bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrodynamic Modeling of Sailing Yachts
Authors: Harries Stefan , Abt Claus , Hochkirch Hochkirch 
Published: May 2021

In modem yacht design geometric modeling is regarded to be directly related to the hydrodynamic performance of the shape of the hull and its appending elements -usually the keel, often with winglets, and the rudder. While the traditional way of shape design - i.e., draw­ing, model building, tank testing, modifying . - is both time consuming and expensive, a complementing ap­proach shall be discussed within this paper. The ap­proach is called hydrodynamic modeling since it tightly combines the hydrodynamic analysis and the geomet­ric modeling in the design process. It is based on ad­vanced Computational Fluid Dynamics (CFD) methods for flow field analysis and unique parametric modeling techniques for shape generation.
The geometry of a yacht is entirely described via im­portant form parameters as discussed in detail by the authors at the 1999 CSYS. The canoe body of the yacht is modeled from a small set of longitudinal curves which provide all parameters needed for sectional design. The longitudinal curves themselves being created via form parameters, a fully parametric description of the hull is achieved which allows to create and modify the geom­etry in a highly sophisticated manner. The fairness of the shapes is an intrinsic part of the form generation procedure. Apart from the canoe body the keel repre­sents the most pronounced hydrodynamic design ele­ment, dominating lift and righting moment of a yacht but also causing a non-negligible resistance component called induced drag. Keel, bulb and winglets are also specified in terms of form parameters.
An application of hydrodynamic modeling is given for an IACC-yacht. Formal optimization can be suc­cessfully employed to identify improved and, eventu­ally, optimal configurations. A reasonably small set of parameters (free variables) was selected and systemati­cally varied making use of a fully automatic optimiza­tion scheme. Two optimization examples are presented in order to demonstrate the potential of the approach: (a) the optimization of a keel-bulb-winglet configuration so as to find a minimum drag solution for a given side force and (b) the optimization of the bare hull with respect to wave resistance.
The examples can be regarded as representative for both racing and touring yachts with draft restrictions and illustrate the methodology of hydrodynamic modeling.
Schooner Brilliant Sail Coefficients and Speed Polars
Authors: Grant Howard , Stubner Walter , Alwang Walter , Henry Charles , Baird John , Spens Paul 
Published: May 2021

The sail coefficients for a schooner rig, as a function of wind angle and heel angle, are presented, based on an experimental program, for historic vessel research, at Mystic Seaport, using the 61'6" schooner Brilliant. The coefficients were determined by full-scale sailing tests and 9- scale model tow-tank tests.
Sail coefficients CR and Cttare defined as the drive force and horizontal side force , due to the sails, rigging, and hull above the waterline, per unit of sail area, per unit of wind pressure. These coefficients can be used to study performance of historic schooner­rigged vessels, predict performance of new designs, and compare performance of schooners and sloops. Sail coefficients for sloops have long been available.
A velocity prediction program for the schooner was also developed. The predicted and actual ship speeds agree, with standard deviation of0.028 in the ratio.
Upwind sail coefficients for the schooner are found to be lower than for historic sloops, and display the expected droop with heel. The schooner velocity made good upwind is largest with the sail plan of four lowers plus fisherman staysail. The schooner and sloop both point higher as wind increases. The sloop outpoints the schooner at all wind speeds, by about 10°.
On a beam reach or broad reach, schooner speed is largest with the sail plan of big jib, golliwobbler, and mainsail. This sail plan also produces the largest downwind velocity made good. The polars suggest that the schooner has the advantage over the sloop on a beam reach.
Los MOOC en la línea del tiempo: una biografía investigativa de una tendencia educativa
Authors: Chiappe Andres , Amaral Monique 
Published: May 2021

