Search results for: adverse drug reaction reporting systems

Authors: Sh. Heidari, A. J. Andrews, A. Oberoi

Abstract:

Electrochemical storage of hydrogen in activated carbon electrodes as part of a reversible fuel cell offers a potentially attractive option for storing surplus electrical energy from inherently variable solar and wind energy resources. Such a system – which we have called a proton flow battery – promises to have a roundtrip energy efficiency comparable to lithium ion batteries, while having higher gravimetric and volumetric energy densities. In this paper, a theoretical model is presented of the process of H+ ion (proton) conduction through an acid electrolyte into a highly porous activated carbon electrode where it is neutralised and absorbed on the inner surfaces of pores. A Butler-Volmer type equation relates the rate of adsorption to the potential difference between the activated carbon surface and the electrolyte. This model for the hydrogen storage electrode is then incorporated into a more general computer model based on MATLAB software of the entire electrochemical cell including the oxygen electrode. Hence a theoretical voltage-current curve is generated for given input parameters for a particular activated carbon electrode. It is shown that theoretical VI curves produced by the model can be fitted accurately to experimental data from an actual electrochemical cell with the same characteristics. By obtaining the best-fit values of input parameters, such as the exchange current density and charge transfer coefficient for the hydrogen adsorption reaction, an improved understanding of the adsorption reaction is obtained. This new model will assist in designing improved proton flow batteries for storing solar and wind energy.

Keywords: electrochemical hydrogen storage, proton flow battery, butler-volmer equation, activated carbon

Procedia PDF Downloads 501

Authors: Monu Verma, Hyunook Kim

Abstract:

Heavy metals and organic dyes are the major sources of water pollution. Herein, a trifunctional β−cyclodextrin−ethylenediaminetetraacetic acid−chitosan (β−CD−EDTA−CS) polymer was synthesized using an easy and simple chemical route by the reaction of activated β−CD with CS through EDTA as a cross-linker (amidation reaction) for the removal of inorganic and organic pollutants from aqueous solution under different parameters such as pH, time effect, initial concentration, reusability, etc. The synthesized adsorbent was characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, field scanning electron microscopy, energy dispersive spectroscopy, Brunauer-Emmett-Teller (BET), thermogravimetric analyzer techniques to investigate their structural, functional, morphological, elemental compositions, surface area, and thermal properties, respectively. Two types of heavy metals, i.e., mercury (Hg²⁺) and cadmium (Cd²⁺), and three organic dyes, i.e., methylene blue (MB), crystal violet (CV), and safranin O (SO), were chosen as inorganic and organic pollutants, respectively, to study the adsorption capacity of β-CD-EDTA-CS in aqueous solution. The β-CD-EDTA-CS shows a monolayer adsorption capacity of 346.30 ± 14.0 and 202.90 ± 13.90 mg g−¹ for Hg²⁺ and Cd²⁺, respectively, and a heterogeneous adsorption capacity of 107.20 ± 5.70, 77.40 ± 5.30 and 55.30 ± 3.60 mg g−¹ for MB, CV and SO, respectively. Kinetics results followed pseudo-second order (PSO) kinetics behavior for both metal ions and dyes, and higher rate constants values (0.00161–0.00368 g mg−¹ min−¹) for dyes confirmed the cavitation of organic dyes (physisorption). In addition, we have also demonstrated the performance of β-CD-EDTA-CS for the four heavy metals, Hg²⁺, Cd²⁺, Ni²⁺, and Cu²⁺, and three dyes MB, CV, and SO in secondary treated wastewater. The findings of this study indicate that β-CD-EDTA-CS is simple and easy to synthesize and can be used in wastewater treatment.

Keywords: adsorption isotherms, adsorption mechanism, amino-β-cyclodextrin, heavy metal ions, organic dyes

Procedia PDF Downloads 108

Authors: Yeidy Sorani Montenegro Camacho, Samir Bensaid, Nunzio Russo, Debora Fino

Abstract:

LiFeO2 nano-powders were prepared via solution combustion synthesis (SCS) method and were used as carbon gasification catalyst in a reduced atmosphere. The gasification of soot with CO2 and H2O in the presence of CO and H2 (syngas atmosphere) were also investigated under atmospheric conditions using a fixed-bed micro-reactor placed in an electric, PID-regulated oven. The catalytic bed was composed of 150 mg of inert silica, 45 mg of carbon (Printex-U) and 5 mg of catalyst. The bed was prepared by ball milling the mixture at 240 rpm for 15 min to get an intimate contact between the catalyst and soot. A Gas Hourly Space Velocity (GHSV) of 38.000 h-1 was used for the tests campaign. The furnace was heated up to the desired temperature, a flow of 120 mL/min was sent into the system and at the same time the concentrations of CO, CO2 and H2 were recorded at the reactor outlet using an EMERSON X-STREAM XEGP analyzer. Catalytic and non-catalytic soot gasification reactions were studied in a temperature range of 120°C – 850°C with a heating rate of 5 °C/min (non-isothermal case) and at 650°C for 40 minutes (isothermal case). Experimental results show that the gasification of soot with H2O and CO2 are inhibited by the H2 and CO, respectively. The soot conversion at 650°C decreases from 70.2% to 31.6% when the CO is present in the feed. Besides, the soot conversion was 73.1% and 48.6% for H2O-soot and H2O-H2-soot gasification reactions, respectively. Also, it was observed that the carbon gasification in mixed atmosphere, i.e., when simultaneous carbon gasification with CO2 and steam take place, with H2 and CO as co-reagents; the gasification reaction is strongly inhibited by CO and H2, as well has been observed in single atmospheres for the isothermal and non-isothermal reactions. Further, it has been observed that when CO2 and H2O react with carbon at the same time, there is a passive cooperation of steam and carbon dioxide in the gasification reaction, this means that the two gases operate on separate active sites without influencing each other. Finally, despite the extreme reduced operating conditions, it has been demonstrated that the 32.9% of the initial carbon was gasified using LiFeO2-catalyst, while in the non-catalytic case only 8% of the soot was gasified at 650°C.

