bluuebunny/crossref_metadata_2025 huggingface dataset:
АКТУАЛЬНОСТЬ ВВЕДЕНИЯ В РАЦИОНЫ ЦЫПЛЯТ-БРОЙЛЕРОВ РЕГУЛЯТОРНОГО КОМПЛЕКСА «БАЙПАС»
Authors: Капитонова Е.А. , Сагинбаева М.Б , Янченко В.В.
Published: October 2021

Наряду с такими факторами, как повышение сохранности, улучшение качества кормов, суточных рационов, оптимизация условий содержания птицы, широкое применение получают различные кормовые добавки. Эффект таких добавок обусловлен их регули-рующим влиянием на интенсивность процессов переваривания и использования питательных веществ корма, что создает возможность целенаправленного управления этими процессами. В статье приведены результаты исследований при использовании регуляторного комплекса «Байпас» в кормлении цыплят-бройлеров по периодам роста и развития. Регуляторный комплекс «Байпас» нормализует энергетический обмен (набор органических кислот принимающих участие в цикле трикарбоновых кислот), активирует деятельность печени (гепатопротектор, флавоноиды), стимулирует функционирование кишечника (пробиоти-ческие компоненты) повышает ферментативную активность (витамины) и обогащает организм птицы комплексом аминокислот. «Байпас» является специальной кормовой добавкой, которая содержит аминокислоты, несинтезирующие в организме птицы, такие как лизин, метионин, триптофан, треонин [13]. Рядом исследований выявлено, что «Байпас» отлично замещает функции искусственных аминокислот в организме, в особенности метионина. Способствует улучшению обмена веществ у птицы при ликвидации метабо-лических нарушений, что приводит к удлинению периода продуктивности и повышением нормативных показателей. В результате проведенных исследований отмечено, что наличие в комбикормах данного комплекса положительно сказывается на жизнеспособности и динамики роста и развития птицы. Замена стандартных аминокислот на регуляторный комплекс «Байпас» (3-я группа) позволила раскрыть генетический потенциал цыплят-бройлеров кросса «Росс-308» и получить максимальные результаты по продуктивности.
АЛМАТЫ ХАЙУАНАТТАР БАҒЫНДА МЕКЕН ЕТЕТІН АҚБӨКЕНДЕРДІҢ БИОЛОГИЯЛЫҚ ЕРЕКШЕЛІКТЕРІ ЖӘНЕ ОЛАРДЫ КҮТІП БАҒУДАҒЫ МІНЕЗ ҚҰЛҚЫНЫҢ ОРТАҒА БЕЙІМДЕЛУІ
Authors: Байбатшанов М.К , Бейсенбаева М.Т , Акилбеков С.О
Published: October 2021

Мақалада Алматы хайуанаттар бағында мекен ететін ақбөкендердің бетпақдала және орал популяцияларында мекен ететін түршелері, биологиялық еркешеліктері, таралу ареалы, ғылымдағы жүйеленуі, елімізде мекендейтін ақбөкендердің таралуы, әлемдегі хайуанаттар бағындағы ақбөкендердің өсуі және оларды өсіруде туындайтын мәселелерді шешу туралы мәліметтер келтірілген. Ақбөкендерді қолда өсірудің жолдары, мінез құлқының ортаға бейімделуі, азықтандыру ерекшеліктері, мінез-құлықтағы өзгешеліктері жан-жақты қарастырылған. Алматы хайуанаттар бағының құрылу кезеңдері, ERAZA, WAZA, SEAZA сияқты зообақтар мен аквариумдардың әлемдік ассоциациясына мүше екендігіне тоқталған. Жануарлардың мінез-құлқын зерттеудің негізгі тәсілдерін хайуанаттар бағында үздіксіз қолдана отырып тұрақты зерттеу жұмыстарын жүргізілетіне, соның ішінде тұяқтылардың мінез құлқын басқарудың жаңа әдістемелері қалыптасқанын келтірген. Алматы хайуанаттар бағында тұрақты түрде өсіп өніп келе жатқан ақбөкендердің мінез құлқына жан-жақты тоқталып соның ішінде көбею кезіндегі аталықпен аналықтың іс-әрекеттеріне тоқталып, иіс сезудің ақбөкеннің өміріндегі маңызына, өзара дыбыстауы, демалу яғни ұйықтаудың өмірдегі алатын орны, шудың алатын орны, жалпы ақбөкендердің мінез-құлқының өзгерістерге ұшырағанын, олардың адамнан қорғану рефлексі өзгергенің, адам жақындауына назар аудармайтын қарастырған. Ақбөкендерді өсірудегі қоршаудың басты талаптарына көбірек зерттеу жүргізетін хайуанаттар бағының қызметкерлерінің зерттеулеріне тоқталған.
СКРИНИНГ ПРИЗНАКОВОЙ КОЛЛЕКЦИИ ЧЕЧЕВИЦЫ В УСЛОВИЯХ АЛМАТИНСКОЙ ОБЛАСТИ
Authors: Сайкенова А.Ж. , Кудайбергенов М.С. , Нургасенов Т.Н. , Сайкенов Б.Р. , Сейлхан А.С.
Published: October 2021

