418 research outputs found
Hysteretic metal–ferroelectric– semiconductor capacitors based on PZT/ZnO heterostructures
Interfacing of ferroelectric and semiconductor materials provides a means of coupling unique properties associated with ferroelectric materials to high performance semiconductor devices. In this work we report the electronic properties of ferroelectric/ZnO heterostructures, where (Pb,Zr)TiO3 (PZT) is used as a prototypical ferroelectric oxide. Metal–PZT–metal structures demonstrate ferroelectric hysteresis with remanent polarization of 28 µC cm−2 and coercive field of 75 kV cm−1 for a loop of 15 V. The metal–PZT–ZnO capacitor structures demonstrate a characteristic metal–insulator–semiconductor capacitance–voltage (C–V) behaviour with a hysteretic memory window of approximately 4 V. The heterostructure C–V characteristics do not change significantly with varying frequency. Metal–PZT–ZnO capacitors are also used as part of a simple RLC circuit to demonstrate the ability to shift resonant frequency of the circuit with switching ferroelectric polarization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58136/2/d7_8_003.pd
Tree Growth Yield and Fruit Quality of Different Apple Cultivars Trained as Super Spindle
This study was carried out on Topaz, Cooper 39 and Muscat apple cultivars grafted on M27 rootstocks under Tokat ecological conditions during 2008 - 2010. The trees planted in 2.0 m x 0.5 m row spacing (10,000 trees ha-1) and trained to super spindle (SS) training system. The vegetative development, yield and fruit quality performances of the trees supported by wire – pole combination were observed for three years. At the end of the experiment, it was determined that Cooper 39 had a higher trunk cross sectional area (TCA) than Topaz and Muscat. While cumulative yield (CY) per tree and cumulative yield efficiency (CYE) were determined to be the highest in Cooper 39, these values were found to be the lowest in Topaz. CY per hectare over the first three crop year was found to be the highest in Cooper 39 and the yield reached to 142.9 t.ha1. The lowest CY per hectare (69.6 ton ha-1) was determined in Topa
Beyond the exponential horn:a bush-cricket with ear canals which function as coupled resonators
Bush-crickets have dual-input, tympanal ears located in the tibia of their forelegs. The sound will first of all reach
the external sides of the tympana, before arriving at the internal sides through the bush-cricket’s ear canal, the
acoustic trachea (AT), with a phase lapse and pressure gain. It has been shown that for many bush-crickets, the AT has
an exponential horn-shaped morphology and function, producing a significant pressure gain above a certain cut-off frequency. However, the underlying mechanism of different AT designs remains elusive. In this study, we demonstrate
that the AT of the duetting Phaneropterinae bush-cricket Pterodichopetala cieloi function as coupled resonators,
producing sound pressure gains at the sex-specific conspecific calling song frequency, and attenuating the
remainder—a functioning mechanism significantly different from an exponential horn. Furthermore, it is demonstrated
that despite the sexual dimorphism between the P. cieloi AT, both male and female AT have a similar biophysical
mechanism. The analysis was carried out using an interdisciplinary approach, where micro-computed
tomography was used for the morphological properties of the P. cieloi AT, and a finite-element analysis was applied on
the precise tracheal geometry to further justify the experimental results and to go beyond experimental
limitations
Interview with Marjorie Harkins Buchanan Kiewit
In this interview with Julia Stringfellow, Marjorie Harkins Buchanan Kiewit, LU class of 1943, discusses her time as a student as well as her time on the Board of Trustees.https://lux.lawrence.edu/oralhistories/1036/thumbnail.jp
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
Investigation of in vitro effects of ethephon and chlorpyrifos, either alone or in combination, on rat intestinal muscle contraction
A range of pesticides is widely used in pest management and the chances of exposure to multiple organophosphorus (OP) compounds simultaneously are high, especially from dietary and other sources. Although health hazards of individual OP insecticides have been relatively well characterized, there is lesser information on the interactive toxicity of multiple OP insecticides. The aim of this study is to elicit the possible interactions in case combined exposure of an OP pesticide chlorpyrifos (CPF) and a plant growth regulator ethephon (ETF) which are used worldwide. The ileum segments of 3 months old Wistar Albino male rats were used in isolated organ bath containing Tyrode solution. ETF and CPF were incubated (10−7 M concentration) separately or in combination with each other to ileum and their effects on acetylcholine-induced contractions were studied. The data obtained from this study show that, single and combined exposure to the agents caused agonistic interactions with regard to potency of ACh whereas they caused a decrease on Emax value of ACh. These findings suggest that exposure to these agents which have direct and indirect cholinergic effects, may cause developing clinical responses with small doses and earlier but the extent of toxicity will be lower
Diagnostic approach of tuberculous lymphadenitis in a multicenter study
Introduction: Tuberculous lymphadenitis (TBLN) is the most common infectious etiology of peripheral lymphadenopathy in adults, in Turkiye. This study aimed to identify the demographic, clinical, and laboratory variables that differentiate TBLN from non-tuberculous lymphadenitis (NTBLN), as well as the etiology of lymphadenopathy in adults. Methodology: Patients who were over 18 years old and were referred to the infectious disease outpatient clinics with complaints of swollen peripheral lymph nodes, and who underwent lymph node biopsy between 1 January 2010 and 1 March 2021, were included in this multicenter, nested case-control study. Results: A total of 812 patients at 17 tertiary teaching and research hospitals in Turkiye were included in the study. TBLN was the most frequent diagnosis (53.69%). The proportion of patients diagnosed with TBLN was higher among females; and among those who had a higher erythrocyte sedimentation rate, positive purified protein derivative test, and positive interferon-gamma release test result (p < 0.05). However, TBLN was less frequent among patients with generalized lymphadenopathy, bilateral lymphadenopathy, axillary lymphadenopathy, inguinal lymphadenopathy, hepatomegaly, splenomegaly, leukocytosis, and moderately increased C reactive protein levels (p < 0.05). Conclusions: Identifying the variables that predict TBLN or discriminate TBLN from NTBLN will help clinicians establish optimal clinical strategies for the diagnosis of adult lymphadenopathy
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