Search Results (438)

Water-ice occurs inside many minor bodies almost throughout the Solar System. To have an overview of the inventory of water-ice in asteroids, beside the general characteristics of their activity, examples are presented with details, including the Hilda zone and among the Trojans. There might be several extinct comets among the asteroids with only internal ice content, demonstrating the complex evolution of such bodies. To evaluate the formation of ice-hosting small objects, their migration and retention capacity by a surface covering dust layer are also overviewed to provide a complex picture of volatile occurrences. This review aims to support further work and search for sublimation-induced activity of asteroids by future missions and telescopic surveys. Based on the observed and hypothesized occurrence and characteristics of icy asteroids, future observation-related estimations were made regarding the low limiting magnitude future survey of LSST/Vera Rubin and also the infrared ice identification by the James Webb space telescope. According to these estimations, there is a high probability of mapping the distribution of ice in the asteroid belt over the next decade. Full article

Classical thermodynamics omits rigidity, which property distinguishes solids from gases and liquids. By accounting for rigidity (i.e., Young’s elastic modulus, ϒ), we recently amended historical formulae and moreover linked heat capacity, thermal expansivity, and ϒ. Further exploration is motivation by the importance of classical thermodynamics to various applied sciences. Based on heat performing work, we show here, theoretically, that density times sublimation enthalpy divided by the molar mass (ρΔH_sub/M, energy per volume), depends linearly on ϒ (1 GPa = 10⁹ J m⁻³). Data on diverse metals, non-metallic elements, chalcogenides, simple oxides, alkali halides, and fluorides with cubic structures validate this relationship at ambient conditions. Furthermore, data on hcp metals and molecular solids show that ρΔH_sub/M is proportional to ϒ for anisotropic materials. Proportionality constants vary only from 0.1 to 0.7 among these different material types (>100 substances), which shows that the elastic energy reservoir of solids is large. Proportionality constants depend on whether molecules or atoms are sublimated and are somewhat affected by structure. We show that ductility of refractory, high-ϒ metals affect high-temperature determinations of their ΔH_sub. Our results provide information on sublimation processes and subsequent gas phase reactions, while showing that elasticity of solids is the key parameter needed to assessing their energetics. Implications are highlighted. Full article

This study describes both experimental and numerical investigations into the heat and mass transfer processes governing the vacuum freeze drying of camel milk, with a specific focus on improving the energy efficiency. A three-dimensional model was developed and solved using the finite element method to simulate temperature evolution and sublimation interface progression during drying. The numerical model was validated against experimental data, achieving strong agreement, with an $R^2$ value of 0.94. A detailed parametric analysis examined the effects of the shelf temperature, sample thickness, and chamber pressure on the drying kinetics and energy input. The results indicate that optimising these parameters can significantly reduce the energy consumption and processing time while maintaining product quality. Notably, reducing the sample thickness to 4 mm shortened the drying time by up to 40% and reduced the specific energy consumption (SEC) from 358 to 149 kWh/kg. These findings offer valuable insights for the design of more energy-efficient freeze drying systems, with implications for sustainable milk powder production and industrial-scale process optimisation. Full article

Mars’ south polar cap hosts dynamic landforms known as Swiss cheese features (SCFs), which form through the sublimation of carbon dioxide (CO₂) ice driven by the planet’s extreme seasonal and diurnal solar insolation cycles. These shallow, rounded depressions—first identified by Mars Global Surveyor in 1999 and later monitored by the Mars Reconnaissance Orbiter (MRO)—have been observed to increase in size over time. However, large-scale analysis of SCF formation and growth has been limited by the slow and labor-intensive nature of manual mapping techniques. This study applies object-based image analysis (OBIA) to automate the detection and measurement of SCFs using High-Resolution Imaging Science Experiment (HiRISE) images spanning five Martian years. Results show that SCFs exhibit a near-linear increase in area, suggesting that summer sublimation consistently outpaces winter CO₂ deposition. Validation against manual digitization shows discrepancies of less than 1%, confirming the reliability of the OBIA method. Regression-based extrapolation of growth trends indicates that the current generation of SCFs likely began forming between Martian years 7 and 16, approximately corresponding to Earth years 1976 to 1998. These findings provide a quantitative assessment of SCF evolution and contribute to our understanding of recent climate-driven surface changes on Mars. HiRISE images were processed using the eCognition software to detect, classify, and measure SCFs, demonstrating that OBIA is a scalable and effective tool for analyzing dynamic planetary landforms. Full article

