6746 research outputs found
Sort by
Combination of Measurements of the Top Quark Mass From Data Collected by the Atlas and Cms Experiments at √=7 and 8 Tev
No full textA combination of fifteen top quark mass measurements performed by the ATLAS and CMS experiments at the LHC is presented. The datasets used correspond to an integrated luminosity of up to 5 and Formula Presented of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, respectively. The combination includes measurements in top quark pair events that exploit both the semileptonic and hadronic decays of the top quark, and a measurement using events enriched in single top quark production via the electroweak Formula Presented channel. The combination accounts for the correlations between measurements and achieves an improvement in the total uncertainty of 31% relative to the most precise input measurement. The result is Formula Presented, with a total uncertainty of 0.33 GeV. © 2024 CERN, for the CMS and ATLASs Collaboration.H2020 Marie Skłodowska-Curie Actions, MSCA; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, NWO; Leverhulme Trust; Baden-Württemberg Stiftung, BWS; Neubauer Family Foundation, NFF; Javna Agencija za Raziskovalno Dejavnost RS, ARRS; Generalitat de Catalunya; Agencia Nacional de Investigación y Desarrollo, ANID; Research Council of Finland, AKA; Canarie; Horizon 2020 Framework Programme, H2020; Göran Gustafssons Stiftelser; European Commission, EC; Nella and Leon Benoziyo Center for Neurological Diseases, Weizmann Institute of Science; Royal Society; Minerva Foundation; Generalitat Valenciana, GVA; CERN; RYC2020-030254-I, RYC2021-031273-I, NextGenEU-PCI2022-135018-2, FEDER-PID2021-125273NB, RYC2019-028510-I, RYC2022-038164-I; Instituto Nazionale di Fisica Nucleare, INFN: 754496; Instituto Nazionale di Fisica Nucleare, INFN; 101033496; PE00000013; Japan Society for the Promotion of Science, JSPS: JP21H05085, 22KK0227, JP22H04944, JP22H01227; Japan Society for the Promotion of Science, JSPS; Deutsche Forschungsgemeinschaft, DFG: DFG - 469666862, DFG - CR 312/5-1; Deutsche Forschungsgemeinschaft, DFG; Norges Forskningsråd: RCN-314472; Norges Forskningsråd; National Natural Science Foundation of China, NSFC: 12275265, NSFC—12175119, PRIMUS/21/SCI/017, NSFC-12075060; National Natural Science Foundation of China, NSFC; Fundación BBVA, FBBVA: LEO22-1-603; Fundación BBVA, FBBVA; LCF/BQ/PI20/11760025, IDIFEDER/2018/048; PPN/PPO/2020/1/00002/U/00001; CC-IN2P3; CHIST-ERA-19-XAI-00; 2014-2021; TK202; VR 2022-03845, VR 2022-04683, VR 2018-00482, 2021-03651; 1230987, 1210400, 1190886, 1230812; 21/SCI/017; J1-3010; CIDEGENT/2019/027, CIDEGENT/2019/023; SCI/013; Agence Nationale de la Recherche, ANR: ANR-20-CE31-0013, ANR-21-CE31-0013, ANR-11-LABX-0012, ANR-21-CE31-0022; Agence Nationale de la Recherche, ANR; UMO-2019/34/E/ST2/00393, 2021/42/E/ST2/00350, 2022/47/B/ST2/03059, UMO-2020/37/B/ST2/01043, UMO-2021/40/C/ST2/00187; European Research Council, ERC: 948254; European Research Council, ERC; IN2P3-CNRS; Knut och Alice Wallenbergs Stiftelse: KAW 2017.0100, KAW 2018.0157, KAW 2018.0458, KAW 2019.0447; Knut och Alice Wallenbergs Stiftelse; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, SNF: RPG-2020-004, SNSF—PCEFP2_194658; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, SN
Search for Heavy Neutral Leptons in Final States with Electrons, Muons, and Hadronically Decaying Tau Leptons in Proton-Proton Collisions at √s = 13 TeV
