bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical study on steady state performance enhancement of partial textured hydrodynamic journal bearing
Authors: Sharma Sanjay , Jamwal Gourav , Awasthi R.K. 
Published: June 2019

Purpose
The purpose of this paper is to provide the various steady state parameters of hydrodynamic journal bearings have been determined to get maximum performance enhancement ratio. For this, the bearings inner surface is textured with triangular shape with different texture depths and a number of textures in pressure increasing region. The textured region acts as a lubricant reservoir, which provides additional film-thickness and reduce friction. Therefore, enhance the overall performance of bearing.

Design/methodology/approach
In the present study, the effect of triangular shaped texture on the static performance characteristics of a hydrodynamic journal bearing has been studied. Different values of texture depths and a number of textures have been numerically simulated in pressure developing region. The static performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous Newtonian fluid. The performance enhancement ratio, which is the ratio of load carrying capacity (LCC) to the coefficient of friction (COF) has been calculated from results to finalized optimum design parameters.

Findings
The paper provides numerically obtained results indicate that surface texturing can improve bearing performance if the textured region is placed in the pressure increasing region. Moreover, surface texturing is the most effective at bearing performance enhancement when the bearing operates at lower eccentricity ratios and texture depth. The performance enhancement ratio, which is the ratio of LCC to the COF is found to be a maximum value of 2.198 at texture depth of 1.5, eccentricity ratio of 0.2 and the textured region located in the increasing pressure region.

Research limitations/implications
The present study is based on a numerical based research approach, which has its limitations. So, researchers are encouraged to investigate the same work experimentally.

Practical implications
The paper includes implications to be beneficial for designers for designing better hydrodynamic journal bearings.

Originality/value
For the triangular shaped texture, considered in the present study, the optimum values of texture depth and texture distribution region have also been determined. While designing, designers should focus on those values of texture depth, texture region and a number of textures, which give the maximum value of performance enhancement ratio, which represents maximum LCC at the lowest value of the COF.
Experimental comparison of CuAl10Fe3 journal bearings sliding against two different coatings
Authors: Wang Xinbo , Yin Zhongwei , Li Hulin , Gao Gengyuan , Cao Jun 
Published: June 2019

Purpose
The purpose of this paper is to study the frictional behaviors of CuAl10Fe3 journal bearings sliding against chromium electroplated 42CrMo shafts and diamond-like carbon-coated 42CrMo shafts, respectively, under two different conditions and to compare the two kinds of friction pairs.

Design/methodology/approach
All journal bearing samples underwent 24 h running-in and repeatability verification. Then, the journal bearing friction experiments were carried out under two different conditions. After testing, the torques, friction coefficients, power consumptions and other parameters were obtained.

Findings
The pair of CuAl10Fe3 journal bearing and diamond-like carbon–coated shaft could drive greater load to start up than the pair of CuAl10Fe3 journal bearing and chromium electroplated 42CrMo shaft, but it had greater power consumption during the steady running period under the identical condition. With the changing of specific pressure or rotational speed, the friction coefficients had different variations. The frictional oscillations appeared at 32 rotations per minute under heavy loads for both kinds of pairs, the oscillation frequencies were equal to rotational frequency of the test shaft and the oscillation amplitude for diamond-like carbon coating was much greater.

Originality/value
These results have guiding significance for practical industrial applications.
Tribological behavior of laser textured nodular cast iron surface
Authors: Zhu Yongmei , Chen Junjie , Du Jiajun , Fan Yujie , Zheng Jifei 
Published: June 2019

Purpose
Previous publications were mainly focused on the effect of textures under lubrication. Under dry sliding, area ratio of surface texturing (pit area ratio) and diameter of pit affect the tribological behavior. This paper aims to investigate the effect of laser surface texturing on tribological behavior of nodular cast iron under dry sliding.

Design/methodology/approach
Pit-like textures with different diameters and spaces were fabricated by laser on nodular cast iron (QT600-3). Using nodular cast iron (QT600-3) as the disc specimen and resin matrix composites (UCV018) as the pad specimen, the tribological test was performed with pin-on-disk reciprocating tribo-tester.

Findings
The coefficient of friction (COF) of the non-textured specimen was larger than that of the textured one. For the same pit diameter, a larger pit area ratio induced a slight decrease of COF, while wear volume decreased significantly. The pit diameter induced a slight decrease of COF as the pit area ratio, but its effect was weaker.

Practical implications
The experimental studies will help to improve the brake system such as structure modeling of brake disc. Predicting the performance and life of the brake disc in vehicle based on tribological behavior checked in test, it was proved that pit-like texture had application value in vehicle brake system.

