This paper presents failure mechanisms of the soil at the caisson-tip with fillet during suction-assisted penetration of suction caissons in undrained clay.Theoretical solutions of resistance factor N_c of the caisson...This paper presents failure mechanisms of the soil at the caisson-tip with fillet during suction-assisted penetration of suction caissons in undrained clay.Theoretical solutions of resistance factor N_c of the caisson-tip are obtained in terms of the caisson-tip geometry ratio of the flat section of the caisson-tip to the caisson wall thickness m/t and adhesion factorsα_i along inside of caisson wall andα_b at the base of the caisson-tip.It is indicated that the factor N_c increases with the increase of m/t,α_i and a_b.The resistance factors N_c for the rough base(α_b=1)are larger by 0.57than that for the smooth base(α_b=0).Besides,the factors N_c of caisson-tip with flat base(m=t)are larger by 1.14 than that with full internal fillet(m=0).The required suction to penetrate suction caissons with various fillets is obtained in terms of the force equilibrium in vertical direction.The finite element limit analysis and centrifuge model test results are used to verify the rationality of the presented failure mechanisms and theoretical predictions.展开更多
In this study, trace metals [Cadmium (Cd), Mercury (Hg) and Lead (Pb)] consentration of 76 pieces of frozen European sea bass (Dicentrarchus labrax Linnaeus-1758) and gilthead sea bream (Sparus aurata Linnaeus-1758) f...In this study, trace metals [Cadmium (Cd), Mercury (Hg) and Lead (Pb)] consentration of 76 pieces of frozen European sea bass (Dicentrarchus labrax Linnaeus-1758) and gilthead sea bream (Sparus aurata Linnaeus-1758) fillets, produced and marketed in Turkey, were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after microwave damp burning process, and results obtained were assessed in terms of public health. This study was conducted from June 2010 to July 2011. At the end of study, maximum heavy metal levels for sea bass and sea bream fillets were determined as 256.50, 216.22 μg/kg for Cd;414.79, 338.46 μg/kg for Hg ve 1047.61, 147.14 μg/kg for Pb, respectively. At the end of the study, the levels of cadmium (for 3 samples) and lead (for 1 samples) were higher than the recommended legal limits of the European Union for human consumption. It was detected that the fillets which were analyzed was good quality from the point of cadmium, mercury and lead contents.展开更多
The temperature field and flow field were analyzed to solve the problems of unstable penetration and poor forming quality,which always happen in asymmetric fillet welding. In order to explore the effect of the welding...The temperature field and flow field were analyzed to solve the problems of unstable penetration and poor forming quality,which always happen in asymmetric fillet welding. In order to explore the effect of the welding parameters on welding and improve the quality of forming,a three-dimensional mathematical model of asymmetric fillet welding was established by using the finite element software COMSOL and the coupling equation. The model was considered about the surface tension gradient,the electromagnetic force,gravity and the effect of temperature,radiation and convection heat on physical properties of the material. The flow field and the growth pattern of the weld pool were analyzed,and the weld pool geometry under different welding currents was compared. The results show that,the thin metal was preferentially penetrated,and with the welding process the weld width expanded until the weld beam was fullpenetration. The heat affected zone was got from weld experiments,its shape and size agreed well with the simulation results,which verifies the validity of the theoretical analysis.展开更多
This paper presents a mechanical calculation and numerical simulation of the fillet weld of sleeve repair.The mechanical analysis based on the yield criteria is performed to obtain the minimum value of the fillet weld...This paper presents a mechanical calculation and numerical simulation of the fillet weld of sleeve repair.The mechanical analysis based on the yield criteria is performed to obtain the minimum value of the fillet weld leg height to ensure the strength and loadbearing capacity of the weld. Within the framework of numerical simulation,the parameters of double ellipsoid heat source are determined by fitting method and the simulated molten pool morphology agrees well with the practical weld. Finite element models with various weld leg height are performed to predict the distribution and magnitude of the deformation and stress. The simulation takes into account thermal,metallurgical and mechanical factors,and the maximum value of the fillet weld leg height is obtained based on the magnitude of the deformation and stress.The mechanical calculation and numerical simulation results show that 1.2-2 times wall thickness is an optimal range of fillet weld leg height. And reasonable parameters of sleeve repair for in-service welding are provided for engineering field,which can improve the service life of the weld and production efficiency.展开更多
