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Techniques Reliability in Chromium-Rich Stainless Steels Failure Assessment
Faraj Ahmed Emhmmed Alhegagi
Issue:
Volume 2, Issue 4, December 2017
Pages:
125-129
Received:
19 June 2017
Accepted:
5 July 2017
Published:
18 August 2017
DOI:
10.11648/j.css.20170204.11
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Abstract: Specimens of duplex stainless steels 50:50 ferrite –Austenite were heat treated at 475°C for different times and pulled to failure. Fracture toughness testing was performed according to BS 7448, clip gauge, to monitor specimen displacement. In addition, the direct current potential drop (DCPD) technique was used to monitor the crack propagation. The Crack Tip Open Displacement (CTOD) was evaluated. Computational data, Shear model, were fit to the experimental ones. Discrepancy was observed between the experimental data and the computational ones. The model was able to expect the crack tip open displacement (CTOD), experimental data, only within a certain range of the material hardness. In addition, the direct current potential drop technique was more sensitive to detect the crack propagation process than that observed for the clip gauge. This work aims to study the fracture mechanism during cracking of duplex stainless steels.
Abstract: Specimens of duplex stainless steels 50:50 ferrite –Austenite were heat treated at 475°C for different times and pulled to failure. Fracture toughness testing was performed according to BS 7448, clip gauge, to monitor specimen displacement. In addition, the direct current potential drop (DCPD) technique was used to monitor the crack propagation. Th...
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Treatment of Tannery Effluent by Tunisian Clay
Chaari Islem,
Ayari Sana,
Jridi Kamel
Issue:
Volume 2, Issue 4, December 2017
Pages:
130-136
Received:
16 June 2017
Accepted:
18 August 2017
Published:
11 September 2017
DOI:
10.11648/j.css.20170204.12
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Abstract: The tannery effluent from the wet finishing stage is a complex, highly charged rejected of organic and mineral matter. It has variable characteristics over time and is not readily biodegradable. Its physicochemical treatment by adsorption on the smectitic clay of Khlédia proves to be effective. The reduction of dye, BOD, COD, heavy metals are remarkable. The decrease of the conductivity is due to the phenomenon of the cations adsorption on the negatively charged support colloids.
Abstract: The tannery effluent from the wet finishing stage is a complex, highly charged rejected of organic and mineral matter. It has variable characteristics over time and is not readily biodegradable. Its physicochemical treatment by adsorption on the smectitic clay of Khlédia proves to be effective. The reduction of dye, BOD, COD, heavy metals are remar...
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Tribological Properties of Multilayer TiN and MoS2 Thin Films
Omer Ahmed,
Sorin Cioc,
Carmen Cioc,
Ahalaptiya H. Jayatissa
Issue:
Volume 2, Issue 4, December 2017
Pages:
137-142
Received:
22 May 2017
Accepted:
25 May 2017
Published:
13 October 2017
DOI:
10.11648/j.css.20170204.13
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Abstract: This paper presents tribological behavior of titanium nitride and molybdenum sulfide thin film coatings on a workpiece. The titanium nitride films were coated by RF magnetron sputtering method and molybdenum sulfide films were coated by vacuum thermal evaporation. Titanium nitride is a hard ceramic materials, which has excellent mechanical properties. However, the friction coefficient of titanium nitride is rather high. To improve the tribological properties of the titanium nitride films, a thin layer of molybdenum sulfide was coated as a solid lubricant. The results showed a substantial decrease in the coefficient of friction of dual-layered MoS2 over TiN compared with the titanium nitride film or as-received aluminum substrate. The low coefficient of friction can directly be correlated to the MoS2 layer whereas the TiN film acts as a robust and durable base material. The coefficient of friction was measured using a pin on a disc tribometer with a steel pin as the counter face. Our results demonstrated that the coating of MoS2 over TiN has a low coefficient of friction. In addition, it was also found that wear resistance of MoS2 coated TiN was better than both MoS2 and TiN films.
Abstract: This paper presents tribological behavior of titanium nitride and molybdenum sulfide thin film coatings on a workpiece. The titanium nitride films were coated by RF magnetron sputtering method and molybdenum sulfide films were coated by vacuum thermal evaporation. Titanium nitride is a hard ceramic materials, which has excellent mechanical properti...
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Entropy in the Brownian Motion (BM) and Coagulation Background
Issue:
Volume 2, Issue 4, December 2017
Pages:
143-161
Received:
7 November 2017
Accepted:
16 November 2017
Published:
28 December 2017
DOI:
10.11648/j.css.20170204.14
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Abstract: This review aims to highlight entropy in the Brownian motion (BM) and coagulation process background. In water treatment processes, pertinent questions relating to entropy, BM, and coagulation are often asked: Since entropy measures disorder of a system, does disorder manifest in polluted water with its stable colloids, microorganisms, molecules and ions? Are BM and molecular agitation favourable to separation processes? Since high salinity (as in seawater) decreases the disorder, would be increasing surface water salinity a convenient water treatment process? This review has found some links between entropy, BM, and coagulation such as: entropy is neither ‘disorder’ nor does it has anything to do with ‘mixed-up things’ like disorderly desks or shuffled cards. This review has also detailed the ordinary physical and chemical events whose spontaneity can be seen to be due to energy dispersing or spreading out. Coagulation/flocculation processes are employed to separate suspended solids from water whenever their natural subsidence rates are too slow to provide effective clarification. Adding salts to simply increase the ionic strength is almost never a practical option and other additives would be used; however, in seawater, where ionic strength is higher due to its proper dissolved salts, coagulation process is easier. Photovoltaically aided distillation process using large basins simulating sea open sky distillation process would be the greenest and healthiest water treatment technology.
Abstract: This review aims to highlight entropy in the Brownian motion (BM) and coagulation process background. In water treatment processes, pertinent questions relating to entropy, BM, and coagulation are often asked: Since entropy measures disorder of a system, does disorder manifest in polluted water with its stable colloids, microorganisms, molecules an...
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Developments/Application of Ionic Liquids/Poly Ionic Liquids in Magnetic Solid-Phase Extraction and Solid Phase Microextraction
Almojtaba Abd Alkhalig Ahmed Bakheet,
Zhu Xiashi
Issue:
Volume 2, Issue 4, December 2017
Pages:
162-170
Received:
27 October 2017
Accepted:
20 November 2017
Published:
3 January 2018
DOI:
10.11648/j.css.20170204.15
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Abstract: This review gives a survey on the latest most representative progress concerning ionic liquids and poly ionic liquids in magnetic solid phase extraction, from their fundamental Approaches to their developments and applications. It also highlights the recent advancements in the ionic liquid and poly ionic liquid in magnetic solid phase extraction and Solid phase microextraction.
Abstract: This review gives a survey on the latest most representative progress concerning ionic liquids and poly ionic liquids in magnetic solid phase extraction, from their fundamental Approaches to their developments and applications. It also highlights the recent advancements in the ionic liquid and poly ionic liquid in magnetic solid phase extraction an...
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