This work addresses the alloying of titanium aluminides used in aircraft engine applications and automobiles. The oxidation resistance behavior of two titanium aluminides of α2 ＋ γ （Ti3Al ＋ TiAl） and orthorhombi...This work addresses the alloying of titanium aluminides used in aircraft engine applications and automobiles. The oxidation resistance behavior of two titanium aluminides of α2 ＋ γ （Ti3Al ＋ TiAl） and orthorhombic Ti2NbAl, recognized as candidates for high-temperature applications, was investigated by exposure of the alloys for 100 h in air. Thus, oxidation resistance was expressed as the mass gain rate, whereas surface aspects were analyzed using scanning electron microscopy in conjunction with energy-dispersive X-ray spectroscopy, and the type of oxidation products was analyzed by X-ray diffraction and Raman spectroscopy. The orthorhombic Ti2NbAl alloy was embrittled, and pores and microcracks were formed as a result of oxygen diffusion through the external oxide layer formed during thermal oxidation for 100 h.展开更多
In this study, the lycopene concentration and physico-chemical properties of tropical fruits in ripe for immediate consumption was evaluated. Chonto tomatoes had greater lycopene contents than Milano or Long Life Mila...In this study, the lycopene concentration and physico-chemical properties of tropical fruits in ripe for immediate consumption was evaluated. Chonto tomatoes had greater lycopene contents than Milano or Long Life Milano tomatoes, 107 as against 89 and 58 μg/(g fresh weight), respectively展开更多
Colombo is the capital of Sri Lanka and the only wetland city in South Asia under the Ramsar Convention. Crow Island Beach Park and associated coastal area belong to the Colombo urban coastal wetland ecosystems. Crow ...Colombo is the capital of Sri Lanka and the only wetland city in South Asia under the Ramsar Convention. Crow Island Beach Park and associated coastal area belong to the Colombo urban coastal wetland ecosystems. Crow Island wetland contributes diverse habitats for numerous flora and fauna species. The present study was conducted to assess the status of floral diversity in the Crow Island Beach Park and associated coastal ecosystem during the months of August to October 2021. Study area is divided in to three sites (A, B, C). Line transects method and field observations were used in the study. This coastal wetland consists of mosaic of five major vegetation types: Herbaceous, tree, shrub, creeper, grass and other than that marine algae namely<em> Chaetomorpha antennina</em>, <em>Rhizoclonium africanum</em>, <em>Ulva compressa</em> belonging to chlorophyta (green algae) and <em>Grateloupia</em> <em>lithophila</em> belonging to rhodophyta (red algae) were found in the study area. A total number of 102 flora species belonging to 50 families were recorded from the study area. There were two true mangrove species and 16 mangrove associated species in the study sites. Out of the 102 plant species 46 were recognized and documented as plants with medicinal values. Shannon-Wiener diversity indexes for mangrove and mangrove associated species were recorded as 2.378, 2.304 and 1.676 in site A, B and C respectively. Simpson’s diversity index for mangrove and mangrove associated species was recorded as 0.889, 0.874 and 0.735 respectively in site A, B and C and Jaccard index of similarity between three study sites showed high values ranging from 41% to 69% for mangrove and mangrove associated species.展开更多
This project investigates the hypothesis for keeping the environment safe by using human resources at the local government level. Strategic decision-making in the management of human recourses in the field of environm...This project investigates the hypothesis for keeping the environment safe by using human resources at the local government level. Strategic decision-making in the management of human recourses in the field of environmental protection is crucial for the countries in transition. Lack of financial and technological resources can be compensated with other potentials. Therefore, it is necessary to emphasize the decision-making process. Optimization of the existing resources under real conditions is needed in order to get better results of the implementation of adopted strategies. As an example, the scheme of optimal solution based on PROMETHEE method （multi-criteria method of optimization） is given.展开更多
The environmental problems can not be addressed in all their depth and complexity, and the most viable solutions can be made only by direct and continuous reference to the large issues of the development of the societ...The environmental problems can not be addressed in all their depth and complexity, and the most viable solutions can be made only by direct and continuous reference to the large issues of the development of the society as a whole. Environment and economic development are indissoluble, the first is where we all live, and development is what we all do to improve our fate in this environment. A main cause is the attitude of economic operators towards the environment, an attitude according to which profit should be pursued immediately, while nature protection is left for later. Ecological crisis is a new phenomenon, but derived from anthropological crisis. This reflects, at a global level, man＇s inner crisis. Every man in part, and not people or humanity in general, is responsible for this crisis. Individual responsibility is not a question of quality, but a question of quantity. The ecological crisis is linked to the personal and social life of man as a whole. The convenience, lack of respect for things, irrational waste, lack of measure, irresponsibility, injustice, exploitation, winning dirty money, eudemonism, which manifest on all aspects of life and human activity, are factors that provoke it. And, unfortunately, they maintain it.展开更多
This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to d...This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to determine whether the boiler can be retrofitted for the fulfilment of the prospective environmental protection regulations relating to levels of NO_X emissions. The improvement of the air staging via the dual-fuel technique was based on the indirect co-firing technology. The impact of two arrangements of dedicated syngas nozzles(below and above the existing coal burners), two syngas compositions and two heat replacements(5% and 15%) on the course of thermal processes in a furnace was tested. The reductions in NO_X emissions were predicted relative to the baseline when only coal is combusted. The highest reduction of about 38% was achieved with the syngas nozzles below the existing coal burners and 15% heat replacement. This arrangement of nozzles offers the residence time sufficient to co-fire coal with waste derived syngas. A lower reduction in NO_X emissions was obtained with the nozzles above the burners as the enlargement of local fuel rich zone near syngas injection becomes significant for 15% heat replacement. Results provide for the decreasing impact of methane content along with the increase of syngas heat input. The avoided CO_2 emissions through the syngas indirect co-firing with coal in the boiler are linear function of heat replacements.展开更多
基金funded by National Project PCCA contract No.65/2012POS-CCE O 2.2.1 project INFRANANOCHEM-No 19/January 3,2009 of the EU(ERDF)and Romanian Government
文摘This work addresses the alloying of titanium aluminides used in aircraft engine applications and automobiles. The oxidation resistance behavior of two titanium aluminides of α2 ＋ γ （Ti3Al ＋ TiAl） and orthorhombic Ti2NbAl, recognized as candidates for high-temperature applications, was investigated by exposure of the alloys for 100 h in air. Thus, oxidation resistance was expressed as the mass gain rate, whereas surface aspects were analyzed using scanning electron microscopy in conjunction with energy-dispersive X-ray spectroscopy, and the type of oxidation products was analyzed by X-ray diffraction and Raman spectroscopy. The orthorhombic Ti2NbAl alloy was embrittled, and pores and microcracks were formed as a result of oxygen diffusion through the external oxide layer formed during thermal oxidation for 100 h.
