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Bottom Quark Energy Loss and Hadronization with B+ and BS0 Nuclear Modification Factors Using pp and PbPb Collisions at √sNN=5.02 TeV
No full textThe production cross sections of B-s(0) and B+ mesons are reported in proton-proton (pp) collisions recorded by the CMS experiment at the CERN LHC with a center-of-mass energy of 5.02 TeV. The data sample corresponds to an integrated luminosity of 302 pb(-1). The cross sections are based on measurements of the B-s(0)-> J/psi(mu(+)mu(-))phi(1020)(K+K-) and B+-> J/psi(mu(+)mu(-))K+ decay channels. Results are presented in the transverse momentum (p(T)) range 7-50 GeV/c and the rapidity interval |y| 2.4 for the B mesons. The measured p(T)-differential cross sections of B+ and B-s(0) in pp collisions are well described by fixed-order plus next-to-leading logarithm perturbative quantum chromodynamics calculations. Using previous PbPb collision measurements at the same nucleon-nucleon center-of-mass energy, the nuclear modification factors, R-AA, of the B mesons are determined. For p(T)> 10 GeV/c, both mesons are found to be suppressed in PbPb collisions (with R-AA values significantly below unity), with less suppression observed for the Bs0 mesons. In this p(T) range, the R-AA values for the B+ mesons are consistent with those for inclusive charged hadrons and D-0 mesons. Below 10 GeV/c, both B+ and B-s(0) are found to be less suppressed than either inclusive charged hadrons or D-0 mesons, with the B-s(0) R-AA value consistent with unity. The R-AA values found for the B+ and B-s(0) are compared to theoretical calculations, providing constraints on the mechanism of bottom quark energy loss and hadronization in the quark-gluon plasma, the hot and dense matter created in ultrarelativistic heavy ion collisions.We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centers and personnel of the Worldwide LHC Computing Grid and other centers for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC, the CMS detector, and the supporting computing infrastructure provided by the following funding agencies: SC (Armenia), BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES and BNSF (Bulgaria); CERN; CAS, MoST, and NSFC (China); MINCIENCIAS (Colombia); MSES and CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); ERC PRG, RVTT3 and MoER TK202 (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); SRNSF (Georgia); BMBF, DFG, and HGF (Germany); GSRI (Greece); NKFIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LMTLT (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MES and NSC (Poland); FCT (Portugal); MESTD (Serbia); MCIN/AEI and PCTI (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); MHESI and NSTDA (Thailand); TUBITAK and TENMAK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 724704, 752730, 758316, 765710, 824093, 101115353, 101002207, and COST Action CA16108 (European Union); the Leventis Foundation; the Alfred P. Sloan Foundation; the Alexander von Humboldt Foundation; the Science Committee, project no. 22rl-037 (Armenia); the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the F.R.S.-FNRS and FWO (Belgium) under the "Excellence of Science - EOS" - be.h project n. 30820817; the Beijing Municipal Science ; Technology Commission, No. Z191100007219010 and Fundamental Research Funds for the Central Universities (China); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Shota Rustaveli National Science Foundation, grant FR-22-985 (Georgia); the Deutsche Forschungsgemeinschaft (DFG), among others, under Germany's Excellence Strategy - EXC 2121 "Quantum Universe" - 390833306, and under project number 400140256 - GRK2497; the Hellenic Foundation for Research and Innovation (HFRI), Project Number 2288 (Greece); the Hungarian Academy of Sciences, the New National Excellence Program - uNKP, the NKFIH research grants K 131991, K 133046, K 138136, K 143460, K 143477, K 146913, K 146914, K 147048, 2020-2.2.1-ED-2021-00181, and TKP2021-NKTA-64 (Hungary); the Council of Science and Industrial