TOBB ETU GCRIS Database
Not a member yet
9778 research outputs found
Sort by
Histological and Biomechanical Effects of Local Anesthetics and Steroids on Achilles Tendon: a Study in Rats
No full textBackground: Peritendinous injection of local anesthetics, alone or in combination with corticosteroids, is widely used in the treatment of tendinopathies. Toxicity of local anesthetics has been demonstrated in many cells, including myocytes, chondrocytes, and neurons. Bupivacaine and lidocaine are known to have time- and dose-dependent cytotoxicity in these cells. The effects of these agents on the tendon remain unknown. Purpose: To show histological and biomechanical effects after the injection of different local anesthetics and steroids, both single and combined, at different concentrations into the peritendinous sheath of rat Achilles tendon. Study Design: Controlled laboratory study. Methods: In the study, 100 rats were divided into 10 groups with equal body weights. Inflammation was induced in both Achilles tendons of each rat by means of the ball drop technique; 7 hours later, injections were made into the peritendinous sheaths of both Achilles tendons using lidocaine, bupivacaine, and dexamethasone as appropriate for the rat's group. At the end of the first week, the right Achilles tendons of the rats were removed for histological study. Left Achilles tendons were evaluated in terms of biomechanics. Results: Histological findings demonstrated that the group with the most toxicity to the tendon was the group that received injection of dexamethasone alone. The groups with the least toxicity were those receiving dexamethasone combined with low- or high-dose bupivacaine. Biomechanical findings showed that the experimental groups had similar results to each other with the exception of the groups receiving 0.25% bupivacaine alone and dexamethasone alone, in which tendons revealed higher tensile strength. Conclusion: Local anesthetic and steroid applications have different histological and biomechanical effects on the tendon. Although the dexamethasone-injected group was the most affected in terms of histology, these changes could not be demonstrated biomechanically
Regular Integral Transformations on Time Scales and Generalized Statistical Convergence
No full textIn this work, using regular integral transformations on time scales, we generalize the concept of statistical convergence. This enables us not only to unify discrete and continuous cases known in the literature but also to derive new convergence methods with choices of appropriate transformations and time scales. This is a continuation of our earlier work and includes many new methods. We obtain sufficient conditions for regularity of kernel functions on time scales and also we prove a characterization theorem for the generalized statistical convergence. At the end of the paper we display some applications and special cases of our results
Simultaneous Optimization of Topology and Process Parameters for Laser-Powder Bed Fusion Additive Manufacturing
No full textAdditive manufacturing (AM) technology is used in sectors such as automotive and aerospace, due to its advantages in producing complex and lightweight structures. However, it is necessary to reduce the total manufacturing costs for AM technology to become widespread. The topology optimization (TO) studies in the literature typically optimize only the design without taking into account the manufacturing phase or sequentially optimize the topology first and then the process parameters. On the other hand, simultaneous optimization of topology together with process parameters provides more efficient and less costly solutions. This paper describes a strategy for simultaneous optimization of topology along with process parameters of the laser-powder bed fusion (L-PBF) process. The topology, laser power, scanning speed, energy density, and yield strength are controlled by integrating the overall process-property-structure-performance relationship of the L-PBF process into the optimization. The proposed simultaneous optimization method aims to minimize the total cost function including material, manufacturing, and energy costs. Moreover, the constraint functions of the optimization include the volume fraction, the strength of the structure, and the energy density calculated according to the process parameters. The proposed method is successfully applied to three different design problems as cantilever beam, MBB beam, and L bracket, respectively. The results of different