Otomotiv sektöründe kullanılan dp600 çeliklerinin CMT kaynak yöntemi kullanılarak birleştirilmesi ve mekanik özelliklerinin incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Teknolojinin gelişmesi ile otomotiv sektöründe yakıt tasarrufu, yolcu güvenliği ve dayanım açısından ihtiyaçlar ortaya çıkmıştır. Bu ihtiyaçlar otomotiv tasarım ve araştırmacılarını yüksek mukavemetli çelikler üzerinde çalışmalar yapmaya yönlendirmiştir. Yüksek mukavemet değerlerine sahip, kolay işlenebilir ve yüzeylerindeki çinko kaplamasından dolayı korozif ortamlara karşı dayanımları olan DP600 çelikleri otomotiv sektöründe geniş kullanım yelpazesine sahip olmuştur. Günümüzde kaynaklı birleştirme tekniklerindeki gelişmeler ile yeni araştırmalar ve AR-GE çalışmaları sonucu Soğuk Metal Transfer Kaynağı (CMT) tekniği bulunmuş ve kullanılmaya başlanmıştır. DP 600 çeliklerinin birleştirilmesinde geleneksel birleştirme yöntemleri olan Metal Inert Gaz (MIG), Metal Aktif Gaz (MAG) ve Direnç Nokta Kaynak yöntemleri yerine daha düşük ısı girdileri sağlayan Soğuk Metal Transferi kaynağının (CMT) kullanılabilirliği bu tez çalışmasında araştırılmıştır Yapılan bu çalışmada 1,2 mm kalınlığında DP600 çift fazlı çelik saclar CMT kaynak yöntemi ile bakır esaslı CuSn1, CuSn6 ilave telleri kullanılarak, farklı akım şiddetlerinde, bindirme ve alın birleştirme geometrilerinde birleştirilmişlerdir. Hazırlanan bu numuneler için çekme mukavemet testleri, kaynak bölgesindeki mikrosertlik dağılımları incelenmiştir. Taramalı elektron mikroskobu (SEM) ve noktasal element analiz cihazı (EDS) ile element analizleri yapılmıştır. Bağlantının makro ve mikro yapı görüntüleri optik mikroskop aracılığı ile alınarak ıslatma açıları, kaynak yükseklikleri, kaynak genişlikleri hesaplanmıştır. Anahtar Kelimeler: DP600 çift fazlı çelik, CMT kaynak yöntemi, Otomotiv endüstrisiWith the development of technology, there has been a need for fuel saving, passenger safety and durability in the automotive sector. These needs have led automotive designers and researchers to work on high strength steels. DP600 steels with high strength values, easy workability and resistance to corrosive environments due to their zinc coating on the surface have a wide use range in the automotive sector. With the developing technology in today's techniques, Cold Metal Transfer (CMT) welding, which is the result of new researchs and AR-GE studies, has begun to be used. The DP600 steels are joined with the CMT, which provides lower heat inputs, instead of the Metal Inert Gas (MIG) and Metal Active Gas (MAG) welding methods, which are traditional assembling methods. In this study, DP600 dual phase steel sheets with 1.2 mm thickness were prepared by using CMT welding method and copper based CuSn1, CuSn6 with additional wires, different current intensities, overlapping and picking methods. Tensile strength tests and microhardness distributions in the weld zone were investigatedfor prepared specimens. Elements were analyzed by scanning electron microscope (SEM) and point element analyzer (EDS). Wetting angles, weld heights and weld widths were calculated by taking through macro and microstructure images of connection through an optical microscope. Keywords:DP600 dual phase steel, CMT welding method, automotive industryandstee

Reactions of anthocyanin rich in maize genotypes to low temperature treatments according to photosynthesis, gas exchange properties, and bio-active compounds

