Satisfaction with employee relationship management systems: the impact of usefulness on systems quality perceptions

The ability to effectively manage external customer satisfaction through IT-based Customer Relationship Management systems (CRM) is well documented in the literature. The concept of applying such technologies in Business to Employee relationships to manage the firm's relationships with its employees is not. By extending the CRM paradigm to consider the service of internal customers, we characterize the emergent concept of Employee Relationship Management systems (ERM) for investigation. We find that employee satisfaction with ERM systems designed to provide access to benefits and other important employee services is largely a function of systems quality perceptions, as moderated by employee perceptions of system usefulness. Specifically, we believe our results suggest that high-quality systems implementations will not produce high degrees of employee satisfaction with ERM systems unless such systems are also found by the employee to be highly useful for their intended purpose. This highlights the critical role of accurate assessments of user requirements matched to specific needs from human resources-based systems support in the analysis phase of system design.     

A quantum chemical study of the mechanism of action of Vitamin K epoxide reductase (VKOR) II. Transition states

A reaction path including transition states is generated for the Silverman mechanism [R.B. Silverman, Chemical model studies for the mechanism of Vitamin K epoxide reductase, J. Am. Chem. Soc. 103 (1981) 5939-5941] of action for Vitamin K epoxide reductase (VKOR) using quantum mechanical methods (B3LYP/6-311G**). VKOR, an essential enzyme in mammalian systems, acts to convert Vitamin K epoxide, formed by Vitamin K carboxylase, to its (initial) quinone form for cellular reuse. This study elaborates on a prior work that focused on the thermodynamics of VKOR [D.W. Deerfield II, C.H. Davis, T. Wymore, D.W. Stafford, L.G. Pedersen, Int. J. Quant. Chem. 106 (2006) 2944-2952]. The geometries of proposed model intermediates and transition states in the mechanism are energy optimized. We find that once a key disulfide bond is broken, the reaction proceeds largely downhill. An important step in the conversion of the epoxide back to the quinone form involves initial protonation of the epoxide oxygen. We find that the source of this proton is likely a free mercapto group rather than a water molecule. The results are consistent with the current view that the widely used drug Warfarin likely acts by blocking binding of Vitamin K at the VKOR active site and thereby effectively blocking the initiating step. These results will be useful for designing more complete QM/MM studies of the enzymatic pathway once three-dimensional structural data is determined and available for VKOR.     

Measurement of thrombus formation on intravascular catheters

War is a complex social situation due to the interplay of multiple factors. Economical and political ones are of utmost importance, but human attitudes and motivations must be also taken into account. Being desirable to modify human transactions in such a way that they do not interfere with the basic right of everyone to a condition of physical and mental well-being, war must be abolished. The author contends that an understanding of behaviour through Psychology can be helpful in that aim. Aggression is considered the principal psychological cause of war. It is worth while to differentiate between aggression as an instrument for attaining a special end, and as pure hostility. Only in the first form, it is held here, does it play an important role in war. Psychogists must deal also with a wide range of states of mind that can be "served" by aggression: feelings of inferiority or insecurity, fear, greed, projections, compensations, rationalizations, etc. Scientific approach is not the only one Physiology brings to war prevention. It is equally important the wide dissemination of its conclusions among the general public. Information on the dynamics that prompt people to decide war would make it easier to control. This applies not only to political or military leaders, but also to civil populations. Concerning those two possible contributions of psychologists, scientific and educative, it is suggested the extensive use of psychodramatic techniques. Their richness lie in the lifelike experiences they convey to the participants, and particular aptitude to promote changes of attitudes. Investigation and information on the psychological processes related to war should be undertaken by international organizations of social scientists, acting simultaneously in several countries. Some of the initial steps they could further: 1) that prevention of war be a current subject matter in psychological courses; 2) that the World Health Organization take interest in this subject; 3) that psychologists participate in international political and economical bodies in order to clarify the psychological factors leading to war.     

Two MILP models for the N × M SDST flowshop sequencing problem

This paper presents the derivation and evaluation of two new MILP models for the SDST flowshop sequencing problem. The first model, TS1, was derived directly from the assignment-problem-based MILP model for the regular flowshop that Stafford modified from the original Wagner three-machine all-integer model. The second model, TS2, combined the properties of model TS1 with the looser constraints approach of Srikar and Ghosh, as modified by Stafford and Tseng (model SG*). Three experiments were used to compare both new models to the SG* model. Both new models were found to use significantly less computation time than the SG* model, especially for problem sizes of 6 or more jobs and 5 or more machines. The TS1 model used significantly less computation time than the TS2 model, making it the current best MILP model in the SDST flowshop literature.     

