Search results for: active and reactive power
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 9942

Search results for: active and reactive power

2292 Leveraging the Power of Dual Spatial-Temporal Data Scheme for Traffic Prediction

Authors: Yang Zhou, Heli Sun, Jianbin Huang, Jizhong Zhao, Shaojie Qiao

Abstract:

Traffic prediction is a fundamental problem in urban environment, facilitating the smart management of various businesses, such as taxi dispatching, bike relocation, and stampede alert. Most earlier methods rely on identifying the intrinsic spatial-temporal correlation to forecast. However, the complex nature of this problem entails a more sophisticated solution that can simultaneously capture the mutual influence of both adjacent and far-flung areas, with the information of time-dimension also incorporated seamlessly. To tackle this difficulty, we propose a new multi-phase architecture, DSTDS (Dual Spatial-Temporal Data Scheme for traffic prediction), that aims to reveal the underlying relationship that determines future traffic trend. First, a graph-based neural network with an attention mechanism is devised to obtain the static features of the road network. Then, a multi-granularity recurrent neural network is built in conjunction with the knowledge from a grid-based model. Subsequently, the preceding output is fed into a spatial-temporal super-resolution module. With this 3-phase structure, we carry out extensive experiments on several real-world datasets to demonstrate the effectiveness of our approach, which surpasses several state-of-the-art methods.

Keywords: traffic prediction, spatial-temporal, recurrent neural network, dual data scheme

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2291 Design of the Ice Rink of the Future

Authors: Carine Muster, Prina Howald Erika

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Today's ice rinks are important energy consumers for the production and maintenance of ice. At the same time, users demand that the other rooms should be tempered or heated. The building complex must equally provide cooled and heated zones, which does not translate as carbon-zero ice rinks. The study provides an analysis of how the civil engineering sector can significantly impact minimizing greenhouse gas emissions and optimizing synergies across an entire ice rink complex. The analysis focused on three distinct aspects: the layout, including the volumetric layout of the premises present in an ice rink; the materials chosen that can potentially use the most ecological structural approach; and the construction methods based on innovative solutions to reduce carbon footprint. The first aspect shows that the organization of the interior volumes and defining the shape of the rink play a significant role. Its layout makes the use and operation of the premises as efficient as possible, thanks to the differentiation between heated and cooled volumes while optimising heat loss between the different rooms. The sprayed concrete method, which is still little known, proves that it is possible to achieve the strength of traditional concrete for the structural aspect of the load-bearing and non-load-bearing walls of the ice rink by using materials excavated from the construction site and providing a more ecological and sustainable solution. The installation of an empty sanitary space underneath the ice floor, making it independent of the rest of the structure, provides a natural insulating layer, preventing the transfer of cold to the rest of the structure and reducing energy losses. The addition of active pipes as part of the foundation of the ice floor, coupled with a suitable system, gives warmth in the winter and storage in the summer; this is all possible thanks to the natural heat in the ground. In conclusion, this study provides construction recommendations for future ice rinks with a significantly reduced energy demand, using some simple preliminary design concepts. By optimizing the layout, materials, and construction methods of ice rinks, the civil engineering sector can play a key role in reducing greenhouse gas emissions and promoting sustainability.

Keywords: climate change, energy optimization, green building, sustainability

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2290 Precision Grinding of Titanium (Ti-6Al-4V) Alloy Using Nanolubrication

Authors: Ahmed A. D. Sarhan, Hong Wan Ping, M. Sayuti

Abstract:

In this current era of competitive machinery productions, the industries are designed to place more emphasis on the product quality and reduction of cost whilst abiding by the pollution-preventing policy. In attempting to delve into the concerns, the industries are aware that the effectiveness of existing lubrication systems must be improved to achieve power-efficient and pollution-preventing machining processes. As such, this research is targeted to study on a plausible solution to the issue in grinding titanium alloy (Ti-6Al-4V) by using nanolubrication, as an alternative to flood grinding. The aim of this research is to evaluate the optimum condition of grinding force and surface roughness using MQL lubricating system to deliver nano-oil at different level of weight concentration of Silicon Dioxide (SiO2) mixed normal mineral oil. Taguchi Design of Experiment (DoE) method is carried out using a standard Taguchi orthogonal array of L16(43) to find the optimized combination of weight concentration mixture of SiO2, nozzle orientation and pressure of MQL. Surface roughness and grinding force are also analyzed using signal-to-noise(S/N) ratio to determine the best level of each factor that are tested. Consequently, the best combination of parameters is tested for a period of time and the results are compared with conventional grinding method of dry and flood condition. The results show a positive performance of MQL nanolubrication.

Keywords: grinding, MQL, precision grinding, Taguchi optimization, titanium alloy

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2289 A Compact Ultra-Wide Band Antenna with C-Shaped Slot for WLAN Notching

Authors: Maryam Rasool, Farhan Munir, Fahad Nawaz, Saad Ahmad

Abstract:

A patch antenna operating in the Ultra-Wide Band of frequency (3.1 GHz – 10.6 GHz) is designed with enhanced security from interference from other applications by incorporating the notching technique. Patch antennas in the Ultra-Wide Band are becoming widely famous due to their low power, light weight and high data rate capability. Micro strip patch antenna’s patch can be altered to increase its bandwidth and introduce UWB character in it. The designed antenna is a patch antenna consisting of a conductive sheet of metal mounted over a large sheet of metal called the ground plane with a substrate separating the two. Notched bands are public safety WLAN, WLAN and FSS. Different techniques used to implement the UWB antenna were individually implemented and there results were examined. V shaped patch was then chosen and modified to an arrow shaped patch to give the optimized results operating on the entire UWB region with considerable return loss. The frequency notch prevents the operation of the antenna at a particular range of frequency, hence minimizing interference from other systems. There are countless techniques for introducing the notch but we have used inverted C-shaped slots in the UWB patch to get the notch characteristics as output and also wavelength resonators to introduce notch in UWB band. The designed antenna is simulated in High Frequency Structural Simulator (HFSS) 13.0 by Ansoft.

