18 research outputs found
Greenhouse Gas Sensor using a Novel Conducting Polymer-GQD Composite Material
As Greenlandâs ice is melting by a record amount with the concurrent increase in greenhouse gases in the atmosphere, there is a concern for examining global warming in more detail. To control and keep the levels monitored, the precise measurement of greenhouse gases is desirable as there are interferences in the measurements. A novel method is developed to make sensors from conducting polymers. An Emeraldine Green (EG) â Graphene Quantum Dots (GQD) composite material is synthesized and used as the active material with enhanced sensing properties, owing to the larger surface area available. The active material is characterized to ensure the binding of the polymer and the GQD particles. A greenhouse gas sensor is designed and fabricated based on the electrochemical changes in the active material on exposure to greenhouse gases in a two-stage operation. In the first stage, the response of the interfering gases along with the analyte chosen is recorded and in the second stage, the thermal pulse is applied corresponding to the desorption energies of the interfering gases and could be used to isolate the interfering components. The sensor was tested on carbon dioxide gas with a response time of 46 seconds for a concentration of 200 ppm and shows negligible interference from methane gas at atmospheric concentrations
A Comparative Study on the Derivation of Unit Hydrograph for Bharathapuzha River Basin
AbstractSeveral techniques are available for the development of the unit hydrograph. But most of these traditional methods require manual fitting of the unit hydrograph through few points, which does not guarantee the area under the unit hydrograph to be unity. More over most of the stations are ungauged, due to which it becomes difficult to develop the unit hydrograph. So in order to overcome these problems, two methods have been considered in this study for the development of the unit hydrograph for Bharathapuzha river basin. They are the âtwo parameter Gamma distributionâ and âthree parameter Beta distributionâ, both of which are based on Probability Distribution Functions (pdfs). The unit hydrograph developed by the two parameter Gamma distribution match well with the one developed by CWC method, but the unit hydrograph developed by the three parameter Beta distribution does not match well with the one developed by the CWC method. From the unit hydrograph, runoff hydrograph is convoluted for the year 2008. For this the hourly rainfall are generated from daily rainfall values by disaggregation. But on plotting, the simulated discharge hydrograph is found to be greater than the observed discharge. This may be due to non incorporation of the inflow outflow processes of many hydraulic structures such as dams, irrigation schemes etc, existing in the basin in the model study. The data related to these structures could not be obtained due to certain restriction in acquiring the data from authorized agencies
Identification of Suitable Sites for Water Harvesting Structures in Kecheri River Basin
AbstractWater is the most precious resource on the earth which is essential for the existence of life. Though Kerala is blessed with two prominent monsoons with an average rainfall of around 3000mm, it experiences water scarcity in off monsoon seasons. Peculiarities such as steep slope and undulating terrain accelerate surface flow and hence most of the water received as rainfall goes as unutilized. Water Harvesting is the best technique which can be used effectively to trap the unutilized surface runoff and thereby increase the groundwater recharge. But these structures have to be located at places where water is available in excess and conditions are favourable for enhanced infiltration. The objective of this study is to identify suitable sites for water harvesting structures. For ideally locating the sites, the guidelines put forward by NRSA, Hyderabad for Integrated Mission for Sustainable Development (IMSD), is being followed. ArcGIS is used for the spatial analysis and the sites are located by overlaying thematic maps of land use, soil, slope, runoff potential, soil permeability and stream order. It is found that 37 percentage of the total area is ideal for constructing check dam, 7 percentage for farm pond, 4 percentage for percolation pond and about 2 percentage for subsurface dyke. Check dams are the most suited one and location for subsurface dykes is sparse. Locations of water harvesting structures are suggested by conducting meteorological and topographical analysis. However, for the practical implementation of these structures, viability of other considerations such as economy, social implications, practical feasibility etc. need to be considered
Design of Multiplexers using Reversible Logic Technique