A sub‐Saharan African perspective on mycotoxins in beer – a review

Beer is an alcoholic beverage made from a cereal grain extract and is widely consumed in sub‐Saharan Africa and the world at large. However, beer consumption could expose consumers to mycotoxins. In this review, we appraised the different mycotoxins associated with beer contamination, elucidating their structures and incidence in cereals involved in beer production. The common mycotoxins that are found within the brewing process are reviewed. These include aflatoxin B₁ (AFB₁), fumonisin (FB), ochratoxin A (OTA), zearalenone (ZEA) and deoxynivalenol (DON), which are the prime contaminants in beer produced in sub‐Saharan Africa. Residual levels of <20% of AFB₁, OTA and FB₂ together with the transformation of ZEA (into a less toxic compound β‐zearalenol) can be achieved during the production of beers originating from Europe/America, while >50% of DON and higher ratios of FB₁ can be recovered in finished beer. Adsorption is the major means of mycotoxin removal during beer production. In contrast, traditional African beer processes show no significant efficient removal of mycotoxins. This is because the prevailing environmental conditions during beer production are favourable to mycotoxigenic fungal proliferation. This subsequently leads to relatively high concentration of mycotoxins in freshly processed beer, with a possible increase during the beer shelf‐life owing to the absence of appropriate microbial stabilisation treatments in the finished processed beer. © 2019 The Institute of Brewing & Distilling     

太阳能发电面临的挑战与机遇

在所有可再生能源中,光伏太阳能只占一小部分,然而在早期采用它的国家中,如日本和德国,却对全球工业体系起到了促进作用,对未来能源需求产生了意义深远的影响。讨论了光伏模块的当前成本和计划中的成本以及为了拓宽光伏太阳能的应用,材料科学能够为降低此成本壁垒而作出贡献的途径。文章对当前统辖市场的相对成熟的单晶硅光伏电池和有可能降低光伏模块成本的薄膜光伏电池进行了比较,指出薄膜光伏电池的转换效率需要提高而且应该能够进行大规模生产。文中给出了当前碲化镉光伏电池材料研究的一些实例,并对它们应如何在将来进行改进提出了建议。     

输电线路自适应无通道保护(一)故障分析与保护原理

在故障分析的基础上，提出了利用单端故障信息的输电线路全线速动保护原理和动作判据。保护原理由互为补充的两种动作模式－－延时动作模式和瞬时动作模式构成。延时模式利用线路对端开关动作信息加速本端保护动作；瞬时模式根据阻抗继电器Ⅱ段动作定值瞬时动作跳闸，再利用重合闸并根据开关动作后的信息纠正错误动作的结果。保护动作判据由4个独立的故障序分量的比值构成，仿真实验证实了所提保护原理和动作判据的正确性。     

Importance of initial nucleation step on low temperature photoassisted MOVPE growth of ZnSe

In this work, low temperature photoassisted metal-organic vapor phase epitaxy (MOVPE) growth of ZnSe on GaAs was carried out using dimethylzinc (DMZn) as the Zn precursor and dimethylselnium (DMSe) or diethylselnium (DESe) as the Se precursor at atmospheric pressure under H₂ carrier gas, using the 458 nm wavelength from an Ar⁺ laser. In situ laser interferometry showed that the growth rate for thin films is non-linear and was explained in terms of the efficiency of coupling of the photo-irradiation with the growing film. The growth rate (GR) can be described by GR = P F (1 – exp (– d)) where is the photo-chemical quantum efficiency, d is the film thickness, F is a structural factor, P is the laser intensity and is the absorption coefficient. In situ laser interferometry has been essential in making these measurements to observe the initial non-linearity and ensure that characteristic growth rates are taken from steady state growth. Growth using DMSe as the Se precursor was very photosensitive due to its higher photochemical quantum efficiency arising from the additional source of CH ₃ ^. radicals. These layers were mostly rough due to the slight variation in laser intensity across a region giving different degree of enhancement which is magnified by the growth rate non-linearity leading to non-uniform, and roughened growth. In the case of growth using DESe, it was possible to grow an initial nucleation layer of ZnSe pyrolyticaly prior to photo-assisted growth which ensured that there was sufficient thickness, d, of ZnSe such that the exponential term in the above equation became negligible and the growth rate was dependent only on the linear terms. The slight variation in laser intensity across the surface does not then cause a very significant variation in growth rate, thus maintaining smooth morphology and uniform growth rate.