Search Results (852)

Passive evaporative cooling technology using the building envelope is a crucial measure to mitigate the urban heat island effect. This study aims to enhance the cooling efficiency of the surface of enclosure structures by utilizing volcanic ash, potassium–sodium stone powder, and silica-based mesoporous oxide (SMO) as primary materials. These components are incorporated into the ceramic brick production process to create innovative humidity-controlling ceramic bricks (HCCTs). This study extensively investigates the impact of SMO and the amount of applied glaze on the physical and mechanical characteristics of these HCCTs. Additionally, it examines the water absorption and evaporative cooling properties of the studied materials under optimal substitution conditions. Numerical calculations are used to determine the heat and moisture transfer properties of HCCTs. The results indicate that incorporating 2% SMO and applying 70 g/m² of glaze results in a moisture absorption capacity of 385 g/m² and a moisture discharge capacity of 370 g/m². These conditions also yield a notable flexural strength of 15.2 MPa. Importantly, the HCCTs exhibit significantly enhanced capillary water absorption and water retention capabilities. Increased water absorption reduces surface temperature by 2–3 °C, maintaining the evaporative cooling effect for 20 to 30 h. It is also found that the temperature of HCCTs decreases linearly with increasing water content and porosity, while the temperature difference gradually decreases with thickness. Water migration in HCCTs with greater thickness is notably influenced by gravity, with water moving from top to bottom. Therefore, it is recommended that brick thickness does not exceed 15 mm. Full article

Rock burst is a worldwide prevention and control problem, and the main reason for its occurrence is the concentration of stress in the surrounding rock of the coal roadway. Therefore, it is of great significance to realize the rapid and accurate detection of the stress distribution in the surrounding rock of the roadway for the prevention and control of rock burst. Based on the principle of charge induction, this paper adopts a research method combining theoretical analysis and indoor and field tests to carry out a study on the charge induction detection of stress distribution of surrounding rock in coal seam roadways using the self-developed coal rock charge induction monitor. A theoretical analysis of the charge induction intensity in relation to the stress level is carried out. Indoor tests on the law of charge induction for graded loading of large sized coal samples are carried out. Field detection tests of the charge induction law at different drilling depths on the solid coal side and the large coal pillar side of the coal seam roadway are carried out. The results show a positive correlation between the charge signal intensity and the stress magnitude. The induced charge of coal samples has a tendency to increase with the increase in graded loading stress level. The magnitude of the induced charge can reflect the stress level of the coal body. On the solid coal side, the induced charge has a tendency of increasing and then decreasing with the increase in detection depth. The final results are in good agreement with the results of the drill chip method, which better reflects the distribution of the lateral support pressure of the roadway. On the side of the large coal pillar, the induced charge has a tendency to increase, then decrease, and then increase with the increase in probing depth, which is in good agreement with the distribution of lateral support pressure formed in the elastic core area of the large coal pillar. Therefore, the charge induction technology can be used as a fast, non-contact detection means for the partitioning and stress distribution of the roadway enclosure, which can provide guidance for the target prevention and controlling rock burst and for designing roadway support. Full article

The newly constructed Bois d’Arc Lake Reservoir in Fannin County, Texas, USA, inevitably flooded a large ground surface area (67.34 km²) when the reservoir began impounding water in April 2021. Inside this (now) flooded area, land-based archaeological data recovery investigations discovered and documented several archaeological sites, now registered in the state of Texas; though, only two neighboring sites, namely, 41FN178 and 41FN244, are examined here. The first phase of archaeological testing at these sites included shovel testing, test unit excavations, and geoarchaeological trenching that yielded archaeological artifacts suggesting that Middle Caddo Indian peoples (AD 1200–1400) might have occupied this landscape. As the sites were recognized before the reservoir’s impoundment phase, this merited a non-invasive, non-destructive, high-resolution near-surface geophysical study to map strategic areas within sites 41FN178 and 41FN244 that might yield potential shallow targets of archaeological context. The adopted geophysical survey comprised 3D direct current electrical resistivity imaging (ERI) and land horizontal magnetic gradiometry (HMG), each mapping a total surface area of 2133 and 15,640 m², respectively. The combination of 3D ERI and land HMG surveys was instrumental in rapidly mapping the horizontal and vertical extent of shallowly buried anomalies within a large area prior to the completion of the dam and the beginning of water impoundment. Based on the geophysical insights, the outline of several Caddo houses with functional internal and external features (e.g., burnt cooking surfaces, storage pits, refuse pits, fired soil, ditches, a dump site, and a compound fence) are thought to exist within the uppermost 2 m of the Quaternary stratigraphy at both sites. At site 41FN244, 3D ERI found numerous resistive anomalies surrounding a conductive anomaly, collectively interpreted as a group of post-holes surrounding the remains of a Caddo house’s inner clay floor. It also found a cluster of several resistive anomalies interpreted as midden or middens. The HMG survey carried across areas from which archaeological test units also yielded positive findings, at sites 41FN178 and 41FN244, identified numerous scattered monopolar and dipolar anomalies interpreted as post-molds of Caddo houses, compound enclosures or fences, and adjacent middens. Archaeological excavations guided by the geophysical results yielded significant cultural material and post-mold features at site 244, which validate the geophysical interpretation in a preliminary context. Additionally, several dispersed magnetic anomalies are thought to be shallowly buried hearths, burn cooking surfaces, storage pits, and ditches. The mapped magnetic anomalies agree with the location and distribution of previously found archaeological artifacts and the extent of resistive and conductive resistivity anomalies. Follow-up archaeological excavations of these geophysical anomalies have preliminarily confirmed interpretations. Full article

