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Non-chemical weeds control is a crucial aspect of sustainable organic agriculture. This paper explored the state-of-the-art deep learning networks applicability for weed detection and proposed a novel, simple deep learning model. The proposed network, CovWNET, is the second smallest network among the implementations compared in this study. It has roughly 1/3 times more parameters; however, it achieves 1.8% higher accuracy than the smallest network, MobileNetV2. Correspondingly, CovWNET has approximately five times fewer parameters and 2 % less accuracy than the best achieving model of DenseNet201.

Nimonic 80A alloy has been subjected to aluminizing process to improve its high temperature oxidation and wear properties. Pack aluminizing process was carried out for 3 and 5 h at 650 and 700 °C temperatures without using a protective atmosphere. Aluminising treatment was carried out using metallic aluminium, ammonium chloride (NH4Cl) and alumina as a filler. The morphology and structure of aluminide layers was analysed by SEM-EDS. It was observed that there was a super bonding between matrix and coating layers which are smooth, dense and porosity free. Dominant phases of Ni2Al3 and Al80Cr20 were detected by XRD analysis. Layer thickness was measured from the surface to the matrix and changed from 20 to 70 μm which was increased with increasing process duration and temperature. The matrix hardness is 400 HVN while the hardness of coating layer raised to 1025 HVN with the process time and temperature. Wear losses decreased with the increase in coating temperature and time in both high temperature and room temperature tests. After isothermal oxidation tests at 1000 °C up to 75 h, all aluminized samples consist of alumina scale while Nimonic 80A consist of Cr2O3 and TiO2 mixed oxides with high thickness. The increased aluminizing temperature and time provide better protection against high temperature oxidation.

The aim of this study was to investigate the effect of low-temperature aluminizing process on the microstructure and dry sliding wear properties of Mirrax steel. Low-temperature aluminizing process was applied on Mirrax steel at 600, 650, and 700 °C for 2, 4, and 6 h. The packs for the process were prepared using pure aluminum powder as aluminum deposition source. Ammonium chloride NH4Cl and Seydisehir Al2O3 powder were used as the activator and the inert filler, respectively. Scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis were applied for characterization of the coating surfaces. The through-thickness variation in the layer microstructure was determined and it was found to vary between 1 µm and 45 µm which increased with higher process temperature and time. After the deposition process, the coating layer hardness increased to 1000 HVN, whereas the hardness of the matrix was 250 HVN. The wear tests were performed using a ball-on-disc tribometer under 5 N load at room temperature and 500 °C on aluminized and untreated Mirrax steel. In both room temperature and high-temperature wear tests, it was determined that the aluminizing process increased the wear resistance of Mirrax steel. Increasing aluminizing time and temperature also increased the wear resistance. The uncoated and thin-coated samples generally exhibited wear in the form of plastic deformation and adhesion related ruptures. A high degree of tribological layer was observed on the wear trace on samples with high coating thickness, especially in high-temperature tests. Therefore, the volume losses in these samples were induced by fatigue crack formation and delamination.

The thermal fatigue behavior of chromium vanadium carbide (Cr − V − C) coatings and the wear of the coatings after thermal fatigue cycling was studied. The Cr − V − C coatings were grown on the surface of a ductile iron using thermo-reactive diffusion (TRD) and subjected to thermal fatigue in the temperature range of 25 to 750 °C for up to 500 cycles. Characterizations were made using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, microhardness measurements and wear tests. The Cr − V − C coated samples displayed superior thermal fatigue and wear resistance compared to the untreated ductile iron, mainly due to the dissolution of graphite nodules in the vicinity of the surface during TRD. The dissolution of graphite reduced the possibility of failure initiating from graphite nodules and graphite-matrix interfaces. Increasing the number of cycles resulted in increased flaking and decreased wear resistance in both the Cr − V − C coatings as well as the untreated ductile iron. Although much of the Cr − V − C coating was lost (due to flaking) after thermal cycling, the absence of graphite near the surface still provided improved resistance to wear in the TRD-treated samples. The results of this study indicate that TRD coatings hold great promise for use in the industrial applications.

Inconel 718 has a wide area of applications in gas turbines, aircraft, turbocharger rotor equipment, and so many other applications, including applications with temperatures up to ~700 °C. In this study, Ni-based aluminide coating on Inconel 718 alloy was applied by pack cementation technique. Phase structures, layer coating thickness, hardness, wear, and oxidation behaviors were studied for different aluminization temperatures and times (600 and 700 °C for 3 and 5 h). The change in the layer from the surface to the inside was varied from 8 to 80 μm and this was increased with higher aluminization temperature and more time. The hardness value of 960 HV was determined in the coating layer whereas the hardness of the matrix was 260 ± 10 HV. The wear resistance of the samples was tested under dry sliding conditions with different loads. The wear resistance of Inconel 718 has increased with aluminization. Increased aluminization duration and temperature reduced wear losses. Isothermal oxidation test results at 1000 °C for 5, 25, and 125 h show that Inconel 718 has a poor oxidation resistance under these conditions while aluminized Inconel 718 samples exhibit better results. The comparison of the aluminized Inconel 718 samples after oxidation tests showed that the aluminization at higher temperatures allowed the formation of a compact and continuous alumina layer while the formation of porosities under the oxide scale weakened the adherence and durability in the others.