Keywords: HFSS, Notch, UWB, WLAN

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2288 Seroepidemiological Study of Toxoplasma gondii Infection in Women of Child-Bearing Age in Communities in Osun State, Nigeria

Authors: Olarinde Olaniran, Oluyomi A. Sowemimo

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Toxoplasmosis is frequently misdiagnosed or underdiagnosed, and it is the third most common cause of hospitalization due to food-borne infection. Intra-uterine infection with Toxoplasma gondii due to active parasitaemia during pregnancy can cause severe and often fatal cerebral damage, abortion, and stillbirth of a fetus. The aim of the study was to investigate the prevalence of T. gondii infection in women of childbearing age in selected communities of Osun State with a view to determining the risk factors which predispose to the T. gondii infection. Five (5) ml of blood was collected by venopuncture into a plain blood collection tube by a medical laboratory scientist. Serum samples were separated by centrifuging the blood samples at 3000 rpm for 5 mins. The sera were collected with Eppendorf tubes and stored at -20°C analysis for the presence of IgG and IgM antibodies against T. gondii by commercially available enzyme-linked immunosorbent assay (ELISA) kit (Demeditec Diagnostics GmbH, Germany) conducted according to the manufacturer’s instructions. The optical densities of wells were measured by a photometer at a wavelength of 450 nm. Data collected were analysed using appropriate computer software. The overall seroprevalence of T. gondii among the women of child-bearing age in selected seven communities in Osun state was 76.3%. Out of 76.3% positive for Toxoplasma gondii infection, 70.0% were positive for anti- T. gondii IgG, and 32.3% were positive for IgM, and 26.7% for both IgG and IgM. The prevalence of T. gondii was lowest (58.9%) among women from Ile Ife, a peri-urban community, and highest (100%) in women residing in Alajue, a rural community. The prevalence of infection was significantly higher (P= 0.000) among Islamic women (87.5%) than in Christian women (70.8%). The highest prevalence (86.3%) was recorded in women with primary education, while the lowest (61.2%) was recorded in women with tertiary education (p =0.016). The highest prevalence (79.7%) was recorded in women that reside in rural areas, and the lowest (70.1%) was recorded in women that reside in peri-urban area (p=0.025). The prevalence of T. gondii infection was highest (81.4%) in women with one miscarriage, while the prevalence was lowest in women with no miscarriages (75.9%). The age of the women (p=0.042), Islamic religion (p=0.001), the residence of the women (p=0.001), and water source were all positively associated with T. gondii infection. The study concluded that there was a high seroprevalence of T. gondii recorded among women of child-bearing age in the study area. Hence, there is a need for health education and create awareness of the disease and its transmission to women of reproductive age group in general and pregnant women in particular to reduce the risk of T. gondii in pregnant women.

Keywords: seroepidemiology, Toxoplasma gondii, women, child-bearing, age, communities, Ile -Ife, Nigeria

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2287 Opportunities and Challenges to Local Legislation at the Height of the COVID-19 Pandemic: Evidence from a Fifth Class Municipality in the Visayas, Philippines

Authors: Renz Paolo B. Ramos, Jake S. Espina

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The Local Government Academy of the Philippines explains that Local legislation is both a power and a process by which it enacts ordinances and resolutions that have the force and effect of law while engaging with a range of stakeholders for their implementation. Legislative effectiveness is crucial for the development of any given area. This study's objective is to evaluate the legislative performance of the 10th Sangguniang of Kawayan, a legislative body in a fifth-class municipality in the Province of Biliran, during the height of the COVID-19 pandemic (2019-2021) with a focus on legislation, accountability, and participation, institution-building, and intergovernmental relations. The aim of the study was that a mixed-methods strategy was used to gather data. The Local Legislative Performance Appraisal Form (LLPAF) was completed, while Focus Interviews for Local Government Unit (LGU) personnel, a survey questionnaire for constituents, and ethnographic diary-writing were conducted. Convenience Sampling was utilized for LGU workers, whereas Simple Random Sampling was used to identify the number of constituents participating. Interviews were analyzed using thematic analysis, while frequency data analysis was employed to describe and evaluate the nature and connection of the data to the underlying population. From this data, the researchers draw opportunities and challenges met by the local legislature during the height of the pandemic.

Keywords: local legislation, local governance, legislative effectiveness, legislative analysis

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2286 Flipped Learning in Interpreter Training: Technologies, Activities and Student Perceptions

Authors: Dohun Kim

Abstract:

Technological innovations have stimulated flipped learning in many disciplines, including language teaching. It is a specific type of blended learning, which combines onsite (i.e. face-to-face) with online experiences to produce effective, efficient and flexible learning. Flipped learning literally ‘flips’ conventional teaching and learning activities upside down: it leverages technologies to deliver a lecture and direct instruction—other asynchronous activities as well—outside the classroom to reserve onsite time for interaction and activities in the upper cognitive realms: applying, analysing, evaluating and creating. Unlike the conventional flipped approaches, which focused on video lecture, followed by face-to-face or on-site session, new innovative methods incorporate various means and structures to serve the needs of different academic disciplines and classrooms. In the light of such innovations, this study adopted ‘student-engaged’ approaches to interpreter training and contrasts them with traditional classrooms. To this end, students were also encouraged to engage in asynchronous activities online, and innovative technologies, such as Telepresence, were employed. Based on the class implementation, a thorough examination was conducted to examine how we can structure and implement flipped classrooms for language and interpreting training while actively engaging learners. This study adopted a quantitative research method, while complementing it with a qualitative one. The key findings suggest that the significance of the instructor’s role does not dwindle, but his/her role changes to a moderator and a facilitator. Second, we can apply flipped learning to both theory- and practice-oriented modules. Third, students’ integration into the community of inquiry is of significant importance to foster active and higher-order learning. Fourth, cognitive presence and competence can be enhanced through strengthened and integrated teaching and social presences. Well-orchestrated teaching presence stimulates students to find out the problems and voices the convergences and divergences, while fluid social presence facilitates the exchanges of knowledge and the adjustment of solutions, which eventually contributes to consolidating cognitive presence—a key ingredient that enables the application and testing of the solutions and reflection thereon.

Keywords: blended learning, Community of Inquiry, flipped learning, interpreter training, student-centred learning

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2285 Digital Transformation of Payment Systems Using Field Service Management

Authors: Hamze Torabian, Mohammad Mehrabioun Mohammadi

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Like many other industries, the payment industry has been affected by digital transformation. The importance of digital transformation in the payment industry is very crucial. Because the payment industry is considered a leading industry in digital and emerging technologies, and the digitalization of other industries such as retail, health, and telecommunication, it also depends on the growth rate of digitalized payment systems. One of the technological innovations in service management is Field Service Management (FSM). Despite the widespread use of FSM in various industries such as petrochemical, health, maintenance, etc., this technology can also be recruited in the payment industry, transforming the payment industry into a more agile and efficient one. Accordingly, the present study pays close attention to the application of FSM in the payment industry. Given the importance of merchants' bargaining power in the payment industry, this study aims to use FSM in the digital transformation initiative with a targeted focus on providing real-time services to merchants. The research method consists of three parts. Firstly, conducting the review of past research, applications of FSM in the payment industry are considered. In the next step, merchants' benefits such as emotional, functional, economic, and social benefits in using FSM are identified using in-depth interviews and content analysis methods. The related business model in helping the payment industry transforming into a more agile and efficient industry is considered in the following step. The results revealed the 10 main pillars required to realize the digital transformation of payment systems using FSM.

