The paradox of technology innovativeness and risk perceptions – A profile of Asian smartphone users

Risk perceptions and technology innovativeness are the two primary factors related to the adoption of mobile technologies. The current study examines the role of technology innovativeness and risk perceptions on smartphone use and dependence in an Asian context. A total of 9086 participants were recruited through online surveys from ten Asian countries. Ordinary least squares regression analyses revealed the effects of technology innovativeness, information security, privacy concern, and their interactions on smartphone use and dependence. Moreover, based on users’ smartphone usage patterns and perceptions, this paper identified four homogeneous groups using cluster analysis. Results shows that Asian smartphone users can be segmented into four groups: innovators, conservatives, moderators, and laggards. The four clusters show significant differences in demographic features. Theoretical and practical implications are discussed based on these findings.     

The barrel aged beer wheel: a tool for sensory assessment

There has been an increasing interest in the wooden barrel aging of beer in breweries worldwide. Monitoring of the barrel aging process relies mostly on changes in sensory parameters over time. This may be difficult for teams or brewers with little or no appropriate experience. The beer sensory wheel presents a broad approach to sensory aspects and generalised attributes for many beer styles. Accordingly, this tool may result in confusion through excessive visual information. The work reported here is based on literature research and sensory panel analysis employing ultra-flash profile with the aim to build a new visual tool for wooden barrel aged beer. This will aid the evaluation, training and quality assessment of barrel aged beer. It also provides specific terminology to describe the sensory changes during the barrel aging process. This approach was used to elucidate the characteristics of different wood species (amburana, cabreúva and American oak), and evaluate the flavour transformation of wooden barrel aged beer compared to non-aged beer. The barrel aged beer wheel comprises attributes and references for flavour evaluation and also terms that define the main transformational pathways, namely oxidation, wood extraction and biotransformation. The wheel described here is intended to meet academic and professional needs for the quality assessment of wooden barrel aged beer based on sensory analysis. © 2020 The Institute of Brewing & Distilling     

Understanding trust in ms-commerce: The roles of reported experience,linguistic style,profile photo,emotional, and cognitive trust

This paper examines what influences trust in mobile social commerce environment. Drawing on trust-based acceptance model (i.e. cognitive and emotional trust) and online review features (i.e. profile photo, linguistic style, and reported experience), we examine how these factors affect trust in mobile social commerce. Hypotheses were tested using survey data. The results of our model showed that there are significant influences of profile photo, reported experience, cognitive, and emotional trust towards trust in ms-commerce. This work contributes to existing literature by examining the roles of previous trust in mobile payments and online reviews on trust in mobile social commerce.     

A novel profile with high efficiency for hydrogen-circulating Roots pumps used in FCVs

Low flow rate is one of the primary disadvantages of Roots pumps when they are applied in hydrogen fuel cell vehicles. A novel profile for Roots pumps was developed in this paper to increase the working volume and reduce the internal leakage. The available range of the design parameters of the Roots pump with the new profile was determined analytically, and an improvement in the working volume was validated. The flow dynamics inside the traditional and new pumps were investigated by experiments and numerical simulations. The analytical results indicated that the maximum area utilization of the new profile was approximately 10.4% higher than that of the traditional profile at the same lobe number. The numerical results demonstrated the superiority of the proposed profile in high flow rate and sealing. The tip concentric arcs of the new profile reduced the internal leakage via the radial gap. The characteristic of multipoint meshing within a certain range of rotational angles reduced the interlobe leakage.     