Research, India; ICSC - National Research Center for High Performance Computing, Big Data and Quantum Computing and FAIR - Future Artificial Intelligence Research, funded by the NextGenerationEU program (Italy); the Latvian Council of Science; the Ministry of Education and Science, project no. 2022/WK/14, and the National Science Center, contracts Opus 2021/41/B/ST2/01369 and 2021/43/B/ST2/01552 (Poland); the FundacAo para a Ciencia e a Tecnologia, grant CEECIND/01334/2018 (Portugal); the National Priorities Research Program by Qatar National Research Fund; MCIN/AEI/10.13039/501100011033, ERDF "a way of making Europe", and the Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de Maeztu, grant MDM-2017-0765 and Programa Severo Ochoa del Principado de Asturias (Spain); the Chulalongkorn Academic into Its 2nd Century Project Advancement Project, and the National Science, Research and Innovation Fund via the Program Management Unit for Human Resources ; Institutional Development, Research and Innovation, grant B39G670016 (Thailand); the Kavli Foundation; the Nvidia Corporation; the SuperMicro Corporation; the Welch Foundation, contract C-1845; and the Weston Havens Foundation (USA).FWF; FNRS; FWO (Belgium); CNPq; CAPES; FAPERJ; FAPERGS; FAPESP (Brazil); BNSF (Bulgaria); MoST; NSFC (China); CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); ERC PRG [MoER TK202]; Academy of Finland; MEC; CEA; CNRS/IN2P3 (France); SRNSF; BMBF; DFG; HGF (Germany); NKFIH (Hungary); DAE; DST; IPM; SFI (Ireland); INFN (Italy); NRF (Republic of Korea); MES (Latvia); MOE; UM (Malaysia); BUAP; CONACYT; UASLP-FAI (Mexico); PAEC (Pakistan); FCT (Portugal); MESTD (Serbia); PCTI (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); NSTDA; TUBITAK; DOE; NSF (USA); Marie-Curie program; European Research Council; Horizon 2020 Grant [675440, 724704, 752730, 758316, 765710, 824093, 101115353, 101002207]; COST Action [CA16108]; Leventis Foundation; Alfred P. Sloan Foundation; Alexander von Humboldt Foundation; Science Committee [22rl-037]; Belgian Federal Science Policy Office; Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); FWO (Belgium) under the "Excellence of Science - EOS [30820817]; Beijing Municipal Science ; Technology Commission [Z191100007219010]; Fundamental Research Funds for the Central Universities (China); Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; Shota Rustaveli National Science Foundation [FR-22-985]; Deutsche Forschungsgemeinschaft (DFG) [EXC 2121, 390833306, 400140256 - GRK2497]; Hellenic Foundation for Research and Innovation (HFRI) [2288]; Hungarian Academy of Sciences [K 131991, K 133046, K 138136, K 143460, K 143477, K 146913, K 146914, K 147048, 2020-2.2.1-ED-2021-00181, TKP2021-NKTA-64]; Council of Science and Industrial Research, India; ICSC - National Research Center for High Performance Computing, Big Data and Quantum Computing - NextGenerationEU program (Italy); Latvian Council of Science; Ministry of Education and Science [2022/WK/14]; National Science Center [Opus 2021/41/B/ST2/01369, 2021/43/B/ST2/01552, CEECIND/01334/2018]; National Priorities Research Program by Qatar National Research Fund; ERDF "a way of making Europe" [MDM-2017-0765]; Programa Severo Ochoa del Principado de Asturias (Spain); National Science, Research and Innovation Fund via the Program Management Unit for Human Resources ; Institutional Development, Research and Innovation [B39G670016]; Kavli Foundation; Nvidia Corporation; SuperMicro Corporation; Welch Foundation [C-1845]; Weston Havens Foundation (USA
Search for Heavy Long-Lived Charged Particles with Large Ionization Energy Loss in Proton-Proton Collisions at S = 13 TeV
