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Number of results: 140
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Abstract

In 1979 54 water samples were collected at two oceanographic stations located in Admiralty Bay. Ranges of seasonal changes were found for the values of ten parameters: water temperature, salinity, dissolved О, pH, the contents of PO4 , Si, NO2, NO3, chlorophyll α and plant carotenoids at six depths between surface and 400 m. Data for temperature and salinity showed the absence of distinct thermoclines or haloelines which reflects the very low stability of waters in the Bay. The concentrations of nutrients were high during the entire year and they were not limiting for phytoplankton growth. Only nitrates decreased distinctly during algal blooms. The high dynamics of waters in the Bay causes a lowering in the chlorophyll α content to a maximum of about 2 mg/m3. Oceanographic, hydrochemical and hydrological conditions in Admiralty Bay are typical for the Antarctic shelf waters in this geographical region.
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Abstract

Early lactation period in dairy cows could be harmful to their health since it is challenging and demanding. Proinflammatory cytokine concentrations are increased in the early phase of the inflammatory response and during the early lactation period in cows. The aim of this study was to determine if ketoprofen treatment in the first days following parturition would decrease proinflammatory cytokine concentration and their correlation between lipid mobilization, ketogenesis and metabolic parameters in cows. The study was conducted on 30 cows divided into two groups of 15 cows each. The experimental group was treated with 3 mg × kg.bw.-1 ketoprofen for three consecutive days after parturition. The blood samples were collected on the first day of treatment and in the first and second week postpartum and they were analyzed for biochemical parameters such as non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), glucose, cholesterol and total bilirubine and inflammatory parameters such as tumour necrosis factor-α (TNF-α), interleukin-1α (IL-1α) and interferon-γ (IFN-γ). The results suggested that ketoprofen- treated cows had a significantly lower concentration of TNF-α, IL-1α, IFN-γ, NEFA and BHBA in the first and second postpartum week compared to the control group. Ketoprofen administration increased glucose levels (the first week, p<0.05), increased cholesterol levels (the second week, p<0.01) and decreased serum total bilirubin levels (second week, p<0.01) compared to the control group of cows. A positive correlation was found between TNF-α and NEFA and total bilirubin, significantly more expressed in the control than in experimental group of cows (p<0.01) and it was also found between IL-1α and NEFA (p<0.01). A negative correlation was found between TNF-α and glucose and cholesterol, significantly more expressed in the control than in experimental group of cows (p<0.01). A positive correlation was also found between IL-1α and glucose (p<0.01). Ketoprofen given parenterally to Holstein cows immediately after calving could reduce inflammation and decrease the relation between inflammatory response and lipogenesis and ketogenesis in postpartum cows.
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Abstract

Flying bird counts were carried out at Esperanza Bay (62°24'S, 56°59'W), Antarctic Peninsula, between November 1989 and February 1990. Six breeding species (Oceanites oceanicus, Chionis alba, Catharacta lonnbergi, Catharacta maccormicki, Larus dominicanus and Sterna vittata) and six visitor species (Macronectes giganteus, Fulmarus glacialoides, Daption capense, Pagodroma nivea, Fregetta tropica and Phalacrocorax atriceps) were recorded. Kelp gull and Antarctic tern populations have decreased in relation to the data by previous authors, perhaps as a result of the increased activity at Esperanza Station. Cygnus melanocoryphus was recorded for the first time at Esperanza Bay.
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Abstract

The paper presents the results of the Ti10V2Fe3Al alloy crack resistance assessment using the Rice’s J-integral technique as a function of morphology and volume fraction of α-phase precipitates. Titanium alloys characterized by the two-phase structure α + β are an interesting alternative to classic steels with high mechanical properties. Despite the high manufacturing costs and processing of titanium alloys, they are used in heavily loaded constructions in the aerospace industry due to its high strength to density ratio. The literature lacks detailed data on the influence of microstructure and, in particular, the morphology of α phase precipitates on fracture toughness in high strength titanium alloys. In the following work an attempt was made to determine the correlation between the microstructure and resistance to cracking in the Ti10V2Fe3Al alloy.
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Abstract

