Strong strain path dependence of strain localizations and fracture in magnesium AZ31 sheet

This study compares the deformation and fracture behavior of a basal-textured Mg AZ31 alloy sheet under uniaxial tension and biaxial stretching by using an in-plane biaxial test setup capable of observing and measuring the deformation at both meso (millimeter) and microstructure scales. Strain distributions at the mesoscale and accompanying fracture surfaces indicate a significant dependence on strain path. At the microscale, limited slip activity in biaxial case promotes contraction twins, where severe strain localizations (epsilon(max)/epsilon(mean) approximate to 20) to the twins and their boundaries cause mainly transgranular fracture. This leads to a brittle, and a more pronounced shear-type fracture under biaxial stretching. In uniaxial case, considerable tensile twinning activity reorients the initial texture for slip activity. Strain localizations (epsilon(max)/epsilon(mean) approximate to 2) to the grain interiors and boundaries initiate mainly intergranular fracture. Samples fail by displaying both brittle and ductile fracture structures, with smaller shear lips compared to the biaxial case.Publisher's Versio

ATTITUDES OF PREHOSPITAL EMERGENCY HEALTH CARE WORKERS TOWARDS SPINAL CORD IMMOBILIZATION IN PATIENTS WITH MULTIPLE TRAUMA

INTRODUCTION: To evaluate the attitudes of prehospital emergency health care workers towards spinal cord immobilization in trauma patients. MATERIAL AND METHODS: This is a descriptive study, and its participants were 407 pre-hospital emergency healthcare workers working in a province in the west of the country between April 2022 and October 2022. The data were collected online with a questionnaire consisting of twenty-four questions. Statistical significance was defined as a p-value of 0.05 for all analyses. RESULTS: 73% of the participants that they decided to perform routine spinal cord immobilization in all trauma patients regardless of the clinical findings. 85% of the participants said they generally preferred the backboard for spinal cord immobilization of trauma-injured people. CONCLUSIONS: The study showed that prehospital emergency health care workers stated that they routinely perform spinal cord immobilization in every traumatized patient, despite knowing the indication for spinal cord immobilization of trauma patients

Preoperative MELD-Na Score Predicts 30-day Post-operative Complications After Colorectal Resection for Malignancy

Introduction:Predicting possible complications in colon surgery is important in terms of reducing postoperative mortality and morbidity rates. Various scoring methods have been used to predict these complications. The MELD score was developed to predict mortality following Transjugular Intrahepatic Portosystemic Shunt (TIPS) placement in cirrhotic patients. This model was revised by adding Na data and used to predict complications in non-cirrhotic patients. We investigated the value of the MELD-Na score in predicting postoperative 30-day complications in patients undergoing colorectal resection for malignancy.Methods:Patients who underwent colorectal resection for malignant diseases were included in the study. Demographics and clinical outcomes were recorded. The MELD-Na scores of the patients were calculated within 48 h before the surgery. Patients were divided into 2 groups according to the status of development of any complication.Results:Age, gender, operative time, and length of stay was not statistically significant for developing complications. The MELD-Na score was significantly higher in patients with any complications. Also, MELD-NA score, stoma creation, and postoperative erythrocyte suspension replacement were found to be independent risk factors for developing complications in patients undergoing surgery for colon cancer.Conclusion:The MELD-Na score may predict the complications that may develop in the first 30 days postoperatively in patients undergoing colorectal resection for malignant diseases

Children in 2077: Designing Children’s Technologies in the Age of Transhumanism

What for and how will we design children’s technologies in the transhumanism age, and what stance will we take as designers? This paper aims to answer this question with 13 fictional abstracts from sixteen authors of different countries, institutions and disciplines. Transhumanist thinking envisions enhancing human body and mind by blending human biology with technological augmentations. Fundamentally, it seeks to improve the human species, yet the impacts of such movement are unknown and the implications on children’s lives and technologies were not explored deeply. In an age, where technologies can clearly be defined as transhumanist, such as under-skin chips or brain-machine interfaces, our aim is to reveal probable pitfalls and benefits of those technologies on children’s’ lives by using the power of design fiction

