Experimental investigation of cooling of heated circular disc using inclined circular jet

An experimental study is performed to examine the heat transfer characteristics of impinging circular jet onto a heated circular disc. The disc is heated under constant heat flux and it has an inclination angle with impinging jet in the range of 90° ≤ φ ≤ 150°. The air is supplied using a radial fan. The fluid flows through a designed tunnel. Experiments were performed under different Reynolds number, 2800, 9000, and 36,000, and different values of inclination angle of the disk and jet-to-plate distance to jet diameter ratio H/D_h as 5, 10, and 15. The results of experiments showed that the most effective parameter is the inclination angle between jet and heater. Both locations of stagnation point and heat transfer are affected from this parameter.     

Tobacco and cancer in Turkey

Although the smoking epidemic is decreasing steadily in other parts of the world, it continues to spread at an accelerated rate in underdeveloped and developing countries. Turkey, among other developing countries, faces the increasing threat of tobacco-related cancers, particularly lung cancer, which is the leading cause of cancer death in both sexes. We investigated the relationship between cigarette consumption and the relative mortality rates due to lung cancer in men and women between 1965 and 1992. We found a parallelism between the increasing total and per capita cigarette consumption and the rising relative mortality from lung cancer in both sexes. Total per capita cigarette consumption rose from 1230 cigarettes per year in 1985 to 1495 in 1991, and the per capita yearly cigarette consumption over the age of 15 increased from 1850 in 1965 to 2600 in 1992. During the same period, the relative mortality from lung cancer increased from 25 to 40% in men and from 11 to 16% in women. The tar, nicotine, and carbon monoxide determinations of locally produced and imported cigarettes suggested that the high tar and carbon monoxide content of most locally produced cigarettes smoked over many years could also be a contributory factor to the increased mortality rates due to lung cancer. Only two brands of locally produced cigarettes contained lower than 12 mg of tar per cigarette as allowed in European community states, whereas half of the imported brands of cigarettes met this standard. Four of the six imported brands of cigarettes contained higher tar and carbon monoxide compared with the same brands sold in England. These findings indicate that urgent measures are necessary not only to ban all activities promoting the sale of cigarettes but also to establish standards for both national and foreign brands of cigarettes while making a greater effort to reduce active and passive smoking in the Turkish population.     

The majority of myeloid-antigen-positive (My+) childhood B-cell precursor acute lymphoblastic leukaemias express TEL-AML1 fusion transcripts

BACKGROUND & AIMS: Crohn's disease and ulcerative colitis show a familial aggregation. In both diseases, anti-goblet cell autoantibodies (GABs) have been described. The aim of this study was to define the role of GABs in the pathogenesis of inflammatory bowel disease. METHODS: The study population comprised 61 patients with ulcerative colitis, 76 patients with Crohn's disease, 101 first-degree relatives of patients with ulcerative colitis, and 105 first-degree relatives of patients with Crohn's disease. Thirty-five patients with infectious enterocolitis and 56 healthy unrelated subjects served as controls. Autoantibodies were detected by indirect immunofluorescence. RESULTS: Thirty-nine percent of patients with ulcerative colitis (24 of 61) and 30% of patients with Crohn's disease (23 of 76) were positive for GABs. GABs were detected in 21% (21 of 101) of first-degree relatives of patients with ulcerative colitis and in 19% (20 of 105) of first-degree relatives of patients with Crohn's disease. In patients with infectious enterocolitis and in healthy controls, GABs were seen in 3% (1 of 35) and 2% (1 of 56), respectively. The differences between control groups and both groups of patients or their first-degree relatives were significant. CONCLUSIONS: The high prevalence in first-degree relatives suggests that GABs may represent a marker characterizing susceptibility to inflammatory bowel disease.     

Synthesis of chitosan beads as boron sorbents

Parameters, such as pH, temperature, initial boron concentration, adsorbent dosage, and ionic strength, affecting boron adsorption onto chitosan beads were examined in this study. The following values were obtained as the optimum conditions in our studied ranges: pH 8.0, temperature = 308 K, amount of chitosan beads = 0.15 g, initial boron concentration = 4 mg L⁻¹, and ionic strength = 0.1 M NaCl]. The adsorption kinetics were also examined in terms of three kinetic models: the pseudo‐first‐order, pseudo‐second‐order, and intraparticle diffusion models. The pseudo‐second‐order kinetic model showed very good agreement with the experimental data. Intraparticle plots seemed to have two steps and indicated multilinearity. Equilibrium data were evaluated with nonlinear and linear forms of the Langmuir and Freundlich equations. The experimental data conformed to the Freundlich equation on the basis of the formation of multilayer adsorption. To characterize the synthesized chitosan beads, we used Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analyses. As shown by FTIR analysis, the boron species may have interacted with the NH₂ groups on chitosan. Microparticles of about 5 μm appeared in the SEM micrographs of the chitosan beads. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