Citrus fruit are well-known for their characteristic flavour and nutritional value. Global citrus production has increased by 528% between 1961 and 2021, and in Australia, citrus is the most exported fresh fruit product by volume. There are six described Citrus species endemic to Australia: C. australasica (Australian finger lime), C. australis (round lime), C. garrawayi (Mount White lime), C. glauca (desert lime), C. gracilis (Humpty Doo lime), and C. inodora (Russell River lime). Australian Citrus possess unique flavours, aromas, and phytochemical profiles, suggesting a potential use as novelty crops and/or ‘functional foods’. Furthermore, the native Australian Citrus germplasm is a valuable source of desirable traits in citrus breeding, including drought, cold, heat, salinity, and disease resistance. These may help solve some challenges facing citrus growers globally, including disease, a declining soil quality, changing climates, and narrowing profit margins. However, many Australian citrus species’ nutritional value, chemical composition, and bioactive properties remain unknown. This review focuses on these under-investigated native Citrus species, their distribution, production, physiology, disease tolerance, traditional use, taxonomy, flavour, nutritional composition, bioactivity, and commercial production. It concludes with a perspective on the future of these native species in the Australian and global citrus context. Full article

The new mineral achyrophanite (K,Na)₃(Fe³⁺,Ti,Al,Mg)₅O₂(AsO₄)₅ was found in high-temperature sublimates of the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with aphthitalite-group sulfates, hematite, alluaudite-group arsenates (badalovite, calciojohillerite, johillerite, nickenichite, hatertite, and khrenovite), ozerovaite, pansnerite, arsenatrotitanite, yurmarinite, svabite, tilasite, katiarsite, yurgensonite, As-bearing sanidine, anhydrite, rutile, cassiterite, and pseudobrookite. Achyrophanite occurs as long-prismatic to acicular or, rarer, tabular crystals up to 0.02 × 0.2 × 1.5 mm, which form parallel, radiating, bush-like, or chaotic aggregates up to 3 mm across. It is transparent, straw-yellow to golden yellow, with strong vitreous luster. The mineral is brittle, with (001) perfect cleavage. D_calc is 3.814 g cm^–3. Achyrophanite is optically biaxial (+), α = 1.823(7), β = 1.840(7), γ = 1.895(7) (589 nm), 2V (meas.) = 60(10)°. Chemical composition (wt.%, electron microprobe) is: Na₂O 3.68, K₂O 9.32, CaO 0.38, MgO 1.37, MnO 0.08, CuO 0.82, ZnO 0.48, Al₂O₃ 2.09, Fe₂O₃ 20.42, SiO₂ 0.12, TiO₂ 7.35, P₂O₅ 0.14, V₂O₅ 0.33, As₂O₅ 51.88, SO₃ 1.04, and total 99.40. The empirical formula calculated based on 22 O apfu is Na_1.29K_2.15Ca_0.07Mg_0.34Mn_0.01Cu_0.11Zn_0.06Al_0.44Fe³⁺_2.77Ti_1.00Si_0.02P_0.02S_0.14V_0.04As_4.90O₂₂. Achyrophanite is orthorhombic, space group P222₁, a = 6.5824(2), b = 13.2488(4), c = 10.7613(3) Å, V = 938.48(5) ų and Z = 2. The strongest reflections of the PXRD pattern [d,Å(I)(hkl)] are 5.615(59)(101), 4.174(42)(022), 3.669(31)(130), 3.148(33)(103), 2.852(43)(141), 2.814(100)(042, 202), 2.689(29)(004), and 2.237(28)(152). The crystal structure of achyrophanite (solved from single-crystal XRD data, R = 4.47%) is unique. It is based on the octahedral-tetrahedral M-T-O pseudo-framework (M = Fe³⁺ with admixed Ti, Al, Mg, Na; T = As⁵⁺). Large-cation A sites (A = K, Na) are located in the channels of the pseudo-framework. The achyrophanite structure can be described as stuffed, with the defect heteropolyhedral pseudo-framework derivative of the orthorhombic Fe³⁺AsO₄ archetype. The mineral is named from the Greek άχυρον, straw, and φαίνομαι, to appear, in allusion to its typical straw-yellow color and long prismatic habit of crystals. Full article

