scholarly journals Microstructural Characteristics of Arc Beads with Overcurrent Fault in the Fire Scene

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4521
Author(s):  
Zhijin Yu ◽  
Shuangshuang Chen ◽  
Jun Deng ◽  
Xueyan Xu ◽  
Weifeng Wang
Keyword(s):  
Trace Elements ◽  
Copper Wire ◽  
Grain Morphology ◽  
Average Diameter ◽  
Electric Discharges ◽  
Microstructural Characteristics ◽  
Cu Content ◽  
Copper Conductor ◽  
Fire Scene ◽  
Two Bodies

Arc beads are high-temperature luminous electric discharges that form across a gap between two bodies, which is one of the vital forensic pieces of evidence for the evaluation of electrical fires. In this study, based on an actual electrical fire, the microstructure of arc beads from a copper wire that experienced an overcurrent fault was investigated by optical microscopy and scanning electron microscopy. Moreover, the effects of the overcurrent intensity on the grain morphology, trace elements, and microstructure of the arc beads were analyzed. The results showed that the simulated metallographic structure of the arc beads is mainly dendrite at four times the rated current, which is consistent with the fire scene. With an increase in the overcurrent, the average diameter, perimeter, and area of the grains increased, while the dendrite growth was inhibited by the overcurrent. In addition, the main trace elements were Cu, C, O, and Cl. When the current increased, the Cu content gradually decreased and tended to be stable, while the C content gradually increased. The conclusion of this research provided a scientific reference for identifying the melting trace in a copper conductor under overcurrent fault.

Magnetron Sputtering Deposition of Calcium Phosphate Films with Nanoscale Grain Morphology in their Surface

2006 ◽  
Vol 975 ◽  
Author(s):  
Wilfredo Otaño ◽  
Víctor M. Pantojas ◽  
Juan M. Figueroa ◽  
Darimar Hernández ◽  
Alejandro Rodríguez-Navarro
Keyword(s):  
Calcium Phosphate ◽  
Surface Morphology ◽  
Magnetron Sputtering ◽  
Deposition Time ◽  
Grain Morphology ◽  
Average Diameter ◽  
Deposition Process ◽  
Medical Implants ◽  
Sputtering Deposition ◽  
Coated Implant

ABSTRACTHydroxyapatite (HA) is a calcium phosphate mineral analogous to the mineral part of bone. This similarity makes this material bioactive and suitable to coat medical implants. However, at present, there is not a coating technique which gives the coated implant the desired properties and long life required for medical implants.In an effort to produce HA coatings with improved properties, calcium phosphate films were prepared using magnetron sputtering deposition on a silicon substrate at 600°C. Initial efforts resulted in the deposition of amorphous films with a distinctive grain-like surface morphology. The morphological grain size was studied using SEM and found that it was possible to control the average diameter value of the round shaped grains by adjusting the deposition time. Increasing the deposition time increases the mean grain diameter. EDS spectra showed the unintentional addition of carbon, iron and nickel to the samples during deposition. After eliminating the impurities, it was possible to prepare calcium phosphate films in the HA phase but without the grain-like surface morphology. These results suggested that the impurities prevented the formation of the calcium phosphate HA phase while acting as nuclei for the heterogeneous nucleation of the grains. This is an important result where the deposition process parameters can be controlled to functionalize the films in order to produce distinctive nanoscale features in the surface morphology.

scholarly journals Chemical and mineral composition of sulfide nodules from the Mikhaylovsky and Belousovsky ancient mines, Orenburg Gis-Urals

2020 ◽  
pp. 35-45
Author(s):  
I.A. Blinov
Keyword(s):  
Trace Elements ◽  
Mineral Composition ◽  
Oxidation Zone ◽  
Cu Content

Cu-sulfde and rare Fe-sulfde nodules up to 2–5 cm in size are found in gray marl siltstones, which occur in a sequence of Permian sandstones of Orenburg Cis-Urals. The Cu-sulfde nodules are characterized by high Cu content (>20 %) and low contents of trace elements (Fe <1.2 %, As, Ag, V, and Pb <130 ppm). They are composed of Cu sulfdes (minerals of the chalcocite group and covellite) with minor barite and mottramite. The Cu sulfdes are transformed to malachite and, to a lesser degree, to chrysocolla and brochantite. The decomposition of Ag-bearing Cu sulfdes leads to the formation of a Ag sulfde. The Fe-sulfde nodules of the Belousovsky mine are composed of pyrite. In the oxidation zone, pyrite is replaced by ferrous opal; single grains of plumbogummite are associated with Fe hydroxides.