No full textA search for heavy neutral leptons (HNLs) of Majorana or Dirac type using proton-proton collision data at s = 13 TeV is presented. The data were collected by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 138 fb−1. Events with three charged leptons (electrons, muons, and hadronically decaying tau leptons) are selected, corresponding to HNL production in association with a charged lepton and decay of the HNL to two charged leptons and a standard model (SM) neutrino. The search is performed for HNL masses between 10 GeV and 1.5 TeV. No evidence for an HNL signal is observed in data. Upper limits at 95% confidence level are found for the squared coupling strength of the HNL to SM neutrinos, considering exclusive coupling of the HNL to a single SM neutrino generation, for both Majorana and Dirac HNLs. The limits exceed previously achieved experimental constraints for a wide range of HNL masses, and the limits on tau neutrino coupling scenarios with HNL masses above the W boson mass are presented for the first time. © 2025 Elsevier B.V., All rights reserved
The Effect of Crustal Density Variation on Pite (primary Indirect Topography Effect)
No full textIn geoid determination studies, the main goal is to create a geoid model with an accuracy of 1 centimeter. Solving this goal in a way of theoretically correct and practically fast makes it easier to implement some engineering problems. For this reason, the methods used to determine the geoid are being developed day by day. The Stokes-Helmert approach is one of the classical geoid modeling options. If the topography is not handled carefully in the solution of the boundary value problem, it is an obstacle to achieving the desired goal. In the final stage of the Stokes-Helmert approach, the exact geoid height is obtained by calculating the PITE (Primary Indirect Topographic Effect). The density change causes a significant difference in the PITE's calculation and, therefore, in the geoid heights. To see this difference, it is enough to use the digital elevation model and the crustal density model. In geosciences studies related to topography, the density value is usually taken as an average of 2.67 g/cm3. However, this value varies in some regions, approaching 20%. Such a ratio, which can be observed in the density change, affects the values obtained from the PITE calculation at the decimetre level. In this study, the effect of density change on PITE will be examined. In this way, an important contribution will be made to the centimeter accuracy geoid determination studies in our country. The PITE values depend on the height and density of the calculation point. As a result of numerical application, the density change gives PITE values between -43 cm and -1 cm, while under constant density these values are between -39 cm and -1 cm.Jeoit belirleme çalışmalarında 1 santimetre doğruluklu jeoit modeli oluşturmak ana hedeftir. Bu hedefin kuramsal anlamda doğru ve pratik şekilde çözülmesi bazı mühendislik problemlerinin çözülmesini kolaylaştırmaktadır. Bu nedenle jeoit belirmek için kullanılan yöntemler gün geçtikçe geliştirilmektedir. Stokes-Helmert yaklaşımı klasik jeoit modelleme seçeneklerinden biridir. Sınır değer probleminin çözümünde topoğrafya dikkatli bir şekilde ele alınmaz ise istenen hedefe ulaşmaya engeldir. Stokes-Helmert yaklaşımının son aşamasında PITE'nin (Birincil Dolaylı Topoğrafik Etki) hesabıyla yaklaşık jeoit yüksekliği elde edilmektedir. Yoğunluk değişimi, PITE'nin hesabında ve dolayısıyla, jeoit yüksekliklerinde anlamlı farklılığa neden olur. Bu farkı görmek için bir sayısal yükseklik modeli ve kabuk yoğunluğu modelinden yararlanmak yeterlidir. Topoğrafyayı ilgilendiren yerbilimleri çalışmalarında yoğunluk değeri genelde ortalama 2.67 gr/cm³ alınır. Ancak bu değer bazı bölgelerde %20'lere yaklaşan farklılık gösterir. Yoğunluk değişimindeki böyle bir oran PITE hesabından bulunan değerleri desimetre mertebesinde etkiler. Bu çalışmada yoğunluk değişiminin PITE üzerindeki etkisi incelenecektir. Bu sayede ülkemizde santimetre doğruluklu jeoit belirleme çalışmalarına önemli bir katkı sağlanacaktır. PITE değerleri hesap noktasının yüksekliğine ve yoğunluğuna bağlıdır. Sayısal uygulama sonucunda değişken yoğunluklu PITE değerleri -43 cm ile -1 cm arasında değişirken, sabit yoğunluk kullanıldığında bu değerler -39 cm ile -1 cm arasındadı
Investigation of Heavy Metal Pollution in Konya Beyşehir Lake Waters
