Incorporation of Graphitic Porous Carbon for Synthesis of Composite Carbon Aerogel with Enhanced Electrochemical Performance

Singh, Ashish,Kohli, D.K.,Singh, Rashmi,Bhartiya, Sushmita,Singh, M.K.,Karnal, A.K. The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.2

We report, synthesis of high surface area composite carbon aerogel using additive based polymerization technique by incorporating graphitic porous carbon as additive. This additive was separately prepared using sol-gel polymerization of resorcinol-furfuraldehyde in iso-propyl alcohol medium at much above the routine gelation temperature to yield porous carbon (CA-IPA) having graphitic layered morphology. CA-IPA exhibited a unique combination of meso-pore dominated surface area (~ 700 m²/g) and good conductivity of ~ 300 S/m. The composite carbon aerogel (CCA) was synthesized by traditional aqueous medium based resorcinol-formaldehyde gelation with CA-IPA as additive. The presence of CA-IPA favored enhanced meso-porosity as well as contributed to improvement in bulk conductivity. Based on the surface area characteristics, CCA-8 composition having 8% additive was found to be optimum. It showed specific surface area of ~ 2056 m²/g, mesopore area of 827 m²/g and electrical conductivity of 180 S/m. The electrode formed with CCA-8 showed improved electrochemical behavior, with specific capacitance of 148 F/g & ESR < 1 Ω, making it a better choice as super capacitor for energy storage applications.

Ruthenium doped carbon aerogel with CO2 surface activation for enhanced electrochemical capacitance

Ashish Singh,D.K. Kohli,Sushmita Bhartiya,Rashmi Singh,M.K. Singh,P.K. Gupta 한국물리학회 2017 Current Applied Physics Vol.17 No.6

With the aim of enhancement of electrochemical capacitance, CO2 activation of carbon aerogel (CA) prepared by polycondensation of resorcinol with formaldehyde was performed to obtain activated carbon aerogel (ACA) having improved surface area properties. Ruthenium oxide nano-particles were loaded by impregnation method for utilizing pseudo-capacitive property of ruthenium oxide (RuO2) and the effect of activation treatment was studied. RuO2 loading of 20% by weight was accomplished in CA and ACA to synthesize RuO2 doped carbon aerogel (CA/RuO2) and activated carbon aerogel (ACA/RuO2). While the specific capacitance of carbon aerogel improved from 95 to 153 F/g on activation, RuO2 loading further led to enhancement in capacitance and specific capacitance of 308 F/g was obtained for ACA/ RuO2. The studies being important for Ru economy, showed the influence of surface area enhancement of base matrix in achieving high specific capacitance.

Patients with celiac disease are at high risk of developing metabolic syndrome and fatty liver

( Ashish Agarwal ),( Alka Singh ),( Wajiha Mehtab ),( Vipin Gupta ),( Ashish Chauhan ),( Mahendra Singh Rajput ),( Namrata Singh ),( Vineet Ahuja ),( Govind K. Makharia ) 대한장연구학회 2021 Intestinal Research Vol.19 No.1

Background/Aims: Gluten-free diet has an excess of fats and simple sugars and puts patients with celiac disease at risk of metabolic complications including metabolic syndrome and fatty liver. We assessed prevalence of metabolic syndrome and fatty liver in two cohorts of celiac disease. Methods: Study was done in 2 groups. In group 1, 54 treatment naïve patients with celiac disease were recruited. Of them, 44 returned after 1-year of gluten-free diet and were reassessed. In group 2, 130 celiac disease patients on gluten-free diet for ≥1 year were recruited. All patients were assessed for anthropometric and metabolic parameters and fatty liver. Metabolic syndrome was defined as per consensus definition for Asian Indians. Fatty liver was defined as controlled attenuation parameter value >263 decibels by FibroScan. Results: In group 1, of 44 treatment naïve patients with celiac disease, metabolic syndrome was present in 5 patients (11.4%) at baseline and 9 (18.2%) after 1 year of gluten-free diet. Patients having fatty liver increased from 6 patients (14.3%) at baseline to 13 (29.5%) after 1year of gluten-free diet (P=0.002). In group 2, of 130 patients with celiac disease on gluten-free diet for a median duration of 4 years, 30 out of 114 (26.3%) and 30 out of 130 patients (23%) had metabolic syndrome and fatty liver, respectively. Conclusions: Patients with celiac disease are at high risk of developing metabolic syndrome and fatty liver, which increases further with gluten-free diet. These patients should be assessed for nutritional and metabolic features and counseled about balanced diet and physical activity regularly. (Intest Res 2021;19:106-114)

Effect of Ba and Ho co-doping on crystal structure, phase transformation, magnetic properties and dielectric properties of BiFeO3

Jogender Singh, Ashish Agarwal,Ashish Agarwal,Sujata Sanghi,Tanvi Bhasin,Manisha Yadav,Umesh Bhakar,Ompal Singh 한국물리학회 2019 Current Applied Physics Vol.19 No.3

