The effect of solar cells distribution on the Performance of solar panel

Three different distribution modules of silicon solar cells in a panel are used in this study . Each module consists of five identical circular silicon solar cells of radius (5cm) and then the total panel areas are identical. The five solar cells are arranged in the panel in different shapes: circular, triangular and rectangular .The efficiency for these three panel distribution are measured indoor and outdoor. The results show that the efficiency is a function of the cells distribution

Third Order Nonlinear Properties of Rhodamine B Dye Doped PVA Polymer Determined by Eclipsing Scan Technique

Link to publisher's homepage at http://ijneam.unimap.edu.myNonlinear (NL) optical properties were observed in Rhodamine B (RB) dyes doped in poly (vinyl alcohol) (PVA) polymer films. Eclipsing Z‐scan (EZ‐scan) with a continuous wavelength of 532 nm was used to investigate the effect of dye concentration on its NL properties. The open aperture EZ‐scan indicates a reverse saturable absorption behavior (positive type) of NL absorption (NLA) coefficient (β) in the RB+VA matrix, whereas the closed aperture EZ‐scan exhibits transition from positive (focusing) to negative (defocusing) nonlinearity at increasing dye concentration. The NL refractive index 2, NLA coefficient , third‐order susceptibility 3, and second‐order hyperpolarizability increase with the increase in dye concentrations. The magnitude of the n2, , 3, and were in the order of 10‐12 (2/W), 10‐1 (/W), 10‐8 (esu), and 10‐12 respectively

Enhancement of Porous Silicon Formation by Using Ultrasonic Vibrations

Anodic electrochemical etching enhanced by ultrasonically is developed to fabricate luminescent porous silicon (PS) material. The samples prepared by the new etching method exhibit superior characteristics to those prepared by conventional direct current etching. By applying ultrasonically enhanced etching, PS microcavities with much higher quality factors can be fabricated. The improved quality induced by ultrasonic etching can be ascribed to increased rates of escape of hydrogen bubbles and other etched chemical species from the porous silicon pores surface

Nano-Particle doped polymers to improve contact lenses optical quality

Link to publisher's homepage at https://ijneam.unimap.edu.my/Polymer-based nanocomposites exhibit different optical virtues such as high refractive index (RI), Abbe number (νd) and visible light transmittance (T %) above 90%. These hybrid materials attract more interest in optoelectronic applications such in the ophthalmic optics. The aim of this work is to study the impact of contact lenses doped with aluminum nanoparticles on aberrated human eye. ZEMAX mainstream optical design software was used for eye modeling based on Liou & Brennan eye model and then the BHESP/PA/AL contact lens was applied. Ocular performance was evaluated by modulation transfer function (MTF), spot diagram root mean square (RMS) and the geometric encircled energy (EE) metrics. The used criteria show that the best visual performance is obtained when BHESP/PA/AL-CL is used (P < 0.0001) because it reduced the generated monochromatic and polychromatic aberrations inside the eye. The required balance between the refractive index and abbe number of the chosen polymer affect the transparency, transmittance and refractive errors correction

Optimal Sizing of Photovoltaic Irrigation Water Pumping System in Samara

Water pumping from wells and rivers for irrigation is a well established procedure on many farms in Iraq and is practical on various levels around the world. Typical irrigation systems consume a great amount of conventional energy through the use of electric motors and generators powered by fuel. The overall objective of this research was to determine the feasibility of using photovoltaic (PV) modules to power a water pump for a small-scale irrigation system in the North-West of Iraq (Samara). The study involved field observations, simulations of global solar radiation and PV electrical output. Field observations involved an installation of 24-monocrystaline silicon PV modules as shown in figure (1). This system was installed to give maximum power equal to (1960 watt) with maximum open circuit voltage (Voc = 175 volts) and maximum short circuit ( Isc= 14 Amp ). This module was connected to the pump via a charge controller and AC inverter. The parameters monitored were voltage, current, back-of-panel temperature, pressure, and flow. These observed parameters were used to determine PV electrical output and volume of water pumped. Site latitude, elevation, and panel tilt were applied to the solar radiation and PV electrical output models. PV electrical output and volume of water pumped were monitored between January 2000 and December 2000. As expected, an increase in power causes an increase in the volume of water pumped