Originality/value
This paper showed that the effect of pit area ratio on friction and wear was greater than that of pit diameter. The experimental results will be useful to the design on safety brake disc.
Collision detection method for industrial robot based on envelope-like lines
Authors: Zhang Tie , Hong JingDong 
Published: June 2019

Purpose
Successful sensorless collision detection by a robot depends on the accuracy with which the external force/torque can be estimated. Compared with collaborative robots, industrial robots often have larger parameter values of their dynamic models and larger errors in parameter identification. In addition, the friction inside a reducer affects the accuracy of external force estimation. The purpose of this paper is to propose a collision detection method for industrial robots. The proposed method does not require additional equipment, such as sensors, and enables highly sensitive collision detection while guaranteeing a zero false alarm rate.

Design/methodology/approach
The error on the calculated torque for a robot in stable motion is analyzed, and a typical torque error curve is presented. The variational characteristics of the joint torque error during a collision are analyzed, and collisions are classified into two types: hard and soft. A pair of envelope-like lines with an effect similar to that of the true envelope lines is designed. By using these envelope-like lines, some components of the torque calculation error can be eliminated, and the sensitivity of collision detection can be improved.

Findings
The proposed collision detection method based on envelope-like lines can detect hard and soft collisions during the motion of industrial robots. In repeated experiments without collisions, the false alarm rate was 0 per cent, and in repeated experiments with collisions, the rate of successful detection was 100 per cent. Compared with collision detection method based on symmetric thresholds, the proposed method has a smaller detection delay and the same detection sensitivity for different joint rotation directions.

Originality/value
A collision detection method for industrial robots based on envelope-like lines is proposed in this paper. The proposed method does not require additional equipment or complex algorithms, and highly sensitive collision detection can be achieved with zero false alarms. The proposed method is low in cost and highly practical and can be widely used in applications involving industrial robots.
Market transparency and international real estate investment
Authors: Sadayuki Taisuke , Harano Kei , Yamazaki Fukuju 
Published: June 2019

PurposeThe purpose of this paper is to provide new empirical evidence on the important role of market transparency in international real estate investment.Design/methodology/approachThe authors apply the augmented panel regression method (or the correlated random effects approach) by using national panel data from 44 countries from 2004 to 2016.FindingsCountries with better accessibility to market information and higher enforceability of regulations have less information asymmetry and attract more inward real estate investment. In contrast, the accounting quality of corporate governance is negatively correlated with investment, indicating the possibility that foreign investors enjoy high excess returns by investing in real estate in countries with poor accounting quality.Practical implicationsCountries lacking market transparency can increase inward investments by providing richer market information to foreign investors and by boosting enforceability of regulation to mitigate the uncertainty of returns on investment. Investors and public sectors in countries facing a saturated real estate market may expand investment by investigating less-explored markets and by seeking bilateral negotiations to secure higher predictability of return on investment in targeted countries.Originality/valueThe authors utilize updated multiple transparency indices instead of a conventional aggregate index to examine how the investment is attributed to different aspects of market transparency and employ the augmented panel regression method for investigation of the intra- and international determinants of the investment.
Study of lamination quality of solar modules with PMMA front layer
Authors: Drabczyk Kazimierz , Sobik Piotr , Starowicz Zbigniew , Gawlińska Katarzyna , Pluta Anna , Drabczyk Bogusław 
Published: June 2019

Purpose
The photovoltaic modules with front glass as a protective layer are the most popular type in the industry, but for some applications it can be considered as too heavy. One of the approaches is to laminate the cells using PMMA [Poly(methyl methacrylate)] as the front layer. This polymer has good mechanical strength and optical properties but exhibits low adhesion to lamination foil. To increase adhesion between these two materials, PMMA surface treatment may be required.

Design/methodology/approach
To examine the PMMA treatment influence on the sample, adhesion samples’ surfaces were modified by grinding and laser cutting. Also two types of PMMA available in the market were tested, namely, smooth and satin types. The quality of lamination was determined using two methods, namely, tear test with recorded maximal tear force achieved for the samples, and environment chamber tests, in which the system resistance against the cyclic temperature variation was evaluated.

Findings
Additional treatment of the PMMA surface lead to increased adhesion of the lamination foil used. Ethylene-vinyl acetate foil in the PMMA system is sensitive to temperature variation, which can lead to system delamination, whereas polyvinyl butyral foil exhibits better environmental performance and even its adhesion to PMMA is lower.

Originality/value
This paper presents atypical surface modification methods that contributed to higher adhesion of lamination systems in glass-free solar modules. Glass front sheet and polymeric backsheet were replaced with PMMA. As the adhesion mechanism in the PMMA-lamination foil system differs from that in the traditional glass system, different PMMA surface treatments need to be evaluated.
Customers as “partial” employees of organizations: good or bad?
Authors: Zhuang Weiling , Babin Barry J. , Borges Adilson 
Published: June 2019

Purpose
The purpose of this study is to address the following research questions: How do customer input and service provider (in this study, the terms firm and service provider are used interchangeably) input coproduce customer experience and response? Do different components of customer input influence customer experience differently?

