In this study, the optical performance of plastic (acrylic-polycarbonate-acrylic, acrylic-polystyrene-acrylic, PMMA-polycarbonate-PMMA, and PMMA-polystyrene-PMMA) diffraction-limited air-spaced Cooke triplet lens designs optimized for the spectral range 0.995 to 1.01 µm are presented. Comparing the acrylic-polycarbonate-acrylic air-spaced Cooke triplet lens design with the other three plastic lens designs, the obtained results indicate that the acrylic-polycarbonate-acrylic design can achieve the best image quality performance at 50% contrast 56 cycles/mm and Strehl ratio= 0.989 for the on-axis field-of-view (FOV= 0°). Furthermore, over the temperature range 18.30 to 22.25 °C and over +12° FOV the acrylic-polycarbonate-acrylic air-spaced Cooke triplet lens design performance remained diffraction-limited (Strehl ratio < 0.8). The low cost and the light weight of plastic optical components makes them attractive for several industrial applications. As an example, plastic lenses are incorporated into cell phone cameras and LED collimation optics.
Many studies have been carried out on information technology/information systems (IT/IS) in the Western world, but little research has been conducted in the Saudi private sector. This study has been conducted to identify and examine the IT/IS evaluation processes employed in the Saudi private sector and any factors that hinder such organisations from evaluating their systems effectively. This article concentrates on the results of those interviews. Numerous studies have been conducted on the mechanisms of IT/IS evaluation techniques and the factors affecting their implementation, but there are very few studies in this field in Saudi Arabia, and they are generally sections of other main studies about IT implementation, use, and investment. This article aims to identify means of evaluating IT/IS in the private sector. 30 IT managers in private-sector companies were randomly selected from the list of top companies issued by the Council of Saudi Chambers of Commerce in the Kingdom of Saudi Arabia.
Radiation patterns are produced from concentric ring arrays by using practical elements, such as dipoles and waveguides which is presented in this article. Ring arrays, which produces high sidelobes, create electromagnetic interference (EMI) problems. To overcome this problem, analysis and synthesis is carried out and generates the directional patterns of concentric ring arrays using practical radiators. The directivity is observed for concentric dipole ring arrays and concentric waveguide ring arrays is 72.21 dB. The comparative data is presented in the result.
Monopole L-shaped slits are embedded on rectangular patch antenna is designed for S-band applications. The proposed antenna is a square patch radiator with four L-shaped slits are presented. The proposed antenna radiates at 3GHz resonance frequency with bandwidth of 1.9GHz and -26.4dB return loss. The impedance bandwidth is enhanced 62.7% with proposed antenna model. The proposed L-shaped slit patch antenna is small in size and compact. The radiation pattern is presented in the results and it works at S-band applications.
In this article, the design of a 45.5X (numerical aperture (NA) =0.5) infinity corrected, or infinite conjugate, Schwarzschild reflective microscope objective lens is discussed. Fast Fourier transform modulation transfer function (FFT MTF= 568.4 lines/mm at 50% contrast for the on-axis field-of-view), root-mean-square wavefront error (RMS WFE= 0.024 waves at 700 nm), point spread function (PSF, Strehl ratio= 0.972), encircled energy (0.88 µm spot radius at 80% fraction of enclosed energy), optical path difference (OPD=-0.644 waves) and Seidel coefficients calculated with Zemax® are provided to show that the design is diffraction-limited and aberration-free. Furthermore, formulas expressing the relationship between the parameters of the two spherical mirrors and the Schwarzschild objective lens focal length are given. In addition, tolerance and sensitivity analysis for the Schwarzschild objective lens, two spherical mirrors indicate that tilting the concave mirror (or secondary mirror) has a higher impact on the modulation transfer function values than tilts introduced by the convex mirror (or primary mirror). Finally, the performed tolerance and sensitivity analysis on the lens design suggests that decentering any of the mirrors by the same distance has the same effect on the modulation transfer function values.
This article presents a microcontroller-based system for measurement and monitoring voltage of a three-phase electrical system with real-time data logging abilities. The proposed system uses voltage signals and time data as input. The output is an LCD and data files. The system accurately records abnormal voltage variations which have occurred on the system. A PC software is developed to receive and save data in two spreadsheet files through a serial port. Ihe log file contains the measured voltage, which is recorded periodically with a predefined time interval, and the second file contains the type of the fault. The proposed system is first simulated by ISIS-Proteus and then realized and implemented on an electronic board. It is beneficial to make detailed, scientific judgments and analysis for the voltage system to be supplied to a load. Because of the very simple circuit, it finds applications in industrial facilities. It is also useful in applying final circuits for both investigation and monitoring purposes.