No full textA search for heavy, long-lived, charged particles with large ionization energy loss within the silicon tracker of the CMS experiment is presented. A data set of proton-proton collisions at a center of mass energy at s = 13 TeV, collected in 2017 and 2018 at the CERN LHC, corresponding to an integrated luminosity of 101 fb−1, is used in this analysis. Two different approaches for the search are taken. A new method exploits the independence of the silicon pixel and strips measurements, while the second method improves on previous techniques using ionization to determine a mass selection. No significant excess of events above the background expectation is observed. The results are interpreted in the context of the pair production of supersymmetric particles, namely gluinos, top squarks, and tau sleptons, and of the Drell-Yan pair production of fourth generation (τ′) leptons with an electric charge equal to or twice the absolute value of the electron charge (e). An interpretation of a Z’ boson decaying to two τ′ leptons with an electric charge equal to 2e is presented for the first time. The 95% confidence upper limits on the production cross section are extracted for each of these hypothetical particles. © 2025 Elsevier B.V., All rights reserved
Examination of Wake Characteristics for Tandem Circular Cylinders via Computational Fluid Dynamics
No full textWake characteristics of the cylinders have been numerically investigated for tandem arrangement. The study was done for airflow at a diameter-based Reynolds number of Re = 200 via ANSYS-Fluent 2021 R1. Variations of horizontal distances between two cylinders with the same diameter have been considered in the 1.5 ≤ L* ≤ 6 range. The drag coefficients have been attained, and these results have been presented along with flow characteristics of velocity components, magnitude values for vorticity, and pressure distributions. In front of the upstream cylinder, flow stagnated in all cases. Nonetheless, it has been observed for L* ≥ 4.5 in terms of the downstream cylinder. The periodical clusters for cross-stream velocity components have been attained in the wake region. Vortex shedding has been observed in the flow patterns. The unsteady flow structures have been seen. The spacing between the circular cylinders influenced the drag force. Nevertheless, the effect of an upstream cylinder on the downstream one disappeared for L* ≥ 4.5 in this study. The drag coefficient of the upstream cylinder is approximately the same concerning the value of a single one in terms of L* ≥ 4.5 as a result of the stud
Effect of Vibratory Peening Pretreatment on Boriding Kinetics of Hadfield Steel by Taylor Expansion Model
No full textX120Mn12 high-manganese steel is widely used for its excellent toughness, yet its limited wear resistance under low-impact conditions necessitates surface enhancement. While boronizing improves surface hardness, the role of vibratory peening pretreatment (VPP) in influencing boride layer growth remains underexplored. In this study, the influence of VPP on the boronizing kinetics of X120Mn12 austenitic manganese steel was systematically evaluated. VPP was conducted at 50 Hz with a 5 mm amplitude, using 3 mm diameter AISI 52100 bearing balls (approximate to 58 HRC) for 2 h. Subsequent pack boronizing was performed at temperatures of 1023 K, 1173 K, and 1323 K for durations of 1, 3, and 5 h. Microstructural analysis revealed that peening induced significant near-surface plastic deformation to a depth of approximately 150 mu m, resulting in a 12 % reduction in grain size and a two-fold increase in surface hardness. The boride layer thickness ranged from 13.63 to 193.15 mu m, with microhardness values ranging from 984 to 1741 HV0.1 in peened specimens, compared to 11.89-180.89 mu m and 898-1720 HV0.1 in the as-cast counterparts. Enhanced dislocation density and vacancy formation decreased the boron activation energy, which was determined using a Taylor-expansion diffusion model, yielding values of 150.53 kJ center dot mol- 1 for the peened samples and 155.72 kJ center dot mol- 1 for the as-cast samples. These findings demonstrate that VPP effectively refines the microstructure and accelerates boron diffusion by generating high-density defect structures.This research was supported TUBITAK by the Scientific and Technological Research Council of Turkiye (TUBITAK) under the M-ERANET 2022 and 1071 Program with project number 123N421. This measure is co-financed with tax revenue on the basis of the budget approved by the Saxon state parliament, Saspacing diaeresis>chsische Aufbaubank-Fospacing diaeresis>rderbank/SAB-100689195. The research was co-financed by NCRiB (The National Center for Research and Development, Warsaw Poland) under grant no. M-ERA.NET3/2022/86/IronWorkCoat/2023.TUBITAK by the Scientific and Technological Research Council of Turkiye (TUBITAK) under the M-ERANET 2022 and 1071 Program [123N421]; NCRiB (The National Center for Research and Development, Warsaw Poland) [-ERA.NET3/2022/86/IronWorkCoat/2023
