Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "V50" wg kryterium: Temat


Tytuł:
Gas Electronegativity Influence οn Electrical Breakdown Mechanisms
Autorzy:
Lončar, B.
Radosavljević, R.
Vujisić, M.
Stanković, K.
Osmokrović, P.
Tematy:
51.50.+v
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1505340.pdf  Link otwiera się w nowym oknie
Opis:
This paper discusses the role of different gas breakdown mechanisms depending on electronegativity of the gas, at low values of pressure and inter-electrode gap. Static (dc) electrical breakdown of electropositive, electronegative and noble gases has been investigated theoretically, experimentally and numerically. In the case when the electron mean free path is comparable with characteristic dimension of the electrode system (inter-electrode distance d), then the breakdown occurs through the Townsend mechanism. In the case when the electron mean free path is much shorter than the characteristic dimension of the electrode system, the breakdown is said to occur through the streamer mechanism. But, between the regions where the breakdown occurs solely by either the Townsend or the streamer mechanism, there is a region where breakdown occurs by the combination of these two mechanisms. The width of this region expressed by the quantity of pd product (product of pressure, p, and inter-electrode distance, d) depends on observed gas tendency to form negative or positive ions (electronegative and noble gases, respectively). The level of the anomalous Paschen effect expression is dependent on whether the observed gas is electronegative or noble. The combined mechanism effects of breakdown and anomalous Paschen effect are quantitatively determined and theoretically explained within this paper.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrical Breakdown Mechanisms in Vacuum Diodes
Autorzy:
Osmokrović, P.
Ilić, D.
Stanković, K.
Vujisić, M.
Lončar, B.
Tematy:
51.50.+v
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1535645.pdf  Link otwiera się w nowym oknie
Opis:
This paper investigates the roles of different mechanisms constituting the process of electrical breakdown in vacuum. Random variable "vacuum breakdown voltage" was measured for pulse breakdowns in five types of vacuum diodes, with different values of vacuum pressure and inter-electrode gap. Conclusions about the influence of vacuum pressure and inter-electrode distance on the parameters of theoretical statistical distributions have been drawn. Based on the distribution to which the "vacuum breakdown voltage" random variable adheres, the dominance of certain breakdown mechanisms has been established for specific ranges of vacuum pressure. The observed absence of anode vacuum breakdown at small inter-electrode gaps has been given a theoretical interpretation.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aramidowo-polietylenowy balistyczny kompozyt hybrydowy na przykładzie czerepu hełmu - wykonanie i badania
Aramid/polyethylene based hybrid ballistic composite for helmet splinter – fabrication and research
Autorzy:
Habaj, W.
Podgórzak, P.
Fejdyś, M.
Tematy:
kompozyt włóknisty
osłona balistyczna
granica ochrony balistycznej V50
odrywanie międzyfazowe
międzywarstwa
fiber-based composite
ballistic protected panel
V50 ballistic limit
interfacial adhesion
Pokaż więcej
Wydawca:
Wojskowy Instytut Techniczny Uzbrojenia
Powiązania:
https://bibliotekanauki.pl/articles/234716.pdf  Link otwiera się w nowym oknie
Opis:
W artykule przedstawiono wycinek wyników prac związanych z opracowaniem kulo- i odłamkoodpornego hełmu z czerepem z kompozytu hybrydowego wykonanym na bazie włókien aramidowych TWARON® i polietylenowych DYNEEMA®. Opisano technologię wykonania tego kompozytu na przykładzie czerepu hełmu oraz przedstawiono wyniki badań odporności balistycznej tych czerepów dla różnych rozwiązań materiałowych. Wyniki badań przedstawiono w odniesieniu do siły odrywania w obszarze kompozytu jednorodnego (polietylenowego i aramidowego) oraz na granicy faz kompozyt aramidowy – kompozyt polietylenowy, która jest miarą spójności materiałowej kompozytu hybrydowego. Stopień zrównoważenia struktury kompozytu oceniono za pomocą prędkości ΔV, która jest wyznaczana podczas określania granicy ochrony balistycznej V50 i stanowi różnicę najwyższej prędkości odłamka standardowego przy penetracji częściowej pancerza i najniższej prędkości tego odłamka, przy której nastąpiła penetracja całkowita pancerza.
