Digital Commons Network^™

The Effects Of Environmental Copper Exposure On Developing Zebrafish, Christina Kaucic

Christina Kaucic

The Double-Edges Role Of Copper In The Fate Of Amyloid Beta In The Presence Of Anti-Oxidants, Hui Ye, Jing Yang, Xueli Zhang, Yiying Zhu, Emily Lenzowski, Yanli Tian, Can Zhang, Markus Hardt, Chunhua Qiao, Rudolph E. Tanzi, Anna Moore, Chongzhao Ran

Hui Ye

The biological fate of amyloid beta (Aβ) species is a fundamental question in Alzheimer’s disease (AD) pathogenesis. The competition between clearance and aggregation of Aβs is critical for the onset of AD. Copper has been widely considered to be an inducer of harmful crosslinking of Aβs, and an important triggering factor for the onset of AD. In this report, however, we present data to show that copper can also be an inducer of Aβ degradation in the presence of a large excess of well-known intrinsic (such as dopamine) or extrinsic (such as vitamin C) anti-oxidants. The degraded fragments were identified …

Thesis Document 07172017 Revised.Pdf, Jesse Gray

Jesse Gray

The Effect Of Frictional And Adhesion Forces Attributed To Slurry Particles On The Surface Quality Of Polished Copper, Yi-Koan Hong, Ja-Hyung Han, Tae-Gon Kim, Jin-Goo Park, Ahmed A. Busnaina

Ahmed A. Busnaina

The effect of frictional and adhesion forces attributed to slurry particles on the quality of copper surfaces was experimentally investigated during copper chemical mechanical planarization process. The highest frictional force of 9 Kgf and adhesion force of 5.83 nN were observed in a deionized water-based alumina slurry. On the other hand, the smallest frictional force of 4 Kgf and adhesion force of 0.38 nN were measured in an alumina slurry containing citric acid. However, frictional (6 Kgf) and adhesion (1 nN) forces of silica particles in the slurry were not significantly changed regardless of the addition of citric acid. These …

The Effect Of Frictional And Adhesion Forces Attributed To Slurry Particles On The Surface Quality Of Polished Copper, Yi-Koan Hong, Ja-Hyung Han, Tae-Gon Kim, Jin-Goo Park, Ahmed A. Busnaina

Ahmed A. Busnaina

The effect of frictional and adhesion forces attributed to slurry particles on the quality of copper surfaces was experimentally investigated during copper chemical mechanical planarization process. The highest frictional force of 9 Kgf and adhesion force of 5.83 nN were observed in a deionized water-based alumina slurry. On the other hand, the smallest frictional force of 4 Kgf and adhesion force of 0.38 nN were measured in an alumina slurry containing citric acid. However, frictional (6 Kgf) and adhesion (1 nN) forces of silica particles in the slurry were not significantly changed regardless of the addition of citric acid. These …

Defect Levels In Cu₂Znsn(Sₓse₁₋ₓ)₄ Solar Cells Probed By Current-Mode Deep Level Transient Spectroscopy, S. Das, S. K. Chaudhuri, R. N. Bhattacharya, K. C. Mandal

Krishna C. Mandal

No abstract provided.

Defect Levels In Cu₂Znsn(Sₓse₁₋ₓ)₄ Solar Cells Probed By Current-Mode Deep Level Transient Spectroscopy, S. Das, S. K. Chaudhuri, R. N. Bhattacharya, K. C. Mandal

Krishna C. Mandal

No abstract provided.