No full textBeyşehir Lake is Turkiye's third largest lake and has the largest fresh water resource, located in the provinces of Konya and Isparta.. The main livelihood of the area is agriculture, animal husbandry, and fishing. The lake water is crucial for irrigation in agriculture, industrial use, drinking water supply, as well as recreation and tourism. Additionally, there are various scales of industrial facilities in the basin. The basin's economy is undergoing a similar transformation to the national economy, evolving from an agriculture-focused structure towards industry. The increase in industrial facilities around the basin has led to the presence of heavy metal pollution in the lake water. The use of lake water, declining water quality, increasing pollution, challenges in determining the coastline, and the adverse effects of large-scale plans, along with management and planning deficiencies, are the primary issues in the basin. Beyşehir Lake is affected by the increase in untreated industrial wastewater due to the rise of arms factories in the vicinity and the influence of agricultural irrigation waters. The trophic level of the lake changes negatively due to the impact of point and non-point pollution sources. The study identified two different points where heavy metals from Beyşehir Lake contribute to water systems. The first point selected is where the Büyükköprü Stream, discharging from arms factories in Huğlu and Üzümlü, mixes with the lake water. The second point is determined as a location within the lake where dilution is high. Samples will be collected seasonally (autumn, winter, spring) from these identified points, and the lake water analyses will be evaluated according to the Water Pollution and Control Regulation (SKKY) criteria. During the sampling processes, these stations were determined on the map using Geographic Information Systems (GIS). The analyses examined alkalinity, temperature, dissolved oxygen, pH, conductivity, and heavy metals (Fe, Al, Cd, Cr, Cu, Ni, Mn, As, Ag, and Zn). The objective was to investigate the levels of metal pollution in the lake and their seasonal variations. The results showed a decreasing metal concentration profile in the order of Fe > Al > As > Cu > Mn > Cr > Ni > Zn > Cd. This situation is presumed to be due to the presence of aluminum and chromium used in the region's arms industry.Beyşehir gölü, Konya ve Isparta illeri topraklarında bulunan, Türkiye'nin üçüncü büyük gölü ve en büyük tatlı su kaynağıdır. Bölgenin ana geçim kaynağı tarım, hayvancılık ve balıkçılıktır. Göl suyu; tarımda sulama, endüstride, içme suyu temininde, rekreasyon ve turizm de önemli bir yere sahiptir. Bunların yanı sıra havzada çeşitli ölçeklerde sanayi tesisleri de bulunmaktadır. Havza ekonomisi, ülke ekonomisiyle benzer bir dönüşüm geçirerek tarımsal odaklı bir yapıdan sanayiye doğru evrilme eğilimindedir. Havza çevresinde sanayi tesislerinin artmasıyla göl suyunda ağır metal kirliliği varlığını göstermiştir. Göl suyunun kullanımı, su kalitesinin düşmesi ve kirliliğin artması, kıyı şeridi belirleme zorlukları ve üst ölçekli planların olumsuz etkileri, yönetim ve planlama eksiklikleri havzadaki önde gelen sorunlardır. Beyşehir Gölü çevresinde silah fabrikalarının artışıyla arıtılmamış endüstriyel atıksuların artması ve tarımsal sulama sularının tesiri altındadır. Gölün trofik seviyesi, noktasal ve noktasal olmayan kirletici kaynakların etkisiyle negatif yönde değişmektedir. Çalışmada; Beyşehir Gölü'ndeki ağır metallerin oluşturduğu kirletici kaynakların su sistemlerine karıştığı 2 farklı nokta belirlenmiştir. İlk nokta olarak, Huğlu ve Üzümlü bölgelerindeki silah fabrikalarının deşarj yaptığı Büyükköprü Çayının göl suyuna karıştığı nokta seçilmiştir. İkinci nokta ise göl içerisinde seyrelmenin fazla olduğu nokta olarak belirlenmiştir. Bu belirlenen noktalardan mevsimsel (sonbahar, kış, ilkbahar) olarak numuneler alınmış ve göl suyunun analizleri yapılarak elde edilen sonuçlar Su Kirliliği ve Kontrolü