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ABSTRACT Polishing experiments were carried out on eight different carbonate stones with a machine designed for simulating industrial scale tile polishing process. Polishing was performed at 0.8, 1.3, 1.8 and [...]

Experimental and analytical studies have been performed to determine the temperature distribution as a function of reactor power in the TRIGA Mark-II reactor at the Istanbul Technical University (ITU). The lumped parameter model with four governing equations was used in the analytical model. Based on the mathematical model, a computer code has been developed for calculating fuel and coolant temperatures in the reactor core. The calculated results for fuel and coolant temperature in the reactor core for different reactor power levels have been compared with the experimental data. Agreements between experiment and results from the computer code are fairly good.

Objectives:This paper investigates the associations of social competence with cognitive representation and communication skills in children with Autism Spectrum Disorders (ASD), by measuring these skills in an expansive way through assessing both mental and internal-state understanding, and verbal and non-verbal communication.Methods:The data were collected from 45 Turkish children (Mage=8.52 years, SD=3.05, min-max=3–14) with a diagnosis of ASD. Individual assessments were used to measure mental- and internal-state understanding. Teacher-rated scales were used to assess child’s verbal and non-verbal communication skills, and social competence.Results:The results showed that social competence, cognitive representation, verbal and non-verbal communication skills were all significantly associated, but over and above cognitive representation skills and verbal communication, non-verbal communication had a salient role in adaptive social relationships of children with ASD.Conclusions:These findings have important applied implications for intervention studies and suggest that improvements of non-verbal communication skills in children with ASD might be important for increasing their positive social relations.

Study design:The study was designed as a cross-sectional survey.Objectives:The purpose of the study was to examine the level of feelings of burden in family caregivers of people with spinal cord injury (SCI) in Turkey, and to explore its predictors.Setting:Turkey.Methods:One hundred family caregivers of people with SCI completed measures of burden of caregiving, depression, social support and physical health. The SCI participants completed a measure of functional independence. Multivariate statistics and structural equation modeling (SEM) were conducted to identify significant predictors of caregiver burden.Results:Caregiver burden was significantly related to caregivers’ feelings of depression. SEM analysis showed that social support from family and from friends predicted caregiver burden via depression. Caregivers’ age, sex, educational level, physical health and household income did not significantly predict their feelings of depression or burden.Conclusions:Our findings revealed that support received from both families and friends is an important source for alleviating the depressive feelings of caregivers and, in return, their burden in the caregiving. In Turkey, high support from family members is expected and is important for psychological well-being, yet the current study showed that the support received from friends also has unique contribution to the well-being of the caregivers of persons with SCI. Overall, our findings highlight the importance of supportive relationships between family as well as friends for the caregivers who may have to provide lifetime care for their family member with special needs.

Background:Obstructive sleep apnea syndrome (OSAS) is a widespread disorder characterized by recurrent, partial or complete episodes of apnea due to upper airway tract obstruction during sleeping period. Deficiency of vitamin D has roles in development of many diseases. Association between presence and severity of OSAS and vitamin D has recently gained research interest. Aim:The aim of our study was to investigate the association between serum 25-hydroxy [25 (OH)] vitamin D levels and severity of disease in patients with OSAS. Material and Methods:One hundred and fifty OSAS patients (50 patients with mild, 50 with moderate, 50 with severe OSAS) who were diagnosed by polysomnography (PSG) and 32 non-OSAS controls who were referred to the Health Ministry Ankara Numune Training and Research Hospital, Endocrinology and Metabolism Department, from January 2010 to May 2011 were included in the study. Serum 25(OH)D, PTH, calcium and phosphorus levels were evaluated in all the patients who were recruited to the study. Results:There was no statistically significant difference in serum 25(OH)D levels between OSAS and controls (p>0.05). However, in subgroup analysis of OSAS, we found that the patients with severe OSAS had significantly lower levels of 25(OH)D as compared with other groups (p=0.003). Also, the number of patients with serum 25(OH)D deficiency (<10 µg/dl) were higher in OSAS group than in controls (p<0.05). Conclusions:We found that when the severity of OSAS increases, 25(OH)D deficiency becomes more pronounced.

