Aiming at the deficiency of the robustness of thermal error compensation models of CNC machine tools, the mechanism of improving the models＇ robustness is studied by regarding the Leaderway-V450 machining center as t...Aiming at the deficiency of the robustness of thermal error compensation models of CNC machine tools, the mechanism of improving the models＇ robustness is studied by regarding the Leaderway-V450 machining center as the object. Through the analysis of actual spindle air cutting experimental data on Leaderway-V450 machine, it is found that the temperature-sensitive points used for modeling is volatility, and this volatility directly leads to large changes on the collinear degree among modeling independent variables. Thus, the forecasting accuracy of multivariate regression model is severely affected, and the forecasting robustness becomes poor too. To overcome this effect, a modeling method of establishing thermal error models by using single temperature variable under the jamming of temperature-sensitive points＇ volatility is put forward. According to the actual data of thermal error measured in different seasons, it is proved that the single temperature variable model can reduce the loss of fore- casting accuracy resulted from the volatility of tempera- ture-sensitive points, especially for the prediction of cross quarter data, the improvement of forecasting accuracy is about 5 μm or more. The purpose that improving the robustness of the thermal error models is realized, which can provide a reference for selecting the modelingindependent variable in the application of thermal error compensation of CNC machine tools.展开更多
The forecast of sterile alteration for the temperature-sensitive genic male sterile （TGMS） line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. Th...The forecast of sterile alteration for the temperature-sensitive genic male sterile （TGMS） line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. The article put forward a new approach based on plant temperature, which was more exact and direct than the traditional method. The result of the simulation of the self-seeded setting rate of a widely used TGMS line, Peiai64S, by several temperature parameters and durations, showed that the fertility was directly affected by the plant temperature at a height of 20 cm or the air temperature around it in three days duration. Using the stem temperature of three days at a height of 20 cm as the simulation parameter, the fertility of Peiai64S had the maximum, minimum and optimum temperatures as 22.8, 21.7 and 22.5℃, respectively, whereas 23.2, 21.5 and 21.8℃ when using the air temperature of three days around the height of 20 cm as the parameter. Such temperature indices can be used to conclude the sterile alteration of TGMS for safeguarding seed production of twoline hybrid rice. The article also established a statistic model to conclude plant temperature by water temperatures at inflow and outflow, and air temperature and cloudage from weather station.展开更多
Baladi bread is a staple food in Egypt and high nutritive value however, stales rapidly. The aim of the study was to conduct a comparative evaluation of pullulan and hydrocolloid combinations on rheological properties...Baladi bread is a staple food in Egypt and high nutritive value however, stales rapidly. The aim of the study was to conduct a comparative evaluation of pullulan and hydrocolloid combinations on rheological properties and quality parameters of wheat-soy baladi bread. Pullulan polysaccharides (Pu) and hydrocolloids as Arabic gum (AG), K-carrageenan (KC), pectin (P), and xanthan gum (XG) were applied. Rheological properties of samples included Pu and hydrocolloids were analyzed through extensiograph and farinograph. The crust color, staling, and sensory attributes of bread were evaluated. Results revealed that wheat flour (WF) has lower water absorption capacity, dough development time, mixing tolerance index, and resistance to extension however, has higher dough stability, extensibility, and dough energy compared to wheat-soy flour (WSF). Pu and/or hydrocolloids addition to WSF dough evidently improved bread quality. Pu was significantly enhanced crust color and yielded fresher bread relative to control. Additionally, Pu showed the highest Alkaline Water Retention Capacity (AWRC) value after 5 days at 25°C ± 2°C. Results demonstrated that hydrocolloids especially pullulan can significantly improve dough properties, baking quality, sensory acceptability, and delay staling of wheat-soy baladi bread.展开更多
