Due to lack of energy sources in the world, we are obliged to use our current energy sources in the most efficient way. Therefore, in the automotive industry, research works to manufacture more economic cars in terms of fuelconsumption and environmental friendly cars, at the same time satisfying the required performance have been intensively increasing. Some positive results have been obtained by the studies, aimed to change the compression ratio according to the operating conditions of engine. In spark ignition engines in order to improve the combustion efficiency, fuel economy and exhaust emission in the partial loads, the compression ratio must be increased; but, under the high load and low speed conditions to prevent probable knock and hard running compression ratio must be decreased slightly. In this paper, various research works on the variable compression ratio with spark ignition engines, the effects on fuel economy, power output and thermal efficiency have been investigated. According to the results of the experiments performed with engines having variable compression ratio under the partial and mid-load conditions, an increase in engine power, a decrease in fuel consumption, particularly in partial loads up to 30 percent of fuel economy, and also severe reductions of some exhaust emission values were determined.

In literature, pumps which are known as vertical turbine pump (VTP) have been designed to work vertically. Today, they are known as deep well pumps. These pumps are especially used in narrow and very deep wells where the surface sources are insufficient. Therefore, it is necessary to select suitable stage number to benefit from deep well pumps efficiently. In this study, a new deep well pump has been designed and the performances of three stage deep well pumps have been investigated experimentally using different number of blades. Efficiency increase ratio of these three stage deep well pumps has been determined at the best efficiency point with respect to single stage deep well pumps.

In this study, the erosion-corrosion behaviour of Cu-10 % Ni copper-nickel alloy in artificial sea water has been investigated. The erosion-corrosion tests have been conducted using a cylindrical electrot rotating at different speeds. In the experiments, free corrosion potential tests, cycle polarization tests, electrochemical impedance spectrum (EIS) analysis, weight loss tests, and optic microscope observation were performed. The corrosion rate of Cu-10 % Ni copper-nickel alloy in artificial sea water increased with increasing rotation speed and time. It was also determined that the breakdown of the protective film began after 3 hours at the rotation speed of 1600 rpm, and 1 hour at the 2000 rpm, and grew with increasing time.

In a direct sequence/code division multiple access (DS/CDMA) system, the role of the spreading sequences (codes) is crucial since the multiple access interference (MAI) is the main performance limitation. In this study, we propose an accurate criterion which enables the determination of the reference spreading codes which yield lower bit error rates (BER’s) in a given code set for a DS/CDMA system using despreading sequences weighted by stepping chip waveforms. The numerical results show that the spreading codes determined by the proposed criterion are the most suitable codes for using as references.

The technique of heating by electromagnetic induction is a well established and an invaluable tool for industries engaged in the heat treatment of hot working of metals. In this study, it is shown that induction heating can succesfully be applied for domestic cooking applications. For this purpose, a complete induction heating system has been designed and a prototype of the proposed system has been built and tested. By the use of resonant technique, switching losses have been reduced significantly. Coil design procedure of the proposed system was also given. It is shown that induction heating system has many advantages among the conventional heaters.

The effect of window functions on the ARMA (Autoregressive Moving Average) model parameters estimated by PORLA (Pure Order Recursive Ladder Algorithm) method is presented. The PORLA method has an algorithm structure, in which the tracking and the modelling problems are treated as independent sub algorithms. In this method, first, the tracking of the nonstationary data is performed by the time-recursive calculation of the input/output data covariance block matrix. Second, the modelling problem is solved by the two-channel PORLA method in which the ARMA modelling problem is embedded. Error propagation in time can not occur in the PORLA method. Arbitrary windowing techniques can be easily incorporated to control the fast start-up and tracking capability. To illustrate the effect of window functions on the ARMA model parameters estimated by PORLA method, the simulation results are given for the different window functions such as the rectangular, triangular, Bartlett, Hanning, Hamming, exponential, modified Barnwell, Blackman and Kaiser windows.

In the active regions of the semiconductor lasers electrons interact with the electromagnetic fields and exchange their energy states and so the atomic energy levels and meanwhile their excess energy is transferred to optical energy. During this exchange the energy states of electrons change. Because the change of the electron energy states affects the threshold current, this energy change is important in the semiconductor laser band engineering. In this work the behaviour of the energy of the electrons and their eigenstates on the heterojunction semiconductor lasers and so the atomic energy levels are investigated.

Computer program which investigates the effectiveness of confinement regions of shear walls was developed.Specimens which have unique web reinforcement and different confinement regions were analyzed by using this computer program. Data needed for theoratical computations were obtained by tensile testing of steel rods and by concrete specimen tests. Mander Method was applied to reflect confined concrete behavior. Strain hardening behavior of steel was included in computations. Effect of stirrup spacing and hook reinforcement was introduced together and seperately to understand the moment-curvature response of specimens.

Milk proteins are a source of various biologically active peptides, which are formed enzymatically either by digestive enzymes or during milk fermentation. These peptides have been shown to have different biochemical and physiological effects, such as binding to opioid receptors, inhibition of angiotensin I-converting enzyme (ACE), antimicrobial, antihypertensive, antioxidative, antithrombotic, immunomodulatory and mineral binding effects. This review will focus on chemical structure, physiological properties, production and formation mechanisms in dairy food of milk-derived bioactive peptides and their usage potential as functional food ingredient.

