Deep drawing is one of the most important processes for forming sheet metal parts.It is widely used for mass production of cup shapes in automobile,aerospace and packaging industries.Cup drawing,besides its importance...Deep drawing is one of the most important processes for forming sheet metal parts.It is widely used for mass production of cup shapes in automobile,aerospace and packaging industries.Cup drawing,besides its importance as forming process,also serves as a basic test for the sheet metal formability.The effect of equipment and tooling parameters results in complex deformation mechanism.Existence of thickness variation in the formed part may cause stress concentration and may lead to acceleration of damage.Using TAGUCHI's signal-to-noise ratio,it is determined that the die shoulder radius has major influence followed by blank holder force and punch nose radius on the thickness distribution of the deep drawn cup of AA 6061 sheet.The optimum levels of the above three factors,for the most even wall thickness distribution,are found to be punch nose radius of 3 mm,die shoulder radius of 8 mm and blank holder force of 4 kN.展开更多
Coffee cultivation by using shade trees is simple of agroforestry, this system could get better ecosystem service and sustainable agricultural. The aims of this research are to study the possibility of some species of...Coffee cultivation by using shade trees is simple of agroforestry, this system could get better ecosystem service and sustainable agricultural. The aims of this research are to study the possibility of some species of industrial woods as shade trees of Coffea canephora. The research was conducted in Jember, Indonesia (45 m asl., D rainfall type according to Schmidt and Ferguson), and arranged in split plot design. The main plots were (A) coffee-T, grandis (3 m × 2.5 m ×12 m), (B) coffee-P, falcataria single row (2.5 m ×6 m), (C) coffee-P, falcataria double rows (3 m× 2.5 m × 12 m), (D) coffee-P, falcataria vat. Solomon (3 m× 2.5 m × 12 m), (E) coffee-M, azedarach (3 m ×5 m ×22.5 m), (F) coffee-H, macrophyllus (3 m ×5 m ×12.5 m), and (G) coffee-Leucaena sp. (3 m × 2.5 m) as control. The sub plots were coffee clones, i.e., BP 534, BP 409, BP 936, dan BP 939. Among those timber trees, Leucaena was planted as the alternative shade trees. The result showed that in comparison with control, all of coffee agroforestry system improved carbon sequestration. Total C-stock on (B) was highest, i.e., 1,007 percent to control while the lowest one was (A) 317.44% to control. During one year observation, litter weight of H. macrophyllus was heaviest followed by T. grandis. The lightest litter was obtained from M. azedarach. Based on its mineral contents, litters of T. grandis potentially supplied back nutrients that equaled to total Urea, SP-36, KC1, Dolomite, and Kieserite as much as 574.14 g; P. falcataria 287.57 g, P. falcataria var. Solomon 453.59 g, M. azedarach 450.84 g, H. macrophyllus 877.56 g, and Leucaena 445.12 g per tree per year. Because of heavily fallen leaves of M. azedarach during dry season and conversely too dense shading of H. macrophyllus, bean yield at 4 and 5 years old by using both species were consistently lower than that under T. grandis, P. falcataria and control. At those ages, effect of clone on cherry yield was still not consistent but there was a tendency that BP 939 was most productive, while BP 534 was the less. Its outturn was not influenced by agroforestry system but by clones. The agroforestry pattern influence physical bean characters, more dense of shading, more single bean and empty bean. That bean abnormality also genetically, on BP 939 percentage of round and empty bean was highest while on BP 936 was lowest. It was concluded that coffee agroforestry improve ecology service, but M. azedarach and H. macrophyllus were not appropriate to be used as coffee shade trees. P. falcataria is recommended as an alternative shade tree beside Leucaena sp.展开更多
An approach for the economic analysis of chemical product design is proposed. It takes into account of customers' preference on product quality and economic considerations such as pricing, profit, market share, ca...An approach for the economic analysis of chemical product design is proposed. It takes into account of customers' preference on product quality and economic considerations such as pricing, profit, market share, capital investment, and operating cost. The activities needed to support business decision making – identifying product quality, estimating product cost, calculating financial metrics, and performing make–buy analysis – are discussed.The design of a Ganoderma lucidum dietary supplement, a traditional Chinese medicinal(TCM) product, is used to illustrate all the activities in this approach.展开更多
Fermented Callliandra, Gliricidia and Leucaena browses and maize material (milk stage) were applied to the soil to determine their effect on soil productivity. Hopi Red Dye Amaranthus (Amaranthus cruentus) was use...Fermented Callliandra, Gliricidia and Leucaena browses and maize material (milk stage) were applied to the soil to determine their effect on soil productivity. Hopi Red Dye Amaranthus (Amaranthus cruentus) was used as the test crop. Its DM yield was determined. The browse materials had higher total N and narrower C:N ratio than the maize material. Calliandra material had higher levels of insoluble fiber (ADF), fiber bound N (ADFN) and lignin. Application of the browse and maize materials raised C, N, and C:N ratio of the soil in which they were applied compared to the control soil. The treated soils maintained higher levels of C and N and a narrower C:N ratio up to the third crop. Amaranthus DM yield was highest (P 〈 0.05) with browse