Influence of Humidity on the NO₂ Sensing Properties of SrCo₀.₁Ti₀.₉O₃

Strontium Cobalt Titanate (SCT) was synthesized via solid state route. Phase formation was analyzed using X-ray diffraction (XRD) technique. Resistive sensors were made using screen printing technique and corresponding sensing properties were investigated in dry as well as humid environment (RH 50%). Experimental results demonstrated that sensors displayed least humidity interference at 400 °C. The operating temperature of the sensor was optimized for best responsiveness. These type of sensors can be effectively used in environmental monitoring of NO2 gas at low ppm

Role of actin dependent nuclear deformation in regulating early gene expression

The nucleus of a living cell is constantly undergoing changes in shape and size as a result of various mechanical forces in physiology. These changes correlate with alterations in gene expression, however it is unclear whether nuclear deformation alone is sufficient to elicit these alterations. We used T-cell activation as a model system to test the coupling between nuclear deformation (elongation) and gene expression. Naïve T-cell activation with surrogate antigens resulted in actin dependent nuclear elongation. This was accompanied with Erk and NF-κB signaling to the nucleus to induce CD69 expression. Importantly, inhibiting actin polymerization abolished both nuclear elongation and CD69 expression, while inhibiting Erk, NF-κB or microtubule depolymerization only abolished expression but not elongation. Immobilization of antigen-coated beads, under conditions where actin polymerization was inhibited, rescued both nuclear elongation and CD69 expression. In addition, fibroblast cells plated on fibronectin micropatterns of different sizes showed correlation between nuclear shape index and tenascin C expression. Upon inhibiting the signaling intermediate Erk, tenascin C expression was down regulated although the nuclear shape index remained unaltered. Our results highlight the importance of specific signaling intermediates accompanied with nuclear deformation in the modulation of cellular genomic programs

A Metamaterial Backed Dipole Antenna for High Gain Directional Communications

The enhanced radiation performance of a dipole antenna backed by the split ring resonator-continuous wire pair array working in the H┴ excitation scenario is presented in this paper.  The H┴ excitation scenario of the metamaterial is used to get zero reflection phase resulting in enhanced gain performance. The two layer meta-structure along with the dipole is fabricated on a low cost substrate of dielectric constant 4.4 and height 1mm. The reflection properties of the metamaterial structure and its effect on the radiation performance of the dipole antenna are presented in this paper

Corrosion Protection of SiC-Based Ceramics with CVDMullite Coatings

Silicon carbide ceramics are the leading candidate materials for use as heat exchangers in advanced combined cycle power plants because of their unique combination of high temperature strength, high thermal conductivity, excellent thermal shock resistance, and good high temperature stability and oxidation resistance. Ceramic coatings are being considered for diesel engine cylinder liners, piston caps, valve faces and seats, piston rings, and for turbine components such as combustors, blades, stators, seals, and bearings. Under such conditions ceramics are better suited to high temperature environments than metals. For the first time, adherent crystalline mullite coatings have been chemically vapor deposited onto SiC substrates to enhance its corrosion/oxidation resistance. Thermodynamic and kinetic considerations have been utilized to produce mullite coatings with a variety of growth rates, compositions, and morphologies. The flexibility of processing can be exploited to produce coated ceramics with properties tailored to specific applications and varied corrosive environments. These corrosive environments include thermal, Na{sub 2}SO{sub 4}, O{sub 2} and coal slag

Нейтронографическое исследование структурного перехода кубическая–тетрагональная фаза в монокристаллах твердых растворов оксида циркония с оксидом иттрия

