Maximum Work Efficiency Research Articles

Flexo-Ferroelectricity and a Work Cycle of a Two-Dimensional-Monolayer Actuator.

Well recognized mechanical flexibility of two-dimensional (2D) materials is shown to bring about unexpected behaviors to the recently discovered monolayer ferroelectrics, especially those displaying normal, off-plane polarization. A "ferro-flexo" coupling term is introduced into the energy expression, to account for the connection of ferroelectricity and bending (strain gradient) of the layer, to predict and quantify its spontaneous curvature and how it affects the phase transitions. With InP as a chemically specific representative example, the first-principles calculations indeed reveal strong coupling ∼P·ϰ between the ferroelectric polarization (P) and the curvature of the layer (ϰ ≡ 1/r), having profound consequences for both mechanics and ferroelectricity of the material. Due to flexural relaxation, the spontaneous polarization and the transition barrier rise significantly, leading to large changes in the Curie temperature, coercive field, and domain wall width and energy, based on Monte Carlo simulations. On the other hand, the polarization switching, characteristic to ferroelectrics, does induce an overall layer bending, enabling a conversion of electrical signal to movement as an actuator; its possible work-cycles and maximum work-efficiency are briefly discussed.

Analisis Line Balancing pada Proses Produksi Style Order Long Pants

Line balancing is an assignment of a number of jobs into interconnected work stations in one production line. PT PB Tbk. is a company engaged in garment industry producing apparel. One of the products is long pants, there are 137 work elements which are divided into 4 work stations, where each work element consists of 1 operator. During production process, unbalance workload problems often occur such as a lot of idle time for some operatorsand overload for other operators. Based on this issue, it is necessary to recalculate the number of work stations and distribute the workload to avoid excessive idle time so that work can be more effective and efficient. One way to overcome this problem is applying line balancing method, with the aim that implementation of this line balancing method may achieve optimal results and each work station works effectively and has maximum work efficiency. The results of this study showed that there were additional work stations from 4 to 57, however there were adjustments to the workload.
 Keywords: line balancing, work station, bottleneck, work elements, efficiency

Formation of Emotional Climate in Human Resource Management

Research is concentrated on efficient human resource management while pursuing organizational goals and benefits for every employee and organization as a whole. Under the requirements of global market, managers expect their subordinates to be effortlessly managed, confident, dynamic in completion of assigned tasks, and ensuring maximum work efficiency. Such a possibility is theoretically analysed in this article by employing deductive thinking in interdisciplinary integration. The article describes the formation of employee emotional climate, which has impact on employee behaviour in individual as well as in team work, based on application of human resource evaluation factor with contribution of manipulations. Hypothetical presumptions resulted in assumptions that have shown dominance of disjunction (or); it means that interaction between alternatives is impossible. Therefore, logical interactions were prepared on the basis of deductive thinking by usage of Law (or principle) of the Excluded Third. These logical interactions resulted in models of emotional climate formation.

Indoor Thermal Environment Control System Based on Maximum Work Efficiency

Based on the indoor thermal environment on the influence of the office personnel work efficiency on the basis of experimental research. In this paper, a control method based on maximizing work efficiency is proposed, which aims at maximizing indoor staff’s work efficiency and rest efficiency, and takes Predicted Mean Vote (PMV) as control parameter to control indoor environment, taking into account the requirements of comfort. The operation effect of the control method based on maximum work efficiency is estimated. It is found that compared with the traditional control system based on PMV index, the system not only improves the work efficiency and rest efficiency of indoor personnel, but also is more comfortable. The indoor environment control system based on maximizing work efficiency is still in the theoretical stage. The construction and actual operation effect of the system need to be further studied.

Study of available thermal energy on OTEC

Thermal efficiency is commonly applied in the power plants for the purpose of evaluating heat engines. However, the maximization of the thermal efficiency does not lead the maximization of the available power output from ocean thermal energy conversion (OTEC), which converts the finite thermal energy stored between different temperature seawaters into work. The maximum work efficiency based on the theoretical maximum work from the ideal heat engine has been identified for evaluation; however, the implication in the available thermal energy has not yet been substantially identified. This paper theoretically reveals the available thermal energy from the ocean thermal gradient and the effective energy, which is known as the exergy, using the reference of the equilibrium temperature as the dead state. By employing the finite-time thermodynamics, the available energy and the exergy calculation methods for OTEC are obtained. For the evaluation of the systems, the normalized thermal efficiency is proposed instead of the conventional thermal efficiency and the exergy efficiency for OTEC is proposed as well. The results indicated that increases in the normalized thermal efficiency increase the power output from the OTEC system and the maximum normalized thermal efficiency conditions correspond to the maximum power output heat balance. They also showed the effectiveness of the proposed exergy for OTEC derived by entropy generation minimization.

