Search

Recently, a layered material with composition Li1+xV1−xO2 has been discovered as a promising alternative anode material to graphite due to its high volumetric capacity and low operation potential. Herein, we demonstrate a mild and cost-effective synthetic methodology to construct a novel nanoporous anode material (P-LVO@C), comprising Li1+xV1−xO2 nanocrystals embedded in a porous carbon matrix. The thermal decomposition of organic materials, including a triblock copolymer (P123) and citric acid, in a N2 atmosphere is the source of the nanoporous carbon in the porous composite material, while citric acid also plays a crucial role in maintaining the reductive environment of the synthetic medium. Due to the novel composition of Li1+xV1−xO2 (x≥ 0.03), as well as its porous structure and well-integrated conductive framework, our P-LVO@C has great applicability as a high performance anode material for lithium-ion batteries. Our P-LVO@C composite electrode shows high reversible capacity with an excellent cycling performance (100 cycles) and good capacity retention (82%) at a higher rate (0.48C). [ABSTRACT FROM AUTHOR]

Mesostructured manganese oxide (Mn3O4) is prepared by a soft-templating method employing sodium dodecyl sulfate (SDS) as a structure-directing agent. By removing the template from the as-prepared mesostructured Mn3O4 by extraction or calcination, we successfully synthesized highly crystallized mesoporous Mn3O4 or Mn2O3, respectively, with different crystalline structures. [ABSTRACT FROM AUTHOR]

Herein, we introduce a new polypeptide-functionalized mesoporous silica template fabricated from a biodegradable poly(ethylene oxide- b-ɛ-caprolactone) (PEO- b-PCL) diblock copolymer and a poly(tyrosine) (PTyr) biopolymer. The crystallization behavior of the PEO- b-PCL diblock copolymer changes after blending, but the secondary structure of PTry remains stable. After selective solvent extraction in THF, the PEO- b-PCL is removed, but PTyr remains within the silica matrix due to its different solubility. Fourier-transform IR spectroscopic analysis (FTIR), thermal gravitometry analysis (TGA), small-angle X-ray scattering (SAXS), and X-ray diffraction (XRD) studies confirm the retention of PTyr to form a polypeptide-functionalized mesoporous material. The adsorption of methylene blue hydrate (MB) from aqueous solution into the polypeptide-functionalized mesoporous silica is investigated, thus revealing that the nanocomposite exhibits a high adsorption capacity relative to pure silica due to hydrogen-bonding interactions between the hydroxy phenolic group of PTyr and the N-containing aromatic ring from MB. [ABSTRACT FROM AUTHOR]

We report the synthesis of electrode materials based on one-dimensional α-NiMoO4 nanorods for application as a supercapacitor. The structure and morphology of the electrodes were characterized by powder X-ray diffraction, Raman analysis, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. The maximum specific capacitance obtained from electrochemical measurements on a standard three-electrode system was 730 F g-1 at a scan rate of 5 mV s-1. Furthermore, an asymmetric supercapacitor (ASC) was fabricated in which the NiMoO4 nanorods were used as the positive electrode and reduced graphene oxide was used as the negative electrode. The maximum specific energy obtained from the ASC study was 12.31 Wh kg-1 at a specific current of 0.5 A g-1 in an aqueous KOH electrolyte. This ASC cell showed good stability with 85 % capacitance retention up to 2000 cycles. These results reveal that our ASC shows a high performance and specific energy as well as good cycling stability. [ABSTRACT FROM AUTHOR]

