Search results for: hydrogen trap sites
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3020

Search results for: hydrogen trap sites

2810 Towards the Inhibition Mechanism of Lysozyme Fibrillation by Hydrogen Sulfide

Authors: Indra Gonzalez Ojeda, Tatiana Quinones, Manuel Rosario, Igor Lednev, Juan Lopez Garriga

Abstract:

Amyloid fibrils are stable aggregates of misfolded protein associated with many neurodegenerative disorders. It has been shown that hydrogen sulfide (H2S), inhibits the fibrillation of lysozyme through the formation of trisulfide (S-S-S) bonds. However, the overall mechanism remains elusive. Here, the concentration dependence of H2S effect was investigated using Atomic force microscopy (AFM), non-resonance Raman spectroscopy, Deep-UV Raman spectroscopy and circular dichroism (CD). It was found that small spherical aggregates with trisulfide bonds and a unique secondary structure were formed instead of amyloid fibrils when adding concentrations of 25 mM and 50 mM of H2S. This could indicate that H2S might serve as a protecting agent for the protein. However, further characterization of these aggregates and their trisulfide bonds is needed to fully unravel the function H2S has on protein fibrillation.

Keywords: amyloid fibrils, hydrogen sulfide, protein folding, raman spectroscopy

Procedia PDF Downloads 187
2809 Sustainable Membranes Based on 2D Materials for H₂ Separation and Purification

Authors: Juan A. G. Carrio, Prasad Talluri, Sergio G. Echeverrigaray, Antonio H. Castro Neto

Abstract:

Hydrogen as a fuel and environmentally pleasant energy carrier is part of this transition towards low-carbon systems. The extensive deployment of hydrogen production, purification and transport infrastructures still represents significant challenges. Independent of the production process, the hydrogen generally is mixed with light hydrocarbons and other undesirable gases that need to be removed to obtain H₂ with the required purity for end applications. In this context, membranes are one of the simplest, most attractive, sustainable, and performant technologies enabling hydrogen separation and purification. They demonstrate high separation efficiencies and low energy consumption levels in operation, which is a significant leap compared to current energy-intensive options technologies. The unique characteristics of 2D laminates have given rise to a diversity of research on their potential applications in separation systems. Specifically, it is already known in the scientific literature that graphene oxide-based membranes present the highest reported selectivity of H₂ over other gases. This work explores the potential of a new type of 2D materials-based membranes in separating H₂ from CO₂ and CH₄. We have developed nanostructured composites based on 2D materials that have been applied in the fabrication of membranes to maximise H₂ selectivity and permeability, for different gas mixtures, by adjusting the membranes' characteristics. Our proprietary technology does not depend on specific porous substrates, which allows its integration in diverse separation modules with different geometries and configurations, looking to address the technical performance required for industrial applications and economic viability. The tuning and precise control of the processing parameters allowed us to control the thicknesses of the membranes below 100 nanometres to provide high permeabilities. Our results for the selectivity of new nanostructured 2D materials-based membranes are in the range of the performance reported in the available literature around 2D materials (such as graphene oxide) applied to hydrogen purification, which validates their use as one of the most promising next-generation hydrogen separation and purification solutions.

Keywords: membranes, 2D materials, hydrogen purification, nanocomposites

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2808 Social Networking Sites and Employee Engagement

Authors: Sultan Ali Suleiman AlMazrouei

Abstract:

Purpose: The purpose of this paper is to examine the effect of communication through social networking sites (Facebook, Twitter) on employee engagement. Methodology: A quantitative survey was used to collect data from 440 employees from the Ministry of Education in Oman. SPSS software was used to analyze the data. Findings: The results revealed a positive significant relationship between communication via Facebook and employee engagement. However, communication via Twitter does not influence employee engagement significantly. Practical implications: Managers can benefit from the study by understanding the importance of communication via Facebook with employees in order to increase their engagement. They should post their views and thoughts on Facebook and encourage their employees to be members which would be reflected on their psychological side positively. That gives them a feeling of belonging to a network. Originality/value: The study enriches the human resources management literature by examining a theoretical framework about the influence of social networking sites usage on employee engagement. This is one of the few studies that focus on the relationship of social networking sites usage with employees' engagement. It is the first study in an Omani context.

Keywords: employee engagement, social networking sites, Facebook, Twitter

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2807 Screening of Metal Chloride Anion-based Ionic Liquids for Direct Conversion of Hydrogen Sulfide by COSMO-RS

Authors: Muhammad Syahir Aminuddin, Zakaria Man, Mohamad Azmi Bustam Khalil

Abstract:

In order to identify the best possible reaction media for performing H₂S conversion, a total number of 300 different ILs from a combination of 20 cations and 15 anions were screened via COSMO-RS model simulations. By COSMO-RS method, thermodynamic and physicochemical properties of 300 ILs, such as Henry's law constants, activity coefficient, selectivity, capacity, and performance index, are obtained and analyzed. Thus, by comparing the performance of ILs via COSMO-RS, a series of TSILs containing cation of [P66614] with metal chloride anions such as Fe, Ga, and Al were chosen and selected for synthesis based on their performance predicted by COSMO-RS and their economic values. Consequently, the physiochemical properties such as density, viscosity, thermal properties, as well as H₂S absorptive oxidation performances in those TSILs will be systematically investigated.