Los cursos online masivos y abiertos (MOOC) se han convertido en un fenómeno educativo emergente con un enorme potencial de transformación y democratización educativa. Luego de casi una década de su primer lanzamiento, gran cantidad de investigación se ha realizado para intentar comprender sus alcances y limitaciones como instrumento de aprendizaje flexible y personalizado. Con el propósito de aumentar tal comprensión, se ha llevado a cabo una revisión sistemática de literatura sobre estudios publicados entre 2009 y 2019 acerca de los MOOC. Se aplicó un método de 6 pasos para revisar 486 estudios, a partir de procesos de filtrado, abstracting, lectura en profundidad y extracción e interpretación de datos. Los resultados muestran una gran cantidad y diversidad de focos de investigación sobre los MOOC, algunos en auge, otros en declive y otros de naturaleza efímera. Se resaltan entre ellos las Prácticas Educativas Abiertas, el diseño de los MOOC, el engagement, la deserción y el conectivismo. Los focos de investigación representan las principales preocupaciones de educadores e investigadores sobre lo que pareciera ser el advenimiento de un nuevo orden educativo que soportaría el aprendizaje a lo largo de la vida y los entornos de aprendizaje enmarcados en la sociedad 4.0.
Massive and open online courses (MOOC) have become an emerging educational phenomenon with enormous potential for educational transformation and democratization. After almost a decade of its first launch, a great deal of research has been carried out to try to understand its scope and limitations as a flexible and personalized learning instrument. In order to increase such understanding, a systematic review of literature on studies published between 2009 and 2019 about MOOCs has been carried out.A 6-step method was applied to review 486 studies, based on filtering, abstracting, in-depth reading and data extraction and interpretation processes.The results show a large number and diversity of research focuses on MOOCs, some booming, others in decline and others of ephemeral nature. Among them are the Open Educational Practices, the design of MOOCs, the generation of engagement, dropout and connectivism.The research focuses represent the main concerns of educators and researchers regarding what appears to be the advent of a new educational order, which currently supports lifelong learning and future learning environments framed in society 4.0.
Content analysis of research papers on flipped learning
Authors: Uzunboylu Huseyin , Prevalle Ethemi Blerta , Hamidi Mentor 
Published: May 2021

Abstracto
El propósito de este estudio es describir el estado actual de la publicación de investigaciones y las tendencias en el aprendizaje invertido, que se encuentran en "Web of Science" durante el período 2014-2018. Hay 262 artículos investigados, publicados e indexados en "Web of Science" con la palabra clave: "aprendizaje invertido" y "aula invertida". Los resultados del estudio se analizan según la revista de publicación según estos criterios: autor, países, agencias de financiación, tipos de documentos, idiomas, organización, años de publicación y título de la fuente. El aprendizaje invertido cambia la clase tradicional dando la vuelta al aula en el sentido de escuchar las videoconferencias en casa y realizar actividades dinámicas en grupo en el aula. Esto involucra a los estudiantes en el aprendizaje activo, el pensamiento crítico y mejora las habilidades interpersonales.Se recomienda a los autores explorar la posibilidad de utilizar este método, experimentar y publicar los hallazgos que permitan crear mejores prácticas y un marco unificado para instructores líderes que deseen adoptar esta metodología de enseñanza.
Palabras clave: aprendizaje invertido, aula invertida, análisis de contenido,

The purpose of this study is to describe the current state of research publication and trends in flipped learning, found on ‘Web of Science’ during the period 2014–2018. There are 262 papers investigated, published and indexed on ‘Web of Science’ with the keyword: “flipped learning” and “flipped classroom”. The results of the study are analysed according to the journal of publication by these criteria: author, countries, funding agencies, document types, languages, organisation, publication years and source title. Flipped learning changes the traditional lecturing by flipping the classroom in the sense of listening to the video lectures at home and doing dynamic, group-based activities in the classroom. This engages the students in active learning, critical thinking, and meliorates interpersonal skills.It is recommended to authors to explore the possibility of utilising this method, experimenting and publish the findings which allows to create best practices and a unified framework for leading instructors who want to adopt this teaching methodology.
Keywords: Flipped learning, flipped classroom, content analysis,
The hepcidin regulator erythroferrone is a new member of the erythropoiesis-iron-bone circuitry
Authors: Castro-Mollo Melanie , Gera Sakshi , Ruiz-Martinez Marc , Feola Maria , Gumerova Anisa , Planoutene Marina , Clementelli Cara , Sangkhae Veena , Casu Carla , Kim Se-Min , Ostland Vaughn , Han Huiling , Nemeth Elizabeta , Fleming Robert , Rivella Stefano , Lizneva Daria , Yuen Tony , Zaidi Mone , Ginzburg Yelena 
Published: May 2021