Design/methodology/approach
Structural equation modeling (SEM) was adopted to conduct tests of the measurement model and the main hypotheses represented in Figure 1. LISREL 8.80 (Jöreskog and Sörbom, 1993) was applied for data analysis in the current study. A survey instrument was designed and used to gather data for use in this study. Data were collected using an online survey administration tool (www.qualtrics.com).

Findings
The results indicate that two dimensions of customer participation – information resource and codeveloper activities – demonstrate distinct impacts on customers’ responses. Specifically, customer participation (information resource) is negatively related to customer shopping values and satisfaction. However, another dimension of customer participation (codeveloper activities) is positively related to the same outcomes.

Originality/value
To the best of the authors’ knowledge, this study is among the first to integrate customer participation and customer orientation to understand the phenomenon of customer co-creation. The study applies for a two-dimensional customer input construct and empirically tests their impacts on customer experience. Both utilitarian value and hedonic value are included in the research framework to assess customer value experience.
Transformation leadership and creativity
Authors: Al Harbi Jaithen Abdullah , Alarifi Saud , Mosbah Aissa 
Published: June 2019

PurposeThe purpose of this paper is to examine empirically the effect of transformational leadership on followers’ inventiveness and organizational innovation. It studies transformational leadership and innovation at the organizational level and creativity at the individual level.Design/methodology/approachA theoretical model was created, which entailed the development of variables and hypotheses. A survey instrument was used to obtain data, through a self-completion questionnaire. The final sample was made up of 503 individuals, recruited using a random sampling technique.FindingsThe results showed that transformational leadership has a significant positive relationship with both followers’ creativity and organizational innovation. Furthermore, a significant positive relationship was found between followers’ creativity and organizational innovation. In addition, the relationship between transformational leadership and followers’ creativity, through the mediating role of employees’ psychological empowerment, support for innovation, workplace relationships and employee learning, was also found to be both positive and significant. However, the data showed that intrinsic motivation does not significantly affect the relationship between transformational leadership and creativity.Practical implicationsThe study provides guidance to organizations that need to change their leadership style and approach, as well as their innovation and creativity mechanisms, at a strategic level. The resulting guidance provides organizations with insight into how they can improve the creativity of their employees through motivating, supporting and inspiring them.Originality/valueThis study is an attempt to illustrate the extent to which transformational leadership can affect organizational innovation in Saudi Arabia, specifically in the public sector, and to explore how employees’ creativity can be improved. This research is beneficial for academics, organizations and policy makers, especially in the Gulf countries.
Value-added innovation in infrastructure systems, lessons learned from wastewater treatment plants
Authors: Jamshidi Shervin 
Published: June 2019

PurposeWastewater treatment plants (WWTPs) are evolving toward sustainability. The purpose of this paper is to discuss how innovation can develop these mission-based service industries to value-added manufacturing enterprises. Here, innovation is embedded in altering the understanding of stakeholders toward the objectives and managerial systems of these infrastructures.Design/methodology/approachThis study uses multidisciplinary principles in management, economics and engineering to assess the integration of innovation and quality management with different perspectives. It initially compares the conventional and innovative approach for operating WWTPs. Subsequently, it emphasizes the contribution of the tailor-made managerial system of wastewater treatment enterprises through prospective markets, customers’ preferences, probable competitions and shared values.FindingsThe tailor-made managerial system for wastewater treatment can add economic values by manufacturing multiple demand products for local markets. Water, green energy, organic fertilizers and raw materials are the main products that can be simultaneously recovered according to the customers’ demand. The Kano model also verifies that the new managerial system has this potential to turn the conventional must-be treatment systems into delightful enterprises. It can provide different stakeholders with shared social and environmental values. Accordingly, locals and customers can be engaged in monitoring the quality of products to consider their feedback for decision making and upgrading. This indirectly defines shared values among operators and society to reinforce localization and ecosystem protection. Additionally, this research reveals that the market of the aforementioned strategic products is promising as a blue ocean for set sail due to the lack of competitors.Originality/valueThis study introduces wastewater treatment as a promising enterprise for integrating innovation and quality management.
Common‐offset common‐reflection‐surface attributes estimation with differential evolution
Authors: Barros Tiago , Lopes Renato , Krummenauer Rafael , Chauris Hervé 
Published: June 2019

