The contributions of external and internal hydration (OH and H2O) on the shape and strength of hydration related features at 3 and 6 mu m for lunar relevant nominally anhydrous minerals were investigated under vacuum conditions. Understanding the effect of hydration on the reflectance spectra of lunar analog materials in the laboratory can provide insights into remote sensing observations of the lunar surface and the potential for 3 and/or 6 mu m observations to determine the speciation of hydration on the Moon. We demonstrate changes in the shape and strength of the broad 3 mu m absorption feature in olivine and anorthite that is associated with the removal of hydration under changing environmental conditions. The overlapping nature of OH and H2O related absorption features in the similar to 3 mu m region makes it difficult to uniquely determine the speciation of hydration. Despite evidence of H2O loss in the 3 mu m region, we do not observe the fundamental bending mode of H2O at 6 mu m, posing potential challenges for the detection H2O on the lunar surface and throughout our solar system.

The MAJIS (Moons And Jupiter Imaging Spectrometer) instrument, part of the JUICE (JUpiter ICy moons Explorer) mission, is a crucial tool for investigating the composition and dynamics of Jupiter's atmosphere, and the surfaces and exospheres of its icy moons. To optimize observational planning and assess instrument performance, we have developed a radiometric simulator that accurately models MAJIS expected signal from various Jovian system targets. This simulator incorporates instrumental parameters, the spacecraft trajectory, observational constraints, and Jupiter's radiation environment. It provides essential outputs, including Signal-to-Noise Ratio (SNR) predictions and optimized instrument settings for different observational scenarios. By simulating both radiometric performance and de-spiking strategies to mitigate the impact of Jupiter radiation belt, the tool aids in refining observation strategies throughout the MAJIS operations. Several scientific applications demonstrate the simulator capabilities, from mapping the surfaces of Ganymede and Europa to detecting exospheric emissions and atmospheric composition on Jupiter. This simulator is a critical asset for maximizing MAJIS scientific return and ensuring optimal data acquisition during MAJIS exploration of the Jovian system. Study cases are presented for illustrating the capability of the simulator to model scenarios such as high-resolution mapping of Ganymede, exosphere characterization and hotspot detection on Io and Europa. These simulations confirm the potential of MAJIS for detecting key spectral features with high signal to noise ratio so as to provide major contributions to the main goals of the mission: habitability and compositional diversity in the Jovian system.

In this study, a novel 2D method for measuring soil surface suction, leveraging infrared thermal imaging technology is presented. The main principle of this method is the establishment of a correlation between soil surface water content and a normalized interfacial temperature difference. Subsequently, we link unsaturated soil surface suction to the normalized interfacial temperature difference through the soil-water characteristic curve. To validate the proposed method, an in-situ calibration test was conducted to ascertain the requisite parameters. Then, the method was tested under varying meteorological conditions at two distinct in-situ sites using the same test protocol as the calibration phase. The results demonstrate a strong agreement compared to measured values, affirming the feasibility and robustness of the proposed approach. This method offers several noteworthy advantages, including rapidity, non-contact operation, non-destructiveness, and robustness to environmental fluctuations. It holds promise for advancing investigation of the spatial and temporal evolution of hydro-mechanical properties of in-situ soil under the influence of climate change.

The use of various sustainable materials and cement is a frequent and successful strategy for stabilizing problematic soil. The current research discusses the potential use of discarded millet husk ash (MHA) and cement (C) as subgrade ingredients to improve the geotechnical qualities of soil (S). MHA and cement are mixed in different proportions and the engineering characteristics of the stabilized soil are studied. The study involves examining fundamental properties, such as specific gravity and Atterberg's limits, as well as engineering properties, including Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) tests. These evaluations are conducted to assess the feasibility of using the MHA-cement blend as a construction material. Additionally, FTIR & SEM analysis shows the addition of MHA-cement blend effectively couples with the soil. The test findings demonstrate that adding MHA to soil lead to decreased liquid limits and plasticity indices. The maximum dry density (MDD) was observed to decrease when MHA was mixed with soil. When 8% cement was incorporated to the S:MHA (84.5:7.5) combination, the UCS value rose even higher reaching 1600.1 kPa. The S:MHA:C arrangement in the ratio of 84.5:7.5:8 had the greatest California bearing ratio (CBR). Fourier transform infrared spectroscopy (FTIR) elucidated the various types of bond formations present within the soil composite and deeper peaks depicted greater presence of cementitious compounds after curing period. SEM analysis exhibited a greater density of N-A-S-H and C-A-S-H gels in comparison to natural soil samples. The findings suggest that the MHA-cement blend can effectively enhance the geotechnical properties of problematic soils, while addressing issues of agricultural waste management. This research contributes to several Sustainable Development Goals (SDGs), including SDG 9 (Industry, Innovation, and Infrastructure) by promoting innovative construction materials.

