Integrated interpretation of dual frequency induced polarization measurement based on wavelet analysis and metal factor methods

In mineral exploration, the apparent resistivity and apparent frequency （or apparent polarizability） parameters of induced polarization method are commonly utilized to describe the induced polarization anomaly. When the target geology structure is significantly complicated, these parameters would fail to reflect the nature of the anomaly source, and wrong conclusions may be obtained. A wavelet approach and a metal factor method were used to comprehensively interpret the induced polarization anomaly of complex geologic bodies in the Adi Bladia mine. Db5 wavelet basis was used to conduct two-scale decomposition and reconstruction, which effectively suppress the noise interference of greenschist facies regional metamorphism and magma intrusion, making energy concentrated and boundary problem unobservable. On the basis of that, the ore-induced anomaly was effectively extracted by the metal factor method.

The Effect of Lanthanide and Transition Metal Ions on the Fluorescence Spectra for the Anticoagulation Factor of Snake Venom

The effect of lanthanide and transition metal ions on the fluorescence spectra of the anticoagulation factor(ACF)of snake venom has been studied.It is postulated that the quenching of tryptophan residue fluorescence by lanthanide and transition metal ions is caused by the metal ion-induced conformation change of ACF.

Distribution of heavy-metals in the Grand Canal(Hangzhou section)and its contributing factors

The Grand Canal (Hangzhou section), People's Republic of China, has been highly contaminated by heavy metals from both industrial and municipal sources since 1950s. This study investigated the distribution of heavy metals including As, Cr, Cd, Cu, Ni, Pb, and Zn. The results showed that these metals are largely accumulated in the top 0 3 meter layer of the river sediment.Despite the contamination, heavy metal concentrations in solution are increased in some locations only. The only exception is Zn whose concentrations are extremely high both in solution and in the top layer sediment. The top layer sediment appears to have reached almost its sorption capacity with respect to aqueous Zn. The extent of contamination is in the sequence of Zn>Cu>Pb>As>Cd. It is speculated that Cu distribution has been significantly affected by its binding to organic matter in the top layer sediment. Based on Pb distribution in both water and sediment, it is suggested that Pb transport in the canal is associated with colloids or particles suspended in water. The study showed that the top layer sediment in the Grand Canal serves as a sink to anthropogenic contaminants consisting of heavy metals as well as organic compounds.

Evaluation of Nutrients and Trace Metals and Their Enrichment Factors in Soil and Sugarcane Crop Irrigated with Wastewater

The study was conducted to investigate enrichment factor of wastewater (WW) irrigation to agricultural soils and the bioconcentration factor of trace metals uptake by sugarcane and to determine the concentrations of nutrients in sugarcane by growing the same on a contaminated soil, during the growth period of crop in Vidyaranyapuram area in the South West of Mysore, Karnataka. The concentrations of macronutrients and trace metals in the soil sampled sugarcane crop were found highly significant in Ca, Mg, K, Na, N, Mn, Cu, Ni and Cr. The enrichment factor was maximum for N and Na, and the values of N and Na were in the significant enrichment category. Whereas the values of following elements (K, P, Ca, SO4, Cu, Cr, Mg, Mn, Ni, Cd, Fe, Pb, Cl, Co and Zn) in soil irrigated with WW were in moderate enrichment category. The mean concentrations of N, P, K, Ca, Na, Fe, Mn, and Pb in sugarcane leaves in wastewater treatment crops were significantly higher than those with ground water (GW) treated which showed the lowest concentrations. Calculation of the bioconcentration factor (BCF) indicated that the accumulation of heavy metals in sugarcane crop was in the order Cd > Zn > Co > Pb > Mn > Ni > Cu > Cr > Fe. Pearson’s correlation coefficient indicated the relationship between different elements content in soil and plant. The results showed that the elements, Ca, Mg, Na, K, N, P, Mn, Zn and Cr, were significantly positively correlated, between the soil and the plant.

Kinetic Factors for Intensive Reaction of Magnesium-Based Spheroidiser in Hot Metal

The spheroidiser is a necessary additive to manufacture ductile iron.Sometimes with the same hot metal,spheroidisers and treated technology,reactions differ greatly from each other.The reaction may be quite normal in one case,but very intensive for another one.The effects of kinetic factors such as size,surface area and morphology o f spheroidiser on the reaction of spheoidization are studied.

