Large Abundance Research Articles

Estimation of Radon/Thoron and their progeny concentration in some dwellings and exhalation rates from soils of Samana city, Patiala

The study of indoor pollutants and radioactive nuclides imposes importance on human health as we spend most of our time indoors. Out of all the natural radioactive elements, Radon-222 and Radon220 are present in large abundance indoors. Both are radioactive and decay to various short-lived progenies by emitting high-energy alpha particles, so inhalation of such gases can harm the human body in various ways. In the present report, the concentration of Rn-222 and Rn-220 and its progenies are estimated from some dwellings of Samana city of Patiala district, Punjab. Pin-hole dosimeters with DRPS and DTPS were employed in 15 houses in the study area to measure indoor Rn-222 and Rn-220 concentrations. The concentration of Rn-222 ranges between 401.96 Bq/m3 and 27.36 Bq/m3 with mean value of 138.82 Bq/m3, and the concentration of Rn-220 varies from 222.2 Bq/ m3 to 50 Bq/m3 with the mean weight of 131.12 Bq/m3. The average inhalation dose was also calculated from the results and was found to have an average value of 2.19 mSv per year. The average weight of radon concentration was below the ICRP recommendation of 200-300 Bq/m3 but the value is above these limits at some locations. Radon and thoron emission rates from soil samples near to the dwellings was also calculated.

Probing the early Milky Way with GHOST spectra of an extremely metal-poor star in the Galactic disc

ABSTRACT Pristine_183.6849 + 04.8619 (P1836849) is an extremely metal-poor ([Fe/H] = −3.3 ± 0.1) star on a prograde orbit confined to the Galactic disc. Such stars are rare and may have their origins in protogalactic fragments that formed the early Milky Way, in low-mass satellites accreted later, or forming in situ in the Galactic plane. Here, we present a chemo-dynamical analysis of the spectral features between 3700−11 000 Å from a high-resolution spectrum taken during Science Verification of the new Gemini High-resolution Optical SpecTrograph. Spectral features for many chemical elements are analysed (Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Fe, Ni), and valuable upper limits are determined for others (C, Na, Sr, Ba). This main sequence star exhibits several rare chemical signatures, including (i) extremely low metallicity for a star in the Galactic disc, (ii) very low abundances of the light α-elements (Na, Mg, Si) compared to other metal-poor stars, and (iii) unusually large abundances of Cr and Mn, where [Cr, Mn/Fe]NLTE > +0.5. A comparison to theoretical yields from supernova models suggests that two low-mass Population III objects (one 10 M⊙ supernova and one 17 M⊙ hypernova) can reproduce the abundance pattern well (reduced χ2 < 1). When this star is compared to other extremely metal-poor stars on quasi-circular, prograde planar orbits, differences in both chemistry and kinematics imply there is little evidence for a common origin. The unique chemistry of P1836849 is discussed in terms of the earliest stages in the formation of the Milky Way.

Characterizing phase transitions for titan's surface molecules: Implications for Dragonfly

The potential commonality of organic synthesis and prebiotic processes on the surface of Titan and primitive Earth makes Saturn's largest moon an indispensable location to seek answers for the origins of life on Earth and elsewhere. NASA's New Frontiers Mission, Dragonfly, is set to arrive on Titan's surface in the mid-2030s. Two of the main scientific goals of the Dragonfly mission are to identify chemical components and potential processes responsible for the production of biologically relevant compounds, and to search for potential biosignatures. To address these mission goals, Dragonfly is equipped with a linear ion trap mass spectrometer, called the Dragonfly Mass Spectrometer, or DraMS. This instrument will measure the molecular composition of Titan's surface at various locations inside and near Selk Crater, where prebiotic chemistry is expected to have occurred. Some molecules of interest on Titan's surface are thought to be sensitive to phase changes within the expected range of the sample handling chain, 94–165 K and 0.04–1.5 bar. A large abundance of such materials may therefore impact the capture efficiency and physical properties of the sampled materials within the DraMS system. In this work, we explore the potential for some of the hypothesized abundant organic molecules to be induced into phase transitions during the end-to-end sampling process by DraMS.

