A study of the local site effects on the ground response for the city of Eskişehir,Turkey

Bulletin of Engineering Geology and the Environment - Local soil characteristics play a key role in determining soil-structure interaction and reliability of the superstructure behavior under...     

Swenson's operation for neonatal Hirschsprung's disease

OBJECTIVE: To describe our experience with Swenson's operation for Hirschsprung's disease done during the neonatal period. DESIGN: Retrospective study. SETTING: University department of paediatric surgery. SUBJECTS: 10 Neonates with Hirschsprung's disease. INTERVENTIONS: Rectosigmoidectomy and pull through (Swenson's operation), with covering transverse colostomy. MAIN OUTCOME MEASURES: Mortality, morbidity, and continence. RESULTS: The median age at definitive operation was 25 days (range 15-35). There was one late death three weeks after discharge from hospital of respiratory and cardiac failure. Two patients presented with caecal perforation and two with intestinal obstruction; in all four Hirschsprung's disease was diagnosed on frozen section, a transverse colostomy was done, and the Swenson's operation was done electively. The other six were diagnosed by barium enema examination and biopsy, and underwent total bowel irrigation followed by Swenson's operation and transverse colostomy. The colostomies were closed three to four weeks later. There were no postoperative complications. All nine surviving patients were continent (3-4 stools/day), at a mean (SD) follow up of 21 (5) months. CONCLUSION: With the current high standards of anaesthesia and neonatal intensive care, and an experienced surgeon, Swenson's operation for neonatal Hirschsprung's disease is safe and the procedure of choice for this condition.     

High-mobility pentacene phototransistor with nanostructured SiO2 gate dielectric synthesized by sol-gel method

We have fabricated a pentacene based phototransistor by employing a modified nanostructured SiO₂ gate dielectric. The photosensing properties of the pentacene thin film transistor fabricated on n-Si substrate with nanostructured SiO₂ as gate dielectric have been investigated. The photocurrent of the transistor increases with an increase in illumination intensity. This suggests that the pentacene thin film transistor behaves as a phototransistor with p-channel characteristics. The photosensitivity and responsivity values of the transistor are 630.4 and 0.10 A/W, respectively at the off state under AM 1.5 light illumination. The field effect mobility of the pentacene phototransistor was also found to be 2.96 cm²/Vs. The nanostructured surface of the gate possibly is the cause of the high-mobility value of the phototransistor due to light scattering from the increased surface area.     

Effect of ethanol–gasoline blends on engine performance and exhaust emissions in different compression ratios

Renewable energy sources for the gasoline engines alcohols gain importance recently. These renewable energy sources have attracted the attention of researchers as alternative fuel due to their high octane number. In addition, these are also clean energy sources and can be obtained from the biomass alcohols with low carbon like ethanol. In this study, the effect of compression ratio on engine performance and exhaust emissions was examined at stoichiometric air/fuel ratio, full load and minimum advanced timing for the best torque MBT in a single cylinder, four stroke, with variable compression ratio and spark ignition engine.     

Influence of treated sewage sludge applications on temporal variations of plant nutrients and heavy metals in a Typic Xerofluvent soil

The objective of this study is to determine influence of Treated Sewage Sludge (TSS) rates as organic matter and nutrient resource on temporal variations of some macronutrients and micronutrients and heavy metals concentrations in a Typic Xerofluvent soil. The experiment was conducted in Menemen Plain, in the Western Anatolia Region of Turkey in 2003–2005. Moist TSS was added to the soil at the rates of 0, 30, 60 and 90 Mg ha⁻¹ on May 1, 2003. Peanut (Arachis hypogaea) was planted as the first crop. On the other hand, mixture of green barley (Hordeum vulgare) and common vetch (Vicia sativa L.) was planted as the second crop. During the experiment, soil samples were taken five times. Increasing TSS applications to this soil resulted in significantly increased concentrations of total N, Cu, Pb and Ni, and available P, K, Ca, Fe, Cu, Zn, Mn concentrations in soil. However, concentrations of available Mg and Na, total Fe, Zn, Mn, Cd, Co and Cr in soil did not significantly change. Micronutrients and heavy metals concentrations in soil were found under threshold values in all sampling periods in this study. Available nutrient concentrations in the soil decreased particularly in the last sampling periods because of plant uptake of nutrients from the applied TSS. It is recommended that 90 Mg ha⁻¹ moist TSS can be added once in a 2-year period for improving nutrient concentrations in Typic Xerofluvent soil.     

The effect of different knitted fabrics’ structures on the moisture transport properties

In this study, fabrics with different plain, tuck and float stitch combinations in three different tightness levels as tight, medium and loose are produced from combed ring spun cotton yarn. It is aimed at determining the effect of fabric structure on liquid absorption, transport and permeability properties, which are important factors in the people’s perception of wear comfort. The air permeability, wicking ability and moisture management measurements of the produced fabrics are made. It is determined that the increase in the fabric tightness decreases the air permeability and increases the wicking ability especially in 60?min measurements. The fabric tightness has also different effects on different knitting types in terms of moisture management properties. It is observed that structures with float stitches show high wicking ability and moisture management properties in terms of plain, tuck and float stitches combinations.     

Investigation of pore parameters of woven fabrics by theoretical and image analysis methods

Fluid permeability property is an important performance feature of fabrics and must be considered during the designing processes of products. Since the rate of fluid flow through a textile is a function of viscosity, density, pressure gradient of fluid, and the pore properties of fabric, it is necessary to define pore properties by controlling the structural parameters of fabric for a certain area of use. Due to the complexity of fabric structure, modeling of pore structure and predicting the pore parameters are difficult. In this study, the interyarn porosity, pore size, and pore-size distribution of cotton woven fabrics were calculated by using two-dimensional (2D) and three-dimensional (3D) geometrical pore models and image analysis method. The effect of weave types and weft settings on the pore parameters and air permeability of fabrics were investigated, and the advantages of 2D, 3D geometrical pore models and image analysis method were compared.