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Solid oxide fuel cell (SOFC) has attracted wide attention because its efficiency is not limited by the efficiency of Carnot cycle. The structure of flow channel in SOFC has great effects on the internal mass distribution, which influences current density. In this paper, the height of flow channel and the position, arrangement, number and height of the fin which is placed in channel, are changed to get different structures of bi-layer interconnector, and they are applied to three layers SOFC stack. The effects of each structural parameter on the current density are studied by numerical simulation. The results show that, increasing the number of fins and bi-layer interconnector height can make more reactant gas enters the electrode. In addition, compared with the conventional structure, the current density can be increased by the bi-layer interconnector up to 31.256%, and the bi-layer interconnector structure could save n-1 layers of interconnector, which reduces the volume of SOFC stack. Among the five structural parameters, the position of fins has the least influence on temperature distribution and current density, while the arrangement of fins has the highest influence on volume current density, reaching 30%. Using a staggered arrangement and higher bi-layer interconnector can also improve the temperature distribution. • A three-dimensional SOFC stack with bi-layer interconnector was established. • Changing geometry of fins and channel height to get different structures. • Increasing number of fins and channel height improve concentration distribution. • The arrangement of fins has the greatest impact on current density. • Staggered fins and higher bi-layer interconnector reduce the highest temperature. [ABSTRACT FROM AUTHOR]

This paper details the cross-section measurements of 38 fission-like events in 19F + 181Ta system at energy 115 MeV, originating from complete and/or incomplete fusion-fission processes. The recoil-catcher off-beam activation technique followed by γ-ray spectroscopy has been used to measure production cross sections of fission-like events. The measured cross-section data of fission-like events align well with Gaussian distributions indicating their production via de-excitation of equilibrated compound nucleus formed. Additionally, the study explores mass and isotopic yield distributions of fission fragments, with the presently measured isotopic yield variance which is found to be consistent with literature values for other fissioning systems. [ABSTRACT FROM AUTHOR]

Copyright of Advanced Textile Technology is the property of Zhejiang Sci-Tech University Magazines and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The correlation between the variations of multiplicity of prompt fission neutrons and the total kinetic energy of fission fragments was studied using a double ionization chamber in combination with a prompt fission neutron detector. An estimate was made of the systematic errors introduced by crosstalk caused by the multi-module structure of the neutron detector. [ABSTRACT FROM AUTHOR]

AbstractThe reactive material-metal composite jet (RMM-CJ), exhibiting a dual penetration-enhancement effect is of growing concern. In the present study, the composite jets of reactive material-copper (RM–Cu), reactive material-titanium (RM–Ti), and reactive material-aluminum (RM–Al) impacting multi-spaced plates were studied experimentally and numerically. A comprehensive analysis of the damage effects was conducted based on experimental and simulation results. The results show that the damage area of each layer of plate is closely related to the mass distribution of reactive material. The relationship of the mass of each layer of reactive material with time is given, and the deflagration gain is quantified. The research results provide a useful reference for the design and optimization of reactive material-metal composite liners. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiaotong University (Science) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Several commonly used ceramics in ballistic protection were compared in terms of ballistic resistance and failure behavior, including alumina (Al2O3), silicon carbide (SiC), boron carbide (B4C), and silicon nitride (Si3N4). Hybrid ceramic ultrahigh molecular weight polyethylene composite armors were impacted by 12.7 mm armor‐piercing incendiary projectiles, with a velocity of around 490 m/s. Moreover, there was a layer of aramid fabric composite covering on the impacted side of the ceramic plate. These composite armors were paneled with four different types of ceramics as faceplates and had the same sizes. The ballistic test results show that B4C ceramic provides the worst protection performance, and SiC provides the best protection performance. The angles of ceramic cones formed by different ceramic plates under the same impact load are different, SiC is the widest and Al2O3 is the narrowest. Numerical simulation shows that several ceramic composite targets have the same resistance to the projectile at the pit stage. The fragment mass was quantified by using the screening method, and the results show that the Schumann distribution is more consistent with the experimental results. [ABSTRACT FROM AUTHOR]

Anthropogenic groundwater arsenic (As) pollution is common in many aquifers in Southwest China. It is concerned that long-term random disposal of As smelting slag could induce the transport of high-As groundwater into previously uncontaminated aquifers. Here, we used HELP-MODFLOW-MT3DMS model simulations to integrate the percolation, groundwater flow, and solute transport processes at an aquifer at site scale, constrained by weather, hydrogeology, and monitoring data. Our simulations provide a new method framework of the simulated percolation by HELP model and have induced As spatiotemporal distribution in the aquifer. According to the HELP model simulation results, percolation volume accounts for 24% of rainfall over 18 years. This work determined that the As discharge trend was fitted by double-constants kinetics based on the leaching experiment. And this work calculates total mass distribution of As in the aquifer over 18 years. We have found that the sustained As pollution relies on the rainfall that acts as the primary contributor of elevated As concentrations. Model simulation results suggest that 51.70% of the total As mass (1.96 × 104 kg) was fixed in low permeability solid media. The total As mass discharged into groundwater reached 9.3 × 103 kg, accounting for 24.68%. The accumulative outflow mass of arsenic was 8.0 × 103 kg, accounting for 21.62%. [ABSTRACT FROM AUTHOR]