The article shows part of research results on creating bullet- and fragment-proof helmet made of hybrid composite based on aramide TWARON™ and polyethylene DYNEEMA™ fibers. Production technology as well as results of ballistic tests of different material arrangements are shown. Results are presented in comparison with tensile strength of homogeneous composite (polyethylene and aramid) and on the interface of aramid and polyethylene which is the measure of consistency of materials. Degree of composite structure sustainability was evaluated using ΔV velocity which is set when determining the V50 ballistic limit and is the difference between highest velocity of Fragment Simulating Projectile (FSP) for which partial armor penetration has occurred and lowest velocity of that fragment for which complete armor perforation was observed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchronization Study and Introductory Experiment οf Laser-Triggered Surface Flashover in Voltage Pulse
Autorzy:
Pan, R.
Wang, J.
Sun, Y.
Sun, G.
Yan, P.
Zhang, D.
Tematy:
52.80.-s
51.50.+v
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1807974.pdf  Link otwiera się w nowym oknie
Opis:
With the aim of studying the characteristics of laser-triggered surface flashover in voltage pulse, synchronization problem of laser pulse and voltage pulse should be solved. A single/double harmonic, with wavelength λ of 1064/532 nm, Q-switched Nd:YAG laser is used to trigger the surface flashover. The synchronization problem is solved using a self-made digital delay/pulse generator. The delay time and jitter of Marx's trigger input and output, Marx's trigger output and Marx's output, laser input and output are respectively measured. Based on the result of the delay time and the timing sequence of the laser triggering system, the synchronization of laser pulse and voltage pulse is obtained through adjusting the channel delay time of digital delay/pulse generator. In addition, introductory experiment of laser-triggered surface flashover is carried out using the flat electrodes and columned insulators.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Worst Case for the Ballistic Test of the Soft Armour System Using the 9mm FMJ Bullets Differing in the Structure
Autorzy:
Łandwijt, Marcin
Struszczyk, Marcin H.
Kubiak, Paweł
Góreczna-Skrzyńska, Emilia
Wydawca:
Sciendo
Cytata wydawnicza:
Góreczna-Skrzyńska, E., Łandwijt, M., Kubiak, P. & Struszczyk, M.H.. Determination of the Worst Case for the Ballistic Test of the Soft Armour System Using the 9mm FMJ Bullets Differing in the Structure. Fibres & Textiles in Eastern Europe, 2023, Sciendo, vol. 31 no. 6, pp. 63-72. https://doi.org/10.2478/ftee-2023-0056
Opis:
Ballistic tests require significant rigor and the development of a worst case model during the research processes. The purpose of this study was to evaluate the effect of bullet type (manufacturer) on V50 and Behind Armor Blunt Trauma (BABT) results for two ballistic applications: p-aramid and UHMWPE fibre. The results confirmed the thesis that the source of the bullets implies the test results obtained in terms of the number of penetrated layers in the ballistic system, backface signature deformation profiles (p-BFS) and the level of residual energy transferred to the user of the personal protection.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Determination of the Worst Case for the Ballistic Test of the Soft Armour System Using the 9mm FMJ Bullets Differing in the Structure
Autorzy:
Góreczna-Skrzyńska, Emilia
Łandwijt, Marcin
Kubiak, Paweł
Struszczyk, Marcin H.
Tematy:
bulletproofness
BABT risk
behind armor blunt trauma
V50
backface signature deformation profile
p-BFS
backface deformation
BFD
Pokaż więcej
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:
https://bibliotekanauki.pl/articles/59115035.pdf  Link otwiera się w nowym oknie
Opis:
Ballistic tests require significant rigor and the development of a worst case model during the research processes. The purpose of this study was to evaluate the effect of bullet type (manufacturer) on V50 and Behind Armor Blunt Trauma (BABT) results for two ballistic applications: p-aramid and UHMWPE fibre. The results confirmed the thesis that the source of the bullets implies the test results obtained in terms of the number of penetrated layers in the ballistic system, backface signature deformation profiles (p-BFS) and the level of residual energy transferred to the user of the personal protection.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of Microstructure and Properties of Extruded Mg-Li-Al Alloys of α and α+ β Phase Composition using ECAP Processing
Autorzy:
Dutkiewicz, J.
Rusz, S.
Maziarz, W.
Skuza, W.
Kuc, D.
Hilser, O.
