Hot Regions Research Articles

Thermal comfort in a two-storey malaysian terrace house: Are passive cooling methods sufficient in present and future climates?

Rising temperatures due to climate change will impact both the indoor thermal comfort of naturally-ventilated housing and the cooling energy needs of air-conditioned housing in tropical regions. This study aims to evaluate the impact of rising temperatures based on the IPCC A2 scenario on indoor thermal comfort and cooling energy in a typical Malaysian terrace house. It addresses three key questions: 1) Can passive cooling (PC) achieve future thermally acceptable conditions? 2) How will PC impact cooling energy with air conditioning (AC)? 3) What is the effectiveness of various PC methods, individually and combined, in controlling indoor climate and saving energy under present and future conditions? We evaluated the effectiveness of eight PC measures—including shading, insulation, solar reflectivity, and nighttime natural ventilation—using EnergyPlus simulations. Results indicate that without PC and AC, indoor temperatures range from 26 to 31 °C, rising to 29–36 °C by the 2050s, often exceeding ASHRAE 55 standards. Currently, combined PC and nighttime ventilation can improve thermal comfort time fraction by up to 87 %. However, by the 2050s, this drops to 38 %, indicating PC alone will be insufficient, and AC systems will be essential. Additionally, in an AC scenario, PC measures reduce cooling energy by 6 % compared to the baseline under future conditions, yet demand is 67 % higher than current conditions. These findings underscore the need for integrating both PC measures and efficient AC systems to mitigate future greenhouse gas emissions from residential sectors in Malaysia and other developing hot climate regions.

Effects of solar energy absorbed by south wall on carbon emission from space heating in hot summer-cold winter region

Carbon emission caused by space heating (CEH) in hot summer and cold winter climate zone has increased dramatically. Taking advantage of the solar energy absorbed by south wall (SEASW) can effectively reduce CEH, however, the accurate quantification of its impact remains a challenge. The study investigates the potential of SEASW in mitigating CEH. Key parameters affecting CEH, such as sunny day ratio, insulation form, and outer surface heat transfer coefficient of south wall (h), were analyzed. Results show the reduction in carbon emissions caused by the solar energy absorbed by each unit area of the south-facing wall (ΔCreduction) can be as high as 18.61 kgCO2⋅m−2 for the wall employing internal insulation and smaller h. A prediction model of ΔCreduction was further developed by using multivariate nonlinear regression, which can estimate the reduction in CEH for different fuels as heating source by a south wall in different sizes. Besides, the potential of SEASW on the reduction of carbon emission per unit floor area can reach 12.2 %. This study underscores the importance of SEASW as a carbon-neutral heating strategy, particularly for regions characterized by short winter heating periods and lower heating loads compared to colder climates. It provides valuable insights for sustainable energy practices and policy formulation.

A NICER View of the Nearest and Brightest Millisecond Pulsar: PSR J0437–4715

We report Bayesian inference of the mass, radius, and hot X-ray emitting region properties—using data from the Neutron Star Interior Composition ExploreR (NICER)—for the brightest rotation-powered millisecond X-ray pulsar, PSR J0437−4715. Our modeling is conditional on informative tight priors on mass, distance, and binary inclination obtained from radio pulsar timing using the Parkes Pulsar Timing Array (PPTA; Reardon et al.), and we use NICER background models to constrain the nonsource background, cross-checking with data from XMM-Newton. We assume two distinct hot emitting regions and various parameterized hot region geometries that are defined in terms of overlapping circles; while simplified, these capture many of the possibilities suggested by detailed modeling of return current heating. For the preferred model identified by our analysis, we infer a mass of M = 1.418 ± 0.037 M ⊙ (largely informed by the PPTA mass prior) and an equatorial radius of R=11.36−0.63+0.95 km, each reported as the posterior credible interval bounded by the 16% and 84% quantiles. This radius favors softer dense matter equations of state and is highly consistent with constraints derived from gravitational wave measurements of neutron star binary mergers. The hot regions are inferred to be nonantipodal and hence inconsistent with a pure centered dipole magnetic field.

