108 results on '"R. Roshan"'
Search Results
2. Deformation Behavior of Hydrogenated Palladium-Based Membrane Alloy
- Author
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O. V. Akimova, R. D. Svetogorov, S. V. Gorbunov, and N. R. Roshan
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General Physics and Astronomy - Published
- 2022
3. Effect of Doping Elements on Magnetic Properties of Palladium-Based Membrane Alloys
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O. V. Akimova, Yu. A. Ovchenkova, R. D. Svetogorov, and N. R. Roshan
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General Physics and Astronomy - Published
- 2022
4. Hydrothermally synthesized strontium-modified ZnO hierarchical nanostructured photocatalyst for second-generation fluoroquinolone degradation
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R. Roshan Chandrapal, S. Bharathkumar, G. Bakiyaraj, V. Ganesh, J. Archana, and M. Navaneethan
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Materials Science (miscellaneous) ,Cell Biology ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Atomic and Molecular Physics, and Optics ,Biotechnology - Published
- 2022
5. Sunlight assisted photocatalytic decomposition of protonated-g-C3N4/LaCoO3 nanocomposites for environmental remediation
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K. Sathiyamoorthy, S. Bharathkumar, R. Roshan Chandrapal, S. Harish, and M. Navaneethan
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Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2022
6. Intranasal Carbetocin Reduces Hyperphagia, Anxiousness, and Distress in Prader-Willi Syndrome: CARE-PWS Phase 3 Trial
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Elizabeth Roof, Cheri L Deal, Shawn E McCandless, Ronald L Cowan, Jennifer L Miller, Jill K Hamilton, Elizabeth R Roeder, Shana E McCormack, Tamanna R Roshan Lal, Hussein D Abdul-Latif, Andrea M Haqq, Kathryn S Obrynba, Laura C Torchen, Alaina P Vidmar, David H Viskochil, Jean-Pierre Chanoine, Carol K L Lam, Melinda J Pierce, Laurel L Williams, Lynne M Bird, Merlin G Butler, Diane E Jensen, Susan E Myers, Oliver J Oatman, Charumathi Baskaran, Laura J Chalmers, Cary Fu, Nathalie Alos, Scott D McLean, Ajay Shah, Barbara Y Whitman, Brent A Blumenstein, Sarah F Leonard, Jessica P Ernest, Joseph W Cormier, Sara P Cotter, and Davis C Ryman
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Endocrinology ,Endocrinology, Diabetes and Metabolism ,Biochemistry (medical) ,Clinical Biochemistry ,Biochemistry - Abstract
Context Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by endocrine and neuropsychiatric problems including hyperphagia, anxiousness, and distress. Intranasal carbetocin, an oxytocin analog, was investigated as a selective oxytocin replacement therapy. Objective To evaluate safety and efficacy of intranasal carbetocin in PWS. Design Randomized, double-blind, placebo-controlled phase 3 trial with long-term follow-up. Setting Twenty-four ambulatory clinics at academic medical centers. Participants A total of 130 participants with PWS aged 7 to 18 years. Interventions Participants were randomized to 9.6 mg/dose carbetocin, 3.2 mg/dose carbetocin, or placebo 3 times daily during an 8-week placebo-controlled period (PCP). During a subsequent 56-week long-term follow-up period, placebo participants were randomly assigned to 9.6 mg or 3.2 mg carbetocin, with carbetocin participants continuing at their previous dose. Main outcome measures Primary endpoints assessed change in hyperphagia (Hyperphagia Questionnaire for Clinical Trials [HQ-CT]) and obsessive-compulsive symptoms (Children's Yale-Brown Obsessive-Compulsive Scale [CY-BOCS]) during the PCP for 9.6 mg vs placebo, and the first secondary endpoints assessed these same outcomes for 3.2 mg vs placebo. Additional secondary endpoints included assessments of anxiousness and distress behaviors (PWS Anxiousness and Distress Behaviors Questionnaire [PADQ]) and clinical global impression of change (CGI-C). Results Because of onset of the COVID-19 pandemic, enrollment was stopped prematurely. The primary endpoints showed numeric improvements in both HQ-CT and CY-BOCS which were not statistically significant; however, the 3.2-mg arm showed nominally significant improvements in HQ-CT, PADQ, and CGI-C scores vs placebo. Improvements were sustained in the long-term follow-up period. The most common adverse event during the PCP was mild to moderate flushing. Conclusions Carbetocin was well tolerated, and the 3.2-mg dose was associated with clinically meaningful improvements in hyperphagia and anxiousness and distress behaviors in participants with PWS. Clinical Trials Registration Number NCT03649477
- Published
- 2023
7. Structure, Texture, and Substructure of Foil in Sequential Rolling Steps of Cu–36.4 at % Pd Alloy
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S. V. Gorbunov, T. N. Il’inova, V. M. Ievlev, Konstantin Solntsev, A. I. Dontsov, S. V. Kannykin, N. R. Roshan, and A. S. Prizhimov
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Inorganic Chemistry ,Materials science ,General Chemical Engineering ,Alloy ,Materials Chemistry ,Metals and Alloys ,engineering ,Substructure ,Texture (crystalline) ,engineering.material ,Composite material ,FOIL method - Published
- 2021
8. The Structure Stability of Metal Diffusion Membrane-Filters in the Processes of Hydrogen Absorption/Desorption
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Olga V. Akimova, Roman D. Svetogorov, Alexey V. Ovcharov, and Nataliya R. Roshan
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Process Chemistry and Technology ,Chemical Engineering (miscellaneous) ,Filtration and Separation ,X-ray diffraction ,palladium—lead membrane alloys ,SEM-EDXS analysis ,hydrogen - Abstract
The evolution of a nanostructured state of palladium—lead membrane alloys during their interaction with hydrogen was studied using precision X-ray diffraction with synchrotron radiation (SR) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDXS). The importance of this topic is due to the need and demand for improving the performance characteristics of dense metal diffusion filters for high purity hydrogen separation processes. Palladium-based membrane filters with lead concentrations of 5 and 20 wt.% were prepared via electric arc melting from high purity metals (99.95%). The thickness of the filters was 50 μm. Hydrogenation was carried out from a gas medium at 573 K and the pressure of 16 atm. within 150 min. The focus of the study is on the structural state of diffusion filter membranes depending on the content of the palladium-alloying element—lead—and on analysis of the substructure of alloys before and 5300 h relaxation after hydrogenation is carried out. Specific features of the surface morphology and the structure of the membrane filters depending on the concentration of lead in the alloys are determined. The formation and development of deformation processes in metal systems upon the hydrogenation is shown. The establishment of peculiarities of hydrogen interaction with metals will contribute to obtaining new potentially important characteristics of membrane filters.
- Published
- 2022
9. Reassessment of Power Losses and Enhancement of Techno-Economic Feasibility in a Radial Distribution System
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R Roshan, B S Ravishankar, N Mohan, K J Sandeep Kumar, and Dayakar G Devaru
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- 2022
10. Photocatalytic waste-to-renewable energy nexus using solar light induced quantum dots
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R. Roshan, B.K. Nahak, D. Mahata, P. Yadav, S. Panda, Santanu Patra, S.S. Mahato, Ashutosh Tiwari, and S. Mahata
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Fuel Technology ,Nuclear Energy and Engineering ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology - Published
- 2023
11. Demonstration of Smart Waste Segregation and Utilization System for Smart City
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G. B. Praveen G. B. Praveen, Puneeth Puneeth, Roshan R Roshan R, Shree rakshitha S Shree rakshitha S, and Nischitha P Nischitha P
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General Medicine - Abstract
The world faces major environmental challenges associated with waste generation and waste collection , transport, treatment and disposal, by increase in population, volume of waste generation is also increased, this impacts on the environment and public health. Even the private areas which are clean enough failed to utilize the resources efficiently. This waste management system includes segregation of waste into different parts at the local area itself and which are further used as raw material for different process such as power generation, recycling etc. Also it creates clean, hygienic and advanced waste damping area. The generated power can be utilized for domestic and commercial purpose.
