Search results for: alternative raw materials

Authors: Neda Valizadeh, Soudabeh Shafiee Ardestani, Arvin Najafi

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Objectives: The aim of this study is to evaluate the association of mid-regional pro-atrial natriuretic peptide (MRproANP), procalcitonin (PCT), proendothelin-1 (proET-1) levels with sepsis severity in Emergency ward patients. Materials and Methods: We assessed the predictive value of MRproANP, PCT, copeptin, and proET-1 in early sepsis among patients referring to the emergency ward with a suspected sepsis. Results-132 patients were enrolled in this study. 45 (34%) patients had a final diagnosis of sepsis. A higher percentage of patients with definite sepsis had systemic inflammatory response syndrome (SIRS) criteria at initial visit in comparison with no-sepsis patients (P<0.05) and were admitted to the hospital (P<0.05). PCT levels were higher in sepsis patients [P<0.05]. There was no significant differences for MRproANP or proET-1 in sepsis patients (P=0.47). Conclusion: A combination of SIRS criteria and PCT levels is beneficial for the early sepsis diagnosis in emergency ward patients with a suspicious infection disease.

Keywords: emergency, prolactin, sepsis, biomarkers

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Authors: Kholoud Abdulaziz, Kholoud Al-Najdi, Abdullah Kadri, Konstantinos E. Kakosimos

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The Middle East area is highly affected by air pollution induced by anthropogenic and natural phenomena. There is evidence that air pollution, especially particulates, greatly affects the population health. Many studies have raised a warning of the high concentration of particulates and their affect not just around industrial and construction areas but also in the immediate working and living environment. One of the methods to study air quality is continuous and periodic monitoring using active or passive samplers. Active monitoring and sampling are the default procedures per the European and US standards. However, in many cases they have been inefficient to accurately capture the spatial variability of air pollution due to the small number of installations; which eventually is attributed to the high cost of the equipment and the limited availability of users with expertise and scientific background. Another alternative has been found to account for the limitations of the active methods that is the passive sampling. It is inexpensive, requires no continuous power supply, and easy to assemble which makes it a more flexible option, though less accurate. This study aims to investigate and evaluate the use of passive sampling for particulate matter pollution monitoring in dry tropical climates, like in the Middle East. More specifically, a number of field measurements have be conducted, both indoors and outdoors, at Qatar and the results have been compared with active sampling equipment and the reference methods. The samples have been analyzed, that is to obtain particle size distribution, by applying existing laboratory techniques (optical microscopy) and by exploring new approaches like the white light interferometry to. Then the new parameters of the well-established model have been calculated in order to estimate the atmospheric concentration of particulates. Additionally, an extended literature review will investigate for new and better models. The outcome of this project is expected to have an impact on the public, as well, as it will raise awareness among people about the quality of life and about the importance of implementing research culture in the community.

Keywords: air pollution, passive samplers, interferometry, indoor, outdoor

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Authors: Mahdokht Sadeghvishkaei, Azizah Abdul-Hamid, Amin Ismail, Nazamid Saari

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Hypertension is a common and serious chronic health problem and known as the most important risk factor for development of many diseases such as stroke. Since angiotensin I-converting enzyme (ACE) is the key enzyme involved in blood pressure, one of the well accepted mechanisms to control hypertension is through ACE inhibition. The ACE inhibitory effect of Actinopyga lecanora (stone fish) proteolysate in vitro had been reported. Hence, this study aimed to evaluate the ACE inhibitory potential of Actinopyga lecanora proteolysate in vivo in normotensive rats. Therefore the ACE inhibitory capability of the proteolysate to prevent increasing systolic blood pressure, after inducing hypertension by angiotensin I was examined. The pre-fed rats with the proteolysates at various doses (200, 400, 800 mg/kg body weight) revealed the significant (p ≤ 0.05) suppression effect compared with control groups. Furthermore, different doses of the proteolysate (200, 400, 800 mg/kg body weight) were examined to find its optimum effective dose. Results depicted that 800 mg proteolysate/kg body weight significantly reduced systolic blood pressure without negative effect on normal blood pressure (p ≤ 0.05). Furthermore, Sub-acute toxicity study based on OECD guideline demonstrated the safety of the proteolysate in vivo. The present study indicated that the proteolysate at a dose of 1000 mg/kg daily for 14 days did not cause toxicity signs such as death, changes in activity, or piloerection. Since there are no significant differences between treated groups and control groups, hematological and biochemical analysis confirmed safety of the proteolysate (p > 0.05). In addition, there were no significant differences between organs weights of the treated groups and the control groups. Morphologically, neither histopathological changes, nor gross abnormalities were observed. However, the proteolysate caused significant decrease in body weight in relation to the control groups (p ≤ 0.05) probably due to appetite stimulation by the proteolysate, leading to decreased food consumption in sub-acute group. It is concluded that the proteolysate generated from Actinopyga lecanora possess a significant anti-hypertensive effect and would be potentially used as natural alternative of ACE inhibitors.

