PROTECTION FOR SAFETY RELATED ITEMS FROM ACID OR ALKALI MEDIUM SPRAY IN NUCLEAR STATION

Author(s):  
Lin Daping ◽  
Huang Xiaoyun
Nanomedicine ◽  
2021 ◽  
Author(s):  
Jean Valdir Uchôa Teixeira ◽  
Fátima Raquel Azevedo Maia ◽  
Mariana Carvalho ◽  
Rui Reis ◽  
Joaquim Miguel Oliveira ◽  
...  

Aim: To established a simple, controlled and reproducible method to synthesize gallium (Ga)-coated polydopamine (PDA) nanoparticles (NPs). Materials & methods: PDA NPs were synthesized in alkali medium with posterior Ga shell formation due to ion chelation on the NP surface. Results: The obtained results with energy-dispersive x-ray spectroscopy confirmed the incorporation of Ga on the PDA NP surface. The cytotoxicity of Ga-coated PDA NPs was evaluated in vitro at different concentrations in contact with human adipose-derived stem cells. Further cell analysis also demonstrated the benefit of Ga-coated PDA NPs, which increased the cell proliferation rate compared with noncoated PDA NPs. Conclusion: This study indicated that Ga could work as an appropriate shell for PDA NPs, inducing cell proliferation at the analyzed concentrations.


Author(s):  
Mark S. Denton ◽  
Josh Mertz

On March 11, 2011, now two years ago, the magnitude 9.0 Great East Japan earth quake, Tohoku, hit off the Fukushima coast of Japan. This was one of the most powerful earthquakes in recorded history and the most powerful one known to have hit Japan. The ensuing tsunami devastated a huge area resulting in some 25,000 persons confirmed dead or missing. The perfect storm was complete when the tsunami then found the four-reactor, Fukushima-Daiichi Nuclear Station directly in its destructive path. Some 2 million people were evacuated from a fifty mile radius of the area and evaluation and cleanup began. A tremendous effort has been made, by many nationalities, since this time to restore this damaged plant and surrounding area and to return a great deal of the residents to their homes and farm lands. While most of the outcome of this unprecedented natural and manmade disaster was negative, both in Japan and worldwide, there have been some extremely valuable lessons learned and new emergency recovery technologies and systems developed to cope with the aftermath of this disaster. This paper describes new technology developed to selectively remove radioactive materials dangerous to workers, local citizens, and the natural environment from seawater used to cool the damaged reactors at Fukushima. As always, the mother of invention is necessity.


2020 ◽  
Vol 24 (2) ◽  
pp. 163-182
Author(s):  
Edison Omollo Oduor ◽  
Lucy Wanjiru Ciera ◽  
Vijay Adolkar ◽  
Odoch Pido

Purpose This paper aims to determine the best conventional degumming technique for use by rural farmers practicing Eri silk fiber production in Kenya. Design/methodology/approach Three conventional silk degumming methods (water, soap and alkali) were analyzed under the factors, namely, time, pressure and degumming media, following the multilevel factorial design of experiments. The effect of variables on degumming weight loss was determined. The effects of the conventional degumming methods that produced complete sericin removal on chemical structure, surface morphology, thermal properties, crystallinity and fiber strength on Eri silk fibers produced in Kenya were then determined. The optimal degumming condition was then evaluated. Findings Soap and water degumming led to incomplete sericin removal. Alkali degumming media had the most effect, especially when pressure cooked at 103 kPa. Increasing time during alkali degumming beyond 30 min did not to have any major difference on degumming loss (at p 0.05). There were no major changes in chemical and thermal properties after degumming. However, the tensile strength and elongation deteriorated especially on alkali medium. Decreasing degumming time in alkali medium from 120 min to 30 min reduced the strength loss from 45% to 33%. Optimal degumming was found to be in an alkali media at 103 kPa for 30 min. Originality/value There is very little information available on Eri silk fibers produced in Kenya. Results of this study provide an optimized conventional degumming procedure suitable for small scale farmers in rural areas practicing Eri silk fiber production.


Author(s):  
Merwin W. Jones ◽  
Kim M. Massey ◽  
David Voisin

This paper describes the numerous challenges involved in the partial retubing of the Belleville Nuclear Station Unit 2 steam surface condenser using 64,242 tubes. Specific challenges of the project included retubing with both duplex stainless steel tubes and with brass alloy tubes, analyzing the risk of flow induced tube vibration and designing a staking system to prevent such vibration, and, replacement of six tubesheets. The tubesheet stresses were analyzed using a beam strip analysis and ANSYS, and new tubesheets were reverse engineered from original drawings. Tubesheets were aligned to the support plate holes using a newly developed laser alignment system. Prior to the retubing, extensive mockup tests were performed to optimize the rolling torque, and to determine rolling parameters that limit the work-hardening of the brass tubes. Testing also included leak testing the mockup joints with a small pressure vessel and then performing a helium leak test of the pressurized tube joints. Tests were performed with both smooth and serrated holes.


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