Processes of Reclaiming Rubber and Their Relative Merits

1944 ◽  
Vol 17 (2) ◽  
pp. 544-550 ◽  
Author(s):  
E. W. B. Owen
Keyword(s):  
Tensile Strength ◽  
Surface Finish ◽  
Thermal Process ◽  
Large Scale ◽  
New Products ◽  
The Other ◽  
Permanent Set ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

Abstract 1. A more complete reclamation is possible by the thermal and pan process than with the alkali process, and both the former effect a saving in time. 2. The thermal process calls for a higher temperature, but the after-treatment consumes less power for grinding. The pan process makes use of a lower temperature; but the expenditure of more power for grinding before and after treatment, as well as a drying period, are entailed. 3. The new products are neutral, and softer than alkali reclaim. 4. Accelerated with BA, stocks with these new types of reclaim give poor results. On the other hand, MBT offers good prospects, both for aging and acceleration. 5. Whether refined or not, the pan reclaim produced a tensile strength 95 per cent of alkali reclaim, and the thermal reclaim 80 per cent, in MBT stocks. 6. With modified acceleration, thermal reclaim stock can be made to give improved tensile properties. 7. Laboratory abrasion resistance of both new types was superior to the standard, the losses being 92 per cent and 74 per cent for thermal and pan reclaims, respectively. 8. The permanent set was lower despite the softener in the pan reclaim. 9. Despite the lack of refining, articles formed by extrusion from stocks containing thermal and pan reclaims compared favorably with those from alkali reclaim with regard to surface finish. 10. Thermal reclaim ages extremely well. Independent workers in the field of thermal reclaim have been able to exercise a finer control of the process, and a large scale plant is in course of erection as a result of the improvements effected. Further work is proceeding, and it is hoped that a product superior in all respects to alkali reclaim will be obtained.

Effects of Sr Addition on Mechanical Properties and Microstructure of Mg-6Al Magnesium Alloy

2011 ◽  
Vol 686 ◽  
pp. 120-124
Author(s):  
Jin Ping Fan ◽  
She Bin Wang ◽  
Bing She Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Strengthening Mechanism ◽  
Microstructure And Mechanical Properties ◽  
Higher Temperature ◽  
Lower Temperature

The effects of Sr addition on the mechanical properties and microstructure of Mg-6Al mag- nesium alloy both at 25 °C and at 175 °C were investigated by means of OM, SEM and EDS and XRD. Upon the Sr addition of 2%, the tensile strength was increased by 7.2% to 184.4MPa at 25 °C, while it was increased by 30% to 155.4MPa at 175 °C. The strengthening mechanism of Mg-6Al-xSr at lower temperature (25 °C) was different from that at higher temperature (175°C). The results show that the addition of strontium effectively improved the microstructure and mechanical properties of magnesium alloy.

Large-scale and facile fabrication of PbSe nanostructures by selenization of a Pb sheet

2015 ◽  
Vol 08 (05) ◽  
pp. 1550063 ◽  
Author(s):  
Sara Hoomi ◽  
Ramin Yousefi ◽  
Farid Jamali-Sheini ◽  
Abdolhossein Sáaedi ◽  
Mohsen Cheraghizade ◽  
...  
Keyword(s):  
Large Scale ◽  
Chemical Vapor ◽  
Infrared Region ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Facile Fabrication ◽  
Higher Temperature ◽  
Set Up ◽  
Lower Temperature

PbSe nanostructures were synthesized by selenization of lead sheets in a chemical vapor deposition (CVD) set-up under a selenium ambiance. The lead sheets were placed in the different temperature zones, between 300°C and 450°C. Field emission scanning electron microscope (FESEM) images showed that, PbSe nanostructures grown on the lead sheets with different morphologies. PbSe nanostructures with flakes shape were grown on the lead sheets that were placed in the lower temperature, while PbSe nanocubes and nanorods, which were grown on the nanocubes, were grown on the lead sheets in the higher temperature. The phase and composition of the product were identified by X-ray diffraction (XRD) pattern and X-ray photoelectron spectra (XPS). The XRD and XPS results showed that, the PbSe phase was started to form after 350°C and completed at 450°C. However, the XPS results showed that the Se concentration was different in the samples. In addition, Raman measurements confirmed the XRD and XPS results and indicated three Raman active modes, which belonged to PbSe phase for the nanostructures. The optical properties of the products were characterized by UV–Vis. The optical characterization results showed a band gap for the PbSe nanostructures in the infrared region.

Synthesis, Characterization and Properties of Polyesteramides Based on ε-Caprolactone and 6-Aminocaproic Acid

2011 ◽  
Vol 287-290 ◽  
pp. 1538-1547 ◽  
Author(s):  
Yi He ◽  
You Ru Du ◽  
Xiao Bo Liu
Keyword(s):  
Tensile Strength ◽  
Tensile Testing ◽  
Aminocaproic Acid ◽  
Amide Bond ◽  
Ester Bond ◽  
Degradation Temperature ◽  
Melt Polycondensation ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Thermal Degradation Temperature

Biodegradable aliphatic polyesteramides were synthesized from ε-caprolactone and 6-aminocaproic acid by melt-polycondensation method. FTIR, 1H-NMR, DSC, WAXD, TG, and tensile testing were used to characterize the polyesteramides. With the increase in 6-aminocaproic acid content, the melting temperature, thermal degradation temperature and tensile strength at break increased accordingly. The ester bond decomposes at lower temperature, and then the amide bond decomposes at higher temperature.

