Greater Radius Research Articles

Calculation of Some Crude Oil Flow Parameters in A Cylindrical Tube and Their Modelization in Small and Great Variable Radius

In this work, we establish the kinematic of flowing of crude oil inside a cylindrical tube which is rare in the literature. From velocity expression, we find kinematic. Pressure, temperature and heat distribution of crude oil flowing are also find from equations in the literature. Silmilation of these expressions shows that Kinematic of crude oil is similar to a flow of a fluide with a small viscosity what is true in the reality. Velocity of crude oil is not similar in any points during the flowing but increasing and decreasing according to the position point and seams like to be more fast in the border than in the center with a small radius and more fast in the center than in the border with a great radius. Temperature of the crude oil is not similar in any points during the flowing. It is more elevated in the the border than in the center. Pressure in small radius is more important in the center than in the border contrarily in great radius. results are more conformable in the reality in small than in great radius. Results of the heat is more conformable in the reality in small than in great radius.

Cation-Induced Interfacial Hydrophobic Microenvironment Promotes the C-C Coupling in Electrochemical CO2 Reduction.

The electrochemical carbon dioxide reduction reaction (CO2RR) toward C2 products is a promising way for the clean energy economy. Modulating the structure of the electric double layer (EDL), especially the interfacial water and cation type, is a useful strategy to promote C-C coupling, but atomic understanding lags far behind the experimental observations. Herein, we investigate the combined effect of interfacial water and alkali metal cations on the C-C coupling at the Cu(100) electrode/electrolyte interface using ab initio molecular dynamics (AIMD) simulations with a constrained MD and slow-growth approach. We observe a linear correlation between the water-adsorbate stabilization effect, which manifests as hydrogen bonds, and the corresponding alleviation in the C-C coupling free energy. The role of a larger cation, compared to a smaller cation (e.g., K+ vs Li+), lies in its ability to approach the interface through desolvation and coordinates with the *CO+*CO moiety, partially substituting the hydrogen-bonding stabilizing effect of interfacial water. Although this only results in a marginal reduction of the energy barrier for C-C coupling, it creates a local hydrophobic environment with a scarcity of hydrogen bonds owing to its great ionic radius, impeding the hydrogen of surrounding interfacial water to approach the oxygen of the adsorbed *CO. This skillfully circumvents the further hydrogenation of *CO toward the C1 pathway, serving as the predominant factor through which a larger cation facilitates C-C coupling. This study unveils a comprehensive atomic mechanism of the cation-water-adsorbate interactions that can facilitate the further optimization of the electrolyte and EDL for efficient C-C coupling in CO2RR.

Anatase-Rutile phase transition of Ca@TiO2 nanostructures for the removal of environmental pollutants under visible photon illumination

Regulating the crystalline structure of titanium dioxide is essential granting the potential purposes for oxide. In the present investigation, we employed X-ray diffraction to investigate the significance of calcium doping on the anatase–rutile transition of phase. Preparation of Calcium-doped TiO2 by sonochemical approach, followed by sintering at 700 °C temperatureencompasses a phase transition. The inclusion of calcium into the TiO2 lattice was hampered by the calcium ion's greater radius when contrasted to the titanium ion. Ca@TiO2 nanostructures exhibited a reduced estimated band gap energy compared to pristine TiO2. The Ca2+ substitutesinto the TiO2 surface were demonstrated by the Fourier transform infrared (FT-IR) spectral investigation. By conducting photocatalytic decomposition of persisting Congo red (CR) dye during visible photonradiation exposure, the photocatalytic effectiveness of the produced Ca@TiO2 nanostructures was examined. Ca@TiO2 nanostructures have been discovered to have more catalytic capability than pristine TiO2 nanoparticles. In 4 h of exposure duration with the Ca@TiO2 nanostructures, the maximal degradation of the CR dye, or 88 %, was accomplished with efficient regeneration.