Keywords: ACE inhibition, Actinopyga lecanora, anti-hypertensive activity, bioactive peptides, normotensive rats

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Authors: Clifford Lewis

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This paper aims to advance the conversation of an alternative view of leadership, namely ‘leadership as the management of meaning’. Here, leadership is considered as a social process of the management of meaning within an employment context, as opposed to a psychological trait, set of behaviours or relational consequence as seen in mainstream leadership research. Specifically, this study explores the relationship between intersectional identities and the management of meaning. Design: Semi-structured, one-on-one interviews were conducted with women and men of colour working in the South African private sector organisations in various leadership positions. Employing an intersectional approach using gender and race, participants were selected by using purposive and snowball sampling concurrently. Thematic and Axial coding was used to identify dominant themes. Findings: Findings suggest that, both gender and race shape how leaders manage meaning. Findings also confirm that intersectionality is an appropriate approach when studying the leadership experiences of those groups who are underrepresented in organisational leadership structures. The findings points to the need for further research into the differential effects of intersecting identities on organisational leadership experiences and that ‘leadership as the management of meaning’ is an appropriate approach for addressing this knowledge gap. Theoretical Contribution: There is a large body of literature on the complex challenges faced by women and people of colour in leadership but there is relatively little empirical work on how identity influences the management of meaning. This study contributes to the leadership literature by providing insight into how intersectional identities influence the management of meaning at work and how this impacts the leadership experiences of largely marginalised groups. Practical Implications: Understanding the leadership experiences of underrepresented groups is important because of both legal mandates and for building diverse talent for organisations and societies. Such an understanding assists practitioners in being sensitive to simplistic notions of challenges individuals might face in accessing and practicing leadership in organisations. Advancing the conversation on leadership as the management of meaning allows for a better understanding of complex challenges faced by women and people of colour and an opportunity for organisations to systematically remove unfair structural obstacles and develop their diverse leadership capacity.

Keywords: intersectionality, diversity, leadership, sensemaking

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Authors: Nusrat Praween, Krishna Thej Pammi Guru, Palash Kumar Basu

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Designing non-invasive biosensors for cancer diagnosis is essential for developing an affordable and specific tool to measure cancer-related exosome biomarkers. Exosomes, released by healthy as well as cancer cells, contain valuable information about the biomarkers of various diseases, including cancer. Despite the availability of various isolation techniques, ultracentrifugation is the standard technique that is being employed. Post isolation, exosomes are traditionally exposed to detergents for extracting their proteins, which can often lead to protein degradation. Further to this, it is very essential to develop a sensing platform for the quantification of clinically relevant proteins in a wider range to ensure practicality. In this study, exosomes were immobilized on the Au Screen Printed Electrode (SPE) using EDC/NHS chemistry to facilitate binding. After immobilizing the exosomes on the screen-printed electrode (SPE), we investigated the impact of the electric field by applying various voltages to induce exosome lysis and release their contents. The lysed solution was used for sensing TSG101, a crucial biomarker associated with various cancers, using both faradaic and non-faradaic electrochemical impedance spectroscopy (EIS) methods. The results of non-faradaic and faradaic EIS were comparable and showed good consistency, indicating that non-faradaic sensing can be a reliable alternative. Hence, the non-faradaic sensing technique was used for label-free quantification of the TSG101 biomarker. The results were validated using ELISA. Our electrochemical immunosensor demonstrated a consistent response of TSG101 from 125 pg/mL to 8000 pg/mL, with a detection limit of 0.125 pg/mL at room temperature. Additionally, since non-faradic sensing is label-free, the ease of usage and cost of the final sensor developed can be reduced. The proposed immunosensor is capable of detecting the TSG101 protein at low levels in healthy serum with good sensitivity and specificity, making it a promising platform for biomarker detection.

Keywords: biosensor, exosomes isolation on SPE, electric field lysis of exosome, EIS sensing of TSG101

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Authors: María Canal-Rodríguez, María Arnaiz, Natalia Rey-Raap, Ana Arenillas, Jon Ajuria

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The constant demand of electrical energy, as well as the increase in environmental concern, lead to the necessity of investing in clean and eco-friendly energy sources that implies the development of enhanced energy storage devices. Li-ion batteries (LIBs) and Electrical double layer capacitors (EDLCs) are the most widespread energy systems. Batteries are able to storage high energy densities contrary to capacitors, which main strength is the high-power density supply and the long cycle life. The combination of both technologies gave rise to Li-ion capacitors (LICs), which offers all these advantages in a single device. This is achieved combining a capacitive, supercapacitor-like positive electrode with a faradaic, battery-like negative electrode. Due to the abundance and affordability, dual carbon-based LICs are nowadays the common technology. Normally, an Active Carbon (AC) is used as the EDLC like electrode, while graphite is the material commonly employed as anode. LICs are potential systems to be used in applications in which high energy and power densities are required, such us kinetic energy recovery systems. Although these devices are already in the market, some drawbacks like the limited power delivered by graphite or the energy limiting nature of AC must be solved to trigger their used. Focusing on the anode, one possibility could be to replace graphite with Hard Carbon (HC). The better rate capability of the latter increases the power performance of the device. Moreover, the disordered carbonaceous structure of HCs enables storage twice the theoretical capacity of graphite. With respect to the cathode, the ACs are characterized for their high volume of micropores, in which the charge is storage. Nevertheless, they normally do not show mesoporous, which are really important mainly at high C-rates as they act as transport channels for the ions to reach the micropores. Usually, the porosity of ACs cannot be tailored, as it strongly depends on the precursor employed to get the final carbon. Moreover, they are not characterized for having a high electrical conductivity, which is an important characteristic to get a good performance in energy storage applications. A possible candidate to substitute ACs are carbon aerogels (CAs). CAs are materials that combine a high porosity with great electrical conductivity, opposite characteristics in carbon materials. Furthermore, its porous properties can be tailored quite accurately according to with the requirements of the application. In the present study, CAs with controlled porosity were obtained from polymerization of resorcinol and formaldehyde by microwave heating. Varying the synthesis conditions, mainly the amount of precursors and pH of the precursor solution, carbons with different textural properties were obtained. The way the porous characteristics affect the performance of the cathode was studied by means of a half-cell configuration. The material with the best performance was evaluated as cathode in a LIC versus a hard carbon as anode. An analogous full LIC made by a high microporous commercial cathode was also assembled for comparison purposes.

