Constraints on water activity at the Zhurong landing site in Utopia Planitia,Mars

Mineralogical evidence of water–rock interactions is a strong indicator of the presence of liquid water on ancient Mars.Previous observations have found widely distributed hydrated minerals in the southern highlands,whereas such discoveries have been rare in the younger northern lowlands.China’s first Mars exploration mission successfully landed a rover(Zhurong)in southern Utopia Planitia,providing an opportunity to analyze the exposed rocks in the northern lowlands.Using data from the short-wave infrared(SWIR)spectrometer and the laser-induced breakdown spectrometer(LIBS)onboard the Zhurong rover,we found evidence for the widespread presence of hydrated minerals(probably sulfates or silica)around the landing site.The basaltic-like elemental compositions of the targeted samples further indicated that hydrated minerals are likely minor components.The results from Zhurong suggest that active aqueous activities occurred during the overall cold and dry Amazonian era on Mars.However,further evaluations are needed on the duration and scale of these activities.

Oxygen Fugacity and Water Activity during Thermal Peak and Retrogression of Granulites around the Sarvapuram Area, Karimnagar Granulite Terrane, Andhra Pradesh, India

The investigated area around Sarvapuram represents a part of the Karimnagar granulite terrane of the Eastern Dharwar Craton, India. Garnet–bearing gneiss is hosted as enclaves, pods within granite gneiss and charnockite. It is largely made up of garnet, orthopyroxene, cordierite, biotite, plagioclase, K–feldspar, sillimanite and quartz. The peak metamorphic stage is represented by the equilibrium mineral assemblage i.e. garnet, orthopyroxene, cordierite, biotite, plagioclase, sillimanite and quartz. Breakdown of the garnet as well as preservation of the orthopyroxene–cordierite symplectite, formation of cordierite with the consumption of the garnet + sillimanite + quartz represents the decompressional event. The thermobarometric calculations suggest a retrograde P–T path with a substantial decompression of c. 3.0 kbar. The water activity(XH2 O) conditions obtained with the win TWQ program for core and symplectite compositions from garnet–bearing gneiss are 0.07–0.14 and 0.11–0.16 respectively. The quantitative estimation of oxygen fugacity in garnet–bearing gneiss reveal log f O2 values ranging from-11.38 to-14.05. This high oxidation state could be one of the reasons that account for the absence of graphite in these rocks.

Mineralogical evidence of water activity in the northern lowlands of Mars based on inflight-calibrated spectra from the Zhurong rover

Hydrated minerals provide direct indications of the early Martian water environment. The various clay minerals and evaporite salts found to date are mainly exposed in the ancient southern highlands of Mars. While it is believed that the area of the northern lowlands could have hosted a global ocean in the past, its surface is covered with a layer of spectrally nonabsorbing materials, and orbital hyperspectral remote sensing has found only sparse evidence for the presence of water. China's first Mars exploration mission, Tianwen-1, landed in the putative ancient shoreline zone of the northern lowlands of Mars. Its rover,Zhurong, conducted high-spatial-resolution reconnaissance to reveal the geological and environmental evolution of this region.Owing to frequent dust storms, not only is the Martian surface covered with dust, but also the spectral calibration panels on the rover are affected by dust coverage. Data from the shortwave infrared(SWIR) spectrometer onboard the rover are also affected by other environmental factors such as instrumental temperature changes and atmospheric carbon dioxide absorption. This study recalibrated the in situ SWIR data to minimize the impact of the above factors. The recalibrated spectral data show that the reflectance of the landing area falls within the normal range of Martian soil, and confirm the presence of several important absorption peaks. The absorption characteristics indicate the presence of polyhydrated sulfates, gypsum, and hydrated silicates in the surface materials along the rover track, with sulfate content of <27–39 wt.%. Our results further confirm past activity of liquid water in the Zhurong rover landing area, providing mineralogical evidence supporting hypotheses related to underground water or an ancient shoreline.

CARBOXYMETHYLPACHYMAN(Ⅰ),A NEW WATER SOLUBLE POLYSACCHARIDE WITH MARKED ANTITUMOUR ACTIVITY

Carboxymethylpachyman(Ⅰ)was formed by carboxymethylation of β-pachyman.The antitumour activity of carboxymethylpachyman(Ⅰ)against S_(180)、EAC、 MA、U_(14)was measured.The structure of carboxymethylpachyman(Ⅰ)was proved by IR ^(13)CNMR spectroscopy.

