Impact of the Cd2+ treatment on the electrical properties of Cu2ZnSnSe4 and Cu(In,Ga)Se2 solar cells

The present contribution aims at determining the impact of modifying the properties of the absorber/buffer layer interface on the electrical performance of Cu₂ZnSnSe₄ (CZTSe) thin‐film solar cells, by using a Cd²⁺ partial electrolyte (Cd PE) treatment of the absorber before the buffer layer deposition. In this work, CZTSe/CdS solar cells with and without Cd PE treatment were compared with their respective Cu(In,Ga)Se₂ (CIGSe)/CdS references. The Cd PE treatment was performed in a chemical bath for 7 min at 70 °C using a basic solution of cadmium acetate. X‐ray photoemission spectroscopy measurements have revealed the presence of Cd at the absorber surface after the treatment. The solar cells were characterized using current density–voltage (J–V), external quantum efficiency, and drive‐level capacitance profiling measurements. For the CZTSe‐based devices, the fill factor increased from 57.7% to 64.0% when using the Cd PE treatment, leading to the improvement of the efficiency (η) from 8.3% to 9.0% for the best solar cells. Similar observations were made on the CIGSe solar cell reference. This effect comes from a considerable reduction of the series resistance (R_S) of the dark and light J–V, as determined using the one‐diode model. The crossover effect between dark and light J–V curves is also significantly reduced by Cd PE treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

Acetaldehyde in Mineral Water Stored in Polyethylene Terephthalate (PET) Bottles: Odour Threshold and Quantification

The use of PET bottles for packaging soft drinks and mineral waters is still growing world wide. The production process for these bottles is improving constantly. These improvements are focussed on bottles with better barrier properties, higher inertness and higher heat stability. One of the factors determining the quality of PET bottles is the release of acetaldehyde into the product during storage. A literature survey was conducted on the odour and taste detection threshold of acetaldehyde in water. A method is described to rapidly determine the concentration of acetaldehyde in water up to a level of 1 μg/l. This method was used to determine the concentration of acetaldehyde in mineral water during storage in PET bottles. In still water no acetaldehyde could be found, whereas the concentration of acetaldehyde in carbonated mineral water increased steadily upon storage. Model experiments were performed to find an explanation.     

Global data and control in multicomputers: Operating system primitives and experimentation with a parallel branch-and-bound algorithm

The static distribution of work among tasks is not possible in many parallel applications. Therefore, it is essential to implement convenient and efficient abstractions for ‘work sharing’ on multicomputers. This paper compares the utility of two operating system facilities for the implementation of such ‘work sharing’: (1) a system for the migration of processes from heavily to less loaded processors and (2) a more general OS construct for the implementation of arbitrary distributed objects. Both were implemented as extensions to the Intel iPSC/1 operating system on a 32-node hypercube. Their experimental evaluation is based on a parallel implementation of a branch-and-bound algorithm. Two sets of results are attained. First, the necessity of the constructs for dynamic work sharing is demonstrated for applications with dynamic data domains, such as parallel branch-and-bound algorithms. This is followed by measurements that demonstrate the acceptable cost of process migration for a specific parallel branch-and-bound algorithm. These measurements are then compared with results attained with the construct for the implementation of distributed objects. Second, when using branch-and-bound to solve the Travelling Salesperson Problem (TSP), evaluation of the resulting parallel TSP program shows that some analytical and simulation results attained in past, published work may not hold.     

Cobalt-Containing Hyperbranched Poly(silylenearylene)s

A group of hyperbranched poly(silylenearylene)s are synthesized by homopolycyclotrimerizations of A₂-type silylenediynes. The polymers can be readily metallized by complexations of their periphery triple bonds with cobalt octacarbonyls Co₂(CO)₈. Pyrolysis of these organometallic polymers gives magnetic ceramics in good yields. Analyses by SEM, TEM, XPS, EDX, and XRD demonstrate that the ceramics comprise ferromagnetic Co and paramagnetic Co₂Si nanocrystallites wrapped by carboneous shell. The ceramics show high magnetic susceptibilities (M _s up to ~50 emu/g) and near-zero coercivity (H _c down to ~0.14 kOe), suggesting that they are good soft magnetic materials with low hysteresis loss. This article was to be included in the March issue of Volume 19, which was dedicated to Professor Takakazu Yamamoto. The journal editors sincerely apologize for the omission and delay in publication for which the authors and the guest editor bare no responsibility. M. Zeldin and A. S. Abd-El-Aziz, Editors.     

Retention of Eucalyptol,a Natural Volatile Insecticide,in Delivery Systems Based on Hydroxypropyl‐β‐Cyclodextrin and Liposomes

Eucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc‐loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug‐in‐cyclodextrin‐in‐liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze‐dried using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as cryoprotectant. The liposomes are characterized before and after freeze‐drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze‐drying. Moreover, HP‐β‐CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze‐dried DCL and HP‐β‐CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP‐β‐CD/Euc and Euc‐loaded DCL decrease Euc evaporation and improve its retention. Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol‐in‐cyclodextrin‐in‐liposome are effective delivery systems for encalyptol encapsulation, retention, and release.     

基于组态软件和工业以太网技术的自来水厂自控系统设计

利用工业组态软件强大的人机界面功能和灵活实用的网络功能,结合工业以太网技术在组网中方便可靠的特性,设计了一个自来水厂的自动监测系统。     

A survey and taxonomy on virtual data center embedding

The Journal of Supercomputing - Data center network virtualization is being considered as a promising technology to provide a performance guarantee for cloud computing applications. One important...     

Rapid and efficient hand gestures recognizer based on classes discriminator wavelet networks

Multimedia Tools and Applications - The vision based on hand gesture recognition is one of the key challenges in behavior understanding and computer vision. It offers to machines the possibility of...     

Properties of InAs grown on misoriented GaAs substrates by atmospheric pressure metal–organic vapor phase epitaxy

InAs epilayers were grown by atmospheric pressure metal–organic vapor phase epitaxy on GaAs (1 0 0) exactly oriented substrates and misoriented by 2° and 10° toward [1 1 1]A. The layers had varying thicknesses and were deposited under the same growth conditions. Atomic force microscopy analysis show that surface morphology depends on surface misorientation and presents a low root mean square. High resolution X-ray diffraction analysis and Hall effect measurements were preformed to check the substrate misorientation effect on the crystalline quality and electrical properties respectively.     

An improved machine learning technique based on downsized KPCA for Alzheimer's disease classification

Alzheimer's disease (AD), a neurodegenerative disorder, is a very serious illness that cannot be cured, but the early diagnosis allows precautionary measures to be taken. The current used methods to detect Alzheimer's disease are based on tests of cognitive impairment, which does not provide an exact diagnosis before the patient passes a moderate stage of AD. In this article, a novel classifier of brain magnetic resonance images (MRI) based on the new downsized kernel principal component analysis (DKPCA) and multiclass support vector machine (SVM) is proposed. The suggested scheme classifies AD MRIs. First, a multiobjective optimization technique is used to determine the optimal parameter of the kernel function in order to ensure good classification results and to minimize the number of retained principle components simultaneously. The optimal parameter is used to build the optimized DKPCA model. Second, DKPCA is applied to normalized features. Downsized features are then fed to the classifier to output the prediction. To validate the effectiveness of the proposed method, DKPCA was tested using synthetic data to demonstrate its efficiency on dimensionality reduction, then the DKPCA based technique was tested on the OASIS MRI database and the results were satisfactory compared to conventional approaches.