Physical Obstructions Research Articles

Enhanced Underground Communication: A Circularly Polarized Smart Antenna with Beam Steering for Improved Coverage

The underground mining industry faces significant challenges in maintaining reliable communication due to multipath fading and physical obstructions, leading to weak signals and dead spots. This study addresses these issues by proposing a smart antenna system with circular polarization and beam steering capabilities. The system utilizes a four-element square patch array and a Butler matrix for beamforming, enabling directional signal transmission. The antenna was designed and optimized using CST simulations. The experimental results demonstrate the antenna’s ability to steer beams in four directions, significantly reducing signal interference and improving coverage. The antenna achieved a bandwidth of 400 MHz (5.52–5.99 GHz) and a gain of up to 9.69 dBi, effectively mitigating polarization mismatches. The novelty of this study lies in the integration of circular polarization and beam steering into a compact, cost-effective system, specifically designed to enhance communication in underground mining environments. This solution improves both safety and operational efficiency by providing reliable communication in harsh conditions.

Contextualizing microplastic pollution in different river habitats through rapid habitat assessment in South Africa

There has been a notable increase in research into microplastics in rivers over the last decade. However, no clear or concise standardized monitoring method exists for the sampling of microplastics in rivers. Many guidelines exist for the sampling and analysis of microplastics from rivers, but researchers continue to use methods and tools that may contaminate samples, such as plankton nets, or collect and filter bulk water samples with differing volumes and numbers of replicates. This can result in the same river system being shown to have notably varying levels of microplastics between sites. The aim of this study was to determine microplastic abundances in water and sediment, together with a critical evaluation of the sampling sites, to ascertain which environmental factors impacted microplastic distribution. This was achieved by applying the rapid habitat assessment method and simultaneously sampling microplastics. The results indicated that factors such as water velocity, physical obstructions to water flow and, most importantly, discharge, can change the context of a site with respect to its microplastic content, which can impact niche-specific organisms. The results were used to develop a new measurement unit, the microplastic discharge unit. The MDU provides a contextualized representation of the microplastics moving through a river, and can be used as an indicator of microplastic pollution at a site and its impact on biota. The results will be used further to produce a guide for the accurate sampling of microplastics in rivers.

Syndromic and Non-Syndromic Primary Failure of Tooth Eruption: A Genetic Overview

Primary failure of tooth eruption (PFE) is a rare genetic disorder characterized by the failure of teeth to erupt in the absence of obvious physical obstructions, often resulting in a progressive open bite that is resistant to orthodontic treatment. While PFE can be caused by genetic or systemic factors (such as cysts, tumors, and endocrine imbalances), the non-syndromic causes are primarily genetic, with an autosomal dominant inheritance pattern with variable expressivity. Several genes have been closely associated with the non-syndromic PFE form. The PTH1R (parathyroid hormone 1 receptor) is the most commonly PFE-associated gene. Additional genes associated with minor frequency are Transmembrane protein 119 (TMEM119), which reduces the glycolytic efficiency of bone cells, limiting their mineralization capacity and causing bone fragility; Periostin (POSTN), which regulates the extracellular matrix and the bone’s response to mechanical stress; and Lysine (K)-specific methyltransferase 2C (KMT2C), which establishes histone methylation near the Wnt Family Member 5A (WNT5A) gene involved in dental development (odontogenesis). Syndromic forms of PFE are typically associated with complex multisystem disorders, where dental eruption failure is one of the clinical features of the spectrum. These syndromes are often linked to genetic variants that affect ectodermal development, craniofacial patterning, and skeletal growth, leading to abnormal tooth development and eruption patterns. Notable syndromes include GAPO syndrome, ectodermal dysplasia, and cleidocranial dysplasia, each contributing to PFE through distinct molecular mechanisms, such as disruptions in dental structure development, cranial abnormalities, or systemic developmental delays. The main aim of this review is to provide a comprehensive overview of the genetic basis underlying both syndromic and non-syndromic forms of PFE to facilitate precision diagnosis, foster the development of personalized therapeutic strategies, and offer new insights into managing this complex dental anomaly.

