Annealing Conditions Research Articles

Development of Predictive Models for Tempering Behavior in Low-Carbon Bainitic Steel Using Integrated Tempering Parameters

Low-carbon bainitic steels are known for their excellent combination of strength and toughness, making them suitable for various industrial applications. Understanding the tempering behavior of these steels is crucial for optimizing their mechanical properties through heat treatment. This study presents predictive models for tempering behavior based on empirical data, which is fundamental for understanding the thermal stability and transformation kinetics of the steel. Through integrated tempering parameters, we established predictive models that integrate tempering temperature and time, yielding a robust framework for predicting hardness. The equivalent tempering kinetic curves and nomographs plotted in this study allow for the direct determination of hardness under various tempering conditions, facilitating the optimization of tempering parameters. The nomogram approach provides a practical method for adjusting tempering parameters to achieve desired mechanical properties efficiently. The accuracy of the predictive models was validated through statistical tests, demonstrating a high correlation between predicted and experimental values.

Ionic liquid engineering enables 1D/3D perovskite photovoltaics with > 25 % efficiency: A real-time study exploring formation mechanism of 1D perovskites

The advancements in low-dimensional/three-dimensional (LD/3D) perovskite devices represent a promising approach to enhancing both the efficiency and stability of of perovskite solar cells (PSCs). However, while significant efforts have been dedicated to understanding the role of already formed low-dimensional perovskites in passivating defects, refining the work function, little attention has been given to the crystallization process of LD perovskites, particularly when induced by ionic liquids (ILs) as green and stable additive. In this work, the formation process of IL Tetrabutylammonium Thiocyanate (TBASCN)-induced 1D perovskite onto the 3D perovskite under varying annealing conditions were explored by in-situ Grazing-Incidence Wide-Angle X-ray Scattering (GIWAXS) technology, providing a comprehensive investigation into the distinct impacts of 1D perovskite formed under diverse annealing processes on device performance. Owing to the robust interaction and favorable binding energy between the IL TBASCN and perovskite components, coupled with the low formation energy of 1D perovskites, 1D perovskites exhibit rapid formation on the surface of 3D perovskites and display markedly distinct crystallization processes under distinguished annealing conditions. Achieving full crystallization of 1D perovskites necessitates optimal temperature of 100 °C and adequate duration of 100 s. Once fully crystallized, the highly crystalline 1D perovskites and anions SCN- present in ILs can synergistically passivate defects in 3D perovskites, mitigate ion migration and impeding moisture infiltration. Benefiting from the optimized formation process of 1D perovskites, the champion device achieves a power conversion efficiencie (PCE) of 25.18 % and retains 91.0 % of its initial efficiency after 2000 h under RH=40 %. Our research provides new insights for optimizing the formation process of LD perovskites induced by different materials and their application in high-performance LD/3D PSCs.

Risk of invasion and disease transmission by the Australasian freshwater snail Orientogalba viridis (Lymnaeidae): a field and experimental study

