Enhanced cholesterol‐ and triglyceride‐ lowering effect of West African green tea

‘The Vert’ is a special type of green tea widely consumed in West Africa and locally associated with many health benefits. However, limited research has been conducted to evaluate its health benefits, such as its enhanced hypolipidemic potential. The objectives of this study were to (1) evaluate the cholesterol‐ and triglyceride‐lowering effects of West African green tea (WAGT) as affected by diet and tea intake, (2) determine the impact of WAGT consumption on the CHD risk ratio, and (3) explore possible mechanisms through which WAGT improves serum lipid profile. Forty‐five male Wistar rats were randomly assigned to one of nine treatment combinations, three diets (regular, high‐cholesterol, and trans‐fat diets) and three fluid sources (no tea, diluted tea, and concentrated tea). After 6 weeks of feeding, animal blood, liver, and feces were harvested. Total cholesterol, HDLc, LDLc, and triglycerides in serum, liver, and feces were determined. The concentrations of bile acids in feces were also measured. WAGT significantly lowered serum and liver cholesterol (30% and 15%, respectively) and increased serum HDL cholesterol (30%). It also reduced liver enlargement caused by storage of excess lipids in high‐cholesterol diet. Overall, the CHD risk ratio was cut by two‐thirds in rats fed high‐cholesterol diet and WAGT. A marked increase in fecal total lipids, cholesterol (60%), and bile acids (50%) was observed in rats that consumed WAGT compared to the control group. These beneficial effects could be attributed to the significantly high flavonoid content of WAGT. Copyright © 2007 Society of Chemical Industry     

Use of different alkylammonium salts in clay surface modification for epoxy‐based nanocomposites

Layered silicates become widely used reinforcement material in the polymer nanocomposite production in recent years due to their high aspect ratio, ease of processing, and low cost. In this present study, the aim was to evaluate the usability of a raw clay source (Resadiye, Turkey) in the production of epoxy/clay nanocomposites and to investigate the effects of different surface modifiers. For this purpose, raw Na–montmorillonite clay was first purified and then surface modified by using different types of alkylammonium salts: tetramethyl ammonium bromide, benzyl triethyl ammonium bromide, dodecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, and octadecyl trimethyl ammonium bromide. Purification and surface modification of this clay were evaluated by using the following analyses; X‐ray diffraction (XRD), cation exchange capacity (CEC), particle size distribution, and dissolved organic content. These analyses simply indicated that surface modification increased both interlayer spacing between the silicate layers and CEC of the clay. These improvements were directly proportional with the chain length of the surface modifier. Nanocomposite specimens were produced by adding 0.5 wt% surface modified clay into the epoxy matrix. These specimens were characterized by XRD, Si‐mapping facility of SEM, and mechanical tests. XRD results indicated an exfoliated structure whereas Si‐mapping showed the uniform distribution of clay particles in epoxy, leading to improved mechanical properties, for instance more than 100% increase in fracture toughness of the neat epoxy specimen. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

An investigation of the effect of SiC particle size on Cu–SiC composites

In this study mechanical properties of copper were enhanced by adding 1 wt.%, 2 wt.%, 3 wt.% and 5 wt.% SiC particles into the matrix. SiC particles of having 1 μm, 5 μm and 30 μm sizes were used as reinforcement. Composite samples were produced by powder metallurgy method and sintering was performed in an open atmospheric furnace at 700 °C for 2 h. Optical and SEM studies showed that the distribution of the reinforced particle was uniform. XRD analysis indicated that the dominant components in the sintered composites were Cu and SiC. Relative density and electrical conductivity of the composites decreased with increasing the amount of SiC and increased with increasing SiC particle size. Hardness of the composites increased with both amount and the particle size of SiC particles. A maximum relative density of 98% and electrical conductivity of 96% IACS were obtained for Cu–1 wt.% SiC with 30 μm particle size.     

