Reliability-based approach for fragility assessment of bridges under floods

Raj Kamal Arora,Swagata Banerjee 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.88 No.4

Riverine flood is one of the critical natural threats to river-crossing bridges. As floods are the most-occurred natural hazard worldwide, survival probability of bridges due to floods must be assessed in a speedy but precise manner. In this regard, the paper presents a reliability-based approach for a rapid assessment of failure probability of vulnerable bridge components under floods. This robust method is generic in nature and can be applied to both concrete and steel girder bridges. The developed methodology essentially utilizes limit state performance functions, expressed in terms of capacity and flood demand, for probable failure modes of various vulnerable components of bridges. Advanced First Order Reliability Method (AFORM), Monte Carlo Simulation (MCS), and Latin Hypercube Simulation (LHS) techniques are applied for the purpose of reliability assessment and developing flood fragility curves of bridges in which flow velocity and water height are taken as flood intensity measures. Upon validating the proposed method, it is applied to a case study bridge that experiences the flood scenario of a river in Gujarat, India. Research outcome portrays how effectively and efficiently the proposed reliability-based method can be applied for a quick assessment of flood vulnerability of bridges in any flood-prone region of interest.

The effect of annealing in forming gas on the a-IGZO thin film transistor performance and valence band cut-off of IGZO on SiNx

Raj Kamal,Piyush Chandravanshi,최덕균,Santosh M. Bobade 한국물리학회 2015 Current Applied Physics Vol.15 No.5

In this investigation, the carrier concentration gradient between channel and contact region is achieved to improve the Thin film Transistors (TFT) performance by employing annealing at 350 ℃ in forming gas (N2 + 5% H2). The contact region is covered with Mo metal and the channel region is only exposed to forming gas to facilitate the diffusion controlled reaction. The TFT using a-IGZO active layer is fabricated in ambient of Ar:O2 in ratio 60:40 and the conductivity of the order of 10-3 S/cm is measured for asdeposited sample. The electrical conductivity of an annealed sample is of the order of 102 S/cm. The device performance is determined by measuring merit factors of TFT. The saturation mobility of magnitude 18.5 cm2V-1 s-1 has been determined for W/L (20/10) device at 15 V drain bias. The extrapolated field effect mobility for a device with channel width (W) 10 mm is 19.3 cm2V-1 s-1. The on/ off current ratio is 109 and threshold voltage is in the range between 2 and 3 V. The role of annealing on the electronic property of a-IGZO is carried out using X-ray photoelectron spectroscopy (XPS). The valance band cut-off has been approximately shifted to higher binding energy by 1 eV relative to asdeposited sample.

Population structure, behavior, and current threats to the sarus crane (Grus antigone antigone) in Nepal

Kamal Raj Gosai,Tej Kumar Shrestha,Samuel D. Hill,Surya Man Shrestha,Bigya Gyawali,Daya Nidhi Gautam,Achyut Aryal 국립중앙과학관 2016 Journal of Asia-Pacific Biodiversity Vol.9 No.3

The sarus crane (Grus antigone antigone) is listed as “vulnerable” in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Sarus cranes are distributed in the lowlands, but most live outside protected areas, especially in agricultural areas and wetlands of Nepal. The continuous expansion of agricultural land and the reduction of wetland habitats pose the greatest threats to the conservation of the species. We studied the sarus crane in the Rupandehi District of Nepal to understand their population structure, behavior, and current threats. We used the line (i.e., road) transect method from August 2013 to February 2014. The study area contained 147 sarus cranes. Agricultural land and wetland areas contained the highest number of sarus cranes. Our analysis showed that the population of sarus crane in the area has declined since 2007. Most sarus cranes lived in pairs. A single flock contained 13 cranes at maximum. Sarus crane behavior was not significantly different before and after the breeding seasons. Human–sarus crane conflict began when cranes started utilizing agricultural areas. The main threats to the hatching success and survival of sarus cranes in the Rupendehi District are egg theft and the hunting of cranes for meat. The findings of this study establish baseline information on the overall conservation status, habitat availability, and ecological behavior of sarus cranes in the district. We propose regular surveys to monitor sarus crane population levels in the face of multiple anthropogenic threats to their survival.

