Local Spots Research Articles

Improved thermal hydraulic network modelling and error analysis in disc‐type transformer windings

AbstractTemperature distribution in transformer windings is a crucial factor that influences the safe operation, and lifespan of an insulating system in an oil‐immersed power transformer. Thermal hydraulic network modelling (THNM) has been the subject of numerous studies because of its lower computation cost as compared to a computational fluid dynamics (CFD) simulation. This study proposes improvements to THNM, with primary focus on non‐uniformity of temperatures in the entry and exit vertical oil ducts, and the feasibility of using a piecewise fitting formula for Nusselt number (Nu) of convection heat transfer coefficient in transformer windings. The deviation of hot spot temperature was 0.3°C, and the location of hot spot for CFD and THNM was 34th disc and 35th disc, respectively. The calculation time of CFD and THNM was about 34 h and 35 s under the same computer hardware situations. This provides an acceptable THNM method for the rapid prediction of transformer hot spot temperature and location at low costs for digital twin.

STRATEGI PENGEMBANGAN OBYEK WISATA TAMAN BEJI GRIYA WATERFALL DI DESA PUNGGUL KEC. ABIANSEMAL BADUNG BALI

This research aims to identify the strengths, weaknesses, opportunities, and threats, as well as the development strategy of the Taman Beji Griya Waterfall tourism object in Punggul Village, Abiansemal Sub-district, Badung Regency, Bali. The analytical tools used are EFAS, IFAS, and SWOT analysis to formulate strategies for achieving goals based on logic to maximize strengths and opportunities while minimizing weaknesses and threats. The results of this research are as follows: Opportunities include government policies in tourism development, collaboration with local and adjacent tourist spots, government support in digitally promoting tourist destinations, the potential development of tourist spots with additional attractions, and the increasing popularity of natural and spiritual tourism. Threats include the impact of climate change and its effects on tourist attractions, public interest in other tourism object destinations, and a lack of awareness of the positive impact of natural and spiritual tourism among the community, as well as the emergence of spiritual tourism in various places in Bali. Strengths include a strategically located, easily accessible tourist spot, natural beauty and scenery, the availability of facilities such as restaurants and coffee shops, there are construction of roads or paths to the tourist park, the support and involvement of the local community, and Taman Beji Griya Waterfall as a natural and spiritual attraction. Weaknesses include ineffective promotion of tourist spots, a lack of security and comfort for tourists' belongings, ineffective management, and limitations in visitor facilities. The suitable strategy for the development of the Taman Beji Griya Waterfall tourism object in Punggul Village, Abiansemal Sub-district, Badung Regency, based on SWOT analysis, is the Strength-Opportunities strategy.

Surface distribution of small-scale magnetic field on the active cool star LQ Hydrae

It is well known that small-scale magnetism dominates the surface magnetic field topologies of active late-type stars. However, little information is available on the spatial distribution of this key magnetic field component. Here, we take advantage of the recently developed magnetic field diagnostic procedure relying on the magnetic intensification of iron atomic lines in the optical. We extend this methodology from measuring a single average field strength value to simultaneous Doppler imaging reconstruction of the two-dimensional maps of temperature and magnetic field strength. We applied this novel surface mapping approach to two spectroscopic data sets of the young active Sun-like star LQ Hya. For both epochs, we found a fairly uniform field strength distribution, apart from a latitudinal trend of the field strength increasing from 1.5–2.0 kG at low latitudes to 3.0–3.5 kG, close to the rotational poles. This distribution of the small-scale field does not display a clear correlation with the locations of temperature spots or the global magnetic field structure reconstructed for the same epochs.

IMPDH2 forms spots at branching sites and distal ends of astrocyte stem processes.