Yoga egzersizlerinin, çalışanlarda esenlik ve yaşam kalitesi üzerine etkisi

YOGA EGZERSİZLERİNİN, ÇALIŞANLARDA ESENLİK ve YAŞAM KALİTESİ ÜZERİNDEKİ ETKİSİBu çalışma; Yoga’nın özel sektörde, çalışanlara Esenlik ve Yaşam Kalitesine olumlu katkısının olacağı sonucunu ortaya çıkarmak amacıyla tarama modeli ile yapılmış bir çalışmadır. Araştırma, yaşları 18 ile 69 arasında değişen haftada bir defa düzenli Yoga eğitimine katılmış ve hiç Yoga eğitimi almamış toplam 292 çalışan bireylere uygulanmıştır.Algılanan Esenlik Ölçeği (Perceived Wellness Survey) kapsamlı bir çalışma olan Algılanan Esenlik Modeli (Adams, Benzer, Steinhardt 1997) temel alınarak geliştirilen bir çalışmasıdır. Çalışma, bireylerin fiziksel, psikolojik, duygusal, entelektüel, sosyal ve manevi olmak üzere, altı Esenlik boyutu hakkındaki algılarını ölçmeyi amaçlamaktadır. Ölçeğin Türkiye örneklemine geçerlilik ve güvenilirliği, Serkan Memnun tarafından “Algılanan Esenlik Ölçeğinin (Perceived Wellness Scale) Geçerlilik ve Güvenilirlik Çalışması ve Beden Eğitimi Öğretmenlerinin Esenlik Algıları” isimli yüksek lisans tezinde 2006 yılında yapılmıştır. Cronbach Alpha katsayıları birinci uygulamada, 80,84; ikinci uygulamada ise, 82,33 olarak bulunmuştur. Yaşam Kalitesini ölçme ve değerlendirme çalışmaları, Dünya Sağlık Örgütü tarafından 1980’ den beri yapılmaktadır. Bu amaçla kişinin iyilik halini ölçen ve kültürler arası karşılaştırmaya olanak veren geniş kapsamlı bir Yaşam Kalitesi ölçeği (Dünya Sağlık Örgütü Yaşam Kalitesi-WHOQOL) geliştirmiştir. Dünya çapında 15 merkezde yapılan pilot çalışmalar sonucu 100 soruluk WHOQOL-100 ve bunlardan seçilen 26 sorudan oluşan WHOQOL-BREF oluşturulmuştur. WHOQOL-BREF'’in ülkemizdeki geçerlilik ve güvenilirlik çalışması Fidaner ve arkadaşları tarafından yapılmıştır (Fidaner 1999). Böylece tüm parametrelerin karşılıklı olarak birbirleri üzerindeki etkileşimleri değerlendirilmeye çalışılacaktır. Anahtar Kelimeler: Esenlik, İş Hayatı, Stres, Yaşam Kalitesi, YogaTHE EFFECTS OF YOGA EXERCISES ON THE WELLNESS AND QUALITY OF LIFE OF THE EMPLOYEESSUMMARYThis study is based on survey in order to test whether Yoga has a positive effect on the wellness and quality of life of the employees of the private sector. The survey has been conducted on 292 working individuals with different ages varying between 18 and 69. The comparison sets are constituted of working individuals who have never participated in Yoga classes and those who have participated in Yoga classes once a week.Perceived Wellness Survey is developed based on the Perceived Wellness Model (Adams, Benzer, Steinhard 1997). This study aims at measuring the perceptions of the individuals about six wellness dimensions: physical, psychological, emotional, intellectual, social and spiritual. The reliability and the validity check of this scale in the case of Turkey was studied in the master’s thesis of Serkan Memnun (“The Study of Reliability and Validity of Perceived Wellness Scale and the Wellness Perception of Physical Education Teachers”) in 2006. Cronbach Alpha coefficients were 80,84 in the first implementation and 82,33 in the second.The studies to measure and assess the quality of life are being conducted by World Health Organization since 1980. For this purpose, a scale for measuring the quality of life of the individuals enabling a comparison between cultures and wellness of the individuals has been developed (WHOQOL). In 15 pilot studies conducted worldwide, a survey with 100 questions (WHOQOL-100) and a shorter version based on selected 26 questions out of that 100 (WHOQOL-BREF) were created. The validity and reliability of WHOQOL-BREF were studied by Fidaner and her colleagues (Fidaner, 1999). Taking all this into account, the aim of this study is to assess the interactions of these parameters and their effect upon each other.Keywords: Quality of Life, Stress, Wellness, Work Life, Yog