Keywords: conversion of hydrogen sulfide, hydrogen sulfide, H₂S, sour natural gas, task specific ionic liquids

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2806 Stationary Methanol Steam Reforming to Hydrogen Fuel for Fuel-Cell Filling Stations

Authors: Athanasios A. Tountas, Geoffrey A. Ozin, Mohini M. Sain

Abstract:

Renewable hydrogen (H₂) carriers such as methanol (MeOH), dimethyl ether (DME), oxymethylene dimethyl ethers (OMEs), and conceivably ammonia (NH₃) can be reformed back into H₂ and are fundamental chemical conversions for the long-term viability of the H₂ economy due to their higher densities and ease of transportability compared to H₂. MeOH is an especially important carrier as it is a simple C1 chemical that can be produced from green solar-PV-generated H₂ and direct-air-captured CO₂ with a current commercially practical solar-to-fuel efficiency of 10% from renewable solar energy. MeOH steam reforming (MSR) in stationary systems next to H₂ fuel-cell filling stations can eliminate the need for onboard mobile reformers, and the former systems can be more robust in terms of attaining strict H₂ product specifications, and MeOH is a safe, lossless, and compact medium for long-term H₂ storage. Both thermal- and photo-catalysts are viable options for achieving the stable, long-term performance of stationary MSR systems.

Keywords: fuel-cell vehicle filling stations, methanol steam reforming, hydrogen transport and storage, stationary reformer, liquid hydrogen carriers

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2805 Identification and Characterization of in Vivo, in Vitro and Reactive Metabolites of Zorifertinib Using Liquid Chromatography Lon Trap Mass Spectrometry

Authors: Adnan A. Kadi, Nasser S. Al-Shakliah, Haitham Al-Rabiah

Abstract:

Zorifertinib is a novel, potent, oral, a small molecule used to treat non-small cell lung cancer (NSCLC). zorifertinib is an Epidermal Growth Factor Receptor (EGFR) inhibitor and has good blood–brain barrier permeability for (NSCLC) patients with EGFR mutations. zorifertinibis currently at phase II/III clinical trials. The current research reports the characterization and identification of in vitro, in vivo and reactive intermediates of zorifertinib. Prediction of susceptible sites of metabolism and reactivity pathways (cyanide and GSH) of zorifertinib were performed by the Xenosite web predictor tool. In-vitro metabolites of zorifertinib were performed by incubation with rat liver microsomes (RLMs) and isolated perfused rat liver hepatocytes. Extraction of zorifertinib and it's in vitro metabolites from the incubation mixtures were done by protein precipitation. In vivo metabolism was done by giving a single oral dose of zorifertinib(10 mg/Kg) to Sprague Dawely rats in metabolic cages by using oral gavage. Urine was gathered and filtered at specific time intervals (0, 6, 12, 18, 24, 48, 72,96and 120 hr) from zorifertinib dosing. A similar volume of ACN was added to each collected urine sample. Both layers (organic and aqueous) were injected into liquid chromatography ion trap mass spectrometry(LC-IT-MS) to detect vivozorifertinib metabolites. N-methyl piperizine ring and quinazoline group of zorifertinib undergoe metabolism forming iminium and electro deficient conjugated system respectively, which are very reactive toward nucleophilic macromolecules. Incubation of zorifertinib with RLMs in the presence of 1.0 mM KCN and 1.0 Mm glutathione were made to check reactive metabolites as it is often responsible for toxicities associated with this drug. For in vitro metabolites there were nine in vitro phase I metabolites, four in vitro phase II metabolites, eleven reactive metabolites(three cyano adducts, five GSH conjugates metabolites, and three methoxy metabolites of zorifertinib were detected by LC-IT-MS. For in vivo metabolites, there were eight in vivo phase I, tenin vivo phase II metabolitesofzorifertinib were detected by LC-IT-MS. In vitro and in vivo phase I metabolic pathways wereN- demthylation, O-demethylation, hydroxylation, reduction, defluorination, and dechlorination. In vivo phase II metabolic reaction was direct conjugation of zorifertinib with glucuronic acid and sulphate.

Keywords: in vivo metabolites, in vitro metabolites, cyano adducts, GSH conjugate

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2804 Evaluating the Effect of Splitting Wind Farms on Power Output

Authors: Nazanin Naderi, Milton Smith

Abstract:

Since worldwide demand for renewable energy is increasing rapidly because of the climate problem and the limitation of fossil fuels, technologies of alternative energy sources have been developed and the electric power network now includes renewable energy resources such as wind energy. Because of the huge advantages that wind energy has, like reduction in natural gas use, price pressure, emissions of greenhouse gases and other atmospheric pollutants, electric sector water consumption and many other contributions to the nation’s economy like job creation it has got too much attention these days from different parts of the world especially in the United States which is trying to provide 20% of the nation’s energy from wind by 2030. This study is trying to evaluate the effect of splitting wind farms on power output. We are trying to find if we can get more output by installing wind turbines in different sites rather than installing all wind turbines in one site. Five potential sites in Texas have been selected as a case study and two years wind data has been gathered for these sites. Wind data are analyzed and effect of correlation between sites on power output has been evaluated. Standard deviation and autocorrelation effect has also been considered for this study. The paper has been organized as follows: After the introduction the second section gives a brief overview of wind analysis. The third section addresses the case study and evaluates correlation between sites, auto correlation of sites and standard deviation of power output. In section four we describe the results.

Keywords: auto correlation, correlation between sites, splitting wind farms, power output, standard deviation

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2803 Social Networking Sites and Narcissism among Generation Z

Authors: Christine Mappala

Abstract:

Social Networking Sites has an undeniable contribution but also a downgrading effect in our society when used inappropriately. It has effects on an individual’s physical, academic, social, emotional, and behavioral aspects in life, a reason to take account to the possible risks it can have with the future generations, specifically the Generation Z. Determining if SNS Usage has an effect on an individual’s Narcissistic Tendencies, how common narcissism is among these individuals and to provide additional information about the Generation Z in the Philippines is the purpose of this study. A total of 342 participants were gathered. Results indicated that there is a low significance of SNS as a predictor to Narcissism. Also, results showed that there is a low level of narcissism among Generation Z.

