Ahi Evran University

About: Ahi Evran University is a education organization based out in Kırşehir, Turkey. It is known for research contribution in the topics: Density functional theory & Ab initio. The organization has 842 authors who have published 2270 publications receiving 21904 citations.

Experimental Investigation on Wire Electric Discharge Machining of Biodegradable AZ91 Mg Alloy

Abstract: The AZ91 magnesium alloy, used commonly as a biodegradable material in biomedical applications, is generally formed by conventional casting method (CCM) and high-pressure die casting method (HPDCM). The AZ91 alloys exhibit poor machinability with conventional chip removal methods since they degrade at elevated temperatures. In this study, the wire electric discharge machining (WEDM) was presented as a candidate process to machine the AZ91 alloy since no cutting stresses and plastic deformations were applied by the cutting tool to the part causing elevated temperatures. In this context, the WEDM machinability of the AZ91 alloy samples produced by cold chamber HPDCM and CCM at different process parameters, was experimentally investigated. The machining performance outputs (the machining current (I), the machining rate (MR), the average surface roughness (Ra), and surface topography) were found for the varying process parameters [pulse time (ts), pulse-off time (toff), dielectric flushing pressure (Pd), and wire speed (Vw)]. The present study revealed that the I and the MR were significantly dependent on the density, the porosity, and the micro structure of the samples, and the HPDCM samples gave the higher MR and the smoother surface than that of the CCM.

Exploring the perceptions of student teachers about ‘creative school’ in early childhood education

Abstract: Creative school environments use creative approaches in their curriculum, content, and teaching and learning. Considering that creativity is fostered by all elements of educational processes such as teachers, classrooms, and school environments, the purpose of the current study was to explore perceptions of Turkish student teachers in an early childhood education program about the concept of 'creative school' as a holistic system of creativity in early childhood. A case study design was used in the current study. Findings indicated that the student teachers described the 'creative school' as a space for active engagement, supporting inquiries of children through play-based activities, design of nature- and community-based schools, child participation and freedom of speech, and open-ended experiences. Moreover, descriptive analyses of drawings reflected the same or similar perceptions. Themes that emerged in the current study reflected the philosophy, curriculum, teachers, or children within a 'cre...

The Association of Skinfold Anthropometric Measures, Body Composition and Disease Severity in Obese and Non-obese Fibromyalgia Patients: A Cross-sectional Study

Abstract: Objectives This study aims to determine the effects of obesity and obesity related anthropometric and body composition determiners on the severity of fibromyalgia syndrome (FS) and to compare obese, overweight and normoweight FS patients according to general health and psychological status. Patients and methods The study included 42 obese (mean age 48.8±11.6; range 24 to 65 years), 27 overweight (mean age 47.3±3.4; range 24 to 61 years) and 32 normoweight (mean age 47.1±7.8 years; range 31 to 60 years) female FS patients. Widespread pain scores and symptom severity scores were noted. Pain pressure thresholds of tender points and control points were measured and total myalgic score (TMS) was calculated. The anthropometric assessments and skinfold measurements of all participants were recorded. Quality of life was evaluated by Health Assessment Questionnaire while psychological status was evaluated using Beck Depression Inventory. Results Control points, TMS values and hand grip strength values of obese FS patients were significantly lower, while disease duration, symptom severity, widespread pain scores, visual analog scale and Health Assessment Questionnaire scores were significantly higher than normoweight and overweight FS patients. Fat free mass, fat mass, body fat percentage and waist/hip ratio values were significantly higher in obese FS patients than overweight and normoweight FS patients (p<0.001 for all values). Stepwise linear regression analysis showed that increased body mass index, decreased fat free mass (R2=0.11) and increased disease duration (R2=0.13) were associated with lower TMS. Conclusion We found that obesity had significant negative effects on pain, disease severity and quality of life in patients with FS.

Effect of Different substrate Disinfection Methods on the Production of Pleurotus ostreatus

Abstract: The aim of this paper is to estimate which of disinfection method is more effective in case of higher yield and fewer cost in cultivation of Pleurotus ostreatus in rural areas. For this purpose, four different treatments; scalping in hot water (60, 80 and 100°C), and chemical disinfection (1% formaldehyde) were compared with sterilization by autoclave. It has been noticed that method of disinfection affects mycelium growing duration(day), yield(g/kg), biological efficiency (BE%), avarage weight of fruitbody(g), diameter of pileus(cm), stipe lenght(cm) and width(cm). P. ostreatus took significantly much time to colonise the substrate (19.9 days) disinfected by chemical disinfection compared with others. Chemical disinfection (271.28 g/kg and 91.96%) and scalding hot water at 80 o C (263.42 g/kg and 90.83%) had highest productivity in terms of yield and BE, respectively, while scalding hot water at 60 o C (136.08 g/kg and 46.92%) had least productivity. The largest diameter of fruitbody was obtained by scalding in hot water at 80 o C, while the longest stipes were harvested in disinfected substrate by chemicals. In conclusion, cheaper and more easily applecable scalping in hot water 80°C and chemical disinfection may be use for the disinfection of growing substrates instead of sterilization with autoclave in rural areas. Keywords: mushroom growing substrate, disinfection methods, autoclaved, scalding, chemical disinfection, Pleurotus ostreatus