Intense UV-light absorption of ZnO nanoparticles prepared using a pulse combustion-spray pyrolysis method

We report the synthesis and characterization of ZnO nanoparticles prepared via pulse combustion-spray pyrolysis (PC-SP) at a high rate. Instead of using an ultrasonic nebulizer as the atomizer during PC-SP synthesis, a two-fluid nozzle was used to enhance the production rate. A high production rate was achieved by the use of a two-fluid nozzle, which efficiently generated droplets in large quantities, and by controlling the rate of precursor flow. ZnO nanoparticles were characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–vis spectroscopy. The prepared ZnO nanoparticles were spherical and highly crystalline with an average size of 15.6 nm. In addition, high UV-light absorption and visible-light transparency properties were successfully obtained for a dispersion of ZnO nanoparticles in glycerol. The high UV-blocking capacity of the ZnO particle dispersion makes the dispersion potentially useful in cosmetic applications.     

德德玛庆从艺50周年——新专辑《望草原》举行首发式

“食在广东”,人人称道,“广东音乐”,其知名度一点也不比“广东菜”低!有近百年历史的广东音乐是中国民间音乐的明珠,她旋律欢快流畅,既充满生活情趣,又蕴含人生哲理。听广东音乐,你不仅仅可以领略音乐之美,还能感受广东人恬淡、乐观、生猛的性格!创新是广东音乐的一大特色,观众不仅能聆听到悠悠古韵,更能感受到民族音乐强劲的时代脉搏。     

Specification,Mapping and Control for QoS Adaptation

In this paper we describe a fuzzy-control approach for quality of service (QoS) adaptation, needed in distributed multimedia applications. QoS adaptation is necessary (a) due to sudden variations in network resource availability, especially in the case of Internet, and (b) due to multiple applications requiring shared resource such as bandwidth. To solve the problem of QoS adaptation, several sub-problems need to be considered: (1) mapping of user perception and different combinations of application QoS values onto a uniform quality metric, (2) estimation, control and adjustment of application QoS parameters in case of network and other resource congestion, and (3) enforcement algorithm which reacts according to adapted QoS parameters. Our approach is to solve the QoS adaptation using the integration of (a) quality degree function, which maps the application QoS parameters into a metric, called quality degree, (b) fuzzy controller, which controls, estimates and adjusts the application QoS parameters according to resource availability, and (c) filter algorithms, which are the services to enforce the adapted QoS parameters. The quality degree function associates quality degree as the quality measure with different combinations of application QoS values. This function is influenced by the users perception of quality. The fuzzy control takes the results of the quality degree function, estimates the new quality degree and its corresponding quality level, predicts the new application QoS parameters, and adjusts them. The results of the adapted QoS parameters are then used by the filter algorithms to enforce the changes, proposed by the fuzzy controller, by allocating bandwidth to the application according to its QoS parameter values. We have implemented and applied the quality degree function, the fuzzy controller, and the filter algorithms to the video distribution system (VDS). The results of VDS over the local area network show that (1) the target system improves user perceived QoS at the receivers, and (2) the bandwidth utilization increases significantly when using our fuzzy-control approach for QoS adaptation.     

Authentication and Authorization Mechanisms for Multi-Domain Grid Environments

This article discusses the authentication and the authorization aspects of security in grid environments spanning multiple administrative domains. Achievements in these areas are presented using the EU DataGrid project as an example implementation. It also gives an outlook on future directions of development.     

Clinical versus counseling psychology: Is there a difference?

Compared the professional interests and employment conditions of counseling and clinical psychologists, drawing data from the American Psychological Association's Biographical Directory (1975). Ss were 50 fellows and 50 members from each of 3 divisions (12, 17, and 29). Most Ss with clinical as well as counseling division membership emphasized clinical activities. (1 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Outbreak of Escherichia coli O157:H7 infections associated with nonintact blade-tenderized frozen steaks sold by door-to-door vendors

