Papers by Pritam Choudhary
Technoeconomics of large-scale clean hydrogen production – A review
International Journal of Hydrogen Energy
Estimation of Glucose and Galactose Content in a Natural Polysaccharide Isolated from Tubers of Colocasia Esculenta using a Validated RP-HPLC Method
Current Materials Science, 2022
Background: Nowadays, natural polysaccharides are preferred over synthetic polymers because they ... more Background: Nowadays, natural polysaccharides are preferred over synthetic polymers because they are biocompatible, cheap, and easily available than synthetic ones. The polysaccharide obtained from the tuber of the Colocasia esculenta was reported to exhibit many pharmaceutical applications as an excipient. Objective: The application of any polymer in formulating various dosage forms depends upon its qualitative and quantitative chemical composition. Therefore, in the current research work, the quantitative composition of the polysaccharide isolated from Colocasia esculenta was determined by the validated HPLC method. Methods: RP-HPLC analysis was performed on an Agilent, Zorbax Eclipse XDB C8 column (250 mm × 4.6 mm, 5 μm) with the mobile phase consisting of citrate buffer of pH 5.5: Tetrahydrofuran: Acetonitrile (87.1:11.9:1 v/v) at a flow rate of 0.6 mL/min. UV detection was performed at 307 nm. The method was validated for various parameters as per ICH guidelines. Results: The c...
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium... more Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Due to advances in drug delivery technology, currently, excipients are included in novel dosage forms to fulfil specific functions and in some cases they directly or indirectly influence the extent and/or rate of drug release and drug absorption. Recent trends towards use of plant based and natural products demand the replacement of synthetic additives with natural ones. Today, the whole world is increasingly interested in natural drugs and excipients. These natural materials have many advantages over synthetic ones as they are chemically inert, nontoxic, less expensive, biodegradable, and widely available.This review discusses majority of the plant-derived polymeric compounds (gums and mucilage’s), their sources, chemical constituents, uses, and some recent investigations as excipients in novel drug delivery systems. 1.
Nuclear Hydrogen Production by Thermochemical Cycles
How embryology knowledge can help radiologists in the differential diagnosis of canal of Nuck pathologies
La radiologia medica, 2021
The Canal of Nuck (CN) is an anatomical structure which is often forgotten. It is the female equi... more The Canal of Nuck (CN) is an anatomical structure which is often forgotten. It is the female equivalent of the male processus vaginalis and corresponds to a protrusion of parietal peritoneum that extends from the inguinal canal to labia majora. Radiologists rarely encounter patients with pathology of CN, especially in adult population. It is well known that CN diseases can occur in paediatric patient (especially younger than 5 years of age) and they are associated to high morbidity (for example ovarian hernia with high risk of incarceration and torsion). The aim of our work is to review embryology, anatomy and pathologies of the CN thanks to a multi modal approach—ultrasound (US), Computed Tomography (CT) and Magnetic Resonance imaging (MRI)—to make radiologists more aware of such conditions and guarantee a prompt and correct diagnosis not only in paediatric patients but also in the adult population.
Advances in Recycling & Waste Management, 2018
Turmeric (Curcuma longa L. Family: Zingiberaceae) is a widely cultivated spice in India and other... more Turmeric (Curcuma longa L. Family: Zingiberaceae) is a widely cultivated spice in India and other Asian countries. Curcumin is the main coloring substance in Curcuma longa and two related compounds, demethoxycurcumin and bisdemethoxycurcumin are altogether known as curcuminoids. Turmeric is rich in curcuminoids, and recognized for their broad spectrum of biological activities. During isolation and purification of curcuminoids from oleo resin, the volatile oil present turmeric solubilizes curcumin creating problem in recrystallization process. To eliminate the interference of volatile oil and resolve the problem recrystallization, the present research work was undertaken. Various organic solvents and their combinations were tried for selective recrystallization of curcuminoids. Mixture of hot isopropyl alcohol: hexane (1:1.5) was found to be the best recrystallization solvent for purification of curcuminoids. The identity of curcuminoids was further confirmed by thin layer chromatography (TLC) and Fourier Transform Infra-Red spectroscopy (FTIR). The total curcumin content of crude curcuminoid powder was found to be 76.82% W/W whereas in recrystallized powder the purity was increased to 99.45% W/W.