BackgroundBiological invasions pose risks to the normal functioning of ecosystems by altering the structure and composition of several communities. Molluscs stand out as an extensively studied group given their long history of introduction by either natural or anthropogenic dispersal events. An alien population of the lymnaeid species Orientogalba viridis was first sighted in 2009 in southern Spain. In its native range (Australasian), this species is one of the main intermediate hosts of Fasciola hepatica, a major worldwide trematode parasite largely affecting humans, domestic animals and wildlife.MethodsWe collected field populations of O. viridis from its native (Malaysia) and invaded (Spain) ranges. We performed detailed morphoanatomical drawings of the species and screened for natural infection of parasites. Individuals were molecularly characterized using ITS2 for comparison with existing sequences in a fine phylogeography study. We founded experimental populations at two different conditions (tropical, 26 °C and temperate, 21 °C) to study the life-history traits of exposed and non-exposed individuals to different F. hepatica isolates.ResultsWe found a 9% natural prevalence of trematode infection (98% similarity with a sequence of Hypoderaeum conoideum [Echinostomatidae]) in the Spanish field population. The haplotypes of O. viridis found in our study from Spain clustered with Australian haplotypes. Experimental infection with F. hepatica was successful in both experimental conditions but higher in tropical (87% prevalence) than in temperate (73%). Overall lifespan, however, was higher in temperate conditions (mean 32.5 ± 7.4 weeks versus 23.3 ± 6.5) and survivorship remained above 70% during the first 20 weeks. In parasite-exposed populations, life expectancy dropped from an overall 37.75 weeks to 11.35 weeks but still doubled the time for initial cercariae shedding. Cercariae shedding started at day 23 post-exposure and peaked between days 53 and 67 with an average of 106 metacercariae per snail.ConclusionsWhether O. viridis will succeed in Europe is unknown, but the odds are for a scenario in which a major snail host of F. hepatica occupy all available habitats of potential transmission foci, ravelling the epidemiology of fasciolosis. This research provides a comprehensive understanding of O. viridis biology, interactions with parasites and potential implications for disease transmission dynamics, offering valuable insights for further research and surveillance.Graphical

Enhanced optical and electrical properties of Nb-doped TiO2 thin films synthesized by atomic layer deposition using the supercycle strategy

Herein, we report highly transparent and conductive Nb-doped TiO2 thin films successfully grown by a thermal ALD process at 300 °C using titanium tetraisopropoxide, niobium(V) ethoxide, and water. The deposition was carried out by employing a supercycle approach, alternating cycles of Ti precursor followed by a monocycle of Nb precursor, thereby enabling precise control over the Nb dopant concentration. We demonstrate the crucial impact of the dopant concentration and annealing conditions played on the thickness, structure, morphology, composition, and optical and electrical properties of the resulting films. The incorporation of niobium dopants led to significant improvements in the film's characteristics. The Nb-doped TiO2 films exhibited an enhanced optical transmission efficiency up to 15 %, along with a remarkable reduction in resistivity by four orders of magnitude, reaching 10−3 Ω.cm, compared to undoped TiO2 films. These high performances establish Nb-doped TiO2 thin films as promising TCOs with wide-ranging applications in fields that require efficient current collection or injection in conjunction with optical radiation transmission.

Oxygen-deficient annealing boosts performance of CoNiFe oxide electrocatalyst in oxygen evolution reaction

Mixed oxides of transition metals have emerged as promising catalysts for the oxygen evolution (OER) reaction in alkaline water electrolysis. Since OER is significantly slower than hydrogen evolution, developing stable and easily accessible materials that effectively promote OER is one of the keys to improving overall efficiency. In this context, we present a promising method for preparing Co-Ni-Fe oxides which is based on a straightforward sol–gel procedure. Key to success is a thermal treatment under oxygen-deficient atmosphere, which renders superior electrocatalytic properties compared to a treatment under reductive and aerobic conditions, respectively. Attractive performance characteristics are thereby obtained, e.g., a η10 value of 291 mV and a Tafel slope of 32 mV dec−1. The impact of the annealing conditions on the material properties has been elaborated using cyclic voltammetry, impedance spectroscopy, and structural analyses. Stability and strong performance under practical conditions were confirmed in long-term studies using an AEM electrolyzer.