Keywords: soot gasification, nanostructured catalyst, reducing environment, syngas

Procedia PDF Downloads 263

Authors: Y. Z. Gad

Abstract:

Disorders of Sex Development (DSD) are defined as congenital conditions in which development of chromosomal, gonadal or anatomical sex is atypical. The DSD are relatively prevalent in Egypt. In spite of that, the relative rarity of the individual disease types or their molecular pathologies frequently resulted in reporting on single or few cases. This augmented the challenging nature of phenotype-genotype correlation in this disease group and its utilization in the management of such medical emergency. Through critical assessment of the published DSD reports, the current review aims at analyzing the clinical characteristics of the various DSD forms in relation to the underlying molecular pathologies. A systematic literature search was done in Pubmed, using relevant keywords (Egypt versus DSD, genital ambiguity or ambiguous genitalia, the old terms of 'intersex, hermaphroditism and pseudohermaphroditism', and a list of the DSD entities and their related genes). The search yielded 24 reports of molecular data in Egyptian patients presenting with ambiguous genitalia. However, only 21 publications fulfilled the criteria of inclusion of detailed clinical descriptions and definitive molecular diagnoses of individual patients. Curation of the data yielded a total of 53 cases that were ascertained from 40 families. Fifty-one patients present with ambiguous genitalia only while 2 had multiple congenital anomalies. Parental consanguinity was noted in 60% of cases. Sex of rearing at initial presentation was female in 75% and 60% in 46,XY and 46,XX DSD cases, respectively. The external genital phenotype in 2/3 of the 46,XY DSD cases showed moderate undermasculinization [Quigley scores 3 & 4] and 1/3 had severe presentations [scores 5 & 6]. For 46,XX subjects, 1 had severe virilization of the external genitalia while 8 had moderate phenotype. Hormonal data were inconclusive or contradictory to final diagnosis in a forth of cases. Collectively, 31 families [31/40, 77.5%] with 46,XY DSD had molecular defects in the genes, 5 alpha reductase 2 (SRD5A2) [12/31], 17 beta-hydroxysteroid dehydrogenase 3 [8/31], androgen receptor [7/31], Steroidogenic factor 1 [2/31], luteinizing hormone receptor [1/31], and fibroblast growth factor receptor 1 [1/31]. In a multiethnic study, 9 families afflicted with 46,XX DSD due to 11 beta hydroxylase (CYP11B1) deficiency were documented. Two recurrent mutations, G34R and N160D, in SRD5A2 were present, respectively, in 42 and 17% of cases. Similarly, 4 recurrent mutations resulted in 89% of the CYP11B1 presentations. In conclusion, this analysis highlights the importance of autosomal recessive inheritance and inbreeding among DSD presentations, the importance of founder effect in at least 2 disorders, the difficulties in relating the genotype with the indeterminate genital phenotype, the under-reporting of some DSD subtypes, and the notion that the reported mutational profiles among Egyptian DSD cases are relatively different from those reported in other ethnic groups.

Keywords: disorders of sex development, genital ambiguity, mutation, molecular diagnosis, Egypt

Procedia PDF Downloads 139

Authors: A. Kumar, D. Himanshu, Ak Vaish, K. Usman , A. Singh, R. Misra, V. Atam, S. P. Verma, S. Singhal

Abstract:

Introduction: Resistant and uncontrolled hypertension offer great challenge, in terms of higher risk of morbidity, mortality and not the least, difficulty in diagnosis and management. Our study tries to identify the importance of two crucial aspects of hypertension management, i.e. drug compliance and optimum dosing and also the effect of spironolactone on blood pressure in cases of resistant hypertension. Methodology: A prospective study was carried out among patients, who were referred as case of resistant hypertension to Hypertension Clinic at Gandhi memorial and associated hospital, Lucknow, India from August, 2013 to July 2014. A total of 122 Subjects having uncontrolled BP with ≥3 antihypertensives were selected. After ruling out secondary resistance and with appropriate lifestyle modifications, effect of adherence and optimum doses was seen with monitoring of BP. Only those having blood pressure still uncontrolled were true resistant. These patients were given spironolactone to see its effect on BP over next 12 weeks. Results: Mean baseline BP of all (n=122) patients was 150.4±7.2 mmHg systolic and 92.1±5.7 mmHg diastolic. After promoting adherence to the regimen, there was reduction of 4.20±3.65 mmHg systolic and 2.08±4.74 mmHg Diastolic blood pressure, with 26 patients achieving target blood pressure goal. Further reduction of 6.66±5.99 mmHg in systolic and 2.59±3.67 mmHg in diastolic BP was observed after optimizing the drug doses with another 66 patients achieving target blood pressure goal. Only 30 patients were true resistant hypertensive and prescribed spironolactone. Over 12 weeks, mean reduction of 20.62±3.65 mmHg in systolic and 10.08 ± 6.46 mmHg in diastolic BP was observed. Out of these 30, BP was controlled in 24 patients. Side effects observed were hyperkalemia in 2 patients and breast tenderness in 2 patients. Conclusion: Improper adherence and suboptimal regimen appear to be the important reasons for uncontrolled hypertension. By virtue of maintaining proper adherence to an optimum regimen, target BP goal can be reached in many without adding much to the regimen. Spironolactone is effective in patients with resistant hypertension, in terms of blood pressure reduction with minimal side effects.

Keywords: resistant, hypertension, spironolactone, blood pressure

Procedia PDF Downloads 279

Authors: Bhekisipho Twala, Mantepu Masetshaba, Ramapulana Nkoana

Abstract:

Multiple classifier systems combine several individual classifiers to deliver a final classification decision. However, an increasingly controversial question is whether such systems can outperform the single best classifier, and if so, what form of multiple classifiers system yields the most significant benefit. Also, multi-target tracking detection using multiple sensors is an important research field in mobile techniques and military applications. In this paper, several multiple classifiers systems are evaluated in terms of their ability to predict a system’s failure or success for multi-sensor target tracking tasks. The Bristol Eden project dataset is utilised for this task. Experimental and simulation results show that the human activity identification system can fulfill requirements of target tracking due to improved sensors classification performances with multiple classifier systems constructed using boosting achieving higher accuracy rates.