Keywords: li-ion capacitors, energy storage, tailored porosity, carbon aerogels

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Authors: Bok Check Meng, Goh Ying Soon

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Giving additional learning materials such as Chinese fantasy novel to non-native learners can be strenuous. Instructors have to understand the underpinning theories about cognitive theory for new word instruction. This paper discusses the underpinning theories. Relevant literature reviews are given. There are basically five major areas of cognitive related theories mentioned in this article. These include motivational learning theory, Affective theory of learning, Cognitive psychology theory, Vocabulary acquisition theory and Bloom’s cognitive levels theory. A theoretical framework has been constructed. Thus, this will give a hand in ensuring non-native learners might gain positive outcomes in the instruction process. Instructors who are interested in teaching new word from Chinese fantasy novel in specific to support additional learning might be able to get insights from this article.

Keywords: Chinese fantasy novel, new word teaching, non-native learners, cognitive theory, bloom

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Authors: Weitao Zhou, Qing Wang, Jianxin He, Shizhong Cui

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Mesoporous Tussah silk fibroin (TSF) spheres were fabricated via the self-assembly of TSF molecules in aqueous solutions. The results showed that TSF particles were approximately three-dimensional spheres with the diameter ranging from 500nm to 6μm without adherence. More importantly, the surface morphology is mesoporous structure with nano-pores of 20nm - 200nm in size. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) studies demonstrated that mesoporous TSF spheres mainly contained beta-sheet conformation (44.1 %) as well as slight amounts of random coil (13.2 %). Drug release test was performed with 5-fluorouracil (5-Fu) as a model drug and the result indicated the mesoporous TSF microspheres had a good capacity of sustained drug release. It is expected that these stable and high-crystallinity mesoporous TSF sphere produced without organic solvents, which have significantly improved drug release properties, is a very promising material for controlled gene medicines delivery.

Keywords: Tussah silk fibroin, porous materials, microsphere, drug release

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Authors: Nagi Greesh

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This study highlights a new method to obtain multiphase composites particles containing hydrophobic (wax) and inorganic (clay) compounds. Multiphase polystyrene-clay-wax nanocomposites were successfully synthesized. Styrene monomer were polymerized in the presence of different wax-clay nanocomposites concentrations in miniemulsion. Wax-clay nanocomposites were firstly obtained through ultrasonic mixing at a temperature above the melting point of the wax at different clay loadings. The obtained wax-clay nanocomposites were then used as filler in the preparation of polystyrene-wax-clay nanocomposites via miniemulsion polymerization. The particles morphology of PS/wax-clay nanocomposites latexes was mainly determined by Transmission Electron Microscopy ( TEM) , core/shell morphology was clearly observed, with the encapsulation of most wax-clay nanocomposites inside the PS particles. On the other hand, the morphology of the PS/wax-clay nanocomposites (after film formation) ranged from exfoliated to intercalated structures, depending on the percentage of wax-clay nanocomposites loading. This strategy will allow the preparation materials with tailored properties for specific applications such as paint coatings and adhesives.

Keywords: polymer-wax, paraffin wax, miniemulsion, core/shell, nanocomposites

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Authors: Gabriela Dârzan

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This study examines the relationship between subjective executive functioning, memory control, and psychiatric symptoms (anxiety and depression), addressing a critical gap in aligning self-reported executive dysfunction with objective measures of memory suppression. Using the Behavior Rating Inventory of Executive Function – Adult Version (BRIEF-A) and the Think/No-Think (TNT) task, the study evaluates how these measures relate to psychiatric symptoms and assesses suppression-induced forgetting (SIF). Fifty-four adults aged 21–59 first completed the Think/No-Think (TNT) task under Thought Avoidance (TA) and Thought Substitution (TS) conditions, followed by the Behavior Rating Inventory of Executive Function – Adult Version (BRIEF-A), Generalized Anxiety Disorder-7 (GAD-7), and Patient Health Questionnaire-9 (PHQ-9). Statistical analyses included correlations, mediation models, and ANOVAs. Results indicated significant correlations between each of the BRIEF-A scales and indices and psychiatric symptoms. Higher self-rated executive dysfunction (Global Executive Composite, Behavioral Regulation Index, and Emotional Control) predicted higher anxiety levels. Similarly, the Global Executive Composite and Material Organization predicted higher depression levels. However, TNT task performance did not correlate with self-reported executive dysfunction, nor did it mediate the relationship between executive functioning and psychiatric symptoms. No significant SIF effect was observed, with no differences between the No-Think and Baseline trials. Additionally, instructional (TA and TS) and test (Independent-Probe - IP and Same-Probe - SP) conditions did not significantly influence thought suppression performance, and the severity of anxiety and depression symptoms did not affect task outcomes. These findings indicate that subjective executive dysfunction is associated with higher anxiety and depression, but memory suppression performance does not demonstrate a mitigating effect on these symptoms. Clinically, interventions focusing on broader executive functioning rather than memory suppression may better address these conditions. Practitioners could explore tailored cognitive strategies and alternative techniques to help patients manage intrusive thoughts effectively.