Steaks have not been recognized as an important vehicle of Escherichia coli O157:H7 infection. During 11 to 27 June 2003, the Minnesota Department of Health (MDH) identified four O157 infection cases with the same pulsed-field gel electrophoresis (PFGE) subtype. All four case patients consumed brand A vacuum packed frozen steaks sold by door-to-door vendors. The steaks were blade tenderized and injected with marinade (i.e., nonintact). Information from single case patients in Michigan and Kansas identified through PulseNet confirmed the outbreak. The MDH issued a press release on 27 June to warn consumers, prompting a nationwide recall of 739,000 lb (335,506 kg) of frozen beef products. The outbreak resulted in six culture-confirmed cases (including one with hemolytic uremic syndrome) and two probable cases in Minnesota and single confirmed cases in four other states. The outbreak PFGE subtype of O157 was isolated from unopened brand A bacon-wrapped fillets from five affected Minnesota households. A fillet from one affected household was partially cooked in the laboratory, and the same O157 subtype was isolated from the uncooked interior. The tenderizing and injection processes likely transferred O157 from the surface to the interior of the steaks. These processing methods create new challenges for prevention of O157 infection. Food regulatory officials should reevaluate safety issues presented by nonintact steak products, such as microbiologic hazards of processing methods, possible labeling to distinguish intact from nonintact steaks, and education of the public and commercial food establishments on the increased risk associated with undercooked nonintact steaks. Information on single cases of O157 infection in individual states identified through PulseNet can be critical in solving multistate outbreaks in a timely manner.     

The effect of structural properties of natural silica precursors in the mesoporogen-free synthesis of hierarchical ZSM-5 below 100 °C

The low-temperature synthesis of zeolite ZSM-5 below 100 °C is gaining new attention. This is due to the fact that such synthesis may simultaneously implement the introduction of mesopores into crystalline microporous zeolite structure. Herein, we report the use of natural silica precursors from rice husks in the mesoporogen-free synthesis of hierarchical ZSM-5 below 100 °C and their structural properties which govern the course of crystallization. Rice husks are agricultural wastes with high silica content, which should be exploited to give a positive impact, i.e. highly value-added materials. In this study, the amorphous silica from rice husks was extracted using sequential base-acid treatment. The extracted silica was similarly reactive as Ludox HS-40, even with the reduced amounts of the organic structure-directing agent (OSDA). The product was highly crystalline ZSM-5 with spherical morphology composed of small crystallites, enabling the presence of intercrystallite mesopores. The subjection of extracted silica into the calcination at 550 °C for 6 h, prior to the low-temperature synthesis, altered the silica structure via hydroxyl condensation. The distinct structural properties affected the occurring crystallization in which the resulted products were ZSM-5–disordered-mesoporous silica composites. The possible mechanisms of these two different results may involve the dual roles of tetrapropylammonium ion (TPA⁺) as zeolite OSDA and non-templating structure directing agent. These insights were based on the spectroscopic (FTIR, Raman, ²⁹Si and ²⁷Al MAS NMR spectroscopy), microscopic (TEM and HRTEM) and physicochemical characterizations (XRD and N₂ adsorption-desorption isotherm).     

Hyperchaos permutation on false-positive-free SVD-based image watermarking

Multimedia Tools and Applications - This paper reports the effect of hyperchaos permutation on the False-Positive-Free (FPF) Singular Value Decomposition (SVD)-based image watermarking scheme. To...     

A metaheuristic‐based approach to optimizing color design for military camouflage using particle swarm optimization

Enhancing an existing military camouflage is an important component during the assessment of military camouflage. The current study proposed a new and practical approach to enhancing the undetectability of a military camouflage using particle swarm optimization (PSO). Eight different locations (20 × 50 pixels) in the one swamp background were selected to be the place of a human‐shaped target. The PSO would generate newly proposed camouflage as an empirical parameter based on the lower and the upper bounds from selected four different colors in swamp background. The predictive algorithm was applied to adjust the optimum shift of %L*, %a*, and %b* from the original to the empirical parameter. Thirty participants were recruited to evaluate the original and newly proposed camouflages. Paired sample t test indicates that the newly proposed military camouflage had a significant lower camouflage similarity index value and a longer detection time. The PSO shows to be a method with good results; however, a comprehensive study using multiple backgrounds and patterns would be required to generalize the methodology to other background environments or camouflage patterns.