bluuebunny/crossref_metadata_2025 huggingface dataset:
Gold Nanoparticles from Plant Materials: Green Extraction, Biological Synthesis and Its Beneficials Properties for Cosmeceutical Applications
Authors: Siti Nur Khairunisa binti Mohd Amir  , Mariam Firdhaus binti Mad Nordin  , Kamyar Shameli  , Mariani Abdul Hamid
Published: May 2021

Green technologies have become trends among researchers and it is developing as the current demand is increased towards products that are processed through green technologies. In this regard, green extraction and green synthesis of gold nanoparticles (GNPs) from plants are presented and discussed. Rapid development in green extraction makes the researchers are competing in providing the best extraction techniques which will use safe extracting solvent, low energy consumption, and did not release hazardous materials as residues of the processes. The same thing goes for the green synthesis of GNPs, plant extracts are used as reducing agent and it does not release any hazardous residues as compared to chemical synthesized GNPs. The application of the GNPs in this paper is reviewed on their properties that are beneficial for cosmeceutical applications. Even though the application of GNPs in the cosmeceutical application in research papers is relatively unexplored, but it has a high potential to be studied since there is existing research that recognizes the properties played by GNPs. The properties that are mostly studied by researchers are an antioxidant, anti-inflammatory, and antibacterial activity that is found to be advantageous in the production of cosmeceutical products.
Green synthesis of Sodium alginate mediated Fluorapatite Nanoparticle via Sol-Gel method
Authors: Pooneh Kia  , Mansor Bin Ahmad  , Kamyar Shameli
Published: May 2021

Fluorapatite (FA) can be used as a bioactive substance in the body, especially the teeth implants. The FA nanoparticle was synthesized by adding the fluorine to the structure of HA using sol–gel method and the heat treatment of 700 °C. Being low costs, eco-friendly and safer features are obvious advantages of the green synthesis of FA nanoparticles by using bio stabilizer of sodium alginate. Calcium nitrate tetrahydrate, diammonium phosphate, ammonium fluoride were used as precursors of Ca, P and F respectively with the ratio of 1:67 Ca/P. The presence of crystal structure of HA and FA investigated by the results of XRD which confirmed the substitution of hydroxyl groups with the fluorine in the crystal structure of apatite. FTIR obtained that fluorine was substituted by hydroxyl groups in the structure of fluoridated hydroxyapatite by disappearing the hydroxyl groups at 3600 cm-1 in the FA. TGA investigated the thermal stability of the nanoparticles that showed the discrepancy of weight loss for HA and FA between 600?C to 800?C. By using TEM, average sizes of 35 and 49 nm were determined for HA and FA respectively. FESEM results confirmed the shapes and distribution of particles of HA and FA in that, round like for the former and rode like for the later. The overall performance of utilizing sodium alginate (SA) as a bio-stabilizer is to obtain better precipitate which leads to having better crystallinity and smaller particle size and thermal stability remarkably improved.
Synthesis of Ag/ZnO Photocatalysts for the Photodegradation of Methyl Orange Dye
Authors: Abdul Halim Abdullah  , Elisa Rasouli  , Ernee Noryana Muhamad  , Pooneh Kia
Published: May 2021

ZnO and a series of Ag/ZnO photocatalysts were prepared by a precipitation- irradiation method and their photocatalytic performance in photodegradation of methyl orange dye was evaluated. The physicochemical properties of the catalysts were characterized by various characterization techniques. The photocatalysts have a hexagonal phase and were highly agglomerated. TEM images showed a change in morphology of ZnO from rod to nearly spherical with the addition of Ag. Ag/ZnO catalysts exhibited better photocatalytic activity in the degradation of methyl orange compared to pure ZnO. Ag/ZnO contains 2% silver shows the best performance as photocatalyst.
Eficiência da justiça criminal: avaliação dinâmica em um estudo de caso
Authors: Simonassi Andrei Gomes , Oliveira Denise Xavier Araújo de , Arraes Ronaldo de Albuquerque e
Published: May 2021

O artigo tem como foco central uma das principais causas que contribuem para a manutenção ou incremento de crimes de homicídios dolosos consumados: a impunidade. Este fato motivou a condução de uma análise dinâmica ao longo dos processos judiciais. Foram utilizados dados para os casos de homicídios dolosos ocorridos em 2014 na cidade de Fortaleza, e a sua apuração temporal foi acompanhada de forma a viabilizar a verificação da representatividade da parcela desses crimes aos quais não houve imposição da pena prevista em lei. Com aplicação de técnicas de análise de sobrevivência às fases do processo de investigação, sobressai-se o fato de que o maior entrave à apuração de crimes emerge na fase de investigação policial, além da comprovação de apenas 1% de crimes ter sido julgado de um total de 1.896 cometidos. Somados os demais resultados do estudo, conclui-se que há necessidade premente de elaboração de novas metodologias de trabalho, no sentido de efetivar, dentro dos limites legais, a captura do autor do crime ainda em situação de flagrante delito.
CHANGES IN MANAGING PROJECTS DUE TO COVID-19 IN THE CZECH REPUBLIC
Authors: SMOLÍKOVÁ Lenka
Published: May 2021

