The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low allo...The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low alloy cast steel for automobile cold pressing die insert. For the evaluation of the applicability as the die insert, the mechanical properties were measured after spheroidization annealing (SA), quenching and tempering (Q/T), and flame hardening (FH) treatments, respectively. The developed 0.8%-1.6%Si containing Mo and V free alloy cast steels showed excellent matrix strengthening effect, hardenability, and weldability, fulfilling the industrial criterion of the mechanical properties for the die insert.展开更多
The main objective of this research was to determine the amount of oil fish were extracted from fish west resulted from butchering,cutting and splitting processes before salmon smoking by using cold pressing methods.T...The main objective of this research was to determine the amount of oil fish were extracted from fish west resulted from butchering,cutting and splitting processes before salmon smoking by using cold pressing methods.The amount and the characteristics of extracted of oil were tested at Regional Centre for food and feed the USDA Agricultural Research Center laboratory.The samples were used from fresh Salmon waste about 1000g from each of the(head,skin,viscera,backbone,frames and cuts off).This waste recorded more than 22%of the total mass from salmon fish with used modern extract machine.in this experiment the results revealed the fresh salmon waste have more than 16%of oil fish per one kg of salmon waste.The oil weight from Salmon waste for(head,skin,viscera,backbone,frames and cuts off).was increased with pressing time increase as well as oil productivity increased.The optimum conditions at pressing time was 200 min,for all salmon waste components.Oil productivity fluctuated according to waste sources was 190,210,86,188,178 and 90 g.oil/1000 g.by head,skin,off cuts,terming,,viscera,and backbone frames,Salmon by-products,oil productivity was ranged between 8.60 to 21.00%at constant pressure.High contents of functional EPA(20:5ω3)and DHA(22:6ω3)for oil fish.展开更多
A combined method of selective laser sintering (SLS) and cold isostatic pressing (CIP) was applied to manufacturing metal parts rapidly. Finite element method was used to predict final dimensions and decrease cost...A combined method of selective laser sintering (SLS) and cold isostatic pressing (CIP) was applied to manufacturing metal parts rapidly. Finite element method was used to predict final dimensions and decrease cost. The simulations of CIP of selective laser sintered parts were carried out by Drucker-Prager-Cap constitutive model with ABAQUS computer program. The property of metal powder was measured by CIP experiments. The results show the rubber bag and the friction coefficient have little influence on results of simulations. The parts only have uniform shrinkage and have no obvious distortion in shape. The results of simulations show a good agreement with the experimental results and the calculated results, indicating that the Drucker-Prager-Cap model is an effective model to simulate CIP process. The simulations could give a useful direction to forming process of the CIP of selective laser sintered components. K展开更多
Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing (CIP) was applied to fabricate...Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing (CIP) was applied to fabricate porous lithium sodium potassium niobate (Li0.06Na0.5K0.44) NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague- Dawley rats were examined by a scanning electron microscopy (SEM) and metbylthiazol tetrazolium (MTT) assay. Results The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Conclusion Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.展开更多
In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an in...In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO2 to CaCl2(nTiO2/nCaCl2)in the pellets.The results show that metallic Ti was obtained from the reduction of TiO2 in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when TRedu=1273 K,tRedu=6 h,and nTiO2/nCaCl2=4;the reasonable nTiO2/nCaCl2 value is 3−5 for the pellets with enough strength and high RM.展开更多
Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key ...Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key problems of visualization simulation in pressing die. The final aim is that numerical simulation system can simulate the process of processing forming technique, which can supply some necessary and accurate key parameters for die design. The detail description of mechanical characteristic and key technique of sheet forming technique is discussed. Pressing forming method is one of the most important forming techniques of metal forming, which has special mechanical characteristics. The character of sheet pressing forming is that the deformation of thickness direction is very small in contrast to other directions. The deformation mode of sheet forming mainly has the following kinds: bi-directional stretch, plane stress, stretches, depths extend, bending and counter-bending. The essence of press forming is the transferring course that the transferring region of rough comes to deformation by outside force, which is main researching principle in forming and the transferring field. The analysis of pressing forming course, disclose the feature of stress-strain and their changing rule, then pressing process and forming parameters could be obtained. So the states of force and deformation of transferring region is key to determine character about the varieties of pressing transferring. The paper analyzes these factors, which may influence forming precision in pressing process. In traditional methods, some key parameter such as spring-back, bending radius for die design are calculated by experience formula or select from data table. The paper brings forward the calculation methods of key parameter in the case of drawing finite element method and numerical simulation into pressing die design. In order to calculate the value of key parameters based on data supplied by FEM, a numerical simulation application is finished combined with two descriptions of work piece deformation NURBS and discrete piece. The numerical simulation is programmed on Microsoft Visual C++ with OpenGL as the graphics tool. It establishes numerical simulation program, dynamically simulates the process of sheet pressing figuration, and gets good effects.展开更多