treatments. Treatment with maize material did not have DM yield advantage over the control soil. Treatments with browse materials could have given higher yields because the materials had more N and fermentation could not only have increased the proportion of soluble N, but also degradability of the materials, thus making the N and other nutrients in the fermented materials available for plant growth. DM yield was highest (P 〈_ 0.05) with the first and third crops but lowest (P 〈 0.05) with the second crop. Plant growth in the second crop could have coincided with high demand for the N by the soil micro-organisms decomposing the added materials. During the third crop, decomposition of the readily degradable components of the added materials could have been complete and the N became available for plant growth. DM yield dropped (P 〈 0.05) with the fourth crop as the available N could have been depleted from the soil for plant growth.展开更多
Freeze drying or lyophilization of aqueous solutions is widely used in pharmaceutical industry. The in-creased importance Of the process is gaining a worldwide interest of research. A growing body of literature has de...Freeze drying or lyophilization of aqueous solutions is widely used in pharmaceutical industry. The in-creased importance Of the process is gaining a worldwide interest of research. A growing body of literature has demonstrated that the scientific approach can result in improved product quality with minimum trial and error em-piricism. Formulation and process development need a systematical understanding of the physical chemistry of freezing and freeze drying, material science and mechanisms of heat and mass transfer. This paper presents an overview on freeze ding of aqueous solutions based on publications in the past few decades. The important issuesof the process are analyzed.展开更多
Tomato is one of the most widely produced and consumed vegetable crops in Ethiopia. It is not produced during the rainy season, mainly due to high disease pressure and low soil temperature. Therefore, an experiment wa...Tomato is one of the most widely produced and consumed vegetable crops in Ethiopia. It is not produced during the rainy season, mainly due to high disease pressure and low soil temperature. Therefore, an experiment was conducted to study the effect of different types of mulch (black and white plastic mulch as well as grass mulch) on early yield of tomato varieties (Miya & Cochoro) under polyhouse growing condition at Bahir Dar during the rainy season in 2012. Treatments were arranged in 4 - 2 factorial combinations in randomized complete block design with three replications. One month old seedlings were transplanted on 8.4 m2 gross plots size (3 m x 2.8 m) at a spacing of 70 cm x 40 cm between rows and plants, respectively. Data recorded from plants found in the two middle rows of each plot. Di-ammonium phosphate (DAP) and Urea fertilizers were applied at the rate of 200 kg and 100 kg/ha, respectively. Sixteen plants were considered for data collection in each plot. White plastic mulch resulted in significantly (P 〈 0.05) earlier flowering, fruit setting and fruit maturity compared to other mulching materials. Varieties were also significantly different in days required to flowering, fruit setting and fruit maturity. Miya took significantly short period to flower, fruit set and fruit maturity compared to Cochoro variety. The effect of different mulch types on early fruit yield was found statistically significant. The highest early marketable fruit yield of 10.99 ton/ha and 10.54 ton/ha were recorded when Miya variety was grown with white and black plastic mulch, respectively. Therefore, use of white and black plastic mulches recommended for early tomato fruit yield.展开更多
Cassava (Manihot esculenta Crantz) is a perennial woody shrub with an edible root, which grows in tropical and subtropical areas of the world. In Africa, cassava provides a basic daily source of dietary energy. It p...Cassava (Manihot esculenta Crantz) is a perennial woody shrub with an edible root, which grows in tropical and subtropical areas of the world. In Africa, cassava provides a basic daily source of dietary energy. It plays an important role in food security and incomes of many rural households in the southern Ethiopia. However, information available on production practices of cassava for the region is insufficient. Hence, field experiment was conducted at Awassa Agricultural Research Center for two successive cropping seasons from 2004 to 2006 to investigate the response of cassava to planting position and planting material. The treatments used were three planting positions (slant, vertical and horizontal) and five planting materials (main stem top part, main stem middle part, main stem bottom part, branch stake top part and branch stake bottom part) were combined in factorial arrangement and laid out in randomized complete block design with three replications. The result revealed that root yield was significantly (P 〈 0.05) affected by the interaction effects of the planting position and planting material. The highest yield (25.2 ton ha^-1) was obtained from the main stem top part planted in slant position whereas the least yield (6.5 ton ha^-1) was obtained from main stem bottom part planted in horizontal position. Based on the findings of this study, areas like Awassa with moderate rainfall slant and vertical planting of main stem top and middle parts could be used as planting material.展开更多
Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advance...Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advances necessitates a change and evolution in building envelopes. Controlling the energy consumption of the buildings is mostly through controlling the energy performance of the building envelopes. New technologies lead to the intelligent facades and envelopes. The envelope can be designed to be a part of the whole building's metabolism (energy production, storage and consumption) and morphology. The envelope would be a controlled part of the building which is managed through the central control system of the building, which connects it to other parts. It caused building envelope design to be changed fundamentally, so that there is a need to interact with engineering disciplines including computer engineering, mechanical engineering, material engineering and so on. All of these caused building envelope to get closer to biological and living systems. The physical restrictions which affect buildings system and living systems are the same. So they cause the same forces to shape the structure and form of the systems and the same rules to interact with the environment. The restrictions of material and energy resources caused living systems to be energy efficient and consuming less material. But the most important difference between living systems and building systems is in maximum use of different resources. As living systems use information maximally, the building system technology is based on using maximum energy. Now, there are many reasons and restrictions that building envelopes cannot act like living systems. But technological developments and contributing more disciplines in design and construction of building envelopes caused the future way of these envelopes get close to living systems for their energy efficiency. Some of living systems characteristics which the future building envelopes would have partially or benefit for the design process or construction are self-organization, evolution principles, hierarchical levels, processing energy, reaction to environmental stimuli and self-adjustment. Self-organization is achieved in some design software and in building material production for creating formal patterns. Evolution principles provide infrastructure for soft wares for optimization purposes and form creation. Hierarchical levels refer to giving hierarchical structure to the building envelopes through layering and designing different scales. Processing energy (metabolism) would be achieved through photovoltaic and solar collectors to produce energy and in passive systems for energy storage and distribution. Controlling solar radiation absorption and transmittance would help energy transfer from outside to building and vice versa. Reaction to environmental stimuli which is one of the most important characteristics of future building envelopes would use different types of active and passive sensors to create envelope mechanical reactions through material properties or collect data for processing in the control center to determine the right reaction. The reaction would be through different strategies such as changing properties and moving. Reaction could be passive or active. Self-adjustment can be achieved by control systems and processing units. All of these mean intelligent envelopes are essential parts of future buildings. Though it is now started with new design soft wares based on biological principles to optimize different parameters affecting the envelope function or to create the most efficient form.展开更多
It is observed contamination and subsequent growth of various types of mycotoxins in the production and processing of grain and non-grain crops. The contamination of grain and non-grain cereals crops harvest was analy...It is observed contamination and subsequent growth of various types of mycotoxins in the production and processing of grain and non-grain crops. The contamination of grain and non-grain cereals crops harvest was analyzed. The aim of this research is using of microwave energy to disinfect grains of harvest and giving new properties to the grains and plants materials. The author has presented researches of the grains disinfection, during seedbed preparation and post processing. Rational parameters of heating rates of different biological objects were identified, revealed their dependence and impact on infection pathogens, through using of microwave energy technology. The author found a reduction of the number of pathogenic microbes and organisms at the various stages of processing agricultural products during using of microwave energy, and found new qualitative indicators of the products properties.展开更多
Semiconducting silicon(Si)nanomaterials have great potential for the applications in electronics,physics,and energy storage fields.However,to date,it is still a challenge to realize the batch production of Si nanomate...Semiconducting silicon(Si)nanomaterials have great potential for the applications in electronics,physics,and energy storage fields.However,to date,it is still a challenge to realize the batch production of Si nanomaterials via efficient and low-cost approaches,owing to some long-standing shortcomings,e.g.,complex procedures and time and/or energy consumption.Herein,we report a green and inexpensive method to rapidly obtain two-dimensional(2D)free-standing Si/SiO_(x) nanosheets via the rapid thermal exfoliation of layered Zintl compound CaSi_(2).With the help of the rapid exfoliation reaction of CaSi_(2) in the atmosphere of greenhouse gas CO_(2),and the following mild sonication,2D free-standing Si/SiO_(x) nanosheets can be produced with very high yield.After applying the coating of a thin carbon outer layer,the electrodes of Si/SiO_(x)/C nanosheets serving as the anodes for lithium-ion batteries exhibit ultrahigh reversible capacity and outstanding electrochemical stability.We expect this study will provide new insights and inspirations for the convenient and batch production of nanostructural Si-based anode materials towards high-performance lithium-ion batteries.展开更多