Effect of different process conditions on the physicochemical and antimicrobial properties of plasma-activated water

The physicochemical properties of plasma-activated water(PAW)generated under different process conditions were investigated,and their changes under different storage conditions were also studied.The results showed that increasing the processing time and power,and decreasing generated water volume,could cause an increase in the redox potential,conductivity,and temperature of PAW,and a decrease in its pH.A slower dissipation of the reactive oxygen and nitrogen species in PAW was found on storage at 4℃in a sealed conical flask than on storage at room temperature.The inactivation ability of plasma-activated lactic acid(LA)to Listeria monocytogenes(L.monocytogenes)and Pseudomonas aeruginosa(P.aeruginosa)was higher than that of PAW or LA alone under the same experimental conditions.The results of this study may provide theoretical information for the application of PAW as a potential antimicrobial agent in the future.

Effect of Fertilizer Diammonium Phosphate on Liver,Kidney and Muscle 5-Nucleotidase Activity of Fresh Water Teleost Fish Clarias batrachus

The toxic effect of fertilizer Diammonium phosphate resulted in alterations of 5'-Nucleotidase activity of tissues liver, kidney and muscles offish C. batrachus at varying intervals and exposures. Alterations in 5'-Nuclcotidase activity of body organs gave an idea of the toxicity caused by the fertilizer. Thus the enzyme 5'-Nucleotidase can be used to monitor the pollution in aquatic ecosystem.

Spatial and Temporal Variations of Dissolved Inorganic Nutrients and Relationship with Phytoplankton Density in Coastal Water of Kudat, Sabah, Malaysia

Coastal areas of Kudat are dominated by fisheries activities. Development of infrastructure for fishing facilities like jetty, landing centre and other human activities can increase the loading of nutrients in coastal area. High load of nutrients accelerates the blooming of phytoplankton and in long run creates eutrophication. This study was conducted to determine the temporal and spatial variations of nutrients and relationship of phytoplankton density in coastal water of Kudat. Five stations were selected with three replicated in the study area. Phytoplankton samples, water samples and in situ environmental parameters were collected from May 2019 to February 2020 (10 months). The highest concentration of nitrate (NO3) was observed in May 2019, but the highest concentration of phosphate (PO4) observed in July 2019. On the other hand, higher concentrations of phosphate (PO4) were determined than the concentration of nitrate (NO3) in all stations during study period. The distribution of nutrients is due to monsoonal runoff from surrounding areas as well due to anthropogenic activities. Among the 21 species three of them are from harmful algal species and but dominated by diatoms. Poor relationship observed among the dissolved inorganic nutrients and phytoplankton density, indicates that the relationship does not depend on only nutrients but with favourable environmental parameters. Anthropogenic activity can lead to excessive load of nutrients in Kudat coastal water and in long run cause eutrophication problem in ecosystem with potentially larger economic impacts in a long run period.

Water sorption isotherms of globe artichoke leaves

One third of the artichoke production is used in industrial processes, where up to 70% - 85% of the initial raw material is transformed into solid wastes. For an adequate management of these wastes, it is necessary to know their water sorption properties, because physical, chemical andbiological changes which occur during theirstorage depend on water-solid interactions. The objectives of this work are to experimentally determine equilibrium sorption (adsorption anddesorption) data of artichoke wastes at different temperatures (25&#176;C - 55&#176;C), as well as correlate and predict water sorption isotherms using bibliographic models. Equilibrium moisture content ranged 0 - 0.6 kg water/kg dry solid (water activity 0.05 - 0.9). Water sorption isotherms were classified between Types II and III. Hysteresis phenomenon was not observed, neither was the dependence of the equilibrium data with temperature. BET, GAB, Oswin and Peleg correlation models were satisfactorily fitted to experimental data. A predictive model based on composition and physical state of artichoke waste components was also successfully used to reproduce experimental data.