Since prehistoric times, herbs have been acclaimed for their efficacy to improve health, accelerate the healing process following injuries and the body's recovery from exercise. There exists a number of such well known curative and healing herbs like arnica, calendula, St. John's wort etc, which have been used for treating different kinds of sports injuries. This brief review comes up with an illustration of these promising herbs used as commonest remedies against different sports injuries.

More successful results have been obtained in butt- and overlap-joining of Al-alloy plates by a recently developed solid state joining technique, namely friction stir welding (FSW), than in more conventional fusion welding processes. In this joining technique, no fusion takes place in the joint area of the plates welded. This novel joining method also offers the potential to weld some other materials rather than Al-alloys, such as Mg-alloys, brasses and low strength steels. In this study, the applicability of friction stir welding to brasses, namely 90Cu-10Zn and 70Cu-30Zn alloys, has been investigated. The joint performance was determined by conducting optical microscopy, microhardness mesurements and mechanical testing (e.g. tensile and bend tests). The effect of welding speed on the joint quality at a given rotational speed of the stirring pin (i.e. 1600 rpm) was also determined for both alloys. The highest joint performances were obtained at a welding speed of 210 mm/min for both alloys.

The aim of this study is to prepare ion-imprinted poly(2-hydroxyethyl methacrylate) (HEMA) based membranes which can be used for the selective removal of Fe3+ions from Fe3+-overdosed human plasma. N-methacryloyl-(L)-glutamic acid (MAGA) was chosen as the ioncomplexing monomer. In the first step, Fe3+was complexed with MAGA and then, the Fe3+-imprinted poly(HEMA-MAGA) membranes were prepared by UV-initiated photo-polymerization of HEMA and MAGA-Fe3+complex in the presence of an initiator (benzoyl peroxide). After that, the template (i.e., Fe3+ions) was removed by using 0.1 M EDTA solution at room temperature. The specific surface area of the Fe3+-imprinted poly(HEMA-MAGA) membranes was found to be 49.2 m2/g and the swelling ratio was 92%. According to the elemental analysis results, the polymeric membranes contained 145.7 µmol MAGA/g polymer. The maximum adsorption capacity was 164.2 µmol Fe3+/g membrane. The relative selectivity coefficients of ion-imprinted membranes for Fe3+/Zn2+and Fe3+/Cr3+were 12.6 and 62.5 times greater than the non-imprinted matrix, respectively. The Fe3+-imprinted poly(HEMA-MAGA) membranes could be used many times without decreasing their Fe3+adsorption capacities significantly.

Porous monolith was obtained by the bulk polymerization of ethylene dimethacrylate (EDMA) and glycidyl methacrylate (GMA) conducted in a glass tube. Poly(EDMA-GMA) monolith had a specific surface area of 98.7 m²/g. Poly(EDMA-GMA) monolith was characterized by swelling studies, FTIR, scanning electron microscopy, and elemental analysis. Poly(EDMA-GMA) monolith with a swelling ratio of 48%, and containing 45.7 μmol Cibacron Blue F3GA/g, were used in the adsorption/desorption of human serum albumin (HSA) from aqueous solutions and human plasma. The nonspecific adsorption of HSA was very low (0.8 mg/g). The maximum amount of HSA adsorption from aqueous solution in phosphate buffer was 22 mg/g at pH 5.0. Higher HSA adsorption value was obtained from human plasma (up to 53.2 mg/g) with a purity of 92%. Desorption of HSA from Cibacron Blue F3GA-attached poly(EDMA-GMA) monolith was obtained using 0.1 M Tris/HCl buffer containing 0.5 M NaCl. It was observed that HSA could be repeatedly adsorbed and desorbed with poly(EDMA-GMA) monolith without significant loss in the adsorption capacity.

In this study, the transient in which the pool water is lost throughout one or more of the main coolant pipes which are supposed to be broken guillotine-like is investigated for the TR-2 research reactor in Istanbul. The applicability of the methods used for other similar types of research reactors is shown. Decrease of the pool water level until the top of the core, and from the top to the bottom of the core are examined as two successive phases of the accident. Finite difference scheme and integral methods are employed to solve energy equations and the results of both methods are compared. The finite difference solution uses an explicit form for the analysis of the first phase, and a moving boundary approach for the second phase. The integral method is based on the assumption that the temperatures appearing in the energy equations have the same profiles during the transient as the steady state ones. Analyses are done both for nominal and hot channel, and the results of both methods are observed to be in agreement.

