bluuebunny/crossref_metadata_2025 huggingface dataset:
The Need of Non-traditional Techniques to Screen for the Virus
Authors: Borroni Davide , Gadhvi Kunal
Published: May 2020

BACKGROUND: At the present moment, the etiological diagnosis of SARS-CoV-2 is based on the polymerase chain reaction (PCR). False negative cases are increasingly reported in several studies using reverse transcription-PCR (RT-PCR). For example, the positive rate of RT-PCR for throat swabs was reported to be about 60% in early stage of COVID-19.
AIM: We aimed to present metagenomic next-generation sequencing (mNGS) as a potential tool to detect pathogens.
METHODS: In the recent year, mNGS is shown the potential to detect pathogens without the need of hypothesis guided approach and is proven to be highly effective.
RESULTS: A recent prospective study in the United States compared the diagnostic performance of routine diagnostic tests with mNGS and showed that mNGS detected a bacteria or virus in the CSF of 13 of 58 patients presenting with meningoencephalitis who were negative for or not assessed with routine diagnostic test including PCR. NGS also has the advantage to cover entire viral genomes.
CONCLUSION: As viral metagenomics has significantly improved in recent years and become more cost effective, we think that a change in the approach toward a shot-gun metagenomic testing should be explored and could potentially aid the diagnosis of COVID-19 cases and the management of this pandemic.
Molecular taxonomy of Tomares hairstreaks (Lepidoptera, Lycaenidae, Theclinae)
Authors: Nazari Vazrick , ten Hagen Wolfgang
Published: May 2020

Tomareshairstreaks comprise about 10 species distributed from Europe and North Africa to Central Asia. The taxonomy of the genus is hampered by the absence of diagnostic characters by which specimens can be unambiguously assigned to species. Our investigation of morphology and DNA barcode variations within and betweenTomaresspecies shows that while well-defined species (T. ballus,T. mauritanicus,T. callimachus,T. desinensandT. fedtschenkoi) diverge, poorly characterized taxa (T. nogelii,T. nesimachus,T. dobrogensis,T. romanoviandT. telemachus) show very little to no differentiation in mtDNA. We reinstateTomares callimachusspp.hafis(Kollar, 1849) as a valid subspecies (stat. rev.) and propose taxatelemachusZhdanko, 2000 anduighuricaKoçak, Seven & Kemal, 2000 as synonyms ofT. romanoviandT. nogelii nogeliirespectively (syn. nov). We relegatePolyommatus epiphaniaBoisduval, 1848, recently revived as a valid subspecies ofT. callimachus, back to synonymy under the latter, and reconsider the status ofT. nogelii dobrogensis(Caradja, 1895) in the light of new molecular data. We use a nuclear gene (EF-1α) in addition to COI barcodes to reconstruct the phylogeny of the group.
Troubles du neurodéveloppement : mécanismes
Authors: Gressens Pierre
Published: May 2020

Les troubles du neurodéveloppement doivent être appréhendés de façon dimensionnelle plutôt que catégorielle. Leur dimension génétique (certainement complexe) est évidente mais des facteurs d’environnement (notamment l’inflammation/neuro-inflammation et ce, par exemple, dans le cadre de la grande prématurité) jouent vraisemblablement un rôle important dans de nombreux cas. De plus des modifications épigénétiques pourraient expliquer certains dysfonctionnements persistant à long terme et représentent une nouvelle voie de recherche pouvant potentiellement déboucher sur de nouvelles pistes thérapeutiques.
Troubles du développement intellectuel
Authors: Des Portes Vincent , Héron Delphine
Published: May 2020

La déficience intellectuelle ( di ) ou trouble du développement intellectuel ( tdi ) est l’un des principaux troubles du neuro-développement et concerne 2 % de la population, soit plus d’un million de personnes en France. Elle se caractérise par une capacité réduite à raisonner et à comprendre une information abstraite ou complexe, ce qui retentit fortement sur les apprentissages scolaires et limite les capacités d’adaptation dans la vie quotidienne, y compris à l’âge adulte. Le handicap intellectuel, ou handicap mental, résulte d’une interaction de la vulnérabilité individuelle d’une personne avec di avec son écosystème , c’est-à‑dire l’environnement familial, culturel, institutionnel, qui peut être obstacle ou facilitateur. Le repérage d’un enfant avec une trajectoire développementale inhabituelle nécessite une bonne connaissance du développement psychomoteur par les professionnels. La di peut être isolée mais elle est aussi très souvent intriquée à d’autres troubles du neurodéveloppement, dont l’autisme, des troubles moteurs ou sensoriels (audition, vision), des troubles graves du sommeil, de l’alimentation ou des pathologies médicales comme l’épilepsie ou des troubles psychopathologiques très variés tels qu’anxiété, dépression et des troubles de régulation émotionnelle. Les causes de di sont multiples, plus d’une fois sur deux d’origine génétique, avec plusieurs centaines de maladies rares, mais restent encore souvent inconnues. La diffusion des nouvelles techniques de génétique (séquençage à haut débit) devrait faire reculer le nombre de personnes sans diagnostic, et redonne toute sa place à une démarche diagnostique raisonnée basée sur la clinique. Une évaluation multidimensionnelle régulière des compétences cognitives, scolaires, socio-émotionnelles, adaptatives, tout au long de la vie, permet de mieux appréhender le fonctionnement des personnes avec une di et d’envisager des stratégies adaptées d’apprentissages, de soins, d’accompagnements et de soutiens, pour une meilleure qualité de vie et de participation à la vie de la société.
Les troubles des apprentissages en 2020
Authors: Mazeau Michèle
Published: May 2020

