Arsenic adsorption on goethite nanoparticles produced through hydrazine sulfate assisted synthesis method

Malay Kumar Ghosh,Gérrard Eddy Jai Poinern,Touma B. Issa,Pritam Singh 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.1

Goethite nanoparticles synthesized using hydrazine sulfate as a modifying agent were evaluated for As(V)adsorption capacity. The nanoparticles were characterized for their morphological and structural features. The precipitated goethite particles were spherical with particle size of less than 10 nm. Batch adsorption study was carried out systematically varying parameters such as pH, contact time, initial As(V) concentration and adsorbent doses. The Langmuir isotherm represented the equilibrium data well and the estimated monolayer adsorption capacity at ambient temperature was 76 mg/g, which is significantly higher than most of the adsorbents reported in the literature. Adsorption kinetic data were better represented by the pseudo-second order kinetic model. Intra-particle diffusion played a significant role in the rate controlling process in the initial hour. Desorption study showed that the loaded adsorbent could be regenerated when treated with dilute sodium hydroxide solution of pH 13.

Semiparametric Stein estimators

Malay Ghosh,김달호 한국통계학회 2009 Journal of the Korean Statistical Society Vol.38 No.3

Stein [Stein, C. (1956). Inadmissibility of the usual estimator for the mean of a multivariate normal distribution. In Proc. 3rd Berkeley symp. math. statist. and pro. (pp. 197206). University of California Press], in his seminal paper, came up with the surprising discovery that the sample mean is an inadmissible estimator of the population mean in three or higher dimensions under squared error loss. The past five decades have witnessed multiple extensions and variations of Stein's results. In this paper we develop Stein-type estimators in a semiparametric framework and prove their coordinatewise asymptotic dominance over the sample mean in terms of Bayes risks.

Evaluation of a Real-Time PCR Assay for Simultaneous Detection of Kingella kingae and Staphylococcus aureus from Synovial Fluid in Suspected Septic Arthritis

Malay Haldar,Meghan Butler,Criziel D. Quinn,Charles W. Stratton,Yi-Wei Tang,Carey-Ann D. Burnham 대한진단검사의학회 2014 Annals of Laboratory Medicine Vol.34 No.4

Direct plating of synovial fluid (SF) on agar-based media often fails to identify pathogens in septic arthritis (SA). We developed a PCR assay for the simultaneous detection of Kingella kingae and Staphylococcus aureus from SF to evaluate molecular detection in SF and to estimate the incidence of K. kingae in SA in North America. The assay was based on de- tection of the cpn60 gene of K. kingae and the spa gene of S. aureus in multiplex real-time PCR. K. kingae was identified in 50% of patients between 0 and 5 yr of age (n=6) but not in any patients >18 yr old (n=105). Direct plating of SF on agar-based media failed to de- tect K. kingae in all samples. The PCR assay was inferior to the culture-based method for S. aureus , detecting only 50% of culture-positive cases. Our findings suggest that K. kingae is a common pathogen in pediatric SA in North America, in agreement with previous reports from Europe. PCR-based assays for the detection of K. kingae may be considered in chil- dren with SA, especially in those with a high degree of clinical suspicion.

High Embedding Capacity and Robust Audio Watermarking for Secure Transmission Using Tamper Detection

Arashdeep Kaur,Malay Kishore Dutta 한국전자통신연구원 2018 ETRI Journal Vol.40 No.1

Robustness, payload, and imperceptibility of audio watermarking algorithms are contradictory design issues with high-level security of the watermark. In this study, the major issue in achieving high payload along with adequate robustness against challenging signal-processing attacks is addressed. Moreover, a security code has been strategically used for secure transmission of data, providing tamper detection at the receiver end. The high watermark payload in this work has been achieved by using the complementary features of third-level detailed coefficients of discrete wavelet transform where the human auditory system is not sensitive to alterations in the audio signal. To counter the watermark loss under challenging attacks at high payload, Daubechies wavelets that have an orthogonal property and provide smoother frequencies have been used, which can protect the data from loss under signal-processing attacks. Experimental results indicate that the proposed algorithm has demonstrated adequate robustness against signal processing attacks at 4,884.1 bps. Among the evaluators, 87% have rated the proposed algorithm to be remarkable in terms of transparency.

