Experimental investigation of the maximum quality factor axes temperature deviation in metallic coriolis vibratory gyroscopes resonator

A metallic cylindrical resonator is a well known base detail of the significant part of Coriolis vibratory gyroscopes (CVG) [1] including a MEMS gyro. It own parameters just after mechanical manufacture in main are determine an advisability of further utilize and the future gyroscope accuracy potential. Initial testing CVG resonators directly after their manufacture often done using the optical method [2, 3] or acoustic method [4, 5]. Unfortunately investigated manufacture quality of the resonators by using acoustic method not very well describe in scientific literature. A paper presents the results of some extension acoustic investigations of the metallic CVG resonators. This result describes the behavior of maximum quality factor (Q factor) axes and own resonant frequencies axes under stabilized temperature step influences and can be used in prediction for CVG bias minimization during it works in temperature range.Металевий циліндричний резонатор є загальновідомою базовою деталлю значної частини вібраційних гіроскопів Коріоліса (CVG) [1], у тому числі гіроскопа MEMS. Його власні параметри відразу після механічного виготовлення в основному визначають доцільність подальшого використання та майбутній потенціал точності гіроскопа. Початкові випробування CVG резонаторів безпосередньо після їх виготовлення часто проводять оптичним методом [2, 3] або акустичним методом [4, 5]. На жаль, досліджена якість виготовлення резонаторів за допомогою акустичного методу не дуже добре описана в науковій літературі. У статті представлено результати деяких розширених акустичних досліджень металевих CVG резонаторів. Цей результат описує поведінку осей максимального коефіцієнта якості (Q фактор) і осей власних резонансних частот під впливом стабілізованих температурних кроків і може бути використаний для прогнозування для мінімізації зміщення CVG під час його роботи в діапазоні температур

Study of ATLAS sensitivity to FCNC top decays

The ATLAS experiment sensitivity to top quark Flavour Changing Neutral Current (FCNC) decays was studied at LHC using ttbar events. While one of the top quarks is expected to follow the dominant Standard Model decay t->bW, the other decays through a FCNC channel, i.e. t-> Z u(c), t-> gamma u(c) or t-> g u(c). Different types of analyses, applied to each FCNC decay mode, were compared. The FCNC branching ratio sensitivity (assuming a 5sigma signal significance) and 95% confidence level limits on the branching ratios (in the hypothesis of signal absence) were obtained

Muon-spin rotation and magnetization studies of chemical and hydrostatic pressure effects in EuFe_{2}(As_{1-x}P_{x})_{2}

The magnetic phase diagram of EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ was investigated by means of magnetization and muon-spin rotation studies as a function of chemical (isovalent substitution of As by P) and hydrostatic pressure. The magnetic phase diagrams of the magnetic ordering of the Eu and Fe spins with respect to P content and hydrostatic pressure are determined and discussed. The present investigations reveal that the magnetic coupling between the Eu and the Fe sublattices strongly depends on chemical and hydrostatic pressure. It is found that chemical and hydrostatic pressure have a similar effect on the Eu and Fe magnetic order.Comment: 11 pages, 10 figure

Probing Colored Particles with Photons, Leptons, and Jets

If pairs of new colored particles are produced at the Large Hadron Collider, determining their quantum numbers, and even discovering them, can be non-trivial. We suggest that valuable information can be obtained by measuring the resonant signals of their near-threshold QCD bound states. If the particles are charged, the resulting signatures include photons and leptons and are sufficiently rich for unambiguously determining their various quantum numbers, including the charge, color representation and spin, and obtaining a precise mass measurement. These signals provide well-motivated benchmark models for resonance searches in the dijet, photon+jet, diphoton and dilepton channels. While these measurements require that the lifetime of the new particles be not too short, the resulting limits, unlike those from direct searches for pair production above threshold, do not depend on the particles' decay modes. These limits may be competitive with more direct searches if the particles decay in an obscure way.Comment: 39 pages, 9 figures; v2: more recent searches include

Определение подлинности куркумы

The paper examines the problem of the composition instability in the ready ground spice, turmeric. Analysis of the prevalent methods for turmeric adulteration and substances used for these purposes is given. The visual assessment of color tints of the turmeric root, spices containing it and chemical dyes based on chromium salts is presented. The studies on determination of the lead and chromium content were carried out to study the content of these metals and test the hypothesis of using lead chromate as a dye in adulteration of turmeric. Using the method of electrothermal atomic absorption spectroscopy, it was found that the lead content in the analyzed turmeric samples varied from 1.72 ± 0.58 to 5.03 ± 1.80 mg/kg, while the chromium content was in a range of 5.56 ± 0.85 to 16.15 ± 2.32 mg/kg. As a result of species specific PCR, wheat DNA was revealed in all purchased samples of ground turmeric. The levels of the main raw material replacement were established, which were 0.14% to 14.95% with the correlation coefficient close to 100%; efficiency of the reaction was 1.95, which was 97.5% when expressed as percentage. These levels of an undeclared allergen in the product composition can cause a serious allergic reaction. The authors tested the hypothesis of introduction of sodium and potassium salts for correction of the color spectrum in the ready spice and its correspondence to the natural color within the color spectrum of turmeric. As a result of the complex study of the spice composition, quite high values of chromium were found, presumably not only from the lead chromate compound but also from chromic acid salts, as the high level of potassium that significantly exceeded the native content of this element was found.В работе рассмотрена проблематика нестабильности состава готовой молотой специи — куркума. Дан анализ наиболее распространенных способов фальсификации куркумы и веществ, применяемых для этих целей. Дана визуальная оценка цветовых оттенков корня куркумы, специй ее содержащих и химических красителей на основе солей хрома. Проведены исследования по содержанию свинца и хрома, с целью изучения содержания этих металлов и проверки гипотезы использования хромата свинца в качестве красителя при фальсификации куркумы. Методом электротермической атомно-абсорбционной спектрометрии установлено, что содержание свинца в исследованных образцах куркумы изменялось в пределах от 1,72 ± 0,58 до 5,03 ± 1,80 мг/кг, а содержание хрома варьировалось в диапазоне от 5,56 ± 0,85 до 16,15 ± 2,32 мг/кг. В результате проведения видоспецифической ПЦР была выявлена ДНК пшеницы во всех закупленных образцах молотой куркумы. Установлены уровни подмены основного сырья, которые составили от 0,14% до 14,95% с коэффициентом корреляции близким к 100%, эффективность реакции составила 1,95 что в процентном отношении составляет 97,5%. Такие уровни незаявленного в составе продукта аллергена могут вызывать серьезную аллергическую реакцию. Проверена гипотеза внесения солей натрия и калия, для коррекции цветовой гаммы готовой специи и соответствия ее натуральному цвету цветовой гамме куркумы. В результате комплексного изучения состава специи, обнаружены достаточно высокие значения хрома, предположительно не только из соединения хромата свинца, но и солей хромовой кислоты, т. к. было обнаружено высокое значение металла калия, значительно превышающее нативное содержание данного элемента

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction