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Copyright of Duzce University Journal of Science & Technology is the property of Duzce University Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The process, which is defined as ultrasonic treatment or cavitation, ensures that the dirt is removed from the surfaces without damaging the fabric surface. There are studies on the ultrasonic washing processes of denim fabrics in the literature, but there is no study on the effect of the cavitation process on the thermal comfort of denim fabrics. For this purpose, denim fabrics were treated at three different times, 15, 30, and 45 minutes, and at two different frequencies 8khz and 16khz in the ultrasonic homogenizer test device. It was observed that the applied cavitation process reduces the air permeability, thermal conductivity, and thermal absorptivity values. On the other hand, the cavitation process increased the water vapour permeability value by cleaning the materials such as dirt and oil on the surface. It can be concluded that the applied cavitation process provides comfort by enabling quick throwing of the sweat to the outer surface, provides less heat conduction from the fabric, and the denim fabric felt warmer after the cavitation process.

The thermal diffusivity value of a building wall can be calculated theoretically by using the thermophysical properties of its materials listed in standards and literature. In these lists, building materials in the same category can be defined by different thermal properties; therefore, the theoretically-calculated thermal diffusivity values can be misleading. In this study, an experimental setup was developed that can directly measure the thermal diffusivity (α, m2 /s) value of building walls by the combined use of infrared thermography and guarded hot box methods. A 19cm-thick wall sample made of lightweight concrete block with pumice aggregate and mortar was prepared; this wall is positioned between a controlled warm ambient on its one side and a cold ambient on the other side, where its surfaces were monitored by sequential IR imaging. The thermal diffusivity value of the sample wall was calculated by using the data showing temperature change versus time and the relevant theoretical equation. The reference thermal diffusivity value (αREF) of the sample wall, calculated by using thermal properties measured by standard laboratory tests, is 3.40x10-7 m²/s. The thermal diffusivity (αIRT) of the same wall, measured with the proposed IRT-GHB experimental setup, is 3.38x10-7 m²/s. The value measured with that new setup is similar to the reference thermal diffusivity value. The results show that the new experimental setup can directly measure the thermal diffusivity of a wall. Compared to the existing ones, the proposed experimental setup presents a measurement technique that saves time and sets the basis of a scientific, practical, and more economical analytical method. [ABSTRACT FROM AUTHOR]

This study aims to investigate the thermal properties of the phase transformation that may occur with the effect of temperature in Cu-14.70wt.%Al-4.72wt.%Ni shape memory alloy. The sample was annealed at 1203 K for 30 min in an argon atmosphere and then cooled rapidly in salt-ice water. By using Differential Scanning Calorimetry (DSC), the martensitic phase transformation parameters of the sample were found. The activation energy required for these transformations was calculated using the Kissinger, Augis-Bennett, and Takhor methods. Thermogravimetric Analysis (TGA) measurements investigated the mass changes that may occur with the effect of temperature. Surface morphology was analyzed using an optical micrograph.

Biodegradable products are considered as an important solution in reducing the waste generated by the use of synthetic polymers. Thermoplastic starch (TPS) stands out with its success and low cost in the preparation of biodegradable products. In order to improve the low mechanical and physical properties of biodegradable polymeric products, morphology in co-continuous form was chosen as the target of our study as a promising solution. For this purpose, thermoplastic starch samples were prepared by melt processing method using starch and various plasticizers. TPS samples were examined from the perspective of morphological, rheological and thermal properties. Based on the obtained results, suitable TPS was determined that will allow obtaining the co-continuous morphology in the polymer blends to be prepared with polyethylene (PE). Polymer blends were prepared by melt processing method so that the selected TPS sample and PE were in different compositions. TPS/PE polymer blends were examined in terms of mechanical, rheological, morphological and thermal properties, and the most appropriate methods and parameters were determined for the preparation of samples with high TPS composition and co-continuous phase morphology. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Traditional fireplaces (ocaks), which have been commonly utilized in Anatolian historical buildings, possess functional values in addition to their aesthetic significance. Specifying the thermal properties of these elements is an evaluation field, which assists in determining the extent of the interventions that are undertaken to sustain the thermal comfort for contemporary reuse of historical houses. The aim of this study is to determine the potential of traditional ocaks to meet the thermal needs depending on contemporary utilization scenarios. The studied building type is open-hall (sofa) historical houses. The method of the study consists of collecting annual on-site thermal readings on two cases from rural and urban settlements, determining the thermophysical properties of construction materials used in these buildings and modeling the buildings on DesignBuilder v5.4.0.21 software for conducting their transient thermal analyses after calibrating the models. The changing values of spatial heating energy rate demands were calculated by analyses, were compared to the maximum heating powers of the ocaks in the chosen case buildings and the demand fulfillment rate of the ocaks were calculated. The presented analysis stages aim to contribute to the methodology of heating system evaluations for historical houses. As a result of this study, it was determined that two of the three ocaks in urban case are highly satisfactory for their corresponding spaces however one lacks this high-level of sufficiency, and all analyzed ocaks in rural case have adequate heating levels. Thus, data were generated to determine the scope of possible heating arrangements to be designed in the examined buildings. [ABSTRACT FROM AUTHOR]

