Laminar Mixed-Convection Heat Transfer in a Lid-Driven Cavity with Modified Heated Wall

In this numerical study, steady laminar mixed-convection heat transfer in a two-dimensional square lid-driven cavity with a modified heated wall is investigated over a range of Richardson numbers, including 0.01, 1, and 10. The heated bottom wall of the cavity is characterized by rectangular, triangular, and sinusoidal wave shapes. The cooled top wall of the cavity is sliding with constant velocity, while the vertical walls are kept stationary and adiabatic. The governing equations are solved using a finite-volume technique. The results are presented in the form of streamlines, isotherms, and Nusselt number plots. The effects of the number of undulations and the amplitude on the flow field and heat transfer are also investigated. The predicted results demonstrate that the heat transfer enhancement is generally observed with the modification of the heated wall, while the improvement is found to be more profound for the case of rectangular wave and at low Richardson number.     

Nanoleakage within adhesive-dentin interfaces made with simplified ethanol-wet bonding

Objective: The aim of the present study was to evaluate the effects of the simplified ethanol-wet bonding technique and conventional water-wet bonding technique on short term nanoleakage within hybrid layers made with two different etch-and-rinse adhesives (Single Bond 2 and Prime & Bond NT). Materials and methods: Flat dentin surfaces from bovine incisors were prepared and finished with wet 600-grit abrasive papers, then divided into groups to be bonded with one of the adhesives. After etching and rinsing, dentin surfaces were either moistened with water (water-wet bonding technique) or moistened with absolute ethanol for 1 min (ethanol-wet bonding technique). Then, adhesives were applied, and composite buildups were done. Bonded teeth samples were sectioned into resin–dentin samples by means of a low speed diamond saw under water cooling. Specimens were immersed into a 50% (w/v) solution of silver ammoniacal nitrate for 18 h and exposed to photodeveloping solution for 6 h. The amount of silver nitrate uptake within the adhesive layer, or hybrid layer, was measured with energy dispersive spectroscopy (EDS) in different regions (n = 30). Results: Simplified ethanol-wet bonding significantly reduced nanoleakage within resin–dentin interfaces made with Single Bond 2 and Prime & Bond NT, but improvement at the nanoleakage of Single Bond 2 was only significant. Conclusion: Simplified ethanol-wet bonding may improve quality of hybrid layers made with commercially available simplified etch-and-rinse adhesives. But benefits of ethanol-wet bonding may depend on product.     

Chromosome 8, occupational exposures, smoking, and acute nonlymphocytic leukemias: a population-based study

In a previous epidemiological study on acute myelocytic leukemia (M. M. Crane et al., Cancer Epidemiol. Biomark. Prev., 5: 639-644, 1996), clonal aberrations in chromosome 8 have been reported to be in excess in smokers and in workers exposed to paints. In that study, cytogenetics was performed after therapy. In our report, we describe a population-based survey on nonlymphocytic leukemias in northern Italy, in which 79 patients (acute myelocytic leukemia, myelodysplastic syndromes, or other nonlymphocytic leukemias) were studied before cytotoxic therapy. We found 9 aberrations involving chromosome 8 (six +8, two -8, and one translocation), whereas abnormalities involving chromosomes 5 and 7 occurred with a low frequency compared with previous studies. Aberrations involving chromosome 8 were associated with smoking (odds ratio, 6.3; 95% confidence interval, 0.9-42.3; among smokers of 10 or more cigarettes/day: odds ratio, 14.2; 95% confidence interval, 1.4-142.3); +8 aberrations were found in 1 of 24 nonsmokers and in 5 of 38 smokers. Three +8 aberrations were found in 22 subjects potentially exposed to solvents or polycyclic aromatic hydrocarbons. The low frequency of chromosome 5 and 7 aberrations in our population-based series (compared with other studies) can be attributed to the recruitment before cytotoxic therapies. Aberrations involving chromosome 8 (particularly +8) were associated with smoking habits. Chromosome 8 includes the c-myc oncogene.     

The Bleaching of Soybean Fabric by Different Treatments Combined with Ozonation

This article is about bleaching of soybean fibers. Although the studies related to dyeing of soybean fibers have been found in the literature, little has been reported on the effect of bleaching. The natural color of soybean protein fibers is pale yellow or cream, and it is therefore usually necessary to bleach them to improve their whiteness. Different bleaching treatments combined with ozonation were performed in order to establish the effect on whiteness, yellowness, lightness, wettability, hydrophility, moisture sorption, and fiber damage properties of knitted soybean fabric. As a result of study, bleaching process combined with ozonation (ozonation + oxidative bleaching + reductive bleaching) supplied soybean fabric with a white appearance (highest whiteness degree), highest hydrophility, and minimal fiber damage.     