Transit and radial velocity method for exoplanet detection

This article introduces some basic methods that human usually uses nowadays to detect exoplanets, including transits method, radial velocity method, direct imaging method, gravitational microlensing method, and astrometry method. As we all know, none of these methods are perfect, each of them has its advantages: some of them are good at detecting planets with great mass, some are good at detecting planets with great radius, and some of the methods are good at detecting planets far away from their host star. But at the same time, each method has its own disadvantages. That is the reason why sometimes some of these methods are used together to get information about specific exoplanets. This chapter will introduce these methods by giving information on how these methods work, the equipment each of them requires, the advantages and limitations of these methods, and the history and development of these methods. Finally, there is a conclusion that states the characteristics of the planets each method is good at detecting.

Public access defibrillation: challenges and new solutions.

The purpose of this article is to review the current status of public access defibrillation and the various utility modalities of early defibrillation. Defibrillation with on-site automated external defibrillators (AEDs) has been the conventional approach for public access defibrillation. This strategy is highly effective in cardiac arrests occurring in close proximity to on-site AEDs; however, only a few cardiac arrests will be covered by this strategy. During the last decades, additional strategies for public access defibrillation have developed, including volunteer responder programmes and drone assisted AED-delivery. These programs have increased chances of early defibrillation within a greater radius, which remains an important factor for survival after out-of-hospital cardiac arrest. Recent advances in the use of public access defibrillation show great potential for optimizing early defibrillation. With new technological solutions, AEDs can be transported to the cardiac arrest location reaching OHCAs in both public and private locations. Furthermore, new technological innovations could potentially identify and automatically alert the emergency medical services in nonwitnessed OHCA previously left untreated.

Effect of Single Atom Doping on Structural, Electronic and Magnetic Properties of Hexagonal Silicon Carbide (4H-SiC) for Spintronic Application: A first principle study

In this paper, the structural geometry, electronic and magnetic properties of single magnesium (Mg) and vanadium (V) atoms doped 4H-SiC system were investigated. For the structural geometry of each sample, the energy substitution, as well as bond length, were calculated; results obtained indicate that the bond length of Silicon-Magnesium (Si-Mg) and SiliconVanadium (Si-V) was 1.90 Å and 2.02 Å respectively, greater than that of silicon-carbon (SiC) 1.89 Å in pure SiC. This result indicates that the bond length increases due to the introduction of dopants with greater radii than that of Si. It also shows that both Mg and V doping change the structure from non-magnetic ordering to magnetic in nature. The band structure result for both undoped and doped shows the presence of valence band maximum (VBM) and conduction band minimum (CBM) around different symmetry points which indicate an indirect band gap nature. The calculated band gap of pure 4H SiC is found to be ~2.21 eV, which is at a wide band gap material range, but with the introduction of Mg and V dopants, the band gap reduced significantly to ~0.4 eV and ~0.45 eV respectively. The density of state (DOS) and projected density of state (PDOS) show the contributions of the various states in both the VBM and CBM; after doping the Fermi energy is shifted towards higher energy and enters into the conduction band, exhibiting spin polarization. Both DOS and PDOS indicated that the magnetic moments mainly come from the 2p orbitals of Si atoms and 3p for Mg dopant and 3d orbitals for V dopant. The magnetic moment for 4H-SiC/Mg and 4H-SiC/V was calculated to be 2.23 μB and 3.24 μB.

Simulation of positive streamer discharges in transformer oil

To reveal the impact of formation and development of the streamer discharge on the dielectric liquid formed between pin-plate electrodes, a numerical model of transformer oil discharge in the electrode system is built which is based on the continuity equations coupled with Poisson’s equation. The influence of applied impulse voltage parameters such as rise time and voltage magnitude on the formation and development of the streamer discharge is evaluated in this model. In addition, the characteristic of the streamer discharge such as streamer velocity, electric field, and radius of streamer head have been investigated. Modeling results reveal that the higher impulse voltage amplitude form streamer discharges with longer paths, thicker columns, higher velocity, and greater radius. In addition, we find that the radius of the streamer head is greatly affected by the percentage of the predetermined electric field tube at the head, and slightly affected when streamer length increased. Modeling results also showed that the rise times had a clear effect on the radius streamer discharge and the distribution of electric fields.

Schistosome infection in Senegal is associated with different spatial extents of risk and ecological drivers for Schistosoma haematobium and S. mansoni.

