Chemical Impurities Research Articles

X-ray fluorescence for lithium metal anode quality inspection

A novel X-ray fluorescence (XRF) method is proposed in this study for quality inspection of thin Li metal anodes. The method can be used to determine Li coating thickness and to calculate Li mass absorption coefficient. The high correlation between the calculated Li mass absorption coefficient (263.9 cm2/g and 259.7 cm2/g at 930 eV) and the reported values in literature (NIST 260.0 cm2/g and CRXO 279.2 cm2/g) indicates this method can be a promising quality inspection tool. The suggested XRF method can also potentially be used to detect internal and surface defects in Li coatings, as well as to identify chemical impurities. The XRF analysis method is non-destructive, non-contact, covers large areas, provides compositional data and is amenable to online production. This study shows the potential of incorporating XRF analysis system as a quality inspection tool for the commercialization and large-scale manufacturing of Li metal anodes and next generation EV batteries.

Can element chemical impurities in aragonitic shells of marine bivalves serve as proxies for environmental variability?

In many biogenic and geogenic materials, ion impurities can provide serviceable proxies for environmental conditions. However, the element/Ca ratios of bivalve shells are notoriously challenging to interpret. Due to strong vital effects, nonclassical nucleation and growth mechanisms, and/or kinetic processes, the concentration of trace and minor elements in marine shells typically remains below values observed in inorganic CaCO3 precipitated from a solution resembling seawater chemistry but above those expected for thermodynamic equilibrium. The interpretation is further complicated by non-lattice bound and microstructure-specific element content. If environmental conditions were still encoded in the shells, they should result in statistically significantly reproducible element/Ca chronologies between contemporaneous specimens from the same site. Here, we tested this hypothesis and exemplarily studied seven elements in twelve modern specimens of Arctica islandica collected from four different localities in the North Atlantic (Faroe Islands, NE Iceland, Isle of Man, Gulf of Maine). Age-detrended chronologies of weighted annual B, Mg, Sr and Ba/Ca ratios (Al, Zn and Pb largely remained below detection limit) measured in the shells were reproducible between most specimens from the same site, supporting the hypothesis that the incorporation of these elements was at least partly controlled by environmental forcings. Notably, the agreement (explored with linear regression analyses and sign tests) between shell element/Ca ratios and environmental quantities was weaker than the agreement of respective element/Ca ratios between specimens suggesting that the available information on temperature, food and water chemistry did not properly reflect the in-situ conditions to which the bivalves were exposed or other extrinsic factors were at work. As in inorganic aragonite – but in contrast to thermodynamic expectations –, annual Sr/Ca, Mg/Ca and B/Ca ratios were negatively correlated to water temperature (up to 40% explained variability). The link between Ba/Ca and bulk phytoplankton often remained below the significance threshold, but was otherwise positive. Quantitative environmental reconstructions based on ion impurities in bivalve shells will remain challenging or impossible unless the chemistry of the parent solution (= extrapallial fluid) from which the shell actually formed is known, including temporal changes thereof. This information is crucial to compute representative partition coefficients required to calibrate transfer functions.

Chemometrics-assisted analysis of chemical impurity profiles of tabun nerve agent using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry

A route determination strategy through non-targeted screening of chemical attribution signatures was developed to identify tabun samples from three different synthetic routes. The CAS profiles of tabun samples were obtained by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometer (GC×GC-TOFMS). The structures of 109 CAS were identified by NIST library and mass spectrometry fragment analysis. A few identified compounds could be traced to impurities in precursor compounds used in tabun synthesis. Based on the gas chromatography/mass spectrometry peak data of the selected CAS, partial least squares-discriminant analysis (PLS-DA) was used to extract the chemical attribution signatures of the characteristic compounds. The trained PLS-DA model performed well, with the lowest specificity and sensitivity values of 1.000 and 0.882, respectively. The performance of the PLS-DA model was further verified by unknown sample test set. The model demonstrated its ability to differentiate all the unknown tabun samples. The stability of chemical attribution signatures from different time periods was also investigated, and was further evaluated.

Improving the purification of aqueous solutions by controlling the production of reactive oxygen species in non-thermal plasma; a systematic review.

