In the process of meeting the growing demand for electric power and heat, coal will play an increasingly important role in the world wide. Fluidized combustion offers a clean and relatively inexpensive method for coal combustion, a method insensitive to fuel quality and capable of reducing sulfur and nitric oxides emission. At the work, a prototype fluid bed was produced and the distance between the holes had been narrower towards to the center of the distributor sieve in order to balance the distribution of the air. Later on, the quantity of the coal was decreased continuously and at the end of the measurements, the heights of the solids and the rates of the solid had been defined and the effects of the coal quantity had been investigated.

In this paper a complete design procedure for a 500W induction heating system is given. An induction heating system basically consists of a coil and a DC/AC inverter. The use of a single switch resonant inverter, which is operated with Discontinuous Conduction Mode (DCM), allows the switching device to turn off under zero current conditions, therefore switching losses are much reduced. This inverter system transforms the DC into AC for the induction heater coil. The proposed coil design method is applicable to a load of any shape so long as the coil surrounds the workpiece. The basis of this method of coil design is the reduction of the induction heater coil and workpiece to their equivalent resistance and inductance.

In this study, an orthotropic composite cantilever, which is made of T300/976 Grafit-Epoxy and Carbon-Epoxy materials subjected to a uniformly distributed load, is considered. The deflection of this cantilever is calculated by finite element method and calculated analytically. These results are compared. For finite element calculation, Ansys 50a program is used. The calculations are made for 0°, 15°, 30°, 45°, 60°, 75°, 90° of fiber directions.

High pressure turbine components are subjected to a wide variety of thermal and mechanical loading during service. In addition, the components are exposed to a highly oxidizing atmosphere which may contain contaminants such as sulphates, chlorides and sulphuorous gases along with erosive media. So the variety of surface coatings and deposition processes available for the protection of blade and vane components in gas turbines are summarised in this study. Coating types range from simple diffusion aluminides to modified aluminides and a CoCrAlY overlayer. The recommendations for corrosion-resistant coatings (for low temperature and high temperature hot corrosion environments) are as follows: silicon aluminide and platinumchromium aluminide for different gas turbine section superalloys substrates. Platinum metal additions are used to improve the properties of coatings on turbine components. Inorganic coatings based on ceramic films which contain aluminium or aluminium and silicon are very effective in engines and gas turbines. Diffusion, overlayer and thermal barrier coatings which are deposited on superalloys gas turbine components by pack cementation, plasma spraying processes and a number of chemical vapour deposition, physical vapour deposition processes (such as electron beam, sputtering, ion plating) are described. The principles underlying the development of protective coatings serve as a useful guide in the choice of coatings for other high temperature applications.

The improvements of adaptive control and computer aided manufacturing need to be sensitively determined tool wear rate during machining. Reserarchers working on this topic have developed direct and indirect methods. To determine tool wear rate during machining by measuring of cutting temperature is an indirect method. In this study, two measuring techniques, work-tool thermocouple technique and a method that is realized by using a thermocouple assambed by embeding in the tool have been used. Both of them have been tested by obtaining tool wear using hard metal insert and turning mild steel and compared one with the other using different point of views.

In this study, a expert system has been developed using Leonardo expert system package programming for screw operation, According to DIN standard norm. The designed program decide the most suitable screw type considering to material, cutting speed, working condition etc. This program also directs to user.

This study is concerned with the imperfection and aspect-ratio sensitivity of the uniaxial strength of rectangular steel plates. To investigate the imperfection and aspect ratio sensitivity of the uniaxial strength of rectangular plates, over 90 different plate problems have been modelled and solved by using the user-element in ANSYS 5.0 which is a commercial finite element package. The user-element which is offered by ANSYS 5.0 as an extension of the element library, is used to implement subroutines written for analysing large deflection elastic-perfectlyplastic material behaviour of plates by using finite element method. The results obtained for each plate problem have been presented in figures. The maximum average strength of plates have been obtained for the different aspect ratios, the initial geometric imperfection modes and the complex initial geometric imperfections, achieved by combination of these modes. The levels of initial geometric imperfections are assumed as found in the literature. The effects of complex initial geometric imperfections and aspect ratios on plate strength for various modes have been determined. The combination of initial imperfection modes creates new geometrical imperfections and magnitudes, generally higher than previous values. These factors are shown to effect the plate by reducing its strength. The results obtained can help to design the rectangular plates and plated structures under uniaxial compression.