In this work, a single-stage C-band erbium-doped fiber amplifier (EDFA) has been constructed and characterized. Gain (G) and noise figure (NF) measurements collected for the C-band EDFA as a function of wavelength (1528.8 to 1562.3 nm) and laser pump powers are discussed. Further, the EDFA conversion efficiency (CE) as a function of laser pump powers is presented. Simplified mathematical expressions for the EDFA gain, NF, and CE are provided. The C-band EDFA signal gain remained flat in the spectral region 1539 to 1562 nm. Moreover, the C-band EDFA NF increased with wavelength and decreased with the 1480 nm laser pump powers. Additionally, the C-band EDFA maximum achieved conversion efficiency and signal gain is 22.64% at P1=19.49 mW and 22.6 dB at 1531.1 nm, respectively.
This article describes a new approach for performing full field imaging ellipsometry. In this new technique, the objective lens of a high numerical aperture microscope is used to illuminate the surface of a 2D object. The light reflected from each point of the surface is gathered by the same lens and projected onto a 2D CCD detectors array; thus, enabling the measurement of numerous surface points simultaneously. Using this simple method, areas of up to 0.9 cm 2 can be measured with high accuracy. Since the nanotechnology domain is rapidly growing, such a technique can bring benefits to the scientific community, facing the need to analyze large surfaces of thin films.
This article describes how in recent years the need for the quality control, reliability and traceability of analytical results has been strongly emphasised. The National Institute of Metrology, Quality and Technology, is involved in improving calibration and measurement capabilities to provide high confidence level in accordance with the latest regulation regarding greenhouse gases standards. This article describes the gravimetric production of certified gaseous reference materials of carbon dioxide in atmospheric synthetic air that are used to monitor its concentration in the atmosphere. Considering the contributions from gravimetry preparation and its verification analysis by cavity ringdown system (CRDS) the relative expanded uncertainty of the standard mixture of carbon dioxide was lower than 0.5% for the range studied from 370 to 550 μmol/mol, which is comparable to the average of 0,25% relative uncertainties presented on international standards mixtures.
In this article, the wavelength dependence of bend loss in a step-index multimode optical fiber 100 µm core diameter; fused silica was investigated for fiber bend radii ranging between 2.0 and 4.5 mm using six excitation wavelengths, namely, 337.1, 470, 590, 632.8, 750 and 810 nm. The results obtained from fitting the bend loss measurements to Kao's model and utilizing MATLAB indicate that bend loss is wavelength dependent and transmission loss in multimode optical fibers increases with the decrease in the fiber bend radius. Furthermore, the response of a microbend fiber optic displacement sensor was characterized at 337.1, 470, 632.8, 750 and 810 nm. Measurements obtained from the microbend sensor indicate that the sensor output power is linear with the applied displacement and the sensor output is wavelength dependent.
This article describes how a realistic prediction of the exon regions in deoxyribonucleic acid (DNA) is a key task in the field of genomics. Learning of the protein coding regions is a key aspect of disease identification and designing drugs. These sections of DNA are known as exons, that show three base periodicity (TBP) which serves as a base for all exon locating methods. Many techniques have been applied successfully, but development is still needed in this area. We develop a novel adaptive exon predictor (AEP) using singular value decomposition (SVD) which notably reduces computational complexity and provides better performance in terms of accuracy. Finally, the exon locating capability of proposed SVD based AEP is tested using a real DNA sequence with accession AF099922, obtained from the National Center for Biotechnology Information (NCBI) database and compared with the existing LMS methods. It was shown that proposed AEP is more efficient for locating the exon regions in a DNA sequence.
Phase measurements obtained by high-coherence interferometry are restricted by the 2π ambiguity to height differences smaller than λ/2. A further restriction considers linear and nonlinear aberrations evolving in most interferometric systems due to the CCD-type array detectors. The authors present a new method to overcome the 2π ambiguity in interferometry when using a stereoscopic approach. In this method, a reconstructed wavefront reflected from an object was propagated into two different angles to obtain two different images of the object. These two different images were subsequently processed by stereo algorithms to resolve the 2π ambiguity. Such a method of wavefront propagation may enable several applications such as focusing and resolving the 2π ambiguity, as described in the article.
This article describes how one of the biggest challenges in designing of high-speed intermittent contact atomic force microscope AFM is the construction of a fast amplitude detector. The measurement techniques commonly used in commercial microscopes, such as RMS to DC converters or lock-in amplifiers often do not provide sufficient bandwidth to perform high speed imaging. On the other hand, many techniques developed especially for high-speed AFM are characterized by poor signal-to-noise ratio. In this paper, a novel amplitude estimation method based on the generalized Goertzel algorithm is presented. The detection system, composed of 16-bit 100 mega-samples per second analog-to-digital converter and field-programmable gate array device, allows to measure the signal amplitude within the time comparable to one oscillation cycle of the AFM cantilever. The effectiveness and validity of the designed detector were investigated by computer simulation. High spatial resolution of the presented method implemented in the actual atomic force microscopy system is also demonstrated.
