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Pixelated colorimetric nucleic acid assay
No full textPubMed: 31892020Conjugated polyelectrolytes (CPEs) have been widely used as reporters in colorimetric assays targeting nucleic acids. CPEs provide naked eye detection possibility by their superior optical properties however, as concentration of target analytes decrease, trace amounts of nucleic acid typically yield colorimetric responses that are not readily perceivable by naked eye. Herein, we report a pixelated analysis approach for correlating colorimetric responses of CPE with nucleic acid concentrations down to 1 nM, in plasma samples, utilizing a smart phone with an algorithm that can perform analytical testing and data processing. The detection strategy employed relies on conformational transitions between single stranded nucleic acid-cationic CPE duplexes and double stranded nucleic acid-CPE triplexes that yield distinct colorimetric responses for enabling naked eye detection of nucleic acids. Cationic poly[N,N,N-triethyl-3-((4-methylthiophen-3-yl)oxy)propan-1-aminium bromide] is utilized as the CPE reporter deposited on a polyvinylidene fluoride (PVDF) membrane for nucleic acid assay. A smart phone application is developed to capture and digitize the colorimetric response of the individual pixels of the digital images of CPE on the PVDF membrane, followed by an analysis using the algorithm. The proposed pixelated approach enables precise quantification of nucleic acid assay concentrations, thereby eliminating the margin of error involved in conventional methodologies adopted for interpretation of colorimetric responses, for instance, RGB analysis. The obtained results illustrate that a ubiquitous smart phone could be utilized for point of care colorimetric nucleic acids assays in complex matrices without requiring sophisticated software or instrumentation
Bose-Einstein correlations of charged hadrons in proton-proton collisions at √s = 13 TeV
No full textBose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at s = 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at s = 7 TeV, as well as with theoretical predictions
Multiparticle correlation studies in pPb collisions √s(NN)=8.16 TeV
No full textThe second- and third-order azimuthal anisotropy Fourier harmonics of charged particles produced in pPb collisions, at root s(NN) = 8.16 TeV, are studied over a wide range of event multiplicities. Multiparticle correlations are used to isolate global properties stemming from the collision overlap geometry. The second-order "elliptic" harmonic moment is obtained with high precision through four-, six-, and eight-particle correlations and, for the first time, the third-order "triangular" harmonic moment is studied using four-particle correlations. A sample of peripheral PbPb collisions at root s(NN) = 5.02 TeV that covers a similar range of event multiplicities as the pPb results is also analyzed. Model calculations of initial-state fluctuations in pPb and PbPb collisions can be directly compared to the high-precision experimental results. This work provides new insight into the fluctuation-driven origin of the v(3) coefficients in pPb and PbPb collisions, and into the dominating overall collision geometry in PbPb collisions at the earliest stages of heavy ion interactions
Electrocaloric properties of Ba0.8Sr0.2Ti1-xZrxO3 (0 <= x <= 0.1) system: The balance between the nature of the phase transition and phase coexistence
No full textWOS: 000527383100111We investigate the electrocaloric effect of Ba0.8Sr0.2Ti1-xZrxO3 (0 <= x <= 0.1) system by comparing the electrocaloric temperature change (Delta T) of different compositions belonging to the different regions of the phase diagram. We show that as the amount of Zr increases, electrocaloric temperature change initially decreases as the phase transition gets diffuse then increases again as the composition of the samples are located closer to the critical point where different ferroelectric phases coexist. Since the critical point is reached at relatively low Zr substitution levels (i.e. around x = 0.07), the phase transition doesn't get too diffuse and thefore the compositions between x = 0 and x = 0.10 (which contains higher Zr than the critical point composition) have comparable Delta T values. Electrocaloric efficiency of these compositions (x = 0.03, 0.05 and 0.07) is around 0.20 K mm/kV at 20 kV/cm. We discuss the results in terms of the balance between the nature of the phase transition and proximity to the critical point, based on the phase diagram
A search for the standard model Higgs boson decaying to charm quarks
No full textA direct search for the standard model Higgs boson, H, produced in association with a vector boson, V (W or Z), and decaying to a charm quark pair is presented. The search uses a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb(-1), collected by the CMS experiment at the LHC in 2016, at a centre-of-mass energy of 13 TeV. The search is carried out in mutually exclusive channels targeting specific decays of the vector bosons: W -> l nu, Z -> ll, and Z -> nu nu, where l is an electron or a muon. To fully exploit the topology of the H boson decay, two strategies are followed. In the first one, targeting lower vector boson transverse momentum, the H boson candidate is reconstructed via two resolved jets arising from the two charm quarks from the H boson decay. A second strategy identifies the case where the two charm quark jets from the H boson decay merge to form a single jet, which generally only occurs when the vector boson has higher transverse momentum. Both strategies make use of novel methods for charm jet identification, while jet substructure techniques are also exploited to suppress the background in the merged-jet topology. The two analyses are combined to yield a 95% confidence level observed (expected) upper limit on the cross section sigma(VH) corresponding to 70 (37) times the standard model prediction
Strange hadron production in pp and pPb collisions at √s(NN)=5.02 TeV
No full textThe transverse momentum (pT) distributions of Lambda, Xi(-), and Omega(-) baryons, their antiparticles, and K-S(0) mesons are measured in proton-proton (pp) and proton-lead (pPb) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV over a broad rapidity range. The data, corresponding to integrated luminosities of 40.2 nb(-1) and 15.6 mu b(-1) for pp and pPb collisions, respectively, were collected by the CMS experiment. The nuclear modification factor R-pPb, which is defined as the ratio of the particle yield in pPb collisions and a scaled pp reference, is measured for each particle. A strong dependence on particle species is observed in the pT range from 2 to 7 GeV, where R-pPb for K-S(0) is consistent with unity, while an enhancement ordered by strangeness content and/or particle mass is observed for the three baryons. In pPb collisions, the strange hadron production is asymmetric about the nucleon-nucleon center-of-mass rapidity. Enhancements, which depend on the particle type, are observed in the direction of the Pb beam. The results are compared with predictions from EPOS LHC, which includes parametrized radial flow. The model is in qualitative agreement with the R-pPb data, but fails to describe the dependence on particle species in the yield asymmetries measured away from midrapidity in pPb collisions
Extended dynamical symmetries of Landau levels in higher dimensions
No full textContinuum models for time-reversal (TR) invariant topological insulators (Tis) in d >= 3 dimensions are provided by harmonic oscillators coupled to certain SO(d) gauge fields. These models are equivalent to the presence of spin-orbit (SO) interaction in the oscillator Hamiltonians at a critical coupling strength (equivalent to the harmonic oscillator frequency) and leads to flat Landau Level (LL) spectra and therefore to infinite degeneracy of either the positive or the negative helicity states depending on the sign of the SO coupling. Generalizing the results of [1] to d >= 4, we construct vector operators commuting with these Hamiltonians and show that SO(d, 2) emerges as the non-compact extended dynamical symmetry. Focusing on the model in four dimensions, we demonstrate that the infinite degeneracy of the flat spectra can be fully explained in terms of the discrete unitary representations of SO(4,2), i.e. the doubletons. The degeneracy in the opposite helicity branch is finite, but can still be explained exploiting the complex conjugate doubleton representations. Subsequently, the analysis is generalized to d-dimensions, distinguishing the cases of odd and even d. We also determine the spectrum generating algebra in these models and briefly comment on the algebraic organization of the LL states w.r.t. an underlying "deformed" AdS geometry as well as on the organization of the surface states under open boundary conditions in view of our results
