Search results for: Víctor Hernández-Villalobos

Authors: Joao Paulo De Oliveira Paschoal, Andre Victor Rodrigues Dantas, Fernando Almeida Da Silva Fernandes, Eugenio Jose Zoqui

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With the adoption of High Pressure Die Casting technologies for the production of automotive bodies by the famous Giga Castings, the technology of processing metal alloys in the semi-solid state (SSM) becomes interesting because it allows for higher product quality, such as lower porosity and shrinkage voids. However, the alloys currently processed are derived from the foundry industry and are based on the Al-Si-(Cu-Mg) system. High-strength alloys, such as those of the Al-Zn-Mg-Cu system, are not usually processed, but the benefits of using this system, which is susceptible to heat treatments, can be associated with the advantages obtained by processing in the semi-solid state, promoting new possibilities for production routes and improving product performance. The current work proposes a new range of alloys to be processed in the semi-solid state through the modification of aluminum alloys of the Al-Zn-Mg-Cu system by the in-situ formation of Al3Ti intermetallic. Such alloys presented the thermodynamic stability required for semi-solid processing, with a sensitivity below 0.03(Celsius degrees * -1), in a wide temperature range. Furthermore, these alloys presented high hardness after aging heat treatment, reaching 190HV. Therefore, they are excellent candidates for the manufacture of parts that require low levels of defects and high mechanical strength.

Keywords: aluminum alloys, semisolid metals processing, intermetallics, heat treatment, titanium aluminide

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Authors: Gabriella Fardhiyanti, Victor Wee

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Air connectivity is the crucial factors to boost a region economics growth. It will open the accessibility to support regional competitiveness and helps to achieve ASEAN (Association of Southeast Asian Nations) integration in term of economic integration, business investment, promote intra-regional trade, and creates the sense of belongingness among ASEAN people in the region. An increasing number of air connectivity and transportation will be benefiting the region because air transportation is a vital hub for ASEAN. The aim of this paper is to address the importance of air connectivity in promoting ASEAN Integration, by focusing on the ASEAN vision for a more integrated region. The assessment uses based on the Netscan Air connectivity model based on the flight destination and airport connectivity index, further analysis present that air connectivity significantly influence ASEAN tourism sector. Follow by the implications of open skies policy for the liberation of the aviation industry and the growth of low cost-carriers (LCCs) in the region. This paper provides recommendation and strategy for overcoming the challenges faced by ASEAN to boost ASEAN tourism integration successfully. The findings can assist in guiding policy and industry stakeholders in the future decision relating to air liberalization and more integrated system in the region.

Keywords: air connectivity, ASEAN integration, low-cost carries, NetScan connectivity model, open skies policy

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Authors: Carlos Theran, Yohn Parra Bautista, Victor Adankai, Richard Alo, Jimwi Liu, Clement G. Yedjou

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Alzheimer's disease (AD) is a neurodegenerative disorder primarily characterized by deteriorating cognitive functions. AD has gained relevant attention in the last decade. An estimated 24 million people worldwide suffered from this disease by 2011. In 2016 an estimated 40 million were diagnosed with AD, and for 2050 is expected to reach 131 million people affected by AD. Therefore, detecting and confirming AD at its different stages is a priority for medical practices to provide adequate and accurate treatments. Recently, Machine Learning (ML) models have been used to study AD's stages handling missing values in multiclass, focusing on the delineation of Early Mild Cognitive Impairment (EMCI), Late Mild Cognitive Impairment (LMCI), and normal cognitive (CN). But, to our best knowledge, robust performance information of these models and the missing data analysis has not been presented in the literature. In this paper, we propose studying the performance of five different machine learning models for AD's stages multiclass prediction in terms of accuracy, precision, and F1-score. Also, the analysis of three imputation methods to handle the missing value problem is presented. A framework that integrates ML model for AD's stages multiclass prediction is proposed, performing an average accuracy of 84%.

Keywords: alzheimer's disease, missing value, machine learning, performance evaluation

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Authors: Victor R. Thulari, John Akach, Haleden Chiririwa, Aoyi Ochieng

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Solar-light activated titanium dioxide photocatalysts were prepared by hydrolysis of titanium (IV) isopropoxide with thiourea, followed by calcinations at 450 °C. The experiments demonstrated that methyl orange in aqueous solutions were successfully degraded under solar light using doped TiO₂. The photocatalytic oxidation of a mono azo methyl-orange dye has been investigated in multi ion doped TiO₂ and solar light. Solutions were irradiated by solar-light until high removal was achieved. It was found that there was no degradation of methyl orange in the dark and in the absence of TiO₂. Varieties of laboratory prepared TiO₂ catalysts both un-doped and doped using titanium (IV) isopropoxide and thiourea as a dopant were tested in order to compare their photoreactivity. As a result, it was found that the efficiency of the process strongly depends on the working conditions. The highest degradation rate of methyl orange was obtained at optimum dosage using commercially produced TiO₂. Our work focused on laboratory synthesized catalyst and the maximum methyl orange removal was achieved at 81% with catalyst loading of 0.04 g/L, initial pH of 3 and methyl orange concentration of 0.005 g/L using multi-ion doped catalyst. The kinetics of photocatalytic methyl orange dye stuff degradation was found to follow a pseudo-first-order rate law. The presence of the multi-ion dopant (thiourea) enhanced the photoefficiency of the titanium dioxide catalyst.

