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Abstrakt

The transitional siliceous rocks from the Belchatow lignite deposit belong to the deposits with heterogeneous petrographic composition. The research allows us to identify among others, opoka-rocks and gaizes. The mineralogical-chemical analysis proves that the main ingredients of the studied rocks commonly used as building material are minerals of the SiO₂ group. Laboratory tests show that the nature of siliceous mineral phases has several effects on the geomechanical parameters of the studied transitional rocks. They are a reduction in water content and rock porosity, which leads to the transition of opal type A to opal type crystobalit and trydymit and then to quartz or microquartz. Their density and strength parameters are increased.

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Autorzy i Afiliacje

A. Pękala

Abstrakt

The text discusses the problems of sensory processing disorders (SPD) and their impact on difficulties children have at school. Individual categories of sensory processing disorders were characterized and examples of behavior of children who may have those problems were described. Certain strategies which teachers can use when working with a child with SI disorders were also offered.

It should be noted that the early diagnosis of symptoms that may indicate the occurrence of sensory processing disorders, followed by apt diagnosis and therapy allow children to function properly in the school environment and positively influence their self-esteem. This in turn facilitates the process of learning and contributes future success.

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Autorzy i Afiliacje

Barbara Cygan

Abstrakt

W artykule zostaje poddana analiza katolickiej nauki społecznej, szczególnie jej sformułowanie w encyklice papieża Franciszka Laudato si’ i innych dokumentach Magisterium. Zostają przedstawione główne cechy charakterystyczne „kultury troski” oraz „kultury wyrzucania”, a także pytanie związane z bio-władzą, pozytywną i negatywną biopolityką (tanatopolityka) wraz z niektórymi alarmującymi przykładami (legalizacja aborcji, selektywna aborcja dziewczynek, niszczenie nadliczbowych zamrożonych embrionów, lobbowanie na rzecz legalizacji eutanazji). W dalszej części zostaje podkreślony wkład Kościoła w tych debatach w aspektach biblijnym, teologicznym i etycznym, jak też znaczenie aktywności w tych obszarach. Największe wyzwania w ramach bioetyki muszą zostać przezwyciężone przez kreatywność w społecznym, moralnym i politycznym obszarze. „Kultura troski” jest kulturą akceptacji innych, uformowaną przez chrześcijańską nadzieję i miłość. Jest kulturą obecności i zainteresowania innymi według przykładu Jezusa Chrystusa.
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Autorzy i Afiliacje

Ján Ďačok SJ

Abstrakt

Artykuł przedstawia szereg uwag dotyczących sztucznej inteligencji (SI), a które nie są oczywiste dla osób, które tą dziedziną na co dzień się nie zajmują. Na początku jest dyskutowana sama nazwa „sztuczna inteligencja” oraz czym ona jest. Jest to potrzebne dla śledzenia dyskusji na temat tego, jaka jest owa SI. Potem opisano, jak SI powstawała – na świecie i w Polsce. Omówione są też konsekwencje pojawienia się programu Chat GPT, a także zasady jego działania. Na fali szerokiego zainteresowania SI pojawiło się też wiele dyskusyjnych wypowiedzi, często pochodzących od autorytetów naukowych z obszarów nauki odległych od informatyki. Polemika z takimi wypowiedziami jest w punkcie zatytułowanym „Chwasty do wyplewienia”. W dalszej części artykułu wykazano, że ludzie pragnęli SI już w starożytności oraz opisano, co potrafi zrobić inteligentny awatar. Zaprezentowano też, jakie prawne regulacje usiłuje się obecnie nałożyć na systemy SI – odpowiednio w Stanach Zjednoczonych oraz w Unii Europejskiej, a więc też w Polsce. Na koniec podjęto temat wzajemnych relacji między SI a cyberbezpieczeństwem.
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Autorzy i Afiliacje

Wacław Iszkowski
1 2
Ryszard Tadeusiewicz
3

  1. Polskie Towarzystwo Informatyczne
  2. Polska Izba Informatyki i Telekomunikacji
  3. Akademia Górniczo-Hutnicza, Kraków

Abstrakt

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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M.A. Malik
K.N. Braszczyńska-Malik
K. Majchrzak

Abstrakt

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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Autorzy i Afiliacje

Jiayan Li
Liang Wang
Jianjie Hao
Ping Ni
Yi Tan

Abstrakt

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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Autorzy i Afiliacje

Hanna Belghit
Hichem Farh
Toufik Ziar
Mosbah Zidani
Meryem Guemini
Słowa kluczowe Ti Zr Si silicide oxidation

Abstrakt

In this study, the combined effect of Zr and Si on isothermal oxidation of Ti for 25 and 50 h at 820°C, which is the temperature related to exhaust valves operation, was investigated. Si addition into Ti-5mass%Zr alloy led to a distribution of silicide Ti5Si3 phase formed by a eutectic reaction. The Ti sample containing only Zr showed more retarded oxidation rate than Ti-6Al-4V, the most prevalent Ti alloy, at the same condition. However, while a simultaneous addition of Zr and Si resulted in greater increase of oxidation resistance. The oxide layer formed after the addition of Zr and Si comprised TiO2, ZrO2, and SiO2.