Exploring the interplay between inflammation and male fertility.

Male fertility results from a complex interplay of physiological, environmental, and genetic factors. It is conditioned by the properly developed anatomy of the reproductive system, hormonal regulation balance, and the interplay between different cell populations that sustain an appropriate and functional environment in the testes. Unfortunately, the mechanisms sustaining male fertility are not flawless and their perturbation can lead to infertility. Inflammation is one of the factors that contribute to male infertility. In the testes, it can be brought on by varicocele, obesity, gonadal infections, leukocytospermia, physical obstructions or traumas, and consumption of toxic substances. As a result of prolonged or untreated inflammation, the testicular resident cells that sustain spermatogenesis can suffer DNA damage, lipid and protein oxidation, and mitochondrial dysfunction consequently leading to loss of function in affected Sertoli cells (SCs) and Leydig cells (LCs), and the formation of morphologically abnormal dysfunctional sperm cells that lay in the basis of male infertility and subfertility. This is due mainly to the production and secretion of pro-inflammatory mediators, including cytokines, chemokines, and reactive oxygen species (ROS) by local immune cells (macrophages, lymphocytes T, mast cells) and tissue-specific cells [SCs, LCs, peritubular myoid cells (PMCs) and germ cells (GCs)]. Depending on the location, duration, and intensity of inflammation, these mediators can exert their toxic effect on different elements of the testes. In this review, we discuss the most prevalent inflammatory factors that negatively affect male fertility and describe the different ways inflammation can impair male reproductive function.

Relationship between fat embolism and endothelial glycocalyx

Fat embolism (FE) is acknowledged as one of the significant causes of sudden death following traumatic injury. To clarify the relevance of vascular endothelial glycocalyx (EGC) damage and FE, temporal changes in the mRNA levels of inflammatory cytokines associated with EGC components were investigated in an experimental fat embolization rat model. Nine-week-old rats were used as FE models through triolein injection (TO) and femoral fracture (FX), and physiological saline was administered to the control group. RT-qPCR and fat staining were performed. The target genes were Il6, Il10, Tnf, Elane, Sdc1, Sdcbp, Vcan, Hyal1, Fn1, and CD14. Notably, FE was detected in 100% and 5.6% of the TO and FX groups, respectively, using fat staining. Bimodal peaks in the mRNA expression levels of Sdc1, Tnf, Elane, IL6, and IL10 were observed 4 and 20 h after treatment in both groups. In the TO group, mRNA expression peaked at 4 h and then declined to the lowest level at 16 h. The incidence of fat emboli due to trauma was consistent with that reported in previous studies. Bimodal mRNA peaks may correspond to FE progression, in which physical obstructions are followed by biochemical reactions. The fluctuation in Sdc1 expression suggests that the initial peak resulted from physical EGC damage. The subsequent peak could be because of EGC damage caused by the secretion of inflammatory cytokines induced by oleic acid from lipid droplet decomposition. These results suggest that EGC disorders caused by lipid droplets may induce lung damage during FE.

Model Predictive Control for Enhanced Trajectory Tracking of Autonomous Deep-Sea Tracked Mining Vehicles

This paper explores the effectiveness of Model Predictive Control (MPC) for trajectory tracking in autonomous deep-sea tracked mining vehicles operating within polymetallic nodule mining environments, considering model uncertainties and external disturbances. Traditional applications of MPC in autonomous vehicle trajectory tracking, which typically rely on kinematic models under minimal external disturbance, often fail when faced with model inaccuracies and external disruptions. To address these challenges, we propose an MPC-based trajectory tracking algorithm that includes a speed correction controller for the drive wheel. This controller, developed through experimental data fitting, aims to mitigate issues such as vehicle body subsidence and track slippage. Tracking accuracy, particularly in curve navigation, is further enhanced through the use of Kalman Filtering (KF) and Adaptive Kalman Filtering (AKF) to counteract external disturbances. Moreover, we introduce an obstacle avoidance strategy utilizing a tri-circular arc trajectory with uniform curvature for path re-planning. This strategy effectively addresses dead zones and physical obstructions encountered during operation. The superiority of our approach compared to conventional Nonlinear MPC (NMPC) is demonstrated through extensive Simulink and Recurdyn co-simulations.