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Artvin Çoruh Üniversitesi Orman Fakültesi Dergisi is the property of Artvin Coruh University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, different ratios of SiC reinforced Al4.5Cu alloy matrix composites were produced by mechanical alloying method at different grinding times. The effect of reinforcement amount and grinding time on thermal and structural properties of the composite was investigated. The microstructure properties of the composites were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their thermal behavior was investigated by differential thermal analysis (DTA). The produced powder composites were subjected to sintering process after pressing. Surface analyzes of the sintered samples were examined by optical microscope, and surface hardness was also measured. XRD and SEM results showed that as the grinding time increased, the grain size decreased and a more homogeneous structure was formed. According to DTA results, a series of endothermic peaks indicating phase transformation were observed in the temperature range 550-650 C during continuous heating. The results of the optical microscope were found to be in agreement with the SEM analysis, and also the surface hardness increased as the amount of reinforcement and grinding time increased.

Bimetallic or layered materials are an important group of advanced engineering materials, which are the materials where the physical, mechanical and thermal properties of the core particle can be improved. Therefore, in this study, the fabrication of silver-plated copper bimetallic particles was investigated by electroless coating method. Moreover, in this study, the effect of the amount of ion trapping / reducing agent in the electroless coating method on the physical properties of the bimetallic particles obtained as a result of the coating was investigated. Morphology, microstructure and silver layer thickness of the silver coated copper particles were characterized by scanning electron microscope (SEM) and Xray diffraction. SEM investigations revealed the presence of a silver coating layer on copper particles in the range of 0.873 - 2.3 μm. This result showed that the silver coating layer can be successfully synthesized on copper particles by using the electroless coating method. Thus, low cost of copper and high thermal conductivity and oxidation resistance of silver are combined in a single metal particle. [ABSTRACT FROM AUTHOR]

The radiative in the UV and visible spectra and the conductivity properties at low temperatures of hematite (α-Fe2O3) samples of different particle size distributions and compositions obtained by the pressure welding procedure within temperatures of 900-1100°C were investigated. In this study, the two samples which have different chemical properties were called as Case 1 and Case 2. Debris iron oxides samples, which are in the morphology of hematite, were separated according to particle sizes by sieve analysis. The absorbancewavelength change and the thermal conductivity-temperature change of the samples of, the smallest, medium and largest of which the particle size were analysed. The coating on particles due to the aging effect was examined using scanning electron microscopy (SEM) images. It has been concluded that the content and size of the particles and the oxidation effect are effective in the variation of the radiation properties of the samples with the wavelength and the temperature of the thermal conductivity coefficient. Radiative and thermal transfer properties of debris hematite particles increase as the particle size increases. However, the radiative property decreases with increasing wavelength and the thermal conductivity property decreases with increasing temperature. [ABSTRACT FROM AUTHOR]