В статье представлены результаты трехлетних исследовании, основной целью работы являлось оценка и отбор сортообразцов чечевицы с высокой урожайностью, пригодных для механизированной уборки - высокорослых с высоким прикреплением нижних бобов, дружно созревающих и неосыпающихся, а так же устойчивых к стрессовым факторам для исполь-зования в селекции. При этом задачами исследованиии было изучение сортообразцов чечевицы в двух агроэкологических зонах: в условиях полуобеспечененной богары и в условиях орошения на Юго-Востоке Казахстана, с установлением сроков вегетации; фенотипированием хозяйственно-ценных признаков и свойств; определением качества зерна чечевицы. В качестве материала были использованы сортообразцы чечевицы различного эколого-географического происхождения (31 сортообазец). Они различались между собой по основным хозяйственно-ценным признакам и биологическим свойствам. Были проведены фенологические наблюдения и оценка в двух агроэкологических зонах. Фенотипирование элементов продуктивности проводились по методике изучения коллекции зернобобовых культур. Биохимическим анализом определили содержание белка в зерне чечевицы. Авторами данной статьи были выделены сортообразцы с высокой урожайностью и высоким содержанием протеина, которые представляют интерес для селекции. Все выделенные сортообразцы будут использованы в селекционном процессе с целью создания высоко-урожайных, высококачественных, устойчивых к засухе.
CASE ANALYSIS OF HEAT PUMP INTEGRATION IN DISTRICT HEATING SYSTEM
Authors: Rogoža Artur , Šiupšinskas Giedrius , Bielskus Juozas
Published: October 2021

The installation of heat pumps in district heating (DH) systems is one of the most promising technologies to increase the efficiency of heat supply by using renewable energy sources and reducing heat carrier temperatures in the networks. The possibilities of installing heat pumps in DH systems are very wide, but most often the main purpose of their application is to increase the temperature of the supplied heat carrier at the heat substations of individual consumers or their groups. This paper describes a study that analyzed the possibilities of integrating an individual heat pump at a heat substation in a building to reduce the temperature of the heat carrier in the return line. The results of the study revealed the dependences of the reduction of the heat demand of the building from the DH network, the power of the heat pump, the coefficient of performance (COP), and the reduction of the return temperature.
orvara: An Efficient Code to Fit Orbits Using Radial Velocity, Absolute, and/or Relative Astrometry
Authors: Brandt Timothy D. , Dupuy Trent J. , Li Yiting , Brandt G. Mirek , Zeng Yunlin , Michalik Daniel , Bardalez Gagliuffi Daniella C. , Raposo-Pulido Virginia
Published: October 2021

We present an open-source Python package, Orbits from Radial Velocity, Absolute, and/or Relative Astrometry (orvara), to fit Keplerian orbits to any combination of radial velocity, relative astrometry, and absolute astrometry data from the Hipparcos-Gaia Catalog of Accelerations. By combining these three data types, one can measure precise masses and sometimes orbital parameters even when the observations cover a small fraction of an orbit. The computational performance of orvara is achieved with an eccentric anomaly solver 5–10 times faster than commonly used approaches and low-level memory management to avoid Python overheads and by analytically marginalizing out parallax, barycenter proper motion, and instrument-specific radial velocity zero-points. Through its integration with the Hipparcos and Gaia intermediate astrometry package htof, orvara can properly account for the epoch astrometry measurements of Hipparcos and the measurement times and scan angles of individual Gaia epochs. We configure orvara with modifiable .ini configuration files tailored to any specific stellar or planetary system. We demonstrate orvara with a case study application to a recently discovered white dwarf/main-sequence system, HD 159062. By adding absolute astrometry to literature radial velocity and relative astrometry data, our comprehensive Markov Chain Monte Carlo analysis improves the precision of HD 159062B’s mass by more than an order of magnitude to

0.6083

−
0.0073

+
0.0083

M
☉. We also derive a low eccentricity and large semimajor axis, establishing HD 159062AB as a system that did not experience Roche lobe overflow.
UV Fluorescence Traces Gas and Lyα Evolution in Protoplanetary Disks
Authors: Arulanantham Nicole , France Kevin , Hoadley Keri , Schneider P. C. , Espaillat Catherine C. , Günther H. M. , Herczeg Gregory J. , Brown Alexander
Published: October 2021

Ultraviolet spectra of protoplanetary disks trace distributions of warm gas at radii where rocky planets form. We combine Hubble Space Telescope Cosmic Origins Spectrograph observations of H2 and CO emission from 12 classical T Tauri stars to more extensively map inner disk surface layers, where gas temperature distributions allow radially stratified fluorescence from the two species. We calculate empirical emitting radii for each species under the assumption that the line widths are entirely set by Keplerian broadening, demonstrating that the CO fluorescence originates further from the stars

r
∼
20

au

than the H2

r
∼
0.8

au

. This is supported by 2D radiative transfer models, which show that the peak and outer radii of the CO flux distributions generally extend further into the outer disk than the H2. These results also indicate that additional sources of Lyα photons remain unaccounted for, requiring more complex models to fully reproduce the molecular gas emission. As a first step, we confirm that the morphologies of the UV–CO bands and Lyα radiation fields are significantly correlated and discover that both trace the degree of dust disk evolution. The UV tracers appear to follow the same sequence of disk evolution as forbidden line emission from jets and winds, as the observed Lyα profiles transition between dominant red wing and dominant blue wing shapes when the high-velocity optical emission disappears. Our results suggest a scenario where UV radiation fields, disk winds and jets, and molecular gas evolve in harmony with the dust disks throughout their lifetimes.
Metallicity Dependence of the H/H2 and C+/C/CO Distributions in a Resolved Self-regulating Interstellar Medium
Authors: Hu 胡 Chia-Yu 家瑜 , Sternberg Amiel , van Dishoeck Ewine F.
Published: October 2021