Fiber-shaped energy storage devices are indispensable parts of wearable and portable electronics.Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic ...Fiber-shaped energy storage devices are indispensable parts of wearable and portable electronics.Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic electrolytes, high ionic conductivity, and low cost. Unfortunately, the low energy density,poor power density and cycling performance hinder its further practical applications. In this study, in order to obtain high performance negative iron-based material, we first synthesized a-iron oxide(α-Fe2O3) nanorods(NRs) with superstructures on the surface of highly conductive carbon nanotube fibers(CNTFs), then electrically conductive polypyrrole(PPy) was coated to enhance the electron, ion diffusion and cycle stability. The as-prepared α-Fe2O3@PPy NRs/CNTF electrode shows a high specific capacity of 0.62 Ah cm-3 at the current density of 1 A cm-3. Furthermore, the Ni/Fe battery that was assembled by the above negative electrode shows a maximum volumetric energy density of 15.47 mWh cm-3 with228.2 mW cm-3 at a current density of 1 A cm-3. The cycling durability and mechanical flexibility of the Ni/Fe battery were tested, which show good prospect for practical application. In summary, these merits make it possible for our Ni/Fe battery to have practical applications in next generation flexible energy storage devices.展开更多
This paper deals with the output improvement of heating and cooling cycle by using the work-fluid including phase change material.The experimental study is carried out by heat exchange between work-fluid and heat tran...This paper deals with the output improvement of heating and cooling cycle by using the work-fluid including phase change material.The experimental study is carried out by heat exchange between work-fluid and heat transfer surface.The work-fluid is flown to a high temperature or a low temperature heat transfer surface from the narrow path.In order to increase the amount of the heat transmission,a trace of Diethylether(boiling point 34.8 ℃),as a phase change material(PCM),is added to the work-fluid.The parameters of the experiment are additive amount of PCM,the rotational speed of the displacer piston and the temperature of heat transfer surface.It is clarified that the increasing of engine cycle output is brought by the PCM addition.The effect of PCM addition is evaluated by output ratio which is defined from the experimental cycle output data.The requirements for acquiring the increasing effect of output by adding PCM are clarified.展开更多
The use of plant materials as soil amendments is an uncommon practice amongst major farming communities in Ghana, although it is necessary for soil fertility improvement. An examination of the effects of soil amendmen...The use of plant materials as soil amendments is an uncommon practice amongst major farming communities in Ghana, although it is necessary for soil fertility improvement. An examination of the effects of soil amendments is necessary to encourage the use of under-utilized organic resources in Ghana. Thus, a field experiment was conducted using 8 different tropical plant materials mixed with chicken manure as soil amendments for growth of tomato as a test crop. The plant materials included Leucaena leueocephala, Centrosema pubescens, Sesbania sesban, Gliricidia sepium, Mucuna pruriens, Pueraria phaseoloides, Azadirachta indiea, and Theo- broma cacao. There were two other treatments: one with equivalent amounts of chemical fertilizers and the other with no-fertilizer input (control). Plant materials were mixed with chicken manure to obtain a uniform carbon-to-nitrogen (C:N) ratio of 5:1. Except the no-fertilizer control, all treatments received the same amount of nitrogen (N). To clarify the decomposition pattern of the plant materials in soil, an incubation experiment was conducted using only the plant materials before the field experiment. The Glirieidia treatment released significantly more mineral N than the other plant materials in the incubation experiment. However, the tomato fruit yield was not enhanced in the Gliricidia treatment in the field experiment. The known quality parameters of the tested plant materials, such as total N, total carbon (C), C:N ratio, and total polyphenols, had minimal effects on their mineralization dynamics. Azadirachta showed the best synergistic effect with chicken manure through significantly increasing soil microbial biomass and fruit yield of tomato. This result provides insights into the possible adoption of Azadirachta in combination with chicken manure as a soil amendment in small-scale agricultural holdings.展开更多
文摘Deep drawing is one of the most important processes for forming sheet metal parts.It is widely used for mass production of cup shapes in automobile,aerospace and packaging industries.Cup drawing,besides its importance as forming process,also serves as a basic test for the sheet metal formability.The effect of equipment and tooling parameters results in complex deformation mechanism.Existence of thickness variation in the formed part may cause stress concentration and may lead to acceleration of damage.Using TAGUCHI's signal-to-noise ratio,it is determined that the die shoulder radius has major influence followed by blank holder force and punch nose radius on the thickness distribution of the deep drawn cup of AA 6061 sheet.The optimum levels of the above three factors,for the most even wall thickness distribution,are found to be punch nose radius of 3 mm,die shoulder radius of 8 mm and blank holder force of 4 kN.
