The present study evaluated the stabilizing effect of starch produced from corns and cassava on the stability of cow milk yogurt. A sample of both corn and cassava starch was selected and used in the yogurt making as ...The present study evaluated the stabilizing effect of starch produced from corns and cassava on the stability of cow milk yogurt. A sample of both corn and cassava starch was selected and used in the yogurt making as stabilizers. The yogurt samples have been analyzed for their WHC, syneresis and protein content. The yogurt with no added starch has found to have very low WHC and high syneresis compared to other samples. The yogurt made with the addition of corn starch as a stabilizer was highly accepted than the yogurt with cassava starch and the yogurt without starch. The findings from this study provide an alternative to add the value of local corns and cassava.展开更多
The current study deals Swith thermo-mechanical properties of stabilized soil small bricks with the help of organic binders of sugar cane molasses and cassava starch. Different formulations of soil concrete have been ...The current study deals Swith thermo-mechanical properties of stabilized soil small bricks with the help of organic binders of sugar cane molasses and cassava starch. Different formulations of soil concrete have been suggested after the geotechnical characterization of samples of soil was taken. From these, it arises that the studied soil is the most plastically clay (of type A<sub>3</sub>) according to GTR classification. Samples made of small bricks and measured out at 4%, 6% and 8% of binders (molasses, starch or molasses + starch) have been warmed up to different temperatures (100°C, 150°C, 200°C and 250°C) for the rising of the thermic behavior under different conditions and submitted to crushing testings for the estimation of characteristic resistances to the compression. According to the mechanical behavior, we note an improvement of resistances for small bricks measured 4%, 6% and 8%, of molasses respectively of 32.44%, 32.06% and 23.43% against the value of reference for small bricks without molasses. In the same way, the binder (molasses + starch) also reveals an improvement of resistance to the compression of 13.27%, 26.17% and 26.17%. On the contrary, the stabilization with the starch binder did not bring a significative improvement. According to the thermic influence, the heating at 100°C of stabilized small bricks at 4%, 6% and 8% of molasses, reveals a significative improvement of resistances. Moreover, the stabilization with the starch reveals on the contrary a good behavior for heatings at 150°C and 250°C. In short, for the binder (molasses + starch), it is the heating at 200°C that shows some improvements of remarkable resistances. Different analyses of realized statistics also show the effectivity of obtained results. For all realized formulations, the measuring out at 6% of binders (molasses, or molasses + starch) seems as optimal in front of the best thermo-mechanical revealed properties.展开更多
In order to find out a new way for environment-friendly and resourcelized utilization of cassava starch processing wastewater, the cassava starch anaerobic fermentation liquid was applied in watermelon production, and...In order to find out a new way for environment-friendly and resourcelized utilization of cassava starch processing wastewater, the cassava starch anaerobic fermentation liquid was applied in watermelon production, and its effects on the growth and development, yield and fruit quality of watermelon were investigated. The results showed that the cassava starch anaerobic fermentation liquid significant- ly promoted the vegetative and reproductive growth and improved the yield and fruit quality of watermelon. Compared with conventional fertilization, the application of cassava starch anaerobic fermentation both with COD concentration of 1 200 mg/L according to the amount of 150 t/hm2 promoted the growth of vines and leaves of watermelon plants, brought forward the flowering, fruiting and harvest of watermelon and significantly increased the fruit number, fruit weight, yield, fruit size, fruit shape index, soluble solid content, soluble sugar content, soluble protein content and Vita- min C content of watermelon. At the same time of improving the yield and quality of watermelon, cassava starch anaerobic fermentation liquid was turned into treasure as a liquid fertilizer. This study provides a new ideal for the yield and quality im- provement of watermelon and the wastewater treating of starch factories.展开更多