The effect of Tracerglass-L on the copper, cobalt and selenium status of lambs

1984 ◽  
Vol 1984 ◽  
pp. 151-151
Author(s):  
S. B. Telfer ◽  
G. M. Carlos ◽  
G. Zervas
Keyword(s):  
Trace Elements ◽  
Surface Area ◽  
Glass Structure ◽  
Average Diameter ◽  
Aqueous Environment ◽  
Selenium Status ◽  
Rumen Microbes ◽  
Adult Sheep ◽  
Steady Rate

Tracerglass is a phosphate-based glass which dissolves in an aqueous environment at a slow and steady rate in proportion to the surface area of the glass (Telfer, Zervas & Knott, 1983). Tracerglass contains the trace elements copper, cobalt and selenium as part of the glass structure and therefore as the glass dissolves these trace elements are released into the aqueous environment. When placed in the reticulo-rumen of a ruminant by means of the normal balling gun method the Tracer-glass will dissolve, release the elements into the reticulo-rumen and thus make these elements available for utilisation by the rumen microbes and the animal itself. The Tracerglass-L form is a tapered bullet of average diameter 14 mm, length 40 mm and weight of 18 g which has been produced for use in lambs from 6 to 8 weeks pf. age. The Tracerglass-L dissolves at a rate that will maintain its effectiveness in lambs for up to 6 months while the adult sheep and cattle Tracerglasses will last for 12 months.

Corrosive Action of Sulfur against Metallic Copper during Vulcanization

1936 ◽  
Vol 9 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Shozo Satake
Keyword(s):  
Copper Wire ◽  
Metallic Copper ◽  
Tin Coating ◽  
Copper Salts ◽  
Rubber Mixture ◽  
Tetramethylthiuram Disulfide ◽  
Copper Conductor ◽  
The Status ◽  
Long Time ◽  
Marine Cables

Abstract The use of copper wire electroplated with tin for insulated electric wires was originated by Siemens eighty-five years ago (through Saito, J. Soc. Chem. Ind. Japan, 18, 248 (1915)), and its merits lie in the fact that it prevents a lowering of the electrical conductivity and mechanical strength from corrosion of copper by the sulfur in the rubber, and also prevents the rubber from deteriorating abnormally fast by contact with the copper. The manufacture of rubber for coating wire has improved rapidly since the appearance of organic accelerators and combined accelerating and vulcanizing agents, such as the polynitrobenzenes and benzoyl peroxide of Ostromislensky, the selenium of Boggs and tetramethylthiuram tetrasulfide and tetramethylthiuram disulfide. Recently, it was reported (India Rubber World, 87, 38 (1933)) that rubber compounded with 2 per cent of 1,3,5-trinitrobenzene as vulcanizer does not corrode wire conductors and does not deteriorate abnormally fast when the rubber mixture is covered directly on the wire and vulcanized. The prediction was also made that tin-coated copper wire will disappear entirely from the cable world. As a matter of fact, marine cables have for a long time been covered with an insulator consisting chiefly of gutta-percha or balata hydrocarbon, in direct contact with the copper conductor, and have given good service. The para-gutta insulation of marine cables, recently developed by the Western Electric Company, U. S. A., is composed partly of rubber, with no tin coating on the copper conductor. Nevertheless, the principal factor which decides the “electrical life” of rubber submerged in water is, according to Curtis (J. Res. Natl. Bur. Standards, 5, 539 (1930)) the deterioration of the rubber by copper salts, and Asano (J. Soc. Chem. Ind. Japan, 24, 336 (1921)) reported that smoked sheet became so sticky that it required considerable strength to separate after it had been held between two copper plates for six months. The status of the electric insulating wire industry today is such that a thorough investigation of the tin coating of copper wire and the methods of tin coating in connection with the deterioration of rubber by the copper wire is desirable. The investigation described in the present paper was carried on with this object, and it deals with experiments on the corrosion of metallic copper by sulfur during vulcanization, and shows the formation of copper sulfides as corrosion products.

Dependence of magnetic, phase-transformation and microstructural characteristics on the Cu content of Nd–Fe–B sintered magnet

2014 ◽  
Vol 66 ◽  
pp. 12-21 ◽  
Author(s):  
Tae-Hoon Kim ◽  
Seong-Rae Lee ◽  
Min-Woo Lee ◽  
Tae-Suk Jang ◽  
Jin Woo Kim ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Magnetic Phase ◽  
Microstructural Characteristics ◽  
Sintered Magnet ◽  
Cu Content

scholarly journals Mobility, ecotoxicity, bioaccumulation and sources of trace elements in the bottom sediments of the Rożnów reservoir