Purpose – this paper investigates the changes in managing and leading the projects due to COVID-19 in the
Czech Republic.
Research methodology – a literature review, qualitative analysis based on conducted interviews with project managers in
the Czech Republic. The main research objective is to obtain best practices and lessons learned from project managers
in the IT sector.
Findings – the findings are based on interviews with project managers and reflect the reality in the Czech Republic
in the field of project management. It describes what the project teams and project managers had to face during the
pandemic. Findings are derived from the research and presented at the end of the paper.
Research limitations – the limitation of this paper is related to the research location, which was in the Czech Republic.
The author suggests to extend the sample of data and include other countries in future investigations.
Practical implications – findings provide recommendations for successful project management in the future projects.
Originality and value – can be found in the recommendations for companies and lessons learned that can be used in
managing new projects.
The RR Lyrae Delay-time Distribution: A Novel Perspective on Models of Old Stellar Populations
Authors: Sarbadhicary Sumit K. , Heiger Mairead , Badenes Carles , Mateu Cecilia , Newman Jeffrey A. , Ciardullo Robin , Hallakoun Na’ama , Maoz Dan , Chomiuk Laura
Published: May 2021

The delay-time distribution (DTD) is the occurrence rate of a class of objects as a function of time after a hypothetical burst of star formation. DTDs are mainly used as a statistical test of stellar evolution scenarios for supernova progenitors, but they can be applied to many other classes of astronomical objects. We calculate the first DTD for RR Lyrae variables using 29,810 RR Lyrae from the OGLE-IV survey and a map of the stellar age distribution (SAD) in the Large Magellanic Cloud (LMC). We find that ∼46% of the OGLE-IV RR Lyrae are associated with delay times greater than 8 Gyr (main-sequence progenitor masses less than 1 M
⊙), and consistent with existing constraints on their ages, but surprisingly about 51% of RR Lyrae appear to have delay times of 1.2–8 Gyr (main-sequence masses between 1 and 2 M
⊙ at LMC metallicity). This intermediate-age signal also persists outside the Bar region, where crowding is less of a concern, and we verified that without this signal the spatial distribution of the OGLE-IV RR Lyrae is inconsistent with the SAD map of the LMC. Since an intermediate-age RR Lyrae channel is in tension with the lack of RR Lyrae in intermediate-age clusters (noting issues with small-number statistics), and noting the age–metallicity constraints on LMC stars, our DTD result possibly indicates that systematic uncertainties may still exist in SAD measurements of old stellar populations, perhaps stemming from the construction methodology or the stellar evolution models used. We describe tests to further investigate this issue.
The Photometric Metallicity and Carbon Distributions of the Milky Way’s Halo and Solar Neighborhood from S-PLUS Observations of SDSS Stripe 82
Authors: Whitten Devin D. , Placco Vinicius M. , Beers Timothy C. , An Deokkeun , Lee Young Sun , Almeida-Fernandes Felipe , Herpich Fábio R. , Daflon Simone , Barbosa Carlos E. , Perottoni Hélio D. , Rossi Silvia , Tissera Patricia B. , Yoon Jinmi , Youakim Kris , Schoenell William , Ribeiro Tiago , Kanaan Antonio
Published: May 2021

We report photometric estimates of effective temperature, T
eff, metallicity, [Fe/H], carbonicity, [C/Fe], and absolute carbon abundances, A(C), for over 700,000 stars from the Southern Photometric Local Universe Survey (S-PLUS) Data Release 2, covering a substantial fraction of the equatorial Sloan Digital Sky Survey Stripe 82. We present an analysis for two stellar populations: (1) halo main-sequence turnoff stars and (2) K-dwarf stars of mass 0.58 < M/M
⊙ < 0.75 in the Solar Neighborhood. Application of the Stellar Photometric Index Network Explorer (SPHINX) to the mixed-bandwidth (narrow- plus wide-band) filter photometry from S-PLUS produces robust estimates of the metallicities and carbon abundances in stellar atmospheres over a wide range of temperatures, 4250 < T
eff(K) < 7000. The use of multiple narrow-band S-PLUS filters enables SPHINX to achieve substantially lower levels of “catastrophic failures” (i.e., large offsets in metallicity estimates relative to spectroscopic determinations) than previous efforts using a single metallicity-sensitive narrow-band filter. We constrain the exponential slope of the Milky Way’s K-dwarf halo metallicity distribution function (MDF), λ
10,[Fe/H] = 0.85 ± 0.21, over the metallicity range −2.5 < [Fe/H] < −1.0; the MDF of our local-volume K-dwarf sample is well-represented by a gamma distribution with parameters α = 2.8 and β = 4.2. S-PLUS photometry obtains absolute carbon abundances with a precision of ∼0.35 dex for stars with T
eff < 6500 K. We identify 364 candidate carbon-enhanced metal-poor stars, obtain assignments of these stars into the Yoon–Beers morphological groups in the A(C)-[Fe/H] space, and we derive the CEMP frequencies.
Measuring Stellar Masses of Emission-line Galaxies at 1.2 < z < 1.9
Authors: Nagaraj Gautam , Ciardullo Robin , Lawson Alex , Bowman William P. , Zeimann Greg , Yang Guang , Gronwall Caryl
Published: May 2021

