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Статті в журналах з теми "Plasma du borde":
1
Trebichavský, I., H. Kozáková, and IŠplíchal. "Plasma lipopolysaccharide level and enterocyte brush border enzymes in gnotobiotic piglets infected with Salmonella typhimurium." Veterinární Medicína 47, No. 10 - 11 (March 30, 2012): 289–94. http://dx.doi.org/10.17221/5837-vetmed.
Анотація:
Gnotobiotic piglets were orally infected either with the virulent LT2 strain or the non-pathogenic SF1591 rough mutant of Salmonella enterica serotype Typhimurium. They were sacrificed 6 or 24 h after the infection. All piglets infected for 24 h developed systemic infection with an increase of plasma lipopolysaccharide. Infection with the virulent strain caused a significant decrease (P < 0.001) of gamma-glutamyl transpeptidase (GGT) activity in the enterocyte brush border of both the jejunum and ileum, infection with the rough mutant caused a decrease of GGT activity in the ileum only. The activities of other brush border enzymes (lactase, sucrase, glucoamylase, alkaline phosphatase and dipeptidylpeptidase IV) did not change significantly after infection.
2
Derfoul, H., E. Leboucher-Dalimier, I. Gharbi, and A. Poquerusse. "Radial inhomogeneity diagnostics deduced from space-resolved X-ray emission." Laser and Particle Beams 12, no. 3 (September 1994): 485–93. http://dx.doi.org/10.1017/s026303460000834x.
Анотація:
Radial inhomogeneity diagnostics in hot and dense laser plasmas are presented. By means of an analysis of the spatially resolved X-ray transverse emission of the plasma and of a theoretical modeling, we can access directly to the radial emission coefficient and to the transverse gradients. The intense aluminum Lyβ line has been chosen for this study, and different structured targets have been used to control the radiative transfer in the transverse direction. These targets (large or narrow emissive strips) give complementary results for the emission in the core (i.e., near the laser-target axis) or in the border of the plasma.
3
La Celle, P., FA Blumenstock, and TM Saba. "Blood-borne fragments of fibronectin after thermal injury." Blood 77, no. 9 (May 1, 1991): 2037–41. http://dx.doi.org/10.1182/blood.v77.9.2037.2037.
Анотація:
Abstract Fibronectin is an adhesive protein that can promote phagocytosis and endothelial cell adhesion. Plasma fibronectin declines following burn in animals and patients, potentially due to its complexing with circulating collagenous debris as well as its rapid binding to sites of tissue injury. Such depletion of fibronectin initiates an opsonic deficiency of the plasma. In view of the sensitivity of fibronectin to proteolytic enzymes, an additional factor that could contribute to the decrease of plasma opsonic activity after burn is the proteolytic fragmentation of fibronectin in the blood. In the current study, we determined if fibronectin fragments appear in the blood of anesthetized rats after a sublethal full-thickness skin burn of 15% to 16% of body surface. Plasma fibronectin concentration was quantified by enzyme- linked immunosorbent assay and the presence of fibronectin fragments in plasma was determined by immunoblot analysis. All blood was collected in an antiprotease mixture to yield final plasma concentrations of 0.15% EDTA, 3mmol/L phenylmethylsulfonyl fluoride, and 3 mmol/L iodoacetate to prevent degradation of fibronectin after sampling. Plasma fibronectin decreased 60% to 70% within 30 minutes post-burn, and this low level lasted for at least 4 hours. Within 30 minutes post- burn, two prominent fragments of fibronectin with a molecular weight of 110 +/- 2.2 kd and 122 +/- 3.3 Kd, respectively, were also detected in the plasma. Peak concentration of these fragments was detected at 60 minutes post-burn, but their level declined by 4 hours. By 4 hours, both bands appeared to resolve into doublets. To rule out the possibility that the fragments of fibronectin detected in the plasma were actually generated by coagulation enzymes activated at the site of peripheral blood sampling, rapid direct inferior vena cava sampling was performed, which also yield the presence of the fragments. Thus, fibronectin fragments exist in the plasma following thermal injury. Because fragments of fibronectin can compete with the intact fibronectin molecule with respect to its ability to stimulate macrophage phagocytosis, such fragments may contribute to altered systemic phagocytic host defense following thermal injury. Furthermore, because fibronectin peptides can compete with matrix fibronectin and impair adhesion of cultured endothelial cells, such circulating fragments may also influence the integrity of the vascular barrier.
4
La Celle, P., FA Blumenstock, and TM Saba. "Blood-borne fragments of fibronectin after thermal injury." Blood 77, no. 9 (May 1, 1991): 2037–41. http://dx.doi.org/10.1182/blood.v77.9.2037.bloodjournal7792037.
Анотація:
Fibronectin is an adhesive protein that can promote phagocytosis and endothelial cell adhesion. Plasma fibronectin declines following burn in animals and patients, potentially due to its complexing with circulating collagenous debris as well as its rapid binding to sites of tissue injury. Such depletion of fibronectin initiates an opsonic deficiency of the plasma. In view of the sensitivity of fibronectin to proteolytic enzymes, an additional factor that could contribute to the decrease of plasma opsonic activity after burn is the proteolytic fragmentation of fibronectin in the blood. In the current study, we determined if fibronectin fragments appear in the blood of anesthetized rats after a sublethal full-thickness skin burn of 15% to 16% of body surface. Plasma fibronectin concentration was quantified by enzyme- linked immunosorbent assay and the presence of fibronectin fragments in plasma was determined by immunoblot analysis. All blood was collected in an antiprotease mixture to yield final plasma concentrations of 0.15% EDTA, 3mmol/L phenylmethylsulfonyl fluoride, and 3 mmol/L iodoacetate to prevent degradation of fibronectin after sampling. Plasma fibronectin decreased 60% to 70% within 30 minutes post-burn, and this low level lasted for at least 4 hours. Within 30 minutes post- burn, two prominent fragments of fibronectin with a molecular weight of 110 +/- 2.2 kd and 122 +/- 3.3 Kd, respectively, were also detected in the plasma. Peak concentration of these fragments was detected at 60 minutes post-burn, but their level declined by 4 hours. By 4 hours, both bands appeared to resolve into doublets. To rule out the possibility that the fragments of fibronectin detected in the plasma were actually generated by coagulation enzymes activated at the site of peripheral blood sampling, rapid direct inferior vena cava sampling was performed, which also yield the presence of the fragments. Thus, fibronectin fragments exist in the plasma following thermal injury. Because fragments of fibronectin can compete with the intact fibronectin molecule with respect to its ability to stimulate macrophage phagocytosis, such fragments may contribute to altered systemic phagocytic host defense following thermal injury. Furthermore, because fibronectin peptides can compete with matrix fibronectin and impair adhesion of cultured endothelial cells, such circulating fragments may also influence the integrity of the vascular barrier.