Influence of Composite Phosphate Inorganic Antibacterial Materials Containing Rare Earth on Activated Water Property of Ceramics

Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating water and improving seed germinative property were tested by nuclear magnetic resonance (NMR) and the method of testing oxygen dissolved in activated water. Results show that the half peak width of (()^(17)O-NMR) for tap water activated by the antibacterial ceramic drops from 115.36 to 99.15 Hz, and oxygen concentrations of activated water increase by 20%, germinate rate of horsebean and earthnut seeds increases by 12.5% and 7.5%, respectively. Therefore antibacterial ceramic doped enamel slurry with inorganic antibacterial additives containing rare earth can reduce the volume of clusters of water molecules, improve activation of tap water, and promote plant seeds germinate.

Rice plant growth and yield: foliar application of plasma activated water

Plasma activated water(PAW)was prepared for 10 min to be applied one tofive times as a foliar spray to rice plants,to investigate plant growth,yield and the concentrations of total soluble protein and sugar in the rice grains produced.The results reveal that(1)the plant height,stem diameter,dry weight,chlorophyll and total carotene concentrations were improved by∼15%,∼25%,∼24%,∼47%and∼45%,respectively,with respect to control,(2)defense mechanisms of the plants treated with PAW were improved,(3)concentrations of total soluble protein and sugar were enhanced in the rice grains of PAW treated plants and(4)yield was increased by∼14%.

On the spatial characteristic of the short-term and imminent anomalies of underground water behaviors before strong earthquake

Observational results of underground water regime (water level and flow) in some strong earthquakes and moderate earthquakes (in this paper we also call them by 'strong earthquakes')in Chinese mainland are studied and the following conclusions are obtained. For one strong earthquake, the spatial distributions of the anomalies which include medium term anomalies of one year scale, short term anomalies and imminent anomalies, and underground water stations without the anomalies were mainly related to the causative mechanism and active master faults (active abyssal faults or strongly active faults) around the focal region; The spatial distribution of the anomalies coincided with the specific relation among the anomalies, the focal site, the causative mechanism and active master faults. Finally, the mechanism of the relation was briefly discussed, and the importance about the research result in this paper was set forth.

Experimental Research on the Sterilization of Escherichia Coli and Bacillus Subtilis in Drinking Water by Dielectric Barrier Discharge

The bactericidal effect on the representative type of Gram-negative Escherichia coli（E.coli） and Gram-positive Bacillus subtilis in drinking water was investigated in this paper by using dielectric barrier discharge（DBD） advanced oxidation technology.The sterilizing rates under different conditions of reaction time t,input voltage V,p H value,and initial concentration of bacteria C_0 were investigated to figure out the optimum sterilization conditions.Our observations and comparisons of cell morphology alteration by scanning electron microscopy and transmission electron microscopy revealed the sterilization mechanisms.The results showed that the sterilizing rate increased obviously with the extension of reaction time t and the rise of input voltage V.The optimal sterilization effect was achieved when the p H value was 7.1.As the initial concentration of bacteria rose,the sterilizing rate decreased.When the input voltage was 2.2 k V and the initial concentration of bacteria was relatively low,the sterilizing rate almost reached 100% after a certain treatment time in neutral aqueous solution.The reasons for the great damage of cell structure and the killing of bacteria are the oxidation of O_3,OH and the accumulation of active species produced by DBD.The article provides a certain theoretical and experimental basis for DBD application in water pollution treatment.

Structural Characteristics and Photocatalytic Activity of Ambient Pressure Dried SiO2/TiO2 Aerogel Composites by One-step Solvent Exchange/Surface Modification

An ambient pressure synthesis of SiO2/TiO2 binary aerogel was prepared through the low-cost precursors of titanium tetrachloride（TiCl4） and sodium silicate（Na2O·nSiO2）.After gelation,solvent exchange and surface modification were performed simultaneously and the modified gel was finally dried under ambient pressure.Microstructural analyses by transmission electron microscope（TEM） indicate that fabricated SiO2/TiO2 aerogel composite shows similar sponge-like nanostructure as silica aerogel,and the Brunauer-EmmettTeller（BET） analysis shows that the specific surface area of the composite reaches 605 m^2/g,and the average pore size is 9.7 nm.Such binary aerogel exhibits significant photocatalytic performance in this paper for treating model pollutant of methyl orange（MO）,and the decolorizing efficiency of MO is detected as 84.9%after 210 mins exposure to UV light irradiation.Degraded gel suspends in the water so as to separate from solution for reuse,and after 4 times recycling,70%degradation efficiency can be easily reached when composite catalyzed system is exposed for 210 mins under UV irradiation.

