Microstructural Characterization and Deformation of X10CrAlSi24 Sheet Material Applied V-Bending Process

This study used X10CrAlSi24 (1.4762) sheet material, which is widespread in bending processes of the energy sector. During bending of X10CrAlSi24 (1.4762) sheet materials, cracking and tearing occur due to these materials’ brittleness at room temperatures. To avoid this phenomenon, bending was carried out by applying normalization treatments at 800 ºC, 850 ºC, 900 ºC and 950 ºC. V-bending processes were performed at three different bending angles (30º, 60º, 90º) and by a 4.5 mm punch tip radius. V-bending processes were carried out without leaving the punch on the material, and crushing of the punch on the sheet material sectional area was allowed. As a result of the bending processes, spring-go occurred in the 30º and 60º bending applications, whereas spring-back occurred in the 90º bending applications. The formation mechanism of capillary cracks (depending on deformation) due to internal stress especially at low temperatures was introduced by the microstructural characterization of the specimens

Differential Pulse Voltammetric Determination of Clozapine in Drug Dosage Forms at Bismuth Film Electrode

A new differential pulse voltammetric method for the determination of clozapine in drug dosage forms has been described. In this study, the amount of clozapine in commercial forms has been determined at bismuth modified glassy carbon electrode by taking advantage of the electrochemical oxidation of it. The glassy carbon electrode was modified with BiCl3 to prepare the bismuth film electrode. The acetate buffer solution at pH = 5.00 was selected as the supporting electrolyte in where the maximum current was observed for clozapine at the bismuth film electrode. The effect of pH on peak current and peak potential of clozapine was investigated by differential pulse voltammetry (DPV), and the effect of scan rate on the peak current was examined by cyclic voltammetry (CV). With this developed voltammetric method, the detection limit for clozapine in the working range of 1×10-6 M and 10×10-6 M was found to be 6.112×10-9. The amount of clozapine in the drug tablets was stated after the determination of analytical parameters. The recovery study was executed to check the accuracy and precision of the applied method

Monitoring of Lead and Some Heavy Metals in Wheat Flour of Corum Province, Turkey: An Air Quality Comparison

Food security is a priority issue for sustainable global development. Metal uptake by plants could have a significant impact on crop quality in areas of rapid industrialization with high fallout of airborne particles. In this study, concentrations of some heavy metals (copper, Cu; zinc, Zn; and lead, Pb) in flour samples supplied in Çorum, defined as one of the “New Industry Focus”, were investigated using inductively coupled plasma-optical emission spectrometry (ICP-OES) to determine the heavy metal contamination. The results showed that the concentration of Pb in all samples examined exceeded the maximum permissible limit. To monitor the increase in Pb concentration and its relationship with air pollution, a two-year laboratory experiment was conducted. It was found that the increase in Pb concentration of about 47% and 77% for two flour samples was consistent with the increase in annual average particulate matter with diameter 10 micrometers PM10 concentrations (55% and 82%) obtained from two stations

Super-tough biodegradable poly(vinyl alcohol)/poly(vinyl pyrrolidone) blends plasticized by glycerol and sorbitol

Tough biodegradable films were prepared using a poly(vinyl alcohol) (PVA)/poly(vinyl pyrrolidone) (PVP) (1:1) blend with plasticizers of glycerol (GLY), sorbitol (SOR), and their (one to one) mixture. We studied the effect of plasticization on the structural, thermal, and mechanical properties of the PVA/PVP blend films. Fourier transform infrared spectra indicated good miscibility of the two components due to the H-bonding between the PVA and PVP molecules. The addition of plasticizers reduced the interaction between PVA and PVP, evidenced by an increase in the intensity of PVA diffraction peaks observed in the X-ray diffraction (XRD) characterization. Thermal degradation of the blends increased as a function of the plasticizer used. GLY affected thermal degradation more than SOR and the mixtures. The incorporation of the plasticizers promoted the growth of PVA crystals as evidenced by XRD patterns and the enthalpy of fusion (ΔHf) obtained by differential scanning calorimetry measurements. The introduction of SOR to the binary blend increased toughness seven times and imparted simultaneous and pronounced improvements to maximum tensile stress and elongation at break. This behavior holds out great promise for the development of a new generation of mechanically robust, yet thoroughly biodegradable materials that could effectively supplant conventional polymers in demanding applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46406