Four oat β-glucan enriched hydrocolloids (Nutrim10, C-Trim20, C-Trim30, C-Trim50), oat bran concentrate (OBC), and β-Glucan95 were investigated for antioxidant and pasting properties. C-Trim30 had the highest solubl...Four oat β-glucan enriched hydrocolloids (Nutrim10, C-Trim20, C-Trim30, C-Trim50), oat bran concentrate (OBC), and β-Glucan95 were investigated for antioxidant and pasting properties. C-Trim30 had the highest soluble phenolic content, followed by C-Trim20. The trend of antioxidant activity was similar with that of phenolic contents. The phenolic content of the extracts increased with increasing temperatures. The highest content of soluble phenolic compounds was found at temperatures up to 100℃ for most samples regardless of solvent. Water extracts had significantly higher phenolic contents than extracts from 50% ethanol at 100℃ for all samples with the exception of C-Trim30. However, the effect of temperature and solvent concentrations was not as apparent for antioxidant activity as that observed for phenolic content. In general, the differences in three different solvents were not as apparent. Significantly higher water holding capacities were found for C-Trim30 and C-Trim50 than the other samples while β-Glucan 95 had substantially the highest paste viscosity followed by C-Trim50 and C-Trim30.展开更多
With the developing of juices and beverages industry, the processors need to bring new nutritional fortified products to capture the market as per the demand of the consumer who needs healthier product. Thus, this stu...With the developing of juices and beverages industry, the processors need to bring new nutritional fortified products to capture the market as per the demand of the consumer who needs healthier product. Thus, this study aimed to the production of mango beverage and mango flavored beverage fortified with chia seeds;evaluate the chemical properties of chia seeds and study the effect of adding carboxymethyl cellulose, xanthan gum and low acyl gellan gum at the concentrations of 0.05% and 0.1% on the stability of suspension chia seeds in beverage during storage at ambient temperature for six months. Viscosity, color, zeta potential, suspension of seeds and organoleptic properties were evaluated. Results showed that chia seeds were rich in protein, omega-3 fatty acids and dietary fiber. The addition of 0.05% gellan gum led to improved appearance attributes and the highest stability of suspension of chia seeds for six months, and was the sample which scored highest for overall acceptability compared to the other samples of beverages. Results indicated that using chia seeds with the addition of 0.05% low acyl gellan gum led to the production of fortified mango beverage and mango flavored beverage with high stability for six months.展开更多
A novel series of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (p(NIPAM-co-HEMA)) microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron micro...A novel series of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (p(NIPAM-co-HEMA)) microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and dynamic light scattering (DLS) were employed to characterize the microgels. The experimental results indicate that the prepared microgels with narrow distribution remain good temperature sensitivity after incorporation of functional-OH groups. In marked contrast to the general rule, incorporation of hydrophilic HEMA makes the volume-phase-transition temperature shift to the lower temperature due to the strong intermolecular H-bonding between amide and -OH groups, -OH and -OH groups.展开更多
A temperature-sensitive (ts) mutant of the CHO-K1 cell line, tsTM18, grows at 340C but not at 390C. Smu1 is the gene responsible for ts defects of tsTM18 cells. Previously, we found that the Smu1 ts defect altered the...A temperature-sensitive (ts) mutant of the CHO-K1 cell line, tsTM18, grows at 340C but not at 390C. Smu1 is the gene responsible for ts defects of tsTM18 cells. Previously, we found that the Smu1 ts defect altered the localization (as indicated by enlargement of speckles) of SRSF1 (SF2/ASF) in tsTM18 cells cultured at 390C, suggesting a functional association between Smu1 and SRSF1. Speckles are subnuclear structures that may function as storage/assembly/ modification compartments to supply splicing factors to active transcription sites. The effect of the ts defect of Smu1 on the localization of other factors related to splicing has not been characterized yet. The mechanisms underlying the enlargement of speckles of SRSF1 remain unclear. In the present study, we found that the ts defect of Smu1 affected the nuclear localization of a splicing factor, SRSF2 (SC35), and factors involved in the exon-exon junction complex, Y14 and ALY. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the ts defect of Smu1 affected alternative splicing of endogenous Clk1/ Sty and SRSF2 genes. Mammalian Clk family kinases are shown to phosphorylate serine/arginine (SR) proteins in vitro and SRSF1 in vivo. RT-PCR analysis of Clk1/Sty showed an accumulation of the truncated form lacking kinase activity in tsTM18 cells incubated at 39?C. These data indicate that an accumulation of kinase-negative Clk1/Sty may lead to alteration of the localization of factors related to splicing resulting in the enlargement of speckles.展开更多