Keywords: narcissism, social networking sites, Generation Z, normal narcissism

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2802 Paleogene Syn-Rift Play Identification in Palembang Sub-Basin, South Sumatera, Indonesia

Authors: Perdana Rakhmana Putra, Hansen Wijaya, Sri Budiyani, Muhamad Natsir, Alexis badai Samudra

Abstract:

The Palembang Sub-Basin (PSB) located in southern part of South Sumatera basin (SSB) consist of half-graben complex trending N-S to NW-SE. These geometries are believe as an impact of strike-slip regime developed in Eocene-Oligocene. Generally, most of the wells in this area produced hydrocarbon from late stage of syn-rift sequences called Lower Talang Akar (LTAF) and post-rift sequences called Batu Raja Formation (BRF) and drilled to proved hydrocarbon on structural trap; three-way dip anticline, four-way dip anticline, dissected anticline, and stratigraphy trap; carbonate build-up and stratigraphic pinch out. Only a few wells reached the deeper syn-rift sequences called Lahat Formation (LAF) and Lemat Formation (LEF). The new interpretation of subsurface data was done by the tectonostratigraphy concept and focusing on syn-rift sequence. Base on seismic characteristic on basin centre, it divided into four sequences: pre-rift sequence, rift initiation, maximum rift and late rift. These sequences believed as a new exploration target on PSB mature basin. This paper will demonstrate the paleo depositional setting during Paleogene and exploration play concept of syn-rift sequence in PSB. The main play for this area consists of stratigraphic and structure play, where the stratigraphic play is Eocene-Oligocene sediment consist of LAF sandstone, LEF-Benakat formation, and LAF with pinch-out geometry. The pinch-out, lenses geometry and on-lap features can be seen on the seismic reflector and formed at the time of the syn-rift sequence. The structural play is dominated by a 3 Way Dip play related to reverse fault trap.

Keywords: syn-rift, tectono-stratigraphy, exploration play, basin center play, south sumatera basin

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2801 Determination of Viscosity and Degree of Hydrogenation of Liquid Organic Hydrogen Carriers by Cavity Based Permittivity Measurement

Authors: I. Wiemann, N. Weiß, E. Schlücker, M. Wensing

Abstract:

A very promising alternative to compression or cryogenics is the chemical storage of hydrogen by liquid organic hydrogen carriers (LOHC). These carriers enable high energy density and allow, at the same time, efficient and safe storage under ambient conditions without leakage losses. Another benefit of this storage medium is the possibility of transporting it using already available infrastructure for the transport of fossil fuels. Efficient use of LOHC is related to precise process control, which requires a number of sensors in order to measure all relevant process parameters, for example, to measure the level of hydrogen loading of the carrier. The degree of loading is relevant for the energy content of the storage carrier and simultaneously represents the modification in the chemical structure of the carrier molecules. This variation can be detected in different physical properties like permittivity, viscosity, or density. E.g., each degree of loading corresponds to different viscosity values. Conventional measurements currently use invasive viscosity measurements or near-line measurements to obtain quantitative information. This study investigates permittivity changes resulting from changes in hydrogenation degree (chemical structure) and temperature. Based on calibration measurements, the degree of loading and temperature of LOHC can thus be determined by comparatively simple permittivity measurements in a cavity resonator. Subsequently, viscosity and density can be calculated. An experimental setup with a heating device and flow test bench was designed. By varying temperature in the range of 293,15 K -393,15 K and flow velocity up to 140 mm/s, corresponding changes in the resonation frequency were determined in the hundredths of the GHz range. This approach allows inline process monitoring of hydrogenation of the liquid organic hydrogen carrier (LOHC).

Keywords: hydrogen loading, LOHC, measurement, permittivity, viscosity

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2800 Deflagration and Detonation Simulation in Hydrogen-Air Mixtures

Authors: Belyayev P. E., Makeyeva I. R., Mastyuk D. A., Pigasov E. E.

Abstract:

Previously, the phrase ”hydrogen safety” was often used in terms of NPP safety. Due to the rise of interest to “green” and, particularly, hydrogen power engineering, the problem of hydrogen safety at industrial facilities has become ever more urgent. In Russia, the industrial production of hydrogen is meant to be performed by placing a chemical engineering plant near NPP, which supplies the plant with the necessary energy. In this approach, the production of hydrogen involves a wide range of combustible gases, such as methane, carbon monoxide, and hydrogen itself. Considering probable incidents, sudden combustible gas outburst into open space with further ignition is less dangerous by itself than ignition of the combustible mixture in the presence of many pipelines, reactor vessels, and any kind of fitting frames. Even ignition of 2100 cubic meters of the hydrogen-air mixture in open space gives velocity and pressure that are much lesser than velocity and pressure in Chapman-Jouguet condition and do not exceed 80 m/s and 6 kPa accordingly. However, the space blockage, the significant change of channel diameter on the way of flame propagation, and the presence of gas suspension lead to significant deflagration acceleration and to its transition into detonation or quasi-detonation. At the same time, process parameters acquired from the experiments at specific experimental facilities are not general, and their application to different facilities can only have a conventional and qualitative character. Yet, conducting deflagration and detonation experimental investigation for each specific industrial facility project in order to determine safe infrastructure unit placement does not seem feasible due to its high cost and hazard, while the conduction of numerical experiments is significantly cheaper and safer. Hence, the development of a numerical method that allows the description of reacting flows in domains with complex geometry seems promising. The base for this method is the modification of Kuropatenko method for calculating shock waves recently developed by authors, which allows using it in Eulerian coordinates. The current work contains the results of the development process. In addition, the comparison of numerical simulation results and experimental series with flame propagation in shock tubes with orifice plates is presented.