Matter at ultra-high densities finds a physical realization inside neutron stars. One key property is their maximum mass, which has far-reaching implications for astrophysics and the equation of state of ultra dense matter. In this work, we employ Bayesian analysis to scrutinize the mass distribution and maximum mass threshold of galactic neutron stars. We compare two distinct models to assess the impact of assuming a uniform distribution for the most important quantity, the cosine of orbital inclination angles (i), which has been a common practice in previous analyses. This prevailing assumption yields a maximum mass of 2.25   M ⊙ (2.15–3.32 M ⊙ within 90 % confidence), with a strong peak around the maximum value. However, in the second model, which indirectly includes observational constraints of i, the analysis supports a mass limit of 2.56 − 0.58 + 0.87 M ⊙ ( 2 σ uncertainty), a result that points in the same direction as some recent results gathered from gravitational wave observations, although their statistics are still limited. This work stresses the importance of an accurate treatment of orbital inclination angles, and contributes to the ongoing debate about the maximum neutron star mass, further emphasizing the critical role of uncertainties in the individual neutron star mass determinations. [ABSTRACT FROM AUTHOR]

Steelmaking processes inevitably generate large amounts of byproducts, including slags, specks of dust, etc., and their treatment has been a critical issue for the steelmaking industry. Kish graphite is a valuable substance existing in steelmaking byproducts, and the recovery of Kish graphite has attracted more attention in recent years. The purpose of this study was to use a multi-stage froth flotation process for the beneficiation of Kish graphite and to investigate the influence of flotation conditions on the mass distribution of graphite and impurities. The results showed that the dust D2 contained ~34 wt.% of graphite and thus had the highest potential for the recovery of Kish graphite. The dosages of frother (methyl isobutyl carbinol, MIBC) at 0.005 kg/t and collector (kerosene) at 1 kg/t were optimal for the flotation of Kish graphite. After three-stage froth flotation, the graphite content of the concentrate was progressively increased to 84.09 wt.%, and the entire recovery rate was 93.05%. During the multi-stage froth flotation process, most of the impurities were separated in stage I, but the Fe-containing impurities were mainly separated in stage II. Some Ca2+, Na+, and K+ were leached out, and there were barely any heavy metals in the liquid phases. [ABSTRACT FROM AUTHOR]

This paper reports the result of an investigation of a hypothesis that the melting polar ice of Earth flowing down to the equatorial region causes volcano eruptions. We assumed a cube inside the spherical body of Earth, formulated a 3-dimensional inertia tensor of the cube, and then simulated the redistribution of the mass that is to be caused by the movement of melted ice on the Earth’s surface. Such mass distribution changes the inertia tensor of the cube. Then, the cube’s rotation inside Earth was simulated by multiplying the Euler angle matrix by the inertia tensor. Then, changes in the energy intensity and the angular momentum of the cube were calculated as coefficients of Hamiltonian equations of motion, which are made of the inertia tensor and sine and cosine curves of the rotation angles. The calculations show that the melted ice increases Earth’s internal energy intensity and angular momentum, possibly increasing volcano eruptions.

Research suggests that the rotational dynamics of an object underpins our perception of its weight. We examine the generalisability of that account using a more ecologically valid way of manipulating an object's mass distribution (mass concentrated either at the top, bottom, centre, near the edges or evenly distributed throughout the object), shape (cube or sphere), and lifting approach (lifting directly by the hand or indirectly using a handle or string). The results were in line with our predictions. An interaction effect was found where the mass distribution and lifting approach both associated with the lowest rotational dynamics made the stimulus appear lighter compared to other combinations. These findings demonstrate rotational dynamic effects in a more run-of-the-mill experience of weight perception than what has been demonstrated before using cumbersome stimuli. [ABSTRACT FROM AUTHOR]

According to the actual structure and size of plasma spraying gun, a simulation model based on the Euler-Euler multi-phase model was established with the parameters of medium energy in this study. The distribution nephogram of the temperature and velocity fields of tungsten powder particles and the working gas used in the spraying process were obtained. Additionally, through the mass distribution nephogram, the heating and melting processes of tungsten powder particles in the flame flow were analyzed, and the deposition behavior of the molten droplets of the tungsten powder was investigated. In order to verify the correctness of the simulation, an experiment is performed with the parameters of low energy, medium energy and high energy. This study was of significance in the development of spraying technology, as well as for the improvement on product performance. [ABSTRACT FROM AUTHOR]

Walnut shell is lightweight material with high‐strength and toughening characteristics, but it is different from other nut shells' microstructure with two or three short sclerotic cell layers and long bundle fibers. It is essential to explore the fracture resistance biomechanism of lightweight walnut shell and how to prevent damage of bionic structure. In this study, it is found that the asymmetric mass center and geometric center dissipated impact energy to the whole shell without loading concentration in the loading area. Diaphragma juglandis is a special structure improved walnut shell's toughening. The S‐shape gradient porosity/elastic modulus distribution combined with pits on single auxetic sclerotic cells requires higher energy to crack expansion, then decreases its fracture behavior. These fantastic findings inspire to design fracture resistance devices including helmets, armor, automobile anti‐collision beams, and re‐entry capsule in spacecraft. [ABSTRACT FROM AUTHOR]