Low temperatures during the early growing stages limit the productivity of maize considerably. Investigating responses of different coloured corns (Zea mays L.) to chilling may reveal alternative genotypes which can be preferred under early sowing conditions of water-shortage farming areas. The aim of this study is determining whether the color factor affects the tolerance to chilling in maize and which properties are effective on the low temperature tolerance. We exposed corns with different colours (white, yellow, red, purple) to different temperatures [8°C, 12°C, 16°C, 25°C (control)] and analysed the effects of temperature on morphological, physiological, bio-active properties and stress indicators. Using 14-day old seedlings, we noted that purple corn had the highest seedling length, seedling weight, chlorophyll content, stomatal conductance, chlorophyll B and total phenolic content in the 8°C and followed by white (photosynthesis rate, chlorophyll fluorescence, chlorophyll A and carotenoids), yellow (transpiration rate, sub stomatal CO2, and total antioxidant activity) and red corns (water use efficiency, total anthocyanin content and proline). On the other hand, white corn maintained its superiority in other treatments, receiving the highest values in 9 of 17 characteristics at 12°C, in 8 of 17 at 16°C and in 10 of 17 in the control. Performance of purple corn in the 8°C was the most remarkable one in all genotypes and treatments. Based on our results, it has been concluded that white and purple corns are more chilling tolerant genotypes and may be alternative for early sowing conditions in drought farming areas

Sex-hormone-binding globulin early in pregnancy for the prediction of severe gestational diabetes mellitus and related complications

Aims: The aim of this study was to evaluate the predictive value of sex-hormone-binding globulin (SHBG) for the diagnosis of gestational diabetes mellitus (GDM), and to clarify the association between SHBG levels and GDM complications/medication requirements. Material and Methods: Among the participants (n = 93) who provided blood samples between 13 and 16 weeks’ gestation, 30 cases subsequently developed GDM. Complications and medical interventions were noted. The best cut-off point of SHBG and diagnostic performance were calculated. Results: The mean age was 28.45 - 5.0 years. SHBG levels were lower in the GDM group (n = 30) when compared with non-GDM (n = 63) cases (<0.01). Among the GDM women, SHBG was lower in the insulin therapy group (n = 15) compared with medical nutritional therapy alone (n = 15) (P < 0.01). A good predictive accuracy of SHBG was found for GDM requiring insulin therapy (area under the curve: 0.866, 95% confidence interval: 0.773–0.959). An SHBG threshold for 97.47 nmol/L had a sensitivity of 80.0%, specificity 84.6%, positive predictive value 50.0% and negative predictive value 95.7%. The calculated odds ratio for SHBG < 97.47 nmol/L was 12.346 (95% confidence interval: 1.786–83.33). Conclusions: SHBG is valuable for screening women early in pregnancy for GDM risk; however, a standard assay for analyses and a threshold level of serum SHBG for a constant gestational week has to be determined