A new family of mesoporous iron phosphonate(FeP) materials hasbeen prepared through cooperative assembly of cetyltrimethylammoniumbromide (CTAB), iron nitrate, and nitrilotris(methylene)triphosphonicacid (NMPA). CTAB is used as a structure directing agent, while theother two chemicals are used as precursors for the formation of porewalls. An extraction procedure is employed to remove the templatewithout damaging the as-prepared ordered mesostructure. The obtainedmesoporous FeP materials are well characterized by low angle X-raydiffraction (XRD), N2adsorption isotherms, and transmissionelectron microscopy. The mesostructural ordering of the obtained materialsstrongly depends on the synthetic conditions. The morphology and thecrystallinity of the pore walls are investigated by scanning electronmicroscopy and wide-angle XRD measurements, respectively. It is revealedthat the FeP framework is crystallized in the tetragonal crystal phase(I41/amd), accordingto the Rietveld refinement of the XRD patterns through the MAUD program.The unit cell parameters of the obtained crystals are a= b= 5.1963 (3) Å, c= 12.9808(1) Å (α = β = γ = 90°). Also, the homogeneousdistribution of both Fe species and organo-phosphonic acid groupsin the mesoporous architectures is confirmed by Fourier transforminfrared spectroscopy and elemental mapping. Mesoporous FeP materialswith high surface area have great applicability as high performanceelectrode materials for lithium-ion (Li-ion) batteries, due to severaladvantages including a large contact area with the electrolyte, highstructural stability, and short transport paths for Li+ions. Mesoporous FeP electrodes exhibit high reversible specificcapacity with very good cycling stability and excellent retentionof capacity. [ABSTRACT FROM AUTHOR]

Vanadium exchanged zeolite Y has been synthesized by simple ion-exchange on NaY and resulting V-Y material has been employed as a heterogeneous catalyst for highly selective and direct one-pot liquid phase oxidation of cyclohexane to cyclohexanone under solvent-free conditions at room temperature. The catalyst (V-Y) has been thoroughly characterized by powder X-ray diffraction (PXRD), N2 sorption, transmission electron microscopic (TEM), Fourier transform infrared (FT IR), UV-visible, X-ray photoelectron spectroscopic (XPS) and atomic absorption spectroscopic (AAS) analyses. The selective oxidation reaction proceeds smoothly over this V-containing heterogeneous catalyst in the presence of tert-butylhydroperoxide (TBHP) as oxidant and the progress of the reaction has been monitored thoroughly by gas chromatographic (GC) and gas chromatography coupled with mass spectrometric (GC-MS) analyses. The recycling efficiency of the V-Y catalyst has been tested by conducting the catalytic reaction repeatedly with the recovered catalyst, where almost retention of the original catalytic activity and selectivity after five reaction cycles has been observed. The effect of oxidant amounts on the catalytic reaction has been studied. Mechanistic pathway for the catalytic reaction over this inexpensive, non-air sensitive, eco-friendly and reusable vanadium exchanged zeolite has been proposed, suggesting future potential of V-Y in solvent-free liquid phase selective oxidation reactions under very mild conditions. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid chromium oxophenylphosphate CPP-1 has been synthesized hydrothermally in the presence of phenylphosphonic acid as a phosphorus source without the aid of any structure directing agent (SDA). The material has high BET specific surface area of 315m2 g−1 and consists of large supermicropores of dimension ca. 1.4nm. Powder XRD analysis revealed the crystalline feature and a new orthorhombic phase for CPP-1 with unit cell parameters of a=14.8232Å, b=6.87167Å, c=18.2501Å, α=β=γ=90°. Magnetic measurements suggested that in CPP-1 the metal centers are bridged via the phenylphosphate group and they are antiferromagnetically coupled. The coupling strength is relatively weak (−2.33cm−1) in this porous network and much lower than the conventional M–O–M superexchange interaction. CPP-1 also showed good catalytic activity in the liquid phase partial oxidation of aldehydes to the respective acids in the presence of dilute aqueous H2O2 as oxidant at room temperature. [ABSTRACT FROM AUTHOR]