CoCrFeNiAl0.25Ti0.5 high entropy alloy alloys (HEA), produced by powder metallurgy were subjected to boriding to improve their mechanical properties. Sintering was carried out at 1200 degrees C for 2 h in Ar, and boriding was performed at 900, 1000 and 1100 degrees C for 2 h using a 90 wt% B4C + 10 wt% NaBF4 boriding powder mixture. Microstructures, densities, surface roughnesses, and mechanical properties (hardness, fracture toughness and nanoindentation responses) of the samples were investigated. FCC, BCC and sigma phases had been observed after sintering, whereas complex metal borides were formed on the surfaces after boriding. Relative density values were between 85% and 90%. Significant increases in surface hardness were observed after boriding due to formation of hard, silicide-free boride layers. The boride layer thickness and hardness increased with increasing boriding temperature. The elastic modulus of the surface of the sintered sample (47.07 GPa) increased with the boriding process to values in the range of 140-151 GPa. Fracture toughness values between 3.57 and 4.25 MPa m(1/2) were obtained in borided samples, and increasing the boriding temperature reduced the fracture toughness.

Nickel-based superalloy Nimonic 80A was pack-borided in a solid medium at temperatures of 850 degrees C and 950 degrees C for 2 h and 4 h using silicon-free boriding powders. To investigate the effects of the boriding treatments on mechanical properties (hardness, modulus of elasticity, fracture toughness) and high temperature oxidation resistance, the layers grown on the surfaces were characterized using optical and scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffractometry, and evaluated using microhardness, nanoindentation, wear and oxidation tests. Wear tests were performed on untreated and borided Nimonic 80A alloys using a ball-on-disc tribometer at room temperature and at 500 degrees C under dry sliding conditions. Oxidation tests were carried out in air at 1000 degrees C for 5 h, 25 h and 75 h. Characterization studies revealed a smooth, 22 to 86 mu m thick crack-free boride layer consisting mainly of Ni2B and minor quantities of CrB, Cr2B and Cr5B3 in the borided samples. The hardness and elastic modulus of the boride layer was measured as 15.57-18.95 GPa and 142-217 GPa, respectively. Increasing the boriding temperature and time increased the concentrations of chromium in the boride layer. The hardness and elastic modulus of the boride layer increased with chromium content while its fracture toughness decreased. The boriding treatments improved the dry sliding wear resistance. Increasing boriding time and temperature generally led to a higher wear resistance values. However, the treatments had no significant effect on oxidation resistance. The results of this study show that boriding can significantly improve the wear resistance of Nimonic 80A without compromising its oxidation resistance.

Ever-increasing energy costs and environmental restrictions have compelled researchers to focus on the reutilization of vast amounts of industrial by-products such as blast furnace slag and steelmaking slag, in energy extensive and material extensive industries such as iron-steel production and construction. Attempts to reutilize these waste materials all around the world have yielded successful results up to date, such that, in some of these attempts they even surpassed their intended use as blend or replacement materials and became serious rivals to their industrial counterparts. Various ways to reutilize these waste materials have been explored up to date, including waste heat recovery, clinker substitute in cement production, and a number of comparatively more value added applications. The ongoing attempts have come to a point that pushes the limits for more technological uses such as alternative ceramic coating materials in surface engineering applications. In this regard, this review study aims to provide an overview of and a collective approach to various uses of blast furnace and steelmaking slag in diverse applications and fields, with a view to provide insight into the current attempts to optimize or improve their use, as well as emerging trends as to the potential use of these waste materials in higher value-added applications.

In recent years, carbon fiber-reinforced polymer (CFRP) composites materials are frequently used in many areas such as aerospace, military, automotive, construction, marine vehicles, wind turbines, motorcycles, bicycles, sport, electrical and household appliances due to superior properties of this material such as high specific strength, high stiffness and high corrosion resistance. While the parts produced with this material are durable and lightweight, the increase in CFRP composite material usage requires the development of processing methods with low cost and high quality. The surface quality in milling of CFRP composite materials is an important issue due to the influence of surface quality of the produced parts on the assemblage. It has also importance on the fatigue resistance of the machined parts. On the other hand, CFRP composite material is seen as one of the hard-to-cut materials due to its low thermal conductivity and abrasive nature. Rapid tool wear occurring during the milling process deteriorates the surface quality, leads to the decline in production due to the machine tool downtime and it thereby causes a cost increase accordingly. Therefore, diamond tools are widely used in machining of CFRP composite material due to their high hardness, while these tools are expensive. In order to overcome the tool cost issue, cemented carbide tools are used to cut CFRP composite material. Although carbide tools have higher toughness than diamond ones, their hardness is low. Therefore, they are commonly protected by a hard coating to increase their surface hardness and wear resistance. However, the tool life and cutting performance of the carbide tools in machining of CFRP material need to be improved. In this study, after investigation the studies on milling process of CFRP composite materials in the current literature, the emerging developments were presented. Cutting tool geometry and materials used in the relevant area are compiled. Tool wear mechanisms that occur during the milling process, the failures in CFRP composite material and the solutions to prevent these failures are discussed.