TO methods including conventional TO (compliance minimization), structural TO (similar to stress-constrained TO), and sequential process parameters and topology optimization are compared with the results of the proposed method. It is found that the proposed method provided the minimum cost results, and the obtained designs met the structural requirements.Scientific and Technological Research Council of Turkey (TUEBITAK) [5189901]This study is a part of the project (# 5189901) supported by The Scientific and Technological Research Council of Turkey (TUEBITAK) under the Frontier R ; amp;D Laboratory Support Program and performed in Turkish Aerospace Industries Inc. The funding provided by TUEBITAK under Grant No. 5189901 is gratefully acknowledged
Tasarım Stüdyolarında Gün Güneş Işığının Etkin Kullanımı Üzerine Bir Analiz
No full textIn contemporary times, with a growing emphasis on energy efficiency across various domains of life, the utilization of natural light sources, often referred to as clean energy, remains limited in indoor design. Therefore, a judicious approach involves actively integrating natural lighting during daylight and sunlight to effectively enhance indoor spaces. This integration not only maximizes the benefits of daylight/sunlight but also mitigates the consumption costs associated with artificial lighting. Consequently, this research focuses on educational structures, with a specific analysis of design studios, known for their frequent occupancy throughout the day. Design studios represent highly utilized spaces within university departments, including Interior Design, Architecture, Visual Communication, and Industrial Product Design. This research critically examines the significance of natural light, encompassing daylight, sunlight, and reflected light, as foundational elements of indoor design, followed by an extensive literature review of design decisions and criteria related to these aspects. A detailed description of the physical and functional attributes of design studios helps to contextualize the research area. In the first section of the research, the significance, purpose, scope, methodology, and structure of the topic are presented. The second section comprehensively examines daylight, sunlight, and reflected light design decisions and criteria based on the fundamental concept of natural light, forming the basis of the thesis. The third section describes design studios to better understand the physical and functional characteristics of the research area. In the fourth section, the chosen research area, TOBB ETÜ design studios, is analyzed in terms of daylight/sunlight design criteria and evaluated using simulation programs. The fifth and final section presents the results of the obtained data and provides recommendations based on these findings.Hayatın her alanında enerji verimliliği gözetilirken, temiz enerji olarak adlandıran doğal ışık kaynaklarının iç mekân tasarımında kullanımı asgari düzeyde tutulmaktadır. Bu nedenle gün ve güneş ışığının aktif olduğu süre boyunca doğal aydınlatmayı etkin bir biçimde iç mekân tasarımına dahil etmek doğru bir yaklaşım olacaktır. İç mekânda çeşitli tasarım kararları ile gün/güneş ışığından üst düzeyde fayda sağlanırken, o mekânda yapay aydınlatma enerjisinin tüketimine yönelik maliyetlerde bir düşüş yaşanmasına olanak sağlanacaktır. Bu bağlamda tez kapsamında araştırma alanı olarak eğitim yapılarına odaklanılmıştır. Çalışma alanını daha özele indirgemek adına gün içerisinde kullanım yoğunluğu oldukça fazla olan tasarım stüdyoları özelinde bir analiz gerçekleştirilmiştir. Tasarım stüdyoları, üniversitelerin içmimarlık ve çevre tasarımı, mimarlık, görsel iletişim ve endüstri ürünleri tasarımı bölümleri tarafından haftanın her günü ve her saati yoğunlukla kullanılan mekânlar olarak tanımlanabilir. Üniversite içerisinde bulunan diğer dersliklere göre daha yoğun kullanım sürelerine sahiptir. Bu bağlamda yapılan literatür taraması sonrası ortaya konan tasarım kriterleri kapsamında çalışma alanı analiz edilmiş ve iç mekânların azami düzeyde doğal ışık alımının sağlanması yönünde tasarımın önemi ortaya konmuştur. Araştırma kapsamında birinci bölümde, konunun önemi, amacı – kapsamı, yöntemi ve kurgusu aktarılmıştır. İkinci bölümde, tezin temelini oluşturan doğal aydınlatma kapsamında gün ışığı, güneş ışığı ve yansıyan ışık tasarım kararları ve kriterleri detaylı bir literatür taraması ile ortaya konmuştur. Üçüncü bölümde ise araştırma alanının fiziksel ve fonksiyonel özelliklerini daha iyi anlamak adına tasarım stüdyoları tariflenmiştir. Dördüncü bölümde, araştırma alanı olarak seçilen TOBB ETÜ tasarım stüdyoları gün /güneş ışığı tasarım kriterleri kapsamında incelenerek simülasyon programları ile analiz edilmiştir. Beşinci ve son bölümde elde edilen verilerin sonuçları ve bu sonuçlara göre öneriler ortaya konmuştur