Keywords: anxiety, depression, subjective executive function, suppression-induced forgetting, think/no-think task

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Authors: Ammar Ouahab, Meriem Houichi , Sanna Mihoubi

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Background: Nigella sativa is an annual flowering plant, belongs to the Ranunculaceae family. It has many pharmacological activities such as anti-inflammatory; anti-bacterial; anti-hepatotoxic activities etc. Materials: In order to predict the pharmacological activity of Nigella Sativa’s compounds, some web based servers were used, namely, PubChem, Molinspiration, ADMET-SAR, PASS online and PharMapper. In addition to that, AutoDOCK was used to investigate the different molecular interactions between the selected compounds and their target proteins. Results: All compounds displayed a stable interaction with their targets and satisfactory binding energies, which means that they are active on their targets. Conclusion: Nigella sativa is an effective medicinal plant that has several ethno-medical uses; the latter uses are proven herein via an in-silico study of their pharmacological activities.

Keywords: Nigella sativa, AutoDOCK, PubChem, Molinspiration, ADMET-SAR, PharMapper, PASS online server, docking

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Authors: George N. Prodromidis, Frank A. Coutelieris

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Biogas can be currently considered as an alternative option for electricity production, mainly due to its high energy content (hydrocarbon-rich source), its renewable status and its relatively low utilization cost. Solid Oxide Fuel Cell (SOFC) stacks convert fuel’s chemical energy to electricity with high efficiencies and reveal significant advantages on fuel flexibility combined with lower emissions rate, especially when utilize biogas. Electricity production by biogas constitutes a composite problem which incorporates an extensive parametric analysis on numerous dynamic variables. The main scope of the presented study is to propose a detailed thermodynamic model on the optimization of SOFC-based power plants’ operation based on fundamental thermodynamics, energy and exergy balances. This model named THERMAS (THERmodynamic MAthematical Simulation model) incorporates each individual process, during electricity production, mathematically simulated for different case studies that represent real life operational conditions. Also, THERMAS offers the opportunity to choose a great variety of different values for each operational parameter individually, thus allowing for studies within unexplored and experimentally impossible operational ranges. Finally, THERMAS innovatively incorporates a specific criterion concluded by the extensive energy analysis to identify the most optimal scenario per simulated system in exergy terms. Therefore, several dynamical parameters as well as several biogas mixture compositions have been taken into account, to cover all the possible incidents. Towards the optimization process in terms of an innovative OPF (OPtimization Factor), presented here, this research study reveals that systems supplied by low methane fuels can be comparable to these supplied by pure methane. To conclude, such an innovative simulation model indicates a perspective on the optimal design of a SOFC stack based system, in the direction of the commercialization of systems utilizing biogas.

Keywords: biogas, exergy, efficiency, optimization

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Authors: Adriana Anselmo Oliveira

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The present project showcases a tile work from the Franco-Portuguese artist Maria Helena Vieira da Silva (1908-1992). It is a set of 8 panels composed of figurative and geometric tiles, with extra tiles framing nearby doors and windows in a study room in the (UFRRJ, Universidade Federal Rural do Rio de Janeiro). The aforementioned work was created between 1942 and 1943, during the artist's 6 year exile in the Brazilian city. This one-of-a-kind tileset was designed and made by Vieira da Silva between 1942 and 1943. Over the years, several units were lost, which led to their replacement in the nineties. However, these replacements don't do justice to the original work of art. In 2007, a project was initiated to fully repair and maintain the set. Three panels are removed and restored, but the project is halted. To this day, the three fully restored panels remain in boxes. In 2016 a new restoration project is submitted by the (Faculdade de Belas Artes da Universidade de Lisboa) in collaboration with de (Fundacão Árpád Szenes-Vieira da Silva). There are many varied opinions on restoring and conserving older pieces of art, however, we have the moral duty to safeguard the original materials used by the artist along with the artists original vision and also to care for the future generations of students who will use the space in which the tile-work was inserted. Many tiles have been replaced by white tiles, tiles with a divergent colour pallet and technique, and in a few cases, the incorrect place or way around. These many factors make it increasingly difficult to maintain the artists original vision and destroy and chance of coherence within the artwork itself. The conservative technician cannot make new images to fill the empty spaces or mark the remaining images with their own creative input. with reliable photographic documentation that can provide us with the necessary vision to allow us to proceed with an accurate reconstruction, we have the obligation to proceed and return the piece of art to its true form, as in its current state, it is impossible to maintain its original glory. Using the information we have, we must find a way to differentiate the original tiles from the reconstructions in order to recreate and reclaim the original message from the artist. The objective of this project is to understand the significance of tiles in Vieira da Silva's art as well as the influence they had on the artist's pictorial language since the colour definition on tile work is vastly different from the painting process as the materials change during their merger. Another primary goal is to understand what the previous interventions achieved besides increasing the artworks durability. The main objective is to submit a proposal that can salvage the artist's visual intention and supports it for posteriority. In summary, this proposal goes further than the usual conservative interventions as it intends to recreate the original artistic worth, prioritising the aesthetics and keeping its soul alive.