Comprehensive Investigations on QUEST: a Novel QoS-Enhanced Stochastic Packet Scheduler for Intelligent LTE Routers

( Suman Paul ),( Malay Kumar Pandit ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.2

In this paper we propose a QoS-enhanced intelligent stochastic optimal fair real-time packet scheduler, QUEST, for 4G LTE traffic in routers. The objective of this research is to maximize the system QoS subject to the constraint that the processor utilization is kept nearly at 100 percent. The QUEST has following unique advantages. First, it solves the challenging problem of starvation for low priority process - buffered streaming video and TCP based; second, it solves the major bottleneck of the scheduler Earliest Deadline First’s failure at heavy loads. Finally, QUEST offers the benefit of arbitrarily pre-programming the process utilization ratio. Three classes of multimedia 4G LTE QCI traffic, conversational voice, live streaming video, buffered streaming video and TCP based applications have been considered. We analyse two most important QoS metrics, packet loss rate (PLR) and mean waiting time. All claims are supported by discrete event and Monte Carlo simulations. The simulation results show that the QUEST scheduler outperforms current state-of-the-art benchmark schedulers. The proposed scheduler offers 37 percent improvement in PLR and 23 percent improvement in mean waiting time over the best competing current scheduler Accuracy-aware EDF.

Multiple Scale Analysis of a Delayed Predator Prey Model within Random Environment

Tapan Saha,Malay Bandyopadhyay 한국전산응용수학회 2008 Journal of applied mathematics & informatics Vol.26 No.5

We consider a delayed predator prey model. The local stability and Hopf bifurcation results are stated taking the time delay as a control parameter. We apply multiple scale analysis to analyze the effects of additive white noises near the Hopf bifurcation point at the positive interior equilibrium state. The governing equations for the amplitude of oscillations on a slow time scale are derived. We identify the process of amplitude of oscillations and derive its transient properties. We show that oscillations, which would decay in the deterministic system whenever time delay lies below its critical value, persists for long time under the validity of multiple scale analysis.. We consider a delayed predator prey model. The local stability and Hopf bifurcation results are stated taking the time delay as a control parameter. We apply multiple scale analysis to analyze the effects of additive white noises near the Hopf bifurcation point at the positive interior equilibrium state. The governing equations for the amplitude of oscillations on a slow time scale are derived. We identify the process of amplitude of oscillations and derive its transient properties. We show that oscillations, which would decay in the deterministic system whenever time delay lies below its critical value, persists for long time under the validity of multiple scale analysis..

Physiological and Biochemical Monitoring of Indian Female Hockey Players

( Pralay Majumdar ),( Malay Mandal ),( Devashish Yadav ),( Ankush Gupta ) 한국스포츠정책과학원(구 한국스포츠개발원) 2008 International Journal of Applied Sports Sciences Vol.20 No.2

Female hockey is a sport, which requires moderate to good aerobic capacity. The present study was taken up to find out the iron status of Indian female hockey players and its changes in six week training. The iron supplementation was administered to find out the recovery. The experiment was performed on 21 female hockey players age 16 to 26 in the laboratory (25 ℃ and 60% relative humidity). All the parameters estimated at the initial and final phase of the training camp of six weeks. Iron supplementation significantly (p<0.01) improve hemoglobin level, pre and post test depicts it increases the percentage of certain iron deficiency from 42% to 57%. The players demonstrated high CPK level, LDH found significantly higher (p<0.05) when compared to the previous test results. Sudden increase of training load possibly causes muscle hypoxia that results efflux of muscle enzyme CPK and LDH, VO2max, PWC170has shown significant (p<0.01) improvement. Iron and TIBC level were found significant (p<0.01) in post test. Iron supplementation improved Hb level but no effect on serum ferritin. High training stresses possibly cause certain iron deficiency. So it is recommended that female hockey players participating in team sports should be checked regularly for iron and Hb status and CPK/LDH, which is a handy tool to understand overreaching/overtraining.