Temporal variations of heavy metals in coral Porites lutea from Guangdong Province, China: Influences from industrial pollution, climate and economic factors

The eight heavy metals Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb have been determined in samples of coral Porites lutea collected from Dafangji Island waters (21°21′N, 111°11′E), Dianbai County, Guangdong Province, China, by the ICP-MS method. The samples represent the growth of coral in the period of 1982-2001. The results showed that the waters were polluted by the heavy metals Cu, Ni, Zn, and Pb in certain years, but not by other metals. The contamination may have come from industrial sources, including electroplating, metallurgy, mining, and aquatic industries in the coastal areas.; The correlation coefficients among the metals and climatic and economic factors indicate that the metals Ni, Zn, and Cd behave similarly. Copper and Mn are positively correlated, and cobalt is negatively correlated with Cr, Ni, Zn, and Cd. Lead is not correlated with any other metals but is correlated with sea surface water temperature, air temperature, GDP and industrial-agricultural production in Dianbai County. Lead in corals is related to the enhanced pollution level of ocean waters as a result of increased industrial activities.

FACTOR ANALYSIS ON IMPROVING THE PRODUCTIVITY OF THE NONFERROUS METALS INDUSTRY (1)

The productivity of China’s nonferrous metals industry during 1980-1990 has been analysed. The important factors which constrain the productivity of the nonferrous metals industry have been studied, the methods of improving the productivity of the nonferrous metals industry have been discussed.

Investigating the Distribution of Selected Major and Trace Metals in Lithogenic Environment near Cement Factory, Mekelle, Ethiopia

Sixteen physicochemical parameters including four major and ten trace metals were analyzed for seven top soil and six top stream sediment samples collected around the vicinity of cement factory in Mekelle, Ethiopia. Water and aqua regia extraction techniques were deployed to determine the water soluble and near total concentration of the metals in the samples. Water extraction results verified the magnitude of loading of the metals from anthropogenic sources. The mean values of the water soluble metals are found to exceed the reference values except for Ca and Zn in both lithogenic media indicating the severity of pollution. Spatial distribution of the metals suggested that cement factory dust and traffic emissions represent the most important pollutant sources for the investigated area.? The mean proportion of the major and trace metals in the water soluble phase of soil can be put on a descending order as: Mg (57.76%) > Fe > Ca > K > Na > Mn (3.77%) and Mo (53.17%) > Cu > Co > As > Ni > Zn > Pb > Cr (5.02%) respectively. The order of major metals is almost reverse in the case of the stream sediment with slight difference in the order of the trace metals. Factor analysis has revealed that the first factor represents the contribution of metals (Mn, Cr, As, Co, Zn, Na, K, Cu, Pb and Ni) from local anthropogenic activities, whereas the second factor represents the contribution of metals (Na, Fe, Cu, Pb, Ni, Ca, As, Co, Zn and Mo) from both lithogenic and anthropogenic origins. Third factor consists of Ca, Mo, Mg, and Fe from geogenic source of the local geology. It is spatially evident that the cement dust emission has an impact on the soil’s Cr, Co, Mo and Ni content which drastically decreases downstream. The spatial pattern of Cu, Pb, As, Zn and Co shows significant association with the cement dust and loadings from the traffic movement on the road.

Factors Controlling the Distribution of Trace Metals in Macroalgae

This paper presents the concentrations of trace metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb) in macroalgae from five areas. Significant differences were noticed in trace metal concentration in macroalgae, and a large range of variations between the minimum and maximum concentrations of trace metals was found. Trace metals detected in macroalgae generally occur in adsorbed and absorbed forms. Environmental and biological factors jointly control the trace metal compositions and concentrations in macroalgae. The complexity and variation of these factors cause significant differences in trace metal concentrations in macroalgae. Environmental factors play a more important role in controlling trace metal compositions and concentrations when external available trace metals are beyond requirement for algal metabolism and growth, especially for non-essential trace metals; however, when the external available trace metals just satisfy the needs of algal metabolism and growth, biological factors would play a more important role, especially for essential trace metals. Interactions among the trace metals can also influence their compositions and concentrations in macroalgae. It is also discussed how to make macroalgae as an excellent biomonitor for trace metals.