WOS: 000473267000005 Objective: The purpose of this study was to investigate the influence of 25(OH)D3 levels on glycemic control, diastolic functions, and carotid intima-media thickness in patients with Type 2 diabetes mellitus. Material and Methods: Patients admitted to the endocrinology department, with the diagnosis of Type 2 diabetes mellitus, who were under follow-up for at least six months and also had 25(OH)D3 deficiency [25(OH)D3 levels

Reduction of machining times and optimization of cutting parameters and conditions hold great importance in machining processes. Milling is among the most important machining processes used for machining of fiber-reinforced composite materials. The present research was carried out to investigate the effect of cutting parameters on tool wear during the milling of carbon fiber reinforced polymer (CFRP) materials which are widely used in aviation and aerospace industries. A multidirectional CFRP composite material with 6 mm width and 24 layers was used as the workpiece. The tests were performed under dry conditions on a CNC vertical processing center with 100, 200 and 300 m/min cutting speeds; 0.05 – 0.15 and 0.25 mm/tooth feedrates and at 1 mm constant cutting width. To understand the wear process, scanning electron microscopy (SEM) analyses of the worn surfaces were performed.

WOS: 000446711300053, The corrosion resistances of three different thermochemical coatings (grown using titanizing, boriding, and borotitanizing treatments) applied to STKM-13A steel surfaces were investigated. The coatings were characterized using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometry, 2D profilometry, and microhardness experiments. The corrosion tests were conducted using both electrochemical and static immersion methods, in 3.5 pct NaCl and 40 pct HF acid solutions, respectively. The corrosion resistance of STKM-13A steel was enhanced after the coating process. The specimens were exposed to more corrosion in the HF solution than in the NaCl solution. The best corrosion resistance was obtained in the borotitanized and borided specimens immersed in the NaCl and HF solutions, respectively. The borided STKM-13A steel sample showed even less cumulative weight loss than Inconel 625 in the static immersion HF acid solution test. This suggests potential use of the borided STKM-13A steel in the uranium production units of nuclear power plants as an alternative to more costly alternatives such as Monel, Inconel, and Hastelloy. (C) The Minerals, Metals & Materials Society and ASM International 2018

The present investigation aimed to understand the effects of dressing fertilizers and different nitrogen (N) doses on yield and nutrient uptake of chickpea (Cicer arietinum L.) plant. The study has been carried out with three repetitions under the greenhouse conditions. Nitrogen doses were; 0 kg N ha-1, 30 kg N ha-1, 60 kg N ha-1, 90 kg N ha-1 and 120 kg N ha-1 (in CaNO3.4H2O form) and dressing fertilizers were applied as 40 kg N ha-1. The results indicated that the dressing fertilizer application significantly increased average shoot dry weight with 8.18 g poƒ-1. Also, N (2.88 % N), P (0.40 % P), K (3.90 % K) and Fe (114.2 mg kg-1) concentrations increased with dressing fertilizer application of chickpea plant as compared to without dressing fertilizer application. However, dressing fertilizer application did not affect Mg, Zn, Mn and Cu concentrations of chickpea plant. Generally, in this study dressing fertilizer application increased yield and some macro and microelements concentrations of chickpea plant.

This study covers the physical, thermal, mechanical, and microstructural properties of porous ceramic materials produced from mixtures containing refractory clay and diatomite in different proportions. The raw materials were characterized by chemical (X-ray fluorescence), thermal (thermogravimetry), morphological (scanning electron microscopy), and phase (X-ray diffraction) analysis techniques. The prepared samples were sintered at different firing temperatures between 900 and 1100 °C in an electrical furnace. The bulk densities, apparent porosities, linear dimensional shrinkages, compression strengths, thermal conductivities, and microstructural properties of the sintered samples were investigated. The porosity of the sample with 90% diatomite content increased to 55.4%, density decreased to 1.02 g/cm3, and thermal conductivity coefficient decreased to 0.32 W/mK.

Ductile iron (DI) owes many of its attractive mechanical properties to the graphite nodules in its structure. However, since galvanic coupling can occur between the graphite nodules and the matrix in aggressive environments, these nodules can, at the same time, reduce its corrosion resistance. In this study, composite carbide coatings were grown on the surface of GGG-80 using the thermoreactive diffusion (TRD) process. The process was carried out at 900, 1000, and 1100 °C for 1 h using nanosized Fe-V and Fe-Cr powders. The coatings were characterized by X-ray diffractometry (XRD), two-dimensional profilometry, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and microhardness tests. The corrosion behavior of the coatings were evaluated in three different solutions (3.5 wt% NaCl, 5 wt% H2SO4, and 5 wt% HNO3) using electrochemical open-circuit potential (OCP) and potentiodynamic polarization measurements. Microstructures and hardness tests showed that the nodular graphite in the surface was dissolved at the TRD process temperatures and that a coating of 12–36 µm thickness and 2461–3200 HV0.05 hardness was obtained. The corrosion resistance of the composite coating was up to 10, 33.5, and 75 times higher than the uncoated GGG-80 in NaCl, H2SO4, and HNO3, respectively. The improvement in corrosion resistance was a direct result of the formation of complex carbides and the elimination of graphite nodules in the surface of the alloy.