In order to provide a scientific basis for the utilization of cassava alcohol fermentation mash and the high-yield and high-efficiency cultivation of cassava,compound microbial inoculum was inoculated into the cassava...In order to provide a scientific basis for the utilization of cassava alcohol fermentation mash and the high-yield and high-efficiency cultivation of cassava,compound microbial inoculum was inoculated into the cassava alcohol fermentation mash to prepare bacterial manure,which was then applied to two cassava varieties,Nanzhi 199 and SC 205 to explore the optimum application amount,application method and application concentration. The results showed that when the inoculation amount of the compound microbial inoculum was 2‰ of the mass of the mash,the requirements of industrial production of liquid bacterial manure and agricultural application can be met,saving costs. After the emergence of cassava seedlings,if they were drenched with the bacterial manure of cassava alcohol fermentation mash through roots once according to the amount of 67. 5 t/ha and irrigated with the bacterial manure once every 15 d under drought conditions,both the yield and quality of cassava can be improved significantly. The yield and starch content of Nanzhi 199 reached 26 196. 23 kg/ha and 30. 32%,36. 57% and4. 75 percentage points higher than those of CK. The yield and starch content of SC 205 reached 41 126. 06 kg/ha and 23. 74%,99. 25% and3. 19 percentage points higher than those of CK. Under the application modes of foliar spray,root irrigation and foliar spray + root irrigation,the fertilization effect was more obvious. When undiluted bacterial manure of cassava alcohol fermentation mash was applied according to the amount of 52. 5 t/( ha·time),the fertilization effect of the application mode of foliar spray + root irrigation was the best. The bacterial manure from cassava alcohol fermentation mash can be directly applied without dilution,and the fertilizer efficiency will be reduced significantly after dilution.展开更多
The morphology and properties of corn starch and cassava starch were compared by SEM, DSC and TGA. Theeffects of amylose and amylopectin content on starch properties were studied by FT-IR, XRD and XPS. The plywood wa...The morphology and properties of corn starch and cassava starch were compared by SEM, DSC and TGA. Theeffects of amylose and amylopectin content on starch properties were studied by FT-IR, XRD and XPS. The plywood was pressed with the prepared adhesive and the bonding strength of the plywood was tested to analyze thedifference among the adhesives from different plant sources and the difference after blending PAPI prepolymer.FT-IR results showed that the hydroxyl peak of cassava starch was stronger and wider. TGA showed that the residue of cassava starch was lower, but the thermal stability of cassava starch was almost the same. XPS data showedthat the oxygen content of cassava starch was slightly higher, but the carbon content was slightly lower. SEM analysis showed that corn starch granules were more irregular and sharper than cassava starch, and cassava starchgranules were more uniform, regular and round.展开更多
In this study, the mechanical properties (tensile strength, elongation at break and folding resistance) of edible biopolymer film blends formed from blended cassava starch and rice flour at different compositions wi...In this study, the mechanical properties (tensile strength, elongation at break and folding resistance) of edible biopolymer film blends formed from blended cassava starch and rice flour at different compositions with sorbital used as a plasticizer. A suitable ratio of cassava starch and rice flour to water at 10% w/v was used to form a film solution. The addition of a plasticizer agent up to 30% w/w of blending compositions improved the mechanical properties of the generated films. The mechanical properties of the edible blended films with 30% plasticizer were strongly dependent on the blending compositions. Our results pointed out that the cassava starch and rice flour films at a ratio of 70:30 with sorbitol 30% (w/w) had the highest tensile strength which related to folding endurance of the films.展开更多