Effect of annealing treatment on texture evolution, microstructure and mechanical properties of Mg–Mn–Ce alloy

Magnesium alloys have received a lot of attention in aerospace, automotive, electronic communications and other fields due to their low density, high specific strength and damping performance. However, magnesium alloy sheets prepared by conventional thermomechanical processing usually have a strong basal texture, resulting in poor formability. In this paper, Mg–Mn–Ce alloys with good plastic forming ability were prepared by studying and optimizing the annealing process. Under the low-temperature annealing condition, it can promote the static recrystallization and grain refinement of Mg–Mn–Ce alloy, and also eliminate the internal stress. With the increase of annealing temperature, a large amount of dispersed Mg12Ce as a stable second phase effectively hindered the grain boundary migration, while the nanoscale α-Mn forms a fine second phase to inhibit grain growth, and both of them together greatly stabilize the deformation structure of the alloy, and maintain a good grain organization under the condition of annealing temperature of 300 °C and holding time of 30 min. The present work also improves the Arrhenius constitutive equation for the Mg–Mn–Ce alloy with respect to the degree of deviation, which significantly improves the accuracy of the model in predicting the thermoforming behavior. Meanwhile, to address the shortcomings of the traditional forming method of magnesium alloy, the processing process of spreading the centrifugal casting tube flat is proposed, the forming process is simulated, and the location of easy breakage in the forming process is predicted. These findings provide microanalytical support for the improvement of forming properties of magnesium alloys by annealing.

Micro-to-Nanoscale Characterization of Femtosecond Laser Photo-Inscribed Microvoids.

Fiber Bragg gratings are key components for optical fiber sensing applications in harsh environments. This paper investigates the structural and chemical characteristics of femtosecond laser photo-inscribed microvoids. These voids are at the base of type III fs-gratings consisting of a periodic array of microvoids inscribed at the core of an optical fiber. Using high-resolution techniques such as quantitative phase microscopy, electron transmission microscopy, and scattering-type scanning near-field IR optical microscopy, we examined the structure of the microvoids and the densified shells around them. We also investigated the high-temperature behavior of the voids, revealing their evolution in size and shape under step isochronal annealing conditions up to 1250 °C.

Synthesis of low-k SiONC thin films by plasma-assisted molecular layer deposition with tetraisocyanatesilane and phloroglucinol

Low-k SiONC thin films with excellent thermal stabilities were deposited using plasma-assisted molecular layer deposition (PA-MLD) with a tetraisocyanatesilane (Si(NCO)4) precursor, N2 plasma, and phloroglucinol (C6H3(OH)3). By adjusting the order of the N2 plasma exposure steps within the PA-MLD process, we successfully developed a deposition technique that allows accurate control of thickness at the Ångström level via self-limiting reactions. The thicknesses of the thin films were measured through spectroscopic ellipsometry (SE). By tuning the N2 plasma power, we facilitated the formation of –NH2 sites for phloroglucinol adsorption, achieving a growth per cycle of 0.18 Å cycle−1 with 300 W of N2 plasma power. Consequently, the thickness of the films increased linearly with each additional cycle. Moreover, the organic linkers within the film formed stable bonds through surface reactions, resulting in a negligible decrease in thickness of approximately −11% even upon exposure to a high annealing temperature of 600 °C. This observation was confirmed by SE, distinguishing the as-prepared film from previously reported low-k films that fail to maintain their thickness under similar conditions. X-ray photoelectron spectroscopy (XPS) and current–voltage (I–V) and capacitance–voltage (C–V) measurement were conducted to evaluate the composition, insulating properties, and dielectric constant according to the deposition and annealing conditions. XPS results revealed that as the plasma power increased from 200 to 300 W, the C/Si ratio increased from 0.37 to 0.67, decreasing the dielectric constant from 3.46 to 3.12. Furthermore, there was no significant difference in the composition before and after annealing, and the hysteresis decreased from 0.58 to 0.19 V owing to defect healing, while maintaining the leakage current density, breakdown field, and dielectric constant. The low dielectric constant, accurate thickness control, and excellent thermal stability of this MLD SiONC thin film enable its application as an interlayer dielectric in back-end-of-line process.

Neutron Reflectivity Study on the Adsorption Layer of Polyethylene Grown on Si Substrate.