Le cerveau de l’enfant est organisé d’emblée en réseaux spécialisés, certes massivement interconnectés, mais chacun de ces systèmes spécifiquement dédié à une fonction cognitive peut dysfonctionner, donnant lieu alors à un trouble des apprentissages. Les plus fréquents (5 à 15 % selon l’intensité prise en compte) touchent la lecture et l’orthographe (dyslexie-dysorthographie), les gestes et le graphisme manuel (dyspraxie) ou l’arithmétique (dyscalculie). Tous entraînent une lenteur et des difficultés dans les situations de double tâche. Les apprentissages, les rééducations et les remédiations modifient le cerveau de l’enfant (plasticité cérébrale) mais ne permettent cependant pas de retrouver une organisation typique, parfaitement fonctionnelle. C’est pourquoi la prise en charge devra rapidement viser à développer des adaptations et des compensations du handicap pour favoriser les apprentissages et préserver l’avenir de ces jeunes, intelligents et motivés. Enfin, il ne faut pas confondre la spécificité du trouble neurodéveloppemental et les symptômes qu’il induit. Il est donc nécessaire d’identifier les mécanismes sous-jacents aux difficultés rencontrées par l’enfant, ce qui nécessite une démarche diagnostique rigoureuse.
Les troubles moteurs des enfants porteurs de troubles du neurodéveloppement
Authors: Leroy Malherbe Véronique , Lefévère-Renard Gwenaëlle
Published: May 2020

Le trouble de développement des coordinations motrices est révélé par une maladresse gestuelle qui retentit dans la vie quotidienne et la scolarité de l’enfant. Nous abordons les hypothèses physiopathologiques basées sur la cognition du geste, le déroulement du diagnostic et les propositions de remédiations qui en découlent.
Intersubjectivité et troubles du neurodéveloppement : l’autisme est-il un trouble des « cognitions sociales » ?
Authors: Georgieff Nicolas
Published: May 2020

La clinique des anomalies des interactions relationnelles peut être définie dans le cadre général de l’intersubjectivité, et en termes neuroscientifiques dans le cadre des « cognitions sociales ». Tous les troubles dits « neurodéveloppementaux » présentent des anomalies dans cette dimension clinique, dont bien sûr tout particulièrement les troubles du spectre de l’autisme. Notre propos est ici de discuter de la pertinence et des limites du cadre des cognitions sociales pour définir cette clinique ; de mettre en question le modèle de l’autisme comme déficit ou trouble des cognitions sociales au regard de modèles alternatifs : sur-fonctionnements et/ou « autre socialisation » ; enfin de souligner la non-spécificité de ces troubles dans le champ des troubles du neurodéveloppement et donc l’intérêt de définir l’autisme – et les autres troubles – selon d’autres critères. Par ailleurs, l’accent mis sur les anomalies relationnelles ou intersubjectives dans tous ces troubles tient pour une part à un biais méthodologique : la relation interpersonnelle est en effet le principal outil de l’exploration clinique dans notre domaine.
L’expert au sein des organisations : définition et cadrage théorique
Authors: Bootz Jean-Philippe , Lièvre Pascal , Schenk Eric
Published: May 2020

Les experts constituent depuis quelques années une figure de plus en plus incontournable au sein des organisations. En particulier, l’avènement de l’économie fondée sur les connaissances a propulsé cet acteur au centre des préoccupations dans la mesure où il joue un rôle clé dans les processus d’innovation. Les processus visant le développement et la valorisation des experts tendent ainsi à se multiplier. Si les démarches menées dans ce sens sont louables, elles souffrent fréquemment d’un déficit d’analyse et de compréhension des composants fondamentaux de l’expertise. En effet la qualification d’expert est souvent en pratique associée au nombre d’années d’expériences ou envisagée uniquement en lien avec des compétences techniques, de sorte qu’une confusion généralisée apparait entre expert et expérience et entre expert et spécialiste, ce qui pose des problèmes managériaux. Dans ce cadre, notre contribution vise à proposer un modèle définitionnel de l’expert au sein des organisations. La lecture des approches de l’expert en psychologie, en knowledge management ou en sociologie nous conduit à caractériser l’expert par une dimension à la fois cognitive et sociale qui sont ici regroupées au sein d’un cadre unique. L’expert est ainsi appréhendé comme un individu qui dispose d’une compétence à analyser et résoudre des situations diverses et non triviales en s’appuyant sur une capacité à combiner et à mobiliser rapidement connaissances scientifiques et expérientielles. Il dispose, par ailleurs, d’une légitimité sociale qui repose soit sur des signaux forts (appartenance à une structure formelle institutionnelle) soit sur des signaux faibles (au sein de réseaux informels auto-organisés).
Semiparametric estimation of structural functions in nonseparable triangular models
Authors: Chernozhukov Victor , Fernández-Val Iván , Newey Whitney , Stouli Sami , Vella Francis
Published: May 2020