Periodontal management during orthodontic-surgical treatment of maxillary impacted incisors: Acase report

The treatment of impacted teeth is a multidisciplinary process requiring close collaboration between periodontics and orthodontics. Impaction can have several causes, including physical obstructions in the eruption pathway, arch length discrepancies, or dental deformity. The management of these cases lies in the diagnosis established after an appropriate clinical and radiological examination. The age, position, etiology, and amount of space in the dental arch of an unerupted tooth determine how it should be treated. In several cases, orthodontic creating space, removing physical obstructions, and exposing the patient surgically with or without traction are general guidelines for treatment. In addition, ensuring adequate access to the tooth and the possibility of attaching an orthodontic anchor, the periodontal plastic surgery procedures associated with surgical clearance must preserve the integrity of the periodontium of the impacted tooth, as well as that of adjacent teeth, and above all promote the long-term maintenance of their periodontal health.

An agent-based workflow for evaluating interpersonal visibility in healthcare environment

ABSTRACT Healthcare environment design evaluation (HEDE) can help create a safe environment, and interpersonal visibility among users is a key metric for assessing the safety of HEDE due to its role in caregiving observation. Traditional tools for visibility evaluation mainly focus on physical obstructions, neglecting the impact of the user’s mobility behavior, which is common in the healthcare environment. To address this challenge, this study developed a five-step workflow to evaluating interpersonal visibility among mobile users in healthcare environment: 1) collection of empirical behavior data from users; 2) construction of user journeys; 3) validation of agent-based simulation (ABS) reliability; 4) utilization of ABS to simulate user behavior in a virtual environment; and 5) computation of total visibility duration and time intervals between users using the parametric computation tool. This workflow was tested in 25 long-term care facilities for the elderly with dementia and subsequently evaluated by experts. The evaluation results confirm the effectiveness of this workflow. The core contribution and novelty of this workflow lie in its integration of ABS and parametric computation, which enables the evaluation of interpersonal visibility among mobile users, thereby contributing to the safety of the healthcare environment.

RESILIENT CIRCULARITY IN MANUFACTURING: SYNERGIES BETWEEN CIRCULAR ECONOMY AND RECONFIGURABLE MANUFACTURING

Abstract Reconfigurability in manufacturing signifies a system's capacity to promptly adapt to evolving needs. This adaptability is critical for markets to maintain operations during unexpected disruptions, including weather anomalies, cyber-attacks, and physical obstructions. Concurrently, the concept of a circular economy is gaining popularity in manufacturing to mitigate waste and optimize resource utilization. Circular economy principles aim to reduce environmental impacts while maximizing economic benefits by emphasizing the reuse of goods and resource byproducts. The nexus between reconfigurability and the circular economy stems from their shared pursuit of sustainability and resilience. Interestingly, biological ecosystems also exhibit these traits, showcasing exceptional adaptability to disturbances alongside the ability to effectively utilize available resources during normal operations. This study explores various manufacturing system configurations to assess both their adaptability and connection to circular economy principles. 44 configurations are categorized based on layout (e.g., job shop, flow line, cellular) and analyzed using convertibility, cyclicity, and Degree of System Order metrics. A significant positive correlation (R2 = 0.655) is found between high convertibility and ecologically similar levels of structural cycling, suggesting that effective resource utilization supports adaptability in manufacturing systems. Furthermore, this paper proposes the existence of a possible “window of vitality” for cyclicity, as it demonstrates a significant correlation (R2 = 0.855) between the Degree of System Order and cyclicity. Identifying systems that strike a balance between redundancy, efficiency, convertibility, and cyclicity can aid manufacturing system designers and decision-makers in making choices that address increasing requirements for both sustainability and resilience.

