843 research outputs found
Digestive enzyme complement of Liza parsia (Hamilton)
An attempt was made to survey various digestive enzymes present in different regions of the digestive tract of the
mullet, Liza parsia. The crude enzyme extracts from the digestive tract could hydrolyse a wide range of carbohydrate
substrates. Amylase and maltase were the major carbohydrases detected throughout the alimentary canal with higher in
pyloric caecae and intestine. Cellulase was not detected. Trace of acid protease activity was detected in the cardiac
stomach extracts. High alkaline protease activity was observed in the phyloric caecae, followed by anterior inte,tine.
Trypsin and chymotrypsin were the major endoproteases. Carboxypeptidases were detected in trace amounts: leucine
aminopeptidase was the important exopeptidase
GROWTH AND CHRACTRAZATION OF L-ARGININE ACETATE CRYSTALS
Single crystals of pure L- Arginine acetate been grown by slow evaporation technique at roomtemperature. The crystalline nature of grown crystal was long-established by powder X-raydiffraction analysis (XRD). The structure of the grown crystal determined by X-ray diffractionanalysis reveals that it belongs to the monoclinic system. The purposeful group of the growncrystals was established by FTIR analysis. The UV-Vis study was performed to know the opticalbehavior of the grown crystals. The optical transmittance of the spectrum of solid material wasmeasured in the range of 190 to 800 nm. The crystal shows a high-quality transmittance in thevisible region. The transmittance above 74% is observed from 354 to 800 nm, which clearlyshows the crystal possesses good optical transparency for the second harmonic generation
Digestive Enzymes Complement of Freshwater Prawn Macrobrachium idella (Heller)
The prawn Macrobrachium idella (Heller) is a candidate species for aquaculture. Analysis of digestive enzymes serves as an efficient tool in the assessment of digestive ability and design of optimal diet for aquacultural practices
Gripe water-mediated green synthesis of silver nanoparticles and their applications in nonlinear optics and surface-enhanced Raman spectroscopy
Preparation, Characterization and Evaluation of Elvitegravir-Loaded Solid Lipid Nanoparticles for Enhanced Solubility and Dissolution Rate
Purpose: To enhance the aqueous solubility and dissolution rate of elvitegravir (EVG) by formulating the drug as solid lipid nanoparticles (SLNs) using solvent injection method.Methods: EVG-loaded SLNs were prepared by solvent injection method. Four different formulations of SLN were prepared using gelucire - 44/14 as lipid core in ethanol, soya lecithin as emulsifier, and polysorbate 80 as surfactant in the aqueous phase. The SLNs were characterized for various physical properties, including particle size, zeta potential, polydispersity, release profile and entrapment efficiency.Results: The yield of SLNs was in the range 151.0 ± 2.4 to 199.1 ± 2.7 nm. Significant changes were observed in mean particle size (nm), Z - potential (mV) and polydispersity index (PDI) of the SLNs by varying the concentration of cryoprotectant. EVG – SLNs demonstrated a 800 – 1030-fold enhancement in aqueous solubility compared with plain EVG. The dissolution efficiency (DE) for SLNs was > 63 % in all cases and increased up to 83 % with increasing lipid load.Conclusion: Successful preparation and characterization of elvitegravir–loaded solid lipid nanoparticles by solvent injection method has been accomplished in this study.Keywords: Elvitegravir, Solid lipid nanoparticles, Cryoprotectant, Lipid load, Entrapment efficienc
Quadcopter based Automatic Spattering of Pesticides and Fertilizers
Agriculture plays a major role in Indian Economy. The crop yield depends upon the pesticides and fertilizers applied in the fields. But the manual handling of these things leads to health hazards. The World Health Organization (WHO) estimated that over 3 million cases of pesticides poison each year, which is majority in developing countries like India. This paper aims to overcome the problem by automating the spray of pesticides and fertilizers in the fields. The system is constituted by an aerial sprayer which consists of a Quadcopter and spraying mechanism. The Quadcopter is controlled by the Radio Frequency signals and the spraying of pesticides is achieved with less manual labour without any health issues. This paper is to mainly overcome the ill-effects of pesticides on human beings and also to cover larger areas with short span of time
Switching pulse generation for DC-DC boost converter using Xilinx-ISE with FPGA processor