In studies of dynamic stability and power quality, it is necessary to know the values of the mechanical parameters determining the transient response of wind turbines. Their exact values are not as decisive as the power curve, but an inaccurate estimate can distort or even invalidate the simulation results. From a review of the literature, it has been found that, despite their importance, the values of inertia, stiffness and damping are hardly available for any turbine model. Another detected problem is the lack of confidence in the data origin. This article aims to solve the issue of the scarcity and unreliability of data on inertia, and gathers the information found on the remaining mechanical parameters. Available blade inertia values in kg · m 2 are presented. Special treatment has been given to those providing the mass distribution along the blade span, for which the provided values of inertia have been compared with those obtained numerically, showing good matching. With this, different reliable relations are obtained that allow for the calculation of the turbine rotor inertia, based on the mass and length of the blade. When the center of gravity is also available, a very correlated expression ( r 2 = 0.975 ) is provided to obtain the inertia. The references to the stiffness and damping constant of the drive train, which are even more rare, will also be presented. In addition, the study includes a revision of gearboxes, generators and blade weight, according to their IEC-class and material. [ABSTRACT FROM AUTHOR]

BACKGROUND: In view of the low economic benefit for direct utilization of lignite, the ionic liquid 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl) has been used to extract Inner Mongolia lignite (IML) in order to efficiently separate lignite, develop the technology for clean and value‐added utilization of lignite, and alleviate the enormous pressure of ecological environment pollution. Subsequently, sequential extraction of IML by [Bmim]Cl/N‐methyl‐2‐pyrrolidone (NMP), acetonitrile and ether was employed to separate group components in lignite. RESULTS: Functional group results show that hydrogen bonds of IML including OHether, COOH dimers and SHN, and weak covalent bonds such as CalO, CalN, CalS and SS, can be cleaved by [Bmim]Cl. Extraction experiments using mixed solvents of [Bmim]Cl and NMP or water indicate that the synergistic effect of NMP and [Bmim]Cl plays a vital role in increasing lignite extraction yield, but for water an opposite effect is observed. Importantly, the group components extracted by [Bmim]Cl/NMP and consecutively by acetonitrile and ether show a clear difference in composition according to gas chromatography–mass spectrometry. Specifically, polycyclic aromatic hydrocarbons and long‐chain alkanes are present in the acetonitrile phase, with relative content of 8% and 88%, respectively, while most of esters, aliphatic acids and phenols are dissolved in ether with proportions of 35.24%, 35.53% and 16.57%, respectively. CONCLUSION: This work demonstrates that sequential extraction of lignite by [Bmim]Cl/NMP, acetonitrile and ether may provide new insights for the separation of group components and clean utilization of lignite in industry. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Abstract Walnut shell is lightweight material with high‐strength and toughening characteristics, but it is different from other nut shells’ microstructure with two or three short sclerotic cell layers and long bundle fibers. It is essential to explore the fracture resistance biomechanism of lightweight walnut shell and how to prevent damage of bionic structure. In this study, it is found that the asymmetric mass center and geometric center dissipated impact energy to the whole shell without loading concentration in the loading area. Diaphragma juglandis is a special structure improved walnut shell's toughening. The S‐shape gradient porosity/elastic modulus distribution combined with pits on single auxetic sclerotic cells requires higher energy to crack expansion, then decreases its fracture behavior. These fantastic findings inspire to design fracture resistance devices including helmets, armor, automobile anti‐collision beams, and re‐entry capsule in spacecraft.

The quantitative analysis of seismic performance under small and moderate earthquakes is of great significance. However, only using the stiffness distribution index is no longer applicable to seismic performance evaluation, and the influence of mass distribution must be introduced. In this study, under the action of small and medium earthquakes, the equation of motion can be simplified into the equilibrium equation of the dynamic matrix by the quasi-static method. Furthermore, a condition number index of dynamic matrix is proposed to evaluate the seismic performance of truss structures, which can consider both stiffness distribution and mass distribution. Then, the correctness of the proposed index is verified by comparing with the displacement and strain indexes. In addition, the performance of truss structure is studied by the condition number of stiffness matrix, mass matrix and dynamic matrix. It is found that since the condition number of stiffness matrix and the condition number of mass matrix cannot consider both stiffness and mass, it is not comprehensive to use these two indexes to evaluate the seismic performance of truss structures. The evaluation result based on the condition number of dynamic matrix is more reasonable under small and medium earthquakes. [ABSTRACT FROM AUTHOR]