Keywords: single classifier, ensemble learning, multi-target tracking, multiple classifiers

Procedia PDF Downloads 272

Authors: Mohamed M. El-Awad

Abstract:

This paper describes an educational platform for design analyses of pump-pipe systems by using Microsoft Excel, its Solver add-in, and the associated VBA programming language. The paper demonstrates the capabilities of the Excel-based platform that suits the iterative nature of the design process better than the use of design charts and data tables. While VBA is used for the development of a user-defined function for determining the standard pipe diameter, Solver is used for optimising the pipe diameter of the pipeline and for determining the operating point of the selected pump.

Keywords: design analyses, pump-pipe systems, Excel, solver, VBA

Procedia PDF Downloads 169

Authors: Alessio Varotto, Lorenzo Freschi, Umberto Pasqual Laverdura, Anastasia Moschovi, Davide Pumiglia, Iakovos Yakoumis, Marta Feroci, Maria Luisa Grilli

Abstract:

Dry reforming of Methane (DRM) is considered one of the most valuable technologies for green-house gas valorization thanks to the fact that through this reaction, it is possible to obtain syngas, a mixture of H₂ and CO in an H₂/CO ratio suitable for utilization in the Fischer-Tropsch process of high value-added chemicals and fuels. Challenges of the DRM process are the reduction of costs due to the high temperature of the process and the high cost of precious metals of the catalyst, the metal particles sintering, and carbon deposition on the catalysts’ surface. The aim of this study is to demonstrate the feasibility of the synthesis of catalysts using a leachate solution containing Pt coming directly from the recovery of spent diesel oxidation catalysts (DOCs) without further purification. An unusual perovskite support for DRM, the BaCe₁₋ₓ₋ᵧZrₓGdᵧO₃ (BCZG) perovskite, has been chosen as the catalyst support because of its high thermal stability and capability to produce oxygen vacancies, which suppress the carbon deposition and enhance the catalytic activity of the catalyst. BCZG perovskite has been synthesized by a sol-gel modified Pechini process and calcinated in air at 1100 °C. BCZG supports have been impregnated with a Pt-containing leachate solution of DOC, obtained by a mild hydrometallurgical recovery process, as reported elsewhere by some of the authors of this manuscript. For comparison reasons, a synthetic solution obtained by digesting commercial Pt-black powder in aqua regia was used for BCZG support impregnation. Pt nominal content was 2% in both BCZG-based catalysts formed by real and synthetic solutions. The structure and morphology of catalysts were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Thermogravimetric Analysis (TGA) was used to study the thermal stability of the catalyst’s samples. Brunauer-Emmett-Teller (BET) analysis provided a high surface area of the catalysts. H₂-TPR (Temperature Programmed Reduction) analysis was used to study the consumption of hydrogen for reducibility, and it was associated with H₂-TPD characterization to study the dispersion of Pt on the surface of the support and calculate the number of active sites used by the precious metal. Dry reforming of methane (DRM) reaction, carried out in a fixed bed reactor, showed a high conversion efficiency of CO₂ and CH4. At 850°C, CO₂ and CH₄ conversion were close to 100% for the catalyst obtained with the aqua regia-based solution of commercial Pt-black, and ~70% (for CH₄) and ~80 % (for CO₂) in the case of real HCl-based leachate solution. H₂/CO ratios were ~0.9 and ~0.70 in the first and latter cases, respectively. As far as we know, this is the first pioneering work in which a BCGZ catalyst and a real Pt-containing leachate solution were successfully employed for DRM reaction.

Keywords: dry reforming of methane, perovskite, PGM, recycled Pt, syngas

Procedia PDF Downloads 40

Authors: Ferdinando Montemari, Antonio Vitale, Nicola Genito, Luca Garbarino, Urbano Tancredi, Domenico Accardo, Michele Grassi, Giancarmine Fasano, Anna Elena Tirri

Abstract:

The development of guidance, navigation and control algorithms and avionic procedures requires the disposability of suitable analysis and verification tools, such as simulation environments, which support the design process and allow detecting potential problems prior to the flight test, in order to make new technologies available at reduced cost, time and risk. This paper presents a simulation environment for avionic software development and qualification, especially aimed at equipment for general aviation aircrafts and unmanned aerial systems. The simulation environment includes models for short and medium-range radio-navigation aids, flight assistance systems, and ground control stations. All the software modules are able to simulate the modeled systems both in fast-time and real-time tests, and were implemented following component oriented modeling techniques and requirement based approach. The paper describes the specific models features, the architectures of the implemented software systems and its validation process. Performed validation tests highlighted the capability of the simulation environment to guarantee in real-time the required functionalities and performance of the simulated avionics systems, as well as to reproduce the interaction between these systems, thus permitting a realistic and reliable simulation of a complete mission scenario.

Keywords: ADS-B, avionics, NAVAIDs, real-time simulation, TCAS, UAS ground control station

Procedia PDF Downloads 231

Authors: M. E. Joret, F. Germeys, P. Van de Craen

Abstract:

Background: Previous studies have shown that ‘full’ bilingualism seems to enhance the executive functions in children, young adults and elderly people. Executive functions refer to a complex cognitive system responsible for self-controlled and planned behavior and seem to predict academic achievement. The present study aimed at investigating whether similar effects could be found in children learning their second language at school in immersion education programs. Methods: In this study, 44 children involved in immersion education for 4 to 5 years were compared to 48 children in traditional schools. All children were between 9 and 11 years old. To assess executive functions, the Simon task was used, a neuropsychological measure assessing executive functions with reaction times and accuracy on congruent and incongruent trials. To control for background measures, all children underwent the Raven’s coloured progressive matrices, to measure non-verbal intelligence and the Echelle de Vocabulaire en Images Peabody (EVIP), assessing verbal intelligence. In addition, a questionnaire was given to the parents to control for other confounding variables, such as socio-economic status (SES), home language, developmental disorders, etc. Results: There were no differences between groups concerning non-verbal intelligence and verbal intelligence. Furthermore, the immersion learners showed overall faster reaction times on both congruent and incongruent trials compared to the traditional learners, but only after 5 years of training, not before. Conclusion: These results show that the cognitive benefits found in ‘full’ bilinguals also appear in children involved in immersion education, but only after a sufficient exposure to the second language. Our results suggest that the amount of second language training needs to be sufficient before these cognitive effects may emerge.