Novel Atmospheric Dynamics Shape the Inner Edge of the Habitable Zone around White Dwarfs

White dwarfs offer a unique opportunity to search nearby stellar systems for signs of life, but the habitable zone around these stars is still poorly understood. Since white dwarfs are compact stars with low luminosity, any planets in their habitable zone should be tidally locked, like planets around M dwarfs. Unlike planets around M dwarfs, however, habitable white dwarf planets have to rotate very rapidly, with orbital periods ranging from hours to several days. Here we use the ExoCAM global climate model to investigate the inner edge of the habitable zone around white dwarfs. Our simulations show habitable planets with ultrashort orbital periods (P ≲ 1 day) enter a “bat rotation” regime, which differs from typical atmospheric circulation regimes around M dwarfs. Bat rotators feature mean equatorial subrotation and a displacement of the surface’s hottest regions from the equator toward the midlatitudes. We qualitatively explain the onset of bat rotation using shallow water theory. The resulting circulation shifts increase the dayside cloud cover and decrease the stratospheric water vapor, expanding the white dwarf habitable zone by ∼50% compared to estimates based on 1D models. The James Webb Space Telescope should be able to quickly characterize bat rotators around nearby white dwarfs thanks to their distinct thermal phase curves. Our work underlines that tidally locked planets on ultrashort orbits may exhibit unique atmospheric dynamics, and guides future habitability studies of white dwarf systems.

Modeling Transition Region Hot Loops on the Sun: The Necessity of Rapid, Complex Spatiotemporal Heating and Nonequilibrium Ionization

The study examines the heating profile of hot solar transition region loops, particularly focusing on transient brightenings observed in IRIS 1400 Å slit-jaw images. The findings challenge the adequacy of simplistic, singular heating mechanisms, revealing that the heating is temporally impulsive and requires a spatially complex profile with multiple heating scales. A forward-modeling code is utilized to generate synthetic Interface Region Imaging Spectrograph (IRIS) emission spectra of these loops based on HYDRAD model output, confirming that emitting ions are out of equilibrium. The modeling further indicates that density-dependent dielectronic recombination rates must be included to reproduce the observed line ratios. Collectively, this evidence substantiates that the loops are subject to impulsive heating and that the components of the transiently brightened plasma are driven far from thermal equilibrium. Heating events such as these are ubiquitous in the transition region, and the analysis described above provides a robust observational diagnostic tool for characterizing the plasma.

Unraveling the Trigger Mechanism of Explosive Reconnection in Partially Ionized Solar Plasma

Plasmoid instability usually accounts for the onset of fast reconnection events observed in astrophysical plasmas. However, the measured reconnection rate from observations can be one order of magnitude higher than that derived from magnetohydrodynamic (MHD) simulations. In this study, we present the results of magnetic reconnection in the partially ionized low solar atmosphere based on 2.5D MHD simulations. The whole reconnection process covers two different fast reconnection phases. In the first phase, the slow Sweet–Parker reconnection transits to the plasmoid-mediated reconnection, and the reconnection rate reaches about 0.02. In the second phase, a faster explosive reconnection appears, with the reconnection rate reaching above 0.06. At the same time, a sharp decrease in plasma temperature and density at the principle X-point is observed, which is associated with the strong radiative cooling, the ejection of hot plasma from the local reconnection region, or the motion of the principle X-point from a hot and dense region to a cool and less dense region along the narrow current sheet. This causes gas pressure depletion and increases magnetic diffusion at the main X-point, resulting in the local Petschek-like reconnection and a violent and rapid increase in the reconnection rate. This study for the first time reveals a common phenomenon where the plasmoid-dominated reconnection transits to an explosive faster reconnection with a rate approaching the order of 0.1 in partially ionized plasma in the MHD scale.

Enhancing Transport Processes in Stratified Fluids: Exploring Rotational and Stretching Effects Coupled with Magnetic Fields, Heat, Mass Transfer and Thermal/Solutal Slip

