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Wyszukujesz frazę "Sawicki, B." wg kryterium: Autor


Tytuł:
Effect of grinding conditions of gears made of 20MnCr5 steel after single-piece flow heat treatment on the condition of the surface layer of the tooth working surface
Autorzy:
Stachurski, W.
Janica, J.
Januszewicz, B.
Pawłowski, W.
Sawicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/24200636.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
thermo-chemical treatment
vacuum carburizing
single-piece flow method
gear grinding
technological surface layer
obróbka cieplno-chemiczna
nawęglanie próżniowe
jednoczęściowa metoda przepływowa
szlifowanie kół zębatych
technologiczna warstwa wierzchnia
Opis:
Purpose: The paper investigated the effect of selected processing conditions during gear grinding on the value and distribution of microhardness and residual stress formed in the technological surface layer of gears after thermochemical treatment (TCT) conducted by a continuous single-piece flow method. Design/methodology/approach: The gears were carburised with LPC at 920°C, then quenched in a 4D Quenching chamber at 7 bar and tempered at 190ºC for 3 hours. In the next step, the working surfaces of the gear teeth were ground by supplying grinding fluid (GF) to the grinding zone using the WET method and the MQL method with a minimum amount. Measurements were made on the distribution of microhardness and residual stress formed in the technological surface layer of gears after thermochemical treatment and after the grinding process. Findings: The results of the study showed the influence of workpiece speed vw and the method of delivery to the grinding zone GF on selected parameters describing the condition of the technological surface layer of the teeth of gears made of 20MnCr5 steel. The grinding process with a white aluminium oxide grinding wheel causes deterioration in the material's residual stress state. For each of the three analysed workpiece speeds vw, smaller changes in microhardness with respect to the microhardness of the material before grinding occur in the surface layer of samples ground with GF fed with the MQL method. Similarly, residual stress values are in the area of favourable compressive stresses. Research limitations/implications: Environmental considerations and the need to comply with increasingly stringent environmental protection and worker safety regulations are pushing researchers and entrepreneurs to completely eliminate or reduce the consumption of grinding fluids in the grinding process. Based on the research and analysis carried out in this study, it was concluded that applying minimum GF by the MQL method could be an alternative to the conventional WET method.Practical implications: In sustainable manufacturing, it is extremely important to produce high-quality items while reducing the cost of manufacturing and taking care of the environment and workers' health. This includes the manufacture of gears, a basic component used in gear transmissions in the automotive industry, for example. The research has established that it is possible to use the MQL method, which reduces the amount of GF used when grinding the working surfaces of gear teeth, as an alternative to the conventional WET method. Originality/value: The conducted research was the first to determine the most favourable conditions, in terms of the obtained residual stresses and microhardness, for grinding the working surface of gear teeth using the MQL method.
Źródło:
Archives of Materials Science and Engineering; 2023, 120, 2; 60--69
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of crystallographic texture and residual stresses of aluminium alloy RSA-501 after selected processes of twist extrusion (TE)
Autorzy:
Byczkowska, P.
Sawicki, J.
Adamczyk-Cieślak, B.
Januszewicz, B.
Powiązania:
https://bibliotekanauki.pl/articles/24200596.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
severe plastic deformation
twist extrusion
aluminium
FEM
crystallographic texture
stress
hardness
odkształcenie plastyczne
wyciskanie skrętne
tekstura krystalograficzna
naprężenie
twardość
Opis:
Purpose: This study presents the residual stress analysis for the twist extrusion (TE) process after the experiment and numerical simulation and the analysis of the crystallographic texture changes and changes in hardness before and after the TE process for an RSA-501 aluminium alloy (Al; Mg5%; Mn1.5%; Sc0.8%; Zr0.4%). Design/methodology/approach: Crystallographic textures were obtained with the PANAlytical Empyrean X-ray diffractometer. The stresses were measured by applying the X-ray method with the use of using the PROTO iXRD diffractometer. Findings: The use of severe plastic deformation processes in the mass of the material leads to a significant change difference in the stress distribution in the workpiece and a change in texture compared to the reference material. The stress distribution in the sample cross-section and stress values varied and depended on the stage of the twisting process to which the surface was subjected. The highest stress (about 600 MPa) appears at the peaks of the front surface when exiting the twist area die TE. Higher stress values at the edges of the specimen are caused by friction (deformation) of the material against the die surface. The TE process strengthened – the highest crystallographic texture background level was 49%. Practical implications: The conducted tests and the obtained results allow the determination of the process parameters and critical areas of the sample by carrying out a numerical simulation. Originality/value: Microhardness increases due to the TE process and the largest values were observed at the edges. This phenomenon is confirmed by the numerical simulation results presented in this paper.