In this work, detailed information on the phase-transition thermodynamics of the analgesic and antipyretic drug phenazone, also known as antipyrine, is reported. It was found that the compound forms two polymorphs. Fusion thermodynamics of both forms was studied between 298.15 K and T_m using the combination of differential scanning calorimetry and solution calorimetry. The vapor pressures above crystalline and liquid phenazone were measured for the first time using thermogravimetry—fast scanning calorimetry technique. These studies were complemented by computation of the ideal gas entropy and heat capacity and by measurements of the condensed phase heat capacities. On the basis of experiments performed, we derived sublimation and vaporization enthalpies and vapor pressure above liquid and both crystalline modifications of phenazone in a wide range of temperatures. Full article

In this work, the influences of the Ar flow-rate and sublimation temperature on the phase composition and morphological structure of the sublimation products of analytical reagent MoO₃ are investigated. The results show that the sublimation products are always composed of thermodynamically stable orthorhombic molybdenum trioxide (α-MoO₃) and metastable monoclinic molybdenum trioxide (β-MoO₃) under different reaction conditions, among which the proportion of β-MoO₃ gradually increases with the increase in Ar flow-rate and the decrease in sublimation temperature. The formation temperature of α-MoO₃ is mainly between 780 K and 847 K, with the particles exhibiting an obvious sheet-like morphology. This work also finds that β-MoO₃ is mainly generated below 500 K; however, due to the co-actions of the deposition of gaseous MoO₃ molecules, the adsorption of Ar molecules, and the collision effect between the different particles, the newly formed β-MoO₃ is more inclined to take a spherical-shaped morphology in order to maintain its lowest energy state. Full article

The relationship between natural environments and psychological well-being has gained increasing attention in environmental and health sciences. However, there is still a lack of robust quantitative instruments to assess the restorative potential of different environments. This study aimed to adapt and validate the Portuguese version of the Perceived Restorativeness Scale (PRS), an instrument based on Attention Restoration Theory that evaluates the perceived restorative qualities of environments. In Study 1, exploratory and confirmatory factor analyses were conducted on data from 410 participants. The results supported a refined 20-item version of the scale, comprising four factors—being away, fascination, compatibility, and legibility—with good internal consistency and acceptable model fit. Measurement invariance analysis confirmed configural, metric, and scalar invariance across gender. In Study 2, a separate sample of 212 participants completed the PRS along with additional validated measures: the Sublime Emotion toward Nature Scale (SEN), an aesthetic evaluation of landscapes, and the Positive and Negative Affect Schedule (PANAS). The PRS showed strong convergent and discriminant validity and significantly predicted restorative outcomes. These findings support the psychometric adequacy of the Portuguese PRS and its relevance as a valid tool for assessing perceived restorativeness in both natural and built environments. The scale may inform future research and public policies aimed at designing spaces that promote psychological restoration and mental well-being. Full article

This study presents a methodology for developing a cyclodextrin-based delivery system for ceftobiprole, a poorly water-soluble and amphoteric drug, chemically stable in acidic conditions. Ceftobiprole is a broad-spectrum cephalosporin antibiotic administered clinically as its water-soluble prodrug, ceftobiprole medocaril, due to limited aqueous solubility of the parent compound. Solubility enhancement was achieved through complexation with anionic sulfobutylether-β-cyclodextrin (SBE-β-CD). At a pH below 3, ceftobiprole is protonated and cationic, which facilitates electrostatic interactions with the anionic cyclodextrin. An optimised high-performance liquid chromatography (HPLC) method was used to assess solubility, the impurity profile, and long-term chemical stability. X-ray powder diffraction (XRPD) confirmed the amorphous nature of the system and the absence of recrystallization. Nuclear magnetic resonance (NMR) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy supported the formation of a host–guest complex. The freeze-dried system prepared from 0.1 M formic acid solution contained negligible residual acid due to nearly complete sublimation. The most promising formulation was a ternary system of ceftobiprole, maleic acid, and SBE-β-CD (1:25:4 molar ratio), showing ~300-fold solubility improvement, low levels of degradation products, and stability after eight months at −20 °C. After pH adjustment to a parenterally acceptable level, the formulation demonstrated solubility and a pH comparable to the marketed drug product. Full article