A Preprocessing Method Based on 3D U-Net for Abdomen Segmentation
No full textDeep learning methods have made significant progress in the field of biomedical automatic segmentation but still open to developments, especially due to the insufficient use of preprocessing methods. In this study, a pre-processing step is proposed both to improve segmentation performance and to produce faster segmentation results. In this context, it is intended to obtain the abdomen region of interest (ROI) by using 3D U-Net, which has been shown to be effective in numerous studies. The presented work involves training a 3D U-Net using the CHAOS dataset and samples from the AbdomenCT-1K dataset, comprising a training dataset with 6998 slices. Afterwards, the network was exclusively tested using samples from the AbdomenCT-1K dataset, which consists of 1311 slices, to showcase its generalizability across diverse datasets. The study systematically examined the impact of fine-tuning parameters, including k value for k-fold cross-validation (CV), batch sizes (bs), and learning rates (lr), on the overall segmentation performance. Additionally, the study extended to training 3D U-Net using distinct loss functions, specifically Dice, Focal Dice, and Focal Twersky, to evaluate their respective effects on segmentation outcomes. In various scenarios, the best Dice score recorded was 99.71 %. Using the best models obtained from classical training and CV, each data in the test dataset was evaluated for its Hausdorff Distance (HD), 95th percentile of Hausdorff Distance (HD95), and Average Symmetric Surface Distance (ASSD). Following the segmentation process, the abdomen ROI was identified for each 2D slice using Connected Components Analysis (CCA) and established based on the largest bounding box to mitigate information loss. After applying CCA on the predicted image from the best model, an average reduction of 33.34 % in dimensionality was achieved for the entire test dataset. © 2025 Elsevier Lt
Synthesis of CeO2@SiO2 Nanocomposites for Adsorption of Cu(II) and Pb(II): Insights from Batch and Column Studies
No full textZeidan, Hani/0000-0002-5891-3887;CeO2@SiO2 nanocomposites were synthesized via rotary evaporation and co-precipitation for efficient removal of Cu(II) and Pb(II) from aqueous media. Among the tested compositions, CeSi-3 (CeO2:SiO2 = 1:0.5) exhibited the best performance, achieving maximum adsorption capacities of 160 mg/g for Pb(II) and 138 mg/g for Cu(II) at pH 6. Adsorption followed a pseudo-second-order kinetic model and fit the Langmuir isotherm. Desorption was successfully performed using both diluted HCl and 0.01 M EDTA. HCl achieved complete desorption of Pb(II) and 86% for Cu(II), while EDTA reached 97% for Pb(II) and 85% for Cu(II), with both maintaining the structural integrity of the adsorbent. Only a slight decrease in adsorption efficiency was observed after 10 regeneration cycles using HCl and after 3 cycles using EDTA, confirming the excellent reusability of the material. In fixed-bed column studies, CeSi-3 showed similar breakthrough capacities of around 60 mg/g for both metal ions, well-described by the Thomas model. These findings demonstrate that CeO2@SiO2 nanocomposites are efficient, reusable, and chemically stable adsorbents for sustainable water purification applications.This work was generously supported by two grants from TUBITAK (The Scientific and Technological Research Council of Turkey): Grant 121C402 under the 2218 National Postdoctoral Research Fellowship Program. The authors gratefully acknowledge this support.TUBITAK [121C402
