• RULE-BASED MAMDANI-TYPE FUZZY MODELING OF PERFORMANCE OF HYDROXY (HHO) DRY CELL WITH 12×12 PLATE COMBINATION

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 9, pg(s) 378-381

    The fossil fuels and the natural gas reserves that have undertaken the role of the locomotive of the industrial period are limited. It is also the biggest factor in environmental problems. All these reasons lead to the need for alternative fuels or resources. Hydrogen is the candidate to be one of these alternatives; is an unlimited clean and efficient fuel. Hydrogen may assume the role of carrier in the process of storage of other alternative energy sources. Today, interest in hydrogen energy is increasing. One of the reasons for this is that hydrogen can be produced from renewable energy sources such as water, biomass, wind and sun as well as hydrogen from primary energy sources. There is no polluting gas emissions when hydrogen is used as fuel. The HHO dry cell is a device that converts water into HHO (oxyhydrogen) gas. In this study, performance of HHO dry cell with 12×12 plate combination was experimentally investigated and modeled with a Rule-Based Mamdani-Type Fuzzy (RBMTF) modeling technique. Input parameters are; plate number, time, current; output parameter is mass flow rate. The coefficient of multiple determination (R2=98.5) for the mass flow rate. RBMTF results indicated that RBMTF can be successfully used in HHO dry cell with 12×12 plate combination.

  • INVESTIGATION OF ELECTRICAL CONDUCTIVITY AND HYDROPHOBIC/HYDROPHILIC INTERACTION OF PAN + PMMA COMPOSITE NANOFIBERS WITH AG NANOWIRE PRODUCED BY ELECTROSPINNING METHOD

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 8, pg(s) 329-332

    In this study, the electrical conductivities and hydrophobic/hydrophilic properties of Polyacrylonitrile (PAN) + Polymethyl methacrylate (PMMA) composite nanofibers reinforced with nanowires were be investigated. The nanofibers are produced by the electrospin method. Their electrical conductivities and their hydrophobic/ hydrophilic properties were examined. The maximum the electrical conductivity value is 0.00298 S/cm at PAN + PMMA composite nanofibers with Ag nanowires (5 wt. %). The the biggest static contact angle occurred in PAN+PMMA composite nanofibers with 1 wt. % Ag nanowire. The static contact angles of all PAN + PMMA composite nanofibers with Ag nanowire were found to be bigger than those of PAN + PMMA composite nanofibers.

  • INVESTIGATION OF THE EFFECT OF DIAMETERS OF POLYACRYLONITRILE NANO FIBER WITH CARBON NANOTUBE ON MECHANICAL PROPERTIES

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 7, pg(s) 298-301

    In this study, pure polyacrylonitrile (PAN) nano fiber (8 wt. %) and PAN nano fiber with multi-walled carbon nanotubes (MWCNT) were prepared. The content of MWCNT was (1, 3 and 5 wt.%). Electrospin device was used in nanofiber production. Nano diameters of the produced nanofibers were examined by Scanning electron microscopy (SEM). The nanofiber samples were cut 0.5 cm wide and 2 cm long. These samples were subjected to a tensile test on the Shimadzu device. The effect of nanofiber diameters on mechanical properties was investigated. All the MWCNT based composite nanofibers presented larger diameters than those of pure PAN nanofibers. The maximum stress value (76.60 kN) was found to be at PAN nanofiber with 1% MWCNT (average nano fiber diameter is 369.45 nm).

  • INVESTIGATION OF THE EFFECT OF PRODUCTION PARAMETERS ON POLYSTYRENE NANO FIBER FORMATION FOR 12 WT %, 14 WT % AND 16 WT %

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 6, pg(s) 262-265

    Polystyrene (PS) is a versatile plastic used to produce a wide variety of consumer products. It is used as a hard, solid plastic, mostly as food packaging and laboratory products. When polystyrene is mixed with various colorants, additives or other plastic materials, it is used to make electronic parts, automobile parts, toys, pots and equipments and more. Polystyrene is a vinyl polymer. It is structurally a long hydrocarbon chain with a phenyl group attached to the carbon atom. Polystyrene is produced by free radical vinyl polymerization from monomer styrene. In this study, the effect of production parameters on the formation of PS nanofibers was investigated. For this purpose, solutions were prepared at various mixing ratios (12 wt %, 14 wt % and 16 wt %) consisting of PS + dimethylformamide (DMF). The nanofiber structure was determined from these solutions. Electrospin method was used in production of nanofibers.