Yönetmeliği (SKKY) kriterlerine göre değerlendirilmiştir. Örnekleme işlemleri sırasında bu istasyonlar Coğrafi Bilgi Sistemleri (CBS) kullanılarak harita üzerinde belirlenmiştir. Analizlerde alkalinite, sıcaklık, çözünmüş oksijen, pH, iletkenlik ile ağır metaller (Fe, Al, Cd, Cr, Cu, Ni, Mn, As, Ag ile Zn) incelenmiştir. Amaç, göldeki metal kirliliği seviyelerini ve mevsimsel değişimlerini incelemekti. Sonuçlar, Fe > Al > As > Cu > Mn > Cr > Ni >Zn> Cd şeklinde azalan bir metal konsantrasyon profili göstermiştir. Bu durumun, bölgede silah sanayinde kullanılan alüminyum ve kromun varlığından kaynaklandığı tahmin edilmektedir
Examination of the Impact of Contemporary Additions on the Historical Building's Energy Performance
No full textHistorical buildings are being destroyed over time and energy losses are increasing. Therefore, energy efficient preservation of historical buildings is an important issue. However, the application of contemporary additions has increased in cases such as the revival of building units that have not survived to the present day or when a new post-functional space is required. The aim of this study is to evaluate the impact of contemporary additions on the energy performance of historic buildings through a case study. For this purpose, energy simulation analyzes of the historical Süleyman Pasha Bath in Kocaeli province were performed through Design Builder. Before the simulations applied, information about stone, which is the original material of the building, and glass applied with contemporary materials were entered into the programme. The provinces of Izmir, Konya, Sivas, and Erzurum were selected from five climatic regions for the contemporary additional analysis. In these provinces there are many traditional bathing buildings with similar plan types. According to simulated results, it was concluded that the application of modern additions after the restoration negatively affected the energy performance in all five climate zones. Before applying contemporary additions to historical buildings, factors such as the microclimate, material properties and geometry of the building should be taken into consideration during the design phase and a decision should be made as a result of various analyses. Consequently, when contemporary additions to historic buildings are required, using the most effective construction techniques and materials is important in terms of building sustainability and effectiveness
Search for Dark Qcd With Emerging Jets in Proton-Proton Collisions at √s=13 Tev
No full textMartinez Rivero, Celso/0000-0002-3224-956X; Lunerti, Leonardo/0000-0002-8932-0283; Troiano, Donato/0000-0001-7236-2025; Kim, Jaebak/0000-0002-2072-6082; Shevelev, Alexey/0000-0003-4600-0228; Shopova, Mariana/0000-0001-6664-2493; Milosevic, Vukasin/0000-0002-1173-0696; Della Ricca, Giuseppe/0000-0003-2831-6982; Navarrete Ramos, Efren/0000-0002-5180-4020; Pozniak, Krzysztof/0000-0001-5426-1423; Swain, Sanjay Kumar/0000-0001-6871-3937; Yalvac, Metin/0000-0003-4915-9162; Sarkar, Tanmay/0000-0003-0582-4167; Matorras, Francisco/0000-0003-4295-5668; Moscatelli, Francesco/0000-0002-7676-3106; Calderon, Dr. Alicia/0000-0002-7205-2040; Grunewald, Martin/0000-0002-5754-0388; Tiwari, Praveen Chandra/0000-0002-3667-3843; Menzio, Luca/0000-0002-9697-5608; Ramos, Dayron/0000-0002-7165-1017; Tcherniaev, Evgueni/0000-0002-3685-0635; Dash, Ganapati/0000-0002-7451-4763; Giommi, Luca/0000-0003-3539-4313; Wuchterl, Sebastian/0000-0001-9955-9258; Borshch, Vladislav/0000-0002-5479-1982; Tedeschi, Tommaso/0000-0002-7125-2905; Pedraza Morales, Maria Isabel/0000-0002-2669-4659; Venditti, Rosamaria/0000-0001-6925-8649; Cerci, Salim/0000-0002-8702-6152; Perez Adan, Danyer/0000-0003-3416-0726; Macchiolo, Anna/0000-0003-0199-6957; Rossi Tisbeni, Simone/0000-0001-6776-285X; Musich, Marco/0000-0001-7938-5684; Hernandez Calama, Jose Maria/0000-0001-6436-7547; Shchedrolosiev, Mykyta/0000-0003-3510-2093A search for "emerging