Niobium, with its unique properties, plays a key role in high-tech industries, but its recovery from secondary sources remains poorly studied. The kinetics of niobium leaching from niobium-containing middlings obtained via the water treatment of dust chamber sublimations of titanium chlorinators is considered in this study. The leaching process was conducted using a fluoride–sulphuric acid solution. The experiments were performed at 25–90 °C in agitation mode. Kinetic data were analysed using compression-core and mixed-control models, which made it possible to establish the limiting stages of the process. A mixed mechanism, including a chemical reaction on the surface and diffusion through a layer of products with an activation energy of 30.05 kJ/mol, was established. The niobium recovery degree increased from 35.25 to 93.5% as the temperature increased, highlighting its effect on the process. The insoluble residue, rich in titanium, and the liquid phase with niobium and zirconium have the potential for further processing. The results provide the basis to optimise technologies intended to recover niobium from man-made raw materials, contributing to an increase in resource efficiency. Full article

Salvation through Refinement (liandu 鍊度) is a distinctive Daoist rite aimed at rescuing the souls of the deceased from hell, enabling their rebirth, and ultimately facilitating their transcendence. The Golden Writings on the Great Achievement of Deliverance by the Numinous Treasure of Highest Clarity (Shangqing Lingbao Jidu Dacheng Jinshu 上清靈寶濟度大成金書), compiled by Zhou Side 周思得 (1359–1451), preserves a wealth of material related to Salvation through Refinement. This content can be divided into two parts: the ritual procedures of Salvation through Refinement and the associated internal practices (neishi 内事). Zhou explicitly stated that the Salvation through Refinement ritual originated from the Golden Book of Salvation according to the Lingbao Tradition (Lingbao Lingjiao Jidu Jinshu 靈寶領教濟度金書), compiled by Lin Lingzhen 林靈真 (1239–1302), whereas the internal practices are not attributed to any specific source. Comparative analysis confirms that the section on internal practices derives from the Brief Discussions of Inner Method of Taiji for Sacrificing to and Sublimating [the Souls of the Deceased] (Taiji Jilian Neifa Yilüe 太極祭鍊內法議略), compiled by Zheng Sixiao 鄭思肖 (1241–1318). Zheng Sixiao’s Salvation through Refinement method centers on Visualization and Actualization (cunxiang 存想), with the entire process taking place internally within the ritual master’s body. Building upon this foundation, Zhou Side incorporated additional ritualized actions and recitations, striving to integrate external ritual with internal practice. In doing so, he constructed a model of Salvation through Refinement characterized by the union of inner methods and outer rites. Inner Sublimation emerged during the Southern Song period, likely influenced in both principle and method by the then-prevalent School of the Mind (xinxue 心學). It sought to counter the increasing complexity of ritual practices at that time. Meanwhile, the continued practice of traditional forms of Retreats (zhai 齋) and Offerings (jiao 醮) reflected the Ming (1368–1644) rulers’ emphasis on the didactic function of such rituals. In his compilation, Zhou cited the views and materials of others under the name of Tian Sizhen 田思真 (fl. early 12th century) to articulate the inner meanings and core doctrines of the Numinous Treasure (lingbao 靈寶) rites. By positioning Tian Sizhen as an intermediary, Zhou not only established a line of transmission between the rites he compiled and the orthodox Numinous Treasure lineage represented by Lu Xiujing 陸修靜 (406–477) but also affirmed his conscious identification with the Daoist ritual tradition and his stance regarding its lineage. Full article