5
Astashov, A. G., A. V. Samokhin, N. V. Alekseev, V. A. Sinayskiy, Yu P. Kalashnikov, and Yu V. Tsvetkov. "Synthesis of Al-B system nanostructures by interaction of disperse aluminium with boron and diborane in arc discharge plasma." Physics and Chemistry of Materials Treatment, no. 3 (2020): 11–18. http://dx.doi.org/10.30791/0015-3214-2020-3-11-18.
Анотація:
Experimental studies of aluminium boride synthesis as a result of interaction of disperse aluminum with diborane B2H6 and disperse boron in a flow of thermal plasma of different composition generated in electric arc plasma torch have been carried out. Experimental work on the synthesis of aluminium boride nanoparticles from elements (a mixture of disperse aluminum and boron) has shown the possibility of obtaining in thermal plasma arc discharge of such phases of the boride as AlB12 and AlB31. The specific surface of the powders obtained is from 3 to 27 m2/g. According to X-ray phase analysis, the powders obtained, except for aluminum boride phases, also contain boron, aluminum, aluminum nitride and boric acid phases. The greatest yield of aluminum boride phases is provided by using the nitrogen plasma with hydrogen and enthalpy 4.5 kWt∙h/m3 in the reactor with increased high-temperature zone. The use of gaseous diborane made it possible to eliminate restrictions on the evaporation of boron particles but did not provide an opportunity to obtain aluminum borides in the plasma-chemical process. It was concluded that it is necessary to perform quenching of high-temperature gas flow containing boron and aluminum vapor to form aluminum borides from the gas phase in plasma-chemical synthesis. Such an approach should ensure that the temperature is reduced to the values at which aluminum borides are stable and that the formation of aluminum boride nanoparticles will occur as a result of condensation from the gas phase under these conditions.
6
Fujimura, Yu, Ken Natsuga, Riichiro Abe, Yusuke Morita, Toshifumi Nomura, and Hiroshi Shimizu. "Plasma cell cheilitis extending beyond vermillion border." Journal of Dermatology 42, no. 9 (June 16, 2015): 935–36. http://dx.doi.org/10.1111/1346-8138.12985.
7
Misra, N. N., B. K. Tiwari, K. S. M. S. Raghavarao, and P. J. Cullen. "Nonthermal Plasma Inactivation of Food-Borne Pathogens." Food Engineering Reviews 3, no. 3-4 (October 5, 2011): 159–70. http://dx.doi.org/10.1007/s12393-011-9041-9.
8
Song, Lihao, Bowen Bai, Xiaoping Li, Gezhao Niu, Yanming Liu, Liang Zhao, and Hui Zhou. "Analysis of Hypersonic Platform-Borne SAR Imaging: A Physical Perspective." Remote Sensing 13, no. 23 (December 5, 2021): 4943. http://dx.doi.org/10.3390/rs13234943.
Анотація:
The usage of a hypersonic platform for remote sensing application has promising prospects, especially for hypersonic platform-borne synthetic aperture radar (SAR) imaging. However, the high-speed of hypersonic platform will lead to extreme friction between the platform and air, which will cause the ionization of air. The ionized gas forms the plasma sheath wrapped around the hypersonic platform. The plasma sheath will severely affect the propagation of SAR signal and further affect the SAR imaging. Therefore, hypersonic platform-borne SAR imaging should be studied from a physical perspective. In this paper, hypersonic platform-borne SAR imaging under plasma sheath is analyzed. The SAR signal propagation in plasma sheath is computed using scatter matrix method. The proposed SAR signal model is verified by using a ground experiment system. Moreover, the effect of attenuation caused by plasma sheath on SAR imaging is studied under different SAR parameters and plasma sheath. The result shows that attenuation caused by plasma sheath will degrade the SAR imaging quality and even cause the point and area targets to be submerged into the noise. The real SAR images under plasma sheath also illustrate this phenomenon. Furthermore, by studying imaging results under different SAR and plasma parameters, it can be concluded that the severe degradation of SAR imaging quality appears at condition of high plasma sheath electron density and low SAR carrier frequency. The work in this paper will be beneficial for the study of hypersonic platform-borne SAR imaging and design of hypersonic SAR imaging systems in the future.
9
Orlov, N. Yu. "Temperature diagnostics for Z-pinches plasma in dependence on compression degree." Laser and Particle Beams 37, no. 4 (November 5, 2019): 364–69. http://dx.doi.org/10.1017/s0263034619000570.
Анотація:
AbstractCalculations of the spectral coefficients for X-ray absorption and spectral brightness's for X-ray radiation were performed for niobium Z-pinch plasma at the temperature of 1 keV and at different plasma densities to determine the compression degree where the spectral lines become indistinguishable. As known, traditional methods of temperature diagnostics of hot dense radiating plasmas are based on analysis of the spectral line shape in dependence on plasma temperature and density. In this case, the interval of photon radiation energies is used, where the spectral lines are well distinguishable in an experiment. On the other hand, Z-pinch plasma has high compression, and an increase of plasma density leads to the deformation of the spectral line shape because of Doppler broadening, Stark broadening, and so-called “additional” broadening of spectral lines that take place in a quantum statistical ensemble of plasma ions and atoms. The traditional method of temperature diagnostics becomes impossible and different methods, which do not use spectral line characteristics, should be applied. The aim of this paper is to determine the density border where the spectral lines become indistinguishable. Important features of the quantum mechanical model, which is known as ion model of plasma, and which is used for calculations in the presented paper, are considered and discussed. A brief review of the theoretical models that have been earlier developed to calculate the radiative opacity characteristics of hot dense plasma is presented as well.