Çokal Barajı (Çanakkale) çökme modeli ve taşkın risk analizi

The source of the hazard which is the main factor of disasters can be made by naturally or man. These are generally independent sources, but sometimes reason of one hazard such as flood can be both naturally and man-made. Certainly, all examples in our country and the world show that, the fail of constructed structures on the rivers (e.g. dam, embankment) produce a very large amount of water and damage more than the normal river floods. In this study, based on cofferdam of &Ccedil;okal Dam breaching which occurred in 16 November 2007 on the Kavak River (&Ccedil;anakkale), 1D modeling of probable &Ccedil;okal Dam break take in the account tectonic properties of the area and analyzing of the flood risk have been done. For these purposes, Digital Elevation Model (DEM) gathered contours from 1:25000 scaled topographic maps and GPS points, high and medium resolution satellite images, hydrological soil data gathered from soil maps scaled 1:25000, precipitation and discharge data in 30 years, technical properties of structures on the Kavak River and field measurement have been used as a database. All these data is processed and analyzed using Geographic Information System (GIS), Hec-GeoRAS and HEC-RAS hydraulic models and hydrologic model. Hence, &Ccedil;okal Dam break modeling based on cofferdam breach modeling reveals that probable flood after the dam-break will affect Evreşe Plain and the people which get livelihood from the plain. General probable lost in agricultural product after probable flood reaches TL 12 million. Thus, as a result of human interventions to the nature will cause great harm to himself again.&nbsp;&nbsp;&nbsp;Afetlerin oluşmasında &ouml;nemli etkiye sahip tehlikeler, doğa kaynaklı olabildikleri gibi insan kaynaklı da olabilmektedir. Bunlar genelde birbirinden bağımsız tehlike t&uuml;rleri iken bazen taşkınlar gibi kaynağını hem doğadan hem insandan alan tehlikeler olarak da karşımıza &ccedil;ıkmaktadır. Ş&uuml;phesiz ki &uuml;lkemizdeki ve d&uuml;nyadaki &ouml;rneklerin tamamı ortaya koymuştur ki, insan kaynaklı olarak akarsular &uuml;zerine inşaa edilen yapıların (baraj, set vb.) bir şekilde zarar g&ouml;rmesiyle sonu&ccedil;ları normal taşkınlardan da fazla olmuştur. Bu &ccedil;alışmada, 16 Kasım 2007'de Kavak Deresi (&Ccedil;anakkale) &uuml;zerindeki &Ccedil;okal Barajı menba batardosunda meydana gelen &ccedil;&ouml;kmenin oluşturduğu taşkına bağlı olarak, g&uuml;n&uuml;m&uuml;z itibariyle halen yapımına devam edilen &Ccedil;okal Barajı'nın sahanın tektonik &ouml;zellikleri de g&ouml;z&ouml;n&uuml;nde tutularak, olası &ccedil;&ouml;kmesinin tek boyutlu (1D) hidrolik modellemesi yapılmış ve buna bağlı taşkın risk analizi ger&ccedil;ekleştirilmiştir. &Ccedil;alışmada altlık verileri, 1:25000 &ouml;l&ccedil;ekli topografik eşy&uuml;kselti eğrisi ve saha GPS verileriyle &uuml;retilmiş Sayısal Y&uuml;kselti Modeli (SYM), y&uuml;ksek ve orta &ccedil;&ouml;z&uuml;n&uuml;rl&uuml;kl&uuml; uydu g&ouml;r&uuml;nt&uuml;leri, hidrolojik toprak&nbsp; verileri, 30 yıllık yağış ve akım verileri, Kavak Dere &uuml;zerindeki yapılara ait teknik &ouml;zellikler ve arazi &ouml;l&ccedil;&uuml;mleri oluşturmaktadır. B&uuml;t&uuml;n bu altlık veriler Coğrafi Bilgi Sistemleri (CBS), Hec-GeoRAS ve HECRAS hidrolik modelleri&nbsp; ve hidrolojik modellerde kullanılmış ve analiz edilmiştir. Sonu&ccedil; olarak, menba batardosu &ccedil;&ouml;kme modeli temelinde oluşturulan &Ccedil;okal Barajı &ccedil;&ouml;kme modeli g&ouml;stermiştirki, olası baraj &ccedil;&ouml;kmesi sonucunda oluşacak taşkın, Evreşe Ovası ve buradan ge&ccedil;imini sağlayan insanlar i&ccedil;in b&uuml;y&uuml;k zararlar ortaya &ccedil;ıkartacaktır. Sadece tarım &uuml;r&uuml;nleri &uuml;zerindeki genel tahmini kayıplar 12 milyon TL yi bulmaktadır. B&ouml;ylelikle insanın doğaya yapmış olduğu m&uuml;dahale sonucunda yine insanın kendisi b&uuml;y&uuml;k zararlar g&ouml;recektir.&nbsp; &nbsp;&nbsp;&nbsp;&nbsp

A study on relation between unit cost of the ırrigationwater used andwater charges determined by water user association