257 Effects of Prebiotic Galactooligosaccharide (GOS) on Hindgut Microbial Composition of Pigs During the Peri-Weaning Period

Abstract Galactooligosaccharide (GOS) is a prebiotic containing beta-linked galactose oligomers of 2 to 8 units. Previously, GOS positively impacted post-weaning growth performance and altered jejunal morphology. In this study, GOS-enriched whey permeate (Milk Specialties Global, Eden Prairie MN) was supplemented to piglets in farrowing and nursery phases. To maximize pre-weaning GOS intake, novel gruel creep feeders were used. Piglets from 24 litters received either no creep feed (NC), creep without GOS (CG-) or creep with 5.0% GOS (CG+) followed by a phase 1 nursery diet without (NG-) or with 3.8% GOS (NG+). At d 22 (pre-weaning) and d 31 (post-weaning), 6 pigs per treatment were euthanized for sample collection. DNA was extracted from cecal and rectal swabs for downstream 16S rRNA sequencing via Illumina MiSeq (Zymo Research Corp, Irvine CA). An amplicon sequence variant (ASV) table was created using the DADA2 pipeline in R and taxonomy assignment was performed using the SILVA database. Average sequencing depth after filtering was 138,323 and low sequencing counts were discarded based on 20% prevalence. Data were analyzed using the lmer and adonis procedures in RStudio ver. 4.2.2. Analysis of 16S rRNA genes did not detect pre- or post-weaning GOS effects on Chao1, Simpson, or Shannon alpha diversity measures (P > 0.1). Similarly, no pre-weaning GOS effects were detected in Principal Coordinates Analysis (PCoA) beta diversity plots (P > 0.1); however, pigs fed GOS post-weaning segregated from controls (P < 0.01). The relative abundance of several genera including Fusicatenbacter and Collinsella increased by 2.0 and 1.3-fold, respectively, in the cecum of NG+ pigs, whereas, Bacteroides decreased by 3.8-fold (FDR, P < 0.05). In the rectum, relative abundance of Corprococcus decreased by 2.0-fold and Fusicatenbacter increased by 1.5-fold in NG+ pigs compared with NG- pigs (FDR, P < 0.05). Collectively, these genera in the cecum and rectum comprise of less than 3% of the total community. In contrast, lactobacillus in the cecum (33%) and rectum (21%) had a large relative abundance but was unaffected by treatment. We conclude that supplementation of GOS in the post-weaning phase 1 nursery diet alters the hindgut microbial community and may contribute to improvements in growth performance.

Preparation of Graphene Oxide Hydrogels and Their Adsorption Applications toward Various Heavy Metal Ions in Aqueous Media

Graphene oxide is a two-dimensional material that has been extensively studied in various fields due to its good mechanical properties, water dispersibility, and a large number of oxygen-containing functionalities on its surface. In this study, graphene oxide powder was prepared using graphite powder to take advantage of its large specific surface area and abundance of oxygen-containing functional groups. The graphene oxide powder was cross-linked with acrylic acid and acrylamide and polymerized to produce graphene oxide hydrogels, which were used to adsorb four metal ions including Cu(II), Pb(II), Zn(II), and Cd(II) from aqueous solutions. The adsorption performance of the graphene oxide hydrogels was investigated at different pHs, temperatures, initial metal ion concentrations, and competition principles, as well as their adsorption and desorption after three repeated adsorption–desorption experiments. It was found that the graphene oxide hydrogels exhibited good adsorption performance for all four metal ions under different conditions. The graphene oxide hydrogels for the adsorption of Cu(II), Pb(II), Zn(II), and Cd(II) ions were best fitted using the Langmuir monolayer adsorption model and the quasi-secondary reaction kinetic model. Good adsorption was achieved for all four metal ions under different competing adsorption principles. After three adsorption–desorption cycles, the adsorption capacity of the graphene oxide hydrogels for all four metal ions remained at 88% and above. These results indicate that graphene oxide hydrogels are a stable, efficient, low-cost, and reusable adsorbent material for the treatment of metal ions in solution.

Evaluation of nitrous oxide emission during ammonia retention from simulated industrial wastewater by microaerobic activated sludge process