Sixty seven zooplankton taxa were recorded in a total of 5 WP-2 net vertical hauls carried out in a year round cycle in Admiralty Bay. Copepoda were the most common and abundant group and Oithona similis was the dominant species throughout the area. Polychaeta, Ostracoda and Chaetognatha were also rather common and abundant. Euphausiacea, Amphi-poda and Salpae occured mainly in the central part and the outlet area of the bay. No differences in zooplankton assemblages diversity in the four investigated areas of Admiralty Bay were en­countered. However, distinct differences in species richness between the zooplankton of Ezcurra Inlet and the main basin of the bay were observed. The composition of zooplankton was rather stable throughout the year, but seasonal occurrences of larvae of Polychaeta, Crustacea, Echino-dermata and Ascidiacea were noted. A Ust of the 174 zooplankton taxa ever found in Admiralty Bay is presented by combining the present results with the existing scientific data.
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Abstract

After several years of research, the foraminiferal fauna of Admiralty Bay (King George Island, South Shetland Islands) has become themost studied fiord in West Antarctica with respect to foraminifera. As such, it provides actualistic data for better understanding of paleoenvironmental records from this dynamically changing area. Over a few years, the bay was systematically sampled down to 520 m water depth, for multi−chambered and mono− thalamous benthic foraminifera, including soft−walled allogromiids often overlooked in for− mer studies. Altogether, 138 taxa were identified, and three new taxa described. This paper aims to integrate these results, put them into a broader perspective, and supplement them with information that was not presented to date. Most notably, a record of the vertical distribution of Rose Bengal stained foraminifera below the sediment surface and the proportions of soft and robustly−testate forms at different sites are described.
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Abstract

At the turn of October 1985, the abundance of breeding Adelie penguins was estimated at the Hope Bay oasis on the Antarctic Peninsula and on Seymour Island. In the Hope Bay rookery, 123850 pairs of penguins were recorded, beginning their breeding at the end of October. Data so far obtained indicate a continuous increase in the number of birds sat this rookery. On the other hand, the Seymour Island colony consisted of 21954 pairs of Adélie penguins. Clear differences in the geomorphological structure of areas occupied by penguins in those two places are discussed. No gentoo penguins were detected in either of the colonies.
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Abstract

Pinnipeds were monitored in Admiralty Bay between 1988 and 1992. No particular trends during this period were found, but seasonal changes in each are distinct. It is suggested that the phenology of pinnipeds and that of penguins ensures low competition for food between these groups.
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Abstract

Studies on the quantity and distribution of organic carbon (DOC and РОС) in the water of the Admiralty Bay were conducted between 20 December 1978 and 15 February 1979. The С org. content ranged from 1.62 to 3.22 mg 1-1 for DOC and from 0.22 to 0.65 mg x 1-1 for РОС. Maximal DOC amounts were observed at the depth 25—50 m (on average about 2.50 mg x 1-1 ) and in chosen regions of surface waters of the Admiralty Bay, among others, in the vicinity of a large penguin colony. Mean content of DOC in waters of the Admiralty Bay (about 2.26 mg x 1-1 ) is lower as compared to mean DOC content in waters of the Bransfield Strait (about 4.12 mg x 1-1).
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Abstract

This study describes the seasonal and annual changes in the diet of non-breeding male Antarctic fur seals (Arctocephalus gazella) through the analysis of faeces collected on shore during four summer seasons (1993/94-1996/97) in the area of Admiralty Bay (King George Island, South Shetlands). Krill was the most frequent prey, found in 88.3% of the 473 samples. Fish was present in 84.7% of the samples, cephalopods and penguins in 12.5% each. Of the 3832 isolated otoliths, 3737 were identified as belonging to 17 fish species. The most numerous species were: Gymnoscopelus nicholsi, Electrona antarctica , Chionodraco rastrospinosus, Pleuragramma antarcticum, and Notolepis coatsi. In January, almost exclusively, were taken pelagic Myctophidae constituting up to 90% of the total consumed fish biomass. However, in February and March, the number of bentho-pelagic Channichthyidae and Nototheniidae as well as pelagic Paralepididae increased significantly, up to 45% of the biomass. In April the biomass of Myctophidae increased again. The frequency of squid and penguin occurrence was similar and low, but considering the greater individual body mass of penguins, their role as a food item may be much greater. In March and April, penguins could be as important prey item as fish. The amount of krill in the diet of Antarctic fur seals declined with a concomitant decrease in the mature krill availability. This appears to have been compensated by an increased frequency of the fur seal to eat fish and penguins.
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Abstract