A kind of novel copolymer hydrogel of poly（N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide） （poly[DMAEMA/NIPAAm]） was synthesized by the initiation of K2S2O8, N, N＇-methylene-bis（acrylamide） （Bis...A kind of novel copolymer hydrogel of poly（N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide） （poly[DMAEMA/NIPAAm]） was synthesized by the initiation of K2S2O8, N, N＇-methylene-bis（acrylamide） （Bis） was used as the crosslinker. The effects of monomer content, pH and temperature on swelling ratio of the hydrogel were investigated; the thermo-sensitivity in deionized water and in physiological saline was determined. It showed that the swelling ratio of the hydrogel could be changed by changing the temperature or pH alternately. Both swelling ratio and LCST （Lower Critical Solution Temperature） of the hydrogel decreased with the increase of NIPAAm in the co-polymer content.展开更多
Gluten,the protein responsible for the superior viscoelastic properties of refined wheat flour dough over glutenfree cereals,causes celiac disease in people susceptible to gluten-allergy.Moreover,the sustainability of...Gluten,the protein responsible for the superior viscoelastic properties of refined wheat flour dough over glutenfree cereals,causes celiac disease in people susceptible to gluten-allergy.Moreover,the sustainability of using wheat flour in baked foods is threatened by its high cost,especially in countries that depend on imported wheat for their bakery industry.Research has shown that hydrocolloids serve as gluten replacements in baked foods,in response to these challenges.Food hydrocolloids are a class of high-molecular weight polysaccharides and proteins,which serve as functional ingredients in the food industry that modify the foods’rheological and textural properties.They function as stabilizers,viscosity modifiers,gelling agents,water binders,fibres,and inhibitors of ice crystal in foods.Further,food hydrocolloids have also been reported to possess health-promoting properties,such as lowering of postprandial blood glucose and plasma cholesterol concentrations,colon cancer prevention,and modulation of intestinal transit and satiety.They are obtained from plants,animals or microorganisms,and can be used in their natural or modified forms.The aim of this paper is to review the functional benefits of natural and modified hydrocolloids as gluten replacements in baked foods,emphasizing their physicochemical,nutraceutical,and sensorial importance.The application effects of food hydrocolloids as gluten substitutes in gluten-free baked products’quality were discussed.Also,some practical approaches to improve the quality of gluten-free baked products,in response to an increasing consumers’demand and the rising cost of refined wheat flour were highlighted.展开更多
The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytic...The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.展开更多
基金Supported by Key Project of National Natural Science Fund of China(Grant No.51490660/51490661)National Natural Science Foundation of China(Grant No.51175142)
文摘Aiming at the deficiency of the robustness of thermal error compensation models of CNC machine tools, the mechanism of improving the models＇ robustness is studied by regarding the Leaderway-V450 machining center as the object. Through the analysis of actual spindle air cutting experimental data on Leaderway-V450 machine, it is found that the temperature-sensitive points used for modeling is volatility, and this volatility directly leads to large changes on the collinear degree among modeling independent variables. Thus, the forecasting accuracy of multivariate regression model is severely affected, and the forecasting robustness becomes poor too. To overcome this effect, a modeling method of establishing thermal error models by using single temperature variable under the jamming of temperature-sensitive points＇ volatility is put forward. According to the actual data of thermal error measured in different seasons, it is proved that the single temperature variable model can reduce the loss of fore- casting accuracy resulted from the volatility of tempera- ture-sensitive points, especially for the prediction of cross quarter data, the improvement of forecasting accuracy is about 5 μm or more. The purpose that improving the robustness of the thermal error models is realized, which can provide a reference for selecting the modelingindependent variable in the application of thermal error compensation of CNC machine tools.