Keywords: degradation, kinetics, methyl orange, photocatalysis

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Authors: A. Irudaya Veni Mary, M. Victor Louis Anthuvan, P. Christie, A. Indira

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In India, social enterprises are working to create social value in various fields including education; health; women and child development; environment protection and community development. Although social enterprises have brought about tremendous changes in the lives of beneficiaries, the importance of their works is not understood thoroughly. One of the ways to prove themselves is to measure the impact, which in recent times has received much attention. This paper focuses on the study of social value created by the social enterprises in the field of community development. It also aims to put forth a research tool for measuring the social value created by the social enterprises in the field of community development. A close-ended interview schedule was prepared to measure the social value creation and it was administered among 60 beneficiaries of two social enterprises who work in the field of community development. The study results show that the social enterprises have brought four types of impact in the life of their beneficiaries; economic impact, social impact, political impact and cultural impact. This study is limited to the social enterprises those who work towards community development. This empirical finding will enable the reader to understand various types of social value created by the social enterprises working in the field of community development. This study will also serve as guide for social enterprises in community development activities to measure their impact and thereby improve their operation towards the betterment of the society. This paper is derived from an empirical research carried out to describe the different types of social value created by the social enterprises in India.

Keywords: social enterprise, social entrepreneurs, social impact, social value, tool for social impact measurement

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Authors: K. Julia Rose Mary, Victor Arokia Doss

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Electrical and chemical stimulations up-regulate phosphorylaion of CREB, a transcriptional factor that induces its target gene production for memory consolidation and Late Long-Term Potentiation (L-LTP) in CA1 region of the hippocampus. L-LTP requires complex interactions among second-messenger signaling cascade molecules such as cAMP, CAMKII, CAMKIV, MAPK, RSK, PKA, all of which converge to phosphorylate CREB which along with CBP induces the transcription of target genes involved in memory consolidation. A differential equation based model for L-LTP representing stimulus-mediated activation of downstream mediators which confirms the steep, supralinear stimulus-response effects of activation and inhibition was used. The same was extended to accommodate the inhibitory effect of the Inducible cAMP Early Repressor (ICER). ICER is the natural inducible CREB antagonist represses CRE-Mediated gene transcription involved in long-term plasticity for learning and memory. After verifying the sensitivity and robustness of the model, we had simulated it with various empirical levels of repressor concentration to analyse their effect on the gene induction. The model appears to predict the regulatory dynamics of repression on the L-LTP and agrees with the experimental values. The flux data obtained in the simulations demonstrate various aspects of equilibrium between the gene induction and repression.

Keywords: CREB, L-LTP, mathematical modeling, simulation

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Authors: Courtney Laurey Davids

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Mary Shelley’s two 19th century novels, the seminal Frankenstein (1818) and the less popular The Last Man (1826) draw on Gothic elements that invite a futuristic questioning and critique of man’s fallibility and propensity to be the author of his own demise be it by transgressing natural law through a scientific endeavour or ‘birthing’ a plague. Recent scholarship about ‘prophetic’ voices in fiction considers The Last Man an influential but overlooked novel deserving of renewed scholarly interest. Through close textual analysis and comparative reading, this paper seeks to explore the continuities (and discontinuities) in thematic concern of creator and creation in Frankenstein and The Last Man, emblematic in the oppositional characters of Victor Frankenstein and the Creature and Adrian, Earl of Windsor and Lionel Verney, his ‘creation’ in The Last Man. It argues that the creator/creation dynamic between Frankenstein and the Creature is to an extent revisited and inverted in Adrian and Verney but presented as no less problematic in The Last Man’s critique of man’s inevitable folly despite nurturing and acceptance of the marginalised figure. Drawing on Romanticism ideals of nature, its foregrounding of a scourging pandemic as punishment for man’s self-dislocation and with nature is a mirroring of Frankenstein and the Creature’s own plague-like deterioration and alienation from self and nature. In a sense, both Verney and the Creature as solitary figures at the novels' denouement are ‘last men’, having learned much about man and society and upon whom the moral injunction rests. In Verney, however, the moral warning coupled with the hope that man can yet be saved offers a different reading perhaps from Frankenstein regarding the creator/creation dichotomy.

Keywords: creator/creation, Frankenstein, Mary Shelley, The Gothic, The Last Man

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Authors: Gina Zavaleta-Espejo, Segundo R. Jáuregui-Rosas, Fanny V. Samanamud-Moreno, José Saldaña Jiménez, Anibal Felix-Quintero, Víctor Montero-Del Aguila, Elsi Mejía-Uriarte

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Vicugnapacos "alpaca" fabrics are considered special for their finesse, and the garments in the textile market are very luxurious. It has many special characteristics such as antiallergic, soft, hygroscopic, among others. In this sense, the research aimed to evaluate the antimicrobial activity of alpaca fabrics functionalized with silver nanoparticles on the bacteria Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. For the functionalization of the fabrics, AgNO3 and different concentrations of trisodium citrate (TSC) 2, 6, and 10 mg. Tissue characterization was performed using Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The determination of the antimicrobial activity of the alpaca tissues was made by the Kirby-Bauer method with alpaca tissue discs functionalized with silver nanoparticles, an experimental design was made in completely randomized blocks with three treatments and a negative control with three repetitions. The results showed that inhibition halos were formed for both bacteria, therefore, the functionalized tissues have a high antimicrobial activity, whose mechanism of action is attributed to the free radicals (ROS) generated by the nanoparticles that cause oxidative damage to the bacteria. proteins and lipids of the bacterial cell wall.

