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Effect Of Ion Concentration On Mechanosynthesis Of Carbonated Chlorapatite Nanopowders
Effect Of Ion Concentration On Mechanosynthesis Of Carbonated Chlorapatite Nanopowders
Faculty of Engineering University of Malaya
Carbonated chlorapatite nanopowders (n-CCAp) with different degrees of substitution were successfully synthesized by the one-step mechanochemical process. Results demonstrated that the formation of n-CCAp was influenced strongly by the carbonate content (x). From X-ray analysis, crystallite size, crystallinity degree, and unit cell volume of n-CCAp decreased significantly as carbonate content (x) increased from 0 to 2. Conversely, the lattice strain and the volume fraction of grain boundaries grew considerably. Microscopic analysis showed the average particle size of the synthesized powders was 15 +/- 10 nm. The influence of carbonate concentration on mechanosynthesis of pure n-CCAp utilizing a facile solid-state process …
Effect Of High-Energy Ball Milling On The Formation And Micro Structural Features Of Carbonated Chlorapatite Nanopowders
Faculty of Engineering University of Malaya
Carbonated chlorapatite nanopowders (n-CCAp) were synthesized by mechanochemical process from calcite (CaCO3), phosphorus pentoxide (P2O5), and calcium chloride (CaCl2) as raw materials. Results demonstrated that the formation of n-CCAp was influenced strongly by the milling time. At the beginning of milling (up to 15 min), CaCO3 and CaCl2 were the dominant phases, while P2O5 disappeared entirely due to its very high deliquescent nature. With increasing the milling time to 600 min, the progressive mechanochemical reaction was completed which resulted in the formation of nanostructured carbonated chlorapatite. According to the X-ray diffraction data, crystallite size of the product decreased from 24 …
Effect Of Molybdenum Disulfide Particle Sizes On Wear Performance Of Commercial Lubricant, Innovative Research Publications Irp India, S. M. Muzakkir, Harish Hirani
Effect Of Molybdenum Disulfide Particle Sizes On Wear Performance Of Commercial Lubricant, Innovative Research Publications Irp India, S. M. Muzakkir, Harish Hirani
Innovative Research Publications IRP India
Experimental investigations have been conducted for determination of effectiveness of employing a combination of three particle sizes (40 nm size, 1.75 μm size and 53 μm size) of Molybdenum Disulphide as anti-wear additive in a commercial lubricant. The conformal block and disk configuration has been used to conduct experiments for determination of wear of the sliding surfaces. The performance of the proposed combined particle sizes anti-wear additive is compared with single particle size anti-wear additives to establish its robustness under varying surface conditions.
Too Enthusiastic To Care For Safety: Present Status And Recent Developments Of Nanosafety In Asean Countries
Faculty of Engineering University of Malaya
Nanotechnology has the prospect to vibrate the imagination of human being and has the ability to be used in almost every sector of human need. With its limitless potentials, there are many environmental, health and safety related concerns due to extremely ambivalent effects of nanoparticles. Studies revealed that nanoparticles can enter the human body through the lungs, intestinal tract, and skin. Therefore, the researchers and workers who handle nanoparticles and nanomaterials can theoretically and primarily be affected, whereas on the consumers this will have secondary effects. This paper aims at sharing and evaluating the investment scenario, present status and recent …
Eulerian-Lagrangian Analysis Of Solid Particle Distribution In An Internally Heated And Cooled Air-Filled Cavity
Faculty of Engineering University of Malaya
A parametric study has been conducted to investigate particle deposition on solid surfaces during free convection flow in an internally heated and cooled square cavity filled with air. The cavity walls are insulated while several pairs of heaters and coolers (HACs) inside the cavity lead to free convection flow. The HACs are assumed to be isothermal heat source and sinks with temperatures T-h and T-c (T-h > T-c). The problem is numerically investigated using the Eulerian-Lagrangian method. Two-dimensional Navier-Stokes and energy equations are solved using finite volume discretization method. Applying the Lagrangian approach, 5000 particles, distributed randomly in the enclosure, were …
Influence Of Ni Nanoparticle On The Morphology And Growth Of Interfacial Intermetallic Compounds Between Sn-3.8ag-0.7cu Lead-Free Solder And Copper Substrate
A.S. Md Abdul Haseeb
This paper reports on the effects of adding Ni nanoparticles to a Sn-3.8Ag-0.7Cu solder. The nanocomposite was prepared by manual blending of SAC solder paste with various percentages of Ni particles. Results showed that the addition of Ni nanoparticles did not bring any significant change in the onset melting temperature of the solder. An increase in the weight percentage of nanoparticles in the solder caused an increase of the wetting angle and a decrease of spreading rate. Moreover, the addition of Ni nanoparticles changed the interfacial intermetallic compound morphology from a scalloped structure into a planar type structure, enhanced the …
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 …
Tem Analysis As A Tooll For Toxicology Assessment Of Occupational Exposure To Airborne Nanoparticles From Welding, João F. Gomes
Tem Analysis As A Tooll For Toxicology Assessment Of Occupational Exposure To Airborne Nanoparticles From Welding, João F. Gomes
João F Gomes
No abstract provided.
