Rise In Density Research Articles

Interfacial Stabilization by Prelithiated Trithiocyanuric Acid as an Organic Additive in Sulfide-Based All-Solid-State Lithium Metal Batteries.

Sulfide-based all-solid-state battery (ASSB) with a lithium metal anode (LMA) is a promising candidate to surpass conventional Li-ion batteries owing to their inherent safety against fire hazards and potential to achieve a higher energy density. However, the narrow electrochemical stability window and chemical reactivity of the sulfide solid electrolyte towards the LMA results in interfacial degradation and poor electrochemical performance. In this direction, we introduce an organic additive approach, that is the mixing of prelithiated trithiocyanuric acid, Li3TCA, with Li6PS5Cl, to establish a stable interface while preserving high ionic conductivity. Including 2.5 wt % Li3TCA alleviates the decomposition of the electrolyte on the lithium metal interface, decreasing the Li2S content in the solid-electrolyte interface (SEI) thus forming a more stable interface. In Li|Li symmetric cells, this strategy enables a rise in the critical current density from 1.0 to 1.9 mA cm-2 and stable cycling for over 750 hours at a high current density of 1.0 mA cm-2. This approach also enables Li|NbO-NCM811 full cell to operate more than 500 cycles at 0.3 C.

Governing green change to improve resilience by assessing urban risks for localizing nature based solutions in fast sprawling Dehradun, India

Considering the increasing disaster risks, vulnerability and reduced resilience across Himalayas due to urban sprawling, our study attempts to understand the crucial environmental concerns in the valley town of Dehradun. We assessed the long-term risks due to the rise in population density, changing land use patterns, land surface temperature, groundwater shortage, air pollution concerns, vegetation loss and concretization using remote sensing tools. Results reveal the deleterious impact of urban sprawling affecting different wards of the city, with the burgeoning population pressure in the central part of the city (200 people per hectare (pph)) while, peripheral areas have lesser pressure (4 pph) but projected to rise. Loss of vegetation for development across the city has resulted in insufficient and unequal distribution of green spaces. The builtup area increased from 23.63 to 59.78 % after the city became the state capital has led to the increased heat islands and surface temperature (21.23–25.53 °C). Depleting groundwater levels in erstwhile water sufficient wards of Raipur (01), Shastradhara (02) and Adhoiwala N (28) is alarming. Increasing air pollutants (P.M.10, SO2 and NO2) and the risk of urban floods are severe for 10 wards. Dehradun city seems to be at tipping point about to cross its bearing capacity, any additional pressure may have serious repercussions for city residents. City municipal corporation along with diverse stakeholder groups need to mainstream Nature based Solutions, designing and implementing ward specific customized solutions for addressing societal challenges according to Sendai Framework for Disaster Risk Reduction and the UN SDG 11.

Nanostructuring and Hardness Evolution in a Medium‐Mn Steel Processed by High‐Pressure Torsion Technique

Severe plastic deformation (SPD) is performed on a newly developed medium‐Mn steel with the composition of Fe–7.66Mn–2Ni–1Si–0.23C–0.05Nb (wt%) to achieve a nanocrystalline microstructure. The SPD process utilizes the high‐pressure torsion (HPT) technique, resulting in a nominal shear strain of approximately 36 000% after processing the disk for 10 turns. In X‐Ray diffraction line profile analysis, an increase in dislocation density to around 230 × 1014 m−2 is observed. In addition, under high strains, a face‐centered cubic (fcc) secondary phase emerges within the body‐centered cubic (bcc) matrix. In analytical transmission electron microscopy, using energy‐dispersive X‐Ray spectroscopy, it is indicated that the secondary‐phase particles are enriched in Al, Mn, and Si. As the strain imposed during HPT increases, the simultaneous rise in dislocation density and nanostructuring lead to material hardening. However, the partial phase transformation from bcc to fcc contributes to material softening. As a result of these two opposite effects, the hardness exhibits a non‐monotonic variation with the shear strain, displaying, for 10 turns of HPT, a lower hardness compared to fewer turns, despite the continuous increase in dislocation density and decrease in crystallite size.

Turbulence-reduced high-performance scenarios in Wendelstein 7-X

In the Wendelstein 7-X (W7-X) stellarator, turbulence is the dominant transport mechanism in most discharges. This leads to a ‘clamping’ of ion temperature over a wide range of heating power, predominantly flat density profiles where hollow profiles driven by neoclassical thermo-diffusion would be expected and by rapid impurity transport in injection experiments. Significantly reduced turbulent transport is observed in the presence of strong core density gradients found transiently after core pellet injection and irregularly after boronisation or boron pellet injection. Density peaking is also achieved in a controlled manner in purely neutral beam heated discharges where particle transport analysis reveals an abrupt reduction in the main-ion particle flux leading to significant density profile peaking not explained by the NBI particle source alone. The plasmas exhibit a heat diffusivity of around χ=0.25±0.1m2 s−1 at mid radius, a factor of around 4 lower than ECRH dominated discharges. Despite the improved confinement, the achieved ion temperature is limited by broader heat deposition and the lower power-per-particle given the higher density. This is overcome with limited reintroduction of ECRH power, where the low heat diffusivity diffusivity is maintained, the density rise supressed and ion temperatures above the clamping limit are achieved. The applicability of these plasmas for a high performance scenario on transport relevant time scales is assessed, including initial predictions for planned heating upgrades of W7-X, based on a range of assumptions about particle transport.

Exploring the spatial trade-off effects of green space on older people’s physical inactivity: Evidence from Shanghai

Given that green space patterns and population density often show opposing trends over space, this could lead to trade-off (distance/population decay) relationships. Consequently, this paper utilized the Study on Global Ageing and Adult Health (SAGE) data from Shanghai, China, to investigate whether there is a spatial trade-off in the health effects of green spaces on people’s inactivity. Our findings confirmed the trade-off effects of green spaces in reducing sedentary time, using interaction terms to highlight how the health impacts of green spaces vary across different population densities and may thus lead to inconsistent relationships between green space and health outcomes. Generally, the ability of green spaces to affect sedentary time decreased as population density increases, particularly regarding park proximity and the Normalized Difference Vegetation Index (NDVI). Our research also revealed that the trade-off in health benefits from green spaces was influenced by the type of green space. For instance, park proximity, park area, and NDVI showed trade-off effects, with higher population densities enhancing the impact of NDVI on increasing sedentary time (β = 133.871), despite NDVI itself decreasing with a rise in population density (r = -0.68). Conversely, the Green Vegetation Index (GVI) did not demonstrate such an effect. The unequal spatial distribution and composition of green space may further exacerbate health inequities. Therefore, this paper recommends that future provisioning of green spaces should take into account the local urban spatial structure.

Numerical design of non-toxic high-efficiency tandem solar cell with distinct hole transport materials

The metal-halide perovskite is at the forefront of photovoltaic research and has the potential to combine low manufacturing costs with excellent power conversion efficiency. In this study, a solar cell capacitance simulator was used to analyze the performance of a tandem solar cell in which MASnI3 was used as the lower cell active layer, and NaZn0.7Cu0.3Br3 was used as the upper cell active layer. The primary objective of this research is to search for a device structure with enhanced efficiency. Here, it is evaluated how absorber thickness, temperature, hole transport layer, defect density, and metal work function affect solar cell performance to reach this aim. After looking at the data for several different solar cell configurations, it is seen that indium tin oxide (ITO) / titanium dioxide (TiO2)/sodium zinc copper bromide (NaZn0.7Cu0.3Br3)/ methylammonium tin iodide (MASnI3) / copper oxide (CuO)/gold (Au) offers the best efficiency at 32.58 %, fill factor at 82.19 %, short circuit current density at 34.8389 mA/cm2, and open circuit voltage at 1.1375 Vs. Device simulations showed an optimal MASnI3 absorber thickness of about 1 µm. Finally, the simulation results reveal that the device's efficiency declines when the absorber's defect density and cell operation temperature rise. The device topologies are stable at around 300 Kelvin. Last but not least, any conductive material can be used as an anode if it has a work function that is more than or roughly equivalent to 5.10 eV.

Assessment of Physico-Chemical Properties of Soil from Different Blocks of Eluru District, Andhra Pradesh, India

The experiment was conducted in 2023 to assess the physical and chemical properties of different blocks of Eluru district, Andhra Pradesh. Three distinct villages were chosen from each block for the study. The physical properties of Eluru district soils, soil colour, texture, bulk density(mg m-3), particle density (mg m-3), percent pore space and percent water retaining capacity and chemical properties pH, EC (dSm-1 ) at 25˚C, percent organic carbon, available nitrogen, phosphorus and potassium (kg ha-1), calcium C mol (p+) kg-1 and magnesium C mol(p+) kg at 0-15, 15-30 and 30-45 cm depth. Findings showed that in terms of depth, there was a minor rise in both bulk and particle density. The water retaining capacity of the soil and the overall physical condition of the soil was found good and supportive for plant growth. The soils of selected villages of different blocks in Eluru district were found to acidic to basic in nature due to soil minerals producing sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) upon weathering. The organic carbon, nitrogen and phosphorus were observed as medium to high. The potassium content was low in all locations. There was enough calcium present, however there were several regions where magnesium was lacking. The deficiency of the nutrients can be mitigated by the use of organic and inorganic fertilizers.

Enhancing plasma discharge dynamics through analysis of secondary electron emission: A numerical modeling approach for improved thin film deposition

This research examines the impact of the coefficient of secondary electron emission (SEE) on various discharge features of plasma to improve the performance of deposited thin films. Unlike previous studies, we employed two-dimensional numerical modeling (2D) of an ICP reactor at a radiofrequency of 13.56 MHz and a low pressure of 1 Torr, using a finite element approach. This detailed investigation into parameters such as ionization rate, electric field, electron temperature, and electron density provides new insights into plasma interactions. Our findings reveal a significant correlation between the SEE coefficient and key plasma attributes. Notably, increased secondary electrons lead to a substantial rise in electron density and a reduction in sheath thickness, indicating an impactful change in the spatial distribution of plasma particles. Additionally, electron temperature increases exclusively in sheath regions, a novel observation not reported in earlier studies. Furthermore, higher SEE coefficients correlate with increased ionization rates within each sheath, suggesting a crucial role in maintaining discharge processes. This comprehensive analysis uncovers complex interdependencies within the plasma discharge system, offering valuable advancements for thin film deposition techniques.

Enhanced tribological performance of TiO2-hBN/CNT double-layer coating by CNT-assisted plasma electrolytic oxidation with nanoparticles addition

Hexagonal boron nitride (h-BN) is considered a very promising anti-friction material, however, how to assemble them densely and uniformly on metal surfaces remains a challenge. In this study, CNT-assisted plasma electrolytic oxidation (PEO) with the addition of h-BN nanoparticles was employed to create a double-layer coating on titanium alloy, demonstrating exceptional tribological characteristics. The CNTs not only acted as lubricating phases to improve the anti-friction performance but also as additives to facilitate the transition from the nanocomposite coating to the double-layer coating. The later stage of the PEO process with CNT doped in the electrolyte produces an interesting sudden rise in current density, which generates strong and dense discharge that facilitates the deposition and sintering of h-BN. As a result, the double-layer coating has a higher adhesion and hardness as well as more h-BN nanoparticles incorporated into the coating compared to coatings without CNTs-assisted deposition. Further, the double-layer coating exhibits a lower friction coefficient (∼ 0.11), attributed to the high release rate of h-BN under shear to form a lubrication film in conjunction with CNTs on the contact surface. The simple technique offers a novel approach to fabricating self-lubricating ceramic coatings on light alloys, which has huge potential for application in the anti-friction materials field.

Impact of incoming turbulence intensity and turbine spacing on output power density: A study with two 5MW offshore wind turbines

Turbulence intensity in offshore environments has significant effects on the performance of offshore wind turbines. To maximize output power of offshore wind turbines within a limited space, i.e., achieving maximum output power density, it is essential to investigate the influences of incoming turbulence intensity and turbine spacing on output power density. The Large Eddy Simulation coupled Actuator Line Method (LES-ALM) is used in this study to simulate two utility-scale NREL-5 MW wind turbines in different turbulent environments and turbine spacings. The optimal incoming turbulence intensity and turbine spacing are identified using an active learning method. The determined optimal parameters act as a benchmark for the impact analysis. The findings indicate that the increase of turbine spacing initially results in a considerable rise in the output power density of the two NREL-5 MW wind turbines, followed by a slight downward trend across various turbulent environments. The increase of the incoming turbulence leads to a steady rise of the output power density when the turbine spacing is less than 5.1D (D is the rotor diameter), while a rise followed by a decrease in the output power density is observed for the turbine spacing exceeding 5.1D. Notably, when the turbine spacing is 5.9D and the reference value of turbulence intensity is 15.2%, the output power density reaches its global maximum.

Physical and Thermoelectric Properties of Ternary Semiconducting NiO–V2O5–TeO2 Glasses

Five samples of ternary semiconducting 65V2O5 –xNiO–(35–x) TeO2 glasses, with 5 ≤ x ≤ 25 (x in mol%), were prepared using a press-quenching method from a glass melt. The thermoelectric Power (TEP), density, oxygen molar volume (Vm) and x-ray diffraction (XRD) were analyzed. TEP measurements were conducted within the temperature range of 300 – 506 K for the mentioned glass compositions. Information on the creation of polarons and the disorder energy arising from random fields was gathered. By applying Heikes’ equation and the small polaron model theory to the TEP, the results obtained from experimental data were effectively explained. The study revealed that an increase in the NiO content in the glass led to a rise in density and a consistent decrease in molar volume. All glasses exhibited a singular phase structure.

Enhancement of radiation shielding properties in BaTiO3 added with Bi2O3 at the energy range of 356keV -1333keV

Abstract The investigation on the radiation shielding properties of BaTiO3-xBi2O3 with (x=0, 2, 4, 6, 8 %) ceramic samples has been discussed in this paper. This study targeted especially on the radiation shielding properties such as tenth value layer (TVL) and effective electron density (Neff) by including density of sample as one of the parameters. The prepared ceramic samples radiation shielding properties were quantified with help of radioactive sources Ba133, Na22, Cs137, and Co60 at the energies 356keV, 511keV, 1173keV, 1275keV and 1333keV. The obtained experimental values compared with theoretical values by using Phy-X/PSD software. Obtained results revealed that, attenuation abilities improved due to addition of Bi2O3 at different concentration to BaTiO3 causes the rise in density of ceramic samples from 5.483 to 5.498g/cm3. S1 sample has maximum TVL value found at 10.098cm and sample S4 noticed with lowest value 9.842cm at 1333keV. The maximum Neff value recorded as 2.72 at 1333keV for sample S4 which indicating promising radiation shielding abilities.

Urbanization and primary productivity mediate the predator–prey relationship between deer and coyotes

AbstractPredator–prey interactions are important for regulating populations and structuring communities but are affected by many dynamic, complex factors across large scales, making them difficult to study. Integrated population models (IPMs) offer a potential solution to understanding predator–prey relationships by providing a framework for leveraging many different datasets and testing hypotheses about interactive factors. Here, we evaluate the coyote–deer (Canis latrans–Odocoileus virginianus) predator–prey relationship across the state of North Carolina (NC). Because both species have similar habitat requirements and may respond to human disturbance, we considered net primary productivity (NPP) and urbanization as key mediating factors. We estimated deer survival and fecundity by integrating camera trap, harvest, and biological and hunter observation datasets into a two‐stage, two‐sex Lefkovich population projection matrix. We allowed survival and fecundity to vary as functions of urbanization, NPP, and coyote density, and projected abundance forward to test eight hypothetical scenarios. We estimated initial average deer and coyote densities to be 11.83 (95% CI: 5.64, 20.80) and 0.46 (95% CI: 0.02, 1.45) individuals/km2, respectively. We found a negative, though highly uncertain, relationship between the current levels of coyote density and deer fecundity in most areas that became more negative under hypothetical conditions of lower NPP or higher urbanization, leading to lower projected deer abundances. Though not conclusive, our results indicate the possibility that coyotes could have stronger effects on deer populations in NC if their densities rise, but primarily in less productive and/or more suburban habitats. Our case study provides an example of how IPMs can be used to better understand the complex relationships between predator and prey under changing environmental conditions.

Improving the Efficiency and Stability of Perovskite Solar Cells by Refining the Perovskite-Electron Transport Layer Interface and Shielding the Absorber from UV Effects.

This study aims to enhance the performance of perovskite solar cells (PSCs) by optimizing the interface between the perovskite and electron transport layers (ETLs). Additionally, we plan to protect the absorber layer from ultraviolet (UV) degradation using a ternary oxide system comprising SnO2, strontium stannate (SrSnO3), and strontium oxide (SrO). In this structure, the SnO2 layer functions as an electron transport layer, SrSnO3 acts as a layer for UV filtration, and SrO is employed to passivate the interface. SrSnO3 is characterized by its chemical stability, electrical conductivity, extensive wide band gap energy, and efficient absorption of UV radiation, all of which significantly enhance the photostability of PSCs against UV radiation. Furthermore, incorporating SrSnO3 into the ETL improves its electronic properties, potentially raising the energy level and improving alignment, thereby enhancing the electron transfer from the perovskite layer to the external circuit. Integrating SrO at the interface between the ETL and perovskite layer reduces interface defects, thereby reducing charge recombination and improving electron transfer. This improvement results in higher solar cell efficiency, reduced hysteresis, and extended device longevity. The benefits of this method are evident in the observed improvements: a noticeable increase in open-circuit voltage (Voc) from 1.12 to 1.16 V, an enhancement in the fill factor from 79.4 to 82.66%, a rise in the short-circuit current density (Jsc) from 24.5 to 24.9 mA/cm2 and notably, a marked improvement in the power conversion efficiency (PCE) of PSCs, from 21.79 to 24.06%. Notably, the treated PSCs showed only a slight decline in PCE, reducing from 24.15 to 22.50% over nearly 2000 h. In contrast, untreated SnO2 perovskite devices experienced a greater decline, with efficiency decreasing from 21.79 to 17.83% in just 580 h.

AlN and Nb(C,N) Composite Precipitation Behaviors and Their Effects on Austenite Grain Growth in SCr420H High‐Temperature Carburized Gear Steel

The effects of nitrogen (N) and niobium (Nb) contents on the precipitation behaviors of AlN, Nb(C,N), and AlN‐Nb(C,N) precipitates and austenite grain growth during the pseudo‐carburizing process are investigated for the carburized steel SCr420H. The results indicate that an increase of N content from 0.011% to 0.019% leads to the emergence of fine and uniform austenite grain structure in the sample while being held at 930 °C for 6 h, which is attributed to a notable rise in the number density of AlN and a decrease in the coarsening rate of AlN. In the steel containing 0.023% Nb, the composite precipitates AlN‐Nb(C,N) play a primary role in the pinning effect on austenite grains growth. The isolated Nb(C,N) and AlN precipitates have minor pinning effects due to their very low volume fractions. Nb(C,N) cap forming on AlN substrate obeys the Shoji–Nishiyama orientation relationship. The favorable lattice matching between AlN and Nb(C,N) and accelerated coarsening rate of Nb(C,N) cap decrease hindrances to the nucleation, growth, and coarsening of Nb(C,N) on AlN substrate. Meanwhile, these simultaneous effects also suppress the same processes for the isolated Nb(C,N) in the matrix.

Research on high power and heat flux aerospace electronic products of integrated thermal conduction technology

In response to the increasing demand for enhanced computational capabilities within satellite systems, there has been a simultaneous rise in the heat flux density of onboard electronic components. The thermal output of these components has significantly increased compared to traditional satellite processing electronics, leading to a concurrent elevation in the heat flux density related to processing chips and the surfaces accommodating equipment installations. This paper establishes a model for conduction heat dissipation in aviation electronic products. The outlined calculation methodology facilitates a preliminary assessment of the system’s heat dissipation capacity. The article further examines the inherent heat dissipation capabilities in two commonly employed structural configurations. Additionally, it introduces an integrated design approach for structural heat dissipation, including experimental considerations and validation outcomes. The assessment methodologies and design principles detailed in this article are particularly relevant and applicable to the thermal design imperatives associated with high-power electronic products deployed for the extended operational durations typical of spacecraft.

Blind Spot Detection for Autonomous Driving Using RADAR Technique

The ever-changing landscape of the automotive sector has been significantly influenced by technological advancements, particularly the incorporation of Radar technology, have played a vital role in shaping the safety features of modern vehicles. In the automotive industry, radar sensors play a important role in advanced driver assistance systems (ADAS), improving road safety and driver convenience and One of the ADAS latest application is the Blind Spot Monitoring (BSM) system, which addresses the great challenge of driver visibility in certain areas around the vehicle. The BSM system uses radar sensors to detect obscured vehicles or objects, thereby reducing accident risk and improving road safety and driver convenience. As traffic densities rise and vehicles become more interconnected, BSM systems have become essential for safer and more efficient driving. The continuous evolution of radar technology integration demonstrates the automotive industry’s commitment to driver safety and its dedication to using advanced technologies to enhance the driving experience.

The Phenomenon of a Cathode Spot in an Electrical Arc: The Current Understanding of the Mechanism of Cathode Heating and Plasma Generation

A vacuum arc is an electrical discharge, in which the current is supported by localized cathode heating and plasma generation in minute regions at the cathode surface called cathode spots. Cathode spots produce a metallic plasma jet used in many applications (microelectronics, space thrusters, film deposition, etc.). Nevertheless, the cathode spot is a problematic and unique subject. For a long time, the mechanisms of spot initiation, time development, instability, high mobility, and behavior in magnetic fields have been described by approaches that caused some controversy. These spot characteristics were discussed in numerous publications over many years. The obscurity and confusion of different studies created the impression that the cathode spot is a mysterious phenomenon. In the present work, a number of typical representative publications are reviewed with the intention of clarifying problems and contradictions. Two main theories of cathodic arcs are presented along with an analysis of the experimental data. One of the approaches illustrates the cathode heating by Joule energy dissipation (volume heat source, a sharp rise in current density, etc.), nearly constant cathode potential drop, and other certain initial conditions. On the other hand, a study using a mathematically closed approach shows that the spot initiation and development are determined not by electron emission current rise but by a rise in arc power density, affecting heat sources including the energy of ion flux to the cathode (surface heat source).

DEVELOPMENT OF METHODOLOGY FOR MONITORING AND ASSESSING THE NATIONAL GREENING PROGRAM USING OPTICAL AND SAR DATA

Abstract. Launched primarily to address the growing concern of environmental sustainability and to combat climate change, the National Greening Program (NGP) is the most ambitious reforestation program undertaken in the Philippines. Given the enormous number of resources invested in the program, it is crucial to monitor and assess the effectiveness of this initiative. To do this, the success of the selected NGP site in Zambales Province was evaluated using land cover maps, Normalized Difference Vegetation Index (NDVI) from Sentinel-2 and MODIS, and Radar Vegetation Index (RVI) and Radar Forestation Degradation Index (RFDI) from Sentinel-1 Synthetic Aperture Radar (SAR) images. The index time series were processed in Google Earth Engine cloud computing platform. The findings indicate that the rise in vegetation density shown by the generally increasing trend in the NDVI and RVI was consistent with the increase in vegetation cover indicated by the land cover maps. This work contributes towards the field of environmental monitoring and resource management, with potential applications that extend beyond monitoring and assessment of the NGP and towards dealing with global issues regarding land use and environmental protection.

Interpretative 3D MHD modelling of deuterium SPI into a JET H-mode plasma

The pre-thermal quench (pre-TQ) dynamics of a pure deuterium ( D2 ) shattered pellet injection (SPI) into a 3MA / 7MJ JET H-mode plasma is studied via 3D non-linear MHD modelling with the JOREK code. The interpretative modelling captures the overall evolution of the measured density and radiated power. The simulations also identify the importance of the drifts of ablation plasmoids towards the tokamak low field side (LFS) and the impurities in the background plasma in fragment penetration, assimilation, radiative cooling and MHD activity in D2 SPI experiments. It is found that plasmoid drifts lead to an about 70% reduction of the central line-integrated density (compared to a simulation without drifts) in the JET D2 SPI discharge considered. Impurities that pre-exist before the SPI as well as those from possible impurity influxes related to the SPI are shown to dominate the radiation in the considered discharge. With inputs from JOREK simulations, modelling with the Lagrangian particle-based pellet code PELOTON reproduces the deviation of the SPI fragments in the direction of the major radius as observed by the fast camera. This confirms the role of rocket effects and plasmoid drifts in the considered discharge and reinforces the validity of the JOREK modelling. The limited core density rise due to plasmoid drifts and the strong radiative cooling and MHD activity with impurities (depending on their species and concentration) could limit the effectiveness of LFS D2 SPI in runaway electron avoidance and are worth considering in the design of the ITER disruption mitigation system.