Triangular systems with nonadditively separable unobserved heterogeneity provide a theoretically appealing framework for the modeling of complex structural relationships. However, they are not commonly used in practice due to the need for exogenous variables with large support for identification, the curse of dimensionality in estimation, and the lack of inferential tools. This paper introduces two classes of semiparametric nonseparable triangular models that address these limitations. They are based on distribution and quantile regression modeling of the reduced form conditional distributions of the endogenous variables. We show that average, distribution, and quantile structural functions are identified in these systems through a control function approach that does not require a large support condition. We propose a computationally attractive three‐stage procedure to estimate the structural functions where the first two stages consist of quantile or distribution regressions. We provide asymptotic theory and uniform inference methods for each stage. In particular, we derive functional central limit theorems and bootstrap functional central limit theorems for the distribution regression estimators of the structural functions. These results establish the validity of the bootstrap for three‐stage estimators of structural functions, and lead to simple inference algorithms. We illustrate the implementation and applicability of all our methods with numerical simulations and an empirical application to demand analysis.
Towards a New Educational Engineering Model for Moroccan University Based on ICT
Authors: Chergui Meriyem , Tahiri Ahlam , Chakir Aziza , Mansouri Hajar
Published: May 2020

Today, Moroccan decision makers of higher education are aware of the importance of digitalization for the improvement of the educational system and their alignment with international standards. This is the reason why several priority programs have been launched in recent years: Digital Work Environment, Network Virtual Campus and digital gadgets distribution operations. Meanwhile, the pedagogical impact remains limited on the scale of the Substitution, Augmentation, Modification and Redefinition (SAMR) model of Information and Communication Technologies. The present work relates to an engineering model that aims to reach the level of maturity of successful pedagogical models and to make possible the use of digital tools not only in a quantitative way, but also on qualitative and measurable way compared to the performance indicators of Moroccan university. The aim of the article is to propose a pedagogical meta-model for Moroccan university designed from a national high education perception study. The model is implemented by IMS LD, involving digital tools and different pedagogical objects in an environment that is both educational and entrepreneurial to catch the gaps in methodologies and content. This model allows the teacher to make available to the student necessary information, methods and techniques in an easy way. The model is integrated into a digital environment, dynamic and open to the business world.
Le spectre de la dépendance aux médicaments chez les usagers. Sens et enjeux d’une notion
Authors: Fainzang Sylvie
Published: May 2020

Dans le contexte des scandales sanitaires liés aux médicaments et de la nécessité d'une pharmacovigilance, la question se pose des décisions que les individus prennent face aux prescriptions qui leur sont délivrées. Compte tenu des risques, réels ou non, associés à la prise de médicaments, les patients tendent de plus en plus à évaluer leurs prescriptions et à les aménager. Parmi ces risques figure la dépendance, dont la crainte incite souvent les usagers à refuser ou à modifier leurs prescriptions. Mais de quoi les usagers parlent-ils lorsqu’ils parlent de dépendance dans le champ médicamenteux ? On tentera ici de cerner les diverses acceptions de cette notion pour les sujets, afin d’éclairer les stratégies (modifications, réduction, sélection, adaptations) qu’ils adoptent pour limiter le risque de dépendance. On verra que, bien au-delà de la définition que lui donne la pharmacologie, c’est une relation existentielle et politique à la substance qui est redoutée, et qu’elle ne saurait être comprise sans être rapportée au développement contemporain de la notion d’autonomie.
The Influence of the Shape and Size of the Nanostructures to the Atoms and Molecules Transport
Authors: Kalashnikov Evgenii , Tolstikhin Igor , Belova Nadezhda
Published: May 2020

The discrete Frenkel-Kontorova model for the movement of a foreign atom in a solid, obtained in the local chains approximation, led to the movement of the atom in the Frenkel-Kontorova (F-K) soliton form. This model made it possible to reveal the structure of the F-K soliton, to design the shapes of nanostructures and to take into account their influence on the F-K soliton. The transition to field variables leads the Frenkel-Kontorova equation to the sine-Gordon equation for the displacement field of an atom having solutions also in the form of a soliton. This equation and its solution (soliton) contains coefficients depending on the shape and size of nanostructures. The transition to the sine-Gordon equation allowed us to use the results of Theodorakopoulos 's works related to the consideration of the interaction of elastic vibration modes with a soliton. This made it possible to calculate the diffusion coefficient of the soliton and find the dependence of the diffusion coefficient on the shape and size of nanostructures and temperature.
Effect of Solvent Concentration on Scaling Butane Solvent Enhanced Oil Recovery Processes Using Reservoir Simulation
Authors: Lorimer Shelley , Kumar Govind , Abdelkareem Sherif
Published: May 2020

