Physical Structure Research Articles

Examining the Impact of Social Factors on Spatial Desirability of Urban Neighbourhoods

The increasing importance of neighbourhoods in urban planning, combined with an enhanced focus on the social aspects of designing desirable communities and societies, has emanated the necessity of developing a clear understanding of spatially desirable neighbourhoods. When considering various dimensions of social vitality and existing urban planning norms for residential neighbourhoods, it appears essential to consider and integrate both social and spatial aspects to formulate a desirable community. This article examines the impact of social factors on spatial desirability and vitality of residential neighbourhoods in the context of Iran. The historic city of Yazd has been selected as the case study. Following thorough evaluation of existing neighbourhoods in the city, three study areas have been selected for detailed study; Zortosht neighbourhood, Shahrak University residential complex and Baqiyatullah Azam residential complex. Based on the nature of this study, a qualitative method has been adopted to conduct this research. Extracting from the literature review, three factors of safety and security, sense of attachment to place and social interaction are among the most important socio-cultural factors that can affect the social vitality of a neighbourhood. After the content analysis of the interviews (through semi-structured questionnaires) from the stakeholders and residents of the study areas, observation and documentation of physical and spatial structure of the neighbourhoods and analysing data by interrelating social, as well as spatial aspects, the study concluded that social and spatial aspects are interconnected and both are impacting each other to result in social vitality and spatial desirability of a neighbourhood. Moreover, it was observed that spatial layout of neighbourhoods can increase the potential for social vitality and liveliness. Finally, research recommends design policies for socially integrated and spatially desirable neighbourhoods in the context of Iran, which may be applicable in other similar contexts too.

Recent Progress in Electro‐Optic Modulators: Physical Phenomenon, Structures Properties, and Integration Strategy

AbstractElectro‐optic modulators (EOMs), serving as indispensable components within photonic integrated circuits, are essential for enabling energy‐efficient, high‐speed, and high‐capacity optical communication systems. This review illustrates the principal physical phenomenon exploited in EOMs and provides a comprehensive analysis of the cutting‐edge EOMs featuring interference structures (Mach–Zehnder modulators and Michelson‐interferometer modulators) and resonance structures (microring modulators, racetrack modulators, and photonic crystal modulators). The comparative analysis of the performance merits and limitations in EOMs is presented, highlighting the combination of diverse electro‐optic material compositions with different optical structures, which reveals a promising integration strategic so as to pursue a trade‐off in modulation performance. It is contributed to the ongoing discourse on optimizing EOMs for the subsequent communication technologies and the advancement of photonic chips.

3D reconstruction and depth estimation method for local anomalies of rail surface based on multi-view stereo matching

Abstract Detecting rail surface anomalies has become crucial for ensuring the safety of train operations. However, manual detection methods are time-consuming and labor-intensive. Although traditional detection models based on one-dimensional signals or two-dimensional images can effectively identify the existence of defects, they are difficult to use to obtain local depth characteristic information, leading to difficulties in accurately assessing the extent of damage in abnormal regions. Rail track maintenance strategies are typically developed based on the detected different depth ranges of defects. To address this issue, this paper proposes a local depth estimation method based on the point cloud of the target rail surface reconstructed by PatchmatchNet. Firstly, according to the acquisition method of multi-view images and the sampling environment at the site, a practical data collection protocol is established for generating a multi-view dataset of rail surface. Next, dense point cloud of the target rail surface were reconstructed by PatchmatchNet. Subsequently, a method for estimating the local anomaly depth is developed based on the point cloud. Experimental results demonstrate that the proposed method achieves a minimum error of approximately 5.5% within a maximum depth range of 0.35mm, when compared to depth measurements obtained using a structured light camera. Finally, this paper presents a more comprehensive three-dimensional representation of the local abnormal physical structure, surpassing traditional one-dimensional and two-dimensional forms. This enhanced representation offers richer information for the effective determination of whether the anomalies constitute defects and aids in distinguishing true defects from other surface irregularities. Such advancement significantly improves the precision of defect assessment and supports the development of highly precise repair strategies.