1930'lar Dönemi Edebiyatımızda Eleştiri ve Öne Çıkan Bazı Eleştirmenler
No full text[No Abstract Available
How Does Hemodynamics Affect Rupture Tissue Mechanics in Abdominal Aortic Aneurysm: Focus on Wall Shear Stress Derived Parameters, Time-Averaged Wall Shear Stress, Oscillatory Shear Index, Endothelial Cell Activation Potential, and Relative Residence Time
No full textAn abdominal aortic aneurysm (AAA) is a critical health condition with a risk of rupture, where the diameter of the aorta enlarges more than 50% of its normal diameter. The incidence rate of AAA has increased worldwide. Currently, about three out of every 100,000 people have aortic diseases. The diameter and geometry of AAAs influence the hemodynamic forces exerted on the arterial wall. Therefore, a reliable assessment of hemodynamics is crucial for predicting the rupture risk. Wall shear stress (WSS) is an important metric to define the level of the frictional force on the AAA wall. Excessive levels of WSS deteriorate the remodeling mechanism of the arteries and lead to abnormal conditions. At this point, WSS-related hemodynamic parameters, such as time-averaged WSS (TAWSS), oscillatory shear index (OSI), endothelial cell activation potential (ECAP), and relative residence time (RRT) provide important information to evaluate the shear environment on the AAA wall in detail. Calculation of these parameters is not straightforward and requires a physical understanding of what they represent. In addition, computational fluid dynamics (CFD) solvers do not readily calculate these parameters when hemodynamics is simulated. This review aims to explain the WSS-derived parameters focusing on how these represent different characteristics of disturbed hemodynamics. A representative case is presented for spatial and temporal formulation that would be useful for interested researchers for practical calculations. Finally, recent hemodynamics investigations relating WSS-related parameters with AAA rupture risk assessment are presented. This review will be useful to understand the physical representation of WSS-related parameters in cardiovascular flows and how they can be calculated practically for AAA investigations. © 2023NPRP13S-0108–200024; IRCC 2020-002; Qatar National Research Fund, QNRF; Qatar National Library, QNL; Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTAK: 221M001This study is funded by Qatar University International Research Collaboration Co-Funds (IRCC) Program ( IRCC 2020-002 ) to HCY, Qatar National Research Fund (QNRF), National Priority Research Program ( NPRP13S-0108–200024 ) to HCY and OM, and TÜBİTAK (Scientific and Technological Research Council of Turkey) 3501 – Career Development Program (Project number: 221M001 ) to HES. The publication of this article was funded by the Qatar National Library
Asıl İşveren Alt İşveren İlişkisinde Asıl İşin Bir Bölümünün Verilmesi
No full textA principal employer-subcontractor relationship is the relationship established between an employer and the other employer, which takes work from another employer in the auxiliary tasks related to the production of goods or services carried out in the workplace or in a part of the main activity that requires specialization due to the requirements of the enterprise and work and technological reasons, and employs its employees assigned for this work only in this workplace. Accordingly, in order for a part of the main activity to be subcontracted, the work to be subcontracted must be a work that requires specialization due to the requirements of the enterprise and the work and technological reasons. It has been discussed in the doctrine whether the condition in question should be understood as divisible or as a whole. This regulation, which aims to limit the practice of subcontracting, which should be an exceptional method, has not achieved its purpose in practice, and the practice of subcontracting has gradually increased in our country. Within the scope of this study, the nature and purpose of this condition is discussed in detail, and whether the said condition can be applied in public workplaces is examined in detail in the light of the opinions in the doctrine and judicial decisions. In this context, it is