Precision manufacturing of turbine wheel slots by trim-offset approach of WEDM

The present study aims to precisely manufacture the turbine wheel slot using a novel trim-offset approach of wire-electrical-discharge-machining (WEDM) in order to overcome the challenges of a conventional broaching process. Two dimensional model of turbine wheel slot is prepared in ‘ELCAM’ software to generate the computer-numerical-control (CNC) code of fir-tree-profile geometry. The experimental plan based on a trim-offset approach is executed to minimize the thermal damage and to improve the surface fatigue strength, which is most desirable for a long operating life of the jet engine. An average cutting speed of ~1.5 mm/min is observed for rough-cut and ~5 mm/min for trim-cut operation. Six categories of wires are used to manufacture the turbine wheel slots without any wire breakage and gap-short issue. The fabricated profile slots have demonstrated an average roughness (Ra) of 0.65 μm, profile accuracy within ±5 μm, minimum hardness alteration (34.87 Hv), and negligible recast layer (<5 μm) using B-150 wire and fulfilled the essential requirements of the gas turbine industries. Compared to wire-electrochemical-machining (WECM), WEDM trim-offset approach is quite advantageous and should be beneficial for the researchers working in ‘Precision machining of aerospace materials’.     

纳微米微球在低渗透油藏注入参数优化实验

纳微米微球作为一种新型调驱剂,由于其良好的注入性在低渗透油藏已展开应用。为了指导现场纳微米微球注入参数以达到更好的调驱效果,用纳微米微球进行了室内低渗透岩心调驱参数优化实验。以采收率的变化趋势为主要参考标准,综合考虑采油速度、成本与收益等,优选的注入参数为:最佳注入浓度为2 000mg/L,最佳注入量为0.2 PV,最佳注入速度为0.3 m L/min,并以优选出的参数注入低渗透天然岩心进行调驱效果评价实验,采收率提高值能达到14%左右。     

发动机配气凸轮轮廓曲线设计与研究

配气凸轮作为配气系统的核心零部件,其轮廓曲线的设计是整个配气机构设计的关键。通过对Solid Works软件进行二次开发,得出一种配气凸轮轮廓曲线的参数化设计方法。此方法能够满足精度要求较高的凸轮轮廓曲线设计,为发动机配气凸轮轮廓线的设计提供了一种依据。     

A practical sampling method for profile measurement of complex blades

Blade is one of the most important parts in turbine machinery. The complex geometry of blades not only makes them difficult to fabricate, but also leads them difficult to inspect. Typically, the surface of blades is measured by using coordinate measuring machine (CMM). Since the measurement time and cost increase proportionally as the increase of measurement points, it is essential to sample measurement points which can represent entire blade with sufficient confidence and accuracy. In order to achieve a certain allowable deviation with a suitable set of points, a practical sampling method for surface measurement of blades was studied. Firstly, the leading edge curve and trailing edge curve were supposed to represent the twisted and bend information of blades. A sampling method based on maximum chordal deviation for leading edge curve and trailing edge curve was researched. Further, a fusion approach for sampling points on both edge curves, which determine the cross-sections, was proposed. Secondly, the inspection points sampling method for sectional curves were investigated. Finally, two simulation and one experimental examples were used to demonstrate the sampling methodology. The results indicated that the approach of this study can ensure the measurement precision at high curvature potion by measuring a small number of points.     

Influence of process variables on development of camber during hot rolling of strip steel

Abstract

Experimental design techniques have been used to study the effects of variations in horizontal scale breaker process parameters in relation to camber generation during the early reduction stages in a hot strip mill. A fractional factorial experiment was designed and performed to identify which process variables are most influential to camber generation. The parameters which emerge from this analysis as being significant are: slab wedge, temperature differentials across the strip width, the deviation of the slab from the mill centreline, and mill tilt. A full factorial experiment was then designed and performed to further investigate these significant process parameters to determine where to set influential and controllable variables so that camber is minimised. The results show that none of the process parameters is significant to camber generation when acting alone; however, they are all significant when combined with one or two other process parameters. This study has enabled a predictive equation to be developed which is able to predict camber to within ±4 mm. This equation may be used in conjunction with mill tilting strategies to reduce camber in the early reduction stages of a hot strip mill.     

H181成型磨床改进

本文介绍了活塞环H181成型磨床由液压进给改进方式为数控进给方式，包括：砂轮修整部分和磨削进给部分。