This paper reports the result of an investigation of a hypothesis that the melting polar ice of Earth flowing down to the equatorial region causes volcano eruptions. We assumed a cube inside the spherical body of Earth, formulated a 3-dimensional inertia tensor of the cube, and then simulated the redistribution of the mass that is to be caused by the movement of melted ice on the Earth’s surface. Such mass distribution changes the inertia tensor of the cube. Then, the cube’s rotation inside Earth was simulated by multiplying the Euler angle matrix by the inertia tensor. Then, changes in the energy intensity and the angular momentum of the cube were calculated as coefficients of Hamiltonian equations of motion, which are made of the inertia tensor and sine and cosine curves of the rotation angles. The calculations show that the melted ice increases Earth’s internal energy intensity and angular momentum, possibly increasing volcano eruptions. [ABSTRACT FROM AUTHOR]

Copyright of Vie et Sciences de l'Entreprise is the property of ANDESE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A variable frequency piezoelectric motor is studied, which can generate rotational motion under the excitation of variable-mode vibration response units. Two variable-mode vibration response units fixed in the inclined plane are excited by the square wave and drive the friction disk to achieve the rotation and translation. Thus, the friction torque on the rotor changes periodically, and the rotor is driven to produce positive displacement output. By adjusting the mass distribution of the variable-mode piezoelectric wafer vibration response unit, the natural frequency of the low-frequency motor is adjustable. In order to achieve the maximum displacement output of the low-frequency motor, the simulation analysis is initially performed on the stiffness, mode, and vibration shape in line with the motion principle. Then the experiments of the variable-natural-frequency motion characteristics of the low frequency motor are carried out, and the maximum rotation speed of the designed piezoelectric motor is improved by the variable-natural-frequency motion characteristics and reaches 520 mrad/s.

Abstract Numerical studies were carried out to investigate the thermal performance of the muzzle flow with strong shock discontinuities and gas–gas heat transfer mechanism in the base bleed unit (BBU) of an aerodynamic vehicle under the combined effects of muzzle flow and depressurization process. The process was modeled using the Navier–Stokes equations with chemical kinetics and interior ballistic equations. The results show that the muzzle phenomena with large temperature gradients and different wave structures appear after the supersonic vehicle enters into the free‐flight stage. The BBU also experiences a strong depressurization process with the release of high‐temperature propellant gas at 2200 K. However, the igniter combustion gas at a higher temperature of 3050 K in the BBU develops downstream and upstream repeatedly under the combined effects of the base wave and depressurization process, which makes the energy conversion process in the unit more complicated. With the projectile leaving the control of the muzzle flow, the BBU is full of the igniter combustion gas and the energy in the unit is uniformly distributed gradually. The high‐temperature area, at approximately 2750 K, propagates downstream along the axial and radial directions simultaneously until it finally dominates the entire unit. The maximum temperature of the combustion gas acting on the propellant surface is always 2740 K and the maximum heat flux remains approximately 1250 W/cm2 at later periods.

Objective: In order to optimize the process parameters of tobacco sheet of heated cigarette. Methods: 12 gradient grades of tobacco sheets with glycerol addition ratio of 5%~30% were prepared under laboratory conditions. The mass of moisture, nicotine and glycerol in heated cigarette smoke, filter condensation section and tobacco core section were detected by GC-TCD method. And the mass distribution characteristics of main components, release rate, filtration rate and transfer rate were analyzed. Results: When 5%~30% glycerol was applied to the heated cigarette tobacco sheets, the water release rate was 88.6%~92.3%, which was mainly distributed in the smoke and filter condensation section; The nicotine release rate was 25.5%~34.2%, which was mainly distributed in the filter condensing section and tobacco core section; The glycerol release rate was 13.9%~21.3%, which was mainly distributed in the tobacco core section. Conclusion: When 10%~18% glycerol was added to tobacco sheets, nicotine and glycerol in heated cigarettes had higher transfer rate and lower filtration rate.

Purpose: To determine whether kinetic chain pattern during knee extensor strength training influences quadriceps femoris center of mass and moment of inertia about the hip in a predictable manner as such changes can affect running economy. Methods: Twelve participants completed 8 weeks of both unilateral open (OKC) and closed (CKC) kinetic chain resistance training on opposing legs. Changes in quadriceps femoris muscle volume (VOLQF), center of mass location (CoMQF), and moment of inertia (IQF) about the hip were determined from magnetic resonance images scans. Regional hemodynamics of the vastus lateralis taken at 30% and 70% of muscle length during OKC and CKC bouts early in the training program were measured using near-infrared spectroscopy (NIRS) and used post hoc to predict changes in CoMQF. Results: While increases in VOLQF were similar between OKC (Δ79.5 ± 87.9 cm³) and CKC (Δ60.2 ± 110.5 cm³, p = 0.29), the patterns of hypertrophy differed; a distal shift in CoMQF (Δ2.4 ± 0.4 cm, p < 0.001) and increase in IQF (Δ0.017 ± 0.014 kg m², p < 0.001) occurred in OKC but not in CKC (CoMQF: Δ-2.2 ± 2.0 cm, IQF: Δ-0.022 ± 0.020 kg m², p > 0.05). Regional hemodynamics assessed by NIRS during a single training session displayed similar exercise and regional differences and predicted 39.6% of observed changes in CoMQF. Conclusions: Exercise selection influences muscle shape sufficiently to affect CoMQF and IQF, and these changes may be predicted in part from NIRS measurements during a single workout. Given IQF is inversely related to running economy and since CKC exercise provides a more proximal pattern of hypertrophy than OKC, it may be more preferential for running. The results from the present study also highlight the potential of NIRS as a tool for predicting patterns of hypertrophy between different exercises and exercise conditions [ABSTRACT FROM AUTHOR]

