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Niobium is recently considered one of the potential alloying elements for tool steels due to the formation of hard and stable carbides of MC type. Its use is limited by the fact that these carbides tend to coarsen during conventional melting metallurgy processing. This work explores the potential of additive manufacturing for processing Nb-alloyed tool steel with a high content of carbon. Directed energy deposition was used as the processing method. It was found that this method allowed us to obtain a microstructure very similar to that obtained after the use of consolidation via spark plasma sintering when subsequent heat treatment by soft annealing, austenitizing, oil quenching and triple tempering for secondary hardness was applied. Moreover, the soft annealing process could be skipped without affecting the structure and properties when machining would not be required. The hardness of the steel was even higher after additive manufacturing was used (approx. 800–830 HV 30) than after spark plasma sintering (approx. 720–750 HV 30). The wear resistance of the materials processed by both routes was almost comparable, reaching 5–7 × 10−6 mm3N−1m−1 depending on the heat treatment. [ABSTRACT FROM AUTHOR]

The launch of gravity-dedicated satellite missions at the beginning of the new millennium led to an accuracy improvement of global Earth gravity field models (GGMs). One of these missions was the Gravity field and steady-state Ocean Circulation Explorer (GOCE) launched in 2009. As the first European Space Agency's Earth Explorer Mission, the satellite carried a novel instrument, a 3-D gradiometer, which allowed measurement of the second-order directional derivatives of the gravitational potential (gravitational gradients) with a uniform quality and a near-global coverage. The main mission goal was to determine the static Earth's gravity field with the ambitious precision of 1-2 cm in terms of geoid heights and 1 mGal in terms of gravity anomalies for spatial resolution of 100 km (half wavelength at the equator). More than three years of the outstanding measurements resulted in three levels of data products (Level 0, Level 1b and Level 2), six releases of GGMs, and several global grids of gravitational gradients. The grids, which represent a step between gravitational gradients measured directly along the GOCE orbit and those represented by GGMs, found their usage mainly in geophysical applications. In this contribution, we validate the official Level 2 product GRD_SPW_2 using height anomalies over two test areas located in central and northern Europe (Czechia/Slovakia and Norway). A mathematical model based on the least-squares spectral weighting is employed with corresponding spectral weights estimated for validation of gravitational gradient grids. This model continues gravitational gradients from the mean orbital altitude of GOCE down to the irregular Earth's surface (not to a sphere) and transforms them to height anomalies in one computational step. Analytical downward continuation errors of the model are estimated using a closed-loop test. Prior to the comparison of height anomalies estimated from gravitational gradients with their reference values derived from Global Navigation Satellite Systems (GNSS)/levelling over the two test areas, the gravitational gradients and reference data are corrected for all systematic effects such as the tide system conversion. Moreover, the high-frequency part of the gravitational signal is estimated and subtracted from reference data as it is attenuated in the gravitational gradients measured by GOCE. A relative improvement between the release 6 and release 2 gradient grids reaches 48 % in terms of height anomalies in Czechia/Slovakia. The relative improvement in Norway is even more significant and reaches 55 % . The release 6 of the official Level 2 product GRD_SPW_2 gained the absolute accuracy with the standard deviation of 8.7 cm over Czechia/Slovakia and 9.3 cm over Norway. Article Highlights: A mathematical model based on the least-squares spectral weighting for validation of the official Level 2 product GRD_SPW_2 is presented Possibilities of the spectral combination method for the downward continuation of gravitational gradients and their transformation into height anomalies are investigated A review of quality of the official Level 2 product GRD_SPW_2 with respect to GNSS/levelling points over two test areas (Czechia/Slovakia and Norway) is provided [ABSTRACT FROM AUTHOR]

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A new housing technology double-chamber cow waterbeds should provide the animals with greater comfort improve their health and increase milk production. The study was carried out in the stable for dairy cows and heifers. They were stabled in free-stall housing. Rubber mattresses had been replaced with double-chamber cow waterbeds. The aim of the study was to determine their effect on comfort, health, occurrence of mastitis, count of somatic cells, total milk production. The study confirmed the reduction of number of animals with injuries of feet and incidence of mastitis. The values of somatic cells in milk were constant. Positive effect was shown with fluent increase in milk production. It increased the number of cows and heifers lying in the boxes.