Keywords: digital transformation, field service management, merchant support systems, payment industry

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2284 European Prosecutor's Office: Chances and Threats; Brief to Polish Perspective

Authors: Katarzyna Stoklosa

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Introduction: European Public Prosecutor’s Office (EPPO) is an independent office in European Union which was established under the article 86 of the Treaty on the Functioning of the European Union by the Treaty of Lisbon following the method of enhanced cooperation. EPPO is aimed at combating crimes against the EU’s financial interest et fraud against the EU budgets on the one hand, EPPO will give a chance to effective fight with organized criminality, on the other it seems to be a threat for member-states which bound with justice the problem of sovereignty. It is a new institution that will become effective from 2020, which is why it requires prior analysis. Methodology: The author uses statistical and comparative methods by collecting and analyzing the work of current institutions such as Europol, Eurojust, as well as the future impact of EPPO on detection and prosecution of crimes. The author will also conduct questionnaire among students and academic staff involved in the perception of EU institutions and the need to create new entities dealing with inter-agency cooperation in criminal matters. Thanks to these research the author will draw up present ways of cooperation between member-states and changes in fighting with financial crimes which will grow up under new regulation. Major Finding of the Study: Analysis and research show that EPPO is an institution based on the principle of mutual recognition, which often does not work in cooperation between Member States. Distrust and problems with the recognition of judgments of other EU Member States may significantly affect the functioning of EPPO. Poland is not part of the EPPO, because arguments have been raised that the European Public Prosecutor's Office interferes too much with the Member States’ pro-active sovereignty and duplicates competences. The research and analyzes carried out by the author show that EPPO has completely new competences, for example, it may file indictments against perpetrators of financial crimes. However, according to the research carried out by the author, such competences may undermine the sovereignty and the principle of protecting the public order of the EU. Conclusion: After the analysis, it will be possible to set following thesis: EPPO is only possible way to effective fight with organized financial criminality. However in conclusion Polish doubts should not be criticized at all. Institutions as EPPO must properly respect sovereignty of member-states. Even instruments like that cannot provoke political contraventions, because there are no other ways to effective resolving of international criminality problem.

Keywords: criminal trial, economic crimes, European Public Prosecutor's Office, European Union

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2283 Creating an Enabling Learning Environment for Learners with Visual Impairments Inlesotho Rural Schools by Using Asset-Based Approaches

Authors: Mamochana, A. Ramatea, Fumane, P. Khanare

Abstract:

Enabling the learning environment is a significant and adaptive technique necessary to navigate learners’ educational challenges. However, research has indicated that quality provision of education in the environments that are enabling, especially to learners with visual impairments (LVIs, hereafter) in rural schools, remain an ongoing challenge globally. Hence, LVIs often have a lower level of academic performance as compared to their peers. To balance this gap and fulfill learners'fundamentalhuman rights¬ of receiving an equal quality education, appropriate measures and structures that make enabling learning environment a better place to learn must be better understood. This paper, therefore, intends to find possible means that rural schools of Lesotho can employ to make the learning environment for LVIs enabling. The present study aims to determine suitable assets that can be drawn to make the learning environment for LVIs enabling. The study is also informed by the transformative paradigm and situated within a qualitative research approach. Data were generated through focus group discussions with twelve teachers who were purposefully selected from two rural primary schools in Lesotho. The generated data were then analyzed thematically using Braun and Clarke's six-phase framework. The findings of the study indicated that participating teachers do have an understanding that rural schools boast of assets (existing and hidden) that have a positive influence in responding to the special educational needs of LVIs. However, the participants also admitted that although their schools boast of assets, they still experience limited knowledge about the use of the existing assets and thus, realized a need for improved collaboration, involvement of the existing assets, and enhancement of academic resources to make LVIs’ learning environment enabling. The findings of this study highlight the significance of the effective use of assets. Additionally, coincides with literature that shows recognizing and tapping into the existing assets enable learning for LVIs. In conclusion, the participants in the current study indicated that for LVIs’ learning environment to be enabling, there has to be sufficient use of the existing assets. The researchers, therefore, recommend that the appropriate use of assets is good, but may not be sufficient if the existing assets are not adequately managed. Hence,VILs experience a vicious cycle of vulnerability. It was thus, recommended that adequate use of assets and teachers' engagement as active assets should always be considered to make the learning environment a better place for LVIs to learan in the future

Keywords: assets, enabling learning environment, rural schools, learners with visual impairments

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2282 Modal Composition and Tectonic Provenance of the Sandstones of Ecca Group, Karoo Supergroup in the Eastern Cape Province, South Africa

Authors: Christopher Baiyegunhi, Kuiwu Liu, Oswald Gwavava

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Petrography of the sandstones of Ecca Group, Karoo Supergroup in the Eastern Cape Province of South Africa have been investigated on composition, provenance and influence of weathering conditions. Petrographic studies based on quantitative analysis of the detrital minerals revealed that the sandstones are composed mostly of quartz, feldspar and lithic fragments of metamorphic and sedimentary rocks. The sandstones have an average framework composition of 24.3% quartz, 19.3% feldspar, 26.1% rock fragments, and 81.33% of the quartz grains are monocrystalline. These sandstones are generally very fine to fine grained, moderate to well sorted, and subangular to subrounded in shape. In addition, they are compositionally immature and can be classified as feldspathic wacke and lithic wacke. The absence of major petrographically distinctive compositional variations in the sandstones perhaps indicate homogeneity of their source. As a result of this, it is inferred that the transportation distance from the source area was quite short and the main mechanism of transportation was by river systems to the basin. The QFL ternary diagrams revealed dissected and transitional arc provenance pointing to an active margin and uplifted basement preserving the signature of a recycled provenance. This is an indication that the sandstones were derived from a magmatic arc provenance. Since magmatic provenance includes transitional arc and dissected arc, it also shows that the source area of the Ecca sediments had a secondary sedimentary and metasedimentary rocks from a marginal belt that developed as a result of rifting. The weathering diagrams and semi-quantitative weathering index indicate that the Ecca sandstones are mostly from a plutonic source area, with climatic conditions ranging from arid to humid. The compositional immaturity of the sandstones is suggested to be due to weathering or recycling and low relief or short transport from the source area. The detrital modal compositions of these sandstones are related to back arc to island and continental margin arc. The origin and deposition of the Ecca sandstones are due to low-moderate weathering, recycling of pre-existing rocks, erosion and transportation of debris from the orogeny of the Cape Fold Belt.