Male infertility: an overview of etiology, diagnosis and management

Male infertility, a multifaceted condition characterized by the inability to achieve pregnancy within a partner after a year of unprotected intercourse, affects approximately 7% of men globally. The etiology of male infertility is diverse, including genetic abnormalities, hormonal imbalances, physical obstructions, and lifestyle factors. This review synthesizes current knowledge on the causes, diagnostic methods, and therapeutic interventions for male infertility, with an emphasis on recent advances in genetic and assisted reproductive technologies (ART). The diagnostic approach to male infertility involves a comprehensive evaluation, including semen analysis, hormonal profiling, genetic testing, and imaging techniques, to identify underlying causes. Management strategies range from lifestyle modifications and pharmacological treatments to surgical interventions and ART, such as in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Emerging technologies, including the use of artificial intelligence in semen analysis and the development of novel sperm retrieval techniques, promise to enhance diagnostic accuracy and treatment outcomes. Despite significant progress, challenges remain in improving access to care and addressing ethical considerations in the use of ART. This review highlights the importance of a multidisciplinary approach to the management of male infertility, integrating advances in medical science with considerations of patient well-being and ethical standards. Future research directions include elucidating the genetic basis of idiopathic male infertility, optimizing ART outcomes, and developing personalized treatment strategies. The ultimate goal is to improve the reproductive health and quality of life for affected individuals and couples.

Analysis of Professional Badminton: Performance and Global Disparities

This study analyzes and investigates the impediments of badminton and portrays verifiable player execution measurements utilizing the Badminton World Federation (BWF) World Visit dataset. The consider employments progressed computational strategies such as Python and factual conditions to dismember numerous confinements and benchmarks agent player execution against chronicled information. This examination points to shed light on the physical and vital obstructions that have verifiably influenced players' capacities, giving a comparative viewpoint on the improvement of badminton. In expansion, this ponder analyzes the socio-cultural variables and framework advancement that have impacted the advancement of badminton. By joining a wide extent of information focuses and expository procedures, this consider looks for to supply a comprehensive understanding of the advancement of badminton and the variables that drive tip top execution. The arrange and structure of this document strictly follows to the desired rules submitted to Trans Tech Distributions for camera generation, guaranteeing compliance with endorsed page format and typographical traditions.

ANALYSIS OF A PRECAST SEGMENTAL BRIDGE WITH RCC BRIDGE USING CSI BRIDGE SOFTWARE: A REVIEW

Bridges are those structures which built to span physical obstructions without closing the way underneath such as a water body, valley, or roads the purpose is to provide passage over obstructions. Precast bridges with segmental structure are commonly used for long span, due to researchers increasing interest in bridge modeling by using various span condition to check deflection of segmental bridge and RCC bridge, segmental bridge shows better results in comparison to RCC bridge, which is economical for longer spans, as the span increases then the most important factor dead load also increases. In This Paper We Are Conduction A Research On “Analysis Of A Precast Segmental Bridge With Rcc Bridge Using Csi Bridge Software”.

Geophysics for the environment in Indonesia

This paper explores the hidden potential of geophysics for the environment, focusing on subsurface mapping activities in Indonesia. Geophysics plays a crucial role in understanding the Earth’s physical characteristics and addressing environmental challenges. It is particularly relevant in water-related environmental problems, such as groundwater contamination and infiltration monitoring. Geophysics is also used to detect metals in fertile soils and plants, providing insights into agricultural practices and potential health risks. However, applying geophysics in urban areas poses challenges due to physical obstructions, cultural noise, limited workspace, permits, and safety concerns. This article emphasizes the integration of geophysics with environmental studies, the need for further research on water-related environmental problems and metal detection, and the development of techniques tailored for urban environments. It suggests focusing on understanding the specific environmental challenges in Indonesia and leveraging advancements in technology for more accurate and efficient geophysical investigations. In the Indonesian context, geophysics has diverse applications, including energy exploration, seismology, and oceanography. However, it has not been properly utilized in the field of environmental studies, particularly in urban areas.

Suppressing a Blocked Balance Recovery Step: A Novel Method to Assess an Inhibitory Postural Response.