Universality of maximum-work efficiency of a cyclic heat engine based on a finite system of ultracold atoms

We study the performance of a cyclic heat engine which uses a small system with a finite number of ultracold atoms as its working substance and works between two heat reservoirs at constant temperatures Th and Tc(<Th). Starting from the expression of heat capacity which includes finite-size effects, the work output is optimized with respect to the temperature of the working substance at a special instant along the cycle. The maximum-work efficiency ηmw at small relative temperature difference can be expanded in terms of the Carnot value {{boldsymbol{eta }}}_{{boldsymbol{C}}}={bf{1}}-{{boldsymbol{T}}}_{{boldsymbol{c}}}/{{boldsymbol{T}}}_{{boldsymbol{h}}}, {{boldsymbol{eta }}}^{{boldsymbol{m}}{bf{w}}}={{boldsymbol{eta }}}_{{boldsymbol{C}}}/{bf{2}}+{{boldsymbol{eta }}}_{{boldsymbol{C}}}^{{bf{2}}}({bf{1}}/{bf{8}}+{{boldsymbol{a}}}_{{bf{0}}})+{boldsymbol{ldots }}, where a0 is a function depending on the particle number N and becomes vanishing in the symmetric case. Moreover, we prove using the relationship between the temperatures of the working substance and heat reservoirs that the maximum-work efficiency, when accurate to the first order of ηC, reads {{boldsymbol{eta }}}^{{boldsymbol{m}}{bf{w}}}={{boldsymbol{eta }}}_{{boldsymbol{CA}}}+{bf{O}}(ΔT2). Within the framework of linear irreversible thermodynamics, the maximum-power efficiency is obtained as {{boldsymbol{eta }}}^{{boldsymbol{mp}}}={{boldsymbol{eta }}}_{{boldsymbol{CA}}}+{bf{O}}(ΔT2) through appropriate identification of thermodynamic fluxes and forces, thereby showing that this kind of cyclic heat engines satisfy the tight-coupling condition.

OTECの有効熱エネルギーに関する研究

For the evaluation of the heat engines, the thermal efficiency is commonly applied in the power plants. However, the maximization of the thermal efficiency do not lead the maximization of the available power output from OTEC, which converts into the work from the finite thermal energy stored between different temperature seawaters. The maximum work efficiency based on the theoretical maximum work from the ideal heat engine has been counseled for the evaluation, however, the implication in the available thermal energy has not identified substantially. This paper theoretically reveals the available thermal energy from the ocean thermal gradient and the effective energy, which is called the exergy, using the reference of the equilibrium temperature as the dead state. By employing the finite-time thermodynamics, the available energy and the exergy calculation methods are obtained and the normalized thermal efficiency for OTEC and the exergy efficiency are proposed.

A study of UHF-RFID data model construction in university libraries

Purpose – The purpose of this paper is to put forward a Ultra-high Frequency Radio Frequency Identification (UHF-RFID) data model construction scheme for university libraries, hoping to realize the opening, uniform, compatible and interoperable RFID application between different libraries and manufacturers. Design/methodology/approach – This article uses the practical application needs of university libraries as the starting point, and proposes the UHF-RFID data model construction scheme for university libraries based on the study of applicable standards, such as ISO 28560. Findings – Based on practical application demand of university libraries and some international standards, the paper puts forward an UHF-RFID data model construction scheme for university libraries. First, the scheme explains and defines six user data elements different from ISO28560: version, owner library identifiers, temporary item location, subject, International Standard Serial Number (ISSN) and International Standard Book Number (ISBN). Furthermore, different encoding rules for electronic product code (EPC) data area and user data area are designed to achieve maximum work efficiency. Practical implications – This paper tries to bring forward a set of referential UHF-RFID data model standards for university libraries. Hopefully, this standard will offer uniform data models for university libraries to comply with, integrate the disordered market and further make the opening, unified, compatible and interoperable RFID application possible. Originality/value – Although there are several formally published RFID standard documents, they are primarily designed for high frequency RFID technology. Concerning UHF-RFID technology, there are still no internationally unified data model standards. Hence, this paper brings forward the UHF-RFID data model construction scheme for university libraries.

A Planting Machine for Chrysanthemum Cuttings with a Supply Mechanism Using Rotating Cups

The purpose of this study was to mechanize the task of planting chrysanthemum cuttings in plug trays. Seedling production using these trays is common in Japan to produce high-quality chrysanthemums, other flowers, and vegetables. However, chrysanthemum cuttings must be planted manually, which takes considerable time. Two models of planting machines suitable for chrysanthemum cuttings have been developed: a standard model for cuttings with no lower leaves, and a model that automatically removes the lower leaves. Both models are semi-automatic and employ a mechanism using rotating cups to facilitate a supply task of an operator and let two operators work side by side. In our laboratory and field experiments, the standard model had a failure rate of 0.5-3.1% and increased the maximum work efficiency to 2.4 times that of manual planting. The model that removed lower leaves had a failure rate of 0.8-4.5%, but also increased maximum work efficiency to 2.4 times that of manual planting. Although both models are influenced by individual supply variations from the workers, we believe they are ready for commercial use.

Thermodynamic cycles with nearly universal maximum-work efficiencies

Important thermodynamic heat engine cycles can be regarded as special cases of a more universal 'generalised' cycle. For specific choices of a continuously variable parameter, this generalised cycle reduces to the Carnot, Otto, Joule-Brayton, Diesel and other known cycles. Of particular interest is the thermal efficiency when characteristic temperatures between the highest and lowest operating temperatures (T+ and T-) are chosen to maximise the work output per cycle. This maximum-work efficiency is found to be equal to, or to be well approximated by, the Curzon-Ahlborn efficiency, eta CA identical to 1-(T-/T+)1/2 for a broad spectrum of cycles and temperatures.