沥青混凝土心墙土石坝在新疆坝工建设中的 应用现状及施工技术

结合沥青混凝土心墙土石坝在新疆坝工建设中的应用成果和建设经验,对沥青混凝土心墙在施工阶段的原材料选择、制备方式,沥青混凝土心墙主要施工程序、施工方法和施工技术在新疆的应用及存在的问题进行了分析、探讨。     

Position only pattern nulling of linear antenna array by using a clonal selection algorithm (CLONALG)

In this paper, a clonal selection algorithm (CLONALG) based on clonal selection principle of immune system has been used for null steering in the antenna radiation pattern by controlling only the element positions of a linear array. Numerical examples of Chebyshev pattern with the single, multiple and broad nulls imposed at the directions of interference are given to show the accuracy and flexibility of the CLONALG. The sensitivity of the achieved patterns due to small variations of the element positions is also investigated by truncating the element positions.     

Influence of ground water effect on shallow tunnel: A case study

The studies done about shallow tunnels have been going on extensively. In the shallow tunnels especially driven in population dense areas, soil-rock problems are encountered as well as ground water. Although ground water is the most common problem, it does not take place so much in literature. During tunneling, the drainage of the groundwater is the most important point that should be considered. In some cases, the drainage of ground water through the tunnel cause ground settlements in the surrounding buildings. This problem particularly seen in weak soil/rock formations could be turned into a handicap by the surface injection applications. Sometimes, injection application to prevent settlement problem and to reinforce the ground creates risky conditions such as face burst, roof collapse during tunneling. This problematic situation risks both the work safety and the environmental safety. This study investigates retrospectively the collapse of the tunnel roof and faces burst during the construction of Izmir Metro 2nd phase. Eventually, in the zone where ground water regime exists and very weak formation is present, injection study did not seem to serve the purpose.     

Rehydration of Polymeric,Aqueous, Biphasic System Facilitates High Throughput Cell Exclusion Patterning for Cell Migration Studies

This paper describes a cell‐exclusion patterning method facilitated by a polymeric aqueous two‐phase system. The immersion aqueous phase (polyethylene glycol) containing cells rehydrates a dried disk of the denser phase (dextran) on the substrate to form a dextran droplet. With the right properties of the phase‐forming polymers, the rehydrating droplet remains immiscible with the immersion phase. Proper formulation of the two‐phase system ensures that the interfacial tension between the rehydrating droplet and the surrounding aqueous phase prevents cells from crossing the interface so that cells only adhere to the regions of the substrate around the dextran phase droplet. Washing out the patterning two‐phase reagents reveals a cell monolayer containing a well‐defined circular gap that serves as the migration niche for cells of the monolayer. Migration of cells into the cell‐excluded area is readily visualized and quantified over time. A 96‐well plate format of this “gap healing” migration assay demonstrates the ability to detect inhibition of cell migration by known cytoskeleton targeting agents. This straightforward method, which only requires a conventional liquid handler and readily prepared polymer solutions, opens new opportunities for high throughput cell migration assays.     

Computation of resonant frequency for equilateral triangular microstrip antennas using the adaptive neuro-fuzzy inference system

A new method based on the adaptive neuro-fuzzy inference system (ANFIS) for calculating the resonant frequency of the equilateral triangular microstrip patch antenna is presented. The ANFIS has the advantages of the expert knowledge of the fuzzy inference system and the learning capability of neural networks. A hybrid-learning algorithm, which combines the least-square method and the backpropagation algorithm, is used to identify the parameters of ANFIS. The results of the new method show better agreement with the experimental results, as compared to the results of previous methods available in the literature. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 134–143, 2004.     

A new real-time suboptimum filtering and prediction scheme for general nonlinear discrete dynamic systems with Gaussian or non-Gaussian noise

A new suboptimum state filtering and prediction scheme is proposed for nonlinear discrete dynamic systems with Gaussian or non-Gaussian disturbance and observation noises. This scheme is an online estimation scheme for real-time applications. Furthermore, this scheme is very suitable for state estimation under either constraints imposed on estimates or missing observations. State and observation models can be any nonlinear functions of the states, disturbance and observation noises as long as noise samples are independent, and the density functions of noise samples and conditional density functions of the observations given the states are available. State models are used to calculate transition probabilities from gates to gates. If these transition probabilities are known or can be estimated, state models are not needed for estimation. The proposed scheme (PR) is based upon state quantisation and multiple hypothesis testing. Monte Carlo simulations have shown that the performance of the PR, sampling importance resampling (SIR) particle filter and extended Kalman (EK) filter are all model-dependent, and that the performance of the PR is better than both the SIR particle filter and EK filter for some nonlinear models, simulation results of three of which are given in this article.