International Journal of Biological Macromolecules, 2018
The objective of the present work was to isolate and characterize polysaccharide from fruits of C... more The objective of the present work was to isolate and characterize polysaccharide from fruits of Cordia dichotoma G. forst. (Family Boragenaceae). Polysaccharide was isolated by using 1% Hydrochloric acid solution. The isolated polysaccharide was tested for physicochemical characteristics such as solubility, pH (1% w/w in water), swelling capacity, loss on drying, ash value, bulk and tapped density, Carr's capacity, Hausner's ratio and angle of repose. Also isolated polysaccharide was characterized by Differential scanning colorimeter (DSC), Estimation of total sugar content, Rheological study and infrared spectroscopy (FT-IR). The isolated mucilage showed positive results for Molisch's test and negative for Ruthenium red test which indicated presence of carbohydrate and gum. The result of physicochemical characteristics reveals that isolated Cordia dichotoma polysaccharide possesses good flow properties. The total polysaccharide content of Cordia dichotoma polymer isolate was found to be 86.24% (w/w). From this study it can be concluded that the polysaccharide isolated from Cordia dichotoma fruits has the required properties and could be used as an excipient for pharmaceutical dosage forms.
The Proceedings of the International Conference on Nuclear Engineering (ICONE), 2011
SuperCritical Water-cooled Reactors (SCWRs) are one of the six nuclear reactor concepts being dev... more SuperCritical Water-cooled Reactors (SCWRs) are one of the six nuclear reactor concepts being developed in the Generation-IV International forum (GIF). The development of SCWRs will increase the thermal efficiency of Nuclear Power Plants (NPPs) to 45-50% as opposed to approximately 30-34% efficiency of the current NPPs. This increase in efficiency is a result of operating at high temperatures of 350⁰C-625⁰C and a pressure of 25 MPa. The current fuel bundle proposed for use in pressure-channel SCWR concepts is the Varient-20 bundle containing 43elements. Studies have shown that when the 43-element fuel bundle was examined, the fuel centerline temprature might exceed the industry accepted limit of 1850°C for the UO 2 fuel. The objective of this paper is to examine the use of a higher thermal conductivity fuel such as UO 2 +SiC in the variant-20 (43-element) , and the newly developed 54-and 64-element bundles. Four different Axial Heat Flux Profiles (AHFPs) are examined for the 43-, 54-and the 64-element bundles. Results of this analysis indicate that the use of UO 2 +SiC fuel in the proposed fuel bundles show a significant decrease in the fuel centerline temperature compared to the conventional 43-element bundle design using UO 2 fuel.
The Proceedings of the International Conference on Nuclear Engineering (ICONE), 2011
The development of SuperCritical Water-cooled Reactors (SCWRs) is currently undertaken worldwide ... more The development of SuperCritical Water-cooled Reactors (SCWRs) is currently undertaken worldwide as part of the Generation-IV International Forum (GIF) initiative. SCWRs will operate at high operating temperatures and pressures: outlet temperatures up to 625°C and pressures of 25 MPa. Since the development of SCWRs is in the conceptual-design stage, there are still various design issues that need to be addressed. The fuel-bundle configuration is not yet finalized; however, bundles with larger number of elements coupled with smaller element outside diameters seem to be preferred for use in SCWRs due to high fuel centerline temperatures. The most recent bundle designs for pressure channel SCWRs consists of 54 and 64 elements in total. The 54-element bundle has 53 heated fuelled elements (9.5-mm OD), and the 64-element bundle has 63 heated fuelled elements (9.13-mm OD). Both bundle designs have one unheated central element (20-mm OD). These new fuel bundles with Thoria fuel were analyzed. Thoria nuclear fuel, also known as Thorium dioxide (ThO 2), is currently considered as the primary choice in some SCWRs. The objective of this study is to examine the possibility of using Thoria as the nuclear fuel in SCWRs. Also, Thoria possesses a slightly higher thermal conductivity compared to that of Uranium dioxide (UO 2), which may help to decrease the fuel centerline temperature. Additionally, thorium is widely distributed in nature and is approximately three times as abundant as Uranium.