In this study quality changes of rainbow trout fillet wrapped with quince seed mucilage QSM film incorporated with 0–2%(V/V)thyme or oregano essential oil,as natural preservatives,during storage of 18 d at 4◦C were i...In this study quality changes of rainbow trout fillet wrapped with quince seed mucilage QSM film incorporated with 0–2%(V/V)thyme or oregano essential oil,as natural preservatives,during storage of 18 d at 4◦C were investigated.The control and wrapped fillet samples were analyzed for texture,lipid oxidation,and color characteristics.After 6 d of storage,a significantly increasing trend was observed for lipid oxidation in control samples.Peroxidation values(PV)varied for all treatments and remained lower than 8 meq/kg throughout the storage time(18 d).The lowest PV was obtained in fillets wrapped with QSM film containing 2%oregano essential oil.Compared to control samples,fillet samples wrapped with QSM films presented a significant reduction in pH after 12 d(P<0.05).L*and b*color parameters were increased while parameter a*was decreased linearly for all treatments during the storage time.展开更多
The exact solution of stress distribution in fillet welds under the action of bending moment M is presented in this paper. Together with the exact solution of stress distribution in fillel welds under the action of co...The exact solution of stress distribution in fillet welds under the action of bending moment M is presented in this paper. Together with the exact solution of stress distribution in fillel welds under the action of concentrated force P given in an earlier paper[1], designers of weldments can improve their work on the foundation of exact analytical solutions.展开更多
The effect of fillet formed from structural adhesive differing in elastic modulus on the stress distribution along the length of bi-adhesive bonded single lap aluminum joints was studied under the condition of one adh...The effect of fillet formed from structural adhesive differing in elastic modulus on the stress distribution along the length of bi-adhesive bonded single lap aluminum joints was studied under the condition of one adhesive or bi-adhesive arranged along the bondline by an elastic finite element model. The results obtained from the numerical simulation show that the fillet can reduce the peak value of stress obviously. It is not recommended to arrange a higher modulus adhesive with a lower one along the bondline for the peak stress may be maintained nearly the same. The lower the fillet formed by the elastic modulus adhesive is, the lower the stress concentration towards the end of a bonded lap joint is. It may be benefit to raise the shear strength of aluminum single lap joint.展开更多
Fish processing environment is very favorable for the growth of microorganisms and highlights a potential risk associated with microbial hazards. The present study investigated the growth behavior of aerobic bacteria,...Fish processing environment is very favorable for the growth of microorganisms and highlights a potential risk associated with microbial hazards. The present study investigated the growth behavior of aerobic bacteria, yeasts and molds, and bacterial pathogens or surrogate (Listeria monocytogenes and Clostridium sporogenes) on thawed and fresh catfish fillets during refrigerated storage (5°C - 7°C). Thawed and fresh fillets were respectively inoculated with L. monocytogenes and C. sporogenes, and packaged in LDPE bags. In uninoculated catfish, the populations of aerobic bacteria, and yeasts and molds increased significantly (P C. sporogenes vegetative cells on fresh catfish fillets. These results indicated that the microbiological quality of refrigerated thawed catfish would become unacceptable within 3 - 4 days. Our results also implied that environmental pathogens such as L. monocytogenes and Clostridium sp. can survive on catfish fillets for extended periods during refrigerated storage. Proper sanitation and hygienic practices are essential to control microbial hazards during handling and processing of catfish fillets.展开更多