Comparative Transcriptome Analyses Of Pseudomonas Aeruginosa, Deepak Balasubramanian, Kalai Mathee

Kalai Mathee

One of the hallmarks of bacterial survival is their ability to adapt rapidly to changing environmental conditions. Niche adaptation is a response to the signals received that are relayed, often to regulators that modulate gene expression. In the post-genomic era, DNA microarrays are used to study the dynamics of gene expression on a global scale. Numerous studies have used Pseudomonas aeruginosa--a Gram-negative environmental and opportunistic human pathogenic bacterium--as the model organism in whole-genome transcriptome analysis. This paper reviews the transcriptome studies that have led to immense advances in our understanding of the biology of this intractable human pathogen. Comparative …

Determination Of Transport And Electrochemical Kinetic Parameters Of Bare And Copper-Coated Lani4.27Sn0.24 Electrodes In Alkaline Solution, G. Zheng, Branko N. Popov, Ralph E. White

Ralph E. White

Electrochemical properties of bare and copper-coated LaNi_4.27Sn_0.24 electrodes were investigated in alkaline solution. The exchange current density, polarization resistance, and equilibrium potential were determined as functions of the state of charge in the electrodes. The symmetry factors for bare and copper-coated electrodes were estimated to be 0.53 and 0.52, respectively. By using a constant current discharge technique, the hydrogen diffusion coefficient in bare and coated LaNi_4.27Sn_0.24 was estimated to be 6.75 × 10^–11 cm²/s.

Hardystonite From The Desert View Mine, California, James A. Van Fleet, Earl R. Verbeek Phd

James A. Van Fleet

The fluorescent mineral hardystonite is confirmed in a specimen from the Desert View Mine, California. Hardystonite had been known only from Franklin, New Jersey for over 100 years.

Paleolimnological Analysis Of The History Of Metals Contamination In The Great Salt Lake, Utah, Wayne A. Wurtsbaugh, Katrina Moser, Peter R. Leavitt

Wayne A. Wurtsbaugh

Three sediment cores from the Great Salt Lake were analyzed to determine the magnitude and timing for the deposition of 21 metal contaminants. In the main lake (Gilbert Bay) concentrations of copper, lead, zinc, cadmium, silver, molybdenum, tin, mercury and others began increasing in the sediments in the late 1800s or early 1900s and peaked in the 1950s. These increases were coincident with increases in mining and smelting activities for these metals in Utah. Contamination indices in the 1950s were 20-60 fold above background concentrations for silver, copper, lead and molybdenum, and <15-fold for most other metals. Since the 1950s, concentrations of most metals in the sediments have decreased 2-5 fold coincident with decreases in mining and improved smelting technologies. Nevertheless concentrations for many metals in surficial sediments are still above acceptable criteria established for freshwater ecosystems. In contrast to most metals, concentrations of selenium and arsenic were stable or increasing slightly in the Gilbert Bay sediments. In a coring site located in Farmington Bay near an EPA Superfund Site discharge canal, concentrations of metals were high and showed no indication of decreasing in more recent sediments. Surficial sediments from additional sites in the Great Salt Lake indicated that metals were more concentrated towards the southern end of the lake where the primary sources of contamination were located.

Tuning Supported Catalyst Reactivity With Dendrimer-Templated Pt-Cu Nanoparticles, Natalie N. Hoover, Bethany J. Auten, Bert D. Chandler

Bert D Chandler

The effects of particle composition on heterogeneous catalysis were studied using dendrimer-encapsulated nanoparticles (DENs) as precursors to supported Pt-Cu catalysts. Bimetallic Pt-Cu DENs with varying Pt/Cu ratios were prepared in an anaerobic aqueous solution and deposited onto a high-purity commercial alumina support. The dendrimer template was then thermally removed to yield supported nanoparticle catalysts, which were studied with toluene hydrogenation and CO oxidation catalysis as well as infrared spectroscopy of adsorbed CO. Incorporating Cu into Pt nanoparticles had opposite effects on the two test reactions. Cu acted as a mild promoter for CO oxidation catalysis, and the promoting effect was …

Corrosion Mechanism Of Copper In Palm Biodiesel

A.S. Md Abdul Haseeb

Biodiesel is a promising alternative fuel. However, it causes enhanced corrosion of automotive materials, especially of copper based components. In the present study, corrosion mechanism of copper was investigated by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Compositional change of biodiesel due to the exposure of copper was also investigated. Corrosion patina on copper is found to be composed of Cu2O, CuO, Cu(OH)2 and CuCO3. Dissolved O2, H2O, CO2 and RCOO- radical in biodiesel seem to be the leading factors in enhancing the corrosiveness of biodiesel. © 2012 Elsevier Ltd.