Inosine monophosphate dehydrogenase (IMPDH) is a rate-limiting enzyme in the de novo GTP biosynthesis pathway. Recent studies suggest that IMPDH2, an isoform of IMPDH, can localize to specific subcellular compartments under certain conditions and regulate site-specific GTP availability and small GTPase activity in invasive cancer cells. However, it is unclear whether IMPDH2 plays a site-specific regulatory role in subcellular functions in healthy cells. In this study, we focused on brain cells and examined the localization pattern of IMPDH2. We discovered that IMPDH2 forms localized spots in the astrocytes of the adult mouse hippocampus. Further analysis of spot distribution in primary astrocyte cultures revealed that IMPDH2 spots are predominantly localized on branching sites and distal ends of astrocyte stem processes. Our findings suggest a potential unidentified role for IMPDH2 and GTP synthesis specifically at specialized nodes of astrocyte branches.

Detecting local spots in network materials prone to mechanical failure

AbstractThe prediction of the onset of fracture is a challenging issue in the mechanics of disordered materials. In this contribution, we show that the fracture process in network glasses, such as silica glass, turns out to be a complex phenomenon that originates from specific spots that have the size of a few hundred atoms only. We apply pure shear deformation to identify local rearrangement spots prone to material damage. These spots are analyzed using stress drop steps, originally used for densely packed disordered systems.

Influence of Dose, Particle Size and Concentration on Dermal Penetration Efficacy of Curcumin.

The influence of size, particle concentration and applied dose (finite vs. infinite dose) on the dermal penetration efficacy of curcumin was investigated in this study. For this, curcumin suspensions with different particle sizes (approx. 20 µm and approx. 250 nm) were produced in different concentrations (0.625-5% (w/w)). The dermal penetration efficacy was determined semi-quantitatively on the ex vivo porcine ear model. The results demonstrated that the presence of particles increases the dermal penetration efficacy of the active compounds being dissolved in the water phase of the formulation. The reason for this is the formation of an aqueous meniscus that develops between particles and skin due to the partial evaporation of water from the vehicle after topical application. The aqueous meniscus contains dissolved active ingredients, and therefore creates a small local spot with a locally high concentration gradient that leads to improved dermal penetration. The increase in penetration efficacy depends on the number of particles in the vehicle, i.e., higher numbers of particles and longer contact times lead to higher penetration efficacy. Therefore, nanocrystals with a high particle concentration were found to be the most suitable formulation principle for efficient and deep dermal penetration of poorly water-soluble active ingredients.

Revisiting a classical theory of sensory specificity: assessing consistency and stability of thermosensitive spots.

Thermal sensitivity is not uniform across the skin, and is particularly high in small (∼1 mm2) regions termed "thermosensitive spots." These spots are thought to reflect the anatomical location of specialized thermosensitive nerve endings from single primary afferents. Thermosensitive spots provide foundational support for "labeled line" or specificity theory of sensory perception, which states that different sensory qualities are transmitted by separate and specific neural pathways. This theory predicts a highly stable relation between repetitions of a thermal stimulus and the resulting sensory quality, yet these predictions have rarely been tested systematically. Here, we present the qualitative, spatial, and repeatability properties of 334 thermosensitive spots on the dorsal forearm sampled across four separate sessions. In line with previous literature, we found that spots associated with cold sensations (112 cold spots, 34%) were more frequent than spots associated with warm sensations (41 warm spots, 12%). Still more frequent (165 spots, 49%) were spots that elicited inconsistent sensations when repeatedly stimulated by the same temperature. Remarkably, only 13 spots (4%) conserved their position between sessions. Overall, we show unexpected inconsistency of both the perceptual responses elicited by spot stimulation and of spot locations across time. These observations suggest reappraisals of the traditional view that thermosensitive spots reflect the location of individual thermosensitive, unimodal primary afferents serving as specific labeled lines for corresponding sensory qualities.NEW & NOTEWORTHY Thermosensitive spots are clustered rather than randomly distributed and have the highest density near the wrist. Surprisingly, we found that thermosensitive spots elicit inconsistent sensory qualities and are unstable over time. Our results question the widely believed notion that thermosensitive spots reflect the location of individual thermoreceptive, unimodal primary afferents that serve as labelled lines for corresponding sensory qualities.