Keywords: Vieira da Silva, tiles, conservation, restoration

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Authors: Joel Bonales, Venecia Solorzano, Carlos Garcia

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A great percentage of the wastewater generated in developing countries don’t receive any treatment, which leads to numerous environmental impacts. In response to this, a paradigm change in the current wastewater treatment model based on large scale plants towards a small and medium scale based model has been proposed. Nevertheless, small scale wastewater treatment (SS-WTTP) with novel technologies such as anaerobic digesters, as well as the utilization of derivative co-products such as biogas, still presents diverse environmental impacts which must be assessed. This study consisted in a Life Cycle Assessment (LCA) performed to a SS-WWTP which treats wastewater from a small commercial block in the city of Morelia, Mexico. The treatment performed in the SS-WWTP consists in anaerobic and aerobic digesters with a daily capacity of 5,040 L. Two different scenarios were analyzed: the current plant conditions and a hypothetical energy use of biogas obtained in situ. Furthermore, two different allocation criteria were applied: full impact allocation to the system’s main product (treated water) and substitution credits for replacing Mexican grid electricity (biogas) and clean water pumping (treated water). The results showed that the analyzed plant had bigger impacts than what has been reported in the bibliography in the basis of wastewater volume treated, which may imply that this plant is currently operating inefficiently. The evaluated impacts appeared to be focused in the aerobic digestion and electric generation phases due to the plant’s particular configuration. Additional findings prove that the allocation criteria applied is crucial for the interpretation of impacts and that that the energy use of the biogas obtained in this plant can help mitigate associated climate change impacts. It is concluded that SS-WTTP is a environmentally sound alternative for wastewater treatment from a systemic perspective. However, this type of studies must be careful in the selection of the allocation criteria and replaced products, since these factors have a great influence in the results of the assessment.

Keywords: biogas, life cycle assessment, small scale treatment, wastewater treatment

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Authors: Nitin Ghule, S. G. Taji

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A mathematical model of hot-wall condensers used in refrigerators is presented. The model predicts the heat transfer characteristics of condenser and the effects of various design and operating parameters on condenser tube length and capacity. A finite element approach was used to model the condenser. The condenser tube is divided into elemental units, with each element consisting of adhesive tape, refrigerant tube and outer metal sheet. The heat transfer characteristics of each section are then analyzed by considering the heat transfer through the tube wall, tape and the outer sheet. Variations in inner heat transfer coefficient and pressure drop are considered depending on temperature, fluid phase, type of flow and orientation of tube. Variation in outer heat transfer coefficient is also taken into account. Various materials were analysed for the tube, tape and outer sheet.

Keywords: condenser, domestic refrigerator, heat transfer, mathematical model

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Authors: Amel Ourici

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An electrical machine failure that is not identified in an initial stage may become catastrophic and it may suffer severe damage. Thus, undetected machine faults may cascade in it failure, which in turn may cause production shutdowns. Such shutdowns are costly in terms of lost production time, maintenance costs, and wasted raw materials. Doubly fed induction generators are used mainly for wind energy conversion in MW power plants. This paper presents a detection of an inter turn stator fault in a doubly fed induction machine whose stator and rotor are supplied by two pulse width modulation (PWM) inverters. The method used in this article to detect this fault, is based on Park’s Vector Approach, using a neural network.

Keywords: doubly fed induction machine, PWM inverter, inter turn stator fault, Park’s vector approach, neural network

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Authors: Pamphile Ndagijimana, Xuejiao Liu, Zhiwei Li, Yin Wang

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Enhancing the properties of activated carbon is very imperative for various applications. Indeed, the activated carbon has promising physicochemical properties desired for a considerable number of applications. In this regard, we are proposing an enhanced and green technology for increasing the efficiency and performance of the activated carbon to various applications. The technique poses on the use of natural extracts from tuberous and cereals based-solutions. These solutions showed high potentiality to be used in the synthesis of activated carbon-graphene composite with only 3 mL. The extracted liquid from tuberous sourcing was enough to induce precipitation within a fraction of a minute in contrast to that from cereal sourced. Using these extracts, a synthesis of activated carbon-graphene composite was successful. Different characterization techniques such as XRD, SEM, FTIR, BET, and Raman spectroscopy were performed to investigate the composite materials. The results confirmed a conjugation between activated carbon and graphene material.

Keywords: activated carbon, cereals, extract solution, graphene, tuberous

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Authors: Hasna Elalaoui Elabdallaoui, Abdelaziz Elfazziki, Mohamed Sadgal

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Outlines: The social economy is a moral approach to solidarity applied to the projects’ development. To reconcile economic activity and social equity, crowdfunding is as an alternative means of financing social projects. Several collaborative blockchain platforms exist. It eliminates the need for a central authority or an inconsiderate middleman. Also, the costs for a successful crowdfunding campaign are reduced, since there is no commission to be paid to the intermediary. It improves the transparency of record keeping and delegates authority to authorities who may be prone to corruption. Objectives: The objectives are: to define a software infrastructure for projects’ participatory financing within a social and solidarity economy, allowing transparent, secure, and fair management and to have a financial mechanism that improves financial inclusion. Methodology: The proposed methodology is: crowdfunding platforms literature review, financing mechanisms literature review, requirements analysis and project definition, a business plan, Platform development process and implementation technology, and testing an MVP. Contributions: The solution consists of proposing a new approach to crowdfunding based on Islamic financing, which is the principle of Mousharaka inspired by Islamic financing, which presents a financial innovation that integrates ethics and the social dimension into contemporary banking practices. Conclusion: Crowdfunding platforms need to secure projects and allow only quality projects but also offer a wide range of options to funders. Thus, a framework based on blockchain technology and Islamic financing is proposed to manage this arbitration between quality and quantity of options. The proposed financing system, "Musharaka", is a mode of financing that prohibits interests and uncertainties. The implementation is offered on the secure Ethereum platform as investors sign and initiate transactions for contributions using their digital signature wallet managed by a cryptography algorithm and smart contracts. Our proposal is illustrated by a crop irrigation project in the Marrakech region.

