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The purpose of this paper is to investigate the effect of reciprocating and unidirectional sliding motions on friction and wear of phenolic resin-based composite.

The phenolic resin-based composite was fabricated by hot press molding, and then the tribological properties were tested on a CSM tribometer with two types of friction motion modes – reciprocating friction and unidirectional friction.

The results showed that the composite exhibited low friction coefficient in unidirectional test. However, the wear factor recorded under unidirectional sliding condition was 12-16 times higher than the reciprocating friction results. The SEM and optical microscopy test results showed that changing the relative motion mode resulted in different topography of transfer film, which is responsible for the different friction and wear characteristics of the composite under reciprocating and unidirectional friction conditions.

Effect of different friction modes, reciprocating friction and unidirectional friction, on friction characteristics of the composite is sought. Different topography of transfer film formed under reciprocating and unidirectional friction conditions contributed to the different friction characteristics.

Manufacturing of products loaded with torque in an incremental process should take into account the strength in relation to the internal structure of the details. Incremental processes allow for obtaining various internal structures, both in the production process itself and as a result of designing a three-dimensional computer-aided design model with programmable strength. Finite element analysis (FEA) is often used in the modeling process, especially in the area of topological optimization. There is a lack of data for numerical simulation processes, especially for the design of products loaded with torque and manufactured additive manufacturing (AM). The purpose of this study is to present the influence of the internal structure of samples produced in the material extrusion (MEX) technology on the tested parameters in the process of unidirectional torsion and to present the practical application of the obtained results on the example of a spline connection.

The work involved a process of unidirectional torsion of samples with different internal structures, produced in the MEX technology. The obtained results allowed for the FEA of the spline connection, which was compared with the test of unidirectional torsion of the connection.

The performance of the unidirectional torsion test and the obtained results allowed us to determine the influence of the internal structure and its density on the achieved values of the tested parameters of the analyzed prototype materials. The performed FEA of the spline connection reflects the deformation of the produced connection in the unidirectional torsion test.

There are no standards for the torsional strength of elements manufactured from polymeric materials using MEX methods, which is why the industry often does not use these methods due to the need to spend time on research, which is associated with high costs. In addition, the industry is vary of unknown solutions and limits their use. Therefore, it is important to determine, among others, the strength parameters of components manufactured using incremental methods, including MEX, so that they can be widely used because of their great potential and thus gain trust among the recipient market. In addition, taking into account the different densities of the applied filling structure of the samples made of six prototype materials commonly available from manufacturers allowed us to determine its effect on the torsional strength. The presented work can be the basis for constructors dealing with the design of elements manufactured in the MEX technology in terms of torsional strength. The obtained results also complement the existing material base in the FEA software and perform the strength analysis before the actual details are made to verify the existing irregularities that affect the strength of the details. The analysis of unidirectional torsion made it possible to supplement the material cards, which often refer to unprocessed material, e.g. in MEX processes.

The authors aim to examine the effect of location-driven logo placement on attention and memory on the web addressing differences between individuals that read unidirectionally (left-to-right [LTR]) versus bidirectionally (both right-to-left and LTR).

Using an eye-tracking approach combined with traditional verbal measures, the authors compared attention and memory measures from a sample composed of bidirectional (Arab/English) readers and unidirectional readers.

The findings reveal that unidirectional and bidirectional readers differ in attention patterns. Compared to bidirectional readers, unidirectional readers pay less attention to the logo on the bottom right corner of the webpage based on verbal measures. The eye-tracking data of the two groups further identify differences based on total hits and duration time. Unidirectional LTR readers demonstrate higher fluency in feature-based attention whereas bidirectional readers show higher fluency in spatial attention.

The authors expand on scarce research on reading direction bias effect on location-driven stimuli placement in online settings. They contribute to the understanding of the differences between unidirectional and bidirectional readers in their cognitive responses (attention and memory) to organization of marketing stimuli.

The magnetic characterization of electrical steel is typically examined by measurements under the condition of unidirectional sinusoidal flux density at different magnetization frequencies. A variety of iron loss models were developed and parametrized for these standardized unidirectional iron loss measurements. In the magnetic cross section of rotating electrical machines, the spatial magnetic flux density loci and with them the resulting iron losses vary significantly from these unidirectional cases. For a better recreation of the measured behavior extended iron loss models that consider the effects of rotational magnetization have to be developed and compared to the measured material behavior. The aim of this study is the adaptation, parametrization and validation of an iron loss model considering the spatial flux density loci is presented and validated with measurements of circular and elliptical magnetizations.