The accurate measurement of stellar masses over a wide range of galaxy properties is essential for better constraining models of galaxy evolution. Emission-line galaxies (ELGs) tend to have better redshift estimates than continuum-selected objects, and have been shown to span a large range of physical properties, including stellar mass. Using data from the 3D-HST Treasury program, in this work, we construct a carefully vetted sample of 4350 ELGs at redshifts of 1.16 < z < 1.90. We combine the 3D-HST emission-line fluxes with far-UV through near-IR photometry, and use the MCSED spectral energy distribution fitting code to constrain the galaxies’ physical parameters, such as their star-formation rate and stellar masses. Our sample is consistent with the z ∼ 2 mass–metallicity relation. More importantly, we show that there is a simple, but tight correlation between stellar mass and absolute magnitude in a near-IR filter, which should prove particularly useful in terms of the rapid calculation of accurate stellar masses for millions of galaxies in upcoming missions such as Euclid, and the Nancy Grace Roman Space Telescope.
Metallicity of Galactic RR Lyrae from Optical and Infrared Light Curves. I. Period–Fourier–Metallicity Relations for Fundamental-mode RR Lyrae
Authors: Mullen Joseph P. , Marengo Massimo , Martínez-Vázquez Clara E. , Neeley Jillian R. , Bono Giuseppe , Dall’Ora Massimo , Chaboyer Brian , Thévenin Frédéric , Braga Vittorio F. , Crestani Juliana , Fabrizio Michele , Fiorentino Giuliana , Gilligan Christina K. , Monelli Matteo , Stetson Peter B.
Published: May 2021

We present newly calibrated period–ϕ
31–[Fe/H] relations for fundamental-mode RR Lyrae stars in the optical and, for the first time, mid-infrared. This work’s calibration data set provides the largest and most comprehensive span of parameter space to date, with homogeneous metallicities from −3 ≲ [Fe/H] ≲ 0.4 and accurate Fourier parameters derived from 1980 ASAS-SN (V band) and 1083 WISE (NEOWISE extension, W1 and W2 bands) RR Lyrae stars with well-sampled light curves. We compare our optical period–ϕ
31–[Fe/H] relation with those available in the literature and demonstrate that our relation minimizes systematic trends in the lower and higher metallicity range. Moreover, a direct comparison shows that our optical photometric metallicities are consistent with both those from high-resolution spectroscopy and globular clusters, supporting the good performance of our relation. We found an intrinsic scatter in the photometric metallicities (0.41 dex in the V band and 0.50 dex in the infrared) by utilizing large calibration data sets covering a broad metallicity range. This scatter becomes smaller when optical and infrared bands are used together (0.37 dex). Overall, the relations derived in this work have many potential applications, including large-area photometric surveys with James Webb Space Telescope in the infrared and LSST in the optical.
Undetected Binary Stars Cause an Observed Mass-dependent Age Gradient in Upper Scorpius
Authors: Sullivan Kendall , Kraus Adam L.
Published: May 2021

Young stellar associations represent a key site for the study of star formation, but to accurately compare observations to models of stellar evolution, the age of an association must be determined. The Upper Scorpius region is the youngest section of the Scorpius–Centaurus OB association, which is the largest collection of nearby, young, low-mass stars. The true age of Upper Scorpius is not clear, and an observed mass-dependent age gradient in Upper Scorpius, as well as in other star-forming regions, complicates age measurements. The age gradient may indicate a genuine astrophysical feature or may be an artifact of unrecognized systematic effects in stellar age measurements. We have conducted a synthetic red-optical low-resolution spectroscopic survey of a simulated analog to the Upper Scorpius star-forming region to investigate the effects of unresolved binary stars (which have mass-dependent demographics) on age measurements of a stellar population. We found that the observed mass-dependent age gradient in Upper Scorpius can be explained by a population of undetected binary stars. For a simulated population with an age of 10 (rms = 2) Myr, we measured an age of 10.5 (rms = 3.5) Myr for F stars and of 7.5 (rms = 5.8) Myr for M stars. This discrepancy is caused by the mass-dependent mass ratio distribution and the variable steepness of the mass–luminosity relation. Our results support the previously suggested 10 Myr age for Upper Scorpius, with a small intrinsic age spread.
Stability of Atmospheric Redox States of Early Mars Inferred from Time Response of the Regulation of H and O Losses
Authors: Koyama Shungo , Terada Naoki , Nakagawa Hiromu , Kuroda Takeshi , Sekine Yasuhito
Published: May 2021

The ratio of total losses of H and O from the atmosphere is crucial for determining the Martian atmospheric redox state. The H and O escapes are shown to be regulated in a stoichiometric 2:1 ratio in a converged model of present-day Mars over a timescale of ∼105 yr, which is called self-regulation. Self-regulation timescales under different atmospheric conditions on early Mars are not well understood. Here we use a 1D photochemical model to calculate the timescales of self-regulation for denser CO2 atmospheres with various surface temperatures as benchmark cases for early Mars. Self-regulation is driven by variations in the amount of O2 or CO in the atmosphere, depending on the atmospheric redox state. Self-regulation timescales are likely to be controlled by the net redox balance. A 1 bar CO2 atmosphere with a surface temperature of 240 K has a self-regulation timescale of a few million years. Denser atmospheres of early Mars have a longer regulation timescale and are less redox-stable than the atmosphere of present-day Mars. Obliquity variations cause atmospheric CO2 fluctuations, producing a difference in the self-regulation timescale between high and low obliquity. Because an increase in CO2 suppresses H escape, the net effect of the obliquity cycle could have driven the atmospheric redox states to be more reducing. Our results also suggest the possibility of a CO-dominated atmosphere of 10–100 mbars at 3 Ga. The redox state of ancient Mars might have fluctuated more easily than that of the present.
On the Origin of the Asymmetry of the Ejecta Structure and Explosion of G350.1–0.3
Authors: Tsuchioka Tomoya , Uchiyama Yasunobu , Higurashi Ryota , Iwasaki Hiroyoshi , Otsuka Shumpei , Yamada Shinya , Sato Toshiki
Published: May 2021

