Precise Molecular Engineering of Photosensitizers with Aggregation‐Induced Emission over 800 nm for Photodynamic Therapy

Owing to efficient singlet oxygen (¹O₂) generation in aggregate state, photosensitizers (PSs) with aggregation‐induced emission (AIE) have attracted much research interests in photodynamic therapy (PDT). In addition to high ¹O₂ generation efficiency, strong molar absorption in long‐wavelength range and near‐infrared (NIR) emission are also highly desirable, but difficult to achieve for AIE PSs since the twisted structures in AIE moieties usually lead to absorption and emission in short‐wavelength range. In this contribution, through acceptor engineering, a new AIE PS of TBT is designed to show aggregation‐induced NIR emission centered at 810 nm, broad absorption in the range between 300 and 700 nm with a large molar absorption coefficient and a high ¹O₂ generation efficiency under white light irradiation. Further, donor engineering by attaching two branched flexible chains to TBT yielded TBTC8 , which circumvented the strong intermolecular interactions of TBT in nanoparticles (NPs), yielding TBTC8 NPs with optimized overall performance in ¹O₂ generation, absorption, and emission. Subsequent PDT results in both in vitro and in vivo studies indicate that TBTC8 NPs are promising candidates in practical application.     

An outbreak of Salmonella mikawasima associated with doner kebabs

During October 1992 an increase in the number of isolates of Salmonella mikawasima, a rare serotype, was noted including a cluster of nine cases in the South West Thames region. A case control study was conducted and univariate analysis showed a statistical association between illness and eating at take-away A for cases compared with household controls (P = 0.003) and with neighbourhood controls (P = 0.0245). Cases were also more likely to have eaten kebabs than were controls or average take-away A customers, implicating doner kebabs as the most likely vehicle of infection. Plasmid profile analysis of the nine cases' isolates showed them to be indistinguishable and to be characterized by a single plasmid of approximately 60 MDa. The original source of the Salmonella mikawasima contamination was not determined, but food preparation practices for kebabs at take-away A were insufficient to protect against illness if contaminated. This outbreak was only recognized because of the unusual serotype, but could be an indication of a more widespread problem with doner kebabs.     

Selected Papers on Improving Heat Transfer via Electrohydrodynamic Technique

Penetrative convection in a stably stratified fluid has been reproduced in laboratory by employing a tank filled with water and subjected to heating from below. The goal of the experiments is predicting the mixing layer growth as a function of initial and boundary conditions and describing the fate of a tracer dissolved in the fluid phase. The equipment employed is suitable for simultaneously providing temperatures inside the domain through thermocouples and Lagrangian particle trajectories by feature tracking. The field of view is illuminated through a thin light sheet with suitable optical equipment. To fully characterize the transport feature of the phenomenon under investigation, the mixing layer growth is detected employing both temperature data and statistics of the velocity field, i.e., the vertical velocity component standard deviation. The velocity spatial correlation allows the plume horizontal dimension to be determined. This information coupled with the knowledge of the mixing layer height allows the spatial extension of the convective region to be fully described.     

Applying different optimization approaches to achieve optimal configuration of a dual pressure heat recovery steam generator

The optimal design for heat recovery steam generator (HRSG) should be chosen based on technical and economic considerations. Therefore, parameters that are related to thermodynamic and economic aspects should be considered in optimization approaches. It is worth mentioning that one of the significant issues in the HRSG design is the diversity of arrangements between various components (economizer, evaporator, and superheater), which absolutely affect the HRSG performance. According to these facts, in the present article, different arrangements of a dual pressure HRSG are analyzed, and the economizer at the high‐pressure level is divided into two parts; these arrangements are optimized by applying different optimization approaches to achieve the optimal configuration. These approaches include the reduction of gas pressure drop, the reduction of generated steam cost and the consideration of both approaches as the third approach. These three approaches are also considered to perform economic and thermodynamic optimization. With regard to the limitations of optimization such as the pinch and approach point, seven different configurations are considered. First, a comprehensive model is developed for calculating thermodynamic, heat transfer, and pressure loss. To perform a thorough optimization, both thermodynamic and geometric variables as well as diversity of various arrangements is considered using genetic algorithm. The results of the optimization study show that the best arrangement is not unique, and each arrangement has different characteristics. Hence, the best arrangement for the HRSG is chosen according to the importance of the objective functions. Copyright © 2012 John Wiley & Sons, Ltd.     