This research paper presents an in-depth investigation into the complex interactions governing stratified fluid flow in the presence of rotational and stretching phenomena, magnetic field influences, heat and mass transfer effects, and the incorporation of thermal and solutal-slips at fluid interfaces. Stratified fluid systems are commonly encountered in various natural and industrial processes, ranging from geophysical flows to chemical engineering applications, making a thorough understanding of these phenomena paramount.The study commences by formulating a comprehensive set of governing equations that account for the unique interplay of these multifaceted physical phenomena. Integrating thermal and solutal slip conditions at fluid interfaces introduces innovative prospects for precisely controlling and manipulating mass and heat transfer in these systems. This research paper extensively explores layered fluid dynamics, encompassing phenomena such as rotation and stretching, influences from magnetic fields, effects of heat and mass transfer, and the examination of thermal and solutal slip conditions. The insights obtained from this study not only enhance our comprehension of multi-physics fluid dynamics but also offer practical implications for streamlining processes across diverse fields. The principal findings and implications of this research can be summarized as follows: Various factors that affect fluid flow exhibit evident and discernible patterns.The mathematical model includes the Navier-Stokes equations with rotational and stretching terms, the Maxwell equations describing magnetic field effects, and the transport equations for heat and mass transfer. Additionally, thermal and solutal slip conditions at the fluid interfaces are incorporated to capture boundary layer dynamics.Numerical simulations are conducted to explore the intricate dynamics arising from this amalgamation of physical effects. The results reveal complex flow patterns, including stratification, boundary layer development, and vortical structures, offering insights into the behavior of fluids under the joint influence of rotational and stretching phenomena, magnetic fields, and thermal and solutal gradients. Furthermore, the impact of key parameters, such as rotation rate, stretching rate, magnetic field strength, and concentration gradients, is systematically analyzed to elucidate their effects on flow characteristics, heat and mass transfer rates, and concentration profiles within the stratified fluid layers. The Soret effect, or thermophoresis, causes nanoparticles to migrate away from hot regions due to fluid molecule flow and high energy levels. Elevating ξNt results in decreased heat and mass transfer. The Prandtl number shows minimal influence on heat and mass transfer when increased. The disk separation, and fluid viscosity, significantly affect the rotational spectrum. As the rotational parameter increases, heat and mass transfer decrease.

Impact of transition spaces on the indoor thermal environment: A case study of traditional dwellings in Southern Shaanxi, China

Transition space connecting internal space and external environment of buildings, which has a buffering effect on improving the indoor thermal environment and saving energy consumption. This research focuses on thermal environment regulation performance of the corridor space of traditional dwellings in hot summer and cold winter region in China was investigated. Firstly, the field investigation and thermal comfort measurement were conducted to clarify the regulating performance of corridor space in the indoor thermal comfort and human adaptability to the environment. Then, the research uses the Grasshopper and Energy plus platforms to analyze and quantitatively verify the effectiveness of the corridor space in enhancing the indoor thermal comfort. Finally, based on the multi-objective optimization by NSGA-II, the Pareto set is generated to obtain the optimal solution for the corridor space to meet the thermal comfort. The results show that corridor of dwelling has a width of 2 m, a slope of 15°, and a height of 3.9 m. The traditional dwellings with corridor space could improve the thermal comfort hours increase by 5.1 %, the energy consumption reduce by 18.7 %. This research could help inhabitants achieve the adaptive design of corridor space and improve the livability of residential habitats in southern Shaanxi.

Effect of Thermal Cycles on Creep Behavior of Bituminous Binder in Hot Regions

Effect of Thermal Cycles on Creep Behavior of Bituminous Binder in Hot Regions

A life cycle carbon dioxide equivalent emissions assessment of zero carbon building in hot semi-arid climate region: Case study

As societies are shifting toward carbon neutral environments, they are beginning to account for their carbon emissions. One of the primary contributors of greenhouse gas emissions and global warming is the building industry; therefore, Life Cycle Assessment (LCA) is one of the instruments that allows an assessment of the energy and the energy-related environmental impacts of the buildings from cradle to grave, according to ISO 14040. In this context, the aim of this research study is to assess the Life Cycle carbon dioxide (LC CO2eq) emissions over a 50-year-lifespan of a zero-carbon solar-powered earth-based building, built with carbon-free adobe bricks, in the hot semi-arid climate of Morocco. While research on the carbon dioxide equivalent (CO2eq) emissions across the life cycle is crucial to determine the energy-intensive stages, this study looks into global tendencies of CO2eq emissions arising during the cradle-to-gate embodied (A1-3) and operational (B6) phases of a Zero Carbon Building (ZCB) case study, and which should be offset by carbon-free energy in order to abide by the ZCB definition. Results show that the LC CO2eq emissions of the eco-friendly zero-carbon residential building falls in 48.62 Kg CO2eq/m2.y., with an operational phase that has a share of around 93 % of global LC CO2eq emissions. In addition, when conventional construction materials such as concrete, bricks, and insulation materials are used as an alternative, embodied carbon emissions accounts for 6.3 kg CO2eq/m2.y. and is 85 % higher than the eco-friendly building, and it constitutes approximately 12.5 % of the overall carbon footprint. Moreover, the annual embodied and operational CO2eq emissions are offset by the 3.3-kWc-building-added-photovoltaic system. Hence, the conducted case study offers valuable insight into the good practices for decarbonization of Morocco's building stock.Through that case study, we aim to generate knowledge of net zero carbon buildings within the African continent, promoting the perks of decentralized solar energy in leaping forward a carbon-free electrified continent and valorizing the local construction techniques and knowhow in the building sector.