The difference of soluble sugar contents and starch synthetic key enzyme activities between high starch cultivar and low starch cultivar were studied in this experiment, of which FuXuan01, GR891, SC124, and SC201 were...The difference of soluble sugar contents and starch synthetic key enzyme activities between high starch cultivar and low starch cultivar were studied in this experiment, of which FuXuan01, GR891, SC124, and SC201 were used as materials. The results showed that the contents of reducing sugar in root tube of low starch cultivars were higher than those of high starch cultivars in all growth periods, the contents of sucrose in root tube of high starch cultivar were higher than those of low starch cultivars in the early growth period, but, lower in the late growth period, and there were almost no difference in the contents of soluble sugar in root tube between high starch cultivar and low starch cultivar in the early growth period, but notable difference in the late growth period and the soluble sugar contents of low starch cultivars were higher than those of high starch cultivars. It also-showed that the activities of ADPGPpase, SSS, and SBE (starch branching enzyme) of high starch cultivars were higher than those of low starch cultivars. It was evident that there were close correlations between the content of sucrose, reducing sugar and soluble sugar in root tube, and the activities of ADPGPpase, SSS, SBE, and the starch accumulation in the root tubers of cassava. It was quite evident in this experiment that the soluble sugar and starch synthetic key enzyme were main factors controlling starch accumulation in root tubers. These results provided important indication for physiological controlling in high starch cultivation and gene engineering breeding of high starch cultivar of cassava.展开更多
With the exponential growth of the computing power,machine learning techniques have been successully used in various applications.This paper intended to predict and optimize the shear strength of single lap cassava st...With the exponential growth of the computing power,machine learning techniques have been successully used in various applications.This paper intended to predict and optimize the shear strength of single lap cassava starch-based adhesive joints for comparison with the application of artificial intelligence(AI)methods.The shear strength was firstly determined by the experiment with three independent experimental variables(starch content,NaOH concentration and reaction temperature).The analysis of range(ANORA)and analysis of variance(ANOVA)were applied to investigate the optimal combination and the significance of each factor for the shear strength based on the orthogonal experiment.The performance of all AI models was char acterized by mean absolute error(MAE),root mean square error(RMSE)and regression coefficient(R^(2))compared with the experi-mental ones.The GA optimized ANN model was combined with the genetic algorithm(GA)to find the optimal combination of factors for the finalized optimized cassava starch adhesives(CSA-OP).The physicochemical prop-erties of the cassava starch and CSA-OP were determined by the FTIR,TGA and SEM EDS,respectively.The results showed that the numerical optimized condition of the GA optimized ANN model was superior to the orthogonal experimental optimized condition.The sensitivity analysis revealed that the relative importance of variables was consistent with the results from ANOVA.FTIR results showed that there were high hydroxyl groups in cassava starch.TGA results showed that the residue of CSA OP was higher than the assava starch.SEM EDS results showed that both the cassava starch and CSA OP had abundant carbon and oxygen functional groups.Consequently,the obtained results revealed that the use of AI methods was an adequate approach to model and optimize the experimental variables of the shear strength of single lap cassava starch-based adhesive joints.展开更多
Many factors including depletion of the forest, environmental awareness, and generation of large quantities of agro-forest residues have increased the need to partially or wholly replace wood with agro-forest residue ...Many factors including depletion of the forest, environmental awareness, and generation of large quantities of agro-forest residues have increased the need to partially or wholly replace wood with agro-forest residue for particleboard production. This study assessed the decay resistance of particleboards produced from four agro-forest residues using cassava starch and urea formaldehyde as adhesives. <i><span>Musa paradisiaca pseudostem</span></i><span>, </span><i><span>Theobroma cacao </span></i><span>stem and pod, and sawdust of </span><i><span>Ceiba pentandra</span></i><span> were used for the study. Properties determined were: Weight loss, decay resistance rating and decay susceptibility index. These properties were evaluated after 12 weeks of exposure to </span><i><span>Coriolopsis polyzona</span></i><span> in accordance with ASTM D 2017</span><span>-</span><span>05. The results indicate that the weight loss for </span><i><span>Musa paradisiaca pseudostem</span></i><span> particleboard was least for both urea formaldehyde and cassava starch adhesives. Even though almost all the particleboards produced were classified as resistant or highly resistant to fungi attack, those produced with urea formaldehyde had better decay resistance properties than that of cassava starch. Furthermore, particleboards coated with synthetic polyvinyl lacquer had better resistance to fungi attack than the uncoated ones. At 5% level of significance, the agro-forest residue, adhesive and surface finish as well as their interactions had significant effects on decay resistance of the particleboards produced. It is recommended that further studies which aim at determining the effect of combination of the agro-forest residues and that of urea formaldehyde and cassava starch be conducted to determine their effects on decay properties of particleboards.</span>展开更多
The structural and thermomechanical properties of starch-based plastic films reinforced with kaolin and metakaolin have been studied by various techniques (X-ray diffraction, IR-TF spectroscopy, scanning electron micr...The structural and thermomechanical properties of starch-based plastic films reinforced with kaolin and metakaolin have been studied by various techniques (X-ray diffraction, IR-TF spectroscopy, scanning electron microscopy, tensile tests, and thermal resistance). The results obtained showed that kaolin, an inert material, prevents the starch from losing its granular structure and to solubilize during the heating, generating plastic films of low Young’s modulus (7 MPa). On the other hand, metakaolin, an amorphous and dehydroxylated material obtained after heating of kaolin at 700°C for 1 hour, substantially improves the thermomechanical properties of the plastic films. The Young’s modulus increases from 19 MPa to 25 MPa while the thermal resistance increases from 90°C to 120°C. This was attributed to good dispersion of the metakaolin in the polymer matrix after the loss of the granular structure of the starch during heating.展开更多
Drilling mud is a key component in drilling operations and in accessing oil and gas reservoirs. Bentonite is applied as a viscosifier, fluid loss control agent, and as a weighting material in water-based drilling mud....Drilling mud is a key component in drilling operations and in accessing oil and gas reservoirs. Bentonite is applied as a viscosifier, fluid loss control agent, and as a weighting material in water-based drilling mud. The type of bentonite used in drilling mud formulation is sodium bentonite due to its high dispersion properties and high swelling capacity. Nigeria has a huge bentonite clay deposit resources which can be evaluated and enhanced in order to be utilized as drilling mud. However, bentonite clay from different parts of Nigeria was investigated and found to be calcium bentonite which is not suitable for drilling mud, because it has low swelling capacity and poor rheological properties. In this study, local bentonite obtained from Afuze, Edo state was used to formulate different samples of drilling mud with each treated using thermo-chemical beneficiation process with sodium carbonate and cassava starch, and then undergo characterization to identify the changes in physical properties and finally, draw comparison with API values for standard drilling mud. The results obtained from this study indicates that, the flow and rheological properties of the beneficiated drilling mud developed through thermo-chemical treatment, showed significant improvement compared to the untreated mud. Therefore, pure calcium bentonite from natural deposits in Nigeria can be modified to sodium bentonite and sufficiently used in drilling mud formulation.展开更多
文摘The present study evaluated the stabilizing effect of starch produced from corns and cassava on the stability of cow milk yogurt. A sample of both corn and cassava starch was selected and used in the yogurt making as stabilizers. The yogurt samples have been analyzed for their WHC, syneresis and protein content. The yogurt with no added starch has found to have very low WHC and high syneresis compared to other samples. The yogurt made with the addition of corn starch as a stabilizer was highly accepted than the yogurt with cassava starch and the yogurt without starch. The findings from this study provide an alternative to add the value of local corns and cassava.