Environmental damage costs in Iran by the energy sector

On the basis of the energy supply and demand, this paper assesses the environmental damage from air pollution in Iran using the Extern-E study that has extended over 10 years and is still in progress in the European Union (EU) commission. Damage costs were transferred from Western European practice to the conditions of Iran by scaling according to GDP per capital measured in PPP terms.     

Influence of Gating System,Sand Grain Size,and Mould Coating on Microstructure and Mechanical Properties of Thin-Wall Ductile Iron

 In this study, the effect of gating systems, mould coating and sand grain size on metallurgical and mechanical properties of TWDI casting were investigated. Two different gating systems; stepped and tapered runners, were used to cast strip samples. The thicknesses of the samples cast were 2.3, 3.3, 4.5, 5.4, 6.5, 7.5 and 8.5 mm. The samples were cast in CO2/silicate process moulds of two different sand grain sizes of 151 and 171 according to the AFS standard. To assess the effect of mould coat on the properties of TWDI, half of the moulds were coated with graphite-based zircon whilst the rest were left uncoated. The carbon equivalent (CE) of the molten metal prepared was 4.29% and poured at the temperatures of 1450°C. The microstructure of the cast specimens was analyzed by optical and scanning electron microscopes. Clemex Image Analyzer (CIA) was used to evaluate graphite nodule count, graphite nodules area fraction, roundness and diameter of the nodules of the TWDI cast samples. Brinell hardness and tensile tests were also conducted on all the samples. The results show that by using stepped runner gating system with uncoated and coarse sand grain size mould, roundness and graphite nodule counts decrease. However, graphite nodules diameter and area fraction increase. The results also show that finer sand grain size and coated mould produce longer distance of molten metal travel.     

Observer‐based adaptive optimal output containment control problem of linear heterogeneous Multiagent systems with relative output measurements

This paper develops a relative output‐feedback–based solution to the containment control of linear heterogeneous multiagent systems. A distributed optimal control protocol is presented for the followers to not only assure that their outputs fall into the convex hull of the leaders' output but also optimizes their transient performance. The proposed optimal solution is composed of a feedback part, depending of the followers' state, and a feed‐forward part, depending on the convex hull of the leaders' state. To comply with most real‐world applications, the feedback and feed‐forward states are assumed to be unavailable and are estimated using two distributed observers. That is, a distributed observer is designed to measure each agent's states using only its relative output measurements and the information that it receives by its neighbors. Another adaptive distributed observer is designed, which uses exchange of information between followers over a communication network to estimate the convex hull of the leaders' state. The proposed observer relaxes the restrictive requirement of having access to the complete knowledge of the leaders' dynamics by all the followers. An off‐policy reinforcement learning algorithm on an actor‐critic structure is next developed to solve the optimal containment control problem online, using relative output measurements and without requiring the leaders' dynamics. Finally, the theoretical results are verified by numerical simulations.     

以无线克服电动汽车的里程焦虑

正随着动力传动系统从内燃机(ICE)向电动机发展,汽车行业正在经历史上最大的变化时期之一。虽然现代电动汽车(EV)续航里程方面的技术进展显著,但对于采用的最大障碍之一是消费者担心受困于电池没电,即所谓的"里程焦虑"。为应对这一挑战,大多数努力都致力于让电池变得更好、车辆更高能效,但其它方法也开始崭露头角。其中最有意思的就是为EV无线充电的能力,这     

Healing of double oxide film defects in A356 aluminium melt

The possibility of the bonding of the two layers of a double oxide film defect when held in liquid A356 Al alloy was investigated. The defect was modelled experimentally by maintaining two aluminium oxide layers in contact with each other and the atmosphere trapped between them in the A356 liquid alloy for varying lengths of time of between 30 s and 48 h. Any changes in the composition and morphology of these layers were studied by SEM, EDX and XRD. The results showed that the two layers of a double oxide film defect might bond to each other by two different mechanisms, one during the transformation of Al₂O₃ to MgAl₂O₄ spinel in relatively short holding times, which would cause the layers to bond at several points and the other during the gradual transformation of spinel to MgO in longer times, which would cause strong bonding between the layers. It was shown that any bonding can take place essentially only after the oxygen and nitrogen of the atmosphere within the defect are consumed.