Au Nanoparticles@Si Nanowire Oligomer Arrays for SERS: Dimers Are Best.

We report the synthesis of vertically aligned silicon nanowire (VA-SiNW) oligomer arrays coated with Au nanoparticle (NP) monolayers via a combination of colloidal lithography, metal-assisted chemical etching, and directed NP assembly. Arrays of SiNW monomers (i.e., isolated NWs), dimers, and tetramers are synthesized, decorated with AuNPs, and tested for their performance in surface-enhanced Raman spectroscopy. The ∼20 nm AuNPs easily enter within the ca. 40 nm gaps of the SiNW oligomers, thus reaching the hot spot region. At 785 nm excitation, the AuNPs@SiNW dimer arrays provide the highest Raman signal, in agreement with electromagnetic simulations showing a high electric field enhancement at the Au/Si interface within the dimer gap region.

Assessing the winter indoor environment with different comfort metrics in self-built houses of hot-humid areas: Does undercooling matter for the elderly?

Thermal comfort in housing is vital for well-being. Despite hot and humid regions experiencing shorter cold periods compared to heatwaves, vulnerable populations are susceptible to threats from cold snaps. However, existing research overlooks undercooling risks in hot regions during winter. This study examines self-built houses in densely populated, hot and humid areas, mainly occupied by elderly residents. We conducted an on-site measurement recording hourly indoor air temperature, humidity, and black globe temperature during wintertime. Two thermal comfort metrics (aPMV and adaptive regression model) and two resilience metrics (SET degree-hour, Hours of Safety) were used to quantify thermal conditions during cold periods under current and future climate conditions. The results show that undercooling hours in recent years exceed 90 % of wintertime using aPMV index and adaptive regression models. Under future climate scenarios (Representative Concentration Pathways), undercooling hours only decrease by 10 %–25 % from 2020 to 2100 across all metrics. Extreme cold events in 2018 saw SET degree-hours double the thermal resilience threshold, while they pose health risks to the elderly for up to 21 days according to the HOS metrics. This study aims to identify the importance of addressing winter thermal comfort in hot and humid regions and to assess the risk posed by cold snaps to vulnerable populations. By quantifying these risks, the study contributes to better decision-making regarding hot-humid region housing thermal retrofit strategies for architects, engineers, and other stakeholders.

Unraveling the advantages of site-specific nutrient management in maize (Zea mays L.) for enhancing the growth and productivity under varied plant populations in the hot and moist sub-humid region of Odisha

In developing countries like India, a cereal-based cropping system is one of the important practices, having a significant role in food security and the country’s economy. Among the cereal crops cultivated in India, maize is one among them having a huge market demand, and yield potential and can perform under various agroclimatic conditions. In the cultivation of cereal crops like maize, input optimization and intensification of farming by altering plant population are highly essential for agricultural sustainability as well as crop productivity. Nutrients can be efficiently applied through site site-specific approach by using a decision support system, namely, Nutrient Expert (NE) rather application of a recommended dose for an agroclimatic region. Considering the above fact, the research was carried out in the rabi season of 2022-2023 at the Post Graduate Research Farm ofCenturion University of Technology and Management (23?38' N latitude and 87?42' E longitude) in Odisha. The experiment was laid out in a split-plot design with different spacings and NE-based nutrient recommendations. The main factor consisted of 3 different spacings and 4 different nutrient recommendations were considered in sub-plots. The recommended dose of fertilizer for maize was 120-60-60 kg ha-1 of N: P2O5:K2O respectively. The results of the experiment revealed that the highest plant height (249 cm), dry matter accumulation (1556 g m-2), leaf area (5674 cm2 plant-1), grain yield (6362 kg ha-1), and stover yield (9334 kg ha-1) were obtained in 60 cm × 15 cm spacing. The NE-based nutrient management for a target yield for 10 t ha-1 recorded the highest values in terms of growth attributes, yield attributes, and yield of maize. The experiment concluded that providing fertilizers through NE-based nutrient recommendation for a target yield of 10 t ha-1 with a spacing of 60 cm × 15cm can be considered for obtaining better growth, yield attributes, and yield of maize.