10
Tian, Yuan Yu, Ying Yun Qiao, and Ke Chang Xie. "Study on Coking Mechanism during the Pyrolysis of Coal to Acetylene in the Plasma." Advanced Materials Research 634-638 (January 2013): 1630–36. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.1630.
Анотація:
Based on characterization of various properties of coking formation during the processing of pyrolysis of coal to acetylene in the plasma, and the chemical group composition of the coal, the reaction central - border zone characteristics of plasma and the specific circumstances of the reactor, the mechanism of coking on reactor wall is put forword during pyrolysis of the coal to acetylene in the plasma, which aromatics, colloids, asphaltenes and carbenes happen condensation reaction by dehydrogenation in plasma border reaction zone. Besides, a method is proposed that double peak particle size distribution of coal particle can eliminate coking continuously, and it get experimental validation.
Дисертації з теми "Plasma du borde":
1
Scotto, d'Abusco Manuel. "Modélisation numérique du transport turbulent cœur-bord dans un tokamak en géométrie réaliste par une méthode numérique avancée." Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0173.
Анотація:
De nos jours, un défi reste la conception de scénarios de plasma optimisés pour le fonctionnement du tokamak afin de contrôler le flux de chaleur. Cela nécessite le développement de codes numériques efficaces et fiables avec des capacités prédictives pour les simulations de plasma. Ce travail vise à développer un code d'éléments finis d'ordre élevé basé sur un schéma numérique de Galerkin discontinu hybride avec d'intégration en temps implicite pour résoudre des équations de Braginskii dans différent géométries de tokamak et d'équilibre magnétique. Le schéma numérique permet d'effectuer des simulations avec des configurations magnétiques évoluant dans le temps, évitant un remaillage coûteux du domaine de calcul. La réalisation de l’outil numérique est présentée. La faisabilité de ce dernier est étudiée à travers une opération minutieuse de validation et de benchmarking avec SolEdge3X. Des sources de particules, dues au recyclage du plasma, et d'énergie, due au chauffage ohmique, sont introduites pour effectuer une simulation 2D d'une section poloidal de tokamak. Avec un tel modèle, les principales caractéristiques d'un plasma détaché sont étudiées pour la machine tokamak WEST. Les premières simulations cœur-bord d'une décharge WEST entière (plan #54487) sont présentées de la phase de démarrage à l'éitant du plasma. Les comparaisons entre l'interférométrie expérimentale et les données de simulation synthétique montrent un accord remarquable. L'évolution temporelle des particules et les flux de chaleur à la paroi sont analysés et exploités pour évaluer le sputtering du tungstène, en utilisant soit un modèle cinématique simple et soit le code Monte-Carlo ERO2.0Nowadays a challenge remains the design of optimized plasma scenarios for tokamak operation to control the heat flow from the core region to the wall. This calls for the development of efficient and reliable numerical codes with predictive capabilities for plasma simulations. The present work aims to develop a high-order finite elements code based on hybrid discontinuous Galerkin numerical scheme and an efficient implicit time integration method for solving non isothermal Braginskii reduced fluid equations in versatile tokamak and magnetic equilibrium geometries. The use of such numerical scheme allows to perform simulations with time evolving magnetic configurations, avoiding expensive re-meshing of the computational domain. The structure and the realization of such a numerical tool is presented. The feasibility of the latter is then investigated through a careful validation and benchmarking operation with SolEdge3X. Self-consistent sources of particle, due to plasma recycling, and energy due to Ohmic heating are introduced to perform 2D simulation of a full poloidal tokamak cross section. With such a model the main features of a detached plasma are investigated for the WEST tokamak machine. The first core-edge transport simulations of an entire WEST discharge (shot #54487) are shown from the start-up phase to the final plasma landing. Comparisons between experimental interferometry and synthetic simulation data show a remarkable agreement. The time evolution of the particles and heat fluxes at the wall, are analyzed and exploited to assess the tungsten sputtering, using both a simple cinematic model and the impurity tracker monte-carlo code ERO2.0
2
Sugita, Satoru. "Etude par simulation numérique du transport radial dans le plasma de bord du tokamak." Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10010/document.
Анотація:
Il est maintenant accepté expérimentalement que les filaments de plasma alignés sur le champ magnétique, appelés “blobs”, jouent un rôle important dans le transport dans le plasma de bord. Dans cette thèse, les phénomènes fondamentaux du transport dans le plasma de bord sont étudiés en mettant l'accent sur le phénomène de filaments plasma. Dans un premier temps, les mécanismes de propagation de blobs uniques sont envisagés. Puis la génération de blobs par la turbulence de bord est étudiée, et le transport turbulent est discuté entant que phénomène collectif. Des particularités du transport turbulent, incluant les blobs auto-organisés, sont reliées à un transport de type Bohm (c'est à dire des perturbations avec des corrélations radiales longues, et un coefficient de transport effectif quisuit la dépendance Bohm). De plus, en prolongement de ce travail, un effort initial vers une transposition du transport non-local au plasmade bord est décriteRecently, it has been accepted that magnetic field aligned plasma filaments, referred to as "blobs" play important roles in the transport of Scrape-off Layer (SoL) plasmas. In this thesis, putting an emphasis on the plasma blob phenomenon, we study fundamental processes of SoL transport using numerical simulation. At first, weinvestigate the propagation mechanisms of single and isolated blobs.Next, we study the generation of blobs from edge turbulence, and discuss the SoL turbulent transport as a collective phenomenon. Features of turbulent transport, which includes the self-organized blobs in SoL, are identified as Bohm-like transport (i.e., the perturbation with long radial correlations and the effective transport coefficient that follows the dependence of Bohm-like transport). Additionally, as an advancement of study, we describe an initial effort to extend the view of non local transport to edge plasmas
3
Medvedeva, Anna. "Étude expérimentale de la turbulence au bord du plasma du tokamak ASDEX Upgrade par réflectométrie à balayage ultra rapide." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0240/document.