Keywords: antimicrobial, animal fibers, fabrics, functionalization, trisodium citrate

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Authors: Desmond Chinedu Oparaku, Emmanuel Uwazie Anyanwu, Oyemike Victor Benson, Ogbonna Isaac-Nnadimele

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The purpose of this paper is to provide a theoretical discourse that highlights the challenges associated with management of indigenous knowledge with reference to developing countries. Literature review and brainstorming were used to collect relevant data and draw inferences. The findings indicate that non-existence of indigenous knowledge management policy (IKMP), low level of partnership drive among library and information services providers, non-uniformity of format and content of indigenous knowledge, inadequate funding, and lack of access to ICTs, lack of indigenous people with indigenous expertise and hoarding of knowledge as challenges to indigenous knowledge management. The study is based on literature review and information gathered through brain storming with professional colleagues the geographic scope as developing countries. The study has birth several implication based on the findings made. Professionally, it has necessitated the need for formulating a viable indigenous knowledge management policy (IKMP), creating of collaborative network through partnership, and integration of ICTs to indigenous knowledge management practices by libraries in developing countries etc. The originality of this paper is revealed in its capability as serving as an eye opener to librarians on the need for preserving and managing indigenous knowledge in developing countries. It further unlocks the possibilities of exploring empirical based researches to substantiate the theoretical issues raised in this paper. The findings may be used by library managers to improve indigenous knowledge management (IKM).

Keywords: developing countries, ICTs, indigenous knowledge, knowledge management

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Authors: Thiago Victor Cordeiro Marcos, Joao Felipe de Araujo Martos, Ronaldo de Lima Cardoso, David Romanelli Pinto, Paulo Gilberto de Paula Toro, Israel da Silveira Rego, Antonio Carlos de Oliveira

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Currently, the use of 3D rapid prototyping, also known as 3D printing, has been investigated by some universities around the world as an innovative technique, fast, flexible and cheap for a direct plastic models manufacturing that are lighter and with complex geometries to be tested for hypersonic shock tunnel. Initially, the purpose is integrated prototyped parts with metal models that actually are manufactured through of the conventional machining and hereafter replace them with completely prototyped models. The mechanical design models to be tested in hypersonic shock tunnel are based on conventional manufacturing processes, therefore are limited forms and standard geometries. The use of 3D rapid prototyping offers a range of options that enables geometries innovation and ways to be used for the design new models. The conception and project of a prototyped model for hypersonic shock tunnel should be rethought and adapted when comparing the conventional manufacturing processes, in order to fully exploit the creativity and flexibility that are allowed by the 3D prototyping process. The objective of this paper is to compare the conception and project of a 3D rapid prototyping model and a conventional machining model, while showing the advantages and disadvantages of each process and the benefits that 3D prototyping can bring to the manufacture of models to be tested in hypersonic shock tunnel.

Keywords: 3D printing, 3D prototyping, experimental research, hypersonic shock tunnel

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Authors: Oluwole Victor Falobi, Lawrence Olusola Ige

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The cardinal drawing force of this study is to examine the influence of audio-visual resources in teaching business subjects in selected secondary schools in IfakoIjaiye Local Government Area of Lagos State, Nigeria. A descriptive survey research design was employed for the study. By using a quantitative research approach and a sample size of 120 students were randomly selected from four public schools. Three research questions with one hypothesis guided the study. Data collected were analysed using frequency, the mean and standard deviation for the research questions, and Pearson Product Moment Correlation PPMC were used to analysed the inferential statistic. Findings from the study revealed that the Influence of audio-visual resources in teaching business subjects in selected secondary schools in IfakoIjaiye Local Government Area of Lagos State is low. It further revealed data the knowledge of teachers on the use of audio-visual resources is high in Ifako Local Government Area. It was recommended that government should create a timely monitoring system in other to check secondary school laboratories and classrooms to replace outdated facilities and also purchase needed facilities for effective teaching and learning to take place.

Keywords: audio-visual resources, business subjects, school, teaching

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Authors: Lourdes Yareth Herrera-Chavez, Alberto Ruiz, Victor H. Lopez

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Superalloys are used in components that operate at high temperatures such as pressure vessels and heat exchanger tubing. Design standards for these components must consider creep resistance among other criteria. Fusion welding processes are commonly used in the industry to join such components. Fusion processes commonly generate three distinctive zones, i.e. heat affected zone (HAZ), namely weld metal (WM) and base metal (BM). In nickel-based superalloy, the microstructure developed during fusion welding dictates the mechanical response of the welded component and it is very important to establish these effects in the mechanical response of the component. In this work, two plates of Inconel 600 superalloy were Gas Metal Arc Welded (GMAW). Creep samples were cut and milled to specifications and creep tested at a temperature (650 °C) using stress level of 350, 300, 275, 250 and 200 MPa. Microstructural analysis results showed a progressive creep damage evolution that depends on the stress levels with a preferential accumulation of creep damage at the heat affected zone where the creep rupture preferentially occurs owing to an austenitic matrix with grain boundary precipitated of the type Cr23C6. The fractured surfaces showed dimple patterns of cavity and voids. Results indicated that the damage mechanism is due to cavity growth by the combined effect of the power law and diffusion creep.