Low-frequency working standards of inductance are generally uniformly wound toroids on a ceramic core. Planar inductors made using printed circuit board (PCB) technology are simple and cheap to manufacture in comparison to inductors wound on toroid cores, but they are significantly prone to the influence of external magnetic fields. In this paper, we propose the design of a PCB inductance working standard of 10 μH, consisting of a duplex system of planar PCB coils, electrostatic shielding, and an enclosure. Alongside an electromagnetic analysis and design procedure, the measurements on the manufactured prototype included the generated magnetic field, the thermal time constant of the enclosure, temperature coefficients, and its error analysis. The measurements show negligible generated magnetic fields (<$1.68\mathrm{n}\mathrm{T}\mathrm{a}\mathrm{t}7\mathrm{c}\mathrm{m}$, 49 mA, 10 kHz). The minimum thermal time constant of the enclosure is 1270 s and the temperature coefficient of resistance is $0.003841/℃$. The presented method of temperature coefficient measurement using a climate chamber allows for measurements in the temperature range of 10 °C to 40 °C. In this temperature range, the results show an inductance variation of 0.05 µH at 50 kHz, while the uncertainty of inductance measurement at this frequency was 0.03 µH (k = 2). Full article

For decades, the traditional precepts of “Turkish Islam” have defined the community structure for Turkish immigrants in The Netherlands. Today, spiritualism rather than Islamic morality is emerging as the more compelling religious practice among young people, especially among women who are looking to break out of their culturally enclosed communities. This study uses the terms “enclosure” and “opening up” as metaphors for immigrant participation in Dutch society and suggests that religious Muslim women immigrants are both the founders and dismantlers of the two metaphors. Through their own narratives, women are shown to challenge and resolve social compartmentalization, and the role of cultural transmission through “Ummahtism” (the global Islamic community) is detailed as it is reinterpreted in Europe by Dutch–Turkish women. The findings of this paper are based on field research conducted in The Netherlands between September 2020 and April 2022. Full article

This paper presents an examination regarding the DC–DC converter output behavior at variable loads. An example of a circuit with two-quadrant operation with different control methods is shown. The presented mathematical approach is used to determine the main output values and could have an enclosure as the calculation methodology. The examination data for the step-down circuit configuration with a single-ended output LC filter are provided. A modified excel model is used to extract the parameters for the circuit output gain at the rated frequency. The simulations of the load factor variation are shown in four different plots, where the area of the steady operation is presented. The results are derived to estimate the relationship between the circuit output and load characteristics’ deviation. The converter dynamic range of the operation is determined by the presented graphics. A proper LC output filter design is essential for reducing the ripple currents and increasing the overall circuit effectivity. Full article

With the increasing energy consumption in buildings, the proportion of energy consumption in public buildings continues to grow. As an essential component of public buildings, sports buildings are receiving more attention regarding energy-saving technologies. This paper aims to study the passive energy-saving design methods of small-and medium-sized sports halls in hot summer and cold winter regions, exploring how to reduce building energy consumption by improving the spatial design and thermal performance of the enclosure structures of sports halls. Taking the Wuhu County Sports Center as an example, this study uses computer simulation software to analyze the building’s wind environment and the thermal performance of its external walls and roof. The results show that the large volume of the sports hall significantly impacts the distribution of wind speed and pressure around it, and this impact decreases with height. The thermal simulation of the enclosure structures demonstrates that adding insulation layers to the interior and exterior of the walls and roof of the sports hall is an effective way to reduce energy consumption in both winter and summer. Additionally, wind environment simulations of different roof shapes reveal that flat roofs have the most significant blocking effect on wind and are prone to inducing strong vortices on the leeward side; concave arch roofs have the least blocking effect on airflow, and arch and wave-shaped roofs maintain lower vortex intensity on the leeward side. Hopefully, this study can provide significant references for the energy-saving design of future small- and medium-sized sports buildings. Full article

Studies on environmental enrichment for captive bearded dragons (Pogona vitticeps) are still very scarce in the literature, but they are of the utmost importance in the search for quality of life for these animals when they are under human care. Environmental enrichment items should be inclusive, allowing disabled animals to explore them and providing good experiences. Therefore, this study aimed to evaluate food enrichment strategies to increase the foraging behavior of captive non-disabled and disabled bearded dragons. This work was carried out with six adult bearded dragons, three of which had one limb amputated and three that had all limbs, kept at the São Paulo Aquarium. Live kingworm larvae (Zophobas morio) were offered as food in three different levels of enrichment challenge (low, medium, high). Behavioral data were collected using focal sampling with instantaneous recording, with a time interval of every 30 s. Results showed that the more complex the food enrichment challenge, the greater the frequency of bearded dragon foraging. In addition, both amputees and non-amputees responded similarly to the enrichment items, differing primarily in their activity levels, where amputee individuals showed more tendencies toward ‘stationary’ and ‘lying down’ behaviors. More studies with reptiles should be encouraged so that good management practices become daily protocols for a better quality of life and for rescuing the natural behaviors of animals kept under human care, even those with anatomical disabilities. Full article

In this study, we implemented a compact wind direction sensor on a palm-sized quadcopter to achieve wind source localization (WSL). We designed an anemotaxis algorithm based on the sensor data and experimentally validated its efficacy. Anemotaxis refers to the strategy of moving upwind based on information on the wind direction, which is essential for tracing odors propagating through the air. Despite the limited research on quadcopter systems achieving WSL directly through environmental wind measurement sensors, debate remains regarding the relationship between sensor placement and the anemotaxis algorithm. Therefore, we experimentally investigated the placement of a wind direction sensor capable of estimating wind source direction even when propellers are rotating. Our findings demonstrated that placing the sensor 50 mm away from the enclosure of the quadcopter allowed accurate wind direction measurement without being affected by wake disturbances. Additionally, we constructed an anemotaxis algorithm based on wind direction and speed data, which we integrated into the quadcopter system. We confirmed the ability of the quadcopter to execute anemotaxis behavior and achieve WSL irrespective of environmental wind strength through wind source localization experiments. Full article

Gated communities have spread globally, though unevenly. However, their early popularity and expansion from North America to other different localities have led to their physical and social diversification (i.e., morphological design and locking mechanisms and their resident profiles, which are not limited to the richest classes). This diversity has resulted in varied and sometimes conflicting concepts and classification criteria. Given this situation, this study aims to propose a typology of these developments that encompasses all current forms, based on an exhaustive census we compiled. We used a broader concept adapted to the research context, that of the ‘Residential Compound’, based on the idea that total closure is not an essential condition for consideration. Although the empirical work is based on the metropolitan area of Granada (Spain), we believe it is representative of most Spanish and possibly European metropolitan areas. Using satellite images and the Spanish electronic cadastre, we compiled a census of 642 residential compounds, classified based on over 50 variables. These compounds were categorized into five types depending on the enclosure level: (1) protected compounds; (2) controlled compounds; (3) structurally self-isolated compounds; (4) individualistic compounds; and (5) symbolic compounds. Full article

