Aluminium corrosion studies. I. Potential-pH-temperature diagrams for aluminium

1974 ◽  
Vol 27 (1) ◽  
pp. 105 ◽  
Author(s):  
RT Lowson

The potential-pH-temperature relationships for the aluminium-water system have been calculated by the methods of de Bethune, Khodakovskiy, Criss and Cobble, and Helgeson and a critical comparison made. The Criss and Cobble method produced the most consistent results and was used to construct a corrosion diagram for the range 25-300�C. The effect of the hydrolysed ions Al(OH)2+, Al(OH)2+ and Al(OH)30 was also calculated. The work has shown up a temperature effect which should be taken into account when designing and operating aluminium circuits in which different parts are operated at different temperatures.

2016 ◽  
Vol 30 (01) ◽  
pp. 1550253 ◽  
Author(s):  
Xinjian Liu ◽  
Yu Jin ◽  
Congliang Huang ◽  
Jingfeng He ◽  
Zhonghao Rao ◽  
...  

Temperature and pressure have direct and remarkable implications for drying and dewatering effect of low rank coals such as lignite. To understand the microenergy change mechanism of lignite, the molecular dynamics simulation method was performed to study the self-diffusion of lignite/water under different temperatures and pressure. The results showed that high temperature and high pressure can promote the diffusion of lignite/water system, which facilitates the drying and dewatering of lignite. The volume and density of lignite/water system will increase and decrease with temperature increasing, respectively. Though the pressure within simulation range can make lignite density increase, the increasing pressure showed a weak impact on variation of density.


2021 ◽  
Vol 1 (01) ◽  
pp. 27-30
Author(s):  
IRANI KHATUN ◽  
RIYAD HOSSEN

Seed germination performance test of Taherpuri onion (a local variety of onion) under six different temperatures (15, 20, 25, 30, 35 and 40°C) was the main goal of this experiment. Germination percentage (GP) was calculated at highest 60.25% at 25°C, and the highest germination rate 20.08 was observed in the same temperature condition. The lowest germination performance (13.25 % germi-nation and 3.32 seeds per day as germination rate) was found at 40°C temperature. Finally, the authors mentioned the temperature 20 to 30°C as optimum range, and suggested the temperature 25°C as best suited for obtaining highest results in case of both germination percentage and germination rate of these seeds. To produce maximum seedlings of the local variety of onion, the mentioned temperature should be followed by the local farmers.


2018 ◽  
Vol 782 ◽  
pp. 227-232
Author(s):  
Sianny Surya Putri Kurnia ◽  
Dede Taufik ◽  
Veni Takarini ◽  
Zulia Hasratiningsih

Dental porcelain is one of the indirect restoration material with excellent aesthetic properties,on the other hand porcelain hardness frequently causing excessive wear of antagonist teeth. This study aiming to evaluate the effect of sintering temperature on the self-synthesized porcelain hardness. In this experiment, 25 porcelain samples were synthesized using Sumatran sand from Pangaribuan and Belitung regions, with the composition of 65 wt% Pangaribuan feldspar, 25 wt% Belitung silica and 10 wt% potassium salt. The samples were sintered in five different temperatures, which were 1110°C (A), 1120°C (B), 1130°C (C), 1140°C (D), and 1150°C (E). These samples were then invested on 5cm diameter resin each. The hardness was tested using Zwick Roell ZHμ Micro Vickers with 900 gram load for 15 seconds in 5 different indented areas for each sample. The result shows average hardness of 435.8 VHN (A), 461.0 VHN (B), 472.0 VHN (C), 487.6 VHN (D), and 528.7 VHN (E), which were increasing as the sintering temperature increased. Statistic result shows that sintering temperature significantly affected the hardness value of the porcelain (p value < 0.05). In conclusion sintering temperature affects the hardness of self-synthesized porcelain made from Sumatran natural sand without kaolin, although the average hardness of self-synthesized porcelain is still higher than average hardness of teeth enamel.


2012 ◽  
Vol 13 (3) ◽  
pp. 250
Author(s):  
Novri Nelly ◽  
Trimurti Habazar ◽  
Rahmat Syahni ◽  
Damayanti Buchori

Temperature effect on development time of the preadult parasitoid Eriborus argenteopilosus Cameron(Hymenoptera: Ichneumonidae) were studied to know development time, degree days and survival rate.Crocidolomia pavonana (Fabricius)(Lepidoptera: Pyralidae) larvae was exposed to E. argenteopilosus female andreared at four different temperatures i.e 160C, 200C, 250C and 300C. Data were analyzed using anova and linearregression to calculate degree day. At 200C E. argenteopilosus showed the highest degree day and survival rate(18.67 %), while at 300C nothing adult parasitoid emergenced. Degree day to development time of parasitoid attemperature 200C i.e fase egg-adult: 300.05; egg-pupae 173.35; pupae-adult 171.