Colemanite mineral (C-3 mm) and milled colemanite minerals (C-75 μm and C-45 μm powders) were obtained from Eti Maden Bigadic Boron Operation Directorate. The C-3 mm initial material was milled in a high-energy ball mill. This material was then sifted using a sieve with a size of 25 μm according to the ASTM standard (C-25 μm) for the purpose of producing submicron-sized/nano-sized particles. Thermal properties of the C-3 mm mineral, C-75 μm powder, C-45 μm powder and C-25 μm powder were examined using ThermoGravimetry (TG)/Differential Thermal Analysis (DTA) device. In DTA measurement, first decomposition temperature appeared with a high intensity endothermic peak at 406°C for the C-3 mm mineral and existed with an endothermic peak at 388°C for the C-25 μm powder. In Differential TG measurement, the first decomposition temperature seemed with a high intensity-narrow endothermic peak at 403°C for the C-3 mm mineral and occurred with an endothermic peak at 388°C for the C-25 μm powder. In a previous study, the C-75 μm, C- 45 μm and C-25 μm powders have been added to Portland cement concrete at varying ratios. Based on the results obtained, it was noted that the compressive strength of concrete increases significantly. Such findings are thought to shed light on engineering research related to nano-sized boron minerals. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Textiles & Engineers / Tekstil ve Mühendis is the property of Union of Chambers of Turkish Engineers & Architects, Chamber of Textile Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Natural fiber filled/reinforced composite materials are heavily studied in the academy and industry. Lignin is both a natural filling material and a side product of cellulosic bioethanol and paper industries. Lignin has been used as a filling/reinforcing material for twenty years in order to create value-added products. In this study, 10 % wt. soda lignin reinforced polypropylene composites with and without coupling agents was produced by using twin-screw extruder in order to investigate the effect of coupling agent type and the effect of coupling agent content (0.1 %, 0.3 %, and 0.5 % wt.). Mechanical, thermal and morphological properties of the composites were investigated. The results showed that the optimum amount of coupling agents in composites was 0.3% for the best interaction with lignin and polymer. According to TGA analysis, it can be concluded that lignin filled composite is more stable compared to neat copolymer.

In recent years, polymer matrix nanocomposites production and usage ratio is increased and therwithal the applicability of these composites to other areas has also improved significantly. Textile industry is one of these areas. With the used of polymer matrix nanocomposites in textile applications, it become possible to produced improved products with high strength, functional, antibacterial and good mechanical properties. Textile recycling yarns get popular day by day. Lots of textile company producing recycled PET fiber yarns and this is contributed to the environment. In this study recycled PET polymer was used as a matrix and enriched nanoparticles to investigate mechanic, microstructure and thermal properties. Melting method was used for producing of nanocomposite multifilament yarns. Filament thickness was 120 nm and TiO2, ZnO and CNT was used as a reinforcement to ratio %0.1, %0.3, %0.5 respectively. After analysis and experiments, it was seen clearly reinforcements was affected positively the mechnanical, microstructure and thermal properties of r-PET nanocomposites. According to the result of tensile strength tests, it was seen that CNT reinforcement increased tensile strength of r-PET polymer about %15. [ABSTRACT FROM AUTHOR]

İnsan teni ile temas eden tekstil ürünlerinin tercihinde konfor önemli bir parametredir. Konforu belirleyen en önemli parametrelerden biri de tekstil ürününün elyaf içeriğidir. Luxicool elyafı göreceli yeni bir hammadde olup, polimer yapısı sayesinde mükemmel nem ve ısı transferi sağlayarak üstün konfor hissi verdiği üretici firma tarafından iddia edilmektedir. Bu çalışmada luxicool elyafı bandaj üretiminde ve örme kumaşta kullanılarak konfora yaptığı etki objektif ve subjektif olarak test edilmiştir. Bandaj üreticisi bir firmada PA 6 ve PU iplikler ile üretilen standart ürünün yanında PET/luxicool karışımı iplikler de kullanılarak yeni bandaj üretimi gerçekleştirilmiştir. Ayrıca örme makinelerinde PA 6/luxicool, PA 6.6/luxicool, PET/luxicool, PET/PET ve PA 6.6/PA 6.6 katlı iplikler ile kumaşlar örülmüştür. Bandaj ve kumaşlara patlama mukavemeti, boncuklanma, ısıl özellikler (ısıl iletkenlik, ısıl direnç, ısıl soğurganlık), kalınlık, su buharı geçirgenliği, hava geçirgenliği ve dinamik sürtünme katsayısı testleri yapılmıştır. Aynı zamanda bandajlar yoğun fiziksel aktivite yapan kişilere kullandırılarak genel konfor, yumuşaklık, kuruluk, serinlik parametreleri anketler ile karşılaştırılmıştır. Sonuç olarak; luxicool elyafı içeren numunede diğer numuneye göre hava geçirgenliği, su buharı geçirgenliği, ısıl iletkenlik, ısıl soğurganlık değerleri daha yüksektir. Luxicool elyafı içermeyen numunede ise su buharı direnci, ısıl direnç, dinamik sürtünme katsayısı, kalınlık değerleri daha yüksektir. Anketlere göre luxicool elyafı içeren bandajlar diğer bandajlara göre daha iyi performans göstermiştir. En anlamlı farka kuruluk parametresinde ulaşılmıştır.

