Rattapon Somna, Teerapon Saowapun, Kiatsuda Somna, Prinya Chindaprasirt,
This research aimed to utilize rice husk ash (RHA) to produce rice husk ash and fly ash (FA) geopolymer hollow block based on NaOH activated. RHA was ground for 15, 30, 60, and 90 min. The RHA to FA ratios of 10:90, 20:80, 30:70, 40:60, and 50:50 by weight and 14 molar sodium hydroxide were used. The compressive strengths of geopolymer paste were tested at 7, 28, and 60 days. The compressive strengths and percentages of water absorption of the geopolymer blocks were tested at 7 and 28 days. The microstructure ...
Tópico(s): Magnesium Oxide Properties and Applications
2022 - Elsevier BV | Case Studies in Construction Materials
Xiaozhang Zheng, Somna R. Salgia, Walter B. Thompson, Elwood O. Dillingham, S.E. Bond, Zixia Feng, Keshav Prasad, R. Gollamudi,
... 3-carboxamides as Human Platelet Aggregation InhibitorsXiaozhang Zheng, Somna R. Salgia, Walter B. Thompson, Elwood O. Dillingham, ...
Tópico(s): Synthetic Organic Chemistry Methods
1995 - American Chemical Society | Journal of Medicinal Chemistry
Nicole Cockayne, Helen Christensen, Kathleen M Griffiths, Sharon L. Naismith, Ian B. Hickie, Frances P. Thorndike, Lee M. Ritterband, Nick Glozier,
Insomnia is a significant risk factor for depression onset, can result in more disabling depressive illness, and is a common residual symptom following treatment cessation that can increase the risk of relapse. Internet-based cognitive behavioural therapy for insomnia has demonstrated efficacy and acceptability to men who are less likely than women to seek help in standard care. We aim to evaluate whether internet delivered cognitive behavioural therapy for insomnia as an adjunct to a standard depression ...
Tópico(s): Circadian rhythm and melatonin
2015 - BioMed Central | BMC Psychiatry
Somna S. Mahajan, Anuradha Dhaul, Robert Laishram, Sonalee Kapoor, Seema Vinayak, B. K. Sehgal,
In this work, ohmic contacts were formed by varying the Ti/Al thickness ratio in the metal stack of Ti/Al/Ni/Au on Al.28Ga.72N/GaN HEMT epistructure followed by annealing in the temperature range 740–860 °C by rapid thermal processor (RTP). The contacts were electrically characterized for contact resistance (Rc) and the sheet resistance (Rs) of AlGaN/GaN epistructure. The ohmic contacts formed by Ti/Al metal thickness ratio of 1/5 exhibited lowest Rc values and better surface morphology compared to ...
Tópico(s): Semiconductor materials and interfaces
2014 - Elsevier BV | Materials Science and Engineering B
... spruce, and 1 stand of Lutz spruce in Sømna area. Bark thickness differed between the sites within ...
Tópico(s): Forest Biomass Utilization and Management
2012 - EDP Sciences | EPJ Web of Conferences
Rattapon Somna, Chai Jaturapitakkul, Amde M. Amde,
This research aims to study the effect of ground fly ash (GFA) and ground bagasse ash (GBA) on the durability of recycled aggregate concrete. Recycled aggregate concrete was produced with recycled aggregate to fully replace crushed limestone in the mix proportion of conventional concrete (CON) and GFA and GBA were used to partially replace Portland cement type I at the rate of 20%, 35%, and 50% by weight of binder. Compressive strength, water permeability, chloride penetration depth, and expansion ...
Tópico(s): Concrete and Cement Materials Research
2012 - Elsevier BV | Cement and Concrete Composites
Rattapon Somna, Chai Jaturapitakkul, Pokpong Rattanachu, Wichian Chalee,
In this study, bagasse ash, which is a large disposal landfill waste from sugar mill industries, is utilized as a pozzolanic material to improve the mechanical properties and durability of recycled aggregate concrete. Ground bagasse ash (GBA) was used to replace Portland cement Type I at the percentages of 20, 35, and 50 by weight of binder. Compressive strength, modulus of elasticity, water permeability, and chloride penetration depth of the concretes were determined. The results revealed that the ...