文摘The forecast of sterile alteration for the temperature-sensitive genic male sterile （TGMS） line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. The article put forward a new approach based on plant temperature, which was more exact and direct than the traditional method. The result of the simulation of the self-seeded setting rate of a widely used TGMS line, Peiai64S, by several temperature parameters and durations, showed that the fertility was directly affected by the plant temperature at a height of 20 cm or the air temperature around it in three days duration. Using the stem temperature of three days at a height of 20 cm as the simulation parameter, the fertility of Peiai64S had the maximum, minimum and optimum temperatures as 22.8, 21.7 and 22.5℃, respectively, whereas 23.2, 21.5 and 21.8℃ when using the air temperature of three days around the height of 20 cm as the parameter. Such temperature indices can be used to conclude the sterile alteration of TGMS for safeguarding seed production of twoline hybrid rice. The article also established a statistic model to conclude plant temperature by water temperatures at inflow and outflow, and air temperature and cloudage from weather station.
文摘Baladi bread is a staple food in Egypt and high nutritive value however, stales rapidly. The aim of the study was to conduct a comparative evaluation of pullulan and hydrocolloid combinations on rheological properties and quality parameters of wheat-soy baladi bread. Pullulan polysaccharides (Pu) and hydrocolloids as Arabic gum (AG), K-carrageenan (KC), pectin (P), and xanthan gum (XG) were applied. Rheological properties of samples included Pu and hydrocolloids were analyzed through extensiograph and farinograph. The crust color, staling, and sensory attributes of bread were evaluated. Results revealed that wheat flour (WF) has lower water absorption capacity, dough development time, mixing tolerance index, and resistance to extension however, has higher dough stability, extensibility, and dough energy compared to wheat-soy flour (WSF). Pu and/or hydrocolloids addition to WSF dough evidently improved bread quality. Pu was significantly enhanced crust color and yielded fresher bread relative to control. Additionally, Pu showed the highest Alkaline Water Retention Capacity (AWRC) value after 5 days at 25°C ± 2°C. Results demonstrated that hydrocolloids especially pullulan can significantly improve dough properties, baking quality, sensory acceptability, and delay staling of wheat-soy baladi bread.
文摘Four oat β-glucan enriched hydrocolloids (Nutrim10, C-Trim20, C-Trim30, C-Trim50), oat bran concentrate (OBC), and β-Glucan95 were investigated for antioxidant and pasting properties. C-Trim30 had the highest soluble phenolic content, followed by C-Trim20. The trend of antioxidant activity was similar with that of phenolic contents. The phenolic content of the extracts increased with increasing temperatures. The highest content of soluble phenolic compounds was found at temperatures up to 100℃ for most samples regardless of solvent. Water extracts had significantly higher phenolic contents than extracts from 50% ethanol at 100℃ for all samples with the exception of C-Trim30. However, the effect of temperature and solvent concentrations was not as apparent for antioxidant activity as that observed for phenolic content. In general, the differences in three different solvents were not as apparent. Significantly higher water holding capacities were found for C-Trim30 and C-Trim50 than the other samples while β-Glucan 95 had substantially the highest paste viscosity followed by C-Trim50 and C-Trim30.
文摘With the developing of juices and beverages industry, the processors need to bring new nutritional fortified products to capture the market as per the demand of the consumer who needs healthier product. Thus, this study aimed to the production of mango beverage and mango flavored beverage fortified with chia seeds;evaluate the chemical properties of chia seeds and study the effect of adding carboxymethyl cellulose, xanthan gum and low acyl gellan gum at the concentrations of 0.05% and 0.1% on the stability of suspension chia seeds in beverage during storage at ambient temperature for six months. Viscosity, color, zeta potential, suspension of seeds and organoleptic properties were evaluated. Results showed that chia seeds were rich in protein, omega-3 fatty acids and dietary fiber. The addition of 0.05% gellan gum led to improved appearance attributes and the highest stability of suspension of chia seeds for six months, and was the sample which scored highest for overall acceptability compared to the other samples of beverages. Results indicated that using chia seeds with the addition of 0.05% low acyl gellan gum led to the production of fortified mango beverage and mango flavored beverage with high stability for six months.