Анотація:
La turbulence au sein d’un plasma contribue de manière significative à l’augmentation du transport de l’énergie et des particules. Ce transport diminue la qualité de confinement du plasma réduisant la possibilité d’atteindre le seuil de fusion. Notre travail a consisté à étudier et à mesurer l’évolution des caractéristiques de la turbulence ainsi que son rôle durant la transition d’un mode à faible confinement (L-mode) à un mode de confinement amélioré (H-mode) des plasmas du tokamak ASDEX Upgrade. Nous avons, en particulier, étudié la phase de transition intermédiaire (I-phase) où la turbulence et le cisaillement des structures turbulentes par les flux interagissent. Une des théories prévoit que la turbulence au bord du plasma est stabilisée par des gradients de champs électriques radiaux: le cisaillement de flux E×B stabilise la turbulence et diminue la taille radiale des structures. Le mécanisme physique détaillé de la formation de la barrière de transport n’est pas encore bien compris. Afin d’étudier la dynamique radiale et temporelle de la transition L-H, nous nous sommes servis d’un réflectomètre à balayage en fréquence ultra-rapide. Durant nos campagnes expérimentales nous sommes parvenus à réduire ce temps de balayage à 1 μs. La dynamique de densité électronique, du niveau de turbulence et des spectres lors des transitions L-H ont été réalisées. Les mesures montrent que le niveau des fluctuations de grande échelle diminue après une transition L-H, ce qui confirme les prédictions théoriques. La I-phase a été documentée pour diverses conditions du plasma. Enfin, ces réflectomètres ont aussi permis l’observation de modes cohérents à haute fréquence au bord du plasmaPlasma confinement is limited by energy and particle transport, in which turbulence plays an important role. In this work the measurements of the turbulence characteristics carried out on the ASDEX Upgrade tokamak are presented during the transition from the Low (L) to the High (H) confinement mode which goes through an Intermediate (I) phase where turbulence and shear flows strongly interact. One of the most widely accepted theories concerning the L-H transition describes how the turbulence in the plasma edge is stabilized by radial electric field gradients: the E×B flow shear stabilizes turbulence and decreases the radial size of turbulent structures. As a consequence, a transport barrier forms in the edge where the plasma density, the temperature, and their gradients increase. The detailed physical mechanism of the formation of the transport barrier as well as the reason for the residual transport across this barrier are not yet well understood. The density dynamics is measured by an ultra-fast swept reflectometer with a time resolution as high as 1 μs. Studies of the electron density profile dynamics, the density turbulence level, radial wavenumber and frequency spectra during L-H transitions have been performed. The reflectometer measurements show that the density large scale fluctuations decrease after an L-H transition, which confirms the theoretical predictions of the turbulence reduction by sheared flows and supports previous experimental evidences. I-phases for various plasma conditions are documented and the density evolution is compared with the turbulence level. Moreover the results on high frequency coherent modes appearing at the plasma edge are presented
4
Touati, Ahmed Kamel. "Analyse spectroscopique des plasmas en présence d'un champ magnétique : application au plasma de bord des tokamaks." Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11004.
Анотація:
Après avoir posé le formalisme de base nécessaire pour la modélisation des profils de raies, ce travail examine l'effet Zeeman dans le cas général d'un émetteur arbitraire. Un modèle qui retient simultanément l'effet Stark et l'effet Zeeman est ensuite proposé, et appliqué, à plusieurs émetteurs dans les plasmas. Nous avons étudié par exemple les profils des raies d'émission Dα et D[delta] du deutérium, et de la raie 9-4 de He+, en prenant en compte les effets Doppler, Zeeman et Stark. Une étude a été menée sur un spectre du carbone neutre afin de caractériser la température des atomes au bord du plasma. Les spectres sont observés dans le visible par une visée parallèle à un neutraliseur du divertor ergodique du Tokamak Tore supra. Une analyse de l'importance relative de ces effets a été faite dans les conditions de densité (10[19] < Ne <10[20] m[-3]) et de température (10 < Te < 50 eV) que l'on rencontre dans les plasmas de bord du Tokamak Tore-Supra. Nous montrons que pour certaines conditions de plasma, la largeur de ces raies dépend à la fois de la température de l'émetteur, du microchamp électrique local du plasma, et du champ magnétique.
5
Janisson, Stéphane. "Etude des jets de plasma et du traitement des particules en projection plasma avec mélanges ternaires de gaz en atmosphère et température contrôlées." Limoges, 1999. http://www.theses.fr/1999LIMO0046.
Анотація:
Ce travail porte sur l'utilisation de mélanges ternaires de gaz plasmagènes Ar-He-H2 pour la projection plasma d'arc du carbure de bore. L'ensemble des sous-systèmes qui interviennent dans le procédé de projection plasma a été étudié : la formation du jet de plasma dans la tuyère, l'écoulement plasma, les interactions plasma/particules et la réalisation et analyse de dépôt. La projection est réalisée en atmosphère d'argon avec un refroidissement cryogénique du substrat. .This work deals with the use of ternary gas mixtures Ar-He-H2 for plasma spraying, in controlled atmosphere and temperature. These ternary gas mixtures were used to spray boron carbide powder in argon atmosphere at ambient pressure. The various sub-systems that make up the whole plasma spraying process have been studied : (i) plasma jet formation in the anode-nozzle, (ii) plasma flow outside the gun, (iii) plasma/particle interactions and (iv) coating formation. .
6
Tazedakis, A. S. "Orbital plasma welding of small bore tubes." Thesis, Cranfield University, 1997. http://dspace.lib.cranfield.ac.uk/handle/1826/10436.
Анотація:
This work was
primarily motivated by the industrial need for control of
problems associated with the Gas
Tungsten Arc Welding (GTAW) of small bore
titanium and austenitic stainless steel tubes. These include:
pore creation and
entrapment in the weld zone, and variability of the fusion zone
geometry. The
primary aim of this study was the development of a low current orbital
plasma
welding capability using a structured approach which could lead to defect
minimisation. The
methodology should also have the potential to be used in a number
of different
conditions, extending the use of plasma welding in both melt-in and
keyhole modes for the orbital
welding of small bore tubes.
The
project originally involved the modification of a
totally enclosed orbital
GTAW
welding head for low current
welding operations. It was established that for
the current
range required for small bore and small to medium thickness
tubes, the
use of a solid
copper torch was sufficient to provide the required heat absorption. A
stable arc was
produced even for very low current values (down to 7A) while arc
voltages were within the operating range of a standard GTA welding power source.