文摘Coffee cultivation by using shade trees is simple of agroforestry, this system could get better ecosystem service and sustainable agricultural. The aims of this research are to study the possibility of some species of industrial woods as shade trees of Coffea canephora. The research was conducted in Jember, Indonesia (45 m asl., D rainfall type according to Schmidt and Ferguson), and arranged in split plot design. The main plots were (A) coffee-T, grandis (3 m × 2.5 m ×12 m), (B) coffee-P, falcataria single row (2.5 m ×6 m), (C) coffee-P, falcataria double rows (3 m× 2.5 m × 12 m), (D) coffee-P, falcataria vat. Solomon (3 m× 2.5 m × 12 m), (E) coffee-M, azedarach (3 m ×5 m ×22.5 m), (F) coffee-H, macrophyllus (3 m ×5 m ×12.5 m), and (G) coffee-Leucaena sp. (3 m × 2.5 m) as control. The sub plots were coffee clones, i.e., BP 534, BP 409, BP 936, dan BP 939. Among those timber trees, Leucaena was planted as the alternative shade trees. The result showed that in comparison with control, all of coffee agroforestry system improved carbon sequestration. Total C-stock on (B) was highest, i.e., 1,007 percent to control while the lowest one was (A) 317.44% to control. During one year observation, litter weight of H. macrophyllus was heaviest followed by T. grandis. The lightest litter was obtained from M. azedarach. Based on its mineral contents, litters of T. grandis potentially supplied back nutrients that equaled to total Urea, SP-36, KC1, Dolomite, and Kieserite as much as 574.14 g; P. falcataria 287.57 g, P. falcataria var. Solomon 453.59 g, M. azedarach 450.84 g, H. macrophyllus 877.56 g, and Leucaena 445.12 g per tree per year. Because of heavily fallen leaves of M. azedarach during dry season and conversely too dense shading of H. macrophyllus, bean yield at 4 and 5 years old by using both species were consistently lower than that under T. grandis, P. falcataria and control. At those ages, effect of clone on cherry yield was still not consistent but there was a tendency that BP 939 was most productive, while BP 534 was the less. Its outturn was not influenced by agroforestry system but by clones. The agroforestry pattern influence physical bean characters, more dense of shading, more single bean and empty bean. That bean abnormality also genetically, on BP 939 percentage of round and empty bean was highest while on BP 936 was lowest. It was concluded that coffee agroforestry improve ecology service, but M. azedarach and H. macrophyllus were not appropriate to be used as coffee shade trees. P. falcataria is recommended as an alternative shade tree beside Leucaena sp.
文摘An approach for the economic analysis of chemical product design is proposed. It takes into account of customers' preference on product quality and economic considerations such as pricing, profit, market share, capital investment, and operating cost. The activities needed to support business decision making – identifying product quality, estimating product cost, calculating financial metrics, and performing make–buy analysis – are discussed.The design of a Ganoderma lucidum dietary supplement, a traditional Chinese medicinal(TCM) product, is used to illustrate all the activities in this approach.