the aim of our study was to evaluate influence of probiotic agents (Lactovita) and seaweed extracts (Biopolym) with antidiarrheal effects on the prevention of diarrhoea in calves. In the experiment 22 experimental and 22 control calves were observed. The results of the observed incidence of diarrhoea in the control and experimental groups showed a positive effect of probiotic Lactovita and seaweed extracts Biopolymer. 32% of calves in the experimental group and 45% of calves in the control group became sick. Unfortunately, we could not demonstrate the statistical significance of these differences. The weight gains found in the 4th week after birth were by 37.6% higher in the group with Lactovita and Biopolym than in the control group.

in this experiment it was used contactless measurement method using a thermographic camera. Surface temperatures were recorded from three different parts of the animal,(the surface of the core body, the eyes and the udde)r. The aim of this study was to determine how much the temperature values that are obtained using the thermographic camera are accurate.. Its accuracy depends on many factors such as particularly good settings of the thermographic camera, a microclimate of environment, an emissivity of measured object, the character and colour of the coat or the degree of muscles. It was also monitor the correlation of the measured surface temperatures with a rectal temperature, which is an indicative of the internal body temperature.

The aim of this study was to evaluate the effect of the housing system on the behaviour, performance, and health of dairy calves. The two-year study was conducted on 56 Holstein bull calves (from birth to 60 days of age) that were placed in individual hutches immediately after their birth. At the age of 31 days, 28 bull calves were moved to group hutches by four. The calves were weighed at birth, at 30 days, and at 60 days of age. The starter intake and health were recorded once a day. The behavioural activities of calves (lying, standing and cross-sucking, etc.) were analysed in 24-h cycles at 38 days and 53 days of age. The results showed that grouphoused calves spent less time lying and resting (P < 0.01) and more time standing (P < 0.01), receiving the starter (P < 0.05), drinking (P < 0.01), cross-sucking (P < 0.01), and social playing (P < 0.01) compared to individually housed calves. Conversely, calves from individually housing spent more time licking the housing surfaces (P < 0.05) and individual playing (P < 0.05). Bull calves housed from day 31 of age in the group hutches achieved a non-significantly higher body weight at weaning (by +3.0 kg), weight gain (by +2.8 kg), and a significantly higher (P < 0.05) starter intake (by +7.9 kg) compared to the individually housed calves. These results showed that housing in small groups allowed for the natural behaviour of calves and improved their growth without having adverse effects on their health. [ABSTRACT FROM AUTHOR]

Znalost rozsahu záplavových území pro jednotlivé N-leté povodňové události a konkrétní povodňové scénáře, včetně získané představy o hloubkách a rychlostech v podélném či příčném profilu vodního toku, které poskytují hydrodynamické modely, zaujímá výsadní postavení z pohledu ochrany životů a zmírnění škod na majetku občanů. Stěžejním faktorem pro tvorbu hydrodynamických modelů jsou vstupní data pro vytvoření výpočetní geometrie vodního toku. Požadavky na vstupní data se liší s ohledem na použitý hydrodynamický model. Jednorozměrné (1D) hydrodynamické modely se vyznačují nižšími požadavky na vstupní data, kdy výpočetní trať je tvořena příčnými profily koryta, naproti tomu u dvourozměrných (2D) hydrodynamických modelů je nutné sestavit pro celé řešené území digitální model reliéfu. S ohledem na vstupní data a použitý model roste i finanční náročnost celého projektu. Nárůst finančních prostředků je způsoben především vysokými náklady na geodetické zaměření koryta toku. Cílem příspěvku bylo ověřit a prezentovat vhodnost využití hydrologického měření při tvorbě schematizace (geometrie) vodních toků na podkladě výškopisných dat získaných metodou leteckého laserového skenování, které zabezpečuje Český úřad zeměměřický a katastrální. Zohlednění hydrologického měření při schematizaci vodního toku do hydrodynamického modelu spočívá v odvození dosaženého průtoku v době pořizování dat metodou leteckého laserového skenování a takto stanovené průtoky lze využít jako podklad pro zahloubení digitálního modelu reliéfu připraveného z dat leteckého laserového skenování. Daný princip tak nahrazuje zbývající část profilu koryta, která není metodou leteckého laserového skenování v digitálním modelu reliéfu reflektována. Je tak dosaženo požadované geometrie koryta vodního toku, jehož kapacita je shodná s hodnotou průtoku v přirozeném korytě.