Diamond tools with orderly arrangements of diamond grits have drawn considerable attention in the machining field owing to their outstanding advantages of high sharpness and long service life.This diamond super tool,a...Diamond tools with orderly arrangements of diamond grits have drawn considerable attention in the machining field owing to their outstanding advantages of high sharpness and long service life.This diamond super tool,as well as the manufacturing equipment,has been unavailable to Chinese enterprises for a long time due to patents.In this paper,a diamond blade segment with a 3D lattice of diamond grits was additively manufactured using a new type of cold pressing equipment(AME100).The equipment,designed with a rotary working platform and 16 molding stations,can be used to additively manufacture segments with diamond grits arranged in an orderly fashion,layer by layer;under this additive manufacturing process,at least 216000 pcs of diamond green segments with five orderly arranged grit layers can be produced per month.The microstructure of the segment was observed via SEM and the diamond blade fabricated using these segments was compared to other commercial cutting tools.The experimental results showed that the 3D lattice of diamond grits was formed in the green segment.The filling rate of diamond grits in the lattice could be guaranteed to be above 95%;this is much higher than the 90%filling rate of the automatic array system(ARIX).When used to cut stone,the cutting amount of the blade with segments made by AME100 is two times that of ordinary tools,with the same diamond concentration.When used to dry cut reinforced concrete,its cutting speed is 10%faster than that of ARIX.Under wet cutting conditions,its service life is twice that of ARIX.By applying the machine vision online inspection system and a special needle jig with a negative pressure system,this study developed a piece of additive manufacturing equipment for efficiently fabricating blade segments with a 3D lattice of diamond grits.展开更多
The development of alternative wood composites based on the use of waste or recycled materials can be beneficial due to over exploitation of natural resources.Under this frame,an option for the successful utilization ...The development of alternative wood composites based on the use of waste or recycled materials can be beneficial due to over exploitation of natural resources.Under this frame,an option for the successful utilization of waste polystyrene which avoids environmental problems that formaldehyde adhesives cause and also reduces waste dis-posal,is its potential application as a binder for the production of value-added environmentally friendly and low cost wood composites.Two types of panel were successfully made,consisting of wood dust and two recycled poly-styrene contents,namely,15%and 30%.Both physical properties,water absorption and thickness swelling,and mechanical properties,modulus of rupture,shear strength parallel in the plane of the board and glue line shear strength,were significantly improved as the recycled polystyrene content increased from 15%to 30%.Water absorption and thickness swelling after 24 h immersion in water were improved by 165%and 750%as the recycled polystyrene content increased from 15%to 30%.The magnitude of the improvement in mechanical properties however,was less pronounced than of the physical properties since modulus of rupture,shear strength parallel in the plane of the board and glue line shear strength were increased by 43.6%,50%and 61.5%,respec-tively.The low viscosity of the recycled polystyrene caused more mobility inside the panel matrix and therefore,an improved penetration took place into adequate depth of the compressed dust particles.It is concluded that boards can be successfully produced using these waste raw materials,wood dust and recycled polystyrene in organic solvent as a binder,and therefore it can reduce waste disposal and provide cleaner production for the development of wood-based boards.展开更多
[Objectives]The differences in indices of different peanut oil were found out by analyzing the quality of peanut oil obtained by different oil-making processes.[Methods]The effects of different oil-making processes on...[Objectives]The differences in indices of different peanut oil were found out by analyzing the quality of peanut oil obtained by different oil-making processes.[Methods]The effects of different oil-making processes on the quality of peanut oil were analyzed and compared through the determination of the main physicochemical indices,V_(E) contents and fatty acid compositions of peanut oil obtained by cold pressing,hot pressing and leaching and refining.[Results]The leached refined peanut oil had the lightest color and the lightest fragrance;the hot-pressed peanut oil had the highest V_(E) content;the refractive index,relative density and main fatty acid compositions of the three kinds of peanut oil had no significant differences;and there were trans-fatty acids in the leached refined peanut oil,and the trans-fatty acid contents in the leached refined fresh and aged peanut oil were 1.90%and 4.39%,respectively.The trans-fatty acid content is expected to be a characteristic index to distinguish pressed peanut oil from leached refined peanut oil.[Conclusions]This study can provide a theoretical basis for distinguishing and identifying peanut oil obtained from different oil-making processes.展开更多