In this study, the thermal properties and fire resistances of the wood plastic composites produced with waste lignocellulosic materials were investigated. For this purpose, lignocellulosic waste, high density polyethylene, (HDPE) sodium borate (borax) and boric acid was used to produce the wood-plastic composites. A twin-screw extruder was used during the production of the wood plastic composites. The produced composite granule was pressed at 175 °C hot press. The effects of boric acid and borax added to wood plastic composites were investigated with the thermal gravimetric analysis (TGA), the horizontal burning rate and the limiting oxygen index (LOI). According to the results, it was understood that as the amount of the boron compounds was increased, the burning degree (°C) of the composite material increased. Furthermore, the using of the boric acid and sodium borate in the production of the wood plastic composite decreased burning speed.

In this study, the phase transition temperatures and enthalpy changes of a novel liquid crystal synthesized from the binary complex of mesogenic 4-octyloxy benzoic acid (8OBA) and non-mesogenic adipic acid (ADA) were investigated by differential scanning calorimeter (DSC) and phase structures by polarized optical microscopy (POM). The hydrogen bonding that occurs between 8OBA and ADA was confirmed by attenuated total reflection-infrared spectroscopy (ATR-IR). In addition, the chemical structure of the 8OBA/ADA liquid crystal complex was studied by 1H-NMR study. The 1H-NMR results also showed that some chemical shifts occurred and a new liquid crystal was synthesized. According to DSC and POM results, it appears that the new liquid crystal complex synthesized exhibits liquid crystalline properties. The 8OBA/ADA binary complex shows phase transition peaks during continuous heating and cooling with DSC. The observed smectic C (SmC) phase during cooling was not observed during continuous heating. The phase transition temperature and enthalpy change values obtained during continuous heating are higher than the phase transition temperature and enthalpy change values obtained during continuous cooling, but the nematic range is lower. Also, the dependence of these values on the heating rate has been investigated. As the heating rate increased, it was seen that the phase transition temperatures increased but enthalpy values decreased. It was observed that the phase transition temperature values measured by DSC are approximately the same as the phase transition temperature values measured by POM. Phase transition activation energies for the phase transitions of the 8OBA/ADA liquid crystal complex were calculated using Kissinger, Ozawa and Takhor equations, and the values obtained indicated that the phase transition activation energies were increased relative to the phase sequence. This result shows that the phase transitions of 8OBA/ADA liquid crystal complex occur regularly during continuous heating. [ABSTRACT FROM AUTHOR]