基金This work was financially supported by the Research Directorate of the National University of Colombia at Palmira(DIPAL).
文摘In this study, the lycopene concentration and physico-chemical properties of tropical fruits in ripe for immediate consumption was evaluated. Chonto tomatoes had greater lycopene contents than Milano or Long Life Milano tomatoes, 107 as against 89 and 58 μg/(g fresh weight), respectively
文摘Colombo is the capital of Sri Lanka and the only wetland city in South Asia under the Ramsar Convention. Crow Island Beach Park and associated coastal area belong to the Colombo urban coastal wetland ecosystems. Crow Island wetland contributes diverse habitats for numerous flora and fauna species. The present study was conducted to assess the status of floral diversity in the Crow Island Beach Park and associated coastal ecosystem during the months of August to October 2021. Study area is divided in to three sites (A, B, C). Line transects method and field observations were used in the study. This coastal wetland consists of mosaic of five major vegetation types: Herbaceous, tree, shrub, creeper, grass and other than that marine algae namely<em> Chaetomorpha antennina</em>, <em>Rhizoclonium africanum</em>, <em>Ulva compressa</em> belonging to chlorophyta (green algae) and <em>Grateloupia</em> <em>lithophila</em> belonging to rhodophyta (red algae) were found in the study area. A total number of 102 flora species belonging to 50 families were recorded from the study area. There were two true mangrove species and 16 mangrove associated species in the study sites. Out of the 102 plant species 46 were recognized and documented as plants with medicinal values. Shannon-Wiener diversity indexes for mangrove and mangrove associated species were recorded as 2.378, 2.304 and 1.676 in site A, B and C respectively. Simpson’s diversity index for mangrove and mangrove associated species was recorded as 0.889, 0.874 and 0.735 respectively in site A, B and C and Jaccard index of similarity between three study sites showed high values ranging from 41% to 69% for mangrove and mangrove associated species.
文摘This project investigates the hypothesis for keeping the environment safe by using human resources at the local government level. Strategic decision-making in the management of human recourses in the field of environmental protection is crucial for the countries in transition. Lack of financial and technological resources can be compensated with other potentials. Therefore, it is necessary to emphasize the decision-making process. Optimization of the existing resources under real conditions is needed in order to get better results of the implementation of adopted strategies. As an example, the scheme of optimal solution based on PROMETHEE method （multi-criteria method of optimization） is given.
文摘The environmental problems can not be addressed in all their depth and complexity, and the most viable solutions can be made only by direct and continuous reference to the large issues of the development of the society as a whole. Environment and economic development are indissoluble, the first is where we all live, and development is what we all do to improve our fate in this environment. A main cause is the attitude of economic operators towards the environment, an attitude according to which profit should be pursued immediately, while nature protection is left for later. Ecological crisis is a new phenomenon, but derived from anthropological crisis. This reflects, at a global level, man＇s inner crisis. Every man in part, and not people or humanity in general, is responsible for this crisis. Individual responsibility is not a question of quality, but a question of quantity. The ecological crisis is linked to the personal and social life of man as a whole. The convenience, lack of respect for things, irrational waste, lack of measure, irresponsibility, injustice, exploitation, winning dirty money, eudemonism, which manifest on all aspects of life and human activity, are factors that provoke it. And, unfortunately, they maintain it.
基金carried out in the framework of 3190/23/P and S/WZ/1/2015 works financed by Ministry of Science and Higher Education of Poland from the funds for science
文摘This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to determine whether the boiler can be retrofitted for the fulfilment of the prospective environmental protection regulations relating to levels of NO_X emissions. The improvement of the air staging via the dual-fuel technique was based on the indirect co-firing technology. The impact of two arrangements of dedicated syngas nozzles(below and above the existing coal burners), two syngas compositions and two heat replacements(5% and 15%) on the course of thermal processes in a furnace was tested. The reductions in NO_X emissions were predicted relative to the baseline when only coal is combusted. The highest reduction of about 38% was achieved with the syngas nozzles below the existing coal burners and 15% heat replacement. This arrangement of nozzles offers the residence time sufficient to co-fire coal with waste derived syngas. A lower reduction in NO_X emissions was obtained with the nozzles above the burners as the enlargement of local fuel rich zone near syngas injection becomes significant for 15% heat replacement. Results provide for the decreasing impact of methane content along with the increase of syngas heat input. The avoided CO_2 emissions through the syngas indirect co-firing with coal in the boiler are linear function of heat replacements.
