Comparison between synthesis techniques to obtain ZnO nanorods and its effect on dye sensitized solar cells

This paper reports additive-free, reproducible, low-temperature solution-based process for the preparation of crystalline ZnO nanorods by homogeneous precipitation from zinc acetate. Also, ZnO nanorod structured dye sensitized solar cells using ruthenium dye (Z907) have been fabricated and characterized. The formation and growth of zinc oxide nanorods are successfully achieved. We analyzed three different synthesis method using solution phase, autoclave and microwave. The calcination effects on the morphology of ZnO nanorods are also investigated. Analysis of ZnO nanorods shows that calcination at lower temperature is resulted in a nanorod growth. Additive-free, well-aligned ZnO nanorods are obtained with the length of 330–558 nm and diameters of 14–36 nm. The XRD, SEM, and PL spectra have been provided for the characterization of ZnO nanorods. Microwave-assisted ZnO nanostructured dye sensitized solar cell devices yielded a short-circuit photocurrent density of 6.60 mA/cm², an open-circuit voltage of 600 mV, and a fill factor of 0.59, corresponding to an overall conversion efficiency of 2.35% under standard AM 1.5 sun light.     

Analysis of a discrete time table polling system with MAP input and time‐limited service discipline

An iterative procedure based on the MAP/PH/1 and MAP/PH/1/K queues with vacation is presented for approximating the performance measures of a table polling system. Each queue has a time limit after which it relinquishes the server. This is formally known as the token holding time (THT) in IEEE 802.5 and IEEE 802.4 standards. The polling table can be tailored such that queues with limits on the cycle time are visited more frequently, thus, limiting the delays for real time applications. The visit period and vacation period distributions were obtained based on the properties of the discrete phase distribution. Several examples are presented and they show that the algorithm converges fairly fast and gives reasonable results. This revised version was published online in June 2006 with corrections to the Cover Date.     

Deterministic model for dynamic assignment of time-varying traffic demand

Two algorithms are presented for assigning time-varying traffic demand to a road network during peak period. The algorithms are heuristics based on the principle of deterministic equilibrium, and they are iterative. Discrete time approach is adopted for computational simplicity. The model presented is suitable for simulating traffic flow in a road network during peak period in urban areas for strategic planning of transport systems.     

Demystifying 3D ICs: the pros and cons of going vertical

This article provides a practical introduction to the design trade-offs of the currently available 3D IC technology options. It begins with an overview of techniques, such as wire bonding, microbumps, through vias, and contactless interconnection, comparing them in terms of vertical density and practical limits to their use. We then present a high-level discussion of the pros and cons of 3D technologies, with an analysis relating the number of transistors on a chip to the vertical interconnect density using estimates based on Rent's rule. Next, we provide a more detailed design example of inductively coupled interconnects, with measured results of a system fabricated in a 0.35-/spl mu/m technology and an analysis of misalignment and crosstalk tolerances. Lastly, we present a case study of a fast Fourier transform (FFT) placed and routed in a 0.18-/spl mu/m through-via silicon-on-insulator (SOI) technology, comparing the 3D design to a traditional 2D approach in terms of wire length and critical-path delay.     

Population migration and the epidemic situation of parasitoses in Belgorod Province]

Paper summarized a concise evaluation of short wounds according to the Red Cross Classification published in Geneva. It is supposed to attract the forensic physician's attention due to informative purpose.     

A New Approach For Locating Public Standpipes In A Water Supply Distribution Network

ABSTRACT

The majority of houses in Nigeria do not have direct connections to water supply mains. These households obtain water from public standpipes for their daily needs. Presently, the criteria which are employed to locate the standpipes are not clearly defined. A new approach using simulation techniques is proposed for finding the number and location of public standpipes, so as to improve the efficiency of water delivery services. In a case study of the Alanamu ward in Ilorin, it was found that 17 standpipes are optimal to provide a 100% service level for a population of 42,000 people. The maximum service distance would be 650 m roundtrip Economically nearly N96,000 [N = naira, N1.00 = $0.25 U.S.] in annual income foregone would be saved when 10 standpipes are added to supplement the existing 7 standpipes in the ward. The annual investment cost of N1,250 for installing and maintaining the new standpipes is small compared to the savings that would accrue to the community.     

猫眼观市——MP3、MP4行情

经过国庆黄金周之后，MP5市场再度趋于平淡，众多商家都为迎接12月的圣诞节和新年做准备，厂商也是如此。本月MP5等产品的价格将会比较平稳，没有太多的波动和起伏。     

Epidemiology of ROP in the Stockholm area of Sweden

A prospective, population-based study of the epidemiology of ROP in a well-defined geographical area of Sweden was performed. Two hundred and sixty children with a birth weight of 1500 g or less, and surviving for at least eight weeks, were included in the study. ROP was seen in 40.4% of the children. We suggest that prematurely born children with a gestational age of 32 weeks or less ought to be screened for ROP.     

Housing Careers of Minority Ethnic Groups: Experiences,Explanations and Prospects

The housing careers of minority ethnic groups is an under-researched topic. Filling this knowledge gap is important for several reasons. Increased knowledge within this field may help explain the disadvantaged position of minority ethnic groups in housing markets in cities on different continents. Policy strategies can be formulated when it is known whether minority ethnic groups have specific preferences or suffer from specific barriers in the housing market. In this introduction to this special issue on the housing careers of minority ethnic groups, attention is paid to the concept of housing career and the definition of minority ethnic groups in different countries. The focus of the main part of the paper is the identification of factors affecting the course of housing careers in general and those of minority ethnic groups in particular.