Procedural
(i.e. off line) control was adopted for identification and
optimisation of welding parameters. Since no procedure was available for the
proposed welds it was
necessary to generate the parameters required for the
production of consistent weld
profiles. Simultaneously, an expert system has been
developed for the determination of
optimum process parameters based on empirical
models, developed using statistical techniques. Parameter combinations were selected
based on
physical as well as statistical relevance, providing a measure of confidence
when
predicting the required weld bead output characteristics. The approach also
indicates the influence of the
major input parameters on weld bead
geometry and
defect
formation, such as undercut.
Two
quality acceptance criteria were employed during this investigation, weld
bead dimensional
accuracy, and the type and seriousness of defects
present
(penetration / burn-through, porosity and undercut). Off line
programming was
utilised to control heat build
up and to ensure welds were obtained with the desired
geometry and minimal defect levels. The end result was the
development of a
prototype system for low current orbital
plasma welding (in both melt-in and keyhole
mode) of small bore tubes in a
totally enclosed head. Tolerant procedures for low
current orbital melt-in and
particularly keyhole welding have been generated and a
systematic methodology for the prediction and optimisation of welding procedures
based on
predetermined criteria has been
developed.
7
Tazedakis, Athanassios S. "Orbital plasma welding of small bore tubes." Thesis, Cranfield University, 1997. http://dspace.lib.cranfield.ac.uk/handle/1826/10436.
Анотація:
This work was primarily motivated by the industrial need for control of problems associated with the Gas Tungsten Arc Welding (GTAW) of small bore titanium and austenitic stainless steel tubes. These include: pore creation and entrapment in the weld zone, and variability of the fusion zone geometry. The primary aim of this study was the development of a low current orbital plasma welding capability using a structured approach which could lead to defect minimisation. The methodology should also have the potential to be used in a number of different conditions, extending the use of plasma welding in both melt-in and keyhole modes for the orbital welding of small bore tubes. The project originally involved the modification of a totally enclosed orbital GTAW welding head for low current welding operations. It was established that for the current range required for small bore and small to medium thickness tubes, the use of a solid copper torch was sufficient to provide the required heat absorption. A stable arc was produced even for very low current values (down to 7A) while arc voltages were within the operating range of a standard GTA welding power source. Procedural (i.e. off line) control was adopted for identification and optimisation of welding parameters. Since no procedure was available for the proposed welds it was necessary to generate the parameters required for the production of consistent weld profiles. Simultaneously, an expert system has been developed for the determination of optimum process parameters based on empirical models, developed using statistical techniques. Parameter combinations were selected based on physical as well as statistical relevance, providing a measure of confidence when predicting the required weld bead output characteristics. The approach also indicates the influence of the major input parameters on weld bead geometry and defect formation, such as undercut. Two quality acceptance criteria were employed during this investigation, weld bead dimensional accuracy, and the type and seriousness of defects present (penetration / burn-through, porosity and undercut). Off line programming was utilised to control heat build up and to ensure welds were obtained with the desired geometry and minimal defect levels. The end result was the development of a prototype system for low current orbital plasma welding (in both melt-in and keyhole mode) of small bore tubes in a totally enclosed head. Tolerant procedures for low current orbital melt-in and particularly keyhole welding have been generated and a systematic methodology for the prediction and optimisation of welding procedures based on predetermined criteria has been developed.
8
Malhouitre, Stéphane. "Etude et réalisation de couches minces de nitrure de bore par dépôt ionique réactif." Limoges, 1997. http://www.theses.fr/1997LIMO0010.
Анотація:
L'etude et la realisation de couches minces de nitrure de bore par depot ionique reactif a fait l'objet de ce travail. L'objectif principal a ete d'obtenir des depots de nitrure de bore cubique ayant une composition proche de la stchiometrie. Pour dissocier et ioniser les molecules d'azote, divers modes d'activation du gaz ont ete employes lors de la synthese des films. Tout d'abord, un plasma radiofrequence seul a ete utilise, puis il a ete assiste d'un dispositif d'intensification de la decharge. Le second mode d'activation a consiste en une source portee a haute temperature sur laquelle est dirige l'azote. Enfin, un plasma microonde a ete employe. Les resultats obtenus montrent que la composition et la structure des couches deposees sont etroitement liees. Les depots qui presentent des liaisons sp#3 possedent un rapport atomique n/b faible (n/b 0,1) et ne sont pas cristallises. Ces couches sont en fait composees de nitrure de bore sous forme de liaisons sp#2 et sp#3, ainsi que du bore non lie a l'azote. Les depots qui presentent une composition plus riche en azote ont une structure de type h-bn et possedent une excellente transmission optique dans le visible.
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Torres, Israel da Silva. "Magnetoplasmons de borda em sistemas bidimensionais: estudo do Helicon de Borda." Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/4542.
Анотація:
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
In this work we will make a theoretical investigation over some general properties of edge magnetoplasmos (EMP) - collective quiral excitations which propagates at the edges of a bidimensional solid state plasma (often called bidimensional electronic system- 2DES) under the quantum Hall regime (QHR) with lling factor of = 1(2),with very strong dissipation in the edges, where the Landau levels (LL) intercept the Fermi levels (FL). We will take into account only homogenuous samples, that means, without a consideration of a gate nor an air substrate over the heterostructure; pointed out that the EMP behaviour, especially the wave quality, has a strong dependence on the gate. EMP s were rst reported in the 80 s, and have attracted much attention in the past decade with advent of some new nano-2DES, new experimental methods - as the time- resolved experiments, and nano electronic aplications. Adopting a microscopic model, we could con rm recent works (2010), and we con rmed that even in the strong dissipation regime, here considered, there is still a mode that persists, an edge helicon (EH), with excelent quality - when all other modes are very damped. We also nd new interesting properties of this EH, in fact, we can show that the "window of transparency" of this EH is 10 times bigger then the value so far known from the scienti c literature, its spatial structure was also here accquired with better precision; and it exibits a more smooth behavior if compared to recent articles.