Stepping to recover balance is an important way we avoid falling. However, when faced with obstacles in the step path, we must adapt such reactions. Physical obstructions are typically detected through vision, which then cues step modification. The present study describes a novel method to assess visually prompted step inhibition in a reactive balance context. In our task, participants recovered balance by quickly stepping after being released from a supported forward lean. On rare trials, however, an obstacle blocked the stepping path. The timing of vision relative to postural perturbation was controlled using occlusion goggles to regulate task difficulty. Furthermore, we explored step suppression in our balance task related to inhibitory capacity measured at the hand using a clinically feasible handheld device (ReacStick). Our results showed that ReacStick and step outcomes were significantly correlated in terms of successful inhibition (r = 0.57) and overall reaction accuracy (r = 0.76). This study presents a novel method for assessing rapid inhibition in a dynamic postural context, a capacity that appears to be a necessary prerequisite to a subsequent adaptive strategy. Moreover, this capacity is significantly related to ReacStick performance, suggesting a potential clinical translation.

Evaluation of Dual Domain Mass Transfer in Porous Media at the Pore Scale.

Dual-porosity models are often used to describe solute transport in heterogeneous media, but the parameters within these models (e.g., immobile porosity and mobile/immobile exchange rate coefficients) are difficult to identify experimentally or relate to measurable quantities. Here, we performed synthetic, pore-scale millifluidics simulations that coupled fluid flow, solute transport, and electrical resistivity (ER). A conductive-tracer test and the associated geoelectrical signatures were simulated for four flow rates in two distinct pore-scale model scenarios: one with intergranular porosity, and a second with an intragranular porosity also defined. With these models, we explore how the effective characteristic-length scale estimated from a best-fit dual-domain mass transfer (DDMT) model compares to geometric aspects of the flow field. In both model scenarios we find that: (1) mobile domains and immobile domains develop even in a system that is explicitly defined with one domain; (2) the ratio of immobile to mobile porosity is larger at faster flow rates as is the mass-transfer rate; and (3) a comparison of length scales associated with the mass-transfer rate (Lα ) and those associated with calculation of the Peclet number (LPe ) show LPe is commonly larger than Lα . These results suggest that estimated immobile porosities from a DDMT model are not only a function of physically mobile or immobile pore space, but also are a function of the average linear pore-water velocity and physical obstructions to flow, which can drive the development of immobile porosity even in single-porosity domains.

Study on coupling characteristics of supersonic inlet and pulse detonation combustor

Coupling model for two-dimensional mixed-compression supersonic inlet with Mach number of 2.5 at design point and pulse detonation combustor was established, and three working schemes were designed to investigate multi cycle working process by using unsteady numerical simulation with chemical reaction. The results show that the following two measurements can both restrain the back-propagating compression wave and broaden the stability margin of the inlet and increase the frequency, one of which is the pressure relief at the outlet of the combustor, the other is valve at the inlet of the combustor. Nevertheless, the former will lose thrust, while the latter can greatly increase thrust. Meanwhile, the valve will reflect the compression wave in the production; increase the turbulence in the combustor, and make the gas entrained into the diffuser section of the inlet at the moment of opening the valve. However, the reflected compression wave in the hot production will not affect the velocity and shape of the detonation wave. Furthermore, in the period of detonation wave initiation and propagation, the blockage ratio of physical obstructions at the inlet of the combustor should be expanded as much as possible. At the same time, the flow at the outlet of the inlet should not be blocked to increase the flow resistance.

Jamming Threats in Free-Space Optics

Free space optical (FSO) technology has recently found a strong foothold in the telecommunication market due to its technical superiority and high-end applicability. Its technological advancement has caused rising implementation of FSO systems in defence, aerospace, and telecommunication industries. Although it is cutting edge, the fundamental benefits of this technology may be adversely affected by several foreign elements such as atmospheric turbulence, physical obstructions, and weather conditions. Along with these natural disrupting phenomena, for the deployment of FSO systems in security-constrained sectors like military and defence units, where extra data protection mechanism is needed, fabricated adversaries like jamming become feasible which is concerning for FSO applicability. It therefore becomes a challenging task to decipher legitimate FSO data in the presence of jammers and to secure an FSO system from jamming activities. On this account, a detailed discussion on jamming effects in FSO communication systems is showcased in this article. Also, the potential efforts to mitigate jamming in FSO networks are highlighted.