Fruit Yield and Quality, and Irrigation Water Use Efficiency of Summer Squash Drip-Irrigated with Different Irrigation Quantities in a Semi-Arid Agricultural Area

Fruit yield, yield components, fruit mineral content, total phenolic content, antioxidant activity and irrigation water use efifciency （IWUE） of summer squash responses to different irrigation quantities were evaluated with a ifeld study. Irrigations were done when the total evaporated water from a Class A pan was about 30 mm. Different irrigation quantities were adjusted using three different plant-pan coefifcients （Kcp, 100% （Kcp1）, 85% （Kcp2） and 70% （Kcp3））. Results indicated that lower irrigation quantities provided statistically lower yield and yield components. The highest seasonal fruit yield （80.0 t ha-1） was determined in the Kcp1 treatment, which applied the highest volume of irrigation water （452.9 mm）. The highest early fruit yield, average fruit weight and fruit diameter, length and number per plant were also determined in the Kcp1 treatment, with values of 7.25 t ha-1, 264.1 g, 5.49 cm, 19.95 cm and 10.92, respectively. Although the IWUE value was the highest in the Kcp1 treatment （176.6 kg ha-1 mm-1）, it was statistically similar to the value for Kcp3 treatment （157.1 kg ha-1 mm-1）. Total phenolic content and antioxidant activity of fruits was higher in the Kcp1 （44.27 μg gallic acid equivalents （GAE） mg-1 fresh sample） and in the Kcp2 （84.75%） treatments, respectively. Major （Na, N, P, K, Ca, Mg and S） and trace （Fe, Cu, Mn, Zn and B） mineral contents of squash fruits were the highest in the Kcp2 treatment, with the exception of P, Ca and Cu. Mineral contents and total phenolic content were signiifcantly affected by irrigation quantities, but antioxidant activity was not affected. It can be concluded that the Kcp1 treatment was the most suitable for achieving higher yield and IWUE. However, the Kcp2 treatment will be the most suitable due to the high fruit quality and relatively high yield in water shortage conditions.

Molecular mechanism study of Astragalus adsurgens Pall synergistically induced by plasma and plasma-activated water

The mutagenic effects of discharge plasma and plasma+PAW(plasma and its activated water combined) on Astragalus adsurgens Pall seeds were explored. Needle array-plate dielectric-barrier discharge plasma was used to treat A. adsurgens Pall seeds and PAW was prepared at the same time.The deionized water and the obtained PAW were used to cultivate plasma-treated seeds in groups and the survival rate of each group was counted. Results showed that the survival rate of the treated seeds of A. adsurgens Pall when cultured with deionized water was not significantly different from that of the control check(CK). The culture with PAW had an obvious lethal effect and each group reached the half-lethal dose. Reactive oxygen species(ROS) and RNA-Seq analysis of seedlings in the 3 h treatment group showed that the content of ROS in the 3 d post-treatment group was significantly higher than that of the CK. Because expression of the gene with the function of scavenging superoxide free radicals was upregulated, the ROS content of seedlings on the sixth day was significantly lower than that on the third day. Plasma and plasma+PAW treatments changed a large number of gene expressions;particularly, the plasma+PAW group caused plant-growth genes to be significantly upregulated. After treatment, the seedlings of A. adsurgens Pall may grow faster and have higher nutritional value. This research is of great significance to the wider application of isoelectronic bodies and their activated water physicochemical mutagens in biological effects and breeding research.

Plasma activated water prepared by different plasma sources:physicochemical properties and decontamination effect on lentils sprouts

The pulsed corona discharge(CD)generated in contact with water and directly in water,and high-power air plasma jet(APJ)were studied for production of plasma activated water(PAW).The changes of physical(pH,redox potential,conductivity,temperature)and chemical(peroxides,nitrites,nitrates concentrations)properties of treated water were investigated.The comparison of CD generated in gas/water interface and underwater configuration in the same system showed that the interaction of reactive oxygen and nitrogen species formed in ambient air in gas/water system induces different chemical processes,leading to lower pH,higher oxidation-reduction potential(ORP)and higher conductivity of PAW than in underwater discharge.High yield of peroxide was observed in both configurations.The PAW prepared by APJ exhibits high concentration of nitrites and nitrates according to supplied energy,and related significant decrease of pH and increase of ORP and conductivity after treatment.The antimicrobial effect of PAW prepared by CD and plasma jet on lentils sprouts was studied in different treatment and washing times.The APJ appears to have great efficacy on water activation resulted in strong decontamination effect.The PAW treated by APJ for 10 min led to bacterial reduction from initial 8.3 to 5.9 and 4.0 log10 CFU g^(-1)after 10 and 30 min of washing,respectively.

