This study aimed to investigate the release properties of slow release ure- a coated by industrial lignin and the influences of temperature, pH and post-ripening period on the release of nutrients in coated urea. Acco...This study aimed to investigate the release properties of slow release ure- a coated by industrial lignin and the influences of temperature, pH and post-ripening period on the release of nutrients in coated urea. According to the experimental results, the release of nutrients in coated fertilizers showed an S-shaped curve; on the 28th d, the nutrient release rate reached 73.77%; the differential solubility was 1.83%, and the theoretical release period was 50.25 d. The release of nutrients was significantly influenced by temperature. As the incubation temperature rose from 25 to 40 ℃, preliminary solubility increased from 8.03% to 16.24%; differential solubility increased from 1.83% to 1.88%; theoretical release period was reduced from 51.25 d to 45.55 d. The release of nutrients was promoted by H＋ and OH-. After they were placed at room temperature within 30 d, coated fertilizers exhibited the optimal release properties.展开更多
In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and ...In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and wood pulp cellulose are used to enhance the filtration by improving filter cake structure and properties in the filtration of a biological health product and a highly viscous chemical fiber polymer melt product. The property of solid/liquidsystems, filtration at different flow rates, specitic cake resistance, cake wetness, filtration rate, filtrate turbidity for filter aid selection and evaluation, and operation optimization are investigated. The results are successfully applied to industrial process, .and can be used as a reference for similar filtration applications.展开更多
The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran. Due to the destruction of the forests and lack of proper ...The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran. Due to the destruction of the forests and lack of proper plantation, replacement of the forest wood by the fast growing wood is vital to satisfy all requirements of these factories. A hierarchy was used to prioritize benefits, opportunities, costs and risks （BOCR） using the Analytic Hierarchy Process （AHP） ratings approach. To evaluate the ＂control criteria＂ of the system, a control hierarchy was also created and prioritized by applying the Analytic Network Process （ANP）. A total of four major control criteria in the system are prioritized where each one controls a network structure evaluated by using ANE The final synthesis results of the system showed that internal poplar tree farming supplied by the forest product factories was the best choice among three potential alternatives （factory procurement, external procurement and mix procurement）.展开更多
The requirements that a business needs to consider when building a wood panels manufacturing plant are much the same as they have been for decades, but today there is also the need for multiple environmental studies a...The requirements that a business needs to consider when building a wood panels manufacturing plant are much the same as they have been for decades, but today there is also the need for multiple environmental studies and permits. These are costly and time consuming additional expenses that often are the longest lead-time items on any project. Most industrialized countries have legislation in place to limit and control the negative impact that emission of pollutants may have on the environment. This paper discusses what is actually happening inside wood drying plants, and the prerequisite conditions for genesis of pyrolytic products relative to the operational parameters, such as choice of input raw materials, driers design and operational regime, choice of fuels for the heat generation and how these factors influence production of stack emission. The characterization of emission condensate by analytical methods is described, and survey of emission control system in use worldwide is described, and means of investigating what may be the optimum design for the control of emission is discussed. Alternate uses of utilizing the condensate, other than burning, are presented for consideration.展开更多
The supply of logs for wood industries during the period 2004-2008 was 13.5-32 million cubic meters per year. Logs from plantation forest reached about 65%, which was exploited from industrial plantation forest, Perum...The supply of logs for wood industries during the period 2004-2008 was 13.5-32 million cubic meters per year. Logs from plantation forest reached about 65%, which was exploited from industrial plantation forest, Perum Perhutani, as a government enterprise, community forest and estate. The changing log supply from natural forest to plantation forest implies changing of wood species, cutting cycle, log diameter and wood properties. Research concerning the utilization of fast growing species, small log diameter, lesser used species and other llignocellulosic material have been intensively done by some research institutes and universities, and were related to wood properties, wood properties enhancement, wood chemistry, bio-composite, wood engineering, and also non-timber forest products.展开更多
The civil engineering profession, in an adaptive reaction to emerging roles for civil engineers, is recognizing the need for new engineers to possess a more robust skill set than just the typical design background. Th...The civil engineering profession, in an adaptive reaction to emerging roles for civil engineers, is recognizing the need for new engineers to possess a more robust skill set than just the typical design background. This paper describes the efforts of Clemson Engineers for Developing Countries （CEDC） to fulfill the more nontraditional and often unaddressed ＂learning outcomes＂ noted by ASCE＇s Civil Engineering Body of Knowledge lbr the 21st Century as important prerequisites for licensure. The learning outcomes are addressed through ongoing international service learning projects in Cange, Haiti. The paper focuses on the following four outcomes and their fulfillment methods： leadership, globalization, teamwork, and communications. The student led organization has allowed students to set up their own fundraising mechanisms, to seek out members to join design review boards, and to develop their own project objectives. This level of student autonomy is n,3ted as key to ensuring that students achieve competency in these four areas.展开更多