Detailed chemical kinetic modeling of fuel-rich n-heptane flame
No full textThe main purpose of this study is to model one-dimensional, premixed, laminar, burner-stabilized, fuel-rich n-heptane flame to understand its combustion characteristics. Detailed chemical kinetic modeling technique was used to obtain more information about the formation nature of emissions in n-heptane flame. A detailed chemical kinetic mechanism was generated by combining several mechanisms from the literature that related with possible products of fuel-rich n-heptane combustion. The mechanism consists of 4185 reactions and 893 species. Validations of the mechanism were done by species mole fractions of premixed laminar flames and jet stirred reactors, and ignition delay times in shock tubes. A detailed investigation of the n-heptane flame was carried out using rate of production and reaction pathway analyses. Propargyl radical (C3H3), vinylacetylene (C4H4) and acetylene (C2H2) were found as the main precursors of benzene formation. The mechanism was able to predict most of the major, minor, and trace species up to four-fused aromatic rings formed in the flame. A skeletal mechanism was also generated using Directed Relation Graph with Error Propagation (DRGEP) method. It consists of 1879 reactions and 359 species. The skeletal mechanism was in a good agreement with the detailed mechanism on the species mole fraction predictions
Kritik altı suda selüloz ve glikozun sorbitole seçici katalitik dönüşümü
No full textText in English; Abstract: Turkish and English.Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020Includes bibliographical references (leaves: 55-61)The goal of this study was to add high value to cellulose as the most abundant source of biomass and glucose by producing a building-block chemical-Sorbitol-, which is not produced in our country and has very large market share. In this manner, the effect of reaction time (1-2 h), catalyst amount (1-2 g) and catalyst type on conversion of cellulose and glucose and yield of sorbitol with presence of various catalysts in subcritical water environment were investigated. The hydrogenation of both glucose and cellulose over Ruthenium based catalysts (Ru/AC, Ru/SiO2, Ru-SBA15 and Ru-SBA15/SO3), using a high pressure-high temperature reactor (Parr 5500 High Pressure Compact Reactor) at a reaction pressure of 5 bar and reaction temperature of 150°C were studied. Ruthenium based catalysts were prepared by wet impregnation method. The synthesized Ru based catalysts with various metal based were characterized by various characterization tools such as Scanning Electron Microscope (SEM), Fouirer Transform Infrared Spektrofotometre (FT-IR) and Brunauer-Emmett-Teller (BET). The catalytic performances were evaluated in hydrogenation of cellulose and also glucose to produce sorbitol under subcritical water conditions. As a result of these analyzes, the highest sorbitol yield and cellulose conversion were found to be 234.98 ppm and 28.64%, respectively for 2 gram of Ru-SiO2 catalyst for 2 hours. For glucose conversion, the catalyst of Ru-SBA15/SO3 showed better catalytic performance than other catalysts.Bu çalışmanın amacı, ülkemizde üretilmeyen ve çok büyük pazar payına sahip bir kimyasal yapı taşı olan sorbitol üreterek, en çok bulunan biyokütle kaynağı olan selüloza ve glikoza yüksek değer katmaktır. Bu şekilde, reaksiyon süresi (1-2 saat), katalizör miktarı (1-2 gram) ve katalizör tipinin selülozun ve glikozun dönüşümü ve sorbitol veriminin kritik altı su ortamında çeşitli katalizörlerin varlığı üzerindeki etkisi
araştırıldı. Hem glikoz hem de selülozun hidrojenasyonu Rutenyum bazlı katalizörler üzerinde (Ru/AC, Ru/SiO2, Ru-SBA15 and Ru-SBA15/SO3), yüksek basınç-yüksek sıcaklık reaktörü kullanarak (Parr 5500 Yüksek Basınçlı Kompakt Reaktör) 5 bar reaksiyon basıncında ve 150°C reaksiyon sıcaklığında çalışıldı. Rutenyum bazlı katalizörler ıslak emprenye yöntemi ile hazırlandı. Çeşitli metaller ile sentezlenmiş Ru
