Gama absorpsiyon tekniği ile kıymetli metallerin analizi ve değerlendirilmesi

Silver, platinum and gold are described as precious metals; they are most popular jewelry and preferable metals in modern society. In this study, a nuclear technique as namely "Gamma Absorption Technique" is used for the analysis of the three main precious metals. Samples have been supplied for four different silver alloys, four different platinum alloys and five different gold alloys. Am-241 has been used for Ag analysis and Ba-133 gamma radioisotopes has been used for Pt and Au analysis as gamma sources. Experiment device consist of a gamma source, collimator, NaI (Tl) detector, multi-channel analyzer with shielding materials. Experiments repeated at least five times and average net counting rate is calculated.  Calibration curves could be drawn as a result of the experiments. These curves were examined by unknown samples and it was shown the reliability of the curves. The mass attenuation coefficients of alloys were measured. Theoretical mass attenuation coefficient values were obtained using the WinXCom program. The comparison of the experimental results with the theoretical values was in a good and acceptable agreement. Precious metals analysis can be observed and mass attenuation coefficients were determined at near energy of elements K absorption edge. So, it can be offered that the gamma absorption technique can be used for the determination of the mass attenuation coefficients.Keywords: Gamma absorption technique, silver, platinum, gold, mass attenuation coefficient.Bu çalışmada, nükleer bir teknik olan gama absorpsiyon tekniği, kıymetli metallerden gümüş, platin ve altının analizine ilişkin olarak kullanılmıştır. Numuneler; gümüş için dört, platin için dört ve altın için beş farklı ayarda temin edilmiştir. Gama radyoizotop kaynağı olarak gümüş için Am-241, platin ve altın için  Ba-133 radyoizotopları kullanılmıştır. Deneylerden elde edilen sonuçlarla kalibrasyon eğrileri çizilebilmiştir. Bu çalışmanın özgünlüğü çerçevesinde çalışılan numunelerin kütle zayıflatma katsayıları deneysel olarak tayin edilmiştir. Deneysel sonuçlar WinXCom programından elde edilen sayısal sonuçlarla mukayese edilmiş ve birbirleri ile ileri derecede uyum sağladığı gösterilmiştir. Bu şekilde, gama absorpsiyon tekniğinin kütle zayıflatma katsayılarının deneysel olarak tayininde kullanılabileceği önerilmektedir.   Anahtar Kelimeler: Gama absorpsiyon tekniği, gümüş, altın, platin,kütle zayıflatma katsayısı.&nbsp

Investigating the effect of recycled cotton included fabrics on the thermal behaviour by using a female thermal manikin

In recent years, with the increase in global awareness of environmental problems, the term “sustainability” became more important for apparel manufacturers and consumers. Therefore, recycling of wastes plays a significant role in environmental sustainability by converting the wastes into raw materials. This study focused on recycled cotton-included fabrics, to evaluate the effect of these fabrics on thermal comfort properties. In this context, first, the 45% recycled cotton/55% polyester blended yarns and 50% virgin cotton/50% blended yarns were obtained. Afterwards, single jersey and rib-structured fabrics were knitted using these yarns. The thermal comfort tests were performed on the fabrics and four long sleeve rounded neck shirts then were manufactured using these fabrics to test by the thermal manikin method. Results showed that the yarns including recycled cotton led to a decrease in the values in air permeability of the fabrics and in the effective clothing insulation of the garments. In contrast, it was observed that, including recycled cotton increased the thermal resistance values of the fabrics.The authors also would like to thank Kempaş İplik Tekstil Ürünleri San. ve Tic. A.Ş. for supplying the yarns and Sun Holding A.Ş. for knitting the fabricThe authors gratefully acknowledge the funding by the project 15-MUH-035 of Ege University funded by Scientific Research Projects Coordination as well as the funding by the project UIDB/00264/2020 of 2C2T – University of Minho, Center for Textile Science and Technology, funded by National Founds through FCT/MCTES

Analysis of the three main precious metals by using gamma absorption technique, determination and evaluation of mass attenuation coefficients