The drivage of the supply gate of a development panel in the presumed low stress zone adjacent to the loader gate of an excavated panel with a very small width of intervening pillar between the two entries, known as skin-to-skin working, resulted in an extensive fall of the supply gate roof at a UK coal mine, Bilsthorpe colliery in 1993. This fall left a question over the application of skin-to-skin drivage of gate entries supported primarily by rock bolts. To investigate the possible reasons behind this fall, both physical and numerical modelling studies were carried out. Physical and numerical models were successful in demonstrating the potential danger of the working method with the rock bolt support system employed. Development of a shear failure plane from the rib edge into roof strata of the loader gate and development of the second shear failure plane at the abutment side of the supply gate exposed the supply gate to the fall of large rock blocks released by shear failure zones. Models demonstrated that the fall of the supply gate roof was not due to the inability of the rock bolts to prevent bed separation, but it was the method of working that made the bolts ineffective due to the height of the block delineated by the shear failure planes. Further physical and numerical models were undertaken to investigate the influence of 5, 7·5 and 10 m wide intervening pillars between the entries on the stability of the rock bolt supported supply gate roof. These studies showed that a 7·5 m or 10 m wide pillar would have prevented development of failure zones and fall of the roof while a 5 m pillar was found to be an undersized pillar width causing the development of extensive failure zones in the roof.

A detailed analysis and comparison of various control architectures is presented in order to meet the challenging design requirements targeted. All the present advanced control systems have certain advantages and disadvantages compared with each other. Due to the lack of an optimal control system with desired capabilities, such a control system has been the focus of recent robotics research programs. The new approach proposed in this paper is a hybrid control system that takes the advantages of various control structure types thereby integrating them in a way that results in an overall increase in synergy. The proposed control architecture presents a new approach to the design of supervisory control system that utilizes reactive, deliberative, distributed and centralised control approaches, and uses fuzzy logic as well as modular hierarchical structure. The architecture carries out supervision, modification and execution of commands generated by the centralised command arbitration module by conducting fuzzy logic integration of activated behaviours from distributed, independent asynchronous decision making processes that takes information from the user, sensory system and task description, thus providing goal-oriented, real-time responsive and tele-operable control system architecture. The resulting control system was experimented on and it was observed that not only was the response time sufficiently short, but also it exhibited robustness, flexibility, adaptability, portability and expandability.

Abstract: We studied the effect of different training patterns on vertebral trabecular and cortical bone mineral density (BMD) in male athletes using quantitative computed tomography. Vertebral trabecular (t) and cortical (c) BMDs of the first three lumbar vertebrae were measured using single energy quantitative computed tomography in 51 athletes including 10 weight lifters (mean age 20 years), 13 soccer players (mean age 27 years), 28 wrestlers (mean age 17 years), and 45 age-matched volunteers (mean age 21 years). Measured BMDs were correlated with age, body height and weight, training hours per week, sports years, and type of physical activity. Vertebral tBMDs were found to be 44%, 23%, and 24% higher in the weight lifters, soccer players, and wrestlers, respectively, compared with the volunteers. The corresponding cBMDs were 18%, 6%, and 11% higher than that of volunteers. There was significant correlation between the trabecular and cBMD, and height of the athletes, sports years, training hours per week, and physical activity. The most significant correlation with BMD was the type of physical activity. Both the height of the subjects and physical activity variables showed variations of 47% and 32% in trabecular and cBMD, respectively. According to the multiple analysis of variance (MANOVA) only the physical activity factor was effective, with a significance level ofP<0.01; the other factors and interactions were not effective (P>0.05) on trabecular and cBMD. Different training patterns have a different anabolic effect on both trabecular and cBMDs of the vertebrae, and this effect is more pronounced on the trabecular compartment. Weight lifting showed the highest anabolic effect on both trabecular and cBMDs compared with soccer playing and wrestling. Of the independent variables, physical activity showed the highest anabolic effect on the vertebrae. These results may have implications for devising exercise strategies to reduce the possibility of fracture in old age.

222Rn concentration was measured in Elazig houses and factories by forty-seven pairs of CR-39 detectors. Detectors were obtained from the laboratory of Cekmece Nuclear Research and Training Centre. They were etched and evaluated at the same laboratory. The measured concentrations were ranging between 17 and 184 Bq.m-3 with a mean value of 47 Bq.m-3.