Free Hydrogen Research Articles

Comparative analysis of methanol generation mechanism in different oil-cellulose insulation based on ReaxFF MD

Currently, methanol is used as an aging indicator to evaluate the aging condition of transformer insulating paper. Nevertheless, the generation mechanism of methanol in vegetable oil-paper insulation is still unclear, which is not conducive to further research on methanol analysis. In this study, three types of oil-paper insulation models of palm fatty acid ester, FR3 natural ester, and mineral oil are established by reaction molecular dynamics (ReaxFF MD) simulation. Firstly, the pyrolysis products of the three oil-paper insulation systems are described. Then the methanol generation pathways are analyzed using the elemental tracing method. There are two identical elementary reactions for the production of methanol in the three types of oil-paper insulation systems. One is that the methyl produced by pyrolysis combines with the hydroxyl group separated from the cellulose to generate methanol, and the other is that the hydroxymethyl separated from the cellulose combines with free hydrogen ion to form methanol. Based on experimental and simulation results, it is demonstrated that vegetable oil produced more methanol than mineral oil as aging progressed. In addition, it is further proved that methanol is co-generated from insulating oil and cellulose-insulating paper during the pyrolysis process. In other words, the methanol produced by the oil-paper insulation system is much higher than that of a single paper/oil insulation. Furthermore, the mineral oil-paper system produced more methanol than the other two vegetable oil-paper systems are observed. Therefore, this study provides a theoretical basis for the employment of methanol in the condition assessment of transformers with different insulating oils.

Selenium nanoparticles induce growth and physiological tolerance of wastewater‑stressed carrot plants

Climate changes have a direct impact on agricultural lands through their impact on the rate of water levels in the oceans and seas, which leads to a decrease in the amount of water used in agriculture, and therefore the use of alternative sources of irrigation such as wastewater and overcoming its harmful effect on plants was one of the solutions to face this problem. In the present study, the impacts of the synthesized selenium nanoparticles (Se NPs) alone or in combination with glycine betaine and proline treatments on the growth, physiological, and yield attributes of wastewater irrigated carrot plants are investigated. Furthermore, to evaluate heavy metals uptake and accumulation in edible plant parts. The usage of wastewater to carrot plants significantly increased free proline contents, total phenols, superoxide dismutase, catalase, peroxidase, polyphenol oxidase, Malondialdehyde (MDA), and hydrogen peroxide (H2O2) throughout the two growth stages. While total soluble carbohydrate and soluble protein content in carrot shoots and roots were significantly reduced. Moreover, the concentrations of nickel (Ni), cadmium (Cd), lead (Pb), and cobalt (Co) in carrot plants were considerably higher than the recommended limits set by international organizations. Application of selenium nanoparticles alone or in combination with glycine betaine and proline reduced the contents of Ni, Cd, Pb, and Co; free proline; total phenols; superoxide dismutase; catalase; peroxidase; polyphenol oxidase; Malondialdehyde (MDA) and Hydrogen peroxide (H2O2) in carrot plants. However, morphological aspects, photosynthetic pigments, soluble carbohydrates, soluble protein, total phenol, and β-Carotene were enhanced in response to Se NPs application. As an outcome, this research revealed that Se NPs combined with glycine betaine and proline can be used as a strategy to minimize heavy metal stress caused by wastewater irrigation in carrot plants, consequently enhancing crop productivity and growth.

Green Synthesis of Silver Nanoparticles from Parinari curatellifolia Methanol Stem Bark Extract and Evaluation of Antioxidant and Antimicrobial Activities