Multiferroics having composition Bi0.80-xBa0.20HoxFeO3 (BBFO, BBHFO5, BBHFO10, BBHFO15 and BBHFO20 for x=0.0, 0.05, 0.10, 0.15 and 0.20 respectively) were synthesized by method of solid state reaction. The crystal structure has been studied using X-ray diffraction technique. The X-ray patterns show enormous transform in crystal structure at concentration x=0.20. The Rietveld refinement of XRD patterns indicates that at concentration x=0.0 sample have rhombohedral structure with R3c space group while for the concentration x=0.05, 0.10, 0.15 and 0.20, the mixed phase including rhombohedral R3c and triclinic P1 space groups were obtained with best fitting. This phase transformation in crystal structure is observed due to mismatching of ionic radii of doped ions and parent ions. Magnetic properties of all samples were carried out by using vibrating sample magnetometry. M-H hysteresis loops shows that with doping of Ba and Ho antiferromagnetic BiFeO3 (BFO) transforms into ferromagnetic. The dielectric and ferroelectric measurements were carried out which shows that dielectric constant, dielectric loss and ferroelectric properties are enhanced with co-doping of Ho in comparison of the pristine BFO due to structure deformation and decrease in oxygen vacancies with higher concentration of Ho. Significant improvement has been observed in dielectric constant and remnant magnetization values with increasing content of Ho and decrease in the dielectric loss.

Vibroacoustic analysis of stiffened functionally graded panels in thermal environments

Ashish K. Singh,Anwesha Pal,Shashi Kumar,Anuja Roy,Atanu Sahu 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.5

Functionally graded materials (FGMs) have gained substantial attention from researchers due to their exceptional strength and thermal resistance. Their utilization in the aviation and automobile industries has significantly improved the efficiency of various structural components. Moreover, stiffened panels find wide applications in aerospace and automobile structures and these panels are frequently exposed to extreme environments. It is from this perspective that our research is focused on analysing the vibroacoustic response of stiffened functionally graded panels subjected to external dynamic excitations in a thermal environment. In the present research work, a finite element model is developed to conduct the dynamic analysis of functionally graded stiffened panels using the first-order shear deformation theory. Subsequently, a boundary element based model is also developed and coupled with the finite element model to investigate the sound radiation behaviour of those panels in a thermal environment. The material properties of FG stiffened panels are considered as temperature dependent, while the thermal environment is assumed to be acting as linearly varying through the panel’s thickness. The present investigation aim to compare the vibroacoustic responses of different panels due to stiffener orientations, material compositions, power law indices and plate thicknesses at various temperatures. The research findings highlight the significant impact of addition of stiffeners, its orientation and material compositions on the sound radiation characteristics of these panels under thermal environments. The present numerical model can easily be employed for analysing the sound radiation behaviour of other types of flat or curved stiffened panels having arbitrary geometry and boundary conditions.

A Comparative Study on the Performance and Emission Analysis of a Dual Fuelled Diesel Engine with Karanja Biodiesel and Natural Gas

Singh, Ashish Kumar,Kumar, Naveen,Amardeep, Amardeep,Kumar, Parvesh The International Promotion Agency of Culture Tech 2016 International Journal of Advanced Culture Technolo Vol.4 No.1

In the present study, a single cylinder four stroke dual fuel diesel engine was tested to investigate the performance and emission characteristics of various test fuels. The engine was tested in dual fuel mode using diesel and Karanja biodiesel blends as pilot fuel along with Natural gas as primary fuel with a constant gas flow rate under different loading conditions. From the experimentation it was found that smoke opacity and oxides of nitrogen (NOx) are at low level for all the prepared test fuels in dual fuel mode but the emissions of carbon monoxide (CO), carbon dioxide ($CO_2$) and hydrocarbon (HC) were found higher. In comparison to diesel fuel, by increasing the blend percentage different emission parameters are found to be reduced. At different loading conditions all the test fuels show poor performance in dual fuel mode of operation when compared with single mode of operation with diesel and biodiesel. With increase in gas flow rates, except (NOx) and smoke emissions, the other emission parameters like CO, HC and $CO_2$ values increased for all test fuels. Again, all blended fuels showed lower performance compared to diesel. The maximum pilot fuel savings for diesel was found decreasing with the increase in karanja biodiesel. From the present work it may be concluded that Karanja biodiesel with Natural gas in dual mode can be can used as promising alternative for diesel with some required engine modifications and further research must be carried out to minimize the emissions of CO, HC and $CO_2$.