This study aims to design a novel air cleaning facility which conforms to the current situation in China, and moreover can satisfy our demand on air purification under the condition of poor air quality, as well as discuss the development means of a prototype product. Air conditions in the operating room of a hospital were measured as the research subject of this study. First, a suitable turbulence model and boundary conditions were selected and computational fluid dynamics (CFD) software was used to simulate indoor air distribution. The analysis and comparison of the simulation results suggested that increasing the area of air supply outlets and the number of return air inlets would not only increase the area of unidirectional flow region in main flow region, but also avoid an indoor vortex and turbulivity of the operating area. Based on the summary of heat and humidity management methods, the system operation mode and relevant parameter technologies as well as the characteristics of the thermal-humidity load of the operating room were analyzed and compiled. According to the load value and parameters of indoor design obtained after our calculations, the airflow distribution of purifying the air-conditioning system in a clean operating room was designed and checked. The research results suggested that the application of a secondary return air system in the summer could reduce energy consumption and be consistent with the concept of primary humidity control. This study analyzed the feasibility and energy conservation properties of cleaning air-conditioning technology in operating rooms, proposed some solutions to the problem, and performed a feasible simulation, which provides a reference for practical engineering.
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Abstract

After the banking crisis, the European Union (EU) introduced a framework for the restructuring and orderly liquidation of credit institutions. The overarching goal of the new rules is to manage severe banking crisis more efficiently. One of the main pillars of the European bank resolution regime are the powers of the resolution authorities to use resolution tools (sale of business, bridge bank, bad bank and bail-in). However, the question arises whether the implemented toolkit will be sufficient to effectively contain systemic banking crisis. The literature regarding empirical research on the effectiveness of the BRRD tools provides ambiguous conclusions. Therefore, the newly established resolution authorities in the EU were asked to express their opinion about their readiness to combat systemic crisis and the usefulness of the accessible toolkit. The evaluation of the effectiveness of the resolution tools in a systemic crises by the resolution authorities showed that the most effective resolution tool seems to be the bad bank, while bank liquidation was rated as the least appropriate. Nevertheless, the resolution authorities also identified many barriers for all resolution tools that may limit the ability of their implementation and possibly translate into the lower effectiveness of the resolution framework.
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Abstract

The new legislative provisions, regulating the trade in solid fuels in our country, draw attention to the need to develop and improve methods and methods of managing hard coal sludge. The aim of the work was to show whether filtration parameters (mainly the permeability coefficient) of hard coal sludge are sufficient for construction of insulating layers in landfills at the stage of their closing and what is the demand for material in the case of such a procedure. The analysis was carried out for landfills for municipal waste in the Opolskie, Śląskie and Małopolskie provinces. For hard coal sludge, the permeability coefficient values are in the range of 10–8–10–11 m/s, with the average value of 3.16 × 10–9 m/s. It can be concluded that this material generally meets the criteria of tightness for horizontal and often vertical flows. When compaction, increasing load or mixing with fly ash from hard coal combustion and clays, the achieved permeability coefficient often lowers its values. Based on the analysis, it can be assumed that hard coal sludge can be used to build mineral insulating barriers. At the end of 2016, 50 municipal landfills were open in the Opolskie, Śląskie and Małopolskie Provinces. Only 36 of them have obtained the status of a regional installation, close to 1/3 of the municipal landfill are within the Major Groundwater Basin (MGB) range. The remaining storage sites will be designated for closure. Assuming the necessity to close all currently active municipal waste landfills, the demand for hard coal sludge amounts to a total of 1,779,000 m3 which, given the assumptions, gives a mass of 2,704,080 Mg. The total amount of hard coal sludge production is very high in Poland. Only two basic mining groups annually produce a total of about 1,500,000 Mg of coal sludge. The construction of insulating layers in landfills of inert, hazardous and non-hazardous and inert wastes is an interesting solution. Such an application is prospective, but it will not solve the problem related to the production and management of this waste material as a whole. It is important to look for further solutions.
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Abstract