文摘A novel series of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (p(NIPAM-co-HEMA)) microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and dynamic light scattering (DLS) were employed to characterize the microgels. The experimental results indicate that the prepared microgels with narrow distribution remain good temperature sensitivity after incorporation of functional-OH groups. In marked contrast to the general rule, incorporation of hydrophilic HEMA makes the volume-phase-transition temperature shift to the lower temperature due to the strong intermolecular H-bonding between amide and -OH groups, -OH and -OH groups.
文摘A temperature-sensitive (ts) mutant of the CHO-K1 cell line, tsTM18, grows at 340C but not at 390C. Smu1 is the gene responsible for ts defects of tsTM18 cells. Previously, we found that the Smu1 ts defect altered the localization (as indicated by enlargement of speckles) of SRSF1 (SF2/ASF) in tsTM18 cells cultured at 390C, suggesting a functional association between Smu1 and SRSF1. Speckles are subnuclear structures that may function as storage/assembly/ modification compartments to supply splicing factors to active transcription sites. The effect of the ts defect of Smu1 on the localization of other factors related to splicing has not been characterized yet. The mechanisms underlying the enlargement of speckles of SRSF1 remain unclear. In the present study, we found that the ts defect of Smu1 affected the nuclear localization of a splicing factor, SRSF2 (SC35), and factors involved in the exon-exon junction complex, Y14 and ALY. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the ts defect of Smu1 affected alternative splicing of endogenous Clk1/ Sty and SRSF2 genes. Mammalian Clk family kinases are shown to phosphorylate serine/arginine (SR) proteins in vitro and SRSF1 in vivo. RT-PCR analysis of Clk1/Sty showed an accumulation of the truncated form lacking kinase activity in tsTM18 cells incubated at 39?C. These data indicate that an accumulation of kinase-negative Clk1/Sty may lead to alteration of the localization of factors related to splicing resulting in the enlargement of speckles.
文摘A kind of novel copolymer hydrogel of poly（N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide） （poly[DMAEMA/NIPAAm]） was synthesized by the initiation of K2S2O8, N, N＇-methylene-bis（acrylamide） （Bis） was used as the crosslinker. The effects of monomer content, pH and temperature on swelling ratio of the hydrogel were investigated; the thermo-sensitivity in deionized water and in physiological saline was determined. It showed that the swelling ratio of the hydrogel could be changed by changing the temperature or pH alternately. Both swelling ratio and LCST （Lower Critical Solution Temperature） of the hydrogel decreased with the increase of NIPAAm in the co-polymer content.
文摘Gluten,the protein responsible for the superior viscoelastic properties of refined wheat flour dough over glutenfree cereals,causes celiac disease in people susceptible to gluten-allergy.Moreover,the sustainability of using wheat flour in baked foods is threatened by its high cost,especially in countries that depend on imported wheat for their bakery industry.Research has shown that hydrocolloids serve as gluten replacements in baked foods,in response to these challenges.Food hydrocolloids are a class of high-molecular weight polysaccharides and proteins,which serve as functional ingredients in the food industry that modify the foods’rheological and textural properties.They function as stabilizers,viscosity modifiers,gelling agents,water binders,fibres,and inhibitors of ice crystal in foods.Further,food hydrocolloids have also been reported to possess health-promoting properties,such as lowering of postprandial blood glucose and plasma cholesterol concentrations,colon cancer prevention,and modulation of intestinal transit and satiety.They are obtained from plants,animals or microorganisms,and can be used in their natural or modified forms.The aim of this paper is to review the functional benefits of natural and modified hydrocolloids as gluten replacements in baked foods,emphasizing their physicochemical,nutraceutical,and sensorial importance.The application effects of food hydrocolloids as gluten substitutes in gluten-free baked products’quality were discussed.Also,some practical approaches to improve the quality of gluten-free baked products,in response to an increasing consumers’demand and the rising cost of refined wheat flour were highlighted.
文摘The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.