Root traits of soybeans exposed to polyethylene films, polypropylene fragments, and biosolids

Biosolid use imports microplastics into the rhizosphere where they may interfere with root-soil-microbial interactions and cause morphological adaptations in crop root systems. Few studies have examined the response of crop roots to microplastics at documented soil concentrations, and many studies collect root traits using destructive techniques. Hence, there is little information on when and how microplastics effect the physical structure of root systems. Using the rhizobox method, soybeans (Glycine max) were grown in soil amended with biosolid microplastic mimics (polyethylene film or polypropylene fragments at 2,000 and 15,000 particles/kg dry soil) or biosolids and imaged weekly until maturity (11 weeks) using a custom scanner system. Plant biomass increased in the polyethylene treatments and decreased in the high concentration polypropylene treatment. Relative to the Control, polyethylene treatments had larger root length, reduced root diameters, reached maturity faster, had deeper root systems, and had a greater number of lateral roots. In contrast, polypropylene treatments had a mixed response, with high concentrations eliciting a lower root length, fewer laterals, and a more vertical root orientation. Segmented linear regression revealed that root growth in the Control and Biosolid treatments continued through the course of the experiment, while the microplastic treatments reached maturity up to two weeks earlier. Imagery revealed that microplastics elicited deeper rooting depth within the first week and differences in all root traits were evident by the development of the first trifoliate leaflets. Microplastic effects on root traits at early life stages suggest soil physiological drivers, while increased branching frequency and lower lateral elongation are suggestive of changes in soil nitrogen availability. The minimal difference in root traits in the biosolid treatment may be attributable to differences in microplastic properties or counteractive effects by other biosolid constituents.

Inconsistences persisting in the conceptual structure of thermal physics and the nature of fundamental constants

AbstractConceptual structure of contemporary thermal physics is by no means simple, understandable and free of contradictions or ambiguities. As many students claim, it is a rather complicated doctrine which is far from to be easy comprehensible (Meltzer in Am J Phys 72:1432–1446, 2004). Therefore, in this polemic contribution, originally the summer school lecture, we will address some lesser-known points, which are likely responsible for such a situation. We start with Black’s path breaking discovery of two aspects of heat, namely the “matter of heat” and the “intensity of heat,” which were later identified with the quantities known as entropy (S) and temperature (T). It can be shown that the product of these two quantities can enter the energy balance equation, which is apt to interconnect various parts of physics. The genesis of these key concepts was, however, not straightforward. An original hypothetical model of heat, a subtle imponderable fluid, caloric (ς), was abandoned after the non-critical acceptance of the “milestone of thermodynamics,” Mayer–Joule’s postulate claiming the equivalence of heat and work. Heat then became a pure energy without any material carrier, but with seriously limited transformation abilities. In addition, the situation is also complicated by the very fact that the definition of Kelvin absolute thermodynamic temperature scale (T) is fully based on the caloric theory. Partial reconciliation brought about only introduction of Clausius’ entropy. This, however, was afterward recognized to be practically identical with the Carnot’s caloric. Furthermore, by analogy identification of phenomenological variables S and T with statistical parameters appearing in the kinetic theory has not withstand extension to the domain of special relativity. Thus, the full equivalence between thermodynamics and statistical physics is not feasible. Another realm of problems is generated by the recent tendency in metrology to define units by means of defining constants with fixed numerical values instead of materialized étalons. In case of thermal physics, one can be skeptic about such an approach, because the universal constancy of entropy and its unit, Boltzmann constant k = 1.380649 × .10−23 J K-1, are only unjustified assumptions, which can be a potential source of future difficulties.