Tópico(s): Concrete and Cement Materials Research
2011 - Elsevier BV | Materials & Design (1980-2015)
Rattapon Somna, Chai Jaturapitakkul, Wichian Chalee, Pokpong Rattanachu,
This research aims to study the effect of water to binder (W/B) ratio and ground fly ash on properties of recycled aggregate concrete. Normal concretes were designed by using Portland cement type I with W/B ratios of 0.45, 0.55, and 0.65. Recycled aggregate concretes were made by using recycled aggregate to fully replace crushed limestone in the mix proportion of the normal concretes. Ground fly ash was also used as a partial replacement of Portland cement type I at 20, 35, and 50% by weight of binder ...
Tópico(s): Innovations in Concrete and Construction Materials
2011 - American Society of Civil Engineers | Journal of Materials in Civil Engineering
Kiatsuda Somna, Chai Jaturapitakkul, Puangrat Kajitvichyanukul, Prinya Chindaprasirt,
NaOH-activated ground fly ash geopolymers, cured at room temperature, were studied in this paper. Ground fly ash (GFA), with a median particle size of 10.5 μm, was used as source material. NaOH concentrations of 4.5–16.5 M (M) were used as an alkali activator. Compressive strength tests and microstructure observations using SEM, EDX, XRD and FTIR were performed. Results indicated that GFA gave higher strength geopolymer paste compared to original fly ash. Ground fly ash could be used as a source material ...
Tópico(s): Nuclear materials and radiation effects
2011 - Elsevier BV | Fuel
Kiatsuda Somna, Chai Jaturapitakkul, Puangrat Kajitvichyanukul,
Microstructures of calcium carbide residue (CCR) and CCR–ground fly ash (CCR-GFA) pastes were examined. A ratio of CCR to GFA of 30 to 70 by weight was used as a binder without portland cement. CCR-GFA pastes with three different water-to-binder (W/B) ratios of 0.3, 0.4, and 0.5 were prepared. Scanning electron microscopy (SEM) was used to study the morphology of the CCR-GFA pastes. X-ray diffractometry (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to provide fundamental information ...
Tópico(s): Advanced ceramic materials synthesis
2010 - American Society of Civil Engineers | Journal of Materials in Civil Engineering
Nita Dilawar, Somna Sah, B. R. Mehta, VD Vankar, DK Avasthi, GK Mehta,
Diamond and DLC thin films deposited using hot-filament chemical vapour deposition technique at various parameters were irradiated with 50 MeV Si4+ ions. The resulting microstructural changes were studied using X-ray diffraction and scanning electron microscopy. All the samples showed the development of β-SiC and hexagonal carbon phases at the expense of the diamond/DLC phase. The ERD analysis was carried out to determine the hydrogen concentration and its distribution in DLC films. The absolute ...
Tópico(s): High-pressure geophysics and materials
1996 - Elsevier BV | Vacuum
D.K. Avasthi, D. Kabiraj, Jaipal, Geeta Mehta, Harish C. Barshilia, Somna Sah, B. R. Mehta, V. D. Vankar,
The content of hydrogen and its depth profile in diamond like carbon (DLC) films deposited by the microwave plasma deposition technique is determined by Elastic Recoil Detection Analysis (ERDA) using 85 MeV 58Ni ions. Simultaneous detection of hydrogen and carbon recoils provided a method to determine the relative number of hydrogen: carbon atoms without using a standard H sample for quantitative calibration.
Tópico(s): Force Microscopy Techniques and Applications
1995 - Elsevier BV | Vacuum
Harish C. Barshilia, Somna Sah, B. R. Mehta, V. D. Vankar, D.K. Avasthi, Jaipal, Geeta Mehta,
The effect of high energy (85 MeV) nickel ions on diamond-like carbon thin films, deposited by microwave discharge of acetylene and methane gases mixed with hydrogen, has been investigated. IR, Raman and spectroscopic ellipsometry studies of irradiated and as-deposited films show large changes in their microstructural features. The effects of irradiation on films prepared from acetylene-hydrogen and methane-hydrogen gas mixtures are very different. Such a behaviour is proposed to be due to the microstructural ...
Tópico(s): Metal and Thin Film Mechanics
1995 - Elsevier BV | Thin Solid Films
Somna S. Mahajan, Harish C. Barshilia, B. R. Mehta, V. D. Vankar,
The carbon bonding ratio in diamond-like carbon (DLC) thin films has been estimated from the e2 spectra obtained by spectroscopic ellipsometry. A method has been developed to find out the atomic fractions of sp3- and sp2-bonded carbon atoms by combining the various features of the existing methods. The atomic fraction of sp2-bonded carbon atoms has been determined by fitting the gaussian curves in the experimentally observed e2, spectra in the low energy range (< 4 eV). The atomic fraction of sp3-bonded ...
