Search results

This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.

Introduction Corrosion inhibitors are used during pickling, oil‐well acidification and in other process industries to control corrosion and hydrogen absorption by steels. The suitability of an inhibitor is judged by measuring the corrosion rate and by the hydrogen absorbed by the material during the operation in the presence of inhibitors. It is generally believed that the efficacy of an inhibitor in controlling hydrogen absorption increases with its increase in corrosion mitigatory properties. This principle is true for the inhibitors which function by uniform film formation but fails in the case of poisons such as compounds of As, S, P and Sb, which strongly polarize the recombination step of the hydrogen evolution reaction on metal surfaces:

Pyridine and some of its derivatives have been evaluated as inhibitors for the corrosion of API‐45 steel in NACE sour solution. Amongst the various methyl and halogen substituted pyridine compounds, 2,4,6‐trimethyl pyridine is found to afford maximum protection followed by 2,6‐dimethyl pyridine, >2,4‐dimethyl pyridine, >3‐bromopyridine, >2‐methyl pyridine, 4‐methyl pyridine, 3,5‐dimethyl pyridine, >2 and 3‐chloropyridine>pyridine. These results have been discussed in the light of availability of the electron densities with the nitrogen atom of the pyridine ring. The inhibitive periormance of all the inhibitors is found to deteriorate with increase in temperature from 30 to 60°C and with passage of time. The values of heat of absorption and free energy of absorption indicates that the inhibitors have a chemical type of absorption at the metal/electrolyte interface. Polarization diagrams and shift in open circuit potential in the presence of inhibitors indicate that these compounds retard the cathodic as well as anodic reaction process.

This paper aims to attempt to examine the effect of firm-customer exchange characteristics, frequency and specificity, on the likelihood of the firm to generate customer-driven innovation. The authors draw from social capital theory and argue that repetitive and customer-specific exchange improves the trusts between firm and customers, which in turn ease the flows of tacit knowledge from customers to the firm. From the perspective of customer knowledge management, the authors contribute by examining the mechanism by which a firm can acquire knowledge from and about customers. The authors further argue that a firm’s ability to absorb knowledge from customers and turn them into innovation also depends on its internal capability. A firm that consistently upgrades its capacity is more likely to generate customer-driven innovation than those that do not. Also, the authors argue that the joint effect of exchange characteristics and internal capability upgrading can further increase the likelihood of customer-driven innovation. Such a joint force implies the positive moderating effect of internal capability upgrading to the relationship between exchange characteristics and customer-driven innovation.

The authors test the hypotheses on 3,000 firms from six countries in Latin America. They take advantage of the 2017 World Bank Enterprises Survey. This most recent of the survey asks questions on various types of innovation and firm-customers exchange characteristics and other firm-level variables.

The authors find support for our hypotheses that repeated exchange and exchanges tailored to specific customers have a positive effect on customer-driven innovation. Also, they find the support that internal capability upgrading, in the form of investment in product design, marketing and organizational development has a positive effect on customer-driven innovation. The authors also find that investment in product design positively moderates the impact of exchange characteristics on the likelihood of customer-driven innovation.

While past studies focus on strategies to acquire and manage customers’ knowledge, little has been said about how exchange attributes can encourage or discourage innovation? This question is important because various theoretical perspectives may have a different prediction on the effect of firm-customer relationship and innovation. This study attempts to bridge such theoretical tension.

The paper develops a model for enhancing R&D productivity for Indian public funded laboratories. The paper utilizes the productivity data of five Council of Scientific and Industrial Research (CSIR) laboratories for analysis and to form the constructs of the model.

The weighted average method was employed for analyzing the rankings of survey respondents pertaining to the significant measures enhancing R&D involvement of researchers and significant non-R&D jobs. The authors have proposed a model of productivity. Various individual, organizational and environmental constructs related to the researchers working in the CSIR laboratories have been outlined that can enhance R&D productivity of researchers in Indian R&D laboratories. Partial Least Squares-Structural Equation Modeling (PLS-SEM) was used to find the predictability of the productivity model.

The organizational factors have a crucial role in enhancing the R&D outputs of CSIR laboratories. The R&D productivity of researchers can be improved through implementing the constructs of the proposed model of productivity.

The R&D productivity model can be adapted by the R&D laboratories to enhance researchers’ R&D involvement, increased R&D outputs and achieving self-sustenance in long run.

The R&D laboratories can initiate exercises to explore the most relevant factors and measures to enhance R&D productivity of their researchers. The constructs of the model can function as a guideline to introduce the most preferable research policies in the laboratory for overall mutual growth of laboratory and the researchers.

Hardly any studies have been found that have focused on finding the measures of enhancing R&D involvement of researchers and the influence of significant time-intensive jobs on researchers’ productivity.

Like aqueous corrosion of metals, atmospheric corrosion of metallic articles has also been a matter of great anxiety due to the individual and joint action of oxygen, humidity and various types of pollution gases and ions in the atmospheres. As there is no limit of oxygen availability in the open atmosphere, this type of corrosion of metals is mainly controlled by humidity. In industrial mines and marine environments, however, metal attack is controlled by aggressive gases, ions and chloride ions respectively.