We present X-ray analysis of the ejecta of supernova remnant (SNR) G350.1–0.3 observed with Chandra and Suzaku, clarify the ejecta’s kinematics over a decade, and obtain a new observational clue to understanding the origin of the asymmetric explosion. Two images from Chandra X-ray Observatory taken in 2009 and 2018 are analyzed with several methods and enable us to measure the velocities in the plane of the sky. A maximum velocity is 4640 ± 290 km s−1 (0.218 ± 0.014 arcsec yr−1) in the eastern region in the remnant. These findings trigger us to scrutinize the Doppler effects in the spectra of the thermal emission, and the velocities in the line-of-sight direction are estimated to be 1000 km s−1. The results are confirmed by analyzing the spectra of Suzaku. Combining the proper motions and line-of-sight velocities, the ejecta’s 3D velocities are ∼3000–5000 km s−1. The center of the explosion is more stringently constrained by finding the optimal time to reproduce the observed spatial expansion. Our findings that the age of the SNR is estimated at most to be 655 yr and the CCO is observed as a point source object against the SNR strengthen the “hydrodynamical kick” hypothesis on the origin of the remnant.
A Case against a Significant Detection of Precession in the Galactic Warp
Authors: Chrobáková Ž. , López-Corredoira M.
Published: May 2021

Recent studies of warp kinematics using Gaia DR2 data have produced detections of warp precession for the first time, which greatly exceeds theoretical predictions of models. However, this detection assumes a warp model derived for a young population (few tens of megayears) to fit velocities of an average older stellar population of the thin disk (several gigayears) in Gaia-DR2 observations, which may lead to unaccounted systematic errors. Here, we recalculate the warp precession with the same approach and Gaia DR2 kinematic data, but using different warp parameters based on the fit of star counts of the Gaia DR2 sample, which has a much lower warp amplitude than the young population. When we take into account this variation of the warp amplitude with the age of the population, we find that there is no need for precession. We find the value of warp precession

β
=

4

−
4

+
6

km s−1 kpc−1, which does not exclude nonprecessing warp.
On a noteworthy habitat type in the savannahs of Central Cuba and a remarkable new species of Elytraria (Acanthaceae)
Authors: Greuter Werner , Rodríguez Rankin
Published: May 2021

A peculiar habitat type found in the savannahs of Central Cuba, Villa Clara Province and characterised by the presence of a surface gravel layer of “perdigones”, an assemblage of small ferralitic concretions, upon the “mocarrero” soil prevailing in the area, is described. On sterile gravel patches, only one species grows: Elytraria serpens, a new species described and named here. It is noteworthy for possessing long and wide creeping, stoloniform subterranean peduncles with apical gemmae developing into rooting leaf rosettes enabling vegetative propagation. The new species is close to E. shaferi and considered to derive from the latter by adaptive evolution, enabling it to survive in its hostile habitat, sheltered from the competition of other plant species. Small soil insects, for example, ants, are believed to act as pollinators.
Repenser la liberté
Authors: Lemoine Philippe
Published: May 2021

Les démocraties contemporaines font face à une crise de leurs valeurs, au premier rang desquelles la liberté, déchirée entre une conception moderne des droits individuels et une vision antique de la participation à la vie civique. À l’heure de la transition écologique et de la transformation numérique, il faut d’urgence dépasser cet antagonisme et repenser la liberté comme une nouvelle organisation planétaire de l’intersubjectivité.
Irving Howe, un socialiste libéral
Authors: Cohen Mitchell , Lalo Alexandra
Published: May 2021

La vie et l’œuvre d’Irving Howe, critique littéraire et politique, fondateur de la revue Dissent , sont une véritable traversée dans l’histoire de la gauche américaine au cours du xx e  siècle. D’abord militant marxiste et révolutionnaire, l’auteur s’est progressivement ouvert aux préceptes libéraux, sans jamais renier l’humanisme radical au fondement de son engagement socialiste.
Pour une liberté sociale et collective
Authors: Pranchère Jean-Yves
Published: May 2021

Il est possible d’opposer au fanatisme du marché et à la volonté d’entraver l’égalité des conditions les idéaux d’un libéralisme à la fois démocratique et social. Les libertés individuelles ne peuvent en effet se maximiser sans la médiation d’une autonomie collective.
La mémoire autrement ?
Authors: Guichard Charlotte
Published: May 2021

Les monuments de papier réalisés par Ernest Pignon-Ernest font émerger les mémoires refoulées des sociétés modernes dans l’espace public, avec une grande attention aux lieux et suivant le canon artistique de la révolte.
Le « logement social » en Turquie depuis le début des années 2000 : méprises conceptuelles, redéfinition des systèmes d’acteurs et invisibilisation des nécessiteux
Authors: Pérouse Jean-François
Published: May 2021