Significant quantities of coal sludge are created during the coal enrichment processes in the mechanical processing plants of hard coal mines (waste group 01). These are the smallest grain classes with a grain size below 1 mm, in which the classes below 0.035 mm constitute up to 60% of their composition and the heat of combustion is at the level of 10 MJ/kg. The high moisture of coal sludge is characteristic, which after dewatering on filter presses reaches the value of 16–28% (Wtot r) (archival paper PG SILESIA). The fine-grained nature and high moisture of the material cause great difficulties at the stage of transport, loading and unloading of the material. The paper presents the results of pelletizing (granulating) grinding of coal sludge by itself and the piling of coal sludge with additional material, which is to improve the sludge energy properties. The piling process itself is primarily intended to improve transport possibilities. Initial tests have been undertaken to show changes in parameters by preparing coal sludge mixtures (PG SILESIA) with lignite coal dusts (LEAG). The process of piling sludge and their mixtures on an AGH laboratory vibratory grinder construction was carried out. As a result of the tests, it can be concluded that all mixtures are susceptible to granulation. This process undoubtedly broadens the transport possibilities of the material. The grain composition of the obtained material after granulation is satisfactory. Up to 2 to 20 mm granules make up 90–95% of the product weight. The strength of the fresh pellets is satisfactory and comparable for all mixtures. Fresh lumps subjected to a test for discharges from a height of 700 mm can withstand from 7 to 14 discharges. The strength of the pellets after longer seasoning, from the height of 500 mm, shows different values for the analyzed samples. The values obtained for hard coal sludge and their blends with brown coal dust are at the level from 4 to 5 discharges. The strength obtained is sufficient to determine the possibility of their transport. At this stage of the work it can be stated that the addition of coal dust from lignite does not cause the deterioration of the material’s strength with respect to clean coal sludge. Therefore, there is no negative impact on the transportability of the granulated material. As a result of mixing with coal dusts, it is possible to increase their energy value (Klojzy-Karczmarczyk at al. 2018). The cost analysis of the analyzed project was not carried out.
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Abstract

In the process of extraction and enrichment of coal waste, considerable quantities of waste material are produced, mainly the gangue and coal sludge, considered as waste or raw material. The main directions of the management development of the waste rock are the production of aggregates, the production of energy products and the liquidation works in hard coal mines and the filling of excavations. The paper proposes the extension of these activities to the use of waste material. The possibility of using aggregates or extractive waste to fill open-pit excavations has been proposed, also in areas within the reach of groundwater and the possibility of building insulation layers of waste material and the production of mixtures of hard coal sludge and sewage sludge to produce material with good energy properties. The analysis was based on the author’s own research and literature data related to selected parameters of waste material. This paper presents our own preliminary studies on the amount of combustion heat and the calorific value of coal sludge combined with other wastes such as sewage sludge. The proposed methods and actions are part of the current directions of development, but they allow the extension of the scope of use of both extractive waste and products produced on the basis of gangue or coal sludge. Due to the frequent lack of the stable composition of these materials, their current properties should be assessed each time before attempting to use them. The fact that it is important to continue research to promote existing economic use and to seek new activities or methods has been concluded.
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Abstract