Notice On A Methodology For Characterizing Emissions Of Ultrafine Particles/Nanoparticles In Microenvironments, João F. Gomes
Notice On A Methodology For Characterizing Emissions Of Ultrafine Particles/Nanoparticles In Microenvironments, João F. Gomes
João F Gomes
No abstract provided.
Preparation And Low-Temperature Sintering Of Cu Nanoparticles For High-Power Devices
Preparation And Low-Temperature Sintering Of Cu Nanoparticles For High-Power Devices
A.S. Md Abdul Haseeb
One of the fundamental requirements for high-temperature electronic packaging is reliable silicon attach with low and stable electrical resistance. This paper presents a study conducted on Cu nanoparticles as an alternative lead-free interconnect material for high-temperature applications. Cu nanoparticles were prepared using pulsed wire evaporation technique in water medium. Pure Cu nanoparticles without any organic mixture were used in this paper. An economical approach to extract the nanoparticles from water was established. In situ Cu nanoparticles oxide reduction was successfully done using forming gas $({\rm N}-{2}{\hbox{-}}5\%{\rm H}-{2})$. Cross-section analysis on bonded interface shows onset of Cu nanoparticles sintering at 400$^{\circ}{\rm …
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 …
Effects Of Co Nanoparticle Addition To Sn-3.8ag-0.7cu Solder On Interfacial Structure After Reflow And Ageing
A.S. Md Abdul Haseeb
Effects of Co nanoparticle additions to Sn-3.8Ag-0.7Cu on the structure of solder/copper interface have been studied after reflow and high temperature ageing (150 °C, up to 1008 h). Results show that the Co nanoparticles substantially suppress the growth of Cu3Sn but enhance Cu 6Sn5 growth. Cobalt nanoparticles reduce interdiffusion coefficient in Cu3Sn. It is suggested that the Co nanoparticles undergo surface dissolution during reflow and exert their influence, at least partially, through alloying effect. © 2011 Elsevier Ltd. All rights reserved.
Characterisation Of Nanoparticle Through Sem, Ftir, Xrd & Dsc, Ajit Behera
Characterisation Of Nanoparticle Through Sem, Ftir, Xrd & Dsc, Ajit Behera
Ajit Behera
Nanoparticles are widely due as Sustained Release Drug Delivery System. Due to their smaller size of controlled drug release potential, targeting ability, enhancement of therapeutic efficacy and reduction of toxicity. Nifedipine one of the calcium channel blocker use for the management of hypertension. Spray drier technique develops Nifedipine loaded nanoparticle. Primary superimulsion phase contains Drug (Nifedipine), Polymer (Ethylcellulose) & suitable non-aqueous Solvent (Dichloromethane) which are sprayed over secondary phase containing aqueous solvent with dispersing polymers (PVA) are prepared by taking drug to polymer weight ratio of 20:90. Formation of films on the surface of secondary phase dried, sieved & forward …
Addition Of Cobalt Nanoparticles Into Sn-3.8ag-0.7cu Lead-Free Solder By Paste Mixing
Addition Of Cobalt Nanoparticles Into Sn-3.8ag-0.7cu Lead-Free Solder By Paste Mixing
A.S. Md Abdul Haseeb
Purpose - The purpose of this paper is to investigate the effects of addition Co nanoparticles on the characteristic properties of Sn-3.8Ag-0.7Cu solder. Design/methodology/approach - Cobalt (Co) nanoparticles were added to Sn-Ag-Cu solders by thoroughly blending various weight percentages (0-2.0 wt%) of Co nanoparticles with near eutectic SAC387 solder paste. Blending was done mechanically for 30 min to ensure a homogeneous mixture. The paste mixture was then reflowed on a hot plate at 250°C for 45 s. The melting points of nanocomposite solder were determined by differential scanning calorimetry. Spreading rate of nanocomposite was calculated following the JIS Z3198-3 standard. …
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
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 …
On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes
On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes
João F Gomes
No abstract provided.
Micro- To Macroscopic Observations Of Mnalpo-5 Nanocrystal Growth In Ionic-Liquid Media, Eng-Poh Ng Dr.
Micro- To Macroscopic Observations Of Mnalpo-5 Nanocrystal Growth In Ionic-Liquid Media, Eng-Poh Ng Dr.
Eng-Poh Ng
Micro- and macroscopic studies of nucleation and growth processes of MnAlPO-5 nanosized crystals under ionothermal synthesis conditions are reported herein. The samples treated at 150 8C were extracted from the reaction mixture at various stages of crystallization, and characterized by XRD; SEM; thermogravimetric analysis (TGA); 31P and 27Al solid-state magic angle spinning (MAS) NMR, Raman, UV/Vis, and X-ray fluorescence spectroscopy (XRF). The starting raw materials (alumina, manganese, and phosphorous) were dissolved completely in the ionic liquid and transformed into an amorphous solid after 5 h of ionothermal treatment. This amorphous solid then undergoes structural changes over the following 5–25 h, …