1,502 research outputs found
The Effect of Landscape Architecture on Climate Change
Permanent environmental influences such as sun, fog, acid rain can destroy structures, buildings and the environment. Improving the quality of urban environment with utilizing green roof and green facades is illustrated for several years and installing them can offer multiple benefits. A detailed integrated presentation of green roof and green facade systems is provided in this paper. The aim of the research is to illustrate the effect of green façade and green roofs and generally greenery structure on the climate changes. The author tries to find a solution for the climate changes and environmental issues and resolving it by above- mentioned landscape architecture methods
Isolation and characterization of polyhydroxyalkanoates (PHAS) producing bacteria from brackish stream
Polyhydroxyalkanoates (PHAs) are biopolymers which have similar characteristics with petrochemical plastics but a step better due to its biodegradable property. A total of 23 strains were isolated from two different brackish sources. In order to detect the PHAs granules, the PHAs producing bacteria were first screened with Sudan Black B staining. Twenty strains were observed with lipid granules and were subjected to further confirmation with Nile blue staining. From the Nile blue staining, only 10 strains have the ability in producing PHAs and 2 were identified as strong PHAs producers. This study focuses on the 2 strains named S1 and L1. Further identification procedure was carried out and found that strain S1 and L1 belongs to Pseudomonas sp. L1 strain was found to be promising for PHAs production since it accumulated PHAs for about 88.3%. The PHAs produced by this strain was analyzed using Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) analysis and was identified as poly-3-hydroxybutyrate (P-3HB)
Comprehensive identification of sensitive and stable ISFET sensing layer high-k gate based on ISFET/electrolyte models
The ISFET sensing membrane is in direct contact with the electrolyte solution, determining the starting sensitivity of these devices. A SiO2 gate dielectric shows a low response sensitivity and poor stability. This paper proposes a comprehensive identification of different high-k materials which can be used for this purpose, rather than SiO2. The Gouy-Chapman and Gouy-Chapman-Stern models were combined with the Site-binding model, based on surface potential sensitivity, to achieve the work objectives. Five materials, namely Al2O3, Ta2O5, Hfo2, Zro2 and SN2O3, which are commonly considered for micro-electronic applications, were compared. This study has identified that Ta2O5 have a high surface potential response at around 59mV/pH, and also exhibits high stability in different electrolyte concentrations. The models used have been validated with real experimental data, which achieved excellent agreement. The insights gained from this study may be of assistance to determine the suitability of different materials before progressing to expensive real ISFET fabrication
Removal of bisphenol A from aqueous media using a highly selective adsorbent of hybridization cyclodextrin with magnetic molecularly imprinted polymer
In this study, a unique magnetic molecularly imprinted
polymer (MMIP) adsorbent towards bisphenol A (BPA) as a
template molecule was developed by bulk polymerization using
β-cyclodextrin (β-CD) as a co-monomer with methacrylic acid
(MAA) to form MMIP MAA–βCD as a new adsorbent. β-CD
was hybridized with MAA to obtain water-compactible
imprinting sites for the effective removal of BPA from aqueous
samples. Benzoyl peroxide and trimethylolpropane
trimethacrylate were used as the initiator and cross-linker,
respectively. The adsorbents were characterized by Fourier
transform infrared spectroscopy, scanning electronic
microscopy, transmission electron microscopy, vibrating sample
magnetometer, Brunauer–Emmett–Teller and X-ray diffraction.
1H nuclear magnetic resonance spectroscopy was used to
characterize the MAA–βCD and BPA–MAA–βCD complex.
Several parameters influencing the adsorption efficiency of BPA
such as adsorbent dosage, pH of sample solution, contact time,
initial concentrations and temperature as well as selectivity and
reusability study have been evaluated. MMIP MAA–βC
User friendly system for the visually impaired in learning Al-Quran
This study presents a method to enable the visually impaired Muslim to learn and read the Al-Quran using Braille Display with software help. The system reads the database which contains all verses of Al-Quran and user will need to select the verse and ayah to read. Besides that, this system can be used in a class to teach visually impaired students to learn Al-Quran. Every word or character typed by the instructor in the main Braille Panel will be transmitted to the sub Braille Panel that is connected to the main Braille Panel. The selected verse of Al-Quran and ayah will also generate an index before being transmitted to the Braille Panel. The index will be transmitted to the Braille Display for people to touch and read the display. A user friendly Graphical User Interface (GUI) will be used to fulfill the ergonomics for the visually impaired user's physical capabilities. Several approaches are used to design and implement the interface for the visually impaired like speech or sound output and Braille display. The Braille codes can be displayed using the Braille panel. The design interface and structure of the system for the visually impaired users in learning Al-Quran is presented
Implementation of Two Way Free Space Quantum Key Distribution
We report an implementation over free space medium of a two way four states
quantum key distribution (QKD) protocol namely the LM05. The fully automated
setup demonstrated a secure key generation rate of 3.54 kbits per second and
quantum bit error rate (QBER) of 3.34% at mean photon number ({\mu}) = 0.15.
The maximum tolerable channel loss for secure key generation considering Photon
Number Splitting (PNS) attack, was 5.68 [dB]. The result successfully
demonstrated the feasibility of a two way QKD protocol implementation over free
space medium.Comment: To appear in the April 2012 issue of Optical Engineering (Vol. 51,
No. 04
Geometric and process design of ultra-thin junctionless double gate vertical MOSFETs
The junctionless MOSFET architectures appear to be attractive in realizing the Moore’s law prediction. In this paper, a comprehensive 2-D simulation on junctionless vertical double-gate MOSFET (JLDGVM) under geometric and process consideration was introduced in order to obtain excellent electrical characteristics. Geometrical designs such as channel length (Lch) and pillar thickness (Tp) were considered and the impact on the electrical performance was analyzed. The influence of doping concentration and metal gate work function (WF) were further investigated for achieving better performance. The results show that the shorter Lch can boost the drain current (ID) of n-JLDGVM and p-JLDGVM by approximately 68% and 70% respectively. The ID of the n-JLVDGM and p-JLVDGM could possibly boost up to 42% and 78% respectively as the Tp is scaled down from 11nm to 8nm. The channel doping (Nch) is also a critical parameter, affecting the electrical performance of both n-JLDGVM and p-JLDGVM in which 15% and 39% improvements are observed in their respective ID as the concentration level is increased from 1E18 to 9E18 atom/cm3. In addition, the adjustment of threshold voltage can be realized by varying the metal WF
Performance analysis of ultrathin junctionless double gate vertical MOSFETs
The main challenge in MOSFET minituarization is to form an ultra-shallow source/drain (S/D) junction with high doping concentration gradient, which requires an intricate S/D and channel engineering. Junctionless MOSFET configuration is an alternative solution for this issue as the junction and doping gradients is totally eliminated. A process simulation has been developed to investigate the impact of junctionless configuration on the double-gate vertical MOSFET. The result proves that the performance of junctionless double-gate vertical MOSFETs (JLDGVM) are superior to the conventional junctioned double-gate vertical MOSFETs (JDGVM). The results reveal that the drain current (ID) of the n-JLVDGM and p-JLVDGM could be tremendously enhanced by 57% and 60% respectively as the junctionless configuration was applied to the double-gate vertical MOSFET. In addition, junctionless devices also exhibit larger ION/IOFF ratio and smaller subthreshold slope compared to the junction devices, implying that the junctionless devices have better power consumption and faster switching capability
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