The aim of the study is to determine the mercury content in hard coal, randomly taken from the USCB and in by-products of hard coal mining (fresh mining waste), i.e. aggregates (gangue) and hard coal sludge and mining waste from the Siersza dump (weathered waste). The 34 samples were intended for analysis. The total mercury content and the amount of mercury leaching from solid samples was determined. The percentage of the leaching form in the total element content, i.e. the level of mercury release from the material (leaching level), was also calculated. The amount of mercury leaching was determined by a static method using a batch test 1:10. The highest possibility of leaching mercury is characterized by weathered waste from the Siersza dump and slightly lower analyzed hard coal from the U pper Silesian Coal Basin (USCB). For hard coal samples, the total mercury content is between 0.0275–0.1236 mg/kg. However, the amount of mercury leaching from coal samples is 0.0008–0.0077 mg/kg. The aggregate is characterized by a higher total mercury content in the finest fraction 0–6 mm, within 0.1377–0.6107 mg/kg and much lower in the 80-120 mm fraction, within 0.0508–0.1274 mg/kg. The amount of elution is comparable in both fractions and amounts to 0.0008–0.0057 mg/kg. Coal sludge has a total mercury content of 0.0937–0.2047 mg/kg. L ow leaching values of 0.0014–0.0074 mg/ kg are also observed. Weathered mining waste has a total mercury content of 0.0622–0.2987 mg/kg. However, leaching values from weathered waste are much higher than from fresh mining waste. This value is 0.0058–0.0165 mg/kg. In the hard coal extracted from U SCB, the leaching level is 4.7% on average. Mining waste is characterized by a large variation in the proportion of mercury leaching form and the differences result from the seasoning time of the samples. Waste or by-products of hard coal production, such as aggregates and coal sludge, show a mercury washout form at an average level of 1.7%. The proportion of leachable form in weathered waste increased strongly to 7.3%. Elution characteristics vary for different groups of materials tested. Factors such as the type and origin of samples, their granulometric composition and the seasoning time of the material are of fundamental importance and demonstrated in the work.
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Abstract

Meteorological conditions at Arctowski Station during 2013–2017 were presented against the background of regional climate changes, especially air temperature decline. Air temperature, relative air humidity, air pressure, solar radiation, wind speed and direction, snow cover and precipitation were collected with an automatic weather station and manual measurements and were further analysed. The obtained results were compared with data from previous years and with data from other stations located on King George Island. Our observations confirm that the vicinity of Arctowski Station experienced a decrease in air temperature during summer, which supports the hypothesis of regional cooling.
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Abstract

Cumacean crustaceans found in 188 qualitative and quantitative samples of zoobenthos collected in Admiralty Bay (King George Island, South Shetlands) by successive Polish Antarctic Expeditions in the years 1977 — 1989 were studied. In over 3000 individuals of these crustaceans 12 taxa were recognized. Eudorella splendida clearly dominated the material. Other common species were Campylaspis maculata and Vaunthompsonia inermis. The highest cumacean density amounted to 2618 ind.m-2 . Clear differences were observed between cumacean faunas of small grain sediment (muddy Ezcurra Inlet) and of mixed, coarser sediments (central part of Admiralty Bay with sand, gravel and mud). The dominance of Eudorella splendida was strongly marked in shallow Ezcurra Inlet whereas in deeper central part of Admiralty Bay the cumacean fauna was much more diversifield.
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Abstract

Net phytoplankton cell numbers in 50 m water column of Admiralty Bay ranged between 0.2 x 10 5 x m-2 on 24 August 1990 and 2.3 x 10 7 x m-2 on 15 November 1990. Cluster analysis has confirmed the presence of two groups of samples: spring and summer ones (October to April), rich in cells and in species, and, on the other hand, winter samples (June to August) impoverished in algae. Spring and summer fluctuations of diatoms were mainly due to Corethron criophilum, Rhizosolenia alata and its varieties, R. hebetata f. semispina, Thalassiosira spp., Chaetoceros spp., and Nitzschia spp. (Fragilariopsis and Pseudonitzschia groups). The abundance and succession of species in Admiralty Bay reflect seasonal differences in diatom growth; they also reflect mixed populations of the Weddell and Bellingshausen seas entering Admiralty Bay via Bransfield Strait. Striking poverty of algae in some summer samples can most likely be attributed to zooplankton grazing.
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Abstract

This paper presents some preliminary data on the quantitative distribution of Tanaidacea in Admiralty Bay, mainly in its Ezcurra Inlet. On the soft bottom of this inlet, and especially its small glacial lagoon, Herve Cove, the highest abundance but the lowest species richness of Tanaidacea was found. In the central basin of Admiralty Bay, much higher species richness was observed along with much lower tanaid abundance.
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Abstract