The Effectiveness of Training Routine with Reference to the Physiological Demand of Squash Match Play

( Pralay Majumdar ),( Malay Mandal ),( Devashish Yadav ) 한국스포츠정책과학원(구 한국스포츠개발원) 2009 International Journal of Applied Sports Sciences Vol.21 No.1

Purpose: The present study was taken up to monitor the physiological demands of squash play based on heart rate and lactate response while in a competitive situation. Four on court specific training programs were evaluated based on lactate response and performance time to find out their effectiveness with the actual demands of the game. Method: 33 male and 9 female junior squash players volunteered for this study. Body fat was calculated indirectly from skin fold thickness a using Harpenden skin fold caliper at four sites: biceps, triceps, sub scapular and supra iliac. Body fat was calculated from body density. The cardio respiratory variables (VO2 max) at maximal effort were determined during a graded protocol of running on a treadmill starting from 8 Km/hr and increasing every 2 min. at the rate of 2 km/hr till volitional exhaustion. The expired air sample was analyzed by Gas Analyzer (Oxycon Champion-Germany). Four on court drills were monitored and lactate level and timing/court coverage were registered. For estimating whole blood lactate, capillary blood samples were drawn from a finger tip between 2 min and 3 min. after the cessation of the activity. The samples were analyzed in a calibrated automatic lactate analyzer in order to estimate whole blood lactate. The data were subjected to statistical treatment such as mean and standard deviation. One-way ANOVA were computed to assess the difference in heart rate and lactate among the three games. Result: Repeated measures of ANOVA demonstrated no significance difference observed in gender in terms of heart rate and lactate response during three games. The heart rate response in males ranged from 157-177, 162-182 and 165-182 beats. min-1 for games 1, 2 and 3 respectively. In females, the heart rate response in 3 games revealed 156-181, 165-183 and 163-181 beats. min-1. Peak game lactate found for males and females were 4.10 and 4.14 mM.l-1 achieved after the third and second game respectively. Estimated peak lactate in four on court drills i.e. ghosting, court run, agility and box sprints were 10.66±3.07, 14.00±1.79, 16.90±2.80 and 13.11±2.40 for males and 12.251.79, 13.78±2.17, 17.30±2.53 and 13.46±4.37 mM.l-1 for females respectively. Conclusion: In all the on court drills, the level of blood lactate was much higher than game lactate. The higher lactate levels cause metabolic acidosis and therefore may not prove to be an effective training routine unless modified in terms of duration/intensity to optimize training benefit.

Dynamical analysis of a plant-herbivore model : bifurcation and global stability

Tapan Saha,Malay Bandyopadhyay 한국전산응용수학회 2005 Journal of applied mathematics & informatics Vol.19 No.1-2

The first part of the paper deals with a brief introduction of the plant-herbivore model system along with deterministic analysis of local stability and Hopf-bifurcations. The second part consists of stability analysis of the limit cycle arising from Hopf-bifurcation and uniqueness of limit cycle. The third part deals with the study of global stability of the model system under consideration.

Room Temperature Synthesis of Perovskite Hydroxide, MnSn(OH)6: A Negative Electrode for Supercapacitor

Manas Mandal,Krishna Chattopadhyay,Malay Chakraborty,Wonjae Shin,Kamal Kanti Bera,Sujit Chatterjee,Akbar Hossain,Dipanwita Majumdar,Arup Gayen,Changwoon Nah,Swapan Kumar Bhattacharya 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.6

A negative electrode is constructed based on MnSn(OH)6 nanocubes prepared by a simple precipitation method at roomtemperature for supercapacitor application. The as-prepared material was structurally and morphologically characterizedwith the help of XRD, FT-IR, Raman, XPS, FESEM, and HRTEM analyses. The uniform structure and fine edge morphologywith high conductivity due to oxygen vacancies promote the redox reaction, which results in high pseudocapacitance. Theelectrochemical performance is investigated through a three-electrode cell system in a negative potential window (− 1.0 to0.0 V). A maximum specific capacitance of 209 F/g is calculated at a specific current of 1 A/g. The electrodes also exhibitexcellent cycling stability (79% specific capacitance retention after 3000 consecutive GCD cycles).