352 research outputs found
Phase discriminating capacitive array sensor system
A phase discriminating capacitive sensor array system which provides multiple sensor elements which are maintained at a phase and amplitude based on a frequency reference provided by a single frequency stabilized oscillator. Sensor signals provided by the multiple sensor elements are controlled by multiple phase control units, which correspond to the multiple sensor elements, to adjust the sensor signals from the multiple sensor elements based on the frequency reference. The adjustment made to the sensor signals is indicated by output signals which indicate the proximity of the object. The output signals may also indicate the closing speed of the object based on the rate of change of the adjustment made, and the edges of the object based on a sudden decrease in the adjustment made
The preparation, metal binding ability and catalytic activity of poly itaconate copolymers with pendant ethylene amine groups
A polymeranalogous reaction in homogeneous medium was carried out to prepare poly itaconate copolymers with pendant ethylene imine groups. Three copolymers, poly- (MHpI+DHpI), poly (MBI+DBI) and poly (MMI+DMI) were prepared, characterised and their composition analysed. The acid groups in the monoesters were reacted with ethylene diamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine in the presence of dicyclohexyl car bodiimide. Two types of polymer-metal complexes, polymer chelates and pendant-type polymer-metal complexes were prepared. The complexation between the polymeric ligands and cobalt(II) chloride or copper(II) chloride was studied by visible spectroscopy. The electron microscopy study of these polymer-metal complexes shows that the size and the number of the metal ion clusters increases proportionally with the mole percentage of the metal ions. The catalytic activity of the polymer-metal complexes on the decomposition of hydrogen peroxide has been studied. Graphical and mathematical methods were used to show and compare the catalytic activity of these polymer-metal complexes. It was found that the catalyst efficiencies were in the decreasing order of: poly(MHpI+DHpI)/EN/ Co(en)2Cl] 2+ 2Cl" ^ poly(MMI+DMI)/EN/[ Co(en)2Cl] 2+ 2C1~ ^ poly(MHpI+DHpI)/TEPA/CoCl2 ^ poly(MHpI+DHpI)/TEPA/CuCl2^ poly (MMI+DMI) /TEPA/CoCl^ poly (MMI+DMI) /TEPA/CuC12. The thermal stability of these modified polymers and polymer-metal complexes confirms that degradation was a random chain scission process and that the thermal stability of the polymer-metal complexes were higher than the polymeric ligands due to crosslinking. The viscoelasticity study shows that the modulus in the rubbery region increases when the mole percentage of the pendant ethylene amine group was less than 6.3. The glass transition temperature increases and becomes broader and ill-defined as the mole percentage of pendant ethylene amine group increases due to enhanced inter molecular interactions in the system
Optical Fiber Biosensor toward E-coli Bacterial Detection on the Pollutant Water
In this study, Zinc oxide (ZnO) nanorods based fiber optic biosensor has been reported for rapid and sensitive detection of Escherichia Coli (E-coli). A thin layer of Gold nanoparticles (Au) (around 50 nm) is coated on the tip of a multimode plastic optical fiber. ZnO Nanorods are grown on Au layer thorough hydrothermal technique. This sensor showed a very fast response within the first 10 second of contacting the present of polluted water with E-coli Different concentrations of E. coli from (1000 to 4000 CFU/ml) have been tested and a sharp trend of sensitivity was observed. This sensing platform shows promising potential for regular water and food quality monitoring of various pathogenic microorganisms
Perceptions of Assistant Principals’ and Principals’ of Bahrain Government Schools about the Impact of the Bahrain Teachers College Educational Leadership Program on Their Performance
This article examines the perceptions of school assistant principals and principals who completed the Bahrain Teachers College higher diploma of education leadership program about its impact on their performance. The study sample consisted of 141 program graduates from 9- cohorts. A multilevel concept in measuring the impact of the educational leadership program on the graduates’ performance was employed. The framework consisted of 4 levels: self-learning, changing others, embedding changes in school practices and sustainability of change and scaling up the school performance. The study questionnaire was designed on the basis of this framework. Results show that the Educational Leadership program positively affected its graduates’ performance in the 4 levels. The majority of the program graduates agreed that the program positively affected their personal qualities, leadership styles and practices to support school development, school staff, students’ performance and school ranking. The majority of the program graduates also agreed that the program positively affected their skills in dealing with curriculum innovations, professional development, research, strategic planning, staff appraisal, communication with community, using ICT, improving students’ learning and applying educational ethics.
