Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Entire DC Network

Travelling In Chile, Fathi Habashi Feb 2011

Travelling In Chile, Fathi Habashi

Fathi Habashi

Chile is at present the largest copper and rhenium producer and was before World War I the largest nitrate producer. She is also an important producer of lithium carbonate and molybdenum oxide. An important event in the history of the country is the Pacific War of 1879-1883 in which she acquired the northern provinces initially belonged to Bolivia and Peru. In 1888 Chile annexed Easter Island. The Chilean mineral and cultural history is briefly reviewed together with the people who contributed to her development. The present report is the result of a number of academic and industrial visits to Chile …


Toxic Effects And Bioaccumulation Of Cadmium, Copper, Lead And Zinc In Post Larval Stages Of Penaeus Monodon, Azhaguraj Ramakrishnan Jan 2011

Toxic Effects And Bioaccumulation Of Cadmium, Copper, Lead And Zinc In Post Larval Stages Of Penaeus Monodon, Azhaguraj Ramakrishnan

Azhaguraj Ramakrishnan

The acute toxicity and bioaccumulation of cadmium, copper, lead and zinc to Penaeus monodon (Tiger prawn) was evaluated in static tests. Each test lasted up to 4 d and LC50 values were also calculated. The toxicity of each metal increased with exposure time for cadmium, copper, lead and zinc. The 96 hours LC50 values for cadmium, copper, lead and zinc were 1.72, 0.66, 0.41, 2.36 mg/l. Lead was toxic metal to P.monodon than zinc followed by cadmium and copper tested. The order of toxicity was Pb>Cu>Cd>Zn. The bioaccumulation study showed that the zinc was accumulated in a …


Interfacial Reaction And Dissolution Behavior Of Cu Substrate In Molten Sn-3.8ag-0.7cu In The Presence Of Mo Nanoparticles Jan 2011

Interfacial Reaction And Dissolution Behavior Of Cu Substrate In Molten Sn-3.8ag-0.7cu In The Presence Of Mo Nanoparticles

A.S. Md Abdul Haseeb

Purpose - In electronic packaging, when solid copper comes in contact with liquid solder alloy, the former dissolves and intermetallic compounds (IMCs) form at the solid-liquid interface. The purpose of this paper is to study the effect of the presence of molybdenum nanoparticles on the dissolution of copper and the formation of interfacial IMC. Design/methodology/approach - Cu wire having a diameter of 250 μm is immersed in liquid composite solders at 250° up to 15 min. Composite solder was prepared by adding various amount of Mo nanoparticles into the Sn-3.8Ag-0.7Cu (SAC) solder paste. The dissolution behavior of Cu substrate is …


Understanding The Effects Of Addition Of Copper Nanoparticles To Sn-3.5 Ag Solder Jan 2011

Understanding The Effects Of Addition Of Copper Nanoparticles To Sn-3.5 Ag Solder

A.S. Md Abdul Haseeb

Purpose - The purpose of this paper is to focus on the fabrication of SAC nanocomposites solder and discuss the effects of nanoCu addition on the structure and properties of resulted nanocomposite solder. Design/methodology/ approach - Ball milling is a nonequilibrium processing technique for producing composite metal particles with submicron homogeneity by the repeated cold welding and fracture of powder particles. This method is believed to offer good processablity, precise control over the solder composition, and produce more homogeneous mixture. Findings - It is found that the melting temperature, the wetting behaviour, and hardness are improved when the Cu nanoparticles …


Low Temperature Growth Of High Purity, Low Resistivity Copper Films By Atomic Layer Deposition, Thomas J. Knisley Jan 2011

Low Temperature Growth Of High Purity, Low Resistivity Copper Films By Atomic Layer Deposition, Thomas J. Knisley

Thomas J Knisley

No abstract provided.


The Analysis Of The Tribological Properties Of Multiple Strengthened Nanocomposite Of The Cu-Al2o3 System, Zeljko J. Kamberovic Dec 2010

The Analysis Of The Tribological Properties Of Multiple Strengthened Nanocomposite Of The Cu-Al2o3 System, Zeljko J. Kamberovic

Zeljko J Kamberovic

This paper presents the results of examined tribological properties of the multiple strengthened nanocomposite Cu-Al2O3 system. Cu-Al2O3 composite powder was obtained by combination of the thermo-chemical procedure and mechanical alloying, which is a completely new approach to synthesis of these materials. The synthesized powders were cold pressed with 940MPa and sintered in hydrogen atmosphere in temperature range of 725-925o C during 15-120 minutes. The samples were thermo- mechanically treated in two stages after sintering: cold rolling with the final reduction degree of 30% and annealing at 800o C for 1h in hydrogen atmosphere. Characterization of the sintered, rolled and annealed …