1,671 research outputs found

    Recrystallization and grain growth at the interface of a bimetallic colaminated strip composed of two different Fe-Ni alloys

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    International audienceRoll bonding is a solid-state welding process widely used to manufacture layered metal composites. Particular properties may thus be obtained using the physical features of each material of the composite. Bimetal plates consisting of two different Fe-Ni alloys were made by roll bonding followed by heat treatment for 90 minutes at various annealing temperatures. The effects of post-rolling heat treatments on the bonding strength of a bimetal strip were investigated in relation to the interface microstructure evolution. Both recrystallization and grain growth took place at the interface during annealing. In particular, nucleation of new grains as well as growing grains crossing the interface may have contributed to the improvement of the bonding strength. Moreover, diffusion through the interface was found to drastically enhance the bonding strength from 850°C up to 1050°C. However, excessive grain growth associated to porosity occurrence probably caused the saturation of the bonding strength beyond 1050°C

    Protecting efficiently sea-migrating salmon smolts from entering hydropower plant turbines with inclined or oriented low bar spacing racks

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    Restoring the longitudinal connectivity of rivers is becoming a conservation priority in countries with high hydroelectric plant (HEP) development. Newly designed downstream passage solutions for fish are being installed in small and medium-sized HEPs in France, and an accurate evaluation of their functionality is needed. Here we addressed the efficiency of protection systems for the downstream migration of Atlantic salmon smolts at four HEPs (three 26° horizontally inclined racks and one 15° oriented to the flow rack in the bank alignment, all with 20 mm spaced bars). Between 239 and 300 hatchery-reared salmon smolts were PIT-tagged and released in 5–6 groups 100 m upstream of each studied HEP. Their passages through the HEPs were detected with radio frequency identification (RFID) antenna in the bypasses for downstream migration and the fish passes for upstream migration. On average between 82.8% and 92.3% of released smolts successfully passed the HEP through one of the two non-turbine routes. Resulting mean bypass passage efficiency ranged from 80.9 to 87.5% and all fish groups reached over 70% passage efficiency. Excepting one site, 50% of smolts passed through the bypass in less than 23 min after release, and 75% of them in less than 2 h 15 min. Combining our findings with previously estimated fish entrainment rates into the intake channel and turbine-related mortality rates, we assessed the overall fish survivals at the studied dam/HEPs which are between 98.24% and near 100%. Our results confirm recommended design criteria for inclined and oriented racks and the interest of the tested devices for the protection of downstream migrating salmon smolts

    Ghost Equations and Diffeomorphism Invariant Theories

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    Four-dimensional Einstein gravity in the Palatini first order formalism is shown to possess a vector supersymmetry of the same type as found in the topological theories for Yang-Mills fields. A peculiar feature of the gravitational theory, characterized by diffeomorphism invariance, is a direct link of vector supersymmetry with the field equation of motion for the Faddeev-Popov ghost of diffeomorphisms.Comment: LaTex, 10 pages; sign corrected in eq. (3.9); added and completed reference

    Abortion Due to Neospora caninum in Dairy Cattle in Southern Santa Catarina State, Brazil

