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Observation of prompt J/ψ meson elliptic flow in high-multiplicity pPb collisions at √s NN =8.16 TeV
No full textA measurement of the elliptic flow (v(2)) of prompt J/psi mesons in high-multiplicity pPbcollisions is reported using data collected by the CMS experiment at a nucleon-nucleon center-of-mass energy root s(NN)= 8.16 TeV. Prompt J/psi mesons decaying into two muons are reconstructed in the rapidity region in the nucleon-nucleon center-of-mass frame (y(cm)), corresponding to either -2.86 < y(cm) < -1.86 or 0.94 < y(cm)< 1.94. The average v(2) result from the two rapidity ranges is reported over the transverse momentum (p(T)) range from 0.2 to 10 GeV. Positive v(2) values are observed for the prompt J/psi meson, as extracted from long-range two-particle correlations with charged hadrons, for 2 < p(T) < 8 GeV. The prompt J/psi results are compared with previous CMS measurements of elliptic flow for open charm mesons (D-0) and strange hadrons. From these measurements, constraints can be obtained on the collective dynamics of charm quarks produced in high-multiplicity events arising from small systems. (c) 2019 The Author(s). Published by Elsevier B.V
Lipozomlardan doksorubisin (DOX) salınımının artırılması
No full textThesis (Master)--Izmir Institute of Technology, Biotechnology and Bioengineering, Izmir, 2019Includes bibliographical references (leaves: 59-66)Text in English; Abstract: Turkish and EnglishCancer is the second most common cause of death in the world and its incidence is increasing day by day. Doxorubicin (DOX) is an anthracycline group drug frequently used in many cancer treatments including breast cancer. However, free DOX has many harmful side effects and need to be encapsulated into nanocarrier such as liposomes. Although liposomal DOX has many advantages over its free form, liposomal DOX has undesirable side effects such as hand and foot syndrome. In this thesis, it was aimed to develop a more effective liposomal DOX delivery and release systems. Liposomes were prepared with alkaline solutions containing tris, sodium carbonate, ammonium chloride, and ammonium sulfate. DOX loading into liposomes and the percentage of release from liposomes were examined. A loading efficiency of about 80% was achieved, while the release was found to be below 13% at room temperature. The release of DOX was found to be enhanced from liposomes in the presence of ammonia (NH3), whose content was dependent on pH. Temperature was also found an important parameter and enhances DOX release at higher temperatures than the phase transition temperature of the lipid. A two-component liposomal system was proposed where ammonia (NH3) would be released from one liposome and enhance the DOX release from other liposomes. It was found that temperature, pH, and ammonia (NH3) concentration affected DOX release from liposomes. As a result, DOX was successfully loaded into liposomes and ready to study their effect on breast cancer cells.Kanser dünyada ölüm nedenleri arasında ikinci sıradadır ve kanser vakaları gün
geçtikçe artmaktadır. Doxorubicin (DOX) meme kanseri dahil birçok kanserin
tedavisinde kullanılan antrasiklin grup ilaçlardandır. Ancak serbest DOX’un birçok yan
etkisi vardır ve lipozomlar gibi nano taşıyıcılar içerisine hapsedilmesi gerekmektedir.