We study the metallicity dependence of the H/H2 and C+/C/CO distributions in a self-regulated interstellar medium (ISM) across a broad range of metallicities (0.1 < Z/Z
⊙ < 3). To this end, we conduct high-resolution (particle mass of 1 M
⊙) hydrodynamical simulations coupled with a time-dependent H2 chemistry network. The results are then post-processed with an accurate chemistry network to model the associated C+/C/CO abundances, based on the time-dependent non-steady-state (“nonequilibrium”) H2 abundances. We find that the time-averaged star formation rate and the ISM structure are insensitive to metallicity. The column densities relevant for molecular shielding appear correlated with the volume densities in gravitationally unstable gas. As metallicity decreases, H2 progressively deviates from steady state (“equilibrium”) and shows shallow abundance profiles until they sharply truncate at the photodissociation fronts. In contrast, the CO profile is sharp and controlled by photodissociation as CO quickly reaches steady state. We construct effective 1D cloud models that successfully capture the time-averaged chemical distributions in simulations. At low metallicities, the steady-state model significantly overestimates the abundance of H2 in the diffuse medium. The overestimated H2, however, has little impact on CO. Consequently, the mass fraction of CO-dark H2 gas is significantly lower than what a fully steady-state model predicts. The mass ratios of H2/C+ and H2/C both show a weaker dependence on

Z

′

than H2/CO, which potentially indicates that C+ and C could be alternative tracers for H2 at low

Z

′

in terms of mass budget. Our chemistry code for post-processing is publicly available.
Multiphase Powerful Outflows Detected in High-z Quasars
Authors: Chartas G. , Cappi M. , Vignali C. , Dadina M. , James V. , Lanzuisi G. , Giustini M. , Gaspari M. , Strickland S. , Bertola E.
Published: October 2021

We present results from a comprehensive study of ultrafast outflows (UFOs) detected in a sample of 14 quasars, 12 of which are gravitationally lensed, in a redshift range of 1.41–3.91, near the peak of the active galactic nucleus (AGN) and star formation activity. New XMM-Newton observations are presented for six of them, which were selected to be lensed and contain a narrow absorption line (NAL) in their UV spectra. Another lensed quasar was added to the sample, albeit already studied because it was not searched for UFOs. The remaining seven quasars of our sample are known to contain UFOs. The main goals of our study are to infer the outflow properties of high-z quasars, constrain their outflow induced feedback, study the relationship between the outflow properties and the properties of the ionizing source, and compare these results to those of nearby AGN. Our study adds six new detections (> 99% confidence) of UFOs at z > 1.4, almost doubling the current number of cases. Based on our survey of six quasars selected to contain a NAL and observed with XMM-Newton, the coexistence of intrinsic UV NALs and UFOs is found to be significant in >83% of these quasars suggesting a link between multiphase AGN feedback properties of the meso- and microscale. The kinematic luminosities of the UFOs of our high-z sample are large compared to their bolometric luminosities (median of L
K/L
Bol ≳ 50%). This suggests they provide efficient feedback to influence the evolution of their host galaxies and that magnetic driving may be a significant contributor to their acceleration.
Reverberation Mapping of Two Luminous Quasars: The Broad-line Region Structure and Black Hole Mass
Authors: Li Sha-Sha , Yang Sen , Yang Zi-Xu , Chen Yong-Jie , Songsheng Yu-Yang , Liu He-Zhen , Du Pu , Luo Bin , Yu Zhe , Hu Chen , Jiang Bo-Wei , Bao Dong-Wei , Guo Wei-Jian , Zhang Zhi-Xiang , Li Yan-Rong , Xiao Ming , Lu Kai-Xing , Ho Luis C. , Bai Jin-Ming , Bian Wei-Hao , Aceituno Jesús , Minezaki Takeo , Horne Keith , Kokubo Mitsuru , Wang Jian-Min
Published: October 2021

We report the results of a multiyear spectroscopic and photometric monitoring campaign of two luminous quasars, PG 0923+201 and PG 1001+291, both located at the high-luminosity end of the broad-line region (BLR) size–luminosity relation with optical luminosities above 1045 erg s−1. PG 0923+201 is monitored for the first time, while PG 1001+291 was previously monitored but our campaign has a much longer temporal baseline. We detect time lags of variations of the broad Hβ, Hγ, and Fe ii lines with respect to those of the 5100 Å continuum. The velocity-resolved delay map of Hβ in PG 0923+201 indicates a complicated structure with a mix of Keplerian disk-like motion and outflow, and the map of Hβ in PG 1001+291 shows a signature of Keplerian disk-like motion. Assuming a virial factor of f
BLR = 1 and FWHM line widths, we measure the black hole mass to be