Treatment with non-thermal plasma is a reliable technology to oxidize chemical impurities that exist inpolluted water, wastewater, and leachate, those degradation-resistant and cannot be removed by conventional treatment methods. In this study, the effective factors affecting in the formation ofreactive oxygen species in non-thermal plasma treatment process, as a new advanced oxidation process method explianed. In this manner, all associated manuscripts existed in the main databases including Google Scholar, Science Direct, PubMed, and Open Access Journal Directory from 1990 until 2022 were explored. The utilized keywords were involved non-thermal plasma, Cold plasma, Measurement, •OH, O3 and UV. Overall, 8,813 articles were gathered and based on the relevance titles and abstracts, 18 paper were selected for further reviewing. In several studies, plasma techniques have been used to treat water, wastewater and leachate, but few studies have evaluated the factors influencing the production of ROS species by non-thermal plasma. The non-thermal plasma destroys pollutants by reactive free radicals spices (hydroxyl, hydrogen atoms, etc.) a combination effect of strong electric fields, energetically charged particles, and ultrasound. Some factors such as water vapor, hydraulic retention time, inter-electrode spacing, discharge power density, and aeration of the effluent as well as use of catalyst have direct effect on the reactive oxygen species formation. If these factors controlled within the best ranges, it will promote the oxidizing radical production and system performance. Also, high-energy electrons and oxidizing species produced in the cold plasma system can well degrade most of pollution in water and wastewater.

Neptunium mononitride as a target material for Pu-238 production

Deep space exploration requires specialized sources for both thermal and power applications. Radioactive decay heat of plutonium-238 (238Pu) provides these sources in the form of radioisotope thermoelectric generators (RTGs). The238Pu is producedvianeutron capture reaction involving neptunium-237 (237Np) target material. Continual optimization of237Np target materials and evaluation of potential alternative targets for production of238Pu RTGs are advantageous for meeting ongoing space power system resource requirements. Current production of238Pu for RTGs for the United States space program utilizes neptunium dioxide (237NpO2) targets; however, the use of neptunium mononitride (237NpN) presents an opportunity to increase the mass of237Np per target compared to the dioxide form, as well as increase the thermal conductivity of the target. To assess the viability of a237NpN target material, the material chemistry must be thoroughly evaluated, including synthesis methods and dissolution and reprocessing schemes. This review presents a summary of synthesis pathways for237NpN based on published literature on actinide mononitrides. Specific literature on237NpN is limited, necessitating evaluation of other actinide systems to gather parallels. This suggests a need for additional experimental studies on237NpN. A particular limitation in the existing literature is a lack of information on the differences in material characteristics, such as morphology, particle size, and trace chemical impurities, as a function of synthesis method. These parameters may affect subsequent reactor performance or dissolution of irradiated targets. The evaluation of existing literature is presented with a focus on the efficacy of237NpN targets for238Pu production.

CONCEPT OF SHODHANA IN AYURVEDIC PHARMACEUTICS: A REVIEW

Rasaushadhis (herbomineral preparations) are a treasure in Ayurveda. They assure fast recovery of diseases as compared with plant-based medicine. These medicines require lengthy processing before conversion into admissible forms. The processes like Shodhana (purification), Marana (incineration), Amrutikarana (nectarization), Bhasmikarana, Satwapatana etc., are adopted to achieve this. Before the metals and minerals are used for therapeutic benefit, it is necessary to eliminate all the physical, chemical, and toxic impurities. Shodhana is the first and most crucial procedure adopted to achieve this. References from Rasashastra textbooks like Rasa Ratna Samuchaya (RRS), Rasa Tarangini (RT), and Ayurveda prakasha (AP) are reviewed and incorporated in this article. Various methods like Nirvapa, Swedana, Pachana, Bhavana, Dhalana, Nimajjana, etc., are adopted for shodhana. These methods are done with the help of instruments like Dolayantra, Swedani Yantra, Lohadarvi (iron spoon), Vanka Nala etc. Various media like Kanji, Takra, Aranala, Gomutra etc., are used depending on the nature of the materials. Shodhana removes the physical and chemical impurities and potentiates the drug's efficacy, which, in turn, reduces the side effect of the drug. Shodhana also impregnates organic materials and their properties into inorganic drugs to facilitate their utilization by the body.