Heavy metals which contaminate water due to ýndustrialization cause a great deal of environmental pollution. In addition to that these metals threaten human health by accumulating in organismas which leave in rivers and seas and being used as nutriment.The aim of this resarch is to determine the mercury, lead and cadmium accumulation in scads (Trachurus trachurus ) caught in the Gulf of Ýzmit and near Tekirdag in the sea of Marmara. The resarch was carried out in April, May and June 1996. Fish sample analysed for mercury, lead and cadmium elements. Heavy metal contents of fish caught in the Gulf of Ýzmit were all higher than those of caught in Tekirdag . Avarege mercury contents were 0.316 ppm and 0.029 ppm in the Gulf of fishes and Tekirdag fishes respectively. Average lead contents were 0.269 ppm and 0.038 ppm in the Gulf fishes and Tekirdag fishes respectively. Average cadmium contents was 0.061 ppm in the Gulf fishes. No cadmium was determined in Tekirdað fishes.

This paper analyses various 2D acoustic wave propagation problems in the time domain BEM through geophysical environments. To this end the existing BEM code for the boundary nodes is expanded to optional internal nodes. Using appropriate and predominant temporal variations for the field quantities the time-related kernels are obtained explicitly. The BEM and FDM solutions presented are generated using synthetic seismograms and are seen to be stable. The qualitative agreement between the two methods is excellent.

In this paper by using a new approach we investigate the resolvent operator and completeness of the system of eigenfunctions of the Sturm-Liouville problem with discontinuous coefficients and weight, one of the boundary conditions of which contained linear eigenparameter. For operator-theoretic formulation of the considered problem we define a new equvalent inner product in the Hilbert space C L [a, b] 2 ? / and suitable selfadjoint linear operator in it. Further, the basic solutions ) ?(x,? and ) ?(x,?)are defined by the special procedure.

The study area is located within the Central Anatolian Massif around Yeþilhisar (Kayseri). The oldest rock units in the area are ophiolitic rocks which are mainly found as gabbro and dunites. The gabbros are dark green,blackish green coloured and hard, thin-medium granular hipidiomorf textured. Main Composition of gabbroic rocks are hornblende, clinopyroxen, plagioclase, quartz and opaque minerals, sphene and spinel are accessory minerals. The dunites are yellowish, greenish yellow coloured and fragile and stockwork textured. The main components of the dunites are olivine, pyroxen and chromite. The gabbroic rocks are mainly toleitic and can be classified as metaaluminious rocks. Main and trace element variations indicate that the fractionation of hornblende and Fe-Ti oxide minerals. Ratio of Condridite normalized Light REE to Heavy REE displays no enrichment La/LuN = 0.26. Trace and REE contents of the gabbroic rocks indicate that these rocks were a product of MORB like source.

The amphibolites and tremolite-bearing gneisses, formed concordantly within metasediments around Ortaköy(Aksaray) area, are composed of mainly magnesio-hornblende, magnesio-hastingsite, plagioclase, sphene, diopsite, quartz, biotite ; and tremolite, actinolite, actinolitic hornblende, ilmenite respectively. It has ever been found out a preserved flowing texture, indicating subvolcanic origin for the amphibolite by this work. A strong zoning structure is determined in plagioclase (An 48 and An94) of the amphibolites by SEM studies. The andesine is indicated to be earlier than anorthite by existence of linear compositional variations in the amphiboles, lack of widespread metasomatic, hydrothermal alterations and migmatisation in the the amphibolites. The anorthite may be formed via breakdown of diopsite to hornblende. Coupled substitutions such as alumino-tschermakite, ferri-tschermakite and edenite had caused compositional variations in the amphiboles of amphibolites and tremolite gneisses. It has been suggested that the amphibolites and tremolite-bearing gneisses are of co-genetic as linear relations exists between their amphiboles

As multi-lane roadways have been widely used in many countries for years, analysis of two-dimensional vehicular interactions acquires special importance in highway design and operation. The simultaneous consideration of both lateral and longitudinal movements of traffic flow becomes vital in many aspects of traffic engineering, like modelling. The former component was reviewed elsewhere. In this paper, previous work on longitudinal characteristics of multi-lane traffic flow is scrutinised. Non-existence of such a review in recent literature was the main motive of the work, and it is hoped that it forms a reference report for other traffic analysts. In addition, the paper underlines a number of possible areas for future research.

It has been considerably studied on the recycling of waste materials in the source besides of wastewater treatment in the last years. It has been important developments on the using of semiconductor membranes in the recycling of toxic materials such as heavy metals, intensifying the environment protection measures especially in the west countries. Wastewater treatment has been achieved with liquid membranes as it has been achieved with polymeric membrane systems such as ultrafiltration, microfiltration, electrodialysis. At the same time, liquid membranes are used for removal of metal ions in hydrometallurgy. Liquid membranes are also used in biotechnology, medical areas and gas separation process.

Memetic algorithms, which use local search techniques, are hybrid structured algorithms like genetic algorithms among evolutionary algorithms. In this study, for Quadratic Assignment Problem (QAP), a memetic structured algorithm using a local search heuristic like 2-opt is developed. Developed in the algorithm, a crossover operator that has not been used before for QAP is applied whereas, Eshelman procedure is used in order to increase thesolution variability. The developed memetic algorithm is applied on test problems taken from QAP-LIB, the results are compared with the present techniques in the literature.