Forming and fracture limits of sheet metals deforming without a local neck

Under certain strain paths (e.g., balanced biaxial) and during some forming processes (e.g., incremental forming, micro forming), sheet metals may deform and fail without forming a local neck. In these cases, it is challenging to determine the forming limits using standard tests and measurement methods (ISO) designed to detect the formability from a sharp, single local neck. In this work, local necking was suppressed in an Al-6061-T6 alloy and a DC-04 steel with an in-plane biaxial (cruciform) test, and the fracture limits of these materials were measured at various strain paths together with the forming limits by an alternative Marciniak-Kuczynski based thickness strain ratio method (TRM). The measured strains were compared with the standard Nakajima tests containing sharp local necks. Due to the unique geometry of the cruciform test, both materials developed strain localizations and deformed until fracture without deviating from the predetermined strain ratio. This enabled a true measure of fracture strains of both materials, which was not possible with the standard tests. Moreover, the ISO method was not applicable to the case without local necking, whereas TRM resulted in similar forming limits in both tests

MAGNEZYUM LEVHA ŞEKİLLENDİRİLMESİ SIRASINDA İÇ YAPININ VE OLUŞAN KUSURLARIN İNCELENMESİ VE KONTRI-OL ALTINA ALINMASI

MAGNEZYUM LEVHA ŞEKİLLENDİRİLMESİ SIRASINDA İÇ YAPININ VE OLUŞAN KUSURLARIN İNCELENMESİ VE KONTRI-OL ALTINA ALINMAS

Evaluation of Internship Programs for Educational Improvements: A Case Study for Civil Engineering

The main goal of this paper is to evaluate civil engineering internship programs for educational improvements by doing statistical analyses on comprehensive survey data gathered from inquiry sheets. A web base online survey tool was prepared and 251 inquiry sheets were statistically analyzed. Univariate analyses were performed to describe the interns' population and their needs. Levene's test was used to test equality of variances and the t-value was used for equality of means. The One-Way ANOVA procedure was used to test the hypothesis that the means of groups are not significantly different. Finally, binary logistic regression was conducted to identify factors that predict the students' satisfaction level. A positive, statistically significant relationship was identified between internship satisfaction level, future carrier planning, multidisciplinary team working, learning theoretical and practical applications, food service during the internship period and worksite internship. This study proved that the civil engineering students are keen to participate in practical training programs during their period of education and also that civil engineering departments should update the theoretical courses taking into consideration the practical applications

MULTI-SCALE CHARACTERIZATION OF DEFORMATION IN ALUMINUM

Materials with deformation behavior sensitive to their microstructure may need deformation analysis at multiple scales to establish the relationship between the microstructure and response to deformation processing. In this work, we use in-plane biaxial test (cruciform) to measure the macro- and microstructure-scale mechanical behavior of a 6061-T6 aluminum alloy at various strain paths. We report flow curves, forming and fracture limits as examples to the macromechanical behavior. As an alternative to the tensile test, it is possible to plot flow curves up to larger strains with the cruciform test. Samples also deform uniformly during the cruciform test and do not develop instabilities in the form of local necks. This allows accurate measurements of forming, and especially fracture limits, under a preset and constant strain ratio. The micromechanical behavior, on the other hand, is quite heterogeneous and microstructure sensitive. Strain localizations at the microstructure scale cause large deviations from the global deformation strains and control the ultimate sample failure at the global scale

Large strain cruciform biaxial testing for FLC detection

Selection of proper test method, specimen design and analysis method are key issues for studying formability of sheet metals and detection of their forming limit curves (FLC). Materials with complex microstructures may need an additional micro-mechanical investigation and accurate modelling. Cruciform biaxial test stands as an alternative to standard tests as it achieves frictionless, in-plane, multi-axial stress states with a single sample geometry. In this study, we introduce a small-scale (less than 10 cm) cruciform sample allowing micro-mechanical investigation at stress states ranging from plane strain to equibiaxial. With successful specimen design and surface finish, large forming limit strains are obtained at the test region of the sample. The large forming limit strains obtained by experiments are compared to the values obtained from Marciniak-Kuczynski (M-K) local necking model and Cockroft-Latham damage model. This comparison shows that the experimental limiting strains are beyond the theoretical values, approaching to the fracture strain of the two test materials: Al-6061-T6 aluminum alloy and DC-04 high formability steel