Keywords: petrography, tectonic setting, provenance, Ecca Group, Karoo Basin

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2281 In vitro and in vivo Anticancer Activity of Nanosize Zinc Oxide Composites of Doxorubicin

Authors: Emma R. Arakelova, Stepan G. Grigoryan, Flora G. Arsenyan, Nelli S. Babayan, Ruzanna M. Grigoryan, Natalia K. Sarkisyan

Abstract:

Novel nanosize zinc oxide composites of doxorubicin obtained by deposition of 180 nm thick zinc oxide film on the drug surface using DC-magnetron sputtering of a zinc target in the form of gels (PEO+Dox+ZnO and Starch+NaCMC+Dox+ZnO) were studied for drug delivery applications. The cancer specificity was revealed both in in vitro and in vivo models. The cytotoxicity of the test compounds was analyzed against human cancer (HeLa) and normal (MRC5) cell lines using MTT colorimetric cell viability assay. IC50 values were determined and compared to reveal the cancer specificity of the test samples. The mechanistic study of the most active compound was investigated using Flow cytometry analyzing of the DNA content after PI (propidium iodide) staining. Data were analyzed with Tree Star FlowJo software using cell cycle analysis Dean-Jett-Fox module. The in vivo anticancer activity estimation experiments were carried out on mice with inoculated ascitic Ehrlich’s carcinoma at intraperitoneal introduction of doxorubicin and its zinc oxide compositions. It was shown that the nanosize zinc oxide film deposition on the drug surface leads to the selective anticancer activity of composites at the cellular level with the range of selectivity index (SI) from 4 (Starch+NaCMC+Dox+ZnO) to 200 (PEO(gel)+Dox+ZnO) which is higher than that of free Dox (SI = 56). The significant increase in vivo antitumor activity (by a factor of 2-2.5) and decrease of general toxicity of zinc oxide compositions of doxorubicin in the form of the above mentioned gels compared to free doxorubicin were shown on the model of inoculated Ehrlich's ascitic carcinoma. Mechanistic studies of anticancer activity revealed the cytostatic effect based on the high level of DNA biosynthesis inhibition at considerable low concentrations of zinc oxide compositions of doxorubicin. The results of studies in vitro and in vivo behavior of PEO+Dox+ZnO and Starch+NaCMC+Dox+ZnO composites confirm the high potential of the nanosize zinc oxide composites as a vector delivery system for future application in cancer chemotherapy.

Keywords: anticancer activity, cancer specificity, doxorubicin, zinc oxide

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2280 Heterogeneous and Homogeneous Photocatalytic Degradation of Acid Orange 10 in Aqueous Solution

Authors: Merouani Djilali Redha, F. Abdelmalek, A. A. Addou

Abstract:

Advanced oxidation processes (AOPs) utilizing Homogenous photocatalysis (Fenton and photo-Fenton reactions), and Heterogeneous photocatalyse (TiO2 and ZnO) were investigated for the degradation of commercial azo dye ‘Orange G’ wastewater. Fenton and photo-Fenton experimental conditions were: Hydrogen peroxide concentration (10-2 M), Ferrous ions concentration (5.10-4 M), pH (2.8 – 3), UV lamp power (6 watt). Adding more ferrous ions enhanced the oxidation rate for the H2O2/Fe2+ and UV/H2O2/Fe2+ processes. The optimum catalyst loading was found 2.0 g.L-1 in our case for both catalysts TiO2 and ZnO. A comparative study of the photocatalytic degradation showed that these two catalysts have a comparable reactivity; it follows a pseudo-first-order kinetics. The degradation trends followed the order: UV365/Fenton > UV365/TiO2 > Solar Fenton > Solar TiO2 > Fenton ~UV365/ZnO. Among AOPs, processes using Fenton type reagent are relatively cheap and easy to operate and maintain. Moreover, UV365/Fenton process has been shown as effective in the treatment of OG dye. Dye was degraded following second-order kinetics. The rate constants was 0,041 .10+6 L.M-1.min-1. The degradation was followed by spectrophotometric method, chemical oxygen demand (COD) measures and high performance liquid chromatography analyses (HPLC). Some aromatic and aliphatic degradation compounds were identified. Degradation of Orange G by UV Fenton mechanism was also proposed.

Keywords: AOPs, homogeneous catalysis, heterogeneous catalysis, acid orange 10, hydroxyl radical

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2279 High Responsivity of Zirconium boride/Chromium Alloy Heterostructure for Deep and Near UV Photodetector

Authors: Sanjida Akter, Ambali Alade Odebowale, Andrey E. Miroshnichenko, Haroldo T. Hattori

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Photodetectors (PDs) play a pivotal role in optoelectronics and optical devices, serving as fundamental components that convert light signals into electrical signals. As the field progresses, the integration of advanced materials with unique optical properties has become a focal point, paving the way for the innovation of novel PDs. This study delves into the exploration of a cutting-edge photodetector designed for deep and near ultraviolet (UV) applications. The photodetector is constructed with a composite of Zirconium Boride (ZrB2) and Chromium (Cr) alloy, deposited onto a 6H nitrogen-doped silicon carbide substrate. The determination of the optimal alloy thickness is achieved through Finite-Difference Time-Domain (FDTD) simulation, and the synthesis of the alloy is accomplished using radio frequency (RF) sputtering. Remarkably, the resulting photodetector exhibits an exceptional responsivity of 3.5 A/W under an applied voltage of -2 V, at wavelengths of 405 nm and 280 nm. This heterostructure not only exemplifies high performance but also provides a versatile platform for the development of near UV photodetectors capable of operating effectively in challenging conditions, such as environments characterized by high power and elevated temperatures. This study contributes to the expanding landscape of photodetector technology, offering a promising avenue for the advancement of optoelectronic devices in demanding applications.