Keywords: CFD, reacting flow, DDT, gas explosion

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2799 The World Heritage List: A Big Data Spatial Econometrics Approach to Sites Promoting the Brand

Authors: David Wuepper, Marc Patry

Abstract:

UNESCO’s World Heritage program requests the inscribed locations to promote the World Heritage brand by clearly presenting information about it on-site. Based on feedback from over 319,000 visitors at 791 locations, we create an index that shows how much the World Heritage sites actually brand themselves as such. We find great heterogeneity throughout the list and explain this econometrically mostly with the economic benefit for the sites but also with cultural brand preferences, which are highest in Asia, followed by Europe and North America. We also find a positive relationship between World Heritage branding and conservation status and a U-shaped relationship between visitor numbers and WH branding. Based on our findings, we recommend to make clear World Heritage branding mandatory for all sites.

Keywords: UNESCO World Heritage, collective brand, cultural tourism, heritage conservation, brand equity, spatial econometrics

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2798 Titania Assisted Metal-Organic Framework Matrix for Elevated Hydrogen Generation Combined with the Production of Graphene Sheets through Water-Splitting Process

Authors: Heba M. Gobara, Ahmed A. M. El-Naggar, Rasha S. El-Sayed, Amal A. AlKahlawy

Abstract:

In this study, metal organic framework (Cr-MIL-101) and TiO₂ nanoparticles were utilized as two semiconductors for water splitting process. The coupling of both semiconductors in order to improve the photocatalytic reactivity for the hydrogen production in presence of methanol as a hole scavenger under visible light (sunlight) has been performed. The forementioned semiconductors and the collected samples after water splitting application are characterized by several techniques viz., XRD, N₂ adsorption-desorption, TEM, ED, EDX, Raman spectroscopy and the total content of carbon. The results revealed an efficient yield of H₂ production with maximum purity 99.3% with the in-situ formation of graphene oxide nanosheets and multiwalled carbon nanotubes coated over the surface of the physically mixed Cr-MIL-101–TiO₂ system. The amount of H₂ gas produced was stored when using Cr-MIL-101 catalyst individually. The obtained data in this work provides promising candidate materials for pure hydrogen production as a clean fuel acquired from the water splitting process. In addition, the in-situ production of graphene nanosheets and carbon nanotubes is counted as promising advances for the presented process.

Keywords: hydrogen production, water splitting, photocatalysts, Graphene

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2797 Evaluation of the Spatial Regulation of Hydrogen Sulphide Producing Enzymes in the Placenta during Labour

Authors: F. Saleh, F. Lyall, A. Abdulsid, L. Marks

Abstract:

Background: Labour in human is a complex biological process that involves interactions of neurological, hormonal and inflammatory pathways, with the placenta being a key regulator of these pathways. It is known that uterine contractions and labour pain cause physiological changes in gene expression in maternal and fetal blood, and in placenta during labour. Oxidative and inflammatory stress pathways are implicated in labour and they may cause alteration of placental gene expression. Additionally, in placental tissues, labour increases the expression of genes involved in placental oxidative stress, inflammatory cytokines, angiogenic regulators and apoptosis. Recently, Hydrogen Sulphide (H2S) has been considered as an endogenous gaseous mediator which promotes vasodilation and exhibits cytoprotective anti-inflammatory properties. The endogenous H2S is synthesised predominantly by two enzymes: cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE). As the H2S pathway has anti-oxidative and anti-inflammatory characteristics thus, we hypothesised that the expression of CBS and CSE in placental tissues would alter during labour. Methods: CBS and CSE expressions were examined in placentas using western blotting and RT-PCR in inner, middle and outer placental zones in placentas obtained from healthy non labouring women who delivered by caesarian section. These were compared with the equivalent zone of placentas obtained from women who had uncomplicated labour and delivered vaginally. Results: No differences in CBS and CSE mRNA or protein levels were found between the different sites within placentas in either the labour or non-labour group. There were no significant differences in either CBS or CSE expression between the two groups at the inner site and middle site. However, at the outer site there was a highly significant decrease in CBS protein expression in the labour group when compared to the non-labour group (p = 0.002). Conclusion: To the best of author’s knowledge, this is the first report to suggest that, CBS is expressed in a spatial manner within the human placenta. Further work is needed to clarify the precise function and mechanism of this spatial regulation although it is likely that inflammatory pathways regulation is a complex process in which this plays a role.