Aksaray Kent Merkezinin Morfoloji Açısından Değişimini İncelemek
No full textAs a result of both local and universal values that societies have created over centuries, cities have been open to development and change. Cities are important and valuable living spaces due to the natural, cultural and social layers they have hosted throughout history. In recent years, the emergence of new sub-centers along with the continuous expansion of urban areas, in addition to the increase in population in cities, has led to a decrease in the functional and symbolic values of traditional city centers; this situation has caused a reduction in the spatial quality in the regions in question. However, the qualified and livable preservation of historical city centers makes significant contributions to the development of belonging by city residents, the maintenance of urban memory and the establishment of a holistic relationship between individuals and the city. Within the scope of this study, the aim is to analyze the morphological changes and development of Aksaray, which gained provincial status in 1989, over time. The Center-1 region was selected as the study area, which was determined within the scope of the zoning plan studies carried out in 2012 and includes the traditional city center and central business districts of Aksaray. The Center-1 region is limited to Cumhuriyet Boulevard in the north, Atatürk Boulevard in the south and the E90 Highway in the west, and covers the areas on both banks of Uluırmak. In the study, a literature review was first conducted regarding urban morphology in the context of the spatial relationship with the city. Subsequently, how urban morphological approaches diversified in terms of their relationship with the city and studies conducted on the historical past of Aksaray city center were examined. The field study aimed to establish the urban morphology of Aksaray, which has an important position historically and geographically, on a mathematical basis through the values of connectivity, integration, intelligibility and choice in the region determined between 1989, when it became a province, and 2024, using the Space Syntax method. In the second part of the field study, the sub-regions where the morphological changes were most intense from the Center-1 region of the Aksaray city center were determined, and the typomorphological analyses of these regions were examined based on roads, parcels, and structures. As a result of the examination and analysis, it was determined that the area covering Aksaray Castle continued to be the city center after becoming a province, but its urban potential decreased. Especially analytical values were high in the streets extending from Atatürk Boulevard, which borders the south of the study area, to the city center. It was determined that the spatial environments located on the city's strong axes have experienced functional changes as typomorphology, and some structures have disappeared in places. In line with the plans made since the 2000s, it was concluded that the growth direction of the city changed, and new spatial structures were formed in the west.Toplumların yüzyıllar boyunca oluşturdukları hem yerel hem de evrensel değerlerin sonucunda kentler gelişime ve değişime açık olmuştur. Kentler tarihsel süreç içerisinde barındırdığı doğal, kültürel, sosyal katmanları nedeniyle oldukça önemli ve değerli yaşam alanlarıdır. Son yıllarda kentlerde nüfusun artmasının yanı sıra kentsel alanların sürekli genişlemesiyle birlikte yeni alt merkezlerin ortaya çıkması, geleneksel kent merkezlerinin işlevsel ve simgesel değerlerinde azalmaya yol açmakta; bu durum söz konusu bölgelerde mekânsal kalitenin düşmesine neden olmaktadır. Oysa tarihi kent merkezlerinin nitelikli ve yaşanabilir biçimde korunması, kent sakinlerinin aidiyet geliştirmesine, kentsel belleğin sürdürülmesine ve bireylerin kentle bütüncül bir ilişki kurmasına önemli katkılar sunmaktadır. Bu