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Abstract

Details

Heavy Metal Youth Identities: Researching the Musical Empowerment of Youth Transitions and Psychosocial Wellbeing
Type: Book
ISBN: 978-1-78756-849-5

Article
Publication date: 1 February 2005

S.A. Mashi, S.A. Yaro and P.N. Eyong

Contamination of the environment by heavy metals is a phenomenon of global importance today. When present in high concentrations in the environment, heavy metals may enter…

515

Abstract

Purpose

Contamination of the environment by heavy metals is a phenomenon of global importance today. When present in high concentrations in the environment, heavy metals may enter the food chain from soils and result in health hazards. Accumulation in street dust is one major way through which heavy metals may find their way into soils and subsequently living tissues of plants, animals and human beings. In this paper, the magnitude and sources of some heavy metals (Cu, Mn, Fe, Cd, Pb and Zn) in street dust samples in and around Gwagwalada, Nigeria, were assessed.

Design/methodology/approach

Street dust samples were collected from 12 sites with and without varying levels of human activities (blacksmithing, motor repair works, metal working and fabrication, vehicular traffic and residential development) in the area and analysed by atomic absorption spectrophotometry to determine the magnitude and sources of accumulation of the above heavy metals in street dust in the study area.

Findings

The mean concentrations were found to be 210, 79, 97, 3.9, 120 and 96 μg g−1 respectively, for Pb, Zn, Cu, Cd, Fe and Mn across the various sampling sites. Samples collected from sites with human activities were found to contain concentrations of the metals that are generally higher than those in background areas (without human activities). However, metal working and fabrication, and motor repair works were found to have a stronger influence on the accumulation of the metals in the dust samples than vehicular traffic.

Practical implications

The results indicate that, contrary to what is expected, based on the observations made in several areas by many researchers elsewhere, metal working and fabrication, and motor repair works have a stronger influence on the accumulation of the metals in the dust samples than vehicular traffic in the study area.

Originality/value

Provides information on heavy metal contamination of the environment in an area of Nigeria.

Details

Management of Environmental Quality: An International Journal, vol. 16 no. 1
Type: Research Article
ISSN: 1477-7835

Keywords

Article
Publication date: 1 June 1994

Hussein I. Abdel‐Shafy, Werner Hegemann and Andrea Teiner

Describes a study carried out to evaluate the accumulation of heavymetals by two different vascular aquatic plants in the artificialwetlands which were constructed for the…

613

Abstract

Describes a study carried out to evaluate the accumulation of heavy metals by two different vascular aquatic plants in the artificial wetlands which were constructed for the treatment of municipal wastewater in Berlin, Germany. The studied plants were Pharagmites australis and Schoenoplectus lacustris. The investigated metals were: Zn, Cr, Cu, Fe, Cd, Ni and Pb. The translocation of such metals in the plant roots, stems and leaves was also determined. The level of metals in the influent and effluent of the wastewater, as well as the sludge, was investigated. The concentration factor of each metal by plants and sludge was further studied. Results revealed that P. australis has a higher tendency for the accumulation of metals than S. Lacustris. The level of metals was higher in roots, followed by leaves, then stems. Metals were more concentrated in the sludge than in the plants. Further study showed that the levels of metals in plants grown in the artificial wetlands were higher than in those grown in a “controlled” area. Concludes that vascular plants can act as scavengers of metals from the municipal wastewater while still maintaining a healthy status.

Details

Environmental Management and Health, vol. 5 no. 2
Type: Research Article
ISSN: 0956-6163

Keywords

Article
Publication date: 1 February 1980

William Sharpe

Introduction Clad metals are composites of two or more metals which are joined in a continuous manner by a metallurgical bond. The composite provides the specific…

Abstract

Introduction Clad metals are composites of two or more metals which are joined in a continuous manner by a metallurgical bond. The composite provides the specific advantages of both metals, usually the good corrosion resistance of the cladding metal and the strength and economy of the backing metal.

Details

Anti-Corrosion Methods and Materials, vol. 27 no. 2
Type: Research Article
ISSN: 0003-5599

Article
Publication date: 1 January 1972

Every metal has a range of environmental conditions against which it is resistant or sufficiently resistant as to make the metal economically feasible. Unfortunately it is

Abstract

Every metal has a range of environmental conditions against which it is resistant or sufficiently resistant as to make the metal economically feasible. Unfortunately it is almost a rule of thumb that the more expensive the metal the smaller the range. In most cases the resistance of the metal is a function of the metal thickness, but the function is such that relatively thin metals can produce very long lives.

Details

Anti-Corrosion Methods and Materials, vol. 19 no. 1
Type: Research Article
ISSN: 0003-5599

Abstract

Details

Australian Metal Music: Identities, Scenes, and Cultures
Type: Book
ISBN: 978-1-78769-167-4

Article
Publication date: 1 May 2006

Saber A. El‐Shafai, Fayza A. Nasr, Fatma A. El‐Gohary, N. Peter van der Steen and Huub J. Gijzen

The main purpose of this study is to investigate the bioaccumulation pattern and fate of heavy metals in duckweed‐based wastewater treatment ponds with different depth.

1134

Abstract

Purpose

The main purpose of this study is to investigate the bioaccumulation pattern and fate of heavy metals in duckweed‐based wastewater treatment ponds with different depth.