Her ne kadar lipozomal DOX’un serbest haline göre birçok avantajı olsa da el ve ayak
sendromu gibi bazı yan etkileri de bulunmaktadır. Bu tezde, daha etkin lipozomal DOX
taşıma ve salınım sistemleri geliştirme amaçlanmıştır. Lipozomlar tris, sodyum karbonat,
amonyum klorit ve amonyum sülfat içeren alkali solüsyonlar ile hazırlandı. Lipozomlara
DOX yüklemesi ve lipozomlardan yüzde salınımları incelendi. Yükleme verimliliği %80
olarak gerçekleştirildi. Salınım hızının oda sıcaklığında %13’den düşük oranlarda olduğu
bulundu. Lipozomlardan DOX salınımının ortamda pH'a bağlı amonyak (NH3)
konsantrasyonuna bağlı artırılabileceği bulundu. Sıcaklığın da önemli bir parametre
olduğu ve lipidin faz geçiş sıcaklığı üzerindeki sıcaklıklarda DOX salınımını artırdığı
bulundu. İki-bileşenli bir lipozomal sistem önerildi, burada amonyak (NH3) bir
lipozomdan salınırken, diğer lipozomlardan DOX salınımını arttıracaktır. Sıcaklığın,
pH’ın ve amonyak (NH3) konsantrasyonunun lipozomlardan DOX salınımını etkilediği
bulundu. Sonuçta, DOX lipozomlara başarı ile yüklendi ve meme kanseri hücreleri
üzerindeki etki çalışmaları için hazırlandı.TUBITAK (213M668
Inelastic ultimate load analysis of steel frames considering lateral torsional buckling under distributed loads
No full textContemporary structural design approaches necessitates ways to determine realistic behavior of structures. For this purpose, inelastic ultimate load analysis methods are used widely since strength and stability of whole structure can be represented. In this study, a numerical method is proposed for determining inelastic ultimate load capacity of steel frames considering lateral torsional buckling behavior under distributed loads. In the analyses, inelastic material behavior, second-order effects and residual stresses of the structural frame system and its members are taken into account. Additionally, lateral torsional buckling behavior is considered in the analysis using finite difference method and it is used for determining the structural load carrying capacity of steel frames. Consequently, the problem associated with flexural capacity decreases due to lateral torsional buckling is precisely considered in the load increment steps of inelastic ultimate load analysis. In order to validate the proposed method, numerical examples from the literature are calculated considering the proposed method, AISC 360-16 design specification equations and approaches from the literature. Results of the numerical examples show that lateral torsional buckling is a key issue in determining structural load carrying capacity. Thus, proposed analysis method is shown to be an ef.cient and consistent tool for inelastic ultimate load analysis
Fast formation of nitro-pahs in the marine atmosphere constrained in a regional-scale lagrangian field experiment
No full textPolycyclic aromatic hydrocarbons (PAHs) and some of their nitrated derivatives, NPAHs, are seemingly ubiquitous in the atmospheric environment. Atmospheric lifetimes may nevertheless vary within a wide range, and be as short as a few hours. The sources and sinks of NPAH in the atmosphere are not well understood. With a Lagrangian field experiment and modeling, we studied the conversion of the semivolatile PAHs fluoranthene and pyrene into the 2-nitro derivatives 2-nitrofluoranthene and 2-nitropyrene in a cloud-free marine atmosphere on the time scale of hours to 1 day between a coastal and an island site. Chemistry and transport during several episodes was simulated by a Lagrangian box model i.e., a box model coupled to a Lagrangian particle dispersion model, FLEXPART-WRF. It is found that the chemical kinetic data do capture photochemical degradation of the 4-ring PAHs under ambient conditions on the time scale of hours to 1 day, while the production of the corresponding NPAH, which sustained 2-nitrofluoranthene/fluoranthene and 2-nitropyrene/pyrene yields of (3.7 ± 0.2) and (1.5 ± 0.1)%, respectively, is by far underestimated. Predicted levels of NPAH come close to observed ones, when kinetic data describing the reactivity of the OH-adduct were explored by means of theoretically based estimates. Predictions are also underestimated by 1-2 orders of magnitude, when NPAH/PAH yields reported from laboratory experiments conducted under high NOx conditions are adopted for the simulations. It is concluded that NPAH sources effective under low NOx conditions, are largely underestimated.Grant Agency of the Czech Republic (P503 16-115375); Izmir Institute of Technology Research Fund (2013IYTE-14); Max Planck Society; European Union (262254); Ministry of Education, Youth & Sports - Czech Republic (LM2015051/CZ.02.1.01/0.0/0.0/16_013/0001761
Search for Higgs and Z boson decays to J/ψ or Y pairs in the four-muon final state in proton-proton collisions at √s=13 TeV