Canadian forest fires, Icelandic volcanoes and increased local dust observed in six shallow Greenland firn cores

Abstract. Greenland ice cores provide information about past climate. Few impurity records covering the past 2 decades exist from Greenland. Here we present results from six firn cores obtained during a 426 km long northern Greenland traverse made in 2015 between the NEEM and the EGRIP deep-drilling stations situated on the western side and eastern side of the Greenland ice sheet, respectively. The cores (9 to 14 m long) are analyzed for chemical impurities and cover time spans of 18 to 53 years (±3 years) depending on local snow accumulation that decreases from west to east. The high temporal resolution allows for annual layers and seasons to be resolved. Insoluble dust, ammonium, and calcium concentrations in the six firn cores overlap, and the seasonal cycles are also similar in timing and magnitude across sites, while peroxide (H2O2) and conductivity both have spatial variations, H2O2 driven by the accumulation pattern, and conductivity likely influenced by sea salt. Overall, we determine a rather constant dust flux over the period, but in the data from recent years (1998–2015) we identify an increase in large dust particles that we ascribe to an activation of local Greenland sources. We observe an expected increase in acidity and conductivity in the mid-1970s as a result of anthropogenic emissions, followed by a decrease due to mitigation. Several volcanic horizons identified in the conductivity and acidity records can be associated with eruptions in Iceland and in the Barents Sea region. From a composite ammonium record we obtain a robust forest fire proxy associated primarily with Canadian forest fires (R=0.49).

ON ASSESSING THE MORBIDITY OF THE POPULATION ASSOCIATED WITH THE ATMOSPHERIC AIR QUALITY ON THE EXAMPLE OF A RUSSIAN CONSTITUENT ENTITY

According to the World Health Organization (WHO), 24% of the global burden of diseases and 23% of all deaths associate with environmental factors. The presence of chemical impurities in the air can have an adverse effect on the health of the population. A connection has been established between the increased content of chemical impurities in the air and the development of such pathologies as diseases of the respiratory system, circulatory system, the formation of malformations, etc. Many countries implement projects to improve air quality. For the purpose of targeted development of management decisions aimed at minimizing the adverse impact of atmospheric air on the health of the population, the study of the morbidity of the population associated with the impact of priority atmospheric air hazard factors is relevant. The research goal is to characterize the morbidity of the population associated with air quality (on the example of Krasnoyarsk Krai) to identify the priority factors of atmospheric air that form the greatest contribution to the associated morbidity. The qualitative characteristics of the atmosphere and the level of morbidity of the population in Krasnoyarsk Krai are estimated on the basis of official data of federal and industry statistics. The analysis of the primary morbidity of the population, designated by the WHO as an indication of the effect of environmental factors, has been carried out. The authors calculate the number of third-party cases of diseases associated with the quality of the atmosphere and determine the priority risk factors. High proportions of air samples that do not meet the standards for the content of heavy metals, benz(a)pyrene, xylenes (59% of samples) have been registered over the territory of Krasnoyarsk Krai. Since 2012, there has been an increase of 0.2%–6.4% in the indicators of primary morbidity, indicated by the WHO as an indicator of the effect of environmental factors and a significant increase in congenital anomalies (the growth rate is 93.2%). Up to 231 thousand third-party cases of diseases of the general population with diseases affecting the respiratory organs, circulatory system, hematopoietic organs, nervous system, eyes and their appendages determine the presence of aromatic hydrocarbons, nitrogen dioxide, hydroxybenzene (as well as its derivatives), benz(a)pyrene, nitrogen oxide, ammonia, dihydrosulfide and carbon disulfide, sulfur dioxide in the air in concentrations exceeding the standards. The most substantial number of diseases associated with air quality forms in the class of respiratory diseases (2020 – 587.4 cases per 100 thousand population, 64.5% of the total air-associated morbidity).

Assay of nuclear grade primary sodium in the fast breeder test reactor for radionuclides and corrosion elements

Periodic assay of primary sodium used as a coolant in the fast breeder test reactor (FBTR) at Kalpakkam is necessary and pre-requisite for the safe and continuous operation of the reactor. Contamination of nuclear grade purity of the primary sodium is monitored either online or offline for the radionuclides and chemical impurities to ascertain the integrity of the various components. Chemical elements which can entrain into sodium due to the corrosion of structural materials is troublesome as they might clog the coolant channels resulting in to a reduced coolant flow which further leads to fuel clad failure. The corrosion elements present in the primary sodium were determined by ICP-OES and their activation products were assayed by high resolution gamma spectrometry. In case of fuel clad rupture, the fission products such as 137Cs, 134Cs, 136Cs, 131I, 90Sr, 125Sb etc. along with actinides U and Pu are released into primary sodium. This paper reports actinides, fission products, corrosion elements as well as their activation products and concentration levels present in the primary sodium of FBTR. Activity variation of one of the long-lived fission products, viz. 137Cs over the period of time, before and after fuel clad rupture is profiled and discussed.

