The purpose of this work is to synthesize the catalytic systems containing palladium nanoparticles and using hydroxycarbonates of yttrium and cerium as supports,and to test the catalytic activity of the obtained catal...The purpose of this work is to synthesize the catalytic systems containing palladium nanoparticles and using hydroxycarbonates of yttrium and cerium as supports,and to test the catalytic activity of the obtained catalysts in the Suzuki cross-couping reaction.Nanocomposites Pd/Y(OH)CO 3 and Pd/Ce(OH)CO 3 were synthesized according to two methods:the first one-simultaneous production of nanoscale substrate and immobilization of palladium nanoparticles on its surface(nanocomposites 1),the second one-the prior synthesis of polyvinylpyrrolidone stabilized palladium nanoparticles followed by their immobilization on the nano sized substrate surface(nanocomposites 2).The reaction between phenylboronic acid and iodobenzene is chosen as a model one.The dependence of the catalytic activity of catalysts on the method of their synthesis was established.It was established that nanocomposites 2 exhibit higher catalytic activity in the selected reaction compared to the nanocomposites 1.The TOF values for the nanocomposites 1 are 6663~14617 h 1 when using the substrate Ce(OH)CO 3 and 13774~27084 h 1 when using the substrate Y(OH)CO 3,while the nanocomposites 2 reveal TOF = 87287 h 1 for the substrate Ce(OH)CO 3 and TOF = 97746 h 1 for the substrate Y(OH)CO 3 under other equal conditions.In addition,nanocomposites 2 "work" at room temperature giving a high yield of the desired product.It is noted that the support nanoparticles Y(OH)CO 3 and Ce(OH)CO 3 also exhibit catalytic activity.The yield of the final product of the reaction using them as catalysts is 55%(TOF = 11 and 8 h 1,respectively).Thus,the use of yttrium and cerium hydroxycarbonates as supports allows to decrease the palladium content in the nanocomposites to 0.01%~1% and,consequently,reduce the cost of the catalyst while maintaining its high catalytic activity.展开更多
Elevating public awareness of waste management at the household level is a cost effective and a win-win social, economic and environmental approach on the table of policymaking. Modern and effective waste management b...Elevating public awareness of waste management at the household level is a cost effective and a win-win social, economic and environmental approach on the table of policymaking. Modern and effective waste management bring about broader economic efficiency and social equity, mitigate consumerism, thus, promoting the conservation of natural resources. In this article, a survey study was conducted among the citizens of Wrocław city, Poland. The city is dynamic, touristic, and industrial. Through random sampling, 160 respondents filled in the questionnaire. The results revealed that the participants appeared aware of the benefits of waste management (WM);however the current WM systems and infrastructures are not very satisfying. The participants identified several shortcomings in the current WM systems such as the lack of sufficient colored bins for glass recycling, overfilled bins and heavy lids, and irregular waste collection system. The study proposes a public-oriented outreach campaign targeting waste separation and less-waste behaviors as economically and environmentally beneficial, accompanied by continuous development of WM regulations and infrastructures and linked it to waste-to-energy systems and technologies to assist in achieving the long-term energy and emissions-reduction targets.展开更多
We review the management of Eucalyptus species under a coppice-with-standards (CWS) silvicultural system. CWS management results in product diversification, permitting production of small and large scale timber from...We review the management of Eucalyptus species under a coppice-with-standards (CWS) silvicultural system. CWS management results in product diversification, permitting production of small and large scale timber from the same stand. Eucalyptus species are suitable candidates for CWS management because: there are large worldwide plantation areas, sprouting capacity is high, and eucalypts are multipur- pose species. We discuss (1) short rotation Eucalyptus coppice manage- ment for energy and pulping and (2) Eucalyptus seedling management for solid wood products. We review the literature and discuss experi- ences with Eucalyptus managed under the CWS system. We also assess projects dealing with Eucalyptus coppice management, stand density regulation, pruning, and stand and wood quality. The growth environ- ment of the standard trees (heavy competition up to the first harvest, free growth afterwards) coupled with long rotations (〉20 years) results in high quality logs for solid wood products. Early pruning should be ap- plied to enhance wood quality. We propose a system for the silvicultural management of Eucalyptus under the CWS system, elaborating on the consequences of initial planting density, site productivity, and standard tree densities as well as timing of basic silvicultural applications.展开更多