The oxidative addition of CF3SO3CH2Si(CH3)3 (NpSiOTf) toward organopnictogen(I) N,C,N-pincer compounds, i.e. [2,6-(DippN＝CH)2C6H3]E (1-E, where E = Sb, Bi; Dipp = 2,6-iPr2C6H3) produced compounds [2,6-(DippN＝CH)2C6H3]E(NpSi)(OTf) (2-E, where E = Sb, Bi). By analogy, the in situ reduction of [2,6-(Me2NCH2)2C6H3]ECl2 (3-E, where E = Sb, Bi) followed by treatment with NpSiOTf or MeI gave compounds [2,6-(Me2NCH2)2C6H3]E(R)(X) (R/X = NpSi/OTf 4-E, where E = Sb, Bi; R/X = Me/I 5-Sb). The reactivity of these compounds toward 1 eq. of K[BEt3H] was examined showing remarkable differences depending both on the ligand backbone and the pnictogen used. Thus in the case of 2-E, the addition of the hydride across the imino-function was achieved thereby yielding azapnicta-heterocyclic compounds [2-(DippNCH2)-6-(DippN＝CH)C6H3]E(NpSi) (6-E, where E = Sb, Bi). The same reaction of 4-Bi produced dibismuthine {[2,6-(Me2NCH2)2C6H3]Bi(NpSi)}2 (7-Bi), but in the case of 4/5-Sb the analogous distibines {[2,6-(Me2NCH2)2C6H3]Sb(R)}2 (R = NpSi7-Sb, Me 8-Sb) were not formed directly and hydrides [2,6-(Me2NCH2)2C6H3]Sb(R)H (R = NpSi9-Sb, Me 10-Sb) could be isolated instead. Nevertheless, heating of both 9-Sb and 10-Sb led to an activation of a labile Sb–H bond and the formation of distibines 7/8-Sb. [ABSTRACT FROM AUTHOR]

Aims: Oak–hornbeam forests and related vegetation types (phytosociological order Carpinetalia betuli) are widespread in temperate western Eurasia. However, their national classification systems are poorly compatible, and a broad‐scale classification based on numerical analyses is lacking. Therefore, we aimed to establish a unified formalized classification system based on a large data set of vegetation plots covering the entire range of these forests. Location: Europe, Anatolia, Caucasus and northern Iran. Methods: We compiled a data set of 15,817 vegetation plots from the European Vegetation Archive and the Hyrcanian Forest Vegetation Database, using the formal definition of the EUNIS habitat type T1E Carpinus and Quercus mesic deciduous forest. We classified the data set using TWINSPAN. Biogeographically and ecologically similar plot clusters were merged into oak–hornbeam forest types, which were interpreted as alliances. We also developed expert systems for automatically classifying vegetation at the alliance level for both the EuroVegChecklist (EVC) system and the revised classification. In addition, we calculated ordinations to show the major gradients in the species composition of the data set. Results: We present a revised classification system of the order Carpinetalia betuli with nine alliances, including basic descriptions of their species composition, distribution, ecology and syntaxonomy. The analyses largely supported the biogeographic concept of classification, analogous to EVC. Compared to EVC, we recognized an additional alliance Physospermo verticillati‐Quercion cerridis (southern Italy) but found no support for the alliances Astrantio‐Carpinion, Erythronio‐Carpinion and Scillo‐Quercion. The greatest difference in species composition was found between the southern and northern‐northeastern Carpinetalia types. Expert systems for the revised classification system (~89% of plots classified) and the EVC system (~72%) are also included. Conclusions: We provide the first comprehensive overview of alliances of the order Carpinetalia betuli across its whole distribution range. The associated expert systems allow consistent application of the classification of these forests in nature conservation, habitat monitoring, and biodiversity and ecological research.We provide the first formal classification for oak–hornbeam forests and related vegetation types (phytosociological order Carpinetalia betuli) across Europe and adjacent areas. It includes both traditional and revised classifications of this vegetation. Furthermore, we developed expert systems for vegetation‐plot assignment to vegetation types, which can be applied in research and biodiversity conservation, monitoring and management. [ABSTRACT FROM AUTHOR]