In order to explore the fresh-keeping methods for zander fillet,we use vacuum packaging and partial freezing to process zander fillet,conduct a comparative analysis of sensory characteristics,percentage of water loss,...In order to explore the fresh-keeping methods for zander fillet,we use vacuum packaging and partial freezing to process zander fillet,conduct a comparative analysis of sensory characteristics,percentage of water loss,stiffness period,muscle stiffness,TVB-N and water activity during the storage,and assess the fresh-keeping effect of zander fillet under the conditions of vacuum packaging and partial freezing. The results show that zander can be dead after being placed into the 2℃ water for 30 min,and the stiffness period can be extended about 100 min compared with natural death; the percentage of water loss under the conditions of vacuum packaging before partial freezing is 2. 6% lower than under the conditions of partial freezing before vacuum packaging; after being stored at- 7℃ and- 4℃ for 15 d,TVB- N of fillet ≤15 mg /kg; TVB- N of fillet at- 7℃ is 25% lower than at- 4℃.展开更多
This project work focuses on the reduction of weld undercuts using the Taguchi method. The phenomenon of weld undercuts constitutes a major problem for the welding industry. When undercuts occur, and particularly when...This project work focuses on the reduction of weld undercuts using the Taguchi method. The phenomenon of weld undercuts constitutes a major problem for the welding industry. When undercuts occur, and particularly when such cuts are deep, it has a negative impact on the weld as it lowers the integrity and quality of the weldment. Therefore, efforts are made globally to reduce the depth of such weld undercuts to the barest minimum. Several optimization methods have been adopted;however, in this study, the Taguchi method is applied. “The smaller the better components” of the Taguchi method is applied. From the results obtained from applying this Taguchi method, the optimum process parameters obtained are A2-B1-C2, which are a voltage of 20 V, a current of 180 A, and a welding speed of 130 mm/s, required to form an undercut of 0.03 mm. Whereas the existing process parameters used by the company are A1-B3-C, which make an undercut to a depth of 0.09 mm. It is concluded that the use of Taguchi method has been able to reduce the depth of undercut as shown in this study. A step-by-step approach is presented in the study.展开更多
Backgrounds: Reconstruction after hemipelvectomy is very important for rehabilitation into society. The pelvis plays an important role for support of the intra-abdominal organs. Methods: We operated 3 cases using fill...Backgrounds: Reconstruction after hemipelvectomy is very important for rehabilitation into society. The pelvis plays an important role for support of the intra-abdominal organs. Methods: We operated 3 cases using fillet flaps with the femoral periosteum for reconstruction of hemipelvectomy defect. Results: It is useful to elevate the flap all around with the femoral periosteum, because the periosteum can be sutured to supporting pelvic structures with the aim to support intra-abdominal organs. Conclusion: Without alternative supports for the bony pelvis, pelvic reconstructions are at risk for hernia and it may be difficult for outpatients to fit their habiliments after radical cure. The rigid support for the intra-abdominal organs occurs in association with the suture pelvic and femoral periosteum.展开更多
The purpose of this thesis is to derive the flexibility formula of the corner-filleted flexure hinge easily and conveniently and use it to design a micro-rotation compliant mechanism. Firstly,we get the corner-fillete...The purpose of this thesis is to derive the flexibility formula of the corner-filleted flexure hinge easily and conveniently and use it to design a micro-rotation compliant mechanism. Firstly,we get the corner-filleted flexure hinge flexibility formula by methods of symmetry transformation and coordinates translation. The correctness of this formula is validated on the basis of the finite element method and under the premise that the effects of shear stress are taken into consideration. Then a micro-rotation compliant mechanism is designed in accordance with the corner-filleted flexure hinge,and the deduction and analysis of its working moment/rigidity are conducted. Moreover,this theoretical formula is proved to be accurate and reliable through the finite element analysis and the experimental verification,based on which the structural design and optimization can be made on the rotating part of a micro adjustment device. The results illustrate that designing and optimizing the structures by the analysis model is convenient and reliable so that complicated 3D modeling and finite element analysis are not needed.展开更多
