A recently reported Nile red (NR) dye conjugated with benzothiadiazole species paves the way for the development of novel organic-based sensitizers used in solar cells whose structures are susceptible to modifications. Thus, six novel NR structures were derived from two previously developed structures in laboratories. In this study, density functional theory (DFT) calculations and time-dependent DFT (TD-DFT) were used to determine the optoelectronic properties of the NR-derived moieties such as absorption spectra. Various linkers were investigated in an attempt to understand the impact of π-linkers on the optoelectronic properties. According to the findings, the presence of furan species led to the planarity of the molecule and a reduction in the band gap between the LUMO and the HOMO. Each one of the aforementioned molecules exhibited great delocalization of π-electrons. Based on the TD-DFT calculations, two furans had the highest value for the red-shift. There is an excellent correlation observed between the computed optoelectronic properties and calculated HOMO-LUMO gaps. In conclusion, the current work aimed at clarifying the impact of π-linkers on the photophysical properties of the NR-derived moieties. Also, the current study provided useful insights into the development of novel species used in optoelectronic devices.
The effect of irradiation and exposure time of laser light on the fluorescence emission of DCM dye in PMMA polymer contained in the composition mold using different metals have been investigated. It was found that the fluorescence intensity decreases as the exposure time increases and then reaches stabilization at long times. The effect of the incident laser power on fluorescence intensity of DCM dye in PMMA polymer at 10-3 M and 20% mixing ratio, using copper disks of composition molds, has been studied too. It was observed that there is an upward knick in the curve at laser intensity of 19.2 W/cm2, which may be associated with the threshold for amplified spontaneous emission (ASE) or laser action. And at intensity higher than about 88.
... Show MoreRemoving of terasil yellow (W-6GS) dye it was studied by using Iraqi Siliceous Rocks Powder (SRP). The study included adsorption isotherms and some effects: temperature, salty medium and the acidity the study that the adsorption isotherms obeys to Temkin equation more than other equations the results showed that the adsorption increased with increasing temperature (Endothermic process. Based on the results, thermodynamic functions (˜H, ˜G, ˜S) were estimated. The amount of adsorbent on the surface increasing with increasing the acidity solution. The kinetics study of the adsorption treated according (Lagergren equation). The kinetic data of experiments properly correlated with the first order kinetic equation.
Firstly, in this study, a brief updated description and applications of different solar collectors used in renewable energy systems for supplying electric and thermal energy was presented. Secondly, an attempt was made to utilize tilting orientation of solar collector for maximizing collector energy with time in respect to horizontal orientation. For energy calculation, global solar radiation was used since they are directly related. For that purpose, field measurements of half-hourly radiation on two flat panels of tilting and horizontal orientations were carried out throughout 8-month period under local climate of Baghdad. Then, energy gain and radiation level averages were calculated based on the field radiation
... Show Morelar water heating systems with heat pipes of three diameter groups of 16, 22 and 28.5 mm. The first and third groups had evaporator lengths of 1150, 1300 and 1550 mm. The second group had an additional length of 1800 mm. all heat pipes were of fixed condenser length of 200 mm. Ethanol at 50% fill charge ratio of the evaporator volume was used as the heat pipes working fluid. Each heat pipe condenser section was inserted in a storage tank and the evaporator section inserted into an evacuated glass tube of the Owens- Illinois type. The combined heat pipe and evacuated glass tube form an active solar collector of a unique design.
The resulting ten solar water heating systems were tested outdoors under the meteorological conditions of Bag
There have been many advances in the solar chimney power plant since 1930 and the first pilot work was built in Spain (Manzanares) that produced 50 KW. The solar chimney power plant is considered of a clean power generation that needs to be investigated to enhance the performance by studying the effect of changing the area of passage of air to enhance the velocity towards the chimney to maximize design velocity. In this experimental and numerical study, the reduction area of solar collector was investigated. The reduction area that mean changing the height of glass cover from the absorbing plate (h1=3.8cm, h2=2.6cm and h3=1.28cm). The numerical study was performed using ANSYS Fluent software package (version 14.0) to solve go
... Show MoreThe thermal performance of indirect expansion solar assisted heat pump, IX-SAHP, was investigated experimentally under Iraqi climate. An Indirect-Solar Assisted Heat Pump system was designed, built, instrumented and tested. Experimental tests were conducted by varying the controlling parameters to investigate their effects on the thermal performance of the IX-SAHP such as cooling water flow rate, heating water flow rate, ambient temperature and solar radiation intensity. The investigation covered values of cooling water flow rate of (2, 3, 4, 5 l/min) and heating water flow rate of (2, 3, 4, 5 l/min) under meteorological condition of Baghdad from November 2014 to January 2015.
The results indicated that the performance of the IX-
... Show MoreWater is the basis of the existence of all kinds of life, so obtaining it with good quality represents a challenge to human existence and development especially in the desert and remote cities because these areas contain small populations and water purification requires great materials and huge amounts of fossil fuels resulting pollution of the environment. Cheap and environmentally friendly desalination methods have been done by using solar distillations. Passive solar stills have low yields, so in this research, the problem is overcome by connecting four heat pipes which are installed on the parabolic concentrator reflector with passive solar still to increase the temperature of hot water to more than 90°C, as a resul
... Show MoreSolar distillers are a sustainable and simple solution for addressing water scarcity, but their limited productivity restricts their effectiveness. This work aimed to assess the thermal performance of a novel tracked, tilted, hexagonal tubular solar still (HTSS) of four-sectioned U-channel receiver. Two identical HTSSs were side-to-side tested in Baghdad-Iraq (33.3°N, 43.3°E) from June to September 2024. The thermal evaluation of single-axis tracking solar still, tilted at (5° to 15°) with the horizontal axis and charged with and without hydrogel beads for water depth of 60 mm. The still's thermal performance is assessed by analyzing heat transfer coefficients, energy and exergy efficiencies, as well as conducting cost and environment
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