Understanding scaling of enhanced oil/bitumen recovery processes is essential in moving laboratory scale experimental results to field scale. Scaling theory for thermal processes is well understood and has been applied to steam processes. However, scaling of hybrid steam (thermal) /solvent (mass transfer) processes is still not well defined nor well understood. This paper investigates the scaling behavior of hybrid steam/butane gravity drainage processes using reservoir simulation (commercial thermal compositional simulator CMG STARSTM). Previous research has used reservoir simulation to confirm scaling groups for waterflooding. A similar strategy was used in this study whereby the scaling of a hybrid (steam) solvent oil recovery process was examined using reservoir simulations at three different reservoir scales: lab scale, semi-field scale and field scale to examine the influence of the mass transfer mechanisms of diffusion and dispersion on the scalability of the process. In particular, the influence of butane solvent concentration on scaling a steam/butane gravity drainage process was investigated by considering several butane mole fraction concentrations injected with steam (1%, 2%, 5%, 7%, 10%, 15%, 21%, 25% and 50%). Temperature contours, and mole fraction contours of butane in both the oil and gas phases were examined for various solvent injection concentrations to examine scalability. Numerical results are provided with no diffusion and dispersion, diffusion only, dispersion only and with both diffusion and dispersion added to the simulations. Results confirmed scalability of the process with no capillary effects when the simulation results were non-dimensionalized, although there were some issues with material balance errors in some of the simulation results particularly at high solvent concentrations. For low injection concentrations, the contours were almost identical (indicating scalability) for the three scales for the operating condition studied. In addition, capillary effects were also studied, and similar to scaling thermal processes, the capillarity effects influenced scalability of the process under the conditions studied particularly at higher injection concentrations. Scalability using reservoir simulation was generally preserved with low injection concentrations, but unusual behavior was observed at higher injection concentrations (>5%). Oil recovery curves were non-dimensionalized to make comparisons amongst the three scales. The oil recovery curves displayed an unusual S-shaped behavior at higher injection concentrations when capillary effects were included especially for the lab and semi-field scales. In all cases when all of the mechanisms are included (diffusion, dispersion and capillary effects), Scale 1 shows a much faster recovery than Scale 3 which suggests that the lab scale might temporally overestimate the field scale recovery for this particular process scenario.
Molecular Dynamics Determination of the Lattice Thermal Conductivity of the Cubic Phase of Hafnium Dioxide
Authors: Momenzadeh Leila , Belova Irina V. , Murch Graeme E.
Published: May 2020

The wide range of industrial applications is the main reason for an increased interest in dioxides such as HfO2. In this study, classical molecular dynamic simulations were performed to calculate the lattice thermal conductivity of the cubic phase of HfO2, over a temperature range of 100-3000 K, based on the Green-Kubo fluctuation method. In this research, the heat current autocorrelation function and lattice thermal conductivity were calculated in the a-direction. The lattice thermal conductivity of the cubic phase of HfO2 was found to be a result of three contributions. These were the optical and acoustic short-range and long-range phonon modes. Comparisons between the results of the research and experimental data when available indicate good agreement. Keywords: lattice thermal conductivity, molecular dynamics, Green-Kubo formalism, heat current autocorrelation function, hafnium dioxid
Analytical Investigation on the Evolution and Growth of β-Ti and Fe-Nb-Based Intermetallics in Diffusion Coupled Joints of Ti6Al4V|Nb|SS
Authors: Thirunavukarasu Gopinath , Kundu Sukumar , Patel Vivek V. , Alankar Alankar
Published: May 2020

Herein, solid-state diffusion-coupled joints (DCJs) were prepared in vacuum between stainless steel (SS) and Ti6Al4V by means of a pure niobium (Nb) interlayer (~200-μm thickness) using uni-axial compressive pressure of 4 MPa at 875 °C for 15 to 120 min. Interfacial characterization revealed the existence of successive layer wise Fe–Nb-based intermetallics like FeNb+(Nb) and Fe2Nb at Nb|SS interfaces of DCJs processed from 60 to 120 min, but the DCJs processed for shorter duration (from 15 to 30 min) do not reveal any intermetallics; however, the DCJs processed for 45 min revealed a single reaction layer of FeNb whereas that of Ti6Al4V|Nb interfaces revealed solid solution behaviour for all bonding time intervals. Required chemical analysis (in at. pct) of the reaction products was found out using spectroscope and X-ray diffractometer. Mechanical characterization (at 32 °C) of the DCJs was carried out with a microhardness tester and tensile testing facility. Ti6Al4V|Nb interface experienced a hardness of ~298 HV (for all bonding time), whereas Nb|SS interface experienced ~200 HV for 15 and 30 min and ~650 HV for 45 min and longer. DCJs treated for 60 min have better strength properties. Manifestation of reaction layers: FeNb, FeNb+(Nb), and Fe2Nb have significant effect on the strength. From the interfacial microhardness, path and surface of fracture surfaces characterizations, it was revealed that failure of the DCJs was transmitted seemingly along Nb|SS interfaces. The analytical finding of intrinsic diffusivity of Ti atoms in Nb along Ti6Al4V|Nb interface is higher by one order of magnitude than the diffusivity results of Fe atoms in Nb along the Nb|SS interface. Experimental evidences show that the growth of the reaction products along Ti6Al4V|Nb interface (adj. R-Square=0.982) and Nb|SS interface (adj. R-Square=0.999) follows a parabolic law. Recently, researchers considered diffusion coupling as the key technology to fabricate Ti|Al|Al-Cf biomimetic structure, graphite|Nb|Cu for fusion reactor devices, Ni|Ni3Al for MEMS applications, hybrid heat exchangers for nuclear applications, etc.
Interdiffusion Studies in the Co-Sb System
Authors: Armugam Amudha , Raju Ravi , Baheti Varun
Published: May 2020

CoSb based compounds have gained much importance in the fields of thermoelectric devices. In this work, we have conducted the solid–state conventional bulk diffusion couple experiments. To study the phase evolutions, Co/Sb diffusion couples are annealed at 450–550 °C. The interdiffusion zone is analysed using field emission gun equipped scanning electron microscope and the composition measurements are done in electron probe micro−analyser to confirm the growth of various product phases. The marker experiment indicates that the CoSb3 phase grows mainly by diffusion of Sb in the binary Co–Sb system. Growth of the CoSb3 phase is discussed based on assessment correlating the difference in mobilities of species with the high homologous temperature, crystal structure of the phase, and the concept of sublattice diffusion mechanism in line compounds.
Resin Injection Process in the Manufacture of a Polymer Composite Reinforced with NiTi Ribbons: A CFD Analysis
Authors: de Araújo Mota Carlos Antonio , Porto T.R. Nascimento , de Lima Antonio Gilson Barbosa , Figueirôa Juliana Andreza , Araújo de Almeida Michelly Dayane , Vieira Neto João de Mélo , Costa de Souza Loredanna Melyssa
Published: May 2020