Keywords: social economy, Musharaka, blockchain, smart contract, crowdfunding

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Authors: Inalegwu Stephany Akipu

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Archaeology being the study of mans past using the materials he left behind has been argued to be classified under sciences while some scholars are of the opinion that it does not deserve the status of being referred to as ‘science’. However divergent the opinions of scholars may be on the classification of Archaeology as a science or in the humanities, the discipline has no doubt, greatly aided in shaping the history of man’s past. Through the different stages that the discipline has transgressed, it has encountered some challenges. This paper therefore, attempts to highlight the need for the inclusion of branches of other disciplines when using Archaeology in reconstructing man’s history. The objective of course, is to add to the existing body of knowledge but specifically to expose the incomparable importance of archaeology as a discipline and to place it on such a high scale that it will not be regulated to the background as is done in some Nigerian Universities. The paper attempts a clarification of some conceptual terms and discusses the developmental stages of archaeology. It further describes the present state of the discipline and concludes with the disciplines that need to be imbibed in the use of Archaeology which is an evolving cultural science to obtain the aforementioned interdisciplinary approach.

Keywords: archaeology, cultural, evolution, interdisciplinary, science

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Authors: Mirna Febriani

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Statement of problem. Alginate impression material is an imported material and a dentist always used this material to make impression of teeth and oral cavity tissues. Purpose. The aim of this study was to compare about compressive strength and tear strength of alginate impression material and alginate impression material combined with cassava. Material and methods.Property measured included compressive strength and tear strength. Results.The compressive strength and tear strength of the impression materials tested of a comparable ANSI/ADA standard no.18.The compressive strength and tear strength alginate impression material combined with cassava have lower than the compressive strength and tear strength alginate impression material. The alginate impression material combined with cassava has more water and silica content more decrease than alginate impression material. Conclusions.We concluded that compressive strength and tear strength of alginate impression material combined with cassava has lower than alginate impression material without cassava starch.

Keywords: compressive strength, tear strength, Cassava starch, alginate

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Authors: Mukhamad Fatkhullah, Arfan Fadli, Marini Kristina Situmeang, Siti Hazar Sitorus

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The emergence of a community of people with disabilities along with the various works produced has made great progress to open the public eye to their existence in society. This study focuses attention on a community that is suspected to be one of the pioneers in pursuing the movement. It is Deaf Art Community (DAC), a community of persons with disabilities based in Yogyakarta, with deaf and speech-impaired members who use sign language in everyday communication. Knowing the movement of disabled communities is a good thing, the description of the things behind it then important to know as the basis for initiating similar movements. This research focuses on the question of how community of people with disabilities begin to take shape in different regions and interact with collaborative events. Qualitative method with in-depth interview as data collection techniques was used to describe the process of formation and the emergence of community. The analytical unit in the study initially focuses on the subject in the community, but in the process, it develops to institutional analysis. Therefore some informants were determined purposively and expanded using the snowball technique. The theory used in this research is Phenomenology of Alfred Schutz to be able to see reality from the subject and institutional point of view. The results of this study found that the community is formed because the existing educational institutions (both SLB and inclusion) are less able to empower and make children with disabilities become equal with the society. Through the SLB, the presence of children with disabilities becomes isolated from the society, especially in children of his or her age. Therefore, discrimination and labeling will never be separated from society's view. Meanwhile, facilities for the basic needs of children with disabilities can not be fully provided. Besides that, the guarantee of discrimination, glances, and unpleasant behavior from children without disability does not exist, which then indicates that the existing inclusion schools offer only symbolic acceptance. Thus, both in SLB and Inclusive Schools can not empower children with disabilities. Community-based assistance, in this case, has become an alternative to actually empowering children with disabilities. Not only giving them a place to interact, through the same community, children with disabilities will be guided to discover their talents and develop their potential to be self-reliant in the future.

Keywords: children with disabilities, community-based assessment, community empowerment, social equity

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Authors: Xuan Sun, Mingbo Tong

Abstract:

To understand the factors which affect impact damage on composite structures, particularly the effects of impact position and ribs. In this paper, a finite element model (FEM) of low-velocity impact damage on the composite structure was established via the nonlinear finite element method, combined with the user-defined materials subroutine (VUMAT) of the ABAQUS software. The structural elements chosen for the investigation comprised a series of stiffened composite panels, representative of real aircraft structure. By impacting the panels at different positions relative to the ribs, the effect of relative position of ribs was found out. Then the simulation results and the experiments data were compared. Finally, the factors which affect impact damage on the structures were discussed. The paper was helpful for the design of stiffened composite structures.

