Tuba Demirel

Hasan Kalyoncu University · Mechanical Engineering

This study investigated the impact of stabilization time on pretreated polyamide 6 (PA6) fibers using various analytical techniques, including thermal analysis (TGA and DSC), infrared (IR) spectroscopy, X-ray diffraction (XRD), tensile testing, and density measurements. The two-step atmospheric air-based stabilization process for pretreated PA6 mul...

Physics is one of the most fundamental sciences in the history of humanity and its origins date back thousands of years. Over the course of its evolution until today, a scientific method has emerged for explaining natural phenomena through the combination of mathematical analysis and observation, complemented by experimentation. Nowadays, the field...

ONLY ABSTRACT: The plastic industry is a sector with a wide range of applications. In this period, while the plastic sector is considered an important sector in Turkey, it is also divided into various subfields. It is necessary to understand the growth level, key factors, and dynamics of this industry. Contributing to the sustainable competitive ad...

Jet engines are designed to provide thrust to aircraft using compressed air. In the design of jet engines, the choice of materials has a significant impact on the engine's performance, weight, durability, and cost. High-performance jet engines typically include specially designed components made from high-strength materials. The selection of materi...

Necmettin Erbakan University Journal of Science and Engineering (NEJSE) ABSTRACT: (Fulltext - Turkish Publishibg) Magnetic abrasive machining (MAF) is a specialized machining technique used to reduce surface roughness and polish the surface of metal. It can be effectively used for machining parts with precision and complex geometries. While the t...

One of the most important challenges in today's world is the elimination of roughness on metal surfaces. When a rough surface is used in a working mechanism, friction can lead to wear. As a result, the component can be damaged. In order to prevent such situations, various methods of surface roughness reduction are being used in the manufacturing se...

Since welding is a non-removable joining method, it requires more care and attention than other joining processes. Welding processes require a good understanding of the knowledge in this field to achieve the desired result and quality level. With the advancement of technology, the welding profession and welding technology are also developing, which...

Corrosion can be explained as the damage of metals as a result of chemical or electrochemical interactions with their environment. As a result of corrosion of the metal, it causes losses in the mass of the material. This results in a deterioration of the material's physical and mechanical properties. Coating processes protect the physical and chemi...

Non-traditional machining with Magnetic Abrasive Finishing (MAF); precision machining technology, is widely used in areas such as semiconductors, optics, aviation, biomedical engineering, etc. Due to its ability to penetrate magnetic fields, the MAF process can be used not only to finish the outer surface of workpieces but also to finish the inner...

Biomaterials play an important role in the human body. However, they have a tendency to corrode due to the environmental conditions they are exposed to inside the body. For this reason, there is a need to improve the corrosion resistance of biomaterials for the longevity of implants used in the body. Surface coating applications offer an important...

ABSTRACT; According to the historical records in Turkey, there are records of earthquakes of around 7 intensities since 1500 years. Under AFAD data, an earthquake with a magnitude of 7.7 occurred in the Pazarcık district of Maraş at around 04:17 on the night of 6 February and caused serious damage to the surrounding provinces. After the earthquake...

ABSTRACT : The Seismic Hazard Map of Turkey (TDTH) was renewed and published by AFAD in 2018 and the earthquake hazard ratio was visualized with an increasing scale from yellow to red. This map clearly shows us once again that Turkey has two major fault lines, namely the East Anatolian Fault Line and the North Anatolian Fault Line. These fault lin...

In current technologies, carbon fiber is important for polymeric composites. The precursor fibers of polyacrylonitrile (PAN) is the main raw material of the carbon fibers most commonly used in the industry. PAN is a petroleum-based product. Heat treatments were carried out in an oxygen-containing environment using different stabilizing temperatures...

ARCENG (INTERNATIONAL JOURNAL OF ARCHITECTURE AND ENGINEERING) JOURNAL https://e-arceng.com/index.php/arceng/article/view/1/3 ISSN: 2822-6895 ABSTRACT : Anisotropic solids that incorporate the fluidity properties of liquids and have a crystalline structure are called liquid crystal substances. In liquid crystals (LC), we also see some propertie...