Keywords: bilingualism, executive functions, immersion education, Simon task

Procedia PDF Downloads 442

Authors: Nadhiya N. Subramony, Jenifer Vaughan, Lesley E. Scott

Abstract:

In South Africa, the World Health Organisation estimated 454000 new cases of Mycobacterium tuberculosis (M.tb) infection (MTB) in 2015. Disseminated tuberculosis arises from the haematogenous spread and seeding of the bacilli in extrapulmonary sites. The gold standard for the detection of MTB in bone marrow is TB culture which has an average turnaround time of 6 weeks. Histological examinations of trephine biopsies to diagnose MTB also have a time delay owing mainly to the 5-7 day processing period prior to microscopic examination. Adding to the diagnostic delay is the non-specific nature of granulomatous inflammation which is the hallmark of MTB involvement of the bone marrow. A Ziehl-Neelson stain (which highlights acid-fast bacilli) is therefore mandatory to confirm the diagnosis but can take up to 3 days for processing and evaluation. Owing to this delay in diagnosis, many patients are lost to follow up or remain untreated whilst results are awaited, thus encouraging the spread of undiagnosed TB. The Xpert® MTB/RIF (Cepheid, Sunnyvale, CA) is the molecular test used in the South African national TB program as the initial diagnostic test for pulmonary TB. This study investigates the optimisation and performance of the Xpert® MTB/RIF on bone marrow aspirate specimens (BMA), a first since the introduction of the assay in the diagnosis of extrapulmonary TB. BMA received for immunophenotypic analysis as part of the investigation into disseminated MTB or in the evaluation of cytopenias in immunocompromised patients were used. Processing BMA on the Xpert® MTB/RIF was optimised to ensure bone marrow in EDTA and heparin did not inhibit the PCR reaction. Inactivated M.tb was spiked into the clinical bone marrow specimen and distilled water (as a control). A volume of 500mcl and an incubation time of 15 minutes with sample reagent were investigated as the processing protocol. A total of 135 BMA specimens had sufficient residual volume for Xpert® MTB/RIF testing however 22 specimens (16.3%) were not included in the final statistical analysis as an adequate trephine biopsy and/or TB culture was not available. Xpert® MTB/RIF testing was not affected by BMA material in the presence of heparin or EDTA, but the overall detection of MTB in BMA was low compared to histology and culture. Sensitivity of the Xpert® MTB/RIF compared to both histology and culture was 8.7% (95% confidence interval (CI): 1.07-28.04%) and sensitivity compared to histology only was 11.1% (95% CI: 1.38-34.7%). Specificity of the Xpert® MTB/RIF was 98.9% (95% CI: 93.9-99.7%). Although the Xpert® MTB/RIF generates a faster result than histology and TB culture and is less expensive than culture and drug susceptibility testing, the low sensitivity of the Xpert® MTB/RIF precludes its use for the diagnosis of MTB in bone marrow aspirate specimens and warrants alternative/additional testing to optimise the assay.

Keywords: bone marrow aspirate , extrapulmonary TB, low sensitivity, Xpert® MTB/RIF

Procedia PDF Downloads 173

Authors: Amanda Cristina de Oliveira, Elias de Souza Monteiro Filho, Roberta Ceriani

Abstract:

Liquid-liquid extraction in aqueous two-phase systems (ATPSs) constitutes a powerful tool for purifying bio-materials, such as cells, organelles, proteins, among others. In this work, the extraction of the bovine serum albumin (BSA) has been studied in systems formed by polyethylene glycol (PEG) (1500, 4000, and 6000 g.mol⁻¹) + potassium sodium tartrate + water at 303.15°K. Phase diagrams were obtained by turbidimetry and Merchuk’s method (1998). The experimental tie-lines were described using the Othmer-Tobias and Bancroft correlations. ATPSs were correlated with the nonrandom two-liquid (NRTL) model. The results were considered excellent according to global root-mean-square deviations found which were between 0,72 and 1,13%. The concentrations of the proteins in each phase were determined by spectrophotometry at 280 nm, finding partition efficiencies greater than 71%.

Keywords: aqueous two phases systems, bovine serum albumin , liquid-liquid extraction, polyethylene glycol

Procedia PDF Downloads 161

Authors: Naci Kalkan, Ihsan Dagtekin

Abstract:

Passive design responds to improve indoor thermal comfort and minimize the energy consumption. The present research analyzed the how efficiently passive solar technologies generate heating and cooling and provide the system integration for domestic applications. In addition to this, the aim of this study is to increase the efficiency of solar systems system with integration some innovation and optimization. As a result, outputs of the project might start a new sector to provide environmentally friendly and cheap cooling for domestic use.

Keywords: passive solar systems, heating, cooling, thermal comfort, ventilation systems

Procedia PDF Downloads 301

Authors: Lukumba Phiri, Simon Tembo, Kumbuso Joshua Nyoni

Abstract:

In Zambia recent initiatives by various power operators like ZESCO, CEC, and consumers like the mines to upgrade power systems into smart grids target an even tighter integration with information technologies to enable the integration of renewable energy sources, local and bulk generation, and demand response. Thus, for the reliable operation of smart grids, its information infrastructure must be secure and reliable in the face of both failures and cyberattacks. Due to the nature of the systems, ICS/SCADA cybersecurity and governance face additional challenges compared to the corporate networks, and critical systems may be left exposed. There exist control frameworks internationally such as the NIST framework, however, there are generic and do not meet the domain-specific needs of the SCADA systems. Zambia is also lagging in cybersecurity awareness and adoption, therefore there is a concern about securing ICS controlling key infrastructure critical to the Zambian economy as there are few known facts about the true posture. In this paper, we introduce a stochastic Edged-based Anomaly Detection for SCADA systems (SEADS) framework for threat modeling and risk assessment. SEADS enables the calculation of steady-steady probabilities that are further applied to establish metrics like system availability, maintainability, and reliability.