Facies and trace fossils of the Upper Cretaceous Sillakudi Formation (Cauvery Basin, S. India) and their palaeoenvironmental significance

The Sillakudi Formation is a sandstone-dominated succession bounded by unconformities. It represents the oldest unit of the Ariyalur Group deposited during the Campanian under fully established passive margin depositional conditions. The present study is an attempt to interpret the depositional palaeoenvironment of Sillakudi Formation based on its trace fossil content, supported by sedimentological evidences. Detailed sedimentological and ichnological observations were undertaken in multiple traverses and spot locations across the Sillakudi Formation. The Sillakudi Formation is subdivided into four facies associations, each represented by a distinct ichnology and environment of deposition. Unit 1 comprises conglomerates grading upwards into pebbly sandstones almost devoid of trace fossils except a few Planolites isp. indicating a high-energy foreshore-to-shoreface environment. Unit 2 consists of glauconitic sandstones with Ophiomorpha nodosa, O. annulata, Thalassinoides isp. and Skolithos linearis, belonging to the Skolithos ichnofacies indicating deposition in shoreface to offshore transition environments. Unit 3 comprises pebbly to very coarse-grained massive sandstones, characterised by an almost monospecific Skolithos ichnofacies indicating rapid colonisation of beds in a delta-front associated debris flows and calcareous sandstones alternating with claystones containing a diverse Cruziana ichnofacies with an ichnoassemblage comprising of Trichichnus isp., Scolicia prisca var. laminites, S. ?prisca, S. vertebralis, Palaeophycus tubularis, Planolites beverleyensis, P. montanus, Taenidium isp., Thalassinoides suevicus, Ophiomorpha isp., Chondrites isp. and Phycodes isp., pointing towards deposition in calmer, possibly dysoxic outer shelf prodeltaic environments. Unit 4 has pebbly to gritty cross-bedded sandstones exhibiting the development of networks of Thalassinoides isp. and Ophiomorpha isp., indicating shallow sub-tidal to intertidal conditions of deposition. The overall succession is interpreted to show initial deepening followed by shallowing.

Hot spots and hot moments of greenhouse gas emissions in agricultural peatlands

AbstractDrained agricultural peatlands occupy only 1% of agricultural land but are estimated to be responsible for approximately one third of global cropland greenhouse gas emissions. However, recent studies show that greenhouse gases fluxes from agricultural peatlands can vary by orders of magnitude over time. The relationship between these hot moments (individual fluxes with disproportionate impact on annual budgets) of greenhouse gas emissions and individual chamber locations (i.e. hot spots with disproportionate observations of hot moments) is poorly understood, but may help elucidate patterns and drivers of high greenhouse gas emissions from agricultural peatland soils. We used continuous chamber-based flux measurements across three land uses (corn, alfalfa, and pasture) to quantify the spatiotemporal patterns of soil greenhouse gas emissions from temperate agricultural peatlands in the Sacramento-San Joaquin Delta of California. We found that the location of hot spots of emissions varied over time and were not consistent across annual timescales. Hot moments of nitrous oxide (N2O) and carbon dioxide (CO2) fluxes were more evenly distributed across space than methane (CH4). In the corn system, hot moments of CH4 flux were often isolated to a single location but locations were not consistent across years. Spatiotemporal variability in soil moisture, soil oxygen, and temperature helped explain patterns in N2O fluxes in the annual corn agroecosystem but were less informative for perennial alfalfa N2O fluxes or CH4 fluxes across ecosystems, potentially due to insufficient spatiotemporal resolution of the associated drivers. Overall, our results do not support the concept of persistent hot spots of soil CO2, CH4, and N2O emissions in these drained agricultural peatlands. Hot moments of high flux events generally varied in space and time and thus required high sample densities. Our results highlight the importance of constraining hot moments and their controls to better quantify ecosystem greenhouse gas budgets.