Possible Impurities in Radiopharmaceuticals and Corresponding Test Methods

The main quality attributes of radiopharmaceuticals that ensure their effectiveness and safety and are unique to their specifications are activity, radionuclide identity, radionuclide purity, and radiochemical purity. The aim of this study was to analyse the possibility of formation and methods for determination of various impurities in radiopharmaceuticals based on radionuclides of several groups: technetium-99m and rhenium-188; iodine and fluorine-18 isotopes; and gallium-68 and some other metallic radionuclides used in theranostic schemes combining radionuclide diagnostics and radionuclide therapy. The article analyses the sources for the formation of radionuclide, radiochemical, and chemical impurities; the influence of these impurities on visualisation quality and dosimetric characteristics of radiopharmaceuticals; various approaches to the methods of impurity detection and quantification; compendial requirements to the quality of radiopharmaceuticals; and research results reported in publications. The article demonstrates the need for the development and certification of Russian reference standards for testing quality attributes of radiopharmaceuticals as part of harmonisation of the State Pharmacopoeia of the Russian Federation with the Pharmacopoeia of the Eurasian Economic Union and the European Pharmacopoeia.

New Phosphatidylethanol (PEth) reference materials by chemical synthetic pathway

Phosphatidylethanol (PEth) is a widely used alcohol biomarker comprising a group of homologous phospholipids with a common polar phosphoethanol head onto which two fatty acid moieties are attached at position sn-1 and sn-2is. PEth are formed in the presence of ethanol by conversion of phosphatidylcholine (PC) to PEth via the catalytic action of the enzyme phospholipase D (PLD). Compared to traditional, indirect biomarkers, PEth is a direct biomarker, is more specific, has wider detection windows in toxicological samples and is not influenced by age, gender, other ingested substances or other pathological conditions. The accurate identification and quantification of PEth homologs in toxicology casework is analytically demanding, made more challenging by the limited number of reference standards available and their cost. Aims: to develop a novel chemical synthesis method to increase production volumes of PEth reference materials; to produce stable isotopically labelled internal standards; to improve the quality/purity of reference materials; and to address the possible impact of regio-isomers and other impurities in PEth reference materials on routine toxicological analysis. Chemical synthetic methods were developed for the synthesis of individual PEth homologs and stable isotope labelled PEth Internal standards. Synthetic methods with levulinyl protection in one of the crucial steps were chosen especially for PEth having one or more double bonds in the fatty acid at sn-2 position, and for PEth internal standards having deuterium or 13C-isotopic labelling in the glycerol moiety. Regio-chemical control has been addressed in the chemical synthesis to avoid or minimize the acyl migration of the two fatty acid moieties. Nuclear magnetic resonance (1H and 13C-NMR) and liquid chromatography mass spectrometry (LC-MS) analysis was used for product characterization and purity assessment. 13C-NMR was also used for identification of PEth regioisomers and the data have been externally validated using LC-MS/MS. PEth (16:0/18:1), penta-deuterium labelled PEth(16:0/18:1)-d5 (ethyl-d5) and PEth (16:0/18:1)-d5 (glycerol-d5) and 13C-labelled PEth (16:0/18:1)-13C3 (glycerol-13C3) as the free acid or as ammonium salt have been synthesized by new chemical synthetic pathways. The PEth reference materials were obtained in high chemical purity and regio-isomeric purity. Reversed position isomer PEth (18:1/16:0) was also synthesized for comparation and identification of regio-isomers and regio-isomeric purity. Analytical differentiation of the regio-isomers by 600 MHz and 800 MHz NMR was performed and different 13C-NMR signals of the carbonyl groups were observed and identified. Compared to the enzymatic route, chemical synthesis of PEth may provide higher quality, and more reproducible reference standards. The regio-isomers of PEth have an identical molecular weight and similar chromatographic and spectral properties making them difficult to differentiate. They can be detected only using NMR and ion ratio evaluation in LC-MS/MS analysis. Chemically and isomerically pure reference standards have been produced using our new synthesis methods. Additionally, PEth-d5 (glycerol-d5) and 13C-labelled PEth-13C3 (glycerol-13C3) both have the isotopic labelling inside the glycerol moiety, different from existing PEth-d5 (ethyl-d5) reference standards. The isotopic labelling in the glycidyl backbone of the molecule is more stable than in the ethyl side chain, whilst by-products were observed by loss of the entire phosphate head group (including the ethyl-d5) from PEth-d5. 13C-labelled internal standards are superior than the deuterium labelled ones due to better ion-suspension effect in MS analysis. Chemical synthetic pathways have been developed for the synthesis of PEth homologues. With the synthetic methods developed it is possible to prepare highly pure PEth homologues without unwanted regio-isomers and without other chemical impurities being present. Similarly, PEth with deuterium and 13C-labelled glycerol moieties have also been prepared. These labelled PEth standards can be used as the new isotopically internal standards for quantitative analysis of PEth.