Rheological studies of performance grade bitumens prepared by blending elastomeric SBS (styrene butadiene styrene) co-polymer in base bitumens

Kamal Kumar,Anand Singh,Samir K. Maity,Manoj Srivastava,Manisha Sahai,Raj K. Singh,Madhukar O. Garg 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.44 No.-

Performance of bituminous binder in terms of viscoelastic behavior can be improved by addition ofrequisite polymers. Two performance grade bituminous binder PG58 and PG64 were prepared byblending an elastomeric styrene butadiene styrene (SBS) co-polymer in 60/70 and 80/100 grade basebitumen respectively. The rheological properties of prepared bitumens have been studied by AR 1500 eXAsphalt Rheometer at minimum instrument inertia of 16.85 mNm2. Resistance to permanentdeformation or deformation resistance is also determined in terms of G0modified bitumen/G0base bitumen,G00modified bitumen/G00base bitumen and G*modified bitumen /G*base bitumen; which helps to predict the viscoelasticbehavior of bituminous binder.

First Synthesis of Highly Crystalline, Hexagonally Ordered, Uniformly Mesoporous TiO₂–B and Its Optical and Photocatalytic Properties

Hossain, Md. Kamal,Koirala, Agni Raj,Akhtar, Umme Sarmeen,Song, Mee Kyung,Yoon, Kyung Byung American Chemical Society 2015 Chemistry of materials Vol.27 No.19

Steam-assisted synthesis of uniformly mesoporous anatase and its remarkably superior photocatalytic activities

Hossain, Md. Kamal,Akhtar, Umme Sarmeen,Koirala, Agni Raj,Hwang, In Chul,Yoon, Kyung Byung Elsevier 2015 CATALYSIS TODAY - Vol.243 No.-

<P><B>Abstract</B></P> <P>The steam treatment of hexagonally ordered uniformly mesoporous (<I>h</I>-UM) amorphous TiO<SUB>2</SUB> at 120°C for 1h leads to highly crystalline <I>h</I>-UM anatase. This process is feasible for the large scale (>50g) preparation. The surface area-normalized photocatalytic activities of <I>h</I>-UM anatase for water reduction and methylene blue and 4-chlorophenol decompositions are remarkably superior to those of wormhole-like randomly mesoporous anatase and anatase nanoparticles, demonstrating an important reason to prepare anatase in UM forms. Due to the extended crystalline interconnection, the band gap energy <I>h</I>-UM anatase decreases by 0.22eV with respect to that of 25nm anatase nanoparticle.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel steam assisted highly crystalline ordered mesoporous anatase TiO<SUB>2</SUB>. </LI> <LI> High surface area with uniformly distributed hexagonal large pores is reported. </LI> <LI> Remarkably higher rate of H<SUB>2</SUB> production from water under one sun light condition. </LI> <LI> Superior photocatalytic dye degradation (MB and 4-CP) under low pressure Hg lamp. </LI> <LI> The extended crystalline interconnection decreases the band gap energy by 0.22eV. </LI> </UL> </P>

Preparation and Characterization of Bioceramic Nanocomposites Based on Hydroxyapatite (HA) and Carboxymethyl Cellulose (CMC)

Annamalai Pratheep Kumar,Kamal Khaja Mohaideen,Sameh A. S. Alariqi,Raj Pal Singh 한국고분자학회 2010 Macromolecular Research Vol.18 No.12