Considering the reciprocating processes of nitrogen gas (N2) fixation to ammonia (NH4-N) and NH4-N removal to N2 through nitrification and denitrification during wastewater treatment, a microaerobic activated sludge process (MAS) is proposed in this study as a pretreatment to retain NH4-N from high-strength nitrogenous wastewater for further NH4-N recovery through membrane technology, that is, inhibit nitrification, with sufficient removal of total organic carbon (TOC). With DO and pH control, the 3-reactor bench-scale MAS systems successfully realized an NH4-N retention rate of over 80 %, with TOC removal rates of over 90 %. In addition, the emissions of carbon dioxide (CO2) and nitrous oxide (N2O) during MAS were evaluated. The total N2O emissions were 407 and 475 mg-N/day when pH was controlled at 6.2 (S1) and 6.8 (S2), respectively, with average emission factors to total nitrogen load over 2 % in both systems. Also, the global warming potential of N2O is one order of magnitude larger than that of CO2, indicating the significance of N2O in the MAS process. Therefore, the mechanisms of N2O emission from each reactor were investigated. The first reactor, where most of the TOC was adsorbed, emitted only 1.98 % (S1) and 2.43 % (S2) of the total N2O emissions through the denitrification of nitrite and nitrate (NOx) from the return sludge. The second reactor emitted 79.9 % (S1) and 69.0 % (S2) of the total N2O with the emission rates the same order of magnitude as the NOx production rates. Multiple pathways were considered to contribute to the high N2O emissions, and biotic NH2OH oxidation was one potential pathway at pH 6.2. Finally, the third reactor emitted 9.98 % (S1) and 16.8 % (S2) of the total N2O by nitrifier denitrification. Overall, this study showed that the large N2O emissions under nitrification-inhibiting conditions of the MAS process owed to the incomplete nitrification under acidic conditions and large abundances of denitrifiers. On the other hand, the lower N2O emissions at pH 6.2 evidenced the potential N2O mitigation under slightly more acidic conditions, underlining the necessity of further study on N2O mitigation when adapting to the trend of NH4-N recovery.

Designing Advanced Polymeric Binders for High‐Performance Rechargeable Sodium Batteries

AbstractSupply restrictions and associated price increase of lithium limit the large‐scale application of rechargeable lithium batteries (RLBs) in electric energy storage. Rechargeable sodium batteries (RSBs) with the advantage of large abundance and low cost of sodium, are developed to relieve the supply pressure of RLBs. Binders serve as a bridge between active materials and other components to maintain electrode integrity and electrical contact; however, they have not been sufficiently explored in RSBs. In this review, the working mechanism of binders for RSBs is proposed and more desirable features of RSB binders than their RLB counterparts are emphasized. The development history and recent progress of binders for RSBs are outlined. It is highlighted that the matching principles of binders to different electrode materials are proposed. Advanced characterization and simulation techniques are presented to interpret the electrochemical findings and reveal the working mechanism of novel binders in various electrodes of RSBs. Finally, perspectives on the development of effective binders for RSBs are presented.

Formation of sodium-bearing species in the interstellar medium

ABSTRACT Sodium-bearing species such as NaCl in the gas phase have been observed in an assortment of carbon-rich and oxygen-rich stellar atmospheres and interstellar environments such as the high-mass protostellar disc surrounding Orion Src1 and the proto-binary system, IRAS 16547−4247. Their detection in relatively low-temperature regions is yet to be made. In this paper, we consider the synthesis of sodium-bearing species with an emphasis on NaCl, via both gas-phase and grain-surface chemistry under assorted interstellar conditions. We also consider the chemistry leading to the gas-phase species NaH and NaOH. Two classes of numerical simulations were run: models under isothermal conditions at temperatures from 10 to 800 K with varied intervals, and three-phase warm-up models that consist of an initial isothermal collapse at 10 K, followed by a warm-up phase in which temperature rises linearly to 200 K, and finally a hot core phase. We have included reactive desorption for both models to produce gaseous NaCl, NaH, and NaOH. We found that for isothermal models over a broad parameter space, the fractional abundances of gaseous NaCl and NaOH can reach above 2 × 10−10 and approx. 1 × 10−10, respectively, are in the detection range of observational facilities such as Atacama Large Millimeter/Submillimeter Array and JWST. For warm-up models, we found that if we consider molecules to be co-desorbed with water, gaseous NaCl can have a sufficiently large abundance for detection. We then conclude that both gaseous NaCl and NaOH can be detected; however, more experiments and quantum mechanical calculations are needed to constrain the relevant reaction rates better.