Setting impurity limits for endogenous substances: Recommendations for a harmonized procedure and an example using fatty acids

Endogenous substances, such as fatty, amino, and nucleic acids, are often purposefully used in parenterally pharmaceuticals, but may be present as impurities. Currently, no consensus guidance exists on setting impurity limits for these substances. Specific procedures are needed, as the amount and types of toxicity data available for endogenous substances are typically far less than those for other chemical impurities. Additionally, the parenteral route of administration of these substances is inherently non-physiological, resulting in potentially different or increased severity of toxicity. Risk Assessment Process Maps (RAPMAPs) are proposed as a model to facilitate the development of health-based exposure limits (HBELs) for endogenous substances. This yielded a framework that was applied to derive HBELs for several fatty acids commonly used in parenteral pharmaceuticals. This approach was used to derive HBELs with further vetting based on anticipated perturbations in physiological serum levels, impacts of dose-rate, and consideration of intermittent dosing. Parenteral HBELs of 100–500 mg/day were generated for several fatty acids, and a proposed class-based limit of 50 mg/day to be used in the absence of chemical-specific data. This default limit is consistent with the low toxicity of this chemical class and ICH Q3C value for Class 3 solvents.

Photocatalytic and antibacterial activity of Yttrium doped TiO2 nanostructure

In this study, TiO2 nanostructures were doped with Yttrium (Y) at various doping concentrations using a low-cost approach called chemical co-precipitation, and then used for photocatalysis and antibacterial activity application. The effects of yttrium doping on TiO2 nanostructure properties such as crystal structure, chemical impurities, and optical features were investigated using EDAX, XRD, TEM, SAED, RAMAN, UV–Vis, and PL techniques. X-ray diffraction (XRD) confirmed the presence of the Rutile tetragonal crystalline phase in both pure and Y doped-TiO2 nanostructure. TEM images of synthesised nanomaterials depict typical nanoellipsoid morphology. UV–Vis absorption spectroscopy revealed that due to doping, the optical band gap was reduced from 3.28 eV to 3.11 eV. Low temperature Raman spectroscopy was used to determine variations in the isobaric Gruneisen parameter for both pure and Y doped materials. The photocatalytic activities of samples were evaluated by the photodegradation of methyl blue (MB) aqueous solution under 250 W UV lamp irradiation. The photodegradation efficiency of TiO2 has been found to vary with Y doping, despite 6% Y doped TiO2 nanostructure are most efficient than other samples. Furthermore, antibacterial analysis indicated that the doping exhibits excellent antibacterial properties when evaluated against E. coli culture.

Mineral-Supported Photocatalysts: A Review of Materials, Mechanisms and Environmental Applications

Although they are of significant importance for environmental applications, the industrialization of photocatalytic techniques still faces many difficulties, and the most urgent concern is cost control. Natural minerals possess abundant chemical inertia and cost-efficiency, which is suitable for hybridizing with various effective photocatalysts. The use of natural minerals in photocatalytic systems can not only significantly decrease the pure photocatalyst dosage but can also produce a favorable synergistic effect between photocatalyst and mineral substrate. This review article discusses the current progress regarding the use of various mineral classes in photocatalytic applications. Owing to their unique structures, large surface area, and negatively charged surface, silicate minerals could enhance the adsorption capacity, reduce particle aggregation, and promote photogenerated electron-hole pair separation for hybrid photocatalysts. Moreover, controlling the morphology and structure properties of these materials could have a great influence on their light-harvesting ability and photocatalytic activity. Composed of silica and alumina or magnesia, some silicate minerals possess unique orderly organized porous or layered structures, which are proper templates to modify the photocatalyst framework. The non-silicate minerals (referred to carbonate and carbon-based minerals, sulfate, and sulfide minerals and other special minerals) can function not only as catalyst supports but also as photocatalysts after special modification due to their unique chemical formula and impurities. The dye-sensitized minerals, as another natural mineral application in photocatalysis, are proved to be superior photocatalysts for hydrogen evolution and wastewater treatment. This work aims to provide a complete research overview of the mineral-supported photocatalysts and summarizes the common synergistic effects between different mineral substrates and photocatalysts as well as to inspire more possibilities for natural mineral application in photocatalysis.