No full textA search for decays of the Higgs and Z boson to pairs of J/psi or Y(nS)(n = 1, 2, 3) mesons, with their subsequent decay to mu(+)mu(-) pairs, is presented. The analysis uses data from proton-proton collisions at root s = 13 TeV, collected with the CMS detector at the LHC in 2017 and corresponding to an integrated luminosity of 37.5 fb(-1). While an observation of such a decay with this sample would indicate the presence of physics beyond the standard model, no significant excess is observed. Upper limits at 95% confidence level are placed on the branching fractions of these decays. In the J/psi pair channel, the limits are 1.8 x 10(-3) and 2.2 x 10(-6) for the Higgs and Z boson, respectively, while in the combined Y(nS) pair channel, the limits are 1.4 x 10(-3) and 1.5 x 10(-6), respectively, when the mesons from the Higgs and Z boson decay are assumed to be unpolarized. When fully longitudinal and transverse polarizations are considered the limits reduce by about 22-29% and increase by about 10-13%, respectively. (C) 2019 The Author(s). Published by Elsevier B.V. </bold
Search for physics beyond the standard model in events with overlapping photons and jets
No full textPubMed: 31922872Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons
Measurements of t t ¯ differential cross sections in proton-proton collisions at √s=13 TeV using events containing two leptons
No full textMeasurements of differential top quark pair t (t) over bar cross sections using events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV containing two oppositely charged leptons are presented. The data were recorded by the CMS experiment at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb(-1). The differential cross sections are presented as functions of kinematic observables of the top quarks and their decay products, the t (t) over bar system, and the total number of jets in the event. The differential cross sections are de fined both with particle-level objects in a fiducial phase space close to that of the detector acceptance and with parton-level top quarks in the full phase space. All results are compared with standard model predictions from Monte Carlo simulations with next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD) at matrix-element level interfaced to parton-shower simulations. Where possible, parton-level results are compared to calculations with beyond-NLO precision in QCD. Significant disagreement is observed between data and all predictions for several observables. The measurements are used to constrain the top quark chromomagnetic dipole moment in an effective field theory framework at NLO in QCD and to extract t (t) over bar and leptonic charge asymmetries
Search for associated production of a Higgs boson and a single top quark in proton-proton collisions at √s=13 TeV
No full textA search is presented for the production of a Higgs boson in association with a single top quark, based on data collected in 2016 by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, which corresponds to an integrated luminosity of 35.9 fb(-1). The production cross section for this process is highly sensitive to the absolute values of the top quark Yukawa coupling, y(t); the Higgs boson coupling to vector bosons, g(HVV); and, uniquely, their relative sign. Analyses using multilepton signatures, targeting H -> WW, H -> tau tau, and H -> ZZ decay modes, and signatures with a single lepton and a b (b) over bar pair, targeting the H -> b (b) over bar decay, are combined with a reinterpretation of a measurement in the H -> gamma gamma channel to constrain y(t). For a standard model-like value of g(HVV), the data favor positive values of y(t) and exclude values of y(t) below about -0.9y(t)(SM)
Yarı iletken yüzeylerde uyarılma dinamiklerinin hesaplamasal olarak çalışılması
No full textThesis (Master)--Izmir Institute of Technology, Materials Science and Engineering, Izmir, 2019Includes bibliographical references (leaves: 64-69)Text in English; Abstract: Turkish and EnglishRecent experimental studies have shown that collodial quantum dots can be produced
in large quantities and their optical properties can be tailored by controlling their
composition, size and surface characteristics. Motivated by these studies, this thesis is
devoted to the investigation of excitation dynamics on semiconductor surfaces, which are
passivated with organic molecules. First, constructing a simplified model, excitation dynamics
is investigated by computing time dependent occupations of frontier molecular
orbitals for various scenarios regarding the values for the energy gap between the highest
occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO), as well as
the coupling strengths. Second, the model is enhanced to address realistic systems. Passivation
of ZnS surface with oleic acid (OA) is modeled using density functional theory
based tight binding (DFTB) simulations. Extracting the Hamiltonian and overlap matrices,
