Efficient and Semiefficient Vulcanization Systems Employing 2-(Morpholinodithio)-Benzothiazole Generated in Situ

1977 ◽  
Vol 50 (1) ◽  
pp. 90-98
Author(s):  
J. P. Lawrence

Abstract The MBTS-N-(morpholinothio)phthalimide vulcanization system has been found to be effective in producing heat resistant semi-EV and EV cures in a variety of representative rubbers. When used as a direct replacement on a molar basis for 2-(morpholinodithio)benzothiazole (MDB), improvements in processing safety were found in all cases studied. In this respect it is most effective in NR, SBR, and NBR. The experimental system also generally gave slower-curing stocks. The heat resistance of the experimental stocks was found to be equal to or better than that of the MDB control stocks. Substantial improvements in heat resistance for both SBR and IIR unexpectedly resulted from the use of the MBTS—imide system. This result suggests that the nature of the crosslinks formed by the two vulcanization systems are to some extent different in these two elastomers. This, in turn, may reflect upon the mechanisms of crosslink formation.

2005 ◽  
Vol 475-479 ◽  
pp. 2857-2860
Author(s):  
Bao Hong Zhu ◽  
Yong'an Zhang ◽  
Bai Qing Xiong ◽  
Hong Wei Liu ◽  
Li Kai Shi

Heat-resistant Al-Fe-V-Si aluminum alloys enhanced by in-situ TiC particles have been prepared by spray forming process with suitable process parameters. Research results show that the microstructure of as-deposited alloy is fine and homogeneous. In-situ TiC particles prevent the unsteady phases from coming into being. On the other hand, the TiC particles increase the volume fraction of heat-resistant phases. So the mechanical properties of the enhanced alloy by in-situ TiC particles are better than that of Al-Fe-V-Si alloy without TiC particles. The hot extrusion temperature is also an important parameter to understand. Under the permission, it is better to extrude the alloy at lower temperature. The tensile strength of the alloy without TiC particles is about 435MPa at room temperature and is about 204MPa at 350°C. However, when the alloy is enhanced by in-situ TiC particles, the strength of alloy is about 482MPa at room temperature and is about 224MPa at 350°C temperature.


2014 ◽  
Vol 543-547 ◽  
pp. 3725-3728
Author(s):  
Rong Hua Zhang ◽  
Biao Wu

Heat-resistant Al-Fe-V-Si aluminum alloys enhanced by in-situ TiC particles have been prepared by spray forming process with suitable process parameters. Research results show that the microstructure of as-deposited alloy is fine and homogeneous. In-situ TiC particles prevent the unsteady phases from coming into being. On the other hand, the TiC particles increase the volume fraction of heat-resistant phases. So the mechanical properties of the enhanced alloy by in-situ TiC particles are better than that of Al-Fe-V-Si alloy without TiC particles. The hot extrusion temperature is also an important parameter to understand. Under the permission, it is better to extrude the alloy at lower temperature. The tensile strength of the alloy without TiC particles is about 435MPa at room temperature and is about 204MPa at 350°C. However, when the alloy is enhanced by in-situ TiC particles, the strength of alloy is about 482MPa at room temperature and is about 224MPa at 350°C temperature.


Author(s):  
P.R. Swann ◽  
A.E. Lloyd

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.


1964 ◽  
Vol 45 (4) ◽  
pp. 535-559 ◽  
Author(s):  
E. Bolté ◽  
S. Mancuso ◽  
G. Eriksson ◽  
N. Wiqvist ◽  
E. Diczfalusy

ABSTRACT In 15 cases of therapeutic abortion by laparotomy the placenta was disconnected from the foetus and perfused in situ with tracer amounts of radioactive dehydroepiandrosterone (DHA), dehydroepiandrosterone sulphate (DHAS), androst-4-ene-3,17-dione (A), testosterone (T) and 17β-oestradiol (OE2). Analysis of the placentas, perfusates and urine samples revealed an extensive aromatisation of DHA, A and T; more than 70% of the radioactive material recovered was phenolic, and at least 80 % of this phenolic material was identified as oestrone (OE1), 17β-oestradiol (OE2) and oestriol (OE3), the latter being detected only in the urine. Comparative studies indicated that A and T were aromatised somewhat better than DHA and that all three unconjugated steroids were aromatised to a much greater extent than DHAS. Radioactive OE1 and OE2 were isolated and identified in the placentas and perfusates, but no OE3, epimeric oestriols, or ring D ketols could be detected in these sources, not even when human chorionic gonadotrophin (HCG) was added to the blood prior to perfusion. Lack of placental 16-hydroxylation was also apparent when OE2 was perfused. Regardless of the precursor perfused, there was three times more OE2 than OE1 in the placenta and three times more OE1 than OE2 in the perfusate. This was also the case following perfusion with OE2. The results are interpreted as suggesting the existence in the pregnant human of a placental »barrier« limiting the passage of circulating androgen. The barrier consists of a) limited ability to transfer directly DHAS and b) an enzymic mechanism resulting in the rapid and extensive aromatisation of the important androgens DHA, A and T.


