Considering the serious barriers/issues induced by the accumulated starch generated in white water system of old corrugated cardboard(OCC)pulping process,large amounts of accumulated starch in white water would be dec...Considering the serious barriers/issues induced by the accumulated starch generated in white water system of old corrugated cardboard(OCC)pulping process,large amounts of accumulated starch in white water would be decomposed by microorganisms and could not be utilized,thereby resulting in severe resource wastage and environmental pollution.This study mainly explored the effects of biodegradation/hydrolysis conditions of the two types of starch substrates(native starch and enzymatically(α-amylase)hydrolyzed starch),which were treated via microorganism degradation within the simulated white water from OCC pulping system and their biodegradation products on the key properties were characterized via X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),and gel permeation chromatography(GPC)technologies.The effects of system temperature,pH value,starch concentration,and biodegradation time on starch biodegradation ratio and the characteristics of obtained biodegradated products from the two types of starches were studied.In addition,the effect ofα-amylase dosage on the biodegradation ratio of enzymatically hydrolyzed starch and its properties was investigated.It was found that the native starch presented a maximal degradation ratio at a system temperature of 55℃and pH value range of 5-7,respectively,the corresponding starch concentration within simulated white water system was 200 mg/L.Whereas the enzymatically hydrolyzed starch exhibited a highest degradation ratio at a system temperature of 50℃and pH value of 5.5,respectively,and the corresponding starch concentration within simulated white water system was 100 mg/L.It was verified that native starch is more readily bio-hydrolyzed and biodegradation-susceptive by microorganisms in simulated white water system of OCC pulping process,while the enzymatically hydrolyzed starch exhibits better biodegradation/hydrolysis resistance to the microbial degradation than that of native starch.This study provides a practical and interesting approach to investigate the starch hydrolysis or biodegradation behaviors in white water system of OCC pulping process,which would greatly contribute to the full recycling and valorized application of starch as a versatile additive during paperboard production.展开更多
A 13% chromium white iron was produced using a stir cast process. Samples of the produced white iron were austenised at 1450°C and then quenched in water to the room temperature. The characterisation tools such a...A 13% chromium white iron was produced using a stir cast process. Samples of the produced white iron were austenised at 1450°C and then quenched in water to the room temperature. The characterisation tools such as X-ray diffractometer, scanning electron microscope, Brinell hardness tester and pin on disc machine were employed in the studies of the phase orientation and morphology, hardness value measurement and investigation of wear behaviour. The results revealed that water quenching the 13% chromium white iron led to the precipitation of fine iron chromides and cementite in the matrix of martensite. Moreover, there is an about 22% to 45% increase in hardness values of the as-cast 13% chromium white iron as the %composition of graphite additions increased from 1.36 to 3.04. However, the impact energy values are sacrificed. The increase in hardness values is attributable to hard intermetallic compounds such as iron chromides and cementite phases in the iron matrix. Also, there is an about 32% - 42% increase in hardness values of the heat treated samples of 13% chromium white iron when compared with those of the as-cast. The increased hardness values are attributable to even distribution of the fine intermetallic compounds in the fine grains of martensitic matrix. The wear rate increased as the sliding moments per unit time increased due to increasing work done by the friction to oppose the rotation of the pin on disc. The water quenched 13% chromium white iron samples have greater wear resistances than the as-cast samples due to their greater hardness values than those of the as-cast samples. The effect of speed increase on decreasing wear resistances is more pronounced on the heat treated samples than on the as-cast samples. Hence, the water quenched 13% chromium white iron is an excellent material in application requiring high wear resistance and low impact energy especially in grinding mill liner plate, bottom or casing used in the concrete pipe production, roller for crushing and pulverising mills.展开更多