The Caucasus Region belongs among the most remarkable biodiversity hotspots globally. Local mountain floodplain forests represent highly endangered ecosystems and possess the status of protective forests. However, they have not been extensively phytosociologically assessed using Braun-Blanquet methods to date. Here, we present a novel dataset of vegetation plots recorded in two remarkable areas of forest plant diversity in this region. They were Enguri (Black Sea watershed) and Aragvi (Caspian Sea watershed) River basins in the Western and Eastern Greater Caucasus, respectively. Based on 49 relevés, sampled on a broad elevation gradient (980-1830 m), we distinguished three vegetation types using unsupervised classification. Main gradients in their species composition reflect biogeographical and climatic differences. Alnus incana dominated two types. The Enguri type (Brunnero macrophyllae-Alnetum incanae) was characterized by numerous species typical of the western part of the Greater Caucasus, including tall forbs and mountain species. The Aragvi type (Veronico filiformis-Alnetum incanae) showed a diagnostic combination of common Caucasian species and relatively thermophilous forest species. The subdivision of this unit included three subtypes according to grazing intensity. The last type (Sedo stoloniferi-Alnetum barbatae) was significant by a putative Tertiary relict Alnus glutinosa subsp. barbata as a canopy dominant. It occupied lower elevations of the Enguri Region, significantly influenced by the nearby Colchic Region. To provide a regional context of the sampled vegetation, we compiled an expanded dataset of alluvial alder forests from the Caucasus and its surroundings. Their joint classification highlighted the uniqueness of the recorded communities with A. incana and clearly distinguished them from the Euxinian alliance Alnion barbatae delimited by relict species typical of the Colchic refugium (e.g. Diospyros lotus, Pterocarya fraxinifolia). A comparison of the Caucasian A. incana forests with the alluvial forests of the boreonemoral alliance Alnion incanae supported the individuality of the Caucasian stands in terms of floristic composition and allowed us to describe them as a new alliance (Veronico filiformis-Alnion incanae all. nova). It is characterized by the dominance of A. incana accompanied by numerous geographically restricted species (e.g. Senecio propinquus, Symphytum asperum) coupled with boreo-montane forest species (e.g. Oxalis acetosella, Polygonatum verticillatum). Caucasian alluvial forests face many ongoing threats, including constructing of new water reservoirs and hydropower plants, overgrazing and illegal cutting. [ABSTRACT FROM AUTHOR]

It has been empirically known that the coercivity of rare-earth permanent magnets depend on the size and shape of fine particles of the main phase in the system. Also, recent experimental observations have suggested that the atomic scale structures around the grain-boundaries of the fine particles play a crucial role to determine their switching fields. In this article, we review a theoretical attempt to describe the finite temperature magnetic properties and to evaluate the reduction of the switching fields of fine particles of several rare-earth permanent magnet materials based on an atomistic spin model that is constructed using first-principles calculations. It is shown that, over a wide temperature range, the spin model gives a good description of the magnetization curves of rare-earth intermetallic compounds such as R2Fe14B (R = Dy, Ho, Pr, Nd, Sm) and SmFe12. The atomistic spin model approach is also used to describe the local magnetic anisotropy around the surfaces of the fine particles, and predicts that the rare-earth ions may exhibit planar magnetic anisotropy when they are on the crystallinestructure surfaces of the particles. The dynamical simulation of the atomistic spin model and the corresponding micromagnetic simulation show that the planar surface magnetic anisotropy causes a reduction in the switching field of fine particles by approximately 20-30%, which may be relevant to the atomic scale surface effects found in the experimental studies. [ABSTRACT FROM AUTHOR]

Commercially supplied inoculation wires have a guaranteed chemical composition but not the size and distribution of individual phases, which are very important for nucleation. Therefore, two commercial alloys used for the inoculation of Al-Si alloys (AlTi3B1 and AlTi5B1) are investigated in this paper. The emphasis is placed on their structural analysis and the size and distribution of individual intermetallic phases. Furthermore, the grain refinement effect will be tested by adding these alloys to the AlSi7Mg0.3 alloy and testing the optimal amount of added inoculation wires. The results showed that the size and distribution of the individual phases in AlTi3B1 and AlTi5B1 meet the requirements for the successful inoculation of aluminum alloys, the intermetallic phases based on the TiAl3 phase are fine enough, and there is no agglomeration that would reduce the number of nuclei. This assumption was confirmed by adding these inoculants to the AlSi7Mg0.3 alloy, and it was found that the most ideal amount of inoculants added is 0.01 wt % when the structure was refined by approximately 32%. [ABSTRACT FROM AUTHOR]