Numerical Investigation on Gas Bubbling Assisted Inclusion Transport and Removal in Multistrand Tundish

Vipul Kumar Gupta,Pradeep Kumar Jha,Pramod Kumar Jain 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

In continuous casting, the molten metal quality in the mold is affected by flow pattern, temperature distribution and inclusiontransport in the multistrand tundish. Natural convection due to thermal buoyancy directly influences these parameters andwith gas bubbling, further improvisation can be made. In the present work, numerical investigation of the effect of thermalbuoyancy is carried out to examine the flow field, temperature distribution and inclusion trajectories. Further, gas bubblingcurtain modeling using the Euler-Euler approach is performed for the different locations on the bottom wall of the tundishand quantitative analysis of tundish performance is presented using residence time distribution (RTD) curves. The resultsshow that big circulation loop generated due to thermal buoyancy assists in inclusion removal and mixing at each outlet. Gas bubbling increases the molten metal flow velocity in the central region of tundish, leading to a decrease in the dimensionlessnumber Gr/Re2 near the outlets which are far away from the inlet of the tundish i.e. outlet 2 and outlet 3. Hence, thedominance of natural convection decreases. The inclusion removal rate is found to increase significantly as the circulationloop formed at each side of the curtain forces them upward direction. However, the reported inclusion removal rate in gasbubbling cases is found to be independent of particle size and curtain location.

Production of Hepatotoxin by the Cyanobacterium Scytonema sp . Strain BT 23

(Kumar),(Ashok),(D . P . Singh),(M . B . Tyagi),(Arvind Kumar),(E . G . Prasuna),(J . K . Thakur) 한국미생물생명공학회 2000 Journal of microbiology and biotechnology Vol.10 No.3

N/A N/A

Estimating Total Factor Productivity and Its components - Evidence from Manufacturing Sector of Tamilnadu, India

Kumar,T. Sampath,Pradeep V. 한국유통과학회 2019 KODISA ICBE (International Conference on Business Vol.2019 No.-

The study applied Data Envelopment Analysis (DEA) to estimate total factor productivity growth and to identify the sources of productivity growth in the manufacturing sector of Tamil Nadu. The study considered 12 major sectors and estimated productivity growth and the major sources of productivity growth during the period 1981-82 to 2007-08. The study found that the productivity growth in the industrial sector of Tamil Nadu at the aggregate level during the test period was almost nil. While it is the case at the aggregate level, there are mixed results at the sectoral level. During the pre-reform period, there was significantly higher productivity growth in almost all the sectors contributed mainly by the improvements in efficiency. On other hand, there was productivity deterioration in the post-reform period since almost all the sectors witnessed negative productivity growth despite a technical change in the post-reform period. The study based on the empirical findings suggests that there will be productivity growth only if any improvement in the technology is accompanied by the corresponding improvement in the efficiency with which the technology can be turned into productivity gains. A well developed and skilled labour force along with the improvements in the technological developments will lead to higher productivity growth in the manufacturing sector both at the aggregate and sectoral level.

Investigation on the Effect of Asymmetric Cyclic Loading on Ratcheting Deformation and Bulk Texture Development in HSLA Steel

Pushpendra Kumar Dwivedi,R. Vinjamuri,S. K. Sahoo,Krishna Dutta 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

Ratcheting deformation in association with bulk texture evolution in HSLA steel is studied in this investigation. The cyclicdeformation behaviors and damage modes of the specimens are obtained at room temperature, employing asymmetric stresscontrolledtests under various combinations of mean stress and stress amplitudes. Bulk texture measurements of the specimensare done adopting an X-ray diffraction analysis. The results exhibit an increase in strain accumulation from 0.23 to 30.61%associated with a sharp reduction in ratcheting life from 3320 to 880 cycles by the increment in mean stress/stress amplitude. A continuous cyclic softening until the final failure is observed for all the ratcheting tests. It is noticed that variation of meanstress is more detrimental than stress amplitude in controlling strain accumulation while the effect of stress amplitude is morepronounced than mean stress for the reduction of ratcheting life. The fracture surface morphology indicates typical striationformation in the crack propagation region along with overload failure. The bulk texture studies indicate that there is a transitionbetween ‘ϒ’ fiber and ‘ζ’ fiber during all loading conditions. The texture intensity is increased from 5.71 to 11.68 withprogressive ratcheting strain accumulation. Here also, influence of stress amplitude is more significant than the mean stress.