Drought variability, changes and hot spots across the African continent during the historical period (1928–2017)

AbstractThe spatiotemporal variability of meteorological droughts, its changes and hot spots location across Africa are analysed for the period spanning 1928–2017 using the Standardized Precipitation Index (SPI) applied to the precipitation products from the Climatic Research Unit (CRU), University of Delaware (UDEL) and Global Precipitation Climatology Centre (GPCC). Spatially, an analysis based on rotational empirical orthogonal function identifies five regions of similar drought variability, namely the Sahel, East Africa, East Southern Africa, West Southern Africa and the Gulf of Guinea. Temporally, the most common periods of drought occurrence are the 1970s, the 1980s and, to a lesser extent, the 1990s. Changes in drought characteristics for the intermediate past (1958–1987) and recent past (1988–2017) compared to the far past (1928–1957) indicate robust increases of drought duration, frequency and severity in the Sahel, and to a lower extent in the Gulf of Guinea, some areas of Central Africa, part of Southern Africa and over Madagascar. These changes are stronger (weaker) along the Sahel during the intermediate past (recent past) and stronger (weaker) over Central and Southern Africa and Madagascar during the recent past (intermediate past). As a consequence, drought hot spots, mostly driven by severity during the regions' wet season, are identified in areas confined in the Sahel during the intermediate past and in regions mainly over Central and Southern Africa and Madagascar during the recent past. Our results are useful for drought disaster risk management across Africa and provide a valuable reference for future drought analysis under global warming conditions.

WebGIS Based Road Crash Information System: A Case Study

Road crashes in India is showing progressive growth since COVID time, despite many road safety measures and program the rate of crashes are not declining. Many a times the road safety measures are not implemented in proper geographical locations owing to lack of proper crash information, which include crash information of the past. Road crash information is thus a vital support for the road safety assessment programs that eyes for a reduction in the road crashes. In India, as in other developing countries, very little effort is taken to providing enough road crash information. The identification of road crash location, analysis and treatment of road accident black spots are widely regarded as one of the most effective approaches to road accident prevention. A user friendly web Geographic Information System (GIS) based Road Crash Information System (RCIS) is developed in the present study for Kerala State, India. An online platform to add, update and maintain the database of road accident black spots is offered by the system, including analysis functionalities. Database maintains a standard guideline for road crash reporting thereby reducing data redundancy. Integration of all crash data from accident locations and to filter data based on different criteria are the core objectives of this study. The study also focused on systematically sharing the accident black spot details to the public user through an online platform.

A novel approach to building digital twin transformers by combining virtual-real sensing: An example of degree of polymerization distribution

Digital twin (DT) in the power industry faces challenges due to complex structures and limited distributed sensors for power equipment. In this work, a novel approach combining virtual-real sensing (VRS) was used to build DT for transformers, taking the degree of polymerization (DP) distribution as an example. Temperature and moisture distributions were calculated, and a dynamic deduction model for DP distribution was established. The visualization of DP distribution was achieved through surface-rebuild. Results showed a 3.5% error in temperature distribution compared to monitoring data. Moisture distribution was concentrated in the cardboard and bottom solid insulation, reaching 3.2% in the 48th year. DP distribution pattern aligned with Cigre’s report, with the lowest value at the hot spot location of the LV windings, deduced to be 252.15 in the 48th year. This study provides a data base for realizing transformers DT and is a key step towards building a vital DT transformer.