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Autorzy i Afiliacje

S.-H. Ha
B.-H. Kim
Y.-O. Yoon
H.-K. Lim
S.K. Kim

Abstrakt

In this paper, we propose a new algorithm that improves the performance of the operation of Handover (HO) in LTE-Advanced (LTE-A) networks. As recognized, Mobility Management (MM) is an important pillar in LTE/LTE-A systems to provide high quality of service to users on the move. The handover algorithms define the method and the steps to follow to ensure a reliable transfer of the UEs from one cell to another without interruption or degradation of the services offered by the network. In this paper, the authors proposed a new handover algorithm for LTE/LTE-A networks based on the measurement and calculation of two important parameters, namely the available bandwidth and the Received Power (RSRP) at the level of eNodeBs. The proposed scheme named LTE Available Bandwidth and RSRP Based Handover Algorithm (LABRBHA) was tested in comparison with well-known algorithms in the literature as the LHHA, LHHAARC and the INTEGRATOR scheme using the open source simulator LTE-Sim. Finally, the network performances were investigated via three indicators: the number of lost packets during the handover operation, the latency as well as the maximum system throughput. The results reported that our algorithm shows remarkable improvements over other transfer schemes.

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Autorzy i Afiliacje

Ismail Angri
Abdellah Najid
Mohammed Mahfoudi

Abstrakt

This paper describes the arithmetic blocks based on Montgomery Multiplier (MM), which reduces complexity, gives lower power dissipation and higher operating frequency. The main objective in designing these arithmetic blocks is to use modified full adder structure and carry save adder structure that can be implemented in algorithm based MM circuit. The conventional full adder design acts as a benchmark for comparison, the second is the modified Boolean equation for full adder and third design is the design of full adder consisting of two XOR gate and a 2-to-1 Multiplexer. Besides Universal gates such as NOR gate and NAND gate, full adder circuits are used to further improve the speed of the circuit. The MM circuit is evaluated based on different parameters such as operating frequency, power dissipation and area of occupancy in FPGA board. The schematic designs of the arithmetic components along with the MM architecture are constructed using Quartus II tool, while the simulation is done using Model sim for verification of circuit functionality which has shown improvement on the full adder design with two XOR gate and one 2-to-1 Multiplexer implementation in terms of power dissipation, operating frequency and area.

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Autorzy i Afiliacje

P. Velrajkumar
C. Senthilpari
J. Sheela Francisca
T. Nirmal Raj

Abstrakt

The main aim of the article is to develop a simulation model of flexible manufacturing

system with applying the ontology on flexibility. Designing manufacturing systems matching

both production and market requirements becomes more and more challenging due to the

variability of demand for a large number of products made in many variants and short

lead times. Manufacturing flexibility is widely recognised as a proven solution to achieve

and maintain both the strategical and operational goals of the companies exposed to global

competition. Generic simulation model of flexible manufacturing system was developed using

FlexSimr 3D software, then the example data were used to demonstrate the developed model

applicability. “The Ontology on Flexibility” was applied for evaluation of achieved flexibility

of manufacturing system.

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Autorzy i Afiliacje

Sławomir Luscinski
Vitalii Ivanov

Abstrakt

Secondary or multiple remelted alloys are common materials used in foundries. For secondary (recycled) Al-Si-Cu alloys, the major problem is the increased iron presence. Iron is the most common impurity and with presence of other elements in alloy creates the intermetallic compounds, which may negatively affect the structure. The paper deals with effect of multiple remelting on the microstructure of the AlS9iCu3 alloy with increased iron content to about 1.4 wt. %. The evaluation of the microstructure is focused on the morphology of iron-base intermetallic phases in caste state, after the heat treatment (T5) and after natural aging. The occurrence of the sludge phases was also observed. From the obtained results can be concluded that the multiple remelting leads to change of chemical composition, changes in the final microstructure and also increases sludge phases formation. The use of heat treatment T5 led to a positive change of microstructure, while the effect of natural aging is beneficial only to the 3rd remelting.