Evolution of TiAlSi thin film coatings under varying target power in DC magnetron sputtering

This study, for the first time, presents the growth, nucleation, and characteristics of TiAlSi thin films sputtered from a partially sintered Ti30Al16Si10 (at. %) composite target under controlled conditions of target power. The TiAlSi thin films were grown on soda-lime glass substrates through Direct Current (DC) sputtering at varying levels of the target power: 73.2 W, 151.2 W, and 269.5 W. The other deposition parameters: the deposition temperature, time, argon mass flow rate, substrate rotation, and deposition pressure, were kept constant at 23 °C, 150 min, 25 sccm, 5 rpm, and 10−3 mbar, respectively. The pre-sputter power, argon flow rate, and time were also kept constant at 73.2 W, 20 sccm, and 5 min, respectively. The physical properties, microstructure, crystal structure, topography, and mechanical properties of the thin film coatings were analysed. The thickness and rate of deposition of the TiAlSi thin films increased with an increase in the target power (73.2 W – 269.5 W) from 414.6 nm and 0.046 nm/s to 1358.8 nm and 0.151 nm/s, respectively. The chemical composition of all the thin films remained constant, with the formation of a uniform TiAlSi alloy with no segregation of elements. However, a thin (wetting) interlayer consisting of Si and O elements was observed between the TiAlSi layer and the glass substrate. Further, the structure sizes and roughness values of the TiAlSi thin films increased with an increase in the target power, with a maximum of 75.4 nm for the size and 4.78 nm for the RMS roughness of thin films deposited at the maximum target power (269.5 W). Lastly, mechanical analysis of the TiAlSi thin films depicted an increase in the hardness as the target power increased, with the highest hardness at maximum power (269.5 W) obtained as 4.76 GPa. Despite having the lowest elastic modulus (50.5 GPa), the coating deposited at the highest power exhibited the highest plasticity index (H/E) and plastic deformation factor (H3/E2) of 0.094 and 0.042 GPa, respectively, which indicated the high resistance to abrasive wear, cracking, and deformation, compared to thin films deposited at the lowest target power (H/E = 0.066 and H3/E2 = 0.015 GPa). This study demonstrates that target power is a significant factor in determining the growth of TiAlSi thin films during the sputtering process and can be used for better control of their physical, structural, and mechanical properties.

Physical Field Effects to Suppress Polysulfide Shuttling in Lithium-Sulfur Battery.

Lithium-sulfur batteries (LSB) with high theoretical energy density are plagued by the infamous shuttle effect of lithium polysulfide (LPS) and the sluggish sulfur reduction/evolution reaction. Extensive research is conducted on how to suppress shuttle effects, including physical structure confinement engineering, chemical adsorption strategy, and the design of sulfur redox catalysts. Recently, the rational design to mitigate shuttle effects and enhance reaction kinetics based on physical field effects has been widely studied, providing a more fundamental understanding of interactions with sulfur species. Herein, the physical field effect is focused and their methods and mechanisms of interaction are summarized systematically with LPS. Overall, the working principle of LSB system, the origin of the shuttle effect, and kinetic trouble in LSB are briefly described. Then, the mechanism and application of rational design of materials based on physical field effect concepts and the external physical field-assisted LSB are elaborated, including electrostatic force, built-in electric field, spin state regulation, strain engineering, external magnetic field, photoassisted and other physical field-assisted strategies are pivotally elaborated and discussed. Finally, the potential directions of physical field effects in enhancing the performance and weakening the shuttle effect of high-energy LSB are summarized and anticipated.

Transient Transformations: Memory and Identity Lessons from Kumbh Mela

The Kumbh Mela, held every twelve years at the confluence of the Ganga and Yamuna rivers in Prayagraj, India, is the largest religious gathering and ephemeral city in the world. This article explores the physical and social dimensions of the festival, drawing parallels with other temporary architectures and paying particular attention to the role of memory. The physical structure of the city, organized into a flexible grid, accommodates millions of pilgrims while preserving spaces for the community and its collective identity. The material memory of the site, layered with historical and spiritual significance, intersects with the intangible memory carried by pilgrims through traditions and cultural practices. This blend of tangible and intangible elements fosters a sense of continuity, even in a temporary setting. By examining the Kumbh Mela, the study highlights the importance of memory in creating cohesive, resilient communities within transient urban landscapes, and offers valuable lessons for the design and planning of other temporary settlements.