Keywords: anomaly, availability, detection, edge, maintainability, reliability, stochastic

Procedia PDF Downloads 112

Authors: Zeyu Zhou, Ziyu Zhao, Xiaochen Yang, Ling AI, Heng Zhai, Stuart Holmes

Abstract:

As a promising sustainable alternative to traditional fossil fuels, fuel cell technology is highly favoured due to its enhanced working efficiency and reduced emissions. In the context of high-temperature fuel cells (operating above 100 °C), the most commonly used proton exchange membrane (PEM) is the Polybenzimidazole (PBI) doped phosphoric acid (PA) membrane. Grafting is a promising strategy to advance PA-doped PBI PEM technology. The existing grafting modification on PBI PEMs mainly focuses on grafting phosphate-containing or alkaline groups onto the PBI molecular chains. However, quaternary ammonium-based grafting approaches face a common challenge. To initiate the N-alkylation reaction, deacidifying agents such as NaH, NaOH, KOH, K2CO3, etc., can lead to ionic crosslinking between the quaternary ammonium group and PBI. Polyvinylpyrrolidone (PVP) is another widely used polymer, the N-heterocycle groups within PVP endow it with a significant ability to absorb PA. Recently, PVP has attracted substantial attention in the field of fuel cells due to its reduced environmental impact and impressive fuel cell performance. However, due to the the poor compatibility of PVP in PBI, few research apply PVP in PA-doped PBI PEMs. This work introduces an innovative strategy to graft PVP onto PBI to form a network-like polymer. Due to the absence of quaternary ammonium groups, PVP does not pose issues related to crosslinking with PBI. Moreover, the nitrogen-containing functional groups on PVP provide PBI with a robust phosphoric acid retention ability. The nuclear magnetic resonance (NMR) hydrogen spectrum analysis results indicate the successful completion of the grafting reaction where N-alkylation reactions happen on both sides of the grafting agent 1,4-bis(chloromethyl)benzene. On one side, the reaction takes place with the hydrogen atoms on the imidazole groups of PBI, while on the other side, it reacts with the terminal amino group of PVP. The XPS results provide additional evidence from the perspective of the element. On synthesized PBI-g-PVP surfaces, there is an absence of chlorine (chlorine in grafting agent 1,4-bis(chloromethyl)benzene is substituted) element but a presence of sulfur element (sulfur element in terminal amino PVP appears in PBI), which demonstrates the occurrence of the grafting reaction and PVP is successfully grafted onto PBI. Prepare these modified membranes into MEA. It was found that during the fuel cell operation, all the grafted membranes showed substantial improvement in maximum current density and peak power density compared to unmodified one. For PBI-g-PVP 30, with a grafting degree of 22.4%, the peak power density reaches 1312 mW cm⁻², marking a 59.6% enhancement compared to the pristine PBI membrane. The improvement is caused by the improved PA binding ability of the membrane after grafting. The AST test result shows that the grafting membranes have better long-term durability and performance than unmodified membranes attributed to the presence of added PA binding sites, which can effectively prevent the PA leaching caused by proton migration. In conclusion, the test results indicate that grafting PVP onto PBI is a promising strategy which can effectively improve the fuel cell performance.

Keywords: fuel cell, grafting modification, PA doping ability, PVP

Procedia PDF Downloads 80

Authors: Shyh-Ming Chern, Te-Hsiu Tang

Abstract:

Hemicellulose is one of the major constituents of all plant cell walls, making up 15-25% of dry wood. It is a biopolymer from many different sugar monomers, including pentoses, like xylose, and hexoses, like mannose. In an effort to gasify real biomass in subcritical and supercritical water in a single process, it is necessary to understand the gasification of hemicellulose, in addition to cellulose and lignin, in subcritical and supercritical water. In the present study, xylose is chosen as the model compound for hemicellulose, since it has the largest amount in most hardwoods. Xylose is gasified in subcritical and supercritical water for the production of higher-valued gaseous products. Experiments were conducted with a 16-ml autoclave batch-type reactor. Hydrogen peroxide is adopted as the oxidant in an attempt to promote the gasification yield. The major operating parameters for the gasification include reaction temperature (400 - 600°C), reaction pressure (5 - 25 MPa), the concentration of xylose (0.05 and 0.30 M), and level of oxidant added (0 and 0.25 chemical oxygen demand). 102 experimental runs were completed out of 46 different set of experimental conditions. Product gases were analyzed with a GC-TCD and determined to be mainly composed of H₂ (10 – 74 mol. %), CO (1 – 56 mol. %), CH₄ (1 – 27 mol. %), CO₂ (10 – 50 mol. %), and C₂H₆ (0 – 8 mol. %). It has been found that the gas yield (amount of gas produced per gram of xylose gasified), higher heating value (HHV) of the dry product gas, and energy yield (energy stored in the product gas divided by the energy stored in xylose) all increase significantly with rising temperature and moderately with reducing pressure. The overall best operating condition occurred at 873 K and 10 MPa, with a gas yield of 54 mmol/g of xylose, a gas HHV of 440 kJ/mol, and an energy yield of 1.3. A seemingly unreasonably energy yield of greater than unity resulted from the external heating employed in the experiments to drive the gasification process. It is concluded that xylose can be completely gasified in subcritical and supercritical water under proper operating conditions. The addition of oxidant does not promote the gasification of xylose.