Synthesis of related chalcone, 4-pyridinyl-3´-hydroxystyryl ketone, was carried out from the reaction of 4-acetyl pyridine and 3-hydroxybenzaldehyde in an aqueous solution of NaOH. The related methacrylate monomer was obtained from acylation of 4-pyridinyl-3´-hydroxystyryl ketone with methacryloyl chloride in the cold. The copolymer of 4-pyridinyl-3´- methacryloyloxystyryl ketone and 2-hydroxypropyl methacrylate was prepared by free radical polymerization in presence of AIBN at 70 °C. FTIR, 1H-NMR and 13C-APT spectroscopic techniques were used for structural characterization of the products. Thermal characterization of the copolymer was carried out using DSC and TGA techniques. DSC curve shows that this copolymer has a glass transition temperature of 82 °C. The TGA curve shows that decomposition given volatile product started at 210 °C and a residue of 16.4% left at 500 °C. Dielectric constant (ε´) of the copolymer decreased rapidly from 3.82 to 2.62 with increasing frequency in the range of 100-700 Hz, and after this frequency ε´ quantity remained nearly constant at a value such as 2.60. The dielectric loss (ε") decreased rapidly from 0.23 to 0.03 with increasing frequency in range of 100-1130 Hz, and after that ε" value remained nearly constant in range of 1130-5000Hz. ε´ Value of the copolymer increased only from 2.57 to 3.03 with increasing temperature from 298 K to 385 K. In the same temperature range, the ε" value increased from 0.02 to 0.20. The ac conductivity of the copolymer increases from 2.40x10-10 S/cm to 64.57x10-10 S/cm as the frequency increased from 100 Hz to 5000 Hz at room temperature. The ac conductivity increases slightly with increasing temperature, 1.36x10-9 S/cm at 298 K, and 1.69x10-9 S/cm at 385 K. [ABSTRACT FROM AUTHOR]

In this study, the monomer 2-(4-methoxyphenylamino)-2-oxoethyl methacrylate (MPAEMA) was synthesized from sodium methacrylate and 2-chloro-N-(4-methoxyphenyl) acetamide. The structure of monomer FT-IR, 1H-NMR and 13C-NMR was characterized by using spectroscopic techniques. The homopolymer and copolymers of MPAEMA with methyl methacrylate (MMA) were prepared by free radical polymerization method. The poly (MPAEMA) homopolymer and poly (MPAEMA-co-MMA) were characterized by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques, gel permeation chromatography-GPC and TGA/DTA thermal analysis methods. The copolymers of MPAEMA monomer with MMA at different ratios were synthesized by 15% conversion in the same way and series were formed. Lowconversion copolymer compositions were determined by Elemental Analysis results and characterized by FT-IR and TGA thermal analysis. The monomer reactivity ratios for copolymer systems were calculated using the linear methods Fineman Ross, Kelen Tüdos and the nonlinear method RREVM, and all results were discussed. [ABSTRACT FROM AUTHOR]

In present study, a copolymer series of a new coumarin derived monomer 3-benzoyl coumarin-7-ylmethacrylate (BKMA) monomer with methyl methacrylate (MMA) at different compositions was prepared. For this purpose, free radical polymerization method was used. Spectral characterizations were performed by FTIR and 1H-NMR techniques. Copolymer compositions were determined with 1H-NMR spectra. From DSC analysis, the glass transition temperature of copolymers was decreased from 179 oC to 165 oC when the level of BKMA ratio decreased to 23% level. In TGA analysis of poly(BKMA) homopolymer and the copolymer with 54% BKMA ratio, the initial decomposition temperatures of both polymers were recorded to be 321 oC and 311 oC, respectively. [ABSTRACT FROM AUTHOR]

Comfort is an important parameter on textile products that has interaction with skin. One of the most important parameter affecting comfort is fiber content. Luxicool fiber is relatively new material and according to its producer, it has superior comfort feeling through perfect moisture and heat transfer capabilities because of its polymer structure. In this study, contribution to comfort of luxicool fibers were tested objectively and subjectively by using in bandage production and knitted fabrics. A bandage producer company is using PA 6 and PU fibers for standard bandage production. Company produced another bandage type using PET/luxicool blended yarn with PA 6 and PU fibers for this study. Besides using doubled yarns with PA 6/luxicool, PA 6.6/luxicool, PET/luxicool, PET/PET and PA 6.6/PA 6.6 fabrics were produced on knitted machines. Bursting strength, pilling, thermal properties (thermal conductivity, thermal resistance, thermal absorptivity), thickness, water vapor permeability, air permeability and dynamic coefficient of friction tests were been made to those bandages and knitted fabrics. In addition bandages were used by people who are doing intensive physical activities. Performances of bandages were investigated by a survey considering general comfort, softness, dryness and coolness parameters. As a result; bandages containing luxicool fibers have higher values on air permeability, water vapor permeability, thermal conductivity, and thermal absorptivity but lower values on water vapor resistance, heat resistance, dynamic coefficient of friction, thickness than the other bandages. Depending on the survey, bandages containing luxicool fibers show better performance than the others. The most significant difference is found on dryness parameter. [ABSTRACT FROM AUTHOR]