çalışma kapsamında 1989 yılında il statüsünü kazanmış Aksaray'ın zamanla değişimi ve gelişiminin morfolojik olarak analiz edilmesi amaçlanmıştır. Çalışma alanı olarak 2012 yılında yürütülen imar planı çalışmaları kapsamında belirlenen ve Aksaray'ın geleneksel kent merkezini ve merkezi iş alanlarını da kapsayan Merkez-1 bölgesi seçilmiştir. Merkez-1 bölgesi, kuzeyde Cumhuriyet Bulvarı ile güneyde Atatürk Bulvarı ve batısında E90 Karayolu ile sınırlı olup Uluırmağın iki yakasındaki alanları kapsamaktadır. Aksaray kent merkezinin morfolojik durumunun 1989 ve 2024 yılları arasında inceleneceği çalışmada ilk olarak kentsel morfolojiye yönelik kent ile mekânsal ilişkisi bağlamında literatür taraması yapılmıştır. Devamında kent ile ilişkisi açısından kentsel morfolojik yaklaşımların nasıl çeşitlendiği ve Aksaray kent merkezinin tarihsel geçmişi hakkında yapılan çalışmalar incelenmiştir. Alan çalışması ile tarihi ve coğrafi olarak önemli bir konuma sahip olan Aksaray'ın il olduğu 1989 yılı ile 2024 yılı arasında belirlenen bölgedeki kentsel morfolojisinin Space Syntax yöntemi ile bağlantılılık, entegrasyon, okunabilirlik ve tercih değerleri üzerinden matematiksel bir zemine oturtulması amaçlanmıştır. Alan çalışmasının ikinci bölümünde ise tarihsel süreçte farklılaşarak biçimlenmiş Aksaray kent merkezinin Merkez-1 bölgesinden morfolojik değişimlerin en yoğun olduğu alt bölgeler belirlenmiş ve bu bölgelerin tipo-morfolojik analizleri yol, parsel ve yapı bazlı olarak incelenmiştir. Yapılan inceleme ve analizler sonucunda il olduktan sonra da Aksaray Kalesini kapsayan alanın kent merkezi olmayı sürdürdüğü ama kentsel potansiyelinin azaldığı tespit edilmiştir. Özellikle çalışma alanının güneyini sınırlandıran Atatürk Bulvarından kent merkezine bağlanan caddelerde analitik değerlerin yüksek olduğu görülmüştür. Kentin güçlü aksları üzerinde yer alan mekânsal çevrelerin tipo morfolojik olarak işlevsel değişimler yaşadığı ve bazı yapıların yer yer kaybolduğu saptanmıştır. 2000'li yıllardan itibaren yapılan planlamalar doğrultusunda ise kentin büyüme yönünün değiştiği ve batı yönünde yeni mekânsal kurguların oluştuğu sonucuna varılmıştır
Düşey Taşıyıcı Elemanlardaki Hasarın Malzeme Mekanik Özelliklerine Etkisinin İncelenmesi
No full textSince Turkey is located in an earthquake-prone region, even minor seismic tremors often bring earthquake-related issues to the forefront of public and scientific discussions. On February 6, 2023, a major earthquake with a magnitude of 7.7 occurred in Pazarcık, Kahramanmaraş, followed by a 7.6 magnitude earthquake in Elbistan, and subsequently a 6.4 magnitude earthquake in Defne, Hatay, all of which caused severe devastation across the region. In the aftermath of the Kahramanmaraş earthquakes, significant variation was observed in the compressive strength values obtained from core samples taken from existing reinforced concrete structures, which were intended to assess the compliance with their original design strength. This variation emphasized the necessity of evaluating core test results separately according to the structural damage status (damaged or undamaged). For the reliable assessment of compressive strength values in structures located in earthquake-affected zones and to inform proper strengthening strategies, it became evident that core strength data must be interpreted independently for damaged and undamaged buildings. Accordingly, in both forensic investigations and performance-based structural assessments, accurate identification of material properties, particularly the concrete compressive strength and reinforcement yield strength, is of critical importance and must take into account whether the structure experienced damage or seismic loading.In this study, five vertical reinforced concrete columns with dimensions of 20x15x130 cm were cast using low-strength concrete, and another five columns with the same dimensions were produced using C20/25 concrete to represent the current structural stock. All vertical load-bearing elements were designed with plain longitudinal and