One-pot bottom-up synthesis involving extended aromatic electrophilic substitution on to a pyrrole has been employed for the design of a novel triazine-functionalized porphyrin-based porous organic polymer, TPOP-1. Hydrothermal treatment of 4,4',4"-(1,3,5-triazine-2,4,6-triyl)tris(oxy)tribenzaldehyde and pyrrole in glacial acetic acid in the presence of FeCl3 leads to the formation of TPOP-1, which is a highly porous and robust material, and which exhibits a high surface area and bimodal pore sizes ranging from large micropores to mesopores. The presence of porphyrin and triazine functionality within the network structure enables formation of electron-donating basic N-sites at the surface of the porous organic framework and thus favors the adsorption of Lewis acidic CO2 molecules and decoration of the material by palladium nanoparticles at its surface to form Pd-TPOP-1. TPOP-1 showed good CO2 storage capacity (6.2 mmol or 27.3 wt% at 3 bar/273 K), suggesting its potential application in environmental clean-up. Moreover, this post Pd-functionalized material forms fine colloidal suspensions in organic solvent and exhibits high catalytic activity for Sonogashira cross-coupling of aryl halides with aryl alkynes under mild reaction conditions. [ABSTRACT FROM AUTHOR]

An efficient procedure for aerobic oxidation of thiols to disulfides catalyzed by new self-assembled hierarchical mesoporous Mn-MFI in the presence of air under solvent-free conditions as well as in aqueous medium is reported. The mesoporosity and Mn4+ loading, together with a highly crystalline microporous pore wall structure of the MFI framework were achieved through a newly designed hydrothermal process. This hydrothermal approach leads to hierarchical self-assembled mesoporous zeolite structures through isomorphous substitution of Si by Mn and Al. It is shown that Mn-containing mesoporous zeolites are capable to form disulfide bonds from thiols in the presence of air. The zeolitic materials were characterized by XRD, field-emission scanning electron microscopy, high-resolution TEM, X-ray photoelectron spectroscopy, 29Si NMR, 27Al NMR, and EPR spectroscopy, as well as AAS analysis and N2 sorption studies. N2 sorption analysis revealed high surface areas and narrow pore size distributions (1.2-6.0 nm) for different samples. The mesoporous Mn-ZSM-5 acted as an efficient heterogeneous catalyst with maximum catalytic activity in the benzenethiol conversion to diphenyldithiol. [ABSTRACT FROM AUTHOR]

• Established prediction-adaptation-resilience (PAR), new pathways in urban simulation. • PAR approach helps to propagate the urban resilience in the small scale cities. • PAR approach strengthens urban planning and human adaptation reciprocally. • It helps to achieve the UNs sustainable development goals of 2030 Agenda. Rapid urban proliferation is an indispensable and reciprocal issue in contemporary urban planning and development. This study envisages the prediction-adaptation-resilience (PAR) approach to analyze the future urban landscape resilience and sustainable development goals (SDGs). We have selected a small, unplanned growing up city, namely, Krishnanagar urban agglomeration (KUA), in India, to apply the PAR approach. Therefore, land use land cover map has been prepared for 2000, 2010, and 2020. The result shows the built-up area has been increased most in past 20 years, from 6.36 km2 to 13.23 km2. Then, the cellular automata-Markov chain model is applied to predict the future potential urban development surface for 2030 and 2040. The receiver operating characteristic (ROC) curve shows 83.6% success rate between the predicted and actual map of CA-Markov. The prediction map of 2030 and 2040 shows that the built-up area continuously expands (13.23 km2 to 16.52 km2) towards KUA's surrounding regions. Consequently, other decreasing land classes will be a threat to SDGs and urban resilience. So, people of KUA are adopting the changing hostile nature of urbanisation and urban vulnerability. Hence, this study will help the local administration to make a proper urban planning and adaptation strategies by maintaining good urban governance to achieve 8 SDGs of UN's 2030 Agenda in future. [ABSTRACT FROM AUTHOR]