Keywords: anti-inflammatory, hydrogen sulphide, labour, oxidative stress

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2796 Real-Space Mapping of Surface Trap States in Cigse Nanocrystals Using 4D Electron Microscopy

Authors: Riya Bose, Ashok Bera, Manas R. Parida, Anirudhha Adhikari, Basamat S. Shaheen, Erkki Alarousu, Jingya Sun, Tom Wu, Osman M. Bakr, Omar F. Mohammed

Abstract:

This work reports visualization of charge carrier dynamics on the surface of copper indium gallium selenide (CIGSe) nanocrystals in real space and time using four-dimensional scanning ultrafast electron microscopy (4D S-UEM) and correlates it with the optoelectronic properties of the nanocrystals. The surface of the nanocrystals plays a key role in controlling their applicability for light emitting and light harvesting purposes. Typically for quaternary systems like CIGSe, which have many desirable attributes to be used for optoelectronic applications, relative abundance of surface trap states acting as non-radiative recombination centre for charge carriers remains as a major bottleneck preventing further advancements and commercial exploitation of these nanocrystals devices. Though ultrafast spectroscopic techniques allow determining the presence of picosecond carrier trapping channels, because of relative larger penetration depth of the laser beam, only information mainly from the bulk of the nanocrystals is obtained. Selective mapping of such ultrafast dynamical processes on the surfaces of nanocrystals remains as a key challenge, so far out of reach of purely optical probing time-resolved laser techniques. In S-UEM, the optical pulse generated from a femtosecond (fs) laser system is used to generate electron packets from the tip of the scanning electron microscope, instead of the continuous electron beam used in the conventional setup. This pulse is synchronized with another optical excitation pulse that initiates carrier dynamics in the sample. The principle of S-UEM is to detect the secondary electrons (SEs) generated in the sample, which is emitted from the first few nanometers of the top surface. Constructed at different time delays between the optical and electron pulses, these SE images give direct and precise information about the carrier dynamics on the surface of the material of interest. In this work, we report selective mapping of surface dynamics in real space and time of CIGSe nanocrystals applying 4D S-UEM. We show that the trap states can be considerably passivated by ZnS shelling of the nanocrystals, and the carrier dynamics can be significantly slowed down. We also compared and discussed the S-UEM kinetics with the carrier dynamics obtained from conventional ultrafast time-resolved techniques. Additionally, a direct effect of the state trap removal can be observed in the enhanced photoresponse of the nanocrystals after shelling. Direct observation of surface dynamics will not only provide a profound understanding of the photo-physical mechanisms on nanocrystals’ surfaces but also enable to unlock their full potential for light emitting and harvesting applications.

Keywords: 4D scanning ultrafast microscopy, charge carrier dynamics, nanocrystals, optoelectronics, surface passivation, trap states

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2795 Impact of Different Fuel Inlet Diameters onto the NOx Emissions in a Hydrogen Combustor

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

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2794 Development of an Attitude Scale Towards Social Networking Sites

Authors: Münevver Başman, Deniz Gülleroğlu

Abstract:

The purpose of this study is to develop a scale to determine the attitudes towards social networking sites. 45 tryout items, prepared for this aim, were applied to 342 students studying at Marmara University, Faculty of Education. The reliability and the validity of the scale were conducted with the help of these students. As a result of exploratory factor analysis with Varimax rotation, 41 items grouped according to the structure with three factors (interest, reality and negative effects) is obtained. While alpha reliability of the scale is obtained as .899; the reliability of factors is obtained as .899, .799, .775, respectively.

Keywords: Attitude, reliability, social networking sites, validity.

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2793 Assessing the Feasibility of Italian Hydrogen Targets with the Open-Source Energy System Optimization Model TEMOA - Italy

Authors: Alessandro Balbo, Gianvito Colucci, Matteo Nicoli, Laura Savoldi

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Hydrogen is expected to become a game changer in the energy transition, especially enabling sector coupling possibilities and the decarbonization of hard-to-abate end-uses. The Italian National Recovery and Resilience Plan identifies hydrogen as one of the key elements of the ecologic transition to meet international decarbonization objectives, also including it in several pilot projects for the early development in Italy. This matches the European energy strategy, which aims to make hydrogen a leading energy carrier of the future, setting ambitious goals to be accomplished by 2030. The huge efforts needed to achieve the announced targets require to carefully investigate of their feasibility in terms of economic expenditures and technical aspects. In order to quantitatively assess the hydrogen potential within the Italian context and the feasibility of the planned investments and projects, this work uses the TEMOA-Italy energy system model to study pathways to meet the strict objectives above cited. The possible hydrogen development has been studied both in the supply-side and demand-side of the energy system, also including storage options and distribution chains. The assessment comprehends alternative hydrogen production technologies involved in a competition market, reflecting the several possible investments declined by the Italian National Recovery and Resilience Plan to boost the development and spread of this infrastructure, including the sector coupling potential with natural gas through the currently existing infrastructure and CO2 capture for the production of synfuels. On the other hand, the hydrogen end-uses phase covers a wide range of consumption alternatives, from fuel-cell vehicles, for which both road and non-road transport categories are considered, to steel, and chemical industries uses and cogeneration for residential and commercial buildings. The model includes both high and low TRL technologies in order to provide a consistent outcome for the future decades as it does for the present day, and since it is developed through the use of an open-source code instance and database, transparency and accessibility are fully granted.

Keywords: decarbonization, energy system optimization models, hydrogen, open-source modeling, TEMOA

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2792 Integrating Music on Construction Sites: Key Benefits and Cautions: A Literature Perspective

Authors: Oluwatayomi Daniel Fadumo, Chinyere Celestina Esimone

Abstract:

The construction industry, as a massive human capital-related sector, requires an always motivated workforce. The inability to maintain this state has been found to hamper productivity which ultimately leads to poor project delivery, infrastructural development decline, and low morale among citizens. The need to develop an approach to keep this set of people inspired before, during, and after work becomes a necessity; this paper aims to evaluate the key benefits and cautions in integrating music on construction sites in Nigeria to improve effective project delivery. In attaining this, the study identified the advantages of music on construction sites, evaluated the key considerations in introducing music on construction sites, and recommended measures for the effective integration of music on construction sites in Nigeria. The study is a descriptive research through the use of secondary data gleaned from relevant literature, journals, and research sites. The study concluded that different forms of music genres can be implemented ranging from Pop music, rock, metal, and classical music. Introducing music has the advantage of industrial branding, improving workers` morale, setting the pace for working, helping in information retention, and improving mental health and happiness. The key consideration, however, is to provide the right volume and music that doesn’t pose health and safety challenges. The study finally recommended that for effective integration of music on construction sites in Nigeria, policies should be drafted regulating its use, specific radio customized for the site be introduced and that research-based music, proven to have previously helped, should be given to a group of workers.

