62 research outputs found

    Transcriptional responses of winter barley to cold indicate nucleosome remodelling as a specific feature of crown tissues

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    We report a series of microarray-based comparisons of gene expression in the leaf and crown of the winter barley cultivar Luxor, following the exposure of young plants to various periods of low (above and below zero) temperatures. A transcriptomic analysis identified genes which were either expressed in both the leaf and crown, or specifically in one or the other. Among the former were genes responsible for calcium and abscisic acid signalling, polyamine synthesis, late embryogenesis abundant proteins and dehydrins. In the crown, the key organ for cereal overwintering, cold treatment induced transient changes in the transcription of nucleosome assembly genes, and especially H2A and HTA11, which have been implicated in cold sensing in Arabidopsis thaliana. In the leaf, various heat-shock proteins were induced. Differences in expression pattern between the crown and leaf were frequent for genes involved in certain pathways responsible for osmolyte production (sucrose and starch, raffinose, Îł-aminobutyric acid metabolism), sugar signalling (trehalose metabolism) and secondary metabolism (lignin synthesis). The action of proteins with antifreeze activity, which were markedly induced during hardening, was demonstrated by a depression in the ice nucleation temperature

    Application of Arduino Module to Research in Surface Physics

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    During the semiconductor or graphene wafers surface were investigated, the Arduino module was applied to control the impact point of the laser beam. While the pulse signal of laser beam impacts to surface selected material and the material is exposed to enough strong magnetic field, the photomagnetoelectric effect takes place. This causes the electrical signal in the measurement coil, which is connected to amplifiers. The paper presents application of Arduino UNO module to control the position in two dimensions (in the XY plane) of investigated silicon or graphene wafers while the photomagnetoelectric effect is measuring. The Arduino drive (through the integrated circuit with power transistors) the steps and shift of a dedicated table with a sample situated at the top of the table. Constructed equipment, based on Arduino board, allows for one step size of 1.25 ÎŒm in X-axis and Y-axis, and in effect, the each square millimeter contains 640000 measurement points. We are able also to modify the Arduino program for motors controller any moment. Moreover, it is also possible to apply the obtain method to investigate another semiconductor materials. The commercially available similar devices don’t have all need functions and they are incomparably more expensive

    Photoelectromagnetic Investigations of Graphene

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    The photoelectromagnetic investigations of graphene has been performed using noncontact technique. The dependence of photoelectromagnetic response on magnetic field induction, illumination intensity for different photon energies, and frequency of illumination chopping is presented. We anticipate our paper to be a starting point for investigations of carrier diffusion length in this material. Such investigations should be essential for development of graphene electronic and optoelectronic devices

    Impact Strength of Austenitic and Ferritic-Austenitic Cr-Ni Stainless Cast Steel in -40 and +20°C Temperature

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    Studies described in this paper relate to common grades of cast corrosion resistant Cr-Ni steel with different matrix. The test materials were subjected to heat treatment, which consisted in the solution annealing at 1060°C followed by cooling in water. The conducted investigations, besides the microstructural characteristics of selected cast steel grades, included the evaluation of hardness, toughness (at a temperature of -40 and +20oC) and type of fracture obtained after breaking the specimens on a Charpy impact testing machine. Based on the results of the measured volume fraction of ferrite, it has been found that the content of this phase in cast austenitic steel is 1.9%, while in the two-phase ferritic-austenitic grades it ranges from 50 to 58%. It has been demonstrated that within the scope of conducted studies, the cast steel of an austenitic structure is characterised by higher impact strength than the two-phase ferritic-austenitic (F-A) grade. The changing appearance of the fractures of the specimens reflected the impact strength values obtained in the tested materials. Fractures of the cast austenitic Cr-Ni steel obtained in these studies were of a ductile character, while fractures of the cast ferritic-austenitic grade were mostly of a mixed character with the predominance of brittle phase and well visible cleavage planes

    Selekcjonowanie mocy strat blach transformatorowych w obwodach magnetycznych zamkniętych i otwartych

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    Moc strat jest podstawowym parametrem przy projektowaniu maszyn i urządzeƄ elektrycznych. W przemyƛle spotyka się blachy rĂłĆŒnych producentĂłw z rĂłĆŒnych serii, dlatego zachodzi koniecznoƛć wstępnego szybkiego ich selekcjonowania pod względem mocy strat caƂkowitych. OprĂłcz metod Epsteina, międzynarodowe normy dopuszczają pomiary na pojedynczych arkuszach czy pasmach w metodach Single Sheet Testing (SST) dla grain-oriented Fe-Si sheet steel. W artykule porĂłwnano realizacje zastosowaƄ koncepcji fizycznych i zastosowaƄ NDT selekcjonowania stratnoƛci caƂkowitej blach transformatorowych z pomiaru skƂadowych impedancji na pojedynczych prĂłbkach paskowych otwartych i pojedynczych arkuszach blach. Do badaƄ uĆŒyto arkuszy blach transformatorowych M130 z rĂłĆŒnych serii poprodukcyjnych. Pomiary parametrĂłw arkuszy blach transformatorowych wykonano na urządzeniu pomiarowym BROCKHAUS STS zgodnie z normami IEC 6040. Mostkiem pomiarowym AGILENT 4294A wyznaczano skƂadowe impedancji cewki pomiarowej PCB (Texas Instrument) przylegającej do arkusza blachy. NiezaleĆŒnie badano paski blachy transformatorowej (prĂłbki otwarte) w solenoidzie. Pomiary wykonano w zakresie częstotliwoƛci do 4 MHz. Pomiar w zakresie częstotliwoƛci rezonansowej miaƂ na celu ocenę uĆŒytecznoƛci sondy pomiarowej LDC (TI) z cewką spiralną PCB.Power loss is the basic parameter important for designers, in the construction of electrical machines and equipment. There are different magnetic steel sheets by various designers with various production series produced by industry. Therefore, it is necessary to pre-fast select them according to their total power loss. In this case, several methods are allowed by international standards, besides the Epstein apparatus (i. e. Single Sheet Tester (SST) for grain-oriented Fe-Si sheet steel). In the present paper, the comparison between the implementation of the physical concept and NDT applications and selection of total power loss of transformer shits was discussed. Investigations were carried out for single open strip samples and single transformer sheets by measured complex impedance components. M 130 type transformer sheets from different post-production series were used. The measurements of these sheets were carried out by applying BROKHAUS STS system according to the IEC 6040 standard. The complex components of impedance for a measure coil PCB (Texas Instrument), adhering to the sheet, were also measured by applying the precision RLC meter (AGILENT 4294A). Independently, the open strip samples were measured in a solenoid coil for the frequency up to 4 MHz. The resonant frequency measurements were carried out in order to test the LDC (TI) probe with a spiral measuring coil PCB

    Dielectric Properties of SbSI in the Temperature Range of 292-475 K

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    Methodology of impedance measurements and ferroelectric hysteresis loops observed in temperature range 292-475 K for antimony sulfoiodide (SbSI) grown from vapour phase are discussed. Temperature dependences of spontaneous polarization and coercive field of SbSI crystals are presented
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