Neste trabalho faremos um estudo teórico acerca de propriedades dos magneto-plasmons de borda (MPB) excitações quirais coletivas e que se propagam nas bordas de um plasma de estado sólido bidimensional (comumente cunhado como um sistema eletrônico bidimensional - SE2D) - sob o regime Hall quântico inteiro (RHQI) com fator de preenchimento = 1(2) e com muito-forte dissipação nas regiões de estados de borda, onde os níveis de Landau (NL) cruzam o nível de Fermi (NF). Serão considerados neste trabalho apenas amostras homogêneas, ou seja, sem a consideração de um gate ou uma camada de ar sobre a heteroestrutura; cujo comportamento dos MPB s, especialmente a qualidade do MPB, tem forte vínculo com propriedades do meio em questão. Os primeiros MPB s foram descobertos na década de 1980, e têm despertado um grande interesse na última década, com o advento de novas nanoestruturas eletrônicas bidimensionais, novos métodos experimentais - como por exemplo os experimentos com tempo-resolvido (time-resolved) e aplicacões diretas em nanoeletrônica. Adotando-se um modelo miscroscópico, pudemos con firmar resultados de trabalhos recentes (2010), e confi rmamos que mesmo no regime de muito-forte dissipação, aqui considerado, ainda há um modo que persiste, um Helicon de Borda (HB), com excelente qualidade - enquanto que todos os outros mo- dos são fortemente amortecidos. Encontramos também novas interessantes propriedades deste HB, em particular, mostramos que "janela de transparência" deste HB é 10 vezes maior do que o valor conhecido na literatura, a estrutura espacial do HB também foi aqui obtida com melhor precisão; e exibe um comportamento mais suave que o apresentado em trabalhos recentes.
10
Sarazin, Yanick. "Etude de la turbulence de bord dans les plasmas de tokamaks." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10265.
Анотація:
Cette these remet en cause la description classique du transport turbulent en terme de diffusion, et propose un nouveau cadre d'analyse theorique. Dans les plasmas, l'approche standard de la turbulence suppose que la taille et la frequence caracteristiques des fluctuations sont tres inferieures a celles de l'equilibre. Cette hypothese permet une etude avec un forcage par un gradient d'equilibre constant. Notre etude privilegie le forcage par un flux, levant ainsi la contrainte de separabilite d'echelle. Nous developpons un modele cellulaire 1d auto-organise critique ou soc. Le transport local a seuil en gradient est couple a l'etat des sites voisins. Le systeme est force par une source coherente en volume, l'ionisation des neutres. En accord avec l'experience, le transport moyen peut etre decrit en termes de diffusion et de convection, bien que le transport local soit d'une toute autre nature. L'instabilite d'interchange est etudiee sur les lignes de champ ouvertes connectees a la paroi. Le modele 2d de cette instabilite a seuil est utilise dans les deux cas de forcage, par un gradient et par un flux. Dans le premier cas, le transport est homogene et diffusif. La taille des cellules turbulentes est fixee par l'allure du taux de croissance et les conditions aux limites imposees par l'interface plasma-paroi ; les processus de cascade d'energie jouent un role negligeable. Lorsque le systeme est force par un flux constant, le transport est inhomogene et caracterise par un flux sortant convectif intermittent, des avalanches. Une statistique sur des particules test ne rend que partiellement compte du transport fluide observe. Le modele reproduit les observations experimentales :les fluctuations relatives de densite sont maximales au bord, et le profil exhibe une decroissance exponentielle, a nouveau compatible avec un transport diffusif, bien que le transport reel ne le soit pas.
Книги з теми "Plasma du borde":
1
United States. National Aeronautics and Space Administration., ed. SPDE, Solar Plasma Diagnostic Experiment: Final contract report, period of performance 1 November, 1993 through 30 September, 1995. [Washington, D.C: National Aeronautics and Space Administration, 1995.
2
Murer, Heini, Jürg Biber, and Carsten A. Wagner. Phosphate homeostasis. Edited by Robert Unwin. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0025.
Анотація:
Inorganic phosphate ions (H2PO4−/ HPO42−) (abbreviated as Pi) are involved in formation of bone and generation of high-energy bonds (e.g. ATP), metabolic pathways, and regulation of cellular functions. In addition, Pi is a component of biological membranes and nucleic acids. Only about 1% of total body Pi content is present in extracellular fluids, at a plasma concentration in adults within the range 0.8–1.4 mMol/L (at pH 7.4 mostly as HPO42−), with diurnal variations of approximately 0.2 mM. A small amount of plasma Pi is bound to proteins or forms complexes with calcium. Under normal, balanced conditions, absorption of dietary Pi along the small intestine equals the output of Pi via kidney and faeces. Renal excretion of Pi represents the key determinant for the adjustment of normal Pi plasma concentrations. Renal reabsorption of Pi occurs along the proximal tubules by sodium-dependent Pi cotransporters that are strictly localized at the apical brush border membrane. Parathyroid hormone (PTH) and FGF23 are key regulators amongst a myriad of factors controlling excretion of Pi in urine, mostly by changes of the apical abundance of Na/Pi cotransporters. Hypophosphataemia may result in osteomalacia, rickets, muscle weakness, and haemolysis. Hyperphosphataemia can lead to hyperparathyroidism and severe calcifications in different tissues.
3
Villalpando, Elisa, and Randall H. McGuire. Sonoran Pre-Hispanic Traditions. Edited by Barbara Mills and Severin Fowles. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199978427.013.19.
Анотація:
The international border between the United States and Mexico has no meaning for the Aboriginal history of the Southwest/Northwest. It has, however, greatly limited the amount of archaeology done in northern Mexico. Since the 1980s, Mexican and U.S. archaeologists have done increasing amounts of research in the Mexican state of Sonora. Here they have developed an international collaborative practice of archaeology unique in North America. Sonora has a rich archaeological record that includes Paleoindian and Archaic sites. This chapter focuses on the agricultural peoples of Sonora, beginning with the Early Agricultural site of La Playa. Archaeologists have defined six ceramic period archaeological traditions in the state (Central Coast, Trincheras, Casas Grandes, Río Sonora, Huatabampo, and Serrana). Contrary to earlier interpretations of these traditions as extensions of events, processes, and cultures found to the south or the north, contemporary archaeology is demonstrating them to be the results of complex local developments.
4
Turow, Scott. Silent Witness. Edited by Henry Erlich, Eric Stover, and Thomas J. White. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190909444.001.0001.