An investigation into the efficiency of biocides in controlling algal biofouling in seawater industrial cooling towers

Al-Bloushi Mohammed,Saththasivam Jayaprakash,Jeong Sanghyun,Al-Refaie Abdullah,Raju S. Arun Kumar1,Choon NG Kim,Amy L. Gary,Leiknes TorOve 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.6

Biofouling in the open recirculating cooling water systems may cause biological corrosion, which can reduce the performance, increase the energy consumption and lower heat exchange resulting in reduced efficiency of the cooling tower (CT). Seawater CTs are prone to bio-fouled due to the presences of organic and inorganic compounds which act as nourishment for various microorganisms like (algae, fungi, and bacteria) for their growth under certain environmental conditions. The most commonly being used method to control the biofouling in CT is by addition of biocides such as chlorination. In this study, diatom and green algae were added to the CT basin and its viability was monitored in the recirculating cooling seawater loop as well as in the CT basin. Three different types of oxidizing biocides, namely chlorine, chlorine dioxide (Chlorine dioxide) and ozone, were tested by continuous addition in pilot-scale seawater CTs and it was operated continuously for 60 d. The results showed that all biocides were effective in keeping the biological growth to the minimum regardless of algal addition. Amongst the biocides, ozone could reduce 99% of total live cells of bacteria and algae, followed by Chlorine dioxide at 97%, while the conventional chlorine showed only 89% reduction in the bioactivities.

Protective efficacy of Coriandrum sativum seeds against arsenic induced toxicity in Swiss albino mice

Kumar Arun,Kumar Vikas,Akhouri Vivek,Kumar Ranjit,Ali Mohammad,Rashmi Tuhin,Chand Gyanendra Bahadur,Singh Sushil Kumar,Ghosh Ashok Kumar 한국독성학회 2022 Toxicological Research Vol.38 No.4

Arsenic poisoning in ground water is one of the most sensitive environmental pollutant causing serious pollution all over the world. Chronic arsenic exposure through drinking water to humans leads to major public health related issues. There have been very meagre studies which reported that, the plant constituents proved to exhibit protective effect from arsenicosis. Therefore, the present study aims to evaluate the protective efficacy of Coriandrum sativum seeds extract against sodium arsenite induced toxicity in Swiss albino mice. In the present study twenty-four male healthy Swiss albino mice (30 ± 5 g) were divided into four groups (n = 6), where the control group received normal diet and water; group II and group III treated with sodium arsenite (2 mg per kg body weight per day) for 2 and 4 weeks respectively. The group IV mice were administered with C.sativum seeds extract at the dose of 150 mg per kg body weight per day for 4 weeks upon sodium arsenite pretreated (2 mg/kg body weight for 4 weeks per day) mice. After the complete dose duration, all the treatment group animals were sacrificed same day for haematological, biochemical and histopathological study. In the arsenic treated mice, there were significant (p < 0.0001) changes in the serum levels of ALT, AST, ALP, urea, uric acid and creatinine as well as in the haematological parameters. In contrast, after the administration with C.sativum seeds extract upon arsenic pretreated mice, there was significant (p < 0.0001) improvement observed in the hepatic and renal biomarker parameters as well as haematological variables. In the arsenic intoxicated mice, after administration with C.sativum seeds extract there was significant (p < 0.0001) reduction in the arsenic concentration in blood, liver and kidney tissues as well as in the serum LPO levels. Furthermore, the histopathological study showed that, C.sativum seeds extract administrated group of mice significantly restored the liver and kidney at cellular level against arsenic induced toxicity. The entire study concludes that C.sativum seeds extract possesses the ameliorative effect against arsenic induced liver and kidney intoxication.

Identifying the leaders and main conspirators of the attacks in terrorist networks

Abhay Kumar Rai(Abhay Kumar Rai ),Sumit Kumar(Sumit Kumar ) 한국전자통신연구원 2022 ETRI Journal Vol.44 No.6

This study proposes a novel method for identifying the primary conspirators involved in terrorist activities. To map the information related to terrorist activities, we gathered information from different sources of real cases involving terrorist attacks. We extracted useful information from available sources and then mapped them in the form of terrorist networks, and this mapping provided us with insights in these networks. Furthermore, we came up with a novel centrality measure for identifying the primary conspirators of a terrorist attack. Because the leaders of terrorist attacks usually direct conspirators to conduct terrorist activities, we designed a novel algorithm that can identify such leaders. This algorithm can identify terrorist attack leaders even if they have less connectivity in networks. We tested the effectiveness of the proposed algorithms on four real-world datasets and conducted an experimental evaluation, and the proposed algorithms could correctly identify the primary conspirators and leaders of the attacks in the four cases. To summarize, this work may provide information support for security agencies and can be helpful during the trials of the cases related to terrorist attacks.