The Environmental and Health Impacts of Steroids and Hormones in Wastewater Effluent, as Well as Existing Removal Technologies: A Review

Micro-pollutants especially estrogens, progesterone, androgens, glucocorticoids, and growth hormones, are biological and chemical impurities that find their way into natural aquatic environments in trace quantities (ng/L), and possess a significant disturbance by impacting human and aquatic life. Due to the significant progress in in the analysis and detection techniques, these trace elements have been observed and quantified in several studies. However, as a result of limited methods and management technology, the adverse effects by these micro-pollutants in surface and coastal water is largely unknown. For this study, the compounds of estrogens, progesterone, androgens, glucocorticoids, and growth hormones have been selected according to their high frequent detection value in environmental waters. The concentration of the selected steroid and hormones ranges from 0.1–196 ng/L (estrogens), less than 0.1 to 439 ng/L (progesterone), 0.06–86 ± 2 (androgens), less than 0.1 to 433 ng/L (glucocorticoids), and 26.6 ng/g to 100 ng/L (growth hormones), and their percentage of removal efficiency varies from less than 10% to 99%, as the measurement of compounds concentration was found to be very low. Here, we report that future studies are necessary to detect the entry routes of these compounds into the environmental water, as well as to explore the technological approaches which are able to resolve this issue permanently.

A Review on Nanocellulose and Superhydrophobic Features for Advanced Water Treatment.

Globally, developing countries require access to safe drinking water to support human health and facilitate long-term sustainable development, in which waste management and control are critical tasks. As the most plentiful, renewable biopolymer on earth, cellulose has significant utility in the delivery of potable water for human consumption. Herein, recent developments in the application of nanoscale cellulose and cellulose derivatives for water treatment are reviewed, with reference to the properties and structure of the material. The potential application of nanocellulose as a primary component for water treatment is linked to its high aspect ratio, high surface area, and the high number of hydroxyl groups available for molecular interaction with heavy metals, dyes, oil-water separation, and other chemical impurities. The ability of superhydrophobic nanocellulose-based textiles as functional fabrics is particularly acknowledged as designed structures for advanced water treatment systems. This review covers the adsorption of heavy metals and chemical impurities like dyes, oil-water separation, as well as nanocellulose and nanostructured derivative membranes, and superhydrophobic coatings, suitable for adsorbing chemical and biological pollutants, including microorganisms.

The Bioburden and Ionic Composition of Hypersaline Lake Ices: Novel Habitats on Earth and Their Astrobiological Implications.

We present thermophysical, biological, and chemical observations of ice and brine samples from five compositionally diverse hypersaline lakes in British Columbia's interior plateau. Possessing a spectrum of magnesium, sodium, sulfate, carbonate, and chloride salts, these low-temperature high-salinity lakes are analogs for planetary ice-brine environments, including the ice shells of Europa and Enceladus and ice-brine systems on Mars. As such, understanding the thermodynamics and biogeochemistry of these systems can provide insights into the evolution, habitability, and detectability of high-priority astrobiology targets. We show that biomass is typically concentrated in a layer near the base of the ice cover, but that chemical and biological impurities are present throughout the ice. Coupling bioburden, ionic concentration, and seasonal temperature measurements, we demonstrate that impurity entrainment in the ice is directly correlated to ice formation rate and parent fluid composition. We highlight unique phenomena, including brine supercooling, salt hydrate precipitation, and internal brine layers in the ice cover, important processes to be considered for planetary ice-brine environments. These systems can be leveraged to constrain the distribution, longevity, and habitability of low-temperature solar system brines-relevant to interpreting spacecraft data and planning future missions in the lens of both planetary exploration and planetary protection.