Reversible logic is promising as it can be applied to different applications in low power like nanocomputing especially in quantum computing. Reversible logic is a technioue for power reduction. Reversible circuits are similar to digital circuits but they work using reversible logic gates. This study focuses on reducing the garbage output and ancilla inputs in reversible multiplexers, thereby reducing the power consumption. In this study two designs of Multiplexers are given. Design1 is using TwinSJ gate and AJ gate. 2:1, 4:1 and 8:1 multiplexers are built. In Design 2, a new gate (SJ gate) is built which functions as 2:1 multiplexer. It has 4*4 configuration. The inputs are suitably configured so that it performs various logic functions. Using this SJ gate and other basic reversible logic gates, 2:1, 4:1 and 8:1 multiplexers are built. In 2:1 multiplexer, Ancilla inputs are improved to '0' from 5 and garbage output has been reduced to 2 against 7 in existing design. 4:1 multiplexers are built with â0â ancilla inputs against 2 and 11 in existing designs. Garbage output of the proposed 4:1 multiplexer is 5 against 6 and 16 in existing designs. 8:1 multiplexer is built with 1 ancilla input and 11 garbage output against 2 and 12 respectively in existing design. This is designed using VHDL code - xilinx 14.7 for verification purpose and simulated on ISIM
Electrodeposition from a Graphene Bath: A Sustainable Copper Composite Alloy in a Graphene Matrix
The leaching effect of metals has led to the introduction of government regulations for the safety of the environment and humans. This has led to the search for new alloys with long-lasting sustainability. Herein, we wish to report a new brass alloy containing carbon with a remarkable sustainability produced by electrodeposition from a graphene quantum dots bath. The electrochemical measurements were carried out using cyclic voltammetry, potentiodynamic analysis, and Tafel measurements, and the deposits were characterized by X-ray fluorescence spectroscopy (XRF), Raman imaging, X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) to understand the surface morphology and elemental compositions. The currentâtime transients in the potential-step electrolysis were used to investigate the nucleation and growth mechanism. The smooth and compact deposit obtained at â0.60 V showed a composition of Cu = 24.33 wt %; Zn = 0.089 wt %; and C = 75.57 wt %. The SEM and energy dispersion X-ray analysis revealed a surface morphology with a uniform distribution of the particles and the presence of Cu, Zn, and C. The corrosion density of the material is very much lower than that of conventional brass, suggesting a higher sustainabilit
Early life child micronutrient status, maternal reasoning, and a nurturing household environment have persistent influences on child cognitive development at age 5 years: Results from MAL-ED
Background: Child cognitive development is influenced by early-life insults and protective factors. To what extent these factors have a long-term legacy on child development and hence fulfillment of cognitive potential is unknown. Objective: The aim of this study was to examine the relation between early-life factors (birth to 2 y) and cognitive development at 5 y. Methods: Observational follow-up visits were made of children at 5 y, previously enrolled in the community-based MAL-ED longitudinal cohort. The burden of enteropathogens, prevalence of illness, complementary diet intake, micronutrient status, and household and maternal factors from birth to 2 y were extensively measured and their relation with the Wechsler Preschool Primary Scales of Intelligence at 5 y was examined through use of linear regression. Results: Cognitive T-scores from 813 of 1198 (68%) children were examined and 5 variables had significant associations in multivariable models: mean child plasma transferrin receptor concentration (ÎČ: â1.81, 95% CI: â2.75, â0.86), number of years of maternal education (ÎČ: 0.27, 95% CI: 0.08, 0.45), maternal cognitive reasoning score (ÎČ: 0.09, 95% CI: 0.03, 0.15), household assets score (ÎČ: 0.64, 95% CI: 0.24, 1.04), and HOME child cleanliness factor (ÎČ: 0.60, 95% CI: 0.05, 1.15). In multivariable models, the mean rate of enteropathogen detections, burden of illness, and complementary food intakes between birth and 2 y were not significantly related to 5-y cognition. Conclusions: A nurturing home context in terms of a healthy/clean environment and household wealth, provision of adequate micronutrients, maternal education, and cognitive reasoning have a strong and persistent influence on child cognitive development. Efforts addressing aspects of poverty around micronutrient status, nurturing caregiving, and enabling home environments are likely to have lasting positive impacts on child cognitive development.publishedVersio
Early Life Child Micronutrient Status, Maternal Reasoning, and a Nurturing Household Environment have Persistent Influences on Child Cognitive Development at Age 5 years : Results from MAL-ED
