In this study, a theoretical scenario has been used to calculate the electronic current in sensitizer N3 molecule contact to TiO2 semiconductor for electrons in functional solar cells. It is known to play an important role on the compute the eficiency of solar cell. Some parameters of electronic current such as the transition energy, driving force energy, barrier height coupling overlapping values are determined. Transition energy is a necessary parameter to calculate the electronic current in solar cell with using wide polarity solvents Acetic acid, 2-Methoxyethanol, 1-Butanol, Methyl alcohol, chloroform, N,N-Dimethylacetamide and Ethyl alcohol via the quantum donor-acceptor system. Here, we show the results of transition energy can be varied by varied the polarity of solvents due to dielectric constant and refractive index. However, the transition energy of N3/TiO2 system has slightly increasing with increasing dielectric constant and decrease refractive index. In general, the results of electronic current decreased with increased driving force as results to decrease chemical potential of N3 dye. The N3/ZnO device is shown higher current (3.247 to10.46) × 106 with Acetic acid and reach minimum with Methyl alcohol in range (1.689 to 5.443)× 106 when the driving energy minimum ΔE0 = 0.35 eV. (5.225 to 16.837) × 104 with 1-Butanol and reach minimum in range (0.952 to3.070 ) × 104 with chloroform while for drive energy (0.55 eV) the current decrease and reach maximum (8.528 to27.481) × 102 with Methyl alcoholsolvent and reach minimum(0.176 to 0.569 ) with chloroform solvents. Consequently,the TiO2 contact with N3 is given accept current results in room temperature with Acetic acid solvent in low drive energy and with 1-Butanol and Methyl alcoholsolvents at large drive energy.
Membrane distillation (MD) is a hopeful desalination technique for brine (salty) water. In this research, Direct Contact Membrane Distillation (DCMD) and Air Gap Membrane Distillation (AGMD) will be used. The sample used is from Shat Al –Arab water (TDS=2430 mg/l). A polyvinylidene fluoride (PVDF) flat sheet membrane was used as a flat sheet form with a plate and frame cell. Several parameters were studied, such as; operation time, feed temperature, permeate temperature, feed flow rate. The results showed that with time, the flux decreases because of the accumulated fouling and scaling on the membrane surface. Feed temperature and feed flow rate had a positive effect on the permeate flux, while permeate temperatu
... Show MoreIn this work an experimental study is performed to evaluate the thermal performance
of locally made closed loop solar hot water system using a shell and helical coiled tube
heat exchanger as a storage tank. Several measurements are taken include inlet and outlet
temperatures of both collectors and supply water and temperature distribution within the
storage tank. This is beside the water flow rate in both collectors and load cycle. The
main parameters of the system are obtained.
In this paper, A.C conductivity of micro and nano grain size- TiO2 filled epoxy composites is measured. The dielectric material used is epoxy resin, while micro and nano-sized titanium dioxide (TiO2) of grain size (1.5μm, and 50nm) was used as filler at low filler concentrations by weight (3%, and 5%). Additionally the effect of annealing temperature range (293-373)º K and at a frequency range of 102-106 Hz on the A.C conductivity of the various specimens was studied.
The result of real permittivity for micro and nanocomposite show that the real permittivity increases with decreasing frequency at range of 102-106Hz. The micron-filled material has a higher real relative permittivity than the nano-filled this is true at all the temper
The Dielectric properties of EP/TiO2 and MgO nanocomposite at
a frequency range of (102-106 Hz) were studied. The composite were
prepared with the state volume ratio (0, 0.05, 0.1) for EP/TiO2 and
MgO respectively. The impedance, dielectric constant and dielectric
loss were found decrease with frequency increase.
Thermal conductivity measurement was done for specimens of Polystyrene/ titanium dioxide, Polycarbonate/ titanium dioxide and Polymethylmetha acrylate/ titanium dioxide composites for weight ratio of 1.9/ 0.1 and 1.8/ 0.2 wt% for different thickness of the samples. The experimental results show that the thermal conductivity is increased with the increasing of thickness of layers and with the weight ratio of TiO2
Abstract
This paper deals with the concept of electronic reference services in academic
libraries , showing forms of communications , training needs for reference librarians
and the role of the librarian in the new technological environment.
The electronic press is one of the distinctive media due to its unique features such as instant publishing and interactivity, uses multimedia, the use of hypertext, the personalization of media content, getting echo of the media messages provision of electronic archive of previous numbers of the newspaper.
The richness theory means that media are different depending on its wealth aspects which distinguish it from other media. The aspects of wealth here represent the features that characterize online press and constitute factors of media richness.
The researcher studies the properties of Iraqi media richness of their users. The researcher uses a field study to get the goals of the research and tests the hypotheses of media ric
... Show MoreStress with all its kinds are the results of a nick development Leading to delinquency burdening the ability of people.. development gas its effect on self and body reflecting on health ( physically, Psychological. And mentally) and finally leading to death (Al emara,2001,2).
Stress refers to he degree of response of the individual to events and environmental changes in his daily life with their physiological effects such as headaches , backaches, and gastric ulcer that have different effect depending on the personality of the person and his psychological characteristics differences airing individuals ( Al emirs, zool,2 )
The aims:
- knowi