Intelligent and Reliable Millimeter Wave Communications for RIS-Aided Vehicular Networks

Utilizing the millimeter-wave (mmWave) frequency is a promising solution to meet fast-growing traffic demand over wireless networks. However, mmWave communications are sensitive to physical obstructions on signal propagation. In this paper, the reconfigurable intelligent surfaces (RISs) are investigated to overcome the limitations of mmWave communications. Particularly, an RIS is deployed to reflect the mmWave signals towards vehicular users who experience direct link blockages that may occur due to static or dynamic obstacles. To this end, a risk-averse optimization problem is designed to optimize the Base Station (BS) precoding matrix and the RIS phase shifts under stochastic link blockages. A solution approach is developed in two phases: the BS precoding optimization and the RIS phase shift control phases. In the first phase, a Decomposition and Relaxation-based Precoding Optimization (DRPO) algorithm is developed to obtain the optimal precoding matrix. In the second phase, a learning-based method is introduced to dynamically adjust the direction of reflected signals under channel uncertainty. Extensive simulations are presented to validate the efficacy of the developed algorithms. The obtained results show that the developed algorithms can ensure reliable transmissions to users in non-LoS areas and improve network performance.

Ungulates and trains – Factors influencing flight responses and detectability

Wildlife-train collisions can have deleterious effects on local wildlife populations and come with high socio-economic costs, such as damages, delays, and psychological distress. In this study, we explored two major components of wildlife-train collisions: the response of wildlife to oncoming trains and the detection of wildlife by drivers. Using dashboard cameras, we explored the flight response of roe deer (Capreolus capreolus) and moose (Alces alces) to oncoming trains and explored which factors, such as lighting and physical obstructions, affect their detection by drivers. In a majority of cases, roe deer and moose fled from an oncoming train, at an average flight initiation distance (FID) of 78 m and 79 m respectively. Warning horns had unexpected influences on flight behaviour. While roe deer initiated flight, on average, 44 m further away from the train when warned, they usually fled towards the tracks, in the direction of danger. FID of moose, however, was unaffected by the use of a warning horn. As train speed increased, moose had a lower FID, but roe deer FID did not change. Finally, detection of wildlife was obstructed by the presence of vegetation and uneven terrain in the rail-side verge, which could increase the risk of collisions. Our results indicate the need for early detection and warning of wildlife to reduce the risk of collisions. We propose that detection systems should include thermal cameras to allow detection behind vegetation and in the dark, and warning systems should use cues early to warn of oncoming trains and allow wildlife to escape the railway corridor safely.

Modeling time delay, external noise and multiple malware infections in wireless sensor networks

The essentiality of wireless sensor networks (WSNs) in military and health applications cannot be overemphasized, and this has made these tiny sensors soft targets for malware attacks. However, with the ubiquity of single-group infection models, few researchers have studied the effects of many concurrent infection types on WSNs. Therefore, we proposed the differential Susceptible–Exposed (virus)–Exposed (worm)–Infectious (virus)–Infectious (worm)–Recovered–Susceptible with Vaccination (SE1E2I1I2RV) epidemic model in order to study the dynamics of malicious-code dissemination in WSNs. Using the multi-group model, which represents multiple infections due to worms and viruses, first, delay analyses were performed and, through the Routh-Hurwitz criteria, sufficient conditions for stability were established. Secondly, the SE1E2I1I2RV model was extended to incorporate external noise, thereby changing the deterministic nature of the original model and allowing stochastic analyses for random factors such as temperature, physical obstructions, etc. The role that delay plays in the model is shown when it surpasses the critical value, thus the system loses stability and allows the occurrence of a Hopf bifurcation. Finally, numerical simulations were performed using Matlab in order to account for theoretical analyses.