A series of natural rubber-snail shell powder vulcanizates were compounded on a two-roll mill, and moulded on a compression moulding machine. The mechanical and end-use properties of the natural rubber vulcanizates we...A series of natural rubber-snail shell powder vulcanizates were compounded on a two-roll mill, and moulded on a compression moulding machine. The mechanical and end-use properties of the natural rubber vulcanizates were investigated at snail shell powder contents, 0 to 20 pphr. The snail shell powder was characterized for filler properties and sieved to 0.075, and 0.30 μm particle sizes. Carbon black was used as the reference filler. Results showed that the tensile strength, modulus, elongation at break, and resilience of the rubber vulcanizates were not enhanced on addition of snail shell powder. The hardness of the rubber vulcanizes were marginally increased at high snail shell powder content. However, the specific gravity of the rubber vulcanizates showed increases with increase in snail shell powder content. At a filler content above 5 pphr, snail shell powder exhibited good flame retardant property in the vulcanizates. The swelling indices of snail shell powder (0.075 μm) filled natural rubber were generally good, and better than those of snail shell powder (0.30 μm) filled natural rubber. Carbon black was found to show more property improvement for the natural rubber vulcanizates when compared to snail shell powder. Although the mechanical properties of snail shell powder filled natural rubber vulcanizates were not good, there were improvements in the end-use properties, an indication that snail shell powder could still find utilization in the rubber industry where specific end-use property of a rubber product is required.展开更多
Polypropylene composites of snail shell powder were prepared at filler contents, 0 to 40 wt%. The particle sizes of the snail shell powder investigated were 0.150, 0.30, and 0.42 μm. Talc, of particle size, 0.150 μm...Polypropylene composites of snail shell powder were prepared at filler contents, 0 to 40 wt%. The particle sizes of the snail shell powder investigated were 0.150, 0.30, and 0.42 μm. Talc, of particle size, 0.150 μm was used as the reference filler. The polypropylene composites were prepared in an injection moulding machine and the resulting composites were extruded as sheets. Some mechanical and end-use properties of the prepared composites were determined. Results showed that the snail shell powder improved the tensile modulus, flexural strength, and impact strength of polypropylene and these properties increased with increases in the filler content and decreases in the filler particle size. The elongation at break of the composites was however observed to decrease with increases in the filler content, and particle size. The elongation at break of talc filled polypropylene was zero, an indication of the brittle nature of polypropylene composites of talc. The hardness, water sorption (24-hr) and specific gravity of the composites were found to increase with increases in the filler content, and decreases in the filler particle size. The level of water absorbed by snail shell powder composites of polypropylene is considerably higher than that of talc filled polypropylene. The flame retardant properties of the prepared composites were however found to decrease with increases in the filler content, and particle size. Generally, snail shell powder was found to show greater property improvement over talc in the prepared composites.展开更多
Snail shell waste (Helix pomatia) has been evaluated as raw material for the preparation of activated carbon using ZnCl2 and CaCl2 with the temperature ranging from 500°C to 800°C. The activated carbon prepa...Snail shell waste (Helix pomatia) has been evaluated as raw material for the preparation of activated carbon using ZnCl2 and CaCl2 with the temperature ranging from 500°C to 800°C. The activated carbon prepared was characterized, showing effect of temperature on ash content, pore volume and porosity. The adsorption isotherm for methylene blue was carried out on the activated carbon in a batch study. The adsorbent exhibited excellent adsorption for methylene blue. The experimental data were used for both Langmuir and Freundlich models. The adsorption coefficients of Langmuir isotherm were found to be 0.996 and 0.957 for CaCl2 and ZnCl2 while 0.969 and 0.962 were obtained for the Freundlich isotherm respectively. The value of RL was found to be 0.75 and 0.38 for samples CC and ZZ respectively, which is an indication that activated carbon impregnated with CaCl2 and ZnCl2 is favourable for adsorption of methylene blue under the conditions used in this study.展开更多