Parinari curatellifolia Planch ex. Benth (Chrysobalanaceae) has been used traditionally for the treatment of cancer, pneumonia, fever, dressing of wounds and fractures. The green synthesized nanoparticles from phytochemicals have been utilized as effective antimicrobial and anticancer agents. The research was designed to synthesize nanoparticles from methanol stem bark extract of P. curatellifolia and to investigate its antioxidant and antibacterial activities. The stem bark was powdered and then extracted by maceration. Silver nanoparticles were synthesised using 5 mM AgNO3 solution. DPPH free radical and hydrogen peroxide scavenging assays were employed to determine the antioxidant activity. The antibacterial activity was determined using agar disk diffusion method on Staphylococcus aureus, Bacillus subtilis, Salmonella typhi and Escherichia coli. The phytochemical screening of the extract revealed the presence of saponins, flavonoids and tannins. XRD analysis of the synthesized silver nanoparticles revealed a crystalline structure with face cantered cubic orientation. The SEM revealed particle size of 1 nm and consisted of highly agglomerated particles which formed large aggregates. The IC50 of DPPH free scavenging activity of the extract, silver nanoparticles and ascorbic acid (standard) were 2.804 mg/mL, 2.367 mg/mL and 2.065 mg/mL respectively. Also, that of H2O2 against the extract, silver nanoparticles and ascorbic acid (standard) were 4.986 mg/mL, 36.56 mg/mL and 6.414 mg/mL respectively. The nanoparticles inhibited the growth of the organisms with zone of inhibition between 8-12 mm whereas that of standard antibiotic (gentamicin) ranged from18-26 mm. This therefore implies that PC extract can be used in the synthesis of nanoparticles for its use against bacteria strains and as antioxidants.

A Review on Research and Technology Development of Green Hydrogen Energy Systems with Thermal Management and Heat Recovery

This paper presents a review of recent research and development progress on green hydrogen energy systems and associated thermal management and waste heat recovery technologies. First, hydrogen production methods are briefed. Second, various electrolysis systems used for carbon free hydrogen production from renewable and nuclear resources are discussed. Then, hydrogen utilization using proton-exchange fuel cells is scrutinized. Next, hydrogen energy systems integrated with metal hydride energy storage are elaborated. A focus of this review is on thermal management and process intensification technologies for hydrogen energy systems and integrated metal hydride hydrogen storage technologies. Various process and heat transfer enhancement techniques for heat removal and utilization are presented. Advanced cooling technologies for hydrogen energy systems such as two-phase and boiling for cooling, microchannels for heat removal, CO2 air conditioner and using nanofluids for heat removal are discussed. Finally, heat recovery technologies in green hydrogen energy systems are summarized. This review has also identified future research and technology development needs for green hydrogen energy utilization, thermal management, and heat recovery systems.

Sonochemically Prepared Ni-Based Perovskites as Active and Stable Catalysts for Production of COx-Free Hydrogen and Structured Carbon

Sonochemically Prepared Ni-Based Perovskites as Active and Stable Catalysts for Production of CO<i>_x</i>-Free Hydrogen and Structured Carbon

Structure-Based Profiling of Potential Phytomolecules with AKT1 a Key Cancer Drug Target

Identifying cancer biomarkers is imperative, as upregulated genes offer a better microenvironment for the tumor; hence, targeted inhibition is preferred. The theme of our study is to predict molecular interactions between cancer biomarker proteins and selected natural compounds. We identified an overexpressed potential molecular target (AKT1) and computationally evaluated its inhibition by four dietary ligands (isoliquiritigenin, shogaol, tehranolide, and theophylline). The three-dimensional structures of protein and phytochemicals were retrieved from the RCSB PDB database (4EKL) and NCBI's PubChem, respectively. Rational structure-based docking studies were performed using AutoDock. Results were analyzed based primarily on the estimated free binding energy (kcal/mol), hydrogen bonds, and inhibition constant, Ki, to identify the most effective anti-cancer phytomolecule. Toxicity and drug-likeliness prediction were performed using OSIRIS and SwissADME. Amongst the four phytocompounds, tehranolide has better potential to suppress the expression of AKT1 and could be used for anti-cancer drug development, as inhibition of AKT1 is directly associated with the inhibition of growth, progression, and metastasis of the tumor. Docking analyses reveal that tehranolide has the most efficiency in inhibiting AKT1 and has the potential to be used for the therapeutic management of cancer. Natural compounds targeting cancer biomarkers offer less rejection, minimal toxicity, and fewer side effects.