Effects Of Reflow On The Interfacial Characteristics Between Zn Nanoparticles Containing Sn-3.8ag-0.7cu Solder And Copper Substrate

A.S. Md Abdul Haseeb

Purpose - The purpose of this paper is to investigate the effects of zinc (Zn) nanoparticles on the interfacial intermetallic compounds (IMCs) between Sn-3.8Ag-0.7Cu (SAC) solder and Cu substrate during multiple reflow. Design/methodology/approach - The nanocomposite solders were prepared by manually mixing of SAC solder paste with varying amounts of Zn nanoparticles. The solder pastes were reflowed on a hotplate at 250 C for 45 s for up to six times. The actual Zn content after reflow was analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The wetting behavior of the solders was characterized by analyzing the contact angles and …

Effects Of Reflow On The Interfacial Characteristics Between Zn Nanoparticles Containing Sn-3.8ag-0.7cu Solder And Copper Substrate

A.S. Md Abdul Haseeb

Purpose - The purpose of this paper is to investigate the effects of zinc (Zn) nanoparticles on the interfacial intermetallic compounds (IMCs) between Sn-3.8Ag-0.7Cu (SAC) solder and Cu substrate during multiple reflow. Design/methodology/approach - The nanocomposite solders were prepared by manually mixing of SAC solder paste with varying amounts of Zn nanoparticles. The solder pastes were reflowed on a hotplate at 250 C for 45 s for up to six times. The actual Zn content after reflow was analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The wetting behavior of the solders was characterized by analyzing the contact angles and …

Effects Of Reflow On The Interfacial Characteristics Between Zn Nanoparticles Containing Sn-3.8ag-0.7cu Solder And Copper Substrate

A.S. Md Abdul Haseeb

Purpose - The purpose of this paper is to investigate the effects of zinc (Zn) nanoparticles on the interfacial intermetallic compounds (IMCs) between Sn-3.8Ag-0.7Cu (SAC) solder and Cu substrate during multiple reflow. Design/methodology/approach - The nanocomposite solders were prepared by manually mixing of SAC solder paste with varying amounts of Zn nanoparticles. The solder pastes were reflowed on a hotplate at 250 C for 45 s for up to six times. The actual Zn content after reflow was analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The wetting behavior of the solders was characterized by analyzing the contact angles and …

Coating Material Interaction On Metal Substrate By Application Of Plasma Spraying, Ajit Behera

Ajit Behera

In this paper, Fly-ash+quartz+illmenite with weight percentage ratio: 60:20:20, is deposited on mild steel and copper substrates by atmospheric plasma spraying at various operating power level ranging from 11 to 21 kW. The properties of the coating depend on the interaction of coating powder with plasma, operating condition and the process parameters. The coating quality and behavior depends on Coating surface & interface morphology are studied with Scanning Electron Microscope. For Mild Steel the adhesion strength has varied from 3.5MPa to 6.56MPa and for Mild steel a maximum of 6.56MPa at the power level of 21 kW. In plasma spraying, …

Degradation Of Automotive Materials In Palm Biodiesel

A.S. Md Abdul Haseeb

As compared to petroleum diesel, biodiesel is more corrosive for automotive materials. Studies on the characterization of corrosion products of fuel exposed automotive materials are scarce. Automotive fuel system and engine components are made from different ferrous and non-ferrous materials. The present study aims to investigate the corrosion products of different types of automotive materials such as copper, brass, aluminum and cast iron upon exposure to diesel and palm biodiesel. Changes in fuel properties due to exposure of different materials were also examined. Degradation of metal surface was characterized by digital camera, SEM/EDS and X-ray diffraction (XRD). Fuel properties were …