Keywords: music, construction sites, workers, construction industry, construction management practice

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2791 Assessment Proposal to Establish the First Geo-Park in Egypt at Abu-Roash Area, Cairo

Authors: Kholoud Abdelmaksoud, Mahmoud Emam, Wael Al-Metwaly

Abstract:

Egypt is known as cradle of civilization due to its ancient history and archeological sites, but Egypt possess also a cradle of Geo-sites, which qualify it to be listed as one of the most important Geo-heritage sites all over the country. Geology and landscape in Abu-Roash area is considered as one of the most important geological places (geo-sites) inside Cairo which help us to know and understand geology and geologic processes, so the area is used mainly for geological education purposes, also the area contain an archeological sites; pyramid complex, tombs, and Coptic monastery which give the area unique importance. Abu-Roash area is located inside Cairo 9 km north of the Giza Pyramids, which make the accessibility to the area easy and safe, the geology of Abu-Roash constitutes a complex Cretaceous sedimentary succession mass with showing outstanding tectonic features (Syrian Arc system event), these features are considered as a Geo-heritage, which will be the main designation of ‘Geo-parks’ establishing. The research is dealing with the numerous geo-sites found in the area, and its geologic and archeological importance, the relation between geo-sites and archeology, also the research proposed a detailed maps for these sites depicting Geo-routes and the hazardous places surrounding Abu-Roash area. The research is proposing a new proposal not applied in Egypt before, establishing a Geo-park, to promote this unique geo-heritage from hazardous factors and anthropogenic effects, also it will offer geo-educational opportunities to the general public and to the scientific community, enhancement of Geo-tourism which will be linked easily with the Ancient Egyptian tourism, it will also provide a significant economic benefit to Abu-Roash residential area. Finally, the research recommends that The United Nations Educational, Scientific and Cultural Organizations promote conservation of geological and geo-morphological heritage to list this area for its importance under the umbrella of geo-parks.

Keywords: geo-park, geo-sites, Abu-roash, archaeological sites, geo-tourism

Procedia PDF Downloads 274
2790 Trapped Versus Stepping Stones: Work Trajectories of Young Workers During the COVID-19 Pandemic

Authors: Goh Mingyuan Asher, Nurul Fadiah Johari, Neo Yu Wei, Kim Aryung, Ho Kong Chong, Irene Y. H. N. G.

Abstract:

The COVID-19 pandemic represents an externally induced force as they face a combination of reduced work, dismissal, and job change for young precarious workers. The paper drew insights from two interview waves of the in-work poverty study in Singapore which were conducted a year apart. By analysing respondents’ job histories before and at the start of the pandemic as well as their job experiences over the two waves of interviews, the study found the presence of what scholars describe as trap and stepping stone trajectories. Trap trajectories refer to how the nature of precarious employment leads respondents to be in dead-end jobs with no room for progression while stepping stone trajectories refer to how poor work provides opportunities for the accumulation of work experiences. We also look at how structure, agency and biographical factors affect job trajectories and discuss the impacts of COVID-19 on work experiences and the implications of the bifurcation of trajectory outcomes on poverty and inequality among the young working poor in Singapore.

Keywords: working poor, precarity, young workers, COVID-19, work trajectories

Procedia PDF Downloads 76
2789 Status of Artisanal Fishery in Libya

Authors: Esmail Shakman, Khaled Etyab, Ibraheim Taboni, Mohamed Et-wail, Abdallah Ben Abdallah

Abstract:

This study was carried out along the Libyan coast during the period from 1st February to 31st March 2013. More than 120 landing sites have been visited in order to investigate their status and fishing activities. The study found that more than 91% of the landing sites were permanent and around 8% were seasonal. The type of landing sites were mostly harbors (42.86%), 31.75% protected bays and 25.4% are open beach. However, seven types of fishing boats were observed; flouka type was the largest percentage (70.06%), then 18.14% for mator, 3.28% for lampara, 0.41% for Tarrad, Gayag (0.16%), 5.97 for Daghesa, and 1.98% for batah. Moreover, the majority of them were concentrated in the western region of the country. The most common used fishing gearsare the trammel nets about 80%, which are used by flouka, mator, Tarrad, and batah. The using of trammel nets rely on the fishing season, fishes size and the target fish species. The other fishing gears are also used but occasionally.

Keywords: fishery, South Mediterranean, landing sites, marine biology

Procedia PDF Downloads 489
2788 Intertidal Fixed Stake Net Trap (Hadrah) Fishery in Kuwait, Distribution, Catch Rate, and Species Composition

Authors: Ali F. Al-Baz, Mohsen M. Al-Husaini, James M. Bishop

Abstract:

Intertidal fixed stake net trap (hadrah) is one of the oldest fishing gears used throughout the Arabian Gulf countries since 1800s and also one of most efficient methods of capturing fish from the intertidal area. This study described the hadrah fishery in Kuwait. From October 2001 to December 2002, more than 37,372 specimens representing 95 species (89 fish, 2 mollusks, 4 crustaceans) were measured from hadrah located in three different areas along Kuwait's coast. In Kuwait Bay, catch rates averaged 62 kg/sir day (range 14 kg/sir-day in February to 160 kg/sir-day in October 2002). Commercial species accounted for 41% of the catches. Catches from Failakah Island averaged 96 kg/sir-day from June through September, with 61% of the catch being commercial species. In the southern area, catches averaged only 32 kg/sir-day, and only 34% were commercially important. Forty percent of the hadrah catches were juveniles which shows that the shallow intertidal waters are prime nursery habitat, particularly in Kuwait Bay. To maintain ecosystem biodiversity and recruitment success of the fishes, we recommended that all hadrah should be removed from Kuwait Bay. In the future, removal of hadrah in other locations should be considered.