- Published
- 2021
12. Operational Stability of the Pd–6 wt % In–0.5 wt % Ru–1 wt % Co Membrane during Its Cyclic Operation in Manufacturing High-Purity Hydrogen
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N. R. Roshan, V. S. Kas’yanov, Kairat Kuterbekov, G. S. Burkhanov, K. Zh. Bekmyrza, S. V. Gorbunov, and G. T. Merzadinova
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Hydrogen atmosphere ,Membrane ,Materials science ,Chemical engineering ,Hydrogen ,chemistry ,Atomic force microscopy ,Permeability (electromagnetism) ,Metals and Alloys ,Membrane structure ,chemistry.chemical_element ,Atmospheric temperature range ,Operational stability - Abstract
The thermobaric and concentrational stresses, which arise during the operation of a membrane element under cyclic conditions, can result in the violation of the integrity of a membrane comprising an element and in failure of the element. Studies of the effect of thermobaric cycling in a hydrogen atmosphere at operating parameters (pressure differential, temperature, time of operation) on the properties of membranes allow us to determine the optimum operation conditions of the membrane element. The stability of the Pd–6 wt % In–0.5 wt % Ru–1 wt % Co membrane structure is estimated using the studied temperature dependence of the specific hydrogen permeability of the membrane during its operation in a hydrogen atmosphere, and the possibility of efficient operation of the membrane under given conditions in a temperature range of 250–600°C is noted. The surface of the Pd–6 wt % In–0.5 wt % Ru–1 wt % Co membrane subjected to thermobaric cycling in a commercial-purity hydrogen atmosphere is studied by atomic force microscopy and X‑ray diffraction analysis.
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- 2021
13. Synergetic effect of 2D/2D Co-SnS2 with reduced graphene oxide heterostructure for Pt-free counter electrode
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J. Raveena, R. Roshan Chandrapal, G. Bakiyaraj, V.S. Manikandan, S. Athitya, J. Archana, and M. Navaneethan
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Mechanics of Materials ,Materials Chemistry ,General Materials Science - Published
- 2023
14. Pediatric medical genetics house call: Telemedicine for the next generation of patients and providers
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Natasha Shur, Andrea J. Cohen, Tamanna R. Roshan Lal, Erin MacLeod, Eyby Leon, Danielle Starin, and Debra S Regier
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0301 basic medicine ,medicine.medical_specialty ,Telemedicine ,Genetics, Medical ,Health Personnel ,media_common.quotation_subject ,Education environment ,Telehealth ,030105 genetics & heredity ,03 medical and health sciences ,Genetics ,medicine ,House call ,Humans ,Genetics(clinical) ,Quality (business) ,Child ,Set (psychology) ,Pandemics ,Genetics (clinical) ,Quality of Health Care ,media_common ,Medical education ,Education, Medical ,SARS-CoV-2 ,Pilot programs ,COVID-19 ,Hospitals, Pediatric ,Quality Improvement ,House Calls ,030104 developmental biology ,Medical genetics ,Patient Care ,Psychology - Abstract
In an era of increasing technology and interaction with the patient bedside, we explore the role of relocating the bedside from the hospital to the home using telemedicine. The COVID-19 pandemic pushed telemedicine from small and pilot programs to widespread practice at an unprecedented rate. With the rapid implementation of telemedicine, it is important to consider how to create a telehealth system that provides both good care for patients and families while maintaining an excellent education environment for trainees of all levels. To this end, we developed telemedicine educational milestones to describe novel skills required to provide high quality telemedicine care, and allow trainees and clinical educators a metric by which to assess trainee progress. We also created methods and tools to help trainees learn and families feel comfortable in their new role as virtual collaborators. We envision a time when safety does not set the venue; instead the needs of the patient will dictate whether a virtual or in-person visit is the right choice for a family. We expect that pediatric medical genetics and metabolism groups across the country will continue to set a standard of a hybrid care system to meet the unique needs of each individual patient, using telemedicine technology.
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- 2021
15. Membrane Pd–7.70 wt % Lu Alloy for the Preparation and Purification of Hydrogen
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S. V. Gorbunov, N. R. Roshan, Nikolay A. Dormidontov, A. S. Bakulina, D. A. Rusinov, T. P. Kaminskaya, G. S. Burkhanov, and Natalia B. Kolchugina
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010302 applied physics ,Materials science ,Hydrogen ,Diffusion ,Alloy ,chemistry.chemical_element ,Atmospheric temperature range ,engineering.material ,Condensed Matter Physics ,01 natural sciences ,Metal ,Membrane ,chemistry ,Chemical engineering ,visual_art ,0103 physical sciences ,Materials Chemistry ,engineering ,visual_art.visual_art_medium ,010306 general physics ,FOIL method ,Palladium - Abstract
The purity of hydrogen, which is an alternative energy carrier in powder sources of distributed energy resource systems and, in particular, is the feed stock for fuel cells, should be no less than 99.9999 vol % purity High-purity hydrogen can be prepared only via its separation as a result of selective diffusion through metallic membranes manufactured from specific membrane palladium-based alloys prepared in the form of thin foils. In the present work, the combination of deformation and annealings under different conditions is used to prepare the Pd–7.70 wt % Lu alloy in the form of foil 50 µm thick, whose specific hydrogen permeability is studied in the course of cyclic heating and cooling in a hydrogen atmosphere in a temperature range of 300–500°С. The Pd–7.70 wt % Lu membrane is shown to demonstrate high and stable hydrogen permeability. The evolution of the surface structure of the membrane in the course of its operation in the hydrogen atmosphere is studied by atomic force microscopy using the phase contrast mode.
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- 2021
16. Thermal Expansion Coefficient of a Pd–Cu Solid Solution
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S. V. Gorbunov, V. M. Ievlev, Konstantin Solntsev, S. V. Kannykin, N. R. Roshan, A. S. Prizhimov, and A. I. Dontsov
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010302 applied physics ,Diffraction ,Materials science ,General Chemical Engineering ,Metals and Alloys ,Thermodynamics ,02 engineering and technology ,Composition (combinatorics) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Thermal expansion ,Inorganic Chemistry ,Lattice constant ,Phase composition ,0103 physical sciences ,Materials Chemistry ,0210 nano-technology ,FOIL method ,Solid solution - Abstract
X-ray diffraction has been used to study the phase composition and determine the lattice parameter of the β- and α-phases in foil of a Pd–Cu solid solution with a composition that ensures reversibility of the β $$ \rightleftarrows $$ α transformations: with the structure of the β- and α-phases and a two-phase structure. The thermal expansion coefficient of the Pd–Cu solid solution has been determined for the first time.
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- 2020
17. Methanol Steam Reforming in a Reactor with a Palladium–Copper Membrane in the Presence of a Nickel–Copper Catalyst
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A. A. Lytkina, M. M. Ermilova, E. Yu. Mironova, V. M. Ievlev, N. A. Zhilyaeva, A. B. Yaroslavtsev, N. V. Orekhova, and N. R. Roshan
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Materials science ,Hydrogen ,Membrane reactor ,010405 organic chemistry ,General Chemical Engineering ,technology, industry, and agriculture ,Energy Engineering and Power Technology ,chemistry.chemical_element ,General Chemistry ,Permeation ,equipment and supplies ,010402 general chemistry ,complex mixtures ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Steam reforming ,chemistry.chemical_compound ,Fuel Technology ,Membrane ,chemistry ,Chemical engineering ,Geochemistry and Petrology ,Methanol ,Palladium - Abstract
A study of methanol steam reforming (MSR) in the presence of a Ni0.2–Cu0.8/Ce0.3Zr0.7O2-δ catalyst in conventional and membrane reactors has revealed that the hydrogen yield in a reactor with a Pd–Cu membrane is higher than that in a conventional flow reactor. It has been shown that the Pd–Cu alloy membrane exhibits high hydrogen permeability. Methanol steam reforming in the membrane reactor provides the production of high-purity hydrogen, because a stream of pure hydrogen free from any impurities is effluent from the permeate zone. Measurements of the hydrogen permeability of the Pd–Cu alloy foil membrane in the membrane reactor before and after catalysis have been conducted.