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2005Thesis (Ph.D.) -- İstanbul Technical University, Institute of Science and Technology, 2005Kıymetli metal olarak nitelenen gümüş, platin ve altın, hem yatırım aracı hem de güncel kullanımlarda tercih edilen yaygın kullanımı olan metallerdendir. Bu özel metallerin analizleri farklı alanlar için önem taşımaktadır. Kıymetli metallerin analizi için çeşitli yöntemler geliştirilmiştir. Ateş analizi, küpelasyon ve spektroskopik tekniklerin yam sıra, X ışınları flüoresans tekniği (XRF), atomik absorpsiyon ve nötron aktivasyon analizi gibi nükleer tekniklerle de kıymetli metallerin analizini yapmak mümkün olmaktadır. Bu çalışmada, nükleer bir teknik olan gama absorpsiyon tekniği ile kıymetli metallerden gümüş, platin ve altın ile çalışılmıştır. Numuneler gümüş için dört, platin için dört ve altın için beş farklı ayarda temin edilmiştir. Gama radyoizotop kaynağı olarak gümüş için Am-241, platin ve altın için Ba-133 radyoizotopları kullanılmıştır. Deney düzeneği; gama radyoizotop kaynağı, kollimatör, NaI(Tl) sintilasyon detektörü, çok kanallı analizör ve zırh elemanlarından oluşmaktadır. Deneyler en az beş kez tekrarlanmış ve doğal ortam sayımlan çıkarılarak net sayımlara ulaşılmıştır. Deneylerden elde edilen sonuçlarla, gümüş, platin ve altın için kalibrasyon eğrileri çizilebilmiştir. Çizilen bu kalibrasyon eğrilerinin sınanması amacı ile bilinmeyen alaşımlı numunelerle çalışılmış ve ayarlan tayin edilebilmiştir. Böylelikle, çizilen eğrilerin güvenilirlikleri kanıtlanmıştır. Çalışılan numunelerin kütle zayıflatma katsayılan deneysel olarak tayin edilmiştir. Deneysel sonuçlar WinXCom programından elde edilen teorik sonuçlarla mukayese edilmiş ve birbirleri ile uyum sağladığı görülmüştür. Böylelikle, çalışmanın genelinde ve özelindeki özgünlükle gama absorpsiyon tekniği kullanılarak kıymetli metallerin analizi yapılabilmiş ve elementlerin K absorpsiyon süreksizliği enerjilerine yakın enerji değerlerinde kütle zayıflatma katsayılan tayin edilebildiği gösterilmiştir. Bu şekilde, gama absorbsiyon tekniğinin kütle zayıflatma katsayılarının deneysel olarak tayininde kullanılabileceği önerilmektedir.Silver, platinum and gold known as precious metals are used as an investment tool and have a wide range of application area in daily usage. The analysis of these special metals plays an important role for different areas. Various methods have been developed for analysis of precious metals. The analysis of precious metals is also possible with nuclear techniques such as X-Ray fluorescence (XRF), atomic absorption and neutron activation analysis besides the fire assay process, cupellation and spectroscopic techniques. In this study, a nuclear technique called as "Gamma Absorption Technique" is used with precious metals as silver, platinum and gold. Samples are prepared with four different alloys for silver and platinum and five different alloys for gold. Am-241 is used for silver and Ba-133 is used for platinum and gold as gamma radioisotope sources. The experiment set up consists of a gamma radioisotope source, a collimator, a Nal (TI) detector, a multi-channel analyzer and shielding materials. The experiments have been carried out for at least five times and back-ground counting values are subtracted for calculating the net counting rates. Calibration curves of silver, platinum and gold are drawn as a result of the experiments. Samples with unknown alloys have been used in order to verify these calibration curves and their alloy rates are determined. As a result, the reliability of the drawn curves has been proved. The mass attenuation coefficients of the samples have been determined by the experiments. The experiment results are compared with the theoretical results obtained from the WinXCom software program and it is observed that the experiment results are in conformity with the theoretical ones. The analyses of precious metals are done with gamma absorption technique and it is seen that mass attenuation coefficients can be determined at the energy levels close to the K-absorption edge energy levels of elements. Therefore, it is offered that the gamma absorption technique can be used experimentally in determining the mass attenuation coefficients of elements.DoktoraPh.D