In this study, Cr-V-C composite carbide layers were grown on the surface of a GGG-80 ductile iron using thermoreactive diffusion (TRD). The TRD process was carried out at temperatures of 900, 1000, and 1100 degrees C for 1 h using nano-sized Fe-V and Fe-Cr powders. The coatings were characterized by X-ray diffractometry (XRD), 2D profilometry, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), microhardness measurements, nanoindentation, and wear tests. The wear tests were performed on untreated and coated samples using a ball-on-disc type wear tester under 10 N load at four different temperatures (25 degrees C, 250 degrees C, 500 degrees C and 750 degrees C) against a 6-mm WC ball. Metallographic investigations revealed that the graphite nodules near the surface were dissolved as a result of the TRD process. Depending on the TRD process temperature, a coating with a thickness of 12-36 mu m, hardness of 24.14-31.38 GPa, and elastic modulus of 198-233 GPa was obtained. An increase in process temperature increased the thickness, hardness, and elastic modulus of the obtained Cr-V-C layers, which resulted in low friction coefficient values and decreased wear rates. Although all coated samples showed improved wear resistance in all wear test conditions, the wear rates were significantly increased at 750 degrees C due to flaking.

Technology-oriented applications are becoming more important in today’s world and the use of technological processes continues to grow rapidly, day by day. Because of the advantages offered by composite materials, there is a great deal of interest in this material group in various industrial applications. Composite materials continue to develop at a great pace in parallel with the developments in metallic, ceramic and polymeric materials. Therefore, composite materials have found wide usage in engineering materials in recent years. In this material group, carbon fiber reinforced polymer (CFRP) composite materials, from the advanced composite material class, are commonly preferred in strategic applications due to their outstanding features such as high load-carrying capacity and low density. In this study, the production, characteristics and industrial usages of CFRP composite materials, milling and drilling operations carried out on them are presented along with current technology-oriented applications.

Carbon fiber-reinforced polymers (CFRPs) have very good mechanical properties, such as extremely high tensile strength/weight ratios, tensile modulus/weight ratios, and high strengths. CFRP composites need to be machined with a suitable cutting tool, otherwise, the machining quality may be reduced, and failures often occur. However, as a result of the high hardness and low thermal conductivity of CFRPs, the cutting tools used in the milling process of these materials complete their lifetime in a short cycle, due to especially abrasive wear and related failure mechanisms. As a result of tool wear, some problems, such as delamination, fiber breakage, uncut fiber and thermal damage, emerge in CFRP composite under working conditions. As one of the main failure mechanisms emerging in the milling of CFRPs, delamination is primarily affected by the cutting tool material and geometry, machining parameters, and the dynamic loads arising during the machining process. Dynamic loads can lead to the breakage and/or wear of cutting tools in the milling of difficult-to-machine CFRPs. The present research was carried out to understand the influence of different machining parameters on tool abrasion, and the work piece damage mechanisms during CFRP milling are experimentally investigated. For this purpose, cutting tests were carried out using a (Physical Vapor Deposition) PVD-coated single layer TiAlN and TiN carbide tool, and the abrasion behavior of the coated tool was investigated under dry machining. To understand the wear process, scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) was used. As a result of the experiments, it was determined that the hard and abrasive structure of the carbon fibers caused flank wear on TiAlN- and TiN-coated cutting tools. The best machining parameters in terms of the delamination damage of the CFRP composite were obtained at high cutting speeds and low feed rates. It was found that the higher wear values were observed at the TiAlN-coated tool, at the feed rate of 0.05 mm/tooth.

In this study, CoCrFeNiTi0.5Al x high-entropy alloys were produced by induction melting and their dry sliding wear behavior was examined at different temperatures. In addition to face-centered cubic (FCC) phases, low amounts of a tetragonal phase were detected in the microstructures of alloys without Al and microscratches were formed by wear particles on the worn surfaces of the alloy specimens. Two body-centered cubic (BCC) phases were detected in the alloy with 0.5Al and a fatigue-related extrusion wear mechanism was detected on the worn surface. The alloy specimen with a high Al content exhibited the best wear characteristics. No wear tracks were formed in single-phase BCC intermetallic alloys at room temperature and they exhibited a higher wear strength at high temperatures when compared to other samples.

In this study, CoNiCrAlY metallic coatings were deposited on an Inconel 718 Nickel-based superalloy substrate material using the detonation gun (D-gun) and supersonic plasma spraying (SSPS) techniques. The microstructural and mechanical properties in addition to their room and high-temperature wear behavior of the produced coatings were evaluated. The wear tests were performed at room temperature (rt), 250 and 500 &deg, C using 2N and X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) analyses of the worn coatings were performed to assess their wear performance. The coatings produced with D-gun process exhibited higher hardness and lower porosity (550 &plusmn, 50 HV0.25 hardness and 1.2 &plusmn, 1.0% porosity) than SSPS coatings (with 380 &plusmn, 30 HV0.25 hardness and 1.5 &plusmn, 1.0% porosity) which resulted in better room- and high-temperature wear performance for D-Gun coatings. The worn surfaces of both coatings exhibited formation of tribological layers and superficial microstructural changes by varying temperature and load conditions. Increasing load and temperature resulted in increased wear loss whereas increasing temperature resulted in reduced COF values for both coatings.