The purpose of this paper is to report on a study conducted for the purpose of learning more about the mindfulness experiences of college students and their teachers. To assist in developing a more inclusive approach to the teaching of mindfulness tailored to the individual needs of more vulnerable students and to inform teacher training and curriculum development.

This three-phase phenomenological study involved face-to-face and online contact with community college students and teachers involved in courses that incorporated mindfulness meditation. The findings from interviews with students in phase 1 were shared with teachers in phase 2 along with suggestions for safeguarding in phase 3 but initial results are promising as a number of safeguards have already been put into place.

This study found that mindfulness meditation is not necessarily a positive experience for vulnerable college students and their teachers and that there was a need for more teacher training, knowledge and ongoing support about the effects of some mindfulness meditations on some vulnerable students and how to adjust their intensity.

While this is a small qualitative study, the majority of students interviewed reported unusual experiences. This this is not well known in the literature on mindfulness in higher education, and a search of the clinical literature supports the findings that significant safeguards and adjustments are needed for mindfulness meditation for vulnerable students in educational, non-clinical settings. Further research is needed.

An implication of this study is that mindfulness meditation in its current form is likely to be unsuitable for vulnerable students. Practical recommendations for safeguarding mindfulness in higher education are already being trialed, as mentioned in this paper and will be the subject of more extensive exploration in another paper.

There are significant implications in these findings that the potential harmful effects of mindfulness may be overlooked and may be more commonly experienced than is currently realized especially for individuals with a history of trauma, with addictions, mental health difficulties or self-harm.

An innovation in this study is its methodology which drew out students’ and teachers’ own experience of mindfulness meditation in their own words when most mindfulness studies are quantitative and tend to focus on outcomes before understanding. In addition, the findings were presented directly to teachers making it possible to see how little they knew about their students’ experiences. This created an opening and a willingness to adopt safeguarding recommendations.

This paper aims to conduct an analysis of the influence of both the breadth and depth of outward foreign direct investment (OFDI) undertaken by Chinese high-tech listed companies during the period spanning 2010–2019. The data pertaining to these companies was used as a research sample to analyze the effects of OFDI on radical innovation performance.

Hierarchical regression analysis was used to test the proposed models, using survey data collected from 442 high-tech companies in China.

The findings of this study indicate a curvilinear (i.e. U-shaped) relationship between the breadth/depth of OFDI and radical innovation performance. Additional analysis reveals that OFDI plays a role in facilitating innovation breakthroughs by enhancing the internal dynamic capabilities of companies. Moreover, it is observed that a well-established institutional environment in the host country of investment can positively moderate the relationship between OFDI breadth/depth and radical innovation performance.

This study proffers a significant contribution to the understanding of the crucial role played by OFDI from emerging economy companies in enhancing radical innovation performance. Moreover, it offers theoretical guidance for multinational companies aiming to foster innovation breakthroughs.

Acidization is one of the most important techniques to increase the productivity of crude petroleum oil and gas wells. The effective way for protecting these oil well tubular materials is by using corrosion inhibitors during the acidization process. The present study deals with the evaluation of inhibition effect of ethanolamines on oil well tubular materials of grade N‐80 steel in 15 per cent hydrochloric acid at room temperature with 0‐2 per cent amine concentrations. The amines such as mono, di and triethanolamine were studied for their inhibiting capacity by mass loss method, DC polarization method and AC Impedance method. The inhibitor efficiency increases with increasing concentration of amines. Monoethanolamine is found to be more effective than the other two amines.

Reliability and maintainability estimation of any system depends on the identification of the best-fitted probability distribution of failure and repair rates. The parameters of the best-fitted probability distribution are also contributing significantly to reliability estimation. In this work, a case study of load haul dump (LHD) machines is illustrated that consider the optimization of failure and repair rate parameters using two well established metaheuristic approaches, namely, genetic algorithm (GA) and particle swarm optimization (PSO). This paper aims to analyze the aforementioned points.

The data on time between failures (TBF) and time to repairs (TTR) are collected for a LHD machine. The descriptive statistical analysis of TBF & TTR data is performed, trend and serial correlation tested and using Anderson–Darling (AD) value best-fitted distributions are identified for repair and failure times of various subsystems. The traditional methods of estimation like maximum likelihood estimation, method of moments, least-square estimation method help only in finding the local solution. Here, for finding the global solution two well-known metaheuristic approaches are applied.

The reliability of the LHD machine after 60 days on the real data set is 28.55%, using GA on 250 generations is 17.64%, and using PSO on 100 generations and 100 iterations is 30.25%. The PSO technique gives the global best value of reliability.

The present work will be very convenient for reliability engineers, researchers and maintenance managers to understand the failure and repair pattern of LHD machines. The same methodology can be applied in other process industries also.

In this case study, initially likelihood function of the best-fitted distribution is optimized by GA and PSO. Reliability and maintainability of LHD machines evaluated by the traditional approach, GA and PSO are compared. These results will be very helpful for maintenance engineers to plan new maintenance strategies for better functioning of LHD machines.