In this research, heating pipe was used in the solar collector in order to take better advantage of the solar energy. The energy obtained from the sun was transferred to the drying air by means of heating pipes and this hot air was blown on the material to be dried. The water on the material to be dried vaporised with the effect of the hot air and drying took place. Because drying took place in the shade, distant from the direct radiation effects of the sun, some of the disadvantages seen in drying outside, under the sun were eliminated. Additionally, it was observed that it took less time to dry in this method than it takes to dry under the open sun.

Cellular Automata (CA) are simple mathematical systems which provide models for a variety of physical processes. They show how minute changes and simple rules lead to enormous changes in the behaviour of a system. They can also be used as computer graphics tools to produce a rich reservoir of interesting figures. In recent years, CA have attracked the attention of many scientists. Today, CA are used in many fields from ecology to image processing. In this paper, it is shown that a large number of complex and interesting patterns can be created with relatively simple CA rules.

In this study, the determination of lateral earth pressures of soils or Ko parameter is considered. For this effect, the deformation and the variations in the shear stresses of the soils placed in an oedometer set up were investigated. Based on this data, a general method which can be used in the calculation of lateral pressures of soils has been proposed. The study was carried out on a cohesive soil having two different group symbol and sandy soils with different relative densities. The lateral pressure values measured by thin wall oedometer technique are in very good agreement with those obtained by calculation. In conclusion, lateral earth pressures or the Ko values are depend upon the distribution of the samples, their relative density and consistancy, the magnitude of the pre-consolidation pressure. The proposed method is a simple and economic technique as regards to the approximation and experimentation.

Freezing is one of the excellent methods for the preservation of foods. If freezing and thawing processes and frozen storage method are carried out correctly, the original characteristics of the foods can remain almost unchanged over an extended periods of time. It is very important to determine the freezing and thawing time period of the foods, as they strongly influence the both quality of food material and process productivity and the economy. For developing a simple and effectively usable mathematical model, less amount of process parameters and physical properties should be enrolled in calculations. But it is a difficult to have all of these in one prediction method. For this reason, various freezing and thawing time prediction methods were proposed in literature and research studies have been going on.

In this study, a simple genetic algorithm for optimising structural systems with discrete design variables are used for the optimum design of plane trusses. Displacement, stress and stability constraints are considered. A computer programme is developed and coded in FORTRAN language for the purpose. Algorithm presented is used to obtain the optimum designs of the different practically employed roof trusses. Finally an optimum geometry design is performed to find out the optimum roof slope by trial and error.

The objective of our study was to determine soil urease and ß-Glucosidase enzyme activities in soil samples taken from three different depths (0-5 cm, 5-15 cm and 15-30 cm) and under different type of vegetation (apple, pine, clover, wheat and followed land). Highest activities, both urease and ß- Glucosidase were determined in soil samples representing parcels planted with clover. Enzyme activity showed increase in parcels which have high level of organic matter and total nitrogen. Urease enzyme activity was found higher than ß -Glucosidase activity in all samples. As the soil deepens, significant increase was monitored in urease activity (P<0.01), whereas, decrease was recorded in ß-Glucosidase activity. We conclude that urease and ß -Glucosidase activities were significantly effected by vegetation types and soil depth.

A finite Markov chain is presented by a P probability matrix, and it is represented by a connected, directed and weighted graph. When the state space of Markov chain is of large dimension, this space is divided into subspaces those have roughly same number states. The main solution is founded from the solutions in these subspaces. It is known that parallel computation in computer sciences. It is important to fýnd a procedure which gives that operation which mentioned above. In this work, a finite Markov chain is considered a probabilistic graph and it is partitioned to its subspaces by using the knowledges of collapsible graphs. An algorithm of the procedure is given.

This study has designed for determination of static bending strenght of mainly boron impregnated scots pine and east beech wood. Other chemicals used as control are polyethylene glycole (PEG-400) and some commercial preservatives such as Vacsol (V), Ammonýum sulphate (AS) and Diammonium phospate (DAP) were used by secondary process on the boron or PEG treated wood by the aim of improving static bending strenght and avoiding the leachability of both chemicals. Result indicated that static bending strenght of scots pine wood were reduced by acidic solutions of salts. In beech wood static bending strenght were also affected by neutral pH of the solution. Water repellent , surprisingly don’t show their aspected protective properties of static bending strength, in general .