Keywords: austenitic microstructure, creep damage evolution, heat affected zone, vickers microhardness

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Authors: Friday G. Okibe, Edit B. Agbaji, Victor O. Ajibola, Christain C. Onoyima

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Controlled drug delivery systems reduce dose-dependent toxicity associated with potent drugs, including anticancer drugs. In this research, hydroxyapatite (HA) and hydroxyapatite-sodium alginate nanocomposites (HASA) were successfully prepared and characterized using Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The FTIR result showed absorption peaks characteristics of pure hydroxyapatite (HA), and also confirmed the chemical interaction between hydroxyapatite and sodium alginate in the formation of the composite. Image analysis from SEM revealed nano-sized hydroxyapatite and hydroxyapatite-sodium alginate nanocomposites with irregular morphologies. Particle size increased with the formation of the nanocomposites relative to pure hydroxyapatite, with no significant change in particles morphologies. Drug loading and in-vitro drug release study were carried out using synthetic body fluid as the release medium, at pH 7.4 and 37 °C and under perfect sink conditions. The result shows that drug loading is highest for pure hydroxyapatite and decreased with increasing quantity of sodium alginate. However, the release study revealed that HASA-5%wt and HASA-20%wt presented better release profile than pure hydroxyapatite, while HASA-33%wt and HASA-50%wt have poor release profiles. This shows that Methotrexate-loaded hydroxyapatite-sodium alginate if prepared under optimal conditions is a potential carrier for effective delivery of Methotrexate.

Keywords: drug-delivery, hydroxyapatite, methotrexate, nanocomposites, sodium alginate

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Authors: Victor Bodell, Lukas Ekstrom, Somayeh Aghanavesi

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Fuel consumption (FC) is one of the key factors in determining expenses of operating a heavy-duty vehicle. A customer may therefore request an estimate of the FC of a desired vehicle. The modular design of heavy-duty vehicles allows their construction by specifying the building blocks, such as gear box, engine and chassis type. If the combination of building blocks is unprecedented, it is unfeasible to measure the FC, since this would first r equire the construction of the vehicle. This paper proposes a machine learning approach to predict FC. This study uses around 40,000 vehicles specific and o perational e nvironmental c onditions i nformation, such as road slopes and driver profiles. A ll v ehicles h ave d iesel engines and a mileage of more than 20,000 km. The data is used to investigate the accuracy of machine learning algorithms Linear regression (LR), K-nearest neighbor (KNN) and Artificial n eural n etworks (ANN) in predicting fuel consumption for heavy-duty vehicles. Performance of the algorithms is evaluated by reporting the prediction error on both simulated data and operational measurements. The performance of the algorithms is compared using nested cross-validation and statistical hypothesis testing. The statistical evaluation procedure finds that ANNs have the lowest prediction error compared to LR and KNN in estimating fuel consumption on both simulated and operational data. The models have a mean relative prediction error of 0.3% on simulated data, and 4.2% on operational data.

Keywords: artificial neural networks, fuel consumption, friedman test, machine learning, statistical hypothesis testing

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Authors: Shilpa Khobragade, Carlos Da Silva Granja, Niklas Sandström, Igor Efimov, Victor P. Ostanin, Wouter van der Wijngaart, David Klenerman, Sourav K. Ghosh

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Rapid, label-free and direct detection of pathogenic bacteria is critical for the prevention of disease outbreaks. This paper for the first time attempts to probe the nonlinear acoustic response of quartz crystal resonator (QCR) functionalized with specific DNA aptamers for direct detection and quantification of viable E. coli KCTC 2571 bacteria. DNA aptamers were immobilized through biotin and streptavidin conjugation, onto the gold surface of QCR to capture the target bacteria and the detection was accomplished by shift in amplitude of the peak 3f signal (3 times the drive frequency) upon binding, when driven near fundamental resonance frequency. The developed nonlinear acoustic aptasensor system demonstrated better reliability than conventional resonance frequency shift and energy dissipation monitoring that were recorded simultaneously. This sensing system could directly detect 10⁽⁵⁾ cells/mL target bacteria within 30 min or less and had high specificity towards E. coli KCTC 2571 bacteria as compared to the same concentration of S.typhi bacteria. Aptasensor response was observed for the bacterial suspensions ranging from 10⁽⁵⁾-10⁽⁸⁾ cells/mL. Conclusively, this nonlinear acoustic aptasensor is simple to use, gives real-time output, cost-effective and has the potential for rapid, specific, label-free direction detection of bacteria.

Keywords: acoustic, aptasensor, detection, nonlinear

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Authors: Daniel Gidey, Kunwar Siddarth Dadhwal, Tagel Wondimu

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There are numerous ways for ending conflict; hitherto, most conflicts are resolved either through negotiated or victor's peace, this article is about the former. Negotiations entail concessions, consensus-building, and mutual trust in order to transform a belligerent situation into a settlement. In such a context, regional and sub-regional organizations play a critical role in mediating conflicting parties so as to prevent, manage, and resolve conflicts between and among conflicting parties. This article is about the AU-led negotiated peace deal on the bloody conflict between the Tigray Peoples Liberation Front (TPLF) and the Federal Democratic Republic of Ethiopia (FDRE) by undertaking the Pretoria Peace Accord as a case study. In terms of research method, the article is based on a critical evaluation of the literature and content analysis on the very research topic. Findings of the study revealed that the AU, through Olusegun Obasanjo and other dignitaries, played a critical role in nurturing compromise and mutual trust between the TPLF and the Ethiopian federal government so as to take along the Pretoria peace deal. Through critical literature review and content analysis of the Peace deal, the article has concluded that negotiated peace is likely, at least, to achieve negative peace.