Standardization of Tritium Water by TDCR Method

The triple-to-double coincidence ratio （TDCR） method of liquid scintillation count- ing is an absolute measurement method of radioactivity. The formulation of the TDCR method and the established TDCR liquid scintillation counter are presented in this paper. The NIST standard reference material （SRM） of tritium water was measured to verify the performance of the TDCR liquid scintillation counter.

An Assessment of Land Cover Change in Gashaka-Gumti National Park, Nigeria

The paper assessed the land cover change in Gashaka-Gumti National Park between 1991 and 2021. To achieve this, LandSat data of years 1991, 2001, 2011 and 2021 were obtained from the United States Geological Survey online resource. The findings of the study revealed that there is decrease in the different land cover types over time as a result of anthropogenic activities of the enclave dwellers. The study observed that the continuous existence of enclaves within and around the Park constitutes a serious threat to the survival of the Park. The study recommended that the federal government should consider resettlement of the enclave dwellers to give way for the development of the Park.

Using dynamic dewpoint isotherms to determine the optimal storage conditions of inert dust-treated hard red winter wheat

Water-solid interactions play a key role in determining the efficacy of inert dusts. The critical water activity(Awc) for phase transition in amorphous materials is an important characteristic of amorphous inert dusts used as grain protectants. As water activity(Aw) rises above Awc, amorphous dusts undergo a transition from glassy or vitreous state to rubbery state. Such a transition induces dramatic changes in material properties, texture and structure, and hence impact their performance as grain protectants. Full Dynamic Dewpoint Isotherms(DDI) of a synthetic amorphous zeolite intended for grain protection were generated using the Vapor Sorption Analyzer(VSA) to determine Awcby investigating the relationship between moisture content and Awat constant temperatures. Sorption experimental data was fitted using three sorption isotherm models: Guggenheim-Anderson-de Boer(GAB), Double Log Polynomial(DLP),and Brunauer-Emmet-Teller(BET). DLP model was the best model to estimate zeolite and wheat sorption isotherms. Full sorption isotherms of zeolite and wheat obtained at 25, 35, and 45 °C clearly showed the hysteresis phenomenon. The hysteresis loops were of type H3 for wheat, and of type H4 for zeolite powder. The intensity of hysteresis remained unchanged for wheat. However, the intensity of hysteresis decreased with increasing temperatures during water adsorption by porous zeolite powder. Monolayer moisture content values for each sorption direction were provided only by GAB and BET models and indicated a decrease in monolayer moisture content with an increase in temperature. The net isosteric heats of sorption and the differential enthalpy of zeolite estimated by the Clausius–Clapeyron equation and determined graphically decreased with increasing moisture content. Conversely, differential entropy of zeolite decreased with increasing zeolite moisture content. The optimal moisture content of inert dust for grain treatment was dependent on wheat moisture content and wheat storage temperature. This is the first time that a synthetic amorphous dust is being investigated for grain protection.Our results recommend the application of inert dusts at the optimal moisture content to mitigate moisture migration within the system "wheat-dust", thus ensuring dust maximal efficacy.

Growth characteristics and pathogenic consequences of predominant entomopathogenic Yukon soil fungi Mortierella alpina and Penicillium expansum,and effectiveness of Met52®,against larvae of the winter tick,Dermacentor albipictus

Water activity-temperature relationships are reported for Yukon soil-isolated strains of Mortierella alpina and Penicillium expansum that are natural enemies to larvae(infestation stage)of the winter tick Dermacentor albipictus.Both fungal strains are psychrotrophs,characterized by low thermal growth ranges,consistent with their occurrence in Yukon soil.In contrast to P.expansum,M.alpina is more temperature sensitive,has a higher requirement,and is more virulent to tick larvae.Researchers and Biological Control Officers should note that for tick population control these M.alpina and P.expansum strains grow and sporulate well under moderate temperature and humid conditions.Our experiments used Met52®Bioinsecticide as a positive control,and this is the first study that demonstrates the effectiveness of this commercial product against winter tick larvae.