1.0wt.% carbon nanotube (CNT) reinforced 2024Al matrix composite was fabricated by cold isostatic press and subsequent hot extrusion techniques. The mechanical properties of the composite were measured by a tensile ...1.0wt.% carbon nanotube (CNT) reinforced 2024Al matrix composite was fabricated by cold isostatic press and subsequent hot extrusion techniques. The mechanical properties of the composite were measured by a tensile test. Mean-while,the fracture surfaces were examined using field emission scanning electron microscopy. The experimental results show that CNTs are dispersed homogeneously in the composite and that the interfaces of the Al matrix and the CNT bond well. Although the tensile strength and the Young’s modulus of the composite are enhanced markedly,the elongation does not decrease when compared with the matrix material fabricated under the same process. The reasons for the increments may be the extraordinary mechanical properties of CNTs,and the bridging and pulling-out role of CNTs in the Al matrix composite.展开更多
Bi2Se3 thin films were electrochemically deposited on Ti and indium tin oxide-coated glass substrates, respectively, at room temperature, using Bi(NO3)3·5H2O and SeO2 as starting materials in diluted HNO3 solut...Bi2Se3 thin films were electrochemically deposited on Ti and indium tin oxide-coated glass substrates, respectively, at room temperature, using Bi(NO3)3·5H2O and SeO2 as starting materials in diluted HNO3 solution. A conventional three-electrode cell was used with a platinum sheet as a counter electrode, and a saturated calomel electrode was used as a reference electrode. The films were annealed in argon atmosphere. The influence of cold isostatic pressing before annealing on the microstructure and thermoelectric properties of the films was investigated. X-ray diffraction analysis indicates that the film grown on the indium tin oxide-coated glass substrate is pure rhombohedral Bi2Se3, and the film grown on the Ti substrate consists of both rhombohedral and orthorhombic Bi2Se3.展开更多
The rods that were shaped from nanocrystalline WC- 10.21 Co-0.42 VC/ Cr3 C2 ( wt% ) composite powders by using powder extrusion molding (PEM) were investigated. The nanocrystalline WC- 10.21 Co- 0. 42 VC/ Cr3 C2 ...The rods that were shaped from nanocrystalline WC- 10.21 Co-0.42 VC/ Cr3 C2 ( wt% ) composite powders by using powder extrusion molding (PEM) were investigated. The nanocrystalline WC- 10.21 Co- 0. 42 VC/ Cr3 C2 ( wt% ) composite powders were prepared by the spray thermal decomposition-continuous reduction and carburization technology. In order to improve the properties of rods shaped by using powder extrusion molding, the cold isostatic pressing (CIP) technology was used before or after debinding. Specimens were siutered by vacuum siutering and hot isostatic pressing (HIP). The density, Rockwell A hardness, magnetic coercivity , and magnetic saturation induction of siutered specimen were measured. The microstructure of the green bodies and the siutered specimens was studied by scanning electron microscopy (SEM). Results show that the rod formed by using powder extrusion molding after debinding and followed by cold isostatic pressing can be siutered to 99.5% density of composite cemented carbide rods with an average grain size of about 200- 300 nm, magnetic coercivity of 30.4 KA / m, Rockwell A hardness of 92.6 and magnetic saturation induction of 85% . Superfine WC- 10 Co cemented carbide rods with excellent properties were obtained.展开更多
Most of the seeds produced by neem (Azadirachta indica A. Juss) trees in Nigeria are currently underutilized. Hence, relevant literature provides only limited information conceming many of the seed oils from this co...Most of the seeds produced by neem (Azadirachta indica A. Juss) trees in Nigeria are currently underutilized. Hence, relevant literature provides only limited information conceming many of the seed oils from this country, especially where it concems the potential applications of these oils as preservatives for ligno-cellulose against bio-deterioration. Using standard procedures therefore, this study was carried out to evaluate and document selected physical and chemical properties of neem seed oil (NSO), mechanically extracted using a cold press at 31.03 N-mm^-2 pressure and a room temperature of 25 ± 2℃. The results show that oil yield was 38.42% with a specific gravity of 0.91 ± 0.01. The amount of acid was 18.24 ± 1.31 mg KOH.g^-1 and that of iodine 93.12 ± 2.01 g-100 g^- 1, while saponification and peroxide values were 172.88 ± 2.06 and 1.42 ± 0.04 mg·g^-1 respectively. The implication of the values obtained, particularly those for the chemical properties, as they concern the potential application of NSO as a preservative for ligno-eellulose, is likely that it may be useful in this regard since the values may support some of the documented anti-microbial properties of the oil, although other physical and chemical properties that may affect this potential are recommended for investigations. Conclusions and other recommendations follow in line with the results of the study.展开更多