Background:Erythroblast erythroferrone (ERFE) secretion inhibits hepcidin expression by sequestering several bone morphogenetic protein (BMP) family members to increase iron availability for erythropoiesis.Methods:To address whether ERFE functions also in bone and whether the mechanism of ERFE action in bone involves BMPs, we utilize the Erfe-/- mouse model as well as β–thalassemic (Hbbth3/+) mice with systemic loss of ERFE expression. In additional, we employ comprehensive skeletal phenotyping analyses as well as functional assays in vitro to address mechanistically the function of ERFE in bone.Results:We report that ERFE expression in osteoblasts is higher compared with erythroblasts, is independent of erythropoietin, and functional in suppressing hepatocyte hepcidin expression. Erfe-/- mice display low–bone–mass arising from increased bone resorption despite a concomitant increase in bone formation. Consistently, Erfe-/- osteoblasts exhibit enhanced mineralization, Sost and Rankl expression, and BMP–mediated signaling ex vivo. The ERFE effect on osteoclasts is mediated through increased osteoblastic RANKL and sclerostin expression, increasing osteoclastogenesis in Erfe-/- mice. Importantly, Erfe loss in Hbbth3/+mice, a disease model with increased ERFE expression, triggers profound osteoclastic bone resorption and bone loss.Conclusions:Together, ERFE exerts an osteoprotective effect by modulating BMP signaling in osteoblasts, decreasing RANKL production to limit osteoclastogenesis, and prevents excessive bone loss during expanded erythropoiesis in β–thalassemia.Funding:YZG acknowledges the support of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (R01 DK107670 to YZG and DK095112 to RF, SR, and YZG). MZ acknowledges the support of the National Institute on Aging (U19 AG60917) and NIDDK (R01 DK113627). TY acknowledges the support of the National Institute on Aging (R01 AG71870). SR acknowledges the support of NIDDK (R01 DK090554) and Commonwealth Universal Research Enhancement (CURE) Program Pennsylvania.
Three Observations on Filming Tactility and Movement in Crafts-based Practice
Authors: Ho Wuon-Gean 
Published: May 2021

This film makes three observations on the filming of tactility and movement in order to adequately convey tacit knowledge in embodied ways. The author, Wuon-Gean Ho, studied the craft of traditional woodblock printmaking in Japan, and demonstrates planning, carving and printing of a woodblock print.
The first observation is that an alteration of the time-base of the film and subsequent manipulation of the soundscape can provide embodied affects. Secondly the film refers to the effect of mirror-touch-synaesthesia with close macro shots and intimate angles. Thirdly, the use of a birds’ eye point of view, with the hands of the artist in the same anatomical position as the viewers’ hands, enables the gaze of the viewer to mimic that of the maker, conveying haptic knowledge through poetic means.The voiceover to the film is made with deliberate reference to ASMR videos that engender a sense of intimacy. The non-objectivity of the recording process is commented upon. The conclusion is that constructed scenarios might convey more than real-time truthful indexical footage.
Prediction and injury risk based on movement patterns and flexibility in a 6-month prospective study among physically active adults
Authors: Koźlenia Dawid , Domaradzki Jarosław 
Published: May 2021

BackgroundPhysical activity has many health benefits but also carries a risk of injury. Some universal factors are connected with an increased risk regardless of the type of sport. Identifying these factors may help predict injuries and aid in their prevention.AimThe aim of this study is to determine the level of injury risk and the accuracy of injury prediction during a prospective 6-month period based on the quality of movement patterns and level of flexibility among average physically active young adults.Material and MethodsA group of 123 young, physically active adults were recruited for this study. The International Physical Activity Questionnaire (IPAQ) was used to determine their level of physical activity. The author’s own Injury History Questionnaire (IHQ) was used to retrospectively collect injury data from the 12 months before the study and prospectively collect data during the six month observation period. The Functional Movement Screen (FMS) test was conducted to assess the movement patterns quality and a sit-and-reach test was conducted to measure lower back and hamstrings flexibility.ResultsLow-quaility movement patterns (14≥ FMS) increased the injury risk level sevenfold. A level of flexibility reduced by one cm increased the risk of injury by 6%. Previous injuries also increased the risk of injury reccurence 6.4 times. Predicting injury occurrence based on the quality of movement patterns allows for an accuracy of 73%, whereas flexibility allows for a 41% accuracy. The simultaneous use of these two factors did not improve injury prediction accuracy.ConclusionThe risk of an injury increases with low-quality movement patterns, a low level of flexibility, and previous injuries. Preventative strategies should include shaping high-quality movement patterns, the right level of flexibility, and the full healing of injuries before resuming activities. The quality of movement patterns is an accurate predictor of injury risk, but lower back and hamstrings flexibility is not a reliable predictor of injury.
Field and laboratory metabolism and thermoregulation in rhinoceros auklets
Authors: Umeyama Aika , Niizuma Yasuaki , Shirai Masaki 
Published: May 2021