Funding Information: The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project (MAL-ED) is carried out as a collaborative project supported by the Bill & Melinda Gates Foundation, the Foundation for the NIH, and the National Institutes of Health/Fogarty International Center. This work was also supported by the Fogarty International Center, National Institutes of Health (D43-TW009359 to ETR). Author disclosures: BJJM, SAR, LEC, LLP, JCS, BK, RR, RS, ES, LB, ZR, AM, RS, BN, SH, MR, RO, ETR, and LEM-K, no conflicts of interest. Supplemental Tables 1â5 and Supplemental Figures 1â3 are available from the âSupplementary dataâ link in the online posting of the article and from the same link in the online table of contents at https://academic.oup.com/jn/. Address correspondence to LEM-K (e-mail: [email protected]). Abbreviations used: HOME, Home Observation for Measurement of the Environment inventory; MAL-ED, The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project; TfR, transferrin receptor; WPPSI, Wechsler Preschool Primary Scales of Intelligence.Peer reviewe
Green-Chemical Strategies for Production of Tailor-Made Chitooligosaccharides with Enhanced Biological Activities
Chitooligosaccharides (COSs) are b-1,4-linked homo-oligosaccharides of N-acetylglucosamine (GlcNAc) or glucosamine (GlcN), and also include hetero-oligosaccharides composed of GlcNAc and GlcN. These sugars are of practical importance because of their various biological activities, such as antimicrobial, anti-inflammatory, antioxidant and antitumor activities, as well as triggering the innate immunity in plants. The reported data on bioactivities of COSs used to contain some uncertainties or contradictions, because the experiments were conducted with poorly characterized COS mixtures. Recently, COSs have been satisfactorily characterized with respect to their structures, especially the degree of polymerization (DP) and degree of N-acetylation (DA); thus, the structureâbioactivity relationship of COSs has become more unambiguous. To date, various green-chemical strategies involving enzymatic synthesis of COSs with designed sequences and desired biological activities have been developed. The enzymatic strategies could involve transglycosylation or glycosynthase reactions using reducing end-activated sugars as the donor substrates and chitinase/chitosanase and their mutants as the biocatalysts. Site-specific chitin deacetylases were also proposed to be applicable for this purpose. Furthermore, to improve the yields of the COS products, metabolic engineering techniques could be applied. The above-mentioned approaches will provide the opportunity to produce tailor-made COSs, leading to the enhanced utilization of chitin biomass
Analyzing Technology Adoption - The Case of Kerala Home Gardens
Homegardens are traditional agroforestry system with a unique structure and function. It is the predominant farming system in Kerala. The study was undertaken in Thiruvananthapuram district covering a sample of 100 homegardens farmers from all the five agro-ecological units with an aim to assess the level of adoption of selected Kerala Agricultural University (KAU) production practices in homegardens. Results of the study identified that majority of the farmers (63%) belonged to medium level of adoption. Adoption quotient was worked out and compared with standard Rogers curve. Correlation analysis of the independent variables with the dependent variable viz., level of adoption indicated that age, farming experience, knowledge, evaluative perception, mass media contribution, livestock possession and extension contribution had direct significant effect on level of adoption of KAU production practices by homegarden farmers
Nanocellulose as an Avenue for Drug Delivery Applications: A Mini-Review
A controlled and sustained release of an accurate dose of medications into a system can cure diseases associated with the human body. Different potential drug delivery vehicles, which are biocompatible and non-toxic, have been synthesized and developed for the controlled release of drugs targeting specific organs or areas. A delivery agent procured from sustainable sources with less or no side effects is more advantageous in terms of compatibility and toxicity. Among a few bioresources, one such material obtained is the nanocellulose-based drug delivery vehicle. They are ideal for the transport and release of drugs since they are biocompatible and possess good mechanical properties. A major characteristic feature of nanocellulose is that different surface modifications are possible due to the presence of a large number of hydroxyl groups, which can strengthen the interactions required with the therapeutic drug for delivery. Pharmaceutical drugs can strongly bind to the nanocellulose material through electrostatic interactions, and the release can occur in a sustained manner to the target within a few minutes to several days. In this mini-review, we have tried to summarize some of the most important works carried out in the field of nanocellulose-based drug delivery, different types of nanocellulose, its surface modification possibilities, and delivery of medications through three main routes, oral, transdermal, and topical, that have been reported to be effective