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- 2020
18. Reversibility of the β ↔ α Phase Transformations as the Key Factor Determining Whether the Pd–Cu Membrane Foil Texture Depends on the Foil Preparation Process
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A. S. Prizhimov, A. I. Dontsov, V. M. Ievlev, Konstantin Solntsev, S. V. Gorbunov, N. R. Roshan, and S. V. Kannykin
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010302 applied physics ,Materials science ,General Chemical Engineering ,Metals and Alloys ,02 engineering and technology ,Sputter deposition ,021001 nanoscience & nanotechnology ,01 natural sciences ,Inorganic Chemistry ,Membrane ,Chemical engineering ,Phase composition ,Scientific method ,0103 physical sciences ,Materials Chemistry ,Texture (crystalline) ,0210 nano-technology ,FOIL method ,Solid solution - Abstract
We have studied the phase composition and texture of a Pd–Cu solid solution with a nearly equiatomic composition in different steps of the preparation of membrane foil by rolling to 300, 175, 100, and 20 μm and 7-μm-thick foil produced by magnetron sputtering of a target having the same composition as the foil. We have identified orientation relationships between the β- and α-phases in the as-prepared two-phase structures and demonstrated that, after heating to 600°C and subsequent cooling, the ordered solid solutions (β-phase) prepared by the two processes, have identical textures, which can be understood in terms of the transformation mechanism.
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- 2020
19. Strain-Induced Lattice Distortions of a Hydrogenated Palladium-Based Alloy
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G. S. Burkhanov, Alexey Veligzhanin, N. R. Roshan, S. V. Gorbunov, O. V. Akimova, and Roman Svetogorov
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Ostwald ripening ,Materials science ,Hydrogen ,Scanning electron microscope ,020502 materials ,Dispersity ,Alloy ,Metals and Alloys ,food and beverages ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,engineering.material ,symbols.namesake ,Membrane ,0205 materials engineering ,chemistry ,Chemical engineering ,symbols ,engineering ,Palladium - Abstract
The structural state of diffusive membrane filters made from a Pd94Y6 alloy, which have undergone a prolonged relaxation after hydrogenation, is studied. The phase composition and structure dispersity are determined. One of the membranes was subjected to secondary hydrogenation, and the effect of occluded hydrogen on the strain processes in the crystal lattice of the inhomogeneous material was demonstrated. High-resolution scanning electron microscopy is used to study the Ostwald ripening of the surface structure of the diffusion membrane filters after secondary hydrogenation. The fact of grain coalescence of an island structure, which can substantially affect the strength characteristics of the membranes, is found.
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- 2020
20. Techniques for Surface Cleaning of Membrane Foil from Palladium-Based Solid Solutions
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Konstantin Solntsev, N. R. Roshan, N. B. Morozova, O. V. Serbin, V. M. Ievlev, A. S. Prizhimov, and A. I. Dontsov
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010302 applied physics ,Flash-lamp ,Materials science ,General Chemical Engineering ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surface cleaning ,Inorganic Chemistry ,Membrane ,chemistry ,0103 physical sciences ,Materials Chemistry ,Surface roughness ,Composite material ,Cyclic voltammetry ,0210 nano-technology ,FOIL method ,Solid solution ,Palladium - Abstract
The effectiveness of flash lamp processing and ion beam sputtering in surface cleaning of membrane foil from a Pd–Cu solid solution produced by rolling has been assessed using cyclic voltammetry and atomic force microscopy. It has been shown that it is reasonable to use cyclic voltammetry for assessing the degree of foil surface cleaning and that combined surface processing of membrane foil is effective in foil surface cleaning. Ion beam processing reproducing the surface elemental composition corresponding to the original composition of the solid solution and increasing surface roughness is a factor of 1.3 more effective than combined surface processing.
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- 2020
21. Membranes of Palladium Alloys for Ultrapure Hydrogen Production
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N. R. Roshan, E. T. Abseitov, Kairat Kuterbekov, K. Zh. Bekmyrza, S. V. Gorbunov, E. M. Chistov, and F. R. Karelin
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010302 applied physics ,Materials science ,Hydrogen ,Hydride ,Annealing (metallurgy) ,Alloy ,General Engineering ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,01 natural sciences ,Membrane ,chemistry ,Chemical engineering ,0103 physical sciences ,engineering ,General Materials Science ,0210 nano-technology ,FOIL method ,Palladium ,Hydrogen production - Abstract
The high-grade leak-tight foils 10–20 μm in thickness were obtained from effective alloys (wt %) Pd–6 In–0.5 Ru, Pd–6 Ru, and Pd–40 Cu by using advanced technology. For the Pd–40% wt Cu alloy, the foil with ordered β phase with the CsCl structure, exhibiting maximum hydrogen permeability in the Pd–Cu system, was formed by the combination of deformation and annealing conditions. The mechanical properties and hydrogen permeability of the obtained foil membranes as compared with the foils of 50 μm in thickness and also their performance for pure hydrogen at the membranes work in the commercially pure hydrogen medium were investigated. The concentration dilatation of the foils in hydrogen was investigated at various temperatures. Data on dilatation of palladium membrane alloys are of paramount importance to design of membrane filter elements and choice of their optimal usage conditions because these data determine the operational life of membrane. The Pd–6 wt % In–0.5 wt % Ru–1.25 wt % Co alloy with improved strength characteristics and lower temperature of α ↔ β hydride transition was developed on the basis of the Pd– 6 wt % In–0.5 wt % Ru alloy.
- Published
- 2020
22. Flash Lamp Processing-Activated Structural Transformations in Foil of a Pd–Cu Solid Solution
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V. M. Ievlev, D. A. Sinetskaya, S. V. Gorbunov, N. R. Roshan, Konstantin Solntsev, O. V. Serbin, A. S. Prizhimov, and A. I. Dontsov
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010302 applied physics ,Phase transition ,Materials science ,General Chemical Engineering ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Inorganic Chemistry ,Crystallography ,Thermal conductivity ,Xenon ,chemistry ,Electrical resistivity and conductivity ,0103 physical sciences ,Materials Chemistry ,Irradiation ,0210 nano-technology ,Joule heating ,FOIL method ,Solid solution - Abstract
The β $$ \rightleftarrows $$ α phase transformations in foil of the Pd–52 at % Cu solid solution prepared by rolling have been studied using X-ray diffractometry and resistivity measurements during thermal heating–cooling cycles or lamp processing (LP) using light from high-power pulsed xenon lamps, followed by cooling. The results demonstrate that complete ordering of the two-phase (α + β) as-prepared (as-rolled) foil follows the sequence (α + β) → β → α → β in the first heating–cooling cycle and β → α → β in the second and subsequent cycles. When a radiative energy critical for a given thickness of foil with an ordered structure is delivered to the foil surface, an irreversible β → α phase transformation occurs, whose rate can be three orders of magnitude higher than the rate characteristic of the disordering process during Joule heating. After LP, the reversibility of the β $$ \rightleftarrows $$ α phase transformations, inherent in the initial, ordered structure, is observed in a second thermal cycle: heating to 700°C and cooling. The sequence of phase transitions is α → β → α → β in the first cycle and β → α → β in the second and subsequent cycles. The localization of light in the skin layer and finite thermal conductivity offer the possibility of producing a structure with a phase composition gradient at subcritical irradiation times. The fact that the LP-stabilized α-phase persists up to 300°C makes it possible to compare the mechanical properties of foil samples having identical elemental compositions but different (ordered and disordered) structures.
- Published
- 2020
23. Peculiarities of Pressure Welding of Pd Foil to Stainless Steel
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E. M. Chistov, N. R. Roshan, A. V. Liushinsky, and G. S. Burkhanov
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010302 applied physics ,Materials science ,Metallurgy ,General Engineering ,Intermetallic ,chemistry.chemical_element ,02 engineering and technology ,Welding ,Diffusion welding ,021001 nanoscience & nanotechnology ,Electric resistance welding ,01 natural sciences ,law.invention ,Nickel ,chemistry ,law ,0103 physical sciences ,General Materials Science ,0210 nano-technology ,Layer (electronics) ,Spot welding ,FOIL method - Abstract
The peculiarities of joining a palladium alloy foil to 12Cr18Ni10Ti stainless steel by diffusion and resistance welding are considered. It is shown that both technologies can be realized only using an intermediate nickel layer with a thickness of 0.1 mm, which provides uniform strength and joint tightness and also prevents the formation of brittle intermetallic compounds. Diffusion welding allows one to obtain high-quality joints of palladium alloy to stainless steel, but this process proceeds at relatively high (950°C) temperatures and takes a long time. Resistance welding does not have these disadvantages, but the outcome significantly depends on the correct choice of welding conditions, upon which the spot weld nugget must be displaced as much as possible toward the stainless steel and the intermediate nickel layer. The connection of the palladium alloy to the intermediate layer occurs owing to mutual diffusion occurring during the passage of the welding pulse.