Hygiene of keeping service horses in the highlands of Armenia

In the Transcaucasus region, the Republic of Armenia is the highest mountainous country, about 90% of its territories are located at altitudes of more than 1000 meters above sea level. On the territory of this region there are high plateaus, volcanic cones with a large abundance of streams and small rivers. With an increase of every 100 meters, the precipitation level increases by approximately 25 mm, and when reaching heights of 3,000 meters, precipitation increases to 1,000 mm per year. A feature of service horse breeding in this region is the tortuosity of most mountain roads, fairly rocky soil, steep ascents and descents, high and inaccessible passes, changes in atmospheric pressure and temperature at different altitudes during the day, frequent and sharp changes in air speed . The difficulty of raising livestock in some high-mountainous regions of Armenia is also due to the presence of landslides, screes, cliffs and glaciers, and in winter conditions, deep snow cover.

Change in the community structure and organic carbon content of meio- and macrobenthos between tidal flat and salt marsh areas colonized by Spartina alterniflora in the Bahía Blanca estuary (SW Atlantic)

Salt marshes are regarded as among the most productive coastal ecosystems, important “blue carbon” sinks and a support for benthic communities with large abundances, whose structure may be strongly influenced by salt marsh vegetation. During the last few decades, Spartina alterniflora has been colonizing bare mudflats in the Bahía Blanca estuary, and a large increase in the area covered by salt marshes has been reported. This colonization can strongly influence the structure of benthic fauna and its role in the carbon cycle. The hypothesis of this study was that the community structure and the organic carbon contained in the meio- and macrobenthos change between tidal flats and salt marshes recently colonized by S. alterniflora. Response variables studied to compare the tidal flat and salt marsh were density, biomass and production to biomass (P/B) ratio of macro- and meiobenthos. Density and biomass of Gastropoda and P/B ratio of Nematoda were higher on the salt marsh than on the tidal flat. By contrast, density and biomass of Polychaeta were higher on the tidal flat. These results suggest that the expansion of S. alterniflora marshes on tidal flats produces changes in the structure of the macro- and meiobenthos community (taxonomic composition and biomass) that have an influence on carbon cycling.

Meteoritic Molybdenum and Ruthenium Isotopic Abundances Document Nucleosynthetic p-process Components

Anomalies in isotopic abundances of Mo and Ru in solar system matter were found to document variable contributions of the nucleosynthetic s-process component. We report isotopic relations of ϵ 92Mo versus ϵ 100Ru in meteorites from chondritic parent bodies, iron meteorites, and achondrites that reveal deviations from expected s-process abundance variations. We show that two p-process isotopes 92Mo and 94Mo require the presence of distinct p-process components in meteoritic materials. The nucleosynthetic origin of abundant magic (N = 50) p-process nuclides, covering the mass range of Zr, Mo, and Ru, has long been an enigma, but contributions by several recognized pathways, including alpha and νp-antineutrino reactions on protons, may account for the observed relatively large solar system abundances. Specific core-collapse supernovae explosive regions may carry proton-rich matter. Since Mo and Ru isotopic records in solar system matter reveal the presence of more than one nucleosynthetic p-process component, these records are expected to be helpful in documenting different explosive synthesis pathways and the implied galactic evolution of p-nuclides.

Computational Study on the Influence of Mo/V Centers on the Electronic Structure and Hydrazine Reduction Capability of [MFe3S4]3+/2+ Complexes.

[MFe3S4] cubanes have for some time been of interest for their ability to mimic the electronic and geometric structure of the active site of nitrogenase, the enzyme responsible for fixing N2 to NH3. Nitrogenase naturally occurs in three forms, with the major difference being that the metal ion present in the cofactor active site is either molybdenum (FeMoco), vanadium (FeVco), or iron. The molybdenum and vanadium versions of these cofactors are more closely studied, owing to their larger abundance and rate of catalysis. In this study, we compare free energy profiles and electronic properties of the Mo/V cubanes at various stages during the reduction of N2H4 to NH3. Our findings highlight the differences in how the complexes facilitate the reaction, in particular, vanadium's comparatively weaker ability to interact with the Fe/S network and stabilize reducing electrons prior to N-N bond cleavage, which may have implications when considering the lower efficiency of the vanadium-dependent nitrogenase.

N-Glycome Profile of the Spike Protein S1: Systemic and Comparative Analysis from Eleven Variants of SARS-CoV-2.

