A versatile and reconfigurable microassembly workstation

In this paper, a versatile and reconfigurable microassembly workstation designed and realized as a research tool for investigation of the problems in microassembly and micromanipulation processes and recent developments on mechanical and control structure of the system with respect to the previous workstation are presented. These developments include: (i) addition of a manipulator system to realize more complicated assembly and manipulation tasks, (ii) addition of extra DOF for the vision system and sample holder stages in order to make the system more versatile (iii) a new optical microscope as the vision system in order to visualize the microworld and determine the position and orientation of micro components to be assembled or manipulated, (iv) a modular control system hardware which allows handling more DOF. In addition several experiments using the workstation are presented in different modes of operation like tele-operated, semiautomated and fully automated by means of visual based schemes

Textile Materials in Liquid Filtration Practices: Current Status and Perspectives in Water and Wastewater Treatment

Filtration is considered the keystone of water and wastewater treatment and is used for various purposes, such as sludge dewatering and concentrating any solution. Moreover, as an advanced filtration technology, membranes can remove materials ranging from large visible particles to molecular and ionic chemical species. Proper selection of filter media/membrane material in filtration processes is often the most important consideration for assuring efficient separation. Filter media can be classified by their materials of construction, such as cotton, wool, linen, glass fiber, porous carbon, metals, and rayons. Recently, new polymeric materials have been used both individually and/or blended in filtration processes for the treatment of waters and wastewaters. The purpose of this chapter is to bring an overview on the textile-originated filter materials in filtration applications from conventional filtration to advanced membrane processes. Although many researches on filter media are available, very few researches have been carried out on the cutting-edge technologies about using filter materials on filtration processes from classical to advanced membrane processes. Therefore, in this part of the book, following major and minor titles are stated truly on the aforementioned new technologies and linked with conventional methods in water and wastewater treatment applications

A Review of State-of-the-Art Technologies in Dye-Containing Wastewater Treatment – The Textile Industry Case

Recently, new single or hybrid/combined processes have attracted much attention for treatment of textile and dyeing wastewaters. These processes which may be termed as “state of the art technologies” are membrane separation processes, ultrasonic, photochemical and electrochemical processes. Although the conventional methods still have been tried with some new materials such as, new adsorbents or coagulants, employing the new generation methods such as, electrocagulation-electrooxidation, sonooxidation or photo oxidation are gaining in popularity when the treatment of textile wastewaters is discussed. The purpose of the book chapter is to bring an overview on the new treatment methods for textile wastewaters, one of the most important source of environmental pollution. Despite the fact that there is no uniform standard currently, many countries have legalized some strict discharging standards and scientists and researchers face new technologies including electrical, sonic, magnetic, optical and thermal methods. Although many researches on treatment of synthetic or real wastewaters with various methods are available, very few researches have been carried out on the cutting-edge technologies. Moreover, there are a lot of review article or book chapters on textile wastewater treatment processes individually based on each conventional process such as coagulation, adsorption, chemical oxidation, and biological decolorization. Therefore, in this part of the book, following major and minor titles are stated truly on the aforementioned new technologies. Besides, these parts are not only about cutting-edge technologies, but also related with conventional methods and their new applications in colored wastewater treatment area briefly

Response surface modeling of a small crossflow hydro turbine rotor

This paper presents the progress made in works aiming to design a modular low cost cross-flow turbine runner that is compatible with mass production. In an earlier study, stress and weight optimization analyses had been presented for a common runner design. This work includes analyses on segmented modular runner design iteration. Obtaining a closed form analytical formulation for complex mechanical structures such as turbine rotors with multiple blade assemblies can be very problematic. Building a prototype without optimizing the structural stress levels may result in unnecessary hardware costs. In this work, mathematical models for highest stress or lowest factor of safety on critical components of a small modular cross-flow hydro turbine rotor have been explored for various design options through a response surface analysis. The response surface model is obtained based on finite element analysis results following design of simulated experiments. Rotor design parameters have been investigated to optimize factor of safety on critical components without violating the specified weight limits. Box-Behnken data tables have been used to obtain the response surface model. The attained response model yields the maximum stress and lowest factor of safety for critical rotor components for various combinations of design parameters. Verification runs indicate that response model successfully predicts factor of safety levels close to finite element calculations

Forward Osmosis Membranes – A Review: Part II

Forward osmosis (FO) is a technical term describing the natural phenomenon of osmosis: the transport of water molecules across a semipermeable membrane by osmotic pressure from a feed solution (FS) to a draw solution (DS). The diluted DS is then reconcentrated to recycle the draw solutes as well as to produce purified water. As the driving force is only the osmotic pressure difference between two solutions, meaning that there is no need to apply an external energy, this results in low fouling propensity of membrane and minimization of irreversible cake forming, which are the main problems controverted by membrane applications, especially in biological treatment systems (e.g., FO membrane bioreactor (FO-MBR)). The purpose of the book chapter is to bring an overview on the FO membrane manufacturing, characterizing and application area at laboratory or full scales. This book chapter is published in two parts. In the second part, which appears here, characterization of mass transport in FO membranes, fouling mechanisms and foulants on FO membranes in naturally asymmetric structure and application areas of FO membranes in the literature are mentioned. Cutting-edge technologies on FO studies are comprehensively reviewed and following major and minor titles are stated truly on the new technologies

Çok Yönlü ve Tekrar Yapılandırılabilir Mikro Montaj İş İstasyonu

Bu makalede, mikro montaj ve mikro manipülasyon süreçlerindeki sorunların incelenmesi amacıyla bir araştırma aracı olarak tasarlanan ve geliştirilen çok yönlü ve tekrar yapılandırılabilir mikro montaj iş istasyonu ve yine aynı grup tarafından geliştirilen bir önceki sistem üzerinde mekanik ve denetim yapıları açısından yapılan geliştirmeler sunulmaktadır. Bu geliştirmeler; (i) daha karmaşık montaj ve manipülasyon işlemlerinin gerçekleştirilebilmesi için ek bir manipülatör modülünün eklenmesi, (ii) sistemi daha yetenekli kılabilmek için görü sistemi ve numune taşıyıcı platformlarına ek hareket serbestlik derecesi eklenmesi (iii) mikro dünyanın görüntülenmesi ve montajı yapılacak veya manipüle edilecek parçaların konum ve yönelimlerinin belirlenebilmesi amacıyla görü sistemi olarak yeni bir optik mikroskobun eklenmesi (iv) daha fazla serbestlik derecesinin denetimini sağlayabilmek amacıyla varolan sistemin daha modüler bir denetim sistemi donanımı ile değiştirilmesi gibi unsurları içermektedir. Ayrıca sistemde kumandalı, yarı otomatik ve görü bazlı yöntemler aracılığı ile tamamen otomatik çalışma modlarında yapılan deney sonuçları da sunulmaktadır