Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and f...Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and fireclay as binding system. The results showed that with temperature rising, Chinese calcined flint clay based plastic refractories shrinked firstly and then expanded. The modulus of rupture （MOR） and the cold crushing strength （CCS） inereased firstly and then decreased from 110 ℃ to 600 ℃ , then increased obviously. Thermal expansion coefficient increased from 110 ℃ to 760 ℃, decreased from 760 ℃ to 1 300 ℃ , and increased from 1 300 ℃ to1500 ℃.展开更多
Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize see...Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize seed threshed at different moisture contents(MCs).Seeds of dent maize JK968 and flint maize DD2 were threshed at 12,15,18,21,and 24% MC.The damage degree was determined by iodine staining,and seed vigor was assessed by standard germination(SG),cold test germination(CTG),accelerated aging germination(AAG),seedling emergence rate,and seedling root and shoot length.The results showed that the damage percentage increased,and the seed vigor parameters decreased with increasing seed MC during threshing in both cultivars.For obtaining high seed quality,indicated by at least 90,85,and 80% of SG,AAG,and CTG,respectively,JK 968 and DD2 should be threshed at MC lower than 15 and 18%,respectively.Furthermore,the damage mainly occurred in the apical part of seeds,irrespective of the threshing MC in both cultivars.When the embryo was damaged,seedling emergence rates were significantly reduced with great influence on shoot length.Damage to the endosperm resulted in little effect on seedling performance.Flint maize DD2 was more tolerant to mechanical threshing than dent maize JK968.These results provided technical reference for the production and processing of high vigor maize seeds.展开更多
Lead contamination in the City of Flint, MI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detr...Lead contamination in the City of Flint, MI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detroit water（Lake Huron） with corrosion control, to Flint River water without corrosion control. Although lead levels are now closer to normal,reports of skin rashes have sparked questions surrounding tap water in some Flint homes.This study investigated the presence of contaminants, including disinfection by-products（DBPs）, in the hot tap water used for showering in the homes of residents in Flint. Extensive quantitative analysis of 61 regulated and priority unregulated DBPs was conducted in Flint hot and cold tap water, along with the analysis of 50 volatile organic compounds and a nontarget comprehensive, broadscreen analysis, to identify a possible source for the reported skin rashes. For comparison, chlorinated hot and cold waters from three other cities were also sampled, including Detroit, which also uses Lake Huron as its source water.Results showed that hot water samples generally contained elevated levels of regulated and priority unregulated DBPs compared to cold water samples, but trihalomethanes were still within regulatory limits. Overall, hot shower water from Flint was similar to waters sampled from the three other cities and did not have unusually high levels of DBPs or other organic chemicals that could be responsible for the skin rashes observed by residents. It is possible that an inorganic chemical or microbial contaminant may be responsible.展开更多
Maize(Zea mays)endosperm is an important food source for humans and animals.In addition,it is considered an excellent model for research on seed development because of its relatively large size for both embryo and end...Maize(Zea mays)endosperm is an important food source for humans and animals.In addition,it is considered an excellent model for research on seed development because of its relatively large size for both embryo and endosperm compared to those of other crop species,such as rice(Oryza sativa)and wheat(Triticum aestivum).After double fertilization,early maize endosperm development includes three stages:(i)a multinucleate coenocyte stage;(i)a cellularization stage,in which the cellular endosperm is formed;and(ii)a stage of differentiation into distinct cells.During early differentiation,four major cell types with specific functions differentiate within the endosperm:starchy endosperm,aleurone layer,basal endosperm transfer layer(BETL),and embryo surrounding region.The subaleurone,conducting zone,basal intermediate zone,and endosperm adjacent to scutellum arise in late differentiation(Sabelli and Larkins 2009).After the main cell types are established,maize endosperm undergoes intensive cell proliferation,which marks the transition to the endosperm-filling stage.During the endosperm-flling stage,the maternal sucrose products are transported to seeds through the BETL region,where they will act as the main carbon substrate for storage products such as starch and proteins(Chen et al.,2023).In fact,the endosperm of maize seeds accounts for approximately 90%of the total grain weight,serving as an important nutrient reservoir(Flint-Garcia et al.,2009).展开更多