2021 ◽  
Author(s):  
Magdalena Szara-Bąk ◽  
Agnieszka Baran ◽  
Agnieszka Klimkowicz-Pawlas ◽  
Joanna Tkaczewska ◽  
Barbara Wojtasik
Keyword(s):  
Trace Elements ◽  
Potential Risk ◽  
Aquatic Organisms ◽  
Biological Indicators ◽  
Cadmium Content ◽  
Ecological Risks ◽  
Sediment Samples ◽  
Cu Content ◽  
Geochemical Indicators ◽  
Low Toxicity

AbstractThe aim of the study was to use of geochemical, chemical, ecotoxicological and biological indicators for a comprehensive assessment of ecological risks related to the mobility, ecotoxicity and bioavailability of trace elements in the bottom sediment of the Rożnów reservoir. The study found three elements deserving attention in the sediments: cadmium, nickel and chromium. Cadmium proved to be the most mobile and bioavailable, although the total cadmium content and geochemical indicators did not reveal any risk to organisms. Geochemical indicators showed that the sediments are contaminated with nickel and chromium, but both elements had a low bioaccumulation factor. Fractional analysis also revealed relatively low mobility of Cr and Ni and a higher potential risk of bioavailability for nickel. Most of the tested sediment samples had low toxicity in relation to the tested organisms. For H. incongruens, 11% of the samples were non-toxic, 50% of the samples had low toxicity, and 39% of the samples were toxic. For A. fischeri, no toxicity was found in 7% of the samples, low toxicity in 76% of the samples and toxicity in 17% of the sediment samples. The As, Cd, Cu content in the F1 fraction correlated significantly positively with the content of these metals in mussel tissues. Both biotesting and chemical analysis can reveal a potential risk to aquatic organisms. For a real assessment of the ecological risks associated with trace elements, it is necessary to use bioindicators taken from the environment and exposed to trace elements in situ.

The Characteristics of Trace Metal Elements Accumulation and Distribution in Elsholtzia Harchowensis

2013 ◽  
Vol 690-693 ◽  
pp. 1543-1546
Author(s):  
Shui Xiong Xiong ◽  
Wei Yi Xie ◽  
Cheng Cai Huang ◽  
Mu Qing Qiu
Keyword(s):  
Trace Elements ◽  
Trace Metal ◽  
Trace Element ◽  
Copper Tolerance ◽  
Metal Elements ◽  
Cu Content ◽  
Trace Metal Elements ◽  
Trace Element Contents ◽  
Element Contents ◽  
Different Parts

In this paper, the characteristics o f trace metal elements were studied in Elsholtzia harchowensis. The relation of trace elements between plant and soil was studied, and the copper tolerance and mechanism of the plant was discussed in details. The results showed that the trace element contents of the soil was higher, Cu content was highest in these elements, and it was as more 200 times as that of control sites. Cu in the plant was highest in these elements and Cd was lowest. The elements sequence in plant was: Cu> Mn> Zn> Pb> Cd. Element contents in different parts of the plant were: Cu, root> flower> leaf> stem; Cd, leaf> flower> root> stem; Mn, leaf> root > flower> stem; Zn, leaf> flower> stem> root; Pb, root> leaf> stem> flower. There is positive correlation in Cu between plant and soil. The tolerance capacity is higher in the plant.

scholarly journals Effects of age and breed on trace elements content in cattle muscle and edible offal

2018 ◽  
Vol 4 (2) ◽  
pp. 157-163
Author(s):  
ÖZLÜ Hayrunnisa ◽  
Mustafa ATASEVER
Keyword(s):  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Biceps Brachii ◽  
Trace Element Content ◽  
Biceps Femoris ◽  
Emission Spectrometry ◽  
Longissimus Dorsi ◽  
Mean Values ◽  
Cu Content ◽  
The Mean

In this study, effects of age and breed on the trace elements content in different muscles (M. longissimus dorsi, M. longissimus thoracis, M. psoas major, M. intercostalis internus, M. semispinalis capitis, M. biceps femoris, M. biceps brachii) and edible offal (liver, kidney, heart) of cattle were investigated. Iron (Fe), zinc (Zn), copper (Cu), lead (Pb) and cadmium (Cd)contents of muscles and edible offal were determined by inductively coupled plasma-optic emission spectrometry (ICP-OES).According to the results obtained in this study, the content of Cu in M. longissimus dorsi of Eastern Anatolian Red (EAR) breed cattle was higher than Brown Swiss (BS) breed cattle, and the content of Cu in M. longissimus dorsi was statistically significant among the breeds (p<0.05). On the other hand, the highest Cu content in kidney and the highest Cd content in liver were observed the 4-year-old cattle, and the content of Cu in kidney and the content of Cd in the liver were statistically significant among the ages (p <0,05). Besides, the highest contents of Fe, Cu and Cd were found in the edible offal of EAR breed cattle aged 4 years. The mean values of the trace elements found in cattle muscles were ranked as Zn>Cu>Fe>Pb>Cd, whereas the mean values of the trace elements found in edible offal of cattle were ranked as Cu>Fe>Zn>Pb>Cd. Our results suggest that trace element content may vary in both muscles and offal depend on the breed and age of the cattle.Asian J. Med. Biol. Res. June 2018, 4(2): 157-163

scholarly journals Structure and Magnetic Properties of Thermodynamically Predicted Rapidly Quenched Fe85-xCuxB15 Alloys