An Assessment of Heavy-Metal Contamination in Soils within Auto-Mechanic Workshops Using Enrichment and Contamination Factors with Geoaccumulation Indexes

Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above background concentrations with most (Ni, Cu, Fe, Cr and Cd) decreasing with soil depth. The distribution pattern were in the following order Fe > Cu > Zn > Pb > Cr > Ni > Cd. Across all the sampling locations and profiles, Fe and Cd showed the highest (476.4 μg·g-1) and least (37.5 μg·g-1) mean concentrations respectively. Pollution load index (PLI) and index of geoaccumulation (Igeo) revealed overall high and moderate contamination respectively but the enrichment factors (EFs) for Pb Ni and Cd are severe. The inter-element relationship revealed the identical source of elements in the soils of the studied area. The accuracy of the results has been cheeked using the standard reference material;SRM (PACS-2). The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.

Effects of environmental factors on corrosion behaviors of metal-fiber porous components in a simulated direct methanol fuel cell environment

Abstract： To enable the use of metallic components in direct methanol fuel cells （DMFCs）, issues related to corrosion resistance must be considered because of an acid environment induced by the solid electrolyte. In this study, we report the electrochemical behaviors of metal-fiber-based porous sintered components in a simulated corrosive environment of DMFCs. Three materials were evaluated： pure copper, AISI304, and AISI316L. The environmental factors and related mechanisms affecting the corrosion behaviors were analyzed. The results demonstrated that AISI316L exhibits the best performance. A higher SO4^2- concentration increases the risk of material corrosion, whereas an increase in methanol concentration inhibits corrosion. The morphological features of the corroded samples were also characterized in this study.

Determination of Metal Content in Soil and Wheat Plant by Inductively Coupled Plasma Mass Spectrometry

This study aims to investigate the level of soil pollution and the grade of accumulation of metals and heavy metals by wheat plants from the soil in different parts of the crop: root, stem, leaf, spike and grain. Sampling campaigns took place in February, April and July when wheat plants were at different growth stages. A number of eight soil samples and eight wheat plant samples were collected. The sampled wheat plant was taken at the same time and from the same place as the soil. Concentrations of Al (aluminium), Cr (chromium), Mn (manganese), Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Zn (zinc), Sr (strontium), Cd (cadmium) and Pb (lead) were determined by inductively coupled plasma mass spectrometry. Bioconcentration and translocation factors were calculated for the samples analysed.

Accumulation of Heavy Metals in Maga-Pouss Rice Fields (Far-North Region, Cameroon) and Transfer to Rice Grains

Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out to determine the accumulation of heavy metals in rice fields and their transfer to rice grains. Soil, irrigation water and rice grains samples were gathered in Maga-Pouss, Far-North, Cameroon. Concentrations of six heavy metals (lead, cadmium, zinc, copper, iron and mercury) were evaluated by Atomic Absorption Spectrophotometer (AAS). Mercury was not detected in this study. Average concentrations of metals were in this order (in mg/kg): Fe (188.60 ± 97.06) > Pb (63.63 ± 7.11) > Cd (2.59 ± 0.29) > Zn (1.10 ± 1.05) > Cu (0.80 ± 0.73) in water and Pb (105.50 ± 31.11) > Fe (105.50 ± 31.11) > Cu (45.93 ± 14.39) > Zn (22.52 ± 6.40) > Cd (3.15 ± 0.49) in soil. Water in Maga-Pouss rice fields appears to be more harmful than the soil, notably for lead, cadmium and copper. In rice grains, heavy metals were found in this order (mg/kg): Fe (188.01 ± 82.62) > Cu (27.20 ± 0.00) > Zn (23.61 ± 12.42) > Pb (19.50 ± 19.91) > Cd (2.02 ± 1.05). The mean bioconcentration factor (BCF) of metals from soil to rice grains was in the following order: Fe (2.60) > Zn (1.05) > Cd (0.64) > Cu (0.59) > Pb (0.18). From water to rice grains, the order is: Cu (37.26) > Zn (22.49) > Cd (6.97) > Pb (2.74) > Fe (1.94). Rice field pH and electrical conductivity favored the uptake of lead, copper and cadmium by rice grains. The findings of this study will be good documentation for risk assessment, and decision-making by environmental managers in this region.