118

−
16

+
11

×

10

7

M

⊙

for PG 0923+201 and

3.33

−
0.54

+
0.62

×

10

7

M

⊙

for PG 1001+291. Their respective accretion rates are estimated to be

0.21

−
0.07

+
0.06

×

L

Edd

c

−
2

and

679

−
227

+
259

×

L

Edd

c

−
2

, indicating that PG 0923+201 is a sub-Eddington accretor and PG 1001+291 is a super-Eddington accretor. While the Hβ time lag of PG 0923+201 agrees with the size–luminosity relation, the time lag of PG 1001+291 shows a significant deviation, confirming that in high-luminosity active galactic nuclei (AGNs), the BLR size depends on both luminosity and Eddington ratio. Black hole mass estimates from single-AGN spectra will be overestimated at high luminosities and redshifts if this effect is not taken into account.
Estimating Magnetic Filling Factors from Simultaneous Spectroscopy and Photometry: Disentangling Spots, Plage, and Network
Authors: Milbourne T. W. , Phillips D. F. , Langellier N. , Mortier A. , Haywood R. D. , Saar S. H. , Cegla H. M. , Collier Cameron A. , Dumusque X. , Latham D. W. , Malavolta L. , Maldonado J. , Thompson S. , Vanderburg A. , Watson C. A. , Buchhave L. A. , Cecconi M. , Cosentino R. , Ghedina A. , Gonzalez M. , Lodi M. , López-Morales M. , Sozzetti A. , Walsworth R. L.
Published: October 2021

State-of-the-art radial velocity (RV) exoplanet searches are limited by the effects of stellar magnetic activity. Magnetically active spots, plage, and network regions each have different impacts on the observed spectral lines and therefore on the apparent stellar RV. Differentiating the relative coverage, or filling factors, of these active regions is thus necessary to differentiate between activity-driven RV signatures and Doppler shifts due to planetary orbits. In this work, we develop a technique to estimate feature-specific magnetic filling factors on stellar targets using only spectroscopic and photometric observations. We demonstrate linear and neural network implementations of our technique using observations from the solar telescope at HARPS-N, the HK Project at the Mt. Wilson Observatory, and the Total Irradiance Monitor onboard SORCE. We then compare the results of each technique to direct observations by the Solar Dynamics Observatory. Both implementations yield filling factor estimates that are highly correlated with the observed values. Modeling the solar RVs using these filling factors reproduces the expected contributions of the suppression of convective blueshift and rotational imbalance due to brightness inhomogeneities. Both implementations of this technique reduce the overall activity-driven rms RVs from 1.64 to 1.02 m s−1, corresponding to a 1.28 m s−1 reduction in the rms variation. The technique provides an additional 0.41 m s−1 reduction in the rms variation compared to traditional activity indicators.
Short-term Spectroscopic Variability of the Early Post-AGB Stage Star IRAS 22272+5435
Authors: Začs Laimons , Puķı̄tis Kārlis
Published: October 2021

High-resolution spectra gathered during an extensive monitoring of IRAS 22272+5435 are inspected to search for spectroscopic variability in the time span of less than 2 weeks. Significant variation are found both in the intensity and position of CN(1, 0) red system lines near the light maximum, when the star is the hottest. The intensity of variable CN lines correlates with their Doppler redshift—an increase in the radial velocity leads to a decrease of its equivalent width. The inward flow of increasing velocity from ≃14.4–21.6 km s−1 was confirmed in the atmosphere, propagating ∼25 R
☉ toward the mass center of the star in 11 days. The variability of CN(1, 0) lines are accompanied by changes in the red wings of strong low-excitation lines. The observed short-term variations are attributed to large-scale convective flows and shock waves in the extended atmosphere of a cool pulsating post-AGB star.
An Arecibo Search for Fast Radio Transients from M87
Authors: Suresh Akshay , Chatterjee Shami , Cordes James M. , Crawford Fronefield
Published: October 2021

The possible origin of millisecond bursts from the giant elliptical galaxy M87 has been scrutinized since the earliest searches for extragalactic fast radio transients undertaken in the late 1970s. Motivated by rapid technological advancements in recent years, we conducted ≃10 hr of L-band (1.15–1.75 GHz) observations of the core of M87 with the Arecibo radio telescope in 2019. Adopting a matched filtering approach, we searched our data for single pulses using trial dispersion measures up to 5500 pc cm−3 and burst durations between 0.3–123 ms. We find no evidence of astrophysical bursts in our data above a 7σ detection threshold. Our observations thus constrain the burst rate from M87 to ≲ 0.1 bursts hr−1 above 1.4 Jy ms, the most stringent upper limit obtained to date. Our nondetection of radio bursts is consistent with expectations of giant pulse emission from a Crab-like young neutron star population in M87. However, the dense, strongly magnetized interstellar medium surrounding the central ∼109
M
⊙ supermassive black hole of M87 may potentially harbor magnetars that can emit detectable radio bursts during their flaring states.
Investigating Toroidal Flows in the Sun Using Normal-mode Coupling
Authors: Mani Prasad , Hanasoge Shravan
Published: October 2021

Helioseismic observations have provided valuable data sets with which to pursue the detailed investigation of solar interior dynamics. Among various methods to analyze these data, normal-mode coupling has proven to be a powerful tool, used to study Rossby waves, differential rotation, meridional circulation, and nonaxisymmetric multiscale subsurface flows. Here, we invert mode-coupling measurements from the Helioseismic Magnetic Imager and the Michelson Doppler Imager to obtain mass-conserving toroidal convective flow as a function of depth, spatial wavenumber, and temporal frequency. To ensure that the estimates of velocity magnitudes are proper, we also evaluate correlated realization noise, caused by the limited visibility of the Sun. We benchmark the near-surface inversions against results from local correlation tracking. The convective power likely assumes greater latitudinal isotropy with a decrease in spatial scale of the flow. We note the absence of a peak in toroidal-flow power at supergranular scales, in line with observations that show that supergranulation is dominantly poloidal in nature.
Optical Transients from Fast Radio Bursts Heating Companion Stars in Close Binary Systems
Authors: Yang Yuan-Pei
Published: October 2021