To investigate the structure of the interface between polyethylene films and substrates, the neutron reflectivity (NR) of deuterated polyethylene (dPE) thin films deposited on Si substrates was measured, demonstrating water accumulation at the interface, even under ambient conditions. After leaching the thermally annealed dPE films in hot p-xylene, NR measurements were conducted on the layers remaining on the substrate, clearly revealing that the adsorption layer of dPE grew during annealing and consisted of two layers, an inner adsorption layer and an outer adsorption layer, as previously proposed for amorphous polymers. The inner adsorption layer was approximately 3.7 nm thick with a density comparable to that of the bulk. The outer adsorption layer was several nanometers thick and appeared to grow insufficiently on top of the inner adsorption layer under the annealing conditions examined in this study. This study clarifying the growth of the adsorption layer of polyethylene at the interface with an inorganic substrate is useful for improving the performance of polymer/inorganic filler nanocomposites due to the wide utility of crystalline polyolefins as polymer matrix materials in nanocomposites.

Piezoelectric Enhancement in P(VDF-TrFE) Copolymer Films via Controlled and Template-Induced Epitaxy.

The surge in wearable electronics and Internet of Things technologies necessitates the development of both flexible sensors and a sustainable, efficient, and compact power source. The latter further challenges conventional batteries due to environmental pollution and compatibility issues. Addressing this gap, piezoelectric energy harvesters emerge as one kind of promising alternative to convert mechanical energy from ambient sources to electrical energy to charge those low-energy-consumption electronic devices. Despite slightly lower piezoelectric performance compared with those inorganic materials, piezoelectric polymers, notably poly(vinylidene fluoride-co-trifluoroethylene) P(VDF-TrFE), offer compelling properties for both flexible mechanical energy harvesting and self-powered strain/stress sensing, though their piezoelectric performance is expected to be further enhanced via varieties of modulation strategies of microstructures. Herein, we reported the controlled epitaxy process of micrometer-thick copolymer films with the cooperation of friction-transferred poly(tetrafluoroethylene) templates and precise modulation of the annealing conditions. Epitaxial P(VDF-TrFE) films present averaged d33 piezoelectric coefficient of -58.2 pC/N between 50 Hz and 1 kHz with good electromechanical and thermal stability. Owing to the nature of anisotropic crystallization, the epitaxial films exhibit an anisotropic transverse piezoelectric property. Epitaxial films were further utilized for mechanical energy harvesting and monitoring of human pulsation and respiration. This study provided a feasible route for the development of high-performance flexible piezoelectric devices to meet the requirement of flexible electronics.

Carbohydrate-based block copolymers with sub-10 nm face-centered cubic nanostructures for low-power-consuming and ultraviolet light-triggered synaptic phototransistors

Addressing environmental concerns and producing sustainable and environmentally friendly electronic devices with low power consumption poses a significant challenge. This study introduces phototransistor devices employing morphologically controlled block copolymers based on maltotriose, maltoheptaose, and β-cyclodextrin as polymer electrets. Ordered self-assembled morphologies can be achieved by utilizing microwave radiation for rapid annealing (within 5 s) with optimized annealing conditions. Herein, face-centered cubic (FCC), vertical, and mixed cylindrical nanostructures are reported. The resulting well-defined morphologies play a pivotal role in enhancing the electron-trapping capability of the block copolymers and facilitating charge carrier transport between the electret and semiconducting layers. Consequently, the phototransistor memory manifests exceptional performance, featuring stability and endurance. Intriguingly, the cavity of β-cyclodextrin provides a stable environment for the trapped charges, leading to a larger memory window than other block copolymers. On the other hand, a device consisting of MT-b-PS exhibited superior current contrast exceeding 106 even under a low drain voltage of −1 V, attributed to sub-10 nm FCC nanostructures. Furthermore, this phototransistor device successfully emulated the synaptic functions of sensing, learning, and short- and long-term memory in the human brain, along with a low energy consumption of 0.312 fJ. Hence, this report opens the pathways for developing promising bio-based electronic devices.