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Autorzy i Afiliacje

M. Matejka
D. Bolibruchová

Abstrakt

The paper deals with problems related to application of aluminum-silicon alloys for combustion engine cylinder liners

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Autorzy i Afiliacje

A. Trytek
M. Tupaj
M. Mróz
A.W. Orłowicz

Abstrakt

The possibility or even necessity of revising definitions of some of the base units of the present SI has been discussed over the past 15 years. The last General Conference of Weights and Measures (2007) recommended to redefine the kilogram, the ampere, the kelvin, and the mole using fixed values of the fundamental constants by the time of the next General Conference in 2011. This paper is a review of proposals of new definitions of units of mentioned quantities and arguments voting for particular variants of definitions. Most relevant papers for this review have been published by Metrologia, the international journal appointed at the BIPM, and many other useful pieces of information are available on www pages of the BIPM. The author notes that not only new definitions have been discussed but as well as the set of the base units of the SI. It means a replacement of the ampere by the volt or the kelvin by the joule. Decisions concerning new definitions are not made and the discussions are still open.
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Autorzy i Afiliacje

Waldemar Nawrocki

Abstrakt

The effect of combination grain refinement with AlTi5B1 master (55 ppm) and Sr-modification with AlSr5 master (20, 30, 40, 50 and 60 ppm) on the microstructure, tensile and hardness properties of AlSi7MgTi cast alloy were systematically investigated. Eutectic silicon was studied by optical and scanning electron microscopy after standard (0.5% HF) and deep etching (HCl). Morphology of eutectic Si changes from compact plate-like (as-cast state) to fibbers (after modification). Si-fibbers in samples with 50 and 60 ppm Sr coarsen probably as a result of over-modification. The optimum mechanical properties has the experimental material which was grain refined and modified with 40 ppm of Sr (UTS = 220.6 MPa; ductility = 6.1%, and 82.3 HBW 5/250/15).

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Autorzy i Afiliacje

L. Kuchariková
E. Tillová
M.S. Bonek
M. Chalupová

Abstrakt

Manganese is an effective element used for the modification of needle intermetallic phases in Al-Si alloy. These particles seriously

degrade mechanical characteristics of the alloy and promote the formation of porosity. By adding manganese the particles are being

excluded in more compact shape of “Chinese script” or skeletal form, which are less initiative to cracks as Al5FeSi phase. In the present

article, AlSi7Mg0.3 aluminium foundry alloy with several manganese content were studied. The alloy was controlled pollution for achieve

higher iron content (about 0.7 wt. % Fe). The manganese were added in amount of 0.2 wt. %, 0.6 wt. %, 1.0 wt. % and 1.4 wt. %. The

influence of the alloying element on the process of crystallization of intermetallic phases were compared to microstructural observations.

The results indicate that increasing manganese content (> 0.2 wt. % Mn) lead to increase the temperature of solidification iron rich phase

(TAl5FeSi) and reduction this particles. The temperature of nucleation Al-Si eutectic increase with higher manganese content also. At

adding 1.4 wt. % Mn grain refinement and skeleton particles were observed.

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Autorzy i Afiliacje

D. Bolibruchová
R. Podprocká

Abstrakt

In this work, the effect of the microstructure on corrosion behavior of selected Mg- and Al-based as cast alloys, was evaluated. The electrochemical examinations were carried out, and then a morphology of corrosion products formed due to local polarization on materials surface, was analyzed. It was documented that the presence of Mg2Si phase plays an important role in the corrosion course of Mg-based alloy. A selective etching was observed in sites of Mg2Si precipitates having “Chinese script”- like morphology. Analogous situation was found for Al-based alloy, where the key role was played by cathodic θ-CuAl2 phase.
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M.M. Lachowicz
R. Jasionowski

Abstrakt

Iron is presented as an impurity in Al-Si alloys and occurs in the form of the β-Al5FeSi phase formations. The presence of iron and other elements in the alloy causes the formation of large intermetallic phases. Due to the high brittleness of this phase, it reduces the mechanical properties and increases the porosity. Manganese is used to inhibit the formation of this detrimental phase. It changes the morphology of the phase to polyhedral crystals, skeletal formations, or Chinese script. The present article deals with the influence of various amounts of manganese (0.1; 0.2; 0.4; 0.6 wt. %) on the formation of iron-based intermetallic phases in the AlSi7Mg0.3 alloy with different levels of iron content (0.4; 0.8, 1.2 wt. %). The increase of iron content in each alloy caused the creation of more intermetallic compounds and this effect has been more significant with higher concentrations of manganese. In alloys where the amount of 1.2 wt. % iron is present, the shape of eutectic silicon grain changes from angular to short needle type.
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Autorzy i Afiliacje

