scholarly journals Towards understanding the Effect of Oil on Phytoremediation of PCB CoContamination in Transformer Oil Using Chromolaena Odorata

Author(s):  
R. O. Anyasi ◽  
H. I. Atagana
Author(s):  
A.V. Nekhorosheva ◽  
◽  
V.P. Nekhoroshev ◽  
I.V. Lodina ◽  
◽  
...  

2019 ◽  
Vol 12 (1) ◽  
pp. 18-21
Author(s):  
V. A. Tikhonov

The influence of the periodicity of diagnostic measurements on the operational state of high-voltage transformers is considered. Examples of defects of switching devices of converter transformers and methods for their detection are given. The rationale for the importance of recognition of defects at an early stage of their occurrence is given. The influence of the multiplicity of overvoltages on the service life of converter transformers in the aluminum industry is investigated. Based on the analysis of the service life of converter transformers of one of the powerful aluminum plants, where 83% of converter transformers have exhausted their standard service life, it is shown that in 40% of cases it would be possible to avoid their failures, with timely detection and elimination of emerging defects. Examples of defects of OLR (on-load regulators) of converter transformers and methods for their detection are given. The importance of recognition of defects at an early stage of their occurrence is substantiated. A method for chromatographic analysis of dissolved gases in transformer oil has been developed for the qualitative determination of defects and ways to eliminate them. Examples of diagnostics of converter transformers at operating voltage and working load are given, providing the best quality operational characteristics of converter transformers. The periodicity of diagnostic measurements and the reduction of defects and failures has been substantiated. The question of diagnosing the state of the converter transformer TDNP-40000/10 at an enterprise of the aluminum industry is investigated. Currently, diagnostic methods are being developed based on chromatographic analysis of dissolved gases in transformer oil. The presented method of evaluating the operating parameters of transformers allows for the safe operation of high-voltage transformers and enables to increase the reliability of the power supply scheme of aluminum industry plants.


2020 ◽  
Vol 38 (8A) ◽  
pp. 1226-1235
Author(s):  
Safa R. Fadhil ◽  
Shukry. H. Aghdeab

Electrical Discharge Machining (EDM) is extensively used to manufacture different conductive materials, including difficult to machine materials with intricate profiles. Powder Mixed Electro-Discharge Machining (PMEDM) is a modern innovation in promoting the capabilities of conventional EDM. In this process, suitable materials in fine powder form are mixed in the dielectric fluid. An equal percentage of graphite and silicon carbide powders have been mixed together with the transformer oil and used as the dielectric media in this work. The aim of this study is to investigate the effect of some process parameters such as peak current, pulse-on time, and powder concentration of machining High-speed steel (HSS)/(M2) on the material removal rate (MRR), tool wear rate (TWR) and the surface roughness (Ra). Experiments have been designed and analyzed using Response Surface Methodology (RSM) approach by adopting a face-centered central composite design (FCCD). It is found that added graphite-silicon carbide mixing powder to the dielectric fluid enhanced the MRR and Ra as well as reduced the TWR at various conditions. Maximum MRR was (0.492 g/min) obtained at a peak current of (24 A), pulse on (100 µs), and powder concentration (10 g/l), minimum TWR was (0.00126 g/min) at (10 A, 100 µs, and 10 g/l), and better Ra was (3.51 µm) at (10 A, 50 µs, and 10 g/l).


Author(s):  
V. A. Poryazov ◽  
◽  
O. G. Glotov ◽  
V. A. Arkhipov ◽  
G. S. Surodin ◽  
...  

The goal of this research is to obtain experimental information about combustion characteristics of the composite propellant containing various metallic fuels. The propellant formulations contained two fractions of ammonium perchlorate (64.6%), inert binder (19.7%) - butadiene rubber SKD plastized with transformer oil, and metal fuel (15.7% of aluminum ASD-4, ASD-6, Alex; boron; aluminum diboride; aluminum dodecaboride; some mixtures of above listed ingredients). Experimental information will be used further as a background to develop the physical and mathematical model of combustion process.


2019 ◽  
Vol 35 (1) ◽  
pp. 145-153
Author(s):  
O. Uyi, ◽  
I.G. Amolo ◽  
A.D. Adetimehin

Several studies have demonstrated the biological efficacy of leaf, stem and root powders or extracts of Chromolaena odorata (L.) King and Robinson against insect pests but those that are focused on the biological efficacy of aqueous leaf extracts against Macrotermes species are scanty. Current management of termites with synthetic insecticides is being discouraged due to human and environmental hazards. Therefore, the insecticidal effectiveness of aqueous leaf extract C. odorata against Macrotermes species was investigated. Five concentrations (0, 2.5, 5.0, 7.5 and 10.0% (w/v)) of the aqueous extract of C. odorata plant were evaluated for repellency and toxicity on the worker caste of Macrotermes species following standard procedures. The filter paper impregnation technique was used for the bioassay. Percentage repellency was monitored for 30 minutes and mortality recorded at 12, 24 and 36 hours post exposure. The leaf extract of C. odorata significantly repelled 95% of Macrotermes species at the highest concentration of 10% (w/v) after 30 minutes post treatment exposure. Mortality of Macrotermes species was independent of treatment concentration, but dependent on duration of exposure. All treatment concentrations of aqueous leaf extract of C. odorata caused significant mortality against Macrotermes species ranging between 94% and 98% compared to the control; indicating very great potential for adoption and use in the management of Macrotermes species.


2019 ◽  
Vol 3 (2) ◽  
pp. 140
Author(s):  
Harlina Harlina ◽  
Hadijah Hadijah ◽  
Kamaruddin Kamaruddin ◽  
Ernaningsih Ernaningsih

Tamangapa village, Ma’rang district is part of the community development program conducted by Universitas Muslim Indonesia in Pangkajene Kepulauan regency. The local shrimp farmers of Tamangapa village have been facing major issue due to expensive artificial feed and high mortality rate. In order to solve the needs of feed and high mortality rate for farmed fish or shrimp, the source of the natural ingredients using kopasanda leaves Chromolaena odorata L is required. The use of a natural ingredient is also used to prevent the vibriosis using simple technology such as the utilization of local raw materials which is affordable and locally available. The present community service aimed to provide the proper knowledge and skills to members of the fish/shrimp farmer’s group through counseling, training and mentoring. This community service program encouraged the local farmers to be able to utilize the local raw materials as a source of shrimp feed, use the feed pellet machine, and packaging leading to independent feed production. The participatory training method, lectures, forum group discussions, and practices of making shrimp feed and packaging were applied. The Implementation of the Community Partnership Program of Shrimp and Fish Cultivation Groups is independently able to produce organic fish or shrimp feed for farmer’s group leading to higher productivity of aquaculture.


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