文摘Fermented Callliandra, Gliricidia and Leucaena browses and maize material (milk stage) were applied to the soil to determine their effect on soil productivity. Hopi Red Dye Amaranthus (Amaranthus cruentus) was used as the test crop. Its DM yield was determined. The browse materials had higher total N and narrower C:N ratio than the maize material. Calliandra material had higher levels of insoluble fiber (ADF), fiber bound N (ADFN) and lignin. Application of the browse and maize materials raised C, N, and C:N ratio of the soil in which they were applied compared to the control soil. The treated soils maintained higher levels of C and N and a narrower C:N ratio up to the third crop. Amaranthus DM yield was highest (P 〈 0.05) with browse treatments. Treatment with maize material did not have DM yield advantage over the control soil. Treatments with browse materials could have given higher yields because the materials had more N and fermentation could not only have increased the proportion of soluble N, but also degradability of the materials, thus making the N and other nutrients in the fermented materials available for plant growth. DM yield was highest (P 〈_ 0.05) with the first and third crops but lowest (P 〈 0.05) with the second crop. Plant growth in the second crop could have coincided with high demand for the N by the soil micro-organisms decomposing the added materials. During the third crop, decomposition of the readily degradable components of the added materials could have been complete and the N became available for plant growth. DM yield dropped (P 〈 0.05) with the fourth crop as the available N could have been depleted from the soil for plant growth.
基金Supported by the National Natural Science Foundation of China(21076042)Research Grants Council of Hong Kong SAR (RGC 600704)
文摘Freeze drying or lyophilization of aqueous solutions is widely used in pharmaceutical industry. The in-creased importance Of the process is gaining a worldwide interest of research. A growing body of literature has demonstrated that the scientific approach can result in improved product quality with minimum trial and error em-piricism. Formulation and process development need a systematical understanding of the physical chemistry of freezing and freeze drying, material science and mechanisms of heat and mass transfer. This paper presents an overview on freeze ding of aqueous solutions based on publications in the past few decades. The important issuesof the process are analyzed.
文摘Tomato is one of the most widely produced and consumed vegetable crops in Ethiopia. It is not produced during the rainy season, mainly due to high disease pressure and low soil temperature. Therefore, an experiment was conducted to study the effect of different types of mulch (black and white plastic mulch as well as grass mulch) on early yield of tomato varieties (Miya & Cochoro) under polyhouse growing condition at Bahir Dar during the rainy season in 2012. Treatments were arranged in 4 - 2 factorial combinations in randomized complete block design with three replications. One month old seedlings were transplanted on 8.4 m2 gross plots size (3 m x 2.8 m) at a spacing of 70 cm x 40 cm between rows and plants, respectively. Data recorded from plants found in the two middle rows of each plot. Di-ammonium phosphate (DAP) and Urea fertilizers were applied at the rate of 200 kg and 100 kg/ha, respectively. Sixteen plants were considered for data collection in each plot. White plastic mulch resulted in significantly (P 〈 0.05) earlier flowering, fruit setting and fruit maturity compared to other mulching materials. Varieties were also significantly different in days required to flowering, fruit setting and fruit maturity. Miya took significantly short period to flower, fruit set and fruit maturity compared to Cochoro variety. The effect of different mulch types on early fruit yield was found statistically significant. The highest early marketable fruit yield of 10.99 ton/ha and 10.54 ton/ha were recorded when Miya variety was grown with white and black plastic mulch, respectively. Therefore, use of white and black plastic mulches recommended for early tomato fruit yield.
文摘Cassava (Manihot esculenta Crantz) is a perennial woody shrub with an edible root, which grows in tropical and subtropical areas of the world. In Africa, cassava provides a basic daily source of dietary energy. It plays an important role in food security and incomes of many rural households in the southern Ethiopia. However, information available on production practices of cassava for the region is insufficient. Hence, field experiment was conducted at Awassa Agricultural Research Center for two successive cropping seasons from 2004 to 2006 to investigate the response of cassava to planting position and planting material. The treatments used were three planting positions (slant, vertical and horizontal) and five planting materials (main stem top part, main stem middle part, main stem bottom part, branch stake top part and branch stake bottom part) were combined in factorial arrangement and laid out in randomized complete block design with three replications. The result revealed that root yield was significantly (P 〈 0.05) affected by the interaction effects of the planting position and planting material. The highest yield (25.2 ton ha^-1) was obtained from the main stem top part planted in slant position whereas the least yield (6.5 ton ha^-1) was obtained from main stem bottom part planted in horizontal position. Based on the findings of this study, areas like Awassa with moderate rainfall slant and vertical planting of main stem top and middle parts could be used as planting material.
