Effect Of Silica Supported Platinum Catalyst On The Performance And Durability Of PEM Fuel Cells

Proton exchange membrane fuel cells (PEMFCs) have a unique property of zero (ultra-low) emission and provide significant technical and overall cost advantages compared to other types of fuel cells. As a result, PEMFCs have attracted considerable attention as an alternative power source for stationary and mobile applications. However, the PEMFCs are yet to realize mass-market commercialization hindered mainly by its poor durability. Therefore, numerous research efforts have been devoted to studying the durability of PEMFCs, motivated by the desire to improve its lifetime without unduly increasing cost or compromising performance. The catalyst support largely determines the stability of supported platinum group metal (PGM) catalysts, overall electrochemical activity and durability of the catalyst layer in PEMFCs. This research was motivated by the desire to improve the stability and durability of the PEMFCs by utilizing the novel silica supported platinum (Pt/Silica) catalyst support. The purpose of this study was to develop a membrane electrode assembly (MEA) from Pt/Silica catalyst and to investigate/analyze the effects of Pt/Silica on the performance and durability of PEMFC. The primary hypothesis of this work is that the Pt/Silica catalyst would enhance the performance and durability of PEMFCs compared to ���������� − ���� − ��ℎ�� − ������ carbon-supported platinum (Pt/Carbon) catalysts. In this dissertation work, two types of MEA’s were prepared using a hot-pressed GDE method. Type-A MEA was prepared using a state − of − the − art Pt/Carbon commercial catalyst and serve as a baseline MEA. Type-B MEA was prepared using novel Pt/Silica in-house fabricated catalyst, and was used as the basis to prove the hypothesis of this work. Finally, the MEA prepared during this research work were mounted in a 25 cm2 unit-cell PEMFC fixture for its ���� − �������� evaluation. The evaluation of both of Type-A and Type-B MEA was performed using Polarization (IV) and Cyclic Voltammetry (CV) electrochemical techniques. The performance and durability data was then compared to test the hypothesis of this research. The maximum power density of Pt/Silica catalyst was found to be 52 % of the commercial Pt/Carbon catalyst under the identical experimental setup and operating conditions. Similar results were demonstrated in CV testing, where the calculated ECASA of Pt/Silica catalyst was found to be 75 % of the commercial Pt/Carbon catalyst. Electrode flooding and low conductivity of silica support were experimentally found as the cause of the reduced performance of the Pt/Silica catalyst. When operated under conditions to eliminate flooding for Pt/Silica, its performance improved, with its maximum power density found to be 62 % of the commercial Pt/Carbon catalyst. When operated under the conditions to eliminate flooding for Pt/Silica, its performance improved, with its maximum power density found to be 62 % of the commercial Pt/Carbon catalyst. When the conductivity of Pt/Silica-based MEA was improved by adding carbon black in the catalyst ink, and operated under the conditions to eliminate flooding for Pt/Silica, its performance improved, with its maximum power density found to be 82 % of the commercial Pt/Carbon catalyst. The durability study showed that the loss in ECASA of the novel Pt/Silica catalyst at the end of the 24-hour potential hold test was 27 % from its baseline condition. The corresponding loss in commercial Pt/Carbon catalyst was found to be 55 %. The Pt/Carbon catalyst deterioration was also more severe during 10,000-cycle potential cycling durability test compared to the baseline ECASA. The Pt/Carbon catalyst was able to retain only 27 % of the active Pt surface area compared to 68 % retained by the Pt/Silica catalyst after the 10,000-cycle test

DC Conductivity Study of Cadmium Sulfide Nanoparticles

The dc conductivity of consolidated nanoparticle of CdS has been studied over the temperature range from 303 K to 523 K and the conductivity has been found to be much larger than that of single crystals

Detecting Brainwaves to Evaluate Mental States and Condition using Neural Network

Human brain contains of approximately 100 billion neurons. Each neuron communicates with few ten thousands of other neurons in order to carry messages in the brain. Significant electrical activity is produced in the brain over synaptic joints of such neurons sending signals at very low frequencies below (50 Hz), thereby forming the brainwave pattern. The brainwaves are categorized as delta, theta, alpha and beta, as per different frequency ranges. In this paper, the effect of binaural beats on human mind is presented. Alpha binaural beats of 10 Hz are produced by creating the auditory illusion of 10 Hz in the brain by playing the binaural beats of 370 Hz and 380 Hz for left and right ear respectively. Binaural beats are effective only when heard through an earphone. In order to examine the effects of binaural beats on human brain, 10 people are subjected to these beats for 3 minutes. Using Processing 3.0.2, the attention level and meditation levels are measured by alpha brainwaves, and the comparison graphs are plotted. Relative comparison is carried out for each person�s state while listening to the binaural beats. This study provides scientific evidences for the common perception that alpha binaural beats and thus music can help a person in achieving a relaxed state of mind i.e., meditative state in a better way

Dynamic and Static Gesture Recognition System Using Moments

Gesture recognition is the novel idea to enhance the signs recognition of those who have speech and hearing disability .Our project discusses an improved method for gesture recognition .The algorithm extracts the gestures from the video given to it and it detects the hand using HSV skin color segmentation in the intent to eliminate the other parts of the body and detect only hands .It distinguishes between static and dynamic gestures and extracts the appropriate feature vector .We used SPHINX parser to form word from set of letters. We strive to enhance the reliability and efficiency by using faster static gesture recognition algorithm

Orthotopic bladder substitution: Surgical aspects and optimization of outcomes.

