Direct Methanol Fuel Cells

G. K. Surya Prakash,Kimberly M. McGrath,George. A. Olah 한국공업화학회 2004 Journal of Industrial and Engineering Chemistry Vol.10 No.7

Direct Methanol Fuel Cells(DMFC)

( G. K. Surya Prakash ) 한국공업화학회 2004 한국공업화학회 연구논문 초록집 Vol.2004 No.-

Carbon-allotropes: synthesis methods, applications and future perspectives

Karthik, P.S.,Himaja, A.L.,Singh, Surya Prakash 한국탄소학회 2014 Carbon Letters Vol.15 No.4

The element carbon has been used as a source of energy for the past few hundred years, and now in this era of technology, carbon has played a significant and very prominent role in almost all fields of science and technology. So as an honour to this marvellous element, we humans should know about its various forms of existence. In this review article, we shed light on all possible carbon-allotropes; similarities in their synthesis techniques and the starting materials; their wide range of possible availability; and finally, future perspectives and applications. A brief introduction is given on the types, structures, and shapes of the allotropes of carbon for a better understanding.

Posterior Urethral Valve: Delayed Presentation in Adolescence

Punit Mahadik,Surya Prakash Vaddi,Chandra-Mohan Godala,Venkat Krishna Sambar,Sushanth Kulkarni,Ramesh Gundala 대한배뇨장애요실금학회 2012 International Neurourology Journal Vol.16 No.3

Posterior urethral valves (PUV) are now commonly suspected on antenatal ultrasound, but can present with a broad spectrum of severity postnatally. Rarely, the diagnosis is missed until adolescence or adulthood when the patient usually presents with lower urinary tract symptoms. We describe an even rarer case of PUV in a late adolescent who first presented with preserved renal function and urinary incontinence. We review the literature on presentation, natural history and outcomes of both early and late presenting PUV cases.

Challenges, Configuration, Control, and Scope of DC Microgrid Systems: A Review

Maurya Rinki,Prakash Surya,Singh Ashutosh Kumar 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

Managing natural resources and air pollution has been challenging for humans for quite a long time. A severe manifestation of natural resource mismanagement has been in the form of CO2 emissions from smoke bellowing thermal power plants (TPPs). Besides evoking global warming, the TPPs also foster limited coal reserve reduction with the increasing electricity demand. The ongoing scenario may lead to severe catastrophes until efficient plans for natural resource management are prepared. Many researchers have suggested DC microgrid as a credible alternative for power generation, significantly reducing carbon emissions. Efficient control strategies have brought microgrid technology to the level of other generation sources in terms of system reliability and efficiency. Renewable energy resources can be implemented as a safe, low voltage (< 50 V) local DC microgrid for DC load, reducing the converter requirement with low transmission losses and overcoming the scarcity of electricity. Seamless integration of solar-PV systems and batteries into the DC microgrid will increase the predominance of clean electricity in the modern power system. It will alleviate the air pollution problems generated by TPPs and sequels to enable natural resource management effectively. In light of the above facts, this paper presents a detailed survey on the challenges, configuration, control, and scope of DC microgrid systems. Various predominant configurations, recent advances in control strategies, operation challenges, and DC microgrid commissioning have been discussed. Moreover, a case study illustrating the benefits of DC systems is presented along with the energy-saving analysis compared with AC systems.

Factors Affecting Trial Without Catheter for First Spontaneous Acute Urinary Retention

Punit Mahadik,Surya Prakash Vaddi,Chandra-Mohan Godala,V. Vijaya Kumar Reddy,Venkat Krishna Sambar 대한배뇨장애요실금학회 2013 International Neurourology Journal Vol.17 No.3

Purpose: To find the association of trial without catheter (TWOC) outcome for first spontaneous acute urinary retention (AUR) in benign prostatic obstruction with age, prior lower urinary tract symptoms (LUTS), retention volume at catheterization (RV), and size of prostate. Methods: Our prospective observational analytical (interventional) study enrolled 77 cases of spontaneous AUR over 24 months. After clinical evaluation, digital rectal examination, and transabdominal ultrasonography, all patients were catheterized per urethra and their RV was recorded. TWOC was administered after 2 or 3 doses of 0.4 mg tamsulosin-oral absorption control system and after 48-72 hours had passed. A successful endpoint was defined as a maximum flow-rate, >5 mL/sec; voided volume, >100 mL; postvoid residue, <200 mL; and voiding within 6 hours of catheter removal. Data obtained from 58 patients were analyzed after excluding the cases lost to follow-up and secondary exclusion. Age, RV, duration of LUTS, and prostate volume on examination and ultrasonography (PUSG) were recorded and statistically analyzed. Prostate-specific antigen levels were obtained on follow-up and cases of cancer, as seen on transrectal ultrasound-guided biopsy, were secondarily excluded. Results: The patients had a mean age of 65.89±8.67 years. Prior LUTS was seen in 35 patients (2.07±2.91 months). The mean PUSG and RV were 46.81±20.58 mL and 854.8±36.26 mL, respectively. Thirty patients underwent a successful TWOC; a mean age of 63.13±8.58 years (mean±standard deviation; unpaired t-test; P=0.0053) and a PUSG of ≤45 mL (Pearson chi-square test; P=0.0427) were significantly associated with a successful outcome. Conclusion: There is a significant association between TWOC outcome, age (P=0.0053), and PUSG (P=0.0427).