Objects that have come within the inventory are the effect of whaling activity car­ried out in the region of South Shetland Islands in the first half of the twentieth century. They in­clude mainly bones of hunted animals, rarely wooden or metal objects, part of which may be re­lated to the whaling industry. In this paper the areas of particular accumulation of these objects have been determined, and the attempts to explain the reasons for such accumulations have been made. In addition, certain suggestions for further investigations into whaling activity in the South Shetland Islands region have been put forward. During the work 158 large fragments of whale skulls, among others, have been inventoried. The total number of individuals whose pre­served relics have been explored within the surveyed sections of the Admiralty Bay shores has been estimated to be 210-230.
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Abstract

Zooplankton community composition, abundance and biomass from two polar localities – Kongsfjorden (Arctic) and Admiralty Bay (Antarctic) is compared. The community composition of zooplankton in both polar regions included similar taxonomic groups and the diversity at the species level was similar. Even though the overall species composition was different, some species were common for both ecosystems, for example Oithona similis, Microcalanus pygmaeus or Eukrohnia hamata. The abundance and biomass of the main zooplankton components (Copepoda) differed greatly between the two ecosystems, both being of an order of magnitude higher in Kongsfjorden than in Admiralty Bay. Kongsfjorden is situated at the border of two regions what induces high productivity with copepods playing an important role, and there is also a strong advection into the fjord. Admiralty Bay is adjacent to the homogenous Antarctic oceanic ecosystem; some advection into the bay occurs as an effect of tide and wind driven processes. Antarctic krill, which was not included in the present study, occupies most of the primary consumers niche and replaces copepods at the second trophic level.
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Abstract

The scope of this work is to investigate the precipitation of two Al-Mg-Si alloys with and without Cu and excess Si by using the differential scanning calorimetry (DSC), transmission electron microscopic (TEM), Vickers hardness measurement and X-ray diffraction. The analysis of the DSC curves found that the excess Si accelerate the precipitation and the alloy contain the excess Si and small addition of copper has higher aging-hardness than that of free alloy (without excess Si and Cu) at the same heat treatment condition. The sufficient holding time for the precipitation of the β'' phase was estimated to be 6 hours for the alloy aged at 100°C and 10 hours for the alloy aged at 180°C. The low Copper containing Al-Mg-Si alloy gives rise to the forming a finer distribution of β (Mg2Si) precipitates which increases the hardness of the alloy. In order to know more about the precipitation reactions, concern the peaks on the DSC curve transmission electron microscopy observation were made on samples annealed at temperatures (250°C, 290°C and 400°C) just above the corresponding peaks of the three phases β'', β' and β respectively.
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Abstract

Temperature gradient zone melting (TGZM) method was used to obtain bulk Si continuously for the efficient separation and purification of primary Si from the Si-Al alloy in this work. The effects of alloy thickness, temperature gradient and holding time in TGZM purification technology were investigated. Finally, the continuous growth of bulk Si without eutectic inclusions was obtained. The results showed that the growth rate of bulk Si was independent of the liquid zone thickness. When the temperature gradient was changed from 2.48 K/mm to 3.97 K/mm, the growth rate of bulk Si was enhanced from 7.9×10–5 mm/s to 2.47×10–4 mm/s, which was increased by about 3 times. The bulk Si could grow continuously and the growth rate was decreased with the increase of holding time from 1 h to 5 h. Meanwhile, low refining temperature was beneficial to the removal of impurities. With a precipitation temperature of 1460 K and a temperature gradient of 2.48 K/mm, the removal rates of Fe, P and B were 99.8%, 94.0% and 63.6%, respectively.
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Abstract

Cast magnesium matrix composites reinforced with silicon carbide particles were investigated by using Raman microscopy. 3C, 4H and 6H polytypes of SiC particles were identified in the investigated composites. Additionally, Mg2Si compound was detected by Raman microscopy in the composites microstructure.
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