Unusual or extraordinary circumstances can cause change to normal husbandry regimes and daily care of managed animals. Increased biosecurity due to disease risk, for example, results in animals experiencing restrictions. Outbreaks of Highly Pathogenic Avian Influenza (HPAI) have caused zoos to remove birds from their regular exhibits and manage them indoors or in covered enclosures to reduce the likelihood of an HPAI outbreak on site. To date, there has been little research on the impacts of such husbandry change on bird behaviour and welfare. This paper examines the effect of an HPAI-induced enforced housing order (HO) on the behaviour and physical condition of a flock of Chilean flamingos in a UK zoo. Using ZooMonitor to record flock-wide behaviour patterns and scoring plumage condition, we collected data on flamingos during a housing order, immediately after lifting of the HO, and after a period of acclimation to their regular routine. Results showed that flamingos were very inactive under a HO and after release, that abnormal, redirected foraging actions occurred during the HO and after release, and that flamingos were more alert under the HO. An increase in records of good plumage condition correlated with social behaviour, inactivity, higher temperatures, and rain. This research highlights the multifactorial influences on zoo animal behaviour and shows why information on the animals, their inputs, the behavioural outputs they present, and their physical attributes should all be gathered and evaluated together to best understand the influences of husbandry and management changes on behaviour and welfare. Full article

The phenomenon of natural convection is the subject of significant research interest due to its widespread occurrence in both natural and industrial contexts. This study focuses on investigating natural convection phenomena within triangular enclosures, specifically emphasizing a valley-shaped configuration. Our research comprehensively analyses unsteady, non-dimensional time-varying convection resulting from natural fluid flow within a valley-shaped cavity, where the inclined walls serve as hot surfaces and the top wall functions as a cold surface. We explore unsteady natural convection flows in this cavity, utilizing air as the operating fluid, considering a range of Rayleigh numbers from Ra = 10⁰ to 10⁸. Additionally, various non-dimensional times τ, spanning from 0 to 5000, are examined, with a fixed Prandtl number (Pr = 0.71) and aspect ratio (A = 0.5). Employing a two-dimensional framework for numerical analysis, our study focuses on identifying unstable flow mechanisms characterized by different non-dimensional times, including symmetric, asymmetric, and unsteady flow patterns. The numerical results reveal that natural convection flows remain steady in the symmetric state for Rayleigh values ranging from 10⁰ to 7 × 10³. Asymmetric flow occurs when the Ra surpasses 7 × 10³. Under the asymmetric condition, flow arrives in an unsteady stage before stabilizing at the fully formed stage for 7 × 10³ < Ra < 10⁷. This study demonstrates that periodic unsteady flows shift into chaotic situations during the transitional stage before transferring to periodic behavior in the developed stage, but the chaotic flow remains predominant in the unsteady regime with larger Rayleigh numbers. Furthermore, we present an analysis of heat transfer within the cavity, discussing and quantifying its dependence on the Rayleigh number. Full article

A prestressed concrete containment is the enclosure structure of a nuclear reactor that serves as the last physical barrier of a nuclear power plant (NPP) safety defense system. It plays a key role in the prestress time-limited aging analysis (TLAA) required for operating license extensions for NPPs. Considering prestress containment systems without long-term monitoring tendons in a nuclear power plant, the technical route for prestress TLAAs involves analyzing operating license extension regulations and in-service monitoring technical requirements for prestressed tendons performance. Using tendons based on theoretical calculations of prestress loss in a nuclear power plant and the minimum required value of prestress determined by numerical simulation, the theoretical predictive value can be compared with the minimum required value for prestressed steel tendons. This comparison can be used to evaluate the 20-year life extension of the prestress system and provide a reference for aging and life management of NPPs. Full article

The debate about how to conduct energy interventions in built heritage remains open. At present, the various European and national regulations allow the absence of energy intervention in cases where the character of a building with recognized heritage value would be jeopardized. This situation means that heritage preservation and energy improvement are divided into two airtight and unconnected blocs. It is possible and necessary to break that dichotomy by taking steps that enable both blocs to interrelate. Based on a methodology previously proposed by the authors to regulate changes in the urban landscape due to the rehabilitation of residential building façades, as a novel aspect, this article proposes taking a further step in the methodological process. Several criteria to balance the level of energy intervention for all buildings are thus introduced, according to the urban and architectural characteristics of each building, irrespective of their use and degree of protection. It is concluded that such a balance is possible when certain indicators are used and when determined action criteria are applied. However, one of the architectural characteristics more susceptible to being affected when undertaking an energy intervention on a building’s thermal enclosure is the materiality, which becomes especially important in the case of brutalist architecture with reinforced concrete, one of its most identifying features, giving it a specific personality. That architectural movement was therefore chosen for a case study, applying the proposed methodology to three brutalist buildings in the area of San Sebastián, Spain. Full article