Schistosome parasites infect more than 200 million people annually, mostly in sub-Saharan Africa, where people may be co-infected with more than one species of the parasite. Infection risk for any single species is determined, in part, by the distribution of its obligate intermediate host snail. As the World Health Organization reprioritizes snail control to reduce the global burden of schistosomiasis, there is renewed importance in knowing when and where to target those efforts, which could vary by schistosome species. This study estimates factors associated with schistosomiasis risk in 16 villages located in the Senegal River Basin, a region hyperendemic for Schistosoma haematobium and S. mansoni. We first analyzed the spatial distributions of the two schistosomes’ intermediate host snails (Bulinus spp. and Biomphalaria pfeifferi, respectively) at village water access sites. Then, we separately evaluated the relationships between human S. haematobium and S. mansoni infections and (i) the area of remotely-sensed snail habitat across spatial extents ranging from 1 to 120 m from shorelines, and (ii) water access site size and shape characteristics. We compared the influence of snail habitat across spatial extents because, while snail sampling is traditionally done near shorelines, we hypothesized that snails further from shore also contribute to infection risk. We found that, controlling for demographic variables, human risk for S. haematobium infection was positively correlated with snail habitat when snail habitat was measured over a much greater radius from shore (45 m to 120 m) than usual. S. haematobium risk was also associated with large, open water access sites. However, S. mansoni infection risk was associated with small, sheltered water access sites, and was not positively correlated with snail habitat at any spatial sampling radius. Our findings highlight the need to consider different ecological and environmental factors driving the transmission of each schistosome species in co-endemic landscapes.

Enabling the Application of Large Footprint Open‐Bottom Permeameters Through New Shape Factors

AbstractOpen‐bottom permeameters (OBP) are commonly used for estimating the hydraulic properties of sediment beds under water bodies and fluxes across the sediment‐water interface. The specific shape factor for an OBP flow situation is necessary for data interpretation. It is determined by the ratio of the permeameter tube radius to the tube's penetration depth within the sediment. Previous permeameter designs favored small radii which allowed for deeper penetration and stability of the tube. The shape factor is provided here for large footprint OBPs that allows for shallow penetration and greater radius. Through a numerical and analytical modeling study of the OBP hydrodynamics, previous knowledge on the OBP shape factor is generalized to the entire range of radius‐to‐penetration ratios that might be practically applied. The results reveal the advantages of the large footprint design, including better sensitivity due to the ability to impose larger discharge over a shorter test duration.

PSV-14 Influence of monsoon rainfall events on movement patterns of Angus crossbred vs. Raramuri Criollo cattle on desert rangeland

Abstract The Chihuahuan Desert averages 247 mm of precipitation annually, 53% of which occurs between July and September. Our objective was to examine movement, activity, pasture use, and watering patterns of Angus x Hereford (AH) and Raramuri Criollo (RC) cows on days with precipitation events (PE, ≥ 1.3 mm rain recorded) vs. days with no precipitation (NP) at the Jornada Experimental Range in southern New Mexico during the summers of 2015, 2016, and 2017. Breeds grazed two adjacent pastures (12A = 1190 ha; 12C = 1165 ha) separately in a crossover design for 4 weeks each year. Seven to nine randomly selected cows per breed were collared with Lotek 3300-LR GPS set to log position every 10 min. An average of 7.6 PE occurred during the 4-week trials each year. On PE days, cows traveled farther (PE = 6.95 vs. NP = 6.43 km, P < 0.01), spent more time grazing (PE = 9.07 vs. NP = 8.76 h/day, P = 0.07) and less time resting (PE = 13.90 vs. NP = 14.38 h/day, P = 0.01), and traveled similar distances from watering points (PE = 0.84 vs. NP = 0.80 km, P = 0.41) compared to NP days. On PE days, cows spent less time within 200 m (PE = 1.32 vs. NP = 2.95 h, P < 0.01) and 100 m (PE = 0.79 vs. NP = 1.90 h, P < 0.01) of drinkers regardless of breed. We detected no rainfall x breed interaction (P > 0.05). Overall, RC cows traveled farther, at higher velocities, spent more time grazing, less time resting, and explored areas with greater radius than AH counterparts (P < 0.05). Precipitation appeared to relax environmental constraints on activity of both breeds, likely due to availability of ephemeral watering sources and a transient drop in temperature.