Sustainable construction in the future will be influenced significantly by the beliefs and actions of civil engineering students studying at university today. A comparative investigation of the appreciation and attitu...Sustainable construction in the future will be influenced significantly by the beliefs and actions of civil engineering students studying at university today. A comparative investigation of the appreciation and attitudes regarding sustainable construction of civil engineering students at The NUCE （National University of Civil Engineering） in Vietnam, and the Universities of Loughborough and Liverpool in the UK were therefore conducted. Results indicate that students at all three universities appreciate the importance of the development of sustainable construction and have positive attitudes with regards to sustainability. Construction design and appropriate use of materials were two issues generally considered the most important with regards to sustainability, but were also thought to be adequately covered on the courses in all three institutions.展开更多
The Natural Forest Protection(NFP) program is one of the Six Key Forestry Projects which were adopted by the Chinese Government since the 1980s to address important natural issues in China. It advanced to protecting a...The Natural Forest Protection(NFP) program is one of the Six Key Forestry Projects which were adopted by the Chinese Government since the 1980s to address important natural issues in China. It advanced to protecting and restoring the structures and functions of the natural forests through sustainable forest management. However, the role of forest carbon storage and tree carbon pool dynamics since the adoption of the NFP remains unknown. To address this knowledge gap, this study calculated forest carbon storage(tree, understory, forest floor and soil) in the forest region of northeastern(NE) China based on National Forest Inventory databases and field investigated databases. For tree biomass, this study utilized an improved method for biomass estimation that converts timber volume to total forest biomass; while for understory, forest floor and soil carbon storage, this study utilized forest type-specific mean carbon densities multiplied by their areas in the region. Results showed that the tree carbon pool under the NFP in NE China functioned as a carbon sink from 1998 to 2008, with an increase of 6.3 Tg C/yr, which was mainly sequestrated by natural forests(5.1 Tg C/yr). At the same time, plantations also acted as a carbon sink, reflecting an increase of 1.2 Tg C/yr. In 2008, total carbon storage in forests covered by the NFP in NE China was 4603.8 Tg C, of which 4393.3 Tg C was stored in natural forests and 210.5 Tg C in planted forests. Soil was the largest carbon storage component, contributing 69.5%–77.8% of total carbon storage; followed by tree and forest floor, accounting for 16.3%–23.0% and 5.0%–6.5% of total carbon storage, respectively. Understory carbon pool ranged from 1.9 to 42.7 Tg C, accounting for only 0.9% of total carbon storage.展开更多
基金Supported by Fund for Transformation of Scientific and Technological Achievements(2011GB24910009)Key Project of National Science&Technology Pillar Program(2011BAC11B01)Science and Technology Cooperation Program of Chinese Academy of Sciences and Hubei Province(YD20111215)~~
文摘This study aimed to investigate the release properties of slow release ure- a coated by industrial lignin and the influences of temperature, pH and post-ripening period on the release of nutrients in coated urea. According to the experimental results, the release of nutrients in coated fertilizers showed an S-shaped curve; on the 28th d, the nutrient release rate reached 73.77%; the differential solubility was 1.83%, and the theoretical release period was 50.25 d. The release of nutrients was significantly influenced by temperature. As the incubation temperature rose from 25 to 40 ℃, preliminary solubility increased from 8.03% to 16.24%; differential solubility increased from 1.83% to 1.88%; theoretical release period was reduced from 51.25 d to 45.55 d. The release of nutrients was promoted by H＋ and OH-. After they were placed at room temperature within 30 d, coated fertilizers exhibited the optimal release properties.
文摘In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and wood pulp cellulose are used to enhance the filtration by improving filter cake structure and properties in the filtration of a biological health product and a highly viscous chemical fiber polymer melt product. The property of solid/liquidsystems, filtration at different flow rates, specitic cake resistance, cake wetness, filtration rate, filtrate turbidity for filter aid selection and evaluation, and operation optimization are investigated. The results are successfully applied to industrial process, .and can be used as a reference for similar filtration applications.
文摘The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran. Due to the destruction of the forests and lack of proper plantation, replacement of the forest wood by the fast growing wood is vital to satisfy all requirements of these factories. A hierarchy was used to prioritize benefits, opportunities, costs and risks （BOCR） using the Analytic Hierarchy Process （AHP） ratings approach. To evaluate the ＂control criteria＂ of the system, a control hierarchy was also created and prioritized by applying the Analytic Network Process （ANP）. A total of four major control criteria in the system are prioritized where each one controls a network structure evaluated by using ANE The final synthesis results of the system showed that internal poplar tree farming supplied by the forest product factories was the best choice among three potential alternatives （factory procurement, external procurement and mix procurement）.