Nigeria waters are rich with a variety of fish species but only very few are cultured and available for consumption.This study was conducted to know the fillet quality,gut content and condition of Parachanna obscura a...Nigeria waters are rich with a variety of fish species but only very few are cultured and available for consumption.This study was conducted to know the fillet quality,gut content and condition of Parachanna obscura and Clarias agboyiensis in Nigeria using Igbokoda river as a reference because it is a the major fishing site in the nation.Studies were conducted on the viscera somatic index based on the organ weight and the body weight of the fish and the food item consumed by Parachanna obscura and Clarias agboyiensis between May to October,2019 to infer on the fillet quality and gut content of P.obscura and C.agboyiensis in the water body respectively.A summary of food items that constituted the diet of Clarias agboyiensis are Baccillariophyta,fish,fat droplets,dinoflagellate,insect and Chlorophyta which constituted the most important food items both occurring in all stomachs containing food.The fishes has more muscle than the viscera organs which indicate that the weight of the fish before dressing out is higher than the weight of the fish after dressing out.This is suggestive of a good quality of food fish.There was a significant correlation between body weight and total length of specimens found in this study.Increases in total length resulted in corresponding increases in body weight.The result for the condition factor showed was below the expected or standard value(K=1)which shows this species was not in favorable environmental condition.It is therefore necessary to allow phytoplanktons grow well in water body to increase availability of food items to Parachanna obscura and Clarias agboyiensis.P.obscura and C.agboyiensis are also good food fishes of a high fillet quality.They are omnivorous feeders therefore having potentials for aquaculture.展开更多
Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria(LAB) as food...Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria(LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19(obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.展开更多
This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight (35...This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight (350±12) g] were divided into three groups (E250, E500 and E1000) and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary α-tocopheryl acetate (289, 553, 1 069 mg/kg). Over the experimental period, fish were fed to satiation and reached a final mean weight of (465±28) g without significant body weight difference and proximate composition difference. Fillet α-tocopherol was significantly (P<0.05) different between groups, reaching levels of 14.2, 22.1, 30.9 μg/mg fillet for groups E250, E500 and E1000, respectively. Total serum superoxide dismutase (SOD) activity increased significantly (P<0.05) in fish fed the diets high in α-tocopheryl acetate, but serum glutathione peroxidase (GPX) activity was unaffected. In storage on ice, fillets of fish fed the diets high in α-tocopheryl acetate exhibited significantly lower (P<0.05) levels of oxidation. These results suggested that increased dietary α-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxi-dation of Sparus macrocephalus fillets in retail storage on ice.展开更多
基金financially supported by the National Natural Science Foundation of China (Grant No.51879044)the Youth Foundation of Shandong Natural Science Foundation (Grant No.ZR2020QE258)+1 种基金Qingdao Postdoctoral Applied Research Project (Grant No.ZX20220202)SDUST Research Fund (Grant No.2015KYJH104)。
文摘This paper presents failure mechanisms of the soil at the caisson-tip with fillet during suction-assisted penetration of suction caissons in undrained clay.Theoretical solutions of resistance factor N_c of the caisson-tip are obtained in terms of the caisson-tip geometry ratio of the flat section of the caisson-tip to the caisson wall thickness m/t and adhesion factorsα_i along inside of caisson wall andα_b at the base of the caisson-tip.It is indicated that the factor N_c increases with the increase of m/t,α_i and a_b.The resistance factors N_c for the rough base(α_b=1)are larger by 0.57than that for the smooth base(α_b=0).Besides,the factors N_c of caisson-tip with flat base(m=t)are larger by 1.14 than that with full internal fillet(m=0).The required suction to penetrate suction caissons with various fillets is obtained in terms of the force equilibrium in vertical direction.The finite element limit analysis and centrifuge model test results are used to verify the rationality of the presented failure mechanisms and theoretical predictions.
文摘In this study, trace metals [Cadmium (Cd), Mercury (Hg) and Lead (Pb)] consentration of 76 pieces of frozen European sea bass (Dicentrarchus labrax Linnaeus-1758) and gilthead sea bream (Sparus aurata Linnaeus-1758) fillets, produced and marketed in Turkey, were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after microwave damp burning process, and results obtained were assessed in terms of public health. This study was conducted from June 2010 to July 2011. At the end of study, maximum heavy metal levels for sea bass and sea bream fillets were determined as 256.50, 216.22 μg/kg for Cd;414.79, 338.46 μg/kg for Hg ve 1047.61, 147.14 μg/kg for Pb, respectively. At the end of the study, the levels of cadmium (for 3 samples) and lead (for 1 samples) were higher than the recommended legal limits of the European Union for human consumption. It was detected that the fillets which were analyzed was good quality from the point of cadmium, mercury and lead contents.
基金supported by the National Natural Science Foundation of China(Grant No.U1733125)Natural Science Foundation of Tianjin(Grant No.17JCZDJC38700)
文摘The temperature field and flow field were analyzed to solve the problems of unstable penetration and poor forming quality,which always happen in asymmetric fillet welding. In order to explore the effect of the welding parameters on welding and improve the quality of forming,a three-dimensional mathematical model of asymmetric fillet welding was established by using the finite element software COMSOL and the coupling equation. The model was considered about the surface tension gradient,the electromagnetic force,gravity and the effect of temperature,radiation and convection heat on physical properties of the material. The flow field and the growth pattern of the weld pool were analyzed,and the weld pool geometry under different welding currents was compared. The results show that,the thin metal was preferentially penetrated,and with the welding process the weld width expanded until the weld beam was fullpenetration. The heat affected zone was got from weld experiments,its shape and size agreed well with the simulation results,which verifies the validity of the theoretical analysis.
基金supported by the Shandong Key Research and Development Plan,Department of Science&Technology of Shandong Province(No.2016ZDJS05B03)China University of Petroleum(East China)Graduate Project Innovation Project(No.YCX2017052)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Independent Innovation Research Project of China University of Petroleum(East China)(No.17CX06005)
文摘This paper presents a mechanical calculation and numerical simulation of the fillet weld of sleeve repair.The mechanical analysis based on the yield criteria is performed to obtain the minimum value of the fillet weld leg height to ensure the strength and loadbearing capacity of the weld. Within the framework of numerical simulation,the parameters of double ellipsoid heat source are determined by fitting method and the simulated molten pool morphology agrees well with the practical weld. Finite element models with various weld leg height are performed to predict the distribution and magnitude of the deformation and stress. The simulation takes into account thermal,metallurgical and mechanical factors,and the maximum value of the fillet weld leg height is obtained based on the magnitude of the deformation and stress.The mechanical calculation and numerical simulation results show that 1.2-2 times wall thickness is an optimal range of fillet weld leg height. And reasonable parameters of sleeve repair for in-service welding are provided for engineering field,which can improve the service life of the weld and production efficiency.
文摘In this study quality changes of rainbow trout fillet wrapped with quince seed mucilage QSM film incorporated with 0–2%(V/V)thyme or oregano essential oil,as natural preservatives,during storage of 18 d at 4◦C were investigated.The control and wrapped fillet samples were analyzed for texture,lipid oxidation,and color characteristics.After 6 d of storage,a significantly increasing trend was observed for lipid oxidation in control samples.Peroxidation values(PV)varied for all treatments and remained lower than 8 meq/kg throughout the storage time(18 d).The lowest PV was obtained in fillets wrapped with QSM film containing 2%oregano essential oil.Compared to control samples,fillet samples wrapped with QSM films presented a significant reduction in pH after 12 d(P<0.05).L*and b*color parameters were increased while parameter a*was decreased linearly for all treatments during the storage time.
文摘The exact solution of stress distribution in fillet welds under the action of bending moment M is presented in this paper. Together with the exact solution of stress distribution in fillel welds under the action of concentrated force P given in an earlier paper[1], designers of weldments can improve their work on the foundation of exact analytical solutions.
文摘The effect of fillet formed from structural adhesive differing in elastic modulus on the stress distribution along the length of bi-adhesive bonded single lap aluminum joints was studied under the condition of one adhesive or bi-adhesive arranged along the bondline by an elastic finite element model. The results obtained from the numerical simulation show that the fillet can reduce the peak value of stress obviously. It is not recommended to arrange a higher modulus adhesive with a lower one along the bondline for the peak stress may be maintained nearly the same. The lower the fillet formed by the elastic modulus adhesive is, the lower the stress concentration towards the end of a bonded lap joint is. It may be benefit to raise the shear strength of aluminum single lap joint.
文摘Fish processing environment is very favorable for the growth of microorganisms and highlights a potential risk associated with microbial hazards. The present study investigated the growth behavior of aerobic bacteria, yeasts and molds, and bacterial pathogens or surrogate (Listeria monocytogenes and Clostridium sporogenes) on thawed and fresh catfish fillets during refrigerated storage (5°C - 7°C). Thawed and fresh fillets were respectively inoculated with L. monocytogenes and C. sporogenes, and packaged in LDPE bags. In uninoculated catfish, the populations of aerobic bacteria, and yeasts and molds increased significantly (P C. sporogenes vegetative cells on fresh catfish fillets. These results indicated that the microbiological quality of refrigerated thawed catfish would become unacceptable within 3 - 4 days. Our results also implied that environmental pathogens such as L. monocytogenes and Clostridium sp. can survive on catfish fillets for extended periods during refrigerated storage. Proper sanitation and hygienic practices are essential to control microbial hazards during handling and processing of catfish fillets.
基金Supported by Key Science and Technology Project in Hainan Province(090110)
文摘In order to explore the fresh-keeping methods for zander fillet,we use vacuum packaging and partial freezing to process zander fillet,conduct a comparative analysis of sensory characteristics,percentage of water loss,stiffness period,muscle stiffness,TVB-N and water activity during the storage,and assess the fresh-keeping effect of zander fillet under the conditions of vacuum packaging and partial freezing. The results show that zander can be dead after being placed into the 2℃ water for 30 min,and the stiffness period can be extended about 100 min compared with natural death; the percentage of water loss under the conditions of vacuum packaging before partial freezing is 2. 6% lower than under the conditions of partial freezing before vacuum packaging; after being stored at- 7℃ and- 4℃ for 15 d,TVB- N of fillet ≤15 mg /kg; TVB- N of fillet at- 7℃ is 25% lower than at- 4℃.
文摘This project work focuses on the reduction of weld undercuts using the Taguchi method. The phenomenon of weld undercuts constitutes a major problem for the welding industry. When undercuts occur, and particularly when such cuts are deep, it has a negative impact on the weld as it lowers the integrity and quality of the weldment. Therefore, efforts are made globally to reduce the depth of such weld undercuts to the barest minimum. Several optimization methods have been adopted;however, in this study, the Taguchi method is applied. “The smaller the better components” of the Taguchi method is applied. From the results obtained from applying this Taguchi method, the optimum process parameters obtained are A2-B1-C2, which are a voltage of 20 V, a current of 180 A, and a welding speed of 130 mm/s, required to form an undercut of 0.03 mm. Whereas the existing process parameters used by the company are A1-B3-C, which make an undercut to a depth of 0.09 mm. It is concluded that the use of Taguchi method has been able to reduce the depth of undercut as shown in this study. A step-by-step approach is presented in the study.
文摘Backgrounds: Reconstruction after hemipelvectomy is very important for rehabilitation into society. The pelvis plays an important role for support of the intra-abdominal organs. Methods: We operated 3 cases using fillet flaps with the femoral periosteum for reconstruction of hemipelvectomy defect. Results: It is useful to elevate the flap all around with the femoral periosteum, because the periosteum can be sutured to supporting pelvic structures with the aim to support intra-abdominal organs. Conclusion: Without alternative supports for the bony pelvis, pelvic reconstructions are at risk for hernia and it may be difficult for outpatients to fit their habiliments after radical cure. The rigid support for the intra-abdominal organs occurs in association with the suture pelvic and femoral periosteum.