文摘The current study deals Swith thermo-mechanical properties of stabilized soil small bricks with the help of organic binders of sugar cane molasses and cassava starch. Different formulations of soil concrete have been suggested after the geotechnical characterization of samples of soil was taken. From these, it arises that the studied soil is the most plastically clay (of type A<sub>3</sub>) according to GTR classification. Samples made of small bricks and measured out at 4%, 6% and 8% of binders (molasses, starch or molasses + starch) have been warmed up to different temperatures (100°C, 150°C, 200°C and 250°C) for the rising of the thermic behavior under different conditions and submitted to crushing testings for the estimation of characteristic resistances to the compression. According to the mechanical behavior, we note an improvement of resistances for small bricks measured 4%, 6% and 8%, of molasses respectively of 32.44%, 32.06% and 23.43% against the value of reference for small bricks without molasses. In the same way, the binder (molasses + starch) also reveals an improvement of resistance to the compression of 13.27%, 26.17% and 26.17%. On the contrary, the stabilization with the starch binder did not bring a significative improvement. According to the thermic influence, the heating at 100°C of stabilized small bricks at 4%, 6% and 8% of molasses, reveals a significative improvement of resistances. Moreover, the stabilization with the starch reveals on the contrary a good behavior for heatings at 150°C and 250°C. In short, for the binder (molasses + starch), it is the heating at 200°C that shows some improvements of remarkable resistances. Different analyses of realized statistics also show the effectivity of obtained results. For all realized formulations, the measuring out at 6% of binders (molasses, or molasses + starch) seems as optimal in front of the best thermo-mechanical revealed properties.
文摘In order to find out a new way for environment-friendly and resourcelized utilization of cassava starch processing wastewater, the cassava starch anaerobic fermentation liquid was applied in watermelon production, and its effects on the growth and development, yield and fruit quality of watermelon were investigated. The results showed that the cassava starch anaerobic fermentation liquid significant- ly promoted the vegetative and reproductive growth and improved the yield and fruit quality of watermelon. Compared with conventional fertilization, the application of cassava starch anaerobic fermentation both with COD concentration of 1 200 mg/L according to the amount of 150 t/hm2 promoted the growth of vines and leaves of watermelon plants, brought forward the flowering, fruiting and harvest of watermelon and significantly increased the fruit number, fruit weight, yield, fruit size, fruit shape index, soluble solid content, soluble sugar content, soluble protein content and Vita- min C content of watermelon. At the same time of improving the yield and quality of watermelon, cassava starch anaerobic fermentation liquid was turned into treasure as a liquid fertilizer. This study provides a new ideal for the yield and quality im- provement of watermelon and the wastewater treating of starch factories.
基金Supported by Guangxi Science and Technology Plan Project(Gui Ke AA16380013)Scientific Research and Technological Development Program of Guangxi(20162106)
文摘In order to provide a scientific basis for the utilization of cassava alcohol fermentation mash and the high-yield and high-efficiency cultivation of cassava,compound microbial inoculum was inoculated into the cassava alcohol fermentation mash to prepare bacterial manure,which was then applied to two cassava varieties,Nanzhi 199 and SC 205 to explore the optimum application amount,application method and application concentration. The results showed that when the inoculation amount of the compound microbial inoculum was 2‰ of the mass of the mash,the requirements of industrial production of liquid bacterial manure and agricultural application can be met,saving costs. After the emergence of cassava seedlings,if they were drenched with the bacterial manure of cassava alcohol fermentation mash through roots once according to the amount of 67. 5 t/ha and irrigated with the bacterial manure once every 15 d under drought conditions,both the yield and quality of cassava can be improved significantly. The yield and starch content of Nanzhi 199 reached 26 196. 23 kg/ha and 30. 32%,36. 57% and4. 75 percentage points higher than those of CK. The yield and starch content of SC 205 reached 41 126. 06 kg/ha and 23. 74%,99. 25% and3. 19 percentage points higher than those of CK. Under the application modes of foliar spray,root irrigation and foliar spray + root irrigation,the fertilization effect was more obvious. When undiluted bacterial manure of cassava alcohol fermentation mash was applied according to the amount of 52. 5 t/( ha·time),the fertilization effect of the application mode of foliar spray + root irrigation was the best. The bacterial manure from cassava alcohol fermentation mash can be directly applied without dilution,and the fertilizer efficiency will be reduced significantly after dilution.
基金This work was supported by the National Natural Science Foundation of China(No.31670569)the Fundamental Research Funds for the Central Universities(No.2572019CG05)Special thanks to the support of the Chinese University Students,Innovation and Entrepreneurship Project(202010225071).