文摘Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advances necessitates a change and evolution in building envelopes. Controlling the energy consumption of the buildings is mostly through controlling the energy performance of the building envelopes. New technologies lead to the intelligent facades and envelopes. The envelope can be designed to be a part of the whole building's metabolism (energy production, storage and consumption) and morphology. The envelope would be a controlled part of the building which is managed through the central control system of the building, which connects it to other parts. It caused building envelope design to be changed fundamentally, so that there is a need to interact with engineering disciplines including computer engineering, mechanical engineering, material engineering and so on. All of these caused building envelope to get closer to biological and living systems. The physical restrictions which affect buildings system and living systems are the same. So they cause the same forces to shape the structure and form of the systems and the same rules to interact with the environment. The restrictions of material and energy resources caused living systems to be energy efficient and consuming less material. But the most important difference between living systems and building systems is in maximum use of different resources. As living systems use information maximally, the building system technology is based on using maximum energy. Now, there are many reasons and restrictions that building envelopes cannot act like living systems. But technological developments and contributing more disciplines in design and construction of building envelopes caused the future way of these envelopes get close to living systems for their energy efficiency. Some of living systems characteristics which the future building envelopes would have partially or benefit for the design process or construction are self-organization, evolution principles, hierarchical levels, processing energy, reaction to environmental stimuli and self-adjustment. Self-organization is achieved in some design software and in building material production for creating formal patterns. Evolution principles provide infrastructure for soft wares for optimization purposes and form creation. Hierarchical levels refer to giving hierarchical structure to the building envelopes through layering and designing different scales. Processing energy (metabolism) would be achieved through photovoltaic and solar collectors to produce energy and in passive systems for energy storage and distribution. Controlling solar radiation absorption and transmittance would help energy transfer from outside to building and vice versa. Reaction to environmental stimuli which is one of the most important characteristics of future building envelopes would use different types of active and passive sensors to create envelope mechanical reactions through material properties or collect data for processing in the control center to determine the right reaction. The reaction would be through different strategies such as changing properties and moving. Reaction could be passive or active. Self-adjustment can be achieved by control systems and processing units. All of these mean intelligent envelopes are essential parts of future buildings. Though it is now started with new design soft wares based on biological principles to optimize different parameters affecting the envelope function or to create the most efficient form.
文摘It is observed contamination and subsequent growth of various types of mycotoxins in the production and processing of grain and non-grain crops. The contamination of grain and non-grain cereals crops harvest was analyzed. The aim of this research is using of microwave energy to disinfect grains of harvest and giving new properties to the grains and plants materials. The author has presented researches of the grains disinfection, during seedbed preparation and post processing. Rational parameters of heating rates of different biological objects were identified, revealed their dependence and impact on infection pathogens, through using of microwave energy technology. The author found a reduction of the number of pathogenic microbes and organisms at the various stages of processing agricultural products during using of microwave energy, and found new qualitative indicators of the products properties.
基金financially supported by the National Key Research and Development Program of China(2017YFA0208200 and 2016YFB0700600)the Fundamental Research Funds for the Central Universities of China(0205-14380219)+3 种基金the Projects of National Natural Science Foundation of China(22022505,21872069 and 51761135104)the Natural Science Foundation of Jiangsu Province(BK20181056,BK20180008 and BK20191042)Jiangsu Postdoctoral Science Fundation(2020Z258)the Funding for School-level Research Projects of Yancheng Institute of Technology(xjr2019006).
文摘Semiconducting silicon(Si)nanomaterials have great potential for the applications in electronics,physics,and energy storage fields.However,to date,it is still a challenge to realize the batch production of Si nanomaterials via efficient and low-cost approaches,owing to some long-standing shortcomings,e.g.,complex procedures and time and/or energy consumption.Herein,we report a green and inexpensive method to rapidly obtain two-dimensional(2D)free-standing Si/SiO_(x) nanosheets via the rapid thermal exfoliation of layered Zintl compound CaSi_(2).With the help of the rapid exfoliation reaction of CaSi_(2) in the atmosphere of greenhouse gas CO_(2),and the following mild sonication,2D free-standing Si/SiO_(x) nanosheets can be produced with very high yield.After applying the coating of a thin carbon outer layer,the electrodes of Si/SiO_(x)/C nanosheets serving as the anodes for lithium-ion batteries exhibit ultrahigh reversible capacity and outstanding electrochemical stability.We expect this study will provide new insights and inspirations for the convenient and batch production of nanostructural Si-based anode materials towards high-performance lithium-ion batteries.