Design/methodology/approach

Three replicates of four reactors were used in this experiment. The reactors were randomly distributed on the bench and filled with 50 percent diluted sewage for the control reactors whereas diluted sewage mixed with 5 mg Pb/l and 5 mg Zn/l was used for the treatment reactors. The reactors were stocked with Lemna gibba at 1,000 g fresh weight per each square meter. The culture tanks were exposed to temperature range of 21‐25°C and light regime of 16 hours light using halogen lamps and 8 hours dark. The light intensity was maintained around 200 μ E m−2 S−1. The experiment extended for 30 days. Regular monitoring of the growth performance of duckweed was carried out with subsequent analysis of dry matter, heavy metals, phosphorous and nitrogen content. Composite samples from the water phase were subjected to the analysis of ammonia, nitrite, nitrate, orthophosphate and sulfate concentration. The analysis of sediment and biofilm were carried out at the end of the experiment. Interpretation of results was carried out using one‐way analysis of variance.

Findings

Statistical analysis showed a significant reduction in the growth rate of duckweed within the first five days exposure time. After five days exposure, the growth rate in the treatments returned to the normal growth till day 15 after which the growth became significantly lower in the small and medium scale ponds. The results revealed that zinc is more bio‐available than lead and both metals are mostly precipitated in the sediment probably as sulfides.

Practical implications

The results help in enhancement of heavy metals removal in a small anaerobic pretreatment unit before entering to the pond system by sulfate addition.

Originality/value

The results of the study confirm the positive effect of pond depth in reducing the heavy metal toxicity to the duckweed‐based wastewater treatment ponds.

Details

Management of Environmental Quality: An International Journal, vol. 17 no. 3
Type: Research Article
ISSN: 1477-7835

Keywords

Article
Publication date: 23 March 2020

Guochao Zheng, Fuli Wang, Baiping Yan and Runting Cheng

The purpose of this study is to suppress the temperature rise of high voltage wall bushing metal plate.

Abstract

Purpose

The purpose of this study is to suppress the temperature rise of high voltage wall bushing metal plate.

Design/methodology/approach

First, the authors built a model of a traditional metal plate and got the magnetic field intensity distribution by FEA tools. Optimized according to the magnetic field intensity distribution, the authors slot the traditional metal plate and embed permanent magnets in the slot. Finally, the authors got the temperature distribution diagrams of the above three cases at different current levels by FEA tools.

Findings

Slotted metal plate is beneficial to suppress magnetic induction intensity, but the improvement of the magnetic induction intensity uniformity is not obvious. The method of embedding a permanent magnet in a slotted metal plate can optimize the magnitude and uniformity of the magnetic induction intensity in the metal plate. The larger the current passing through the metal plate, the better the temperature suppression effect of the slotted metal plate and the slotted metal plate embedded in the permanent magnet.

Originality/value

The effect of structural factors, slotting plate and setting permanent magnets on slots on the temperature of supporting plate is studied. The paper proposes two methods, slotting metal panels and embedding permanent magnet metal panels, to solve the problems of eddy current loss and high calorific value of the panel, which is of great significance to the safety of the grid equipment.

Details

Circuit World, vol. 46 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 December 1997

S. Honma, K. Tateyama, H. Yamada, K. Doi, N. Hirano, T. Okada, H. Aoki, Y. Hiruta and T. Sudo

This paper describes effective thin‐film structure barrier metals for use as eutectic solderbumps. Shear strength and bump interconnection resistance were evaluated. The…

190

Abstract

This paper describes effective thin‐film structure barrier metals for use as eutectic solder bumps. Shear strength and bump interconnection resistance were evaluated. The mutual diffusion in metals was investigated. Barrier metal structures —Cu/Ti,Ni/Ti and Cu/Cr—were evaluated after ageing. The Ni/Ti structure has good reliability according to ageing test results. Pd is used for improvement of solder wettability and as an oxidisation barrier. Consequently, it was concluded that a thin‐film Pd/Ni/ Ti barrier metal is suitable for use as eutectic solder bumps. The broken interfaces of the solder bumps were analysed by scanning auger electron spectrometry. In the thin‐film Cu/Ti structure, decrease in the shear strength is caused by three mechanisms, as determined from the broken interface analysis. The three mechanisms are mixed metal formation, Ti oxidisation and diffusion between barrier metals and Al. Furthermore, TCT and PCT were carried out on these eutectic solder bumps to confirm the interconnection reliability. The TCT and PCT results prove that electrical connection is stable.

Details

Microelectronics International, vol. 14 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 April 1966

K. Sachs, C.W. Tuck and J. Barlow

TWO nickel‐bearing commercial steels were oxidised in the range 1100°–1250°C for up to 8 hr. in air and CO2. The increase in thickness of the scale and the inner layer…

Abstract

TWO nickel‐bearing commercial steels were oxidised in the range 1100°–1250°C for up to 8 hr. in air and CO2. The increase in thickness of the scale and the inner layer with embedded metal particles was followed in detail. A distinction is made between filaments which retain continuity with the base metal and discrete particles. The continuous filaments may be of practical importance in holding the scale to the metal in hot rolling, leading to surface defects on hot‐rolled products.

Details

Anti-Corrosion Methods and Materials, vol. 13 no. 4
Type: Research Article
ISSN: 0003-5599

1 – 10 of over 38000