The proposed iron loss model allows the calculation and separation of the different iron loss components based on the measured iron loss for different spatial magnetization loci. The separation is performed in analogy to the conventional iron loss calculation approach designed for the recreation of the iron losses measured under unidirectional, one-dimensional measurements. The phenomenological behavior for rotating magnetization loci is considered by the formulation of the different iron loss components as a function of the maximum magnetic flux density B_m, axis ratio f_Ax, angle to the rolling direction (RD) θ and magnetization frequency f.

The proposed formulation for the calculation of rotating iron loss is able to recreate the complicated interdependencies between the different iron loss components and the respective spatial magnetic flux loci. The model can be easily implemented in the finite element analysis of rotating electrical machines, leading to good agreement between the theoretically expected behavior and the actual output of the iron loss calculation at different geometric locations in the magnetic cross section of rotating electrical machines.

Based on conventional one-dimensional iron loss separation approaches and previously performed extensions for rotational magnetization, the terms for the consideration of vectorial unidirectional, elliptical and circular flux density loci are adjusted and compared to the performed rotational measurement. The presented approach for the mathematical formulation of the iron loss model also allows the parametrization of the different iron loss components by unidirectional measurements performed in different directions to the RD on conventional one-dimensional measurement topologies such as the Epstein frames and single sheet testers.

The purpose of this paper is to quantify the impact of the constraints of the power take-off system (PTO) on the power extraction of a point absorber wave energy converter (WEC). Such constraints include power, torque and maximum stroke limitations. Two different concepts, unidirectional and bidirectional point absorbers, are analysed, which both are relevant for practical applications in the wave energy industry.

The two different cases of unidirectional and bidirectional point absorbers are analysed and directly compared. Moreover, a simplified control strategy is considered for the point absorber, which is based on a constant torque reference. The WEC performance is first evaluated in selected sea states and then the analysis is extended to assess the impact of the different solutions on the expected yearly wave energy production of the point absorber, when deployed at a specific location. The European Marine Energy Center (EMEC) is selected as the target site for the analysis.

The analysis was performed in selected sea states and then it was extended to all the sea conditions occurring at the EMEC test site. The comparison between unidirectional and bidirectional operated devices suggested a clear superiority of the latter, ensuring similar power extraction at the expense of a halved required torque by the PTO. Moreover, a selective control strategy was implemented, and the results showed an increase in yearly energy production for the bidirectional device.

The study proved the importance of including the actual PTO constraints in the preliminary power assessment in order to avoid unrealistic overestimation of the expected power performance.

The paper quantifies the power performance obtained with the application of such control strategy considering both unidirectional and bidirectional point absorbers. This analysis and comparison is extremely relevant since both unidirectional and bidirectional devices are reaching the market.

The paper aims to clearly differentiate knowledge sharing (KS) and knowledge transfer (KT) besides exemplifying their interconnections to minimize the current confusions in the knowledge management (KM) literature.

An extensive literature review method was used to analyse relevant literature on both KS and KT to clearly delineate their differences and their interconnections.

The paper found that KS is a subset of KT (using personalization strategy), whereas KT as a whole is a broader concept, if compared with KS. However, KS is not one of the immediate processes involved in KT (using codification strategy). The processes involved in KS and KT differ according to the strategy used (in KT) and perspective chosen (in KS). Other findings include KS (unidirectional) as reflective concept (viewed so far), whereas KS (bidirectional), KT (personalization) and KT (codification) as formative concepts.

The findings of this paper were based on the review of selected relevant articles only.

The paper will minimize the current confusions in the KM literature and will assist future researches on both KS and KT to ensure what these concepts entail to avoid construct underrepresentation.

As compared to previous attempts, the present paper has shown the interconnections between KS and KT, as well as the differences based on the two perspectives of KS (unidirectional/bidirectional) and the two strategies of KT (personalization/codification), and such effort is new in the literature.

The purpose of this study is to distinguish the difference in tribological behavior of functionally graded composites in two sliding modes, namely, unidirectional and reciprocating.

A356-(10 Wt.%)SiCp functionally graded composite material (FGM) was prepared by vertical centrifugal casting and then a comparison was made between the tribological characteristics using pin-on-disk and pin-on-reciprocating plate configurations under identical operating conditions (sliding distance (s): 350 m; load (W): 30 = W = 120 N, in steps of 30 N; and velocity (v): 0.2 = v = 1.2 m/s, in steps of 0.2 m/s). Two types of test pins were considered, namely, a test pin taken from the outer zone of the FGM with maximum particle concentration and a test pin taken from the inner zone of the FGM in a matrix-rich region.