The deposition and evolution of ice-rich materials on Martian surfaces offer valuable insights into climatic evolution and the potential driving forces behind global climate change. Substantial evidence indicates that the mid-latitudes of Mars played a crucial role in the formation and development of glacial and periglacial landforms during the Amazonian period. However, few studies have comprehensively examined ice-related landforms in the low-latitude region of Mars. Whether extensive glacial activity has occurred in the equatorial region of Mars and whether there are any potential geological records of such activities remain unclear. In this study, we analyzed remote sensing data from the Martian equatorial region (0°–±30°) and identified existing glacial/periglacial features, as well as remnant landforms of past glaciation. Our findings reveal that glaciation at low latitudes is more widespread than previously thought, with ice-related remnants extending as far equatorward as 13°N in the northern hemisphere and 19°S in the southern hemisphere, highlighting a broader latitudinal range for ice-related landforms. These landforms span multiple episodes of Martian geological history, supporting the hypothesis on the occurrence of repeated glaciation and various high-obliquity events. Evidence of dynamic interactions between ice deposition and sublimation in low-latitude regions demonstrates substantial ice loss over time, leaving ice-related remnants that provide valuable insights into Mars’ climatic evolution. Based on volumetric estimates of the concentric crater fill (CCF), the low-latitude regions of Mars may contain up to 1.05 × 10³ km³ of ice. This corresponds to a global equivalent ice layer thickness ranging from 21.7 mm (assuming a pore ice with 30% ice content) to 65.1 mm (assuming glacial ice with 90% ice content), suggesting a potentially greater low-latitude ice reservoir than previously recognized. Full article

The present study reports on the manufacturing of biphasic calcium phosphate (BCP) honeycomb scaffolds with tailored microporous walls using phase separation-assisted digital light processing (PS-DLP). To create micropores in BCP walls, camphene was used as the pore-forming agent for preparing BCP suspensions, since it could be completely dissolved in photopolymerizable monomers composed of triethylene glycol dimethacrylate (TEGDMA) and polyethylene glycol diacrylate (PEGDA) and then undergo phase separation when placed at 5 °C. Therefore, solid camphene crystals could be formed in phase-separated BCP layers and then readily removed via sublimation after the photopolymerization of monomer networks embedding BCP particles by DLP. This approach allowed for tight control over the microporosity of BCP walls by adjusting the camphene content. As the camphene content increased from 40 to 60 vol%, the microporosity increased from ~38 to ~59 vol%. Consequently, the overall porosity of dual-scale porosity scaffolds increased from ~51 to ~67 vol%, while their compressive strength decreased from ~70.4 to ~13.7 MPa. The mass transport ability increased remarkably with an increase in microporosity. Full article

For decades, in historical research, archeological vestiges have been linked with geomancy and cults of the mythical ancestors of a group of the population. This is particularly true in Eastern Asia and especially in China, Korea, and Japan. A fundamental problem of Japanese archeology is that few of the remnants were realized in stone. One of the most important parts of archeological sciences is the study of Necropolises or ancient interments. From the 1970s onwards, in the relatively “new” and promising land of Hokkaido, cemeteries were built with the concept of landscape in mind; this is also due to the lavish vegetation features of this northernmost island of Japan. In the case of the Takino cemetery on the plains of Sapporo, Hokkaido, whose construction began in 1982, solemnity and religiousness were incorporated by producing exact stone replicas of famous funerary landmarks from antiquity as such materials were inexistent in the Nipponese Isles. This trend to grant eternity included traditional Buddhist funereal monuments like the Stupa, Seokguram grotto, and Kamakura sites, but at a certain and exuberant point, under the influence of Isamu Noguchi, it reached Stonehenge in England and the Moai from Easter Island in Polynesia (being after all located in a remote isle of the Pacific Ocean). In this article we will outline such process of generation and overall conception, analyzing the inclusion and architectural assembly of the different compounds and the recent and extraordinary additions projected and built by the celebrity architect Tadao Ando. We expect, in this manner, to facilitate the comprehension of the significance of venerable landscape sublimated through archeology for the Nipponese modern civilization. Full article