Microwave Assisted Synthesis of Antimicrobial Nano-Films from Water Hyacinth <i>(Eichhornia crassipes)</i> and Roselle <i>(Hibiscus sabdariffa</i>) Plant Extract

Cellulose based nanofilms have large applications in biomedical and related fields due to their antimicrobial properties. Their applicability depends upon purity of cellulose, composition, and structural properties of films. The nanofilms of cellulose extracted from Water Hyacinth (Eichhornia crassipes) and Roselle (Hibiscus Sabdariffa) plant possesses excellent properties for biomedical applications due to their biological origin and ZnO or other metal loading properties. Microwave assisted physical separation of cellulose provided excellent films formation properties and ZnO loading compared without any chemical traces. The presence of chemical impurities to affects structural, morphological properties and contact angle. It affects the biomedical applicability of cellulose based films. The microwave-based extraction was further assisted by use of polyethylene glycol with molecular weight 600, which increases the solubility and extractability of cellulose to 90 %. Formed films showed higher contact angle and hydrophobicity. This increased hydrophobicity of cellulosic nanofilms showed enhanced antimicrobial activities towards gram-negative and gram-positive bacteria by water hyacinth nanofilms. Thus, microwave-based synthesis of cellulose nanofilms resulted into enhanced microbial activities.

Significance of Kuttana in the preparation of Guggulu vati processed in Triphala kwatha

Background: Since vedic period, much importance is given for guggulu (Commiphora wightii, (Arn) Bhandari). One can get reference of guggulu as early as 3000 to 10,000 years ago in the veda, for treating human illnesses. References are available regarding usage of guggulu externally as well as internally during the period of charaka, sushruta and vagbhata for the treatment of medoroga and vatavikara. Śhodhana is a preliminary procedure which assist in removing or modifying the possible physical or chemical impurities from raw material and making them suitable for therapeutic use. It has been found clinically that guggulu kalpa usually pass in the faeces un-disintegrated or partially absorbed. To overcome this the kuttana (pounding) method is mentioned to facilitate quick disintegration which in turn helps in quick absorption of guggulu in the body. So present study was taken to know the effect of kuttana on the physico chemical properties of guggulu. Methodology: Guggulu (Commiphora wightii) Shodhana (procedure) was done in Triphala Kwatha and Guggulu (Commiphora wightii) Vati (tablet) were prepared with and without Kuttana (pounding) method. The prepared samples were tested for analytical parameters like organoleptic character, pH, friability, hardness, disintegration time, uniformity of weight, total ash, loss on drying, acid insoluble ash, alcohol soluble extractive, water soluble extractive and HPTLC was done. Result: The organoleptic characters of all the both samples were same. Triphala Shodhita Guggulu (Commiphora wightii) Vati (tablet) prepared with Kuttana (pounding) showed less disintegration time. Pharmaceutical result revealed that the yield was increased in Triphala Shodhita Guggulu (Commiphora wightii). Conclusion: There was a decrease in pH, acid insoluble ash value, water soluble ash value, water soluble extractive value, weight variation value, hardness, disintegration time and increase in Moisture content, Total ash value, Alcohol soluble ash value of Triphala Shodhita Guggulu (Commiphora wightii) Vati (tablet) after Kuttana (pounding). From chromatographical analysis it is observed that a greater number of components were detected.

Kharaliya Rasayana used in clinical Ayurveda Practice- A Conceptual Review

In Ayurveda different herbs, metals and minerals are used in day to day clinical practice. Parad (Mercury) is commonly used ingredient of number of Rasa Aushadhi. The certain procedures are to be followed to make the Mercury fit for administering it into the body, by which all the physical and chemical impurities of Mercury are mitigated. The numbers of these procedures to purify Mercury are eighteen which is known as Parad Ashtadash Samskar. Kharaliya Rasayana is one of most frequently used Parad Murchhita Aushadha Vargikarana in Ayurveda. References regarding Kharaliya Rasayana were collected and studied in detail and conclusion was drawn. The Kharaliya Rasayana stands foremost in comparison with Parpati, Pottali & Kupipakwa Rasayana in terms of its popularity, wide range of therapeutic utility & ease of preparation. Kharaliya Rasayana are innumerable and most indicated in majority of disease condition. Bhavana & Mardana Samskara are the main principle behind the preparation of Kharaliya Rasayana by which its therapeutic safety and efficacy is determined.