Keywords: responsivity, silicon carbide, ultraviolet photodetector, zirconium boride

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2278 Acetic Acid Adsorption and Decomposition on Pt(111): Comparisons to Ni(111)

Authors: Lotanna Ezeonu, Jason P. Robbins, Ziyu Tang, Xiaofang Yang, Bruce E. Koel, Simon G. Podkolzin

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The interaction of organic molecules with metal surfaces is of interest in numerous technological applications, such as catalysis, bone replacement, and biosensors. Acetic acid is one of the main products of bio-oils produced from the pyrolysis of hemicellulosic feedstocks. However, their high oxygen content makes them unsuitable for use as fuels. Hydrodeoxygenation is a proven technique for catalytic deoxygenation of bio-oils. An understanding of the energetics and control of the bond-breaking sequences of biomass-derived oxygenates on metal surfaces will enable a guided optimization of existing catalysts and the development of more active/selective processes for biomass transformations to fuels. Such investigations have been carried out with the aid of ultrahigh vacuum and its concomitant techniques. The high catalytic activity of platinum in biomass-derived oxygenate transformations has sparked a lot of interest. We herein exploit infrared reflection absorption spectroscopy(IRAS), temperature-programmed desorption(TPD), and density functional theory(DFT) to study the adsorption and decomposition of acetic acid on a Pt(111) surface, which was then compared with Ni(111), a model non-noble metal. We found that acetic acid adsorbs molecularly on the Pt(111) surface, interacting through the lone pair of electrons of one oxygen atomat 90 K. At 140 K, the molecular form is still predominant, with some dissociative adsorption (in the form of acetate and hydrogen). Annealing to 193 K led to complete dehydrogenation of molecular acetic acid species leaving adsorbed acetate. At 440 K, decomposition of the acetate species occurs via decarbonylation and decarboxylation as evidenced by desorption peaks for H₂,CO, CO₂ and CHX fragments (x=1, 2) in theTPD.The assignments for the experimental IR peaks were made using visualization of the DFT-calculated vibrational modes. The results showed that acetate adsorbs in a bridged bidentate (μ²η²(O,O)) configuration. The coexistence of linear and bridge bonded CO was also predicted by the DFT results. Similar molecular acid adsorption energy was predicted in the case of Ni(111) whereas a significant difference was found for acetate adsorption.

Keywords: acetic acid, platinum, nickel, infared-absorption spectrocopy, temperature programmed desorption, density functional theory

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2277 AI Ethical Values as Dependent on the Role and Perspective of the Ethical AI Code Founder- A Mapping Review

Authors: Moshe Davidian, Shlomo Mark, Yotam Lurie

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With the rapid development of technology and the concomitant growth in the capability of Artificial Intelligence (AI) systems and their power, the ethical challenges involved in these systems are also evolving and increasing. In recent years, various organizations, including governments, international institutions, professional societies, civic organizations, and commercial companies, have been choosing to address these various challenges by publishing ethical codes for AI systems. However, despite the apparent agreement that AI should be “ethical,” there is debate about the definition of “ethical artificial intelligence.” This study investigates the various AI ethical codes and their key ethical values. From the vast collection of codes that exist, it analyzes and compares 25 ethical codes that were found to be representative of different types of organizations. In addition, as part of its literature review, the study overviews data collected in three recent reviews of AI codes. The results of the analyses demonstrate a convergence around seven key ethical values. However, the key finding is that the different AI ethical codes eventually reflect the type of organization that designed the code; i.e., the organizations’ role as regulator, user, or developer affects the view of what ethical AI is. The results show a relationship between the organization’s role and the dominant values in its code. The main contribution of this study is the development of a list of the key values for all AI systems and specific values that need to impact the development and design of AI systems, but also allowing for differences according to the organization for which the system is being developed. This will allow an analysis of AI values in relation to stakeholders.

Keywords: artificial intelligence, ethical codes, principles, values

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2276 How Technology Can Help Teachers in Reflective Practice

Authors: Ambika Perisamy, Asyriawati binte Mohd Hamzah

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The focus of this presentation is to discuss teacher professional development (TPD) through the use of technology. TPD is necessary to prepare teachers for future challenges they will face throughout their careers and to develop new skills and good teaching practices. We will also be discussing current issues in embracing technology in the field of early childhood education and the impact on the professional development of teachers. Participants will also learn to apply teaching and learning practices through the use of technology. One major objective of this presentation is to coherently fuse practical, technology and theoretical content. The process begins by concretizing a set of preconceived ideas which need to be joined with theoretical justifications found in the literature. Technology can make observations fairer and more reliable, easier to implement, and more preferable to teachers and principals. Technology will also help principals to improve classroom observations of teachers and ultimately improve teachers’ continuous professional development. Video technology allows the early childhood teachers to record and keep the recorded video for reflection at any time. This will also provide opportunities for her to share with her principals for professional dialogues and continuous professional development plans. A total of 10 early childhood teachers and 4 principals were involved in these efforts which identified and analyze the gaps in the quality of classroom observations and its co relation to developing teachers as reflective practitioners. The methodology used involves active exploration with video technology recordings, conversations, interviews and authentic teacher child interactions which forms the key thrust in improving teaching and learning practice. A qualitative analysis of photographs, videos, transcripts which illustrates teacher’s reflections and classroom observation checklists before and after the use of video technology were adopted. Arguably, although PD support can be magnanimously strong, if teachers could not connect or create meaning out of the opportunities made available to them, they may remain passive or uninvolved. Therefore, teachers must see the value of applying new ideas such as technology and approaches to practice while creating personal meaning out of professional development. These video recordings are transferable, can be shared and edited through social media, emails and common storage between teachers and principals. To conclude the importance of reflective practice among early childhood teachers and addressing the concerns raised before and after the use of video technology, teachers and principals shared the feasibility, practical and relevance use of video technology.

Keywords: early childhood education, reflective, improve teaching and learning, technology

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2275 The Power of Social Media Influencers: A Study of Public Perception of Credibility Among Kuwaitis

Authors: Fatima Alsalem

Abstract:

Objectives: This study aims to explore the perceived credibility of social media influencers and their effect on purchase intention. In addition, the study aims to investigate the relationship between satisfaction with content promoted via social media and its relation to purchasing intention. Methodology: This study uses an exploratory and quantitative methodology. It was implemented through a cross-sectional survey that asked respondents to identify the time they spend using social media, satisfaction with influencers’ content, types of influencers they prefer, motivations to use social media, purchase intention of products promoted by influencers, as well as three credibility dimensions. Sample: the sample included 1184 Kuwaiti nationals, of which 50.4% (N=593) were males and 49.6% (N=584) were females. Results: The analysis of the data indicated that comedy and entertainment influencers are the most preferred type of influencers, while fashion influencers “fashionistas” are the least preferred. Based on the results of the regression analysis, the perceived credibility of influencers and satisfaction with their content is positively related to higher purchase intention. While all dimensions of credibility are positively related to higher purchase intention, attractiveness is the strongest predictor. Conclusion: The significant value of this study is the examination of the perceived credibility of influencers and the type of influencer social media users prefer to follow. The current research proves that the attractiveness of influencers is the highest dimension of their perceived credibility, which was prevalent in the findings.