We report the synthesis of biomimetic nanocomposites based on carboxymethyl cellulose (CMC) and hydroxyapatite (HA) nanoparticles via a co-precipitation method. Physico-chemical characterization was performed before and after calcination by Fourier transform infrared (FTIR) spectroscopy, solid state 31P nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). The formation of nanocomposites was observed by wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM) with energy dispersive Xray analysis (EDX), and transmission electron microscopy (TEM). The spectral and crystallographic data indicated the formation of hydroxyapatite in the presence of CMC. They were observed as aggregates of HA nanoparticles and CMC, whose sizes were approximately ~ 260 ± 40 nm. The crystallite size of the hydroxyapatite particles decreased (with 2 wt% 18 ± 3 nm) with increasing CMC content. The morphological aspects of the calcined samples revealed the sintering ability of HA nanoparticles. Nanocomposites of hydroxyapatite nanoparticles that mimic the process of nucleation and growth in nature can be prepared using biomacromolecules such as CMC.

FINITE ELEMENT MODEL TO STUDY TWO DIMENSIONAL UNSTEADY STATE CYTOSOLIC CALCIUM DIFFUSION

Tewari, Shivendra Gajraj,Pardasani, Kamal Raj The Korean Society for Computational and Applied M 2011 Journal of applied mathematics & informatics Vol.29 No.1

Calcium is a vital second messenger for signal transduction in neurons. Calcium plays an important role in almost every part of the human body but in neuronal cytosol, it is of utmost importance. In order to understand the calcium signaling mechanism in a better way a finite element model has been developed to study the flow of calcium in two dimensions with time. This model assumes EBA (Excess Buffering Approximation), incorporating all the important parameters like time, association rate, influx, buffer concentration, diffusion constant etc. Finite element method is used to obtain calcium concentration in two dimensions and numerical integration is used to compute effect of time over 2-D Calcium profile. Comparative study of calcium signaling in two dimensions with time is done with other important physiological parameters. A MATLAB program has been developed for the entire problem and simulated on an x64 machine to compute the numerical results.

Finite Element Model to Study Two Dimensional Unsteady State Cytosolic Calcium Diffusion

Shivendra Gajraj Tewari,Kamal Raj Pardasani 한국전산응용수학회 2011 Journal of applied mathematics & informatics Vol.29 No.1

Calcium is a vital second messenger for signal transduction in neurons. Calcium plays an important role in almost every part of the human body but in neuronal cytosol, it is of utmost importance. In order to understand the calcium signaling mechanism in a better way a finite element model has been developed to study the flow of calcium in two dimensions with time. This model assumes EBA (Excess Buffering Approximation), incorporating all the important parameters like time, association rate, influx, buffer concentration, diffusion constant etc. Finite element method is used to obtain calcium concentration in two dimensions and numerical integration is used to compute effect of time over 2-D Calcium profile. Comparative study of calcium signaling in two dimensions with time is done with other important physiological parameters. A MATLAB program has been developed for the entire problem and simulated on an x64 machine to compute the numerical results.

A Comparative Study between the Use of Biliary Stent and T-Tube for Biliary Decompression after Laparoscopic Common Bile Duct Exploration

( Vikesh Vij ),( Rahul Yadav ),( Jeevan Kankaria ),( Raj Kamal Jenaw ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Laparoscopic common bile duct exploration (LCBDE) and cholecystectomy as a single-stage treatment of choledocholithiasis have been shown to be superior when compared to the two stage management. Decompression after supra-duodenal choledochotomy is common practice as it reduces the chance of bile leaks. We conducted a randomized comparative study to compare the feasibility and outcomes in patients undergoing biliary stent insertion versus T-tube drainage following LCBDE via choledochotomy. Methods: The study involved 64 patients with choledocholithiasis, half of which underwent biliary decompression after LCBDE using biliary stent and in the other half T-tube was used. Results: Patients in the stent group had significantly shorter operative time, lesser post-operative complications, lesser hospital stay and earlier return to normal activity (P<0.001). Conclusions: In our study, we found there is a significant reduction in length of hospital stay and morbidity for patients that have ante-grade biliary stent decompression of the CBD post laparoscopic choledochotomy when compared to T-Tube drainage. This implies that ante grade biliary stent insertion is likely to reduce costs and increase overall patient satisfaction.