We studied how bioflocculants,produced by white-rot fungi,affect flocculation in slime water.Based on a test in an orthogonal design,flocculation conditions were optimized.The results show that flocculation activity i...We studied how bioflocculants,produced by white-rot fungi,affect flocculation in slime water.Based on a test in an orthogonal design,flocculation conditions were optimized.The results show that flocculation activity is at its highest when the following conditions are met:slime water concentration 27.42 g/L;coagulant aid(CaCl_2) mass concentration 5.0 g/L;two-segment stirrings:the first at a stirring speed of 60 r/min for 180 s and the second 180 r/min for 60 s;a pH of 11 and a flocculant concentration of 15 mL/L.The flocculation activity can be up to 98.71%of bioflocculants at the time.Further experiments indicate that most of the flocculation active material is found outside the mycelium cells.This is the extracellular secretion produced by mycelium cells during the fermentation process.This flocculant has strong thermal stability.Many kinds of cations have a flocculation function to assist bioflocculants.This aid-flocculation effect of the divalent cation Ca^(2+) is obvious in the bioflocculant produced by the white-rot fungus.Therefore,this is of great value when applied to control engineering in the battle against water pollution.展开更多
In order to do a best stipulation on her consumption, it is necessary to know if a food provoke faintly, fairly or highly the glyceamia. The aim of this work was to evaluate the glycemic index of coconut water sugar f...In order to do a best stipulation on her consumption, it is necessary to know if a food provoke faintly, fairly or highly the glyceamia. The aim of this work was to evaluate the glycemic index of coconut water sugar from three coconuts varieties. So, with a cohort of 15 people, a capillary blood was collect after sugar ingestion and the glycaemia read directly on a glucometer. The result showed that the brown and white sugar from coconut sugar can be classified as low glycemic index food. Also, the glycemic indexes of white coconut water sugar are 2 to 3 more lower than that the brown sugar. The glycemic indexes of sugars vary according to the variety of coconut used. The sugars of the coconut palm (MYD) are more hyper-glycemic than those of the hybrid (PB121+) which is more hyperglycemic than the sugars of the coconut palm (WAT). Thus, with a controlled consumption, the coconut water sugars could be the sugars that are best for the health of the healthy and diabetic populations because it raises slightly the postprandial glucose.展开更多
基金financial support from the China Postdoctoral Science Foundation (No. 2022M712379, No. 2021M692401)National Natural Science Foundation of China (No. 32101470)+3 种基金Foundation (No. 2021KF37) of Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control,College of Light Industry and Food Engineering, Guangxi UniversityFoundation of Tianjin Key Laboratory of Pulp & Paper of Tianjin University of Science & Technology (No. 202003, No. 202106)Research Foundation from the University of New BrunswickPost-Doctoral Fellow Programs from Zhejiang Jingxing Paper Co., Ltd
文摘Considering the serious barriers/issues induced by the accumulated starch generated in white water system of old corrugated cardboard(OCC)pulping process,large amounts of accumulated starch in white water would be decomposed by microorganisms and could not be utilized,thereby resulting in severe resource wastage and environmental pollution.This study mainly explored the effects of biodegradation/hydrolysis conditions of the two types of starch substrates(native starch and enzymatically(α-amylase)hydrolyzed starch),which were treated via microorganism degradation within the simulated white water from OCC pulping system and their biodegradation products on the key properties were characterized via X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),and gel permeation chromatography(GPC)technologies.The effects of system temperature,pH value,starch concentration,and biodegradation time on starch biodegradation ratio and the characteristics of obtained biodegradated products from the two types of starches were studied.In addition,the effect ofα-amylase dosage on the biodegradation ratio of enzymatically hydrolyzed starch and its properties was investigated.It was found that the native starch presented a maximal degradation ratio at a system temperature of 55℃and pH value range of 5-7,respectively,the corresponding starch concentration within simulated white water system was 200 mg/L.Whereas the enzymatically hydrolyzed starch exhibited a highest degradation ratio at a system temperature of 50℃and pH value of 5.5,respectively,and the corresponding starch concentration within simulated white water system was 100 mg/L.It was verified that native starch is more readily bio-hydrolyzed and biodegradation-susceptive by microorganisms in simulated white water system of OCC pulping process,while the enzymatically hydrolyzed starch exhibits better biodegradation/hydrolysis resistance to the microbial degradation than that of native starch.This study provides a practical and interesting approach to investigate the starch hydrolysis or biodegradation behaviors in white water system of OCC pulping process,which would greatly contribute to the full recycling and valorized application of starch as a versatile additive during paperboard production.