- Published
- 2020
24. Kinetics of Hydrogen Absorption from a Gas Phase by Diffusion Filtering Pd–Y Membranes
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S. V. Gorbunov, O. V. Akimova, Roman Svetogorov, N. R. Roshan, G. S. Burkhanov, and Alexey Veligzhanin
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010302 applied physics ,Materials science ,Hydrogen ,Hydride ,Alloy ,technology, industry, and agriculture ,Membrane structure ,Analytical chemistry ,chemistry.chemical_element ,engineering.material ,equipment and supplies ,Condensed Matter Physics ,01 natural sciences ,Metal ,Condensed Matter::Materials Science ,Membrane ,chemistry ,visual_art ,0103 physical sciences ,X-ray crystallography ,Materials Chemistry ,visual_art.visual_art_medium ,engineering ,Substructure ,010306 general physics - Abstract
Diffusion filtering metallic palladium–yttrium membranes are subjected to hydrogenation from a gas phase and are studied by X-ray diffraction using synchrotron radiation. Boundaries of the formation of hydrogen-enriched phases are improved for a range of alloying component content, which is critical for their formation. The effect of the initial state of the alloy on conditions of hydride phase formation in the system is demonstrated. The content of hydrogen occluded in the membrane structure and hydrogen-induced lattice dilatations are determined. The parameters of the alloy substructure are calculated.
- Published
- 2020
25. Synthesize and exploration of wet properties of textile-grade glass fibers/hydroxybutanedioic acid treated selective banana fiber hybrid composite
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R. Roshan Roy, Lakkineni Roshith, P. Karthick, A. Abraham Eben Andrews, H.P. Mohamed Kamil, and N. Anirudh Shashang
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010302 applied physics ,Materials science ,Textile ,business.industry ,Glass fiber ,Composite number ,02 engineering and technology ,General Medicine ,Epoxy ,021001 nanoscience & nanotechnology ,01 natural sciences ,Flexural strength ,visual_art ,0103 physical sciences ,Ultimate tensile strength ,visual_art.visual_art_medium ,Fiber ,Composite material ,0210 nano-technology ,business ,Natural fiber - Abstract
The Composite materials are widely acceptable and they are indispensible. The design synthesize and characterize of the new material under wet condition is something special. In particularly, the material used for aesthetic decoration applications. Light weight low strength applications are very wide. This investigation focuses the natural fiber hybrid with artificial fiber based hybrid composite preparation. The banana fiber is used to prepare the composite with textile-grade glass fibers. The banana fiber is here treated with specific concentration of 2-Hydroxysuccinic Acid in the distilled water. The composites synthesized with treated and untreated banana fibers. The alternate fashion of horizontal and vertical is followed for fibers’ orientation. The bio epoxy is employed as matrix material with mix of hardener. The prepared composite are characterized by water absorbability and also characterized by tensile properties, flexural properties and shock absorption capacities in wet condition.
- Published
- 2020
26. Palladiuum-based membranes for separation of high-purity hydrogen
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Kairat Kuterbekov, F. R. Karelin, N. R. Roshan, E. T. Abseitov, S. V. Gorbunov, E. M. Chistov, and K. Zh. Bekmyrza
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Membrane ,Materials science ,Chemical engineering ,Hydrogen ,chemistry ,Separation (aeronautics) ,chemistry.chemical_element - Abstract
In the present study, using the improved technology, high-quality vacuum-tight foils 10 – 20 µm in thickness were prepared from effective Pd – 6 wt. % In – 0.5 wt. % Ru, Pd – 6 wt. % Ru, Pd – 40 wt. % Cu palladium alloys. Using a combination of deformation and annealing modes, the Pd – 40 wt. % Cu alloy foil consisting of the ordered β-phase (97%) with the CsCl-type structure that exhibits the maximum hydrogen permeability in this system. The mechanical properties and hydrogen permeability of the prepared foils were studied and compared with those of alloy foils 50 µm thickness. The thermal concentration dilatation in hydrogen was studied at different temperatures. Data on the dilatation of palladium-based membranes are of primary importance for designing membrane filtering elements and selection of optimal conditions for their operation, since these data determine the operation life membranes. Based on the Pd – 6 wt. % In – 0.5 wt. % Ru alloy, the Pd – 6 wt. % In – 0.5 wt. % Ru – 1.25 wt. % Co alloy was developed; it is characterized by increased strength characteristics and lower α ↔ β hydride transition temperature.
- Published
- 2020
27. The effect of a rapid photon treatment of the foil of the PdCu solid solution of composition close to the equiatomic
- Author
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D. А. Sinetskaya, V. M. Ievlev, N. R. Roshan, О. V. V. Serbin, Konstantin Solntsev, and А. I. Dontsov
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Multidisciplinary ,Xenon ,Photon ,Materials science ,chemistry ,Electrical resistance and conductance ,Thermal ,Analytical chemistry ,chemistry.chemical_element ,Composition (visual arts) ,Radiation ,FOIL method ,Solid solution - Abstract
transformations in a thin ~4 m foil of PdCu solid solution were investigated by x-ray diffractometry and measurement of electrical resistance in heating-cooling cycles during thermal or rapid photon treatment by radiation of high-power pulsed xenon lamps. It has been found that a single rapid photon treatment for 0,3 s (the energy dose of the radiation entering the sample is 10 j cm‑2) leads to a complete disordering of the solid solution at a rate 400 times greater than in the heat treatment mode used (heating at a rate of 15 K min‑1).
- Published
- 2019
28. Solvability of system of Volterra integral equations via measure of noncompactness
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H. Nasiri, J. R. Roshan, and Mohammad Mursaleen
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Computational Mathematics ,symbols.namesake ,Pure mathematics ,Applied Mathematics ,Banach space ,symbols ,Fixed-point theorem ,Fixed point ,Banach *-algebra ,Measure (mathematics) ,Volterra integral equation ,Mathematics - Abstract
In this article, we present some fixed point and coupled fixed point theorems adapted from the notion of F-contraction mappings in Banach spaces (B.S.) via the measure of noncompactness (M.N.C). Then we define and present a new class of generalized F-contractions, to upgrade some results of Falest and Latrach (Bull Bell Math Soc Simon Stevin 22:797–812, 2015). Furthermore, we investigate the solvability of a new system of Volterra integral equations in a Banach Algebra. Finally, the usefulness of the theoretical results is shown by an example.
- Published
- 2021
29. Field efficacy of the parasitoid, Pediobius imbrues (Hymenoptera: Eulophidae) on coconut slug caterpillar, Macroplectra nararia Moore (Lepidoptera: Limacodidae)
- Author
-
G. Krishna Rao, D R Roshan, and N. B. V. Chalapathi Rao
- Subjects
0106 biological sciences ,Eulophidae ,biology ,Bracon hebetor ,010607 zoology ,Hymenoptera ,biology.organism_classification ,01 natural sciences ,Applied Microbiology and Biotechnology ,Limacodidae ,Parasitoid ,Toxicology ,010602 entomology ,Insect Science ,Pediobius ,PEST analysis ,Caterpillar ,Agronomy and Crop Science - Abstract
The coconut slug caterpillar, Macroplectra nararia is one of the major pests of coconut plantations in Andhra Pradesh with periodic out breaks especially under favorable weather conditions. Though many parasitoids were identified against this sporadic out break pest, none were found amenable for laboratory rearing. A new larval parasitoid, Pediobius imbrues (Hymenoptera: Eulophidae) with a natural parasitisation ranging from 2 -10 per cent under field conditions was identified in slug affected coconut gardens in March 2015. This parasitoid was also found amenable for lab rearing on Bracon hebetor probably being facultative hyper parasitoid. Field release studies of lab reared P. imbrues against slug caterpillar in the affected coconut gardens revealed that a maximum of 41.41 and 50.31 per cent parasitsm of slug caterpillar, respectively, in 2017 and 2018 within 30 days after release and this promising parasitism provides scope for large scale field releases during slug caterpillar out breaks in view of major economic losses caused by the pest.