Co-treatment of an industrial wastewater containing dyestuff was studied with a domestic wastewater by the activated-sludge method was investigated. Treatment efficiency was obtained by determining. BOD, COD and total suspended solids values.

At present more than 90 per cent of the world’s alumina is produced by the Bayer process, a simple technology providing high purity final product. A part from some exceptional local conditions, bauxite is processed almost solely by this technology. As a benefication process, alumina production releases the aluminum oxide content of bauxite from other accompanying oxides thus providing alumina suitable for electrolysis in a cryolite melt. The basic theory of the Bayer process was elaborated by K.J. Bayer and described in his patents in 1887 and 1892. The first patent refers to the aid of seed crystals of aluminum hydroxide or of carbonic acid, that is, to the precipitation and carbonation processes. The second patent formulates the concept that the aluminum oxide content of bauxites can be dissolved in sodium hydroxide solutions, with the formulation of sodium aluminate, a process called digestion nowadays. The most important operations of the Bayer technology are bauxite preparation, crushing, grinding, digestion, red mud separation, thickening, washing, filtration, precipitation, calcination and evaporation. In spite of its great significance as regards the complete Bayer technology, the structure of sodium aluminate solutions has not been cleared up definitely yet. Boehmite is the most important aluminum mineral of karstic bauxites. Some experimental results showing the various effects on aluminum hydroxides by alkali process from boehmitic bauxites and the factors gowerning the digestion operation of aluminate solutions were investigated.

Metamorphics of Paleozoýc, ophiolitics of Upper Cretaceous and continental sediments and volcanics of Tertýary-Quaternary are out cropped in the investigated area. The most common rock unit is Upper Miocene Pliocene aged Karakurt volcanics which is of basaltic lawa and tuff. The most important geomorphological unit in the area is the cornice of Aras valley in E - W direction and high landforms around it. Aras river is developed its bed by cutting basaltic and tuffaceous volcanics placed horizontally. Structure plateau and conical shaped volcanic hills are located at N - NW of valley. Strike-slip faults in E - W direction (Horasan Fault Zone) control the forming of the Aras river. The volcanism which started at Late Miocene and finished at Quaternary is alcali and calcalkali in character. This volcanic activity has cansed some higt major lanforms like Süphandað, Kesedað and Aladað. Volcanism also played major role to form recent land forms and river net.

Kalite mukayeseli makine seçimi, 1991 yýlýnda Cokorilo ve Milic tarafýndan geliþtirilmiþ makinelerin oranlamasýna dayalý bir tekniktir. Metodun mantýðý, makinenin teknik özelliklerini içeren matris, kuramsal makinelerin özelliklerini içeren parametre matrisi ve atama matrisi olarak bilinen üç matris model üzerine kuruludur. Ancak bu modeli ilk geliþtiren araþtýrmacýlar kurumsal parametre matrisindeki belirsizlikleri dikkate almayý ihmal etmiþlerdir. Bundan dolayý bu makalede söz konusu matristeki belirsizliði dikkate almak ve tekrar düzenlenmek amacýyla, bulanýk üçgensel sayýlar yaklaþýmýnýn kullanýmý araþtýrýlmýþ ve tekniðin hidrolik kazýcý makinesi seçiminde bir de nümerik uygulamasý yapýlmýþtýr. Neticede elde edilen sonuçlar bulanýk sayýlar yaklaþýmýnýn son derece etkili bir yaklaþým olduðunu ortaya koymuþtur.

For explaining the situation arising from spontaneous combustion, there is a necessity for quick and accurate analysis of the gaseous products of combustion. It is also very important to interpret these data correctly. This interpretation provides information prominence to mine rescue crew and the mine management concerning the withdrawal or continuity of rescue team in a rescue and recovery operation before an explosion takes place. Additionally, it is also of utmost importance to see whether the fire combating techniques are effective or the fire is under control ensuring the security of workers and equipment during and after the sealing works. Therefore, the indices related with spontaneous combustion which are still commonly in use are summarised in this work.