Matter at ultra-high densities finds a physical realization inside neutron stars. One key property is their maximum mass, which has far-reaching implications for astrophysics and the equation of state of ultra dense matter. In this work, we employ Bayesian analysis to scrutinize the mass distribution and maximum mass threshold of galactic neutron stars. We compare two distinct models to assess the impact of assuming a uniform distribution for the most important quantity, the cosine of orbital inclination angles (i), which has been a common practice in previous analyses. This prevailing assumption yields a maximum mass of 2.25 M⊙ (2.15–3.32 M⊙ within 90% confidence), with a strong peak around the maximum value. However, in the second model, which indirectly includes observational constraints of i, the analysis supports a mass limit of 2.56−0.58+0.87M⊙ (2σ uncertainty), a result that points in the same direction as some recent results gathered from gravitational wave observations, although their statistics are still limited. This work stresses the importance of an accurate treatment of orbital inclination angles, and contributes to the ongoing debate about the maximum neutron star mass, further emphasizing the critical role of uncertainties in the individual neutron star mass determinations.

The study of compact object populations has come a long way since the determination of the mass of the Hulse–Taylor pulsar, and we now count on more than 150 known Galactic neutron stars and black hole masses, as well as another 180 objects from binary mergers detected from gravitational-waves by the Ligo–Virgo–KAGRA Collaboration. With a growing understanding of the variety of systems that host these objects, their formation, evolution and frequency, we are now in a position to evaluate the statistical nature of these populations, their properties, parameter correlations and long-standing problems, such as the maximum mass of neutron stars and the black hole lower mass gap, to a reasonable level of statistical significance. Here, we give an overview of the evolution and current state of the field and point to some of its standing issues. We focus on Galactic black holes, and offer an updated catalog of 35 black hole masses and orbital parameters, as well as a standardized procedure for dealing with uncertainties. [ABSTRACT FROM AUTHOR]

The use of the long-lasting insecticide-treated mosquito net (LLIN) is one of the basic interventions recommended by the Global technical strategy for Malaria 2016-2030. Since the start of the LLIN distribution campaigns in 2006 in Democratic Republic of Congo (DRC), it was based on paper tools leading to poor quality data. The first digital campaigns date back to 2014 through "Interchurch medical assistance" (IMA), which used the ODK collect application for recording household count data and LLIN distribution data. In 2020 "Soins de santé primaire en milieu Rurale" (SANRU) developed both household registration and LLIN distribution data recording forms as well as additional modules for supervision, monitoring and training. This article briefly describes the status of the implementation process of this digital-based management of LIIN mass distribution. During the first half of 2020, a roadmap was developed between Sanru and the Global fund to fight Tuberculosis, AIDS and Malaria (GFTAM) on the objectives of digitization, the data to be digitized, and the timelines for implementing the changes. In the last quarter of 2021, an internal Sanru team composed of some members of its technical management, and staff in charge of the digitization of LLIN mass distribution campaign data participated in a document review of the deliverables in comparison with the roadmap and in group discussions. For recording household enumeration data and distribution data, forms configured on smartphones allow data recording and uploading without going through manual calculations and previously necessary transcriptions with management based on paper tools, thus removing sources of errors. Online data delivery and automated production of dashboards allow real-time sharing of information to all stakeholders and shorten data validation times. Feedback to actors in the field is possible thanks to access to information and maps generated on the basis of geolocation data from households. ODK forms for supervision and monitoring have been put in place to ensure that these activities are effectively deployed in the field in accordance with the standards set by geolocating the actors and using the data transmitted online for interactive feedback. The next step is to develop a material flow management module to improve the traceability of inputs. [ABSTRACT FROM AUTHOR]

Numerical studies were carried out to investigate the thermal performance of the muzzle flow with strong shock discontinuities and gas–gas heat transfer mechanism in the base bleed unit (BBU) of an aerodynamic vehicle under the combined effects of muzzle flow and depressurization process. The process was modeled using the Navier–Stokes equations with chemical kinetics and interior ballistic equations. The results show that the muzzle phenomena with large temperature gradients and different wave structures appear after the supersonic vehicle enters into the free‐flight stage. The BBU also experiences a strong depressurization process with the release of high‐temperature propellant gas at 2200 K. However, the igniter combustion gas at a higher temperature of 3050 K in the BBU develops downstream and upstream repeatedly under the combined effects of the base wave and depressurization process, which makes the energy conversion process in the unit more complicated. With the projectile leaving the control of the muzzle flow, the BBU is full of the igniter combustion gas and the energy in the unit is uniformly distributed gradually. The high‐temperature area, at approximately 2750 K, propagates downstream along the axial and radial directions simultaneously until it finally dominates the entire unit. The maximum temperature of the combustion gas acting on the propellant surface is always 2740 K and the maximum heat flux remains approximately 1250 W/cm2 at later periods. [ABSTRACT FROM AUTHOR]