also tried to produce solution suggestions in terms of the law (de lege ferenda).Bir işverenden, işyerinde yürüttüğü mal veya hizmet üretimine ilişkin yardımcı işlerinde veya asıl işin bir bölümünde işletmenin ve işin gereği ile teknolojik nedenlerle uzmanlık gerektiren işlerde iş alan ve bu iş için görevlendirdiği işçilerini sadece bu işyerinde aldığı işte çalıştıran diğer işveren ile iş aldığı işveren arasında kurulan ilişkiye asıl işveren-alt işveren ilişkisi denir. Buna göre, asıl işin bir bölümünün alt işverene verilebilmesi için, alt işverene verilecek işin, işletmenin ve işin gereği ile teknolojik nedenlerle uzmanlık gerektiren bir iş olması gerekmektedir. Söz konusu koşulun bölünebilir mi yoksa bir bütün olarak mı anlaşılması gerektiği öğretide tartışılmıştır. İstisnai bir yöntem olması gereken alt işveren uygulamasını sınırlama amacı güden bu düzenleme, uygulamada amacına ulaşamamış, alt işveren uygulaması ülkemizde giderek artmıştır. Çalışma kapsamında bu koşulun niteliği ve amacı detaylı şekilde ele alınmış, anılan koşulun kamu işyerlerinde uygulanıp uygulanamayacağı, öğretideki görüşler ve yargı kararları ışığında detaylı olarak incelenmiştir. Bu kapsamda olması gereken hukuk (de lege ferenda) açısından da çözüm önerileri üretilmeye çalışılmıştır
Search for Dark Matter Produced in Association With a Dark Higgs Boson Decaying Into W+w- in the One-Lepton Final State at √s=13 Tev Using 139 Fb-1 of Pp Collisions Recorded With the Atlas Detector
No full textSeveral extensions of the Standard Model predict the production of dark matter particles at the LHC. A search for dark matter particles produced in association with a dark Higgs boson decaying into W+W- in the l(+/-)nu q (q) over bar' final states with l = e, mu is presented. This analysis uses 139 fb(-1) of pp collisions recorded by the ATLAS detector at a centre-of-mass energy of 13TeV. The W-+/- -> q (q) over bar' decays are reconstructed from pairs of calorimeter-measured jets or from track-assisted reclustered jets, a technique aimed at resolving the dense topology from a pair of boosted quarks using jets in the calorimeter and tracking information. The observed data are found to agree with Standard Model predictions. Scenarios with dark Higgs boson masses ranging between 140 and 390 GeV are excluded.CERN; ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW; FWF, Austria; ANAS; CNPq; FAPESP, Brazil; NSERC; CFI, Canada; NSFC, China; MEYS CR, Czech Republic; DNRF; DNSRC, Denmark; IN2P3-CNRS; CEA-DRF/IRFU, France; BMBF; MPG, Germany; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT; JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; MESTD, Serbia; MSSR, Slovakia; ARRS; MIZS, Slovenia; MICINN, Spain; Wallenberg Foundation, Sweden; SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; DOE; NSF, United States of America; BCKDF; CANARIE; CRC, Canada [PRIMUS 21/SCI/017, UNCE SCI/013]; Czech Republic; ERC; ERDF; Marie Skodowska-Curie Actions, European Union; Investissements d'Avenir Labex, Investissements d'Avenir Idex; ANR, France; DFG; AvH Foundation, Germany - EU-ESF; Greek NSRF, Greece; BSF-NSF; NCN; La Caixa Banking Foundation; CERCA Programme Generalitat de Catalunya; PROMETEO; Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; Royal Society; Leverhulme Trust, United Kingdom; NDGF (Denmark, Norway, Sweden); KIT/GridKA (Germany); INFN-CNAF (Italy); NL-T1 (Netherlands), PIC (Spain); ASGC (Taiwan); BNL (U.S.A.)We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; Minciencias, Colombia; MEYS CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS and CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF and MPG, Germany; GSRI, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TENMAK, Turkiye; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, CANARIE, Compute Canada and CRC, Canada; PRIMUS 21/SCI/017 and UNCE SCI/013, Czech Republic; COST, ERC, ERDF, Horizon 2020 and Marie Skodowska-Curie Actions, European Union; Investissements d'Avenir Labex, Investissements d'Avenir Idex and ANR, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF, Greece; BSF-NSF and MINERVA, Israel; Norwegian Financial Mechanism 2014-2021, Norway; NCN and NAWA, Poland; La Caixa Banking Foundation, CERCA Programme Generalitat de Catalunya and PROMETEO and GenT Programmes Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; The Royal Society and Leverhulme Trust, United Kingdom.; The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (U.K.) and BNL (U.S.A.), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in ref