Stability Of Molybdenum Nanoparticles In Sn-3.8ag-0.7cu Solder During Multiple Reflow And Their Influence On Interfacial Intermetallic Compounds

A.S. Md Abdul Haseeb

This work investigates the effects of molybdenum nanoparticles on the growth of interfacial intermetallic compound between Sn-3.8Ag-0.7Cu solder and copper substrate during multiple reflow. Molybdenum nanoparticles were mixed with Sn-3.8Ag-0.7Cu solder paste by manual mixing. Solder samples were reflowed on a copper substrate in a 250 °C reflow oven up to six times. The molybdenum content of the bulk solder was determined by inductive coupled plasma-optical emission spectrometry. It is found that upon the addition of molybdenum nanoparticles to Sn-3.8Ag-0.7Cu solder, the interfacial intermetallic compound thickness and scallop diameter decreases under all reflow conditions. Molybdenum nanoparticles do not appear to …

Rapid Reduction Of Copper Sulfide (Cu2s) With Elemental Fe And Mg Using Electrical Discharge Assisted Meachanical Milling (Edamm), Andrzej Calka, David Wexler, Brian J. Monaghan, A Mosbah, P Balaz

Brian Monaghan

The electric discharge assisted mechanochemical milling technique has been applied to the reduction of copper sulphide using either elemental magnesium or elemental iron as the reducing agent. X-ray diffraction was employed for phase identification of starting materials and reaction products. After only 5 min processing using the Electric discharge assisted mechanical milling (EDAMM) method, Cu2S + Mg can be fully reduced to Cu + MgS with small amount of CuO, and Cu2S + Fe can be partially reduced to Cu + Cu5FeS4 (bornite). Secondary electron imaging combined with X-ray mapping was used to investigate the distribution of elements within the …

Die Attach Properties Of Zn-Al-Mg-Ga Based High-Temperature Lead-Free Solder On Cu Lead-Frame

A.S. Md Abdul Haseeb

No abstract provided.

Effects Of Addition Of Copper Particles Of Different Size To Sn-3.5ag Solder

A.S. Md Abdul Haseeb

No abstract provided.

Travelling In Chile, Fathi Habashi

Fathi Habashi

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

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

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

Thomas J Knisley

No abstract provided.

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 …

Comparative Corrosive Characteristics Of Petroleum Diesel And Palm Biodiesel For Automotive Materials

A.S. Md Abdul Haseeb

Corrosive characteristics of biodiesel are important for long term durability of engine parts. The present study aims to compare the corrosion behavior of aluminum, copper and stainless steel in both petroleum diesel and palm biodiesel. Immersion tests in biodiesel (B100) and diesel (B0) were carried out at 80 °C for 1200 h. At the end of the test, corrosion characteristic was investigated by weight loss measurements and changes on the exposed metal surface. Surface morphology was examined by optical microscope and scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS). Fuels were analyzed by using TAN analyzer, FTIR, GCMS and …

Microstructural Effects During Chemical Mechanical Planarization Of Copper, Patrick J. Andersen, Mariela N. Bentancur, Amy J. Moll, Megan Frary

Amy J. Moll

Novel die-stacking schema using through-wafer interconnects require vias to be filled with electroplated Cu, resulting in thick copper films, and requiring an aggressive first-step CMP. This work investigates the effects of microstructure on CMP of copper films, which are not presently well understood. Bulk and local removal rates were investigated for several different microstructures. Surface orientation maps were created and the orientations of individual grains were correlated with topographical data to elucidate local removal behavior. Cu removal depends on the details of the microstructure, and certain microstructures allowed for either faster or more uniform removal of thick Cu films.