Optimum design of the hybrid (diffractive/refractive) multifocal intraocular lenses implanted within human eye

Abstract The human eye natural crystalline lens becomes opaque due to cataract. To improve the eye vision, the crystalline lens was surgically removed and replaced by an Intraocular lens (IOLs). The optimum design of hybrid multifocal intraocular lenses (MIOLs) implanted within human eye model is proposed. The MIOLs are made of AR40N Allergan material which has a good biocompatibility. Two types of hybrid MIOLs (Diffractive/Refractive (D/R) and Refractive/ Diffractive (R/D)) with four foci were designed and evaluated. A comparison between the image quality for healthy eye (Liou & Brennan model) and for eye with the implanted hybrid MIOLs were done depending on ZEMAX-EE optical software. The image characteristics, point spread function (PSF), modulation transfer function (MTF), blur spot size and longitudinal chromatic aberration (LCA), were used as an image criterion in this study. The eye pupil diameter was "3 mm", the visual field of view was 5 degrees and the light spectral region (455- 655 nm). Results indicate that both hybrid MIOLs models achieved good visual acuity (sharp vision) for a distances within range (25 to cm). The MIOLs made a remarkable correction in chromatic aberration than the healthy eye. The MTF for (R/D)-MIOL model improve the vision quality more than ((D/R)-MIOL) and healthy eye models

Effect of HF Concentration on the PS Structures Prepared by Photoelectrochemical Etching

Porous silicon was fabricated at p-n junction wafer byphotoelectrochemical (PEC) etching. Silicon wafer with various electrolytecontaining different HF concentrations was used to explain PS formation by thereaction at the Si/ electrolyte interface. An investigation of the dependence on HFconcentration to formed PS layer was made. The surface morphology of PS layerwas study as a function of HF concentration. Pillar like structures are formed atlow HF concentration and pores structures are obtained a at higher HFconcentration (40%). The etching rate increases with increasing HF concentrationcausing faster silicon dissolution. Thus the total pillar volume would increase byincreasing the HF concentration

General modulation transfer function fitting equation for human eye with contact lens

In this research, a general equation was derived to represent the modulation transfer function (MTF) of the human eye with the presence of the contact lenses (CL) and during the vision with monochrome or multi-wavelength (polychromatic) light. This equation was used to fit the MTF’s curves for the eye with pupil diameters (EPD) (2.5, 4, 6, and 8 mm). The fitting equation accuracy was revealed by using the standard deviation (STD). The results indicated that the image MTF is sensitive to (EPD). Moreover, eye vision degrades as (EPD) increases due to the increased spherical and chromatic aberrations. The new equation consists of two exponential terms in addition to a correction polynomial function (H) to fit the EPD effect. The results showed that H function with power two is sufficient to give a good accuracy when the EPD is less than 4 mm, while H with power five is necessary when the EPD is larger or equal to 5 mm.  Also, it is clear that the equation gives a high accuracy also in the case of vision with white light for the eye with the contact lens

Linear and Nonlinear Optical Properties of Anthocyanin Dye from Red Cabbage in Different pH Solutions

This article studied some linear and nonlinear optical characteristics of different pH solutions from anthocyanin dye extract at 180 oC from red cabbage. First, the linear spectral characteristics, including absorption and transmittance in the range 400-800 nm for anthocyanin solution 5% v/v with different pHs, were achieved utilizing a UV/VIS spectrophotometer. The experimental results reveal a shift in the absorption toward the longer wavelength direction as pH values increment. Then, the nonlinear features were measured using the Z-scan technique with a CW 532 nm laser to measure the nonlinear absorption coefficient through an open aperture. A close aperture (diameter 2 mm) calculates the nonlinear refractive index. The open Z-scan shows that as the pH increases, the sample decreases transmittance, indicative a two-photon absorption process, and the samples act as a collecting lens for the laser beam. In contrast, the results with a closed Z-scan indicate that the nonlinear absorption coefficient displays a self-focusing nonlinearity. Also, the nonlinear susceptibility decreased by increasing the value of the pH solution. Due to obvious anthocyanin dye nonlinearity dependence value on dye pH, it is possible to use the natural anthocyanin dye as a photonic devic