The methods of X-ray diffraction (XRD) and ICP-AES are applied to analyzing the mineral composition of modern and fossil snail shells in Luochuan section and Xifeng section. The results show that the mineral phase of ...The methods of X-ray diffraction (XRD) and ICP-AES are applied to analyzing the mineral composition of modern and fossil snail shells in Luochuan section and Xifeng section. The results show that the mineral phase of calcium carbonate in modern snail shells is aragonite, but for some fossil snail shells in certain layers of loess sequences, a part of aragonite is transformed into calcite. In Luochuan and Xifeng sections, the stratigraphic borderline of arago- nite-calcite transformation appearing obviously is between L5 and L6. Under the earth surface condition, the arago- nite-calcite transformation is influenced by the factor of temperature only in a long time scale. It seems that the pres- sure is not the factor influencing the aragonite-calcite trans- formation. The results also show that existing age of snail shells is possibly the dominant and principal factor for the aragonite-calcite transformation. To a certain extent, the degree of aragonite-calcite transformation in snail shell is controlled by the content of trace element, such as Mg2+. The trace element can improve the stability of snail shell arago- nite and impede the process of aragonite transforming into calcite.展开更多
Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in s...Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in susceptible cultivars, may cause severe economic losses. The goal of this study is to determine the effect of three organic calcium sources on the growth and quality of fruit production of tomatoes. Egg, snail and sea shell powders and extracts have been used as biological fertilizers. The experiment was conducted in a block factorial trial with three replications. The trials comprised two factors: calcium sources and calcium source form (powder and extract). The results showed that the growth parameters and yield were improved by the calcium source, whatever the form. Also, BER was lower in plants treated with calcium contrary to the control. However, plants treated with eggshells showed the best growth (mean) and the lowest rate (0.40%) of BER than the snail and sea shell.展开更多
Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in s...Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in susceptible cultivars, may cause severe economic losses. The goal of this study is to determine the effect of three organic calcium sources on the growth and quality of fruit production of tomatoes. Egg, snail and sea shell powders and extracts have been used as biological fertilizers. The experiment was conducted in a block factorial trial with three replications. The trials comprised two factors: calcium sources and calcium source form (powder and extract). The results showed that the growth parameters and yield were improved by the calcium source, whatever the form. Also, BER was lower in plants treated with calcium contrary to the control. However, plants treated with eggshells showed the best growth (mean) and the lowest rate (0.40%) of BER than the snail and sea shell.展开更多
The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is propose...The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.展开更多
文摘A series of natural rubber-snail shell powder vulcanizates were compounded on a two-roll mill, and moulded on a compression moulding machine. The mechanical and end-use properties of the natural rubber vulcanizates were investigated at snail shell powder contents, 0 to 20 pphr. The snail shell powder was characterized for filler properties and sieved to 0.075, and 0.30 μm particle sizes. Carbon black was used as the reference filler. Results showed that the tensile strength, modulus, elongation at break, and resilience of the rubber vulcanizates were not enhanced on addition of snail shell powder. The hardness of the rubber vulcanizes were marginally increased at high snail shell powder content. However, the specific gravity of the rubber vulcanizates showed increases with increase in snail shell powder content. At a filler content above 5 pphr, snail shell powder exhibited good flame retardant property in the vulcanizates. The swelling indices of snail shell powder (0.075 μm) filled natural rubber were generally good, and better than those of snail shell powder (0.30 μm) filled natural rubber. Carbon black was found to show more property improvement for the natural rubber vulcanizates when compared to snail shell powder. Although the mechanical properties of snail shell powder filled natural rubber vulcanizates were not good, there were improvements in the end-use properties, an indication that snail shell powder could still find utilization in the rubber industry where specific end-use property of a rubber product is required.