KnE Energy ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
G.R. Sunaryo

<p>Hypothetically speaking, hydrazine could suppress the oxygen formation as a major of corrosion initiator. In this work, we developed a calculation model to understand the effect of hydrazine addition toward the oxygen under PWR condition. Our great interest is to study whether this strategy would also be effectively applied in PWRs<a href="file:///C:/Users/Mohamad%20Mostafa/Desktop/Knowledge%20E/In%20Press%20Conferences/ICoNETS-2015/Source-Manuscripts/20_L05-Geni_p136-141.docx#_msocom_1">[P1]</a> . In the present work, the effect of hydrazine on suppressing the molecule oxygen under neutron irradiation is described.  The simulation was done by using FACSIMILE.  The variation dose applied assuming a batch system and at high dose ~10<sup>4</sup> Gy s<sup>-1</sup>.  Three different temperatures were applied, which are room temperature, 250 and 300 <sup>o</sup>C at two system oxygenated water, which are aeration and deaeration. At room temperature, for deaerated condition, added hydrazine under a range of 10<sup>-6</sup> – 10<sup>-4</sup> M into primary coolant were not effective to suppress  O<sub>2 </sub>form since the effect was similar as in the pure water system since for 10<sup>-3</sup> M hydrazine addition, a large produce of O<sub>2 </sub>were obtained. In reverse, for deaerated condition, hydrazine concentrate about 10<sup>-3</sup> M can suppress O<sub>2</sub> form significantly, while hydrazine add in the range between 10<sup>-6</sup> – 10<sup>-4</sup> M is again confirmed to be the same as in pure water system. For high temperature, at 250 and 300 <sup>o</sup>C, the results showed that in deaerated condition, hydrazine addition can suppress  O<sub>2  </sub>form<sub> </sub>proportionally to its concentration while in aerated condition, hydrazine add with concentration of 10<sup>-6</sup> and 10<sup>-5</sup> M were not effectively to suppress O<sub>2  </sub>form,<sub> </sub>a slightly decrease of O<sub>2</sub> occurred due to the addition of 10<sup>-4</sup> M hydrazine and 10<sup>-3</sup> M of hydrazine can suppress the formation of O<sub>2</sub> significantly. <a href="file:///C:/Users/Mohamad%20Mostafa/Desktop/Knowledge%20E/In%20Press%20Conferences/ICoNETS-2015/Source-Manuscripts/20_L05-Geni_p136-141.docx#_msocom_2">[P2]</a> </p><div><hr align="left" size="1" width="33%" /><div><div><p> <a href="file:///C:/Users/Mohamad%20Mostafa/Desktop/Knowledge%20E/In%20Press%20Conferences/ICoNETS-2015/Source-Manuscripts/20_L05-Geni_p136-141.docx#_msoanchor_1">[P1]</a>The added sentence</p><p> </p></div></div><div><div><p> <a href="file:///C:/Users/Mohamad%20Mostafa/Desktop/Knowledge%20E/In%20Press%20Conferences/ICoNETS-2015/Source-Manuscripts/20_L05-Geni_p136-141.docx#_msoanchor_2">[P2]</a>The revised sentence</p></div></div></div>


Author(s):  
Liang Li ◽  
Purong Jia ◽  
Wenge Pan

Experimental and numerical investigations were carried out to study the temperature effect on the stiffness, strength, and failure behaviors of carbon/polyimide composite laminates. Both unnotched laminates and open-hole laminates were tested under tension load at three temperatures (room temperature, 200 ℃, and 250 ℃). A three-dimensional finite element analysis was carried out to study the thermomechanical coupling behavior in the notched laminate. The model considers each layer and interface as a single element in the thickness direction so that in-plane stress and interlaminar stress could be analyzed in the model. The stresses around the open-hole changing characteristics with the temperature and tensile loading have been discussed in detail. Failure analysis was carried out to predict the residual strength of the notched laminates at different temperatures. Compared to the experimental data, the numerical results have an excellent agreement.


2019 ◽  
Vol 969 ◽  
pp. 93-97
Author(s):  
S. Manivannan ◽  
B. Narenthiran ◽  
A. Sivanantham ◽  
S.P. Kumaresh Babu

The experimatal alloys were aged at different temperatures of 180°C, 200°C, 220°C, and 240º C with calcium addition levels of (X=0.5, 1, 1.5, 2%) on Mg-6Al-1Zn-XCa alloy were investigated in 3.5% NaCl solution. All the experimatal alloys were immersed in 3.5% NaCl solutions and the resulted surface were analyzed to study the corrosion behaviour and its surface topography by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersed spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The result shows that corrosion attack occurred predominantly on ß phase and α phase exhibit relatively minor corrosion. In addition to that the increased aging temperature coarsens the intermetallic as well as α- Mg grains, which shows adverse effect to corrosion resistances and the best result were obtained at composition of 0.5wt.% Ca aged at 200°C.


2015 ◽  
Vol 1084 ◽  
pp. 61-65
Author(s):  
Lyudmila V. Gulidova ◽  
Natalya A. Dubrova ◽  
Andrey M. Lider

The paper presents the theoretical foundations of carbon nanotubes, as well as the methods of the saturation of carbon materials containing nanotubes with hydrogen from the gaseous phase. The dependences of hydrogen storage concentration on the pressure (between 0 and 8 atmospheres) at the same temperature for adsorption (–30 degrees Celsius) and different temperatures for desorption have been obtained. Obviously, at 8 atmospheres the concentration of hydrogen storage varies with the change of the temperature. Particular attention was paid to the influence of the temperature on the rate of desorption.


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