In this study, the abrading characteristics of the slags, generated in the form of industrial waste during raw iron, steel and ferrochromium ore production, are investigated. Granulated blast furnace slag (GBFS), basic oxygen furnace slag (BOF) ferrochromium slag (FCS) and commercial Al2O3 powder were used during the tests. Abrasion tests were conducted using Rubber Wheel Abrasion Wear (RWAT) method. Al 6061 was chosen as the counter body material. The tests were conducted under 25, 50, 75 and 100 N loads with 100 r/min rubber wheel rotational speed. The highest rate of abrasion was obtained from GBFS under all loads as a result of the conducted tests. Under high loads, the abrading performance of FCS reached that of the commercial Al2O3 powder. BOF was found to have no abrading capability. Surface morphology and SPQ (spike parameter-quadratic fit) value were as effective as the particle hardness in the evaluation of abrading performance. As dominant wear mechanisms, spalling, ploughing and micro-scratch formation were observed on the specimens abraded with GBFS and Al2O3, whereas severe plastic deformation-induced extrusion was observed on the specimen abraded with FCS.

WOS: 000483462700011, Waste utilization is an important alternative to reduce disposal costs, potential environmental pollution problems, decrement of natural resources and production costs. In this study, it is aimed to create a different usage area for the slag wastes that cause problems to the environment and factories. For this purpose, the usability of slags (blast furnace, ferrochromium and converter) as a reinforcement material in epoxy composites were investigated for tribological applications. Epoxy matrix composites were produced by adding 30% of reinforcements with 61 mu m size. The epoxy composites were tested against a stationary Al2O3 ball in a ball-on-disk tester under the loads of 10, 15 and 20 N, at a sliding distance of 300 m and a rotational speed of 300 rpm. Wear mechanisms were also investigated by Scanning Electron Microscopy. Mostly, the slag fillers showed higher wear resistance than the Al2O3 reinforced composites. Among the slag fillers, the blast furnace exhibited superior tribological performance. While Al2O3 and blast furnace slag reinforced composites showed plastic deformation due to fatigue, transverse cracks and displaced reinforcement particles were observed in ferrochromium slag and converter slag reinforced composites. Increasing the applied load caused acceleration in wear rate. Thermal conductivity was increased by particle addition, which contributed to the improvement of the wear performance. This study provided that industrial wastes can be used as reinforcement material in composites and thus a cleaner environment can be obtained. (C) 2019 Elsevier Ltd. All rights reserved.

WOS: 000465193500040, In the current study, the surface of AISI D2 steel was coated with the powder blends of ferro-vanadium (Fe-V) and ferro-chromium (Fe-Cr). The coatings were performed using a thermo-reactive diffusion (TRD) treatment by the pack cementation method at three different temperatures (900 degrees C, 1000 degrees C, and 1100 degrees C) and three different durations (1 h, 2 h, and 3 h). The structural and mechanical characteristics of the coatings were compared between the treatment groups. For this aim, the types of the formed phases, the microstructure, the microhardness, the surface roughness, and the wear and friction performance of the coated samples were examined. XRD analysis found composite carbide coatings including chromium carbide (Cr-C), vanadium carbide (V-C), and chromium vanadium carbide (Cr-V-C). The coatings' thickness was 11.3-23.2 mu m, hardness was 2100-2500 HV, and average surface roughness (R-a) was 0.286-0.550 mu m, depending on the treatment condition. The vanadium containing phase contents of the coatings increased with the elevating coating temperatures. The formed composite coating layers caused a change in the appearance of wear track and wear mechanism on the material surface. After the coating process, there found to be a decrease in the friction coefficient as well as an improvement in the wear resistance up to 7 times. In the composite coating layers, the increase in V-C content in comparison to Cr-C led to an enhancement in wear resistance on the material surface.

Ti–TiAl3 in-situ composites containing different percentages of Nb and B were effectively produced from Ti, Al, Nb and B powders by electric current assisted sintering (ECAS) technique which is a powder metallurgy processing method. Samples are sintered for 90 s with 2000 A current. The effect of B and Nb on the hardness, fracture toughness and wear resistance of samples were studied. The microstructure properties of the sintered samples were analysed with scanning electron microscopes (SEM), the phases in the samples were determined with XRD and their hardness and fracture toughness values were measured with a Vickers hardness tester with a load of 0.98 N and 98 N respectively. The highest fracture toughness value has been obtained with wt %10 Nb addition as 5.23 MPa m1/2, whereas the highest hardness was determined as 965 HV for wt%5 B reinforced in situ-Ti-TiAl3 composite. Best wear resistance was obtained in the 47.5Ti-47.5Al–5B sample. While Nb additive had a negatory effect on wear resistance, additive B had a positive effect on wear resistance.