Direct Methanol Fuel Cells

McGrath, Kimberly M.,Prakash, G. K.Surya,Olah, George. A. 한국공업화학회 2004 Journal of Industrial and Engineering Chemistry Vol.10 No.7

Over the past 15 years, the electrical performance of direct methanol fuel cells (DMFCs) has increased at least tenfold. With this advancement, portable DMFC-powered devices have come to fruition along with dramatic improvement in small power plant and transportation applications. While the DMFC has a theoretical energy density of 6094 W h/kg, only 1000-3200 W h/kg of this energy is realized in practice. Although most portable power applications only necessitate several W h/kg, performance and cost issues associated with polymer electrolyte membranes (PEMs), anode and cathode catalysts, system design, and operational considerations must be overcome for DMFCs to have a role in the methanol economy. This review covers mostly the chemistry aspects of DMFCs.

Design and Mathematical Modelling of Pressurisation System for Inflatable Aerodynamic Decelerator

Chandan Saxena,Lala Surya Prakash,Unnikrishnan S,Nikesh S,Dilip V,Radhakrishnan M 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.2

The paper depicts design philosophy of a pneumatic pressurization system configured for Inflatable Aerodynamic Decelerator (IAD). The objective is to fine tune parameters in conjunction with mathematical model allowing a better understanding of process. System configuration has been discussed and mathematical model is formulated for estimating thermodynamic properties and mass flow of gas transferring from high pressure storage to IAD through orifice. Theoretical analysis and calculations were made and compared with the simulations carried out in LMS AMESim platform. Experiments were conducted in vacuum conditions to verify pressure change in high pressure storage and in IAD and this experimental data is used for validation of mathematical model.

Robustness Analysis of LFC for Multi Area Power System integrated with SMES–TCPS by Artificial Intelligent Technique

Mandeep Sharma,Raj Kumar Bansal,Surya Prakash 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1

Load frequency control (LFC) plays an essential role in a power system (PS) to sustain the grid frequency for the period of sudden load demand variations. Hence, this manuscript deals with the execution of adaptive neuro fuzzy inference system (ANFIS) approach for LFC of three-area unequal thermal power system. The ANFIS controller proposed in the manuscript combines the advantages of Fuzzy Logic Control (FLC) as well as rapid response and flexible nature of artificial neural network. To improve the LFC performance, offered controller is simulated with superconducting magnetic energy storage (SMES) units and Thyristor controlled phase shifter (TCPS) individually and in combination. The performance of proposed ANFIS controller is superior and robust compared to existing control schemes and improved performance is observed particularly in the presence of SMES-TCPS combination. The realization of SMES & TCPS combination curtail frequency and tie power variation quickly after an unexpected load disturbance. To validate the usefulness of the proposed controller, integral time weighted absolute error (ITAE) and integral square error (ISE) performance error indices are used. Robustness of offered controller is demonstrated against wide variation in the system parameters

Molecular identity for commercially important inter-specific hybrids of Coffea using ISSR-DNA marker: implication on genetic improvement

Amruthakumar Sreedevi,Manivel Bhavatharani,Sivamani Karthiga,Sethuraman Thilaga,Rao Nyani Surya Prakash,Ganesh Doss 한국식물생명공학회 2024 Plant biotechnology reports Vol.18 No.3

Six popular and widely cultivated arabica coffee (Coffea arabica L.) varieties of commercial importance namely Selection 5B, Selection 13, Selection 11, Selection 8, Selection 7.3 and Selection 3 were tested for their genetic identity with ISSR markers. Fifteen ISSR primers were tested using genomic DNA of selected coffee varieties. Pooled genomic DNA of all the six varieties was amplified with each ISSR primer with an average of four loci per primer. The size range of locus amplified by all the fifteen primers was ranging from 100 to 1200 bp depending upon on the ISSR primers. Only three out of fifteen primers, namely ISSR4, ISSR6 and ISSR8, were screened based on the number of amplified locus and size range from low to high. The selective ISSR primers distinguished all the six varieties of coffee with unique markers. ISSR 4 amplified two unique markers with a locus size 1300 bp and 950 bp for Sln.5B and 180 bp and 150 bp for Sln.13. ISSR6 had produced five varietal-specific markers with a locus size of 180 bp in Sln.5B, 1250 bp in Sln.11, 350 bp in Sln.3. ISSR8 had amplified seven unique loci across the coffee varieties with 700 bp and 800 bp in Sln.5B, 200 bp and 500 bp in Sln.11 and one locus each in Sln.7.3 and Sln.3 with 300 bp and 150 bp respectively. Repeated amplification of genomic DNA of all the six varieties of coffee with selective ISSR primers produced consistent ISSR genetic fingerprints. Selective ISSR primers were validated with marker parameters resolving power (RP), effective multiplex ratio (EMR), marker index (MI) and polymorphic information content (PIC). Utilisation of these markers in arabica coffee genetic improvement is discussed.