Machine Learning-Aided Analysis of the Rolling and Recrystallization Textures of Pure Iron with Different Cold Reduction Ratios and Cold-Rolling Directions.

We performed a machine learning-aided analysis of the rolling and recrystallization textures in pure iron with different cold reduction ratios and cold-rolling directions. Five types of specimens with different cold reduction ratios and cold-rolling directions were prepared. The effect of two-way cold-rolling on the rolling texture was small at cold reduction ratios different from 60%. The cold reduction ratio in each stage hardly affected the texture evolution during cold-rolling and subsequent short-term annealing. In the case of long-term annealing, although abnormal grain growth occurred, the crystal orientation of the grains varied. Moreover, the direction of cold-rolling in each stage also hardly affected the texture evolution during cold-rolling and subsequent short-term annealing. During long-term annealing, sheets with the same cold-rolling direction in the as-received state and in the first stage showed the texture evolution of conventional one-way cold-rolled pure iron. Additionally, we conducted a machine learning-aided analysis of rolling and recrystallization textures. Using cold-rolling and annealing conditions as the input data and the degree of Goss orientation development as the output data, we constructed high-accuracy regression models using artificial neural networks and XGBoost. We also revealed that the annealing temperature is the dominant factor in the nucleation of Goss grains.

Deep Learning Methods Utilization in Mechanical Property of Medium‐Mn Steel

This study presents an innovative method to predict the mechanical properties of medium‐Mn steel by deep learning (DL). Based on datasets, an artificial neural network (ANN) model serves as a crucial component of DL, demonstrating a coefficient of determination of 0.996, which indicates high accuracy between experimental and predicted values. Meanwhile, the contents of Mn and C, as well as Al and intercritical annealing (IA) conditions, have higher permutation feature importance (PFI) scores, which are 22.37% and 49.22%, respectively. An ANN model predicts that the experimental steel has good mechanical properties with IA at 710 °C for 60 min, with predicted values of ultimate tensile strength (UTS) and total elongation (TE) being 925 MPa and 45.3%, respectively. The experimental values for UTS (937 MPa) and TE (44.8%) closely correspond to the predicted results. The absolute errors between the experimental and predicted UTS and TE are 1.2% and 1.1%, respectively.

Optimization of In‐Reactor In Situ Activation Annealing Conditions for Tunnel Junction Layers in Multiquantum Shell GaN‐Based Devices

For realizing room‐temperature continuous‐wave operation in core–shell GaN nanowire‐based semiconductor lasers, certain device characteristics are required, namely, a low threshold current and low operating voltage. To reduce the operating voltage and inject current into the m‐plane multiquantum shell (MQS) active region, a new structure with a tunnel junction and embedded n‐GaN is proposed. One of the problems in this proposed device architecture is the high resistance at the tunnel junction layer due to hydrogen passivation in the insufficiently activated p‐GaN shell. In situ activation annealing and suppression of re‐passivation during subsequent growth are necessary to reduce the operating voltage. Herein, the time and temperature dependence of in situ activation annealing in a reactor to lower the resistance of tunnel junction layers grown on nanowires with nonpolar m‐planes is investigated. Subsequent n+‐GaN growth is implemented at 550 °C. As a result, the turn‐on voltage is observed to be dependent on the activation annealing time and temperature. The lowest turn‐on voltage is ≈5.4 V at an activation annealing time of 30 min and activation annealing temperature of 800 °C.