Nuclear fission is one of the most complex physical processes. Up to now, there is still a lack of theory that can well describe the prefission and postfission processes. Mass yields in the neutroninduced fission of 239Pu provide fundamental and significant data support for nuclear energy utilization, but the independent fission yields are scarce and far from precise. In addition, the current evaluation work for fission yields partially refers to the experimental data based on radiochemical methods and mass spectrometric, it will make sense to compare the evaluation data with the data obtained by direct systematic measurement. In order to determine independent mass yield distributions precisely, the fission fragments identification spectrometer (FFIS) device was developed. The axial grid ionization chamber and timing detectors based on microchannel plates were designed and tested for determining the kinetic energy and timeofflight of fission fragments, respectively. Specifically, the intrinsic energy resolution for the ionization chamber was measured to be about 0.5% for 80 MeV 63Cu particles, and the time resolution was about 157 ps (FWHM) determined by 241Am source. By directly coincident measurement of energy and velocity of the fission fragments on their flight path, the postneutronemission masses can be obtained according to the classical formula for kinetic energy. The mass yield distribution in the thermalneutroninduced fission of 239Pu was measured at the inhospital neutron irradiator (IHNI1). With the flight trajectory of 10045 cm, the relative uncertainty of the flight path length is better than 01%, and the time resolution is about 02%. When using the Ev method to measure mass distribution, two vital issues need to be resolved. For one thing, the nonlinear energy response of the detector affects the accuracy of the mass calculation. In this work, energy losses in the carbon foil of the stop timing detector and the silicon nitride window of the ionization chamber were corrected eventbyevent based on Geant4 calculation. For another thing, the scattering of heavy ions or the inhomogeneous of the detector materials may make the recorded energy to be underestimated. These abnormal data points are hard to eliminate in the valley region, which makes the mass yields of symmetric fission fragments being overestimated, and improving statistics may relatively reduce this kind of effect. Taking into account the correction uncertainty, the energy resolution for the light fission fragment is better than 07%, and that is approximately 1% for heavy fragments peak. Thus, the mass resolution is estimated to be 1 amu at 99 amu, and 15 amu at 138 amu.

Recent advancements in high-resolution ion mobility spectrometry-mass spectrometry (IMS-MS) have enabled the separation of isotopologues and isotopomers based on their mass distribution-based isotopic shifts (i.e., changes in center of mass and moments of inertia). To better understand the fundamental nature of these isotopic shifts, we investigated whether they were additive in nature by introducing varying isotopic substitutions (e.g., 13C, 2H/D, and 81Br) through either hydrogen deuterium exchange or permethylation. From there, we measured the relative arrival times between light and heavy isotopologues with high-resolution cyclic ion mobility separations. Globally, we observed that the isotopic shifts were approximately additive in nature regardless of the molecule system or specific isomer studied. Furthermore, we discovered that additivity occurs in the isotopic shifts irrespective of the absolute shift, potentially indicating this observation may be more global in nature. We believe that our findings will serve to better understand the fundamental nature of mass distribution-based isotopic shifts and will inform theoretical ion mobility calculations in the future. [Display omitted] • Mass distribution-based isotopic shifts stem from changes in center of mass and moments of inertia. • Additivity of isotopic shifts was observed across varying molecule classes. • Additivity was observed irrespective of the isomer-specific nature of isotopic shifts. [ABSTRACT FROM AUTHOR]

Steelmaking processes inevitably generate large amounts of byproducts, including slags, specks of dust, etc., and their treatment has been a critical issue for the steelmaking industry. Kish graphite is a valuable substance existing in steelmaking byproducts, and the recovery of Kish graphite has attracted more attention in recent years. The purpose of this study was to use a multi-stage froth flotation process for the beneficiation of Kish graphite and to investigate the influence of flotation conditions on the mass distribution of graphite and impurities. The results showed that the dust D2 contained ~34 wt.% of graphite and thus had the highest potential for the recovery of Kish graphite. The dosages of frother (methyl isobutyl carbinol, MIBC) at 0.005 kg/t and collector (kerosene) at 1 kg/t were optimal for the flotation of Kish graphite. After three-stage froth flotation, the graphite content of the concentrate was progressively increased to 84.09 wt.%, and the entire recovery rate was 93.05%. During the multi-stage froth flotation process, most of the impurities were separated in stage I, but the Fe-containing impurities were mainly separated in stage II. Some Ca2+, Na+, and K+ were leached out, and there were barely any heavy metals in the liquid phases.