jets" produced in proton-proton collisions at a center-of-mass energy of 13 TeV is performed using data collected by the CMS experiment corresponding to an integrated luminosity of 138 fb(-1). This search examines a hypothetical dark quantum chromodynamics (QCD) sector that couples to the standard model (SM) through a scalar mediator. The scalar mediator decays into an SM quark and a dark sector quark. As the dark sector quark showers and hadronizes, it produces long-lived dark mesons that subsequently decay into SM particles, resulting in a jet, known as an emerging jet, with multiple displaced vertices. This search looks for pair production of the scalar mediator at the LHC, which yields events with two SM jets and two emerging jets at leading order. The results are interpreted using two dark sector models with different flavor structures, and exclude mediator masses up to 1950 (1950) GeV for an unflavored (flavor-aligned) dark QCD model. The unflavored results surpass a previous search for emerging jets by setting the most stringent mediator mass exclusion limits to date, while the flavor-aligned results provide the first direct mediator mass exclusion limits to date.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 (U.S.A.).r 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, 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 (FRIABelgium); the Agentschap voor Innovatie doorWetenschap en Technologie (IWT-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), 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 124845, K 124850, K 128713, K 128786, K 129058, K 131991, K 133046, K 138136, K 143460, K 143477, 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, 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 B37G660013 (Thailand); the Kavli Foundation; the Nvidia Corporation; the SuperMicro Corporation; the Welch Foundation, contract C-1845; and the Weston Havens Foundation (U.S.A.).FWF (Austria); FNRS (Belgium); FWO (Belgium); CNPq (Brazil); CAPES (Brazil); FAPERJ (Brazil); FAPERGS (Brazil); FAPESP (Brazil); BNSF (Bulgaria); MoST (China); NSFC (China); CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); MoER (Estonia); ERDF (Estonia); Academy of Finland (Finland); MEC (Finland); CEA (France); CNRS/IN2P3 (France); BMBF (Germany); DFG (Germany); HGF (Germany); NKFIH (Hungary); DAE (India); DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Republic of Korea); MES (Latvia); MOE (Malaysia); UM (Malaysia); BUAP (Mexico); CONACYT (Mexico); UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); FCT (Portugal); MESTD (Serbia); PCTI (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); NSTDA (Thailand); TUBITAK (Turkey); NASU (Ukraine); NSF (USA); Marie-Curie program (European Union); European Research Council (European Union); Horizon 2020 Grant (European Union) [675440, 724704, 752730, 758316, 765710, 824093, 884104]; COST Action (European Union) [CA16108]; Leventis Foundation; Alfred P. Sloan Foundation; Alexander von Humboldt Foundation; Belgian Federal Science Policy Office; Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); FWO (Belgium) under the "Excellence of Science - EOS - be.h project [30820817]; Beijing Municipal Science AMP; Technology Commission [Z191100007219010]; Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; Hellenic Foundation for Research and Innovation (HFRI) (Greece) [2288]; Deutsche Forschungsgemeinschaft (DFG) [EXC 2121, 390833306, 400140256 - GRK2497]; Hungarian Academy of Sciences (Hungary); Council of Science and Industrial Research, India; Latvian Council of Science; National Science Center (Poland) [Opus 2021/41/B/ST2/01369, 2021/43/B/ST2/01552]; National Priorities Research Program by Qatar National Research Fund; MCIN/AEI, ERDF "a way of making Europe"; Programa Severo Ochoa del Principado de Asturias (Spain); Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); National Science, Research and Innovation Fund via the Program Management