Keywords: regional organizations, peace promotion, African Union, negotiating conflicts, Northern Ethiopia, conflict resolution

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Authors: Victor Emery David Jr., Jiang Wenchao, Yasinta John, Md. Sahadat Hossain

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Sludge originates from the process of treatment of wastewater. It is the byproduct of wastewater treatment containing concentrated heavy metals and poorly biodegradable trace organic compounds, as well as potentially pathogenic organisms (viruses, bacteria, etc.) which are usually difficult to treat or dispose of. China, like other countries, is no stranger to the challenges posed by an increase of wastewater. Treatment and disposal of sludge have been a problem for most cities in China. However, this problem has been exacerbated by other issues such as lack of technology, funding, and other factors. Suitable methods for such climatic conditions are still unavailable for modern cities in China. Against this background, this paper seeks to describe the methods used for treatment and disposal of sludge from industries and suggest a suitable method for treatment and disposal in Chongqing/China. From the research conducted, it was discovered that the highest treatment rate of sludge in Chongqing was 10.08%. The industrial waste piping system is not separated from the domestic system. Considering the proliferation of industry and urbanization, there is a likelihood that the production of sludge in Chongqing will increase. If the sludge produced is not properly managed, this may lead to adverse health and environmental effects. Disposal costs and methods for Chongqing were also included in this paper’s analysis. Research showed that incineration is the most expensive method of sludge disposal in China/Chongqing. Subsequent research, therefore, considered optional alternatives such as composting. Composting represents a relatively cheap waste disposal method considering the vast population, current technology and economic conditions of Chongqing, as well as China at large.

Keywords: Chongqing/China, disposal, industrial, sludge, treatment

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Authors: Rejane Maria P. da Silva, Mariana X. Milagre, João Victor de S. Araujo, Leandro A. de Oliveira, Renato A. Antunes, Isolda Costa

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The Al-Cu-Li alloys are advanced materials for aerospace application because of their interesting mechanical properties and low density when compared with conventional Al-alloys. However, Al-Cu-Li alloys are susceptible to localized corrosion. The near-surface deformed layer (NSDL) induced by the rolling process during the production of the alloy and its removal by polishing can influence on the corrosion susceptibility of these alloys. In this work, the influence of surface preparation effects on the electrochemical activity of AA2098-T351 (Al–Cu–Li alloy) was investigated using a correlation between surface chemistry, microstructure, and electrochemical activity. Two conditions were investigated, polished and as-received surfaces of the alloy. The morphology of the two types of surfaces was investigated using confocal laser scanning microscopy (CLSM) and optical microscopy. The surface chemistry was analyzed by X-ray Photoelectron Spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDS). Global electrochemical techniques (potentiodynamic polarization and EIS technique) and a local electrochemical technique (Localized Electrochemical Impedance Spectroscopy-LEIS) were used to examine the electrochemical activity of the surfaces. The results obtained in this study showed that in the as-received surface, the near-surface deformed layer (NSDL), which is composed of Mg-rich bands, influenced the electrochemical behavior of the alloy. The results showed higher electrochemical activity to the polished surface condition compared to the as-received one.

Keywords: Al-Cu-Li alloys, surface preparation effects, electrochemical techniques, localized corrosion

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Authors: Amit Kumar, Davide Lionetti, Victor Day, James Blakemore

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Capture and activation of the water-soluble uranyl dication (UO22+) remains a challenging problem, as few rational approaches are available for modulating the reactivity of this species. Here, we report the divergent synthesis of heterobimetallic complexes in which UO22+ is held in close proximity to a range of redox-inactive metals by tailored macrocyclic ligands. Crystallographic and spectroscopic studies confirm assembly of homologous UVI(μ-OAr)2Mn+ cores with a range of mono-, di-, and trivalent Lewis acids (Mn+). X-ray diffraction (XRD) and cyclic voltammetry (CV) data suggest preferential binding of K+ in an 18-crown-6-like cavity and Na+ in a 15-crown-5-like cavity, both appended to Schiff-base type sites that selectively bind UO22+. CV data demonstrate that the UVI/UV reduction potential in these complexes shifts positive and the rate of electron transfer decreases with increasing Lewis acidity of the incorporated redox-inactive metals. Moreover, spectroelectrochemical studies confirm the formation of [UV] species in the case of monometallic UO22+ complex, consistent with results from prior studies. However, unique features were observed during spectroelectrochemical studies in the presence of the K+ ion, suggesting new insights into electronic structure may be accessible with the heterobimetallic complexes. Overall, these findings suggest that interactions with Lewis acids could be effectively leveraged for rational tuning of the electronic and thermochemical properties of the 5f elements, reminiscent of strategies more commonly employed with 3d transition metals.

Keywords: electrochemistry, Lewis acid, macrocycle, uranyl

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Authors: Victor Romanov, Daria Efimenko

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The focus on innovation in modern economy is the main factor in surviving business in a competitive environment. The innovations are based on the search and use of knowledge in a global context. Nowadays consumers and market demand are the main innovation drivers. This leads to build a business as a system with feedback, promptly restructuring production and innovation implementation in response to market demands. In modern knowledge economy, because of speed of technical progress, the product's lifecycle became much shorter, what makes more stringent requirements for innovation implementation on the enterprises of and therefore the possibility for enterprise for receiving extra income is decreasing. This circumstance imposes additional requirements for the replacement of obsolete products and the prompt release of innovative products to the market. The development of information technologies has led to the fact that only in the conditions of partnership and knowledge sharing with partners it is possible to update products quickly for innovative products. Many companies pay attention to updating innovations through the search for new partners, but the task of finding new partners presents some difficulties. The search for a suitable one includes several stages such as: determining the moment of innovation-critical, introducing a search, identifying search criteria, justifying and deciding on the choice of a partner. No less important is the question of how to manage an innovative product in response to a changing market. The article considers the problems of information support for the search for the source of innovation and partnership to decrease the time for implementation of novelty products.