Highly Efficient Photocatalytic Studies on Bi36 Fe2 O57 Ceramic Synthesized by Chemical Route

Manish Kumar Verma,Vinod Kumar,Upakar Patel,Vishnu Shankar Rai,Anup Kumar,Arup Kumar De,Aditya Kumar Prajapati,Dinesh Prajapati,Kedar Sahoo,Tapas Das,N. B. Singh,K. D. Mandal 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.5

Bi36 Fe2 O57 (BFO) polycrystalline ceramic was synthesized by economical chemical route. The single-phase formation of BFO ceramic was confirmed by powder X-ray diffraction studies. Nanosized formation of BFO ceramics established by XRD and TEM analysis. The bimodal distribution of grain size is observed with size ranging from 50 to 600 nm. It observed that the Bi36 Fe2 O57 photocatalyst exhibited higher catalytic activity for the degradation of Methylene Blue (MB) under visible-light irradiation The oxidation state of elements present in the BFO ceramic, was confirmed by XPS studies. The pseudocapacitive nature of BFO ceramic was observed by cyclic Voltammetry. The dielectric constant of BFO ceramic was found 375 at 1 kHz at 300 K. The dielectric loss was found 0.51 at 100 kHz and 300 K.

Study of electronic structure and dielectric properties of Gd-doped cobalt nanoferrites

Kumar Arvind,Gora Mahendra Kumar,Kumar Sanjay,Choudhary Banwari Lal,Singhal Rishi Kumar,Dolia Satya Narain 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.81 No.9

The current article explores the dielectric and electronic properties of cobalt ferrite nanoparticles with Gd substitution in a series CoGdxFe2-xO4 (0≤x≤0.1, in step x=0.02) synthesized by the sol–gel self-combustion way. All the samples were studied with Fourier transform infra-red (FTIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and impedance (dielectric) analyzer. One absorption band (υ1) was observed in FTIR measurements, which is the characteristic feature of spinel nanoferrites in fcc type structure. The presence of active Raman modes in Raman spectra at room temperature demonstrated single phase formation of cobalt nanoferrites with metallic–metallic and metallic–oxygen bonding vibrations in the tetrahedral and octahedral sites. XPS data analysis confrmed phase purity and revealed incorporation of Gd ion in the spinel fcc lattice. The valence states of Fe, Co & Gd atoms in all these nanoparticles are found as Fe3+, Co2+, & Gd3+. The dielectric constant and dielectric loss are measured in a broad frequency range of 100 Hz to 120 MHz. The dielectric constant reduces with a rise in Gd concentration and frequency. This study reveals that electronic and dielectric properties could be efectively tuned by varying concentrations of gadolinium in cobalt ferrite nanoparticles.

p16 Expression as a Surrogate Marker for HPV Infection in Esophageal Squamous Cell Carcinoma can Predict Response to Neo-Adjuvant Chemotherapy

Kumar, Rajeev,Ghosh, Sankar Kumar,Verma, Akalesh Kumar,Talukdar, Anuradha,Deka, Monoj Kumar,Wagh, Mira,Bahar, H.M. Iqbal,Tapkire, Ritesh,Chakraborty, Kali Pankaj,Kannan, R. Ravi Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

Background: Esophageal squamous cell carcinoma (ESCC) is a common cancer in the north east of India. The present study concerned the prevalence of human papilloma virus (HPV) in the ESCC in north eastern India and its impact on response to chemotherapy. Materials and Methods: p16 expression, a surrogate marker for HPV infection was assessed in 101 pre-treatment biopsies of locally advanced ESCC, reported from a comprehensive cancer centre in north east India, using immunohistochemistry. All patients received neo-adjuvant chemotherapy. Response was assessed clinically and histopathologically with attention to p16 expression. Results: p16 was expressed in 22% of ESCC (22 out of 101) and was more prevalent in patients who were more than 45 years of age (P=0.048). p16 positive tumors appeared more commonly in the upper 2/3 of the thoracic esophagus (18 in 22). Nine of the 22 (41%) p16 positive tumors achieved pathologic complete response following neo-adjuvant chemotherapy (P=0.008). There was a trend towards reduced mortality in this group (P=0.048). Some 9 of the 20 (45%) patients who achieved pathologic complete response were p16 positive. Conclusions: Expression of p16 in ESCC correlates with higher rate of pathologic complete remission in patients undergoing neo adjuvant chemotherapy and could be a predictive marker for response assessment.