Fast radio bursts (FRBs) are bright radio transients with short durations and extremely high brightness temperatures, and their physical origins are still unknown. Recently, a repeating source, FRB 20200120E, was found in a globular cluster in the very nearby M81 galaxy. The associated globular cluster has an age of ∼9.13 Gyr, and hosts an old population of stars. In this work, we consider that an FRB source is in a close binary system with a low-mass main-sequence star as its companion. Due to the large burst energy of the FRB, when the companion star stops the FRB, its surface would be heated by the radiation-induced shock, and make reemission. For a binary system with a solar-like companion star and an orbital period of a few days, we find that the reemission is mainly at an optical band, with delays of a few seconds after the FRB. Its luminosity is several times larger than the solar luminosity, and the duration is about hundreds of seconds. Such a transient might be observable in a future multiwavelength follow-up observation for Galactic FRB sources.
New data on the fauna of casebearer moths (Lepidoptera, Coleophoridae) of Omsk Province, Russia
Authors: Anikin Vasily V. , Knyazev Svyatoslav A.
Published: October 2021

The information on the casebearer moth family Coleophoridae from Omsk Province was summarized based on the determination of materials collected by the second author in 2014-2020. There is a list of 31 species, among them, 21 new regional records from the territory of Omsk Province are given. Two species (Casignetella occatella (Staudinger, 1880) and Ecebalia proterella (Wikström et Tabell, 2016) are new to the Asian part of Russia. The total number of Coleophoridae from Omsk Province is increased to 55.
Description of a new Xenorhina species (Anura, Microhylidae) from northwestern Papua New Guinea
Authors: Günther Rainer , Dahl Chris , Richards Stephen J.
Published: October 2021

Abstract

We describe a new species of the asterophryine microhylid genus Xenorhina from the lowlands of northwestern Papua New Guinea. It is a medium-sized species (SUL of two males 29.2 and 29.9 mm; of four females 29.9–33.0 mm) that can be distinguished from congeners by having a single short, triangular odontoid spike (palatal tooth) on each vomeropalatine bone, moderately short legs (TL/SUL 0.40–0.44) and ventral surfaces heavily spotted with reddish-brown blotches or reticula. The advertisement call comprises 7–10 loud, melodious hooting notes lasting 141–165 ms and produced at a repetition rate of 2.19–2.35 notes/s. Description of this species brings to 41 the number of Xenorhina known from New Guinea and surrounding islands.
Contrôle de gestion « as a system » ou « as a package » : étude comparée des entreprises du Cameroun, de Djibouti et du Sénégal
Authors: Osman Moussa Awaleh , Choukem Claire , Bampoky Boniface
Published: October 2021

Cet article présente une étude qualitative réalisée dans trois pays d’Afrique francophone : Le Cameroun, Djibouti, et le Sénégal. Son objectif est de vérifier que le contrôle de gestion des entreprises de ces trois pays repose sur une démarche formelle en cohérence avec les outils et les pratiques managériales (gestion des ressources humaines, communication, etc.) : en d’autres termes ces derniers orientent-ils ensemble le comportement des salariés (contrôle de gestion « as a system ») ou forment-ils un assemblage plus ou moins cohérent avec d’autres pratiques formelles ou informelles (contrôle de gestion « as a package »). Des entretiens ont été menés auprès de quatre-vingt-huit - 88 - entreprises. Notamment l’étude révèle que la structure de propriété est un facteur déterminant les pratiques de contrôle de gestion au sein des entreprises.
Comment la didactique des mathématiques peut-elle informer l’étude de la cognition numérique ? L’exemple d’une étude collaborative autour de la pédagogie Montessori à l’école maternelle
Authors: Gardes Marie-Line , Croset Marie-Caroline , Courtier Philippine , Prado Jérôme
Published: October 2021

Les études sur l’apprentissage des mathématiques ont tout à gagner de regards croisés et pluridisciplinaires, notamment entre les sciences cognitives et les sciences de l’éducation. Plus particulièrement, la didactique des mathématiques semble pertinente pour apporter des informations complémentaires à l’étude de la cognition numérique. Dans cet article, nous présentons les points de convergences et les spécificités de chacun de ces domaines scientifiques puis nous illustrons les apports d’une approche pluridisciplinaire en discutant d’une étude que nous avons récemment menée sur l’apprentissage des mathématiques au sein de la pédagogie Montessori à l’école maternelle. Nous montrons en quoi le regard didactique a permis de concevoir une méthodologie de recherche à la fois quantitative et qualitative, de questionner et élaborer des outils de mesure et d’interpréter les résultats obtenus.
On the number of critical points of solutions of semilinear elliptic equations
Authors: Grossi Massimo
Published: October 2021

In this survey we discuss old and new results on the number of critical points of solutions of the problem

   $ \begin{equation} \begin{cases} -\Delta u = f(u)&in\ \Omega\\ u = 0&on\ \partial \Omega \end{cases} \;\;\;\;\;\;\;\;(0.1)\end{equation} $

where $ \Omega\subset \mathbb{R}^N $ with $ N\ge2 $ is a smooth bounded domain. Both cases where $ u $ is a positive or nodal solution will be considered.
Explaining the definition of wholesale access prices in the Portuguese telecommunications industry
Authors: Ribeiro Vitor Miguel , Pereira Fernando Lobo , Gonçalves Rui
Published: October 2021

