Person: KARAHAN, MEHMET
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KARAHAN
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MEHMET
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Publication Influence of chemical treatments and nanocellulose spray coating on the mechanical, low velocity impact and compression after impact performance of nonwoven jute composites(Taylor, 2019-04-11) Jabbar, Abdul; Hussain, Jown; Basit, Abdul; Naeem, M. Salman; Javaid, M. Usman; Karahan, Mehmet; Nazir, Ahsan; KARAHAN, MEHMET; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu; AAK-4298-2021This paper reports the preparation and characterization of nonwoven jute composites. The untreated and chemically treated waste jute fibers were used to prepare needlepunched nonwoven fabrics. The treated waste jute fibers were also used to extract nanocellulose by pulverization, followed by acid hydrolysis. The prepared 2 wt% suspension of nanocellulose was spray coated over chemically treated nonwoven jute fabric. Afterward, the composites were prepared by compression molding technique. The surface morphologies of treated jute fibers and nanocellulose were characterized by scanning electron microscopy. The crystallinity of chemically treated jute fibers and nanocellulose was measured by X-ray diffraction. The effect of chemical treatments and nanocellulose spray coating over nonwoven jute reinforcement on the tensile, flexural, drop weight impact, and compression after impact properties of prepared composites has been investigated. The results revealed the improvement in mechanical properties after chemical treatments and nanocellulose coating. The overall better results were shown by composite sample prepared from chemically treated followed by nanocellulose sprayed jute nonwoven reinforcement.Publication Multi-response optimisation for the development of an activated carbon web as interlining for higher electrical conductivity and emi shielding using grey relational analysis(Inst Chemical Fibres, 2021-01-01) Naeem, M. Salman; Ahmad, Naseer; Javed, Zafar; Jabbar, Abdul; Rehman, Ateeq Ur; Zubair, Muhammad; Gilani, Syed Qummer Zia; Ahmad, Zuhaib; Karahan, Mehmet; KARAHAN, MEHMET; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; AAK-4298-2021This paper presents a simple and novel method of producing an activated carbon (AC) non-woven web from acrylic waste derived fin discarded bathmats converted into a nonwoven web by a caidingand needle punching machine. After stabilisation at lower temperature, carbonisation of the stabilised web was performed in a muffle furnace. The carbonisation temperature, the holding time of the activated carbon web at the final temperature, the heating rate to reach the final carbonisation temperature and the number of steps adopted for developing the carbon web were optimised using the grey relational analysis (GRA) approach to get optimum responses of the surface area of the web, electrical conductivity and electromagnetic shielding. The results demonstrated a large improvement in electrical conductivity as surface resistivity decreasedfrom 134.21 Omega.mm to 0.28 Omega.mm, and the corresponding electromagnetic shielding increased to 82.63 dB when the temperature of the carbonisation, the holding time and number of steps were increased. The surface area in the AC web was increased from 73 m(2)g(-1) to 210 m(2)g(-1) with an increase in the carbonisation temperature, the holding time and number of steps to reach thefinal temperature. The optimisation technique used in this work could be successfully used in cost and error reduction while producing an AC web. The optimised AC web was characterised by Brunauer; Emmett and Teller (BET), X-ray diffraction characterisation and elemental analysis (EDX) in order to determine changes in its structure, surface area, degree of crystallinity, inter-layer spacing and proportion of different elements. The AC web developed can be effectively employed as interlining in apparels because of its flexibility and eco-friendly electromagnetic shielding, as it works on the principle of the absorption, reflections and internal reflections of electromagnetic radiations.Publication Investigation of impact properties of para-aramid composites made with a thermoplastic-thermoset blend(Sage Publications, 2021-06-01) Khan, Muhammad Imran; Umair, Muhammad; Hussain, Rizwan; Karahan, Mehmet; Nawab, Yasir; KARAHAN, MEHMET; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu; AAK-4298-2021During impact, thermoset composites show brittle behaviour, whereas thermoplastic composites show a relatively ductile behaviour with higher absorption of impact energy. The research on the investigation of the impact performance of composites with thermoplastic