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    Background: Neosporosis is a cosmopolitan disease known as the main infectious cause of abortion in cattle, reported in several states in Brazil. The transplacental transmission in cattle is responsible for perpetuating the disease in the herd. In the state of Santa Catarina, previous studies on this protozoan in cattle are mostly serological surveys. To increase information about this reproductive disorder, this work describes the diagnosis of abortions due to Neospora caninum in dairy cattle from state of Santa Catarina and the follow-up for 4 years in a farm affected by neosporosis.Case: From 2015 to 2019, necropsy was performed on 10 aborted bovine fetuses, between fifth and eighth month of pregnancy, with 1 fetus aborted in 2015, 3 in 2016, 2 in 2017 and, 4 in 2019, all originating from the same dairy property in the southern region of state of Santa Catarina. No macroscopic lesions were found. Histopathology revealed mild to moderate multifocal mononuclear necrotizing encephalitis in 5 fetuses, and multifocal mild mononuclear myositis and myocarditis in 4 and 3 fetuses, respectively. Polymerase Chain Reaction (PCR) using primers based on the Nc-5 gene was positive for N. caninum in five fetuses. Three visits were performed in the farm for epidemiological evaluation and blood samples collection for IgG antibodies anti-N. caninum (IFAT). The total herd was 170 Jersey, Holstein and crossbred cattle, raised in a semi-confined system with mechanical milking system. Since 2014, there has been a significant increase in abortions cases, approximately 20 cows had abortions; in the year 2015, approximately 10; in 2016, less than 5; in 2017, 4 cows aborted; in 2018, 11 abortions and, in 2019, there were 4 abortions. An increase in the rate of return to estrus was also reported, and both primiparous and multiparous cows had reproductive disorders. Abortions were recorded throughout the year and occurred predominantly between the fourth and sixth month of pregnancy. In 2016, an Indirect Immunofluorescence Reaction (IFAT) was performed on sera from 26 cows (13 with a history of reproductive disorders and another 13 without disorders). Of these, 50.0% (13/26) were seropositive, with titers ranging from 100 to 1600 (cutoff ≥100). The Enzyme Immunoassay (ELISA) of the entire herd was carried out in 2017, with 26.54% (43/162) of seropositivity, 8.02% (13/162) suspect, and 30.4% (17/56) had reproductive disorders. It was observed that only animals born on the property were used for replacement, there was less possibility of direct contact between dogs on the property with milking facilities, placental and fetal remains, properly disposing of these, incinerating or burying. Thirty animals were discarded from the property, 25 of which had reproductive disorders. All young female daughters of seropositive cows remained on the property for replacement. During the evaluation period, all dogs were eliminated.Discussion: In this study, the diagnosis of neosporosis was made through epidemiology, histopathological lesions characterized by mononuclear encephalitis, myocarditis and myositis, and detection of the agent by PCR, associated with serological techniques. The lesions observed are indicative of N. caninum infection and are compatible with lesions observed in other studies. Serological screening is important to complement the diagnosis of abortion by N. caninum and to help control the agent in herds. From this report it is concluded that N. caninum is an important agent of reproductive disorders in cattle in the southern region of Santa Catarina, the different serological analyzes showed a good screening index for the inclusion of control strategies. In addition, the monitoring of reproductive rates of affected properties becomes necessary over the years, allowing better observation of control strategies.Keywords: reproductive disorder, fetal death, protozoan, parasitology.Descritores: distúrbio reprodutivo, morte fetal, protozoário, parasitologia.

    Self-Nanoemulsifying Drug Delivery System (SNEDDS) Using Lipophilic Extract of Viscum album subsp. austriacum (Wiesb.) Vollm.

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    BACKGROUND AND PURPOSE Natural products are potential sources of anticancer components. Among various species, the lipophilic extract of the Viscum album subsp. austriacum (Wiesb.) Vollm. (VALE) has shown promising therapeutic potential. The present work aimed to qualify the plant source and characterize the extract's chemical profile. In addition, a self-nanoemulsifying drug delivery system (SNEDDS) containing VALE (SNEDDS-VALE) was developed. METHODS V. album subsp. austriacum histochemistry was performed, and the chemical profile of VALE was analyzed by GC-MS. After the SNEEDS-VALE development, its morphology was visualized by transmission electron microscopy (TEM), while its stability was evaluated by the average droplet size, polydispersity index (PdI) and pH. Lastly, SNEDDS-VALE chemical stability was evaluated by LC-DAD-MS. RESULTS The histochemical analysis showed the presence of lipophilic compounds in the leaves and stems. The major compound in the VALE was oleanolic acid, followed by lupeol acetate and ursolic acid. SNEDDS was composed of medium chain triglyceride and Kolliphor® RH 40 (PEG-40 hydrogenated castor oil). A homogeneous, isotropic and stable nanoemulsion was obtained, with an average size of 36.87 ± 1.04 nm and PdI of 0.14 ± 0.02, for 14 weeks. CONCLUSION This is the first histochemistry analysis of V. album subsp. austriacum growing on Pinus sylvestris L. which provided detailed information regarding its lipophilic compounds. A homogeneous, isotropic and stable SNEDDS-VALE was obtained to improve the low water solubility of VALE. Further, in vitro and in vivo experiments should be performed, in order to evaluate the antitumoral potential of SNEDDS-VALE

    A Decentralized SDN Framework and Its Applications to Heterogeneous Internets

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    Motivated by the internets of the future, which will likely be considerably larger in size as well as highly heterogeneous and decentralized, we propose Decentralize- SDN, a Software-Defined Networking (SDN) framework that enables both physical- as well as logical distribution of the SDN control plane. D-SDN accomplishes network control distribution by defining a hierarchy of controllers that can "match" an internet's organizational and administrative structure. By delegating control between main controllers and secondary controllers, DSDN is able to accommodate administrative decentralization and autonomy, as well as possible disruptions that may be part of the operation of future internets. D-SDN specifies the protocols used for communication between main controllers as well as for main controller secondary controller- and secondary controller-secondary controller communication. Another distinguishing feature of D-SDN is that it incorporates security as an integral part of the framework and its underlying protocols. This paper describes our D-SDN framework as well as its protocols. It also presents our prototype implementation and proof-of-concept experimentation on a real testbed in which we showcase two use cases, namely network capacity sharing and public safety network services

    Ion concentrations in the solution of an Oxisol under different management systems