Keywords: gasification, subcritical water, supercritical water, xylose

Procedia PDF Downloads 241

Authors: Hassan Medaghri Alaoui

Abstract:

The accounting and financial reporting system in use today is over 500 years old and has failed to capture the new knowledge and innovation economy in which intangible assets are becoming increasingly valuable. Yet, there has been a growing acknowledgment among the research community as to the relevance of intellectual capital as a major enhancer of an organization’s well-being. Much of the research provides great support for how the IC is instrumental in determining financial and stock performances. As far as we know, this article is one of the earliest exploratory attempts to examine the intellectual capital impact on the corporate performance of the IT sector in Morocco. The purpose of this study is to verify empirically the influence of intellectual capital on firm performance. We have undertaken, over a fifteen-year period, a longitudinal (2005–2019) case study of a prominent payment-solutions company based in a developing economy with global operations.

Keywords: intellectual capital, IT sector, measuring intellectual capital, modified value added intellectual capital coefficient, Morocco

Procedia PDF Downloads 125

Authors: Iffat Ara Ebu, Fahmida Islam, Mohammad Abdus Shahid Rafi, Mahfuzur Rahman, Umar Iqbal, John Ball

Abstract:

The application of multi-sensor fusion for enhanced distance estimation accuracy in dynamic environments is crucial for advanced driver assistance systems (ADAS) and autonomous vehicles. Limitations of single sensors such as cameras or radar in adverse conditions motivate the use of combined camera and radar data to improve reliability, adaptability, and object recognition. A multi-sensor fusion approach using an extended Kalman filter (EKF) is proposed to combine sensor measurements with a dynamic system model, achieving robust and accurate distance estimation. The research utilizes the Mississippi State University Autonomous Vehicular Simulator (MAVS) to create a controlled environment for data collection. Data analysis is performed using MATLAB. Qualitative (visualization of fused data vs ground truth) and quantitative metrics (RMSE, MAE) are employed for performance assessment. Initial results with simulated data demonstrate accurate distance estimation compared to individual sensors. The optimal sensor measurement noise variance and plant noise variance parameters within the EKF are identified, and the algorithm is validated with real-world data from a Chevrolet Blazer. In summary, this research demonstrates that multi-sensor fusion with an EKF significantly improves distance estimation accuracy in dynamic environments. This is supported by comprehensive evaluation metrics, with validation transitioning from simulated to real-world data, paving the way for safer and more reliable autonomous vehicle control.

Keywords: sensor fusion, EKF, MATLAB, MAVS, autonomous vehicle, ADAS

Procedia PDF Downloads 48

Authors: Iyai Davies, Olivier L. C. Haas

Abstract:

In this paper, the problem of stability and stabilization for neutral delay-differential systems with infinite delay is investigated. Using Lyapunov method, new delay-independent sufficient condition for the stability of neutral systems with infinite delay is obtained in terms of linear matrix inequality (LMI). Memory-less state feedback controllers are then designed for the stabilization of the system using the feasible solution of the resulting LMI, which are easily solved using any optimization algorithms. Numerical examples are given to illustrate the results of the proposed methods.

Keywords: infinite delays, Lyapunov method, linear matrix inequality, neutral systems, stability

Procedia PDF Downloads 433

Authors: Kidane Workelul, Yohans Tekle, Guesh Negash, Haftay Abraha, Nigus Abebe Shumuye, Yisehak Tsegaye Redda

Abstract:

Bovine papillomatosis (wart) is one of the economically important bovine skin diseases worldwide, caused by a group of viruses named papillomaviruses (PVs). However, it has often been misdiagnosed as other skin diseases and remained untreated. In order to determine the status of the diseases, twenty-two farms were visited, and fourteen infected cattle with cutaneous papillomatosis were identified from a total of 235. Papilloma biopsies were taken for molecular and histopathological characterization, the therapeutic trial of an autogenous vaccine was evaluated on infected animals. The overall status of bovine papillomatosis in this study was calculated as 5.96% (14/235). The disease was found to be statistically significant in the age groups less than two years (X² = 26.69, P = 0.0001). The more prominent histologically characterized lesions in the sampled tissue were identified as squamous papilloma and fibro-papilloma. The Polymerase Chain Reaction (PCR) based identification revealed that all the clinically and histo-pathologically characterized papillomatosis cases were found to be infected with Bovine Papilloma Virus1(BPV1), indicating that BPV1 was the most common and sole causative agent of the diseases in the study area. In immunizing active bovine papillomatosis, an autogenous vaccine therapeutic trial demonstrated excellent results, with practically full recovery and no recurrence of the infection. Hence, it is concluded that bovine papillomatosis is an economically important disease of young age group cattle as well as a treatable disease. So, the production of marketable autogenous vaccines against bovine papillomatosis should be started and given at an early stage.

Keywords: autogenous vaccine, bovine papillomatosis, bovine papilloma virus1 clinical-pathology, polymerase chine reaction, wart

Procedia PDF Downloads 84

Authors: J. J. Mathew

Abstract:

Pulmonary tuberculosis is highly prevalent in the Indian subcontinent. Most cases of pulmonary tuberculosis are diagnosed with sputum examinations and the vast majority of these are undertaken by the government run establishments. However, mycobacterial cultures are not routinely done, unless drug resistance is detected based on clinical response. Modern diagnostic tests like bronchoscopy and Genexpert are not routinely employed in the government institutions for the diagnosis of pulmonary tuberculosis, but have been accepted widely by good private institutions. The utility of these investigations in the private sector is not yet well recognized. This retrospective study aims to assess the usefulness of bronchoscopy and Genexpert in the diagnosis of pulmonary tuberculosis in quaternary care private hospital in India. 30 patients with respiratory symptoms raising the possibility of tuberculosis based on clinical and radiological features, but without any significant sputum production, were subject to bronchoscopy and BAL samples taken for microbiological studies, including Genexpert. 6 out of the 30 patients were found to be Genexpert positive and none of them showed Rifampicin resistance. All the 6 cases had upper zone predominant disease. One of the 6 cases of tuberculosis had another co-existent bacterial infection according to the routine culture studies. 6 other cases were proven to be due to other bacterial infections alone, 2 had a malignant diagnosis and the remaining cases were thought to be non-infective pathologies. The Genexpert results were made available within 48 hours in the 6 positive cases. All of them were commenced on standard anti-tuberculous regimen with excellent clinical response. The other infective cases were also managed successfully based on the drug susceptibilities. The study has shown the usefulness of these investigations as early intervention enabled diagnosis facilitating treatment and prevention of any clinical deterioration. The study lends support to early bronchoscopy and Genexpert testing in suspected cases of pulmonary tuberculosis without significant sputum production, in a high prevalence country which normally relies on sputum examination for the diagnosis of pulmonary tuberculosis.

Keywords: pulmonary, tuberculosis, bronchoscopy, genexpert

Procedia PDF Downloads 246

Authors: Kiamran Radjabli

Abstract:

State Estimator became an intrinsic part of Energy Management Systems (EMS). The SCADA measurements received from the field are processed by the State Estimator in order to accurately determine the actual operating state of the power systems and provide that information to other real-time network applications. All EMS vendors offer a State Estimator functionality in their baseline products. However, setting up and ensuring that State Estimator consistently produces a reliable solution often consumes a substantial engineering effort. This paper provides generic recommendations and describes a simple practical approach to efficient tuning of State Estimator, based on the working experience with major EMS software platforms and consulting projects in many electrical utilities of the USA.

Keywords: convergence, monitoring, state estimator, performance, troubleshooting, tuning, power systems

Procedia PDF Downloads 157

Authors: Celine Shi Ying Lee, Jong Jian Lee

Abstract:

Background: Infectious keratitis is one of the leading causes of blindness worldwide. Prompt treatment with effective medication will control the infection early, preventing corneal scarring and visual loss. fluoroquinolones ophthalmic medication is used because of its broad-spectrum properties, potency, good intraocular penetration, and low toxicity. The study aims to evaluate the treatment outcome of corneal ulcers using Levofloxacin 1.5% ophthalmic solution (LVFX) with adjuvant oral ciprofloxacin when indicated and apply this treatment strategy in primary health care as first-line treatment. Methods: Patients with infective corneal ulcer treated in an eye center were recruited. Inclusion criteria includes Corneal infection consistent with bacterial keratitis, single or multiple small corneal ulcers. Treatment regime: LVFX hourly for the first 2 days, 2 hourly from the 3rd day, and 3 hourly on the 5th day of review. Adjuvant oral ciprofloxacin 500mg BD was administered for 5 days if there were multiple corneal ulcers or when the location of the cornea ulcer was central or paracentral. Results: 47 subjects were recruited. There were 16 (34%) males and 31 (66%) females. 40 subjects (85%) were contact lens (CL) related to corneal ulcer, and 7 subjects (15%) were non-contact lens related. 42 subjects (89%) presented with one ulcer, of which 20 of them (48%) needed adjuvant therapy. 5 subjects presented with 2 or 3 ulcers, of which 3 needed adjuvant therapy. A total of 23 subjects (49%) was given adjuvant therapy (oral ciprofloxacin 500mg BD for 5 days).21 of them (91%) were CL related. All subjects recovered fully, and the average duration of treatment was 3.7 days, with 49% of the subjects resolved on the 3rd day, 38% on the 5thday of and 13% on the 7thday. All subjects showed symptoms of relief of pain, light-sensitivity, and redness on the 3rd day with full visual recovery post-treatment. No adverse drug reactions were recorded. Conclusion: Our treatment regime demonstrated good clinical outcome as first-line treatment for corneal ulcers. A corneal ulcer is a common eye condition in Singapore, mainly due to CL wear. Pseudomonas aeruginosa is the most frequent and potentially sight-threatening pathogen involved in CL related corneal ulcer. Coagulase-negative Staphylococci, Staphylococcus aureus, and Streptococcus Pneumoniae were seen in non-CL users. All these bacteria exhibit good sensitivity rates to ciprofloxacin and levofloxacin. It is therefore logical in our study to use LVFX Eyedrops and adjuvant ciprofloxacin oral antibiotics when indicated as first line treatment for most corneal ulcers. Our study of patients, both CL related and non-CL related, have shown good clinical response and full recovery using the above treatment strategy. There was also a full restoration of visual acuity in all the patients. Eye-trained primary Healthcare practitioners can consider adopting this treatment strategy as first line treatment in patients with corneal ulcers. This is relevant during the COVID pandemic, where hospitals are overwhelmed with patients and in regions with limited access to specialist eye care. This strategy would enable early treatment with better clinical outcome.

Keywords: corneal ulcer, levofloxacin hydrate, treatment strategy, ciprofloxacin

Procedia PDF Downloads 176

Authors: Shola Abidemi Olabode

Abstract:

The technological revolution over the years has impacted journalistic practice. As a matter of fact, journalistic practice has evolved alongside technologies of every generation transforming news and reporting, entertainment, and politics. Alongside these developments, the emergence of new kinds of risks and harms associated with generative AI has become rife with implications for media and journalism. Despite their numerous benefits for research and development, generative AI technologies like ChatGPT introduce new practical, ethical, and regulatory complexities in the practice of media and journalism. This paper presents a preliminary overview of the new kinds of challenges and issues for journalism and media practice in the era of generative AI, the implications for Nigeria, and invites a consideration of methods to mitigate the evolving complexity. It draws mainly on desk-based research underscoring the literature in both developed and developing non-western contexts as a contribution to knowledge.

Keywords: AI, journalism, media, online harms

Procedia PDF Downloads 83

Authors: Rahma Amri, Narjès Bellamine Ben Saoud

Abstract:

Sustainable development or sustainability is one of the most urgent issues in actual debate in almost domains. Particularly the significant way the software pervades our live should make it in the center of sustainability concerns. The social aspects of sustainability haven’t been well studied in the context of software systems and still immature research field that needs more interest among researchers’ community. This paper presents a Goal-Question-Metric based approach to assess social sustainability of software systems. The approach is based on a generic social sustainability model taken from Social sciences.