CFD Investigation of Fin Design Influence on Phase Change Material Melting for Solar Thermal Energy Storage

In this study, an investigation was conducted on four distinct configurations, designated as Case-1, Case-2, Case-3, and Case-4, focusing on parametric analysis. Each configuration features a cylindrical enclosure containing pure Gallium, a phase change material (PCM). The solid-to-liquid phase transition of the encapsulated material was examined using a 2D CFD methodology. Additionally, the effect of applying three temperatures, T1=32∘C, T2=39∘C, and T3=42∘C, along the generator of the enclosure, with or without fins, was also studied. To accurately model the melting process of the PCM, the Enthalpy- Porosity Method was employed, and meticulous detailing of underlying assumptions was under- taken to ensure precise representation. The validation process involved comparing outcomes of the physical solidification/melting model with reference data from a state-of-the-art study. The specific cases comprised Case-1 - a slender finless cylinder; Case-2 - a thin finned cylinder (l=10mm, t=0.6mm); Case-3 - featuring larger fins (l=20mm, t=0.6mm); and Case-4 - incorporating the largest fins (l=30mm, t=0.6mm). Strategically incorporating thin fins accelerates Gallium melting significantly, reducing times by up to 89%. This enhancement is driven by a 96% increase in the heat transfer coefficient (h), leading to faster melting rates. In addition, fins boost the Nusselt number (Nu) by 91%, indicating improved convective heat transfer and enhanced melting. Melting rates increase by around 30%, notably in Case-3. Temperature T1 shifts dominant heat transfer from convection to conduction, as seen in 2D CFD contours with stratified patterns in Case-3 at t=240s and Case-4 at t=240s and t=300s. A localized cold spot at t = 300s in Case-4 signals localized heat transfer effects.

Direct Observation of Transient Flow Kinematics of Environment-Friendly Silica-Based Alcogel at Instantaneous Gelation

This study was intended to exploit the possibility of using the quick gelation of alcogel that is induced by adding catalytic imidazole into a silicate-oligomer-based solution. For this purpose, the experimental viability of the direct observation of the gelation behavior was actually examined. The silicate oligomer, derived from tetraethyl orthosilicate hydrolyzed under an acidic condition (pH ~ 5), was used as the quickly gelling mother solution. The capability of the oligomer solution to form a non-flowable matter in only a few seconds when triggered by the addition of the catalytic solution of imidazole is promising, for example, for stabilizing a sandy ground surface, due to its simplicity. From the practical viewpoint, how long the gelation could take (=gel time) is a crucial parameter when the choice of an appropriate gelling chemical species needs to be made. Thus, this study focused its interest on as simple an experimental method as possible for evaluating the gel time of the gelling systems that actually underwent instantaneous gelation. The silicate oligomer solution was an appropriate material both in its quick gelling behavior and environmental friendliness. For such quick gelation, rheological approaches are not applicable for detecting the boundary in the mechanical properties that delineate the regime of “gel”. In this study, instead, direct observation was employed to capture the short interval during which the gelation was completed. The silicate-oligomer-based gelling solution was observed to lose its flowability within only 0.2 s, as it was seen to come off the bottom of the shaken cylinder at 5 Hz. For a more quantitative estimation, the same gelling solution was observed by high-speed motion picture. The high-speed motion picture could clearly capture the instantaneous gelation as a sudden arrest of the flow. The sub-millisecond direct observation of the gelation behavior revealed that the timescale of the instantaneous termination of the flow was as quick as 1 ms in order of magnitude. Such instantaneous gelation in the sub-millisecond-order timescale could not be forecasted from the observable megascopic gelation, which appeared to last from 102 ms to 103 ms in our naked-eye observation. The noteworthy gap between the timescale of the naked-eye-observed gelation and that of the true gel time at a localized spot determined by the high-speed motion picture should be noted to avoid excess agitation, which can result in total collapse into gel fragments of the just solidifying or already solidified gel under strong deformational influence by mechanical agitation, for example.