This work aims to numerically simulating the resin injection manufacturing process of a polymer composite,reinforced with ribbons of NiTishape memory alloy, using the software Ansys CFX®. The multiphase flow mathematical modeling was used to describe the transient and isothermal resin-air flow during the process. Results of the pressure fields, velocity andvolume fractionsof the involved phases are presented. The fluid flow inside the mold was compared withthe flow between parallel flat plates and showed to be consistent. Process parameters, such as resin volumetric flow rate, resin inlet and air outlet positions have a large influence in the mold filling time, volume and position of voids fractions inside de mold and final product quality.
Development of a TAPE-Agar Liquid Gel Bandage
Authors: Bautista Roela Feliz M. , Tam Marin Rosette H. , Wong Kevin Adrian D. , Tumolva Terence
Published: May 2020

In this study, a liquid gel bandage for wound treatment was synthesized using a combination of tannic acid and polyethylene glycol (TAPE). Agar was added as a stabilizer based on the physical properties of the formed product. Ethanol was chosen as solvent based on the resulting drying rate and mixing consistency. The liquid bandage was characterized in terms of its drying, adhesion, and swelling. Also, its antimicrobial and cytotoxic properties were evaluated. The final formulation had a drying time of 5 minutes, a T-peel adhesion yield point of 591.6 Pa, and a swelling ratio of 64%. The gel was also observed to be anti-microbial towards both S. aureus and E. coli, as well as exhibiting cytotoxic effects. Overall, the gel proved to have comparable properties to previously studied liquid bandages yet can be produced at a significantly lower cost.
Optimization of Methylene Blue Adsorption via Functionalized Activated Carbon Using Response Surface Methodology with Central Composite Design
Authors: Saafie Nabilah , Samsudin Muhamad Fakhrul Ridhwan , Sufian Suriati
Published: May 2020

The commercial activated carbon (AC) with enhanced adsorption performance capacity was studied via green functionalization. The adsorption of methylene blue (MB) from aqueous solution by deionized‑water functionalized activated carbon (DFAC) was investigated in a laboratory‑scale batch mode. The interaction effects of different operating parameters; adsorbent dosage (1‑5 g/L), pH (2-12) and agitation speed (100‑200 rpm) were studied. The ANOVA results suggested the quadratic model and the analyzed model were well fitted. The higher correlation coefficient, R2 value of 0.93 and low p-value (0.0002) indicating the fitness of the response surface quadratic model developed. The optimum conditions were found to be the adsorbent dosage of 4.7 g/L, pH of 12 and agitation speed of 150 rpm, in which 99.74% of MB removal was achieved. Additionally, the confirmatory experiment was conducted to evaluate the accuracy of the optimized conditions in which the range of deviation is was 4.07%.
Effect of Substrate Temperature on the Electronic Properties of MgO Thin Films on Si (100) Grown by Electron Beam Evaporation
Authors: Denny Yus Rama , Firmansyah Teguh , Gustiono Vaka , Lee Sang Su
Published: May 2020

The surface characterization of MgO thin films was investigated by using surface analysis instruments such as X-ray photoelectron spectroscopy (XPS), reflection electron energy loss spectroscopy (REELS) and ultra-violet photoelectron spectroscopy (UPS). The MgO thin films was prepared on Si substrates by using electron beam evaporation deposited at room temperature (RT) and 300 °C in air. The XPS was used to investigate the effect substrate temperature on the chemical state in the thin films surface. The O1s spectra was showed that the hydrate MgO, Mg(OH)2, was detected in the surface of film at RT and it was decreasing at substrate temperature of 300 °C in air. The band gap obtained for MgO thin films using primary energy of 1500 eV were 6.57 and 7.41 eV for film deposited at RT and 300 °C in air, respectively. The work function of MgO thin films were 4.16 and 4.60 eV for films deposited at RT and 300 °C in air, respectively. Our results suggested that the electronic properties can be improved by the heating treatment during deposition.
Analysis of Physical and Mechanical Properties of Backhoe’s Bucket Repairment with Cladding Methode
Authors: Purwaningrum Yustiasih , Hafiz Muhammad , Suparyanto Risky
Published: May 2020

Buckets are the most important component in backhoe construction, the bucket functions as a digger and carrier component in an excavator. Due to the heavy working media of the excavator so that this component is the most easily damaged part, damage that often occurs is wear caused by friction arising so that the thickness of the bucket is reduced which can eventually cause cracks in the bucket and in continuous use can cause the bucket to crack and broken. Cladding method is done to shorten the time or simplify the repair process is to directly patch the damaged part with a welding layer and then do the grading using a grinding. This study aims to determine the physical and mechanical properties of the material from the cladding process when compared with the raw material, the variations used are raw material, cladding with filler welding, and cladding with plates. The welding process is carried out with GMAW (Gas Metal Arc Welding) and low carbon steel. Welding results will be tested tensile strength, bending strength , impact test, hardness test, chemical composition, and corrosion rate. From the hardness test results showed that the weld metal from plate variation has the highest hardness value of 443 VHN. From the results of tensile testing the basic material has the highest value with 359.08 MPa. From the bending test results the highest value obtained from filler verification with 494.01 Mpa and the highest impact price obtained from the plate variation cladding method with a value of 1.49 J / mm2
Fatigue and Fracture Mechanism of Aluminum-Carbon Fiber Reinforced Hybrid Composites
Authors: Rahman S.M. Moshiar , Ferdous Md. Shafiul
Published: May 2020