Objectives. The determination of the phase relations, crystallographic characteristics, microstructure features, and atomic crystal structure of zirconium oxide crystals that are partially and completely stabilized by yttrium oxide additives, and the identification of the crystallographic and crystal-chemical correlations with the physicochemical properties of single crystals.Methods. The neutron structure of the crystals was studied using the neutron time-of-flight and constant wavelength methods using a high-resolution Fourier diffractometer on the IBR-2 pulsed fast reactor and a four-circle neutron diffractometer “Syntex.” Single crystals were grown by directed crystallization from the melts of mixtures (1 − х)ZrO2 ∙хY2O3 , х = 0.03 and х = 0.12 with different growth rates (10 and 40 mm/h).Results. It was observed that when growing single crystals with x = 0.03–0.05, the crystal was stratified into cubic and tetragonal phases, and the ratio between the phases depended on the growth rate. At a growth rate of 40 mm/h, the content of the cubic phase was insignificant. In the crystals of partially stabilized zirconium dioxide (ZrO2) with the additions of 3 mol % Y2O3, the coherent coexistence of cubic and tetragonal phases was established, and the twin law for a tetragonal component (rotation of unit cell axis by 90° around the a (b) axis) that was observed during the phase transition from high-temperature cubic phase to tetragonal phase was determined. For the fully stabilized zirconium oxide of the cubic symmetry (with 12 mol % Y2O3), the 0.3 Å displacements of oxygen atoms from their partial structural positions in the directions [100] and [111] were determined. These displacements correlated with the directions of the ion transport.Conclusions. Previous studies have shown that the ratio between the cubic and tetragonal phases of the single crystals of the ZrO2 –Y2O3 system depends on the growth rate of the single crystals. The content of Y2O3 in the cubic and tetragonal phases of a single crystal was determined using the non-destructive neutronography method on the same volume sample of a solid solution of this system. Moreover, the displacements of oxygen atoms from the main position of the crystal were determined.Цели. Определение фазовых соотношений, кристаллографических характеристик, особенностей микроструктуры и атомно-кристаллической структуры кристаллов оксида циркония, частично и полностью стабилизированных добавками оксида иттрия, выявление кристаллографических и кристаллохимических корреляций с физико-химическими свойствами монокристаллов.Методы. Нейтроноструктурные исследования кристаллов проведены методами времени пролета нейтронов и постоянной длины волны с использованием Фурье дифрактометра высокого разрешения на импульсном быстром реакторе ИБР-2 и четырехкружного нейтронного дифрактометра «Синтекс». Монокристаллы были выращены направленной кристаллизацией из расплавов смесей (1 – х)ZrO2 ∙хY2O3 , х = 0.03 и 0.12 с разными скоростями роста (10 и 40 мм/ч).Результаты. Установлено, что при выращивании монокристаллов с х = 0.03–0.05 происходит расслоение кристалла на кубическую и тетрагональную фазы, соотношение между которыми зависит от скорости выращивания. При скорости роста 40 мм/ч содержание кубической фазы незначительно. В кристаллах частично стабилизированного диоксида циркония ZrO2 (c добавками 3 mol % Y2O3) установлено когерентное сосуществование кубической и тетрагональной фаз и определен закон двойникования для тетрагональной компоненты (вращение осей элементарной ячейки на 90° вокруг осей a (b)), возникающего при фазовом переходе из высокотемпературной кубической фазы в тетрагональную. Для полностью стабилизированного диоксида циркония кубической симметрии (с 12 mol % Y2O3) определены смещения атомов кислорода на 0.3 Å из их частных структурных позиций в направлениях [100] и [111]. Эти смещения коррелирует с направлениями ионного транспорта.Выводы. Исследования показали, что соотношение между кубической фазой и тетрагональной фазой монокристаллов системы ZrO2 –Y2O3 зависит от скорости выращивания монокристаллов. На одном и том же объемном образце твердого раствора этой системы неразрушающим методом нейтронографии определено содержание Y2O3 и в кубической, и в тетрагональной фазе монокристалла. Определены смещения атомов кислорода из основной позиции кристалла

Bacteriophage Infection of the Marine Bacterium Shewanella glacialimarina Induces Dynamic Changes in tRNA Modifications

Viruses are obligate intracellular parasites that, throughout evolution, have adapted numerous strategies to control the translation machinery, including the modulation of post-transcriptional modifications (PTMs) on transfer RNA (tRNA). PTMs are critical translation regulators used to further host immune responses as well as the expression of viral proteins. Yet, we lack critical insight into the temporal dynamics of infection-induced changes to the tRNA modification landscape (i.e., ‘modificome’). In this study, we provide the first comprehensive quantitative characterization of the tRNA modificome in the marine bacterium Shewanella glacialimarina during Shewanella phage 1/4 infection. Specifically, we show that PTMs can be grouped into distinct categories based on modification level changes at various infection stages. Furthermore, we observe a preference for the UAC codon in viral transcripts expressed at the late stage of infection, which coincides with an increase in queuosine modification. Queuosine appears exclusively on tRNAs with GUN anticodons, suggesting a correlation between phage codon usage and PTM modification. Importantly, this work provides the basis for further studies into RNA-based regulatory mechanisms employed by bacteriophages to control the prokaryotic translation machinery

Measuring the nuclear equation of state with neutron star-black hole mergers

Gravitational-wave (GW) observations of neutron star-black hole (NSBH) mergers are sensitive to the nuclear equation of state (EOS). Using realistic simulations of NSBH mergers, incorporating both GW and electromagnetic (EM) selection to ensure sample purity, we find that a GW detector network operating at O5-sensitivities will constrain the radius of a $1.4~M_{\odot}$ NS and the maximum NS mass with $1.6\%$ and $13\%$ precision, respectively. The results demonstrate strong potential for insights into the nuclear EOS, provided NSBH systems are robustly identified.Comment: 9 pages, 4 Figures. Submitted. Comments welcome

Silicon Pad Detectors for the PHOBOS Experiment at RHIC

The PHOBOS experiment is well positioned to obtain crucial information about relativistic heavy ion collisions at RHIC, combining a multiplicity counter with a multi-particle spectrometer. The multiplicity arrays will measure the charged particle multiplicity over the full solid angle. The spectrometer will be able to identify particles at mid-rapidity. The experiment is constructed almost exclusively of silicon pad detectors. Detectors of nine different types are configured in the multiplicity and vertex detector (22,000 channels) and two multi-particle spectrometers (120,000 channels). The overall layout of the experiment, testing of the silicon sensors and the performance of the detectors during the engineering run at RHIC in 1999 are discussed.Comment: 7 pages, 7 figures, 1 table, Late

A Metamaterial Backed Dipole Antenna for High Gain Directional Communications

The enhanced radiation performance of a dipole antenna backed by the split ring resonator-continuous wire pair array working in the H┴ excitation scenario is presented in this paper.  The H┴ excitation scenario of the metamaterial is used to get zero reflection phase resulting in enhanced gain performance. The two layer meta-structure along with the dipole is fabricated on a low cost substrate of dielectric constant 4.4 and height 1mm. The reflection properties of the metamaterial structure and its effect on the radiation performance of the dipole antenna are presented in this paper