Keywords: stiffened, low-velocity impact, Abaqus, impact energy

Procedia PDF Downloads 625

Authors: Alexander Pesin, Denis Pustovoytov, Mikhail Sverdlik

Abstract:

Materials with ultrafine-grained structure and unique physical and mechanical properties can be obtained by methods of severe plastic deformation, which include processes of asymmetric rolling (AR). Asymmetric rolling is a very effective way to create ultrafine-grained structures of metals and alloys. Since the asymmetric rolling is a continuous process, it has great potential for industrial production of ultrafine-grained structure sheets. Basic principles of asymmetric rolling are described in detail in scientific literature. In this work finite element modeling of asymmetric rolling and metal forming processes in multiroll gauge was performed. Parameters of the processes which allow achieving significant values of shear strain were defined. The results of the study will be useful for the research of the evolution of ultra-fine metal structure in asymmetric rolling.

Keywords: asymmetric rolling, equivalent strain, FEM, multiroll gauge, profile, severe plastic deformation, shear strain, sheet

Procedia PDF Downloads 268

Authors: Farhana Arzu, Roslan Hashim

Abstract:

Renewable energy is the only alternative sources of energy to meet the current energy demand, healthy environment and future growth which is considered essential for essential sustainable development. Marine renewable energy is one of the major means to meet this demand. Turbines (both horizontal and vertical) play a vital role for extraction of tidal energy. The influence of swept area on the performance improvement of tidal turbine is a vital factor to study for the reduction of relatively high power generation cost in marine industry. This study concentrates on performance investigation of variable length blade tidal turbine concept that has already been proved as an efficient way to improve energy extraction in the wind industry. The concept of variable blade length utilizes the idea of increasing swept area through the turbine blade extension when the tidal stream velocity falls below the rated condition to maximize energy capture while blade retracts above rated condition. A three bladed horizontal axis variable length blade horizontal axis tidal turbine was modelled by modifying a standard fixed length blade turbine. Classical blade element momentum theory based numerical investigation has been carried out using QBlade software to predict performance. The results obtained from QBlade were compared with the available published results and found very good agreement. Three major performance parameters (i.e., thrust, moment, and power coefficients) and power output for different blade extensions were studied and compared with a standard fixed bladed baseline turbine at certain operational conditions. Substantial improvement in performance coefficient is observed with the increase in swept area of the turbine rotor. Power generation is found to increase in great extent when operating at below rated tidal stream velocity reducing the associated cost per unit electric power generation.

Keywords: variable length blade, performance, tidal turbine, power generation

Procedia PDF Downloads 280

Authors: Amos Sunday Onikanni, Bashir Lawal, Babatunji Emmanuel Oyinloye, Gomaa Mostafa-Hedeab, Mohammed Alorabi, Simona Cavalu, Augustine O. Olusola, Chih-Hao Wang, Gaber El-Saber Batiha

Abstract:

The increasing global burden of diabetes mellitus has called for the search for a therapeutic alternative that offers better activities and safety than conventional chemotherapy. Herein, we evaluated the neuroprotective and antioxidant properties of different fractions (ethyl acetate, N-butanol and residual aqueous) of Clompanus pubescens leaves in streptozotocin (STZ)-induced diabetic rats. Our results revealed a significant elevation in the levels of blood glucose, pro-inflammatory cytokines, lipid peroxidation, neuronal activities of acetylcholinesterase, butyrylcholinesterase, nitric oxide, epinephrine, norepinephrine, and Na+/K+-ATPase in diabetic non treated rats. In addition, decreased levels of enzymatic and non-enzymatic antioxidants were observed. Treatment with different fractions of C. pubescens leaves resulted in a significant reversal of the biochemical alteration and improved the neurocognitive deficit in STZ-induced diabetic rats. However, the ethyl-acetate fraction demonstrated higher activities than the other fractions and was characterized for its phytoconstituents, revealing the presence of Gallic acid (713.00 ppm), catechin (0.91 ppm), ferulic acid (0.98 ppm), rutin (59.82 ppm), quercetin (3.22 ppm) and kaempferol (4.07 ppm). Our molecular docking analysis revealed that these compounds exhibited different binding affinities and potentials for targeting BChE/AChE/ IL-1 β/Na+-K+-ATPase. However, only Kampferol and ferulic exhibited good drug-like, ADMET, and permeability properties suitable for use as a neuronal drug target agent. Hence, the ethyl-acetate fraction of C. pubescent leaves could be considered a source of promising bioactive metabolite for the treatment and management of cognitive impairments related to type II diabetes mellitus.

Keywords: diabetes mellitus, neuroprotective, antioxidant, pro-inflammatory cytokines

Procedia PDF Downloads 126

Authors: Mairo Musa Galadima, Phoebe Mshelia

Abstract:

In Nigeria, the national policy of education stipulates that the kindergarten-primary schools and the legislature are to use the three popular Nigerian Languages namely: Hausa, Igbo, and Yoruba. However, the English language seems to be preferred and this calls for this paper. Attempts were made to draw out the challenges faced by learners in understanding English speech sounds and using them to communicate effectively in English; using 5 (five) selected secondary school in Bauchi. It was discovered that challenges abound in the wrong use of stress and intonation, transfer of phonetic features from their first language. Others are inadequately qualified teachers and relevant materials including textbooks. It is recommended that teachers of English should lay more emphasis on the teaching of supra-segmental features and should be encouraged to go for further studies, seminars and refresher courses.