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7807
Author(s):  
Lukasz Hawelek ◽  
Tymon Warski ◽  
Adrian Radon ◽  
Adam Pilsniak ◽  
Wojciech Maziarz ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Amorphous Matrix ◽  
Average Diameter ◽  
Power Losses ◽  
Treatment Optimization ◽  
Cu Content ◽  
Minimum Value ◽  
Shape Dependence ◽  
Nucleation Sites

In this work, based on the thermodynamic prediction, the comprehensive studies of the influence of Cu for Fe substitution on the crystal structure and magnetic properties of the rapidly quenched Fe85B15 alloy in the ribbon form are performed. Using thermodynamic calculations, the parabolic shape dependence of the ΔGamoprh with a minimum value at 0.6% of Cu was predicted. The ΔGamoprh from the Cu content dependence shape is also asymmetric, and, for Cu = 0% and Cu = 1.5%, the same ΔGamoprh value is observed. The heat treatment optimization process of all alloys showed that the least lossy (with a minimum value of core power losses) is the nanocomposite state of nanocrystals immersed in an amorphous matrix obtained by annealing in the temperature range of 300–330 °C for 20 min. The minimum value of core power losses P10/50 (core power losses at 1T@50Hz) of optimally annealed Fe85-xCuxB15 x = 0,0.6,1.2% alloys come from completely different crystallization states of nanocomposite materials, but it strongly correlates with Cu content and, thus, a number of nucleation sites. The TEM observations showed that, for the Cu-free alloy, the least lossy crystal structure is related to 2–3 nm short-ordered clusters; for the Cu = 0.6% alloy, only the limited value of several α-Fe nanograins are found, while for the Cu-rich alloy with Cu = 1.2%, the average diameter of nanograins is about 26 nm, and they are randomly distributed in the amorphous matrix. The only high number of nucleation sites in the Cu = 1.2% alloy allows for a sufficient level of grains’ coarsening of the α-Fe phase that strongly enhances the ferromagnetic exchange between the α-Fe nanocrystals, which is clearly seen with the increasing value of saturation induction up to 1.7T. The air-annealing process tested on studied alloys for optimal annealing conditions proves the possibility of its use for this type of material.

Trace element nutrition of grazing ruminants. 1. Degree of oxidation, diet, frequency of dosing and location in the gastro-intestinal tract as factors affecting the ability of oxidized copper wire to promote hepatic copper storage

1986 ◽  
Vol 37 (2) ◽  
pp. 179 ◽  
Author(s):  
JP Langlands ◽  
JE Bowles ◽  
GE Donald ◽  
AJ Smith
Keyword(s):  
Copper Wire ◽  
Liver Weight ◽  
Factors Affecting ◽  
Dose Rates ◽  
Cu Content ◽  
Hepatic Copper ◽  
Degree Of Oxidation ◽  
Trace Element Nutrition ◽  
Copper Storage ◽  
Gastro Intestinal Tract

Factors affecting the ability of oxidized copper (Cu) wire to promote hepatic Cu storage in penned and grazing sheep were examined in two experiments. The incorporation of molybdenum (Mo) and sulfur (S) into the diet did not reduce hepatic Cu storage, but storage was negligible when elemental Cu was used as the supplement, and it is suggested that dose rates could be manipulated by varying the extent of oxidation of the particles. Oxidized particles were relatively ineffective when held in the rumen in a nylon bag, and some of the variability in the pattern of hepatic Cu storage after dosing is likely to be associated with the rate of clearance of the particles from the rumen; there was no evidence that particles were rendered ineffective by being held in the rumen for up to 6 weeks. Excessive hepatic Cu concentrations were observed in some sheep and were attributed to the quantity of supplement given, the high Cu content of the basal diets, and to the failure to scale the dose in proportion to liver weight or liveweight. Dosing at 6-monthly intervals reduced variability in hepatic Cu concentration through time, but the strategy may lead to unacceptable hepatic Cu concentrations unless dose rates or the extent of oxidation of the particles are appropriately reduced.

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