In studies of dynamic stability and power quality, it is necessary to know the values of the mechanical parameters determining the transient response of wind turbines. Their exact values are not as decisive as the power curve, but an inaccurate estimate can distort or even invalidate the simulation results. From a review of the literature, it has been found that, despite their importance, the values of inertia, stiffness and damping are hardly available for any turbine model. Another detected problem is the lack of confidence in the data origin. This article aims to solve the issue of the scarcity and unreliability of data on inertia, and gathers the information found on the remaining mechanical parameters. Available blade inertia values in kg · m2 are presented. Special treatment has been given to those providing the mass distribution along the blade span, for which the provided values of inertia have been compared with those obtained numerically, showing good matching. With this, different reliable relations are obtained that allow for the calculation of the turbine rotor inertia, based on the mass and length of the blade. When the center of gravity is also available, a very correlated expression (r2=0.975) is provided to obtain the inertia. The references to the stiffness and damping constant of the drive train, which are even more rare, will also be presented. In addition, the study includes a revision of gearboxes, generators and blade weight, according to their IEC-class and material.

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Marketing Science & Inspirations is the property of Comenius University in Bratislava, Faculty of Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Vector control is an essential component in prevention and control of malaria in malaria endemic areas. Insecticide treated nets is one of the standard tools recommended for malaria vector control. The objective of the study was to determine physical integrity and insecticidal potency of long-lasting insecticidal nets (LLINs) used in control of malaria vector in Kirinyaga County, Kenya. Method The study targeted households in an area which had received LLINs during mass net distribution in 2016 from Ministry of Health. A total of 420 households were sampled using systematic sampling method, where the household heads consented to participate in the study. A semi-structured questionnaire was administered to assess care and use while physical examination was used to determine integrity. Chemical concentration was determined by gas chromatography mass spectroscopy (GC-MS). Data analysis was done using Statistical Package for Social Sciences (SPSS) version 19. Results After 18 months of use, 96.9% (95% CI: 95.2–98.6%) of the distributed nets were still available. Regarding net utilization, 94.1% of household heads reported sleeping under an LLIN the previous night. After physical examination, 49.9% (95% CI: 43–52.8%) of the bed nets had at least one hole. The median number of holes of any size was 2[interquartile range (IQR) 1–4], and most holes were located on the lower part of the nets, [median 3 (IQR 2–5)]. Only 15% of the nets with holes had been repaired. The median concentration for α-cypermethrin was 7.15 mg/m2 (IQR 4.25–15.31) and 0.00 mg/g (IQR 0.00–1.99) for permethrin. Based on pHI, Chi-square test varied significantly with the manufacturer (X (6, N = 389) = 29.14, p = 0.04). There was no significant difference between nets with different number of washes (X2(2) = 4.55, p = 0.103). Conclusion More than three-quarters of the nets supplied had survived and insecticidal potency was adequate in vector control. Standard procedure for field evaluation of surface insecticidal content available to a mosquito after landing on a net to rest is recommended.

To explore the mass distribution characteristics of wet-mix shotcrete, taking shotcrete used for tunnel support as the background, concrete spray in the air and concrete attached to the receiving surface were investigated by some tests at the process scale (spray scale). The differences and relationship of mass distribution between them were compared. Besides, the plastic viscosity regarded as important factor was deeply talked about. The results showed that the three-dimensional shape of mass distribution of spray section and adhesion section exhibited as "cone" and "frustum of a cone", respectively. The mass concentration both of them decreased radially from the central area around the nozzle axis to the edge area away from the nozzle axis, and the variation tendency conformed to the Boltzmann distribution. The central mass concentration of the adhesion section was lower than that of the spray section, and the lateral flow caused by the transition of wet-mix shotcrete from horizontal impact jet to radial wall jet during the adhesion process was the main reason. The plastic viscosity of wet-mix shotcrete and its time-varying characteristics almost had no effect on the mass distribution of concrete spray, but had obvious effect on that of concrete attached to the receiving surface. • Boltzmann formula was used to evaluate the mass distribution characteristics. • The effect of plastic viscosity on mass distribution characteristics was studied. • The radial wall jet was used to explain the lateral flow of concrete. [ABSTRACT FROM AUTHOR]

The performance and stability of proton exchange membrane fuel cells are mainly dependent on mass transports in the gas diffusion layer (GDL). The mass transports in dual‐region including the regions of under‐channel and under‐rib are one of the factors that cause mass uneven distribution. Therefore, the wave structure and the auxiliary flow channel are introduced to enhance these mass transports. Auxiliary conventional parallel flow field (ACPFF), wave flow field (WFF), and auxiliary WFF (AWFF) are transferred into ANSYS MESHING for meshing, then imported into Fuel Cell and Electrolysis module on FLUENT for the solution. This comprehensive AWFF has important influences on mass even distribution and performance. The results reveal that dual‐region forced convections can be made by the periodic waved structure and the auxiliary flow channel. More reactants are forced to appear in GDL of under‐channel and under‐rib. Based on the simulation results, the distributions of oxygen, water, temperature are more even in AWFF. Specifically, the cell performance at high current density is improved obviously. Compared to CPFF, the max power density is increased by more than 4% in this novel flow field (AWFF), which will provide a new trial for the design of a comprehensive flow field. [ABSTRACT FROM AUTHOR]