Unit for Human Resources AMP; Institutional Development, Research and Innovation (Thailand) [B05F650021]; Kavli Foundation; Nvidia Corporation; SuperMicro Corporation; Welch Foundation [C-1845]; Weston Havens Foundation (USA); BMBWF (Austria); MES (Bulgaria); CERN; CAS (China); MINCIENCIAS (Colombia); MSES (Croatia); ERC PUT (Estonia); HIP (Finland); GSRI (Greece); MSIP (Republic of Korea); LAS (Lithuania); CINVESTAV (Mexico); LNS (Mexico); SEP (Mexico); MOS (Montenegro); MES (Poland); NSC (Poland); MCIN/AEI (Spain); MST (Taipei); MHESI (Thailand); TENMAK (Turkey); STFC (United Kingdom); DOE (USA); F.R.S.-FNRS (Belgium); New National Excellence Program - UNKP (Hungary); NKFIH (Hungary) [K 124845, K 124850, K 128713, K 128786, K 129058, K 131991, K 133046, K 138136, K 143460, K 143477, 2020-2.2.1-ED-2021-00181, TKP2021-NKTA-64]; Ministry of Education and Science [2022/WK/14]; Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de Maeztu (Spain) [MDM-2017-0765]; SC (Armenia
Comparison of Warm and Cold Forging With Friction Welding for Inner Constant Velocity Joints (cvjs)
No full textDriveshafts are used in all vehicles, and their service life is expected to be at least three years or 100.000 km. Many driveshaft manufacturers prefer friction welding due to its relatively cheaper cost and ease of the process. However, they should meet some property-related criteria to achieve the expected lifetime. The forging technique becomes essential to succeed in these mechanical requirements. A comparative study evaluates the performance of constant velocity joints (CVJs) produced by multi-step warm-cold forging and friction welding processes. Medium carbon steels were used in both of the techniques. The microstructures, mechanical properties (i.e. hardness, strength, impact energy and shear strength), low-cycle fatigue (LCF) properties, wear resistance and cost-efficiency (number of operations, material saving, number of produced components and cost) are compared in detail for an industrial production point of view. The experimental results reveal that warm-cold forged specimens exhibit superior mechanical properties such as increased strength, hardness, relatively higher impact energy, improved shear strength, relatively longer LCF life and enhanced wear resistance (lower wear volume loss). In addition, it is also assessed that warm-cold forging is a more cost-effective manufacturing process (reduced weight, decreased number of operations and increased yield) in the production of CVJs compared to the friction welding process.T.C. Kucuk ve Orta Olcekli ; Idot;sletmeleri Gelistirme ve Destekleme Idaresi BaskanligiT.C. Kucuk ve Orta Olcekli Idot;sletmeleri Gelistirme ve Destekleme Idaresi Baskanlig
Bir Robot Manipülatörün Optimum Enerji Tüketimi için Yörünge Planlaması
No full textBu çalışma, altı serbestlik dereceli ABB IRB 1010 robot manipülatörünün optimum enerji tüketimi için yörünge planlamasını ele almaktadır. İlk olarak, Denavit Hartenberg (D-H) yöntemi kullanılarak eklem değişkenleri belirlenmiştir. Ardından, bu değişkenler kullanılarak ileri ve ters kinematik hesaplamaları yapılmıştır. Daha sonra, farklı yörünge planlama fonksiyonları kullanılarak yörünge planlaması yapılmış ve dinamik hesaplamalar yapılarak bu yörünge planlama fonksiyonlarına göre eklemlerin tork gereksinimleri ve enerji tüketimleri hesaplanmıştır. Yörünge planlama fonksiyonlarından birisi olan beşinci derece polinom seçilerek bu fonksiyon üzerinde enerji tüketimini azaltmak için Arı Algoritması kullanılarak optimizasyon yapılmıştır. Farklı yörünge planlama fonksiyonlarının ve optimize edilmiş olan beşinci derece polinomun performansları MATLAB – Simulink ortamında gerçekleştirilen simülasyonlarla karşılaştırılmış ve sonuçlar grafikler ve tablolarla sunulmuştur. Bu sonuçlara göre en fazla enerji tüketen yönteme göre %46,90'a kadar daha az enerji tüketimi elde edilmiştir.This study includes trajectory planning for optimum energy consumption