Practical Exploration of Net-Zero Building Technology in Hot Summer and Cold Winter Regions—Qingdao Sino-German Eco-Park Longfor Guangnian Project as an Example

Energy saving and carbon reduction in the building sector is crucial to the realization of China’s “double-carbon” goal, and the development of passive house/net-zero buildings is an important initiative to achieve this goal. This paper takes Longfor Guangnian, a passive house project in Qingdao, as a case study, summarizes the technical practice of net-zero buildings in coastal areas with hot summers and cold winters, and gives an optimization plan in combination with the existing problems of the case. The final result is to improve the building energy efficiency and optimize the building energy structure. It accumulates experience and provides reference for the promotion of net-zero buildings in cold areas, and provides support for green and low-carbon development in the field of housing and urban-rural construction.

An investigation of dust-sand events and possible prediction in hot arid regions of Kuwait

An investigation of dust-sand events and possible prediction in hot arid regions of Kuwait

Optimization Strategies for the Envelope of Student Dormitories in Hot Summer and Cold Winter Regions: Multi-Criteria Assessment Method

Optimization Strategies for the Envelope of Student Dormitories in Hot Summer and Cold Winter Regions: Multi-Criteria Assessment Method

Field measurement study of indoor thermal environment of badminton halls in a hot summer and cold winter region in different seasons in China

The indoor thermal environment has a direct impact on human thermal comfort and health. In order to assess the status of the indoor thermal environment of typical sports buildings in hot summer and cold winter climate zones in China, 14 badminton halls in 10 cities in Hubei Province (including 5 venues in Wuhan) in this climate zone are chosen as research objects for field testing of indoor thermal environment parameters in 4 seasons. All the tested stadiums are naturally ventilated in non-event conditions. The results reveal that the average indoor temperature of badminton halls in summer is excessively high (i.e., 31.89 °C), which is higher than the regulation specified in JGJ31-2003 or GB-T18883-2022 on the reference interval of the indoor air temperature of venues in summer, (i.e., (26–28 °C) or (22–28 °C), respectively). The average indoor temperature of badminton halls in winter is too low (i.e., 12.95 °C), and it is lower than the recommendations of JGJ31-2003 or GB-T18883-2022 on the reference interval of the indoor air temperature of venues in winter (i.e., (16–18 °C) or (16–24 °C), respectively), relative humidity and air velocity are in the thermal comfort interval for all seasons, and the indoor thermal environment factors of badminton courts in spring and autumn meet the comfort requirements. The indoor and outdoor temperatures and the relative humidity of badminton courts are highly correlated. The indoor temperature and relative humidity vary according to changes in those factors outdoors, whereas the air velocity is not affected by outdoor changes. In the hot summer and cold winter climate zones, some discrepancies in the indoor temperature variation patterns of badminton halls at various altitudes are detectable. The results of this study aim to provide a solid basis for the development of indoor thermal-comfort standards for sports stadiums in China.

Growing Importance of Camel Milk in Human Health

Milk is considered as a complete food as it is rich in proteins, fats, minerals, and vitamins that are essential for human nutrition. Camel milk, a dietary staple in hot and arid regions for millennia, has recently gained attention for its nutritional richness and therapeutic properties. With a global camel population of 35 million, countries in East and Central Africa harbor the largest populations, with Ethiopia ranking second in production after Somalia. Beyond its significance in pastoralist communities, camel milk exhibits diverse health benefits, including anti-aging, anti-inflammatory, and immunomodulatory effects. Its unique chemical composition, including high levels of vitamin C, essential minerals, and protective proteins like lactoferrin, lactoperoxidase, immunoglobulins, and lysozyme, makes it a potential alternative to bovine milk. Camel milk lacks β-lactoglobulin, which causes allergic to cow milk proteins. Notably, camel milk's role in managing conditions such as diabetes, allergies, autism, cancer, tuberculosis, hepatitis, and arthritis. Moreover, its hypoallergenic nature and antimicrobial properties make it a promising functional food. Insulin-like proteins, which imitate insulin's role in controlling blood sugar levels and hence improve glucose uptake, contribute to its efficacy. Camel milk has cosmetic effects due to the presence of α-hydroxy acids, which help to plump the skin and smooth fine lines. Despite its importance, camel milk remains underappreciated, necessitating further research and awareness efforts to unlock its full therapeutic potential and promote its consumption. This paper aims to shed light on the diverse health benefits of camel milk.

