Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot ...Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) and Disodium borate (B<sub>4</sub>Na<sub>2</sub>O<sub>7</sub>) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment.展开更多
This study modeled some mechanical properties of clay powder filled recycled low-density polyethylene, rLDPE (rLDPE composite). The rLDPE is commonly referred to as used sachet water bags. The clay powder (filler) was...This study modeled some mechanical properties of clay powder filled recycled low-density polyethylene, rLDPE (rLDPE composite). The rLDPE is commonly referred to as used sachet water bags. The clay powder (filler) was obtained by sun-drying, grinding, and sieving. Two particle sizes of clay powder were used: <span style="white-space:nowrap;">−</span>90 μm and <span style="white-space:nowrap;">−</span>425 μm to represent the passing sizes at different clay powder contents of 5, 10, 15 and 20 wt% which were thoroughly mixed with the recycled low-density polyethylene in an injection molding machine at 173<span style="white-space:nowrap;">°</span>C. The results showed that the tensile strength, tensile modulus, hardness, flexural strength, fatigue strength and hardness increased with increase in clay powder contents. However, there were decreases in strain-at-breakage and shear strength as clay powder content increased. Model equations showed that smaller particle size enhanced the mechanical properties and equations generated can be used to predict the properties of composites at predetermined clay contents. Standard deviations obtained for the various mechanical properties show that the model, in most cases had the lowest degree of scatter (dispersion) than those of <span style="white-space:nowrap;">−</span>90 μm and <span style="white-space:nowrap;">−</span>425 μm. Hence, these models are suitable to predict outcomes of the properties of the clay filled recycled low-density polyethylene composites.展开更多
Extraction of dye from dry fruit of Rothmannia whitfieldii was carried out using four different extraction methods. Solvent and acid extraction methods gave a colourless supernatant solution after extraction time of 4...Extraction of dye from dry fruit of Rothmannia whitfieldii was carried out using four different extraction methods. Solvent and acid extraction methods gave a colourless supernatant solution after extraction time of 45 minutes at 60°C. The alkali method gave a deep brown coloured supernatant solution while the aqueous method gave a dark coloured supernatant solution after extraction under the same conditions. From the result of the FTIR spectroscopy characterization of the coloured solutions and the dry powder of Rothmannia whitfieldii fruit, it was observed that only the alkali method extracted what can be called a dye with likely presence of tannins. The result also showed that the possible functional groups present in the supernatant solution after aqueous extraction are same with the functional groups present in the dry pulverized Rothmannia whitfieldii fruit. Hence, aqueous method did not extract any dye. Similarly, a mixture of the solution after aqueous extraction with drops of alkali solution produced a deep brown coloured solution indicating solubility of the dye component in alkali media.展开更多
文摘Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) and Disodium borate (B<sub>4</sub>Na<sub>2</sub>O<sub>7</sub>) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment.
文摘This study modeled some mechanical properties of clay powder filled recycled low-density polyethylene, rLDPE (rLDPE composite). The rLDPE is commonly referred to as used sachet water bags. The clay powder (filler) was obtained by sun-drying, grinding, and sieving. Two particle sizes of clay powder were used: <span style="white-space:nowrap;">−</span>90 μm and <span style="white-space:nowrap;">−</span>425 μm to represent the passing sizes at different clay powder contents of 5, 10, 15 and 20 wt% which were thoroughly mixed with the recycled low-density polyethylene in an injection molding machine at 173<span style="white-space:nowrap;">°</span>C. The results showed that the tensile strength, tensile modulus, hardness, flexural strength, fatigue strength and hardness increased with increase in clay powder contents. However, there were decreases in strain-at-breakage and shear strength as clay powder content increased. Model equations showed that smaller particle size enhanced the mechanical properties and equations generated can be used to predict the properties of composites at predetermined clay contents. Standard deviations obtained for the various mechanical properties show that the model, in most cases had the lowest degree of scatter (dispersion) than those of <span style="white-space:nowrap;">−</span>90 μm and <span style="white-space:nowrap;">−</span>425 μm. Hence, these models are suitable to predict outcomes of the properties of the clay filled recycled low-density polyethylene composites.
文摘Extraction of dye from dry fruit of Rothmannia whitfieldii was carried out using four different extraction methods. Solvent and acid extraction methods gave a colourless supernatant solution after extraction time of 45 minutes at 60°C. The alkali method gave a deep brown coloured supernatant solution while the aqueous method gave a dark coloured supernatant solution after extraction under the same conditions. From the result of the FTIR spectroscopy characterization of the coloured solutions and the dry powder of Rothmannia whitfieldii fruit, it was observed that only the alkali method extracted what can be called a dye with likely presence of tannins. The result also showed that the possible functional groups present in the supernatant solution after aqueous extraction are same with the functional groups present in the dry pulverized Rothmannia whitfieldii fruit. Hence, aqueous method did not extract any dye. Similarly, a mixture of the solution after aqueous extraction with drops of alkali solution produced a deep brown coloured solution indicating solubility of the dye component in alkali media.