The Proceedings of the International Conference on Nuclear Engineering (ICONE), 2011
The objective of this paper is to design a new fuel bundle for use in a generic pressure-channel ... more The objective of this paper is to design a new fuel bundle for use in a generic pressure-channel SCWR, so that the fuel channel materials, i.e. sheath and fuel, will operate below accepted temperature limits. This was achieved by modifying the flow geometry of a 43-element fuel bundle by increasing the number of fuel elements and decreasing their outer diameter. Throughout this paper, the use of uranium mononitride as a possible fuel will be compared to that of uranium dioxide. Two fuel bundle designs will be compared
The Proceedings of the International Conference on Nuclear Engineering (ICONE), 2011
The objective of this paper is to investigate a possibility of using Uranium Carbide (UC) as a nu... more The objective of this paper is to investigate a possibility of using Uranium Carbide (UC) as a nuclear fuel in the newly developed 54 and 64-element fuel bundles with smaller outer diameter pins (8.5 mm and 9.1 mm, respectively), at supercritical conditions of a generic SuperCritical Watercooled Reactor (SCWR). Uranium Carbide has been used in numerous applications such as fuel in pebble bed reactors. The focus of this paper is to calculate the fuel centerline and cladding temperature profiles in order to ensure that the new fuel-bundle design complies with the industry accepted limits of 1850°C for the fuel centerline temperature and the design limit of 850°C for the cladding temperature.
Medicinal & Aromatic Plants, 2015
The objective of the present study was to evaluate Sunth powder (Dry ginger rhizome powder) and s... more The objective of the present study was to evaluate Sunth powder (Dry ginger rhizome powder) and set standard to decide its purity.
Environmental Entomology, 1998
Little is known about the extent to which traits that can affect the laboratory and field perform... more Little is known about the extent to which traits that can affect the laboratory and field performance of parasitoids as biological control agents are under genetic control. This is patticularly tnle of parasitoids showing potential against the gypsy moth, Lynwntria dispar (L.), the most damaging defoliator of deciduous trees in North America. This study examines the effects of genetic variability on the development times and size of the gypsy moth larval parasitoid Cotesia melanoscela (Ratzburg) (Hymenoptera: Braconidae). Heritability indices of size parameters were higher than those for development times. Implications for laboratory rearing and biological control are discussed.
Current Drug Therapy, 2016
Background: Colocasia esculenta is a fast growing plant and is cultivated for consumption of leaf... more Background: Colocasia esculenta is a fast growing plant and is cultivated for consumption of leaf and tuber. Polysaccharide obtained from the tubers of Colocasia esculenta is known as Taro polymer. Chemically it is neutral heteropolysaccharide of galactose, galactose and arabinose. Objective: The present research work was aimed at the development and characterization of orally disintegrating tablet of Valsartan using natural disintegrant to produce rapid onset of action and patient compliance. Method: Polysaccharide from Colocasia esculenta tubers was isolated using solvent precipitation method. The isolated polysaccharide was investigated as disintegrant in orally disintegrating tablets. Valsartan, an antihypertensive drug, was selected as a model drug. The drug excipient interactions were characterized by FTIR studies. The tablets of Valsartan were prepared separately using different concentrations [2.5, 5, 7.5 and 10 % w/w] of isolated Colocasia esculenta polysaccharide and Kollidon ® , Ac-Di-Sol ® as synthetic superdisintegrants by using direct compression method. The tablets thus prepared were evaluated for various pre-compression and post-compression parameters. The disintegration time and in vitro drug release of the optimized formulation was compared with the available marketed formulation. The stability studies were performed on the optimised batch F12. Results: The formulation F12 containing 10 % of polysaccharide showed rapid wetting time and disintegration time and is comparable to formulations prepared using synthetic superdisintegrants at the same concentration level. Conclusion: Colocasia esculenta polysaccharide can be used as a disintegrant in the formulation of orally disintegrating tablets. Its disintegrating property was found to be comparable with that of the commercially available superdisintegrants.