Seabirds spend most of their lives at sea, except when visiting their breeding sites. Since the thermal conductivity of water is 25 times higher than that of air, seabirds resting on water lose heat and expend a considerable amount of energy for thermoregulation. For example, rhinoceros auklet (Cerorhinca monocerata), a medium-sized (480–620 g) alcid, spends most of its time floating on the sea. In order to estimate the cost of this behavior in terms of their daily energy expenditure (DEE), we studied rhinoceros auklets breeding on Teuri Island, Hokkaido Japan. We measured their resting metabolic rate (RMR) in air and on water by respirometry, and estimated their DEE by the doubly labeled water method. While RMR on water did not vary significantly between 10 °C and 15 °C, it was significantly higher at 5 °C. Air temperature (5.0–20.0 °C) had no effect on RMR. The DEE of free-ranging auklets averaged 1,005.5 kJ day−1(±130.2,n = 3). Our results indicate that RMRs are elevated for auklets resting on water, particularly below their lower critical temperature (LCT), compared with in air. Accordingly, spending time above their LCT on water at any time of year will provide enhanced benefits, particularly to seabirds such as rhinoceros auklets which rest a considerable amount of time on water.
Functional and Sensory Evaluation of Enriched Weaning Food Produced from Cereal, Legume and Vegetable
Authors: Izuwa Iwanegbe 
Published: May 2021

This study examined the functional and sensory properties of enriched weaning food produced from cereal, legume and vegetable. Maize, soybean and carrot were formulated into blends. Sensory evaluation, proximate and functional properties were determined. The data generated were analyzed. The results obtained showed that at 2 weeks, Samples D and F had the highest score (5.00) for colour quality while least score was recorded in sample E (2.00). At 4 weeks, Samples D and F had the same score (5.00) and Sample E also had the least colour score (2.00). At 0 week, there were no significant (p>0.05) change in the texture among Samples A (4.00), B (5.00), C (5.00), D (5.00), and F (5.00). At 0 week, Samples C (5.00) and D (5.00) had the highest score for overall acceptability. The least moisture was seen in defatted soybean (5.07%), this was followed by fermented maize (9.71%) and the highest moisture content was observed in carrot (12.91%). Defatted soybean had the highest (41.2%) protein content next was carrot (10.63%) and the least was maize (6.14%) in that decreasing order. The highest (270%) water holding capacity was observed in Sample E, this was followed by Samples D (240%), C (240%), B (166%) and A (140%) in that decreasing order. The highest value for oil absorption was seen in Sample C (144%), this was followed by Sample A (121%), D (120%), B (105%) and E (90%) in that order. In this study products C and D were preferred as they were able to compete favourably with the commercial diet (F=control). However, product D was more preferred having the best color quality, texture quality as well as good functional properties. This study recommends the complementary of maize flour by the supplementation of carrot at 15% and soybean 20% inclusion level for better sensory and functional characteristics.
Application of Phosphorus and Calcium to Improve Physiological Response of Groundnut (Arachis hypogaea L.)
Authors: Nyuma Henry Tamba , Kollie William S. , Rweyemamu Cornel. L. , Fayiah John S. 
Published: May 2021