Experimental Assessment of the Thermal Performance of Two Corrugated Metal Roofs

This experimental study is a contribution to the search for solutions to reduce indoor heat gain through sheet metal roofing in hot weather. It has evaluated the thermal impact of two different sheet metal roofs inside of two identical test buildings in sunny weather and cloudy weather conditions. Test building 1 has a single sheet corrugated roof and the building 2 is covered with roof made from top to bottom with corrugated sheet metal, a 12 mm thick serpentine copper tube in which water is circulated, a sheet of aluminium foil acting as a heat reflector, a 4 cm thick polystyrene panel and a 1.5 cm thick plywood. A maximum reduction of 15.1˚C in the temperature of the inner face of the test Building 2 roof was obtained comparatively to the temperature of the inner face of the test Building 1 roof consisting of a single sheet of metal at the warmest hours. In addition, the simple corrugated sheet metal roof of the test building generates high and varied temperatures inside the building. Whereas the proposed heat recovery roof favours low and relatively uniform temperatures inside the building. The proposed sheet metal roof construction technique is very effective in reducing the heat gain through the roof considerably;thus improving the thermal comfort inside sheet metal roofed dwellings. Hot water has been produced by recovering heat from the metal sheet of the roof of test building 2. The temperature of the hot water produced reached of 39˚C. This study could be also an alternative for the reduction of energy consumption due to the use of mechanical means for cooling of sheet metal roofed houses and the reduction of the use of fossil fuels for domestic hot water production.

Effect of the Density of Molten Metal on the Raining Phenomenon in Horizontal Centrifugal Casting

In this work the influence of the density of the molten metal on the emergence of the raining phenomenon in the horizontal centrifugal casting process is numerically studied. Transient 2D numerical simulations were carried out using Computational Fluid Dynamics software. Three molten metals with different density, namely aluminum, iron and lead, and three angular frequencies, namely 50, 66 and 77 rad/s were considered. It is found that the density of the molten metal significantly affects the emergence, transient or permanent, of the rain phenomenon. However, the magnitude and duration of the rain phenomenon depend on the angular frequency of the rotating mold. Likewise, since gravitational forces affect the metal according to its density, the value of the critical rotation speed of the mold is also affected.

Geochemical Baseline and Trace Metal Pollution of Soil in Panzhihua Mining Area

A total of 31 topsoil samples were systematically collected from the Panzhihua mining area including steel smelting, coal mining, urban and rural districts. A normalization procedure was adopted to establish the environmental geochemical baseline models for this area. By using the above baseline models, the regional geochemical baseline values of As, Cr, Cu, Ni, Pb and Zn were determined. On the basis of the baselines, the enrichment factors were used to analyze the mechanism of trace metal pollution in topsoil from anthropogenic sources, and the results showed that the serious trace metal pollution is caused by human activities in coal mine, iron mine, smelting factory, tailing dam and other industrial districts in the Panzhihua area.

Seasonal variations in the phytoplankton community and the relationship between environmental factors of the sea around Xiaoheishan Island in China

Seasonal variations in the phytoplankton community and the relationship between environmental factors of the sea area around Xiaoheishan Island are investigated in the present study. Xiaoheishan Island is located at 37°58′14″N and 120°38′46″E in Shandong Province, China. A total of 65 species of phytoplankton belonging to three phyla and 27 genera were identified, with Bacillariophyta having the largest number of species. The annual average chlorophyll a concentration for this area was 3.11 μg/L, and there occurs a Skeletonema costatum bloom in winter. The Shannon-Weaver indexes(log_2) of the phytoplankton from all stations were higher than 1, and the Pielou indexes were all higher than 0.3. The results of the canonical correspondence analysis(CCA) indicated that water temperature, PO_4^(3ˉ) and Cu were the environmental factors that had the greatest influence on the distribution of the phytoplankton community throughout the entire year. Although the concentration of heavy metal is well up to the state standards of the first grade of China(GB 3097-1997), these metals still have an impact on the phytoplankton community from this area.

