1. | Cover-Contents Pamukkale Üniversitesi Mühendislik Bilimleri Dergisi Pages I - III |
2. | USER EQUILIBRIUM AND SYSTEM OPTIMUM TRAFFIC ASSIGNMENTS; ISTANBUL ROAD NETWORK EXAMPLE Banihan GÜNAY Pages 167 - 176 The concept of road networks and traffic flow equilibrium conditions are briefly reviewed and discussed. In order to see whether some benefits for the society (e.g. whole network) by employing a System Optimum assignment approach can be achieved or not, an assessment study was carried out on the Ystanbul road network using the actual data gathered. As a result of the system optimising simulation, queuing times on the Bosphorus Bridge dropped by 12% and speed of an average car increased by 16%, compared to the results produced by the User Equilibrium assignment. Besides, the total system journey time was also reduced by about 4%. |
3. | ELASTO-PLASTIC FINITE ELEMENT ANALYSIS OF HOOK’S JOINT Adnan ATICI, Muammer NALBANT, Adnan Özel Pages 177 - 183 In this study, stress analysis has been done in Hooke’s joint by the finite element method. In finite element meshing, isoparametric quadrilateral elements with four nodes has been chosen and Lagrange polynomial has been used as the interpolation function. The special computer program has been written for the automatic mesh generation. In addition the other program has been developed to solve the finite element problems. Elastoplastic stress analysis is done to calculate the residual stresses in hooke’s joint. Elasto-plastic stress values are calculated under loading from 400 daN to 1000 daN with increment of 100 daN. In this analysis “The initial stress method” is used. |
4. | THEORETICAL AND EXPERIMENTAL ANALYSIS OF A CROSS-FLOW HEAT EXCHANGER R. Tuğrul OĞULATA, Füsun DOBA Pages 185 - 192 In this study, cross-flow plate type heat exchanger has been investigated because of its effective use in waste heat recovery systems. For this purpose, a heat regain system has been investigated and manufactured in laboratory conditions. Manufactured heat exchanger has been tested with an applicable experimental set up and temperatures, velocity of the air and the pressure losses occuring in the system have been measured and the efficiency of the system has been determined. The irreversibility of heat exchanger has been taken into consideration while the design of heat exchanger is being performed. So minimum entropy generation number has been analysied with respect to second law of thermodynamics in cross-flow heat exchanger. The minimum entropy generation number depends on parameters called optimum flow path length, dimensionless mass velocity and dimensionless heat transfer area. Variations of entropy generation number with these parameters have been analysied and introduced their graphics with their comments. |
5. | APPLICATION OF NULLATOR-NORATOR AND NULLOR MODEL TO ELECTRONIC CIRCUITS Mustafa ALÇI, Esma UZUNHİSARCIKLI Pages 193 - 199 The aim of this paper is to introduce the nullor model which is developed for active electronic circuit components. Therefore, nullor models of some electronic devices such as transistor, ideal and nonideal operational amplifiers are given. Applications of this model to negative impedance converters, gyrator, various controlled sources and the active RC circuit synthesis are presented and also the advantages of using this model are discussed. |
6. | GRAVITATIONAL RADIATION Metin SALTIK, Mustafa KURT, Mehmet KAYMAK Pages 201 - 205 According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated mass system, and the systems cousing gravitational radiation are investigated. |
7. | EFFECT OF DIFFERENT K2 HPO4, NaCl LEVELS AND TWO DIFFERENT TEMPARATURES ON SOME EMULSION PROPERTIES OF GOAT MEAT Mustafa KARAKAYA, Hüsnü Yusuf GÖKALP, Ramazan BAYRAK Pages 207 - 213 Different levels of K2 HPO4 (0.00 %, 0.25 % and 0.50 %) and NaCl (2.5 % and 3.0 %) were added into goat meat, at the two different temperatures (11o C and 18o C) in order to investigate the emulsion properties in the model emulsion system. Emulsion capacity (EK), emulsion viscocity (EV), emulsion stability ratio (ES), the ratio of separated water (ESO) and oil (EYO) ratio from the emulsion, and the emulsion pH were determined. K2 HPO4 and NaCl levels and the oil temperatures have significant effect (p<0.01) on EV and ES values, K2 HPO4 and NaCl levels only have significant effect on EK and EYO. As the phosphate and salt addition level increased, EK, EV and ES increased. The lowest EV was seen at 18o C with 2.5 % NaCl and 0.00 % K2 HPO4 NaCl addition and oil temperature on ESO and K2 HPO4 x NaCl combination on EYO have significant effect (p<0.01). In general, as K2 HPO4 and NaCl additions increased, the ESO and EYO ratios decreased, Ph values were incereased by the K2 HPO4 and NaCl additions. |