Electrical and thermal performance of bifacial photovoltaics under varying albedo conditions at temperate climate (UK)

Bifacial photovoltaics (bPV) provide an advantage over their traditional monofacial counterparts as they can utilise solar radiation incident on both the front and rear side of the module, allowing for increased energy production. While this is an advantage on the side of bPV, the amount of energy produced by the rear side of the bPV panel can vary greatly depending on the inclination and azimuth of the panel as well as external climatic and ground albedo conditions. This paper aims to analyse the electrical and thermal performance of bPV under varying albedo conditions, using two different materials: grass, and a reflective material. It also contains an example of bifaciality testing under real-world conditions. Several experiments were conducted to evaluate the electrical performance and the temperature distribution of the bPV panel under different weather conditions at the UK location and then the results were compared with the single diode model of bPV. Furthermore, a bPV panel temperature model has been developed for the temperate climate condition of UK. The results show that the open circuit voltage of the system increases with irradiance up to around 800 W/m2, at which point it decreased due to the increased PV system temperature. The normalised efficiency for the PV system under different conditions were also evaluated, which showed that the bPV module was most efficient under diffuse irradiance conditions, encouraging the use of the bPV technology in the UK.

Pest categorisation of Matsucoccus matsumurae.

The EFSA Panel on Plant Health performed a pest categorisation of Matsucoccus matsumurae (Hemiptera: Matsucoccidae), the Massonian pine bast scale, for the EU territory. This pest categorisation was initiated following the commodity risk assessment of artificially dwarfed plants from China consisting of Pinus parviflora (Japanese white pine) grafted on P. thunbergii (Japanese black pine) performed by EFSA, in which M. matsumurae was identified as a pest of possible concern. However, its identity is not firmly established due to uncertainty regarding its taxonomic relationship with Matsucoccus pini (Green), a species widespread in Europe. M. matsumurae occurs in western China and has been reported as a pest of P. massoniana (Chinese red pine) and P. thunbergii. These hosts occur in the EU as ornamental/amenity trees. Other scales in the Matsucoccus genus feed on a variety of Pinus species and the host range of M. matsumurae could be wider than is currently recorded. The scale has one or two generations per year. All stages occur on the branches and stems of hosts with developing nymphs and adult females feeding through the bark on host phloem vessels. Symptoms include the yellowing/browning of host needles, early needle drop, desiccation of shoots and bark necrosis. The most serious infestations occur in hosts that are 8-25 years old and there can be some host mortality. In principle, host plants for planting and plant products such as cut branches and wood with bark could provide entry pathways into the EU. However, prohibitions on the import of Pinus from non-European third countries regulate these pathways. In China, M. matsumurae occurs in regions with temperate humid conditions and hot summers. These conditions are also found in parts of southern EU. Were M. matsumurae to establish in the EU, it is conceivable that it could expand its host range; however, this remains uncertain. Some uncertainty exists over the magnitude of potential impacts. M. matsumurae satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest, assuming M. pini is not a synonym, which is a key uncertainty.

Effect of Cold vs Temperate Conditions on Physical Performance During Extended Mountain Warfare Training at Moderate Altitude.

The purpose of this study was to investigate the effect of environmental conditions on body composition, upper body power, and lower body power throughout a ∼4-week military mountain training exercise. We hypothesized that countermovement jump and ballistic push-up performance would decrease as a result of extended mountain field training and that winter (cold) conditions would result in greater decrements compared to fall (temperate) conditions. We also expected to observe a strong positive correlation between changes in performance and changes in skeletal muscle mass. Finally, we expected acute changes in performance upon altitude exposure. A total of 111 U.S. Infantry Marines (110 M; 1 F) provided written informed consent to participate in this study according to a protocol approved by the Naval Health Research Center. There were 54 participants in the fall cohort and 57 in the winter cohort. Maximum effort countermovement jump and ballistic push-up performance were assessed at different timepoints: (1) baseline at the sea level, (2) before training at ∼2100 m, (3) midpoint of training at ∼2100 m, (4) end of training at ∼2100 m, and (5) after 3 to 4 weeks of recovery at the sea level. The fall cohort trained at moderate temperatures (average day/night, 20°C/3°C), whereas the winter cohort trained under snowy winter conditions (7°C/-14°C). The results suggested that seasonal conditions did not significantly affect changes in body composition or physical performance. Furthermore, no acute effects of altitude on physical performance were detected. Training exercise did, however, cause performance decrements in countermovement jump height, countermovement jump peak power, and ballistic push-up height. Repeated measure correlation analyses suggested that there was a weak positive correlation between the decrease in skeletal muscle mass and the decrease in countermovement jump peak power throughout the training. The results of our study suggest that explosive movements are negatively affected by extended military training, seemingly independent of environmental training conditions or temperature. Planning and execution of military training should account for the likelihood that warfighter physical power will decline and may not return to pretraining levels within the month following the training event. It may also be advised to consider targeted exercises to aid in recovery of muscular strength and power. Future work should consider additional factors that likely influenced the decrease in physical performance that occurs during extended military training, such as nutrition, sleep, and psychological and cognitive stresses.

