Kelvin-Helmholtz instability of AB interface in superfluid 3He

The Kelvin-Helmholtz instability is well-known in classical hydrodynamics, where it explains the sudden emergence of interfacial surface waves as a function of the velocity of flow parallel to the interface. It can be carried over to the inviscid two-fluid dynamics of superfluids, to study different types of interfaces and phase boundaries in quantum fluids. We report measurements on the stability of the phase boundary separating the two bulk phases of superfluid 3He in rotating flow, while the boundary is localized with the gradient of the magnetic field to a position perpendicular to the rotation axis. The results demonstrate that the classic stability condition, when modified for the superfluid environment, is obeyed down to 0.4 Tc, if a large fraction of the magnetic polarization of the B-phase is attributed to a parabolic reduction of the interfacial surface tension with increasing magnetic field.Comment: 14 pages, 14 figure

Electric fields in plasmas under pulsed currents

Electric fields in a plasma that conducts a high-current pulse are measured as a function of time and space. The experiment is performed using a coaxial configuration, in which a current rising to 160 kA in 100 ns is conducted through a plasma that prefills the region between two coaxial electrodes. The electric field is determined using laser spectroscopy and line-shape analysis. Plasma doping allows for 3D spatially resolved measurements. The measured peak magnitude and propagation velocity of the electric field is found to match those of the Hall electric field, inferred from the magnetic-field front propagation measured previously.Comment: 13 pages, 13 figures, submitted to PR

Hydrogen sulfide emissions from cattle manure: experimental study

Animal waste products, manure, in particular, are the sources of gases harmful to human and animal health. Hydrogen sulfide (H2S), which is produced from the breakdown of organic matter in animal faeces, is one of them. Its concentration in the cow barn air should not exceed 5 mg m−3 . A special laboratory setup was designed and the level of hydrogen sulfide emissions from the cow manure was determined depending on the time and manure temperature and moisture content. The most intensive emission of hydrogen sulfide from manure was in the first 24 hours – the increment of H2S concentration was 0.168 mg m−3 per hour average. During the next 24 hours, it was 0.021 mg m−3 per hour. When the manure temperature increased, H2S concentration increased also; when the temperature manure decreased, H2S concentration decreased also. In 48 hours, the hydrogen sulfide concentration was 1.1 mg m−3 at the manure temperature of +3.0 °C. At the manure temperature of +23.4 °C and 21.3 °C, H2S concentration was 6.53 mg m−3 and 4.97 mg m−3 , respectively. The higher was the manure moisture content, the lower was the emission of hydrogen sulfide into the environment. After 24 hours under the manure moisture content of 88.5% and 92.5% and its temperature of 21 °С ± 0.3 °С, the difference in the hydrogen sulfide concentration was 1.18 times depending on the manure moisture content. The selected regression equations described the dependence of the hydrogen sulfide concentration on the considered factors. The determination coefficients and Student's criteria proved the reliability of the results obtained at the significance level P ≤ 0.05

Approaches for the preparation of dense ceramics and sintering aids for Sr/Mg doped lanthanum gallate: focus review

This review focuses on Sr/Mg doped lanthanum gallate and its use as a dense electrolyte for medium-temperature solid oxide electrochemical devices. Methods for synthesizing the material are discussed, including techniques that lower the temperature required to attain a single-phase crystalline structure. The effects of secondary phases and grain size on conductivity of ceramics are also investigated. Moreover, the techniques used for compacting electrolyte powder and reducing energy expenses, as well as the impacts of sintering aids on ceramic properties, are analyzed. The potential advantages and disadvantages of the proposed alterations to generate an electrolyte from doped lanthanum gallate are evaluated.https://doi.org/10.15826/elmattech.2023.2.02

Flux of nutrients from Russian rivers to the Arctic Ocean: Can we establish a baseline against which to judge future changes?

Climate models predict significant warming in the Arctic in the 21st century, which will impact the functioning of terrestrial and aquatic ecosystems as well as alter land‐ocean interactions in the Arctic. Because river discharge and nutrient flux integrate large‐scale processes, they should be sensitive indicators of change, but detection of future changes requires knowledge of current conditions. Our objective in this paper is to evaluate the current state of affairs with respect to estimating nutrient flux to the Arctic Ocean from Russian rivers. To this end we provide estimates of contemporary (1970s–1990s) nitrate, ammonium, and phosphate fluxes to the Arctic Ocean for 15 large Russian rivers. We rely primarily on the extensive data archives of the former Soviet Union and current Russian Federation and compare these values to other estimates and to model predictions. Large discrepancies exist among the various estimates. These uncertainties must be resolved so that the scientific community will have reliable data with which to calibrate Arctic biogeochemical models and so that we will have a baseline against which to judge future changes (either natural or anthropogenic) in the Arctic watershed