The fatigue limit and fracture behavior of epoxy carbon fiber reinforced composites and hybrid composites were investigated. An aluminum foil and thin aluminum plate were incorporated with the carbon fiber to make the hybrid reinforced composites. Several specimens were prepared, and a series of tests were carried out to investigate the fatigue life and fracture behavior. Then the results were compared among epoxy carbon fiber reinforced composites and the hybrid composites. It is discussed whether the S–N curves shows almost the similar characteristics of these two types of hybrid composites or not. As far as the present result, the stress ratio and the type of hybrid composites effect on the fatigue life. The interfacial bonding plays an important role in the strength and fracture behavior of notched specimen of the fabricated composites.
The Effect of Calcination Temperature on Metakaolin Characteristic Synthesized from Badau Belitung Kaolin
Authors: Ulfiati Ratu , Dhaneswara Donanta , Jaka Fajar Fatriansyah , Harjanto Sri
Published: May 2020

The effect of Metakaolinization on the thermal and physicochemical properties of Badau Belitung kaolin is presented. Calcination of Badau Belitung kaolin indicated that kaolin was transformed to metakaolin at temperature above 500°C. The metakaolin was characterized using X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) and Brunauer-Emmett-Teller (BET). The XRD diffraction pattern of the metakaolin was highly amorphous as a result of calcination effect on the raw kaolin. The FTIR spectra of the metakaolin produced showed that the material was thermally stable at temperature range of 500–700°C, whereas the specific surface area values of the raw kaolin and the metakaolin formed were increased with increasing calcination temperature from 500°C to 700°C.
A New Technology to Prevent the Formation of Limescale in Hot Water Supply Systems
Authors: Jalilov Mardan , Jalilova Ayten , Feyziyeva Gulnar , Azimova Makhanim
Published: May 2020

Given that the quality of water supplied to hot water supply systems must meet drinking water requirements, it is also important that the water preparation process is of great importance. The quality of that water is also important in terms of preventing the formation of heat in hot water systems. It is known that the main cause of the formation of water is the presence of calcium and magnesium cations and bicarbonate and sulfate anions in water. The traditional methods for preventing the limescale include the combination of calcium and magnesium cations from the water and replacing them with cations that are not easy to resolve at high temperatures. The quality of water treated by these methods does not meet drinking water requirements. Taking these into account, the Cl-anionizationprocess of drinking water has been developed in high-tech anionite technology. According to this technology, the first water from the city water gridis processed through anionite and activated carbon filters, which are mechanically charged with high anionite. The treated water is then cleaned out of microbes and bacteria through the ultraviolet disinfection equipment and delivered to the operator according to the quality requirements for drinking water. In the chlorine-anionization process, most of the sulfate and bicarbonate anions in water change to chlorine anions and their solidity remains constant. Thus, the density of the limescale-forming anions in the water decreases sharply and it meets the quality indicators of drinking water. High-grade anionite in the filter (8÷12) is regenerated by NaCl solution. The filtration rate of the solution from the anionite is determined depending on the concentration of calcium cations contained in the salt given for regeneration. Regeneration mode is such that the CaCO3 combination does not crumble when the anionite layer is formed. It is known that the temperature of the heated water in the hot water supply system does not exceed (60÷70)°C. In this case, the decomposition of limescale at Hc<2 mg-eq/l (carbonate hardness) is not observed. As carbonate hardness increases to 4 mg/l, the thin layer in the system shows a collapse. The basic element of the proposed technological schemeCl-anionite filter was applied at ADA University in Baku and positive results were obtained. Early observed collapse of pipes has been prevented and the working regime of hot water heaters has improved. A high-performance anionite such as A200EMBCl, which is a major ingredient of the UK's Purelite, and then the Russian-made AB-17-8 high-anionite anions have been used on the device.
Prediction of the Fatigue Life of the SAE 5160 Carbon Steel Coil Spring Based on Strain-Life Approach
Authors: Putra Teuku Edisah , Husaini Husaini , Prakasa Hary
Published: May 2020

This study aims to identify the effect of road surface to coil spring fatigue life using the strain-life approach. Strain signals were measured by attaching a strain gauge at the critical point of the component. The car was driven on a flat road, as well as uphill, and downhill paths. The results show that the downhill road provided the lowest fatigue life, of 1.5E+4 cycles to failure, which was 53 % lower than that of the uphill and 2,233 % lower than the flat road owing to the braking factor which resulted in a higher stress to the coil spring.
Development of a CuFe2O4 - Reduced Graphene Oxide-Based Electrochemical Sensor for Malathion
Authors: Battad Georgette Anne T. , Estacio Jericho G. , Indiongco Junel Lawrence C. , Mopon Jr. Marlon L.
Published: May 2020