Molecularly and Structurally Designed Polyimide Nanofiber Radiative Cooling Films for Spacecraft Thermal Management

AbstractRadiative cooling films (RCFs) are crucial for spacecraft thermal management, but their optical performance is currently limited by their structures and intrinsic high absorption at short wavelengths. In this study, a novel RCF using electrospun polyimide nanofibers optimized at both the molecular and microscale levels is developed. The newly designed polyimide molecules significantly decrease visible and ultraviolet (UV) light absorption while maintaining excellent thermal radiation properties in the infrared spectrum. By optimizing the diameter and orientation of the nanofibers using Monte Carlo simulations, the resulting film achieves a solar reflectivity of 99.6% and a mid‐infrared emissivity of 0.93. Its physical structures and optical properties remain stable under exposure to UV light, atomic oxygen, and extreme temperature changes. Further vacuum radiative cooling tests reveal that the thermal equilibrium temperature of this film is approximately 28 °C lower than that of Kapton‐based RCFs currently used in spacecraft. These results provide a new approach for creating efficient thermal management materials for space applications, with potential for broader use in architecture, electronic devices, and outdoor equipment.

Thin-film freeze-drying of an influenza virus hemagglutinin mRNA vaccine in unilamellar lipid nanoparticles with blebs

Messenger RNA (mRNA) vaccines have revolutionized the fight against infectious diseases and are poised to transform other therapeutic areas. Lipid nanoparticles (LNP) represent the most successful delivery system for mRNA. While the mRNA-LNP products currently in clinics are stored as frozen suspensions, there is evidence that freeze-drying mRNA-LNP into dry powders can potentially enable their storage and handling at non-freezing temperatures. Previously, we successfully applied thin-film freeze-drying (TFFD) to transform a polyadenylic acid [poly(A)]-LNP formulation from a liquid suspension to dry powders. The poly(A)-LNP were structurally multilamellar spheres without blebs, but the mRNA vaccines in clinics are comprised of mRNA-LNP that are structurally spheres surrounded by a unilamellar lipid bilayer, with some containing blebs, and it was reported that the presence of blebs increases the sensitivity of mRNA-LNP to freeze-drying-induced stress. In the present study, using an influenza A virus hemagglutinin (HA) mRNA in LNP that were structurally similar to that in the COVID-19 mRNA vaccines currently in clinic, we studied the effect of TFFD on the physical properties, internal structure, as well as immunogenicity of the HA mRNA-LNP vaccine. We concluded that TFFD can be utilized to prepare dry powders of the HA mRNA-LNP, but a sufficient amount of excipients were needed to minimize changes in the physical properties, structure, and immunogenicity of the HA mRNA-LNP vaccine.

Jane Jacobs's urban vitality focusing on three-facet criteria and its confluence with urban physical complexity

Urban vitality is crucial for sustainability, contributing to social cohesion, information exchange, and overall quality of life. Understanding and quantifying urban vitality is essential for effective planning and policymaking, yet it remains a complex task. Previous studies have primarily focused on single-dimensional measures of urban vitality, overlooking the multifaceted nature emphasized by Jane Jacobs, including spatiotemporal dimensions. This study revisits Jacobs's urban vitality, focusing on three key indicators of intensity, diversity, and consistency of urban vitality. Additionally, we explore the relationships between urban complexity and urban vitality. We employ variety, uniformity, and connectivity metrics to assess urban complexity, which examines the physical structures of buildings, streets, and blocks. Linear regression and Maximal Information-based Nonparametric Exploration statistics for non-linearity analysis are used to determine the associations between urban complexity and urban vitality. Our findings reveal nuanced details of the relationships. Notably, variety and connectivity variables have more significant influences on urban vitality than those related to uniformity. Furthermore, the analysis highlights the differential impacts of complexity variables on different types of vitality. These insights provide valuable guidance for planners and policymakers, facilitating the design of sustainable and vibrant cities by considering optimal complexity measures of built environment that enhance urban vitality.

