Hydric properties evolution during drying differs from one product to another and has been the subject of various studies due to its crucial importance in modeling the drying process. The variation of these parameters...Hydric properties evolution during drying differs from one product to another and has been the subject of various studies due to its crucial importance in modeling the drying process. The variation of these parameters in the solid matrix and in time during the drying of Spirulina platensis has not known an advanced understanding. The objective of this study was to evaluate the evolution of the water content profile, the mass flow, the concentration gradient and the diffusion coefficient during the drying of Spirulina platensis taking into account the shrinkage. Modeling and experimental analysis (at 50°C and HR = 6%) by the cutting method a cylinder 20 mm in diameter and 40 mm thick were carried. The water content profiles of two different products grown in semi-industrial farms from Burkina Faso and France with initial water contents respectively of the range from 2.73 kgw/kgdb and 3.12 kgw/kgdb were determined. These profiles have been adjusted by a polynomial function. Identical water behavior is observed regardless of the origin of the samples. Water distribution is heterogeneous. Mass flow and concentration gradient are greater at the edge than inside the product. The water transport coefficient, ranging from 1.70 × 10?10 to 94 × 10?10 m2/s, is determined from a linear approach.展开更多
Wetlands, one of the most productive systems in the biosphere are a unique ecosystem. They occur in landscapes that favor the ponding or slow runoff of surface water, discharge of ground water, or both. Wetlands are n...Wetlands, one of the most productive systems in the biosphere are a unique ecosystem. They occur in landscapes that favor the ponding or slow runoff of surface water, discharge of ground water, or both. Wetlands are not only important for maintaining plant and animal diversity, but also for balancing global carbon budget via sequestrating or releasing CO2 from/into atmosphere depending on their management. Therefore, it is imperative to understand how wetlands form and function, then we can better manage, utilize, and protect these unique ecosystems. Hydrie soils,hydrophytic vegetation, and wetland hydrology are the three main parameters of wetlands. These parameters are interrelated with each other which jointly influence the development and functions of wetland ecosystems. The objective of this paper was to report the current understanding of wetlands and provide future research directions. The paper will first focus on aspects of hydrology research in wetlands, and then shift to soil hydrosequence and wetland vegetation to better understand processes, structure, and function of wetlands, and conclude with some possible future research directions.展开更多
The most frequent types of disasters in Brazil are associated with extreme hydrological events. Adding to this situation, in Brazil, there are the extreme sociospatial discrepancies that are historically constructed. ...The most frequent types of disasters in Brazil are associated with extreme hydrological events. Adding to this situation, in Brazil, there are the extreme sociospatial discrepancies that are historically constructed. They leave marks in space, making specific areas, for political interest or not, more vulnerable to the different mentioned processes. To this extent, the public management should plan actions and, also, it may act in a more holistic way adding new trends, such as, the use of geotechnologies that are applied to environmental management in the realm of urban planning. From a case study in the city of Rio de Janeiro, this paper aims to contribute and draw attention to such issues. It may reach its target through pointing and spatially analyzing which areas are in the most critical situation related to the occurrence of extreme hydrological events. To achieve this goal, it was proposed a methodology to inventory the occurrence of inundation/flooding for a certain period, in this case 2001-2008. Besides, the methodology could systematize data and integrate them with other important issues for supporting the process of identification and analysis of the most critical areas. Historical aspects of occupation and the most vulnerable socio-environmental aspects were raised, too, in order to validate the highlighted areas. This integration was enabled concerning the support of geoprocessing techniques. The results of this integration subsidized the mapping and spatial analysis of the affected areas in the city and the criticality in relation to the extreme hydrological events. Finally, it was possible to observe that the identification of the most critical affected areas does not mean the exhaustion of the subject. The location of these areas is directly linked to the sample that was used as the basis for analyses. This data set only represents recorded events by the Municipal Civil Defense respecting the studied time frame. However, the results permit to take notes and raise relevant environmental questions about the roots and the occurred impacts that were originated from the extreme hydrological events, which have been observed in recent decades.展开更多
The paper shows the novel techniques introduction in the region of Latin America and the Caribbean in order to strengthen the surveillance and monitoring of the sedimentation phenomenon in the surface water reservoirs...The paper shows the novel techniques introduction in the region of Latin America and the Caribbean in order to strengthen the surveillance and monitoring of the sedimentation phenomenon in the surface water reservoirs.The integrated use of the nuclear techniques allows a more complete assessment of water and land sustainability.With the development of a regional project,supported by the International Agency of Atomic Energy,Cuba participates as technical leader for 15 countries,to encourage and implement the integrated application of 3 nuclear techniques(Fallout Radionuclides(137Cs,7Be,210pb),Compound Specific Stable Isotopes(fatty acids of the(e)13C)and the Isotopic Hydrology(18O,2H,3H).The methodology used in the last studies referred to RLA 5076 Project is to apply the integration of these three techniques allows evaluating,in the hydraulic facilities and surface water reservoirs,the negative sedimentation impacts in natural and anthropic process as environmental and social risk.These techniques evaluate the sedimentation process and its synergy,obtaining since the soil quantification in the landscape,definition the soil origin deposited until the dynamic characterization of the water body as soil receptor.The integrated application of these nuclear techniques in the Project RLA-5076 confirms it as a useful tool to support the decisions makers in the definition of the national strategies and programs related to the land and the water resources sustainability.With the support of the IAEA projects in the Latin American and Caribbean region,has been evidenced an important increment in the use of these novel techniques.展开更多
Vertebrate embryos require access to water;however,many species nest in terrestrial habitats that vary considerably in moisture content.Oviparous,non-avian reptiles have served as models to understand how environmenta...Vertebrate embryos require access to water;however,many species nest in terrestrial habitats that vary considerably in moisture content.Oviparous,non-avian reptiles have served as models to understand how environmental factors,like moisture availability,influence development because eggs are often exposed to prevailing environments in the absence of parental care.Though much research demonstrates the importance of water absorption by eggs,many ecological factors that influence moisture availability in natural nests have received little attention.For example,the type of substrate in which nests are constructed is understudied.We experimentally incubated eggs of the brown anole lizard(Anolis sagrei)in 2 naturally occurring nest substrates that were treated with varying amounts of water to determine how natural substrates influence development at different moisture concentrations.One substrate consisted of sand and crushed seashells and the other was mostly organic material(i.e.decayed plant material).Both are common nesting substrates at our field site.When controlling for water uptake by eggs,we found that egg survival and hatchling phenotypes were similar between substrates;however,embryos developed more quickly in the sand/shell substrate than the organic substrate,indicating substrate-specific effects on embryo physiology.These results demonstrate that different natural substrates can result in similar developmental outcomes if the water available to eggs is comparable;however,some aspects of development,like developmental rate,are affected by the type of substrate,independent of water availability.Further study is required to determine how natural substrates influence embryo physiology independent of water content.展开更多
文摘Hydric properties evolution during drying differs from one product to another and has been the subject of various studies due to its crucial importance in modeling the drying process. The variation of these parameters in the solid matrix and in time during the drying of Spirulina platensis has not known an advanced understanding. The objective of this study was to evaluate the evolution of the water content profile, the mass flow, the concentration gradient and the diffusion coefficient during the drying of Spirulina platensis taking into account the shrinkage. Modeling and experimental analysis (at 50°C and HR = 6%) by the cutting method a cylinder 20 mm in diameter and 40 mm thick were carried. The water content profiles of two different products grown in semi-industrial farms from Burkina Faso and France with initial water contents respectively of the range from 2.73 kgw/kgdb and 3.12 kgw/kgdb were determined. These profiles have been adjusted by a polynomial function. Identical water behavior is observed regardless of the origin of the samples. Water distribution is heterogeneous. Mass flow and concentration gradient are greater at the edge than inside the product. The water transport coefficient, ranging from 1.70 × 10?10 to 94 × 10?10 m2/s, is determined from a linear approach.
文摘Wetlands, one of the most productive systems in the biosphere are a unique ecosystem. They occur in landscapes that favor the ponding or slow runoff of surface water, discharge of ground water, or both. Wetlands are not only important for maintaining plant and animal diversity, but also for balancing global carbon budget via sequestrating or releasing CO2 from/into atmosphere depending on their management. Therefore, it is imperative to understand how wetlands form and function, then we can better manage, utilize, and protect these unique ecosystems. Hydrie soils,hydrophytic vegetation, and wetland hydrology are the three main parameters of wetlands. These parameters are interrelated with each other which jointly influence the development and functions of wetland ecosystems. The objective of this paper was to report the current understanding of wetlands and provide future research directions. The paper will first focus on aspects of hydrology research in wetlands, and then shift to soil hydrosequence and wetland vegetation to better understand processes, structure, and function of wetlands, and conclude with some possible future research directions.