Global Surface Ocean Acidification Indicators From 1750 to 2100

AbstractAccurately predicting future ocean acidification (OA) conditions is crucial for advancing OA research at regional and global scales, and guiding society's mitigation and adaptation efforts. This study presents a new model‐data fusion product covering 10 global surface OA indicators based on 14 Earth System Models (ESMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6), along with three recent observational ocean carbon data products. The indicators include fugacity of carbon dioxide, pH on total scale, total hydrogen ion content, free hydrogen ion content, carbonate ion content, aragonite saturation state, calcite saturation state, Revelle Factor, total dissolved inorganic carbon content, and total alkalinity content. The evolution of these OA indicators is presented on a global surface ocean 1° × 1° grid as decadal averages every 10 years from preindustrial conditions (1750), through historical conditions (1850–2010), and to five future Shared Socioeconomic Pathways (2020–2100): SSP1‐1.9, SSP1‐2.6, SSP2‐4.5, SSP3‐7.0, and SSP5‐8.5. These OA trajectories represent an improvement over previous OA data products with respect to data quantity, spatial and temporal coverage, diversity of the underlying data and model simulations, and the provided SSPs. The generated data product offers a state‐of‐the‐art research and management tool for the 21st century under the combined stressors of global climate change and ocean acidification. The gridded data product is available in NetCDF at the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information: https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0259391.html, and global maps of these indicators are available in jpeg at: https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/synthesis/surface-oa-indicators.html.

CuSeO4 and Cu(SeO3OH)2·6H2O, two novel copper–selenium(VI) oxysalts

The two new copper(II) salts Cu(SeO4) and Cu(SeO3OH)2·6H2O were synthesized at low-temperature hydrothermal conditions (220 °C), and room temperature, respectively. Their atomic arrangements were studied based on single-crystal X-ray investigations [P21/n, a = 4.823(1), b = 8.957(2), c = 6.953(1) Å, β = 94.82(1)°, Z = 4; $$P{\overline 1}$$ , a = 6.133(1), b = 6.303(1), c = 8.648(2) Å, α = 70.45(1), β = 84.60(1), γ = 73.44(1)°, Z = 1]. Cu(SeO4) adopts the MnAsO4 structure type. It exhibits structural as well as topological relations with two formerly known isochemical compounds. They crystallize in the structure type ZnSO4 (mineral name zincosite, Pnma) respectively NiSO4 (Cmcm). The two minerals dravertite, CuMg(SO4)2, and hermannjahnite, CuZn(SO4)2, are isotypic with CuSeO4-P21/n; interestingly, also α-NaCu(PO4) belongs to this structure type: some rotation of the XO4 group allows a supplementary position for the Na atom. — Cu(SeO3OH)2·6H2O represents a new structure type. The protonated selenate group shows an extended Se—Oh bond distance (1.695 Å) as compared to the other Se—O bonds (1.614 to 1.626 Å). One OH dipole of the three independent H2O molecules represents a rather free hydrogen bond. For the other H atoms, the O—H···O lengths vary from 2.585 to 2.799 Å. Interestingly, the distance Ow7···Ow7 of only 2.791 Å does not represent an edge in a coordination polyhedron and it is not preliminary involved in the hydrogen bond scheme. All Cu2+ ions in the two title compounds are in a pronounced [4 + 2] coordination. The Cu2+[4+2] atoms in Cu(SeO4) are linked to chains along [100]; in Cu(SeO3OH)2·6H2O they are not connected among each other.

A comparative study on DNA and protein binding properties of thymol and thymoquinone

Two phytochemicals, thymol and thymoquinone obtained from thymes (Thymus vulgaris L., Lamiaceae etc.) and Nagila Sativa seed, respectively. Both the phytochemicals show several biochemical activities like anticancer, antimicrobial etc. In this paper, we studied the affinities of thymol and thymoquinone towards calf thymus DNA (CT-DNA) and protein (bovine serum albumin). Spectroscopic and molecular modelling studies revealed that both compounds have a high affinity toward both the receptors; DNA and protein. Both phytochemicals binds to the minor grooves of DNA and suitable pockets of protein. Several free energy function and hydrogen bonding play significant role during the binding phenomenon. Communicated by Ramaswamy H. Sarma

Non-local thermodynamic equilibrium analysis of the methylidyne radical molecular lines in metal-poor stellar atmospheres