Recent developments in the physical structure of solid formulations: a comprehensive review

Recent developments in the physical structure of solid formulations: a comprehensive review

De novo protein design with a denoising diffusion network independent of pretrained structure prediction models.

The recent success of RFdiffusion, a method for protein structure design with a denoising diffusion probabilistic model, has relied on fine-tuning the RoseTTAFold structure prediction network for protein backbone denoising. Here, we introduce SCUBA-diffusion (SCUBA-D), a protein backbone denoising diffusion probabilistic model freshly trained by considering co-diffusion of sequence representation to enhance model regularization and adversarial losses to minimize data-out-of-distribution errors. While matching the performance of the pretrained RoseTTAFold-based RFdiffusion in generating experimentally realizable protein structures, SCUBA-D readily generates protein structures with not-yet-observed overall folds that are different from those predictable with RoseTTAFold. The accuracy of SCUBA-D was confirmed by the X-ray structures of 16 designed proteins and a protein complex, and by experiments validating designed heme-binding proteins and Ras-binding proteins. Our work shows that deep generative models of images or texts can be fruitfully extended to complex physical objects like protein structures by addressing outstanding issues such as the data-out-of-distribution errors.

Basic Mathematical form Of Nature of Space And Dimension of Observable Universe and Beyond

In this innovative research I have advanced the theory of space with definition of space, definition of types of space, and introduced energy-mass transformation, gravity and gravitation force. With this advance research, finally I have defined basic mathematical form of “Nature of space and Dimension of Observable Universe and beyond”.As we know the universe is defined as all space-time and their contents. However, several questions still remain open regarding higher dimension, singularity, gravity collapse at horizon of black hole, unified gravity, theory of everything, dark matter, dark energy, existence of observable universe and beyond, question for mathematical form of everything, question for matter itself, and question for the space itself. These open questions have driven this scientific research of “Basic Mathematical form Of Nature of Space and Dimension of Observable Universe and beyond”. My research findings indicate that the space itself is the entity with having physical properties. The space can be described by physical structure and its transformation. The space has two fundamental properties of energy and mass, and space can be described by energy- mass transformation. From these energy-mass transformation and physical structure transformation, I have defined the gravity, gravitation force and basicmathematical form of“Nature of space and Dimension of Observable Universe and beyond”. This basic mathematical form covers scope of higher dimension, unified gravity, singularity, horizon of black hole, and nature of space of observable universe and beyond. Several research have been conductedfor look into nature of space,space-time, gravity, unified gravity, higher dimensions, unified mathematical formof everything by Minkowski space,Higgs field, Aether medium, Newton’s law of universal gravitation, Electromagnetism, Planck constant,General relativity,Standard Model,Loop Quantum Gravity, Super symmetry, Super gravity, String theory and M-Theory. Despite these research, the questions still remain open for unified nature and for unified mathematical form of “Nature of space and Dimension of Observable Universe and beyond”. By researching the existence of matter, I found the existence of space was just accepted as the void, empty, and space-time background framework. My research reflects “Dimension of Observable Universe and beyond”encompasses all existence of observable universe and beyond it. The advance definition of space, definition of type of space, space transformation and energy-mass transformation perfectly describe existence of entire space & universe and its nature at very fundamental level. This very fundamental nature is presented in basic mathematical form. It is the most accurate foundation to answer those open questions. It is the novelty in astrophysics and foundation of entire existence.