In aggressive environments, including acidic environments, low and high-plasticity clays play an important role in transmitting and spreading dangerous pollution. Stabilisation of these types of soils can improve their characteristics. In this research, different ratios of two precursors with a low calcium percentage, for example, waste statiti-ceramic sphere powder (WS-CSP) and a high calcium percentage (e.g. ground granulated blast furnace slag [GGBFS], were employed to investigate the properties of soils with different plasticity indices [PIs]). Low and high-plasticity-stabilised and stabilised with 5 wt% Portland cement specimens were prepared and exposed to an acidic solution with a pH of 2.5 in intervals of 1, 3, 6 and 9 months. The long-term durability of specimens was evaluated using the uniaxial compressive strength test (UCS) and bending strength test (BS). Additionally, the microstructures of these specimens under various time intervals were analyzed using scanning electron microscopy and Fourier-transform infrared. According to the results, in an acidic environment, the reduction in UCS, BS, toughness and secant modulus of elasticity (E50) for low-plasticity-stabilised specimens and containing 100% WS-CSP was lower than that of other specimens. The Taguchi method and ANOVA were used to investigate the effect of each control factor on the UCS and BS.

The impact of four distinct calcium sources on the microbial solidification of sand in the Kashi Desert, Xinjiang, was investigated. A wind tunnel test over a 60-day period revealed the cracking behavior of four different complex calcium nutrient solutions. By comparing the bearing capacity and the results from dry-wet cycling and freeze-thaw cycle tests, it was concluded that the sample treated with calcium gluconate exhibited superior sand fixation performance, whereas the sample treated with calcium acetate showed weaker sand fixation effects. The microstructure of the treated sand samples was analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Elemental analysis was conducted via energy dispersive spectroscopy (EDS), and functional groups were identified through Fourier transform infrared spectroscopy (FTIR). These experimental findings hold significant implications for soil remediation, pollutant removal in soil, enhancement of soil fertility, and desert soil stabilization.

Using infrared thermography (IRT) has been proven as an effective technology for early damage detection within the superstructure/substructure of the ballasted railway tracks. Performing statistical processing and integrating principle component analysis (PCA) underpinned by extensive data sources of infrared imaging technology can effectively detect complex features exhibiting temperature variation. The present study employs these processing techniques on thermal images to investigate the drainage health of railway ballast layer using IRT technology. Specifically, clean and clay-fouled ballast specimens are prepared to study the effect of contamination/fouling in ballast layer (porous granular media) on water retention (indicated by water level) during severe rainfall intensity. IRT is utilized to monitor the water level as the indicator of ballast layer drainage health condition. Results show that the IRT image-processing technology confirms the capability of IRT for detecting water surface/water retention based on the thermal images captured from ballast specimen surface. In addition, an appropriate time for monitoring via IRT is after heavy rainfall upon which the water retention in the ballast layer can be more effectively detected. Particularly, presence of water and fouling material among ballast particles results in lower and more uniform surface temperature compared to dry or clean ballast specimens.