A portable non-enzymatic electrochemical sensor for malathion detection based on CuFe2O4 and reduced graphene oxide nanocomposites was developed. CuFe2O4-rGO nanocomposites were synthesized using a facile one-pot co-precipitation method. X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy confirmed successful synthesis of the nanocomposites. Square wave voltammetry was performed using a portable potentiostat (CheapStat) and a three-electrode setup in order to determine the electrochemical behavior of the nanocomposite and its interaction with malathion. Maximum inhibition was observed at conditions corresponding to 15% rGO loading, pH 4 buffer solution, and five-minute accumulation time. Calibration of the sensor established a linear detection range of 0.5-8 ppm and a detection limit of 0.992 ± 0.007 ppm. Altogether, the performance parameters indicate good selectivity and potential applicability of the system for malathion monitoring particularly in agricultural products.
Numerical Simulation of Material Plastic Deformation Using the Drawing Forming Process of Contoured Internal Surface Tubes
Authors: Necpal Martin , Hodúlová Erika , Martinkovič Maroš
Published: May 2020

Production of multi-rifled seamless steel tubes employing cold draw process using multi-rifled mandrel is quite a modern technology. The important characteristic of the tube drawing process, unlike the tube with internal rifling, is the corner filling which influences the dimension accuracy of the internal shape of the tube. In this study, the influence of drawing tool dimensions and mandrel shape on to final rifling filling was investigated. Draw process has been simulated by using the three-dimensional rigid-plastic finite element method (FEM) by using DEFORM 3D software. The results of numerical simulation show that the shape of drawing tools and process conditions have a significant influence on the forming process and final shape and properties of the workpiece.
Study on Morphology Features and Mechanical Properties of Nanofibers Films Prepared by Different Composite Electrospinning Methods
Authors: He Chao , Wang Han , Huang Li Xiong , Wang Ping , Gao Wei
Published: May 2020

Electrospinning is an important method for preparing nanofibers, which are highly promising for applications in a wide range of fields such as purification/filtration, photoelectric devices, battery separators, catalysis and tissue engineering. These applications often use composite materials and have specific requirements for mechanical properties. Therefore, how to get nanofibers films with ideal mechanical properties by changing the composite mode is an important process problem for the given two or more materials. Based on the far-field electrospinning, this study selected polyacrylonitrile (PAN) and thermoplastic polyurethane (TPU) to explore the differences of three composite methods: mixed spinning, multi-nozzle simultaneous spinning and superposition spinning. Three kinds of analysis can be seen in this study, which include morphology features, thickness measurement and mechanical properties of samples. Multi-nozzle simultaneous spinning has very limited changes. Mixed spinning and superposition spinning are beneficial to the improvement of nanofibers films morphology and mechanical properties. Among them, the composite films through superposition spinning are thinner.
Meteorological Tidal Predictions in the Mekong Estuary Using an Evolved ANN Time Series
Authors: Chen Tim , Chen C.Y.J.
Published: May 2020

Retraction NoticeThe Marine Technology Society Journal was contacted in April 2022 pointing to major concerns, including forged
affiliations, related to this publication. The claimant noted the unethical practice of these two authors has been reported
in relation to 60+ articles published in more than one dozen other journals. Recently, these authors plausibly changed
their forenames/first names to repeat similar misconducts.
In the paper 'Meteorological Tidal Predictions in the Mekong Estuary Using an Evolved ANN Time Series' (doi:
10.4031/mtsj.53.6.3), the affiliation of the author CYJ Chen to NAAM Research Group, King Abdulaziz University
Saudi Arabia, is false. This university did not employ CYJ Chen between 2018 and 2021.
Spectra Adaptive Correction Based on the Empirical Mode Decomposition and Thresholding Algorithms: Application to the Ocean Turbulence Time Series
Authors: Liu Xiuyan , Luan Xin , Yang Hua , Song Dalei , Wu Qu , Zhou Zewei
Published: May 2020

AbstractMeasurements and observations of turbulence in the open sea have contributed significantly to improving our understanding of ocean mixing processes. However, the measured microstructure shear time series are strongly nonstationary and easily contaminated by various
types of noise. Extended observation data sets with higher accuracy are needed to resolve significant issues in ocean circulation systems. In this article, an adaptive and multiscale correction algorithm is developed to eliminate vortex-induced vibration contamination from the calculated turbulent
kinetic energy. First, an adaptive empirical mode decomposition method is implemented to decompose three-axis vibration accelerations into a series of oscillatory intrinsic mode functions (IMFs) and a residual mode. Then, a statistical noise model is developed from the energy density distribution
function of the extracted IMF components. The key modes that are noise dominated are minimized, and the remaining shear IMFs are used to reconstruct the true signals. Finally, a technique is developed to automatically set a threshold for severe vortex-induced turbulent conditions. The developed
method is verified using a turbulence data set recorded in the South China Sea, and the results show that this adaptive noise correction algorithm is fairly effective in removing vortex-induced vibration noise in comparison with the classical cross-spectrum method.
Effects on the Various Aluminum Foam Fenders of a Tripod Offshore Wind Turbine Collision Due to a Ship
Authors: Han Zhiwei , Zhao Xinlei , Li Chun , Ding Qinwei
Published: May 2020