文摘Polypropylene composites of snail shell powder were prepared at filler contents, 0 to 40 wt%. The particle sizes of the snail shell powder investigated were 0.150, 0.30, and 0.42 μm. Talc, of particle size, 0.150 μm was used as the reference filler. The polypropylene composites were prepared in an injection moulding machine and the resulting composites were extruded as sheets. Some mechanical and end-use properties of the prepared composites were determined. Results showed that the snail shell powder improved the tensile modulus, flexural strength, and impact strength of polypropylene and these properties increased with increases in the filler content and decreases in the filler particle size. The elongation at break of the composites was however observed to decrease with increases in the filler content, and particle size. The elongation at break of talc filled polypropylene was zero, an indication of the brittle nature of polypropylene composites of talc. The hardness, water sorption (24-hr) and specific gravity of the composites were found to increase with increases in the filler content, and decreases in the filler particle size. The level of water absorbed by snail shell powder composites of polypropylene is considerably higher than that of talc filled polypropylene. The flame retardant properties of the prepared composites were however found to decrease with increases in the filler content, and particle size. Generally, snail shell powder was found to show greater property improvement over talc in the prepared composites.
文摘Snail shell waste (Helix pomatia) has been evaluated as raw material for the preparation of activated carbon using ZnCl2 and CaCl2 with the temperature ranging from 500°C to 800°C. The activated carbon prepared was characterized, showing effect of temperature on ash content, pore volume and porosity. The adsorption isotherm for methylene blue was carried out on the activated carbon in a batch study. The adsorbent exhibited excellent adsorption for methylene blue. The experimental data were used for both Langmuir and Freundlich models. The adsorption coefficients of Langmuir isotherm were found to be 0.996 and 0.957 for CaCl2 and ZnCl2 while 0.969 and 0.962 were obtained for the Freundlich isotherm respectively. The value of RL was found to be 0.75 and 0.38 for samples CC and ZZ respectively, which is an indication that activated carbon impregnated with CaCl2 and ZnCl2 is favourable for adsorption of methylene blue under the conditions used in this study.
基金This work was supported by the National Key Program for Basic Research(Grant No.2001 CCB00100)the Key Pro-gram of National Natural Science Foundation of China(Grant No:4033 1001)the National Basic Research Program of China(Grant No:2004CB720204).
文摘The methods of X-ray diffraction (XRD) and ICP-AES are applied to analyzing the mineral composition of modern and fossil snail shells in Luochuan section and Xifeng section. The results show that the mineral phase of calcium carbonate in modern snail shells is aragonite, but for some fossil snail shells in certain layers of loess sequences, a part of aragonite is transformed into calcite. In Luochuan and Xifeng sections, the stratigraphic borderline of arago- nite-calcite transformation appearing obviously is between L5 and L6. Under the earth surface condition, the arago- nite-calcite transformation is influenced by the factor of temperature only in a long time scale. It seems that the pres- sure is not the factor influencing the aragonite-calcite trans- formation. The results also show that existing age of snail shells is possibly the dominant and principal factor for the aragonite-calcite transformation. To a certain extent, the degree of aragonite-calcite transformation in snail shell is controlled by the content of trace element, such as Mg2+. The trace element can improve the stability of snail shell arago- nite and impede the process of aragonite transforming into calcite.
文摘Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in susceptible cultivars, may cause severe economic losses. The goal of this study is to determine the effect of three organic calcium sources on the growth and quality of fruit production of tomatoes. Egg, snail and sea shell powders and extracts have been used as biological fertilizers. The experiment was conducted in a block factorial trial with three replications. The trials comprised two factors: calcium sources and calcium source form (powder and extract). The results showed that the growth parameters and yield were improved by the calcium source, whatever the form. Also, BER was lower in plants treated with calcium contrary to the control. However, plants treated with eggshells showed the best growth (mean) and the lowest rate (0.40%) of BER than the snail and sea shell.
文摘Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in susceptible cultivars, may cause severe economic losses. The goal of this study is to determine the effect of three organic calcium sources on the growth and quality of fruit production of tomatoes. Egg, snail and sea shell powders and extracts have been used as biological fertilizers. The experiment was conducted in a block factorial trial with three replications. The trials comprised two factors: calcium sources and calcium source form (powder and extract). The results showed that the growth parameters and yield were improved by the calcium source, whatever the form. Also, BER was lower in plants treated with calcium contrary to the control. However, plants treated with eggshells showed the best growth (mean) and the lowest rate (0.40%) of BER than the snail and sea shell.
基金financially supported by the Postgraduate Research & Practice Innovation Program of Jiangsu Province(Grant No.KYCX18_2311)
文摘The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.