Źródło:
Archives of Materials Science and Engineering; 2022, 118, 1; 5--28
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of workpiece speed on microhardness and residual stresses in vacuum-carburised 20MnCr5 steel using the single-piece flow method
Autorzy:
Sawicki, J.
Januszewicz, B.
Sikora, M.
Witkowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/24200559.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
surface grinding
microhardness
residual stress
vacuum carburising
single-piece flow
szlifowanie powierzchni
mikrotwardość
naprężenie szczątkowe
nawęglanie próżniowe
przepływ jednoczęściowy
Opis:
Purpose: To determine the impact of selected conditions of abrasive treatment on the value and distribution of microhardness and residual stresses in layers carburised by a continuous single-piece flow method. Design/methodology/approach: Reference pieces were low pressure carburised at 920°C and then heat-treated in a 4D Quench heat treatment chamber at a pressure of 7 bar and tempered at 190ºC for 3 hours. In the next stage, samples were ground at various vw piece speeds, introducing grinding fluid into the cutting zone using the WET spraying method or using the MQL method at a minimum flow rate. The distribution of microhardness and residual stresses generated in the technological outer layer of the pieces following heat and chemical treatment and the grinding process was measured. Findings: Results of the tests indicated that the vw piece speed and method used to supply cooling and lubricating fluid to the grinding zone had an impact on selected parameters of the technological outer layer of flat samples made of 20MnCr5 steel. The process of grinding using an electrocorundum grinding wheel results in a deterioration of residual stresses in the material. For each of the three analysed vw piece speeds, reduced changes in material microhardness prior to cutting occur in the outer layer of samples ground using GF supplied at a minimum flow rate using the MQL method. Research limitations/implications: Environmental considerations and having to conform to increasingly stringent regulations related to environmental protection and employee safety motivate researchers and businesses to entirely eliminate or reduce the use of grinding fluids in the grinding process and, therefore, to optimise grinding technology. Practical implications: Modern manufacturing industry requires the grinding process, which follows heat and chemical treatment, to be performed with the highest possible efficiency. However, retaining high parameters of the technological outer layer in comparison to the sample material following vacuum carburisation (before grinding) is extremely difficult. An optimised configuration of parameters of the grinding process and method of supplying grinding fluids enables meeting the current and future high expectations of the industry in this regard. Originality/value: The tests have enabled us to determine the impact of the applied vw workpiece speed and method of supplying grinding fluid on microhardness and residual stresses. Generally speaking, grinding with an electrocorundum grinding wheel results in a deterioration of residual stresses. For both methods of supplying GF (WET and MQL), the distribution of microhardness in the material of the samples ground with the highest workpiece speed (18.0 m/min) indicated no significant differences with regard to the distribution of microhardness in the material of the samples following heat and chemical treatment.
Źródło:
Archives of Materials Science and Engineering; 2022, 115, 2; 66--75
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Air pollution: how many cigarettes does each Pole ‘smoke’ every year and how does it influence health, with special respect to lung cancer?
Autorzy:
Chudzik, R.
Rybojad, P.
Jarosz-Chudzik, K.
Sawicki, M.
Rybojad, B.
Panasiuk, L.