Effect of Sintering Process on Microstructure and Properties of (Zr0.2Ta0.2Ti0.2Cr0.2Hf0.2)Si2 High-Entropy Silicide Ceramics

In this study, five kinds of (Zr0.2Ta0.2Ti0.2Cr0.2Hf0.2)Si2 high-entropy ceramics were prepared by a two-step method under different vacuum pressureless pre-sintering processes, and the microstructures and mechanical properties of the ceramics under different parameters of the pre-sintering process were systematically discussed. The results show that the physical structure of the ceramic samples remains basically unchanged by changing the pre-sintering conditions; the longer the holding time of the initial pre-sintering, the higher the densification of the samples and all of them are above 95%. The hardness of the ceramics was around 10 GPa, with the best hardness of 10.11 GPa at 1300 °C for 3 h. This conclusion provides data support for the optimization of the high-entropy ceramics preparation process.

Successive monoculture of Eucalyptus spp. alters the structure and network connectivity, rather than the assembly pattern of rhizosphere and bulk soil bacteria

Eucalyptus as a fast-growing timber tree plays a crucial role in maintaining wood supplication and ecosystem balance worldwide. Nonetheless, the management practices of Eucalyptus plantation in southern China have resulted in productivity decline and soil degradation due to high-intensity successive cultivation. Soil bacteria is a sensitive indicator of soil quality, how does the successive planting of Eucalyptus regulate the soil bacterial community structure for instance the abundance of oligotrophic bacteria, network complexity, and soil bacteria assembly remain ambiguity. To explicate the underlying influencing mechanisms of successive cultivation of Eucalyptus plantations on soil bacterial community structure. Four harvests of Eucalyptus plantations that underwent 0, 1, 2, and 3 times of harvesting were conducted to examine variations in the bacterial community between rhizosphere and bulk soils after successive planting of Eucalyptus. An adjacent evergreen broadleaf forest was employed as control. The present study revealed that successive planting of Eucalyptus increased and reduced the relative abundance of Chloroflexi (oligotrophic bacteria) and Proteobacteria (copiotrophic bacteria), respectively. Continuous planting of Eucalyptus did not modify the assembly pattern of soil bacterial communities, which was governed by stochastic processes. Successive planting of Eucalyptus decreased co-occurrence network complexity, and elevated the proportion of rare microorganisms in the keystone bacterial taxa. Soil particle size composition (clay, silt, sand) indirectly influenced the structure of soil bacterial communities by directly affecting pH, carbon, nutrients, and their stoichiometric ratios. Improving soil physical structure, increasing the input of soil carbon, nitrogen, and other nutrient resources, and maintaining a balanced resource allocation may be effective strategies for ensuring enhanced productivity and sustainable utilization of soil in successive Eucalyptus plantations.

Three-Dimensional Morphological Study of MnTe-like Structures by Assessment of Tortuosity Tensor Using Computational Fluid Dynamics

This paper focuses on a morphological study of the MnTe-like structures, carried out by the evaluation of the tortuosity tensor and other related parameters using a computational fluid dynamics approach recently developed by our research group. The present work focuses on all possible crystals—existing or not developed yet—having the same structure as that of the manganese telluride. This analysis provides new information not present yet in the open literature. The motivation behind this study lies in the importance of this type of structure in physics and material science. In particular, the structures investigated are anisotropic and bi-disperse, with two independent geometrical parameters controlling the structure shape: the ratio of the particle diameters (r1) and the normalised inter-particle distance (r2). Exploiting this fact, several different structures of the same family are created, changing these two parameters independently, also allowing inter-penetration of particles to enlarge the study’s applicability. The results are primarily obtained in terms of the tortuosity tensor, needed to catch and quantify the anisotropy of the structures. Then, other morphological parameters, such as connectivity, principal diffusion directions, and anisotropy factors, are evaluated, obtaining in this way a novel morphological characterisation of the structure. It is found that high values of tortuosity are observed at lower and higher values of {r1, r2}, which means that there exists a minimum value between them. Additionally, the anisotropy factor is found to be higher at lower values of {r1, r2} and lower at higher ones. This is in accordance with the fact that, as the inter-particle distance and the ratio between particle diameters increase, the structure enlarges, which implies a lower influence of the particle distribution and, thus, a gradually more isotropic structure.