Keywords: influencers, social media, mass media, credibility

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2274 Estimation of the Antioxidant Potential of Microalgae With ABTS and CUPRAC Assays

Authors: Juliana Ianova, Lyudmila Kabaivanova, Tanya Toshkova- Yotova

Abstract:

Background: Microalgae are widely known for their nutritional and therapeutic applications due to the richness in nutrients and bioactive elements. The aim of this research was to investigate the growth and production of bioactive compounds with antioxidant properties by different microalgal strains: Scenedesmus acutus M Tomaselli 8, Scenedesmus obliquus BGP, Porphyridium aerugineum and Porphyridium cruentum (Chlorophyta and Rhodophyta). Most of them are freshwater species, with only one marine microalga P. cruentum. Methods: Monoalgal, non-axenic cultures of the investigated strains were grown autotrophically in 200 ml flasks, CO2 - 2% at 132 μmol m-2 s-1 photon flux density and T 25°C. Algal biomass concentration was measured daily by the dry weight. The ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid, C18H18N4O6S4) scavenging assay and CUPRAC assay (cupric ion reducing antioxidant capacity) were used to establish the antioxidant activity of the four algae at the end of the cultivation process, when stationary phase of growth was reached. Results: The highest biomass yield was achieved by Scenedesmus obliquus BGP- (6.6 g/L) after 144 hours of cultivation. Scenedesmus obliquus showed much higher levels of antioxidant properties from the assessed strains. The red microalga Porphyridium aerugineum also exhibits promising reducing antioxidant power. Conclusion: This study confirmed the view that microalgae are promising producers of food supplements and pharmaceuticals.

Keywords: microalgae, dry weight, antioxidant activity, CUPRAC, ABTS

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2273 Predictive Maintenance of Industrial Shredders: Efficient Operation through Real-Time Monitoring Using Statistical Machine Learning

Authors: Federico Pittino, Thomas Arnold

Abstract:

The shredding of waste materials is a key step in the recycling process towards the circular economy. Industrial shredders for waste processing operate in very harsh operating conditions, leading to the need for frequent maintenance of critical components. Maintenance optimization is particularly important also to increase the machine’s efficiency, thereby reducing the operational costs. In this work, a monitoring system has been developed and deployed on an industrial shredder located at a waste recycling plant in Austria. The machine has been monitored for one year, and methods for predictive maintenance have been developed for two key components: the cutting knives and the drive belt. The large amount of collected data is leveraged by statistical machine learning techniques, thereby not requiring very detailed knowledge of the machine or its live operating conditions. The results show that, despite the wide range of operating conditions, a reliable estimate of the optimal time for maintenance can be derived. Moreover, the trade-off between the cost of maintenance and the increase in power consumption due to the wear state of the monitored components of the machine is investigated. This work proves the benefits of real-time monitoring system for the efficient operation of industrial shredders.

Keywords: predictive maintenance, circular economy, industrial shredder, cost optimization, statistical machine learning

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2272 Investigation on Ultrahigh Heat Flux of Nanoporous Membrane Evaporation Using Dimensionless Lattice Boltzmann Method

Authors: W. H. Zheng, J. Li, F. J. Hong

Abstract:

Thin liquid film evaporation in ultrathin nanoporous membranes, which reduce the viscous resistance while still maintaining high capillary pressure and efficient liquid delivery, is a promising thermal management approach for high-power electronic devices cooling. Given the challenges and technical limitations of experimental studies for accurate interface temperature sensing, complex manufacturing process, and short duration of membranes, a dimensionless lattice Boltzmann method capable of restoring thermophysical properties of working fluid is particularly derived. The evaporation of R134a to its pure vapour ambient in nanoporous membranes with the pore diameter of 80nm, thickness of 472nm, and three porosities of 0.25, 0.33 and 0.5 are numerically simulated. The numerical results indicate that the highest heat transfer coefficient is about 1740kW/m²·K; the highest heat flux is about 1.49kW/cm² with only about the wall superheat of 8.59K in the case of porosity equals to 0.5. The dissipated heat flux scaled with porosity because of the increasing effective evaporative area. Additionally, the self-regulation of the shape and curvature of the meniscus under different operating conditions is also observed. This work shows a promising approach to forecast the membrane performance for different geometry and working fluids.

Keywords: high heat flux, ultrathin nanoporous membrane, thin film evaporation, lattice Boltzmann method

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2271 Use of Activated Carbon from Olive Stone for CO₂ Capture in Porous Mortars

Authors: A. González-Caro, A. M. Merino-Lechuga, D. Suescum-Morales, E. Fernández-Ledesma, J. R. Jiménez, J. M. Fernández-Rodríguez

Abstract:

Climate change is one of the most significant issues today. Since the 19th century, the rise in temperature has not only been due to natural change, but also to human activities, which have been the main cause of climate change, mainly due to the burning of fossil fuels such as coal, oil and gas. The boom in the construction sector in recent years is also one of the main contributors to CO₂ emissions into the atmosphere; for example, for every tonne of cement produced, 1 tonne of CO₂ is emitted into the atmosphere. Most of the research being carried out in this sector is focused on reducing the large environmental impact generated during the manufacturing process of building materials. In detail, this research focuses on the recovery of waste from olive oil mills. Spain is the world's largest producer of olive oil, and this sector generates a large amount of waste and by-products such as olive pits, “alpechín” or “alpeorujo”. This olive stone by means of a pyrosilisis process gives rise to the production of active carbon. The process causes the carbon to develop many internal spaces. This study is based on the manufacture of porous mortars with Portland cement and natural limestone sand, with an addition of 5% and 10% of activated carbon. Two curing environments were used: i) dry chamber, with a humidity of 65 ± 10% and temperature of 21 ± 2 ºC and an atmospheric CO₂ concentration (approximately 0.04%); ii) accelerated carbonation chamber, with a humidity of 65 ± 10% and temperature of 21 ± 2 ºC and an atmospheric CO₂ concentration of 5%. In addition to eliminating waste from an industry, the aim of this study is to reduce atmospheric CO₂. For this purpose, first, a physicochemical and mineralogical characterisation of all raw materials was carried out, using techniques such as fluorescence and X-ray diffraction. The particle size and specific surface area of the activated carbon were determined. Subsequently, tests were carried out on the hardened mortar, such as thermogravimetric analysis (to determine the percentage of CO₂ capture), as well as mechanical properties, density, porosity, and water absorption. It was concluded that the activated carbon acts as a sink for CO₂, causing it to be trapped inside the voids. This increases CO₂ capture by 300% with the addition of 10% activated carbon at 7 days of curing. There was an increase in compressive strength of 17.5% with the CO₂ chamber after 7 days of curing using 10% activated carbon compared to the dry chamber.