As one of the main failure mechanisms emerging in the milling of carbon (C)-fiber-reinforced polymer (CFRP) materials, delamination is primarily affected by cutting tool material and geometry, machining parameters and the dynamic loads arising during the machining process. In this study, machinability tests were performed without the use of coolants to examine the effect of machining parameters on multidirectional CFRP composite workpieces, which have a wide application in industries. The tests were applied on a computer numerically controlled vertical processing center at three different cutting speeds (100, 200 and 300 m/min), three different feed rates (0·05, 0·15 and 0·25 mm/tooth) and constant cutting depth (1 mm). Following the tests, the changes in the workpiece were examined in terms of surface roughness, cutting forces, tool wear and delamination failures. The average surface roughness increased with increasing feed rate. Cutting forces also increased with increasing cutting speed, which caused improvements on average surface roughness values. As a machining parameter, feed rate was found to be a determining factor in the machining of CFRP composite materials.

In our country, the rapid increase in the number of universities and students in higher education, started in 1990s doubled the total number in last 10 years. As of 2015, the number of universities and students has reached 193 (including some private vocational schools) and 6 million (including open education faculty and distance learning), respectively. However, as the ratio of the graduate students to undergraduate students being only 11% our country is still far behind developed countries. While some developed countries achieved the goal in terms of number of researchers many years ago such as Finland, South Korea, Germany, Spain, France, Italy, the total number of researchers is 5,933 (2,407-11,000) per million people (TÜBİTAK, 2010), in our country this number is 1,688 (Çetinsaya, 2014). Similarly, countries with a degree of sophistication in terms of the average number of researchers in these countries is 87 (38-162) per ten thousand employees, while 70 in OECD countries, this number is 33 in Turkey (TÜBİTAK, 2010). In Turkey, the number of students per faculty member is 51 (Özer, 2011; YÖK, 2015) and 16 in OECD countries (URAP, 2015). The number of researchers planned as Turkey Vision 2023 is 300 thousand (Çetiner, 2012, Çetinsaya, 2014). To this aim, special precautions in increasing the number of graduate students in particular PhD are strongly needed. Because the number of students completing their PhDs is only around 5,000 per year (to achieve 2023 vision target 20,000 per year is needed starting today); according to the latest data in 2012-2013 education year the ratio of number of PhDs to the number of PhD students was 7.5% and to newely registered ones was 33.5% (YÖK, 2015). The similar ratios are observed in other years checked for., Ülkemizde 1990'larda başlayan üniversite ve yükseköğretim öğrenci sayısındaki hızlı artış özellikle son 10 yılda önceki sayısını katlamış; 2015 yılı itibariyle 193 üniversite (bazı Vakıf Meslek Yüksekokulları dahil) (YÖK, 2015), 6 milyonun üzerinde (AÖF ve uzaktan eğitim dahil) toplam öğrenci sayısına ulaşmıştır (ÖSYM, 2015). Ancak, lisansüstü öğrenci sayısının yükseköğretimdeki toplam lisans öğrenci sayısı içindeki oranı itibariyle (%11.6) (YÖK, 2015) ülkemiz hâlen gelişmiş ülkelerin oldukça gerisindedir. Araştırmacı sayısı bakımından hedefe yıllar önce ulaşmış Finlandiya, Güney Kore, Almanya, İspanya, Fransa, İtalya gibi bazı gelişmiş ülkelerin toplam araştırmacı sayısı ortalaması milyon nüfus başına 5.933 (2.407-11.000) iken (TÜBİTAK, 2010), ülkemizde bu sayı 1.688'dir (Çetinsaya, 2014). Yine, ülkelerin gelişmişliği açısından bir ölçüt olan, on bin çalışan başına düşen araştırmacı sayısı bu ülkelerde ortalama 87 (38-162), OECD ülkelerinde 70 iken, ülkemizde 33'tür (TÜBİTAK, 2010). Türkiye'deki üniversitelerde öğretim üyesi başına düşen öğrenci sayısı 51 (Özer, 2011; YÖK, 2015), OECD ülkelerinde 16'dır (URAP, 2015). Türkiye 2023 Vizyon hedefi olarak planlanan araştırmacı sayısı da 300 bindir (Çetiner, 2012; Çetinsaya, 2014). Bu amaca yönelik olarak lisansüstü öğrenci sayısının, özellikle de doktora öğrenci sayısının artırılmasına yönelik önlemlerin alınmasına şiddetle ihtiyaç duyulmaktadır. Zira ülkemizde yıllık doktoralı mezun sayısı ancak 5 bin dolayında (2023 vizyon hedefi için kalan sürede ihtiyaç duyulan yıllık 20 bin); ulaşılabilen son veri yılı itibariyle 2012-2013 eğitim-öğretim yılı doktoralı mezun sayısının toplam doktora öğrenci sayısına oranı %7.5'ta, doktoraya yıllık yeni kayıt sayısına oranı %33.5'ta seyretmiştir (YÖK, 2015). Bu oranların incelenen diğer yıllarda da benzer olduğu görülmektedir.

