383 research outputs found
Evaluation of a wireless infrared thermometer with a narrow field of view
Many agricultural studies rely on infrared sensors for remote measurement of surface temperatures for crop status monitoring and estimating sensible and latent heat fluxes. Historically, applications for these non-contact thermometers employed the use of hand-held or stationary industrial infrared thermometers (IRTs) wired to data loggers. Wireless sensors in agricultural applications are a practical alternative, but the availability of low cost wireless IRTs is limited. In this study, we designed prototype narrow (10◦) field of view wireless infrared sensor modules and evaluated the performance of the IRT sensor by comparing temperature readings of an object (Tobj) against a blackbody calibrator in a controlled temperature room at ambient temperatures of 15 ◦C, 25 ◦C, 35 ◦C, and 45 ◦C. Additional comparative readings were taken over plant and soil samples alongside a hand-held IRT and over an isothermal target in the outdoors next to a wired IRT. The average root mean square error (RMSE) and mean absolute error (MAE) between the collected IRT object temperature readings and the blackbody target ranged between 0.10 and 0.79 ◦C. The wireless IRT readings also compared well with the hand-held IRT and wired industrial IRT. Additional tests performed to investigate the influence of direct radiation on IRT measurements indicated that housing the sensor in white polyvinyl chloride provided ample shielding for the self-compensating circuitry of the IR detector. The relatively low cost of the wireless IRT modules and repeatable measurements against a blackbody calibrator and commercial IR thermometers demonstrated that these wireless prototypes have the potential to provide accurate surface radiometric temperature readings in outdoor applications. Further studies are needed to thoroughly test radio frequency communication and power consumption characteristics in an outdoor setting
Разработка способа очистки газовой среды в процессе выращивания полупроводниковых монокристаллов
An individual’s zinc status has a significant impact on the immune system, and zinc deficiency, as well as supplementation, modulates immune function. To investigate the effects of zinc on different leukocyte subsets, we used microarray technology to analyze and compare the changes in mRNA expression in cell culture models of monocytes (THP-1), T cells (Jurkat), and B cells (Raji), in response to supplementation for 40 h with 50 μM zinc or 2.5 μM of the membrane-permeant zinc chelator TPEN [N,N,N′,N′-tetrakis-(2-pyridyl-methyl)ethylenediamine], respectively. In each cell type, several hundred genes were identified to be zinc sensitive, but only a total of seven genes were commonly regulated in all three cell lines. The majority of those genes were involved in zinc homeostasis, and none in immune function. Nevertheless, further analysis revealed that zinc affects entire functional networks of genes that are related to proinflammatory cytokines and cellular survival. Although the zinc-regulated activities are similar throughout the gene networks, the specific genes that are affected vary significantly between different cell types, a situation that helps to elucidate the disparity of the effects that zinc has on different leukocyte populations
Environmental assessment of the Urban Mining and Recycling (UMAR) unit by applying the LCA framework
Magnetic and superconducting properties of Cd2Re2O7: Cd NMR and Re NQR
We report Cd NMR and Re NQR studies on Cd2Re2O7, the first superconductor
among pyrochlore oxides Tc=1 K. Re NQR spectrum at zero magnetic field below
100 K rules out any magnetic or charge order. The spin-lattice relaxation rate
below Tc exhibits a pronounced coherence peak and behaves within the
weak-coupling BCS theory with nearly isotropic energy gap. Cd NMR results point
to moderate ferromagnetic enhancement at high temperatures followed by rapid
decrease of the density of states below the structural transition temperature
of 200 K.Comment: 4 pages, 4 figure
Coherence effect in a two-band superconductor: Application to iron pnictides
From a theoretical point of view, we propose an experimental method to
determine the pairing symmetry of iron pnictides. We focus on two kinds of
pairing symmetries, and , which are strong candidates for the
pairing symmetry of iron pnictides. For each of these two symmetries, we
calculate both the density and spin response functions by using the two-band
BCS model within the one-loop approximation. As a result, a clear difference is
found between the - and -wave states in the temperature
dependence of the response functions at nesting vector , which connects
the hole and electron Fermi surfaces. We point out that this difference comes
from the coherence effect in the two-band superconductor. We suggest that the
pairing symmetry could be clarified by observing the temperature dependence of
both the density and spin structure factors at the nesting vector in
neutron scattering measurements.Comment: 15 pages, 7 figures, 1 tabl
Interaction of Laser Radiation with Plasmas and Nonadiabatic Motion of Particles in Magnetic Fields
Contains research objectives.United States Atomic Energy Commission (Contract AT(30-1)-3285
B NMR study of pure and lightly carbon doped MgB superconductors
We report a B NMR line shape and spin-lattice relaxation rate
() study of pure and lightly carbon doped MgBC for
, 0.02, and 0.04, in the vortex state and in magnetic field of 23.5 kOe.
We show that while pure MgB exhibits the magnetic field distribution from
superposition of the normal and the Abrikosov state, slight replacement of
boron with carbon unveils the magnetic field distribution of the pure Abrikosov
state. This indicates a considerable increase of with carbon doping
with respect to pure MgB. The spin-lattice relaxation rate
demonstrates clearly the presence of a coherence peak right below in pure
MgB, followed by a typical BCS decrease on cooling. However, at
temperatures lower than K strong deviation from the BCS behavior is
observed, probably from residual contribution of the vortex dynamics. In the
carbon doped systems both the coherence peak and the BCS temperature dependence
of weaken, an effect attributed to the gradual shrinking of the
hole cylinders of the Fermi surface with electron doping.Comment: 8 pages, 6 figures, submitted to Phys. Rev.
A spheroid toxicity assay using magnetic 3D bioprinting and real-time mobile device-based imaging
An ongoing challenge in biomedical research is the search for simple, yet robust assays using 3D cell cultures for toxicity screening. This study addresses that challenge with a novel spheroid assay, wherein spheroids, formed by magnetic 3D bioprinting, contract immediately as cells rearrange and compact the spheroid in relation to viability and cytoskeletal organization. Thus, spheroid size can be used as a simple metric for toxicity. The goal of this study was to validate spheroid contraction as a cytotoxic endpoint using 3T3 fibroblasts in response to 5 toxic compounds (all-trans retinoic acid, dexamethasone, doxorubicin, 5′-fluorouracil, forskolin), sodium dodecyl sulfate (+control), and penicillin-G (−control). Real-time imaging was performed with a mobile device to increase throughput and efficiency. All compounds but penicillin-G significantly slowed contraction in a dose-dependent manner (Z’ = 0.88). Cells in 3D were more resistant to toxicity than cells in 2D, whose toxicity was measured by the MTT assay. Fluorescent staining and gene expression profiling of spheroids confirmed these findings. The results of this study validate spheroid contraction within this assay as an easy, biologically relevant endpoint for high-throughput compound screening in representative 3D environments
New magnetic coherence effect in superconducting La_{2-x}Sr_{x}CuO_{4}
We have used inelastic neutron scattering to examine the magnetic
fluctuations at intermediate frequencies in the simplest high temperature
superconductor, La_{2-x}Sr_{x}Cu_{4}. The suppression of the low energy
magnetic response in the superconducting state is accompanied by an increase in
the response at higher energies. Just above a threshold energy of ~7 meV there
is additional scattering present below T_{c} which is characterised by an
extraordinarily long coherence length, in excess of 50 \AA.Comment: 11 pages, RevTeX, 4 postscript figure
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