Thermal-oxidative stabilization of polyacrylonitrile (PAN) fiber pretreated with ammonium bromide (NH4Br) was performed in the air atmosphere at temperatures between 200 and 250 °C for periods of 5 to 75 min in a multistep approach. The study demonstrates that the NH4Br incorporation is highly effective in accelerating nitrile group cyclization by...

Carbon fiber is a material that has strategic importance in composites used in the defense industry. The most important advantage of composite materials is that they have high mechanical properties and low-density values. The biggest obstacle that limits the use of carbon fibers, which have these superior properties, in areas such as space, aviatio...

Carbon fiber reinforced polymer composites (CFRP) will be in greater demand in the future because they have been shown to exhibit very high stiffness and excellent thermal stability over a wide temperature range. Carbon fibers are in the high performance fiber group. Analysis values and stabilization parameters of viscose rayon precursor fibers, wh...

There is approximately 90-95% carbon element in the molecular structure of carbon fibers. In the industry, polyacrylonitrile (PAN) polymer is mostly used as a raw material in the production of carbon fiber. The first heat treatment step in carbon fiber production is thermal stabilization. In the stabilization process, after gaining incombustibility...

There is approximately 90-95% carbon element in the molecular structure of carbon fibers. The most important feature that makes carbon fibers attractive is that they have lower density and better mechanical properties than metals. In the industry, polyacrylonitrile (PAN) polymer is mostly used as a raw material in the production of carbon fiber. Th...

With the development of the textile industry, a new era has begun in fabrics and protective clothing. Non-combustible fibers are effective in protecting from fires that occur as a result of accidents in the automotive, space, and aviation fields in daily life. Natural or synthetic polymeric raw materials are used for the production of fireproof fib...

The conversion of poly (hexamethylene adipamide) or polyamide 66 precursor fiber to carbon fibers was accomplished through thermal stabilization and carbonization processes. Thermal stabilization was conducted of cupric chloride (CuCl 2 )–ethanol-impregnated polyamide 66 (PA66) fibers in the air. To determine the influence of heating rate on the fi...

Although the light weight of the selected material seems to be advantageous because it will save fuel during the usage phase, when the production and recycling costs or the cost of the resources to be used to eliminate the environmental effects are taken into account, the total cost is higher than the equivalent material. It is important to use mat...

Technical textile fibers are semi-raw products that can be used on the basis of composite material.Fibers in the textile industry; classified as organic and inorganic fibers. Organic fibers also appear as artificial, synthetic and natural fibers. Carbon fibers are in the inorganic fiber group. It contains about 95% carbon in its molecular structure...

The influence of the impregnation of phosphoric acid, boric acid, and urea (in brief PBU) as eco-friendly chemicals and the thermal-oxidative stabilization (TOS) on the properties of poly(hexamethylene adipamide) or polyamide 66 multifilament were studied at temperatures up to 245 °C for different stabilization periods. PBU impregnation followed by...

Thermal‐oxidative stabilization of the polyacrylonitrile (PAN) precursor was performed employing a multi‐step heat treatment strategy in an air circulating furnace. In this approach, the applied temperature was gradually increased from 200°C to 250°C employing several stages for different stabilization durations. Fifteen percent guanidine carbonate...

The thermal stabilization stage is the most important stage of carbon fiber production in terms of the ability of Polyacrylonitrile (PAN) fibers to resist high temperatures throughout the carbonization stage. The degree of stabilization of the PAN fibers determines the final carbon fiber strength. Here, insufficient stabilization and excessive stab...

The thermal oxidative stabilization and carbonization processes of poly(hexamethylene adipamide) or (polyamide 66) fibers were accomplished to transform into carbon fibers. Polyamide 66 fibers were pretreated with a ethanol solution of cupric chloride followed by a stabilization process in the air atmosphere. Carbonization experiments were executed...

Thermal oxidation of polyacrylonitrile (PAN) fibers was accomplished at temperatures up to 250°C for different oxidation times. Chemical integration of PAN fibers with an aqueous solution of ammonium persulfate was performed before starting thermal oxidation. The results recommend that ammonium persulfate integration enhanced the oxidation reaction...