Keywords: olive stone, activated carbon, porous mortar, CO₂ capture, economy circular

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2270 Application of ANN for Estimation of Power Demand of Villages in Sulaymaniyah Governorate

Authors: A. Majeed, P. Ali

Abstract:

Before designing an electrical system, the estimation of load is necessary for unit sizing and demand-generation balancing. The system could be a stand-alone system for a village or grid connected or integrated renewable energy to grid connection, especially as there are non–electrified villages in developing countries. In the classical model, the energy demand was found by estimating the household appliances multiplied with the amount of their rating and the duration of their operation, but in this paper, information exists for electrified villages could be used to predict the demand, as villages almost have the same life style. This paper describes a method used to predict the average energy consumed in each two months for every consumer living in a village by Artificial Neural Network (ANN). The input data are collected using a regional survey for samples of consumers representing typical types of different living, household appliances and energy consumption by a list of information, and the output data are collected from administration office of Piramagrun for each corresponding consumer. The result of this study shows that the average demand for different consumers from four villages in different months throughout the year is approximately 12 kWh/day, this model estimates the average demand/day for every consumer with a mean absolute percent error of 11.8%, and MathWorks software package MATLAB version 7.6.0 that contains and facilitate Neural Network Toolbox was used.

Keywords: artificial neural network, load estimation, regional survey, rural electrification

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2269 Exploring Public Opinions Toward the Use of Generative Artificial Intelligence Chatbot in Higher Education: An Insight from Topic Modelling and Sentiment Analysis

Authors: Samer Muthana Sarsam, Abdul Samad Shibghatullah, Chit Su Mon, Abd Aziz Alias, Hosam Al-Samarraie

Abstract:

Generative Artificial Intelligence chatbots (GAI chatbots) have emerged as promising tools in various domains, including higher education. However, their specific role within the educational context and the level of legal support for their implementation remain unclear. Therefore, this study aims to investigate the role of Bard, a newly developed GAI chatbot, in higher education. To achieve this objective, English tweets were collected from Twitter's free streaming Application Programming Interface (API). The Latent Dirichlet Allocation (LDA) algorithm was applied to extract latent topics from the collected tweets. User sentiments, including disgust, surprise, sadness, anger, fear, joy, anticipation, and trust, as well as positive and negative sentiments, were extracted using the NRC Affect Intensity Lexicon and SentiStrength tools. This study explored the benefits, challenges, and future implications of integrating GAI chatbots in higher education. The findings shed light on the potential power of such tools, exemplified by Bard, in enhancing the learning process and providing support to students throughout their educational journey.

Keywords: generative artificial intelligence chatbots, bard, higher education, topic modelling, sentiment analysis

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2268 Human Trafficking and Terrorism: A Study on the Security Challenges Imposed upon Countries in Conflict

Authors: Christopher Holroyd

Abstract:

With the various terrorist organizations and drug cartels that are currently active, there is a myriad of security concerns facing countries around the world. Organizations that focus their attacks on others through terror, such as what is seen with the Islamic State of Iraq and the Levant (ISIS), have no boundaries when it comes to doing what is needed to fulfill their desired intent. For countries such as Iraq, who have been trying to rebuild their country since the fall of the Saddam Hussein Regime, organizations such as Al-Qaeda and ISIS have been impeding the country’s efforts toward peace and stability. One method utilized by terrorist organizations around the world is human trafficking. This method is one that is seen around the world; modern slavery is still exploited by those who have no concern for human decency and morality, their only concern is to achieve their goals by any means. It is understandable that some people may not have even heard of 'modern slavery', or they just might not believe that it is even an issue in today’s world. Organizations such as ISIS are not the only ones in the world that seek to benefit from the immoral trading of humans. Various drug cartels in the world, such as those seen in Mexico and Central America, have recently begun to take part in the trade – moving humans from state to state, or country to country, to better fuel their overall operations. This now makes the possibility of human trafficking more real for those in the United States because of the proximity of the cartels to the southern border of the country. An issue that, at one time, might have only seen as a distant threat, is now close to home for those in the United States. Looking at these two examples is how we begin to understand why human trafficking is utilized by various organizations around the world. This trade of human beings and the violation of basic human rights is a plague that effects the entire world and not just those that are in a country other than your own. One of the security issues that stem from the trade includes the movement and recruitment of members of the organizations. With individuals being smuggled from one location to another in secrecy, this only puts those trying to combat this trade at a disadvantage. This creates concern over the accurate number of potential recruits, combatants, and other individuals who are working against the host nation, and for the mission of the cartel or terrorist organization they are a part of. An uphill battle is created, and the goals of peace and stability are now harder to reach. Aside from security aspects, it cannot be forgotten that those being traded and forced into slavery, are being done so against their will. Families are separated, children trained to be fighters or worse. This makes the goal of eradicating human trafficking even more dire and important.

Keywords: human trafficking, reconstruction, security, terrorism

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2267 Improvement in Plasticity Index and Group Index of Black Cotton Soil Using Palm Kernel Shell Ash

Authors: Patel Darshan Shaileshkumar, M. G. Vanza

Abstract:

Black cotton soil is problematic soil for any construction work. Black cotton soil contains montmorillonite in its structure. Due to this mineral, black cotton soil will attain maximum swelling and shrinkage. Due to these volume changes, it is necessary to stabilize black cotton soil before the construction of the road. For soil stabilization use of pozzolanic waste is found to be a good solution by some researchers. The palm kernel shell ash (PKSA) is a pozzolanic material that can be used for soil stabilization. Basically, PKSA is a waste material, and it is available at a cheap cost. Palm kernel shell is a waste material generated in palm oil mills. Then palm kernel shell is used in industries instead of coal for power generation. After the burning of a palm kernel shell, ash is formed; the ash is called palm kernel shell ash (PKSA). The PKSA contains a free lime content that will react chemically with the silicate and aluminate of black cotton soil and forms a C-S-H and C-A-H gel which will bines soil particles together and reduce the plasticity of the soil. In this study, the PKSA is added to the soil. It was found that with the addition of PKSA content in the soil, the liquid limit of the soil is decreased, the plastic limit of the soil is increased, and the plasticity of the soil is decreased. The group index value of the soil is evaluated, and it was found that with the addition of PKSA GI value of the soil is decreased, which indicates the strength of the soil is improved.