AbstractThe interest in offshore wind energy is growing all over the world. Increasingly, offshore wind turbines (OWTs) are being installed close to shipping lanes, which puts them at risk of potential collisions with ships during their service period. This article aims to
investigate the structural dynamic response of OWTs to a ship collision. Considering the structure size of the fender as well as the nonlinear characteristics of the structural materials, a finite element model of a 5,000-ton ship colliding with a 4-MW tripod OWT has been developed using the
explicit finite element code LS-DYNA. By observing the collision energy conversion, contact force, fender performance, Von Mises stress on the tripod, shear stress, and dynamic response of a nacelle in differently sized fender collision scenarios, it was observed that when the thickness of
the fender surpasses 1.1 m, it can protect the OWT from a collision more effectively than with no fender case. Otherwise, the local contact force is cushioned by aluminum foam materials, whose contact force leads to a whole movement of the bearing tripod. The tripod with the aforementioned
1.1-m fender generates a contact force, Von Mises stress, and a shear stress, as well as the anticollision characteristics of a fender and the dynamic responses of a nacelle in 15 scenarios. Therefore, the structural design of the fender is essential in the safety of a tripod foundation in
a collision. This article will provide a better understanding of the collision characteristics of the fender in the future.
Time-Domain Flooding Simulation of a Damaged Warship
Authors: Hu Li-fen , Wu Hao , Gong Qingtao , Wang Xiangyang , Lv Wenbin
Published: May 2020

AbstractUnderstanding of the complex dynamic behavior of damaged ships and floodwater remains limited for ship designers and safety authorities. In this work, a Navier-Stokes (NS) solver that combines the volume of fluid (VOF) method with overset mesh techniques is developed
to simulate the flooding process of a damaged ship. The VOF method captures the fluid interface, and the turbulence effect on flows is considered with the k-ω model. The overset mesh techniques are employed to handle the mesh update following transient ship motions. Then,
the results of a damaged barge with dynamic and overset mesh are compared with the experimental data. On the basis of this validation, the solver is applied to the flooding problems of a damaged warship. This research is intended to be a useful step toward the establishment of a stability
criterion for damaged ships in the future.
LA CONVERSIONE DI ENERGIA SOLARE IN ENERGIA CHIMICA
Authors: Selli Elena
Published: May 2020

Energy is the most important issue of the 21st century. Due to severe environmental problems, mainly related to air pollution of urban areas and green house effects leading to global warming, fossil fuels need to be replaced by renewable energy sources. Beside the wind energy, which is progressively more and more exploited, solar energy represents a clean, abundant, diffuse and economical energy which can be converted into heat, electricity or in the form of so called solar fuels, provided special materials are developed able to efficiently absorb solar light and produce charge separation. This is the prerequisite for obtaining electricity from sunlight and solar fuels, e.g. hydrogen from water photosplitting or carbon containing species from carbon dioxide photoinduced reduction, which can be stored and used on need. Converting solar energy into chemical energy is thus a big challenge for chemistry.
Analysis of microfractures in Lower Cretaceous and Upper Jurassic sandstones of the Scotian Basin, offshore Nova Scotia
Authors: Pe-Piper G , Sangster C , Piper D J W
Published: May 2020

Microfractures have been investigated in potential reservoir sandstones in four wells from the eastern Scotian Basin. Samples were selected from within the overpressured zone in Venture B-52, just above overpressure in Venture 1, in an intensely silica-cemented
interval in South Griffin J-13 and from a deeply buried sandstone lacking overpressure in a dry well, Peskowesk A-99. Backscattered electron (BSE) and cathodoluminescent (CL) images were acquired from polished thin sections. Microfractures (<100 micrometres wide) were classified as
intragranular, intergranular, transgranular, intra-cement and hydro-fractures. The size and orientation of different microfractures were measured and their relationship to diagenetic paragenesis was assessed. Most microfractures are either bedding-parallel or at 45° to bedding. Generation 1
fractures probably result from eodiagenetic compaction; Generation 2 fractures are synchronous with mesodiagenesis; and Generation 3 fractures are open. This Open File presents the SEM data, measurements of size and orientation by fracture type, and a preliminary interpretation of the fracture
data.
série histórica da incidência de Sífilis na gestante no Pará entre os períodos de 2013 a 2018
Authors: Nunes Jéssica Patrícia Gonçalves , Barbosa Vanessa Vilhena
Published: May 2020

Objetivo: Demonstrar a incidência da sífilis gestacional no período de 2013 a 2018 no Estado do Pará e descrever o perfil epidemiológico das gestantes analisadas. Método: Trata-se de um estudo epidemiológico descritivo do tipo série histórica, utilizando-se o banco de dados SINAN e DCCI. Resultados: Foram notificados 8.775 casos de sífilis gestacional entre 2013 e 2018, com taxa de detecção a cada 1.000 nascidos vivos crescente ao longo desse período. A maioria das mulheres (46,3%) recebeu diagnóstico durante o 3º trimestre de gestação. Quanto à classificação clínica, prevaleceu a sífilis primária com 46,7% dos casos. A faixa etária mais incidente foi a de 20 a 29 anos de idade (52,2%) e as gestantes classificadas como da cor parda foram as mais afetadas (82,9%). A incidência de sífilis gestacional foi maior em mulheres com escolaridade entre 5ª e 8º série do Ensino Fundamental, enquanto gestantes com Ensino Superior Completo e Incompleto apresentaram poucos casos (0,9% e 1,1%, respectivamente). Conclusão: Percebe-se que a Sífilis Gestacional ainda é um problema com incidência alta e crescente no Estado do Pará. Deve-se investir em uma assistência pré-natal de qualidade, com uma busca precoce da gestante, com ações de promoção da saúde, orientação sexual e reprodutiva e realização de exames preconizados pelo Ministério da Saúde.