Keywords: software assessment approach, social sustainability, goal-question-metric paradigm, software project metrics

Procedia PDF Downloads 397

Authors: Jamal R. Elbergali

Abstract:

Multiple Input Multiple Output (MIMO) systems are wireless systems with multiple antenna elements at both ends of the link. Wireless communication systems demand high data rate and spectral efficiency with increased reliability. MIMO systems have been popular techniques to achieve these goals because increased data rate is possible through spatial multiplexing scheme and diversity. Spatial Multiplexing (SM) is used to achieve higher possible throughput than diversity. In this paper, we propose a Zero-Forcing (ZF) detection using a combination of Ordered Successive Interference Cancellation (OSIC) and Zero Forcing using Interference Cancellation (ZF-IC). The proposed method used an OSIC based on Signal to Noise Ratio (SNR) ordering to get the estimation of last symbol (x ̃_(N_T )), then the estimated last symbol is considered to be an input to the ZF-IC. We analyze the Bit Error Rate (BER) performance of the proposed MIMO system over Rayleigh Fading Channel, using Binary Phase Shift Keying (BPSK) modulation scheme. The results show better performance than the previous methods.

Keywords: SNR, BER, BPSK, MIMO, modulation, zero forcing (ZF), OSIC, ZF-IC, spatial multiplexing (SM)

Procedia PDF Downloads 424

Authors: Marko Čular

Abstract:

The aim of this paper is to raise general awareness of transparency importance for audit firms and for audit services’ users. This paper analyses transparency of audit firms that audited financial statements of listed companies, for year 2011 and 2012. We use this two years because in the meantime Code of Ethics for Professional Accountants has been adopted. This paper investigates whether transparency reports of audit firms are in accordance with the Croatian Audit Act and whether there is a difference on transparency in observed years. For this paper, quality index of transparency report and financial indicators of audit firms are used to get conclusion about condition of audit firms transparency reporting. Results of our study indicate that audit firms are not fully transparent, looking for both years. Transparency of audit firms in 2012 has improved significantly, compared with transparency in 2011.

Keywords: transparency report, index quality of transparency report, Croatian audit act, code of ethics for professional accountants

Procedia PDF Downloads 300

Authors: Song Ni, Junxiang Xu

Abstract:

This paper concerns quasi-periodic perturbations with parameters of 2-dimensional degenerate systems. If the equilibrium point of the unperturbed system is elliptic-type degenerate. Assume that the perturbation is real analytic quasi-periodic with diophantine frequency. Without imposing any assumption on the perturbation, we can use a path of equilibrium points to tackle with the Melnikov non-resonance condition, then by the Leray-Schauder Continuation Theorem and the Kolmogorov-Arnold-Moser technique, it is proved that the equation has a small response solution for many sufficiently small parameters.

Keywords: quasi-periodic systems, KAM-iteration, degenerate equilibrium point, response solution

Procedia PDF Downloads 87

Authors: Amirreza Heidari, Akram Avami, Ehsan Heidari

Abstract:

Evaporative cooling systems are known as energy efficient cooling systems, with much lower electricity consumption than conventional vapor compression systems. A serious limitation of these systems, however, is that they are not applicable in humid regions. Combining a desiccant wheel with these systems, known as desiccant-based evaporative cooling systems, makes it possible to use evaporative cooling in humid climates. This paper evaluates the performane of a cooling system combining desiccant wheel, direct and indirect evaporative coolers (called desiccant-based indirect-direct evaporative cooling (DIDE) system) and then evaluates the energy saving potential of this system over the conventional vapor compression cooling and drying system. To illustrate the system ability of providing comfort conditions, a dynamic hourly simulation of this system is performed for a typical 60 m² building in Sydney, Australia. To evaluate the energy saving potential of this system, a conventional cooling and drying system is also simulated for the same cooling capacity. It has been found that the DIE system is able to provide comfort temperature and relative humidity in a subtropical humid climate like Sydney. The electricity and natural gas consumption of this system are respectively 39.2% and 2.6% lower than that of conventional system over a week. As the research has demonstrated, the innovative DIDE system is an energy efficient cooling system for subtropical humid regions.

Keywords: desiccant, evaporative cooling, dehumidification, indirect evaporative cooler

Procedia PDF Downloads 154

Authors: Annapurna Basavaraju, Arianna Mastrodonato, Franz Heitmeir

Abstract:

The Advisory Council for Aeronautics Research in Europe (ACARE) is creating awareness for the overall reduction of NOx emissions by 80% in its vision 2020. Hence this promotes the researchers to work on novel technologies, one such technology is the use of alternative fuels. Among these fuels hydrogen is of interest due to its one and only significant pollutant NOx. The influence of NOx formation due to hydrogen combustion depends on various parameters such as air pressure, inlet air temperature, air to fuel jet momentum ratio etc. Appropriately, this research is motivated to investigate the impact of the air to fuel jet momentum ratio onto the NOx formation in a hydrogen combustion chamber for aircraft engines. The air to jet fuel momentum is defined as the ratio of impulse/momentum of air with respect to the momentum of fuel. The experiments were performed in an existing combustion chamber that has been previously tested for methane. Premix of the reactants has not been considered due to the high reactivity of the hydrogen and high risk of a flashback. In order to create a less rich zone of reaction at the burner and to decrease the emissions, a forced internal recirculation flow has been achieved by integrating a plate similar to honeycomb structure, suitable to the geometry of the liner. The liner has been provided with an external cooling system to avoid the increase of local temperatures and in turn the reaction rate of the NOx formation. The injected air has been preheated to aim at so called flameless combustion. The air to fuel jet momentum ratio has been inspected by changing the area of fuel inlets and keeping the number of fuel inlets constant in order to alter the fuel jet momentum, thus maintaining the homogeneity of the flow. Within this analysis, promising results for a flameless combustion have been achieved. For a constant number of fuel inlets, it was seen that the reduction of the fuel inlet diameter resulted in decrease of air to fuel jet momentum ratio in turn lowering the NOx emissions.

Keywords: combustion chamber, hydrogen, jet momentum, NOx emission

Procedia PDF Downloads 293