文摘The purpose of this work is to synthesize the catalytic systems containing palladium nanoparticles and using hydroxycarbonates of yttrium and cerium as supports,and to test the catalytic activity of the obtained catalysts in the Suzuki cross-couping reaction.Nanocomposites Pd/Y(OH)CO 3 and Pd/Ce(OH)CO 3 were synthesized according to two methods:the first one-simultaneous production of nanoscale substrate and immobilization of palladium nanoparticles on its surface(nanocomposites 1),the second one-the prior synthesis of polyvinylpyrrolidone stabilized palladium nanoparticles followed by their immobilization on the nano sized substrate surface(nanocomposites 2).The reaction between phenylboronic acid and iodobenzene is chosen as a model one.The dependence of the catalytic activity of catalysts on the method of their synthesis was established.It was established that nanocomposites 2 exhibit higher catalytic activity in the selected reaction compared to the nanocomposites 1.The TOF values for the nanocomposites 1 are 6663~14617 h 1 when using the substrate Ce(OH)CO 3 and 13774~27084 h 1 when using the substrate Y(OH)CO 3,while the nanocomposites 2 reveal TOF = 87287 h 1 for the substrate Ce(OH)CO 3 and TOF = 97746 h 1 for the substrate Y(OH)CO 3 under other equal conditions.In addition,nanocomposites 2 "work" at room temperature giving a high yield of the desired product.It is noted that the support nanoparticles Y(OH)CO 3 and Ce(OH)CO 3 also exhibit catalytic activity.The yield of the final product of the reaction using them as catalysts is 55%(TOF = 11 and 8 h 1,respectively).Thus,the use of yttrium and cerium hydroxycarbonates as supports allows to decrease the palladium content in the nanocomposites to 0.01%~1% and,consequently,reduce the cost of the catalyst while maintaining its high catalytic activity.
基金The work was carried out in the Sustainable Bioenergy Solutions for Tomorrow(BEST)research program coordinated by CLIC Innovation with funding from the Finnish Funding Agency for Innovation,Tekes(http://www.clicinnovation.fi)funded by CONVER-B project(Academy of Finland)and the Karelia CBC Programme 2014-2020 funded project“Reaching congenial region through valorization of municipal and industrial waste waters and sludge”KA4020.
文摘Elevating public awareness of waste management at the household level is a cost effective and a win-win social, economic and environmental approach on the table of policymaking. Modern and effective waste management bring about broader economic efficiency and social equity, mitigate consumerism, thus, promoting the conservation of natural resources. In this article, a survey study was conducted among the citizens of Wrocław city, Poland. The city is dynamic, touristic, and industrial. Through random sampling, 160 respondents filled in the questionnaire. The results revealed that the participants appeared aware of the benefits of waste management (WM);however the current WM systems and infrastructures are not very satisfying. The participants identified several shortcomings in the current WM systems such as the lack of sufficient colored bins for glass recycling, overfilled bins and heavy lids, and irregular waste collection system. The study proposes a public-oriented outreach campaign targeting waste separation and less-waste behaviors as economically and environmentally beneficial, accompanied by continuous development of WM regulations and infrastructures and linked it to waste-to-energy systems and technologies to assist in achieving the long-term energy and emissions-reduction targets.
基金suported by the Coordenacao de Aperfeicoamento de Pessoal de Nível Superior(CAPES),through the PSDE program,process number BEX:2939/12-6.
文摘We review the management of Eucalyptus species under a coppice-with-standards (CWS) silvicultural system. CWS management results in product diversification, permitting production of small and large scale timber from the same stand. Eucalyptus species are suitable candidates for CWS management because: there are large worldwide plantation areas, sprouting capacity is high, and eucalypts are multipur- pose species. We discuss (1) short rotation Eucalyptus coppice manage- ment for energy and pulping and (2) Eucalyptus seedling management for solid wood products. We review the literature and discuss experi- ences with Eucalyptus managed under the CWS system. We also assess projects dealing with Eucalyptus coppice management, stand density regulation, pruning, and stand and wood quality. The growth environ- ment of the standard trees (heavy competition up to the first harvest, free growth afterwards) coupled with long rotations (〉20 years) results in high quality logs for solid wood products. Early pruning should be ap- plied to enhance wood quality. We propose a system for the silvicultural management of Eucalyptus under the CWS system, elaborating on the consequences of initial planting density, site productivity, and standard tree densities as well as timing of basic silvicultural applications.