Aims. An analysis of the methylidyne (CH) radical in non-local thermodynamic equilibrium (NLTE) is performed for the physical conditions of cool stellar atmospheres typical of red giants (log ɡ = 2.0, Teff = 4500 K) and the Sun. The aim of the present work is to explore whether the G band of the CH molecule, which is commonly used in abundance diagnostics of carbon-enhanced metal-poor stars, is sensitive to NLTE effects. Methods. LTE and NLTE theoretical spectra were computed with the MULTI code. We used one-dimensional (1D) LTE hydrostatic MARCS model atmospheres with parameters representing eleven red giant stars with metallicities ranging from [Fe/H] = −4.0 to [Fe/H] = 0.0 and carbon-to-iron ratios of [C/Fe] = 0.0, +0.7, +1.5, and +3.0. The CH molecule model was represented by 1981 energy levels, 18 377 radiative bound-bound transitions, and 932 photo-dissociation reactions. The rates due to transitions caused by collisions with free electrons and hydrogen atoms were computed using classical recipes. Results. Our calculations suggest that NLTE effects in the statistical equilibrium of the CH molecule are significant and cannot be neglected for precision spectroscopic analysis of C abundances. The NLTE effects are mostly driven by radiative over-dissociation, owing to the very low dissociation threshold of the molecule and significant resonances in the photo-dissociation cross-sections. The NLTE effects in the G band increase with decreasing metallicity. When comparing the C abundances determined from the CH G band in LTE and in NLTE, we show that the C abundances are always under-estimated if LTE is assumed. The NLTE corrections to C abundance inferred from the CH feature range from +0.04 dex for the Sun to +0.21 dex for a red giant with metallicity [Fe/H] = −4.0. Conclusions. Departures from the LTE assumption in the CH molecule are non-negligible, and NLTE effects have to be taken into account in the diagnostic spectroscopy based on the CH lines. We show here that the NLTE effects in the optical CH lines are non-negligible for the Sun and red giant stars, but further calculations are warranted to investigate the effects in other regimes of stellar parameters.

Noble metal free efficient photocatalytic hydrogen generation by TaON/CdS semiconductor nanocomposites under natural sunlight

Tantalum oxynitride have narrow band gap and its band potentials are suitable for visible light induced hydrogen generation. However, due to fast electron-hole recombination, the efficiency of photocatalytic hydrogen evolution reaction is very low. Herein, we have synthesized semiconductor heterojunction photocatalyst, i.e., TaON/CdS with suitable band positions by a simple precipitation method. Ratio between two semiconductors is optimized to obtain maximum hydrogen evolution. XRD, XPS and TEM analysis demonstrate the formation of heterojunction between these semiconductors. Among the synthesized catalysts, 3% TaON/CdS heterostructure exhibits the highest hydrogen evolution activity with H2 production rate of 7.5 mmol h−1 under natural solar light, whereas the rate is 11 mmol h−1 under the visible light generated by xenon (Xe) lamp without the addition of any noble metal as the co-catalyst. The CdS and 3% TaON/CdS nanomaterials show an AQE of 5.1% and 12.2%, respectively. Combination of Mott-Schottky, UPS and DR UV–visible spectroscopy studies revealed the formation of S scheme semiconductor heterojunction between these nanomaterials with valence, conduction band positions, i.e., 1.46, −0.78 eV for CdS and 2.19, −0.66 eV for TaON, respectively. These band positions help in efficient e-h pair separation to produce hydrogen from water.

Recent progress for hydrogen production from ammonia and hydrous hydrazine decomposition: A review on heterogeneous catalysts

In response to the growing trend of greenhouse gas emissions from the production and use of conventional fuels, COx free hydrogen generation is introduced as an alternative and efficient energy carrier. Due to hydrogen’s storage challenges, is more efficient to be produced on-site by other chemical compounds for fuel cell applications. This work outlines the production of hydrogen (H2) from ammonia (NH3) and hydrous hydrazine (N2H4·H2O) catalytic decomposition. Both substances are giving nitrogen (N2) as a by-product, which is not toxic. Moreover, heterogeneous catalysts that were studied through the years are presented. Lastly, a reactoristic view of the ammonia decomposition is provided with different reactors such as catalytic membrane reactors (CMRs), fixed-bed reactors (FBRs) and micro-reactors (MRs) for the evaluation of their performance.

