Investigation on efficiency improvement of a Kalina cycle by sliding condensation pressure method

Conventional Kalina cycle-based geothermal power plants are designed with a fixed working point determined by the local maximum ambient temperature during the year. A previous study indicated that the plant’s annual average thermal efficiency would be improved if the ammonia mass fraction of the Kalina cycle could be tuned to adapt to the ambient conditions. In this paper, another sliding condensation pressure method is investigated. A theoretical model is set up and then a numerical program is developed to analyze the cycle performance. The condensation pressure adjustment in accordance to the changing ambient temperature has been numerically demonstrated under various ammonia-water mixture concentrations. The results indicate that the Kalina cycle using sliding condensation pressure method can achieve much better annual average thermal efficiency than a conventional Kalina cycle through matching the cycle with the changing ambient temperature via controlling condensation pressure. Furthermore, the sliding condensation pressure method is compared with the composition tuning method. The results show that the annual average efficiency improvement of the sliding condensation pressure method is higher than that of the composition tuning method

Linking Information Technology and Competitive Strategy: Evidence from China’s Third-Party Logistics Industry

This study examined how information technology (IT) influences competitive strategies of third- party logistics (3PL) providers in mainland China. First, we examined the influences of IT on the firm’s IT advantage over its competitors. Second, the relationship between IT and competitive strategy was examined. The results show that IT has a significant influence on a firm’s IT advantage and its competitive strategy

The Evolution of China’s Sporting Diplomacy since 1949: The History, Experience and Promotion Strategies

The sporting diplomacy in China, as an integral part of China’s overall diplomacy, unswervingly upholds the funda mental foreign policy goal of preserving world peace and promoting common development since New China was founded. After adopting the policy of reform and opening, the sporting diplomacy in China has made historical achievements through intensive participation in international sporting competitions, extensive involvement in international sporting organizations, active hosting of mega sports events, and frequent engagement in cultural sporting exchanges with other countries. In the last decade, with a constant increase in China’s economy, cultural soft power and international influence of sports, China makes an all-round effort in the pursuit of major countrywide sporting diplomacy with Chinese charac teristics. Currently, despite the severe challenges outside China, Beijing is making smooth preparations for the 2022 Winter Olympic and Paralympic Games, which embraces another milestone in the diplomacy of sport in China. This paper analyzes decision environments, goals, actions and defining features of China’s sporting diplomacy in different periods and follows on to summarize practical experiences in the development of the sporting diplomacy in China. The paper shows that the resounding success of China’s sporting diplomacy can be attributed to its commitment to serving the country’s diplomatic strategy and core interests, its commitment to following the Chinese path of sporting diplomacy, and its commitment to the traditional Chinese value of peaceful development. Finally, emerging issues and promotion strate gies are presented

Indole-thiophene conjugate inhibits proliferation of human cervical cancer cell lines through DNA damage

Purpose: To investigate the inhibitory effect of indole-thiophene conjugate (ITC) against cervical cancer cells. Methods: The effect of ITC on the proliferation of cervical cells was determined using 3 (4,5 dimethylthiazol 2 yl) 2,5 diphenyltetrazolium bromide (MTT) assay. The apoptosis-inducing effect of ITC was analysed with flow cytometry, while its effect on cell invasion was assessed using Transwell assay. Results: ITC inhibited proliferation of HeLa and Caski cancer cell lines, but it had no cytotoxicity against HCvEpC normal epithelial cells. Exposure to ITC at a dose of 12 μmol/L reduced the viability of HeLa and Caski cells to 22.56 and 24.78 %, respectively (p < 0.05). ITC treatment of HeLa cells enhanced the proportion of apoptotic cells. Exposure to ITC at a dose of 12 μmol/L led to near-complete inhibition of the invasive potential of HeLa cells. Moreover, exposure of HeLa cells to ITC downregulated the protein expressions of MMP-2 and MMP-9 (p < 0.05). The expressions of Bcl-2, p-ERK1/2 and p-Akt were markedly decreased in HeLa cells by ITC exposure. In addition, ITC increased Bax expression, and decreased Bcl-2/Bax ratio (p < 0.05). Conclusion: ICT inhibits the proliferation and invasion of cervical cancer cells, and induces their apoptosis. It exhibits these effects via the suppression of Akt and ERK phosphorylation, thereby downregulating the PI3K and MAPK pathways. Therefore, ITC may be beneficial for the treatment of cervical cancer

Performance Evaluation and Control Strategy Comparison of Supercapacitors for a Hybrid Electric Vehicle

Electrification of powertrain system is a great technical progress of traditional vehicle, leading to a significant reduction of fuel consumption and emission pollution. Energy storage system (ESS) normally consisting of batteries is a key component of an electric vehicle or hybrid electric vehicle. An ESS can recover braking energy during the regenerative braking process. Currently, lithium-ion batteries are the main energy storage device due to their high energy density. However, sometimes, a sudden large increase of operation current is required during acceleration or regenerative braking processes, which will jeopardize the operation life of batteries. A supercapacitor takes advantage of high power density and can tolerate large current in a short time. Application of supercapacitor in an ESS can reduce the peak current of batteries effectively, and the life time of batteries can be extended. Meanwhile, the braking energy can also be recovered sufficiently. Supercapacitors can be used solely in some hybrid electric vehicles. In this chapter, the application of supercapacitors in electric vehicles or hybrid electric vehicles is reviewed briefly. Then, the performance of a series hybrid transit bus, which uses a compressed natural gas engine and supercapacitors as power sources, is analyzed

A novel voice coil motor-driven compliant micropositioning stage based on flexure mechanism

This paper presents a 2-degrees of freedom flexure-based micropositioning stage with a flexible decoupling mechanism. The stage is composed of an upper planar stage and four vertical support links to improve the out-of-plane stiffness. The moving platform is driven by two voice coil motors, and thus it has the capability of large working stroke. The upper stage is connected with the base through six double parallel four-bar linkages mechanisms, which are orthogonally arranged to implement the motion decoupling in the x and y directions. The vertical support links with serially connected hook joints are utilized to guarantee good planar motion with heavy-loads. The static stiffness and the dynamic resonant frequencies are obtained based on the theoretical analyses. Finite element analysis is used to investigate the characteristics of the developed stage. Experiments are carried out to validate the established models and the performance of the developed stage. It is noted that the developed stage has the capability of translational motion stroke of 1.8 mm and 1.78 mm in working axes. The maximum coupling errors in the x and y directions are 0.65% and 0.82%, respectively, and the motion resolution is less than 200 nm. The experimental results show that the developed stage has good capability for trajectory tracking