Tematy:
83.50.-v
81.40.Lm
81.20.Fw
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1033018.pdf  Link otwiera się w nowym oknie
Opis:
Two magnesium based alloys containing 4.5 wt% Li and 1.5 wt% Al (alloy 1) and 9 wt% Li and 1.5 wt% Al (alloy 2) were cast under argon atmosphere and hot extruded at 350°C. Microstructure of alloy 1 consisted of hexagonal α phase of average grain size 20 μm and small aluminum rich precipitates being the most probably AlLi₂Mg phase. Alloy 2 in the extruded form consisted of lamellas of α+ β phases of thickness 5-20 μm and length above 100 μm. Significant grain refinement down to about 2 μ m was observed in one-phase hexagonal (hcp) alloy 1 after one pass of ECAP processing with helical component. Two-phase (hcp + bcc) alloy 2 showed higher non-homogeneity after the first equal channel angular pressing pass due to easier deformation of softer bcc phase, while both, α and β phases exhibited low angle grain boundaries. The hardness and the yield strength of the alloys were higher for alloy 1 (68 HV and 205 MPa, respectively) than those of alloy 2 (61 HV and 175 MPa). Subsequent equal channel angular pressing passes were performed at lower extrusion stress. The hardness of both alloys did not change significantly after subsequent equal channel angular pressing passes and revealed tendency to decrease. Two-phase alloy showed superplastic properties already after one equal channel angular pressing pass at 160°C with grain growth after superplastic tensile testing. Single phase hcp alloy did not show such properties after 1 pass, but after a few equal channel angular pressing passes it could be superplastically formed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Research on Structured Analysis of Biomaterial of Dental Implant in Computer Aided Biomechanical Engineering Modelling
Autorzy:
Karaçalı, Ö.
Tematy:
83.50.-v
87.85.gp
02.70.Dh
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1181969.pdf  Link otwiera się w nowym oknie
Opis:
The research explained in this paper is about the mechanical principle applications on regulated form and function, forces, motion of teeth and dental implant - influencing the implant length and bone quality - in biomechanics engineering modeling in dentistry. The non-linear finite element method was employed as an advanced computer technique of structural stress analysis tool for biomechanics modeling using mechanical, mathematical, and biological definitions and concepts. A finite element model of dental implant with accurate geometry and material properties was developed to make realistic investigations on the implant biomaterial properties and mechanical behavior of new dental implant. The finite element models with non-linear contact elements were used to simulate an interface fixation within the implant system and the sliding function of the non-rigid connector. This research showed that implant design influences force transmission characteristics in peri-implant bone and mechanical signals affect bone tissue differentiation. Hence, it is important to control biomechanical loads on dental implants to maintain osseointegration and to promote early bone-implant interface healing. The results of this analysis are helpful for implant biomaterial selection and design for clinical interest.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal Plasticity Treated as a Quasi-Static Material Flow through Adjustable Crystal Lattice
Autorzy:
Kratochvíl, J.
Tematy:
62.20.F-
81.40.Lm
83.50.-v
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1418490.pdf  Link otwiera się w nowym oknie
Opis:
Considering high pressure torsion experiments as a motivation, plastic behavior of crystalline solids is treated as a highly viscous material flow through an adjustable crystal lattice. Instead of the traditional decomposition rule considering the deformation gradient as a product of the elastic and plastic parts, the proposed model is based on its rate form: the velocity gradient consists of the lattice velocity gradient and the sum of the velocity gradients corresponding to the slip rates of individual slip systems; the slip strains themselves are not defined in the model. The geometrical changes caused by material flow and the slip strains can be specified a posteriori. Crystal lattice distortions are measured with respect to a lattice reference configuration. In an adopted rigid plastic approximation the lattice distortions are reduced to rotations. Constitutive equations incorporate non-local hardening caused by close range interactions among dislocations.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Volume Breakdown on Surface Flashover in High Pressure $SF_{6}$
Autorzy:
Neuber, A.
Krile, J.
Rogers, G.
Krompholz, H.
Tematy:
51.50.+v
52.80.Mg
52.70.Kz
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1807877.pdf  Link otwiera się w nowym oknie
Opis:
We investigate the pulsed flashover voltage of dielectric samples at up to 4 bar $SF_{6}$ in the simultaneous presence of a high current (>10 kA, ∼20 microsecond pulse) volume discharge nearby. The chosen distance, ∼7 cm, between surface and volume breakdown is consistent with conditions found in the Sandia-Z-machine type rimfire switch. For a flashover gap distance of 24 mm and a simultaneous excitation within ∼ 5 microseconds, we observe an average reduction in the flashover voltage from 164 kV to 142 kV at 3.7 bar when the volume discharge is turned on. The test setup utilizing a magnetic switching scheme operating at 320 kV and 10 kA is briefly discussed along with the breakdown properties and the spectral characterization of the volume/surface flashover discharge plasma. In general, UV light propagates relatively unattenuated for wavelengths >160 nm in the high pressure $SF_{6}$ from the volume discharge to the dielectric surface, setting up conditions which are conducive to photoelectron emission from the dielectric.
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies