2,197 research outputs found
Thickness dependence of spin-orbit torques generated by WTe2
We study current-induced torques in WTe2/permalloy bilayers as a function of
WTe2 thickness. We measure the torques using both second-harmonic Hall and
spin-torque ferromagnetic resonance measurements for samples with WTe2
thicknesses that span from 16 nm down to a single monolayer. We confirm the
existence of an out-of-plane antidamping torque, and show directly that the
sign of this torque component is reversed across a monolayer step in the WTe2.
The magnitude of the out-of-plane antidamping torque depends only weakly on
WTe2 thickness, such that even a single-monolayer WTe2 device provides a strong
torque that is comparable to much thicker samples. In contrast, the
out-of-plane field-like torque has a significant dependence on the WTe2
thickness. We demonstrate that this field-like component originates
predominantly from the Oersted field, thereby correcting a previous inference
drawn by our group based on a more limited set of samples.Comment: 8 pages, 8 figure
Comparison of Pressurized and Gravity Distribution Systems for Wastewater Treatment
Pressurized distribution of domestic wastewater over a sand filter surface achieves better treatment than gravity distribution. The pressurized distribution system caused the filter to better remove organics (BODâ‚…) and suspended solids. Pressurized distribution also caused the sand filter to achieve more complete nitrification than the filter having gravity distribution. Two slow sand filters 15.2 cm wide, 3.1 m long and 15.2 cm deep were built and loaded with domestic septic tank effluent for 250 days at a rate of 5.1 cm per day. Influent and effluent samples were collected and analyzed for five-day Biochemical Oxygen Demand (BODâ‚…), suspended solids, ammonia- nitrogen, and nitrate-nitrogen. One filter received septic tank effluent through a 10 cm nominal diameter PVC perforated pipe viaa distribution box dosed by a pump with gravity flow from the distribution box to the pipe. The other filter received water through a 2.5 cm nominal diameter PVC pipe having 0.4 cm diameter holes drilled 76.2 cm on center. The gravity distribution filter system achieved mean effluent values of 36.4 mg// BODâ‚… , 19.8 mg// suspended solids, 37.6 mg// ammonia-nitrogen, and 46.6 mg// nitrate-nitrogen. The pressurized distribution system achieved 19.1 mg// BODâ‚…\u3e 12.2 mg// suspended solids, 25.3 mg// ammonia-nitrogen, and 64.03 mg// nitrate-nitrogen. Influent to the filters averaged 132.1 mg// , 90.3 mg//, 70.3 mg// , and 3.6 mg// BODâ‚… , suspended solids, ammonia-nitrogen, and nitrate- nitrogen, respectively
The Effect of Prolonged Standing on Touch Sensitivity Threshold of the Foot: A Pilot Study
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146943/1/pmr2117.pd
Mammalian community structure in lowland, tropical Peru, as determined by removal trapping
Amazonian lowland rain forests are complex three-dimensional formations consisting of a variety of arboreal and terrestrial habitats. The small mammal faunas, particularly of arboreal habitats, are poorly studied, and field research generally has been limited to a few faunal inventories. We sampled the terrestrial and arboreal small mammal fauna in two floodplain forest study zones at Reserva Cuzco Amazónico, southeastern Peru, by removal trapping for 12 consecutive days in dry (June–July 1989) and rainy seasons (January–February1990). Nineteen taxa of marsupials and rodents were captured. Small mammals were more abundant in the rainy season than in the dry season, but the relative proportions of the 11 most abundant species remained stable between seasons and study zones. Most species showed no decline in capture rates through the 12-day period, indicating that either population densities were high or animals were quite mobile. The small mammal fauna exhibited strong vertical stratification; among the 11 most abundant species, four exhibited strong biases toward terrestrial and five toward above-ground captures. The distinct arboreal small mammal community is grossly underrepresented if traps are placed only at ground level
Experimental Evaluation of High Performance Integrated Heat Pump
Integrated heat pump (IHP) technology provides significant potential for energy savings and comfort improvement for residential buildings. In this study, we evaluate the performance of a high performance IHP that provides space heating, cooling, and water heating services. Experiments were conducted according to the ASHRAE Standard 206-2013 where 24 test conditions were identified in order to evaluate the IHP performance indices. An 8-in by 8-in Air Monitor Fan Evaluator is used to measure the volumetric flowrate of air discharged from the air handler unit (AHU) in order to evaluate the airside performance. Empirical curve fits of the unit’s compressor maps are used in conjunction with saturated condensing and evaporating refrigerant conditions to deduce the refrigerant mass flowrate, which, in turn is used to evaluate the refrigerant-side performance. Heat pump (compressor, fans, and controls) and water pump power were measured separately per requirements of Standard 206. The system was charged per the system manufacturer’s specifications. System test results are presented for each operating mode along with overall IHP performance metrics according to ASHRAE standard 206-2013. The paper ends with discussion on system operation and impact on typical energy consumption in residential buildings
Comparison of traps and baits for censusing small mammals in Neotropical lowlands.
Snap-traps, live-traps, and baits affect the ability to capture small mammals, but few previous studies have involved sampling communities of small mammals in tropical environments. We tested differences in captures of small marsupials and rodents by Victor snap-traps versus Sherman live-traps and by two types of bait in lowland rainforest at Reserva Cuzco AmazĂłnico, southeastern Peru. Snap-traps took ca. 3.5 times as many individuals as live-traps. Snap-traps also captured more species (and more rare species), but we attribute this to more numerous captures overall because the relative proportions of species captured by the two traps generally were the same. Type of bait had little impact on our trapping results
Role of arginase 2 in systemic metabolic activity and adipose tissue fatty acid metabolism in diet-induced obese mice
Visceral adipose tissue (VAT) inflammation and metabolic dysregulation are key components of obesity-induced metabolic disease. Upregulated arginase, a ureahydrolase enzyme with two isoforms (A1-cytosolic and A2-mitochondrial), is implicated in pathologies associated with obesity and diabetes. This study examined A2 involvement in obesity-associated metabolic and vascular disorders. WT and globally deleted A2(−/−) or A1(+/−) mice were fed either a high fat/high sucrose (HFHS) diet or normal diet (ND) for 16 weeks. Increases in body and VAT weight of HFHS-fed WT mice were abrogated in A2−/−, but not A1+/−, mice. Additionally, A2−/− HFHS-fed mice exhibited higher energy expenditure, lower blood glucose, and insulin levels compared to WT HFHS mice. VAT and adipocytes from WT HFHS fed mice showed greater A2 expression and adipocyte size and reduced expression of PGC-1α, PPAR-γ, and adiponectin. A2 deletion blunted these effects, increased levels of active AMPK-α, and upregulated genes involved in fatty acid metabolism. A2 deletion prevented HFHS-induced VAT collagen deposition and inflammation, which are involved in adipocyte metabolic dysfunction. Endothelium-dependent vasorelaxation, impaired by HFHS diet, was significantly preserved in A2−/− mice, but more prominently maintained in A1+/− mice. In summary, A2 is critically involved in HFHS-induced VAT inflammation and metabolic dysfunction
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