In this study, ferrochromium (FeCr) slag, which is available as an industrial waste, is proposed as a protective surface coating material particularly for protection of continuous casting rolls against oxidation. FeCr slag was successfully deposited with atmospheric plasma spray (APS) method. Before the coating process, FeCr slag powder prepared in the particle size range of 5-38m, was investigated using conventional characterization methods (XRD, SEM, TGA etc.). Thermal Barrier Coating (TBC) system was used as a basis for deposition processes. Accordingly, NiCoCrAlY (Amdry, -45+5m) was firstly deposited as metallic bond coat layer onto the surface of AISI 420 substrate, and then FeCr slag layer was deposited as the top coating layer. After the deposition of FeCr slag powder, the resulting coating layer was found to have low porosity with a homogeneous microstructure. The deposited FeCr slag coatings were subjected to isothermal oxidation tests at different temperatures and test durations for determination of their oxidation behavior and upper operating temperature limits. The results obtained from this study indicate that FeCr slag can be considered as an alternative protective coating material for caster rolls which are subjected to high temperatures up to 800 degrees C.

WOS: 000450762200032, In the present study, the metallographic, mechanical and tribologic behaviors of AISI D2 steel specimens coated with TiC through the titanizing process were investigated. The titanizing treatment was performed at the temperatures of 900 degrees C, 1000 degrees C or 1100 degrees C for 1h, 2h or 3h using a solid-state box thermoreactive diffusion technique. In all cases, the predominant phase in the coating was TiC, but the mechanical properties of the coating varied with treatment condition. The wear resistance of the coated samples against a linear reciprocating Al2O3 ball improved as the hardness and thickness of the coating increased. The effective wear mechanism of samples that had been treated at 900 degrees C, 1000 degrees C and 1100 degrees C were severe plastic deformation, delamination and polishing type wear, respectively. The wear performance was affected by coating layer's thickness and uniformity as well as its surface hardness, elastic modulus and toughness.

WOS: 000437057900015, Externally cooled rolls of a steel plant were coated using three different surface modification techniques, namely titanizing, boronizing and borotitanizing. The grown coatings were examined using optical microscopy, scanning electron microscopy, microhardness measurements, X-ray diffraction and Raman analysis. Depending on the coating technique, a wide range of coating thicknesses and microhardness values were obtained; the highest microhardness was obtained in the titanized sample, while the greatest coating thickness was obtained in the borotitanized sample. Wear tests were performed on the untreated and coated specimens using a ball-on-disc wear tester under two different loads (1 N, 3 N) at three different temperatures (25 degrees C, 25 degrees C, 45 degrees C). The average friction coefficient values decreased at elevated temperatures, and increased under increased load. Temperature had a significant effect on the wear mechanism. At room temperature the effective wear mechanism was delamination, while at 25 degrees C and 45 degrees C oxidative wear was observed. All of the surface modification treatments improved the wear resistance. The highest wear resistance was observed in the borotitanized sample.

The current study focuses on the microabrasion wear and microstructural properties of CoNiCrAlY coatings fabricated on nickel-based superalloy substrates using atmospheric plasma spraying (APS), high-velocity oxygen fuel (HVOF), and cold gas dynamic spraying (CGDS) methods. The microabrasion tests were performed on the samples for different durations in order to understand the wear mechanism of thermally sprayed coatings and influence of the coating microstructure on the wear mechanism. The microstructures of as-sprayed coatings and wear mechanisms on the worn coatings were investigated. Initial surface topography was examined using a surface profilometer. Coating hardness measurements were performed with a microhardness tester. The lateral fracture was observed as the wear mechanism on the samples. The wear resistance of the coatings has changed with the surface features of the samples depending on the coating production process.

WOS: 000395355300044, Inconel 625, a nickel-based superalloy, is used in a wide range of applications including the marine and petroleum industries under where it is subjected to harsh conditions such as high temperatures and highly corrosive environments. However, its wear resistance is limited and can be often considered unsatisfactory in some applications. If this alloy were to be used under abrasive wear conditions, its surface would have to be protected by a wear resistant coating. In this study, a two-step thermo-chemical borotitanizing treatment (including an initial boriding step followed by titanium diffusion) is proposed. Microstructural characterization (optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction) and mechanical properties (induding micro-hardness and micro-abrasion wear) of the coated samples were conducted. Microstructural studies revealed a compact, homogenous, silicide-free coating, consisting of four distinct regions: a TiB2 layer, a multi-phase boride layer, a diffusion zone and the substrate. Hardness values were significantly higher than those obtained by standard boriding treatments. Due to the nano-sized bodding agents used, the coatings formed on the surface were thicker than coatings obtained by methods such as nitriding, paste bodding and pack-boriding, and comparable to that of laser boriding. The wear resistance was improved by up to ten times in comparison with untreated Inconel 625. Grooving was the effective wear mechanism in untreated Inconel 625. How-ever the increase in surface hardness achieved by the borotitanizing treatment changed the wear mechanism in the coated samples from grooving to rolling. (C) 2016 Elsevier B.V. All rights reserved., Scientific Research Council of Mustafa Kemal University [13911], This study was supported by the Scientific Research Council of Mustafa Kemal University (Project Number 13911). The authors wish to thank Mustafa Kemal University for its grant contributions to this study.