The study revealed that, for the test pin taken from the outer zone of the FGM in the low-velocity range (0.2–0.4 m/s), the reciprocating wear of the friction pair was dominant, while unidirectional wear was dominant in the velocity range of 0.6–0.8 m/s for the entire load range investigated. However, when the velocity was increased from 1.0 to 1.2 m/s, conflicting nature of dominancy in the wear characteristics of the friction pair was observed, depending on the loading condition. In addition, the inner zone FGM pin underwent seizure in the reciprocating mode, whereas this phenomenon was not seen in the unidirectional mode.

Differences in wear and friction characteristics of FGM friction pairs in two different sliding modes were investigated over a wide range of operating parameters.

The purpose of this paper is to investigate the influence of trust and perceived risk on investment willingness considering the bidirectional relationship between trust and perceived risk in peer-to-peer (P2P) lending.

Data were collected from a leading Chinese P2P platform, PPDAI.com. In total, 328 valid responses were received and analyzed using structural equation modeling (SEM).

The results show that the influence of trust on investment willingness is significant, whereas that of perceived risk is insignificant. The results also indicate that platform reputation has a positive effect on trust, and the quality of alternatives is positively associated with perceived risk. In addition, the bidirectional perspective should be preferred to cope with the bidirectional relationship between trust and perceived risk in P2P lending.

This study extends existing research on the influence of trust and perceived risk on investment willingness from a bidirectional perspective, which has not been addressed in the P2P lending context. In addition, this research enriches the current literature about trust and perceived risk by providing more evidence that the relationship between trust and perceived risk is bidirectional and thus the bidirectional model should be preferred. For practice, the study suggests that managers can earn trust and reduce the perceived risk of lenders by continuously providing high-quality products, services and enhancing platform reputation, ultimately improving their investment willingness.

The unidirectional measurement and evaluation of the service quality in a specific service encounter is not enough to understand the existing service quality between two actors in a dyadic service encounter. Furthermore, a bi‐directional approach may not always be sufficient to understand the service quality in a specific service encounter. The incorporation of a third actor may improve the understanding of service quality in dyadic service encounters. Therefore, a method is applied to analyze the dynamics of service quality in triadic business networks.

The purpose of this study is to investigate the dynamic relationship that exists between energy consumption, environmental pollution and per capita economic growth in Tanzania. The energy consumption is represented by electricity usage in kilowatt hours (kWh) per capita, while environmental pollution is represented by carbon emission per metric tons and economic growth by gross domestic product (GDP) per capita.

This investigation is made based on the Environmental Kuznets Curve using time series annual data from 1975 to 2013 by applying the more robust causality technique of Toda and Yamamoto non-Causality test (1995), Impulse response and Variance Decomposition, Augumented and Dickey–Fueller test and Philips and Perron Test of unit root tests.

Economic growth rate (LGDP) and energy consumption per capita (LENGY), both being unidirectional, cause environmental pollution through carbon emission (LCO₂) in Tanzania. Interestingly, after using impulse response, a significant and positive economic growth (GDP per capita) was found due to shocks from electricity per capita (energy consumption) and carbon emission (LCO₂) with time. The Variance Decomposition suggested that the percentage of the variations due to shocks or innovations of economic growth (LGDP) and energy consumption (LENGY) to carbon emission is very high and significant, accounting to 46 and 41 per cent, respectively, in 10 years to come.

The study recommends that, in the future, the relationship be examined using super-exogeneity causality tests that takes into consideration the changes in policy or regime in contrast to Toda and Yamamoto. Furthermore, the addition of other variables such as fixed capital formation and labor force, which were not considered in this study, may result in strong correlation.

The results imply that the government of Tanzania can adopt environment conservation and energy saving policies without affecting its economic growth. As a matter of fact, to put a stop to persistent environmental pollution in Tanzania, the energy saving policy should be put in place rather quickly. It is imperative that the government implements policies and strategies that ensure continuous economic growth without forsaking the environment.

Despite the increase in carbon emissions, energy consumption and economic growth in Tanzania since 2000, to date, no previous work has been done to investigate their multivariate relationship. This is the first study that uses the Toda and Yamamoto non-Causality test, Impulse Response and Variance Decomposition Analysis to investigate a trivariate relationship of the variables mentioned above.