Genotype, environment and agronomic practices are key determinants of crop growth and productivity which are important to provide food, feed, raw materials and income to small holder farmers in Africa. The study was conducted at Crop museum, Sokoine University of Agriculture, Morogoro, Tanzania to investigate physiological response of groundnut to calcium and phosphorus nutrition among three improved groundnut genotypes Mangaka (G1), Masasi (G2) and Pendo (G3) with three levels of phosphorus and at calcium control (T0), 125 kg/ha (T1) and 55 kg/ha (T2) supplied from Diammonium Phosphate (DAP) and Minjingu mazao, respectively. Significant (P< 0.05) influence of calcium was observed on leaf area index (LAI) 4.03; crop biomass 88.79 g/plant; number of nodules 66.22, and crop growth rate (CGR) 15.05 g m2/day. Whereas phosphorus had significant influence on net assimilation rate (NAR) 10.84 g m2/day. Similarly, groundnut genotype (Masasi) had significant influence on LAI (3.95); CGR (13.04 g m2/day); NAR (12.36 g m2/day) and number of nodes (64.93). However, there was no significant effect of genotype on crop biomass recorded from the investigation. Growth parameters were significant influenced by genotype and fertilizer interactions with Significant (P=0.2) interaction effect for crop biomass observed between G3 x T1, whileG3 x T2 significantly affected number of nodules and G2 x T1 had Significant interaction effects on CGR and NAR. This is an indication that investment in improved genotype and appropriate application rate of fertilizers has the potential to enhance yield and income of smallholder farmers.
Full-annealing and its effect on the Mechanical Properties of Alloy 304H Stainless Steel
Authors: Onwudili Anthony Edozie , Iweka Sunday Chukwuka 
Published: May 2021

Stainless steel is an alloy of steel which contains at least 10.5% chromium, less than 1.2% carbon, and other alloying elements and it is widely used in many industries globally and their properties are highly influenced by their microstructure, heat treatment or by plastic deformation. But due to hardness, poor wear, and corrosion resistance, leading to short service life, there is need to investigate the effect of annealing on the mechanical properties of alloy 304H stainless steel and how the mechanical properties can be improved with a view of improving its service life and optimizing engineering usage. Sixteen (16) samples of the alloy were used. Twelve (12) samples were annealed at three different temperatures of 950oC, 1000oC and 1050oC inside a muffle furnace. At each temperature four samples were heat-treated inside the muffle furnace for 30 minutes. The result showed that the yield strength decreased from un-annealed sample to annealed samples at 950oC with a value of 504.8MPa and increased at 1000oC with a value of 610MPa and a decrease of 323.8 MPa was obtained at 1050oC. Also, the ultimate tensile strength showed an increase from 950oC with a value of 826.3MPa to 1000oC with a value of 930MPa but there was a slight decrease at 1050oC for all samples. The ultimate tensile strength at 1000oC with a value of 930MPa was the highest in all the samples. The annealed samples at 1000oC had the highest percentage elongation of 13.57% which shows an increase in the ductility of the material. The hardness of the material decreased from 157.25 BHN at 950oC to 134.00BHN at 1000oC. An increase to 169.50BHN was however obtained at 1050oC. Thus, full-annealing of alloy 304H stainless steel at 1000oC increases in ductility as hardness decreases.
Evaluation of Antibacterial Properties of Different Leaf Extracts of Hyptis suaveolens (L) Poit
Authors: Erinle B. A. , Ajayi A. O. , Osuntokun O. T. 
Published: May 2021

Aim: Hyptis suaveolens is well known for its immense medicinal properties and are beneficial as folk medicine. The objective of the study is to investigate the efficacy of the leaves for it antimicrobial activity.
Material and Methods: The leaves of Hyptis suaveolens was subjected to extraction process using n-hexane, ethanol and distilled water as solvents and the antimicrobial activity was analyzed against different bacterial strains viz.; Escherichia coli, Proteus mirabilis, Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella aerogenes, Pseudomonas aeruginosa, Salmonella typhi, Enterococcus faecalis by agar well diffusion method.
Results: Aqueous extracts showed inhibitory effect against the different tested bacteria organisms with variable zone of inhibitory range 6 -21 mm.
Conclusion: The aqueous extracts of Hyptis suaveolens exhibited the presence of highly effective bio-active compounds in these extracts. These can further be evaluated and characterize to improve upon what has been done to create a novel compound that can be useful for various medicinal purposes.