Tópico(s): Metal and Thin Film Mechanics
1997 - Elsevier BV | Thin Solid Films
Kiatsuda Somna, Walairat Bumrongjaroen,
This chapter contains sections titled: Introduction Technical Approach Result and Discussion Summary Acknowledgements
Tópico(s): Nuclear materials and radiation effects
2011 - Wiley | Ceramic engineering and science proceedings
Indranil Bhaumik, M. Soharab, R. Bhatt, A. Saxena, Somna Sah, A.K. Karnal,
Single crystals of undoped, 4.8, 9.3 and 14.1 at.% Al substituted β-Ga2O3 have been grown by optical floating zone technique. It has been observed that it is not possible to grow good quality single crystal with higher Al content unlike the thin film grown by pulsed laser deposition [Appl. Phys. Lett. 105 (2014) 162107]. It has been found that the incorporation of Al in β-Ga2O3 has resulted a shrinkage in the lattice parameters and volume. This leads to a systematic increase in the band gap of the ...
Tópico(s): Advanced Photocatalysis Techniques
2020 - Elsevier BV | Optical Materials
Prinya Chindaprasirt, Kiatsuda Somna,
This research aims to study the effect of addition of microsilica and nanoalumina on compressive strength and products of high calcium fly ash geopolymer with low NaOH concentration. Microsilica and nanoalumina were added in the mixture in order to adjust the Si/Al ratios which resulted in the change of product form of geopolymer pastes. Geopolymer was synthesized using high calcium fly ash and 2 molar sodium hydroxide (NaOH). Microsilica and/or nanoalumina were added as additional sources of silica ...
Tópico(s): Recycling and utilization of industrial and municipal waste in materials production
2015 - Trans Tech Publications | Advanced materials research
Somna S. Mahajan, Amit Malik, Robert Laishram, Seema Vinayak,
Tópico(s): Semiconductor materials and interfaces
2017 - Springer Science+Business Media | Journal of the Korean Physical Society
Somna Mishra, V. K. Katiyar, Vaishali Arora,
Throughout various fields of science and technology, a push towards the use of nanoscale technology is well underway. One area where nanoscale work is already well underway is within the field of drug delivery. Nanoscale devices carrying chemotherapeutic drugs could extravasate from blood vessels and even diffuse through the tissue and enter tumor cells. Drug delivery through nanoparticles presents significant potential advantages over traditional delivery via bolus injection. Drug release kinetics ...
Tópico(s): Cellular Mechanics and Interactions
2006 - Elsevier BV | Applied Mathematics and Computation
Ashish Kumar, Somna S. Mahajan, Seema Vinayak, R. Singh,
High temperature annealing of Ni and Pt Schottky diodes on n-GaN has been investigated. Ni/n–GaN and Pt/n–GaN Schottky diodes were fabricated using ultra high vacuum and annealed at various temperatures (200 °C−700 °C) using rapid thermal anneal system. It was observed that in case of Ni/GaN diodes, the Schottky barrier height increases for 200 °C and then decreases with increase in annealing temperature. For Pt/GaN diodes, the barrier height found to decrease with increase in annealing temperature. ...
Tópico(s): Semiconductor materials and devices
2016 - IOP Publishing | Materials Research Express
R. Gollamudi, Zixia Feng, Elwood O. Dillingham, S.E. Bond, Guangli Han, Somna R. Salgia,
Two synthetic racemic nipecotamides, 1-decyl-3-(N,N-diethylcarbamoyl)piperidine hydrobromide (1) and α,α'-bis[3-(N-benzyl-N-methylcarbamoyl)piperidino]-p-xylene dihydrobromide (2) were resolved on a chiral α1-acid glycoprotein semipreparative HPLC column. Thus, rac.1 was resolved into two enantiomers 1A-(+) and 1B-(-); rac.2 was separated into the optical antipodes 2A-(-) and 2C-(+), and the meso diastereomer 2B-(0). Also on a preparative scale, 97% pure 2C was obtained via diastereomeric salt formation ...