excitation dynamics is studied for Zn rich and S rich surfaces and different coverage
ratios of surfaces. The excitation dynamics is compared and contrasted against the simplified
model. Characteristic features are identified and typical decay rates are calculated
for various molecular configurations. In addition to these, X-Ray diffraction spectra of
quaternary ZnCdSSe nanoalloys have been investigated.Son deneysel çalışmalar kolloidal kuantum noktalarının büyük miktarlarda üretilebileceğini ve optik özelliklerinin kompozisyonlarını, boyutlarını ve yüzey özelliklerini kontrol ederek uyarlanabileceğini göstermiştir. Bu çalışmaların motive ettiği bu tez, organik moleküllerle pasife edilmiş yarı iletken yüzeylerdeki uyarılma dinamiklerini araştırmaya adanmıştır. İlk olarak, basitleştirilmiş bir modelin oluşturulmasıyla uyarılma dinamikleri, etkileşim gücünün yanı sıra, en yüksek dolu ve en düşük boş moleküler orbitaller (HOMO ve LUMO) arasındaki enerji boşluğu değerlerine ilişkin çeşitli senaryolar
için öncü moleküler orbitallerin zamana bağlı doluluk oranları hesaplanarak incelenmiştir. İkinci olarak, bu model gerçekçi sistemleri ele almak için geliştirilmiştir. ZnS yüzeyinin oleik asit (OA) ile pasive edilmesi yoğunluk fonksiyoneli teorisine dayanan sıkı bağlanma simülasyonları kullanılarak modellenmiştir. Hamiltonyen ve örtüşme matrisleri elde edilerek Zn ve S bakımından zengin yüzeylerde ve yüzeylerin farklı kaplama oranlarında uyarılma dinamikleri incelenmiştir. Uyarılma dinamikleri basitleştirilmiş modelle
karşılaştırılmıştır. Karakteristik özellikler tanımlanmış ve çeşitli moleküler konfigürasyonlar
için tipik bozulma oranları hesaplanmıştır. Bunlara ek olarak, kuaterner ZnCdSSe nano alaşımlarının X-ışını kırınım spektrumları incelenmiştir.TUBITAK (115F616
Elyaf takviyeli silindirik kompozit yapıların filament sarma yöntemi ile geliştirilmesi
No full textThesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2019Includes bibliographical references (leaves: 51-55)Text in English; Abstract: Turkish and EnglishFiber reinforced composite structures with superior properties are used for cylindrical structure systems in many application areas nowadays. The major aim of this thesis is development of filament wound composite cylindrical structures with various fiber types on different ply sequence and investigate their mechanical properties. For this purpose, 4 layered glass, carbon and glass/carbon hybrid fiber reinforced cylindrical structures were manufactured with 55 degree winding angle by utilizing filament winding technique. Produced 6 different composite structures have 1 m length and 60 mm inner diameter. Glass/carbon fiber reinforced systems were developed to reduce the cost by reducing carbon fiber usage. Apparent hoop tensile strength and radial compression tests were applied to the manufactured composite structures. In addition to these studies, two different composite plate with glass fiber and carbon fiber reinforcements were produced by filament winding to investigate glass transition temperature. These plates were manufactured with 4 layered by using the same fiber and matrix as used in the previous tube production. Dynamic mechanical analysis was performed with samples which is sectioned from plates to obtain glass transition temperature. Consequently, apparent hoop tensile strength test results showed that hoop strength of glass fiber reinforced cylindrical structures can be improved significantly by hybridization. Based on the radial compression test results, deflection of the structures decreases by hybridizationFiber takviyeli kompozitler üstün özelliklerinden dolayı son dönemlerde silindirik
yapı sistemlerinde sıklıkla kullanılmaya başlanmış ve önemli bir konuma gelmiştir. Bu
çalışmadaki amaç farklı tip fiber ve yönelim kullanılarak hibrit kompozit silindirik yapılar
üretmek, bu silindirik yapıların mekanik özelliklerini ve hibridizasyonun etkilerini
incelemektir. Bu doğrultuda her bir kompozit yapı 4 katmanlı olacak şekilde 55 derece
sarım açısıyla sarılmıştır. 1 metre boyunda 60 mm iç çapa sahip 6 tip farklı kompozit
silindirik yapı filaman sarım yöntemi ile üretilmiş, bu silindirik yapılara fiber içeriği,
halka çekme testi ve radyal basma testleri uygulanmıştır.
Bu çalışmaların yanında, camsı geçiş sıcaklığını incelemek için cam fiber ve
karbon fiber sarılı iki ayrı plaka filaman sarım metodu ile üretildi. Üretilen bu plakalar da
tüp sarımındaki ile aynı fiber ve matris kullanılarak 4 kat sarım yapılmıştır. Bu
üretimlerden alınan numuneler ile dinamik mekanik analiz yapılmış ve camsı geçiş
sıcaklığı incelenmiştir.
Sonuçlar incelendiğinde referans baz alınan cam fiber takviyeli kompozit
silindirik yapılara kıyasla hibridizasyon ile mekanik özelliklerin arttığı gözlenmiş ve
karbon fiber takviyeli silindirik yapılara kıyasla maliyet azaltılmıştır