers and wet bulb globe temperature measurements are conducted for workers engaged in different jobs in construction. Metabolic rates and the workload of the workers from heart rate were calculated using the ISO method 8996 and the PMV values are calculated using the tool developed by Malchaire based on the method ISO 7730. Direct observations and personal interviews were conducted to substantiate the productivity estimations.

The results showed that workers working outdoors with moderate and heavy workload exceeded the threshold limit value of 28°C and had adverse productivity impacts (18-35 per cent productivity loss), whereas the workers engaged in light indoor work was not affected by heat stress and consequent productivity losses. The productivity estimations using the PMV index is found to be statistically significant for three types of construction works (Pearson correlation coefficient value of −0.78) and also correlated well with the observations and self-reported productivities of the workers.

The method used in this paper provides a scientific and reliable estimation of the productivities which may benefit the industry to set realistic project completion goals in hot weather and also implement interventions and policies to protect workers’ health. Developing adaptive strategies and implementing control measures are the need of the hour to protect worker’s health and economic losses in the face of climate change.

This study aims to analyze the productivity patterns of authors in Nigeria using publications indexed in Medline from 2008 to 2012 based on Lotka’s Law. Lotka’s Law of scientific productivity provides a platform for studying inequality in authors’ productivity patterns in a given field and over a specified period.

This study covers all the journal articles on HIV/AIDS pandemic in Nigeria over a period of five years (2008-2012) in Medline, of which 512 articles were reported to have been published during this period. In this paper, 306 articles that had HIV/AIDS in the title, published in 20 journals, and articles that had HIV/AIDS as author keywords were analyzed. Because no local database that indexed biomedical literature from Nigeria was available, Medline was used, which is not only a robust and flexible database that includes articles from Nigeria but is also the largest medical database that indexes over six-and-a-half million articles from 3,400 biomedical journals.

While HIV/AIDS can be considered a global pandemic, Nigeria has the second highest number of new infections reported each year, and an estimated 3.7 per cent of the population is living with the dreaded disease. This study presents a general picture of the distribution of papers as single-author papers, multiple-author papers and the measures of co-authorship. The findings of the study reveal that in the productivity distribution for authors on the subject of HIV/AIDS, only co-authors and non-collaborative authors’ categories fit in the Lotka’s Law, whereas all-authors and first-author categories differ from the distribution of Lotka’s inverse square law.

The empirical evidence used in this paper was based on only articles of HIV/AIDS pandemic in Nigeria that had HIV/AIDS the title. Therefore, the findings of this study might not be the generalized to other biomedical research studies.

The originality of this paper lies in the fact that the productivity pattern of each of the different author categories on the subject of HIV/AIDS is a first of its kind in the Nigerian context.

Within the framework of the valorization of natural resources, a characterization of the biochemical composition of the edible parts of Adansonia Digitata is applied. The antibacterial effect against bacteria is also realized and compared to some synthetic antibiotics.

The biochemical characterization is carried out according to the norms of the French Association of Normalization, methods of Association of Official Analytical Chemists (AOAC International) and gas chromatography (GC). The antibacterial activity is tested by disk diffusion on a solid medium. Parametric tests are used to compare the differences between groups and heat maps to show the expression of the mean inhibitions according to the studied parameters. Multivariate logistic modeling is applied to study the effect of extracts and antibiotics on bacteria.

Biochemical characterization showed a variable importance of proteins, fibers and total sugars, with the presence of highly desired fatty acids such as palmitic, oleic, stearic, linoleic and a-linolenic acids. This gives the tested parts important energy values, especially in the seeds very rich in fatty acids. Methanol proved to be a better extraction solvent than dichloromethane. Antibacterial activity showed that pulp and leaves extracted with methanol had quite similar inhibitory activities against Enterococcus faecalis ATCC29212 and that this effect was better than some antibiotics. Multivariate analysis showed that the leaves had a similar effect to antibiotics, and a significant effect against Staphylococcus aureus ATCC29213.

This important activity and the attractive nutritional value of this plant could justify its extensive use in the traditional pharmacopoeia.

There is a contradictive debate on factors influencing mobile phone usage awareness among scholars. This study aims to examine factors influencing mobile phone usage awareness for accessing agricultural marketing information.

A descriptive cross-sectional research design was used with 400 smallholder grape farmers. The use of structured questionnaires, focus group discussions and key informant interviews helped to collect primary data. Data analysis was subjected to descriptive, ordinal logistic regression and thematic approaches.

This study found that farmers were mostly aware of voice calls helping to access buyers and price information. Education, age and sex were the critical factors influencing mobile phone usage awareness among grape smallholder farmers.

This study contributes to scientific knowledge by providing an understanding of the perceived factors on mobile phone usage awareness within the grape subsector to inform policymakers.

This study aims to test the impact of digital skills on the entrepreneurial intentions of last-year undergraduate students in Jordanian universities, especially after the Coronavirus disease pandemic and the digital transformation in education and business patterns. In addition, it aims to assess the role of entrepreneurial alertness as a mediator and entrepreneurship education as a moderator in the relationship between the independent and dependent variables.