文摘The morphology and properties of corn starch and cassava starch were compared by SEM, DSC and TGA. Theeffects of amylose and amylopectin content on starch properties were studied by FT-IR, XRD and XPS. The plywood was pressed with the prepared adhesive and the bonding strength of the plywood was tested to analyze thedifference among the adhesives from different plant sources and the difference after blending PAPI prepolymer.FT-IR results showed that the hydroxyl peak of cassava starch was stronger and wider. TGA showed that the residue of cassava starch was lower, but the thermal stability of cassava starch was almost the same. XPS data showedthat the oxygen content of cassava starch was slightly higher, but the carbon content was slightly lower. SEM analysis showed that corn starch granules were more irregular and sharper than cassava starch, and cassava starchgranules were more uniform, regular and round.
文摘In this study, the mechanical properties (tensile strength, elongation at break and folding resistance) of edible biopolymer film blends formed from blended cassava starch and rice flour at different compositions with sorbital used as a plasticizer. A suitable ratio of cassava starch and rice flour to water at 10% w/v was used to form a film solution. The addition of a plasticizer agent up to 30% w/w of blending compositions improved the mechanical properties of the generated films. The mechanical properties of the edible blended films with 30% plasticizer were strongly dependent on the blending compositions. Our results pointed out that the cassava starch and rice flour films at a ratio of 70:30 with sorbitol 30% (w/w) had the highest tensile strength which related to folding endurance of the films.
文摘The difference of soluble sugar contents and starch synthetic key enzyme activities between high starch cultivar and low starch cultivar were studied in this experiment, of which FuXuan01, GR891, SC124, and SC201 were used as materials. The results showed that the contents of reducing sugar in root tube of low starch cultivars were higher than those of high starch cultivars in all growth periods, the contents of sucrose in root tube of high starch cultivar were higher than those of low starch cultivars in the early growth period, but, lower in the late growth period, and there were almost no difference in the contents of soluble sugar in root tube between high starch cultivar and low starch cultivar in the early growth period, but notable difference in the late growth period and the soluble sugar contents of low starch cultivars were higher than those of high starch cultivars. It also-showed that the activities of ADPGPpase, SSS, and SBE (starch branching enzyme) of high starch cultivars were higher than those of low starch cultivars. It was evident that there were close correlations between the content of sucrose, reducing sugar and soluble sugar in root tube, and the activities of ADPGPpase, SSS, SBE, and the starch accumulation in the root tubers of cassava. It was quite evident in this experiment that the soluble sugar and starch synthetic key enzyme were main factors controlling starch accumulation in root tubers. These results provided important indication for physiological controlling in high starch cultivation and gene engineering breeding of high starch cultivar of cassava.
基金This work was supported by the Fundamental Research Funds for the Central Universities(Y0201800586)the Regional Cooperative Innovation in Autonomous Region(2019E0241).
文摘With the exponential growth of the computing power,machine learning techniques have been successully used in various applications.This paper intended to predict and optimize the shear strength of single lap cassava starch-based adhesive joints for comparison with the application of artificial intelligence(AI)methods.The shear strength was firstly determined by the experiment with three independent experimental variables(starch content,NaOH concentration and reaction temperature).The analysis of range(ANORA)and analysis of variance(ANOVA)were applied to investigate the optimal combination and the significance of each factor for the shear strength based on the orthogonal experiment.The performance of all AI models was char acterized by mean absolute error(MAE),root mean square error(RMSE)and regression coefficient(R^(2))compared with the experi-mental ones.The GA optimized ANN model was combined with the genetic algorithm(GA)to find the optimal combination of factors for the finalized optimized cassava starch adhesives(CSA-OP).The physicochemical prop-erties of the cassava starch and CSA-OP were determined by the FTIR,TGA and SEM EDS,respectively.The results showed that the numerical optimized condition of the GA optimized ANN model was superior to the orthogonal experimental optimized condition.The sensitivity analysis revealed that the relative importance of variables was consistent with the results from ANOVA.FTIR results showed that there were high hydroxyl groups in cassava starch.TGA results showed that the residue of CSA OP was higher than the assava starch.SEM EDS results showed that both the cassava starch and CSA OP had abundant carbon and oxygen functional groups.Consequently,the obtained results revealed that the use of AI methods was an adequate approach to model and optimize the experimental variables of the shear strength of single lap cassava starch-based adhesive joints.