PRODUCTION WITH GAS ATOMISATION METHOD OF AA 2014 ALLOY POWDER

Bu çalışmada; AA 2014 aluminyum alaşımına ait tozların üretimi, atomizasyon tekniklerinden gaz atomizasyon yöntemi kullanılarak, düşey gaz atomizasyon ünitesinde 790-800-810ºC olmak üzere farklı sıcaklıklarda gerçekleştirilmiştir. Sıcaklık değerindeki artışa bağlı olarak küresel toz şeklinin yerini gözyaşı damlası ve çubuksu toz şeklinin aldığı gözlemlenmiştir. Üretilmiş tozlar elek analizine tabii tutulduktan sonra son dört elek aralığındaki tozların Tava (<53&#956;m) - 270 mesh (53&#956;m) &#8211; 200 mesh (74&#956;m) &#8211; 140 mesh (105&#956;m) homojen bir karışımı sağlanarak toz boyut analizi uygulanmıştır. Toz boyutu analizi sonrasında ortalama toz boyutu 90,66&#956;m olarak tespit edilmiştir. Ortalama toz boyutu 90,66 &#956;m olan tozlar daha sonra presleme işlemine tabii tutulmuştur. Farklı presleme basınçları (250-875 MPa) denenmek suretiyle optimum presleme basıncı olarak 650 MPa tespit edilmiştir. Bu presleme basıncı altında 1x1x2 mm ebatlarında deney numuneleri üretilmiştir. Elde edilen deney numuneleri kullanılarak, farklı sıcaklık (550-560-570-580-590-600- 610-620ºC) ve sürelerde (1-2-4 saat) sinterleme işlemi yapılmıştır. Uygun olan sinterleme sıcaklık ve süresinin tespit edilmesinde, gözenek-yapı etkileşimi göz önünde bulundurularak mikro yapı görüntüleri üzerinden inceleme yapılmıştır. Bu bağlamda 550ºC sıcaklıktaki 4 saat sinterleme süresi, sinterleme pratiğinin anlaşılabilmesi için yeterli olmuştur. Artan sinterleme sıcaklıklarında gözenekliliğin artış gösterdiği, gözenek şekli açısından düzensiz şekilli olduğu tespit edilmiştir. Sinterleme sonrasında deney numunelerine sertlik testi uygulanarak, sinterleme süresinin ve sıcaklığın sertlik üzerinde nasıl bir etki meydana getirdiği tespit edilmeye çalışılmıştır. AA 2014 malzemesi için en yüksek sertlik değeri 560 ºC deki 4 saatlik sinterleme süresi ile 56,84 HV olarak tespit edilmiştir. Yapılan deneysel çalışmalar ile hem optimum şartlar hem de belirlenmiş tüm parametrelerin mikro yapı üzerinde ne derece etkili olduğu araştırılmıştır. Bu amaçla Optik Mikroskop, Taramalı Elektron Mikroskobu (SEM) ve Enerji Dağılım Spektrometresi (EDS) kullanılmıştır. Numunelerin sertlik değerlerinin tespit edilmesinde ise makro ve mikro olmak üzere iki farklı sertlik ölçme cihazından yararlanılmıştır.In this study production of AA 2014 Aluminium alloy powder has been carried out at different temparatures like 790-800-810ºC in the unit of vertical gaz atomisation by using the method of gas atomisation among the atomisation methods. It has been observed that spherical powder type has turned into tear drop and stick toz type. After sieve analysis of the powder which has been produced, powder size analysis has been carried out by having a homogen mix of powder Tava(<53&#956;m)-270mesh(53&#956;m)-200mesh(74&#956;m)-140mesh(105&#956;m) which is among last four sieve values. After powder size analysis, avarage powder size has been found as 90,66 &#956;m. Powders, which avarage size is 90,66 &#956;m has been pressed. 650Mpa has been found as optimum pressing pressure after different pressing pressures (250- 875Mpa) being tried. Under this pressing pressure experiment samples being 1x1x2 sizes have been produced. By using this experiment samples, sintering process has been done at different temparatıres (550-560-570-580-590-600-610- 620 ºC) and times (1-2-4 hours). Micro structure has been investigated by porestructure interaction when suitable sintering temparature and times. So the times of 4 hours sintering at 550 ºC has been enough for sintering process. It has been found that porosity has increased at increasing sintering temparatures and types of porosity have been irregular. After sintering process, hardness testing has been applied to experiment samples and it has been tried to find how sintering times and temparature has effected the hardness. It has been found that the highest hardness value for AA 2014 material has been 4 hours sintering time at 560 ºC and 56,84 HV. It has been searched by the experimental studies how both the whole parameters and optimum conditions have effected the micro structure. Fort his purpose Optical microscope, Scaning Electron Microscope (SEM) and Energy Dispersive Spectrometry (EDS) have been used. Two different hardness measurement device such as macro and micro has been used to find the values of samples hardness

