Digital Commons Network^™

Spectrally-Selective All-Inorganic Scattering Luminophores For Solar Energy-Harvesting Clear Glass Windows, Ramzy Alghamedi, Mikhail Vasiliev, Mohammad Alam, Kamal Alameh

Mikhail Vasiliev

All-inorganic visibly-transparent energy-harvesting clear laminated glass windows are the most practical solution to boosting building-integrated photovoltaics (BIPV) energy outputs significantly while reducing cooling- and heating-related energy consumption in buildings. By incorporating luminophore materials into lamination interlayers and using spectrally-selective thin-film coatings in conjunction with CuInSe2 solar cells, most of the visible solar radiation can be transmitted through the glass window with minimum attenuation while ultraviolet (UV) radiation is down-converted and routed together with a significant part of infrared radiation to the edges for collection by solar cells. Experimental results demonstrate a 10 cm × 10 cm vertically-placed energy-harvesting clear glass …

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 …

Nanoparticle Plasmonics: Going Practical With Transition Metal Nitrides, U. Guler, V. M. Shalaev, A. Boltasseva

U. Guler

Promising designs and experimental realizations of devices with unusual properties in the field of plasmonics have attracted a great deal of attention over the past few decades. However, the high expectations for realized technology products have not been met so far. The main complication is the absence of robust, high performance, low cost plasmonic materials that can be easily integrated into already established technologies such as microelectronics. This review provides a brief discussion on alternative plasmonic materials for localized surface plasmon applications and focuses on transition metal nitrides, in particular, titanium nitride, which has recently been shown to be a …

Different Geometrical Agnps For Vector Control And Their Added Value Of Antibacterial Activity, Namita Soni, Soam Prakash

Soam Prakash

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 …

Enhanced Sonocatalytic Treatment Of Ibuprofen By Mechanical Mixing And Reusable Magnetic Core Titanium Dioxide

Faculty of Engineering University of Malaya

As a reusable sonocatalyst, magnetically separable titanium dioxide (MST) was synthesized by a sol-gel method and was evaluated in the removal of ibuprofen (IBP). MST was carefully characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N-2 gas isotherms, band-gap energy, magnetization, zeta potential, and particle size distribution. The kinetics of IBP removal by sonolysis or MST-assisted sonocatalysis was systematically evaluated with various operational parameters such as pH, temperature, ultrasound (US) frequency, and mechanical mixing intensity. For the first time, authors found that mechanical mixing had an opposite effect on the oxidation rate constants of IBP removal by sonolysis …

Surface States In Template Synthesized Tin Oxide Nanoparticles, A. Cabot, J. Arbiol, R. Ferre, J. R. Morante, Fanglin Chen, Meilin Liu

Fanglin Chen

Tin–oxide nanoparticles with controlled narrow size distributions are synthesized while physically encapsulated inside silica mesoporous templates. By means of ultraviolet-visible spectroscopy, a redshift of the optical absorbance edge is observed. Photoluminescence measurements corroborate the existence of an optical transition at 3.2 eV. The associated band of states in the semiconductor gap is present even on template-synthesized nanopowders calcined at 800 °C, which contrasts with the evolution of the gap states measured on materials obtained by other methods. The gap states are thus considered to be surface localized, disappearing with surface faceting or being hidden by the surface-to-bulk ratio decrease.

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 …

Optimal Energy For Cell Radiosensitivity Enhancement By Gold Nanoparticles Using Synchrotron-Based Monoenergetic Photon Beams, Wan Nordiana Rahman, Stephanie Corde, Naoto Yagi, Siti Aishah Abdul Aziz, Nathan Annabell, Moshi Geso

Stéphanie Corde

Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. …

Real-Time Mri-Guided Catheter Tracking Using Hyperpolarized Silicon Particles, Nicholas Whiting, Jingzhe Hu, Jay V. Shah, Maja C. Cassidy, Erik Cressman, Niki Zacharias Millward, David G. Menter, Charles M. Marcus, Pratip K. Bhattacharya

Nicholas Whiting

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 …

Probing The Enzymatic Activity Of Alkaline Phosphatase Within Quantum Dot Bioconjugates, Jonathan C. Claussen, Anthony Malanoski, Joyce C. Breger, Eunkeu Oh, Scott A. Walper, Kimihiro Susumu, Ramasis Goswami, Jeffrey R. Deschamps, Igor L. Medintz

Jonathan C. Claussen

Enzymes provide the critical means by which to catalyze almost all biological reactions in a controlled manner. Methods to harness and exploit their properties are of strong current interest to the growing field of biotechnology. In contrast to depending upon recombinant genetic approaches, a growing body of evidence suggests that apparent enzymatic activity can be enhanced when located at a nanoparticle interface. We use semiconductor quantum dots (QDs) as a well-defined and easily bioconjugated nanoparticle along with Escherichia coli-derived alkaline phosphatase (AP) as a prototypical enzyme to seek evidence for this process in a de novo model system. We began …

A Dft Study On An Alkali Atom Doped Decahedral Silver Nanocluster For Potential Application In Opto-Electronics And Catalysis

Faculty of Engineering University of Malaya

A systematic study of the structural, electronic and optical properties of the decahedral bimetallic Ag12X cluster is presented in the framework of density functional theory (DFT), where one atom of an alkali metal (X = Li, Na, K, Rb, Cs, Fr) is added, replacing a Ag atom in the decahedral Ag-13 cluster in core (c-doped), vertex (v-doped) and surface (s-doped) positions. Geometrical optimization of the clusters indicated that Li and Na doped clusters exhibited the highest stability. The binding energy (BE), vertical ionization potential (VIP), vertical electron affinity (VEA) and HOMO-LUMO gaps were calculated to compare the electronic stability and …