A Comparative Study of Ascorbic Acid and Capsaicinoid Contents in Red Hot Peppers (Capsicum annum L.) Grown in Southeastern Anatolia Region

The aim of this study was to evaluate selected physico-chemical properties, ascorbic acid, and capsaicinoid (capsaicin, dihydrocapsaicin, norhydrocapsaicin, homodihydrocapsaicin, and total capsaicinoid) quantities of red hot pepper populations (Capsicum annum L.) grown in the South-Eastern Anatolia Region. Fresh and sun-dried red hot peppers and red hot pepper seed samples were collected from Kahramanmara?, pepper of Kahramanmara?; Gaziantep, pepper of Gaziantep; Kilis, pepper of Kilis; Diyarbak?r, pepper of Diyarbak?r; and ?anl?urfa, pepper of ?anl?urfa in the months of September through October 2010. The collected samples were analyzed in terms of certain quality parameters and capsaicinoid contents, while ascorbic acid amounts were determined only in fresh samples. All of the examined prameters were found to be significant statistically (P < 0.05). From the obtained results, it might be considered that these red hot pepper samples were suitable for cultivation due to their high-nutritional quality.     

CFD modeling of heat transfer and fluid flow inside a pent-roof type combustion chamber using dynamic model

A numerical work has been performed to analyze the heat transfer and fluid flow in a pent-roof type combustion chamber. Dynamic mesh model was used to simulation piston intake stroke. Revolution of piston (1000 ≤ n ≤ 5000) is the main governing parameter on heat and fluid flow. k–ε turbulence model was used to predict the flow in the cylinder of a non-compressing fluid. They were solved with finite volume method and FLUENT 12.0 commercial code. Velocity profiles, temperature distribution, pressure distribution and velocity vectors are presented. It is found that the inclined surface of pent-roof type of combustion chamber reduces the swirl effect and it can be a control parameter for heat and fluid flow.     

Fluid migration into lined pipelines

Lining of a pipe with a polymeric liner is a viable trenchless technology for rehabilitating sewer pipelines. Polymeric liners are typically installed within the deteriorated segments of a sewer line, from one access hole to the next, to essentially create a new pipe within the old pipe without the need for excavation and removal. However, some concerns exist regarding the need to grout or seal the joints where the new liner connects with access holes and laterals. The purpose of this study is to provide some insight into the degree of fluid migration into, or from, the system at these connecting points under simulated field conditions. Four groups of three similar vitrified clay pipelines were lined with different types of deformed–reformed or fold-and-form (DR/FF) liners and cured-in-place-pipe (CIPP) liners then tested to assess the conditions of the annular space between the liners and the host pipe. Fluid migration was detected around all liners and flow rates in the annular space increased with the head difference between the upstream and downstream ends of the test pipelines. No significant changes were observed in the flow rates within the annular space in the tested pipelines over the eight-week testing period.     

A comprehensive review of thin-layer drying models used in agricultural products

Drying is one of the widely used methods of grain, fruit, and vegetable preservation. The important aim of drying is to reduce the moisture content and thereby increase the lifetime of products by limiting enzymatic and oxidative degradation. In addition, by reducing the amount of water, drying reduces the crop losses, improves the quality of dried products, and facilitates its transportation, handling, and storage requirements. Drying is a process comprising simultaneous heat and mass transfer within the material, and between the surface of the material and the surrounding media. Many models have been used to describe the drying process for different agricultural products. These models are used to estimate drying time of several products under different drying conditions, and how to increase the drying process efficiency and also to generalize drying curves, for the design and operation of dryers. Several investigators have proposed numerous mathematical models for thin-layer drying of many agricultural products. This study gives a comprehensive review of more than 100 different semitheoretical and empirical thin-layer drying models used in agricultural products and evaluates the statistical criteria for the determination of appropriate model.     

Viscosity and Surface Tension Measurements in Microgravity

The viscosity and surface tension of liquid metals can be measured by observing the oscillations of a levitated drop. The frequency is related to the surface tension, while the viscosity determines the damping of the oscillations. If no external forces are present, as in microgravity, these relations are particularly simple and precise. During the recent Spacelab mission MSL-1, such experiments have been performed on Co–Pd and Pd–Cu–Si using the electromagnetic levitation facility TEMPUS. It was possible to obtain data over a wide temperature range, including the undercooled regime. While the temperature dependence of the surface tension remains linear over the complete range, the temperature dependence of the viscosity is much more pronounced and is discussed in terms of different models.