Observation of Superconductivity Up to 8.7 K in Reduced Potassium Tantalate

AbstractThe observation of superconductivity with a transition temperature (Tc) up to 8.7 K in KTaO3 single crystals annealed with CaH2 at 900–1000 °C is reported. The superconductivity is confirmed by both resistance and magnetization measurements and is 3D in nature. Characterizations of X‐ray photoelectron spectroscopy, X‐ray diffraction, and scanning transmission electron microscopy reveal that it locates in a 1‐µm‐order‐thick polycrystalline surface layer that shows a rock‐salt type structure, with a lattice constant of 0.454 nm, and can be chemically identified as KxTaOy (0.04 ≤ x ≤ 0.08, 1.24 ≤ y ≤ 1.35), depending on annealing conditions. Within the experimental ranges, the Tc is peaked at x ≈0.05, and increases with decreasing y, and the highest Tc is observed in K0.05TaO1.24. The Tc observed here is much higher than that of KTaO3, Ta, and pure TaO, and is also one of the highest among of all the known oxide superconductors with the same rock‐salt structure. The rather high Tc and its close connection with KTaO3 and Ta, both of which are promising materials for quantum computing, make KxTaOy potentially interesting as a building block in constructing future superconducting quantum devices.

Chemical Characteristics of Exotic Apple Cultivars in Kashmir's Temperate Conditions: Impact of Diverse Pollen Sources

Chemical Characteristics of Exotic Apple Cultivars in Kashmir's Temperate Conditions: Impact of Diverse Pollen Sources

Investigating the transient conditions of “Sabat” space and its influence on pedestrian sensations during thermal walks. Algiers’ Casbah case study

Cities are already witnessing the impacts of climate change. Prolonged heat exposure have a direct effect on pedestrians’ thermoregulatory system, causing serious heat-related issues in the form of fatigue and thermal exhaustion. While the human body is capable of maintaining heat balance, excessive heat exposure combined with increasing heat loads can deteriorate the thermoregulatory process which leads to discomfort. Walkability is one of the significant challenges for climate change mitigation. Balancing the dichotomy of walking to mitigate climate change, and mitigating climate change to walk emphasizes the importance of promoting resilient walkability. In this context, the term “resilience” is used to highlight the need to design urban spaces able to adapt to increased urban heat, enabling pedestrians to tolerate and recover from discomfort conditions. This study investigates the potential of the “Sabat”, a traditional semi-outdoor space with lift-up design, and its distribution in generating transient thermal aeraulic conditions, and reducing fatigue sensation, hence, supporting a positive walking experience. Thermal walks have been conducted in Casbah of Algiers during temperate and hot weather conditions, in the context of uphill walking. Results revealed the alliesthesial effect of cool-shaded and ventilated Sabats to reduce fatigue sensation, which was confirmed by the significant correlation at lag-(-1) (r = 0.504, p < 0.001). Findings shed light on the importance of maintaining dynamic alliesthesia to create modulated restorative opportunities and offer starting point for hypothesizing broader trends for future implementation of Sabat design in modern cities.