Protection of atmosphere from harmful emissions of stationary fuelburn installations

The article analyzes domestic and foreign researches in the field of combustion gas cleaning from harmful matters. The drawbacks of the existing methods of cleaning emissions of small-capacity boilers are revealed. The results of the researches conducted by the authors are presented. Complex schemes of cleaning emissions of the industrial boilers of the DKVR series are considered. The results of the tests of afterburning devices installed in the industrial boilers are presented. The simplest design of an afterburning device by the example of an industrial boiler of the DKVR series is considered. It is shown that the application of the afterburning devices prevents emissions of the incomplete burning products (CO, carbon black, benzpyrene) and reduces the nitric oxide content by (50-80)%, depending on the scheme of cleaning. The usage of the afterburning devices improves boiler performance owing to the increase of the radiant component in a furnace chamber, reduction of heat losses, increase of efficiency

Corrigendum to "Time-varying magnetotail magnetic flux calculation: a test of the method" published in Ann. Geophys., 27, 1583–1591, 2009

No abstract available

Behavioral Barriers of Tuberculosis Notification in Private Health Sector: Policy implication and Practice

Under-reporting of new tuberculosis (TB) cases is one of the main problems in TB control, particularly in countries with high incidence and dominating role of a private sector in TB cases diagnosing. The purpose of this paper was to explore behavioral determinants of under-reporting of new TB cases among private sector physicians in Iran. We conducted a population-based, cross-sectional study of physicians working in private clinics. The data collection tool was designed using the theory of planned behavior. We used structural equation models with maximum likelihood estimation to examine attitude towards the notification behavior. Of 519 physicians, 433 physicians completed the questionnaire. Attitude towards notification had the highest score (mean score=87.65; sd=6.79; range: 0-100). The effect of perceived behavioral controls on the notification behavior ((β ̂)= 0.13; CI: .01-.25) was stronger than the total effect of attitude ((β ̂)=0.06; CI: .00-.12) and subjective norms ((β ̂)=0.01; CI: -.00 -.03) on the behavior. However, the attitude was the main predictor of intention and justified 46% of the intention variance. Intention had a significant effect on the behavior ((β ̂)= 0.09; CI:.01- .16). Considering stronger effect of perceived behavioral control on the behavior, interventions aiming at facilitating notification process would be more effective than those aiming at changing the attitude or enhancing intention among physicians. To the best of our knowledge, no other study previously explored determinants of under-reporting from the behavioral and cognitive perspective. Specifically, we explored the role of the theory of planned behavior constructs in predicting intention to notify new TB cases

Observation of nuclei with energies 8-30 MeV per nucleon in the Earth's magnetosphere at the altitudes 350 KM

Observations of the flux of nuclei with an energy of IO MeV per nucleon on the Salyut-7 Station in September 1984 are presented. The observed flux is smaller by a factor of 50 than the flux detected in May, 1981

Contribution of magnetotail reconnection to the cross-polar cap electric potential drop

Since the work of Dungey (1961), the global circulation pattern with two (dayside and nightside) reconnection regions has become a classic concept. However, the contributions of dayside and nightside sources to the cross-polar cap potential (PCP) are not fully understood, particularly, the relative role and specifics of the nightside source are poorly investigated both in quantitative and qualitative terms. To fill this gap, we address the contributions of dayside and nightside sources to the PCP by conducting global MHD simulations with both idealized solar wind input and an observed event input. The dayside source was parameterized by solar wind–based “dayside merging potential” Φd = LeffVBt sin4(θ/2), whereas to characterize the nightside source we integrated across the tail the dawn-dusk electric field in the plasma sheet (to obtain the “cross-tail potential” Φn). For the idealized run we performed simulations using four MHD codes available at the Community Coordinated Modeling Center to show that contribution of the nightside source is a code-independent feature (although there are many differences in the outputs provided by different codes). Particularly, we show that adding a nightside source to the linear fit function for the ionospheric potential (i.e., using the fit function Φfit = KdΦd + KnΦn + Φ0) considerably improves the fitting results both in the idealized events as well as in the simulation of an observed event. According to these simulations the nightside source contribution to the PCP has a fast response time (<5 min) and a modest efficiency (potential transmission factor from tail to the ionosphere is small, Kn < 0.2), which is closely linked to the primarily inductive character of strong electric field generated in the plasma sheet. The latter time intervals are marked by strongly enhanced nightside (lobe) reconnection and can be associated with substorm expansion phases. This association is further strengthened by the simulated patterns of precipitation, the R1-type field-aligned substorm current wedge currents and Hall electrojet currents, which are consistent with the known substorm signatures