Argan oil is most frequently sold as pure oil,which can be directly applied topically due to its cosmetological proprieties or ingested in order to provide several health benefits.It's also commonly mixed into a n...Argan oil is most frequently sold as pure oil,which can be directly applied topically due to its cosmetological proprieties or ingested in order to provide several health benefits.It's also commonly mixed into a number of cosmetic products like shampoos,soaps and conditioners.In this study we aimed to improve the argan oil extraction yield and quality parameters by comparing the effects of different extraction technologies.Argan kernel oils were extracted using four methods:mechanical cold press,Soxhlet extraction with n-hexane,supercritical fluid extraction(SFE),and enzyme assisted extraction with three different enzyme solutions cellulase(cellulast),pectinase(Pectinex)and a mixture of carbohydrase enzymes(Viscozyme®).The quality parameters was evaluated by determining the acid,peroxide and iodine values aswell as the extinction coefficients K_(232) and K_(270) as measures of conjugated dienes and trienes,respectively.The results showed that the highest yield(66.37%±3.3%)was obtained by enzyme assisted extraction using the carbohydrases enzymes mixture(Viscozyme®),followed by Soxhlet extraction(59.5%±3.1%)and pectinase extraction(52.03%±3.55%).All argan oils samples obtained by the different methods showed a good oxidation stability,with acid,peroxide and iodine values lower than 0.8 mg/g,15 meq/kg and 110 g/100 g according to the official argan oil norm,respectively.The results of argan oils quality parameters demonstrated that the enzyme extracted argan oils showed low oxidation,with the following quality parameters:acid values(0.4-0.6 mg/g),iodine values(95-100 g/100 g),dienes(K_(232)<2),trienes(K_(270)<0.35),and peroxide values(<1.5 meq/kg).The results proved that the enzyme assisted extraction method can be applied to improve the argan oil yield without affecting the oil quality.The enzyme extraction method may be a great alternative to solvent and cold press extractions for this eco-friendly processing approach.展开更多
Effect of fabrication conditions on microstructure and thermoelectric properties of the Bi1.9Lu0.lTe3 compound was studied. Starting nanopowder with mean nanoparticle size of -37 nm was synthesized by a microwave-solv...Effect of fabrication conditions on microstructure and thermoelectric properties of the Bi1.9Lu0.lTe3 compound was studied. Starting nanopowder with mean nanoparticle size of -37 nm was synthesized by a microwave-solvothermal method. In order to prepare samples with various micro-grained structures, the synthesized nanopowder was compacted by two methods. The first method is cold isostatic pressing with further high- temperature annealing, while the second method is spark plasma sintering at various temperatures of process (653 and 683 K). It is found that mean grain size is equal to -290,-730 and -1160 nm for cold isostatically pressed and spark plasma sintered at 653 and 683 K samples, respectively. The micro-grained sample with maximum mean grain size shows the best thermoelectric properties. This sample is structurally inhomogeneous and has the lowest thermal conductivity and the specific electrical resistivity. Maximum dimensionless figure of merit for this sample is equal to -0.9 for temperature range of 450-500 K.展开更多
Two experiments were conducted to determine the nitrogen-corrected apparent metabolizable energy(AMEn) of differently processed meals from Juncea(Brassica juncea), yellow and black seeded canola(Brassica napus), with ...Two experiments were conducted to determine the nitrogen-corrected apparent metabolizable energy(AMEn) of differently processed meals from Juncea(Brassica juncea), yellow and black seeded canola(Brassica napus), with or without supplementation of multi-carbohydrase enzymes(Enz) in diets for broiler chickens. The first experiment was a 3×2×2 factorial arrangement with the main factors being seed type(yellow [Yellow] or black [B1] canola seeds and Juncea seeds), processed at two temperatures(high temperature desolventized-toasted [HTDT] at 95℃ or low temperature desolventized-toasted[LTDT] at 57℃), with or without Enz. In Exp. 1, a total of 384 one-day-old male broiler chicks were randomly assigned to 64 battery cages, with 6 birds/cage. The second experiment was a 2×2×2 factorial arrangement with the main factors being seed type(Yellow or black [B2]), seed source(Scott,Saskatchewan or Truro, Nova Scotia) and Enz(with or without) supplementation. A total of 264 one-dayold male broiler chicks were randomly assigned to 44 battery cages, with 6 birds per cage. In Exp, 1 and 2,all birds were fed a common starter diet from 1 to 14 days of age. From d 15 to 21, the birds were fed one of the test treatments, a basal grower diet or the basal grower diet replaced with 30% test ingredient with celite(0.8%) added as an inert marker. Excreta was collected on d 20 and 21. In Exp. 1, there were no interactions(P > 0.05) among seed type, processing temperature and Enz. Processing temperature and dietary Enz did not affect(P > 0.05) AMEn of different canola meals. The AMEn of prepress solvent extracted canola and juncea meals(PSEM) from Yellow(11.2 MJ/kg) was higher(P < 0.05) than B1(10.2 MJ/kg) and Juncea(10.2 MJ/kg). In Exp. 2, there were no interactions(P > 0.05) among seed color,location and Enz. Supplementation of dietary Enz did not affect(P > 0.05) AMEn of different cold press canola meals. The AMEn of cold press canola meals(CPM) from Yellow(14.7 MJ/kg) was higher(P < 0.05)compared with B2(12.2 MJ/kg). In conclusion, among the different processing methods of oil extraction,meals derived from yellow seeded canola had higher AMEn than B seeded canola and Juncea.展开更多
文摘The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low alloy cast steel for automobile cold pressing die insert. For the evaluation of the applicability as the die insert, the mechanical properties were measured after spheroidization annealing (SA), quenching and tempering (Q/T), and flame hardening (FH) treatments, respectively. The developed 0.8%-1.6%Si containing Mo and V free alloy cast steels showed excellent matrix strengthening effect, hardenability, and weldability, fulfilling the industrial criterion of the mechanical properties for the die insert.