2017 ◽  
Author(s):  
Amanda H. Schmidt ◽  
◽  
Paul R. Bierman ◽  
Veronica Sosa-Gonzalez ◽  
Thomas B. Neilson ◽  
...  
Keyword(s):  

2021 ◽  
Vol 9 (3) ◽  
pp. 667
Author(s):  
Zhiwei Tu ◽  
Peter Setlow ◽  
Stanley Brul ◽  
Gertjan Kramer

Bacterial endospores (spores) are among the most resistant living forms on earth. Spores of Bacillus subtilis A163 show extremely high resistance to wet heat compared to spores of laboratory strains. In this study, we found that spores of B. subtilis A163 were indeed very wet heat resistant and released dipicolinic acid (DPA) very slowly during heat treatment. We also determined the proteome of vegetative cells and spores of B. subtilis A163 and the differences in these proteomes from those of the laboratory strain PY79, spores of which are much less heat resistant. This proteomic characterization identified 2011 proteins in spores and 1901 proteins in vegetative cells of B. subtilis A163. Surprisingly, spore morphogenic protein SpoVM had no homologs in B. subtilis A163. Comparing protein expression between these two strains uncovered 108 proteins that were differentially present in spores and 93 proteins differentially present in cells. In addition, five of the seven proteins on an operon in strain A163, which is thought to be primarily responsible for this strain’s spores high heat resistance, were also identified. These findings reveal proteomic differences of the two strains exhibiting different resistance to heat and form a basis for further mechanistic analysis of the high heat resistance of B. subtilis A163 spores.


2019 ◽  
Vol 219 ◽  
pp. 08003
Author(s):  
Maja Verstraeten

The SoLid Collaboration is currently operating a 1.6 ton neutrino detector near the Belgian BR2 reactor. Its main goal is the observation of the oscillation of electron antineutrinos to previously undetected flavour states. The highly segmented SoLid detector employs a compound scintillation technology based on PVT scintillator in combination with LiF-ZnS(Ag) screens containing the 6Li isotope. The experiment has demonstrated a channel-to-channel response that can be controlled to the level of a few percent, an energy resolution of better than 14% at 1 MeV, and a determination of the interaction vertex with a precision of 5 cm. This contribution highlights the major outcomes of the R&D program, the quality control during component manufacture and integration, the current performance and stability of the full-scale system, as well as the in-situ calibration of the detector with various radioactive sources.


1977 ◽  
Vol 25 (7) ◽  
pp. 702-706
Author(s):  
M D Graham

The clinical problem of bacterial identification has been approached by applying pattern-recognition techniques to multi-wavelength surface-scattering and reflectance data derived from real-time scans of isolated colonies. Preliminary results, obtained from blood-agar plates inoculated with a mixture of staphylococci, streptococci and escherichieae, indicate that these organisms can be differentiated with better than 90% certainty, provided the colonies are physically separated and their growth conditions closely controlled. Data collection and classification characteristics of the experimental system are briefly described; it is felt that the technique, possibly expanded to include boundary characteristics of the colonies, may offer a viable means of identifying clinically important bacteria.


2010 ◽  
Vol 97-101 ◽  
pp. 814-817 ◽  
Author(s):  
Jun Deng

One of the greatest drawbacks to predicting the behaviour of bonded joints has been the lack of reliable data on the mechanical properties of adhesives. In this study, methods for determining mechanical properties of structural adhesive were discussed. The Young’s modulus, Poisson’s ratio and tensile strength of the adhesive were tested by dogbone specimens (bulk form) and butt joint specimens (in situ form). The shear modulus and shear strength were test by V-notched specimens (bulk form) and thick adherend lap-shear (TALS) joint specimens (in situ form). The test results show that the elastic modulus provided by the manufacturer is too low, the dogbone specimen is better than the butt joint specimen to test the tensile strength and elastic modulus and the TALS joint specimen is better than the V-notched specimen to test the shear strength.


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