On the relationship between solid particle attractors and thermal inhomogeneities in vibrationally driven fluid-particle systems

The present analysis extends earlier authors' work [Crewdson et al., “Two-dimensional vibrationally-driven solid particle structures in non-uniformly heated fluid containers,” Chaos 32, 103119 (2022); M. Lappa, “Characterization of two-way coupled thermovibrationally driven particle attractee,” Phys. Fluids 34(5), 053109 (2022); M. Lappa and T. Burel, “Symmetry breaking phenomena in thermovibrationally driven particle accumulation structures,” ibid.32(5), 053314 (2020); and M. Lappa, “The patterning behavior and accumulation of spherical particles in a vibrated non-isothermal liquid,” ibid.26(9), 093301 (2014)] on the existence of solid particle attractee in thermovibrational flow in order to identify new physical principles and enable increased control over the ability of particles to target desired locations into the host fluid. The causality between the thermal boundary conditions and the multiplicity and morphology of emerging particle structures is discussed, and new fundamental topological concepts are harnessed through the combination of two-dimensional and three-dimensional simulations. It is shown that the threefold relationship among the inclination of vibrations, the multi-directional nature of the imposed temperature gradient, and the dimensionality of the system itself can open up new pathways for additional classes of attractors. These can manifest themselves as compact particle structures or completely disjoint sets, apparently behaving as they were driven by different clustering mechanisms (coexisting in the physical space, but differing in terms of characteristic size, shape, and position). A variety of new solutions are presented for a geometry as simple as a cubic enclosure in the presence of localized spots of temperature on otherwise uniformly heated or cooled walls. In order to filter out possible asymmetries due to fluid-dynamic instabilities induced by the back influence of the solid mass on the fluid flow, the analysis is conducted under the constraint of one-way coupled phases.

Investigation on dependency of thermal characteristics on gate/drain bias voltages in stacked nanosheet transistors

—In this paper, the gate/drain voltage-dependent self-heating effect (SHE) in gate-all-around (GAA) nanosheet field effect transistors (NSFETs) and FinFETs is investigated by 3-D TCAD simulation. The drain current decreases because of the SHE and is dependent on the gate/drain voltage in different devices. Furthermore, the lattice maximum temperature-rise (ΔTmax), which directly leads to current degradation due to stronger carrier mobility scattering under higher temperature, exhibits complex trends with increased gate/drain voltages. The ΔTmax increases at a decreasing rate with increasing VGS but increases approximately linearly as VDS increases. To investigate the origin of these behaviors, changes in thermal resistance (Rth) due to the shift in hot spot location and the redistribution of heat source under different applied voltages are also examined. The Rth decreases as VGS increases and slightly increases at a larger VDS. The Rth of NSFETs is generally larger than that of FinFETs, and the narrow-width NSFET (N-NSFET) has the largest Rth owing to the GAA structure and narrower sub-fin structure. Additionally, the heat flux ratio of the source thermal contact in N-NSFETs is smaller than that in FinFETs for different gate and sub-fin structures, resulting in reduced mean ΔT (ΔTmean) of N-NSFETs under a larger VGS, and therefore, leading to less current degradation. The study provides one effective design guide for GAA NSFETs optimizing their thermal characteristics in advanced nodes.

Interaction between Local Shielding Gas Supply and Laser Spot Size on Spatter Formation in Laser Beam Welding of AISI 304

Background. Spatter formation at melt pool swellings at the keyhole rear wall is a major issue for laser deep penetration welding at speeds beyond 8 m/min. A gas nozzle directed towards the keyhole, that supplies shielding gas locally, is advantageous in reducing spatter formation due to its simple utilization. However, the relationship between local gas flow, laser spot size, and the resulting effects on spatter formation at high welding speeds up to 16 m/min are not yet fully understood. Methods. The high-alloy steel AISI 304 (1.4301/X5CrNi18-10) was welded with laser spot sizes of 300 μm and 600 μm while using a specially designed gas nozzle directed to the keyhole. Constant welding depth was ensured by Optical Coherence Tomography (OCT). Spatter formation was evaluated by precision weighing of samples. Subsequent processing of high-speed images was used to evaluate spatter quantity, size, and velocity. The keyhole oscillation was determined by Fast Fourier Transform (FFT) analysis. Tracking the formation of melt pool swellings at the keyhole rear wall provided information on the upward melt flow velocity. Results. The local gas flow enabled a significant reduction in the number of spatters and loss of mass for both laser spot sizes and indicated an effect on surface tension by shielding the processing zone from the ambient atmosphere. The laser spot size affected the upward melt flow velocity and spatter velocity.