OBJECTIVES: Orthotopic bladder substitution (OBS) is a management option for urinary diversion in men and women undergoing cystectomy. The aim of the procedure is to provide a functional continent urinary reservoir of adequate capacity, compliance and low pressure. We have provided a narrative review of the existing literature and highlighted areas where improvement and standardization can be recommended. METHODS: Literature search included database search for publications from January 1970 to November 2020, using keywords including OBS, bladder reconstruction, neobladder, radical cystectomy, robotic cystectomy, intracorporeal neobladder, surgical technique, patient selection and outcomes. RESULTS: Due to various factors including indications, operative technique and risk of complications, OBS is an enormous undertaking and commitment for patients, surgeons and health professionals involved in the care pathway. The main considerations for patient selection, the technical elements of the procedure and the rationale behind these are discussed. Previously considered to be a choice for a select few, the inclusion criteria have expanded over the last decade. Similarly, surgical techniques including the choice and configuration of bowel segments, construction of anastomosis and nerve or organ sparing procedures have evolved over the years. Minimally invasive laparoscopic and robotic assisted surgery has added further perspectives to the existing literature on OBS. Understanding the principles of operative techniques and assessing the best evidence to influence patient management is crucial as it has a major impact on clinical outcomes. Peri- and post-operative care, focused on the prevention of complications and morbidity, affects long-term functional and oncological outcomes, which ultimately dictates the quality of life. CONCLUSIONS: This concise overview of OBS literature highlights the importance of pre-operative, peri-operative, and post-operative aspects with regards to the optimization of patient care. To achieve the best results, meticulous attention should be paid in all these areas, surgical and multi-disciplinary. Patient education and counseling, with shared decision making are central to the success of the procedure

A pair of biorthogonal polynomials for the Szegö-Hermite weight function

A pair of polynomial sequences {Snμ(x;k)} and {Tmμ(x;k)} where Snμ(x;k) is of degree n in xk and Tmμ(x;k) is of degree m in x, is constructed. It is shown that this pair is biorthogonal with respect to the Szegö-Hermite weight function |x|2μexp(−x2), (μ>−1/2) over the interval (−∞,∞) in the sense that∫−∞∞|x|2μexp(−x2)Snμ(x;k)Tmμ(x;k)dx=0,   ifm≠n                    ≠0,   ifm=nwhere m,n=0,1,2,… and k is an odd positive integer

A Brief Review of the Medicinally Important Indole Derivatives

Indole is an exceptional heterocyclic molecule with a broad spectrum of pharmacological activity owing to various modes of action. It is also a versatile pharmacophore and a favored scaffold. For drug development, it is an excellent moiety whose only characteristic is that it resembles many protein structures. Plenty of research has been taking place in recent years to synthesize and explore the various therapeutic prospective of this moiety. This review summarizes some of the recent effective chemical synthesis (2014-2018) for indole ring. Some of the most recent efficient chemical synthesis for the indole ring (from 2014 to 2018) is compiled in this review. The structure-activity relationship (SAR) was also given a lot of weight in this review in order to pinpoint the active pharmacophores of different indole analogues that have been the subject of studies for the past five years and are responsible for a variety of effects, including antiviral, antitubercular, anticancer, and anticonvulsant ones. The goals and framework of every research issue are explained in detail to help medicinal chemists have a deeper understanding of the circumstances contextually. Researchers will undoubtedly use this review as a platform to strategically design a variety of novel indole derivatives with lower toxicity and side effects and a range of intriguing pharmacological activit

Implications of Inflammatory Bowel Disease for reconstructive surgery in non-malignant urinary tract dysfunction:an International Continence Society working group report

Potential consequences of inflammatory bowel disease (IBD) need evaluation for patients considering urinary tract reconstruction for benign disease. A working group was formed by the International Continence Society, which considered urinary tract reconstruction in IBD.Methods Nominal group technique was used to derive consensus. Principal aspects of IBD assessment and surgery decision-making were agreed. A questionnaire was used to facilitate the generation of statements by a core focus group of experts, which were modified and ratified by the wider working group. This was followed by final voting by the full working group.Results General considerations included identification importance of the specialist IBD multi-disciplinary team. Peri-operative considerations recommended avoiding pre-operative fasting from midnight and using an enhanced recovery after surgery (ERAS) protocol. Selection of bowel segment, pre-operative optimisation and post-operative issues were considered for both Ulcerative colitis (UC) and Crohn’s disease. UC is not an absolute contraindication to urinary tract reconstruction using small or large bowel. Elective reconstructive surgery should wait at least three months following resolution of any acute UC flare-up to correct all abnormalities. Crohn’s disease is a high-risk disease for urinary tract reconstruction, even if in remission. In Crohn’s, reconstructive surgical options are limited by the location and extent of gastrointestinal segment(s) affected and the phenotype of disease.Conclusion The consensus opinion indicates that urinary tract reconstruction using bowel segments is feasible in carefully selected and optimised patients with IBD lacking alternative management options, provided there is access to appropriate multidisciplinary skills. UC is relatively low risk for surgical procedures, whereas Crohn’s has considerably increased risk of morbidity. The potential risks must be properly discussed with patients considering reconstructive urological procedures. Outcomes should be carefully monitored and published to identify the safety and efficacy of reconstructive surgery in IBD, including full description of the disease status