This paper explains steps to generate switching pulse using Xilinx-ISE with FPGA processor for DC-DC boost converter. The switching pulse generated using Very high speed integrated circuit Hardware Description Language (VHDL) with Xilinx-ISE. VHDL is a programming language, which is used to model and design any complex circuits in a dynamic environment. This paper gives the course of action for generation of switching pulses for dc-dc boost converter using Xilinx-ISE and matlab simulink. The switching pulse generated using Xilinx-ISE with FPGA-Spartan 6 processor compared with switching pulse generated using matlab
Le niveau de la mer actuel : variations globale et régionales
Sea level is an integrated climate parameter that involves interactions of all components of the climate system (oceans, ice sheets, glaciers, atmosphere, and land water reservoirs) on a wide range of spatial and temporal scales. Over the 20th century, tide gauge records indicate a rise in global sea level between 1.6 mm/yr and 1.8 mm/yr. Since 1993, sea level variations have been measured precisely by satellite altimetry. They indicate a faster sea level rise of 3.3 mm/yr over 1993-2015. Owing to their global coverage, they also reveal a strong regional sea level variability that sometimes is several times greater than the global mean sea level rise. Considering the highly negative impact of sea level rise for society, monitoring sea level change and understanding its causes are henceforth high priorities.In this thesis, we first validate the sea level variations measured by the new satellite altimetry mission, SARAL-AltiKa by comparing the measurements with Jason-2 and tide gauge records. We then attempt to close the global mean sea level budget since 2003 and estimate the deep ocean contribution by making use of observational data from satellite altimetry, Argo profiles and GRACE mission. We show that uncertainties due to data processing approaches and systematic errors of different observing systems still prevent us from obtaining accurate results. In the second part of the thesis, by making use of past sea level reconstruction, we study the patterns of the regional sea level variability and estimate climate related (global mean plus regional component) sea level change over 1950-2009 at three vulnerable regions: Indian Ocean, South China and Caribbean Sea. For the sites where vertical crustal motion monitoring is available, we compute the total relative sea level (i.e. total sea level rise plus the local vertical crustal motion) since 1950. On comparing the results from these three regions with already existing results in tropical Pacific, we find that tropical Pacific displays the highest magnitude of sea level variations.In the last part of the thesis, we therefore focus on the tropical Pacific and analyze the respective roles of ocean dynamic processes, internal climate modes and external anthropogenic forcing on tropical Pacific sea level spatial trend patterns since 1993. Building up on the relationship between thermocline and sea level in the tropical region, we show that most of the observed sea level spatial trend pattern in the tropical Pacific can be explained by the wind driven vertical thermocline movement. By performing detection and attribution study on sea level spatial trend patterns in the tropical Pacific and attempting to eliminate signal corresponding to the main internal climate mode, we further show that the remaining residual sea level trend pattern does not correspond to externally forced anthropogenic sea level signal. In addition, we also suggest that satellite altimetry measurement may not still be accurate enough to detect the anthropogenic signal in the 20-year tropical Pacific sea level trends.Le niveau de la mer est une des variables climatiques essentielles dont la variabilité résulte de nombreuses interactions complexes entre toutes les composantes du système climatique sur une large gamme d'échelles spatiales et temporelles. Au cours du XXème siècle, les mesures marégraphiques ont permis d’estimer la hausse du niveau de la mer global entre 1,6 mm/an et 1,8 mm/an. Depuis 1993, les observations faites par les satellites altimétriques indiquent une hausse du niveau de la mer plus rapide de 3,3 mm/an. Grâce à leur couverture quasi-globale, elles révèlent aussi une forte variabilité du niveau de la mer à l’échelle régionale, parfois plusieurs fois supérieure à la moyenne globale du niveau de la mer. Compte tenu de l'impact très négatif de l’augmentation du niveau de la mer pour la société, sa surveillance, la compréhension de ses causes ainsi que sa prévision sont désormais considérées comme des priorités scientifiques et sociétales majeures.Dans cette thèse, nous validons d’abord les variations du niveau de la mer mesurées par la nouvelle mission