D. Bolibruchová
R. Podprocká

Abstrakt

An economical alternative for the steel industry which uses a separate ferrosilicon and aluminum for the deoxidization of steel is a complex deoxidizer in the form of FeSiAl alloys. The effectiveness of complex deoxidizers is higher and they have a positive effect on quality improvement and also for mechanical properties of the finished steel. It is associated with a smaller number of non-metallic inclusions and a more favorable its distribution in the structure of steel. Noteworthy are the waste from the mining industry simultaneously contains SiO2 and Al2O3 oxides with a few of dopants in the form of CaO, MgO, FeO, TiO2 oxides. These wastes are present in large quantities and can be a cheap raw material for obtaining complex FeSiAl ferroalloys by an electrothermal method. “Poor” hard coal grades which so far did not apply as a reducing agent in the ferroalloy industry because of the high ash content can also be a raw material for the electrothermal FeSiAl process. The electrothermal FeSiAl melting process is similar to the ferrosilicon process in the submerged arc furnace. For this reason, a model based on Gibbs’ free enthalpy minimization algorithm was used to analyze the simultaneous reduction of SiO2 and Al2O3 oxides, which was originally elaborated for the ferrosilicon smelting process. This is a system of two closed reactors: the upper one with the lower temperature and the lower one with the higher temperature. Between the reaction system and the environment, and between the reactors inside the system, there is a cyclical mass transfer in moments when the state of equilibrium is reached in the reactors. Based on the model, the basic parameters of the electrothermal reduction process of SiO2 and Al2O3 oxides were determined and a comparative analysis was made towards the ferrosilicon process.
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Autorzy i Afiliacje

B. Machulec
W. Bialik
S. Gil

Abstrakt

The paper deals with the influence of manganese in AlSi7Mg0.3 alloy with higher iron content. Main aim is to eliminate harmful effect of intermetallic – iron based phases. Manganese in an alloy having an iron content of about 0.7 wt. % was graded at levels from 0.3 to 1.4 wt. %. In the paper, the effect of manganese is evaluated with respect to the resulting mechanical properties, also after the heat treatment (T6). Morphology of the excluded intermetallic phases and the character of the crystallisation of the alloy was also evaluated. From the obtained results it can be concluded that the increasing level of manganese in the alloy leads to an increase in the temperature of the β-Al5FeSi phase formation and therefore its elimination. Reducing the amount of β-Al5FeSi phase in the structure results in an improvement of the mechanical properties (observed at levels of 0.3 to 0.8 wt. % Mn). The highest addition of Mn (1.4 wt.%) leads to a decrease in the temperature corresponding to the formation of eutectic silicon, which has a positive influence on the structure, but at the same time the negative sludge particles were also present

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Autorzy i Afiliacje

D. Bolibruchová
R. Podprocká
R. Pastirčák
K. Major-Gabryś

Abstrakt

The paper deals with squeeze casting technology. For this research a direct squeeze casting method has been chosen. The influence of process parameters variation (casting temperature, mold temperature, pressure) on mechanical properties and structure will be observed. The thicknesses of the individual walls were selected based on the use of preferred numbers and series of preferred numbers (STN ISO 17) with the sequence of 3.15, 4.00, 5.00, 6.00 and 8.00 mm. The width of each wall was 22 mm with a length of 100 mm. As an experimental material was chosen the AlSi12 and AlSi7Mg0.3 alloys. The mechanical properties (UTS, E) for individual casting parameters and their individual areas of different thicknesses were evaluated. In the structure the influence of pressure on the change of the eutectic morphology, the change of the volume of eutectic and the primary alpha phase, the effect of the pressure on the more fine-grain and the regularization of the structure were evaluated.

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Autorzy i Afiliacje

R. Pastirčák
J. Ščury
M. Brůna
D. Bolibruchová
J. Jakubski

Abstrakt

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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Autorzy i Afiliacje

R. Bogucki
M. Basiaga
A. Żyra

Abstrakt

The chosen, typical causes of quality defects of cast-iron „alphin” rings embedded in aluminum cast are being presented in this paper.

Diffusive joint of those inserts with the pistons casts is being used, due to extreme work conditions of destructive influence of the fuel mix

and variable thermo-mechanical loads, which reign in the combustion motor working chamber.

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Autorzy i Afiliacje

J. Piątkowski
P. Kamiński

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