of a six degree-of-freedom (6DOF) ABB IRB 1010 robot manipulator. Firstly, joint variables were determined using the Denavit-Hartenberg method. Then, forward and inverse kinematics calculations were made using these variables. Then, trajectory planning was made using different trajectory planning functions and using dynamic calculations, the torque requirements and energy consumption of the joints were calculated according to these trajectory planning functions. The fifth degree polynomial, one of the trajectory planning functions, was selected and optimization was performed on this function using the Bees Algorithm to reduce energy consumption. The performances of different trajectory planning functions and the optimized fifth degree polynomial are compared. The results of MATLAB - Simulink simulation are presented with graphics. According to these results, up to 46.90% less energy consumption was achieved compared to the method that consumes the most energy
The Effect of Cutting Forces on Bone Related Operational Processes: a Literature Review
No full textCutting mechanics must be known in terms of solving the mechanistic problems to be encountered as a result of the operational processes on the bone. In today's applications, operational procedures such as milling, drilling, cutting and screwing can be performed on the bone as a surgical procedure. The uncontrollable cutting forces that occur as a combination of the microstructure of the bone and the geometric features of the cutting tools and the resulting localized heat (fracture and necrosis) may cause bone damage. The fracture of the cutting tool or the cut bone due to the cutting force depends on the intensity and direction of the forces applied during the operation. In this study, a review of the studies in the literature on what the factors causing bone damage and their effects are reduced. In addition, the information given in this study will be useful as a one-stop document for technicians, engineers and researchers who need information on tool design, cutting force measurements in bone processing operations (in surgical applications such as milling, drilling, cutting, etc.) of cutting forces.Selcuk University Scientific Research Projects Unit [22111001]This article is Ph.D. Yusuf Caglar Kagitci's thesis. We would like to thank Selcuk University Scientific Research Projects Unit (Project No: 22111001) for their support of this study
Bent Kapağı Altından Geçen Akimin Oluşturduğu Hidrolik Sıçramanın Konumunun Deneysel ve Nümerik Olarak Belirlenmesi
No full textBent kapakları, rezervuardaki su seviyesini kontrol edilmesini ve kapasitenin üzerindeki fazla suyun belli bir debi ile kontrollü bir şekilde mansap tarafına aktarılmasını sağlarlar. Bir bent kapağının altından geçen akım, serbest veya batmış akım durumda olabilir. Serbest akım durumunda kapak altından sel rejimiyle çıkan akım, nehir rejimine geçişinde, kapak sonrasında bir hidrolik sıçrama meydana getirir. Oluşan hidrolik sıçramanın, etraftaki yapılara ve bulunduğu kanala zarar vermemesi için hidrolik sıçrama konumunun tam olarak bilinmesi gerekmektedir. Bu çalışmada dikdörtgen kesite sahip bir açık kanal sisteminde, hidrolik sıçrama oluşturmak için bent kapağı ve doğrusal savak kullanılmıştır. Oluşan hidrolik sıçramanın konumunun, debi ve kapak açıklığı ile değişimi incelenmiştir. Deneylerde iki farklı kapak açıklığı (e1 =2,5 cm ve e2 =5 cm) kullanılmış ve 34 farklı debi değeri için deneyler yapılmıştır. Hidrolik sıçrama konumunun kapak açıklığına bağlı olarak farklı oranlarda, debi ile lineer değişim gösterdiği görülmüştür. Ayrıca fiziksel deney düzeneklerinin, 2-boyutlu nümerik modelleri oluşturulmuş ve deneylerden elde edilen hidrolik sıçrama konumları ve akım derinlikleri, nümerik modeller ile karşılaştırılmıştır. Elde edilen sonuçlara göre nümerik model ile fiziksel model, e=2,5 cm kapak açıklığı için %92,22 ve e=5 cm kapak açıklığı için %95,69 oranında tutarlılık göstermişlerdir