In this work, the performance of single-mode optical fibers (SMFs) for ultraviolet (UV) radiation monitoring and dosimetry applications is presented. In particular, this work will focus on the Radiation-Induced Absorption (RIA) phenomena in the Near-Infrared domain (NIR). Such phenomena play a very important role in the sensing mechanism for SMF. Single mode fibers with a diameter of 50 µm were used for this purpose. These fibers were dipped into germanium (Ge) solution with different concentrations (1, 3, and 5 wt%) to produce the sensing part of the sensor. For all optical fiber sensors under investigation, the results indicated the dependence of the RIA on the applied UV radiation energy. Also, a redshift in peak wavelength was obtained. The influence of Ge concentration on sensing efficiency was studied and the best results were obtained with 3 wt% concentration as compared to 1 wt % and 5 wt % concentrations. The presented sensor shows good sensitivity to UV radiation which makes it possible to be applied in medical applications.
In this study a composite materials were prepared containing matrix of polymer blend (Epoxy (EP) 90% + unsaturated polyester (UPS) 10%), (Epoxy (EP) 80% + unsaturated polyester (UPS) 20%), reinforced with Kevlar (K) or, and iron woven (Fe) with one value of volume fraction (30) %. This composite are from: (EP 90%, UPE 10% +K), (EP 90%, UPE 10% +K+Fe), (EP 80%, UPE 20% +K), (EP 80%, UPE 20% +K+Fe). All samples were prepared using hand layup method and then impact test was done in both normal condition and after immersion in tap water for the same period time (eight weeks) also diffusion test was done for period's time (three months). The results showed that had been effected differently after immersion, but specimen (EP80%+UPS20%+K+Fe) ha
... Show MoreGlobal warming and environmental damage have become major problems. The production of Portland cement releases large quantities of gas, which cause pollution to the atmosphere. This problem can be solved via the use of sustainable materials, such as glass powder. This study investigates the effect of partial replacement of cement with sustainable glass powder at various percentages (0, 15, 20, and 25%) by weight of cement on some mechanical properties (compressive strength, flexural strength, absorption, and dry density) of Reactive Powder Concrete (RPC) containing a percentage of Polypropylene fibers (PRPC) of 1% by weight. Furthermore, steam curing was performed for 5 hours at 90oC after hardening the sample directly. The RPC was
... Show MoreCarbonized nonwoven nanofibers composite were fabricated using the electrospinning method of a polymeric solution composite followed by heat treatment including stabilization and calcination steps. The spun polymeric solution was a binary polymer mixture/organic solvent. In this study, two types of polymers (Polymethylmethacrylate (PMMA) and Polyethylene glycol (PEG)) were used separately as a copolymer with the base polymer (Polyacrylonitrile (PAN)) to prepare a binary polymer mixture in a mixing ratio of 50:50. The prepared precursor solutions were used to prepare the precursor nanofibers composite (PAN: PMMA) and (PAN: PEG). The fabricated precursors nonwoven fibers composite were stabilized and carbonized to produce carbon nonw
... Show MoreIn this work, the effect of atomic ratio on structural and optical properties of SnO2/In2O3 thin films prepared by pulsed laser deposition technique under vacuum and annealed at 573K in air has been studied. Atomic ratios from 0 to 100% have been used. X-ray diffraction analysis has been utilized to study the effect of atomic ratios on the phase change using XRD analyzer and the crystalline size and the lattice strain using Williamson-Hall relationship. It has been found that the ratio of 50% has the lowest crystallite size, which corresponds to the highest strain in the lattice. The energy gap has increased as the atomic ratio of indium oxide increased.
Tin Oxide (SnO2) films have been deposited by spray pyrolysis technique at different substrate temperatures. The effects of substrate temperature on the structural, optical and electrical properties of SnO2 films have been investigated. The XRD result shows a polycrystalline structure for SnO2 films at substrate temperature of 673K. The thickness of the deposited film was of the order of 200 nm measured by Toulansky method. The energy gap increases from 2.58eV to 3.59 eV when substrate temperature increases from 473K to 673K .Electrical conductivity is 4.8*10-7(.cm)-1 for sample deposited at 473K while it increases to 8.7*10-3 when the film is deposited at 673K
ZnS thin films were grown onto glass substrates by flash evaporation technique, the effects of ? – rays on the optical constants of ZnS these films were studied. It was found that ? – rays affected all the parameters under investigation.
The use of bio-fruit waste has more attention in recent years because of the low cost of bio-fibers and the protection of the environment. In this study, the epoxy was reinforced with fruit residues (cantaloupe peel powder) in proportions (1%, 2%, 3%, 4%, 5%, 7.5%, and 10% by weight) as results of mechanical tests such as impact, hardness, flexural and compression.
Adding sub microns particle size cantaloupe peels particles with a weight ratio of 7.5% improves the epoxy mechanical properties, like impact strength, hardness, flexural strength, and compression strength by 59.43%, 5.8%, 45.7%, and 118.2%, respectively.
Using X-ray diffraction, the crystallite size ( D) of cantaloupe peel the powder was about (3 nm).
In
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That the reduction of costs for products and services provided by economic units is one of the main concerns at the present time to keep pace with competition in the markets, economic units are always striving to stay competitive in a modern business environment and achieve a competitive advantage, (TDABC) in the General Company for Electrical and Electronic Industries / Air cooler engine plant to reduce the costs facing the economic units under the circumstances of the Iraqi environment, especially the industrial, and the need for development events in traditional methods (TDABC) as a technology for reducing costs by relying on time guidelines. The research also concluded that the financial and non-financ
... Show MoreIn this work, MWCNT in the epoxy can be prepared at room temperature and thickness (1mm) at different concentration of CNTs powder. Optical properties of multi-walled carbon nanotubes (CNTs) reinforced epoxy have been measured in the range of (300-800)nm. The electronic transition in pure epoxy and CNT/epoxy indicated direct allowed transition. Also, it is found that the energy gap of epoxy is 4.1eV and this value decreased within range of (4.1-3.5)eV when the concentration of CNT powder increased from (0.001-0.1)% respectively.
The optical constants which include (the refractive index (n), the extinction coefficient (k), real (ε1) and imaginarily (ε2) part of dielectric constant calculated in the of (300-800)nm at different concent
The importance of the study stems from the fact that Iraq’s economy is facing a housing crisis, especially in the Iraqi capital, Baghdad, great demographic pressure due to pronounced population growth over the past two decades. The Central Bank of Iraq undertakes several initiatives represented in granting real estate loans, mainly through the Real Estate Bank at very low interest, and in the last two years, the interest has become zero. The purpose of the study is to analyze the fiscal implications of the Iraqi central bank’s real estate initiatives, as well as its real impact on the spatial dimension of the Iraqi governorates through new housing in those governorates. Using data mainly from the Central Bank of Iraq’s bulleti
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