Oxidative catalytic steam gasification of sugarcane bagasse for hydrogen rich syngas production

Reactive Flash Volatilization (RFV) is an emerging thermochemical method to produce tar free hydrogen rich syngas from waste biomass at relatively lower temperature (<900 °C) in a single stage catalytic reactor within a millisecond residence time. Here, we show catalytic RFV of bagasse using Ru, Rh, Pd, or Re promoted Ni/Al2O3 catalysts under steam rich and oxygen deficient environment. The optimum reaction conditions were found to be 800 °C, steam to carbon ratio = 1.7 and carbon to oxygen ratio = 0.6. Rh–Ni/Al2O3 performed the best, resulting in highest hydrogen concentration in the synthesis gas at 54.8%, with a corresponding yield of 106.4 g-H2/kg bagasse. A carbon conversion efficiency of 99.96% was achieved using Rh–Ni, followed by Ru–Ni, Pd–Ni, Re–Ni and mono metallic Ni catalyst in that order. Alkali and Alkaline Earth Metal species present in the bagasse ash and char, that deposited on the catalyst, was found to enhance its activity and stability. The hydrogen yield from bagasse was higher than previously reported woody biomass and comparable to the microalgae.

Xanthine oxidase mediates chronic stress-induced cerebrovascular dysfunction and cognitive impairment

Xanthine oxidase (XO) mediates vascular function. Chronic stress impairs cerebrovascular function and increases the risk of stroke and cognitive decline. Our study determined the role of XO on stress-induced cerebrovascular dysfunction and cognitive decline. We measured middle cerebral artery (MCA) function, free radical formation, and working memory in 6-month-old C57BL/6 mice who underwent 8 weeks of control conditions or unpredictable chronic mild stress (UCMS) with or without febuxostat (50 mg/L), a XO inhibitor. UCMS mice had an impaired MCA dilation to acetylcholine vs. controls (p < 0.0001), and increased total free radical formation, XOR protein levels, and hydrogen peroxide production in the liver compared to controls. UCMS increased hydrogen peroxide production in the brain and cerebrovasculature compared to controls. Working memory, using the y-maze test, was impaired (p < 0.05) in UCMS mice compared to control mice. However, blocking XO using febuxostat prevented the UCMS-induced impaired MCA response, while free radical production and hydrogen peroxide levels were similar to controls in the liver and brain of UCMS mice treated with febuxostat. Further, UCMS + Feb mice did not have a significant reduction in working memory. These data suggest that the cerebrovascular dysfunction associated with chronic stress may be driven by XO, which leads to a reduction in working memory.

Classical Molecular Dynamics Simulation of Glyonic Liquids: Structural Insights and Relation to Conductive Properties.

Rhamnolipids are biosurfactants that have obtained wide industrial and environmental interests with their biodegradability and great surface activity. Besides their important roles as surfactants, they are found to function as a new type of glycolipid-based protic ionic liquids (ILs)─glyonic liquids (GLs). GLs are reported to have impressive physicochemical properties, especially superionic conductivity, and it was reported in experiments that specific ion selections and the fraction of water content have a strong effect on the conductivity. Also, the shape of the conductivity curve as a function of water fraction in GLs is interesting with a sharp increase first and a long plateau. We related the conductivities to the three-dimensional (3D) networks composed of -OH inside the GLs utilizing classical molecular dynamics (MD) simulations. The amount and size of these networks vary with both ion species and water fractions. Before reaching the first hydration layer, the -OH networks with higher projection/box length ratios indicate better conductivity; after reaching the first hydration layer and forming continuous structures, the conductivity retains with more water molecules participating in the continuous networks. Therefore, networks are found to be a qualitative predictor of actual conductivity. This is explained by the analysis of the atomic structures, including radial distribution function, fraction free volume, anion conformations, and hydrogen bond occupancies, of GLs and their water mixtures under different chemical conditions.

Electrical biosensing system utilizing ion-producing enzymes conjugated with aptamers for the sensing of severe acute respiratory syndrome coronavirus 2