resin and/or with a blend of thermoplastic and thermoset resins found rare. In the present study, both thermoset (phenolic, vinyl ester) and thermoplastic (Polyvinyl butyral - PVB) matrices were used with Para-aramid reinforcement for the development of five-layered composite samples. Drop weight impact, Charpy impact, flexural (three-point), and hardness tests were conducted to assess the performance of the composite samples. The developed thermoplastic composites showed superior impact properties as compared to thermoset composites except for out-of-plane deformation (trauma). This deformation was reduced using a blend of PVB and Phenolic. The composite made with blend absorbs 8-9% more energy as compared to Phenolic composites with almost the same value of trauma. Overall, damage area is also lesser in the case of composite made using a blend. The experimental results are validated by one-way ANOVA (Tukey) statistical analysis.Publication Geometrical model to determine sewing thread consumption for stitch class 406(Inst Chemical Fibres, 2021-11-01) Rehman, Ateeq ur; Rasheed, Abher; Javed, Zafar; Naeem, M. Salman; Ramzan, Babar; Karahan, Mehmet; KARAHAN, MEHMET; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksek Okulu.; AAK-4298-2021This study aimed at developing a geometrical model for predicting the sewing thread consumption of stitch class 406. Stitch class 400 is a multi-thread chain stitch which consumes a less amount of thread as compared with stitch class 500 but more thread as compared with stitch class 300. Sewing thread calculation plays a significant role in determining the exact amount of thread for completing a garment and predicting the right quantity of thread for bulk production. The geometrical model developed was used for predicting sewing thread consumption by using different factors like stitch density (8 and 12 SPI), material thickness (2, 4 and 6 layers of fabric), and type of material (denim, knitted and fleece). The model was validated with a total of 18 samples sewn with different kinds of fabric, SPI, and material thickness. It was concluded that the model could predict sewing thread consumption with more than 97.18% accuracy.Publication Low velocity impact behaviour of aramid and uhmwpe composites(Inst Chemical Fibres, 2015-05-01) Karahan, Mehmet; Yıldırım, Kenan; KARAHAN, MEHMET; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu; 0000-0003-3915-5598; AAK-4298-2021The most popular method to produce composites for ballistic applications is to use aramid and ultra high molecular weight polyethylene (UHMWPE) fibers as reinforcement materials in different matrices. The composite materials used in this type of application, especially those used as armoring materials for explosions, are subjected to a very high level of energy. In this study, the effect of the reinforcement material type and cross-plied condition of reinforcement were examined using high-level impact tests. The impact tests were performed at low speed but high energy, and thus the behaviour of the composite materials that were exposed to high-level impact energy could be examined. According to the results, the UD aramid composite produced the best results with respect to high-level impact tests. In addition, mass optimisation could be achieved without the loss of the high-level impact energy by preparing a hybrid composite with UD UHMWPE and UD aramid fibers.Publication Geometrical analysis of 3d integrated woven fabric reinforced core sandwich composites(Inst Chemical Fibres, 2019-01-01) Jabbar, Abdul; Zubair, Muhammad; Karahan, Mehmet; KARAHAN, MEHMET; Karahan, Nevin; KARAHAN, NEVİN; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; 0000-0001-6900-4147; 0000-0003-3915-5598; 0000-0003-2362-517X; JQW-3721-2023; AAK-4298-2021; JON-7556-2023; O-2447-2015The variability of the internal geometry parameters, such as the waviness of yarns, cross sections of yarns and local fibre volume fraction of 3-dimensional (3D) integrated woven core sandwich composites affects their mechanical properties. The objective of this study was to define the geometrical and structural parameters of 3D integrated woven core sandwich composites, including the fold ratio of pile threads, the fabric areal weight and the fib re volume fraction by changing the core thickness of 3D sandwich core fabric. 3D fabrics with different core thicknesses were used for reinforcement. It was confirmed that the pile fold ratio, slope angle and pile length increase with an increase in the core thickness of the fabric. The difference between the calculated and experimental areal weights of fabrics was in the range of 5-13%. A novel approach was also presented to define the fibre volume fraction of 3D woven core sandwich composites.