Keywords: partnership, novelty, market feedback, alliance

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Authors: V. Linfante

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Catwalks are one of the key moments in fashion: the first and most relevant display where brands stage their collections, products, ideas, and style. The garment is 'the star' of the catwalk and must show itself not just as a product but as a result of a design process endured for several months. All contents developed within this process become ingredients for connecting scenography, music, lights, and direction into a unique fashion narrative. According to the spirit of different ages, fashion shows have been transformed and shaped into peculiar formats: from Pandoras to presentations organized by Parisian couturiers, across the 'marathons' typical of the beginning of modern fashion system, coming up to the present structure of fashion weeks, with their complex organization and related creative and technical businesses. The paper intends to introduce the evolution of the fashion system through its unique process of seasonally staging and showing its production. The paper intends to analyse the evolution of the fashion shows from the intimacy of ballrooms at the beginning of the 20th century, passing through the enthusiasm attitude typical from the '70s and the '80s, to finally depict our present. In this last scenario, catwalks are not anymore a standard collections presentation but become one of the most exciting expression of contemporary culture (and sub-cultures), going from sophisticated performances (as Karl Lagerfeld's Chanel shows) to real artistic happenings (as the events of Victor&Rolf, Alexander McQueen, OFF_WHITE, Vetements, and Martin Margiela), often involving contemporary architecture, digital world, technology, social media, performing art and artists.

Keywords: branding, communication, fashion, new media, performing art

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Authors: Ayobami Solomon Popoola, Victor N. Enujiugha

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Production of soy-yogurt by fermentation of soymilk with lactic acid bacteria isolated from soymilk was studied. Soymilk was extracted from dehulled soybean seeds and pasteurized at 95 °C for 15 min. The soymilk was left to naturally ferment (temperature 40 °C; time 8 h) and lactic acid bacteria were isolated, screened and selected for yogurt production. Freshly prepared soymilk was pasteurized (95 °C, 15 min), inoculated with the lactic acid bacteria isolated (3% w/v starter culture) and incubated at 40 °C for 8 h. The yogurt produced was stored at 4 °C. Investigations were carried out with the aim of improving the sensory qualities and acceptability of soy yogurt. Commercial yogurt was used as a control. The percentage of soymilk inoculated was 70% of the broth. Soy-yoghurt samples produced were subsequently subjected to biochemical and microbiological assays which included total viable counts of fresh milk and soy-based yoghurt; proximate composition of functional soy-based yoghurt fermented with Lactobacillus plantarum; changes in pH, Titratable acidity, and lactic acid bacteria during a 14 day period of storage; as well as morphological and biochemical characteristics of lactic acid bacteria isolated. The results demonstrated that using Lactobacillus plantarum to inoculate soy milk for yogurt production takes about 8 h. The overall acceptability of the soy-based yogurt produced was not significantly different from that of the control sample. The use of isolate from soymilk had the added advantage of reducing the cost of yogurt starter culture, thereby making soy-yogurt, a good source of much desired good quality protein. However, more experiments are needed to improve the sensory qualities such as beany or astringent flavor and color.

Keywords: soy, soymilk, yoghurt, starter culture

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Authors: Snowie Jane Galgo, Victor Asio

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Geochemical composition of soils provides vital information about their origin and development. Highly weathered soils are widespread in the islands of Leyte and Samar but limited data have been published in terms of their nature, characteristics and nutrient status. This study evaluated the total elemental composition, properties and nutrient status of eight (8) deep and highly weathered soils in various parts of Leyte and Samar. Sampling was done down to 3 to 4 meters deep. Total amounts of Al₂O₃, As₂O₃, CaO, CdO, Cr₂O₃, CuO, Fe₂O₃, K₂O, MgO, MnO, Na₂O, NiO, P₂O₅, PbO, SO₃, SiO₂, TiO₂, ZnO and ZrO₂ were analyzed using an X-ray analytical microscope for eight soil profiles. Most of the deep and highly weathered soils have probably developed from homogenous parent materials based on the regular distribution with depth of TiO₂ and ZrO₂. Two of the soils indicated high variability with depth of TiO₂ and ZrO₂ suggesting that these soils developed from heterogeneous parent material. Most soils have K₂O and CaO values below those of MgO and Na₂O. This suggests more losses of K₂O and CaO have occurred since they are more mobile in the weathering environment. Most of the soils contain low amounts of other elements such as CuO, ZnO, PbO, NiO, CrO and SO₂. Basic elements such as K₂O and CaO are more mobile in the weathering environment than MgO and Na₂O resulting in higher losses of the former than the latter. Other elements also show small amounts in all soil profile. Thus, this study is very useful for sustainable crop production and environmental conservation in the study area specifically for highly weathered soils which are widespread in the Philippines.