Powiązania:
https://bibliotekanauki.pl/articles/2085106.pdf
Data publikacji:
2019
Wydawca:
Instytut Medycyny Wsi
Tematy:
lung cancer
PM2.5
air pollution
nitrogen dioxide
PM10
Opis:
Introduction. Air pollution is one of the most important issues of our times. Air quality assessment is based on the measurement of the concentration of substances formed during the combustion process and micro-particles suspended in the air in the form of an aerosol. Microscopic atmospheric particulate matters (PM) 2.5 and 10 are mixtures of organic and inorganic pollutants smaller than 2.5 and 10 μm, respectively. They are the main cause of negative phenomena in the earth’s atmosphere of Earth and human health, especially on the respiratory and cardiovascular systems. Particulates have the ability to cause permanent mutations of tissue, leading to neoplasms and even premature deaths. Nitrogen dioxide (NO2) is one of the main pollutants which arises mainly during the burning of fossil fuels. Based on numerous scientific researches, it has been proved that long-term exposure to NO2 could increase morbidity of cancer due to inflammatory processes increasing abnormal mutations. Materials and method. Data available in the Polish National Cancer Registry, Chief Inspectorate for Environmental Protection and Map of Health Needs in the Field of Oncology for Poland, WHO Air Quality Guidelines 2005 were analyzed. Air pollution was also evaluated: PM2.5, PM10, NO2, and compared with lung cancer morbidity. Results and conclusions. Based on the available data and literature, it can be concluded that in 2009–2017, on average, each Pole smoked ten cigarettes a day +/- 2. Therefore, it can be estimated that after 60 years everyone had 30 package-years of smoking, leading to a high risk of lung cancer and other smoking related diseases. Additionally air quality in Poland is not satisfactory, exceeding the standards presented in the WHO Guidelines 2005. It can be assumed that this may translate into an additional, independent continuous increase in morbidity and mortality dependent on smoking.
Źródło:
Annals of Agricultural and Environmental Medicine; 2019, 26, 4; 566-571
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of economic functions and tourist attractions of “Korzeniowy Dół” in Kazimierz Dolny in the light of sustainable development
Autorzy:
Mazurek-Kusiak, A. K.
Sawicki, B.
Powiązania:
https://bibliotekanauki.pl/articles/96770.pdf
Data publikacji:
2018
Wydawca:
Fundacja Ekonomistów Środowiska i Zasobów Naturalnych
Tematy:
Kazimierz Dolny
tourism
nature protection
commercialization
turystyka
ochrona przyrody
komercjalizacja
Opis:
The purpose of this study is to determine the way of tourism management of the loess ravine “Korzeniowy Dół” in Kazimierz Dolny on the Vistula river, taking into account the principles of sustainable development. This report uses secondary results obtained from the City Hall of Kazimierz Dolny. These were electronic measurements of the tourist traffic on the Vistula Boulevard and the number of tickets sold to the Castle and the Tower as well as Góra Trzech Krzyży. In addition, diagnostic survey was conducted using the questionnaire and direct interview. “Korzeniowy Dół” is one of the products that create the image of Kazimierz Dolny as a tourist town and should be developed in such a way that erosion processes are maximally slowed down. This ravine should be completely closed for traffic.. The bottom of the ravine should be drained and water should be drained through a pipe to the ditch. The bottom of the ravine should remain a ground road used only for pedestrian traffic, as it is only possible way to this tourist and natural attraction preserve for other generations. Visiting the ravine should be paid, like the entrance to Góra Trzech Krzyży, which will contribute to the protection of attractions and will help raise funds for the expansion of accompanying tourist infrastructure. The originality of the work consists in indicating the way of commercialization of the loess ravine in Kazimierz Dolny.
Źródło:
Ekonomia i Środowisko; 2018, 3; 170-180
0867-8898
Pojawia się w:
Ekonomia i Środowisko
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and manufacture of customized medical implants
Autorzy:
Elgalal, M.
Komorowski, P.
Makowski, K.
Styczyński, A.
Ulański, P.
Kubiak, T.
Sawicki, J.
Domżalski, M.
Walkowiak, B.
Powiązania:
https://bibliotekanauki.pl/articles/285113.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
implants
patient anatomy
manufacturing
Źródło:
Engineering of Biomaterials; 2018, 21, 148; 36
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exeltium jako jeden ze sposobów finansowania inwestycji w energetyce jądrowej
Exeltium as a way of financing of nuclear power projects
Autorzy:
Sawicki, Ł.
Horbaczewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/214292.pdf
Data publikacji:
2018
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Exeltium
energetyka jądrowa
projekt inwestycyjny
odbiorcy przemysłowi
odbiorcy energochłonni
Flamanville
spółka obrotu
Komisja Europejska
zakup energii
kontrakty długoterminowe
rynek energii
Opis:
W artykule zaprezentowano jedną z metod finansowania projektów inwestycyjnych w energetyce jądrowej, tzw. model Exeltium. Opisano mechanizm jego funkcjonowania, przyczyny i okoliczności utworzenia oraz zmagania inwestorów z Komisją Europejską w celu uzyskania zezwolenia na jego zastosowanie. Dokonano oceny sposobu jego wdrożenia i działanie w praktyce. Ponadto Autorzy poddali analizie możliwość zastosowania mechanizmu w Polsce i wskazali warunki, jakie powinny być spełnione, aby model ten mógł być wykorzystany do finansowania budowy nowej elektrowni jądrowej.
This paper presents a particular way of financing of nuclear power projects called the Exeltium model. The article consists of a description of this model, causes and circumstances of its creation, as well as struggles of the investors with European Commission for issuing an acceptance against public aid rules. Authors assessed the implementation of the model and its functioning in practice. They also analyzed a possibility of its use in Poland and put forward a conditions that should be met to use this model to finance a new nuclear power plant.
Źródło:
Postępy Techniki Jądrowej; 2018, 1; 30-36
0551-6846
Pojawia się w:
Postępy Techniki Jądrowej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Single-Stage and Duplex Shot Peening on Surface Roughness and Residual Stresses in Al Mg5 Mn1 Sc0,8 Zr0,4 Alloy
Autorzy:
Byczkowska, P.
Sawicki, J.
Januszewicz, B.
Stegliński, M.
Powiązania:
https://bibliotekanauki.pl/articles/353741.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
shot peening
double shot peening
residual stresses
roughness
Opis:
Conventional shot peening (SP) is cheap surface treatment widely used to enhance fatigue life of mechanical components [3,4]. Basically, it is shooting small particles (shots) on the surface of the sample. However, the process itself is so complex that a lot of companies are not able to optimally employ it due to the amount of parameters that must be controlled all at the same time. The duplex process consists in two stages of shot-peening treatment. The first one consist of shot-peening with spherical cast steel shots or cut wire shots. During the second stage the samples processed in stage one were subject to shot-peening with glass beads. In this work, RSA-501 aluminium alloy was shot peened using shots of different material and diameter and tested using a measurement of residual stresses and surface roughness. Tests and studies conducted so far on RSA-501 aluminium alloy demonstrate that bombardment by a treatment medium in the form of glass beads or shots of various shapes and diameters induces permanent plastic deformation of the surface layer. The roughness achieved after the shot-peening process was determined for each treatment medium. The largest value of Ra parameter was achieved for cut wire shots and this result is consistent with the above-mentioned theoretical knowledge. This medium is the most aggressive one to the surface being treated primarily due to the sharp edges of shots. The duplex process was successful in obtaining higher values of compressive stresses in surface layer than values achievable in conventional single-stage shot peening process.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 505-511
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single-domain nanoparticle magnetic power losses calibrated with calorimetric measurements
Autorzy:
Miaskowski, A.
Sawicki, B.
Subramanian, M.
Powiązania:
https://bibliotekanauki.pl/articles/202219.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic fluid hyperthermia
calorimetric experiment
magnetic field
numerical modelling
hipertermia płynu magnetycznego
eksperyment kalorymetryczny
pole magnetyczne
modelowanie numeryczne
Opis:
The purpose of this study was to establish a numerical model for calorimetric measurements of magnetic fluids under an alternating magnetic field (AMF). The modified linear response theory (LRT) and Stoner-Wohlfarth theory were applied to investigate heat dissipation from the ferrofluid. The hysteresis area was calculated once the magnetic field value, applied frequency and number weighted distribution of the nanoparticles were known. Magnetic field distribution was calculated for the setup used for performing calorimetric experiments, and field dependent relaxation times were employed to calculate the specific loss power (SLP) in the sample. Subsequently, the results of numerical investigation were compared with the measurements obtained from calorimetric experiments. The Zeeman energy condition was used to delimit the area where LRT is valid. The numerical model calibrated with the calorimetric measurements allowed for the diffusion coefficient and the parameters involved in power dissipation in a ferrofluid to be determined. These parameters were then used to compute total heat dissipation and temperature distribution within the sample. The numerical model matching the calorimetric measurements of heat dissipation from ferrofluids enhanced the reliability of simulations.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 4; 509-516
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Non-Metallic Inclusions Formed as a Result of Deoxidation on the Fatigue Strength of 15CrNi6 and 16MnCr5 Steel
Autorzy:
Lipa, S.
