33 research outputs found
Structural and optical properties of diamond like carbon films using direct current plasma enhanced chemical vapor deposition
The amorphous diamond like carbon (a - DLC) thin films were deposited in 3 hours on glass substrates at the vacuum pressure, 8.0 x 10-2 Torr ; deposition pressure, 4.0 x 10-1 Torr and deposition temperatures, 300 – 500 °C by using direct current plasma enhanced chemical vapour deposition (DC - PECVD) system with the precursor gas, 1 % of methane, 39 % of hydrogen and 60 % of argon. The (a - DLC) films which have completely been deposited were post annealed for 3 hours in the tube furnace at 500 – 700 °C with nitrogen ambient to obtain the nitrogen doped amorphous diamond like carbon (a:N - DLC) films. The characterizations were studied by using X-Ray Diffractometer, Energy and Dispersive Analysis of X-Ray, Fourier Transform Infrared Spectrometer, UV / VIS / NIR Spectrophotometer and Photoluminescence Spectrometer. The annealed films are verified as amorphous structure as discovered by X-Ray Diffractometer. It was revealed that carbon, nitrogen, oxygen and silicon are emitting the x-ray energy spectra at 0.28 keV, 0.39 keV, 0.5 keV and 1.74 keV, respectively. The infrared absorptions have shown at 880 cm-1 as C-H bending bonds, 1100 and 1220 cm-1 as C-N stretching bonds, 1300 cm-1 as C-C stretching bonds, 1600 cm-1 as C=N stretching bonds and 2200 cm-1 as C=N stretching bonds for the films annealed from 500 °C to 700 °C. Stretching bond has been observed when annealed at 500 °C and C=N stretching bond has formed when annealed at 700 °C. Moreover the transmittance of (a:N - DLC) films was increasing from 24.9 % to 70.7 % when annealing temperature increased from 500 °C to 700 °C; transition changed from allowed indirect transition, r = 2 to forbidden direct transition, r = 3/2; the optical band gap decreases from 1.60 - 0.85 eV at 500 - 650 °C, but increases to 1.62 eV at 700°C. With the fixed excitation wavelength at 245 nm within the measurement range of 200 – 800 nm, the emission wavelengths were obtained at 290 nm and 393 nm which correspond to n - n* transition and violet emission transition, 4P01/2 4P½, respectively
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Performance And Precision Evaluation Of Multidimensional Databases
Explosion of information in the business environment demands acquisition of reliable data warehouse and suitable information extraction technology. Data warehouse in combination with Online Analytical Processing (OLAP) multidimensional database (MDDB) has become the de-facto for decision support systems
Data Mining and Warehousing Approaches on School Smart System: A Conceptual Framework
Data warehouse is a database with tools that stores current and historical data of potential interest. One of them which, will be investigated in this paper, is the state school data. Mining or analyzing data extract from such system would be interesting for possible smart school application. This paper looks at the framework of virtual smart school implementation based on students' exam results
Data mining and warehousing approaches on school smart system : A conceptual framework
Data warehouse is a database with tools that stores current and historical data of potential interest.One of them which, will be investigated in this paper, is the state school data. Mining or analyzing data extract from such system would be interesting for possible smart school application. This paper looks at the framework of virtual smart school implementation based on students’ exam results
Data Mining Approach on Nationwide School Exam System
Knowledge discovery (or data mining approach) for nationwide school exam prototype system not only adds value to the information readily available but it also assist decision-makers to make decision based on the new information. This approach can even include the ability to model and remodel the data from large database. Knowledge discovery for school exam system usage and benefits includes, locating the right information, presenting of information (reports, graphs), discovery of information (which the paper will emphasis), and possible new trend forecasting
Undoped diamond-like carbon thin films grown by direct current-plasma enhanced chemical vapour deposition: structural and electrical properties
Undoped diamond - like carbon thin films have been grown by DC - PECVD system. The synthesis of the DLC films was carried out in the presence of gas of (CH4 + H2 + Ar) in a custom - made reactor. The substrate temperature was initiated from the range of 300 °C to 600 °C under an optimum pressurized medium. The AFM image reveals that the optimization of DLC films growth at the substrate temperature 400 °C has a significant surface roughness and average grain size which is compatible to the result of film thickness measurement. The sample J400 shows an excellent nonlinear rectifying diode-like characteristic across the small potential difference
The effects of 3D presentation and dependency portrayals on philanthropy.
3D technology and its effect on philanthropy is a relatively new and uncharted area of research, as stereoscopic 3DTV technology was only made available to the mass market recently. This study aims to find out if 3D presentation in a philanthropic context can change attitude towards the disabled elderly and increase donations, considering the aging population and rising healthcare costs in Singapore. Although portrayals of the disabled elderly in charity posters have been studied, little has been done to empirically examine the topic in the context of 3D medium. 150 participants were asked to view a charity poster shown on a television before completing a self-report survey. The posters were manipulated in either 2D or 3D format and featured a disabled elderly portrayed as either independent or dependent. The dependency portrayal yielded insignificant results on cognitive and affective attitude towards the disabled elderly, attitude towards charities, and the intention to donate. The results showed significant main effects of 3D presentation on cognitive attitude towards the disabled elderly, social presence, and favour towards the advertisement. However, no main effects were found for 3D on affective attitude, attitude towards charities, and the intention to donate. Results from mediation analyses showed that cognitive attitude towards the disabled elderly, social presence, and favour towards the advertisement were significant mediating factors for the effect of 3D presentation on certain variables. Implications with regards to the use of 3D presentation in attitude towards philanthropy and charities are discussed.Bachelor of Communication Studie