Note on the mass\u2013radius relations for spherical compact objects in general relativity with semi-classical corrections

We consider the effects that modifications to general relativity (GR) at high densities may have on the structure of spherical compact objects. Such effects can be modeled via semi-classical corrections that are manifest in an additional effective (i.e. non-physical) term in the energy momentum tensor. In particular, we consider two kinds of effective corrections that are quadratic in the density: one inspired by loop quantum gravity (LQG) and one inspired by Einstein–Cartan Theory (ECT). For both corrections, we consider two standard toy models of compact objects, one with polytropic equation of state and the other described by the MIT-bag model. We show that the LQG-inspired corrections can produce objects with greater radius and total mass, while the ECT-inspired corrections produce objects that are smaller and less massive than their counterparts in GR.

Tribological characterization of Nb ion implanted WC-5wt%Ni cold sprayed coatings in dry sliding contact

Niobium ions were implanted into WC-5wt%Ni cold sprayed coatings at an acceleration voltage of 60 keV. The ion dosages were varied as 2 × 1016, 5 × 1016, and 8 × 1016 ions cm−2, and the resulting influence on surface, friction, wear, and stress properties of the Nb-implanted layers, in comparison to the non-ion implanted coating, was investigated. Dry sliding wear behaviour was assessed using a ball-on-disk tribometer, with 100Cr6 stainless steel balls as the counterface, at a sliding velocity of 0.05 ms−1 and an applied load of 1 N. The Nb ion dosage of 8 × 1016 ions cm−2 produced the best coating surface properties, achieving a high hardness (14.58 GPa), low plasticity index (53.83), low wear rate (35.7 × 10−12 m2 N−1), low wear coefficient (0.52), high shear strength (891 MPa) and a high local maximum von Mises yield strength (1546 MPa). This coating also produced a low Rq roughness value (10.22 nm), great mean radius of asperities (35.88 × 10−2 nm), and a high reciprocal value of the comprehensive roughness fraction (4.77 × 10−3). The wear mechanisms of all the coatings were found to be similar, showing oxidation, scratching, ploughing, smearing, material transfer, and tribo-layer formation.

Observed Kinematic and Thermodynamic Structure in the Hurricane Boundary Layer during Intensity Change

Abstract The axisymmetric structure of the inner-core hurricane boundary layer (BL) during intensification [IN; intensity tendency ≥20 kt (24 h)−1, where 1 kt ≈ 0.5144 m s−1], weakening [WE; intensity tendency <−10 kt (24 h)−1], and steady-state [SS; the remainder] periods are analyzed using composites of GPS dropwindsondes from reconnaissance missions between 1998 and 2015. A total of 3091 dropsondes were composited for analysis below 2.5-km elevation—1086 during IN, 1042 during WE, and 963 during SS. In nonintensifying hurricanes, the low-level tangential wind is greater outside the radius of maximum wind (RMW) than for intensifying hurricanes, implying higher inertial stability (I2) at those radii for nonintensifying hurricanes. Differences in tangential wind structure (and I2) between the groups also imply differences in secondary circulation. The IN radial inflow layer is of nearly equal or greater thickness than nonintensifying groups, and all groups show an inflow maximum just outside the RMW. Nonintensifying hurricanes have stronger inflow outside the eyewall region, likely associated with frictionally forced ascent out of the BL and enhanced subsidence into the BL at radii outside the RMW. Equivalent potential temperatures (θe) and conditional stability are highest inside the RMW of nonintensifying storms, which is potentially related to TC intensity. At greater radii, inflow layer θe is lowest in WE hurricanes, suggesting greater subsidence or more convective downdrafts at those radii compared to IN and SS hurricanes. Comparisons of prior observational and theoretical studies are highlighted, especially those relating BL structure to large-scale vortex structure, convection, and intensity.