文摘The main objective of this research was to determine the amount of oil fish were extracted from fish west resulted from butchering,cutting and splitting processes before salmon smoking by using cold pressing methods.The amount and the characteristics of extracted of oil were tested at Regional Centre for food and feed the USDA Agricultural Research Center laboratory.The samples were used from fresh Salmon waste about 1000g from each of the(head,skin,viscera,backbone,frames and cuts off).This waste recorded more than 22%of the total mass from salmon fish with used modern extract machine.in this experiment the results revealed the fresh salmon waste have more than 16%of oil fish per one kg of salmon waste.The oil weight from Salmon waste for(head,skin,viscera,backbone,frames and cuts off).was increased with pressing time increase as well as oil productivity increased.The optimum conditions at pressing time was 200 min,for all salmon waste components.Oil productivity fluctuated according to waste sources was 190,210,86,188,178 and 90 g.oil/1000 g.by head,skin,off cuts,terming,,viscera,and backbone frames,Salmon by-products,oil productivity was ranged between 8.60 to 21.00%at constant pressure.High contents of functional EPA(20:5ω3)and DHA(22:6ω3)for oil fish.
基金Project(2007AA03Z115) supported by the High-Tech Research and Development Program of China
文摘A combined method of selective laser sintering (SLS) and cold isostatic pressing (CIP) was applied to manufacturing metal parts rapidly. Finite element method was used to predict final dimensions and decrease cost. The simulations of CIP of selective laser sintered parts were carried out by Drucker-Prager-Cap constitutive model with ABAQUS computer program. The property of metal powder was measured by CIP experiments. The results show the rubber bag and the friction coefficient have little influence on results of simulations. The parts only have uniform shrinkage and have no obvious distortion in shape. The results of simulations show a good agreement with the experimental results and the calculated results, indicating that the Drucker-Prager-Cap model is an effective model to simulate CIP process. The simulations could give a useful direction to forming process of the CIP of selective laser sintered components. K
基金supported by the National Natural Science Foundation of China (59972020)
文摘Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing (CIP) was applied to fabricate porous lithium sodium potassium niobate (Li0.06Na0.5K0.44) NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague- Dawley rats were examined by a scanning electron microscopy (SEM) and metbylthiazol tetrazolium (MTT) assay. Results The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Conclusion Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.
基金Projects(51774071,50804007,51974073)supported by the National Natural Science Foundation of China。
文摘In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO2 to CaCl2(nTiO2/nCaCl2)in the pellets.The results show that metallic Ti was obtained from the reduction of TiO2 in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when TRedu=1273 K,tRedu=6 h,and nTiO2/nCaCl2=4;the reasonable nTiO2/nCaCl2 value is 3−5 for the pellets with enough strength and high RM.
文摘Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key problems of visualization simulation in pressing die. The final aim is that numerical simulation system can simulate the process of processing forming technique, which can supply some necessary and accurate key parameters for die design. The detail description of mechanical characteristic and key technique of sheet forming technique is discussed. Pressing forming method is one of the most important forming techniques of metal forming, which has special mechanical characteristics. The character of sheet pressing forming is that the deformation of thickness direction is very small in contrast to other directions. The deformation mode of sheet forming mainly has the following kinds: bi-directional stretch, plane stress, stretches, depths extend, bending and counter-bending. The essence of press forming is the transferring course that the transferring region of rough comes to deformation by outside force, which is main researching principle in forming and the transferring field. The analysis of pressing forming course, disclose the feature of stress-strain and their changing rule, then pressing process and forming parameters could be obtained. So the states of force and deformation of transferring region is key to determine character about the varieties of pressing transferring. The paper analyzes these factors, which may influence forming precision in pressing process. In traditional methods, some key parameter such as spring-back, bending radius for die design are calculated by experience formula or select from data table. The paper brings forward the calculation methods of key parameter in the case of drawing finite element method and numerical simulation into pressing die design. In order to calculate the value of key parameters based on data supplied by FEM, a numerical simulation application is finished combined with two descriptions of work piece deformation NURBS and discrete piece. The numerical simulation is programmed on Microsoft Visual C++ with OpenGL as the graphics tool. It establishes numerical simulation program, dynamically simulates the process of sheet pressing figuration, and gets good effects.
基金Supported by Scientific Research Funds of Guangdong Province of China(Grant No.2017B090922008)the Scientific Project of Chaozhou of China(Grant No.2018ZD10).
文摘Diamond tools with orderly arrangements of diamond grits have drawn considerable attention in the machining field owing to their outstanding advantages of high sharpness and long service life.This diamond super tool,as well as the manufacturing equipment,has been unavailable to Chinese enterprises for a long time due to patents.In this paper,a diamond blade segment with a 3D lattice of diamond grits was additively manufactured using a new type of cold pressing equipment(AME100).The equipment,designed with a rotary working platform and 16 molding stations,can be used to additively manufacture segments with diamond grits arranged in an orderly fashion,layer by layer;under this additive manufacturing process,at least 216000 pcs of diamond green segments with five orderly arranged grit layers can be produced per month.The microstructure of the segment was observed via SEM and the diamond blade fabricated using these segments was compared to other commercial cutting tools.The experimental results showed that the 3D lattice of diamond grits was formed in the green segment.The filling rate of diamond grits in the lattice could be guaranteed to be above 95%;this is much higher than the 90%filling rate of the automatic array system(ARIX).When used to cut stone,the cutting amount of the blade with segments made by AME100 is two times that of ordinary tools,with the same diamond concentration.When used to dry cut reinforced concrete,its cutting speed is 10%faster than that of ARIX.Under wet cutting conditions,its service life is twice that of ARIX.By applying the machine vision online inspection system and a special needle jig with a negative pressure system,this study developed a piece of additive manufacturing equipment for efficiently fabricating blade segments with a 3D lattice of diamond grits.
基金This research is co-financed by Greece and the European Union(European Social Fund-ESF)through the Operational Programme‘Human Resources,Development,Education and Lifelong Learning 2014-2020’in the context of the project‘Innovative wood plastic composites made from recycled polystyrene and recycled wood chips’(MIS 5048422).
文摘The development of alternative wood composites based on the use of waste or recycled materials can be beneficial due to over exploitation of natural resources.Under this frame,an option for the successful utilization of waste polystyrene which avoids environmental problems that formaldehyde adhesives cause and also reduces waste dis-posal,is its potential application as a binder for the production of value-added environmentally friendly and low cost wood composites.Two types of panel were successfully made,consisting of wood dust and two recycled poly-styrene contents,namely,15%and 30%.Both physical properties,water absorption and thickness swelling,and mechanical properties,modulus of rupture,shear strength parallel in the plane of the board and glue line shear strength,were significantly improved as the recycled polystyrene content increased from 15%to 30%.Water absorption and thickness swelling after 24 h immersion in water were improved by 165%and 750%as the recycled polystyrene content increased from 15%to 30%.The magnitude of the improvement in mechanical properties however,was less pronounced than of the physical properties since modulus of rupture,shear strength parallel in the plane of the board and glue line shear strength were increased by 43.6%,50%and 61.5%,respec-tively.The low viscosity of the recycled polystyrene caused more mobility inside the panel matrix and therefore,an improved penetration took place into adequate depth of the compressed dust particles.It is concluded that boards can be successfully produced using these waste raw materials,wood dust and recycled polystyrene in organic solvent as a binder,and therefore it can reduce waste disposal and provide cleaner production for the development of wood-based boards.
文摘[Objectives]The differences in indices of different peanut oil were found out by analyzing the quality of peanut oil obtained by different oil-making processes.[Methods]The effects of different oil-making processes on the quality of peanut oil were analyzed and compared through the determination of the main physicochemical indices,V_(E) contents and fatty acid compositions of peanut oil obtained by cold pressing,hot pressing and leaching and refining.[Results]The leached refined peanut oil had the lightest color and the lightest fragrance;the hot-pressed peanut oil had the highest V_(E) content;the refractive index,relative density and main fatty acid compositions of the three kinds of peanut oil had no significant differences;and there were trans-fatty acids in the leached refined peanut oil,and the trans-fatty acid contents in the leached refined fresh and aged peanut oil were 1.90%and 4.39%,respectively.The trans-fatty acid content is expected to be a characteristic index to distinguish pressed peanut oil from leached refined peanut oil.[Conclusions]This study can provide a theoretical basis for distinguishing and identifying peanut oil obtained from different oil-making processes.