Keywords: Education Leadership, School Principals’ Performance, Leadership Styles, School Practices, Leadership Skill
Variation in gas chromatography (GC) analysis in setting up laboratory protocols for waste to energy novel fixed bed reactor setups
Gas Chromatography coupled with Mass Spectrometry (GC/MS) has been applied in various analytical chemistry works. However, to fine tune a system that can serve the purposes of pyrolysis oil identification has proven to be a laborious effort, especially when considering the fact that no standard protocol exists for such analysis. In addition, obtained products were yielded from a newly commissioned unit with a unique and novel design. In this study, a US patent office claimed reactor [SULTAN-1, Pyrolysis Reactor System for the Conversion and Analysis of Organic Solid Waste, Patent application number: 15,487,351] that degrades polyolefinc virgin and waste materials to obtain petroleum refinery and petrochemical feedstock, has been commissioned. The reactor produces three distinct physical states of matter products accumulated as testing specimens, i.e. solids, gaseous and oil. The samples analysed in this work were of the gas and oil produced by pyrolysis of end of life tyre (ELTs) shavings that required to have a special recipe to work with in the laboratory. Various MS cords were utilised and experimental setups to fine tune the process, and special emphasis was given on the gas samples variation in this communication. To reach the desired analysis results with high repeatability, a plethora of experiences of lab personnel and laboratory-based experimental work was accumulated. Laboratory protocols were also setup for this work. These will be detailed along the process execution which yielded a standard laboratory best practice analytical method as part of the State of Kuwait newly initiated Government Initiative project
Probiotics: Past, Present and Future Challenges
The term probiotic (prolife) is utilized to describe useful living microorganisms, intended to colonize the large bowel, when consumed in adequate amounts, they confer physiological health benefits to the host. In the last decade, probiotics have been widely used as a nutritional supplement and became a rapidly developing research topic that gained importance in medicine. Recent clinical trials have found that consumption of beneficial bacterial species can manipulate gut flora and reduce or prevent the development of certain serious diseases. This brief review article is intended to discuss the status of research on probiotics, and the value of their consumption in human health
Distributed feedback multimode brillouin–raman random fiber laser in the S-band
A novel S-band multimode Brillouin–Raman random fiber laser based on distributed feedback
of Rayleigh scattered light is demonstrated. It relies on a short length, 7.7 km long
angle-cleaved dispersion compensating fiber in a mirror-less open cavity. Two 1425 nm laser
diodes at a modest operating power amplify a Brillouin pump (BP) signal, which in turn
generates a multi-wavelength laser output through the stimulated Brillouin scattering. Eleven
Brillouin Stokes lines, spanning from 1515.15 to 1516.00 nm, were obtained at a Raman pump
power of 361.66 mW. Out of these, five odd Brillouin Stokes lines were generated with a flat
peak power of about 0 dBm
Q-switched erbium doped fiber laser using antimony telluride-polyvinyl alcohol (Sb2Te3-PVA) as saturable absorber
Q-switched erbium doped fiber laser using antimony telluride-polyvinyl alcohol (Sb2Te3-PVA) as saturable absorberaQ-switched erbium doped fiber laser was demonstrated using antimony telluride (Sb2Te3) as saturable absorber (SA). The SA was fabricated by adding Sb3Te2 powder into PVA suspension and left dry in room temperature for two days. Then, the SA was sandwiched in between two FC/PC fiber ferrules, which can provide easy integration and flexibility into the laser cavity. Stable and self-started Q-switched laser operates at 1531 nm center wavelength. The laser repetition rate increased from 54.5 kHz to 88.4 kHz and pulse duration decreased from 6.84 mu s to 4.58 mu s as the pump power increased. A signal to noise ratio value of 55 dB was achieved at pump power 130 mW. At the maximum pump power, the average output power and pulse energy are 0.26 mW and 2.78 nJ
Emerging factors shaping identity of indigenous urbanism concurrently adopting modernity in qatar: The application of diffusion theory
Forms, designs, and symbols are the components of built environment, which transfer the information of place and identity to users. This research aimed to explore the emerging factors shaping the identity of local urban districts while adopting the global culture and modernity. To achieve this aim, the research has conducted two phases within which include a few steps. Phase one was to explore different urban zoning. It includes a detailed analysis of the different architectural styles and elements that have spread the identity concerning the main constituents of urban zones. Because of the difficulty to survey the whole Doha region, this research has focused on four mega projects with different characteristics in Doha Governorates; Pearl Qatar (representing Islamic architecture), Souq Waqif (representing traditional architecture), Msheireb project (as the combination of traditional and modern architecture), and West Bay (as the reference for global approach). Phase one has two steps; Field Observation and Field survey. Phase two was to explore the new elements spread for built environment's identity with the concentration on the selected sites in Doha. Phase two has two steps; Photo survey and Interviews. To test the proposed premise, this phase prolonged into human geography using Torsten Hagerstrand's diffusion theory. The findings of this research help architects and urban designers to enhance susers' awareness of their natural environment, and provide a better perception of identity in local urban districts and vernacular architecture, based on instinct and strategic view derived from the global culture and societal modern architecture principles.Scopu
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