ABSTRACTCommon‐reflection surface is a method to describe the shape of seismic events, typically the slopes (dip) and curvature portions (traveltime). The most systematic approach to estimate the common‐reflection surface traveltime attributes is to employ a sequence of single‐variable search procedures, inheriting the advantage of a low computational cost, but also the disadvantage of a poor estimation quality. A search strategy where the common‐reflection surface attributes are globally estimated in a single stage may yield more accurate estimates. In this paper, we propose to use the bio‐inspired global optimization algorithm differential evolution to estimate all the two‐dimensional common‐offset common‐reflection surface attributes simultaneously. The differential evolution algorithm can provide accurate estimates for the common‐reflection surface traveltime attributes, with the benefit of having a small set of input parameters to be configured. We apply the differential evolution algorithm to estimate the two‐dimensional common‐reflection surface attributes in the synthetic Marmousi data set, contaminated by noise, and in a land field data with a small fold. By analysing the stacked and coherence sections, we could see that the differential evolution based common‐offset common‐reflection surface approach presented significant signal‐to‐noise ratio enhancement.
Host migration strategy is shaped by forms of parasite transmission and infection cost
Authors: Shaw Allison K. , Craft Meggan E. , Zuk Marlene , Binning Sandra A. 
Published: June 2019

AbstractMost studies on the evolution of migration focus on food, mates and/or climate as factors influencing these movements, whereas negative species interactions such as predators, parasites and pathogens are often ignored. Although infection and its associated costs clearly have the potential to influence migration, thoroughly studying these interactions is challenging without a solid theoretical framework from which to develop testable predictions in natural systems.Here, we aim to understand when parasites favour the evolution of migration.We develop a general model which enables us to explore a broad range of biological conditions and to capture population and infection dynamics over both ecological and evolutionary time‐scales.We show that when migration evolves depends on whether the costs of migration and infection are paid in reduced fecundity or survival. Also important are the parasite transmission mode and spatiotemporal dynamics of infection and recovery (if it occurs). Finally, we find that partial migration (where only a fraction of the population migrates) can evolve but only when parasite transmission is density‐dependent.Our results highlight the critical, if overlooked, role of parasites in shaping long‐distance movement patterns, and suggest that infection should be considered alongside more traditional drivers of migration in both empirical and theoretical studies.
A thermostable mannitol‐1‐phosphate dehydrogenase is required in mannitol metabolism of the thermophilic acetogenic bacterium Thermoanaerobacter kivui
Authors: Moon Jimyung , Henke Laura , Merz Nadine , Basen Mirko 
Published: June 2019

SummaryAcetogenic bacteria recently attracted attention because they reduce carbon dioxide (CO2) with hydrogen (H2) to acetate or to other products such as ethanol. Besides gases, acetogens use a broad range of substrates, but conversion of the sugar alcohol mannitol has rarely been reported. We found that the thermophilic acetogenic bacterium Thermoanaerobacter kivui grew on mannitol with a specific growth rate of 0.33 h−1 to a final optical density (OD600) of 2.2. Acetate was the major product formed. A lag phase was observed only in cultures pre‐grown on glucose, not in those pre‐grown on mannitol, indicating that mannitol metabolism is regulated. Mannitol‐1‐phosphate dehydrogenase (MtlD) activity was observed in cell‐free extracts of cells grown on mannitol only. A gene cluster (TKV_c02830–TKV_c02860) for mannitol uptake and conversion was identified in the T. kivui genome, and its involvement was confirmed by deleting the mtlD gene (TKV_c02860) encoding the key enzyme MtlD. Finally, we overexpressed mtlD, and the recombinant MtlD carried out the reduction of fructose‐6‐phosphate with NADH, at a high VMAX of 1235 U mg−1 at 65°C. The enzyme was thermostable for 40 min at 75°C, thereby representing the first characterized MtlD from a thermophile.
Constructing ‘exceptionality’: a neglected aspect of NHS rationing
Authors: Hughes David , Doheny Shane 
Published: June 2019

AbstractIn the British NHS the principle of exceptionality involves assessing whether a patient is sufficiently different from the generality of patients to justify providing a treatment, such as an expensive cancer drug, not approved for routine funding. In England, individual requests for certain high‐cost treatments are considered by local panels that examine exceptionality alongside treatment efficacy and cost as the main criteria for funding. This was also the case in Wales until September 2017. Our paper draws on audio recordings of panel meetings and interviews in a Welsh Health Board to investigate how exceptionality was constructed in discussions. It focuses on the problematic combination of different decision criteria in meeting talk, particularly regarding the discourses associated with efficacy and exceptionality. Exceptionality is a fluid category that raised questions about the evidence‐based nature of panel decision making. In particular, the paper discusses the use of subgroup data from RCTs and the difficulty of deciding how small a subgroup of patients should be before it is deemed exceptional. Determining exceptionality has been an important mechanism for deciding that a minority of NHS patients can still receive high‐cost treatments not routinely provided for all. As a neglected rationing mechanism it warrants sociological examination.