文摘A 13% chromium white iron was produced using a stir cast process. Samples of the produced white iron were austenised at 1450°C and then quenched in water to the room temperature. The characterisation tools such as X-ray diffractometer, scanning electron microscope, Brinell hardness tester and pin on disc machine were employed in the studies of the phase orientation and morphology, hardness value measurement and investigation of wear behaviour. The results revealed that water quenching the 13% chromium white iron led to the precipitation of fine iron chromides and cementite in the matrix of martensite. Moreover, there is an about 22% to 45% increase in hardness values of the as-cast 13% chromium white iron as the %composition of graphite additions increased from 1.36 to 3.04. However, the impact energy values are sacrificed. The increase in hardness values is attributable to hard intermetallic compounds such as iron chromides and cementite phases in the iron matrix. Also, there is an about 32% - 42% increase in hardness values of the heat treated samples of 13% chromium white iron when compared with those of the as-cast. The increased hardness values are attributable to even distribution of the fine intermetallic compounds in the fine grains of martensitic matrix. The wear rate increased as the sliding moments per unit time increased due to increasing work done by the friction to oppose the rotation of the pin on disc. The water quenched 13% chromium white iron samples have greater wear resistances than the as-cast samples due to their greater hardness values than those of the as-cast samples. The effect of speed increase on decreasing wear resistances is more pronounced on the heat treated samples than on the as-cast samples. Hence, the water quenched 13% chromium white iron is an excellent material in application requiring high wear resistance and low impact energy especially in grinding mill liner plate, bottom or casing used in the concrete pipe production, roller for crushing and pulverising mills.
基金the Shenhuo Mining Group Co.Ltd.,China for its financial support.At the same time,we also thank the National Natural Science Foundation of China(No.40373044)the Natural Science Foundation of Jiangsu Province (No.05KJD610209) for their supportthe Jiangsu Key Laboratory of Resources and Environmental Information Engineering for its technical support.
文摘We studied how bioflocculants,produced by white-rot fungi,affect flocculation in slime water.Based on a test in an orthogonal design,flocculation conditions were optimized.The results show that flocculation activity is at its highest when the following conditions are met:slime water concentration 27.42 g/L;coagulant aid(CaCl_2) mass concentration 5.0 g/L;two-segment stirrings:the first at a stirring speed of 60 r/min for 180 s and the second 180 r/min for 60 s;a pH of 11 and a flocculant concentration of 15 mL/L.The flocculation activity can be up to 98.71%of bioflocculants at the time.Further experiments indicate that most of the flocculation active material is found outside the mycelium cells.This is the extracellular secretion produced by mycelium cells during the fermentation process.This flocculant has strong thermal stability.Many kinds of cations have a flocculation function to assist bioflocculants.This aid-flocculation effect of the divalent cation Ca^(2+) is obvious in the bioflocculant produced by the white-rot fungus.Therefore,this is of great value when applied to control engineering in the battle against water pollution.
文摘In order to do a best stipulation on her consumption, it is necessary to know if a food provoke faintly, fairly or highly the glyceamia. The aim of this work was to evaluate the glycemic index of coconut water sugar from three coconuts varieties. So, with a cohort of 15 people, a capillary blood was collect after sugar ingestion and the glycaemia read directly on a glucometer. The result showed that the brown and white sugar from coconut sugar can be classified as low glycemic index food. Also, the glycemic indexes of white coconut water sugar are 2 to 3 more lower than that the brown sugar. The glycemic indexes of sugars vary according to the variety of coconut used. The sugars of the coconut palm (MYD) are more hyper-glycemic than those of the hybrid (PB121+) which is more hyperglycemic than the sugars of the coconut palm (WAT). Thus, with a controlled consumption, the coconut water sugars could be the sugars that are best for the health of the healthy and diabetic populations because it raises slightly the postprandial glucose.