- Published
- 2019
30. The Effect of Rapid Photon Treatment of the PdCu Solid Solution Foil of Near-Equiatomic Composition
- Author
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A. I. Dontsov, V. M. Ievlev, N. R. Roshan, O. V. Serbin, Konstantin Solntsev, and D. A. Sinetskaya
- Subjects
Photon ,010405 organic chemistry ,Chemistry ,Analytical chemistry ,Radiant energy ,chemistry.chemical_element ,General Chemistry ,Radiation ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Xenon ,Electrical resistance and conductance ,FOIL method ,Powder diffraction ,Solid solution - Abstract
β $$ \rightleftarrows $$ α transformations in a thin ~4 µm foil of the PdCu solid solution have been studied by X-ray powder diffraction and measurement of electrical resistance in heating–cooling cycles during heat treatment or rapid photon treatment by radiation of high-power pulsed xenon lamps. It has been found that a single rapid photon treatment for 0.3 s (the radiation energy dose delivered to the sample is 10 J cm–2) leads to a complete disordering of the solid solution at a rate 400 times higher than in that achieved under heat treatment conditions (heating rate of 15 K min–1).
- Published
- 2019
31. Understanding sustainable strategies in low-cost housing
- Author
-
S. V. Sivapriya, R. Roshan, and J. Gokul Krishna
- Subjects
Government ,Public housing ,0211 other engineering and technologies ,021107 urban & regional planning ,02 engineering and technology ,language.human_language ,Public participation ,Tamil ,Human settlement ,Sustainability ,language ,021108 energy ,Business ,Settlement (litigation) ,Construct (philosophy) ,General Economics, Econometrics and Finance ,Environmental planning - Abstract
Purpose This paper aims to understand the incorporation of sustainability methods of construction through the study of a low-cost housing Tamil Nadu Housing Board settlement in a locality in Chennai, India. Such a study helps to arrive at proper design decisions and incorporate a participatory approach involving the residents to enable the developers, here the decision-makers of the government, cater to the local interests. Design/methodology/approach First, a survey was conducted to understand the local conditions and people’s aspirations. Along with this, the parameters pertaining to a green housing were derived and compared with the needs of the locals, to arrive at the most influencing parameters by decision-making trial and evaluation laboratory model (DEMATEL) analysis. Findings The study finds that parameters viz. “ensuring basic services” and “social inclusivity” happen to be the causal factors that seem to influence the needs of the locals. These factors therefore can guide the future plans to redevelop the settlement or construct similar settlements in a more sustainable way. Originality/value This paper is a unique study to combine the twin pillars of low-cost housing and sustainability, which helps in developing settlements that are conducive to the city’s socio-developmental requirements as well as respectful of the natural environment. Further, the analysis conducted through DEMATEL method could essentially guide the decision-maker to tackle urban challenges in the most locally suitable and sustainable approach.
- Published
- 2019
32. Experimental study on properties of mechanical resistance of polyamide in clay soil
- Author
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J. Gokul Krishnan, Bijivemula Sruthi Reddy, Syed Mohammed, R. Roshan, and S.V. Sivapriya
- Subjects
Ground improvement ,durabilidad ,Materials science ,Atterberg's limit ,Unconfined compressive strength ,Composite number ,Expansive soil ,PA-12 ,límite de Atterberg ,Mechanical resistance ,Durability ,Shear (sheet metal) ,Mejora del suelo ,Polyamide ,Soil water ,Plastic waste ,Composite material ,Clay soil ,resistencia a la compresión no confinada ,suelo expansivo ,Stabilizer (chemistry) - Abstract
The presence of clay soil causes problems at the base of the structure: it swells when wet and shrinks when dry, which provides a reduction in the resistance to cutting of the soil. Plastic waste in the form of polyamide powder (PA-12) from the 3D printing industry can be used to improve the mechanical properties of the soil. This experimental study is an attempt to combine these two objectives of stabilizing the soil by using waste PA-12. The mechanical and shear resistant properties gave us confidence in choosing PA-12 as a stabilizer in clay soils, making them composite soils. Resumen La presencia de suelo arcilloso causa problemas a la base de la estructura: se hincha cuando está mojado y se encoge en estado seco, lo que proporciona una reducción de la resistencia al corte del suelo. Los residuos plásticos en forma de poliamida en polvo (PA-12) de la industria de la impresión 3D se pueden utilizar para mejorar las propiedades mecánicas del suelo. Este estudio experimental es un intento de combinar estos dos objetivos de estabilizar el suelo mediante la utilización de desechos de PA-12. Las propiedades mecánicas y resistentes al cizallamiento dieron confianza al elegir PA-12 como estabilizador en suelos arcillosos, convirtiéndolos en suelos compuestos.
- Published
- 2021
33. Development of Integrated Aerator combining Paddlewheel and Propeller Aspirator Aerators for Shrimp Farming
- Author
-
T. Anand, R. Roshan, and R. Harini
- Subjects
Shrimp farming ,Paddle wheel ,Aquaculture ,business.industry ,Significant difference ,Propeller ,Environmental engineering ,Environmental science ,Water current ,Aspirator ,Aeration ,business - Abstract
Paddle wheel aerators (PWA) are the most commonly used surface aerators in the aquaculture field to increase the dissolved oxygen (DO) level of the shrimp ponds. In Indian shrimp farming sectors, though many types are available in the market, paddle wheel aerators are widely used. The paddles are efficient in increasing DO levels, but there are also certain disadvantages like time consumption to reduce the gradient formation due to temperature and dissolved oxygen levels in the pond’s top and bottom water column. Also, due to the high water current created by the paddle wheel aerators, feeds get accumulated to the center of the pond and forms sludge. In the present scenario, high-density culture poses some severe issues like mortality during feeding due to reduced dissolved oxygen levels. In this research work, to overcome those issues, an aerator was developed by modifying the gearbox to integrate the paddle wheel and propeller aspirator aerators, and it was tested on the field for its efficacy. The energy consumption for the integrated aerator with two output and regular paddle wheel aerators is the same. Furthermore, the results showed a significant difference between the paddle wheel aerator (PWA) and integrated aerator (IA) in maintaining DO stratification, temperature stratification, and water current.
- Published
- 2021
34. Glass Fibre Reinforced Gypsum (GFRG) as an Emerging Technology
- Author
-
S. V. Sivapriya, R. Roshan, S. N. Vinothni, and J. Gokul Krishna
- Subjects
Sustainable development ,Engineering ,Architectural engineering ,Gypsum ,business.industry ,Emerging technologies ,media_common.quotation_subject ,Rapid construction ,engineering.material ,Sustainability ,Affordable housing ,Mainstream ,Quality (business) ,business ,media_common - Abstract
A well-planned and socially inclusive city provides an unprecedented opportunity to transform its challenges like urbanization, management of infrastructure, etc. to a smooth sustainable transformation. The implementation a material technology like Glass Fibre Reinforced Gypsum (GFRG) in construction also links itself to the important Sustainable Development of providing affordable housing for all (besides its other possible applications). This technology involve greater thought in planning and rapid construction of quality eco-friendly homes. Thus, weighing the advantages, uses, and shortcomings of this gypsum composite material through key governing attributes, the technical, economic, and social implications of this perspective solution for mainstream construction challenges were theoretically discussed. Further, the reasons for its limited practice in the Indian industry, user satisfaction, and challenges in the incorporation of this technology were also studied and compared with the conventional methods of construction in our point of view.