d'altimétrie satellitaire, SARAL-AltiKa, en comparant les mesures avec celles de Jason-2 et des marégraphes. Un autre volet de cette première partie de thèse a consisté à estimer les parts respectives des facteurs responsables des variations du niveau de la mer depuis 2003 en utilisant des observations issues de l'altimétrie satellitaire (missions altimétrique Jason-1, Jason-2 et Envisat), de la mission GRACE, et des profils de température et salinité de l’océan par les flotteurs Argo. Une attention particulière est portée à la contribution de l’océan profond non ‘vue’ par Argo. Nous montrons que les incertitudes dues aux approches du traitement des données et aux erreurs systématiques des différents systèmes d'observation nous empêchent encore d'obtenir des résultats précis sur cette contribution.Dans la deuxième partie de la thèse, en utilisant les données de reconstruction du niveau de la mer dans le passé, nous étudions la variabilité régionale du niveau de la mer et estimons sa hausse totale (composante régionale plus moyenne globale) de 1950 à 2009 dans trois régions vulnérables : l’océan Indien, la mer de Chine méridionale et la mer des Caraïbes. Pour les sites où l’on dispose de mesures du mouvement de la croûte terrestre par GPS, nous évaluons la hausse locale du niveau de la mer relatif (hausse du niveau de la mer totale plus mouvement de la croûte locale) depuis 1950. En comparant les résultats de ces trois régions avec une étude précédente sur le Pacifique tropical, nous constatons que le Pacifique tropical présente la plus forte amplitude des variations du niveau de la mer sur la période d’étude.Dans la dernière partie de la thèse, nous nous concentrons par conséquent sur le Pacifique tropical. Nous analysons les rôles respectifs de la dynamique océanique, des modes de variabilité interne du climat et du forçage anthropique sur les structures de la variabilité régionale du niveau de la mer du Pacifique tropical depuis 1993. Nous montrons qu’une partie importante de la variabilité régionale du niveau de la mer du Pacifique tropical peut être expliquée par le mouvement vertical de la thermocline en réponse à l’action du vent. En tentant de séparer le signal correspondant au mode de variabilité interne du climat de celui de la hausse régionale du niveau de la mer dans le Pacifique tropical, nous montrons également que le signal résiduel restant (c’est-à-dire le signal total moins le signal de variabilité interne) ne correspond probablement pas à l’empreinte externe du forçage anthropique
A QTAIM approach on poly tetrahydrothiophene molecular wire
The present investigation of structural, charge density and electrical characteristics of Au and thiol substituted poly tetrahydrothiophene molecular wire by using quantum chemical calculations has been carried out with density functional theory (DFT). The various applied electric field (0.00 – 0.26 VÅ-1) altered the geometrical parameters and the corresponding electrostatic and transport properties of the molecule has been analyzed. Interstingly, the applied electric field is increased from 0 eV, the Au−S bond distance at the right terminal is faintly longer than the left end; this variation is resulted from the gold atom at the left end which practices stronger electric field when compared with at the right end of TET molecule. The variations in the atomic charges (MPA, NPA) of the molecule for the various applied electric fields have been compared. The HOMO-LUMO gap of the molecule for zero bias is 1.96eV, as the field increases this gap decrease to 1.31 eV. The ESP shows the potential difference between charges accumulated of the molecule for various applied electric field. The applied electric field polarizes the DCC molecule; as a result the dipole moment of the molecule rises from 2.47 to 15.33 D
Impairment of chloroplast development and sink strength by blockade of light in chloroembryos of Cyamopsis Tetragonoloba (L.) Taub.
In many members of Fabaceae synthesis of chloroplast pigments
takes place even when the embryo is deep inside the
fruit. Blockade of light totally etiolated the embryos of
developing Cyamopsis fruits upto 16-18 days after anthesis
(DAA), whereas the pigments of the mature embryos, when
shaded, were not significantly affected. Upon illuminatio
resynthesis of green pigments by etiolated embryos occurred
both l n v i v o and in vitro more significantly during the
early stages of growth of the embryos (upto 18 DAA). Shading
of developing fruits at different growth stages of embryos,
reduced the growth of sink. The results are discussed in
relation to the importance of light on embryo greening and
dry matter production
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