Pays désormais massivement urbanisé (et même, d’une certaine manière, métropolisé de force), pays où l’accession à la propriété est l’horizon ultime de toute politique publique de logement, la Turquie n’a pas de politique publique de logement social clairement identifiable. Souvent confondu avec le logement collectif, le logement social n’existe pas comme une catégorie stable de l’action publique, pas plus au niveau de l’Etat qu’au niveau des pouvoirs locaux. Ce constat opéré, il s’agira de voir comment la catégorie « logement social » est manipulée et détournée à des fins partisanes et comment la vision de l’espace social s’en trouve faussée, privilégiant – pour fonder la politique publique de logement – les affiliations politiques et les relations de dépendance au détriment des critères socio-économiques plus objectifs. Autrement dit, alors que les populations les plus nécessiteuses sont invisibilisées et dès lors cantonnées dans l’autoproduction et le bricolage au jour le jour, les politiques publiques de « logement social », tout en étant des instruments d’ingénierie sociale (au service d’une conception conservatrice de l’ordre social), servent soit à récompenser des fidèles, soit à maintenir dans une dépendance totale des groupes sociaux aspirant à accéder à la propriété. Les endettés reconnaissants et les familles de şehit ont évincé les pauvres.
Economic Value Drivers for Brazilian Agricultural Cooperatives
Authors: Figari Anelise Krauspenhar Pinto , Lima Fabiano Guasti , Gatsios Rafael Confetti , Magnani Vinicius Medeiros
Published: May 2021

This article aims to identify the economic value drivers for Brazilian agricultural cooperatives. To this end, we analyzed the potential value drivers for agricultural cooperatives in Paraná and Rio Grande do Sul using panel data regression, considering data from 2008 to 2016. The results showed that net margin, basic purchasing power, investment in fixed assets, circulating assets X sales margin, fixed asset turnover, net revenue, and number of members are the economic value drivers for Brazilian agricultural cooperatives. Moreover, a dynamic panel based on generalized method of moments (GMM) was used to check the robustness of the relationships. With these results, managers and members of agricultural cooperatives can focus their efforts and decisions on maximizing economic value for associated farmers.
Resilience in Crisis
Authors: Slapac Alina , Coppersmith Sarah A. , O'Brien Kathryn G. , Balcerzak Phyllis
Published: May 2021

Teacher action research serves as a framework that can transform practice while supporting inquiry, investigation, and problem-solving. This chapter provides a research report on the challenges experienced, strategies used, and lessons learned from 41 graduate education teacher-researchers who designed and implemented their own educational research during the COVID-19 crisis as part of their Action Research Capstone course before graduation. Graduate students were enrolled in three sections of the Action Research course in a Midwestern university. Methodology included a qualitative approach to data collection and analysis. Findings from discussion board posts, reflections, and research papers captured challenges in facing COVID-19, yet participants' engagement in the community of learners within the course ameliorated and buffered stress, trauma, and compassion fatigue felt due to the pandemic's impact on these frontline workers.
Assessment of Case-Based Instruction in a Graduate Educational Psychology Course
Authors: Bhattacharya Alpana
Published: May 2021

This chapter showcases a teacher educator's assessment of case-based instruction in an advanced level educational psychology course. First, action research, self-study, and reflective practice are explained as constructs of practitioner inquiry. Then, case-based instructional models related to teacher candidates' classroom management proficiencies are reviewed. Next, the teacher educator's examination of own teacher preparation practice is described to highlight development, implementation, and improvement of the target educational psychology course geared towards advancement of teacher candidates' classroom management capacities. Thereafter, solutions and recommendations for promoting teacher candidates' P-12 grades classroom management expertise are discussed. Finally, future research directions are proposed for ascertaining effectiveness of case-based instruction as evidence-based pedagogical approach for strengthening teacher candidates' P-12 grades classroom management aptitudes.
Teaching Action Research to International Educators
Authors: Khan Ruhi , Enriquez Gates Alejandra , Grijalva Rebecca , Nielsen Ann
Published: May 2021

This chapter examines how a team of university experts within the field of education adjusted the focus of a professional development (PD) model to teach action research to 60 international educators. Three key educational elements were used to create the PD model: 1) transformational learning theory, 2) language acquisition and learning methodologies, and 3) a personalized system of instruction (PSI). When the unexpected worldwide pandemic caused a shift to remote learning, the team was tasked with adjusting the original face-to-face model. Evidence from meeting agendas, action plan tracking spreadsheets, and personal communication were analyzed as the program moved to an online learning environment. Based on this data, the team recognized that the theoretical principles and conceptual framework did not change but were refocused and emphasized a more human-centered approach. Future research should explore continued long-term professional development after action research has been implemented to support reflective practice and inquiry.
Effect of Palm Oil Fuel Ash on the Strength and Ammonium By-Product Removal of Biocemented Sandy Soil
Authors: Muhammed Abubakar Sadiq , Kassim Khairul Anuar , Zango Muttaqa Uba , Ahmad Kamarudin , Makinda Jodin
Published: May 2021

Enzyme induced calcite precipitation (EICP) or biocementation has rapidly evolved in the last decade as an environmentally friendly ground improvement technique. In EICP, plant-derived urease enzyme is used to trigger the hydrolysis of urea in the presence of calcium ions to produce calcium carbonate (CaCO3) precipitate within the soil matrix. Despite the advancement in soil improvement technology via biocementation, there are still concerns about the fate of the ammonium produced as one of the by-products. Therefore, this study performed an experimental investigation to ascertain that using palm oil fuel ash (POFA) might reduce the amount of ammonia produced as a result of biocementation. The soil was mixed with POFA at different percentages (1, 2, 3, 4 and 5%) by dry weight of the soil. The effectiveness of the treatment process was evaluated by conducting the unconfined compressive strength (UCS) and the ammonium removal efficiency. Results show that the strength and ammonium removal efficiency of the biocemented soil decreased and increased, respectively, with an increase in the percentage of POFA. The highest UCS of 161 kPa was obtained at 3% POFA content, while the lowest concentration of ammonium of 0.71 mg/L was at 5% POFA content.
Effect of Temperature and Holding Time on Zirconia Toughened Alumina (ZTA) Prepared by Two-Stage Sintering
Authors: Loong Teow Hsien , Soosai Ananthan , Muniandy Suresh
Published: May 2021