文摘The most frequent types of disasters in Brazil are associated with extreme hydrological events. Adding to this situation, in Brazil, there are the extreme sociospatial discrepancies that are historically constructed. They leave marks in space, making specific areas, for political interest or not, more vulnerable to the different mentioned processes. To this extent, the public management should plan actions and, also, it may act in a more holistic way adding new trends, such as, the use of geotechnologies that are applied to environmental management in the realm of urban planning. From a case study in the city of Rio de Janeiro, this paper aims to contribute and draw attention to such issues. It may reach its target through pointing and spatially analyzing which areas are in the most critical situation related to the occurrence of extreme hydrological events. To achieve this goal, it was proposed a methodology to inventory the occurrence of inundation/flooding for a certain period, in this case 2001-2008. Besides, the methodology could systematize data and integrate them with other important issues for supporting the process of identification and analysis of the most critical areas. Historical aspects of occupation and the most vulnerable socio-environmental aspects were raised, too, in order to validate the highlighted areas. This integration was enabled concerning the support of geoprocessing techniques. The results of this integration subsidized the mapping and spatial analysis of the affected areas in the city and the criticality in relation to the extreme hydrological events. Finally, it was possible to observe that the identification of the most critical affected areas does not mean the exhaustion of the subject. The location of these areas is directly linked to the sample that was used as the basis for analyses. This data set only represents recorded events by the Municipal Civil Defense respecting the studied time frame. However, the results permit to take notes and raise relevant environmental questions about the roots and the occurred impacts that were originated from the extreme hydrological events, which have been observed in recent decades.
基金The International Agency of Atomic Energy(IAEA).The support received in Latin American and Caribbean,is fundamental to develop the nuclear techniques application like important assessment tools in the environment degradations
文摘The paper shows the novel techniques introduction in the region of Latin America and the Caribbean in order to strengthen the surveillance and monitoring of the sedimentation phenomenon in the surface water reservoirs.The integrated use of the nuclear techniques allows a more complete assessment of water and land sustainability.With the development of a regional project,supported by the International Agency of Atomic Energy,Cuba participates as technical leader for 15 countries,to encourage and implement the integrated application of 3 nuclear techniques(Fallout Radionuclides(137Cs,7Be,210pb),Compound Specific Stable Isotopes(fatty acids of the(e)13C)and the Isotopic Hydrology(18O,2H,3H).The methodology used in the last studies referred to RLA 5076 Project is to apply the integration of these three techniques allows evaluating,in the hydraulic facilities and surface water reservoirs,the negative sedimentation impacts in natural and anthropic process as environmental and social risk.These techniques evaluate the sedimentation process and its synergy,obtaining since the soil quantification in the landscape,definition the soil origin deposited until the dynamic characterization of the water body as soil receptor.The integrated application of these nuclear techniques in the Project RLA-5076 confirms it as a useful tool to support the decisions makers in the definition of the national strategies and programs related to the land and the water resources sustainability.With the support of the IAEA projects in the Latin American and Caribbean region,has been evidenced an important increment in the use of these novel techniques.
基金The research was approved by Auburn University IACUC(protocol 2019-3465)This study was supported by funds from Auburn University.J.M.H.was supported by the National Science Foundation(NSF DEB-1942145 to DAW)during the preparation of this manuscript.
文摘Vertebrate embryos require access to water;however,many species nest in terrestrial habitats that vary considerably in moisture content.Oviparous,non-avian reptiles have served as models to understand how environmental factors,like moisture availability,influence development because eggs are often exposed to prevailing environments in the absence of parental care.Though much research demonstrates the importance of water absorption by eggs,many ecological factors that influence moisture availability in natural nests have received little attention.For example,the type of substrate in which nests are constructed is understudied.We experimentally incubated eggs of the brown anole lizard(Anolis sagrei)in 2 naturally occurring nest substrates that were treated with varying amounts of water to determine how natural substrates influence development at different moisture concentrations.One substrate consisted of sand and crushed seashells and the other was mostly organic material(i.e.decayed plant material).Both are common nesting substrates at our field site.When controlling for water uptake by eggs,we found that egg survival and hatchling phenotypes were similar between substrates;however,embryos developed more quickly in the sand/shell substrate than the organic substrate,indicating substrate-specific effects on embryo physiology.These results demonstrate that different natural substrates can result in similar developmental outcomes if the water available to eggs is comparable;however,some aspects of development,like developmental rate,are affected by the type of substrate,independent of water availability.Further study is required to determine how natural substrates influence embryo physiology independent of water content.