The quantitative study used a questionnaire distributed to 401 students from different Jordanian universities. The data was collected over 2 months and two structural equation models were developed using AMOS 25 to examine the relationship.

A significant negative relationship was found between digital skills and entrepreneurial intentions of last-year undergraduate students in Jordanian universities post-coronavirus disease 2019 (COVID-19) pandemic. A fully mediating role of the alertness variable has appeared in addition to a significant moderating role of entrepreneurship education.

This is the first study that attempts to investigate the impact of digital skills on students' entrepreneurial intentions in Jordan after the COVID-19 pandemic, In addition, it is one of the few studies that assess the mediator's and moderator's effects on the same conditions. Finally, the study provided a review of the definitions and models used as part of the contribution to upcoming reviews.

This study aims to develop an optimal tolerance allocation strategy involves integrating the unique transfer (UT) approach and the difficulty coefficient evaluation (DCE) routine in an interactive hybrid method. This method combines the strengths of both UT and DCE, ensuring simultaneous utilization for enhanced performance. The proposed tolerancing model manifests an integrated computer-aided design (CAD) tool.

By combining UT and DCE based on failure mode, effects and criticality analysis (FMECA) tool and the Ishikawa diagram, the proposed collaborative hybrid tool ensures an efficient and optimal tolerance allocation approach. The integration of these methodologies not only addresses specific transfer challenges through UT but also conducts a thorough evaluation of difficulty coefficients via DCE routine using reliability analysis tools as FMECA tool and the Ishikawa diagram. This comprehensive framework contributes to a robust and informed decision-making process in tolerance allocation, ultimately optimizing the design and manufacturing processes.

The presented methodology is implemented with the aim of generating allocated tolerances that align with specific difficulty requirements, facilitating the creation of a mechanical assembly characterized by high quality and low cost. To substantiate and validate the conceptual framework and methods, an integrated tool has been developed, featuring a graphical user interface (GUI) designed in MATLAB. This interface serves as a platform to showcase various interactive and integrated tolerance allocation approaches that adhere to both functional and manufacturing prerequisites. The proposed integrated tool, designed with a GUI in MATLAB, offers the capability to execute various examples that effectively demonstrate the benefits of the developed tolerance transfer and allocation methodology.

The originality of the proposed approach is the twining between the UT and DCE simultaneous in an integrated and concurrent tolerance transfer and allocation model. Therefore, the proposed approach is named an integrated CAD/tolerance model based on the manufacturing difficulty tool. The obtained results underscore the tangible advantages stemming from the integration of this innovative tolerance transfer and allocation approach. These benefits include a notable reduction in total cost and a concurrent enhancement in product quality.

The purpose of this paper is to establish a tolerance optimization method based on manufacturing difficulty computation using the genetic algorithm (GA) method. This proposal is among the authors’ perspectives of accomplished previous research work to cooperative optimal tolerance allocation approach for concurrent engineering area.

This study introduces the proposed GA modeling. The objective function of the proposed GA is to minimize total cost constrained by the equation of functional requirements tolerances considering difficulty coefficients. The manufacturing difficulty computation is based on tools for the study and analysis of reliability of the design or the process, as the failure mode, effects and criticality analysis (FMECA) and Ishikawa diagram.

The proposed approach, based on difficulty coefficient computation and GA optimization method [genetic algorithm optimization using difficulty coefficient computation (GADCC)], has been applied to mechanical assembly taken from the literature and compared to previous methods regarding tolerance values and computed total cost. The total cost is the summation of manufacturing cost and quality loss. The proposed approach is economic and efficient that leads to facilitate the manufacturing of difficult dimensions by increasing their tolerances and reducing the rate of defect parts of the assembly.

The originality of this new optimal tolerance allocation method is to make a marriage between GA and manufacturing difficulty. The computation of part dimensions difficulty is based on incorporating FMECA tool and Ishikawa diagram This comparative study highlights the benefits of the proposed GADCC optimization method. The results lead to obtain optimal tolerances that minimize the total cost and respect the functional, quality and manufacturing requirements.

This study aims to analyze the productivity patterns of authors using law literature indexed in Directory of Open Access Journals (DOAJ) from 2016 to 2020 based on Lotka’s law. Lotka’s law of scientific productivity provides a platform for studying the variation between the actual and expected authors’ productivity patterns in a subject area over a specified period.

This study covers 3,334 open access journal articles in law subject. The law journals are subdivided into two basic divisions, namely, public law and private law. This paper focuses on the journal-wise distribution of publications, subject-wise distribution of publications, annual growth rate (AGR) as well as compound AGR and applicability of Lotka’s law in both public and private law by applying the least square method followed by Pao and doing the K-S goodness-of-fit test. Student’s t-test and chi-square test have been applied to verify the significant difference between the public law and the private law literature.

There is no significant difference between the public law and private law publications on their publications per issue. The chi-square test showed that there is no significant difference between the year-wise publications in public law and private law. The authorship productivity in public law differs from the distribution of Lotka’s inverse square law, whereas it follows Lotka’s law in the case of private law.

This study is based on the articles published in open access English language journals which are indexed in the DOAJ.

This study will be useful to know the authorship productivity pattern of law literature for both public and private law individually.