The microstructure and mechanical properties of Zirconia Toughened Alumina (ZTA) produced via two-stage sintering at various sintering temperature of T1 and T2 in addition to effect of various holding time were investigated. T1 temperature was set between the range of 1400°C to 1500°C with a heating rate of 20°C/min. The samples were then sintered at T2 ranging from 1350°C to 1400°C followed by various holding time between 2 hours to 12 hours. The sintered samples’ microstructural properties, bulk density, hardness (Vickers hardness), elastic modulus (Young’s modulus) and fracture toughness (K1C) were then determined. Compared to standard holding time of two-stage sintering which is 12 hours, results show that ZTA produced via two-stage sintering with shorter holding time of 4 hours with T1 set at 1500°C and T2 of 1450°C are capable of achieving full densification. In addition, the same sample were also able to achieve hardness up to 19 GPa, Young’s modulus of 390 GPa and fracture toughness of 6.1 MPam1/2. The improvement in mechanical properties can be mainly attributed to the absent of surface diffusion at T2 above 1400°C and also presence of Y-TZP which contributed to lower grain growth due to the pinning effect.
Magnetic Ferrous Fluid for Microplastics Extraction Application
Authors: Yeo L.S. , Julaihi M.R.M.
Published: May 2021

The study in microplastics removal using nanomaterials is relatively new and the majority of treatment techniques lies in water treatment plant. This research aims to study an innovative approach to mechanically remove microplastics from polluted water inspired by Fionn Ferreira who won the Google Science Fair in 2019. Experiments are designed and conducted to identify the efficiency of the method with varied oil to nanoparticles ratio. Additionally, possible application of the concept was explored presented as a proof of concept. The technique takes advantage of the relatively low surface tension of oil and immiscible properties in water as an adhesive element between the microplastics and magnetic nanoparticles. Stirring the mixture binds all particle components to the oil medium and then removed from the water using a magnet. Since this is a physical interaction, the technique is not limited to microplastics but other solid particles as well. The results presented in this paper concludes the suggested treatment achieved the highest microplastic extraction percentage at 97.312%. The associated ratio was recorded to be a 1:1 unit volume of oil to nanoparticles. The ratio provides sufficient viscosity and surface tension for ease of microplastics extraction. The novelty of the treatment lies in the reusability of the oiled magnetic nanoparticles as a filter medium. Furthermore, a design inspired by gravity sand filter was presented in this paper as a proof of concept and potential application.
Effect of Sintering Temperature to the Mechanical Properties of Different Filler Loading of Zirconia Powder in Hydroxyapatite Composites
Authors: Muniandy Suresh , Soosai Ananthan , Loong Teow Hsien
Published: May 2021

Hydroxyapatite (HA)-Zirconia (ZrO2) composite with varying zirconia composition ranging from 1 to 10 wt% was investigated for biomedical applications in order to produce high compressive strength. Precipitation method was used to prepare both hydroxyapatite and zirconia powders. To find the ideal composition, mixture-containing 1, 3, 5 and 10 wt% ZrO2 powder was added. Each mixture was sintered for 4 hours at 750oC, 1050oC and 1250oC. Hardness and compressive strength test were used for evaluation. It was found that with 1 wt% of ZrO2 sintered at 1250oC showed the greatest structural strength as its volume fraction porosity is the lowest. The hardness and compressive strength of this sample were found to be 2.75 GPa and 72.0 MPa respectively. This can be useful for biomedical applications especially in promoting osteo-integration.
Mechanical Properties of Rice-Straw Reinforced PLA Composite after Alkalization, Heating and Coating Treatments
Authors: Jayamani Elammaran , Yu Chun Jie , Prashanth Hari , Soon Kok Heng
Published: May 2021

Natural fibers have advantages over that of synthetic fibers such as biodegradability, low densities, and low cost of production. Optimum interfacial bonding is crucial since it determines the mechanical properties of a polymer-based composite materials. Surface treatment needs to be performed prior to the composites fabrication in order to improve the interfacial bonding. Coating application is an environmentally friendly alternative to the conventional methods of fiber treatments. In this research, the mechanical properties such as tensile (37.1 per cent increase), flexural strengths (61.7 per cent increase) and hardness (31.4 per cent less prone to surface indentation) of rice straw reinforced Polylactic acid composite at 10 wt% fiber and 90 wt% polymer after fiber treatments are analyzed through fabrication and testing. The fiber treatments involved are alkali treatment, heating treatment and coating. The results showed observable increase in tensile, flexural strengths and hardness for alkali treatment, heat treatment. However, from coating process, there is only slight increase in all the mechanical tests. These results have inferred that heat treatment has the highest improvement in mechanical properties, followed by alkalization and then comes coating.
Low-cost electromyography: validity against a commercial system depends on exercise type and intensity
Authors: Tecchio Paolo , Monte Andrea , Zamparo Paola
Published: May 2021