Biology and Medicine, 2014
Any pharmaceutical formulation contains two ingredients one is the active ingredient and other is... more Any pharmaceutical formulation contains two ingredients one is the active ingredient and other is an excipients. An excipient helps in the manufacturing of dosage form and it also improves physicochemical parameters of the dosage form. Polymers play an important role as excipients in pharmaceutical dosage form. They influence drug release and should be compatible, non-toxic, stable, economic etc. Biopolymers, synthetic polymers and their derivatives are commonly used in medicine and pharmacy. They are broadly classified as natural polymers and synthetic polymers. Nowadays, due to many problems associated with drug release and side effects manufacturers are inclined towards using natural polymers and their derivatives. Natural polymers are basically polysaccharides so they are biocompatible and without any side effects. This review article aims at discussing various sources, pharmaceutical applications and the different techniques used for modification of natural polymers. Figure 1: Structure of monomers and polymers. B io lo g y and M e d ic in e
Chemically Reacting and Particle-Laden Multiphase Flow in an Molten Salt Vessel
10th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, 2010
ABSTRACT
The Coupling of Nuclear Heat and Hydrogen Production Thermochemical Cycles
Volume 2: Structural Integrity; Safety and Security; Advanced Applications of Nuclear Technology; Balance of Plant for Nuclear Applications, 2009
The technology to use nuclear heat to thermally split water into hydrogen and oxygen attracts mor... more The technology to use nuclear heat to thermally split water into hydrogen and oxygen attracts more and more attentions at present. This paper discusses some challenges to couple nuclear heat with thermochemical hydrogen production cycles. The challenges include matching the maximum heat grade of thermal chemical cycles and nuclear reactors, and extracting heat from nuclear reactors. Sulfur-iodine and copper-chlorine cycles are taken as typical examples for analysis and discussion. The heat grade and quantity required by each step of the cycles are discussed. The maximum heat grade of sulfur-iodine cycle is higher than 800°C which cannot be easily coupled by GenIV nuclear reactor and other sources of heat must be provided. In comparison, the maximum heat grade of copper-chlorine cycle is 530°C which can be coupled by more nuclear reactors such as advance Gen-III and future Gen-IV nuclear reactor. It is concluded that thermochemical cycles with lower temperature requirement are easier...
Journal of Pharmaceutics, 2014
Due to advances in drug delivery technology, currently, excipients are included in novel dosage f... more Due to advances in drug delivery technology, currently, excipients are included in novel dosage forms to fulfil specific functions and in some cases they directly or indirectly influence the extent and/or rate of drug release and drug absorption. Recent trends towards use of plant based and natural products demand the replacement of synthetic additives with natural ones. Today, the whole world is increasingly interested in natural drugs and excipients. These natural materials have many advantages over synthetic ones as they are chemically inert, nontoxic, less expensive, biodegradable, and widely available. This review discusses majority of the plant-derived polymeric compounds (gums and mucilage’s), their sources, chemical constituents, uses, and some recent investigations as excipients in novel drug delivery systems.
International Journal of Hydrogen Energy, 2008
Hydrogen as a clean energy carrier is frequently identified as a major solution to the environmen... more Hydrogen as a clean energy carrier is frequently identified as a major solution to the environmental problem of greenhouse gases, resulting from worldwide dependence on fossil fuels. However, most of the world's hydrogen (about 96%) is currently produced from fossil fuels, which does not address the issue of greenhouse gases. Although there is a large motivation of the ''hydrogen economy'', for improvement of urban air quality, energy security, and integration of intermittent renewable energy sources, CO 2 free energy sources are critical to hydrogen becoming a significant energy carrier. Two technologies, applied in tandem, have a promising potential to generate hydrogen without leading to greenhouse gas emissions: 1) electrolysis and 2) thermochemical decomposition of water. This paper will investigate their unique complementary roles to reduce costs of hydrogen production. Together they have a unique potential to serve both decentralized hydrogen needs in periods of low-demand electricity, and centralized base-load production from a nuclear station. Thermochemical methods have a significantly higher thermal efficiency, but electrolysis can take advantage of low electricity prices during off-peak hours, as well as intermittent and decentralized supplies like wind, solar or tidal power. By effectively linking these systems, water-based production of hydrogen can become more competitive against the predominant existing technology, SMR (steam-methane reforming).
International Journal of Hydrogen Energy, 2010
This paper examines cupric chloride solid conversion during hydrolysis in the thermochemical copp... more This paper examines cupric chloride solid conversion during hydrolysis in the thermochemical copper-chlorine (Cu-Cl) cycle of hydrogen production. The hydrolysis reaction is a challenging step, due to the excess steam requirement and decomposition of cupric chloride (CuCl 2) into cuprous chloride (CuCl) and chlorine (Cl 2). In this paper, the hydrolysis and decomposition reactions are analyzed with respect to chemical equilibrium conversion and the reaction kinetics. The effects of operating parameters are examined, including the temperature, pressure and excess steam, on equilibrium conversion. It is shown that the reaction kinetics expression that represents a reversible reaction reflects the equilibrium limitation on the solid conversion, rather than first-order kinetics.
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Papers by Pritam Choudhary