3D cell subculturing pillar dish for pharmacogenetic analysis and high-throughput screening

A pillar dishe for subculture of 3D cultured cells on hydrogel spots (Matrigel and alginate) have been developed. Cells cultured in 3D in an extracellular matrix (ECM) can retain their intrinsic properties, but cells cultured in 2D lose their intrinsic properties as the cells stick to the bottom of the well. Previously, cells and ECM spots were dispensed on a conventional culture dish for 3D cultivation. However, as the spot shape and location depended on user handling, pillars were added to the dish to realize uniform spot shape and stable subculture, supporting 3D cell culture-based high-throughput screening (HTS). Matrigel and alginate were used as ECMs during 6-passage subculture. The growth rate of lung cancer cell (A549) was higher on Matrigel than on alginate. Cancer cell was subcultured in three dimensions in the proposed pillar dish and used for drug screening and differential gene expression analysis. Interestingly, stemness markers, which are unique characteristics of lung cancer cells inducing drug resistance, were upregulated in 3D-subcultured cells compared with those in 2D-subcultured cells. Additionally, the PI3K/Akt/mTOR, VEGFR1/2, and Wnt pathways, which are promising therapeutic targets for lung cancer, were activated, showing high drug sensitivity under 3D-HTS using the 3D-subcultured cells.

Package Design Thermal Optimization for Metal-Oxide Gas Sensors by Finite Element Modeling and Infra-Red Imaging Characterization.

We designed a 3D geometrical model of a metal-oxide gas sensor and its custom packaging and used it in finite element modeling (FEM) analysis for obtaining temperature and heat flux distribution. The 3D computer simulation, performed with GetDP software (version 3.5.0, 13 May 2022), accurately predicted the temperature distribution variation across the entire assembly. Knowing the temperature variation and the location of the hot spots allowed us to select the best electrical interconnect method and to choose the optimal materials combination and optimal geometry. The thermal modeling also confirmed the need to use a low thermal conductivity material to insulate the MOX sensor since the latter is heated to its operational temperature of 250 °C. For that purpose, we used the in-house formulated xerogel-epoxy composite of thermal conductivity of 0.108 W m-1 K-1, which is at least 30% less compared to the best-in-class among commercially available materials. Based on the 3D FEM outputs, we designed, assembled, and characterized a fully functional packaged MOX gas sensor in several configurations. We measured the temperature distribution on all parts of the MOX gas sensor assembly using a thermal imaging infrared (IR) microscope. The results of 3D FEM are in good agreement with the temperature distribution obtained by the non-contact IR thermal characterization.

Black Spot Location Identification for National Highway: A Case Study of Mugling – Kotre Section of Prithivi Highway of Nepal

The rapid development of road infrastructure enhances connectivity and at the same time increases road crashes. A road traffic accident is one of the leading causes of injury and death in Nepal that has a great impact on the country’s economy. The identification of frequent road traffic crash spots and their causes are essential for the implementation of the most efficient countermeasures. Accident black spots are high-risk spots where numbers of accidents take place frequently and repeatedly. The study focused on the identification of black spots on the Mugling-Kotre section of the Prithivi highway of Nepal to provide knowledge for possible preventive measures for the improvement of road safety. The weighted severity index (WSI), prioritization index (PI), and focus group discussion have been performed to evaluate the safety status in the proposed area. The accident data were analyzed based on the weighted severity index (WSI), and the prioritization index (PI) was estimated by assigning a suitable weight to the factors contributing to an accident. Based on these results, six accident spots have been found critical regarding traffic safety. The result obtained from WSI and PI was further evaluated based on the focus group discussion so that essential safety measures could be implemented to enhance road safety.