The aim of this study was to assess the validity of a custom-made low cost (LC) and a commercial surface EMG apparatus in controlled experimental conditions and different exercise types: maximal voluntary contractions (MVC) at 105, 90, 75, 60, 45 and 30° knee angle and explosive fix-end contractions of the knee extensors (75°) at an isometric dynamometer. sEMG of vastus lateralis was recorded from the same electrodes simultaneously, then analyzed in the same way; sEMG were finally expressed in percentage of those collected at 75°MVC. LC underestimated the sEMG signal at the more extended knee angles (30-60°), significant difference was observed only at 30°. In the explosive contractions no differences between devices were observed in average and peak sEMG, as well as in the time to peak and the activation time. Bland-Altman tests and correlation parameters indicate the LC device is not sensible enough to detect the time to peak and the peak values of the sEMG signal properly. Results suggest low-cost systems might be a valid alternative to commercial ones, but attention must be paid when analyzing rapid events.
COMMUNICATION IN AND AROUND MESMERISM. CONTROVERSIES, CASE HISTORIES AND THE CULTURAL IMAGINATION
Authors: Barkhoff Jürgen
Published: May 2021

Mesmerism or animal magnetism was the most controversial and most spectacular medical concept of the late eighteenth- and early nineteenth-century. It was also conceptualised and practiced as a medical therapy based entirely on communication; a communication that worked on many levels: between magnetiser and patient, between body and mind and – in its theoretical explanations – between human beings and the cosmos. This paper will first briefly look at theories of mesmerism from this perspective and then discuss some of the scandalous and provocative communicative phenomena of the so-called magnetic rapport between magnetiser and patient in the somnambulist trance. It will also briefly review the controversies between supporters and sceptics of the magnetic cure around the communicative experience in the rapport. The final part of this paper will turn to Romantic literature, as its rich aesthetic representations of mesmerism transcend enlightenment controversies and offer more complex, nuanced and insightful negotiations of the forms of communication prevalent and observable in the mesmerist phenomena. In mesmerism we can thus observe that around 1800 literature seems to know and understand more about psychodynamic and psychophysical communication than medical science.
CORPOREITÀ E IMMAGINARIO NEL DISCORSO MEDICO SETTECENTESCO: GLI ÉLÉMENTS DE PHYSIOLOGIE DI DIDEROT
Authors: Iotti Gianni
Published: May 2021

L’article part d’une série de considérations sur la précocité des intérêts de Diderot dans le domaine médical. «Pas de livres que je lise plus volontiers que les livres de médecine, pas d’hommes dont la conversation soit plus intéressante pour moi que les médecins», il affirmera vers la fin de sa vie. En fait, le discours médical, dans son oeuvre, s’identifie à un discours philosophique militant sous le signe d’un monisme rigoureux polémiquement opposé au dualisme de la tradition platonicienne-chrétienne, un discours nettement orienté vers la traduction totale de ‘l’âme’ dans le fonctionnement des organes du corps. Cependant, au-delà de la controverse philosophique, chez Diderot la connaissance médicale se révèle comme la base d’une fascinante vision biologique. Contrairement à un Buffon, qui continue de reconnaître une centralité ontologique à l’homme, Diderot tend à nier toute solution de continuité entre l’être humain et le règne animal - et même entre le règne animal et le règne minéral. L’article met en évidence quelques conséquences capitales d’une telle position sur les idées esthétiques de Diderot; et, d’ici, les réflexions sur l’enracinement de la pensée dans le corps présentes dans les Éléments de physiologie sont ramenées à l’un des plus grands changements de paradigme culturel de l’histoire européenne moderne.
Psalm 27:4 – To reflect in his temple: Communion with YHWH as the culmination of the journey of life
Authors: Botha Philippus J.
Published: May 2021

Since the time of Mowinckel, the verb בקר (pi) in Psalm 27:4 was often interpreted as referring to a priest’s function of examining an offering. The parallel part of the verse and other intratextual and intertextual considerations render this interpretation of the verb improbable. The context of the psalm and the cluster of Psalms 25–34, as well as parallels Psalm 27 has with Psalm 23, suggest that the verb בקר refers to reflection on the privilege of being in YHWH’s presence. The enjoyment of such communion with YHWH, which includes the study of his Torah, is portrayed as the culmination of the journey of life in Psalms 25–34. The author argues that this is also hinted at in Psalm 27.Contribution: The contribution of this article towards the focus of HTS as “Historical Thought and Source Interpretation” centered around its use of the literary context of a psalm to question the notion of a reconstructed cultic setting as the only possible hermeneutical key to interpret Psalm 27.
Changes in the Blink Reflex during Migraine with Aura and the Inter-Attack Period
Authors: Ates Mehlika Panpalli , Ferik Sevgi , Pektezel Leyla Das , Guven Hayat , Comoğlu Selim Selcuk
Published: May 2021

Introduction:

This study aimed to investigate the possible excitability changes in the trigeminovascular system based on blink reflex (BR) in patients experiencing migraine and to compare migraine aura attacks and attack-free period.

Materials and Methods:

A total of 56 patients diagnosed with migraine headache with aura and 20 healthy individuals without migraine were evaluated electrophysiologically using the BR test. The BR test was repeated twice in patients with migraines during attacks with aura and attack-free period.

Results:

During the migraine attack with aura, R1 latencies were shorter, and R2 latencies were longer than in the interictal period. Likewise, R1 latencies were shorter, and R2 latencies were longer, in the interictal period compared to normal values obtained in the control group.

Conclusion:

The detected BR abnormalities have been thought to be able to reflect migraine-related dysfunction in the brainstem and trigeminovascular connections.