Characterization and production of nanoparticle boron carbide by mechanochemical synthesis

Ülkemiz bor zenginlikleri göz önünde bulundurulduğunda ve ileri teknoloji ürünleri noktasına dönüştürülmesi aynı zamanda bu ürünlerin nano parçacık boyutunda sentezlenebilirliği oldukça önemlidir. Bu denli önemli malzemelerin, bir oda sıcaklık sentez yöntemi olması sebebiyle mekanokimyasal olarak sentezlenebilirliği ve henüz sanayimizde uygulanmayışı açısından geliştirilebilirliği ön plana çıkmaktadır. Yapılan bu tez çalışması kapsamında mekanokimyasal sentezleme yöntemi kullanılarak nano parçacık boyutunda B4C üretimi gerçekleştirilmiştir. Bu amaç için deneysel çalışmalarda başlangıç malzemeleri olarak, B2O3-C-Al ve B2O3-C-Mg üçlü sistemleri, reaksiyon stokiyometrik oranlarında kullanılmıştır. Deneysel çalışmalarda B2O3 ' ün indirgenmesi işlemleri atritör, planetary ve speks tipi öğütme cihazları kullanılarak yapılmıştır. Farklı öğütme ortamları ve belirlenen çalışma parametreleri altında, nano boyutlu Al2O3 / B4C ve MgO / B4C seramik fazlarının sentezi gerçekleştirilmiştir. Ayrıca sentezlenen malzemelerin, nano parçacık boyut, XRD, FT-IR ve EDS analiz ölçümleri yapılmıştır. Mikro yapısal karakterizasyonları bakımından, SEM ve TEM (görüntüleme ve seçilmiş alan kırınım örgesi) incelemeleri yapılmıştır. Çalışmanın son aşamasında ise, sentezlenen seramik fazların (Al2O3 / B4C ve MgO / B4C) liç işlemi ile safsızlıklarından arındırılarak, tek başına nano parçacık boyutunda B4C' nin üretimi gerçekleştirilmiştir. Speks tipi öğütücü kullanıldığında 2 saatlik öğütme sonunda seramik fazların oluştuğu XRD analizi ile belirlenmiş ve bu dönüşümler 6 saat sonunda tamamlanmıştır. FT-IR analizi ile B-C bağ yapılarının oluşumu belirlenmiştir. Liç işlemleri öncesinde yapılan TEM incelemelerinde, tozlarda aglomerasyon oluştuğu ve toz boyutlarının yaklaşık 350 nm civarında olduğu tespit edilmiştir. Liç işlemleri sonrasında ise sentezlenen tozların bir kısmının 50 nm' nin altında, diğerlerinin ise 50350 nm aralığında değiştiği belirlenmiştir. B4C parçacıklarının liç işlemi sonrasında TEM incelemelerinde, düzlemsel hata olarak gözlenen ikiz oluşumlarının olduğu görülmüştür. TEM kırınım desenlerinin çözümü ile hesaplanan d değerlerine bağlı olarak, nano boyutlu B4C parçacıklarının temsil ettiği düzlemler belirlenmiştir.Considering boron wealth of our country's, be converted into advanced technology products of this product and synthesizability with nano particle size is quite very important. The use of such an important material has come to fore as mechanochemical synthesis by a room temperature method and yet unavailability in our industry. In this thesis, production of boron carbide with nano particle size was performed by mechanochemical synthesis method. For this purpose in experimental studies, the starting materials (B2O3-C-Al and B2O3-C-Mg) were used by reaction stoichiometric ratios. In experimental studies, reduction studies of boron oxide were performed using the milling devices (attritor, planetary and spex). Under the different milling atmosphere and operating parameters, The synthesis of the ceramic phases (Al2O3 / B4C and MgO / B4C ) was carried out. In further work, nano-particle size, XRD, FT-IR and EDS analysis of materials synthesized were measured. In terms of micro-structural characterization, SEM and TEM (imaging and selected area diffraction pattern) investigations were done. In the final part of the study, production of boron carbide with nano particle size purified by leaching from impurities the ceramic phases (Al2O3 / B4C and MgO / B4C) synthesized was carried out. According to XRD analysis in the studies performed with spex, formation of the ceramic phases was determined and the conversion was completed after 6 hours. Bonding structures of B-C were determined by FT-IR analysis. Formation of agglomeration at powders and the particle size (350 nm) was determined before leaching process. Formation of B4C particles of 50 nm and lower was determined and also in the range of 50-250nm after leaching process. The presence of twin formation defined as planar defects at B4C particles was determined by TEM investigations after leaching process. Planes of the boron carbide nanoparticles were identified by the solution of the diffraction pattern in TE