Keywords: depth function, geochemical composition, highly weathered soils, total elemental composition

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Authors: Victor Milanes, Martha Hubertz

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In the wake of COVID-19, all aspects of life have been estranged, and humanity has been forced to shift toward a more technologically integrated mode of operation. Essential work such as Healthcare, business, and public policy are a few notable industries that were initially dependent upon face-to-face modality but have completely reimagined their operation style. Unique to these fields, education was particularly strained because academics, teachers, and professors alike were obligated to shift their curriculums online over the course of a few weeks while also maintaining the expectation that they were educating their students to a similar level accomplished pre-pandemic. This was notable as research indicates two key concepts: Students prefer face-to-face modality, and due to the disruption in academic continuity/style, there was a negative impact on student's overall education and performance. With these two principles in mind, this study aims to inquire what online strategies could be best employed by teachers to educate their students, as well as what strategies could be adopted in a multimodal setting if deemed necessary by the instructor or outside convoluting factors (Such as the case of COVID-19, or a personal matter that demands the teacher's attention away from the classroom). Strategies and methods will be cross-analyzed via a ranking system derived from various recognized teaching assessments, in which engagement, retention, flexibility, interest, and performance are specifically accounted for. We expect to see an emphasis on positive social pressure as a dominant factor in the improved propensity for education, as well as a preference for visual aids across platforms, as research indicates most individuals are visual learners.

Keywords: technological integration, multimodal teaching, education, student engagement

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Authors: Marcela Menah de Sousa Lima, Victor Ushijima Leone, Natasha Aparecida Grande de Franca, Barbara Santarosa Emo Peters, Ligia Araujo Martini

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Conjugated linoleic acid (CLA) intake has been constantly related to benefits to human health since having a positive effect on reducing body fat. The aim of the present study was to investigate the association between CLA intake and biochemical measurements and body composition of adults and the elderly. Subjects/Methods: 287 adults and elderly participants in an epidemiological study in Sao Paulo Brazil, were included in the present study. Participants had their dietary data obtained by two non-consecutive 24HR, a body composition assessed by dual-energy absorptiometry exam (DXA), and a blood collection. Mean differences and a correlation test was performed. For all statistical tests, a significance of 5% was considered. Results: CLA intake showed a positive correlation with HDL-c levels (r = 0.149; p = 0.011) and negative with VLDL-c levels (r = -0.134; p = 0.023), triglycerides (r = -0.135; p = 0.023) and glycemia (r = -0.171; p = 0.004), as well as negative correlation with visceral adipose tissue (VAT) (r = -0.124, p = 0.036). Evaluating individuals in two groups according to VAT values, a significant difference in CLA intake was observed (p = 0.041), being the group with the highest VAT values, the one with the lowest fatty acid intake. Conclusions: This study suggests that CLA intake is associated with a better lipid profile and lower visceral adipose tissue volume, which contributes to the investigation of the effects of CLA on obesity parameters. However, it is necessary to investigate the effects of CLA from milk and dairy products in the control adiposity.

Keywords: adiposity, dairy products, diet, fatty acids

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Authors: Victor Iorungwa Gwa, Ebenezer Jonathan Ekefan

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Potential of Trichoderma harzianum for biological control of postharvest fungal rot of white yam (Dioscorea rotundata Poir) tubers in storage was studied. Pathogenicity test revealed the susceptibility of healthy looking yam tubers to Aspergillus niger, Botryodiplodia theobromae, and Fusarium oxysporum f. sp. melonganae after fourteen days of inoculation. Treatments comprising A. niger, B. theobromae, and F. oxysporum each paired with T. harzianum and were arranged in completely randomized design and stored for five months. Experiments were conducted between December 2015 and April 2016 and December 2016 and April 2017. Results showed that tubers treated with the pathogenic fungi alone caused mean percentage rot of between 6.67 % (F. oxysporum) and 22.22 % (A. niger) while the paired treatments produced only between 2.22 % (T. harzianum by F. oxysporum) and 6.67 % (T. harzianum by A. niger). In the second year of storage, mean percentage rot was found to be between 13.33 % (F. oxysporum) and 28.89 % (A. niger) while in the paired treatment rot was only between 6.67 % (F. oxysporum) and 8.89% (A. niger). Tubers treated with antagonist alone produced 0.00 % and 2.22 % in the first and second year, respectively. Result revealed that there was a significant difference (P ≤ 0.05) in mean percentage rot between the first year and the second year except where B. theobromae was inoculated alone, A. niger and T. harzianum paired and B. theobromae and T. harzianum paired. The most antagonised fungus in paired treatment for both years was F. oxysporum f. sp. melonganae, while the least antagonised, was A. niger and B. theobromae. It is, therefore, concluded that T. harzianum has potentials to control rot causing pathogens of yam tubers in storage. This can compliment or provide better alternative ways of reducing rot in yam tubers than by the use of chemical fungicides which are not environmentally friendly.

