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Wyświetlanie 1-11 z 11
Tytuł:
Study on safe disposal of cephalosporins based on kinetic pyrolysis mechanism
Autorzy:
Fan, Jiangxue
Zhang, Meng
Hou, Xiaofei
Wang, Fang
Bai, Mengyuan
Jiao, Ruoxi
Yang, Zhongyu
Duan, Erhong
Cheng, Fengfei
Zhou, Wen
Powiązania:
https://bibliotekanauki.pl/articles/27315672.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Distillation residues
Thermal analysis kinetics
Template “3-2-2”
Template “1+1”
Pyrolysis mechanism
Opis:
Based on the global goals for cleaner production and sustainable development, the pyrolysis behavior of cephalosporin residues was studied by TG-MS method. The influence of full temperature window on the safe disposal of residues was analyzed based on the “3-2-2” and “1+1” of thermal analysis kinetics, and the gas by-products of thermal degradation were monitored. Results showed that the pyrolysis of distillation residues were divided into low and high-temperature zones, including six stages. Maximum error rate (8.55%) by multiple scan rate was presented based on “3-2-2” pattern and maximum total fluctuation (33.7) by single scan rate was presented based on “1+1” pattern, which implied that the comprehensive multi-level comparison method was very reliable. The E value “E” of six stages showed an increasing trend ranging 166.8 to 872.8 kJ/mol. LgA(mean) was 27.28. Most mechanism function of stage 1, 2 were Z-L-T equation (3D), stage 3, 4, 6 were Avrami-Erofeev equation (AE3, AE4, AE2/3) and stage 5 was Reaction Order (O2). In addition, various small molecular micromolecule substances were detected such as C2H4O, C2H6, NH3, CH4, CO2 under full temperature windows and a possible pyrolysis path of residues was provided.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 4; 52--60
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cavitation erosion phenomenological model of MCrAlY and NiCrMoNbTa metallic coatings deposited via the HVOF method
Fenomenologiczny model erozji kawitacyjnej metalowych powłok MCrAlY I NiCrMoNbTa natryskiwanych metodą HVOF
Autorzy:
Szala, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/2055617.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
cavitation erosion
failure analysis
wear mechanism
thermal spraying
microstructure
roughness
erosion rate
erozja kawitacyjna
analiza uszkodzeń
mechanizm zużycia
natryskiwanie termiczne
mikrostruktura
chropowatość
szybkość erozji
Opis:
The work describes the phenomenological model of cavitation erosion (CE) elaborated for MCrAlY (where M = Co, Ni or Co/Ni) and NiCrMoNbTa. Coatings were deposited via the HVOF method from CoNiCrAlY, NiCoCrAlY and NiCrMoNbTa feedstock powders. CE tests, conducted according to ASTM G32 standard, indicate that MCrAlYs have a 50% higher maximum erosion rate and twice lower CE resistance than the NiCrMoNbTa coating. CE kinetics of coatings were comparatively studied, combining the mass loss, erosion rate, roughness changes of the eroded surface with microstructure, and mechanical properties of the coatings. Results of SEM analysis of damaged coatings allow identifying the mechanism of CE. In the case of both types of coatings, the erosive damage is initiated at the removal of loose splats, cracking at the border splats and peeling off the coating material, and surface pitting. However, NiCrMoNbTa, due to higher ductility and microstructure homogeneity, presents lesser surface pitting contrary to the MCrAlYs, which have multiphase microstructure higher hardness and consequently was prone to cracking, resulting in the formation of craters and higher surface roughening. The CE mechanism of MCrAlYs was dominated by the brittle mode, while the NiCrMoNbTa coating has mainly a ductile damage behaviour.
W pracy opisano fenomenologiczny model erozji kawitacyjnej (EK) opracowany dla powłok MCrAlY (gdzie M = Co, Ni lub Co/Ni) i NiCrMoNbTa. Powłoki wytworzono metodą HVOF z komercyjnych proszków CoNiCrAlY, NiCoCrAlY i NiCrMoNbTa. Testy erozji kawitacyjnej, przeprowadzone zgodnie z normą ASTM G32, wskazują, że MCrAlY mają o 50% wyższą prędkość erozji i dwukrotnie niższą odporność EK niż powłoka NiCrMoNbTa. Kinetyka erozji kawitacyjnej powłok została poddana analizie porównawczej syntetyzującej utratę masy, szybkość erozji, zmiany chropowatości erodowanej powierzchni z mikrostrukturą oraz właściwościami mechanicznymi badanych powłok. Wyniki analizy SEM uszkodzonych powłok umożliwiły zidentyfikowanie mechanizmu EK. Uszkodzenie erozyjne powłok inicjowane jest w wyniku usuwaniu słabo umocowany cząstek materiału, pękaniu na granicach lameli następnie usuwaniu materiału i tworzeniu wżerów. Jednak NiCrMoNbTa ze względu na wyższą ciągliwość i jednorodność mikrostruktury wykazuje mniejsze wżery powierzchniowe w przeciwieństwie do MCrAlYs, które cechują się wielofazową mikrostruktura o wyższej twardości i w konsekwencji są podatne na pękanie, co powoduje powstawanie dużych wżerów i wyższe chropowacenie powierzchni. Mechanizm erozji kawitacyjnej powłok MCrAlY jest zdominowana przez kruche pękanie, natomiast w przypadku powłoki NiCrMoNbTa dominuje plastyczne odkształcenie.