Keywords: palm kernel shell ash, black cotton soil, liquid limit, group index, plastic limit, plasticity index

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2266 A Saltwater Battery Inspired by the Membrane Potential Found in Biological Cells

Authors: Ross Lee, Pritpal Singh, Andrew Jester

Abstract:

As the world transitions to a more sustainable energy economy, the deployment of energy storage technologies is expected to increase to develop a more resilient grid system. However, current technologies are associated with various environmental and safety issues throughout their entire lifecycle; therefore, new battery technology is necessary for grid applications to curtail these risks. Biological cells, such as human neurons and electrolytes in the electric eel, can serve as a more sustainable design template for a new bio-inspired (i.e., biomimetic) battery. Within biological cells, an electrochemical gradient across the cell membrane forms the membrane potential, which serves as the driving force for ion transport into/out of the cell, akin to the charging/discharging of a battery cell. This work serves as the first step to developing such a biomimetic battery cell, starting with the fabrication and characterization of ion-selective membranes to facilitate ion transport through the cell. Performance characteristics (e.g., cell voltage, power density, specific energy, roundtrip efficiency) for the cell under investigation are compared to incumbent battery technologies and biological cells to assess the readiness level for this emerging technology. Using a Na⁺-Form Nafion-117 membrane, the cell in this work successfully demonstrated behavior similar to human neurons; these findings will inform how cell components can be re-engineered to enhance device performance.

Keywords: battery, biomimetic, electrolytes, human neurons, ion-selective membranes, membrane potential

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2265 Research on Steam Injection Technology of Extended Range Engine Cylinder for Waste Heat Recovery

Authors: Zhiyuan Jia, Xiuxiu Sun, Yong Chen, Liu Hai, Shuangqing Li

Abstract:

The engine cooling water and exhaust gas contain a large amount of available energy. In order to improve energy efficiency, a steam injection technology based on waste heat recovery is proposed. The models of cooling water waste heat utilization, exhaust gas waste heat utilization, and exhaust gas-cooling water waste heat utilization were constructed, and the effects of the three modes on the performance of steam injection were analyzed, and then the feasibility of in-cylinder water injection steam technology based on waste heat recovery was verified. The research results show that when the injection water flow rate is 0.10 kg/s and the temperature is 298 K, at a cooling water temperature of 363 K, the maximum temperature of the injection water heated by the cooling water can reach 314.5 K; at an exhaust gas temperature of 973 K and an exhaust gas flow rate of 0.12 kg/s, the maximum temperature of the injection water heated by the exhaust gas can reach 430 K; Under the condition of cooling water temperature of 363 K, exhaust gas temperature of 973 K and exhaust gas flow rate of 0.12 kg/s, after cooling water and exhaust gas heating, the maximum temperature of the injection water can reach 463 K. When the engine is 1200 rpm, the water injection volume is 30 mg, and the water injection time is 36°CA, the engine power increases by 2% and the fuel consumption is reduced by 2.6%.

Keywords: cooling water, exhaust gas, extended range engine, steam injection, waste heat recovery

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2264 Unlocking the Power of Social Media for Tourism Marketing: How Travel Bloggers Shape Destination Trust, Travel Intention with the Moderating Role of Trustworthiness on Social Media Posts

Authors: Saad Saif

Abstract:

Tourism promotion in the digital age is significantly influenced by social media, particularly in developing travel markets such as Pakistan. This study examines how travel bloggers use social media to inspire people to plan journeys and increase trust in destinations. It examines how trustworthiness works as a moderator to enhance the legitimacy of social media posts. This study aims to comprehend the dynamics of social media's influence on the travel and tourism industry. This study investigates the influence of travel bloggers' content, with a focus on tone (positive/negative) and emotional intensity (strong/weak), on prospective Pakistani travelers' travel preferences and levels of trust toward a particular location. The study used an experimental design to validate its hypotheses. The results indicate that the emotive content and tone of bloggers influence travel intentions and that destination trust mediates this relationship. It is interesting to observe that variations in the emotional intensity of positive and negative ratings are not always accompanied by changes in destination trust and travel intent. In addition, the influence of a blogger's review tone on travel intention and destination trust is moderated by the credibility of online reviews, whereas the influence of emotional intensity on these outcomes is unaffected by review credibility.

Keywords: tourism marketing, destination trust, travel intention, trustworthiness

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2263 Teicoplanin Derivatives with Antiviral Activity: Synthesis and Biological Evaluation

Authors: Zsolt Szucs, Viktor Kelemen, Son Le Thai, Magdolna Csavas, Erzsebet Roth, Gyula Batta, Annelies Stevaert, Evelien Vanderlinden, Aniko Borbas, Lieve Naesens, Pal Herczegh

Abstract:

The approval of modern glycopeptide antibiotics such as dalbavancin and oritavancin which have excellent activity against Gram-positive bacteria, encouraged our research group to prepare semisynthetic compounds from several members of glycopeptides by various chemical methods. Derivatives from the aglycone of ristocetin, eremomycin, vancomycin and a pseudoaglycon of teicoplanin have been synthesized in a systematic manner. Interestingly, some of the aglycoristocetin derivatives displayed noteworthy anti-influenza activity. More recently our group has been focusing on the modifications of one of the pseudoaglycons of teicoplanin. The reaction of N-ethoxycarbonyl maleimide derivatives with the primary amino function, the copper-catalysed azide-alkyne click reaction and the sulfonylation of the N-terminus were utilized to obtain systematic series of compounds. All substituents provide a more lipophilic character to the new molecules compared to the parent antibiotics, which is known to be favourable for activity against resistant bacteria. Lipoglycopeptides are also known to have antiviral properties, which has been predominantly studied on HIV by others. The structure-activity relationship study of our compounds revealed the influence of a few structural elements on biological activity. In many cases, minimal changes in lipophilicity and structure produced great differences in efficacy and cytotoxicity. In vitro experiments showed that these compounds are not only active against glycopeptide resistant Gram-positive bacteria but in several cases they prevent the infection of cell cultures by different strains of influenza viruses. This is probably related to the inhibition of the viral entry into the host cell nucleus, of which the exact mechanism is unknown. In some instances, reasonably low concentrations were sufficient to observe this effect. Several derivatives were highly cytotoxic at the same time, but some of them displayed a good selectivity index. The antiviral properties of the compounds are not restricted to influenza viruses e.g., some of them showed good activity against Human Coronavirus 229E. This work could potentially lead to the development of antiviral drugs which possess the crucial structural motifs that are needed for antiviral activity, while missing those which contribute to the antibacterial effect.

Keywords: antiviral, glycopeptide, semisynthetic, teicoplanin

Procedia PDF Downloads 142