The Turkish and Russian Relationships (1920- 1923)

I. Dünya Savaşı sonunda Mondros Mütarekesi imzalanmış ve Batılı Emperyalist Devletler bu antlaşmanın yedinci maddesine dayanarak Osmanlı Devleti topraklarını işgal hareketine girişmişlerdir. Ülke topraklarının işgal edilmesi üzerine Mustafa Kemal Paşa'nın önderliğinde Milli Mücadele hareketi başlamıştır. Ve Türk milletinin Milli Mücadele hareketinden haberdar olmasını sağlamak amacıyla Anadolu Müdâfaa-i Hukûk Cemiyeti adına Mustafa Kemal Paşa tarafından Hâkimiyet-i Milliye gazetesi kurulmuştur. Ancak bu mücadelede başarılı olmak için yalnızca halkın bu harekete katılması yeterli olmayacaktır. Savaşmak için gerekli imkânları sağlayacak emperyalist emeller beslemeyen bir devletin yardımına ihtiyaç duyulmuştur. Mustafa Kemal Paşa aynı düşmana karşı savaşmamız ve aynı doğrultuda bir mücadele vermemiz nedeniyle bu devletin Rusya olması gerektiğine karar vermiştir. Ve bu doğrultuda dış politikayı yönlendirmek amacıyla Millî Mücadele'nin Anadolu'dan yükselen sesi olan Hâkimiyet-i Milliye gazetesini yani basın politikasını en iyi şekilde kullanmayı bilmiştir. Bu çalışma Milli Mücadele döneminde yayınlanmaya başlayan gazetenin Türk- Rus ilişkilerini nasıl yansıttığını ve verilen mücadeleyi nasıl yönlendirdiğini 1920 ve 1923 yılları içerisinde incelemektedir. Bu sürede konumuzla ilgili olan bütün haberler taranıp Arap harflerinden Latin harflerine transkribe edilmiş ve zamanın şartları göz önüne alınarak incelenmiştir. Yayınlanan haberlere bakıldığında Türk-Rus ilişkilerinin her yönüyle gazete sütunlarına taşındığı, olumsuz hiçbir yazının yazılmadığı ve Türklerle Rusların emperyalizme karşı verdikleri ortak mücadele nedeniyle dost olmaları gerektiğinin vurguladığı görülmektedir. Ayrıca Hâkimiyet-i Milliye gazetesinin Millî Mücadelenin liderleri tarafından çıkarıldığı göz önüne alınırsa bir devleti kurmak için sadece askeri ya da siyasi politikanın değil basın politikasının da ne derece ustalıkla yürütülmesi gerektiği anlaşılacaktır.At the end of World World I Mondros Armistice was signed and according to the seventh entry of the armistice Western Imperialist States attempted to occupy the Ottoman State territories. Upon the territories being occupied, the National Struggle started with the leadership of Atatürk. And Hakimiye Milliye newspaper was established by Mustafa Kemal Pasha on behalf of Anadolu Müdâfaa-i Hukûk Cemiyeti in order to make the Turkish People inform about the National Struggle. But the participation of only the people wouldn't be enough so as to be successful in this fight. A country that would provide the necessary needs and that wouldn't be on the side of emperialism was needed. Mustafa Kemal Pasha decided that that country would be the Russian State on account of being on the same side and struggling with the same enemy. Therefore, he was able to use the newspaper Hâkimiyet-i Milliye which was the rising voice of National Struggle of Anatolia efficiently in order to direct the foreign policy. This study is examining how the newspaper, which started to be published during the National Struggle period, reflect Turkish-Russian relationships and how it could direct the struggle between the years 1920 and 1923. Within this period all the news related to our subject have been scanned, transcribed from the Arabic alphabet to the Latin one, and has been examined by taking into consideration of the conditions of their time. According to the published news, it can be clearly seen that all the relations between Turkish and Russian were carried in the articles, there were no negative written articles, and there were a number of emphasis why Turkish and Russian were friends due to giving mutual struggle against emperialism. Furthermore, if the newspaper Hâkimiyet-i Milliye published by the National Struggle leaders taken into consideration, it would fully be understood that not merely military or political but press policy should be carried out in order to found a country