8. | BORON-NITROGEN RELATIONSHIP IN WHEAT (Triticum aestivum L.) GROWN WITH THE NUTRIENT SOLUTION Mehmet ALPASLAN, Süleyman TABAN, Ali İNAL, A. Cihat KÜTÜK, İbrahim ERDAL Pages 215 - 219 The effects of boron applied 0.01, 0.1, 1.0, and 10.0 µg B/ml levels as boric acid (H3 BO3), and nitrogen applied 25, 100, 200, and 400 µg N/ml as ammonium nitrate (NH4 NO3), respectively, on the amount of dry matter yield, and boron, nitrogen and nitrate contents of wheat (Triticum aestivum L.) grown in perlite medium with Ruakura nutrient solution under greenhouse conditions were investigated. Dry matter yield and nitrate contents of wheat were decreased and boron content was increased with increasing boron application. Controversially, application of nitrogen increased dry matter yield, nitrogen and nitrate contents of wheat, while decreases in boron contents. Those effects of boron and nitrogen were found to be statistically significant (P<0.01). It was determined that addition of high levels of nitrogen alleviated boron toxicity. Low-level boron application caused in nitrate accumulation in plants. |
9. | DETERMINATION OF THE USE OF MARDİN-MAZIDAĞI PHOSPHATE ROCK RESIDUES AS FERTILIZER İbrahim ERDAL, Ferhan HATİPOĞLU Pages 221 - 225 In this study, it was aimed to research the possibilities of direct and acidulated usage of phosphate containing material which was obtained from Etibank Phosphate Enrichment Systems. In the greenhouse experiment, acid and neutr-characterized soils were used. Both oat (Avena Sativa) as a preliminary plant with the period of 5.5 months and rape (Brassica napus) as a second plant with the period of 2 months were grown in 6 kg soil containing pots. 1 g P2 O5 was given to pots in the forms of TSP, fine residue, coarse residue, acidulated fine residue and acidulated coarse residue. Additionally, 1.2 g N (NH4 NO3), 1.5 g K2 O (K2 SO4) were applied to the pots. The effects of rock phosphate on dry weight, phosphorus content and phosphorus uptake of plants were determined. According to the results obtained, it was concluded that the effects of rock phosphate on dry weight, phosphorus contents and amount of phosphorus uptake of both plants were found differently. Depending on soils and residues as a phosphate source the effect of acidulated coarse residue on soils was similar to that of TSP when compared with the effect of TSP on soils, that of direct application of coarse residue was lower and that of the acidulated and direct application of fine residue was the lowest. |
10. | REGRESSION MODELS ON DESIGN AND OPERATIONAL PARAMETERS OF SLOW SAND FILTERS Mehmet Emin AYDIN Pages 227 - 236 The aim of this research was to obtain a regression model that relates the design and operational parameters and inflow water quality for slow sand filters. Therefore, three laboratory scale slow sand filters with sands of different effective diameters were operated at three different temperatures and at five flow rates. Stream water was used as inflow. Small quantities of settled sewage were added to the feed water. From the data produced, 72 regression models were developed relating inflow water quality and treatment rate to effluent quality for each of four quality parameters, three sand sizes and three temperatures. Attempts to create more complex models linking sand size, treatment rate, bed depth, temperature, inflow quality and filtrate quality were not possible due to the discontinuities in the data. Nine of these simple models can be readily employed in the design of slow sand filters. Effective removal of all four quality parameters was achieved with all flow rates at 25 o C and 15 o C but a definite reduction in the removal of indicator organisms was recorded with the higher flow rates at 5 o C. No significant variation in effluent quality with sand size was recorded. Maturation of the new filters was apparently complete within a week. |
11. | THE AMOUNTS OF MEDICAL SOLID WASTES FROM A DISPENSARY AND A PRIVATE HOSPITAL M.Talha GÖNÜLLÜ, F.İlter AYDINOL, Orhan SEVİMOĞLU, Cem KURAL Pages 237 - 241 In the disposal of medical wastes, it is important to know about the amount and source of wastes occured for the selection of convenient technologies of disposal. In this research, the kinds and amounts of medical wastes occured in a dispensary and a private hospital in istanbul have been searched. |