Human Reliability Analysis in Spaceflight Applications,Part 2: Modified CREAM for Spaceflight

Human reliability analysis is a crucial for manned spaceflight success. Cognitive Reliability Error Analysis Model (CREAM) has been developed and used by the nuclear industry in predicting human error. Previously, the authors have calculated the probability error for an International Space Station ingress procedure using performance shaping factors (PSF). In this paper, the procedural risk under both ideal and common conditions using the new spaceflight specific PSFs is calculated. The risk was found to vary from the risk calculated using standard PSFs and to vary greatly depending on the spacecraft specific conditions. Under ideal conditions, the risk was found to be 1 in 88, but under common conditions, the risk was 1 in 3. Then, the new PSFs were used to analyze the impact of the three styles of training used at NASA under common conditions. Of skill‐based training, task‐based training, and knowledge‐based training, the CREAM analysis using the new PSFs showed that skill‐based training resulted in the most significant improvement in the risk of human error, from 1 in 3 to 1 in 11. Copyright © 2013 John Wiley & Sons, Ltd.     

Removal of Ni(II) and Zn(II) from an aqueous solutionby reverse osmosis

The removal of Ni⁺² and Zn⁺² from an aqueous solution by reverse osmosis (RO) at different pH, conductivity and EDTA concentrations was investigated. In addition, the removal in the pretreatment units (PU) with filtration (F) and granular activated carbon (GAC) at the same conditions was also determined. It was observed that Zn⁺² rejections did not change much with pH, usually less than 0.88 mg/l, and Ni⁺² rejection was below the detection limits of AAS in the range of pH 4-8. While Ni⁺² and Zn⁺² were removed 23-25% and 25-45%, respectively, by PU, the rejection of Ni⁺² and Zn⁺² was, respectively, determined to be higher than 99.2% and 98.8% by PU+RO at experiments related to the determination of the effect of initial metal concentration on rejection. It was found that the influent conductivity affected metal rejection at an unimportant level, but the increase of conductivity affected the effluent conductivity. The addition of EDTA into the aqueous solution increased Ni⁺² and Zn⁺² rejection from 99.3% to 99.7% and from 98.9% to 99.6% at an EDTA concentration of 240 ppm, respectively.     

An evaluation of human articular cartilage on femoral head

In this study, we investigated stress relaxation behavior of the human articular cartilage on femoral head. Articular cartilage is a white dense connective tissue that covers the bone ends within diarthrodial joints and works as a weight-transmitting and energy-absorbing material. Human articular cartilage on femoral head was used as test material. Relaxation tests were carried out by using the indentation technique via Instron Universal Testing Machine. Test materials were investigated in an isotonic salt solution at 37 °C. To keep the temperature constant, two vessels being in each other were utilized. Thus, hot water was circulated in the outer vessel and isotonic salt solution was kept in the inner vessel. Experimental results showed that there is a remarkable difference between normal and degenerated cartilage for the same age and sex. It was observed that the relaxation percent of normal cartilage as a function of relaxation time is much higher than that of degenerated cartilage.     

Evaluation of elderly people's requirements in public open spaces: A case study in Bornova District (Izmir,Turkey)

The aim of improving the quality and quantities of public open spaces used by each group of people who are in different ages, genders and occupations, is upgrading the users’ life quality by equipping these places with various functions and to make the urban life more attractive and meaningful by creating livable environments.     

REMOVAL OF BORON FROM BALÇOVA-IZMIR GEOTHERMAL WATER BY ION EXCHANGE PROCESS: BATCH AND COLUMN STUDIES

In this study, the efficiency of boron removal from Balçova geothermal water provided by the Izmir Geothermal Energy Company, Turkey, has been investigated using boron selective ion exchange resins Diaion CRB 02 and Dowex (XUS 43594.00) by batch and column methods. The results of the column studies have been evaluated in terms of type of resin and feed flow rate, and the effects of particle size and temperature have been investigated using the results obtained from batch kinetic studies. The data from the kinetic studies have been evaluated using pseudo-first-order and pseudo-second-order kinetics models. In addition, the classical diffusion models have been used to evaluate the kinetic data obtained to understand the rate-controlling mechanisms.     

A reconnaissance report: 1995 Dinar, Turkey, earthquake

During the 1st October 1995 Dinar, Turkey, earthquake, a total of 90 people died and about 240 people were injured. The number of collapsed or heavily damaged buildings exceeded 8000 within a radius of 20 km around the epicentre. The ground rupture was about 11 km long along an unexpected, new fault line. The reinforced concrete moment resisting framed structures as well as brick masonry houses experienced the most severe damage, especially those situated on soft soil layers of alluvium formations.