Examination of Microstructure and Mechanical Properties of Powder Metal AA 2014-SiC-B4C Composite / Hybrid Materials

In this study, the production, microstructure and mechanical properties of AA 2014 aluminum alloy and B4C-SiC ceramic particle reinforced hybrid metal matrix composite materials were investigated by powder metallurgy. For this purpose, SiC (5-10-15%), B4C (5-10-15%) and B4C-SiC (10%-10%) ceramic particle reinforced composite and hybrid composite materials were produced in different volume ratio on aluminum matrix structure. Matrix and reinforcement powder blends were sintered under argon atmosphere at 600ºC for 1 hour by pressing one-way as block-shaped samples under 700MPa. The produced experiment specimens were characterized in terms of SEM (Scanning Electron Microscope), Optical microscope and micro hardness (HV 0. 1) measurements. It was shown that aluminium matrix structure exhibited homogenous distribution depending on the increase in the volume ratio of B4C ve SiC ceramic particles; this was detected with microstructure images. According to the AA 2014 aluminum alloy, the hardness values were found to increase due to the increasing SiC and B4C ceramic particle reinforcement ratio. In B4C-SiC particle reinforced hybrid composite materials, the micro hardness value was relatively reduced compared to the single ceramic phase reinforcement containing B4C 15% ve %15 SiC

The Effect Of Heat Treatment On The Formability Behavior Of Hardox-500 Sheet Material

Gerçekleştirilen çalışmada, Hardox 500 sac malzeme oda sıcaklığında 90º V dip bükme kalıbında şekillendirildiğinde, kırılma ve çatlamalar meydana gelmiştir. Sac malzemenin şekillendirilebilirliğini arttırmak amacıyla farklı sıcaklıklarda (850ºC, 900ºC, 950ºC ve 1000ºC) normalizasyon ısıl işlemi uygulanmıştır. Normalizasyon ısıl işlemi sonrasında sac malzemelere, V dip bükme kalıbı kullanılarak direk ve ezerek bükme işlemleri uygulanmıştır. Bükme işlemleri sonrası sac malzemelerde, makro ve mikro boyutta herhangi bir kırılma veya çatlak oluşumlarının meydana gelmediği tespit edilmiştir. Artan normalizasyon ısıl işlem sıcaklıklarında, geri esneme miktarlarının azaldığı belirlenmiştir. Ezerek bükme işlemlerinde ise, geri esneme değerlerinin azaldığı tespit edilmiştir.In this study, fracture and cracking were occurred when Hardox 500 sheet material formed at 90 V bottoming bending dies at room temperature. Hardox 500 sheet materials were normalized at different temperatures (850ºC, 900ºC, 950ºC and 1000ºC) to increase formability. Direct and crushed bending processing were made using the V bottoming bending die on the sheet materials after the normalization heat treatment. After macro and micro analyses of bended sheet materials, any crack and fracture formation were not observed. The amount of spring back decreased with increasing normalization temperatures. In the crushed bending process, it is also determined that the amount of spring-back value decreased

Effect of Cu addition on microstructure and mechanical properties of NiTi based shape memory alloy

In this research paper, pre-alloyed NiTi based shape memory alloy and 4%Cu were used asstarting powder materials. Starting powder materials were blended for 60 minutes by a turbulamixer. After mix processing, microstructure and phase transformations of powders werecharacterized using X-ray (XRD), elemental distribution spectrometry (EDS), scanning electronmicroscopy (SEM). Prepared powder mixtures as NiTi and NiTi4%Cu alloys were pressed at785MPa in a mold and then sintering process was applied to materials at different temperaturesand time. Formation of multiphase’s (Ni3Ti, NiTi, Ti2Ni, Ni4Ti3 and NiTiCu) and positive effectsof Cu addition were obtained by sintering at different temperatures and time. And also, stabilizedNiTi phase and increasing the value of micro hardness were determined with added 4%Cupowders