Źródło:
Tribologia; 2021, 298, 4; 45--55
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Insight into the Catalytic Mechanism of MFe2O4 (M = Ni, Zn and Co) on the Thermal Decomposition of TKX-50
Autorzy:
Hou, Xiaoting
Zhang, Ming
Zhao, Fengqi
Yang, Yanjing
An, Ting
Li, Hui
Pan, Qing
Wang, Xiaohong
Zhang, Kun
Powiązania:
https://bibliotekanauki.pl/articles/27788010.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
bimetallic iron oxide
thermal decomposition
TKX-50
catalysis
mechanism
Opis:
Synthesized dihydroxylammonium 5,5’-bistetrazole-1,1’-diolate (TKX-50) owes its outstanding application prospects in the field of insensitive solid propellants not only to its high energetic performance but also to its low mechanical sensitivity. Based on the excellent catalytic activity of bimetallic iron oxides for the thermal decomposition of TKX-50, the catalytic mechanism of bimetallic iron oxides (NiFe2O4, ZnFe2O4 and CoFe2O4) for TKX-50 pyrolysis has been explored. For this study, the decomposition process of TKX-50, before and after mixing with the bimetallic iron oxides NiFe2O4, ZnFe2O4 and CoFe2O4 was monitored by in-situ FTIR and gas-phase MS-FTIR instruments. Of the different catalysts, ZnFe2O4 gave the best result for reducing the initial decomposition temperature of TKX-50. Additionally, the activation energy of functional group cleavage of TKX-50, before and after mixing with ZnFe2O4, was also calculated for mechanism analysis from the results of the in-situ FTIR measurements. The results showed that the condensate and the gas-phase decomposition products of TKX-50 remained unchanged after mixing with different catalysts, while the activation energy of tetrazole ring cleavage was significantly reduced. The results of this study will be helpful for the rational design of insensitive solid propellant formulations containing TKX-50, and for understanding the pyrolysis mechanisms of TKX-50 before and after mixing with the efficient catalyst ZnFe2O4.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 2; 223--244
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress evolution mechanism and thermo-mechanical reliability analysis of copper-filled TSV interposer
Autorzy:
Chen, Yuan
Su, Wei
Huang, Hong-Zhong
Lai, Ping
Lin, Xiao-ling
Chen, Si
Powiązania:
https://bibliotekanauki.pl/articles/1841909.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
through silicon vias
thermo-mechanical reliability
failure mechanism
finite element analysis
3D integrated packaging
thermal cycling experiment
Opis:
Through silicon via (TSV) has become one of the key emerging trends of three-dimensional (3D) packages, as it can realize vertically interconnect between stacked-dies. Due to large mismatch in thermal expansion coefficients (CTE) between the copper via and the silicon, significant mechanical stresses are induced at the interfaces when TSV structure is subjected to thermal stresses, which would greatly affect the reliability and electrical performance of TSV 3D device. In this paper, the relationship between the state of stresses and failure of TSV had been explored by combining finite element model simulation (FEM) and failure physical analysis. The position of the maximum stress of the TSV structure was obtained by FEM analysis. The relationship of stress and displacement change with temperature was also studied. And a thermal cycling experiment was conducted to validate the simulation results. Physical failure analysis after thermal cycling experiment was used to verify the degradation mechanism predicted by thermo-mechanical simulation.