Characterization of Gamma Irradiated PP/LDPE Blend

2014 ◽  
Vol 353 ◽  
pp. 90-95
Author(s):  
Tatiana Mayumi Moori ◽  
Mauro Cesar Terence ◽  
Nilson Casimiro Pereira ◽  
Sonia Braunstein Faldini ◽  
Leila Figueiredo de Miranda
Keyword(s):  
Tensile Strength ◽  
Gamma Rays ◽  
The Other ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Average Increase ◽  
Polymeric Chains ◽  
Before And After ◽  
Gamma Irradiated

This study analyzed nine polypropylene (PP) and low-density polyethylene (LDPE) blends where the mass concentrations of each sample were changed, proportionally. The aim was to investigate the tensile strength by means of these polymers best combination, before and after its exposal to gamma rays. The results showed that the 20/80 - PP/LDPE blend had a better performance concerning mechanical properties after irradiation, where the maximums tensile stress had an average increase of 30% in 30 and 50 kGy doses and 33% in the 200 kGy dose. On the other hand, it was verified that the higher blend's PP concentration, the higher its tensile strength will be (except for 100 kGy and 200 kGy doses which PP concentration over 70% can cause eventual degradation in the polymeric chains of the blend).

scholarly journals Cast Steel Filtration Trials Using Ceramic-Carbon Filters

2014 ◽  
Vol 14 (4) ◽  
pp. 61-66 ◽  
Author(s):  
B. Lipowska ◽  
J. Witek ◽  
T. Wala ◽  
A. Karwiński ◽  
P. Wieliczko ◽  
...  
Keyword(s):  
Surface Reaction ◽  
Cast Steel ◽  
Coal Tar ◽  
The Other ◽  
Coal Tar Pitch ◽  
Carbon Precursor ◽  
Flake Graphite ◽  
Before And After ◽  
Lower Temperature ◽  
Secondary Contamination

Abstract Trials of cast steel filtration using two types of newly-developed foam filters in which carbon was the phase binding ceramic particles have been conducted. In one of the filters the source of carbon was flake graphite and coal-tar pitch, while in the other one graphite was replaced by a cheaper carbon precursor. The newly-developed filters are fired at 1000°C, i.e. at a much lower temperature than the currently applied ZrO2-based filters. During filtration trials the filters were subjected to the attack of a flowing metal stream having a temperature of 1650°C for 30 seconds. Characteristic of the filters’ properties before and after the filtration trial were done. It was found, that the surface reaction of the filter walls with molten metal, which resulted in local changes of the microstructure and phase composition, did not affect on expected filter lifetime and filtration did not cause secondary contamination of cast steel.

Effects of filtration temperature, humic acid level and alum dose on cryptosporidium sized particle breakthrough

2006 ◽  
Vol 54 (11-12) ◽  
pp. 353-361
Author(s):  
G.R. Xu ◽  
C.S.B. Fitzpatrick ◽  
L.Y. Deng
Keyword(s):  
High Temperature ◽  
Humic Acid ◽  
Acid Level ◽  
Low Dose ◽  
Optimal Dose ◽  
Influence Of Temperature ◽  
Ζ Potential ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

Recent Cryptosporidium outbreaks have highlighted concerns about filter efficiency and especially particle breakthrough. Understanding the causes of breakthrough is essential, as the parasite cannot be destroyed by conventional disinfection with chlorine. Particle breakthrough depends on many factors. This research aims to investigate the influence of temperature, humic acid (HA) level and chemical dosing on particle breakthrough in filtration. A series of temperatures were set at 5 °C, 15 °C and 25 °C; humic acid level was 5 mg L−1. Each was combined with a series of Al doses. A laser particle counter was used to assess the particle breakthrough online. Turbidity, ζ potential, and UV254 absorption were measured before and after filtration. The results showed that particle breakthrough was influenced significantly by temperature, humic acid and dosing. Particle breakthrough occurred earlier at lower temperature, while at higher temperature it was reduced at the same coagulant dose. With coagulants, even at low dose, particle breakthrough was significantly reduced. With HA 5 mg L−1, particle breakthrough was earlier and the amount was much larger than without HA even at high temperature. There was an optimal dose in filtration and it was well correlated with ζ potential.

scholarly journals Airborne micro-organisms: survival tests with four viruses

1961 ◽  
Vol 59 (4) ◽  
pp. 479-486 ◽  
Author(s):  
G. J. Harper
Keyword(s):  
Relative Humidity ◽  
The Other ◽  
Poliomyelitis Virus ◽  
Virus Particles ◽  
Venezuelan Equine Encephalomyelitis ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Micro Organisms

Airborne virus particles of vaccinia, influenza, Venezuelan equine encephalomyelitis, and poliomyelitis have been tested for viable survival in the dark at controlled temperatures and relative humidity (R.H.) for up to 23 hr. after spraying.Viable survival at each R.H. level was better at lower temperature than at higher temperature. Poliomyelitis virus showed best survival at high R.H.; the other three viruses survived best at low R.H.