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    O objetivo deste trabalho foi avaliar as concentrações de íons na solução de um Latossolo Vermelho, em diferentes sistemas de manejo. Foram avaliados os sistemas de lavoura e pastagem contínua, assim como os rotacionados em integração lavoura-pecuária. O experimento foi iniciado em 1991, e as coletas das soluções foram realizadas em 2005 e 2006. Cápsulas porosas foram instaladas às profundidades de 20 e 150 cm, e as soluções foram extraídas em seis épocas de cada ano. As concentrações de Cl-, SO4(2-), NO3-, H2PO4-, K+, Mg2+ e Ca2+ foram determinadas. Independentemente das profundidades e dos sistemas de manejo, a concentração de íons nas soluções, em ordem decrescente de grandeza, foi: NO3- >Cl- >SO4(2-) >H2PO4- e Ca2+ >K+ >Mg2+. Entre os sistemas de cultivo, a concentração dos íons na solução decresceu e foi maior em lavoura contínua sob preparo convencional, seguida de lavoura contínua sob plantio direto e, finalmente, pelo sistema de integração lavoura-pecuária e pela pastagem contínua. À profundidade de 150 cm, as concentrações dos íons na solução do solo sob pastagem contínua e integração lavoura-pecuária foram sempre baixas, o que indica baixo risco de lixiviação.The objective of this work was to evaluate ion concentrations in an Oxisol solution, in plots subjected to different management systems. Continuous crop and pasture, and the integrated crop-livestock management system were evaluated. The experiment started in 1991, and the soil solutions were collected in 2005 and 2006. Ceramic cups were installed at 20 and 150 cm soil depths, and the solutions were extracted six times each year. The concentrations of Cl-, SO4(2-), NO3-, H2PO4-, K+, Mg2+, and Ca2+ were determined. Irrespective of the depths and cropping systems considered, the concentrations of ions into the soil solutions, in decreasing order, were: NO3- >Cl- >SO4(2-) >H2PO4- and Ca2+ >K+ >Mg2+. Among the cropping systems, the ion concentrations in the soil solution was higher in the continuous crop under conventional tillage, followed by the continuous crop under no-tillage, and finally by the integrated crop-livestock system and the continuous pasture. At 150 cm depth, the ion concentrations in soil solutions under continuous pasture and integrated crop-livestock system were always low, which indicates a low leaching risk

    Concentração de íons na solução de um Latossolo Vermelho sob diferentes sistemas de manejo

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    The objective of this work was to evaluate ion concentrations in an Oxisol solution, in plots subjected to different management systems. Continuous crop and pasture, and the integrated crop-livestock management system were evaluated. The experiment started in 1991, and the soil solutions were collected in 2005 and 2006. Ceramic cups were installed at 20 and 150 cm soil depths, and the solutions were extracted six times each year. The concentrations of Cl-, SO42-, NO3-, H2PO4-, K+, Mg2+, and Ca2+ were determined. Irrespective of the depths and cropping systems considered, the concentrations of ions into the soil solutions, in decreasing order, were: NO3- >Cl- >SO42- >H2PO4- and Ca2+ >K+ >Mg2+. Among the cropping systems, the ion concentrations in the soil solution was higher in the continuous crop under conventional tillage, followed by the continuous crop under no‑tillage, and finally by the integrated crop‑livestock system and the continuous pasture. At 150 cm depth, the ion concentrations in soil solutions under continuous pasture and integrated crop-livestock system were always low, which indicates a low leaching risk.O objetivo deste trabalho foi avaliar as concentrações de íons na solução de um Latossolo Vermelho, em diferentes sistemas de manejo. Foram avaliados os sistemas de lavoura e pastagem contínua, assim como os rotacionados em integração lavoura-pecuária. O experimento foi iniciado em 1991, e as coletas das soluções foram realizadas em 2005 e 2006. Cápsulas porosas foram instaladas às profundidades de 20 e 150 cm, e as soluções foram extraídas em seis épocas de cada ano. As concentrações de Cl-, SO42-, NO3-, H2PO4-, K+, Mg2+ e Ca2+ foram determinadas. Independentemente das profundidades e dos sistemas de manejo, a concentração de íons nas soluções, em ordem decrescente de grandeza, foi: NO3->Cl- >SO42->H2PO4- e Ca2+ >K+ >Mg2+. Entre os sistemas de cultivo, a concentração dos íons na solução decresceu e foi maior em lavoura contínua sob preparo convencional, seguida de lavoura contínua sob plantio direto e, finalmente, pelo sistema de integração lavoura-pecuária e pela pastagem contínua. À profundidade de 150 cm, as concentrações dos íons na solução do solo sob pastagem contínua e integração lavoura-pecuária foram sempre baixas, o que indica baixo risco de lixiviação
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