Źródło:
Eksploatacja i Niezawodność; 2020, 22, 4; 705-714
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal behavior and kinetic decomposition of sweet potato starch by non-isothermal procedures
Autorzy:
Liu, Ying
Yang, Liutao
Zhang, Yingzhe
Powiązania:
https://bibliotekanauki.pl/articles/240460.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
starch
kinetic analysis
thermal degradation
activation energy
mechanism
Opis:
In this study, X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry (DSC) method were used to analyze the main characteristics of sweet potato starch, and to analyze the thermal degradation process of sweet potato starch. Specifically, X-ray diffraction to study its structure, thermogravimetric analysis to study the thermal degradation kinetics, and differential scanning calorimetry to study the thermogram of sweet potato starch. The thermal decomposition kinetics of sweet potato starch was examined within different heating rates in nitrogen atmosphere. Different models of kinetic analysis were used to calculate the activation energies using thermogravimetric data of the thermal degradation process. Activation energies obtained from Kissinger, Flynn-WallOzawa, and Šatava-Šesták models were 173.85, 174.87 and 174.34 kJ/mol, respectively. The values of activation energy indicated that the thermal degradation of the sweet potato starch was a single reaction mechanism or the combination of multi-reaction mechanisms. The differential scanning calorimetry analysis show that two decomposition stages were presented: the first at a low temperature involves the decomposition of long chain; and the second at a high temperature represents the scission of glucose ring. This information was helpful to design the processing process of many natural polymers. Thermogravimetric Fourier transform-infrared (TG–FTIR) analysis showed that the main pyrolysis products included water, methane, carbon dioxide, ammonia, and others.
Źródło:
Archives of Thermodynamics; 2019, 40, 4; 67-82
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors Affecting the Wear Resistance of Forging Tools
Autorzy:
Zwierzchowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/355784.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot die forging
wear mechanism
forging
laboratory thermal test
Opis:
The durability of forging tools is a function of many variables: tool heat treatment, surface quality, temperature, pressure, number of forgings, diffusion layers (nitriding) and many others. The objective of study was to analyze and compare the working conditions of forging tools. For the analysis of selected flat surfaces of tools. Analyzed forging dies subjected to normal use. Presented results of laboratory tests . The effect of temperature and time on the properties of the surface layer of forging tools. The results were compared with the literature data. This article shows the results of microhardness tests for forging dies which have forged the corresponding number of forgings. The results of laboratory studies on microhardness of hot working steel 1.2344 in the furnace at various temperatures and time are also presented. The working conditions of the forging tools are very complex. The most often described in the literature are: thermal fatigue, abrasive wear, mechanical fatigue and cracks. The article discusses the effects of increased temperature on the surface properties of forging tools. Forging dies were made of hot work tool steel 1.2344. FEM modeling of changes in the surface layer should take into account changes in tool hardness as a function of time (number of forgings).
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1567-1576
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study into combustion of sewage sludge as energetic fuel
Badania spalania osadów ściekowych jako paliwa energetycznego
Autorzy:
Kijo-Kleczkowska, A.
Środa, K.
Otwinowski, H.
Powiązania:
https://bibliotekanauki.pl/articles/219220.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
osady ściekowe
termiczna utylizacja
mechanizm i kinetyka spalania paliw
sewage sludge
thermal utilization
fuel combustion mechanism and kinetics
Opis:
Along with the development of civilisation, it can be observed that the amount of waste of different type is growing and the preparation process for further usage of the waste or the utilization process differs. What is to be focused on is municipal sewage sludge which, due to its energetic properties, constitutes a valuable fuel. The problem of usage of municipal sewage sludge remains still unsolved, which stems both from the increasing amount of such waste, and from the lack of properly adjusted systems for thermal processing thereof. What is of an additional obstacle are the increasingly stricter legal regulations regarding disposal of sewage sludge after the year 2013; hence, it is necessary to consider various benefits resulting from thermal processing of such waste. This work presents an overview of methods of disposal of sewage sludge, taking into consideration, in particular, thermal methods including the process of combustion and co-combustion as a means of successful utilization. The research section of the work presents the results of study into the mechanism and kinetics of combustion of sewage sludge in various conditions of the process carried out in air flow. Combustion of sewage sludge has been compared against combustion of coal and biomass.
Wraz z rozwojem cywilizacji zaobserwować można postępujące powstawanie różnego rodzaju odpadów różniących się, m.in. sposobem przygotowania do dalszego wykorzystania, czy procesem utylizacji. Na szczególną uwagę zasługują komunalne osady ściekowe, które z uwagi na właściwości energetyczne stanowią cenne paliwo. Problem wykorzystania komunalnych osadów ściekowych jest nadal otwarty, a wynika to zarówno z rosnącej produkcji tych odpadów, jak i braku odpowiednio przystosowanych instalacji do termicznego ich przekształcania. Dodatkowym utrudnieniem są zaostrzające się przepisy prawne dotyczące składowania osadów ściekowych po 2013 r. skłaniające tym samym do rozważań nad korzyściami płynącymi z termicznej obróbki tych odpadów. W pracy przedstawiono przegląd sposobów unieszkodliwiania osadów ściekowych ze szczególnym uwzględnieniem metod termicznych, głównie spalania i współspalania jako drogi do ich sukcesywnej utylizacji. W części badawczej pracy zaprezentowano wyniki badań mechanizmu i kinetyki spalania osadów ściekowych w różnych warunkach procesu prowadzonego w strumieniu powietrza. Spalanie osadów ściekowych porównano ze spalaniem węgla oraz biomasy.