A morphological characteristic feature of one hundred Nigerian maize cultivars was established. This repository sought a baseline upon which Nigerian maize cultivars could be classified based on kernel morphology, ger...A morphological characteristic feature of one hundred Nigerian maize cultivars was established. This repository sought a baseline upon which Nigerian maize cultivars could be classified based on kernel morphology, germinating properties such as shoots length and percent of growth. Out of all the maize cultivars, forty eight were classified as Dent maize, five were found to be Pop maize, thirteen were Waxy maize and six were also classified as Sweet maize while fourteen were found to be Floury and Flint maize respectively. The information would serve as reference for the selection of appropriate Nigerian maize cultivars for specific use in food processing and allied industries.展开更多
Trace amounts of pharmaceuticals and other chemical compounds in drinking water are known to have adverse effects on human health,animal health,and the environment.This research study will show the presence of pharmac...Trace amounts of pharmaceuticals and other chemical compounds in drinking water are known to have adverse effects on human health,animal health,and the environment.This research study will show the presence of pharmaceuticals and other chemical compounds in Flint River(Madison County,AL)and Flint Creek(Morgan County,AL).Along the Flint River,samples were taken at three sites:Winchester Road,Brian Fork,and Hobbs Road.Similarly,along Flint Creek,samples were taken at three sites:Vaughn Bridge,Mean Bridge and Red Bank Bridge.At each site,samples were taken at four locations:upland from the water,along the banks of the water,at the deposition sediment of the water,and within the surface water itself.Samples were collected and analyzed for the presence of and concentration of chemical compounds by Waypoint Analytical Laboratory using proprietary High-Pressure LC/MS/MS(Liquid Chromatography and Dual Mass Spectroscopy)methods.Between 14 and 26 chemical compounds were identified at each site,adding up to a total of 548 chemical compounds between Flint River and Flint Creek.The chemical compounds and their concentrations were recorded and then sorted into four categories:pharmaceuticals and personal care products(PPCPs),VOCs(Volatile Organic Compounds),petroleum compounds,and CECs(Contaminants of Emerging Concern).Between both Flint River and Flint Creek,PPCPs were the largest category of contaminants,comprising of 46%of compounds identified.This study demonstrates that Flint River and Flint Creek are potentially hazardous to Madison County and Morgan County residents,as trace concentrations of pharmaceuticals in drinking water can cause several health issues.展开更多
Rock-magnetic methods prove that the cultures in Moravia (Europe) 15,000 - 11,500 years ago might know the technique how to enhance knapping properties of Jurassic chert and Cretaceous flint in order to make stone tools.
Introduction Lead pollution as a significant health hazard appears frequently in the news,sometimes spectacularly so as in the case of the recent contamination of the watersupplyof the cityof Flint,Michiganbecause of ...Introduction Lead pollution as a significant health hazard appears frequently in the news,sometimes spectacularly so as in the case of the recent contamination of the watersupplyof the cityof Flint,Michiganbecause of itsuse inlead pipes in the system.'As a result,it is easy to assume that environmental lead pollution is a recent problem,but that is not the case.Lead exposure is,in fact.展开更多
文摘Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and fireclay as binding system. The results showed that with temperature rising, Chinese calcined flint clay based plastic refractories shrinked firstly and then expanded. The modulus of rupture （MOR） and the cold crushing strength （CCS） inereased firstly and then decreased from 110 ℃ to 600 ℃ , then increased obviously. Thermal expansion coefficient increased from 110 ℃ to 760 ℃, decreased from 760 ℃ to 1 300 ℃ , and increased from 1 300 ℃ to1500 ℃.
基金supported by the earmarked fund for China Agriculture Research System(CARS-02-10)the Special Fund for Agro-scientific Research in the Public Interest,China(201303002)the National Natural Science Foundation of China(31771891)
文摘Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize seed threshed at different moisture contents(MCs).Seeds of dent maize JK968 and flint maize DD2 were threshed at 12,15,18,21,and 24% MC.The damage degree was determined by iodine staining,and seed vigor was assessed by standard germination(SG),cold test germination(CTG),accelerated aging germination(AAG),seedling emergence rate,and seedling root and shoot length.The results showed that the damage percentage increased,and the seed vigor parameters decreased with increasing seed MC during threshing in both cultivars.For obtaining high seed quality,indicated by at least 90,85,and 80% of SG,AAG,and CTG,respectively,JK 968 and DD2 should be threshed at MC lower than 15 and 18%,respectively.Furthermore,the damage mainly occurred in the apical part of seeds,irrespective of the threshing MC in both cultivars.When the embryo was damaged,seedling emergence rates were significantly reduced with great influence on shoot length.Damage to the endosperm resulted in little effect on seedling performance.Flint maize DD2 was more tolerant to mechanical threshing than dent maize JK968.These results provided technical reference for the production and processing of high vigor maize seeds.