Анотація:
Forensic DNA evidence has helped convict the guilty, exonerate the wrongfully convicted, identify victims of genocide, and reunite families torn apart by war and repressive regimes. Yet many of the scientific, legal, and ethical concepts that underpin forensic DNA evidence remain unclear to the general public; judges; prosecutors; defense attorneys; and students of law, forensic sciences, ethics, and genetics. This book examines the history and development of DNA forensics; its applications in the courtroom and humanitarian settings; and the relevant scientific, legal, and psychosocial issues. It describes the DNA technology used to compare the genetic profile of a crime scene sample to that of a suspect, as well as the statistical interpretation of a match. It also reviews how databases can be searched to identify suspects and how DNA evidence can be used to exonerate the wrongfully convicted. Recent developments in DNA technology are reviewed, as are strategies for analyzing samples with multiple contributors. The book recounts how the Grandmothers of the Plaza de Mayo searched for children kidnapped during military rule in Argentina, as well as more recent efforts to locate missing children in El Salvador. Other chapters examine the role that DNA forensics played in the identification of victims of genocide in Bosnia and of terrorism in the post-9/11 era. Social anthropologists, legal scholars, and scientists explore current applications of DNA analysis in human trafficking and mass catastrophes; border policies affecting immigration; and the ethical issues associated with privacy, informed consent, and the potential misuse of genetic data.
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Leite, Maria José de Holanda. Características funcionais de árvores em floresta tropical úmida. Editora Amplla, 2021. http://dx.doi.org/10.51859/amplla.cfa436.1121-0.
Анотація:
Em ecossistemas florestais, a área basal é um dos primeiros parâmetros a se recuperar após qualquer tipo de perturbação na comunidade (GILMAN et al., 2016) e que há alteração dos valores das características funcionais das espécies arbóreas (FORTUNEL et al., 2012). Sabe-se ainda que essas características podem ser bons indicadores da ecologia das espécies, ajudando a compreender as respostas a diferentes ambientes ou regimes de perturbação (MENDÉZALONZO et al., 2012). Entretanto, a relação entre área basal, luz e a variação das características funcionais ainda é uma questão pouco explorada, especialmente em florestas tropicais com diferentes regimes de perturbação, como os fragmentos urbanos (CARREÑO-ROCABADO et al., 2012). Em um conceito contemporâneo da sucessão, sabe-se que em paisagens urbanas e periurbanas a sucessão é especialmente singular, pois a proximidade do meio urbano aumenta a probabilidade de perturbações antrópicas contínuas, as quais alteram continuamente o caminho da sucessão (MEINERS et al., 2015). Tais perturbações podem incluir: efeito de borda, poluição da água e do ar, caça, incêndios, deposição de lixo, ruído, retirada de madeira, crescimento das cidades, construção de ruas e mineração, impactando a estrutura e composição da floresta (AMLIN et al., 2012). Essas perturbações alteram as propriedades das plantas, com mudanças nos padrões de sobrevivência e consequentemente os valores das características funcionais. No caso das florestas, onde a luz é o principal recurso, sabe-se que no início da sucessão há maior luminosidade e menores valores de área basal (BOUKILI; CHADZON, 2017). Nesse ambiente tendem a ocorrer espécies com altos valores de área foliar, área foliar específica e conteúdo de clorofila (PÉREZ-HARGUINDEGUY et al., 2013), baixa densidade de madeira do caule e raiz, alto conteúdo de água no caule e raiz, o que aponta para estratégias ligadas à aquisição de recursos (CHADZON, 2007). À medida que a sucessão avança, as copas vão se fechando, o que faz com que mude a quantidade de luz que chega no chão da floresta, levando a maior sobrevivência de plantas com características mais ligadas à conservação do recurso luz (DONOVAN et al., 2011). A avaliação das características funcionais (sensu Violle et al. 2007) no conjunto de plantas de uma determinada área pode ser utilizada para entender as mudanças da vegetação sob diferentes pressões ambientais (LAVOREL; GARNIER, 2002). Em ambientes florestais, ao longo do processo de sucessão, as espécies lidam com variações nos níveis de luminosidade, recurso considerado importante para a regeneração e crescimento de plantas em florestas tropicais úmidas (CHEVIN; HOFFMANN, 2017). As plantas respondem às variações ambientais por meio de ajustes (resposta ecológica) ou adaptações (resposta evolutiva). A variabilidade dentro das populações é reflexo do ajustamento do valor de uma dada característica proveniente de um único genótipo, de acordo com mudanças no ambiente no tempo de vida do indivíduo (VALLADARES et al., 2014). Por outro lado, as adaptações resultam das variações da pressão seletiva ao longo do tempo evolutivo, capazes de produzir diferenças hereditárias entre espécies, pelo processo de evolução (RAMIREZ-VALIENTE et al., 2015). Sabe-se que dos diferentes órgãos da planta, sem dúvida a folha é o que mais se ajusta às variações de luz, especialmente no início da sucessão onde há maior incidência de luz (LAURANS et al., 2012). Conhecer essas características ajudar a entender melhor o funcionamento das florestas tropicas úmidas e planejar uma possível restauração desses fragmentos, caso seja necessário.
Частини книг з теми "Plasma du borde":
1
Kong, Peter C., and Emil Pfender. "Plasma Processes." In Carbide, Nitride and Boride Materials Synthesis and Processing, 359–87. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-0071-4_14.
2
Parks, George K., Theodore J. Freeman, Michael P. Mccarthy, and Scott H. Werden. "The Discovery of Auroral X-Rays by Balloon-Borne Detectors and Their Contributions to Magnetospheric Research." In Auroral Plasma Dynamics, 17–23. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm080p0017.
3
Crannell, C. J. "Imaging Solar Flares in Hard X Rays and Gamma Rays from Balloon-Borne Platforms." In Solar System Plasma Physics, 203–7. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm054p0203.
4
Droes, Stevenx R., Toivo T. Kodas, and Mark J. Hampden-Smith. "Plasma-Enhanced Chemical Vapor Deposition (PECVD)." In Carbide, Nitride and Boride Materials Synthesis and Processing, 579–603. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-0071-4_23.
5
Wells, Daniel R. "Titius-Bode Series Galaxy Group Red Shift Differences Calculated from Roots of the Bessel Equation." In Plasma Astrophysics and Cosmology, 255–63. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0405-0_22.