The 2016–2018 triennium was a period marked by a fierce dispute between the European Commission and Autoridade Nacional de Comunicações, Portugal, on the need to regulate wholesale access prices. While the European Commission defended the imposition of Fiber-To-The-x regulation in non-competitive areas, the Portuguese sectoral regulator argued in favor of the persistence of Fiber-To-The-x deregulation. Following a Game Theory approach, the present study demonstrates that the transition from Fiber-To-The-x deregulation to Fiber-To-The-x regulation should only occur when a given territorial unit becomes a competitive area since the subgame perfect Nash equilibrium captures a regulatory framework optimally characterized by the imposition of active access price deregulation (regulation) in non-competitive (competitive) areas, that is, local administrative units characterized by a weak (strong) degree of vertical spillover, respectively. Meanwhile, ducts access regulation must be permanently imposed throughout the national territory, despite it can be relaxed in competitive areas if the regulator imposes intra-flexibility to establish a monopolistic bottleneck to ensure social welfare maximization. Previous conclusions require to introduce both facility-based and service-based competition at the entry stage as well as active and passive obligations at the regulation stage in a multi-stage game with complete information. The present analysis legitimizes the emergence of a new optimization theory in the telecommunications literature, whose modus operandi is contrary to (coincident with) the ladder of investment theory in non-competitive (competitive) areas, respectively. Differently from the view sustained by the ladder of investment theory, which defends that a short-term regulatory touch combined with long-term market deregulation is a socially optimal strategy, the new theory confirms that a regulatory intervention is socially desirable only in the long run. The conceptual refinement is meticulously explained and labeled as the theory of creative creation because, differently from the Schumpeterian gale of creative destruction, whose processes of industrial mutation are permanently market-driven by assumption, a period of regulatory holidays followed by successive regulatory interventions dependent on the degree of vertical spillover observed in the telecommunications industry can effectively promote investment realization that continuously revolutionizes the market structure from within, incessantly destroying the old technology. The theory of creative creation reflects the regulatory framework currently in force in the Portuguese Telecommunications Industry.
Reduction of impurity sources in Si crystal growth system with electron gun beam heating
Authors: Kravtsov Anatoly , Virbulis Janis , Krauze Armands
Published: October 2021

A new series of experiments was conducted to determine the source of impurities in the process of silicon crystal growth with electron beam heating. A gas-dynamic window was placed between the electron gun and growth chamber. Also positively-charged traps were placed along the crucible to reduce the number of electrons hitting the chamber and the crucible. Five experiments were conducted: two with the window, two with charge traps, and one with both the window and charge traps. The analysis of obtained samples showed that the gas-dynamic window decreases the content of Al, Cu, Fe, Cr and O2, and the trap, used in the experiments, decreases the content of Fe, Cr and Cu in residues of the melt. The content of all impurities, except Al, is close to the goal level. Al impurities come only from the gun, but the gas-dynamic window cannot eliminate them completely. It seems that Al impurities come either as neutral atoms carried by the gas or as positively charged ions. To reduce these impurities, a separation of the Al flow from the beam by the magnetic field is proposed.
Fabrication and Characterization of Composite Materials Using Multiple Waste Materials (Leather & Jute Fabrics) and Unsaturated Polyester Resin
Authors: Ali Md. Farhad , Hossain Md. Sahadat , Ahmed Samina , Chowdhury A.M. Sarwaruddin
Published: October 2021

Now a days environment is getting polluted due to different types of manmade reasons than ever for extreme use of synthetic materials. Various kinds of waste materials from numerous industries are also enhancing this. So, Utilization of waste materials and reduction of synthetic materials will definitely subside the environmental pollution. In this research, waste jute fabric and leather waste (cow hides) were used as reinforcing agent and unsaturated polyester resin (UPR) as matrix to prepare environmental friendly composite materials. Hand-lay up method was conducted to fabricate composite materials. Different percentages of waste leather and used jute fabrics were used with the UPR. Improved mechanical properties, tensile strength (TS), tensile modulus (TM), and percentage elongation at break (EB) were observed with the certain percentage of waste materials. Composites were also characterised by the scanning electron microscope (SEM) and fourier transform infrared (FTIR).
The Effect of Nanoparticles (n-HAp, n-TiO2) on the Thermal Properties and Biomechanical Analysis of Polymeric Composite Materials for Dental Applications
Authors: Mohammed Alaa A. , Oleiwi Jawad K. , Al-Hassani Emad S.
Published: October 2021

Polyetheretherketone (PEEK), as implants is broadly employed in orthopedic and dental uses owing to the brilliant chemical stability, biocompatibility and mechanical strength in addition to the modulus of elasticity alike the human bone. In the present work, the composite materials with PEEK as matrix and (n-HAp, n-TiO2) as the reinforced fillers loaded up to (1.5 wt%) were prepared by internal mixer and hot press. Following analysis by physical properties includes the thermal conductivity and the differential scanning calorimetry. Finite element analysis (FEA) was used to find the total deformation, Max. Von mises stress, elastic strain and safety factor. The results manifested that the thermal properties, total deformation and strain decreased with the increase of the reinforcement weight fraction, while, the stress and safety factor increased with the increased reinforcement weight fraction.
Liquid-Phase Exfoliation of Graphene in Organic Solvents with Addition of Picric Acid
Authors: Shah Syed Sajid Ali , Nasir Habib , Honey Shehla
Published: October 2021