基金funding from the U.S.Environmental Protection Agency, Meghan Franco for assistance with XAD resin extractions, Shealy Environmental, Inc.for VOC analyses
文摘Lead contamination in the City of Flint, MI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detroit water（Lake Huron） with corrosion control, to Flint River water without corrosion control. Although lead levels are now closer to normal,reports of skin rashes have sparked questions surrounding tap water in some Flint homes.This study investigated the presence of contaminants, including disinfection by-products（DBPs）, in the hot tap water used for showering in the homes of residents in Flint. Extensive quantitative analysis of 61 regulated and priority unregulated DBPs was conducted in Flint hot and cold tap water, along with the analysis of 50 volatile organic compounds and a nontarget comprehensive, broadscreen analysis, to identify a possible source for the reported skin rashes. For comparison, chlorinated hot and cold waters from three other cities were also sampled, including Detroit, which also uses Lake Huron as its source water.Results showed that hot water samples generally contained elevated levels of regulated and priority unregulated DBPs compared to cold water samples, but trihalomethanes were still within regulatory limits. Overall, hot shower water from Flint was similar to waters sampled from the three other cities and did not have unusually high levels of DBPs or other organic chemicals that could be responsible for the skin rashes observed by residents. It is possible that an inorganic chemical or microbial contaminant may be responsible.
基金the National Institute of Food and Agriculture SCRI2022-51181-38333.No conflict of interest is declared。
文摘Maize(Zea mays)endosperm is an important food source for humans and animals.In addition,it is considered an excellent model for research on seed development because of its relatively large size for both embryo and endosperm compared to those of other crop species,such as rice(Oryza sativa)and wheat(Triticum aestivum).After double fertilization,early maize endosperm development includes three stages:(i)a multinucleate coenocyte stage;(i)a cellularization stage,in which the cellular endosperm is formed;and(ii)a stage of differentiation into distinct cells.During early differentiation,four major cell types with specific functions differentiate within the endosperm:starchy endosperm,aleurone layer,basal endosperm transfer layer(BETL),and embryo surrounding region.The subaleurone,conducting zone,basal intermediate zone,and endosperm adjacent to scutellum arise in late differentiation(Sabelli and Larkins 2009).After the main cell types are established,maize endosperm undergoes intensive cell proliferation,which marks the transition to the endosperm-filling stage.During the endosperm-flling stage,the maternal sucrose products are transported to seeds through the BETL region,where they will act as the main carbon substrate for storage products such as starch and proteins(Chen et al.,2023).In fact,the endosperm of maize seeds accounts for approximately 90%of the total grain weight,serving as an important nutrient reservoir(Flint-Garcia et al.,2009).
文摘A morphological characteristic feature of one hundred Nigerian maize cultivars was established. This repository sought a baseline upon which Nigerian maize cultivars could be classified based on kernel morphology, germinating properties such as shoots length and percent of growth. Out of all the maize cultivars, forty eight were classified as Dent maize, five were found to be Pop maize, thirteen were Waxy maize and six were also classified as Sweet maize while fourteen were found to be Floury and Flint maize respectively. The information would serve as reference for the selection of appropriate Nigerian maize cultivars for specific use in food processing and allied industries.
基金supported by the U.S.Department of Agriculture National Institute of Food and Agriculture’s Capacity Building Grant Program[#2017-2021-38821-26426].
文摘Trace amounts of pharmaceuticals and other chemical compounds in drinking water are known to have adverse effects on human health,animal health,and the environment.This research study will show the presence of pharmaceuticals and other chemical compounds in Flint River(Madison County,AL)and Flint Creek(Morgan County,AL).Along the Flint River,samples were taken at three sites:Winchester Road,Brian Fork,and Hobbs Road.Similarly,along Flint Creek,samples were taken at three sites:Vaughn Bridge,Mean Bridge and Red Bank Bridge.At each site,samples were taken at four locations:upland from the water,along the banks of the water,at the deposition sediment of the water,and within the surface water itself.Samples were collected and analyzed for the presence of and concentration of chemical compounds by Waypoint Analytical Laboratory using proprietary High-Pressure LC/MS/MS(Liquid Chromatography and Dual Mass Spectroscopy)methods.Between 14 and 26 chemical compounds were identified at each site,adding up to a total of 548 chemical compounds between Flint River and Flint Creek.The chemical compounds and their concentrations were recorded and then sorted into four categories:pharmaceuticals and personal care products(PPCPs),VOCs(Volatile Organic Compounds),petroleum compounds,and CECs(Contaminants of Emerging Concern).Between both Flint River and Flint Creek,PPCPs were the largest category of contaminants,comprising of 46%of compounds identified.This study demonstrates that Flint River and Flint Creek are potentially hazardous to Madison County and Morgan County residents,as trace concentrations of pharmaceuticals in drinking water can cause several health issues.
文摘Rock-magnetic methods prove that the cultures in Moravia (Europe) 15,000 - 11,500 years ago might know the technique how to enhance knapping properties of Jurassic chert and Cretaceous flint in order to make stone tools.
文摘Introduction Lead pollution as a significant health hazard appears frequently in the news,sometimes spectacularly so as in the case of the recent contamination of the watersupplyof the cityof Flint,Michiganbecause of itsuse inlead pipes in the system.'As a result,it is easy to assume that environmental lead pollution is a recent problem,but that is not the case.Lead exposure is,in fact.