In this study, the effects of HDPE (High Density Polyethylene), compatibilizer (Maleic anhydrides grafted polyethylene, PE-g-MA) and nanoclays (modified Montmorillonite) that are added to matrix material of PA6 were investigated for the thermal properties of the prepared polymeric nanocomposites. The effect of HDPE, compatibilizer and nanoclays that are added to matrix material PA6 on the thermal properties of the composites were investigated. TEM investigation has been carried out to determine the agglomeration of the nanoparticles. to determine thermal properties of the produced composites, Vicat softening temperature (VST), Heat Deflection Temperature (HDT), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) experiments were performed. The results of experiments showed that nanoclay and compatibilizer with varying ratios change the VST temperature of the polymeric nanocomposite. Also, the addition of nanoclay and compatibilizer was found to raise the melting and softening temperature of the polymeric nanocomposite, increase the loss of mass and change the enthalpy of melting. [ABSTRACT FROM AUTHOR]

Pectin is a polysaccharide that is widely used in food industry. It is a linear polymer of α(1,4) linked D-galacturonic acid units with varying degrees of methylation. In the present study, the extraction characterization and comparison of some physicochemical, structural and thermal properties of pectins from lemon, mandarin, orange and grapefruit citrus peels were determined. For the production of pectin, citrus peels were extracted in a solution of citric acid (pH 1) and extracted pectins were precipitated with ethanol. All pectins were high methoxylated while lemon and orange peel pectin had better gel strength and liquid holding capacity than the others. Orange peel pectin had higher thermal stability while lemon peel and grapefruit pectins had a more organized structure than the other pectins. [ABSTRACT FROM AUTHOR]

Copyright of Adiyaman University Journal of Science & Technology / Adıyaman Üniversitesi Fen Bilimleri Dergisi is the property of Adiyaman University, Institute of Science / Adiyaman Universitesi Fen Bilimleri Enstitusu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The X-ray molecular structure of Cu (II) complex at 293 K has been determined. The Cu (II) complex, has been prepared and structurally and thermal characterized. The complex crystallizes in monoclinic space group P21/n with a= 12.407(14), b= 8.4476(9), c= 20.0286(12) Å, β= 97.291(7)°. The thermal behavior of the compound was investigated by differential thermal analysis and thermogravimetry. Additionally, Schiff base ligand also characterized by elemental analysis, IR, UV-vis spectroscopy, thermal analysis, ¹H-NMR and 13C-NMR. [ABSTRACT FROM AUTHOR]

The activity of PolyHema-Silico tungstic acid (PH-STA) catalysts were investigated for vapor phase ETBE production conducted between 353-373K with isobutene/ethanol (IB/EtOH) molar ratio of 0.17. IB conversions to ETBE were found to be close to the equilibrium value with these synthesized catalysts. Activity test of PH- STA (25/75 v/v HEMA EGDMA) at 373K revealed a conversion value of 0.17 which was higher than that obtained in the presence of pure STA in our previous study. Comparison of the activity with pure STA revealed an improvement in the activity of PH-STA even though the active material in catalyst had been 8% (w/w). Catalyst stability was tested by repeated experiments conducted in the presence of PH-STA catalysts treated with ethanol. TGA analysis revealed changes in the molecular structure of synthesized catalysts with a change in temperature. Glass transition temperature (Tg) of polyHEMA was determined as 136 °C by DSC analysis. FTIR and XPS analyses of polyHEMA and polyHEMA based STA catalysts revealed formation of polymeric structure in addition to STA. Acidic nature of the synthesized catalysts were determined by DRIFTS analysis. [ABSTRACT FROM AUTHOR]