Understanding the distribution of plant moisture during the seedling stage of greenhouse crops is challenge in developing scientific irrigation strategies and proposing effective cooling methods. This study investigated the effects of different soil moisture contents [W1: 25-35 % (severe drought), W2: 35-45 % (mild drought), W3: 45-55 % (suitable moisture), and W4: 55-65 % (excess moisture)] on tomato seedlings under summer greenhouse thermic extremes. Furthermore, thermal infrared imaging and chlorophyll fluorescence multi-dimensional digital image sensors were used to determine differences in tomato seedling morphology and plant physiology. The increase in canopy area under W1 and W4 soil moisture content was smaller than that of W2 and W3, and the canopy area of the W1 group decreased as the high temperature condition continued. The average canopy temperature of each treatment generally increased first, and then plateaued. From high to low, average temperatures were 28.15 degrees C in W1, 27.73 degrees C in W4, 26.67 degrees C in W2, and 25.72 degrees C in W3. The canopy temperature gradually decreased from the middle to the edge of the leaf (stem temperature > leaf base temperature > leaf vein temperature > leaf edge temperature). The F-v/F-m ratio in the chlorophyll fluorescence index qualitatively expresses the degree of water stress. phi PSII, non-photochemical quenching (NPQ), and qP values were used as indicators to quantitatively analyze stress in leaves of different maturity. A preliminary mathematical relationship between the canopy and NPQ was established. This study quantitatively characterized the morphological and physiological changes of tomato seedlings in the greenhouse during summer, visualized the process of canopy temperature changes, and provided a theoretical basis for mitigating heat-induced damage.

Interactions among microbes, minerals, and organic matter are key controls on carbon, nutrient, and contaminant dynamics in soils and sediments. However, probing these interactions at relevant scales and through time remains an analytical challenge due to both their complex nature and the need for tools permitting nondestructive and real-time analysis at sufficient spatial resolution. Here, we demonstrate the ability and provide analytical recommendations for the submicron-scale characterization of complex mineral-organic microstructures using optical photothermal infrared (O-PTIR) microscopy. Compared to conventional infrared techniques, O-PTIR spectra collected at submicron resolution of environmentally relevant mineral and organic reference compounds demonstrated similar spectral quality and sensitivity. O-PTIR detection sensitivity was greatest for highly crystalline minerals and potentially for low molecular weight organic compounds. Due to photothermal effects, O-PTIR was more sensitive toward organics than minerals compared to conventional IR approaches, even when organics were mineral-bound. Moreover, O-PTIR resolved mineral-bound and unbound organics in a complex mixture at submicron (<500 nm) resolution. Finally, we provide best practices for artifact-free analysis of organic and mineral samples by determining the appropriate laser power using damage thresholds. Our results highlight the potential of O-PTIR microscopy for nondestructive and time-resolved analysis of dynamic microbe-mineral-organic matter interactions in soils and sediments.

The increasing global demand for sustainable agriculture requires accurate and efficient soil analysis methods. Conventional laboratory techniques are often time-consuming, costly and environmentally damaging. To address this challenge, we developed and validated locally calibrated mid-infrared (MIR) spectroscopy models for predicting key soil properties pH, phosphorus (P) and exchangeable cations in soil samples from South Africa's Western Highveld region, using a dataset of 979 soil samples and machine learning algorithms Cubist, partial least squares regression (PLSR) and random forest (RF). A subset of spectra was also submitted to the newly developed Open Soil Spectral Library's (OSSL) prediction models to determine whether global prediction models could be used for local soil property prediction. Accurate predictions for pH, calcium (Ca) and magnesium (Mg), with coefficient of determination (R-2) values exceeding 0.76 were obtained with the local calibration algorithms. The predictions for P, potassium (K) and sodium (Na) did not meet the requirements for reliability. Soil spectroscopic prediction models calibrated with local soils outperformed the corresponding global prediction models considered. The OSSL prediction results were inaccurate, with a RPIQ <1, and consistently underpredicted all soil properties. Furthermore, the OSSL collection of prediction models does not include a pH (KCl) model, the routinely used pH measurement method in South Africa. These findings highlight the importance of local calibration for accurate soil property prediction and underscore the need for regional representation in global spectral libraries. This research serves as the first local calibration of MIR spectroscopy models for the Western Highveld region of South Africa and provides a foundation for future local soil property inference model development. It also serves as a potential starting point for a comprehensive South African soil spectral library that can be contributed to global spectral libraries.