Dinitrogen fixation in pea beans (Phaseolus vulgaris) as affected by growth stage and temperature regime

1981 ◽  
Vol 59 (7) ◽  
pp. 1181-1188 ◽  
Author(s):  
R. J. Rennie ◽  
G. A. Kemp
Keyword(s):  
Phaseolus Vulgaris ◽  
Temperature Regime ◽  
Low Temperatures ◽  
Growth Stage ◽  
Dry Weight ◽  
Growing Season ◽  
The Other ◽  
Higher Temperature ◽  
Reducing Activity ◽  
Lower Temperature

Tolerance of beans (Phaseolus vulgaris L.) to low temperatures is essential for growth under Canadian growing conditions. At air temperatures typical of a southern Alberta growing season (10–23 °C), 'Aurora' fixed 433 mg N per plant, more than 'Sanilac' and 'Comtesse,' which averaged 307 mg N per plant, and 'Kentwood,' which fixed the least: 214 mg N per plant. At a higher temperature regime (15–23 °C), typical of a southern Ontario growing season, 'Aurora' again fixed the most N2 (456 mg N per plant), while the other three cultivars fixed an average of 370 mg N per plant. The amount of N2 fixed increased as the time to reach maximum acetylene (C2H2) reducing activity lengthened. This suggested that it may be advantageous to select beans that have a longer vegetative stage to prolong the time of active N2 fixation within the limits of acceptable season length to ensure maturity. 'Aurora' was not affected by the lower temperature regime, and although these temperatures delayed the initiation of N2 fixation by 21 days, 'Aurora' compensated by producing 26% greater nodule dry weight and 40% higher maximum C2H2-reducing activity than that observed at the higher temperature regime. Growth and N2 fixation of the other three cultivars were adversely affected by the lower temperature regime, not because of lower nodule numbers or mass but because of lower nodule activity. The good root growth of 'Aurora' at low temperatures may explain its superiority for N2 fixation at lower temperatures. C2H2 reduction and nodule dry weight were acceptable indicators of N2 fixation only during early plant growth when all nodules were new and uniformly active. The ideal time to select the bean cultivars for N2-fixing ability was just before the peak of maximum C2H2-reducing activity and corresponded to the stage from buds-near-breaking to anthesis for both temperature regimes. Molar ratios of C2H2 reduced to N2 fixed suggested that the relative efficiency of N2 fixation varied with temperature and growth stage but not with bean cultivar.

Annealing-Induced Transformation of Defects in ZnO Single Crystal and the Effects on the Optical Properties

2013 ◽  
Vol 341-342 ◽  
pp. 311-314
Author(s):  
Wei Feng Li ◽  
Xi Qi Feng
Keyword(s):  
Optical Properties ◽  
Optical Transmittance ◽  
Defect Complexes ◽  
Interstitial Zinc ◽  
Air Atmosphere ◽  
Zinc Interstitial ◽  
Before And After ◽  
Higher Temperature ◽  
Zno Crystal ◽  
Lower Temperature

ZnO single crystals were prepared and then sequentially annealed from 573 to 1073 K in air atmosphere. Optical transmittance spectra (OTS), X-ray excited luminescence (XEL), and photoluminescence (PL) were measured before and after each step of annealing. The lower temperature annealing can enhance the emission but hardly affect the optical transmittance. Contrarily, higher temperature treatments ameliorated the transmittance but degraded emission. Based on experimental results, the blue and green emissions, as well as the 400-500-nm absorption were assigned to isolated zinc interstitial, zinc vacancy and oxygen vacancy in ZnO, respectively. In addition, the defect complexes play important role on optical properties of ZnO crystal. Our results provide further insight into understanding defects and defect complexes in ZnO crystals.

Investigation on Toughness of Fibre Cocktail Reinforced Self Consolidating Concrete after High Temperature

2010 ◽  
Vol 650 ◽  
pp. 67-77
Author(s):  
Yi Ning Ding ◽  
Yue Hua Wang ◽  
Yu Lin Zhang
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Steel Fibers ◽  
Failure Pattern ◽  
Self Consolidating Concrete ◽  
Pull Out ◽  
Hybrid Fibre ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

The effect of different fibres on the residual load-bearing capacity and the failure pattern of high-performance self consolidating concrete (HPSCC) after exposure to high temperature hass been studied in this work. The polypropylene fibers mitigate the spalling of HPSCC element clearly, but did not show clear effect on the mechanic properties of concrete. The macro steel fiber reinforced HPSCC showed higher flexural toughness and ultimate load before and after high temperatures. The mechanical properties of hybrid fibre reinforced HPSCC (HFHPSCC) after heating were better than that of mono-fibre reinforced HPSCC. The failure mode changed from pull-out of steel fibers at lower temperature to broken down of steel fibers at higher temperature. The use of hybrid fibre can be effective in providing the residual strength and failure pattern, and improving the toughness of HPSCC after high temperature.

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