Keywords: catch and effort, hadrah, intertidal fixed stake net, Kuwait, species composition

Procedia PDF Downloads 469
2787 The Effectiveness of Banks’ Web Sites: A Study of Turkish Banking Sector

Authors: Raif Parlakkaya, Huseyin Cetin, Duygu Irdiren

Abstract:

By the development of World Wide Web, the usage rate of Internet has rapidly grown globally; and provided a basis for the emergence of electronic business. As well as other sectors, the banking sector has adopted the use of internet with the developments in information and communication technologies. Due to the public disclosure and transparency principle of Corporate Governance, the importance of information disclosure of banks on their web sites has increased significantly. For the purpose of this study, a Bank Disclosure Attribute Index (BDAI) in Turkey has been constructed through classifying the information disclosure on banks’ web sites into general, financial, investors and corporate governance attributes. All 47 banks in Turkish Banking System have been evaluated according to the index with the aim of providing a comparison between banks. By Chi Square Test, Pearson Correlation, T-Test, and ANOVA statistical tools, it has been concluded that the majority of banks in Turkey have shared information on their web sites adequately with respect to their total index score. Although there is a positive correlation between various types of information on banks’ web sites, there is no uniformity among them. Also, no significant difference between various types of information disclosure and bank types has been observed. Compared with the total index score averages of the five largest banks in Turkey, there are some banks that need to improve the content of their web sites.

Keywords: internet banking, websites evaluation, customer adoption, Turkey

Procedia PDF Downloads 368
2786 Modelling and Optimization of a Combined Sorption Enhanced Biomass Gasification with Hydrothermal Carbonization, Hot Gas Cleaning and Dielectric Barrier Discharge Plasma Reactor to Produce Pure H₂ and Methanol Synthesis

Authors: Vera Marcantonio, Marcello De Falco, Mauro Capocelli, Álvaro Amado-Fierro, Teresa A. Centeno, Enrico Bocci

Abstract:

Concerns about energy security, energy prices, and climate change led scientific research towards sustainable solutions to fossil fuel as renewable energy sources coupled with hydrogen as an energy vector and carbon capture and conversion technologies. Among the technologies investigated in the last decades, biomass gasification acquired great interest owing to the possibility of obtaining low-cost and CO₂ negative emission hydrogen production from a large variety of everywhere available organic wastes. Upstream and downstream treatment were then studied in order to maximize hydrogen yield, reduce the content of organic and inorganic contaminants under the admissible levels for the technologies which are coupled with, capture, and convert carbon dioxide. However, studies which analyse a whole process made of all those technologies are still missing. In order to fill this lack, the present paper investigated the coexistence of hydrothermal carbonization (HTC), sorption enhance gasification (SEG), hot gas cleaning (HGC), and CO₂ conversion by dielectric barrier discharge (DBD) plasma reactor for H₂ production from biomass waste by means of Aspen Plus software. The proposed model aimed to identify and optimise the performance of the plant by varying operating parameters (such as temperature, CaO/biomass ratio, separation efficiency, etc.). The carbon footprint of the global plant is 2.3 kg CO₂/kg H₂, lower than the latest limit value imposed by the European Commission to consider hydrogen as “clean”, that was set to 3 kg CO₂/kg H₂. The hydrogen yield referred to the whole plant is 250 gH₂/kgBIOMASS.

Keywords: biomass gasification, hydrogen, aspen plus, sorption enhance gasification

Procedia PDF Downloads 42
2785 Institutional Preferences of Elites and Society: Paradoxes of Economic Development in Georgia

Authors: Inga Balarjishvili, Ia Natsvlishvili

Abstract:

Article aims to discuss the controversial character of the institutional preferences of elites and society in modern Georgia. Desktop research method is used to formulate the findings and analyze the outcomes. It is accepted that transformation process in Post-Soviet Georgia went with the prevalence of elites’ institutional preferences over the needs of the society that induced voluntarism in the process of formation of institutions. Hypothesis of 'quasi-inclusion trap' is put forward in the article as an effect of authoritarian modernization that is proved by instable paces of wealth and economic growth in the post-authoritarian period. On the one hand, monopolization of institutional choice by the elites, blocking formation of inclusive political and economic institutions for fear of losing status-quo worsen perspectives for achieving free availability regime. On the other hand, consciousness of the society is dominated by informal institutions, judicial nihilism and orientation on 'self-survival values.' This hinders its consolidation as a 'collective principal' against 'institutional utilitarianism,' result of which is hindered economic development.