transverse reinforcement. From the concrete used in the casting process, cube specimens were taken to determine the 7-day and 28-day compressive strengths, while reinforcement samples were tested to determine their yield strengths. The columns were tested under axial loading and reversed cyclic lateral loading conditions, after which a total of 74 core samples—both reinforced and unreinforced—were extracted. Some core samples were carefully trimmed to achieve a length-to-diameter ratio (l/d) of 1 and were capped using sulfur to ensure uniform load application during testing. In contrast, other core samples had l/d ratios different from 1, were poorly capped, or not capped at all, allowing the study to assess how these procedural errors influenced the measured compressive strength.The results indicated that despite careful extraction, it was difficult to obtain suitable test specimens from columns made with low-strength concrete, which in turn complicated the interpretation of compressive strength test results. For columns produced using C20/25 concrete, the importance of performing coring, capping, and compressive strength testing in accordance with relevant codes and standards became apparent. It was found that random or improper procedures during core extraction significantly influenced the resulting compressive strength values. Furthermore, in columns subjected to lateral displacements up to 70 mm and exposed to impact effects, the yield strength of reinforcement extracted from the plastic hinge regions was, on average, 27% lower than the yield strength of the reinforcement used during initial casting.Ülkemiz deprem kuşağında yer aldığı için en ufak bir sarsıntıda depremle ilgili pek çok soru gündemde yerini almaktadır. Merkezi Kahramanmaraş / Pazarcık 6 Şubat 2023 7.7 şiddetindeki bir deprem, Elbistan 7.6 büyüklüğünde büyük bir deprem en son olarakta Hatay- Defne'de 6.4 büyüklüğünde deprem meydana gelmiş, bu sebepten ülkemiz büyük bir felaket geçirmiştir. Kahramanmaraş depremleri sonrasında, mevcut betonarme yapıların tasarımda öngörülen beton sınıfına uygunluğunun belirlenmesi amacıyla alınan karot numunelerinde, elde edilen basınç dayanımı değerlerinin yüksek varyans göstermesi nedeniyle, ölçümlerin yapıların hasar durumuna göre (hasarlı/hasarsız) ayrı ayrı değerlendirilmesi gerekliliği ortaya çıkmıştır. Bu nedenle, yapıların hasarlı ya da hasarsız oluşuna göre ayrı ayrı değerlendirilmesi gerekliliği ortaya çıkmıştır. Deprem bölgelerindeki mevcut yapıların güçlendirilmesi için beton basınç sonuçlarının doğru bir şekilde değerlendirilmesi yapıların hasarlı ya da hasarsız yapılara göre karot dayanımlarının ayrı ayrı değerlendirilmesi gerekliliği doğmuştur. Bu sebeplerden ilk tasarım değerinin özellikle adli vakalar ve performans analizi içinde betonarme yapıları hasarlı ya da hasarsızlık durumları için ayrıca deprem etkisi altında kalmasına göre beton basınç değerlerinin ve donatı akma dayanımlarının belirlenmesi önem arz etmektedir. Bu çalışmada düşük dayanımlı betondan 5 adet 20x15x130 cm boyutlarında düşey taşıyıcı betonarme kolon ve mevcut yapı stokunu temsil etmesi açısından C20/25 dayanımlı 5 adet 20x15x130 cm boyutlarında düşey taşıyıcı betonarme kolon üretilmiştir. Boyuna donatılarda ve etriyelerde düz donatıyla sarılmış düşey taşıyıcı elemanlar tasarlanmıştır. Tasarlanan betonarme elemanların üretiminde kullanılan betondan küp numune örnekleri ve donatı örnekleri alınarak 7 ve 28 günlük beton basınç dayanımları ve donatı akma dayanımları belirlenmiştir. Eksenel yük ve tersinir-tekrarlanır yatay yük etkisi altında test edilen betonarme düşey taşıyıcı elemanlardan toplamda 74 adet donatılı ve donatısız karot örnekleri alınmıştır. Alınan bu karotlardan bazıları, boy ve çap oranı (l/d) 1 olacak şekilde dikkatlice kesilerek karot yüzeylerine uygun şekilde kükürt başlık yapılmıştır. Diğer karotlarda ise (l/d) oranı 1'den farklı tutulmuş, başlıklama işlemi hatalı yapılmış ve bazılarında ise başlıklama yapılmamıştır. Böylece bu hatalı uygulamaların karot basınç dayanım sonuçlarına etkileri