- Published
- 2020
35. Membrane characteristics of palladium-samarium alloy foils: mechanical properties and hydrogen permeability
- Author
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A. S. Bakulina, Mark V. Zheleznyi, N. R. Roshan, Natalia B. Kolchugina, Gennadii S. Burkhanov, Nikolay A. Dormidontov, and Semen V. Gorbunov
- Subjects
Samarium ,Membrane ,Materials science ,Hydrogen ,chemistry ,Chemical engineering ,Permeability (electromagnetism) ,Alloy ,engineering ,chemistry.chemical_element ,engineering.material ,Palladium - Published
- 2020
36. Composite Membranes Based on Pd–Cu and Pd–Pb Solid Solutions
- Author
-
N. R. Roshan, V. M. Ievlev, G. S. Burkhanov, D. A. Sinetskaya, V. I. Novikov, S. V. Gorbunov, and A. I. Dontsov
- Subjects
010302 applied physics ,Materials science ,Nanoporous ,Bilayer ,Metals and Alloys ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Titanium oxide ,Membrane ,Chemical engineering ,Rutile ,0103 physical sciences ,0210 nano-technology ,Porosity ,Layer (electronics) ,Solid solution - Abstract
Composite membranes with a thin selective layer based on the Pd–46 at % Cu or Pd–5 at % Pb solid solution on the surface of a bilayer heterostructure with two-level porosity in the form of Kh18N10T steel/nanoporous titanium oxide (steel/rutile) are fabricated. The structure of the selective 4-μm-thick layer is found to have no through pores, and a metal does not penetrate into the nanopores in titanium oxide. The selective layer in both versions has a fine submicrocrystalline granular structure, which is caused by the presence of a second component in the Pd–Pb layer and by a two-phase composition of the Pd–Cu layer. In the temperature range 200–300°C, the hydrogen permeability of the membrane based on the two-phase Pd–Cu solid solution is higher than the membrane based on the Pd–Pb solid solution by a factor of 1.7–2.0.
- Published
- 2018
37. Intelligent Transaction System for Fraud Detection using Deep Learning Networks
- Author
-
N M Sanjeev Kumaar, K Sakthi Eswaran, J Fenila Naomi, and R Roshan Jeniel
- Subjects
History ,business.industry ,Computer science ,media_common.quotation_subject ,Deep learning ,Payment ,Computer security ,computer.software_genre ,Computer Science Applications ,Education ,Consistency (database systems) ,Credit card ,Issuer ,Order (business) ,Cash ,Artificial intelligence ,business ,Database transaction ,computer ,media_common - Abstract
Detecting online transaction fraud is a basic study of the new era of electronic transactions. Because the payment patterns of customers and the fraud behaviour of offenders are continually changing, improving the consistency of the fraud detection model and ensuring its stability is exceedingly challenging. In this report, we will look at We concentrate on acquiring deep feature representations of legal and fraud transactions from the perspective of a deep neural network’s loss function in this report. Our aim is to increase the separability and discrimination of features in order to boost the efficiency and stability of our fraud detection platform, with the rapid evolution of the technology, the world is turning to use online transaction instead of cash in their daily life, which opens the door to many new ways for fraudsters to use these cards in a nefarious manner. Global losses are projected to reach $35 billion by 2020, according to the Nilson report. To guarantee that users of these credit cards are secure, the credit card issuer should provide a program that protects them from any threats they can experience. As a result, we illustrate our framework for predicting whether transactions are genuine or illegitimate using Kaggel’s IEEE-CIS Fraud Detection dataset. BiLSTM-MaxPooling-BiGRUM is the name of our model. Long bi-directional gated repeated unit and long bi-directional memory term (BiLSTM) are used in axPooling (BiGRU).
- Published
- 2021
38. Reversibility of the $$\beta \rightleftharpoons \alpha $$ β ⇌ α phase transformations in a Pd–Cu solid solution
- Author
-
V. M. Ievlev, A. A. Maksimenko, N. R. Roshan, and A. I. Dontsov
- Subjects
010302 applied physics ,Auger electron spectroscopy ,Materials science ,Hydrogen ,General Chemical Engineering ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Inorganic Chemistry ,chemistry ,Electrical resistivity and conductivity ,Phase (matter) ,0103 physical sciences ,X-ray crystallography ,Materials Chemistry ,0210 nano-technology ,Diffusion bonding ,FOIL method ,Solid solution - Abstract
Thin samples (about 4 μm in thickness) of membrane foil of a Pd–Cu solid solution have been grown on the surface of a SiO2/Si heterostructure by magnetron sputtering. The key features of \(\beta \rightleftharpoons \alpha \) phase transformations have been identified using X-ray diffraction, Auger electron spectroscopy, energy dispersive X-ray microanalysis, and resistivity measurements during a heating–cooling cycle. The results demonstrate that the phase transformations are reversible only in solid solutions containing an excess of copper in the concentration range corresponding to limiting temperatures near the temperature stability limit of the β-phase. Thermal conditions of membrane element operation have been found that ensure stability of the ordered atomic structure of the foil and, accordingly, its high performance. The \(\beta \rightleftharpoons \alpha \) phase transformation has been shown to be reversible after holding the foil at t = 830°C, in a state with a disordered atomic structure, which ensures restoration of its high hydrogen permeability after diffusion bonding to the case of a membrane element.
- Published
- 2017
39. Determining new threshold temperatures for cooling and heating degree day index of different climatic zones of Iran
- Author
-
Shady Attia, A. A. Ghanghermeh, and Gh. R. Roshan
- Subjects
education.field_of_study ,Maximum temperature ,Percentile ,Index (economics) ,Meteorology ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Population ,Thermal comfort ,02 engineering and technology ,Degree day ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Relative humidity ,education ,Heating degree day - Abstract
Iran is a country with a variety of different climates. Determining the threshold temperatures suitable for providing thermal and climatic comfort is necessary and vital to its population well-being. This research presents new threshold temperatures in order to calculate the degree day index required for heating and cooling by taking advantage of the 12 stations that are representative of the diversity of Iran's climate. Using Olgyay diagram, different bioclimatic ranges of 12 weather stations and their frequencies were compiled, processes and analysed. Mean daily data of temperature and relative humidity were used for the period of 1950–2010. Based on the frequencies of temperature readings falling in Olgyay's diagram comfort zone, representive temperature thresholds were selected based on 40 to 60 percentiles or (P20), 25–75% percentile (P50) and the threshold of 10–90% percentile. The findings of this study shows that Mashhad with 29.6% and Anzali with 2.33% of frequencies, have experienced the maximum and minimum days of comfort. After analyzing various percentiles to determine the threshold temperatures, it was observed that there is a little difference among the stations for determining the minimum threshold for the comfort. Differences are more obvious in the maximum thresholds. In total, minimum base temperatures (HDD) belonged to Ardabil stations that were 20.50, 20.90 and 20 deg C for P20, P50 and P80 respectively. The maximum temperature for calculating CDD with values of (P20 = 25 °C; P50 = 26.25 °C; P80 = 27.50 °C) is dedicated to Zabol station. The findings present more reasonable thermal comfort thresholds that can be used by architects, engineers and policy makers to achieve, in turn, more energy efficient homes and high quality indoor and outdoor living environments.
- Published
- 2017
40. Palladium–lead alloys for the purification of hydrogen-containing gas mixtures and the separation of hydrogen from them
- Author
-
T. N. Penkina, N. R. Roshan, S. V. Kannykin, G. S. Burkhanov, E. M. Chustov, and S. V. Gorbunov
- Subjects
010302 applied physics ,Materials science ,Hydrogen ,Hydride ,Transition temperature ,Metallurgy ,Alloy ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,engineering.material ,01 natural sciences ,020501 mining & metallurgy ,Corrosion ,0205 materials engineering ,chemistry ,0103 physical sciences ,engineering ,Solid solution ,Palladium - Abstract
Ingots of palladium alloys with 5, 8, 12, 16, and 20 wt % Pb, which correspond to the Pd-based solid solution region, are prepared by arc melting in a protective atmosphere. Foils 50 μm thick are prepared from the ingots subjected to cold rolling and intermediate vacuum annealing. The membrane characteristics of the foils, which include the strength, the hydrogen permeability, the corrosion resistance, the α ⇄ β hydride transition temperature, and the crystal lattice parameters, have been studied. The Pd–8 wt % Pb alloy is shown to exhibit the maximum specific hydrogen permeability (2.6 N m3 mm/(m2 h MPa0.5)) at 500°C, an adequate plasticity (δ = 12%), a high strength ( $${\sigma _{{u_{hard}}}}$$ = 550 MPa, $${\sigma _{{u_{ann}}}}$$ = 230 MPa), and corrosion resistance against one of the hydrocarbon-conversion products (CO2), which allow us to recommend this alloy for application as the membranes in filtration membrane elements.
