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Öğe Diversity of Electrical Conductivity in a Water-Bearing Rock Material(KOZAN OFSET MALBAACILIK SAN VETIC LTD STI, 2001) Gökay, M. K.; Özkan, I.The electrical conductivity of rock materials was analysed in order to develop practical laboratory-based measurement equipment. In order to proceed with the selected aim, artificial rock materials were prepared by using plaster of Paris. Test samples were prepared in two categories: the first was the original material; the second group of samples contained glass pieces. Glass pieces were located in the test samples in a certain pattern to simulate random joint orientation in natural rock masses. The tests showed that, electrical fields around the joints are higher due to their high water-bearing characteristics. This property was used in the tests to determine hidden joint locations in the selected rock masses and model samples provided. Underground gas, water or petroleum storage excavations or excavations opened for waste dumping are all sensitive to seepage of the gases or liquids both into them and out of them. Evaluation of these rock masses for joint occurrence requires at least seismic and electrical conductivity measurements. In this research study, alternative measuring techniques were investigated for laboratory and field test procedures. The resulting graphics obtained in the laboratory tests illustrate how the joints in the rock masses were detected in the samples.Öğe Effects of hormone replacement therapy on psychiatric symptoms in postmenopausal women(2002) Çelik, Çetin; Özkan, I.; Albeni, Havva; Acar, A.; Akyürek, CemalettinOBJECTIVE: In this study, we aimed to determine the psychological benefits of HRT in postmenopausal women. STUDY DESIGN: 30 postmenopausal women received HRT for 3 month were entered the study in Selçuk University Faculty of Medicine Obstetrics and Gynecology Department; Menopause division. Patients were given continuos 0.625 mg/day conjugated equine estrogen and 2.5 mg/day medroxiprogesteron acetate as HRT. The patients were given Symptom Checklist 90-R (SCL 90-R), Beck Depression Scale (BDS) and Situation Anxiety Inventory I-II (STAI I-II). RESULTS: The patients received HRT for tree months were found to have significant decrease in depression according to BDS and in anxiety levels according to STAI-I and STAI-II (p=0.001, p=0.002, p=0.001). In symptom check list, all subscales and mean of general symptom were found to be decreased in thirth month of HRT. CONCLUSION: HRT has positive influence on both the somatic and psychiatric symptoms in postmenopausal period. Improvement in psychological symptoms via hormonal therapies or other interventions will probably lead to better quality of life for postmenopausal women.Öğe Modeling the Behavior of Longwall Coal Mine Gate Roadways Subjected to Dynamic Loading(PERGAMON-ELSEVIER SCIENCE LTD, 2001) Ünal, E.; Özkan, I.; Çakmakçı, G.In order to characterize the behavior of a main gate during retreating of longwall faces and to evaluate the performances of five different support types, including rock bolts and steel sets, a total of 21 convergence and 18 floor-heave stations were installed. Consequently, about 11,500 convergence and 7200 floor-heave data points were obtained over a period of 14 months. In order to simulate the behavior of a supported main gate roadway, a convergence model, represented by an exponential function, was developed on the basis of statistical analyses. In addition to the convergence model, convergence-velocity and convergence-acceleration models were also derived and interpreted in terms of gate road behavior. It was determined that the convergence depends on the loading region, the time, the location of the upper and lower longwall faces, the support type and pattern, and the static and dynamic support loads. Convergence-velocity and acceleration curves provide better means to interpret the performance of supports and gate roadway behavior.