Examination of Cardiovascular Risk Factors, Physical Activity Level and Anxiety of Urban Public

Amaç: Çalışmamızın amacı; Kırıkkale ilinde şehir içi minibüs şoförlerinde değiştirilebilir Kardiyovasküler hastalık risk faktörlerinin fiziksel aktivite düzeyinin ve anksiyete durumunun belirlenmesiydi. Gereç ve yöntem: Katılımcıların sosyo demografik bilgileri kaydedildi. Sigara, egzersiz alışkanlığı sorgulandı ve vücut kütle indeksi belirlendi. Anksiyete durumu Beck Anksiyete Ölçeği ve fiziksel aktivite düzeyi Uluslararası Fiziksel Aktivite Anketi (UFAA) ile değerlendirildi. Sonuçlar: Çalışmamıza 250 gönüllü minibüs şoförü katıldı (yaş ortalaması, 39.33±10.86 yıl). UFAA puanları dikkate alındığında, bireylerin % 5,2'sinin yeterli fiziksel aktivite düzeyine sahip olduğu görülmüştür. Şoförler % 64,8 i kalp hastalığının önlenebileceğini düzenli egzersiz yapmanın önemini belirtti. Anksiyete durumları ile fiziksel aktivite düzeyleri arasında ilişki saptanmadı. Tartışma: Kardiyovasküler hastalık gelişimi, özellikle tütün kullanımı, sağlıksız beslenme alışkanlıkları, fiziksel inaktivite ve psikososyal stress gibi yaşam tarzını belirleyen faktörler ile yakından ilişkilidir. Katılımcıların genç yaş ortalamasına rağmen, kalp damar hastalıkları, obesite, hipertansiyon gibi sorunlara rastlanmıştır. Tüm bu sağlık sorunlarının önlenebilmesinde sağlıklı yaşam tarzının benimsenmesi en önemli rolü oynamaktadırPurpose: Purpose of this study is to examine the alterable cardiovascular risk factors of urban minibus drivers in the city of Kırıkkale, and to determine physical activity levels and anxiety statuses. Material and Methods: Their socio-demographic data were recorded. Drivers’ habits of smoking and exercise were questioned and their body mass indexes were determined. Anxiety statuses were assessed by using Beck Anxiety Scale and physical activity levels were assessed by using International Physical Activity Questionnaire. Results: 250 volunteering minibus drivers (mean age 39.33±10.86) were participated to the study. Regarding their UFAA scores, 5.2% of the individuals had adequate physical activity levels. 64.8% of participants thought the cardiovascular diseases could be prevented and 31.6% implied the importance of regular exercise program. There was no relationship between physical activity and anxiety. conclusionon: Cardiac diseases are closely related with life style factors such as; smoking, unhealthy eating habits, physical inactivity, and psycho-social stress. Ailments like; cardiovascular diseases, obesity, hypertension were observed, although the participants had a young mean age. Adopting a healthy life style plays the most important role in preventing all these health problem

The evaluation of physical activity levels in Turkish dialysis patients

Aim: Physical inactivity is associated with the increased incidence of hospitalizations, increased risk of mortality due to heart diseases in hemodialysis patients. The aim of study was to evaluate the functional and physical activity levels of chronic renal failure patients receiving hemodialysis treatment.Material and Methods: 96 of whom were hemodialysis patients (63,22 12,84 years) and 107 (51,07 8,33 years) healthy people, participated to the study. The functional activity level was assessed with the Human Activity Profile. The level of physical activity was determined with the Turkish version of the International Physical Activity Questionnaire Short Form.Results: When the hemodialysis patients and the control group were compared in terms of the functional activity and physical activity level after controlled the age variable, Maximum Activity Score (MAS) and the Adjusted Activity Score (AAS) values and Turkish version of the International Physical Activity Questionnaire (IPAQ) levels of the hemodialysis group were significantly lower (p0.05). When the activity levels of the hemodialysis group were compared by gender, the Adjusted Activity Score values of females were significantly lower (p0.05), and the Turkish version of the International Physical Activity Questionnaire Short Form daily activity levels and Maximum Activity Score values were similar (p 0.05).Conclusion: The functional and physical activity levels of chronic renal patients receiving hemodialysis treatment were significantly lower. We believe that the results of our study give a small idea of the possible functional limitations and physical inactivity of the dialysis patients in our country