Prediction of Hybrid Performance Based on the Genetic Distance of Parental Lines in Two-Line Rice (Oryza sativa L.) Hybrids

Singh, Vikas Kumar,Upadhyay, Priti,Sinha, Pallavi,Mall, Ashish Kumar,Ellur, Ranjith K.,Singh, Atul,Jaiswal, Sanjay K.,Biradar, Sunil,Ramakrishna, S.,Sundaram, R.M.,Ahmed, Ilyas,Viraktamath, B.C.,Kole, 한국작물학회 2011 Journal of crop science and biotechnology Vol.14 No.1

A total of six TGMS (thermosensitive genic male sterile lines) and nine pollinator lines were subjected to molecular characterization using 48 genome-wide SSR (simple sequence repeat) markers. Cluster analysis revealed clear differentiation among the TGMS lines according to their source of origin. The SSR-based genetic distance between the hybrids of the parental lines ranged from 0.36 to 0.79 suggesting a high degree of genetic divergence. Among a set of 54 hybrids generated using parental lines, 32 showed better parent heterosis (+21.7%) while 19 showed mid-parent heterosis (+15.0%). For the trait yield per plant genetic distance (GD) was negatively correlated with $F_1$ performance (r = -0.202), mid-parent heterosis (r = $-0.325^*$; P < 0.05), and better parent heterosis (r = -0.261), while it was positively correlated with specific combining ability (r = 0.042). Based on the grouped genetic distance (GGD), the hybrid combinations were divided into four groups. The GGD showed linear correlation with hybrid performance within the group (GGD = 40 - 50: r = -0.07; GGD = 70 - 80: r = 0.32). This information can be utilized in the development of higher yielding, two-line rice hybrids through selection of intermediately diverse parental lines using GGD.

Sulphide passivation of GaN based Schottky diodes

Ashish Kumar,Trilok Singh,Mukesh Kumar,R. Singh 한국물리학회 2014 Current Applied Physics Vol.14 No.3

Wet chemical passivation of n-GaN surface was carried out by dipping GaN samples in ammonium sulphide diluted in aqueous and alcoholic solvent base solutions. Photoluminescence (PL) investigations indicated that sulphide solution effectively led to the reduction of GaN surface states. Increased band edge PL peak showed that S2 ions are more active in alcohol based solvents. X-ray photoelectron spectroscopy revealed reduction in surface oxides by introduction of sulphide species. Ni/n-GaN Schottky barrier diodes were fabricated on passivated surfaces. Remarkable improvement in the Schottky barrier height (0.98 eV for passivated diodes as compared to 0.75 eV for untreated diodes) has been observed.

Management of residual gall bladder

Ashish Singh,Abhimanyu Kapoor,Rajneesh Kumar Singh,Anand Prakash,Anu Behari,Ashok Kumar,Vinay Kumar Kapoor,Rajan Saxena 한국간담췌외과학회 2018 Annals of hepato-biliary-pancreatic surgery Vol.22 No.1

Backgrounds/Aims: A residual gallbladder (RGB) following a partial/subtotal cholecystectomy may cause symptoms that require its removal. We present our large study regarding the problem of a RGB over a 15 year period. Methods: This study involved a retrospective analysis of patients managed for symptomatic RGB from January 2000 to December 2015. Results: A RGB was observed in 93 patients, who had a median age of 45 (25-70) years, and were comprised of 69 (74.2%) females. The most common presentation was recurrence pain (n=64, 68.8%). Associated choledocholithiasis was present in 23 patients (24.7%). An ultrasonography (USG) failed to diagnose RGB calculi in 10 (11%) patients; whereas, magnetic resonance cholangio-pancreatography (MRCP) accurately diagnosed RGB calculi in all the cases except for 2 (4%) and, additionally, detected common bile duct (CBD) stones in 12 patients. Completion cholecystectomy was performed in all patients (open 45 [48.4%]; laparoscopic 48 [51.6%] and 19 [20.4%] patients required a conversion to open). The RGB pathology included stones in 90 (96.8%), Mirizzi’s syndrome in 10 (10.8%) and an internal fistula in 9 (9.7%) patients. Additional procedures included CBD exploration (n=6); Choledocho-duodenostomy (n=4) and Roux-en-Y hepatico-jejunostomy (n=3). The mortality and morbidity were nil and 11% (all wound infection), respectively. Two patients developed incisional hernia during follow up. The mean follow up duration was 23.1 months (3-108) in 65 patients and the outcome was excellent and good in 97% of the patients. Conclusions: Post-cholecystectomy recurrent biliary colic should raise suspicion of RGB. MRCP is a useful investigation for the diagnosis and assessment of any associated problems and provides a roadmap for surgery. Laparoscopic completion cholecystectomy is feasible, but is technically difficult and has a high conversion rate.

Retroperitoneal lymph node metastasis in gallbladder cancer: As bad as distant metastasis

Ashish SINGH,Nalini Kanta GHOSH,Rahul RAHUL,Vinay Kumar KAPOOR,Rajan SAXENA 한국간담췌외과학회 2021 Annals of hepato-biliary-pancreatic surgery Vol.25 No.-