In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iedination on iodine content in iodized salt have been studied. For moni toring the analytical Performanc...In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iedination on iodine content in iodized salt have been studied. For moni toring the analytical Performance, a qoality control exawhnation was also undertaken. The loss of iodine was greater when salt was stored in plastic bag than in glass bottle. The loss was greater in fortified salt stored at 37℃ and under 76% humidity than in that at 20 ~ 25℃ and under lower humidity. The retention of iodine varied with the kind of has and also was influenced by the water content of cooked food. In general, the retention of iodine during cooking varied considerably (from 36. 6% to 86. 1 % ). The iodine concentration in salts varied greater from 3.0 to 100.3 mg/kg in salt for markets, and from 0 to 90.0 mg/kg in salts for households. 48. 3 % of samples from markets were found to be in compliance with national standards (30 ~ 50 mg/kg), and 72.0% of samples from households were in compliance with national standartl (20 ~ 50 mg/kg). Analytical data collected from 8 of the cooperative laheratories foran analytical reference material showed a 95% codridence interval of the population mean for both precision and accuracy, falling within X± 2SD and passing quality control exdrination展开更多
βray online monitoring technique for resin content measurement has been developed, which is characterized by simple operation, short measuring time, and high measuring accuracy. It has been used to measure the resin ...βray online monitoring technique for resin content measurement has been developed, which is characterized by simple operation, short measuring time, and high measuring accuracy. It has been used to measure the resin content of pregreg tapes during manufacturing of them. This paper gives the measuring results. Meanwhile, the effects of the deviation of the βray monitoring system itself and the variation of the release paper on the measuring accuracy have been analyzed and discussed.展开更多
Significant waste resources are generated in the form of water-oil emulsions.These emulsions cannot be effectively destroyed on an industrial scale by traditional methods that rely on the settling of the aqueous phase...Significant waste resources are generated in the form of water-oil emulsions.These emulsions cannot be effectively destroyed on an industrial scale by traditional methods that rely on the settling of the aqueous phase,and therefore,they accumulate in large quantities.Thermomechanical dehydration,based on the evaporation of the water phase,presents a promising process for recycling such waste.However,within the framework of thermomechanical dehydration,the issue of optimizing energy costs for heating raw materials and controlling the water content in the product arises.Standard methods of determining water content under the boiling conditions of highly stable water-hydrocarbon emulsions are characterized by low efficiency,as they require constant sampling and the involvement of additional equipment and personnel.Consequently,this presents a challenge in predicting and creating an automated thermomechanical dehydration process.Therefore,dynamic curves depicting changes in the water content of these emulsions,depending on the temperature of the boiling liquid,have been obtained.It is proposed to determine the rate of temperature increase(dT/dt)of the boiling emulsion for continuous,real-time monitoring of the residual water content and for recording the moment of complete dehydration.Achieving a boiling emulsion temperature of 130-170℃(or higher)and/or the rate of temperature increase from 3.0 to 5.5(or above)indicates the complete dehydration of the emulsion.The proposed method can be implemented in any industrial or laboratory-scale unit for thermomechanical dehydration without significant capital costs.It is based on the use of simple devices consisting of temperature sensors and a computing unit for determining the temperature and rate of heating.展开更多
文摘In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iedination on iodine content in iodized salt have been studied. For moni toring the analytical Performance, a qoality control exawhnation was also undertaken. The loss of iodine was greater when salt was stored in plastic bag than in glass bottle. The loss was greater in fortified salt stored at 37℃ and under 76% humidity than in that at 20 ~ 25℃ and under lower humidity. The retention of iodine varied with the kind of has and also was influenced by the water content of cooked food. In general, the retention of iodine during cooking varied considerably (from 36. 6% to 86. 1 % ). The iodine concentration in salts varied greater from 3.0 to 100.3 mg/kg in salt for markets, and from 0 to 90.0 mg/kg in salts for households. 48. 3 % of samples from markets were found to be in compliance with national standards (30 ~ 50 mg/kg), and 72.0% of samples from households were in compliance with national standartl (20 ~ 50 mg/kg). Analytical data collected from 8 of the cooperative laheratories foran analytical reference material showed a 95% codridence interval of the population mean for both precision and accuracy, falling within X± 2SD and passing quality control exdrination
文摘βray online monitoring technique for resin content measurement has been developed, which is characterized by simple operation, short measuring time, and high measuring accuracy. It has been used to measure the resin content of pregreg tapes during manufacturing of them. This paper gives the measuring results. Meanwhile, the effects of the deviation of the βray monitoring system itself and the variation of the release paper on the measuring accuracy have been analyzed and discussed.
文摘Significant waste resources are generated in the form of water-oil emulsions.These emulsions cannot be effectively destroyed on an industrial scale by traditional methods that rely on the settling of the aqueous phase,and therefore,they accumulate in large quantities.Thermomechanical dehydration,based on the evaporation of the water phase,presents a promising process for recycling such waste.However,within the framework of thermomechanical dehydration,the issue of optimizing energy costs for heating raw materials and controlling the water content in the product arises.Standard methods of determining water content under the boiling conditions of highly stable water-hydrocarbon emulsions are characterized by low efficiency,as they require constant sampling and the involvement of additional equipment and personnel.Consequently,this presents a challenge in predicting and creating an automated thermomechanical dehydration process.Therefore,dynamic curves depicting changes in the water content of these emulsions,depending on the temperature of the boiling liquid,have been obtained.It is proposed to determine the rate of temperature increase(dT/dt)of the boiling emulsion for continuous,real-time monitoring of the residual water content and for recording the moment of complete dehydration.Achieving a boiling emulsion temperature of 130-170℃(or higher)and/or the rate of temperature increase from 3.0 to 5.5(or above)indicates the complete dehydration of the emulsion.The proposed method can be implemented in any industrial or laboratory-scale unit for thermomechanical dehydration without significant capital costs.It is based on the use of simple devices consisting of temperature sensors and a computing unit for determining the temperature and rate of heating.
