Hydrophobic silica aerogels were successfully preparation by an ambient pressure drying method from sodium silicate (Na2SiO3) with different pH values (5, 6, 7, 8, 9 and 10). In this study, acidic HCl (1M), a basic NH4OH (1M) were selected as a catalyst to perform the surface modification in a TMCS (trimethylchlorosilane) solution. The surface chemical modification of the aerogels was assured by the Fourier transform infrared (FTIR) spectroscopic studies. Other physical properties, such as pore volume and pore size and specific surface area were determined by Brunauer-Emmett- Teller (BET) method. The effect of pH values on the bulk density of aerogel. The sol–gel parameter pH value in the sol, have marked effects on the physical properties of the silica aerogels produced by this technique. The density and the hydrophobic tendency of the aerogels were significantly influenced.
The present study aimed to investigate the effects of level pH and the growth phases of Coelastrella saipanensis on Chlorophyll a,b, total, and Carotene. The algae were cultured in BG11 media and grown at different pH levels. We measured chlorophyll a, b, total chlorophyll, growth phases, and carotene concentrations. The results showed that at pH 8.5, the measurements of photosynthetic pigments-chlorophyll a, Chlorophyll b, and the total chlorophyll (0.183, 0.268, and 0.433 mg L-1, respectively). The highest values of chlorophyll a (0.185 mg L-1), and b (0.339 mg L-1), and the total chlorophyll (0.492 mg L-1) were recorded in the stationary phase. In addition, the study found that at pH 8.5 and the beginning of the stationary phase,
... Show MoreThe artistic concepts differ in their expressive and semantic relations, among these concepts are the artistic values, as there are points of view, social concepts and historical values interacted from one generation to another over the time. These values represent symbols and indications reflect reality, which has passed through the time to reach us with environmental forms saved by the history at the Natural History Museum, has an impact on the receives mind with its formal and sensory dimensions and connecting with that history as an environment that lacks to the current reality which has immortal means particularly in the cognitive thinking , and the reflection of that in the Iraqi culture and with the associated concepts of interior
... Show MoreSulphated zirconia (SZ) is one of the most important solid acid catalysts was synthesize at different operating conditions, different calcination temperature and sulfonating time has been used. The prepared catalyst was distinguished by X-ray Diffraction (XRD), particle size and morphology of catalyst were checked by atomic force microscopy (AFM) and scanning electron microscopy (SEM) respectively, in addition to analysis by (DTA) Differential thermally and Energy Dispersive X-Ray (EDX). Finally, the N2 adsorption-desorption was used to measure the surface area (BET) and pore volume. High degree of tetragonal crystallinity was obtained 90 %, and surface area of 169 m2/g and pore volume of 0.39 cm3g-1 at 600°C calcination temperature for 3
... Show MoreThe current study deals with one of the ancient and modern techniques of ceramic art, which has evolved dramatically. This technique is interested in the muddy Body and its coloring, rather than interesting in the coloring of the layer on the surface of the glass port on the ceramic object. It is classified as ceramic techniques of the single heartburn, where use many coloring oxides. As well as, the use of (Pigment), which is often made of metal compounds, or metal oxides such as iron and manganese, copper and cobalt and more others.
The first chapter includes the problem, the importance, the goal, and the boundaries of the study. In addition, focuses on determining the terms such as (Sgrafitto). The second chapter consists of two to
For the most reliable and reproducible results for calibration or general testing purposes of two immiscible liquids, such as water in engine oil, good emulsification is vital. This study explores the impact of emulsion quality on the Fourier transform infrared (FT-IR) spectroscopy calibration standards for measuring water contamination in used or in-service engine oil, in an attempt to strengthen the specific guidelines of ASTM International standards for sample preparation. By using different emulsification techniques and readily available laboratory equipment, this work is an attempt to establish the ideal sample preparation technique for reliability, repeatability, and reproducibility for FT-IR analysis while still considering t
... Show MoreThe result revealed that the peak of population density of cabbage aphid Brevicoryne brassicae was 523.20 individuals/plant on 21 March in edges of rapeseed field and was 1141.67 individuals/plant in center of the field. Results revealed that population density of cabbage aphid in rapeseed fields surrounded by cover crops significantly were low compared with that of monoculture rapeseed. The location of rapeseed plants (in edges or in center) significantly affected (p<0.05) the tested pest density, e.g. optimum density was 146.69 individuals/plant in the center of the field. Whereas was 93.32 in the edges. Effect of the interaction between location and surrounding vegetation was significant on aphid density, which their population densit
... Show MoreTo test the effect of 4 levels of nitrogen (i.e. 0, 45, 90 and 135 Kg N ha-1) as urea (46% N) and 3 levels of phosphorus (i.e. 0, 17.5 and 35 Kg P ha-1) as triple superphosphate (21.8% P) on yield and concentration of dill (Anethum graveolens L. local cultivar) seed oil this experiment was carried out during winter season of 1999 - 2000 at the experimental field of Agriculture College, Abu-Ghraib.
Both fertilizers were applied in two equal splits, first at seeds sowing and the second was added one month after emergence. Dried and ground seed samples were subjected to water distillation for extraction of volatile oils
Result indicated that fertilization of dill plants with 90 Kg N
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