Fire is the most sever environmental condition affecting on concrete structures, thus investigating for fire safety in structural concrete is important for building construction. The slow heat transfer and strength loss enables concrete to be effective for fire resistance. Concrete structures withstand when exposed to fire according to: their thermal properties, rate of heating, characteristic properties of concrete mixes and their composition and on the duration of fire, and concerned as thermal property with other factors such as loss of mass which affected by aggregate type, moisture content, and composition of concrete mix. The present research goal is to study the effect of rising temperature on the compressive strength of the reactive powder concrete samples. Then investigate the behavior of reactive powder concrete when using poly vinyl chloride PVC and exposed to elevated temperature from zero to 600Co .
The current research included obtaining the best performance specifications for a silicon device with a mono-crystalline type pn junction (pn–Si). A simulation of the device was performed by the use of a computer program in one dimension SCAPS-1D in order to reach the optimum thickness for both p and n layers and to obtain the best efficiency in performance of the pn-Si junction. The optimum device efficiency was eta (η) = 12.4236 % when the ideal thickness for the p and n layers was 5µm and 1.175µm, respectively (p=5 µm and n=1.75µm).
The research included studying the effects of different spectra of solar illumination using simulation of the device; the usual solar spectrum AM1_5 G1 sun. Spectrum
... Show MoreThe characterization and design of this study of new liquid crystals with a V shape compounds containing thiazolidine-2,4-dione and 1,3-phenylene as a core unite with mesophase properties were reported. Preparation and characterization of chloroacetic acid, water, and thiourea to produce thiazolidine-2,4-dione [I] in the presence of strong hydrochloric acid. The 4-hydreoxybenzaldehyde and n-alkyl bromide were reacted with potassium hydroxide to create the n-alkoxy benzaldehyde., then the compound [I] reacted with [II]n in presence of piperidine to produce compounds [III]n. Also, converted resorcinol to a corresponding compound [IV] by refluxing pyridine and DMF with two moles of chlora
... Show MoreFour new phenol-formaldehyde resins containing tetrachlorophthalimides in their repeating units were synthesized via condensation of formaldehyde with N-(hydroxy phenyl)tetrachlorophthalimides under conditions similar to those used in novolac preparation. In this work structural modifications were performed first via design and synthesis of new phenolic component represented by phenolic ring linked to thermally stable tetrachlorophthalimide moiety which condense with formaldehyde and second via introducing of phenolic hydroxyl groups present in the new synthesized resins by esterification reaction with acetyl chloride producing the corresponding acetoxy substituted resins. Both the prepared and the cured resins have new properties which
... Show MoreThis study was aimed to assess the efficiency of N.oleander to remove heavy metals such as Copper (Cu) from wastewater. A toxicity test was conducted outdoor for 65-day to estimate the ability of N.oleander to tolerate Cu in synthetic wastewater. Based on a previous range-finding test, five concentrations were used in this test (0, 50, 100, 300, 510 mg/l). The results showed that maximum values of removal efficiency was found 99.9% on day-49 for the treatment 50 mg/l. Minimum removal efficiency was 94% day-65 for the treatment of 510 mg/l. Water concentration was within the permissible limits of river conservation and were 0.164 at day-35 for the 50 mg/l treatment, decreased thereafter until the end of the observation, and 0.12 at d
... Show MoreSome new 2,5-disubsituted-1,3,4-oxadiazole derivatives with azo group were synthesized by known reactions sequence . The structure of the synthesized compounds were confirmed by physical and spectral means .
The characterization and design of this study of new liquid crystals with a V shape compounds containing thiazolidine-2,4-dione and 1,3-phenylene as a core unite with mesophase properties were reported. Preparation and characterization of chloroacetic acid, water, and thiourea to produce thiazolidine-2,4-dione [I] in the presence of strong hydrochloric acid. The 4-hydreoxybenzaldehyde and n-alkyl bromide were reacted with potassium hydroxide to create the n-alkoxy benzaldehyde., then the compound [I] reacted with [II]n in presence of piperidine to produce compounds [III]n. Also, converted resorcinol to a corresponding compound [IV] by refl
... Show MoreOral jelly is a semisolid preparation that could resolve problem associated withdosage form’s swallowing, especially in pediatric and elderly ones. This work aimedto prepare oral flurbiprofen (FBP) jelly to improve patient compliance. Heating andcongealing method was used to prepare FBP jelly using three different polymers (pectin,sodium carboxymethyl cellulose, and hydroxypropyl methylcellulose). The effect ofdifferent concentrations of pectin and sucrose on jelly properties was studied. Theresults revealed that both pectin and sodium carboxymethyl cellulose polymers gaveacceptable jelly appearance and consistency. It was also observed that the increase ofpectin or sucrose concentration had a significant impact on jelly viscosity. All pe
... Show MoreFour new phenol-formaldehyde resins containing tetrachlorophthalimides in their repeating units were synthesized via condensation of formaldehyde with N-(hydroxy phenyl)tetrachlorophthalimides under conditions similar to those used in novolac preparation. In this work structural modifications were performed first via design and synthesis of new phenolic component represented by phenolic ring linked to thermally stable tetrachlorophthalimide moiety which condense with formaldehyde and second via introducing of phenolic hydroxyl groups present in the new synthesized resins by esterification reaction with acetyl chloride producing the corresponding acetoxy substituted resins. Both the prepared and the cured resins have new properties which
... Show MoreThe work involves synthesis of a new homologous series of hydrogen bonding
liquid crystal dimers containing chalcone moiety. All the prepared compounds were
characterized by spectroscopic techniques such as FT – IR, 1H-NMR, 13C-NMR as
well as elemental analysis. All the synthesized dimers exhibited nematic and smectic
A phase. The mesophases behaviour and transitional temperatures were studied by
polarized microscopy and differential scanning calorimetry, and are discussed the
self- assemble of H-bonding donor and acceptor complexes