Sawicki, J.
Dybowski, K.
Pietrasik, R.
Januszewicz, B.
Powiązania:
https://bibliotekanauki.pl/articles/353324.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fatigue strength
non-metallic inclusions
thermo-chemical treatment
Opis:
This paper presents the findings of fatigue strength tests of 15CrNi6 steel following low-pressure carburizing and oil quenching, subjected to cycles of one-sided three-point bending. The fatigue fractures were compared with the results of fatigue strength studies of 16MnCr5 steel following low-pressure carburizing and nitrogen quenching. The fatigue tests for 16MnCr5 steel were conducted as part of a high-cycle resonance test, with a pendular bending load. The study also involved an analysis of the effects on non-metallic inclusions in the structure on the mechanism of fatigue destruction. The inclusions were found to initiate fatigue cracks. In both cases, a similar method of a fatigue fissure initiation was observed, independent of the study method or specimen material.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1345-1350
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An attempt to assess the promotion and intensity of tourism and leisure in Kozłowiecki Landscape Park
Autorzy:
Sawicki, B.
Mazurek-Kusiak, A.
Powiązania:
https://bibliotekanauki.pl/articles/96338.pdf
Data publikacji:
2017
Wydawca:
Fundacja Ekonomistów Środowiska i Zasobów Naturalnych
Tematy:
promocja
turystyka
rekreacja
park krajobrazowy
promotion
tourism
recreation
landscape park
Opis:
The objective of this study is the assessment of the promotion of tourist and recreational traffic in Kozłowiecki Landscape Park by examining the intensity and preferences as well as social structure of the participants. The research was conducted using the methods of observation and diagnostic survey, including the application of the questionnaire and interview techniques, as well as the technique of documentation analysis. The research was conducted in 2015. On the foundation of the analysis conducted on the research outcome, it was found that in the studied park mainly the local recreational activity is developing. The promotion of the attractive qualities of this area in the provincial capital city, located 13 kilometres away, is poor although it actually exists. It was also found that the tourism-oriented development of the area surrounding the park is low, yet it was noted that the services provided by the nearby Zamoyski Museum in Kozłówka are very well promoted – unfortunately only by one-day visitors. A proposal was put forward to join the forces of the local institutions and communities and develop an offer of a well-designed, comprehensive tourism product, which will also be well promoted.
Źródło:
Ekonomia i Środowisko; 2017, 2; 231-241
0867-8898
Pojawia się w:
Ekonomia i Środowisko
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the impact of double shot peening on the value of roughness parameter and distribution of stresses in the RSA 501 alloy
Autorzy:
Byczkowska, P.
Sawicki, J.
Januszewicz, B.
Stegliński, M.
Powiązania:
https://bibliotekanauki.pl/articles/957816.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
shot peening
double shot peening
surface treatment
residual stresses
roughness
Opis:
The bead blasting process is widespread in both the automotive and aerospace industry and is performed in order to improve the fatigue strength of various components. Bead blasting is a cold plastic forming process during which the surface of the material processed is hit by small, hard particles consisting of steel pellets, bearing balls or glass beads. It increases the hardness of the outer layer and establishes compression stresses inside it, which is why this processing is often used to improve fatigue strength. Contrary to other peening methods, bead blasting does not result in a reduction in the height of the processed surface’s unevenness in most cases. Shot peening changes the residual tensile stresses into residual compression stresses, thanks to which, the lifetime of the parts processed is extended and their carrying capacity is increased. The double shot peening process proposed by the authors consists in a two-stage bead blasting process. The first stage consists in blasting with round cast steel pellets, pellets cut from wire or cast iron pellets. During the second stage the same samples underwent glass bead blasting. The tests conducted on the RSA-501 aluminum alloy indicate that as a result of the processing medium’s impact in the form of glass beads or pellets of different diameter and shape, a permanent plastic deformation of the material surface occurs. On the basis of the obtained results it is possible to infer that the choice of parameters of both conventional shot peening and the double shot peening determine the impact thereof on the material’s mechanical properties. Thanks to the application of the double shot peening process there is a noticeable decrease in value of the Ra parameter, by about 40% on average. When analyzing the compressive stress results it is possible to state that after the first blasting process the value of stress was increasing when moving deeply into the sample from its surface, while after the glass bead blasting the value of compressive stress was significantly higher already near the surface. Double shot peening results in an increase in the value of compressive stresses by 40-50% when compared to conventional blasting.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 3; 1-9
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrical Transport Properties of $Yb_{8-x}Y_xV_2O_{17}$ (x=0,2,8)
Autorzy:
Sawicki, B.