Living under intertidal mussels: distribution, reproduction, and condition indices in a brooding sea star, Anasterias minuta, in Patagonia, Argentina

Anasterias minuta is an abundant brooding sea star inhabiting tidepool habitats and mussel beds of Perumytilus purpuratus in Patagonia, Argentina. This study explores the influence of mussel bed complexity and tidal height on the size distribution of A. minuta living under mussel beds, and compares the abundance, reproduction, and condition indices in contrasting intertidal microhabitats (mussel hummocks and tidepools). Distribution patterns in mussel beds were explored at four sites along the coast of Argentina (45.4°S–47.4°S) during the austral spring, 2012/2017. Microhabitat comparisons were done at Caleta Cordova Norte between May 2004 and June 2005. Abundance inside mussel beds was correlated positively with mussel bed thickness and presence of mussel hummocks, and negatively with tidal height. Within mussel beds, early juveniles (recruits) and juveniles (greatest radius R < 15 mm) were generally restricted to low-tidal heights, while adults (R ≥ 15 mm) extended to mid-tidal levels. Sea stars were more abundant and larger in tidepools than under mussel beds. Numbers of recruits and juveniles increased significantly under mussel hummocks during austral spring and summer, coinciding with the release and subsequent growth of early juveniles. Brooding and gonadal cycles were synchronized between the microhabitats; however, the brooding cycle was nearly 2 months shorter under mussel hummocks (April–August) than in tidepools (April–October). The sea stars under mussels were smaller, had a less developed body wall, and greater gonadal production, indicating that more energy was allocated to reproduction compared to sea stars of similar size from tidepools. Further studies are needed to identify the specific environmental conditions that led to the observed adaptations and to understand the underlying physiological mechanisms.

Salt effects on the dilute solution properties of bototo gum (Cochlospermum vitifolium)

&lt;p&gt;&lt;span style="line-height: 113%; font-family: 'Times New Roman',serif; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 14.0pt; mso-contextual-alternates: yes; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"&gt;Salt effects on the dilute solution properties of bototo gum (&lt;em&gt;Cochlospermum vitifolium&lt;/em&gt;) were investigated. There were measured the intrinsic viscosities of the polymer under study in water, in NaCl (at different concentrations) and in NaCl, CaCl&lt;sub&gt;2&lt;/sub&gt; and AlCl&lt;sub&gt;3&lt;/sub&gt;, at the same ionic strength (I = 1), using an Ubbelohde viscometer at 25°C. The Huggins intersection model (R&lt;sup&gt;2&lt;/sup&gt;) is more appropriate to determine the intrinsic viscosity than the Kraemer's equation. This parameter tends to reduce with the increase in the salt concentration and the cation charge. The molecules of &lt;em&gt;C. vitifolium&lt;/em&gt; gum exudate in water (solvent Φ) tend to adopt a “random coil” conformation, of great volume and radius, which exist in two regimes: diluted and semi-diluted; in the presence of salts, the coils exist only in a diluted regime where they are separate each other. The macromolecules in water have probably an extended ellipsoid shape but in presence of salts, they change to another more compact, probably spherical, with radii and smaller volumes. The knowledge of the behavior of &lt;em&gt;C. vitifolium&lt;/em&gt; gum molecules in dilute solutions is an important criterion for its rational use in various industries&lt;/span&gt;&lt;/p&gt;

Euler’s inequality in absolute geometry

Two results are proved synthetically in Hilbert’s absolute geometry: (i) of all triangles inscribed in a circle, the equilateral one has the greatest area; (ii) of all triangles inscribed in a circle, the equilateral one has the greatest radius of the inscribed circle (which amounts, in the Euclidean case, to Euler’s inequality $$R\ge 2r$$ ).