This article describes how a compact, low profile Ultra-wideband (UWB) monopole antenna with a defected ground structure is designed and demonstrated experimentally. The design and experimentation activities have been carried out with the help of a CST Microwave studio tool. The UWB characteristics of the proposed antenna are achieved with a modification of the ground structure of the referenced antenna with novel L shaped defected ground structure (DGS). Both antennas are fabricated on the same substrate with the dimensions of 28.3 x 24 mm2. The comparative analysis of the results for both antennas clearly indicate that the proposed UWB monopole antenna enhanced the impedance bandwidth from 3.7 GHz – 14.9 GHz without DGS and to 3.4 GHz – 20 GHz with DGS. The enhanced bandwidth, constant group delay and good radiation characteristics of the proposed antenna have identified it as a good candidate for portable UWB applications.
Use of radial basis functions(RBFs) in the numerical solution of partial differential equations has gained popularity as it is meshless and can readily be extended to multi-dimensional problems. RBFs have been used in different context and emerged as a potential alternative for numerical solution of PDEs. In this article, a Flow Between Parallel Plates problem was solved using a Multiquadric Radial Basis Function Collocation Method (MQ-RBFCM), then, the results were compared with the analytic ones and the root mean square of the errors between the model and analytic results were calculated. Numerical results are presented for 5 different cases, where the number of inputs or definitions are increased to see whether changing the number of points makes the results better or not. Also, the absolute errors between the results were calculated to have a 3D model of the error rates and this has proven for which cases the MQ-RBFCM are better. As a result, RBF is shown to produce accurate results while requiring a much-reduced effort in problem preparation in comparison to traditional numerical methods.
In the last one decade, the life insurance companies operating in India have made significant progress in terms of business consolidation. In view of the same, it is of interest to make an enquiry about the operating performance of these companies. The present paper compares fifteen life insurance companies operating in India for the period 2005-06 to 2009-10 using the Hybrid Efficiency Model (Tone,2004). The Hybrid Model provides a unified framework for the estimation of technical efficiency integrating the radial and non-radial characterisation of inputs and outputs. The results from the study indicate that out of the fifteen in-sample life insurance companies, the number of technically efficient life insurers declined from 9 in 2005-06 to 4 in 2006-07 and further to 3 in 2007-08 and 2008-09. However, in 2009-10 the number increased to 5. The mean technical efficiency scores of the in-sample life insurers declined sharply between 2005-06 and 2006-07 and improved somewhat thereafter. However, it again declined in 2009-10 implying a greater divergence in performance.
The effects that chronic cocaine administration CCA have on craving, cocaine metabolite concentrations and cytochrome P450 3A4 isoenzyme CYP450 3A4 activities in Sprague-Dawley rats following the administration of Salako Nutritional Supplements SNS were examined. Five groups of fifty rats were used to assess the effect of the SNS following CCA. Craving was analyzed for each rat using a Conditioned Place Preference protocol. Blood samples were obtained at regular intervals and used to measure cocaine plasma metabolite levels. CYP450 3A4 activity was determined in the liver. Administration of the SNS reduced craving of cocaine significantly, upon discontinuing cocaine in the rats. Blood plasma analysis showing higher benzoylecgonine equilibrium and the CYP450 3A4 levels demonstrated that the SNS possibly aided in the removal of the stored metabolites indicative of increased metabolism of cocaine, enhanced by the Supplements. Results indicate that the SNS formulation reduces craving caused by CCA by increasing the liver CYP450 3A4 activity, resulting in better plasma clearance.
Revenue efficiency measurement is one of the most important issues in data envelopment analysis (DEA). Most of the proposed models calculate the revenue efficiency of decision making units (DMUs) which play a main role in the formation of the production possibility set by implementing exact or fuzzy data. The revenue efficiency value of a sample decision making unit with exact and fuzzy data has not been investigated by these models yet. There exist different types of fuzzy numbers, however, only a special type of them has been used in revenue efficiency models with fuzzy data. The concept of vector has not been employed to calculate the measure of the revenue efficiency in any of the studies conducted thus far. However, in this article the authors propose a model for evaluating the revenue efficiency measure of a fuzzy sample DMU without the limitations of previous models with regards to the formation of the production possibility set. In the proposed model, data can be selected from different types of fuzzy numbers and there is no limitation on the type of the used fuzzy data. In addition, the current article employs the concept of vector for revenue efficiency assessment for the first time.