Droughts are one of the most spatially complex geohazards, having a significant impact on the economic status of any region. To mitigate drought risks, a comprehensive drought management plan is required, and the first step towards that goal is to assess the various aspects of drought risks in the preparation of a drought risk map. To produce an integrated drought risk map for Mahanadi River basin, India, the current study combines geospatial methodologies with the Analytical Hierarchy Process (AHP) technique to assess various dimensions, viz. hydrological, meteorological, agricultural and socio-economic drought risk in the region in view of integrated rural-urban management strategies. A total of 17 criteria from different aspects were taken into consideration in different groups. The results showed that districts like Raipur, Bilaspur, Durg and Ragnandgaon faced extreme drought conditions combining assessments of agriculture, water resources, socioeconomic factors and weather patterns, reveals varying levels of risk across the region. According to the findings, 22.01% of the region is vulnerable to extreme drought and 31.64% of the area is suffering from severe drought. The results indicate that the technique used for identifying the region's susceptibility to drought is effective, which will help planners develop strategies for mitigating drought. [ABSTRACT FROM AUTHOR]

Abstract:Climate change is continuously affecting the agriculture, ecosystem, species distribution as well as global biodiversity. The assessment of the species potential distribution, land suitability, and the spatial changes under various climate change scenarios is a significant step towards the conservation planning and policy applications. Therefore, to understand the climate change impacts, the present study considers Garcinia gummi-gutta cash crop species as a case study, which are even exported, adding the nation's foreign reserve. India maintains a global monopoly in this agricultural production. Also, the study aimed to predict the influence of current and future climate on an ecologically vulnerable medicinal cash crops species, Garcinia gummi-gutta, of the Western Ghats using Maximum Entropy (MaxEnt) modeling. The future projections were made for the period of 2050 and 2070 with RCP (Representative Concentration Pathways) scenario of 4.5 and 8.5 using 84 species occurrence data, and climatic variables from three different models (HadGEM2-CC, NorESM1-M, and GFDL-CM3) of Intergovernmental Panel for Climate Change (IPCC) 5th assessment. Climatic variables contributions were assessed using jackknife test and AOC value 0.888 indicates the model perform with high accuracy. The major influencing variables will be annual precipitation (Bio12), precipitation of coldest quarter (Bio19), precipitation seasonality (Bio15), and Precipitation of driest quarter (Bio17). The model result shows that the current high potential distribution of the species is around 1.90% of the study area, 7.78% is good potential, about 90.32% is moderate to very low potential for species suitability. Finally, the results of all model represented that there will be a drastic decline in the suitable habitat distribution by 2050 and 2070 for all the RCP scenarios. HadGEM2-CC climate model results provides more accuracy than NorESM1-M, and GFDL-CM3 climate model as Western Ghats lying in the monsoonal region. more accurate The study also signifies that MaxEnt model might be an efficient tool for agricultural development, ecosystem management, biodiversity protection, and species re-habitation planning under climate change. [ABSTRACT FROM AUTHOR]

A micro-watershed is the smallest hydrological unit with a unique type of common-pool resource, defined by hydrological linkages and requiring coordinated use of natural resources by all users for optimal management. However, the watersheds in the central Himalayan region are particularly vulnerable to land degradation since they are subject to various fluvial and denudation processes. As a result, the present study focused on the Bacchanshiv Gad watershed in the subtropical zone, where soil erosion is more prevalent due to various hydro-geomorphological causes. The analysis considered fourteen different areal, linear, shape, and landscape morphometric parameters by integrating spatial and compromise statistical programming techniques to prioritize 8 micro-watersheds. Moreover, the study gives comprehensive insight about the current land use land cover spatial distribution, lithological and pedan characteristics of the watershed that play a significant role in taking appropriate land and water conservation measures to prevent further soil degradation. [ABSTRACT FROM AUTHOR]