Keywords: stress and intonation, phonetic and challenges, teaching and learning English, secondary schools

Procedia PDF Downloads 357

Authors: Anwaar O. Ali, Mahmoud Fathy Mubarak, Mahmoud Ibrahim Abdou, Hector Cano Esteban, Amany A. Aboulrous

Abstract:

Corrosion resistance and lubrication are crucial characteristics required for geothermal drilling fluids. In this study, a ZnO/Fe₂O₃ nanocomposite was fabricated and incorporated into the structure of Cetyltrimethylammonium bromide (CTAB). Several physicochemical techniques were utilized to analyze and describe the synthesized nanomaterials. The surface morphology of the composite was assessed through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX). The corrosion inhibition capabilities of these materials were explored across various corrosive environments. The weight loss and electrochemical methods were utilized to determine the corrosion inhibition activity of the prepared nanomaterials. The results demonstrate a high level of protection achieved by the composite. Additionally, the lubricant coefficient and extreme pressure properties were evaluated.

Keywords: nanofluid, corrosion, geothermal drilling fluids, ZnO/Fe2O3

Procedia PDF Downloads 73

Authors: J. Castaño, S. Rodriguez, C. M. L. Franco

Abstract:

Starch isolated from non-edible A. hippocastanum seeds was characterized and used for preparing starch-based materials. The apparent amylose content of the isolated starch was 33.1%. The size of starch granules ranged from 0.7 to 35µm, and correlated with the shape of granules (spherical, oval and irregular). The chain length distribution profile of amylopectin showed two peaks, at polymerization degree (DP) of 12 and 41-43. Around 53% of branch unit chains had DP in the range of 11-20. A. hippocastanum starch displayed a typical C-type pattern and the maximum decomposition temperature was 317°C. Thermoplastic starch (TPS) prepared from A. hippocastanum with glycerol and processed by melt blending exhibited adequate mechanical and thermal properties. In contrast, plasticized TPS with glycerol:malic acid (1:1) showed lower thermal stability and a pasty and sticky behavior, indicating that malic acid accelerates degradation of starch during processing.

Keywords: Aesculus hippocastanum L., amylopectin structure, thermoplastic starch, non-edible source

Procedia PDF Downloads 381

Authors: Barbara Urasinska-Wojcik, Neil Chilton, Peter Todd, Christopher Elsworthy, Gregory J. Gibbons

Abstract:

The recent increase in the application of Additive Manufacturing (AM) of products has resulted in new demands on capability. The ability to integrate both form and function within printed objects is the next frontier in the 3D printing area. To move beyond prototyping into low volume production, we demonstrate a UK-designed and built AM hybrid system that combines polymer based structural deposition with digital deposition of electrically conductive elements. This hybrid manufacturing system is based on a multi-planar build approach to improve on many of the limitations associated with AM, such as poor surface finish, low geometric tolerance, and poor robustness. Specifically, the approach involves a multi-planar Material Extrusion (ME) process in which separated build stations with up to 5 axes of motion replace traditional horizontally-sliced layer modeling. The construction of multi-material architectures also involved using multiple print systems in order to combine both ME and digital deposition of conductive material. To demonstrate multi-material 3D printing, three thermoplastics, acrylonitrile butadiene styrene (ABS), polyamide 6,6/6 copolymers (CoPA) and polyamide 12 (PA) were used to print specimens, on top of which our high viscosity Ag-particulate ink was printed in a non-contact process, during which drop characteristics such as shape, velocity, and volume were assessed using a drop watching system. Spectroscopic analysis of these 3D printed materials in the IR region helped to determine the optimum in-situ curing system for implementation into the AM system to achieve improved adhesion and surface refinement. Thermal Analyses were performed to determine the printed materials glass transition temperature (Tg), stability and degradation behavior to find the optimum annealing conditions post printing. Electrical analysis of printed conductive tracks on polymer surfaces during mechanical testing (static tensile and 3-point bending and dynamic fatigue) was performed to assess the robustness of the electrical circuits. The tracks on CoPA, ABS, and PA exhibited low electrical resistance, and in case of PA resistance values of tracks remained unchanged across hundreds of repeated tensile cycles up to 0.5% strain amplitude. Our developed AM printer has the ability to fabricate fully functional objects in one build, including complex electronics. It enables product designers and manufacturers to produce functional saleable electronic products from a small format modular platform. It will make 3D printing better, faster and stronger.

Keywords: additive manufacturing, conductive tracks, hybrid 3D printer, integrated manufacture

Procedia PDF Downloads 170

Authors: M. Amelsakhi, A. Sohrabi-Bidar, A. Shareghi

Abstract:

One of the most important issues about the structural damages caused by earthquake is the evaluating of the spectral response of the site on which the construction is built. This fact has demonstrated during many earlier earthquakes and many researchers’ reports have concerned with it. According to these reports, features of the site materials and geometry of the ground surface are considered the main factors. This study concentrates on the specific form of topographies like hills. Assessing of spectral responses of different points on the hills and beside demonstrates considerable differences between 1D and 2D methods of geotechnical analyses. A general trend of amplifications on the top of the hills and de-amplifications near the toe of the hills has been appeared within the acceleration, velocity and displacement response spectrums of horizontal motion. Evaluating of spectral responses of different sizes of the hills revealed that as much as the hill-size enlarges differences between spectral responses of 1D and 2D analyses transfers to longer range of periods and becomes wider.

Keywords: topography effect, amplification ratio, response spectrum, earth resources engineering

Procedia PDF Downloads 243