In this work, graphene was produced by liquid-phase exfoliation of graphite in different organic solvents with addition of picric acid. The graphene was easily produced by one step ultra-sonication of graphite powder in the organic solvents. The addition of picric acid has increased the graphene production yield in most of the solvents tested in this work. Picric acid serves as a “molecular wedge” to intercalate into the edge of graphite, which plays a key role during sonication and significantly improves the production yield of graphene. The products were analyzed by microscopic techniques, including atomic force microscopy (AFM) and scanning electron microscope (SEM). The AFM images indicate that the exfoliation efficiency and amount of graphene increased by addition of picric acid in organic solvents. Moreover, the AFM images also indicate presence of bilayer graphene. SEM analysis also shows that the addition of picric acid into the organic solvent favors the exfoliation process. The produced graphene was also analyzed by XRD, FTIR, Raman and UV-visible spectroscopy. The XRD results illustrate that exfoliation was best achieved in N-methyl-2-pyrrolidone (NMP) as a solvent. FTIR and Raman results indicate that addition of picric acid has slightly defected the produced graphene surface. The amount of graphene concentration was calculated by using Beer Lambert law, and it was observed that the graphene production yield was increased by using picric acid in most of the solvents. The maximum amount of graphene concentration (0.159 mg/ml) was achieved by adding 30 mg of picric acid in NMP.
Design of High-Strength Concrete for Ready-Mixed Concrete Production
Authors: Ťažký Martin , Křížová Klára
Published: October 2021

The high-strength concrete is a cement composite reaching high compressive strength, namely, pursuant to the legislation, higher than 60 MPa in the terms of cube compressive strength. The development of high-strength concretes exceeding 100 MPa is still an up-to-date issue and the production of these concretes is still limited only to a prefabrication. Contemporary construction industry and projecting activity have begun to focus on a construction of statically demanding buildings, which can include e.g. high-rise buildings. Such projecting often requires using of the state-of-the-art materials like cement composites with high mechanical parameters for construction of more subtle buildings. Within this article, the procedure of ready-mixed concretes development with the compressive strength around 100 MPa designed according to a project documentation for actual construction of high-rise building with the height up to 160 meters and 46 floors is described, together with the influence of the aggregate on the resulting composite strength.
Degradation of Materials Based on Alkali-Activated Blast-Furnace Slag after Exposure to Aggressive Environments
Authors: Plšková Iveta , Hrubý Petr , Topolář Libor , Matysík Michal
Published: October 2021

The paper summarizes partial results of a study of degradation of materials based on alkali-activated blast-furnace slag (AAS) and comparative on cement CEM III/A 32.5 R after exposure to aggressive environments. It further specifies the possibilities for utilising destructive and non-destructive techniques to determine the progress of degradation and characterizes the degree of their correlation. After 28 days of ageing in a water environment, the produced test specimens (40×40×160 mm beams) were placed in aggressive media (ammonium nitrate solutions; sodium sulfate, rotating water) and after subsequent 28, 56 and 84 days of degradation were subjected to testing. Testing comprised both a destructive form (determination of compressive strength and flexural strength) and a selected non-destructive technique (Impact-echo method). The partial outputs were supplemented by the results acquired from monitoring weight changes. In addition, the development of Ultrasonic Pulse Velocity in relation to the progress of the degradation processes was also monitored. While the exposure of both test specimens to water and sodium sulfate did not result in any significant changes, the exposure to the ammonium nitrate solution exhibited rapid signs of degradation associated with a significant reduction in functional characteristics.
Cement-Bonded Sub-Base Layers of Walkable and Running Structures for Rainwater Management
Authors: Ťažký Martin , Hela Rudolf , Hubertová Michala
Published: October 2021

Sub-base layers of walkable and running road structures usually consist of a stable subsoil with sufficient load-bearing capacity under the surface layer itself in the form of concrete covers or prefabricated paving elements. Due to their load-bearing capacity, these sub-base layers are most often constructed using cement-bonded aggregate technology. The current hot topic of rainwater management brings opportunities for the construction of water-permeable structures with good water retention capacity. The retention capacity of such a structure can be ensured in ideal conditions by making this sub-base partially permeable and with an absorbent layer while maintaining its mechanical advantages. The experiment confirmed the possibility of producing cement-bonded sub-base layers using light porous aggregates based on expanded clays. The high absorption rate of the type of aggregate used is a good starting point for increasing the retention capacity of the entire system.
Analysis of Alkali Oxides Influence on the Microstructure of Refractory Grog
Authors: Nevřivová Lenka , Zemánek David
Published: October 2021

The development and subsequent production of these special kind of grog from raw materials available in the Czech Republic is one of the possibilities how to reduce income costs for the production of refractory materials with specific properties. The experimental work is focused on verifying the possibility of producing grog with increased alumina content from available raw materials. The raw materials are kaolins and claystones. To achieve a higher content of alumina in the grog, waste mullite dust is used. In order to improve the physical and mechanical properties of the grog, modifiers are used. Selected modifiers are expected to affect positively on the resulting density while maintaining the heat properties.
A Numerical Approach to Multiscale Simulation of Cement Paste Strength
Authors: Hlobil Michal , Sotiriadis Konstantinos
Published: October 2021