基金Sponsored by the National High-tech R&D Progrom(Grant No.2011AA12A103)the Equipment Development Fund(Grant No.08001SA050)
文摘The purpose of this thesis is to derive the flexibility formula of the corner-filleted flexure hinge easily and conveniently and use it to design a micro-rotation compliant mechanism. Firstly,we get the corner-filleted flexure hinge flexibility formula by methods of symmetry transformation and coordinates translation. The correctness of this formula is validated on the basis of the finite element method and under the premise that the effects of shear stress are taken into consideration. Then a micro-rotation compliant mechanism is designed in accordance with the corner-filleted flexure hinge,and the deduction and analysis of its working moment/rigidity are conducted. Moreover,this theoretical formula is proved to be accurate and reliable through the finite element analysis and the experimental verification,based on which the structural design and optimization can be made on the rotating part of a micro adjustment device. The results illustrate that designing and optimizing the structures by the analysis model is convenient and reliable so that complicated 3D modeling and finite element analysis are not needed.
文摘Nigeria waters are rich with a variety of fish species but only very few are cultured and available for consumption.This study was conducted to know the fillet quality,gut content and condition of Parachanna obscura and Clarias agboyiensis in Nigeria using Igbokoda river as a reference because it is a the major fishing site in the nation.Studies were conducted on the viscera somatic index based on the organ weight and the body weight of the fish and the food item consumed by Parachanna obscura and Clarias agboyiensis between May to October,2019 to infer on the fillet quality and gut content of P.obscura and C.agboyiensis in the water body respectively.A summary of food items that constituted the diet of Clarias agboyiensis are Baccillariophyta,fish,fat droplets,dinoflagellate,insect and Chlorophyta which constituted the most important food items both occurring in all stomachs containing food.The fishes has more muscle than the viscera organs which indicate that the weight of the fish before dressing out is higher than the weight of the fish after dressing out.This is suggestive of a good quality of food fish.There was a significant correlation between body weight and total length of specimens found in this study.Increases in total length resulted in corresponding increases in body weight.The result for the condition factor showed was below the expected or standard value(K=1)which shows this species was not in favorable environmental condition.It is therefore necessary to allow phytoplanktons grow well in water body to increase availability of food items to Parachanna obscura and Clarias agboyiensis.P.obscura and C.agboyiensis are also good food fishes of a high fillet quality.They are omnivorous feeders therefore having potentials for aquaculture.
基金supported by the National Natural Science Foundation of China(No.31301587)Key Laboratory of Aquatic Product Processing,Ministry of Agriculture,China
文摘Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria(LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19(obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.
基金Project (No. 2006c12098) supported by the Science and TechnologyDepartment of Zhejiang Province, China
文摘This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight (350±12) g] were divided into three groups (E250, E500 and E1000) and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary α-tocopheryl acetate (289, 553, 1 069 mg/kg). Over the experimental period, fish were fed to satiation and reached a final mean weight of (465±28) g without significant body weight difference and proximate composition difference. Fillet α-tocopherol was significantly (P<0.05) different between groups, reaching levels of 14.2, 22.1, 30.9 μg/mg fillet for groups E250, E500 and E1000, respectively. Total serum superoxide dismutase (SOD) activity increased significantly (P<0.05) in fish fed the diets high in α-tocopheryl acetate, but serum glutathione peroxidase (GPX) activity was unaffected. In storage on ice, fillets of fish fed the diets high in α-tocopheryl acetate exhibited significantly lower (P<0.05) levels of oxidation. These results suggested that increased dietary α-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxi-dation of Sparus macrocephalus fillets in retail storage on ice.