Źródło:
Archives of Mining Sciences; 2013, 58, 4; 1085-1110
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Thermal Decomposition and Combustion of Guanidinium 5,5’-Azotetrazole Salt
Autorzy:
Sinditskii, V. P.
Levshenkov, A. I.
Levshenkova, L. E.
Powiązania:
https://bibliotekanauki.pl/articles/358742.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
salt of 5,5’-azotetrazole with guanidine
burning rate
temperature profiles
thermal decomposition
combustion mechanism
Opis:
The thermal decomposition and combustion of guanidinium 5,5’-azotetrazole salt (Gu2AzT) have been investigated. Temperature profiles in the Gu2AzT combustion wave were measured using thin tungsten-rhenium micro thermocouples. It was shown that combustion of the salt obeys the condensedphase mechanism. The high burning rate of Gu2AzT is connected with the high decomposition rate in the melt. The kinetic parameters of the controlling chemical reaction have been estimated, and a detailed combustion mechanism for Gu2AzT has been proposed.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 4; 529-539
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations into the degradation mechanism of thermal barrier applied in IC engine
Autorzy:
Hejwowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/242073.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
thermal barrier coating
spark ignited engine
diesel engine
phase stability
degradation mechanism
Opis:
In the present paper the results of investigations into the degradation mechanizm of thermal barrier coating (TBC) applied in spark ignited and naturally aspirated diesel engines are presented. The TBC comprised 0.09 mm thick NiCrAlY bond coat and 0.36 mm thick Al2O3-40%TiO2 top coat. The coating was atmospheric plasma sprayed on piston heads, inlet and outlet valves and engine head. Top coating was heavily damaged in thermal fatigue tests and in exploitation test on spark ignited engine. The mechanism of damage was spalling of the outermost layer of ceramics. Porosity of the ceramic coating increased significantly which made the coating permeable to the products of combustion and thus facilitated corrosion attack on bond layer. Spalling of coating did not increase wear of piston rings and sleeves. X-ray diffraction studies proved high phase stability ofAl2O3-40%TiO2 top coat. Al2Or40%TiO2 APS sprayed coating cannot be considered the alternative top coat to currently used ZrO2-8%Y2O3in engine applications. Thermal barrier coating based on Al2O3-40%TiO2 can not be used for adiabatization of diesel or spark ignited engines. Al2O3-40%TiO2 based TBC can be used in less demanding applications.
Źródło:
Journal of KONES; 2009, 16, 3; 129-134
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decreasing of thermal errors in a lathe by forced cooling of ball screws and a headstock
Autorzy:
Winiarski, Z.
Kowal, Z.
Błażejewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1429161.pdf
Data publikacji:
2008
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
lathe
feed mechanism
cooling
thermal error
calculation
Opis:
The goal of this paper is to present the effective methods of decreasing thermal deformations of a turning centre's structure in order to reduce the thermal error. The design of a machine tool as well as the scope of analyses are described, and calculation methods are specified. The paper also presents the results of computer simulations, concerning studies on the influence of type and parameters of a headstock-cooling liquid on the reduction of spindle displacements. Moreover, the results of feed mechanism's thermal studies are shown, describing the influence of heat generated during the operation of ball screws and their inner liquid cooling, on tool's thermal displacements.
Źródło:
Journal of Machine Engineering; 2008, 8, 4; 122-130
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anisotropy of the neutron emission from PF-360 facility operated without and with solid-state targets
Autorzy:
Czaus, K.
Baranowski, J.
Sadowski, M.
Skladnik-Sadowska, E.
Zebrowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/146908.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
anisotropy
beam-target mechanism
dense plasma focus (DPF)
neutron yield
thermal mechanism
Opis:
The paper reports on detailed studies of an anisotropy of the fusion-produced neutrons emitted from the modernized PF-360 facility [10], which has been operated with a pure deuterium-gas filling, without and with some additional solidstate targets containing deuterium atoms. Under standard operational conditions, anisotropy of the neutron yield from the PF-360 facility is similar to that observed in other PF devices. For the first time the neutron emission anisotropy has been measured in the PF experiments performed with a planar cryogenic target covered with a heavy-ice (D2O) layer. Changes in the Yn(Φ)/Yn(90°) ratio, particularly for angles Φ = 0–60°, have been explained by the known features of the angular distribution of fast deuterons.
Źródło:
Nukleonika; 2001, 46, suppl. 1; 77-80
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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