Amplitude and time response characterization of avalanche signals in InGaAs single-photon avalanche diode

Photon and dark avalanche signals of InGaAs single-photon avalanche diodes (SPAD) are detected and counted indiscriminately, while their specific characteristics are not well understood, which hinders further performance optimization of InGaAs SPAD. Here, we investigate back-incidence InGaAs SPAD operating at room temperature by designing a dual-threshold discriminator and tuning the threshold voltage. The photon count rate and dark count rates (DCR) exhibit different abrupt-voltage variations with the threshold voltage, and the amplitude distribution of dark avalanche signals is more concentrated and slightly larger than that of photon avalanche signals. The smaller photon avalanche signals have a faster time response. It can be inferred that the above characteristics are related to the photon absorption position and carrier transport, depending on physical structure and operating mode, and dark counts are mainly caused by holes drifting from N-type material. We use a dual-threshold discriminator to reduce the time jitter and DCR caused by thermally excited carriers. The experimental results are in good agreement with theoretical analysis, indicating that the insertion of an i-InP layer or the use of a front-incidence technique can further optimize the overall performance and enable InGaAs SPAD with high performance operation at room temperature.

A radar backscatter simulation of a forest canopy using 3D physical structures derived from LiDAR scanning

ABSTRACT This study aims to explore the forest aboveground biomass relationship to C-band backscatter. A one-hectare area in Wytham Woods, located west of Oxford, was selected for this research. The area has a total of 525 trees of seven different tree species. The Michigan Microwave Canopy Scattering Model (MIMICS), a two-layer radiative transfer model, was applied to simulate canopy backscatter responses in this deciduous UK forest. Model parameters related to forest structure were derived from previously published terrestrial laser (LiDAR) data. Simulated backscatter was performed for co-polarized and cross-polarized modes at a C-band frequency range and incidence angles (20° to 45° at 5° increments). The research includes five objectives: i) backscatter sensitivity analysis from the variation of different model parameters; ii) backscatter seasonal effect under spring–summer (leaf-on) and autumn–winter (leaf-off) periods; iii) backscatter comparison between species as well as between simulated and satellite observations in a spatial pattern; iv) relationship between simulated backscatter and aboveground biomass; and v) relationship between MIMICS forest structure parameters and simulated backscatter. Sensitivity analysis results showed significant differences in backscatter from changes in leaf distribution, leaf thickness and water content (leaf, trunk and soil) for both polarization modes in leaf-on scenarios. Leaf-off scenarios presented significant differences from changes in branch distribution but only for the co-polarized mode. Seasonal variations presented significant backscatter differences between spring–summer and autumn–winter scenarios; additionally, backscatter differences among species for each seasonality in the co-polarized mode were observed. The computation of the grid resolution (20 m × 20 m) showed a range of backscatter values depending on the grid and incidence angle. Higher backscatter values were observed for the satellite data than for the simulated data. Finally, the aboveground biomass and the MIMICS input parameters presented high random variability and little systematic co-variation with the total backscatter on both simulated seasons, suggesting that more robust allometric equations for biomass estimation are required.

Water Quality Modeling of Wastewater Discharges for Prediction of Sediment Transport and Deposition in Surface Water

Sediment deposition in surface water bodies can have a range of significant impacts, affecting everything from the aquatic ecosystem to water quality and infrastructure. It can affect the availability of food sources for aquatic organisms; and change the physical structure of habitats, such as riverbeds and lake bottoms. It can equally smother aquatic plants and animals, leading to a decline in biodiversity. A model of the governing equations of particle motion and fluid flow was developed with COMSOL Multiphysics 5.3a. With a coefficient of determination of 0.99, the model result demonstrated good agreement after result validation using experimental data. According to study findings, sediments in the study area, Ele River move more slowly than sediments in the midstream which causes a high deposition of sediments at the river banks. This sediment deposition affects the irrigation system for crop production considering the ability of the sediments to block sprinkler nozzles which limits it from supplying sufficient water for the production of crops.