Simulation of magnetic actuation of ferrofluids in microtubes

Magnetic actuation of ferrofluids with dynamic magnetic fields is one of the most promising research areas with its wide and different potential application areas such as biomedical and micropumping applications. Ferrofluid has the potential of opening up new possibilities. To have more understanding about various fields of engineering, more research should be conducted by considering both the experimental and modeling aspects. The most important parameters determining the flow property, flow rates and overall system efficiency are the quality and the topology of magnetic fields used in these systems. Therefore, the methods of dynamic magnetic field generation constitute a central problem to obtain desired performance. This study includes modeling and simulation of ferrofluid actuation with dynamic magnetic fields by using the COMSOL software and reports that ferrofluid actuation can be successfully used and the simulation results agree well with the experimental results

Is bladder blood flow an etiologic factor for the bladder pain syndrome?

Aim: Bladder pain syndrome (BPS) is a complex disease which causes cognitive, behavioral, sexual, and emotional problems. Vascular factors related to bladder blood supply may be one of the etiologic cause of BPS. This study aims to investigate the bladder blood flow and internal iliac artery resistive indices of patients with BPS. Methods: A total of 30 female patients with the diagnosis of BPS and 30 female as control group were enrolled in the study. Bilateral internal iliac arterial blood flow distal to uterine arteries were examined as the primary source of vesical arterial blood supply. Peak systolic velocities, end diastolic velocities, resistive indices, and flow volumes of internal iliac arteries were measured by color Doppler ultrasonography in a single-blind fashion. Results: The blood flows volume of the right and left internal iliac arteries during empty and full bladder were significantly lower at BPS group compared with control (P 0.05). Aging decreased the bladder blood volume and both BPS and control group internal iliac artery blood volume decreased by aging. The decrease was more significant at the control group, but the internal iliac artery blood volume was still lower at patients with BPS compared with the control group. Conclusion: Arterial blood flow of bladder was lower at patients with BPS compared with the control group. The decrease in the vascular supply of bladder might be one of the related factors for the BPS etiology. © 2019 Wiley Periodicals, Inc

Is bladder blood flow an etiologic factor for the bladder pain syndrome?

Aim: Bladder pain syndrome (BPS) is a complex disease which causes cognitive, behavioral, sexual, and emotional problems. Vascular factors related to bladder blood supply may be one of the etiologic cause of BPS. This study aims to investigate the bladder blood flow and internal iliac artery resistive indices of patients with BPS. Methods: A total of 30 female patients with the diagnosis of BPS and 30 female as control group were enrolled in the study. Bilateral internal iliac arterial blood flow distal to uterine arteries were examined as the primary source of vesical arterial blood supply. Peak systolic velocities, end diastolic velocities, resistive indices, and flow volumes of internal iliac arteries were measured by color Doppler ultrasonography in a single-blind fashion. Results: The blood flows volume of the right and left internal iliac arteries during empty and full bladder were significantly lower at BPS group compared with control (P 0.05). Aging decreased the bladder blood volume and both BPS and control group internal iliac artery blood volume decreased by aging. The decrease was more significant at the control group, but the internal iliac artery blood volume was still lower at patients with BPS compared with the control group. Conclusion: Arterial blood flow of bladder was lower at patients with BPS compared with the control group. The decrease in the vascular supply of bladder might be one of the related factors for the BPS etiology. © 2019 Wiley Periodicals, Inc