In recent decades, dengue has been expanding rapidly in the tropical cities. Even though environmental factors and landscape features profoundly impact dengue vector abundance and disease epidemiology, significant gaps exist in understanding the role of local environmental heterogeneity on dengue epidemiology in India. In this study, we assessed the role of remotely sensed climatic factors (rainfall, temperature and humidity) and landscape variables (land use pattern, vegetation and built up density) on dengue incidence (2012–2019) in Bhopal city, Central India. Dengue hotspots in the city were assessed through geographical information system based spatial statistics. Dengue incidence increased from 0.59 cases in 2012 to 9.11 cases in 2019 per 10,000 inhabitants, and wards located in Southern Bhopal were found to be dengue hotspots. Distributed lag non-linear model combined with quasi Poisson regression was used to assess the exposure-response association, relative risk (RR), and delayed effects of environmental factors on dengue incidence. The analysis revealed a non-linear relationship between meteorological variables and dengue cases. The model shows that the risk of dengue cases increases with increasing mean temperature, rainfall and absolute humidity. The highest RR of dengue cases (~2.0) was observed for absolute humidity ≥60 g/m3 with a 5–15 week lag. Rapid urbanization assessed by an increase in the built-up area (a 9.1% increase in 2020 compared to 2014) could also be a key factor driving dengue incidence in Bhopal city. The study sheds important insight into the synergistic effects of both the landscape and climatic factors on the transmission dynamics of dengue. Furthermore, the study provides key baseline information on the climatic variables that can be used in the micro-level dengue prediction models in Bhopal and other cities with similar climatic conditions. Author summary: Dengue, a viral disease transmitted by infected Aedes mosquitoes, is a major public health concern globally. In addition to its increased incidence in recent years, dengue is also spreading to new geographical regions. Local environmental factors are known to modify the mosquito vector density that directly impacts dengue virus transmission. Understanding the influence of environmental factors (meteorological conditions and landscape features) on dengue epidemiology in local settings is important for focused dengue intervention. Here, by utilizing dengue incidence and remotely sensed environmental data from 2012–2019, we have assessed the role of environmental factors in driving dengue virus transmission in the city of Bhopal in Central India. During the study period, a 14.5 fold increase in dengue incidence was observed in Bhopal city, which is way higher than the 2.3 fold increase reported at the national level. The risk of dengue virus transmission was higher with higher temperature and absolute humidity. An increase in built-up area, a proxy for urbanization, was found to be another predictor of increased dengue incidence in Bhopal. These findings can provide a stepping-stone for the development of dengue prediction models and the identification of dengue hotspots in order to improve vector control of this disease in cities with similar environmental conditions. [ABSTRACT FROM AUTHOR]

Located on the south-facing slope of the Himalayas, Nepal receives intense, long-lasting precipitation during the Asian summer monsoon, making Nepal one of the most susceptible countries to flood and landslide hazards in the region. However, sparse gauging and irregular measurement constrain the vulnerability assessments of floods and landslides, which rely highly on the accuracy of precipitation. Therefore, this study evaluates the performance of Satellite-based Precipitation Products (SPPs) in the Himalayas region by comparing different datasets and identifying the best alternative of gauge-based precipitation for hydro-meteorological applications. We compared eight SPPs using statistical metrics and then used the Multi-Criteria Decision-Making (MCDM) technique to rank them. Secondly, we assessed the hydrological utility of SPPs by simulating them through the GR4J hydrological model. We found a high POD (0.60–0.80) for all SPPs except CHIRPS and PERSIANN; however, a high CC (0.20–0.40) only for CHIRPS, IMERG_Final, and CMORPH. Based on MCDM, CMORPH and IMERG_Final rank first and second. While SPPs could not simulate daily discharge (NSE < 0.28), they performed better for monthly streamflow (NSE > 0.54). Overall, this study recommends CMORPH and IMERG_Final and improves the understanding of data quality to better manage hydrological disasters in the data-sparse Himalayas. This study framework can also be used in other Himalayan regions to systematically rank and identify the most suitable datasets for hydro-meteorological applications. [ABSTRACT FROM AUTHOR]