Thermal stabilization of polyacrylonitrile (PAN) multifilaments was performed using a multi-step annealing approach in an air environment. Ammonium persulfate (APS) pretreatment of PAN multifilaments was performed prior to the thermal stabilization process. APS pretreatment of PAN resulted in the sulfation of polymer chains. The results suggest tha...

A study was carried out on the incorporation of ferric ions (Fe+) in the thermal stabilization of polyamide 6 fibers. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements from fiber characterization techniques were used. Polyamide 6 (PA6) fibers pretreated with 1% ferric chloride and thermally stabilized were re...

The thermal stabilization and carbonization phases of poly(hexamethylene adipamide) (polyamide 66) precursor fibers were executed to convert into carbon fibers. Polyamide 66 (PA66) fibers were impregnated with a solution of cupric chloride (CuCl 2)-ethanol followed by a two-step thermal oxidative stabilization procedure in an oxygen-containing atmo...

The impact of ammonium persulfate (APS) integration and thermal oxidative stabilization (TOS) on the properties of polyacrylonitrile (PAN) multifilament were studied at temperatures up to 250°C by employing a multistep annealing approach. The results suggest that APS pretreatment accelerated the thermal stabilization reactions of the PAN multifilam...

Thermal stabilization of polyacrylonitrile (PAN) original fibers was carried out in the presence of ammonium bromide (NH4Br) impregnation. Structure and properties of thermally stabilized PAN original fibers were characterized utilizing a mixture of volume density, fiber thickness, color change observations, flame tests, X-ray diffraction (XRD), in...

The structure and effects of thermally stabilized PAN original fibers were characterized utilizing a mixture of volume density, color change observations, flame tests, X-ray diffraction (XRD), infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA) measurements. The results obtained from the analysis of XRD work showed the conversion of...

An experimental study was carried out on incorporating ferric ions (Fe +3) in thermally stabilization reactions of polyamide PA6 fibers. The structure and properties of the thermally stabilized PA6 fibers were determined by fiber diameter, volume density, tensile testing, oxygen content (%), infrared spectroscopy (FT-IR), and thermogravimetric (TGA...

The biomedical materials used in the body are in contact with living tissues in the human body. In liquid media in the body, corrosive effects can occur on biomedical material. For this reason, it is necessary to improve the corrosion properties of biomedical materials such as prostheses and implants used in the health field and to increase the lif...

An important part of today's technological research is focused on improving the quality of life of human beings. For this reason, it is necessary to improve the performance of the materials used. The nitriding method, which has been used frequently in the production sector recently, is a surface hardening process. While the parts of the machine ful...

Surveys on coatings aim to increase people's future survival. The use of implants in the health sector is increasing rapidly all over the world. However, the limitations imposed by the implants on the patient are that they have an average of 10 years of use due to the cyclic loads and body ambient conditions they are exposed to. Especially metal im...

Günümüzde teknolojik araştırmaların önemli bir kısmı insan sağlığını, yaşam kalitesini arttırmaya yönelik yoğunlaşmıştır. Biyomedikal alanda insan yaşam kalitesini artıracak kalça ve diz eklemleri, koroner stentler, kalp kapakçıkları gibi çok çeşitli protez ve implant malzemeleri kullanılmaktadır. Medikal malzemelerin hem yüzeysel özelliklerinin vü...

Human health has great prospects in terms of quality of life. For this reason, a significant part of the technological research is concentrated in this area. It is necessary to improve the properties of the biomaterials used in applications such as prosthesis, dental materials and so on in the health field in order to increase their service life. B...

The development of technology has increased the use of thin film coatings in medical implant materials such as crowns, bridges, orthodontics and orthopedics. It has been known for many years that a metal substrate is used for durability in dental treatments. Metals and alloys affect the operating performance of implants, as they are different from...

With the developing technology, the methods used in the processing of sensitive products are increasing. New surface treatment methods are being developed for aerospace, electronics and medical industries. Machining with magnetic abrasives (MAI) is a new manufacturing method that uses sawdust to remove chips by abrasive and magnetic powders, which...