文摘Many factors including depletion of the forest, environmental awareness, and generation of large quantities of agro-forest residues have increased the need to partially or wholly replace wood with agro-forest residue for particleboard production. This study assessed the decay resistance of particleboards produced from four agro-forest residues using cassava starch and urea formaldehyde as adhesives. <i><span>Musa paradisiaca pseudostem</span></i><span>, </span><i><span>Theobroma cacao </span></i><span>stem and pod, and sawdust of </span><i><span>Ceiba pentandra</span></i><span> were used for the study. Properties determined were: Weight loss, decay resistance rating and decay susceptibility index. These properties were evaluated after 12 weeks of exposure to </span><i><span>Coriolopsis polyzona</span></i><span> in accordance with ASTM D 2017</span><span>-</span><span>05. The results indicate that the weight loss for </span><i><span>Musa paradisiaca pseudostem</span></i><span> particleboard was least for both urea formaldehyde and cassava starch adhesives. Even though almost all the particleboards produced were classified as resistant or highly resistant to fungi attack, those produced with urea formaldehyde had better decay resistance properties than that of cassava starch. Furthermore, particleboards coated with synthetic polyvinyl lacquer had better resistance to fungi attack than the uncoated ones. At 5% level of significance, the agro-forest residue, adhesive and surface finish as well as their interactions had significant effects on decay resistance of the particleboards produced. It is recommended that further studies which aim at determining the effect of combination of the agro-forest residues and that of urea formaldehyde and cassava starch be conducted to determine their effects on decay properties of particleboards.</span>
文摘The structural and thermomechanical properties of starch-based plastic films reinforced with kaolin and metakaolin have been studied by various techniques (X-ray diffraction, IR-TF spectroscopy, scanning electron microscopy, tensile tests, and thermal resistance). The results obtained showed that kaolin, an inert material, prevents the starch from losing its granular structure and to solubilize during the heating, generating plastic films of low Young’s modulus (7 MPa). On the other hand, metakaolin, an amorphous and dehydroxylated material obtained after heating of kaolin at 700°C for 1 hour, substantially improves the thermomechanical properties of the plastic films. The Young’s modulus increases from 19 MPa to 25 MPa while the thermal resistance increases from 90°C to 120°C. This was attributed to good dispersion of the metakaolin in the polymer matrix after the loss of the granular structure of the starch during heating.
文摘Drilling mud is a key component in drilling operations and in accessing oil and gas reservoirs. Bentonite is applied as a viscosifier, fluid loss control agent, and as a weighting material in water-based drilling mud. The type of bentonite used in drilling mud formulation is sodium bentonite due to its high dispersion properties and high swelling capacity. Nigeria has a huge bentonite clay deposit resources which can be evaluated and enhanced in order to be utilized as drilling mud. However, bentonite clay from different parts of Nigeria was investigated and found to be calcium bentonite which is not suitable for drilling mud, because it has low swelling capacity and poor rheological properties. In this study, local bentonite obtained from Afuze, Edo state was used to formulate different samples of drilling mud with each treated using thermo-chemical beneficiation process with sodium carbonate and cassava starch, and then undergo characterization to identify the changes in physical properties and finally, draw comparison with API values for standard drilling mud. The results obtained from this study indicates that, the flow and rheological properties of the beneficiated drilling mud developed through thermo-chemical treatment, showed significant improvement compared to the untreated mud. Therefore, pure calcium bentonite from natural deposits in Nigeria can be modified to sodium bentonite and sufficiently used in drilling mud formulation.