Gelismekte olan ülkeler kadar gelismis ülkeler de sulama ücretlerinin uygun seviyesi ve su ücretleri için kullanılacak araçları belirlemede uzlasma saglayamamıstır. Suyun fiyatı, su kayıplarını azaltma, sulama kurumunun finansmanı ve sulama yatırımlarından yararlananların geri ödemesi gibi farklı amaçları içerebilmektedir. Bir çok ülke artan nüfus baskıları ve su kıtlıgını içeren sulama suyu düzenlemelerinde baslıca araç olarak sulama ücret yöntemlerini kullanmaktadır. Dogru fiyatları olusturma suyun etkin olarak tahsisatında arzu edilen bir durumu olusturmaktadır.Ancak, bunun nasıl yerine getirilecegi tartısmakonusudur. Bu çalısmada;Aydın Ovası Sulama Birligi tarafından bitki desenine baglı olarak birim sulanmıs alan yöntemi temel alınarak belirlenen sulama ücretleri ile sulama sebekesine saptırılan sulama suyunun birim maliyeti göz önüne alınarak hesaplanan sulama ücretleri arasındaki iliski arastırılmıstır. Incelenen yıllarda, Aydın sulama sebekesi yerçekimsel ve pompaj sulama alanlarında bitki desenine baglı olarak sulanmıs alan yöntemi ile belirlenen sulama ücretleri, birim su maliyetine göre hesaplanan sulama ücretleri ile örtüsmemektedir. Özellikle, pompaj sulama alanlarında sulama birligi tarafından belirlenen sulama ücretleri olması gerekenin altında gerçeklesmistir. Bu neden ile Aydın Ovası sulama birligi, sulama ücretlerini belirlerken bitki desenine baglı olarak bitkinin birim alan su kullanımı ile suyun birim maliyetini temel alarak hesaplanan sulama ücretlerini kullanmalıdır.In developed as well as developing countries, there is disagreement regarding the appropriate means by which to price water and appropriate level of water charges. The pricing of water may involve different objectives, such as cost recovery, financing the irrigation agency or reducing wastage of water. In addressing water scarcity and increased population pressures many countries are adopting water-pricing mechanisma as their primary means to regulate water consuption. Getting prices right is seen as a desirable way to allocate water efficiently, but how to accomplish tho remain a debatable issue. In this study, it was investigated in relation to between water charges based on the method unit irrigation area, depending on the kind of crops irrigated by Aydın Plain Irrigation Associtiation (APIAs) and the water charges calculated according to unit water cost of the irrigation water diverted the network. The water charges determined by the APIA , according to unit irrigation area, depending on the kind of crop irrigated in gravitation and pump irrigation area of the Aydın Plain irrıgation network are not to compete with the water charges calculated to the unit water cost. Particularly, the water charges determined by the APIAs in the pump irrigation areas are fairly lower than the charges calculated to unit water cost; however, while the charges are determined by APIAs, the water charges based on the unit square water use of crops, depending on the kind of the crops and unit water cost are to be used

Length of Hospital Stays of Patients Operated Due to Glioma Tumours in Neurosurgery Clinics and Intensive Care Units

DergiPark: 963054tmsjAims: To evaluate the relationship between the length of hospital stay and age, gender, and disease characteristics among glioma patients who went under surgery in Trakya University School of Medicine. Methods: The data of 51 glioma patients over 18 years of age, who have been followed up during 2019-2020 in Trakya University School of Medicine, Department of Neurosurgery were analyzed. Patients' data comprised of sex, age, tumour location, grades of the tu- mours, the presence of isocitrate dehydrogenase mutation, whether the patients were hospitalized in the intensive care unit or the neurosurgery clinic, duration of hospitalization, and whether radiotherapy and chemotherapy was received. Length of hospital stay was evaluated separately as intensive care unit and the neurosurgery clinic. Results: Out of 51 patients diagnosed with glioma, 18 (35.3%) were female, and 33 (64.7%) were male. The length of neurosurgery clinic and intensive care unit stays were not associated with radiotherapy and chemotherapy approaches. There was a statistically significant difference between the male and female patients in terms of the number of days stayed in the neurosurgery clinic. Conclusion: In conclusion, gender affected the length of neurosurgery clinic stays with a longer duration for female patients in our clinic. A waste number of parameters, including social ones, affect hospital stays. To reveal predictors of postoperative hospitalization thoroughly and overcome the study’s limitations, further prospective studies with larger sample sizes are needed

Determination of the Best Growth Curve and Measurement Interval in Norduz Male Lambs

The aim of this study, was to determine the best non-linear model and measure interval (biweekly or monthly) in explaining the body weight-age relationship in Norduz male lambs born in 2004. For this aim, Brody, Logistic, Gompertz and Richards non-linear models were fitted to the average body weight-age data with 15 (biweekly) days and 30 (monthly) days of measure intervals. Although, Logistic model become equal to Richards model (99.8%) for two intervals, Logistic model had lower RMSE than Richards model. Therefore, the best non-linear model for 2 intervals was Logistic model having the highest coefficient of determination (R2) but the lowest Root of Means Square Error (RMSE). Contrary to Brody non-linear model, the usage of 30 days of measure intervals performed positive effect on Logistic, Gompertz and Richards non-linear models instead of 15 days of measure interval. As a result, it was concluded that the best non-linear model for Norduz male lambs was Logistic model and the appropriate measure interval for Norduz male lambs was monthly interval