The SARS-CoV-2 virus rapidly spread worldwide, threatening public health. Since it emerged, the scientific community has been engaged in the development of effective therapeutics and vaccines. The subunit S1 in the spike protein of SARS-CoV-2 mediates the viral entry into the host and is therefore one of the major research targets. The S1 protein is extensively glycosylated, and there is compelling evidence that glycans protect the virus' active site from the human defense system. Therefore, investigation of the S1 protein glycome alterations in the different virus variants will provide a view of the glycan evolution and its relationship with the virus pathogenesis. In this study, we explored the N-glycosylation expression of the S1 protein for eleven SARS-CoV-2 variants: five variants of concern (VOC), including alpha, beta, gamma, delta, and omicron, and six variants of interest (VOI), including epsilon, eta, iota, lambda, kappa, and mu. The results showed significant differences in the N-glycome abundance of all variants. The N-glycome of the VOC showed a large increase in the abundance of sialofucosylated glycans, with the greatest abundance in the omicron variant. In contrast, the results showed a large abundance of fucosylated glycans for most of the VOI. Two glycan compositions, GlcNAc4,Hex5,Fuc,NeuAc (4-5-1-1) and GlcNAc6,Hex8,Fuc,NeuAc (6-8-1-1), were the most abundant structures across all variants. We believe that our data will contribute to understanding the S1 protein's structural differences between SARS-CoV-2 mutations.

Primordial black holes from strong first-order phase transitions

We study the formation of primordial black holes (PBHs) in strongly super-cooled first-order phase transitions. The mechanism is based on the presence of remnants dominated by the false vacuum that scale slower with the expansion of the Universe than their surroundings where this energy was already converted into radiation. We compute the PBH formation from these remnants including the contribution from the false vacuum and the bubble walls, by estimating the collapse using the hoop conjecture and by considering both regions collapsing immediately when entering the horizon and sub-horizon regions that collapse as their compactness grows. We show that for exponential bubble nucleation rate, Γ ∝ eβt, the primordial black hole formation implies β/H ≳ 3.8, where H denotes the Hubble rate, if the potential energy of the false vacuum is ∆V ≲ (1012 GeV)4, as otherwise a too large abundance of long-lived PBHs forms. The observed dark matter abundance can be formed in asteroid mass PBHs if β/H ≃ 3.8 and 105 GeV ≲ ∆V1/4 ≲ 108 GeV. Finally, we consider also the effect of the second order correction to the exponential nucleation rate showing that the PBH abundance is mainly determined by the average radius of the true vacuum bubbles.

Evidence supportive of a bacterial component in the etiology for Alzheimer's disease and for a temporal-spatial development of a pathogenic microbiome in the brain.

Over the last few decades, a growing body of evidence has suggested a role for various infectious agents in Alzheimer's disease (AD) pathogenesis. Despite diverse pathogens (virus, bacteria, fungi) being detected in AD subjects' brains, research has focused on individual pathogens and only a few studies investigated the hypothesis of a bacterial brain microbiome. We profiled the bacterial communities present in non-demented controls and AD subjects' brains. We obtained postmortem samples from the brains of 32 individual subjects, comprising 16 AD and 16 control age-matched subjects with a total of 130 samples from the frontal and temporal lobes and the entorhinal cortex. We used full-length 16S rRNA gene amplification with Pacific Biosciences sequencing technology to identify bacteria. We detected bacteria in the brains of both cohorts with the principal bacteria comprising Cutibacterium acnes (formerly Propionibacterium acnes) and two species each of Acinetobacter and Comamonas genera. We used a hierarchical Bayesian method to detect differences in relative abundance among AD and control groups. Because of large abundance variances, we also employed a new analysis approach based on the Latent Dirichlet Allocation algorithm, used in computational linguistics. This allowed us to identify five sample classes, each revealing a different microbiota. Assuming that samples represented infections that began at different times, we ordered these classes in time, finding that the last class exclusively explained the existence or non-existence of AD. The AD-related pathogenicity of the brain microbiome seems to be based on a complex polymicrobial dynamic. The time ordering revealed a rise and fall of the abundance of C. acnes with pathogenicity occurring for an off-peak abundance level in association with at least one other bacterium from a set of genera that included Methylobacterium, Bacillus, Caulobacter, Delftia, and Variovorax. C. acnes may also be involved with outcompeting the Comamonas species, which were strongly associated with non-demented brain microbiota, whose early destruction could be the first stage of disease. Our results are also consistent with a leaky blood-brain barrier or lymphatic network that allows bacteria, viruses, fungi, or other pathogens to enter the brain.