This study investigates the experimental performance of an automotive air conditioning (AAC) system using an orifice tube as an expansion device for fixed and variable capacity compressors (FCC and VCC). An experimental AAC system using R134a as refrigerant has been set up in the laboratory, and instrumented. The system has been operated with FCC and VCC, and tested by varying the compressor speed as well as the temperatures of the air streams entering the condenser and evaporator. By applying energy analysis to the experimental system, its performance parameters have been evaluated for both compressor cases, and presented in comparative graphics. The experimental results show that the cooling capacity and the exergy destruction in the system usually increase with the compressor speed, while the coefficient of performance (COP) decreases with it. The cooling capacity and COP get higher on increasing the temperature of the air stream entering the evaporator or decreasing the temperature of the air stream entering the condenser. it is revealed that using the FCC yields 5-10% higher cooling capacity compared to the case of using the VCC, and causes higher COP values at low speeds. However, as a result of the intervention of the capacity control system, using the VCC yields higher COP values at high speeds. [ABSTRACT FROM AUTHOR]

In this study temperature distributions occurring in samples were analyzed while quenching of the porous stainless steel cylinders produced by Powder Metallurgy. Then cooling curves of the metals were drawn. This problem was modeled in FLUENT software. In the problem, heat transfer coefficient, heat conduction coefficient and the properties of the water are changed with the changing temperature. User defined function (UDF) was written in C compiler for the varying heat transfer coefficient and the heat conduction coefficient then the UDF transferred to the FLUENT software. For size ϕ2.5x3, different points in inner sides, top-bottom sides and outer sides were analyzed. For 10%, 20% and % 40 porosity, cooling curves were compared. Results were compared with other numerical studies and generally it is seen that they are compatible with the other studies. [ABSTRACT FROM AUTHOR]

This paper aims to determine "The Thermal Spring Tourism in Turkey and Problems". Turkey is rich in thermal springs thanks to the large active lands with volcanic and tectonic formations. Turkey hosts over 900 thermal and mineral spring waters in different locations, with varying qualities and quantities, and with temperatures between 20-102 °C. Springs have some physical and chemical specialities that cause to recover varies illness. Most of them have been known and used by people since the early ages. Recently, thermal springs have been recognized more and more and it has taken its right place among the other tourism varies and they have turned into touristic attractions in some regions of the Turkey. Then in this study tries to evaluate the statue the thermal springs, according to region in Turkey. Moreover, the reasons hindering the spring tourism from achieving the goals set are emphasised. [ABSTRACT FROM AUTHOR]

In this study, poli{styrene-co-[3,5-bis(2-chloro-2-acetoxyphenyl)metakrilat]}, poly(St-co-CAPMA%4) twoarmed macroinitiator was prepared from free radical copolymerization of styrene with 3,5-bis(2-chloro-2- acetoxyphenyl)methacrylate in presence of AIBN at 60oC in 1,4-dioxane . A series of two armed grafting studies with n-buthylmethacrylate was carried out in the presence of the poly(St-co-CAPMA%4) as macroinitiator (Mn = 23300 and Mw/Mn = 1.67) and CuBr/2,2′-bipyridyne(bpy) as catalyst at 110 °C in diphenyl ether. All the polymers were structurally characterized by FTIR and 1H-NMR spectra. During the 20 h grafting reaction, the number-average molecular weight of the macroinitiator increased from 23300 to 135900 and the polydispersity decreased from 1.67 to 1.40. All the graft copolymers, which had initial decomposition temperatures (Ti) between 262 ve 222 °C were less thermally stable than macroinitiator (Ti : 305 °C) . The graft copolymers (132- 136°C) showed a higher glass-transition temperature than the macroinitiator (112°C). The dielectric constants (ϵ′) of macroinitiator and graft copolymers were measured at different frequence at room temperature. [ABSTRACT FROM AUTHOR]