Recent experimental investigations on the nanoscale of hardened cement paste revealed that the tensile strengths of the microstructural phases present amount to several hundreds of MPa. Confrontation with macroscopic tensile strength testing, by e.g. Brazilian splitting, shows a decrease over two orders of magnitude. A computational model based on a hierarchical representation of hardened cement paste microstructure is presented in this paper, attempting to shed light on the factors affecting the scaling of strength from the nanoscopic scale up to the macroscopic scale. The model is validated on a case study featuring a Portland-limestone cement paste subjected to an external sulfate attack. Such conditions compromise the nanoscopic integrity of the C-S-H gel as a consequence of the progressive decalcification and affect the overall load-bearing capacity of the macroscopic cement paste specimen.
Monitoring of the Effect of Grinding Raw Material Mixture and Soaking on the Formation of Monoclinic Phases of Alite
Authors: Ravaszová Simona , Dvořák Karel
Published: October 2021

The article monitors the effect of length of grinding in the process of homogenization of raw material mixture and soaking on the number of monoclinic phases of alite M1 and M3 in the sample using the Rietveld method. The wet grinding process in the water environment in the planetary mill PULVERISETTE 6 was chosen for the preparation of raw material mixture. Based on previous research in this area, two firing temperatures 1450 and 1550 °C with soaking of 30, 60 and 90 minutes were selected. The results showed the monoclinic phase M1 is more readily formed during coarser grinding, during which large crystals of M1 are formed. On the contrary, the monoclinic phase M3 is formed at a higher firing temperature, at a larger amount nuclei and finer grinding. The results show that the grinding time has an important effect on the rate of formation of monoclinic phases.
Does gender role influence the pattern of internet and computer use among physiotherapy undergraduates?
Authors: Jayalath L. , Samaranayake D.
Published: October 2021

Gender roles affect some components of life and whether this difference persist in using advanced technologies such as computers and internet is unclear. Aim of this study was to compare the computer and internet using patterns among male and female physiotherapy undergraduates. Methods: Out of the registered physiotherapy undergraduates, 92 participated in the study with a response rate of 80%. A pre-tested self-administered questionnaire was used to collect data from students in first to final academic years. Data analysis was done using SPSS version 20. Results: Out of participants, 37% (n=34) were males and age ranged from 19 to 26 years. Majority of 95.7% (n=88) participants owns a computer and 64.1% (n=59) mainly use it for entertainment. Females tend to seek more formal learning computer classes compared to males. Majority of study participants spend more than 8 hours per week to go online and values were 29.4% (n=10) for males and 25.9% (n=15) for females. Conclusion: A significant relationship was seen between gender and formal learning classes for computers. Usage time and purposes did not show any difference among genders. Internet was used mainly for entertainment and secondly for social communication in both genders.
The Trypanosome-Derived Metabolite Indole-3-Pyruvate Inhibits Prostaglandin Production in Macrophages by Targeting COX2
Authors: Diskin Ciana , Corcoran Sarah E , Tyrrell Victoria J , McGettrick Anne F , Zaslona Zbigniew , O’Donnell Valerie B , Nolan Derek P , O’Neill Luke A J
Published: October 2021

The protozoan parasite Trypanosoma brucei is the causative agent of the neglected tropical disease human African trypanosomiasis, otherwise known as sleeping sickness. Trypanosomes have evolved many immune-evasion mechanisms to facilitate their own survival, as well as prolonging host survival to ensure completion of the parasitic life cycle. A key feature of the bloodstream form of T. brucei is the secretion of aromatic keto acids, which are metabolized from tryptophan. In this study, we describe an immunomodulatory role for one of these keto acids, indole-3-pyruvate (I3P). We demonstrate that I3P inhibits the production of PGs in activated macrophages. We also show that, despite the reduction in downstream PGs, I3P augments the expression of cyclooxygenase (COX2). This increase in COX2 expression is mediated in part via inhibition of PGs relieving a negative-feedback loop on COX2. Activation of the aryl hydrocarbon receptor also participates in this effect. However, the increase in COX2 expression is of little functionality, as we also provide evidence to suggest that I3P targets COX activity. This study therefore details an evasion strategy by which a trypanosome-secreted metabolite potently inhibits macrophage-derived PGs, which might promote host and trypanosome survival.
mRNA vaccines: Why and how they should be modified
Authors: Feliciello Isidoro , Procino Alfredo
Published: October 2021

The COVID-19 pandemic has stimulated the production of different therapeutic approaches for the resolution of coronavirus infections. On one hand, nanobiomolecules have been proposed as bait material for viruses,1,2 on the other hand unconventional messenger RNA vaccines have been produced like SARS-CoV-2 mRNA vaccines (BioNTech/Pfizer BNT162b2 and Moderna mRNA-1273). [...]
Spontaneous Rupture of Hepatocellular Carcinoma at First Presentation
Authors: Ebrahim Ebrahim , Ageila Munir Abu , Abdurabu Mohammed , Twair Akram , Ali Rubab , Neffati Nedia
Published: October 2021

Hepatocellular carcinoma (HCC) is the leading primary malignancy of the liver and typically develops in the background of chronic liver disease, particularly those with cirrhosis due to viral hepatitis B and C. Ruptured tumor is the most serious complication of HCC primarily occurring in older patients with significant mortality rate. In this report, we present a case of acute abdomen with the features of impending shock as the first presentation of a spontaneously ruptured HCC in a previously healthy young man.