A survey of arsenic and other heavy metals in vegetation from markets or mine tailings

This research includes two investigations. The first one is a market basket survey of the levels of arsenic （As） and trace elements in bracken fern （Pteridium aquilinum） originated from three countries： South Korea, China and North Korea. The results showed that the mean As concentrations in stems of samples were significantly higher than those in leaves. As concentrations in all samples did not exceed food safety limits for vegetables. Generally, concentrations of Fe, Mn, Cu and Zn in leaves were higher than those in stems. The second investigation is a survey on the levels of As and other heavy metals in vegetation in the vicinity of Myoungbong mine tailings. The results demonstrated that As, Pb and Cu concentrations and bioaccumulation factors （BCF） in seedlings of the fern（A splenium achilleifolium） were the highest, whereas Marsh horsetail（Equisetum polustre） accumulated the highest levels of Zn. Concentrations of As, Pb, Zn and Cu in vegetable-cress （Lepidium sativum） and the edible herb-aromatic madder （Elasholtzia splendens） were higher than food safety limits. Therefore, a risk assessment of As and other heavy metals in vegetables and herbs on local human health should be conducted in the future.

Accumulation and bioavailability of heavy metals in a soil-wheat/maize system with long-term sewage sludge amendments

A long-term field experiment was carried out with a wheat-maize rotation system to investigate the accumulation and bioavailability of heavy metals in a calcareous soil at different rates of sewage sludge amendment. There are significant linear correlations between the contents of Hg, Zn, Cu, Pb, and Cd in soil and sewage sludge amendment rates. By increasing 1 ton of applied sludge per hectare per year in soil, the contents of Hg, Zn, Cu, Pb, and Cd in soil increased by 6.20, 619, 92.9, 49.2, and 0.500 μg kg–1, respectively. For Hg, sewage sludge could be safely applied to the soil for 18 years at an application rate of 7.5 t ha–1 before content exceeded the soil environmental quality standards in China(1 mg kg–1). The safe application period for Zn is 51 years and is even longer for other heavy metals(112 years for Cu, 224 years for Cd, and 902 years for Pb) at an application rate of 7.5 t ha–1 sewage sludge. The contents of Zn and Ni in wheat grains and Zn, Cu, and Cr in maize grains increased linearly with increasing sewage sludge amendment rates. The contents of Zn, Cr, and Ni in wheat straws and Zn, Cu, and As in maize straws were positively correlated with sewage sludge amendment rates, while the content of Cu in wheat straws and Cr in maize straws showed the opposite trend. The bioconcentration factors of the heavy metals in wheat and maize grains were found to be in the order of Zn>Cu>Cd>Hg>Cr=Ni>Pb>As. Furthermore, the bioconcentration factors of heavy metals in wheat were greater than those in maize, indicating that wheat is more sensitive than maize as an indicator plant. These results will be helpful in developing the critical loads for sewage sludge amendment in calcareous soils.

Heavy Metal Contaminations in Urban Soil within Baghdad City, Iraq

Soil samples were collected from three land use types within Baghdad urban areas. The samples analyzed for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn indicated higher concentration of Cd, Cr, Cu, Fe, Ni, Pb and Zn in the industrial area, while higher concentration of Mn was observed in the residential areas. However, the concentration of Cd, Ni and Pb was higher than the calculated worldwide mean of unpolluted soil. For both roadside and open areas soils, industrial area exhibited high values of Cd, Ni and Pb. The highest Single Element Pollution Index (SEPI) for Cd, Ni and Pb in the industrial soils seems therefore to be that this type of soil is the most polluted in the city of Baghdad. The calculated Combined Pollution Index (CPI) for Cd, Ni and Pb ranged from 0.98 to 2.15 with a mean of 1.28 for the entire urban soil samples, with the highest values in the industrial area which suggest multi-element contamination and in some cases are recommended for treatment. Furthermore, significant to extremely high values of enrichment factors were recorded confirming an important role of anthropogenic pollution.