This article discusses some basic concepts related to meteor astronomy, as well as the use of the correct terminology when working in Bulgarian. Due to the huge volume of topics, this is the second part of an upcoming series that examines only the most general principles in meteor science. The article can serve the public observatories and similar structures related to the teaching of amateur astronomy (due to the lack of such literature in Bulgarian), and meteor phenomena will continue to attract the attention of a wide range of people, giving them mostly a strong, emotional impact! [ABSTRACT FROM AUTHOR]

The behavior of mercury (Hg) species during thermal cogeneration was analyzed in a 10 MWh solid refuse fuel (SRF) utility boiler using a selective non-catalytic reduction unit, semi-dry reactor, and fabric filter with activated carbon injection for air pollution control from the facility. The annual Hg inflow into this facility is 24.2 (from 9.2 to 33.3) kg. The Hg species in flue-gas at inlet and outlet of the air pollution control devices (APCDs) were observed to be a mixture of 14.4 µg-Hg/Sm3 of particulate mercury, 2.6 µg-Hg/Sm3 of oxidized mercury, and 15.6 µg-Hg/Sm3 of elemental mercury and another mixture of 0.0 of particulate mercury, 0.3 of oxidized mercury, and 11.0 of elemental mercury, respectively. Elemental mercury was the major component in the combustion residue. In the emission assessment, the mass distribution of Hg of fly ash, bottom ash, and stack emission was determined as 67% (16.2 kg/yr), 2.0% (0.47 kg/yr) and 31% (7.5 kg/yr), respectively. Although elemental mercury was captured by APCDs configuration, it is best to chemically capture the air-emission mercury. Evaluation of Hg stability was tested for the fly ash by sequential extraction procedure method. [ABSTRACT FROM AUTHOR]

Salvinia natans (Salviniaceae, Polypodiopsida) is a warm-temperate presumably relict fern species that is currently protected not only at the national level in Ukraine, but also internationally in some other countries. It was included in all three editions of the Red Data Book of Ukraine (1980, 1996, 2009), as well as in Appendix I of the Bern Convention, the European Red List (as Near Threatened), and the IUCN Red List of Threatened Species (as Least Concern). An updated analysis of the distribution patterns of S. natans within the territory of Ukraine is provided based on the original research and observations of the authors, herbarium specimens from 37 Ukrainian, Austrian, Czech, Romanian and Russian herbaria, and available literature. As a result, more than 400 localities of this aquatic fern were registered in almost all administrative regions of the country, except Chernivtsi Region and the Autonomous Republic of Crimea. Based on the results of the comparative chorological analysis and the study of the spatial distribution of these localities, it is concluded that the geographic range of S. natans within Ukraine is currently expanding. The studied species in many localities forms large and stable populations, often occupying large areas (over 1 ha) with numerous individuals and projective cover of up to 100% (completely covering the water surface). Due to the active expansion of S. natans throughout Ukraine, the presence of numerous stable populations and over-reproduction of this fern in many regions, it is proposed to exclude (delist) this species from the Red Data Book of Ukraine. However, the need to protect individual natural habitats of the species in the territories included in the Emerald Network and/or in protected areas of the nature reserve fund is emphasized. Populations of S. natans should also be protected at the regional level in geographic regions where the species is infrequent and does not show the expansion trend. In other regions where this fern is excessively abundant, biomass extraction and utilization measures should be developed and implemented.

Abstract Background Insecticide-treated nets (ITNs) are one of the most cost-effective measures for preventing malaria. The World Health Organization recommends both large-scale mass distribution campaigns and continuous distributions (CD) as part of a multifaceted strategy to achieve and sustain universal access to ITNs. A combination of these strategies has been effective for scaling up ITN access. For policy makers to make informed decisions on how to efficiently implement CD or combined strategies, information on the costs and cost-effectiveness of these delivery systems is necessary, but relatively few published studies of the cost continuous distribution systems exist. Methods To address the gap in continuous distribution cost data, four types of delivery systems—CD through antenatal care services (ANC) and the expanded programme on immunization (EPI) (Ghana, Mali, and mainland Tanzania), CD through schools (Ghana and mainland Tanzania), and a combined community/health facility-based distribution (Zanzibar, Tanzania), as well as mass distributions (Mali)—were costed. Data on costs were collected retrospectively from financial and operational records, stakeholder interviews, and resource use surveys. Results Overall, from a full provider perspective, mass distributions and continuous systems delivered ITNs at overlapping economic costs per net distributed (mass distributions: 4.37–4.61 USD, CD channels: 3.56–9.90 USD), with two of the school-based systems and the mass distributions at the lower end of this range. From the perspective of international donors, the costs of the CD systems were, for the most part, less costly than the mass distributions (mass distributions: 4.34–4.55 USD, Ghana and Tanzania 2017 school-based: 3.30–3.69 USD, health facility-based: 3.90–4.55 USD, combined community/health facility 4.55 USD). The 2015 school-based distribution (7.30 USD) and 2016 health facility-based distribution (6.52 USD) programmes in Tanzania were an exception. Mass distributions were more heavily financed by donors, while CD relied more extensively on domestic resource contributions. Conclusions These results suggest that CD strategies can continue to deliver nets at a comparable cost to mass distributions, especially from the perspective of the donor.