PubMedID: 27015815 Background: Our purpose was to show the association of adrenal incidentaloma and metabolic syndrome in consideration of the studies and to detect the increase in the carotid intima-media thickness which is regarded as the precessor of atherosclerosis. Material/Methods: Eighty-one patients who were diagnosed with adrenal mass were included in the study. Hormonal evaluation, insulin rezistance measurement with the HOMA-IR and 1-mg DST were performed of all patients. The patients were classified as follows: mass size

The effects of different soil tillage methods on rhizobial nodulation, biomass yield (root, shoot and nodule) and nitrogen content of soybean as a second crop have been investigated. The experiment was conducted as a field trial in Cukurova Region, Turkey in 2008. Six different tillage methods have been studied in this research. These methods were conventional tillage with residue (CTR), conventional tillage with burnt residue (CTBR), reduced tillage with heavy disking (RTHD), reduced tillage with rotary tiller (RTR), no- tillage with heavy disking (NTHD) and no tillage with direct seeding (NTDS). At the stage of inflorescence, nodulation was investigated in the root, shoot, and nodule samplings by determining the weights of the samples and analyzing them for nitrogen contents. The results have been statically analyzed by using MSTAT-C package programme. According to the results of the study, under the conventional methods in which deep tillage operations are applied to soil, it has been found out that nodule formation and plant nitrogen contents have been negatively affected. The differences among the applications were found to be statistically significant. In general, the best nodulation has been obtained with NTDS and RTHD plots. Moreover, the effects of other tillage methods on some parameters related with rhizobiyal N2-fixation have caused to considerable decrease on the parameters mentined above. Key words: N2-fixation, soil tillage methods, microbial activity.

Low carbon steel surfaces were alloyed with composite powders using the tungsten inert gas welding method. After the alloying process, the effects of welding parameters, such as energy input, progress speed and coating thickness on the microstructural characteristics of the alloyed samples were examined. In the experimental investigation, a low carbon steel surface was alloyed with austenitic stainless steel powder and austenitic stainless steel composites mixed with 4·5% Co, Mo and Ti particles respectively. Following surface alloying, conventional characterisation techniques, such as optical microscopy, scanning electron microscopy, energy dispersive spectrograph and X-ray diffraction, were used to study the microstructure of the alloyed zone. Hardness measurements were also performed across the alloyed zone. Examination of the microstructure revealed the presence of M23C6 carbides, solid melt phases, and intermetallic phases, such as Ni3Ti, depending on the alloying element in the composite. As...

Boron nitride based tribological coatings promise hope in tribological applications thanks to their excellent lubrication and heat resistance properties. However, the applicability of these coatings on cutting tools in machining applications is not well known and it needs to be revealed. Therefore, in this study, a boron nitride (BN) coating was deposited on carbide milling tools. Inconel 718 was used as workpiece material in face milling tests to determine the wear behavior of the BN coated carbide tools. Surface roughness and tool wear was recorded in relation with cutting length. Wear mechanisms on the coated carbide tools were determined using scanning electron microscopy in combination with energy dispersive spectroscopy. Abrasive and adhesive wear was found as main failure mechanisms on the worn tools. Approximately two times longer tool life was obtained with the BN coated carbide tools.

This study examines abrasive and adhesive wear behaviour of austenitic stainless steel and its TiC alloyed composite produced through powder metallurgy technique. Abrasive wear tests have been carried out using a pin on disc wear tester under loads of 10, 20 and 30 N. For adhesive wear tests, a block on ring wear tester has been used under loads of 20, 40, 60 and 80 N. A possible correlation between the hardness, microstructure and wear behaviour of the samples has been investigated. The abrasive wear tests have revealed that the highest rate of mass loss occurred in the austenitic matrix stainless steel sample; also, mass losses decreased with an increased rate of reinforcing material in the composite. In adhesive wear tests, interparticle spacing developed from severe wear and extreme plastic deformation under heavy loads; however, at low loads, oxidation type wear was shown to be dominant.

Using powder metallurgy, composites of austenitic stainless steel were produced along with unreinforced stainless steel mixed with titanium, cobalt and molybdenum particles. Wear resistance of the materials was measured by a two body pin on disc wear tester. SiC abrasive papers of 80 and 220 mesh sizes were used as abrasive media. Wear tests were performed under loads of 10, 20 and 30 N at room temperature. The abrasive wear measurements showed that the softer, unreinforced austenitic stainless steel exhibited higher mass loss than the composites. Furthermore, the abrasive wear resistance of the reinforced austenitic stainless steel composites increased with increasing FeTi, FeMo, or Co volume content. In addition, the wear rate against the 80 grade SiC abrasive paper increased more than against the 220 grade SiC abrasive paper.

PubMedID: 26847505 An intravenous leiomyomatoma is a rare benign smooth muscle tumour originating from myometrial veins. Surgical resection is the best treatment for intracardiac extension of intravenous leiomyoma. Here we present a very rare case of intravascular and intracardiac leiomyomatosis. We successfully performed one-stage surgery to remove the leiomyomatosis with beating heart under cardiopulmonary bypass. © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ).