Expansion Of Region Research Articles

High-pressure Raman scattering and X-ray diffraction study of kaolinite, Al2Si2O5(OH)4

Kaolinite is formed by weathering of continental crustal rocks and is also found in marine sediments in the tropical region. Kaolinite and other layered hydrous silicate minerals are likely to play a vital role in transporting water into the Earth's interior via subducting slabs. Recent studies have experimentally documented the expansion of the interlayer region by intercalation of water molecules at high pressures i.e., pressure-induced hydration. This is counter-intuitive since the interlayer region in the layered silicates is quite compressible, so it is important to understand the underlying mechanism that causes intercalation and expansion of the interlayer region.To address this, we explore the high-pressure behavior of natural kaolinite from Keokuk, Iowa. This sample is free of anatase impurities and thus helps to examine both low-energy (0–1200 cm−1) and high-energy hydroxyl (3000–4000 cm−1) regions using Raman spectroscopy and synchrotron-based powder X-ray diffraction.Our results show that the pressure dependence of the hydroxyl modes exhibits discontinuities at ∼3 GPa and ∼ 6.5 GPa. This is related to the polytypic transformation of Kaolinite from K-1 to K-II and K-II to K-III phase. Several low-energy Raman modes' pressure dependence also exhibits similar discontinuous behavior. The synchrotron-based powder X-ray diffraction results also indicate discontinuous behavior in the pressure dependence of the unit-cell volume and lattice parameters. The analysis of the bulk and the linear compressibility reveals that kaolinite is extremely anisotropic and is likely to aid its geophysical detectability in subduction zone settings. The K-I to K-II polytypic transition is marked by the snapping of hydrogen bonds, thus at conditions relevant to the Earth's interior, water molecules intercalate in the interlayer region and stabilize the crystal structure and help form the super-hydrated kaolinite which can transport significantly more water into the Earth's interior.

From Centre to Suburbs: Investigating How Transit Maps Streamline Residents’ Spatial Representations

ABSTRACT Representations we hold of our cities are acquired not just through direct spatial experience, but also through maps, potentially including schematic maps like transit maps. Following Beck's pioneering work, transit maps include practical schematic modifications, with scale changes that usually result in an expansion of central regions while compressing the peripheries. But it is not yet clear whether such a distortion exists in the minds of residents, and whether it could be due to cognitive biases, or to the transit maps' influence. Here, after showing that the centre–periphery segmentation is stronger in Parisians' minds than in Londoners', we investigated reference and segmentation effects in the way residents placed landmarks on a blank background. Those effects indeed explained part of centre–periphery distortions that were found, but some angular and scale changes could still only be explained by transit maps, confirming they indeed streamline residents' spatial representations.

Estimation and Expansion of Vehicle Stability Region With Sums of Squares Programming

The vehicle stability region can be used to evaluate vehicle stability performance and lay the foundation for vehicle safety improvement. It can be obtained via the region of attraction (RoA) based on sums of squares (SOS) programming. However, it is usually conservative, and the computational burden is large. This article focuses on the above issues and proposes a well-developed method for RoA estimation, with application to the estimation and expansion of the vehicle stability region. For RoA estimation, an improved SOS program is formulated, and its optimization objective combined with the customized algorithm significantly reduces conservatism. In addition, the feasibility prejudgment strategy and the dynamic search range are proposed in the algorithm. As a result, the computational burden is greatly reduced, which also indirectly helps reduce conservatism. Then, a more accurate vehicle stability region is obtained with less time consumption, and a map-based controller is proposed to improve vehicle stability. Better stability performance and larger stability regions are guaranteed under different scenarios due to the adaptive adjustment of controller gains. Finally, simulations and hardware-in-the-loop experiments with an embedded vehicle controller are performed to verify the effectiveness of our method.

Computational Analysis of Subcooled Flow Boiling in a Vertical Minichannel with Two Different Shapes under Various Mass Fluxes

In the current research project, two-dimensional numerical simulations are conducted to analyze the effects of geometrical configuration on flow structures and the thermal performances of subcooled flow boiling. The CFD simulations are carried out in two different configurations (straight and periodic constriction expansion) in a minichannel mounted vertically at four mass fluxes (500 kg/m2s; 836.64 kg/m2s; 1170 kg/m2s; and 2535 kg/m2s). The present predicted results exhibit excellent accordance with the previous experiments, with mean errors of 6.39% and 9.78%, demonstrating the efficiency of the present numerical study. The simulation results show that the periodic constriction expansion design provides good mixing between the layers, leading to a 43.11% mean enhancement of the thermal transfer, which is more important than the slight pressure drop penalty of 4.32 for a mass flux of 500 kg/m2s due to the combined pressure drop along the minichannel that resulted from the periodic constriction and expansion regions. Furthermore, the visualization of flow patterns shows that the bubbly flow is the dominant flow regime in the periodic constriction-expansion configuration.

Identification of the parametric array loudspeaker system using differential Volterra filter

The self-demodulation property of a parametric array loudspeaker (PAL) system can peel off audible sound modulated on ultrasonic wave and deliver it with high directivity, but also introduces nonlinear distortion. The PAL system can be modeled by the Volterra series expansion in any acoustic field region. However, measurements of Volterra kernel using simple frequency sweep excitation signals may not provide adequate information about the nonlinear system, and the use of wideband signals such as speech signals makes convergence difficult. Based on the Westervelt model, we propose a PAL system identification method utilizing the differential Volterra kernel. The results demonstrate superior fitting performance for real swept frequency output data and speech signal output data compared to the existing one-dimensional Volterra filter (ODVF). Additionally, the proposed method exhibits fewer parameters and faster convergence speed than the traditional volterra kernel.

Failure-Averse Active Learning for Physics-Constrained Systems

Active learning is a subfield of machine learning that is devised for design and modeling of systems with highly expensive sampling costs. Industrial and engineering systems are generally subject to physics constraints that may induce fatal failures when they are violated, while such constraints are frequently underestimated in active learning. In this paper, we develop a novel active learning method that avoids failures considering implicit physics constraints that govern the system. The proposed approach is driven by two tasks: the safe variance reduction explores the safe region to reduce the variance of the target model, and the safe region expansion aims to extend the explorable region exploiting the probabilistic model of constraints. The global acquisition function is devised to judiciously optimize acquisition functions of two tasks, and its theoretical properties are provided. The proposed method is applied to the composite fuselage assembly process with consideration of material failure using the Tsai-wu criterion, and it is able to achieve zero-failure without the knowledge of explicit failure regions.

The biophysical effects of potential changes in irrigated crops on diurnal land surface temperature in Northeast China

Irrigated crops have experienced a significant global expansion. The biophysical response of climate change to irrigated crop expansion in different regions, particularly in terms of monitoring the influence mechanism of nighttime land surface temperature (LST) change, however, remains insufficiently explored. Taking the three northeastern provinces of China as our study area, we apply window analysis, partial correlation analysis, and geographical detector to quantitatively characterize the spatial and temporal distribution pattern of daytime and nighttime LST (diurnal LST) and biophysical parameters, and the main driving mechanism of diurnal LST change. The results showed that irrigated crop expansion led to asymmetric changes in daytime (−2.11 ± 0.2°C, 97.4%) and nighttime (0.64 ± 0.2°C, 79.9%) LST. ΔLSTDT had a negative correlation with ΔLE (63%), but a positive correlation with ΔSSR and ΔH (91% and 77%). This revealed that the cooling effect caused by the superposition of the output latent heat flux and the absorbed solar shortwave radiation was greater than its heating effect. ΔLSTNT and ΔLE had a positive connection across 69% of the region. ΔLSTNT demonstrated a negative correlation with ΔSSR and ΔH in 82% and 75% of the regions, respectively. At this time, the superposition of latent heat flux and heating potential term produces a greater heating effect. The explanatory power of the single factor (the mean of q<0.50) of biophysical parameters for diurnal LST variation was significantly smaller than that of the interaction factor (the mean of q>0.50, p<0.01). This study shows more detailed dynamic information of diurnal LST and biophysical parameters from 8day scale. The findings highlighted the critical role of asymmetric changes in the diurnal surface thermal environment caused by irrigated crop expansion in the global climate from a land surface hydrothermal energy balance perspective.

Experimental study on subcooled pool boiling heat transfer under hypergravity

The pool boiling heat transfer experiment was conducted with pure water under subcooled and saturation conditions, both in hypergravity (1–3 g) and normal gravity (1 g) at atmospheric pressure. A turntable was employed to simulate the hypergravity environment. Subcooling was varied at four different levels: 2 °C, 5 °C, 8 °C, and 10 °C, corresponding to gravity levels ranging from 1 g to 3 g. Heat transfer enhancement was observed in the fully developed region under saturation conditions, whereas it was less pronounced in the natural convection region. Specifically, increasing the subcooling degrees leads to an expansion of the natural convection region, where the effects of hypergravity become noticeable at higher heat flux levels. The effect of hypergravity diminishes as the bubble detachment diameter in the fully developed region decreases with increasing subcooling degree, implying that the main effect of hypergravity on heat transfer is due to its influence on the bubble behavior. Additionally, a detailed analysis is presented to further explain the effect of hypergravity on heat transfer, focusing on the bubble dynamical behavior and the impact of buoyancy under hypergravity conditions.

A new species of planthopper in the genus Cobacella (Hemiptera: Auchenorrhyncha: Derbidae) from oil palm (Elaeis guineensis) in Costa Rica.

Recent survey work in Costa Rica has revealed a high diversity of planthoppers in the family Derbidae on palms (Arecaceae). During an expedition to Costa Rica in 2021, specimens were collected from African oil palm (Elaeis guineensis) along the pacific coast and determined to represent a new species of derbid in the genus Cobacella. Herein, the novel taxon, Cobacella palmensis sp. n., is described and compared with the two other species in the genus. Supplemental molecular data for the cytochrome c oxidase subunit I (COI) barcoding region, 18S rRNA gene and D9-D10 expansion region of the 28S rRNA gene are provided to test the placement of the novel taxon relative to available otiocerine planthoppers. We also present a preliminary key to the species of Cobacella and review all available specimen records of the genus.

Spatial modeling of fire in the atlantic forest considering future climate change scenarios in Rio Grande do Sul state – Brazil

Several biomes worldwide have a long history of conflict over fire use and management. The Atlantic Forest Biome (AFB) is a Brazilian biome that suffers the most from land use and cover changes that cause environmental degradation. The impact of climate change is expected to exacerbate this situation, with extreme weather events potentially leading to a higher frequency and intensity of fire. The main goal of this study is to understand the spatiotemporal distribution of fires for future climate scenarios obtained from CMIP6 climate simulations in the AFB in Rio Grande do Sul (RS) state, Brazil, using machine learning algorithms. This study selected several environmental and anthropogenic variables as factors associated with the cause, occurrence, and spread of fire. The results showed an uneven fire density distribution in the study area. An extensive fire cluster was found in pasture areas located northeast of RS state, reaching more than 1500 fire foci per km2 on average per year. The final model had a training R2 value of 0.99 and a test R2 value of 0.93. The most significant variable identified by the model was the average maximum temperature during the warm period, while livestock is the most influential economic activity. Regarding the simulated fire densities, the period between 2021 and 2040 in the SSP 5.8–5 scenario displayed maximum values that were equivalent to those observed in 2018, with an expansion in the occurrence region observed for the same scenario. However, unexpectedly, between 2081 and 2100, fire density decreased across all areas under the SSP 5.8–5 scenario. This study provides useful insights into climate change context scenarios, offering valuable insights into the intricate relationship between natural processes and human influences, ultimately contributing to informed decision-making and sustainable environmental management.

In ovo exposure of F-ions and organo-fluoride insecticide (Bifenthrin) cause developmental anomalies of eye in chick embryos

ObjectiveThe developmental abnormalities of the in-ovo exposure of Fluoride ions (F-ions) and Bifenthrin (BF) on the embryonic chick eye were investigated. Materials and methods165 fresh fertilized eggs of zero day and 40–50 g weight were divided into three groups (55 eggs each) on the basis of inter-vitelline treatment of eggs on zero day of study: 1) Control group (CG); 0.1 ml of 5 % DMSO aqueous solution 2),3) Fluoride group (FG), and Bifenthrin group (BFG); 0.01 mg/kg F-ions (from NaF) and 0.01 mg/kg BF in 0.1 ml of 5 % DMSO aqueous solution respectively. After incubation for 14 days at 37 ± 0.5 °C embryos were externalized. Eyes of each embryo were removed for micro-anatomical, micrometric and histopathological studies. ResultsThe histological sections have shown denser and enlarged marginal mitotic region of the developing eye lenses in FG and BFG. In vertical sections of the eye lenses the nuclei of the crystalline cells in FG and BFG show a highly depressed bow shaped arrangement. Moreover, the nuclei of the core crystalline cells of the lens were apparently smaller in FG and BFG than CG. Out of the six anatomical layers of the retina the nuclear and the plexiform layers were highly enlarged in FG and BFG, similarly the three corneal cell layers (endothelial, parenchymal and epithelial) were enlarged in FG and BFG than CG. The morphometric, histometric and micrometric estimations also show significant variations in FG and BFG than CG. ConclusionThe results indicate subtle developmental anomalies of the eyes attributable to the F-ions and BF exposure indicating their developmental neuro-optic disruption potentials. Results further revealed higher toxicity of BF as compared to F-ions.

Realization of a highly-performing triboelectric nanogenerator utilizing molecular self-assembly

Triboelectric nanogenerator (TENG) is promising as a sustainable power source for energy-autonomous electronics. This work demonstrates for the first time that a highly-performing TENG can be realized by utilizing molecular self-assembly of small molecules. It is found that molecular self-assembly modifies the orbital energy levels of the corresponding tribo-layer that causes reduced energy gap between the tribo-layers for charge transfer. It is also found that an expansion of the electron-rich regions occurs due to molecular self-assembly that in turn increases the probability of the electron cloud/potential well overlap. Both the phenomena result in significantly-enhanced charge transfer between the tribo-positive and tribo-negative layers of a TENG during contact electrification. A low-cost, simple, and straightforward technique that does not require sophisticated equipment is adopted for the molecular self-assembly of a naturally abundant small molecule. Spectroscopic analysis, atomic force microscopy, and electron microscopy reveal that the modified molecules are capable of building high order self-assembled structure. A TENG with a self-assembled layer (SAL-TENG) generated voltage and power density of ∼1340 V and ∼11.75 W m−2, respectively, as compared with, ∼200 V and ∼3.5 W m−2 respectively, for another TENG comprising the same molecules but are not self-assembled (NSA-TENG).

Cropland expansion in Ecuador between 2000 and 2016.

We describe changes in the cropland distribution for physiographic and bioregions of continental Ecuador between 2000 and 2016 using Landsat satellite data and government statistics. The cloudy conditions in Ecuador are a major constraint to satellite data analysis. We developed a two-stage cloud filtering algorithm to create cloud-free multi-temporal Landsat composites that were used in a Random Forest model to identify cropland. The overall accuracy of the model was 78% for the Coast region, 86% for the Andes, and 98% for the Amazon region. Cropland density was highest in the coastal lowlands and in the Andes between 2500 and 4400 m. During this period, cropland expansion was most pronounced in the Páramo, Chocó Tropical Rainforests, and Western Montane bioregions. There was no cropland expansion detected in the Eastern Foothill forests bioregion. The satellite data analysis further showed a small contraction of cropland (4%) in the Coast physiographic region, and cropland expansion in the Andes region (15%), especially above 3500m, and in the Amazon region (57%) between 2000 and 2016. The government data showed a similar contraction for the Coast (7%) but, in contrast with the satellite data, they showed a large agricultural contraction in the Andes (39%) and Amazon (50%). While the satellite data may be better at estimating relative change (trends), the government data may provide more accurate absolute numbers in some regions, especially the Amazon because separating pasture and tree crops from forest with satellite data is challenging. These discrepancies illustrate the need for careful evaluation and comparison of data from different sources when analyzing land use change.

Rate of accelerated expansion of the epidemic region in a nonlocal epidemic model with free boundaries

This paper is concerned with the long-time dynamics of an epidemic model whose diffusion and reaction terms involve nonlocal effects described by suitable convolution operators, and the epidemic region is represented by an evolving interval enclosed by the free boundaries in the model. In Wang and Du (2022 J. Differ. Eqn. 327 322–81), it was shown that the model is well-posed, and its long-time dynamical behaviour is governed by a spreading-vanishing dichotomy. The spreading speed was investigated in a subsequent work of Wang and Du (2023 Discrete Contin. Dyn. Syst. 43 121–61), where a threshold condition for the diffusion kernels J 1 and J 2 was obtained, such that the asymptotic spreading speed is finite precisely when this condition is satisfied. In this paper, we examine the case that this threshold condition is not satisfied, which leads to accelerated spreading; for some typical classes of kernel functions, we determine the precise rate of accelerated expansion of the epidemic region by constructing delicate upper and lower solutions.

An InSAR Deformation Phase Retrieval Method Combined with Reference Phase in Mining Areas

The acquisition of precise deformation data, including the entirety of the subsidence basin resulting from subterranean mining operations, assumes critical significance in the context of surface impairment monitoring during the course of mining activities. In light of the constraints associated with InSAR technology when applied to the surveillance of expansive deformation gradient mining regions, an innovative approach is advanced herein for InSAR deformation phase retrieval. This approach integrates a reference phase, derivable through a variety of means, including pre-existing models or measurements. Initially, the reference deformation phase is subjected to subtraction from the wrapped InSAR deformation phase, culminating in the derivation of the wrapped phase indicative of the residual phase. Notably, it is posited that the fringe density characterizing the wrapped phase of the residual phase is theoretically diminished in comparison to that of the InSAR wrapped phase. This reduction in complexity in phase unwrapping ensues as a direct consequence. Subsequent to this, the phase retrieval process is effectuated through the summation of the reference phase and the unwrapped phase pertaining to the residual phase. The study harnesses Sentinel-1A and ALOS PALSAR-2 data, employing the PIM-predicted outcomes and GNSS-RTK monitoring outcomes as reference phases for the execution of phase retrieval experiments in two designated study areas. The computation of subsidence is subsequently realized through the combination of the displacement vector depression angle model and the retrieved phase, with the accuracy thereof corroborated through the utilization of leveling data. The experimental findings underscore the efficacy of the reference phase retrieval methodology in securing a more precise deformation phase characterization within expansive deformation gradient mining regions, thereby demonstrating the suitability of this methodological approach.

On asymptotic dark energy in string theory

We examine bounds on accelerated expansion in asymptotic regions of the moduli space in string theory compactifications to four spacetime dimensions. While there are conjectures that forbid or constrain accelerated expansion in such asymptotic regions, potential counter examples have been discussed recently in the literature. We check whether such counter examples can arise in explicit string theory constructions, focusing in particular on non-geometric compactifications of type IIB string theory that have no Kähler moduli. We find no violation of the Strong Asymptotic dS Conjecture and thus provide support for the absence of accelerated expansion in asymptotic regions of a barely explored corner of the string landscape. Moreover, working in a simplified setting, we point out a new mechanism for potentially connecting the Sharpened Distance Conjecture and the Strong Asymptotic dS Conjecture. If this argument could be generalized, it would mean that the Sharpened Distance Conjecture is implied by the Strong Asymptotic dS Conjecture, and that their exponential factors are naturally related by a factor of 2.

PRINSIP DAKWAH NABI MUHAMMAD SAW DALAM KONTEKS MAKKAH DAN MADINAH

Islamic da'wah has a long history since the history of mankind, the prophets and apostles sent by Allah SWT from time to time depict an endless series of Islamic da'wah, many examples (uswah) can be taken from the life of the Prophet Muhammad's da'wah. Because basically he was sent on this earth to regulate the order of humanity so that it is in harmony with the rules of Allah SWT. This character radiated from the noble personality of the Prophet and was reflected clearly in his preaching activities and in the life of society and the state at that time. The purpose of writing this scientific work is to find out how the Prophet Muhammad struggled and how to preach in Mecca and Medina. This research method uses a historical method with four research stages, namely, first, searching for documents, second, criticizing documents, third, interpreting or interpreting, and fourth, presentation in the form of historiography. The results of this research are that there were many ways in which the Prophet preached in the cities of Mecca and Medina so that he could successfully spread, maintain and strengthen the religion of Islam in the people of Mecca and Medina. From his character in preaching, the principles of his preaching were also factors in his success. in preaching. Then, through the Prophet's preaching letters to regional rulers, it had a huge impact on the expansion of the Islamic region.

Simulation and analysis of ecological early-warning of urban construction land expansion based on digital sensing feature recognition and remote sensing spatial analysis technology

To improve the analysis effect of the simulation and prediction of the expansion effect of urban construction land, this paper combines the digital sensing feature recognition and remote sensing analysis technology for the earth's surface, and uses Artificial-neural-network-based cellular automaton (ANN-CA) Markov model and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model to study and analyze the expansion effect and trend of urban construction land, and subdivides the spatial and temporal characteristics of land cover. In addition to that, multi-based sensing data is used to generate urban construction land expansion effect drivers. The multi-source sensing data and InVEST model are used to conduct spatial information analysis and ecological early-warning. The research shows that combining digital sensing feature identification and remote sensing analysis technology, using the analysis model of ANN-CA-Markov model and InVEST model can effectively improve the analysis effect of urban construction land expansion effect prediction, and carry out ecological early-warning of construction land expansion on this basis. Overall territorial spatial planning stage of Xuzhou city, the designated ecological space area accounts for 20% of the whole land area. There is a sharp contradiction between constructive land expansion and ecological security in the whole region, so it is appropriate to conduct precise intervention and efficient management of constructive land expansion according to ecological early-warning.

Investigation of the Discharge Chamber Expansion Region Influence on the Electron Density in an Inductively Coupled RF Discharge

Investigation of the Discharge Chamber Expansion Region Influence on the Electron Density in an Inductively Coupled RF Discharge

Analytical and finite element investigation on residual stress analysis for composite thermoplastic cantilever beam under unique load

For a steel-fiber-based low-density homogenous composite thermoplastic cantilever beam, numerical (ANSYS APDL19) and analytical (MATLAB program) for elastoplastic stress distributions are achieved. At its free end, a thermoplastic cantilever structural member is loaded using a steady force. For orientation angles of (0°, 15°, 30°, 45°, 60°, 75° and 90°), the yield region's expansion and (σx)r are calculated. MATLAB program was used to determine the residual distribution of stress analytically. Both the yield zone that expands just at the top surface and the plastic zone that expands on both the top and bottom surfaces simultaneously are subjected to the elastic–plastic analysis. After the applied load has been freed, the components of residual distribution of stress are detected. Additionally, the distributions of the σx residual stress is established. By utilizing residual distribution of stress, the beam can be reinforced. The upper and lower edges of the beam are where the residual stress values are strongest. For the same load in the beam at orientation angles of (0°, 15°, 30°, 45°, 60°, 75° and 90°) the space amidst the free end and the plastically contracted region is determined. Lower discrepancy is evaluated for numerical (ANSYS APDL19) and analytical results.