Viral outbreaks, which include the ongoing coronavirus disease 2019 (COVID-19) pandemic provoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are a major global crisis that enormously threaten human health and social activities worldwide. Consequently, the rapid and repeated treatment and isolation of these viruses to control their spread are crucial to address the COVID-19 pandemic and future epidemics of novel emerging viruses. The application of cost-efficient, rapid, and easy-to-operate detection devices with miniaturized footprints as a substitute for the conventional optic-based polymerase chain reaction (PCR) and immunoassay tests is critical. In this context, semiconductor-based electrical biosensors are attractive sensing platforms for signal readout. Therefore, this study aimed to examine the electrical sensing of patient-derived SARS-CoV-2 samples by harnessing the activity of DNA aptamers directed against spike proteins on viral surfaces. We obtained rapid and sensitive virus detection beyond the Debye length limitation by exploiting aptamers coupled with alkaline phosphatases, which catalytically generate free hydrogen ions which can readily be measured on pH meters or ion-sensitive field-effect transistors. Furthermore, we demonstrated the detection of the viruses of approximately 100 copies/μL in 10 min, surpassing the capability of typical immunochromatographic assays. Therefore, our newly developed technology has great potential for point-of-care testing not only for SARS-CoV-2, but also for other types of pathogens and biomolecules.

Ground state energy of the hydrogen atom inside penetrable spherical cavities; variational approach

In this work we calculate the ground state energy of the hydrogen atom confined in a sphere of penetrable walls of radius Rc. Inside the sphere the system is subject to a Coulomb potential, whereas outside of it the potential is a finite constant V0. The energy is obtained as a function of Rc and V0 by means of the Rayleigh-Ritz variational method, in which, the trial function is proposed as a free particle wave function within a finite square well potential but including an exponential factor that takes into account the electron-nucleus Coulomb attraction. For an impenetrable sphere, , the energy grows fast as Rc approaches zero. On the other hand, when the height of the barrier V0 is finite, the energy increases slowly as Rc goes to zero. We also compute the Fermi contact term, nuclear magnetic screening, polarizability, pressure and tunneling as a function of Rc and V0. As expected, these physical quantities approach the corresponding values of the free hydrogen atom as Rc grows. We also discuss the pressure-induced ionization of the hydrogen atom. The present results are found in good agreement with those previously published in the literature.

The role of free volume, hydrogen bonds, and crosslinks on physical aging in polymers of intrinsic microporosity (PIMs)

Physical aging rates strongly correlate with the initial free volume of microporous polymers. Introducing hydrogen bonds and crosslinks can reduce the initial free volume and significantly impact gas separation selectivity over time.

Study on depolymerization kinetics of formic acid dimers in binary mixture.

In this study, polarization Raman spectra were collected for binary mixtures of formic acid/methanol and formic acid/acetonitrile with different volume fractions. The broad band of formic acid in the CO vibration region was divided into four vibration peaks, corresponding to CO symmetric and anti-symmetric stretching vibration from cyclic dimer, CO stretching from open dimer, and CO stretching from the free monomer. The experiments showed that as the volume fraction of formic acid in the binary mixture decreased, the cyclic dimer gradually converted to the open dimer, and at a volume fraction of 0.1, fully depolymerized into monomer form (free monomer, solvated monomer, and hydrogen bonding monomer clusters with solvent). The contribution percentage of the total CO stretching intensity of each structure at different concentrations was quantitatively calculated using high resolution infrared spectroscopy, and the results were consistent with the conclusions predicted by polarization Raman spectroscopy. Concentration-triggered 2D-COS synchronous and asynchronous spectra also confirmed the kinetics of formic acid diluted in acetonitrile. This work provides a spectroscopic method for studying the structure of organic compounds in solution and concentration-triggering kinetics in mixtures.

The Geochemical Effect of Impact Processing of Polar Regolith on the Moon

The paper considers the geochemical effects of impact processing of the polar regolith of the Moon. It contains an admixture of water ice, which can (should?) provide conditions for possible chemical reactions. To date, only one geochemical effect was reliably found—the formation of hematite Fe2O3, which is uncharacteristic for relatively low selenographic latitudes. In the work, a thermodynamic analysis of the conditions required for the formation of hematite is carried out. It is shown that this requires the presence of free oxygen, which (this is a possible option) can accumulate during the dissipation into outer space of hydro gen formed during water decomposition. The specific process or processes of hematite formation require fur ther study. It is very likely that impact processing of polar regolith also leads to hydration of silicate glasses and to the formation of heavy hydrocarbons. The dissipation of free hydrogen into outer space, which, apparently, is formed in these processes, should lead to an increase in the deuterium content in the remaining hydrogen. The Н2О ice of the polar regolith likely contains a significant amount of heavy water. Future inves tigations in the polar regions of the Moon, especially with the delivery of samples to Earth, should confirm or refute these conclusions and assumptions.