  • TECHNOLOGIES

    EXPERIMENTAL INVESTIGATION AND FUZZY LOGIC MODELING OF 8X8 CM2 MEMBRANE PERFORMANCE OF MICROBIAL FUEL CELL

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 8, pg(s) 404-406

    In this study, microbial fuel cell’s energy conversion performance experimentally investigated from the chemical energy of the organic waste to electrical energy by means of microorganisms. Microbial fuel cell (MFC) consists of two cells which has 15x15x15 cm3 volume. One part of the cell conserves the mud (anode) the other part conserves the water (cathode). The membrane of the microbial fuel cell has 8×8 cm2 area. Two different samples were used in the experiments which are active and settlement mud. The power, volt and current values of the active and settlement mud for different temperature, resistance and bubble were determined. The temperature values consist of ΔT = 8°C, ΔT = 10°C, ΔT = 12°C, ΔT = 14°C. ΔT=Tenvironment- Tmud. For every ΔT value 2 different bubble values were examined (High=21,5 g/h, low=3,5 g/h). For every bubble effect 7 different resistance values were determined (1. Resistance= 3,75 Ω; 2. Resistance =7,5 Ω; 3. Resistance =10,5; 4. Resistance = 14,5 Ω; 5. Resistance = 16 Ω; 6. Resistance = 19 Ω; 7. Resistance = 21,5 Ω) and the performance of the 8×8 cm2 membrane of the MFC is detected. As a result; with the increase of the temperature, resistance and bubble effect the voltage production increases and correspondingly the current decreases. When all the experimental results are evaluated,the highest voltage production (687 mV) occurred at ΔT = 14°C and 21,5 Ω with the high bubble effect in the settlement mud. Also, in this study, MFCs performances in terms of voltage, current, temperature, power was modeled with Rule-Based Mamdani-Type Fuzzy (RBMTF) modeling technique. Input parameters ΔT and time; output parameter power was described by RBMTF if-the rules. 1792 experimental data sets, which obtained for power according to ΔT and time, were used in the training step. The comparison between experimental data and RBMTF is done by using coefficient of multiple determination (R2). The actual values and RBMTF results indicated that RBMTF can be successfully used in MFC.

  • TECHNOLOGIES

    THE EXPERIMENTAL DETERMINATION OF L/D RATIO USING WATER IN MINI CHANNELS TO ANALYSIS OF FLUID TEMPERATURE PERFORMANCE WITH NANO PARTICULATES

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 7, pg(s) 353-355

    Nano fluids is advantageous with high thermodynamic properties compared to pure fluids. In the last half century, rapid developments in production technology, which allows high-precision production of the micro heat exchangers and the use of the micro heat exchangers in different areas. These developments point researchers to enhance new methods in improving the heat transfer. One of these methods is; to improve fluid’s heat transfer by adding different particulates to the fluid. The nano fluids are the new type of heat transfer fluids that are made by adding nano particulates which has high thermal conductivity to a conventional fluid. Since the solid metal has a higher thermal conductivity than the basis fluid, the addition of the metallic particulates to the fluid increases the heat transfer of the mixture. In this study, for analyzing the temperature performance of fluids with Nano particulates; an experimental study was performed using water to determine the optimum mini channel length and mini channel diameter. Performance parameters are; channel length, tube mini channel diameter, the flow and the inlet temperature. According to the experimental results, the maximum temperature performance of the mini channel was found to be at L/D=250/3 (at Selcuk University condition). Therefore, with these results, the optimum mini channel length and mini channel diameter are determined for the high efficiency that is to be achieved by using nano fluids