incelenebilmiştir. Çalışma neticesinde; düşük dayanımlı betondan üretilen kolonlardan karot alma işleminde ne kadarda titiz davranılsa basınç deneyi için uygun örnek alınmasının güç olduğu görülmüştür. Dolaysıyla karot basınç deneylerinden uygun sonuç alma ve yorumlama güçlüğü de ortaya çıkmıştır. C20/25 sınıfı dayanıma sahip beton üretilen kolonlardan, karot örnekleri alınırken, karotların boy kesim işlemleri gerçekleştirilirken, başlıkma yapılırken ve basınç deneyleri yapılırken yönetmelik ve standartlara uygun işlem yapmanın önemi ortaya çıkmıştır. Rastgele yapılacak karot işlemlerinin, karot basınç dayanımını oldukça çok etkilediği görülmüştür. Ayrıca, yatay deplasmanı 70 mm olacak şekilde test edilen ve çarpma etkisine maruz bırakılan kolonların maksimum moment bölgesinden alınan donatıların akma dayanımların, üretimde kullanılan donatıların akma dayanımlarına göre ortalama %27 düştüğü görülmüştür
Bir Üniversite Hastanesinde İş Sağlığı Güvenliğine Yönelik Ses ve Işık Şiddeti İle Hava Kalitesinin Araştırılması
No full textSağlık hizmeti sunan kapalı alanlardan olan hastanelerin iç ortam ışık şiddeti, ses şiddeti ve hava kalitesinin uygun standartlarda olması gerek hastalar gerekse sağlık hizmeti veren çalışanların işe uyumu açısından önem teşkil etmektedir. Amacımız bir üniversite hastanesinde ses ve ışık şiddeti ile hava kalitesi parametrelerinin hastanenin birim ve yerleşkelerine göre karşılaştırılmasıdır. Araştırma kesitsel tiptedir. Örneklem yoğun bakım-ameliyathane, laboratuvar-tıbbi birimler-radyoloji, poliklinik-servis-acil servis, atölyeler-kantin olarak dört gruba ayrıldı. Belirlenen yerlerden sıcaklık, nem, hava akım hızı, gürültü, aydınlatma düzeyi, havada bulunan partiküler maddeler ve gaz ölçümleri yapıldı. Verilerin özetlenmesinde; ortanca (1.3. çeyreklik) değerleri ile sayı ve yüzdelikler kullanıldı. Verilerin analizinde Mann-Whitney-U, Kruskal-Wallis testi, post hoc Bonferroni düzeltmeli Mann-Whitney U testi kullanıldı. Ölçümler sonucunda sıcaklık değeri 24,6 °C, nem %37,3, hava akım hızı 0 mm/s, ışık şiddeti 225 lüks, ses 60,8 dB, Karbon dioksit (CO2) 400 ppm olarak saptandı. Yapılan gaz ölçümleri sonucunda hastane iç ortam havasında NO, H2S, CO, SO2 gazları tespit edilmedi. Bazı alanlarında sınırların dışında değerler tespit edildi. Bu durumun sebeplerinin araştırılması, sorunların giderilmesi için gerekli düzenlemelerin yapılması, koruyucu ekipman verilmesi ve kullanımın teşvik edilmesi önem arz etmektedir
Signaling Improvement Model and Efficiency Analysis of the Model
No full textRecent increases in traffic density have introduced a range of challenges, prompting the development of intelligent transportation technologies as potential solutions. One such solution involves the efficient determination and management of signaling times. This study presents a structure for generating adaptive signal timings through the creation of a signaling improvement model. The proposed model is implemented at the Polatl ; imath; Sanayi Intersection, which was previously managed using a fixed-time signaling system. Subsequently, the delay times per vehicle are calculated and compared between the fixed-time signaling system and the newly developed signaling improvement model. The delay times for both the fixed-time signaling system and the signaling improvement model are evaluated through the use of visual detection methods, with observations conducted via camera during peak hours. The observed delay times are further validated through the Webster model and the SUMO simulation program. The Webster model and SUMO simulations employ real signalized intersection data. The study revealed a 20.24% reduction in delay times when switching from a fixed-time signaling system to an adaptive signaling improvement model. Moreover, the level of service at the intersection, as defined by the level of service criteria outlined in the Highway Capacity Manual, has been enhanced from E (indicating suboptimal performance) in the fixed-time system to D (indicating moderate performance) in the adaptive signalization model