Significance:

It has been concluded that the detected BR abnormalities might reflect migraine-related dysfunction in the brainstem and trigeminovascular connections, indicating increased neuronal excitability in migraine.
Primary pelvic echinococcosis though uncommon but not rare
Authors: Abhishek Kumar S. , Shrimali Twishi , Tak Vibhor , Nag Vijaya Lakshmi , Banerjee Sumit , Khera Sudeep
Published: May 2021

Echinococcosis is caused by larva of Echinococcus granulosus. Liver being most commonly involved, other organs/body parts such as bone involvement is not so uncommon, especially in cattle-raising countries such as India. Primary osseous echinococcosis remains undiagnosed until complications have developed. We report a case of complicated pelvic echinococcosis presented with left gluteal mass, acetabulum and femoral head destruction, and reduced hip mobility. Pre- and postoperative chemotherapy with albendazole and en bloc surgical removal of the cyst were advocated as the preferred option of treatment. Primary osseous echinococcosis must be kept in mind when encountering a case of chronic bony mass not responding to antitubercular therapy, and hydatid serology should be performed along with other imaging and histopathological examinations to support or confirm the diagnosis to prevent long-term complications.
Las tecnologías de la información y comunicación en los programas de gestión de la insuficiencia cardiaca crónica. Retos organizativos y estado de la evidencia
Authors: García Linaza Francisca , Yanes López Virginia
Published: May 2021

Conocer los distintos modelos de gestión de la ICC que utilizan las TICs, su efectividad y la estrategia organizativa de los mismos. Rediseño de un proceso asistencial más eficiente e indicadores de calidad.
An overview of some dating methods of mineralization
Authors: Khuong Hung The ,   Faculty of Geosciences and Geoengineering, Hanoi University of Mining and Geology, Vietnam
Published: May 2021

One of the most important achievements of applying radioactive isotope in the geological study is to determine the age of mineralization. Based on the synthesis, comparison, and evaluation of the popular isotopic systems in dating mineralization, the Rb - Sr, Re - Os, and Ar - Ar dating methods are discussed in this study. The results show that the Rb - Sr dating method is likely to be successfully applied to sulfide mineralization. If the mineralization contains little or no sulfide minerals, then the method is applied to other minerals in an ore mineral association. The Re - Os dating method has shown great success when it is applied to hydrothermal deposits, especially for the molybdenite - bearing vein deposits. The limitation of the method is that when the concentration of the Os element in molybdenite is low, it is difficult to establish the Re/Os ratio in a single mineral. The Ar - Ar isotope system for dating mineralization often uses mica or feldspar minerals, which are minerals with blocking temperatures ranging from 150÷350 0C, and later metamorphic periods have higher than 350 0C often overprinted these minerals. Generally, tectonic, magmatic, and metamorphic events, which occur after mineralization, can cause difficulty in determining the age of mineralization and collecting analysis samples.
Research using seismic waves for orientation of the Ocean - Bottom Seismographs
Authors: Tran Hung Danh , Phan Huong Thien , Yang Ting ,   Department of Geophysics, Hanoi University of Mining and Geology, Vietnam  Department of Ocean Science and Engineering, Southern University of Science and Technology, China
Published: May 2021

Orientation of the Ocean-Bottom Seismograph (OBS) devices is an important task that must complete before using these data. While the OBS direction is determined correctly, we can correct the rotation angle of the coordinate system so that we obtain the maximum amplitude seismic signals for different seismic waves. In this article, we present the method using seismic waves to determine the direction of the OBS. The results obtained from 11 OBSs in the East Sea show that these stations have misdirected from different angles. This method has advantage with high reliability. Specially, we can widely apply for the OBS devices in other oceans.
Comparison of Parameters of Automatic Milking in Selected Countries in European Union and United States
Authors: PIWCZYŃSKI Dariusz , KOLENDA Magdalena , GONDEK Jan , SITKOWSKA Beata
Published: May 2021

The aim of this study was to compare selected parameters of automatic milking in various European Union countries and United States recorded between 2018 and 2020. Statistical analysis showed highly significant effect of country on all tested milking parameters. It was noted that i.e. the average number of cows per one robot, depending on country, ranged between 51.49 (the Netherlands) and 60.03 (Germany). Cows were milked on the average 2.50 (France) – 2.83 (Latvia) per day, with milking speed ranging from 2.30 kg/min (Lithuania) to 2.99 kg/min (US). Daily milk yield obtained from one cow ranged from 25.12 kg (Lithuania) to 34.11 kg (US), while milk efficiency from 1.44 (Lithuania) to 1.77 kg/min (US). Results also showed that the daily milk yield from one robot ranged from 1 351 kg (Latvia) to 1 930 kg (US). The statistical differences between the milking parameters in the compared countries may be the result of the diversified genetic potential of milked cows and the diversity of the feed base.
The Effects of Supplementing Whole Milk with Juniper (Juniperus oxycedrus) Aromatic Water on Growth and General Health Parameters of Holstein Calves
Authors: Isik Ali Riza , Özkaya Serkan
Published: May 2021

The illness of the calves during the suckling period suppresses the growth of calves and causes them to be removed from the breeders. In the present study, it was investigated whether Juniper aromatic water (JOW) would be suitable for promoting healthy growth performance of suckling Holstein calves. Twelve newborn calves (n=3, in each group) were randomly selected and assigned to the following four treatments: Control, 50, 100 and 200 ml JOW supplemented milk per day. The supplementation of JOW showed an increase in calves’ live weight and body measurements. In addition, the supplementation of whole milk with JOW decreased the frequency of occurrence of calves’ diarrhea and disease. The best result was observed in the supplementation of whole milk with 50 ml JOW. The findings of the study showed that Juniper aromatic water, a by-product, can be used safely in the healthy rearing of calves.