Tópico(s): Chemical Synthesis and Analysis
1993 - Elsevier BV | Thrombosis Research
Somna S. Mahajan, Anushree Tomar, Robert Laishram, Sonalee Kapoor, Amit Mailk, AA Naik, Seema Vinayak, BK Sehgal,
Ni/Au Schottky contacts to AlGaN/GaN HEMT were formed by E-beam evaporation technique and lift-off process. The contacts were Rapid thermal annealed at 300 °C for duration of 2–10 min. A significant suppression in gate leakage current was observed at 2 and 4 min annealing. At further higher annealing duration deterioration in the reverse gate characteristics was observed.
Tópico(s): GaN-based semiconductor devices and materials
2013 - Springer Nature | Environmental science and engineering
Balwinder Singh, Somna Oberoi, Amritpal Kaur,
Tópico(s): Magnetic and Electromagnetic Effects
2024 - Elsevier BV | Food Chemistry Advances
Balwinder Singh, Somna Oberoi, Amritpal Kaur,
Summary Sea buckthorn (SB) is used in cuisines and herbal remedies due to its remarkable nutritional composition and health‐enhancing properties. The phenolic compounds present in SB plant include phenolic acids (gallic, p ‐coumaric, protocatechuic and ferulic acids), flavonols (isorhamnetin, quercetin and kaempferol), flavan‐3‐ols and polymeric procyanidins. The highest content of these compounds was reported in branches and leaves than corresponding edible parts of the plant. The antioxidant properties ...
Tópico(s): Medicinal plant effects and applications
2024 - Wiley | International Journal of Food Science & Technology
Somna S. Mahajan, Abhishek Sharma, Deepti Jain, Hemant Kumar Saini, Brajesh S. Yadav, Akshay Naik, Alok Jain,
The present work involves a comparison of sequentially evaporated Ti/Pt/Au and Cr/Au p-ohmic contacts for high power laser diode fabrication. Subsequently, the contacts were annealed at 440 °C in furnace annealing under N2 ambient and their surfaces were evaluated by optical and electron microscopy. The specific contact resistivity of the contacts was determined by circular transfer length method (c-TLM). Secondary ion mass spectroscopy (SIMS) analysis of the annealed contacts indicates considerable ...
Tópico(s): Semiconductor Lasers and Optical Devices
2018 - Elsevier BV | Vacuum
N. K. Babu, K.Karthik Balaji, Somna Nishal,
Tópico(s): Wave and Wind Energy Systems
2018 - International Research Publication House | International Journal of Engineering Research and
... black Common Magpies Pica pica were observed in Sømna, Norway, in 2014. The normally white parts of ... 2015. One moulted feather from the birds in Sømna, analysed under a light microscope, showed that the ...
Tópico(s): Antioxidant Activity and Oxidative Stress
2015 - | Ornis Norvegica
Nita Dilawar, Somna Sah, B. R. Mehta, V. D. Vankar,
Micro-crystalline diamond (MCD) and diamond like carbon (DLC) thin films were deposited on silicon (100) substrates by hot-filament CVD process using a mixture of CH4 and H2 gases at substrate temperature between 400–800°C. The microstructure of the films were studied by X-ray diffraction and scanning electron microscopy. The low temperature deposited films were found to have a mixture of amorphous and crystalline phases. At high temperatures (> 750°C) only crystalline diamond phase was obtained. Scanning ...
Tópico(s): High-pressure geophysics and materials
1996 - Springer Science+Business Media | Bulletin of Materials Science
Xiaozhang Zheng, Somna R. Salgia, Walter B. Thompson, Elwood O. Dillingham, Stephen E. Bond, Zixia Feng, Keshav Prasad, R. Gollamudi,
... to document cited in CA122:95850]Xiaozhang Zheng, Somna R. Salgia, Walter B. Thompson, Elwood O. Dillingham, ...
Tópico(s): Synthesis of β-Lactam Compounds
1995 - American Chemical Society | Journal of Medicinal Chemistry
Girija Somna, Dinakar Challabathula, Kavya Bakka,
Chemical fertilizers are extensively used and are the most expensive agricultural practices to increase crop productivity. Their have very negative impacts on the environment such as long residual action and environmental toxicity. As a better technique for reducing environmental impacts, nanofertilizers are believed to be a promising eco-friendly alternative to chemical fertilizers. Nanofertilizers enhance seed germination, improve soil quality, and increase nutrient use efficiency and pesticide ...
Tópico(s): Carbon and Quantum Dots Applications
2023 - Springer International Publishing | Nanotechnology in the life sciences