Effect of Continuous Positive Airway Pressure on Overactive Bladder Symptoms in Patients with Obstructive Sleep Apnea Syndrome

Objective:To evaluate overactive bladder (OAB) in male and female patients with moderate or severe obstructive sleep apnea syndrome (OSAS) and to investigate the impact of three months of continuous positive airwMethods:Twenty-eight female and 45 male patients with moderate and severe OSAS whose obstructive sleep apnea (OSA) severity was evaluated according to the apnea–hypopnea index were included in the study. Patients’ voiding symptoms were evaluated using the validated Turkish translations of overactive bladder symptom scores (OAB-V8) and the International Consultation on Incontinence Questionnaire Short-Form (ICIQ-SF) at OSAS diagnosis and at 3-months after the CPAP therapy.Results:Patients with moderate and severe OSAS were more likely to have OAB than the average population, and CPAP therapy improved the symptoms of OAB in both male and female patients. In addition, a positive association was observed between OSA severity and OAB-V8 and ICIQ-SF in female patients and between OSA severity and OAB-V8 in male patients.Conclusion:Our findings suggest that CPAP therapy improves the clinical symptoms of OAB. Thus, unnecessary medical or interventional treatment of OAB can be avoided in such patients

Endobronchial Watanabe Spigot in the treatment of bronchobiliary fistula

Bronchobiliary fistula (BBF) is a rare condition in which an abnormal communication exists between the bile ducts and the bronchial tree. Malignancy is the most common etiology of BBF, although many others are possible. A 74-year-old male patient with an inoperable Klatskin tumor presented with a complaint of yellow-green sputum and cough; the patient underwent fiber-optic bronchoscopy based on a preliminary diagnosis of bronchobiliary fistula. Using fiber-optic rigid bronchoscopy, the laterobasal segment of the lower right lung lobe was occluded using three pieces of 5-mm Endobronchial Watanabe Spigot. Bile drainage subsequently ceased. A bronchoscopic approach provides an alternative option for BBF treatment, particularly in patients who choose not to undergo surgery, or for whom surgery is not an option due to their underlying general condition

Remembering the Occam’s Razor: Could simple electrocardiographic findings provide relevant predictions for current hemodynamic criteria of pulmonary hypertension?

Background: We evaluated the predictive value of electrocardiographic (ECG) findings for pulmonary hemodynamics assessed by right heart catheterization (RHC). Methods: Our study population comprised 562 retrospectively evaluated patients who underwent RHC between 2006 and 2022. Correlations between ECG measures and pulmonary arterial systolic and mean pressures (PASP and PAMP) and pulmonary vascular resistance (PVR) were investigated. Moreover, receiver operating characteristic (ROC) curve analysis assessed the predictive value of ECG for pulmonary hypertension (PH) and precapillary PH. Results: The P-wave amplitude (Pwa) and R/S ratio (r) in V1 and V2, Ra in augmented voltage right (aVR), right or indeterminate axis, but not P wave duration (Pwd) or right bundle branch block (RBBB) significantly correlated with PASP, PAMP, and PVR (P 0.16 mV, Ra in aVR > 0.05 mV, QRS axis > 100° and R/Sr in V1 > 0.9 showed the highest area under curve (AUC) values for PAMP > 20 mm Hg. Using the same cutoff value, Ra in aVR, Pwa, QRS axis, and R/Sr in V1 showed highest predictions for PVR > 2 Wood Units (WU). Conclusion: In this study, Pwa, Ra in aVR, right or indeterminate axis deviations, and R/Sr in V1 and V2 showed statistically significant correlations with pulmonary hemodynamics, and Ra in aVR, R/Sr in V2 and V1, QRS axis, and Pwa contributed to variance for PASP, PAMP, and PVR, respectively. Moreover, Pwa, Ra in aVR, QRS axis, and R/Sr in V1 seem to provide relevant predictions for PH and precapillary PH