Keywords: elites, hypothesis of 'quasi-inclusion trap', institutional preferences, post-Soviet Georgia

Procedia PDF Downloads 226
2784 A Study on Diversity of the Family Encyrtidae (Hymenoptera: Chalcidoidea) in Forest Habitat of Doon Valley, Uttarakhand, India

Authors: Rashmi Nautiyal, Sudhir Singh

Abstract:

Encyrtidae is the largest family of superfamily Chalcidoidea of parasitic Hymenoptera group. They are endoparasitoids or hyperparasitoids of other arthropods and have the greatest impact on maintaining diversity. It not only forms a major component of diversity itself but also is very important in sustaining diversity in other groups. They are used as efficient biological control agents against key insect pests world over. The present study is based on the collection of Encyrtidae (Chalcidoidea: Hymenoptera) made during a survey in Doon Valley from 2008 to 2011 in all the five seasons (Spring, Summer cum Pre-monsoon, Monsoon, Post-monsoon, Winter) for each year. The collections were made from forest habitat in different localities of the Valley using sweep net and yellow pan trap methods. A total of 1346 specimens of encyrtids were collected and identified from the forest habitat (745 with a sweep net and 601with yellow pan trap).Of these, season-wise (post monsoon, spring, summer, monsoon, and winter) represented Encyrtids were 30.46%, 19.31%, 17.16%, 16.64% and 16.41%, respectively. A total of 161 species of Encyrtids belonging to 43 genera under 2 subfamilies were recorded.

Keywords: diversity, Encyrtidae, sweep net, yellow pan

Procedia PDF Downloads 253
2783 Design and Performance Evaluation of Plasma Spouted Bed Reactor for Converting Waste Plastic into Green Hydrogen

Authors: Palash Kumar Mollick, Leire Olazar, Laura Santamaria, Pablo Comendador, Gartzen Lopez, Martin Olazar

Abstract:

Average calorific value of a mixure of waste plastic is approximately 38 MJ/kg. Present work aims to extract maximum possible energy from a mixure of waste plastic using a DC thermal plasma in a spouted bed reactor. Plasma pyrolysis and steam reforming process has shown a potential to generate hydrogen from plastic with much below of legal limit of producing dioxins and furans as the carcinogenic gases. A spouted bed pyrolysis rector can continuously process plastic beads to produce organic volatiles, which later react with steam in presence of catalyst to results in syngas. lasma being the fourth state of matter, can carry high impact electrons to favour the activation energy of any chemical reactions. Computational Fluid Dynamic (CFD) simulation using COMSOL Multiphysics software has been performed to evaluate performance of a plasma spouted bed reactor in producing contamination free hydrogen as a green energy from waste plastic beads. The simulation results will showcase a design of a plasma spouted bed reactor for converting plastic waste into green hydrogen in a single step process. The high temperature hydrodynamics of spouted bed with plastic beads and the corresponding temperature distribution inside the reaction chamber will be critically examined for it’s near future installation of demonstration plant.

Keywords: green hydrogen, plastic waste, synthetic gas, pyrolysis, steam reforming, spouted bed, reactor design, plasma, dc palsma, cfd simulation

Procedia PDF Downloads 64
2782 Novel Pyrimidine Based Semicarbazones: Confirmation of Four Binding Site Pharmacophoric Model Hypothesis for Antiepileptic Activity

Authors: Harish Rajak, Swati Singh

Abstract:

A series of novel pyrimidine based semicarbazone were designed and synthesized on the basis of semicarbazone based pharmacophoric model to satisfy the structural prerequisite crucial for antiepileptic activity. The semicarbazones based pharmacophoric model consists of following four essential binding sites: (i) An aryl hydrophobic binding site with halo substituent; (ii) A hydrogen bonding domain; (iii) An electron donor group and (iv) Another hydrophobic-hydrophilic site controlling the pharmacokinetic features of the anticonvulsant. The aryl semicarbazones has been recognized as a structurally novel class of compounds with remarkable anticonvulsant activity. In the present study, all the test semicarbazones were subjected to molecular docking using Glide v5.8. Some of the compounds were found to interact with ARG192, GLU270 and THR353 residues of 1OHV protein, present in GABA-AT receptor. The chemical structures of the synthesized molecules were characterized by elemental and spectral (IR, 1H NMR, 13C NMR and MS) analysis. The anticonvulsant activities of the compounds were investigated using maximal electroshock seizure (MES) and subcutaneous pentylenetrtrazole (scPTZ) models. The neurotoxicity was evaluated in mice by the rotorod test. The attempts were also made to establish structure-activity relationships among synthesized compounds. The results of the present study confirmed that the pharmacophore model with four binding sites is essential for antiepileptic activity.

Keywords: pyrimidine, semicarbazones, anticonvulsant activity, neurotoxicity

Procedia PDF Downloads 229
2781 Development of a Complete Single Jet Common Rail Injection System Gas Dynamic Model for Hydrogen Fueled Engine with Port Injection Feeding System

Authors: Mohammed Kamil, M. M. Rahman, Rosli A. Bakar

Abstract:

Modeling of hydrogen fueled engine (H2ICE) injection system is a very important tool that can be used for explaining or predicting the effect of advanced injection strategies on combustion and emissions. In this paper, a common rail injection system (CRIS) is proposed for 4-strokes 4-cylinders hydrogen fueled engine with port injection feeding system (PIH2ICE). For this system, a numerical one-dimensional gas dynamic model is developed considering single injection event for each injector per a cycle. One-dimensional flow equations in conservation form are used to simulate wave propagation phenomenon throughout the CR (accumulator). Using this model, the effect of common rail on the injection system characteristics is clarified. These characteristics include: rail pressure, sound velocity, rail mass flow rate, injected mass flow rate and pressure drop across injectors. The interaction effects of operational conditions (engine speed and rail pressure) and geometrical features (injector hole diameter) are illustrated; and the required compromised solutions are highlighted. The CRIS is shown to be a promising enhancement for PIH2ICE.

Keywords: common rail, hydrogen engine, port injection, wave propagation

Procedia PDF Downloads 393