Piz, M.
Filipek, E.
Groń, T.
Duda, H.
Powiązania:
https://bibliotekanauki.pl/articles/1398346.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.Pa
72.80.Ga
75.20.-g
Opis:
The UV-vis-NIR and electrical properties of $Yb_{8-x}Y_xV_2O_{17}$ for x=0, 2, and 8 were investigated. The band energy gap of 2.6 eV determined for $Yb_6Y_2V_2O_{17}$ (x=2) and comparable for the remaining compounds with x=0 and 8 is characteristic for insulators. Low electrical conductivity with a characteristic minimum shifting to higher temperatures from 322, via 360 to 370 K in the sequence x=0, 2 and 8, which decreases with increasing content of ytterbium was observed. Temperature dependence of thermoelectric power showed n-p transition at 410 and 467 K for x=0 and 2, respectively, and n-type conductivity for x=8, indicating mainly n-type electrical conductivity. A breakdown voltage of 26 V/mm is mainly observed for the I-V characteristics at 400 K and showing a varistor-like behavior.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 363-366
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and structural studies of GeMnSnTe epitaxial layers
Autorzy:
Grochot, A.
Knoff, W.
Taliashvili, B.
Wołkanowicz, W.
Minikayev, R.
Pieniążek, A.
Łusakowska, E.
Sawicki, M.
Jantsch, W.
Story, T.
Przybylińska, H.
Powiązania:
https://bibliotekanauki.pl/articles/1055147.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Gw
75.50.Pp
76.50.+g
Opis:
MBE grown Ge_{1-x-y}Mn_xSn_yTe layers with Mn content ranging from 10 to 30% and Sn content ranging from 2 to 5% have been characterized with X-ray diffraction, energy-dispersive X-Ray spectroscopy, atomic force microscopy, SQUID magnetometry, and ferromagnetic resonance. All layers (except the one with the highest Mn and Sn content) were found to be single phase rhombohedral, with the distortion axis perpendicular to the layer surface, and ferromagnetic. Ferromagnetic resonance studies have shown that co-doping with a few percent of tin makes the lattice more rigid and changes considerably the magnetocrystalline anisotropy, from purely uniaxial in GeMnTe to distorted cubic in Ge_{1-x-y}Mn_xSn_yTe at the same Mn content.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 340-342
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of grinding conditions on the distribution of residual stress in the surface layer of 17CRNI6-6 steel after carburizing
Autorzy:
Sawicki, J.
Kruszyński, B.
Wójcik, R.
Powiązania:
https://bibliotekanauki.pl/articles/102186.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
synergism
residual stress
carburizing
grinding
cutting fluids
Opis:
This paper presents the results of a study aimed at determining the residual stress which results from developing the surface layer by low-pressure and conventional carburizing and grinding of 17CrNi6-6 steel. A synergistic effect of thermochemical and abrasive treatment was examined on ring samples used to study residual stress by Davidenkov’s method. Samples were subjected to vacuum carburizing and conventional carburizing, which was followed by grinding with a 38A60K8V aloxite grinding wheel and a CBN grinding wheel - RNB80/63B75V. The following cutting fluids were used during the grinding process: oil emulsion 5%, supply rate ca. 20 l/min, Micro5000 oil supplied at the minimum quantity lubrication (MQL) of ca. 25 ml/h, dry machining. The study determined the effect of the type of grinding wheel and the cooling and lubricating agent on the distribution of residual stress in the surface layer. The best effects of grinding with respect to the residual stress were achieved with flood cooling with oil emulsion and grinding with a CBN grinding wheel.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 2; 17-22
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł

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