Mammalian mitochondrial translation infidelity leads to oxidative stress–induced cell cycle arrest and cardiomyopathy

Proofreading (editing) of mischarged tRNAs by cytoplasmic aminoacyl-tRNA synthetases (aaRSs), whose impairment causes neurodegeneration and cardiac diseases, is of high significance for protein homeostasis. However, whether mitochondrial translation needs fidelity and the significance of editing by mitochondrial aaRSs have been unclear. Here, we show that mammalian cells critically depended on the editing of mitochondrial threonyl-tRNA synthetase (mtThrRS, encoded by Tars2), disruption of which accumulated Ser-tRNAThr and generated a large abundance of Thr-to-Ser misincorporated peptides in vivo. Such infidelity impaired mitochondrial translation and oxidative phosphorylation, causing oxidative stress and cell cycle arrest in the G0/G1 phase. Notably, reactive oxygen species (ROS) scavenging by N-acetylcysteine attenuated this abnormal cell proliferation. A mouse model of heart-specific defective mtThrRS editing was established. Increased ROS levels, blocked cardiomyocyte proliferation, contractile dysfunction, dilated cardiomyopathy, and cardiac fibrosis were observed. Our results elucidate that mitochondria critically require a high level of translational accuracy at Thr codons and highlight the cellular dysfunctions and imbalance in tissue homeostasis caused by mitochondrial mistranslation.

Occurrence, spatiotemporal distribution patterns,partitioning and risk assessments of multiple pesticide residues in typical estuarine water environments in eastern China

The low terrain and the prosperous agriculture in the east of China, have caused the accumulation of pesticide residues in the estuaries. Therefore, this study analyzed the spatiotemporal distribution and partition tendency of 106 pesticides based on their abundance, frequencies, and concentrations in the aquatic environment of 16 river estuaries in 7 major basins in the eastern China by using solid-phase extraction (SPE) with high-performance liquid chromatography tandem mass spectrometry (HPLC‒MS/MS) and gas chromatography tandem mass spectrometry (GC‒MS/MS). In addition, potential risk of multiple pesticides was also evaluated. The results showed that herbicides were the dominant pesticide type, while triazines were the predominate substance group of pesticide. In addition, triadimenol, vinclozolin, diethylatrazine, prometryn, thiamethoxam, atrazine, and metalachlor were the major pesticides in the water, while prometryn, metalachlor, and atrazine were the main pesticides in the sediment. The average total concentration of pesticide was 751.15 ng/L in the dry season, 651.17 ng/L in the wet season, and 617.37 ng/L in the normal season, respectively. The estuaries of the Huai River Basin, the Yangtze River Basin, the Hai River Basin, and the Yellow River Basin have been affected by the low pollution treatment efficiency, weak infrastructure, and agricultural/non-agricultural activities in eastern China, resulting in relatively serious pesticide pollution. The estuaries of Huaihe River, Yangtze River, Xiaoqing River, and Luanhe River had large pesticide abundance and comparatively severe pesticide pollution, while the estuaries of Tuhai River and Haihe River had heavy pesticide contamination in the sediment, which might be induced by historical sedimentary factors. The log KOC values showed that except for thioketone, other pesticides were relatively stable due to the adsorption by sediment. The ecological risk assessment results indicated that insecticides had a high risk. Teenagers were the most severely affected by the noncarcinogenic risk of pesticides, while adults were mostly affected by the carcinogenic risk of pesticides. Therefore, pesticide hazards in the water environment of estuaries in eastern China needs to be further close supervision.

A new heavy anion in IRC + 10216: Theory favors C10H− versus C9N−

Continuing Q-band (31–50 GHz) integrations on IRC +10216 with the Yebes 40 m telescope have now reached sub-millikelvin noise with hundreds of new lines arising above an average 3σ detection limit of 0.71 mK (as low as 0.45 mK in the lower frequency end). The recent discovery of the C7N− anion and the relatively large abundance of the HC9N member of the cyanopolyyne family opens the door for searching in the data for harmonically related series of lines belonging to singlet species, with intensities close to the detection limit, that could belong to heavier anions. One such series has been found with rotational quantum numbers from J = 52 − 51 up to J = 74 − 73, with at least 15 distinguishable features clearly detected as isolated or partly blended. There are two main candidates for the carriers of the series: C9N− and/or C10H−, for which our high-level-of-theory ab initio calculations predict a quite compatible rotational constant of ~300 MHz. In this paper we discuss, based on our ab initio calculations and also on chemical models, which of these two candidates is the most likely carrier. There is more evidence for the C10H− candidate. It would be, to date, the heaviest anion discovered in space through a series of detected individual lines.