Keywords: biological control, fungal rot, postharvest, Trichoderma harzianum, white yam

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Authors: Nuno Da Camara, Victor Dulewicz, Malcolm Higgs

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Factors on employee engagement: In particular, although theorists have described the critical role of emotional cognition of the workplace environment as antecedents to employee engagement, empirical research on the impact of emotional cognition on employee engagement is limited. However, previous researchers have typically provided evidence of the link between emotional cognition of the workplace environment and workplace attitudes such as job satisfaction and organisational commitment. This study therefore aims to investigate the impact of emotional cognition of job, role, leader and organisation domains of the work environment – as represented by measures of psychological climate and organizational emotional intelligence (OEI) - on employee engagement. The research is based on a quantitative cross-sectional survey of employees in a UK charity organization (n=174). The research instruments applied include the psychological climate scale, the organisational emotional intelligence questionnaire (OEIQ) and the Utrecht Work Engagement Scale (UWES). The data were analysed using hierarchical regression and partial least squares (PLS) analytical techniques. The results of the study show that both psychological climate and OEI, which represent emotional cognition of job, role, leader and organisation domains in the workplace are significant drivers of employee engagement. In particular, the study found that a sense of contribution and challenge at work are the strongest drivers of vigour, dedication and absorption and highlights the importance of emotionally relevant approaches in furthering our understanding of workplace engagement.

Keywords: employee engagement, organisational emotional intelligence, psychological climate, workplace attitudes

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Authors: Victoria Adamu Pam, Victor Ameh Adejoh, Akwashiki Ombugadu

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The prevalence of gastrointestinal parasites of ruminant has been on the increase leading to great economic and production losses with more fatal cases occurring in developing countries. This study was conducted to investigate and provide data on the prevalence and impact of haemo and gastro intestinal parasites of small ruminants in Akwanga LGA of Nasarawa State. One hundred fecal and blood samples were collected from goats and sheep. The fecal and blood samples were examined using floatation method and thin blood smear method respectively. Four gastro intestinal parasites were identified in the study, these are; Strongyloides spp, Paramphistome spp, Coccidia spp and Moniezia spp. while 2 heamo parasites were identified; Babesia spp. and Anaplasma spp. The most prevalent gastro intestinal parasite encountered was Strongyloide pp with 48(64.86%) and 48(77.42%) in sheep and goat respectively. This is followed by Paramphistome spp with 18(24.32%) in sheep only. The least prevalent was Coccidia spp with 8(10.8%) in sheep and Moniezia spp with 2 (3.23%) in goats. The most prevalent heamo parasites was Babesia spp with 10(71.43%) and 10(100.00%) in sheep and goat respectively while the least prevalent was Anaplasma spp with 4(28.57%) in sheep only. Statistically, there is no significant difference between haemo and gastrointestinal parasites of sheep and goats in the study area. (P > 0.05). The prevalence of gastrointestinal and haemo parasites in relation to sex showed that female had the highest prevalence of 50% than in the male 2.00% while In relation to age the prevalence was higher in adult 58% than in the Young 2.00%. Statistically, there is a significant difference (P < 0.05) between adult and young. The study indicates that parasitic infections are prevalent in ruminants in the study area.

Keywords: akwanga, gastrointestinal, haemo, parasites

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Authors: Victor Emery David Jr., Jiang Wenchao, Daniel Mmereki, Yasinta John

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The fundamentals of public health are access to safe and clean drinking water. The presence of arsenic and other contaminants in drinking water leads to the potential risk to public health and the environment particularly in most developing countries where there’s inadequate access to safe and clean water and adequate sanitation. Liberia has taken steps to improve its drinking water status so as to achieve the Sustainable Development Goals (SDGs) target of ensuring clean water and effective sanitation but there is still a lot to be done. The Sustainable Development Goals are a United Nation initiative also known as transforming our world: The 2030 agenda for sustainable development. It contains seventeen goals with 169 targets to be met by respective countries. Liberia is situated within in the gold belt region where there exist the presence of arsenic and other contaminants in the underground water due to mining and other related activities. While there are limited or no epidemiological studies conducted in Liberia to confirm illness or death as a result of arsenic contamination in Liberia, it remains a public health concern. This paper assesses the drinking water quality, the presence of arsenic in groundwater/drinking water in Liberia, and proposes strategies for mitigating contaminants in drinking water and suggests options for improvement with regards to achieving the Sustainable Development Goals of ensuring clean water and effective sanitation in Liberia by 2030.

Keywords: arsenic, action plan, contaminants, environment, groundwater, sustainable development goals (SDGs), Monrovia, Liberia, public health, drinking water

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Authors: Victor Igwemezie, Ali Mehmanparast

Abstract:

The correct knowledge of corrosion fatigue mechanism in marine steel is very important. This is because it enables the design, selection, and use of steels for offshore applications. It also supports realistic corrosion fatigue life prediction of marine structures. A study has been conducted to increase the understanding of corrosion fatigue mechanism in marine steels. The materials investigated are normalized and advanced S355 Thermomechanical control process (TMCP) steels commonly used in the design of offshore wind turbine support structures. The experimental study was carried out by conducting corrosion fatigue tests under conditions pertinent to offshore wind turbine operations, using the state of the art facilities. A careful microstructural study of the crack growth path was conducted using metallurgical optical microscope (OM), scanning electron microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX). The test was conducted on three subgrades of S355 steel: S355J2+N, S355G8+M and S355G10+M and the data compared with similar studies in the literature. The result shows that the ferrite-pearlite morphology primarily controls the corrosion-fatigue crack growth path in marine steels. A corrosion fatigue mechanism which relies on the hydrogen embrittlement of the grain boundaries and pearlite phase is used to explain the crack propagation behaviour. The crack growth trend in the Paris region of the da/dN vs. ΔK curve is used to explain the dependency of the corrosion-fatigue crack growth rate on the ferrite-pearlite morphology.

Keywords: corrosion-fatigue mechanism, fatigue crack growth rate, ferritic-pearlitic steel, microstructure, phase morphology

Procedia PDF Downloads 160