文摘The requirements that a business needs to consider when building a wood panels manufacturing plant are much the same as they have been for decades, but today there is also the need for multiple environmental studies and permits. These are costly and time consuming additional expenses that often are the longest lead-time items on any project. Most industrialized countries have legislation in place to limit and control the negative impact that emission of pollutants may have on the environment. This paper discusses what is actually happening inside wood drying plants, and the prerequisite conditions for genesis of pyrolytic products relative to the operational parameters, such as choice of input raw materials, driers design and operational regime, choice of fuels for the heat generation and how these factors influence production of stack emission. The characterization of emission condensate by analytical methods is described, and survey of emission control system in use worldwide is described, and means of investigating what may be the optimum design for the control of emission is discussed. Alternate uses of utilizing the condensate, other than burning, are presented for consideration.
文摘The supply of logs for wood industries during the period 2004-2008 was 13.5-32 million cubic meters per year. Logs from plantation forest reached about 65%, which was exploited from industrial plantation forest, Perum Perhutani, as a government enterprise, community forest and estate. The changing log supply from natural forest to plantation forest implies changing of wood species, cutting cycle, log diameter and wood properties. Research concerning the utilization of fast growing species, small log diameter, lesser used species and other llignocellulosic material have been intensively done by some research institutes and universities, and were related to wood properties, wood properties enhancement, wood chemistry, bio-composite, wood engineering, and also non-timber forest products.
文摘The civil engineering profession, in an adaptive reaction to emerging roles for civil engineers, is recognizing the need for new engineers to possess a more robust skill set than just the typical design background. This paper describes the efforts of Clemson Engineers for Developing Countries （CEDC） to fulfill the more nontraditional and often unaddressed ＂learning outcomes＂ noted by ASCE＇s Civil Engineering Body of Knowledge lbr the 21st Century as important prerequisites for licensure. The learning outcomes are addressed through ongoing international service learning projects in Cange, Haiti. The paper focuses on the following four outcomes and their fulfillment methods： leadership, globalization, teamwork, and communications. The student led organization has allowed students to set up their own fundraising mechanisms, to seek out members to join design review boards, and to develop their own project objectives. This level of student autonomy is n,3ted as key to ensuring that students achieve competency in these four areas.
文摘Sustainable construction in the future will be influenced significantly by the beliefs and actions of civil engineering students studying at university today. A comparative investigation of the appreciation and attitudes regarding sustainable construction of civil engineering students at The NUCE （National University of Civil Engineering） in Vietnam, and the Universities of Loughborough and Liverpool in the UK were therefore conducted. Results indicate that students at all three universities appreciate the importance of the development of sustainable construction and have positive attitudes with regards to sustainability. Construction design and appropriate use of materials were two issues generally considered the most important with regards to sustainability, but were also thought to be adequately covered on the courses in all three institutions.
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05060200)National Key Technology Research and Development Program of China(No.2012BAD22B04)Visiting Professorship for Senior International Scientists of Chinese Academy of Sciences(No.2012T1Z0006)
文摘The Natural Forest Protection(NFP) program is one of the Six Key Forestry Projects which were adopted by the Chinese Government since the 1980s to address important natural issues in China. It advanced to protecting and restoring the structures and functions of the natural forests through sustainable forest management. However, the role of forest carbon storage and tree carbon pool dynamics since the adoption of the NFP remains unknown. To address this knowledge gap, this study calculated forest carbon storage(tree, understory, forest floor and soil) in the forest region of northeastern(NE) China based on National Forest Inventory databases and field investigated databases. For tree biomass, this study utilized an improved method for biomass estimation that converts timber volume to total forest biomass; while for understory, forest floor and soil carbon storage, this study utilized forest type-specific mean carbon densities multiplied by their areas in the region. Results showed that the tree carbon pool under the NFP in NE China functioned as a carbon sink from 1998 to 2008, with an increase of 6.3 Tg C/yr, which was mainly sequestrated by natural forests(5.1 Tg C/yr). At the same time, plantations also acted as a carbon sink, reflecting an increase of 1.2 Tg C/yr. In 2008, total carbon storage in forests covered by the NFP in NE China was 4603.8 Tg C, of which 4393.3 Tg C was stored in natural forests and 210.5 Tg C in planted forests. Soil was the largest carbon storage component, contributing 69.5%–77.8% of total carbon storage; followed by tree and forest floor, accounting for 16.3%–23.0% and 5.0%–6.5% of total carbon storage, respectively. Understory carbon pool ranged from 1.9 to 42.7 Tg C, accounting for only 0.9% of total carbon storage.