文摘1.0wt.% carbon nanotube (CNT) reinforced 2024Al matrix composite was fabricated by cold isostatic press and subsequent hot extrusion techniques. The mechanical properties of the composite were measured by a tensile test. Mean-while,the fracture surfaces were examined using field emission scanning electron microscopy. The experimental results show that CNTs are dispersed homogeneously in the composite and that the interfaces of the Al matrix and the CNT bond well. Although the tensile strength and the Young’s modulus of the composite are enhanced markedly,the elongation does not decrease when compared with the matrix material fabricated under the same process. The reasons for the increments may be the extraordinary mechanical properties of CNTs,and the bridging and pulling-out role of CNTs in the Al matrix composite.
基金supported by the Major State Basic Research Development Program of China (No.2007CB607500.)
文摘Bi2Se3 thin films were electrochemically deposited on Ti and indium tin oxide-coated glass substrates, respectively, at room temperature, using Bi(NO3)3·5H2O and SeO2 as starting materials in diluted HNO3 solution. A conventional three-electrode cell was used with a platinum sheet as a counter electrode, and a saturated calomel electrode was used as a reference electrode. The films were annealed in argon atmosphere. The influence of cold isostatic pressing before annealing on the microstructure and thermoelectric properties of the films was investigated. X-ray diffraction analysis indicates that the film grown on the indium tin oxide-coated glass substrate is pure rhombohedral Bi2Se3, and the film grown on the Ti substrate consists of both rhombohedral and orthorhombic Bi2Se3.
基金Funded by Open Foundation of State Key Laboratory of AdvancedTechnologyfor Materials Synthesis and Processing, Wuhan Universi-ty of Technology, the Post PhD Science Foundation of China(2003034504) andthe Foundation of Wuhan University of Technol-ogy(2003XJJ202)
文摘The rods that were shaped from nanocrystalline WC- 10.21 Co-0.42 VC/ Cr3 C2 ( wt% ) composite powders by using powder extrusion molding (PEM) were investigated. The nanocrystalline WC- 10.21 Co- 0. 42 VC/ Cr3 C2 ( wt% ) composite powders were prepared by the spray thermal decomposition-continuous reduction and carburization technology. In order to improve the properties of rods shaped by using powder extrusion molding, the cold isostatic pressing (CIP) technology was used before or after debinding. Specimens were siutered by vacuum siutering and hot isostatic pressing (HIP). The density, Rockwell A hardness, magnetic coercivity , and magnetic saturation induction of siutered specimen were measured. The microstructure of the green bodies and the siutered specimens was studied by scanning electron microscopy (SEM). Results show that the rod formed by using powder extrusion molding after debinding and followed by cold isostatic pressing can be siutered to 99.5% density of composite cemented carbide rods with an average grain size of about 200- 300 nm, magnetic coercivity of 30.4 KA / m, Rockwell A hardness of 92.6 and magnetic saturation induction of 85% . Superfine WC- 10 Co cemented carbide rods with excellent properties were obtained.
文摘Most of the seeds produced by neem (Azadirachta indica A. Juss) trees in Nigeria are currently underutilized. Hence, relevant literature provides only limited information conceming many of the seed oils from this country, especially where it concems the potential applications of these oils as preservatives for ligno-cellulose against bio-deterioration. Using standard procedures therefore, this study was carried out to evaluate and document selected physical and chemical properties of neem seed oil (NSO), mechanically extracted using a cold press at 31.03 N-mm^-2 pressure and a room temperature of 25 ± 2℃. The results show that oil yield was 38.42% with a specific gravity of 0.91 ± 0.01. The amount of acid was 18.24 ± 1.31 mg KOH.g^-1 and that of iodine 93.12 ± 2.01 g-100 g^- 1, while saponification and peroxide values were 172.88 ± 2.06 and 1.42 ± 0.04 mg·g^-1 respectively. The implication of the values obtained, particularly those for the chemical properties, as they concern the potential application of NSO as a preservative for ligno-eellulose, is likely that it may be useful in this regard since the values may support some of the documented anti-microbial properties of the oil, although other physical and chemical properties that may affect this potential are recommended for investigations. Conclusions and other recommendations follow in line with the results of the study.
基金This research was funded by the EU and project EXANDAS-H2020-MSCA-RISE-2015–“Exploitation of aromatic plants'by-products for the development of novel cosmeceuticals and food Supplements”(Grant Agreement No 691247).