基金This work was supported by the National Natural Science Foundation of China (51972162 and 51703241)the Postdoctoral Foundation of Jiangsu Province (2019Z203 and 2019K001)the Science and Technology Project of Nanchang (2017-SJSYS008)
文摘Fiber-shaped energy storage devices are indispensable parts of wearable and portable electronics.Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic electrolytes, high ionic conductivity, and low cost. Unfortunately, the low energy density,poor power density and cycling performance hinder its further practical applications. In this study, in order to obtain high performance negative iron-based material, we first synthesized a-iron oxide(α-Fe2O3) nanorods(NRs) with superstructures on the surface of highly conductive carbon nanotube fibers(CNTFs), then electrically conductive polypyrrole(PPy) was coated to enhance the electron, ion diffusion and cycle stability. The as-prepared α-Fe2O3@PPy NRs/CNTF electrode shows a high specific capacity of 0.62 Ah cm-3 at the current density of 1 A cm-3. Furthermore, the Ni/Fe battery that was assembled by the above negative electrode shows a maximum volumetric energy density of 15.47 mWh cm-3 with228.2 mW cm-3 at a current density of 1 A cm-3. The cycling durability and mechanical flexibility of the Ni/Fe battery were tested, which show good prospect for practical application. In summary, these merits make it possible for our Ni/Fe battery to have practical applications in next generation flexible energy storage devices.
基金the Cooperative Research Program of IOES,Institute of Ocean Energy,Saga University.(Accept15004A)
文摘This paper deals with the output improvement of heating and cooling cycle by using the work-fluid including phase change material.The experimental study is carried out by heat exchange between work-fluid and heat transfer surface.The work-fluid is flown to a high temperature or a low temperature heat transfer surface from the narrow path.In order to increase the amount of the heat transmission,a trace of Diethylether(boiling point 34.8 ℃),as a phase change material(PCM),is added to the work-fluid.The parameters of the experiment are additive amount of PCM,the rotational speed of the displacer piston and the temperature of heat transfer surface.It is clarified that the increasing of engine cycle output is brought by the PCM addition.The effect of PCM addition is evaluated by output ratio which is defined from the experimental cycle output data.The requirements for acquiring the increasing effect of output by adding PCM are clarified.
文摘The use of plant materials as soil amendments is an uncommon practice amongst major farming communities in Ghana, although it is necessary for soil fertility improvement. An examination of the effects of soil amendments is necessary to encourage the use of under-utilized organic resources in Ghana. Thus, a field experiment was conducted using 8 different tropical plant materials mixed with chicken manure as soil amendments for growth of tomato as a test crop. The plant materials included Leucaena leueocephala, Centrosema pubescens, Sesbania sesban, Gliricidia sepium, Mucuna pruriens, Pueraria phaseoloides, Azadirachta indiea, and Theo- broma cacao. There were two other treatments: one with equivalent amounts of chemical fertilizers and the other with no-fertilizer input (control). Plant materials were mixed with chicken manure to obtain a uniform carbon-to-nitrogen (C:N) ratio of 5:1. Except the no-fertilizer control, all treatments received the same amount of nitrogen (N). To clarify the decomposition pattern of the plant materials in soil, an incubation experiment was conducted using only the plant materials before the field experiment. The Glirieidia treatment released significantly more mineral N than the other plant materials in the incubation experiment. However, the tomato fruit yield was not enhanced in the Gliricidia treatment in the field experiment. The known quality parameters of the tested plant materials, such as total N, total carbon (C), C:N ratio, and total polyphenols, had minimal effects on their mineralization dynamics. Azadirachta showed the best synergistic effect with chicken manure through significantly increasing soil microbial biomass and fruit yield of tomato. This result provides insights into the possible adoption of Azadirachta in combination with chicken manure as a soil amendment in small-scale agricultural holdings.