Assessment of heat stress contributing factors in the indoor environment among vulnerable populations in Klang Valley using principal component analysis (PCA)

Rising global temperatures can lead to heat waves, which in turn can pose health risks to the community. However, a notable gap remains in highlighting the primary contributing factors that amplify heat-health risk among vulnerable populations. This study aims to evaluate the precedence of heat stress contributing factors in urban and rural vulnerable populations living in hot and humid tropical regions. A comparative cross-sectional study was conducted, involving 108 respondents from urban and rural areas in Klang Valley, Malaysia, using a face-to-face interview and a validated questionnaire. Data was analyzed using the principal component analysis, categorizing factors into exposure, sensitivity, and adaptive capacity indicators. In urban areas, five principal components (PCs) explained 64.3% of variability, with primary factors being sensitivity (health morbidity, medicine intake, increased age), adaptive capacity (outdoor occupation type, lack of ceiling, longer residency duration), and exposure (lower ceiling height, increased building age). In rural, five PCs explained 71.5% of variability, with primary factors being exposure (lack of ceiling, high thermal conductivity roof material, increased building age, shorter residency duration), sensitivity (health morbidity, medicine intake, increased age), and adaptive capacity (female, non-smoking, higher BMI). The order of heat-health vulnerability indicators was sensitivity > adaptive capacity > exposure for urban areas, and exposure > sensitivity > adaptive capacity for rural areas. This study demonstrated a different pattern of leading contributors to heat stress between urban and rural vulnerable populations.

Corundum ± magnesium‐deltalumite ± hibonite‐bearing objects in the CH chondrite Sayh al Uhaymir 290

AbstractIsolated corundum grains and corundum ± Mg‐deltalumite [(Al,Mg)(Al,◻)2O4] ± hibonite assemblages were investigated in the CH3.0 metal‐rich carbonaceous chondrite Sayh al Uhaymir (SaU) 290. Although very refractory inclusions containing abundant Zr‐ and Sc‐rich oxides and silicates, hibonite, grossite, or perovskite have been previously described in CH chondrites, this is the first discovery of corundum and Mg‐deltalumite in CHs and the first discovery of Mg‐deltalumite in nature. Magnesium‐deltalumite can be indexed by the Fd3m spinel‐type structure and gives a perfect fit to the synthetic Al‐rich spinel cells. Corundum‐Mg‐deltalumite grains, 5–20 μm in size, are occasionally rimmed by a thin layer of hibonite replacing corundum. Some corundum grains contain tiny inclusions of ultrarefractory Zr,Sc‐rich minerals and platinum‐group element (PGE) nuggets. All corundum, hibonite, and Mg‐deltalumite grains studied have 16O‐rich compositions (average Δ17O ± 2SD = −22 ± 3‰). Two corundum grains show evidence for significant mass‐dependent fractionation of oxygen isotopes: Δ18O ~ +34‰ and ~ +19‰. We suggest that the SaU 290 corundum‐rich objects were formed by evaporation and/or condensation in a hot nebular region close to the proto‐sun where the ambient temperature was close to the condensation temperature of corundum. A corundum grain with tiny inclusions of Zr‐ and Sc‐rich phases and PGE metal nuggets recorded formation temperatures higher than the condensation temperature of corundum. Two corundum‐rich objects with highly fractionated oxygen isotopes must have crystallized from a melt that experienced evaporation. Corundum grains corroded by hibonite recorded gas–solid interaction in this region during its cooling. The Mg‐deltalumite ± corundum ± hibonite objects were formed by rapid crystallization of high‐temperature (>2000°C) refractory melts. The lack of minerals with condensation temperatures below those of corundum and hibonite in the SaU 290 corundum‐rich objects suggests that after formation, these objects were rapidly removed from the hot nebular region by disk wind and/or by turbulent diffusion and disk spreading.