- Published
- 2017
41. Defect structure evolution in the process of relaxation of the Pd-Y-H system
- Author
-
Roman Svetogorov, Alexey Veligzhanin, O. V. Akimova, N. R. Roshan, G S Burkhanov, and S V Gorbunov
- Subjects
History ,Materials science ,Scientific method ,Structure (category theory) ,Relaxation (physics) ,Thermodynamics ,Computer Science Applications ,Education - Abstract
X-ray diffraction and high-precision scanning electron microscopy methods were used to study the long-term evolution of the defect structure of diffusion filter-membranes Pd-Y. Analysis of X-ray diffraction data and microelectronic photographs showed that the recovery of the dislocation structure in the membranes was not uniform. Differences in the processes of hydrogen conservation in the structure of membranes are determined reversible hydrogen doping. Preservation by alloy of superstructural ordered regions was detected.
- Published
- 2020
42. Cornelia de Lange syndrome: Correlation of brain MRI findings with behavioral assessment
- Author
-
Amy S. Kimball, Antonie D. Kline, Mark A. Kliewer, Susan L Rebsamen, Julia O'Connor, Thelma Lopes, Marco A. Grados, Tamanna R. Roshan Lal, and Julia L. Clemens
- Subjects
Adult ,Male ,0301 basic medicine ,medicine.medical_specialty ,Pathology ,Cerebellum ,Cornelia de Lange Syndrome ,Adolescent ,Central nervous system ,Article ,White matter ,Applied Behavior Analysis ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,De Lange Syndrome ,Genetics ,medicine ,Humans ,Child ,Psychiatry ,Cerebellar hypoplasia ,Genetics (clinical) ,Retrospective Studies ,Cerebral atrophy ,medicine.diagnostic_test ,business.industry ,Mental Disorders ,Brain ,Magnetic resonance imaging ,medicine.disease ,Magnetic Resonance Imaging ,030104 developmental biology ,medicine.anatomical_structure ,Gliosis ,Child, Preschool ,Female ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Neurobehavioral and developmental issues with a broad range of deficits are prominent features of Cornelia de Lange syndrome (CdLS), a disorder due to disruption of the cohesin protein complex. The etiologic relationship of these clinical findings to anatomic abnormalities on neuro-imaging studies has not, however, been established. Anatomic abnormalities in the brain and central nervous system specific to CdLS have been observed, including changes in the white matter, brainstem, and cerebellum. We hypothesize that location and severity of brain abnormalities correlate with clinical phenotype in CdLS, as seen in other developmental disorders. In this study, we retrospectively evaluated brain MRI studies of 15 individuals with CdLS and compared these findings to behavior at the time of the scan. Behavior was assessed using the Aberrant Behavior Checklist (ABC), a validated behavioral assessment tool with several clinical features. Ten of fifteen (67%) of CdLS patients had abnormal findings on brain MRI, including cerebral atrophy, white matter changes, cerebellar hypoplasia, and enlarged ventricles. Other findings included pituitary tumors or cysts, Chiari I malformation and gliosis. Abnormal behavioral scores in more than one behavioral area were seen in all but one patient. All 5 of the 15 (33%) patients with normal structural MRI studies had abnormal ABC scores. All normal ABC scores were noted in only one patient and this was correlated with moderately abnormal MRI changes. Although our cohort is small, our results suggest that abnormal behaviors can exist in individuals with CdLS in the setting of relatively normal structural brain findings. © 2016 Wiley Periodicals, Inc.
- Published
- 2016
43. Effective parameters for calculating discharge of radial gates
- Author
-
R. Roshan, Javad Farhoudi, and Hossein Khalili Shayan
- Subjects
Engineering ,Flow conditions ,business.industry ,Bar (music) ,Field data ,Energy–momentum relation ,Geotechnical engineering ,Mechanics ,business ,Discharge coefficient ,Water Science and Technology - Abstract
This study presents some theoretical relationships to estimate the discharge exiting from various types of radial gates under free and submerged flow conditions. These equations, which are based on energy and momentum concepts, were calibrated by means of a large number of experimental records retrieved from research conducted on three types of radial gates: hard rubber bar, sharp and music note gates. Results showed that the proposed equations could more accurately estimate the discharge of these radial gates where the mean absolute relative errors were less than 1·5 and 3·5% for free and submerged flow conditions, respectively. It was also observed that under specific circumstances, a hard rubber bar gate permits more discharge than sharp and music note gates. It is recognised that the discharge coefficient decreases with increase of lip angle. The reliability of the proposed equations was tested using 514 field data of multi-radial gates under operation in different irrigation canals. The study showed that calculating the total discharge exiting from individual gates by means of proposed equations was in close agreement with field observations. The predictive errors of the total flow discharge for 78% of the flow data were about ±10%.
- Published
- 2015
44. Preparation of special-purity scandium for designing plastic and breakable materials based on the metal
- Author
-
Nikolay A. Dormidontov, N. R. Roshan, A. S. Bakulina, S V Gorbunov, Kateřina Skotnicová, D. A. Rusinov, G S Burkhanov, N. B. Kolchugina, and Pavel A. Prokofev
- Subjects
Metal ,History ,Materials science ,chemistry ,visual_art ,Metallurgy ,visual_art.visual_art_medium ,chemistry.chemical_element ,Scandium ,Computer Science Applications ,Education - Abstract
The development of advanced technologies is related to the preparation and application of rare-earth metals. The tendency of development of rare-earth metal (REM) industry in Russia consists in tending to shed its dependence on the importation of REMs, to organize their production and products based on them in the required quantities, and to find new application fields for REMs. The aim of the present study is to elaborate the purification technologies of scandium and scandium hydride and to approbate its application as breakable additions to powder mixtures for the preparation of Nd-Fe-B permanent magnets. It is demonstrated the possibility to control the grains size of the 2-14-1 phase in Nd-Fe-B with the ScH∼2 addition. Moreover, our systematic studies are aimed at the development of corrosion-resistant Ag-free Pd-based REM-containing alloys with the high hydrogen permeability for the separation of high-purity hydrogen from hydrogen-containing mixtures. In the present study, the hydrogen permeability and mechanical properties of Pd-Sc thin foils prepared with special-purity scandium are discussed
- Published
- 2020
45. Oriented crystallization of thick Pd–Ru films during magnetron sputtering of target
- Author
-
V. M. Ievlev, S. V. Kannykin, G. S. Burkhanov, B. V. Sladkopevtsev, E. M. Chistov, A. A. Maksimenko, E. K. Belonogov, and N. R. Roshan
- Subjects
Morphology (linguistics) ,Materials science ,Silicon ,Metallurgy ,Dispersity ,General Engineering ,chemistry.chemical_element ,Sputter deposition ,law.invention ,Chemical engineering ,chemistry ,law ,Phase composition ,General Materials Science ,Crystallization ,Anisotropy ,Solid solution - Abstract
The possibility of obtaining thick films (3 to 7 µm) of solid solution Pd–6 wt % Ru by magnetron sputtering of a target having the corresponding composition is shown. The structure, phase composition, and surface morphology of films condensed on the surface of oxidized silicon, fluorphlogopite, and anodic aluminum oxide at 300–950 K are studied. A general trend of formation of a gradient grain structure of thick films (with a high grain dispersity level at the initial growth stage) and subsequent selective growth of grains and subgrains having an anisotropic shape and primary orientation is independent of the structure and morphology of the substrate surface.