bazlı katalizörler, Taramalı Elektron Mikroskobu (SEM), Fourier Dönüşümlü Kızılötesi Spektroskopisi (FT-IR) ve Brunauer-Emmett-Teller (BET) gibi çeşitli karakterizasyon araçları ile karakterize edildi. Katalitik performanslar, kritik altı su koşulları altında sorbitol üretmek için selüloz ve ayrıca glikozun hidrojenasyonunda değerlendirildi. Bu analizler sonucunda, en yüksek sorbitol verimi ve selüloz dönüşümü 2 saat boyunca 2 gram Ru-Si02 katalizörü için sırasıyla 234.98 ppm ve 28.64% olduğu bulunmuştur. Glikoz dönüşümü için Ru-SBA15/SO3 katalizörü, diğer katalizörlerden daha iyi
katalitik performans gösterdi
İnorganik ve organik kaplama katmanlarının bobin kaplamalı alüminyum substratların korozyon davranışına etkisi
No full textThesis (Master)--Izmir Institute of Technology, Chemical Engineering, İzmir, 2020Text in English; Abstract: Turkish and EnglishIncludes bibliographical references (leaves: 61-66)Organic coil coated aluminum substrates are one of the most widely used materials for construction industry. These coated substrates typically consist of 4 separate layers, the aluminum substrate, the inorganic conversion coating (resulting from the pretreatment application), and the organic coating layers that are called the primer and the topcoat. From industrial experience, it is not clearly and quantitatively determined how these layers contribute to the different processes that occur during corrosion, such as water uptake (diffusion of water through the coating) and the corrosion reactions that take place on the substrate. In this thesis, the formation of the inorganic conversion coating as a function of the pretreatment application parameters, immersion time, temperature and pH, and the individual effects of inorganic and organic coating layers on corrosion are investigated. The structure of the various surfaces formed after coating application and after corrosion testing by Neutral Salt Spray Test (NSST) is investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Fluorensence Spectrometer (XRF) and Atomic Force Microscopy (AFM) analysis, while their anticorrosive properties are determined by Electrochemical Impedance Spectroscopy (EIS). The results indicate that the formation of the pretreatment layer is enhanced continuously as function of temperature and immersion time, within the values investigated, while for pH an optimum is observed. The investigation of the corrosion resistance of substrates coated with different coating layers reveal that without organic coating layers, the substrates corrode much faster, indicating the importance of water diffusion on the corrosion reactions.Organik bobin kaplamalı alüminyum substratlar inşaat sektöründe oldukça yaygın kullanılan malzemelerdir. Bobin kaplama sistemi, alüminyum metali, önişlem uygulaması sonucunda oluşan dönüşüm kaplaması (inorganik kaplama), astar ve sonkat (organik kaplama) olarak adlandırılan kaplama katmanlarından oluşur. Endüstriyel çalışmalardan, bu katmanların, su alımı (suyun kaplamadan difüzyonu) ve substrat üzerinde meydana gelen korozyon reaksiyonları gibi korozyon sırasında meydana gelen
farklı proseslere nasıl katkıda bulunduğu açıkça ve niceliksel olarak belirlenmemiştir. Bu tezde, önişlem uygulama parametreleri olan daldırma süresi, sıcaklık ve pH değerinin bir fonksiyonu olarak inorganik dönüşüm kaplamasının oluşumu ve inorganik ve organik kaplama katmanlarının korozyon üzerindeki bireysel etkileri araştırılmıştır. Kaplama uygulamasından ve tuzlu sis korozyon testinden (NSST) sonra oluşan çeşitli yüzeylerin yapısı, Atomik Kuvvet Mikroskobu (AFM), Taramalı Elektron Mikroskobu (SEM),
Elektron Dispersif X-Işını Spektroskopisi (EDX) ve X-Işını Flüoresans Spektroskopisi (XRF) kullanılarak, korozyon önleyici özellikleri ise Elektrokimyasal Empedans Spektroskopisi (EIS) kullanılarak belirlendi. Sonuçlar, önişlem katmanının oluşumunun, sıcaklık ve daldırma süresinin fonksiyonu olarak, araştırılan değerler dahilinde sürekli olarak geliştirildiğini, pH için ise bir optimum değerin gözlemlendiğini göstermektedir. Farklı kaplama katmanları ile kaplanmış substratların korozyon direncinin araştırılması,
organik kaplama katmanları olmadan, substratların çok daha hızlı korozyona uğradığını ve korozyon reaksiyonlarında su difüzyonunun önemini göstermektedir