Fabrication of Internal Electric Field Sns/Sb2S3 with Engineered Porous Structure for Fast Kinetics Sodium Ion Storage

Benefiting from the abundance and low cost of sodium, sodium-ion batteries show great potential as lithium-ion batteries in application of large-scale energy storage. However, anode material graphite with high theoretical capacity 372 mAh g-1, low charge-discharge plateau potential and good cyclability, widely applied in lithium-ion batteries, exhibited poor electrochemical performance. The larger radius of Na-ion compared to Li-ion hinders the mass and ion transfer during charge-discharge cycling. Thus, anode material with large abundance, stability and high conductivity is crucial for the development and further application of sodium-ion batteries.Sodium-ion batteries have the potential to benefit greatly from metallic sulfide anodes, which offer high theoretical capacities. Unfortunately, the practical use of these anodes is limited by poor electrochemical performance, as sulfides tend to expand significantly in volume and Na+ ions exhibit sluggish kinetics during cycling. We have developed a facile and scalable approach to synthesizing a SnS/Sb2S3 heterostructure that is porous and bimetallic, with an additional sulfur and nitrogen co-doped carbon matrix encapsulation (SnS/Sb2S3@SNC). The PAN precursor is mixed homogeneously with SnSbx and S with a ball milling process. The sulfur evaporates from the mixture and reacts with the SnSbx alloy, leading to the formation of bimetallic sulfides SnS/Sb2S3. As a result, voids are generated, which in turn contributes to the development of a porous structure. At the same time, the PAN is carbonized, generating a S, N co-doped carbon matrix. SnS and Sb2S3 are two highly promising anode materials for sodium-ion batteries, with high theoretical specific capacity of 1022 mAh g-1 and 947 mAh g-1, respectively. Moreover, bimetallic sulfides possess different bandgap make them ideal components for generating a strong internal electric field on the hetero-interface, which allows to improve the charge carrier transport and interface reaction kinetics. The porous nature of the structure can contain the volume expansion of sulfides during cycling, thereby ensuring superior structural stability. The distinctive heterostructure, in combination with the S, N co-doped carbon matrix, enables fast-charge transport and accelerate Na-ion storage kinetics.The SnS/Sb2S3@SNC anode demonstrates impressive electrochemical performance, with high capacities of 425 mAh g-1 at 200 mA g-1 after 100 cycles, and 302 mAh g-1 at 500 mA g-1 after 400 cycles. Additionally, the SnS/Sb2S3 @SNC anode exhibits remarkable rate capability, with a capacity of over 200 mAh g-1 at a high current density of 5000 mA g-1. Figure 1

Applying phase equilibria modelling to igneous systems by coupling trace element partitioning and accessory phase saturation to compositionally variable thermodynamic modelling in Rcrust

Phase equilibria modelling techniques can constrain the equilibrium conditions of major rock-forming minerals, however current thermodynamic databases and activity-composition models do not accommodate minor and trace elements as chemical components in modelled systems. This paper presents the integration of trace element partitioning routines between melt and solid phases in the thermodynamic modelling tool Rcrust in order to effectively estimate the trace element composition of stable phases when melt is present. Since trace elements occur in large abundances in accessory phases for which we do not currently have activity-composition models this paper further presents the integration of accessory phase saturation routines for apatite and monazite, two commonly occurring accessory phases in granitic rocks.This provides a novel methodology for approximating trace element distribution among thermodynamically constrained phases with thermodynamically unconstrained accessory phases, apatite and monazite. A case study of the Peninsula Pluton granodiorite, South Africa, is used to validate the use of accessory phase saturation and trace element partitioning with phase equilibria modelling. The results highlight the importance of major element components that also contribute to accessory phase formation such as calcium in apatite (which can accommodate a non-trivial quantity of the available calcium) and the resultant effect on phase equilibria of major phases. Saturating apatite can alter phase equilibria, mainly for calcium-bearing phases, that is equivalent to up to 20°C change in temperature. Modelling results for the Peninsula Pluton predicts LREE concentrations of apatite and monazite that match the natural samples at temperatures below 725°C, corroborating previous findings for emplacement P-T constraints. However, phase assemblages predicted through phase equilibria modelling show that the rock equilibrated to P-T below the emplacement estimates of previous studies. By modelling both major and accessory phases we provide constraints on the formation and crystallisation of crustal magmas which has important implications on geothermobarometry and thermochronology in the crust.