文摘Argan oil is most frequently sold as pure oil,which can be directly applied topically due to its cosmetological proprieties or ingested in order to provide several health benefits.It's also commonly mixed into a number of cosmetic products like shampoos,soaps and conditioners.In this study we aimed to improve the argan oil extraction yield and quality parameters by comparing the effects of different extraction technologies.Argan kernel oils were extracted using four methods:mechanical cold press,Soxhlet extraction with n-hexane,supercritical fluid extraction(SFE),and enzyme assisted extraction with three different enzyme solutions cellulase(cellulast),pectinase(Pectinex)and a mixture of carbohydrase enzymes(Viscozyme®).The quality parameters was evaluated by determining the acid,peroxide and iodine values aswell as the extinction coefficients K_(232) and K_(270) as measures of conjugated dienes and trienes,respectively.The results showed that the highest yield(66.37%±3.3%)was obtained by enzyme assisted extraction using the carbohydrases enzymes mixture(Viscozyme®),followed by Soxhlet extraction(59.5%±3.1%)and pectinase extraction(52.03%±3.55%).All argan oils samples obtained by the different methods showed a good oxidation stability,with acid,peroxide and iodine values lower than 0.8 mg/g,15 meq/kg and 110 g/100 g according to the official argan oil norm,respectively.The results of argan oils quality parameters demonstrated that the enzyme extracted argan oils showed low oxidation,with the following quality parameters:acid values(0.4-0.6 mg/g),iodine values(95-100 g/100 g),dienes(K_(232)<2),trienes(K_(270)<0.35),and peroxide values(<1.5 meq/kg).The results proved that the enzyme assisted extraction method can be applied to improve the argan oil yield without affecting the oil quality.The enzyme extraction method may be a great alternative to solvent and cold press extractions for this eco-friendly processing approach.
基金financially supported by the Ministry of Education and Science of the Russian Federation (No.3.6586.2017/BY and 03.G25.31.0246)
文摘Effect of fabrication conditions on microstructure and thermoelectric properties of the Bi1.9Lu0.lTe3 compound was studied. Starting nanopowder with mean nanoparticle size of -37 nm was synthesized by a microwave-solvothermal method. In order to prepare samples with various micro-grained structures, the synthesized nanopowder was compacted by two methods. The first method is cold isostatic pressing with further high- temperature annealing, while the second method is spark plasma sintering at various temperatures of process (653 and 683 K). It is found that mean grain size is equal to -290,-730 and -1160 nm for cold isostatically pressed and spark plasma sintered at 653 and 683 K samples, respectively. The micro-grained sample with maximum mean grain size shows the best thermoelectric properties. This sample is structurally inhomogeneous and has the lowest thermal conductivity and the specific electrical resistivity. Maximum dimensionless figure of merit for this sample is equal to -0.9 for temperature range of 450-500 K.
基金the Canola Council of Canada Project # 2.2.1Nova Scotia Technology Development Project # Dev26-008+1 种基金Poultry Industry Council Project #PIC 238Advancing Canadian Agriculture and Agri-Food (ACAAF) Project # NS0107 for funding support
文摘Two experiments were conducted to determine the nitrogen-corrected apparent metabolizable energy(AMEn) of differently processed meals from Juncea(Brassica juncea), yellow and black seeded canola(Brassica napus), with or without supplementation of multi-carbohydrase enzymes(Enz) in diets for broiler chickens. The first experiment was a 3×2×2 factorial arrangement with the main factors being seed type(yellow [Yellow] or black [B1] canola seeds and Juncea seeds), processed at two temperatures(high temperature desolventized-toasted [HTDT] at 95℃ or low temperature desolventized-toasted[LTDT] at 57℃), with or without Enz. In Exp. 1, a total of 384 one-day-old male broiler chicks were randomly assigned to 64 battery cages, with 6 birds/cage. The second experiment was a 2×2×2 factorial arrangement with the main factors being seed type(Yellow or black [B2]), seed source(Scott,Saskatchewan or Truro, Nova Scotia) and Enz(with or without) supplementation. A total of 264 one-dayold male broiler chicks were randomly assigned to 44 battery cages, with 6 birds per cage. In Exp, 1 and 2,all birds were fed a common starter diet from 1 to 14 days of age. From d 15 to 21, the birds were fed one of the test treatments, a basal grower diet or the basal grower diet replaced with 30% test ingredient with celite(0.8%) added as an inert marker. Excreta was collected on d 20 and 21. In Exp. 1, there were no interactions(P > 0.05) among seed type, processing temperature and Enz. Processing temperature and dietary Enz did not affect(P > 0.05) AMEn of different canola meals. The AMEn of prepress solvent extracted canola and juncea meals(PSEM) from Yellow(11.2 MJ/kg) was higher(P < 0.05) than B1(10.2 MJ/kg) and Juncea(10.2 MJ/kg). In Exp. 2, there were no interactions(P > 0.05) among seed color,location and Enz. Supplementation of dietary Enz did not affect(P > 0.05) AMEn of different cold press canola meals. The AMEn of cold press canola meals(CPM) from Yellow(14.7 MJ/kg) was higher(P < 0.05)compared with B2(12.2 MJ/kg). In conclusion, among the different processing methods of oil extraction,meals derived from yellow seeded canola had higher AMEn than B seeded canola and Juncea.