- Published
- 2015
46. Heat transfer performance of an anodized two-phase closed thermosyphon with refrigerant as working fluid
- Author
-
Walter Vincent, L. Godson Asirvatham, V.K. Karthikeyan, A. Brusly Solomon, and R. Roshan
- Subjects
Fluid Flow and Transfer Processes ,Materials science ,Mechanical Engineering ,Thermal resistance ,Evaporation ,Thermodynamics ,Heat transfer coefficient ,Condensed Matter Physics ,Refrigerant ,Heat transfer ,Working fluid ,Thermosiphon ,Composite material ,Evaporator - Abstract
Heat transfer characteristics of an anodized two-phase closed thermosyphon (TPCT) with refrigerant as the working fluid is studied and compared with that of a non-anodized one. A simple anodization is performed to make a porous structure on the inner wall of TPCT. The anodized and non-anodized TPCTs charged with a blend of R600a and R290 are tested for the heat input range of 50–200 W. The effects of filling ratio, inclination angle, heat input and anodized surface on the performance of the TPCTs are investigated. Due to the anodization, the evaporator heat transfer coefficient enhances up to 33% at the inclination angle of 45° for the heat input of 200 W. Also, total thermal resistance of the anodized TPCT is reduced by 17%, 20% and 23% respectively for horizontal, inclined and vertical positions when compared to the non-anodized TPCT. Enhancements in the surface area, number of nucleation sites, increased bubble frequency, intensified bubble interaction and thin film evaporation are major factors for the performance enhancement in the anodized TPCT. Also it is found that the filling ratio, inclination angle and heat input have a significant role on the performance of the TPCT.
- Published
- 2015
47. Awareness levels of prevention of cardiac diseases in general population of rawalpindi and requirement of health education
- Author
-
S. Sajjad, S. Tanvir, and R. Roshan
- Subjects
Adult ,Male ,medicine.medical_specialty ,Health Knowledge, Attitudes, Practice ,Heart Diseases ,Cross-sectional study ,Population ,Physical activity ,Disease ,030204 cardiovascular system & hematology ,03 medical and health sciences ,0302 clinical medicine ,Level of consciousness ,Risk Factors ,Environmental health ,Surveys and Questionnaires ,Medicine ,Humans ,Pakistan ,030212 general & internal medicine ,education ,Health Education ,Life Style ,education.field_of_study ,Health Services Needs and Demand ,business.industry ,Public health ,Public Health, Environmental and Occupational Health ,food and beverages ,General Medicine ,Cross-Sectional Studies ,Red meat ,Health education ,Female ,business - Abstract
Objectives To assess the level of awareness in population about cardiac diseases prevention and suggestion of recommendations. Study design Descriptive cross-sectional survey was carried out in Rawalpindi Cantonment in Oct 2016. Methods 100 respondents were selected through convenience sampling. Data was collected through questionnaire. Results Results indicated low levels of awareness as only 30% of the population knew that cardiac diseases can be prevented to certain extent by lifestyle changes. 46% population knew about importance of physical activity and 34% knew that excess of fried and salty food can cause cardiac diseases. Only 22% population knew that red meat use in excess can cause cardiac diseases. 20% population were aware that lack of sleep can cause cardiac disease. 13% (for sodas), 15% (for sweets) 13% (for consuming egg yolk daily) and 28% (for stress) were the statistics for remaining modifiable risk factors. 80% of the population was aware of smoking hazards which shows the success of anti-smoking campaigns. Conclusion These levels of awareness indicate that there is dire need of policy making for health education to make people aware of lifestyle modifications necessary to prevent cardiac diseases.
- Published
- 2017
48. Characteristics and Time Scale of Local Scour Downstream Stepped Spillways
- Author
-
Javad Farhoudi, Younes Aminpour, Hossein Khalili Shayan, and R. Roshan
- Subjects
Spillway ,Scale (ratio) ,0208 environmental biotechnology ,Flow (psychology) ,General Engineering ,Stepped spillway ,020101 civil engineering ,02 engineering and technology ,020801 environmental engineering ,0201 civil engineering ,symbols.namesake ,Hydraulic structure ,Downstream (manufacturing) ,Froude number ,symbols ,Geotechnical engineering ,Excess energy ,Geology - Abstract
Stepped spillways are employed to reduce excess energy encountered with exiting flow from high hydraulic structures. Study of local scour evolution downstream of stepped spillways wilt therefore, provide information to required get benefits from these structures to minimizes the scour hole dimensions. This paper provides the results of 67 experiments downstream of some stepped spillways subjected to different Froude numbers, basin lengths, tail-water depths, sediment sizes and two different sloped spillways. The experiments were continued for 6, 8, 12 and 24 hours from which 824 profiles and 85000 data points were recorded and analyzed. The results show that in certain circumstances the dimensions of scour hole increase in accordance with particle Froude number. It was also observed that increase in the slope of spillway would result in reduction in the geometries of scour hole. At certain conditions, as the tail-water increases, the depth of scour hole increases and elongate the hole. The relationships for duration of scour evolution downstream of stepped spillway are presented in this paper. Finally, it was observed that the stepped spillway would considerably decrease the dimensions of scour hole compared with Ogee spillways which is reflects the excess energy loss downstream of stepped spillway.
- Published
- 2017
49. Vortices in dam reservoir: A case study of Karun III dam
- Author
-
Maryam Azarpira, Hamed Sarkardeh, R. Roshan, Hossein Bakhshi, and Sasan Tavakkol
- Subjects
Multidisciplinary ,Circulation (fluid dynamics) ,Vortex Formation ,Plane (geometry) ,Tangential velocity ,Condensed Matter::Superconductivity ,Contour line ,Flow (psychology) ,Geotechnical engineering ,Mechanics ,Velocity measurement ,Geology ,Vortex - Abstract
The present study focuses on the effect of vortex formation on plane velocities in a reservoir. Velocity measurements are performed in the hydraulic model of Karun III dam and hydropower plant. Different vortices were produced at the horizontal intake by changing the submerged depth. Tangential velocities were measured on a rectangular mesh in the reservoir. The results were then processed to plot the contour lines of the plane velocities and study the effect of vortex formation on the flow condition in the reservoir. Contour lines in different submerged depths show that circulation zones are formed in different potential locations over the intakes causing vortex formation. These results were correlated with the location of the appearing vortices observed in the experiments. Experimental data of this study could be useful for numerical modelling of vortex in the reservoirs.
- Published
- 2014
50. Formation of thin foil of the ordered Pd-Cu solid solution with a CsCl-type lattice during magnetron sputtering
- Author
-
A. I. Dontsov, S. V. Kannykin, V. M. Ievlev, A. A. Maksimenko, N. R. Roshan, E. K. Belonogov, and Konstantin Solntsev
- Subjects
Hydrogen ,Chemistry ,Alloy ,Analytical chemistry ,chemistry.chemical_element ,Activation energy ,engineering.material ,Sputter deposition ,Hydrogen purifier ,Crystallography ,engineering ,Physical and Theoretical Chemistry ,Order of magnitude ,Palladium ,Solid solution - Abstract
Among Pdbased membrane alloys (1), the Pd-Cu system has long attracted attention for deep hydrogen purification. This system is distinguished by the for� mation of a CsCltype ordered solid solution ( β phase) (2) in a rather narrow composition range close to Pd- 40 wt % Cu. It is accepted (3) that the CsCltype lattice, as compared to the less dense fcc lattice of the disordered solid solution ( α) phase), and, respectively, the shorter distance between octahedral voids (involved in hydro� gen diffusion) are responsible for a lower barrier for diffusion and a manyfold enhancement of hydrogen permeability. According to the results of numerous experimental studies summarized in (3), the hydrogen diffusion activation energy is 0.035 eV in the ordered solid solution, 0.325 eV in the disordered solid solu� tion, and 0.23 eV in palladium. The hydrogen diffu� sion coefficient at 300 K in the β phase is almost four orders of magnitude higher than in the α phase and two orders of magnitude higher than in Pd (3). Thus, the first, major, way of improving the perfor� mance of a Pd-Cu alloy membrane is to increase hydrogen permeability through ordering of the solid solution. The kinetics and mechanism of solid solu� tion ordering have been studied for more than three
- Published
- 2014
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