In this work, the copolymer of 3-mesityl-2-oxopropyl methacrylate(MoPMA)] and acrylonitrile (AN) monomers was prepared in the presence of 1,4-dioxane solution using 2,2′-azobisisobutyronitrile (AIBN) as initiator at 60 °C. The structure of copolymer synthesized was characterized by ±H-13C-NMR, FT-IR and GPC techniques. The glass transition temperature of copolymer and initial decomposition temperature of copolymer measured by DSC and TGA techniques, respectively. The thermodynamic properties of non-solvent probe-polymer systems were investigated by using Inverse Gas Chromatography (IGC) technique. At diffirent temperatures, the specific retention volumes, Vgo, were determined by a series hydrocarbons and alcohols as hexane, heptane, octane, nonane, decane and methanol, ethanol, propanol, butanol, pentanol, respectively. Glass transition temperature (Tg) of poly(MoPMA-co-AN)(0,66:0,34) was determined to be 351 K (from 1/T versus lnVgo plot) by IGC technique. The solubility parameters (δ2) of copolymers in the same temperature range above mentioned Above Tg (403-453) K, weight fraction activity coefficients (a1/w1)∞ of solute probes at infinite dilution, Ω1∞, Flory-Huggins thermodynamic interaction parameters, χ12∞, partial molar entalpy (ΔG1∞) between polymers and solvents were determined. Also the solubility parameters for poly(MoPMA-co-) at infinite dilution were found by plotting the graph of [δ1²/RT-χ12∞/V1] versus solubility parameters, δ1, of this probes. [ABSTRACT FROM AUTHOR]

In present study, experimental determination of the thermal conductivity of two different kinds of tubing materials, used in biomedical area is investigated. Measurements were made of the theramal conductivity of Polyther block amide, PEBA tubing in the radial direction and heat-shrink tubing, PTFE in the axial direction. The heat shrink tubing was pre-shrunk prior to the execution of the measurements. Conductivity data were collected over temperature ranges extending from approximately 40 to 130°C for the PEBA tubing and 35 to 160°C for the PTFE. It was found that in these temperature ranges, the thermal conductivity for the PEBAX tubing is 0.128 to 0.196 W/m-°C and for PTFE is 0.224 to 0.253 W/m-°C. [ABSTRACT FROM AUTHOR]

In this study, the effect of LPG using ratio on engine performance, emissions and fuel economy in a spark ignition engine with gasoline and LPG injection systems was investigated. For this purpose, a vehicle has four cylinder spark ignition engine was modified to able to operate with duel fuel. Amount of injection fuels were calculated to obtain same heat value in the duel fuels operation. Experiments were applied in the vehicle dynamometer at different LPG using ratios (as heat value 0%, 25%, 50%, 75%, 100%), constant revolution (3800 d/d) and different load ratios (5%, 30%, 60%, 90%). Experiments gave affirmative results with regard to exhaust emissions and fuel economy at all LPG using ratios. However, positive results were only obtained at 25% LPG using ratio with respect to engine performance. [ABSTRACT FROM AUTHOR]

In this study, the heat transfer subjected to oscillating flow in an open ended vertical annular pipe is investigated experimentally. The oscillating flow within the annular column is created by a piston cylinder mechanism. The experiments are carried out for different frequencies, amplitudes and heat fluxes. The Nusselt numbers correspond to these parameters are calculated by the control volume approach. An empirical correlation which relates the dimensionless numbers of the problem is proposed for the obtained experimental data. [ABSTRACT FROM AUTHOR]

In this study, the investigation of three dimensional heat transfer enhancement was investigated numerically by using turbulator which inside the pipe as a turbulence generator produced of stainless steel and two different winglet distances (b= 0.1 and 0.2 m) and with three different winglet angles (θ=30°, 45° and 60°).The flow and temperature fields are computed numerically with the help of the FLUENT computational fluid dynamics (CFD) code. Reynolds Stress Model (RSM) is used as a turbulence model in numerical analyses. In all investigated cases, it was shown that when turbulator used inside pipe, Nu number increased and also heat transfer was effected by winglet distance(b) and winglet angle(θ) of turbulator. While Re number increased, Nu number increases and friction cofficient decreases. [ABSTRACT FROM AUTHOR]

The present study is aimed at experimentally investigating the drying kinetics of cornelian cherry fruits (Cornus mas L.) in a convective dryer for various values of drying air temperature. Sorption isotherms of the dried cornelian cherry fruit are also determined for different temperatures and equilibrium relative humidity. The experimental moisture data were fitted to some models (namely Henderson and Pabis, Lewis and two-term exponential models) available in the literature. The two-term exponential and Henderson and Pabis models were found to describe the characteristics of cornelian cherry fruits better. [ABSTRACT FROM AUTHOR]