Application of the Continuous and Discontinuous Fields of Plastic Deformations to the Evaluation of the Initial Thickness of Bent Tubes

The paper presents the derived equations for calculations of the initial wall thickness g0 of a tube bent to elbow. The expressions for calculating g0 are presented in a suitable measure of the “great active actual radius Rj” in the bending zone for an exact-generalized solution (continuous fields) and for three formal simplifications (discontinuous fields) of the first-, second-, and third-orders. The expressions to calculate the components of deformation for a generalized solution (continuous fields) are obtained on the basis of kinematically admissible fields of plastic deformations. In any case, a value of initial tube thickness depends on the radius and on the angle of bending αb on the external diameter of the tube, on the displacement of the neutral axis, and on the allowable (required) elbow thickness according to European, American, or other national technical standard or regulations. The initial thickness also depends on the coordinates of the point where the allowable thickness was determined and on the technological–material coefficient of the bending zone range k (defined during the tests). The obtained calculation results are presented in the form of graphs and in table.

Assessing exposure to unconventional gas development and its association with preterm birth in the Barnett Shale, Texas.

Introduction: The present study explores the association between proximity to unconventional gas development (UGD) using varying buffers, and preterm birth among women in the Barnett Shale area, Texas. Methods: This is a retrospective birth cohort study of women living in the Barnett Shale with a birth from Nov 30, 2010-Nov 29, 2012. Information on UGD wells in the completion or production phase from Jan 1, 2010-Nov 29, 2012 were obtained. Gestation and trimester-specific proximity-based exposures were calculated as the inverse distance-weighted count of wells within a specified radius of the maternal address. We considered several radii to define exposure. Metrics consisted of four categories: unexposed women as the referent and the remaining categories represented tertiles among the exposed. Adjusted logistic regression was used to examine associations with preterm birth. Results: A total of 161,126 births and 13,647 UGD wells were included. Approximately 15%, 44% and 68% of women were exposed to ≥1 well within a 0.5, 2 or 10mi radius, respectively. The median number of wells to which women were exposed was similar across trimesters and drilling phase for the 0.5 mi radius but distributions varied by each factor when considering greater radii. We found an association with UGD for the 10mi metric only, with marginally increased odds among women classified in the 2nd and 3rd exposure tertiles for producing wells, compared to unexposed women (OR=1.11; 95% CI=1.06-1.17 and OR=1.05; 95% CI=1.00-1.10, respectively). The results for wells in the completion phase were equivocal. Conclusions: Although we found increased odds of preterm birth associated with UGD within 10mi of the maternal residence, no association was observed at smaller, perhaps more relevant, distances. These data demonstrate the need for more refined exposure assessment to better elucidate risk related to community UGD exposure.

Analysis of pre-hospital emergency resources allocation in Liaoning province

Objective To learn the present pre-hospital emergency resources allocation in Liaoning province. Methods Site survey and questionnaire survey were used to survey the basic information, number of pre-hospital emergency ambulances, human resources, and communication/control systems of 19 pre-hospital emergency centers in Liaoning province in 2014. Results The number of pre-hospital emergency sub-stations, ambulances and human resource fall short of demand.Furthermore, these resources are found with such problems as greater service radius of average pre-hospital emergency service and longer average pre-hospital response time in countryside than cities, insufficient and obsolete ambulances short of onboard equipment and communication systems, not to mention shortage of medical workers of higher degrees and academic titles. Conclusions A great gap is found between urban and rural pre-hospital emergency resource allocation in Liaoning province, with poor resources in the countryside.The government is recommended to step up financial support in increasing pre-hospital emergency substations and resources allocation, regularly update pre-hospital emergency vehicles, set up independent title promotion mechanism, perfect communication scheduling system, in order to satisfy the demands of pre-hospital first aid. Key words: Liaoning province; Pre-hospital emergency; Resources allocation; Aid effectiveness

Theoretical Study of a Diesel‐Filled Airtight Structure Unit Subjected to Shaped Charge Jet Impact

AbstractDiesel composite armor has high penetration resistance and can be used in tank vehicles to improve their protective capability and increase fuel oil storage. This study provides a theoretical calculation method to investigate the interaction between a shaped charge jet and a diesel‐filled airtight structure unit. Disturbance theory can predict the part of the jet that is disturbed by diesel fuel. The lumen radius for the container was varied to study its influence on the disturbance capability. A great lumen radius is found to cause lower maximum and minimum speeds of the disturbance velocity range of the jet, as well as a narrower disturbance velocity range. The reliability of the theoretical results was validated by experiments, and the experimental data show good agreement with the theoretical results.