6
Holzworth, R. H., and E. A. Bering. "Ionospheric electric fields from stratospheric balloon-borne probes." In Measurement Techniques in Space Plasmas: Fields, 79–84. Washington, D. C.: American Geophysical Union, 1998. http://dx.doi.org/10.1029/gm103p0079.
7
Kleinknecht, Konrad, and Ulrich Uwer. "Symmetry Violations and Quark Flavour Physics." In Particle Physics Reference Library, 519–623. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-38207-0_9.
Анотація:
AbstractOne of the surprising facts in our present understanding of the development of the Universe is the complete absence of “primordial” antimatter from the Big Bang about 13.7 billion years ago. The detection of charged cosmic-ray particles by magnetic spectrometers borne by balloons, satellites, and the space shuttle has shown no evidence for such primordial (high-energy) antibaryons; nor has the search for gamma rays from antimatter–matter annihilation yielded any such observation. In the early phases of the expanding Universe, a hot (1032 K) and dense plasma of quarks, antiquarks, leptons, antileptons and photons coexisted in equilibrium. This plasma expanded and cooled down, and matter and antimatter could recombine and annihilate into photons. If all interactions were symmetric with respect to matter and antimatter, and if baryon and lepton numbers were conserved, then all particles would finally convert to photons, and the expansion of the Universe would shift the wavelength of these photons to the far infrared region.
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Venkatesan, Malabi M., and Valerie Burland. "Genome-Scale Analysis of Virulence Plasmids: the Contribution of Plasmid-Borne Virulence Genes to Enterobacterial Pathogenesis." In Plasmid Biology, 393–411. Washington, DC, USA: ASM Press, 2014. http://dx.doi.org/10.1128/9781555817732.ch18.
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Hauri, Hans-Peter. "Biosynthesis and Transport of Plasma Membrane Glycoproteins in the Rat Intestinal Epithelial Cell: Studies with Sucrase-Isomaltase." In Ciba Foundation Symposium 95 - Brush Border Membranes, 132–63. Chichester, UK: John Wiley & Sons, Ltd., 2008. http://dx.doi.org/10.1002/9780470720769.ch9.
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Courvalin, P., C. Poyart-Salmeron, and E. Derlot. "Plasmid-Borne Resistance to 4-Quinolones a Real or Apparent Absence?" In The 4-Quinolones: Anti Bacterial Agents in Vitro, 241–48. London: Springer London, 1990. http://dx.doi.org/10.1007/978-1-4471-3449-7_16.
Тези доповідей конференцій з теми "Plasma du borde":
1
Benson, Robert F., Paul Song, John Foster, Michael Mendillo, and Dieter Bilitza. "Plasma Physics Using Space-Borne Radio Sounding." In RADIO SOUNDING AND PLASMA PHYSICS. AIP, 2008. http://dx.doi.org/10.1063/1.2885028.
2
Lysykh, S. A., P. V. Moskvin, M. S. Vorobyev, V. N. Kornopoltsev, U. L. Mishigdorzhijn, Yu P. Kharaev, and A. S. Milonov. "ELECTRON-BEAM MODIFICATION OF BORIDE DIFFUSION LAYERS ON THE SURFACE OF STEEL 45 AND U10." In Plasma emission electronics. Buryat Scientific Center of SB RAS Press, 2023. http://dx.doi.org/10.31554/978-5-7925-0655-8-2023-273-279.
3
BARRETT, B., ERIC EUBANK, and W. NUNNALLY. "Pressure versus current scaling in a blocked bore rail gun." In 24th Plasma Dynamics, and Lasers Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1993. http://dx.doi.org/10.2514/6.1993-3155.
4
Mathew, J., D. J. Jenkins, R. A. Meger, and J. L. Giuliani. "Initial experiments performed on MRL's 1-cm square-bore railgun." In International Conference on Plasma Sciences (ICOPS). IEEE, 1993. http://dx.doi.org/10.1109/plasma.1993.593481.
5
Sodeoka, S., M. Suzuki, T. Inoue, and K. Ueno. "Effect of Spray Parameters on the Plasma in High Pressure Plasma Spraying Up to 300 kPa." In ITSC 1998, edited by Christian Coddet. ASM International, 1998. http://dx.doi.org/10.31399/asm.cp.itsc1998p1437.
Анотація:
Abstract To develop the spraying parameters for effective and safe operation of high pressure plasma spraying, the influence of nozzle bore diameter and plasma gas flow on the characteristics of plasma torch have been investigated under the chamber pressure ranging from 5 to 300 kPa. Large bore size allows high plasma gas flow rates without excessive increasing electric voltage, which is apt to damage the cathode. High flow rates (Ar: 1.3x10-3, H2: 1.3x10-4, He: 2.7x10-4 m3/s) is effective in imbuing more power into the plasma without nozzle damage under higher chamber pressures. The relationships among the parameters, such as the effective plasma power, the electric efficiency, the chamber pressure, the plasma gas flow and so on, were expressed qualitatively by a multiple regression analysis.
6
Milonov, A. S., D. E. Dasheev, U. L. Mishigdorzhijn, and A. P. Semenov. "FORMATION OF A PROTECTIVE COATING BASED ON CHROMIUM BORIDE ON THE SURFACE OF STEEL X12MF BY ELECTRON BEAM TREATMENT." In Plasma emission electronics. Buryat Scientific Center of SB RAS Press, 2023. http://dx.doi.org/10.31554/978-5-7925-0655-8-2023-224-227.
7
Dasheev, D. E., and N. N. Smirnyagina. "ELECTRON BEAM PROCESSES IN THE SYNTHESIS OF BORIDE COATINGS (FEB AND FE2B) IN VACUUM, THE PHASE COMPOSITION, STRUCTURE AND PROPERTIES." In Plasma emission electronics. Buryat Scientific Center of SB RAS Press, 2018. http://dx.doi.org/10.31554/978-5-7925-0524-7-2018-148-152.
8
Heping Lv, Ming Xu, Paul K. Chu, Jun Wang, and Baode Sun. "Microstructure and mechanical characterization of HVOF sprayed boride-based cermet coatings." In 2008 IEEE 35th International Conference on Plasma Science (ICOPS). IEEE, 2008. http://dx.doi.org/10.1109/plasma.2008.4590719.
9
Hurley, J. D., M. A. Bourham, and J. G. Gilligan. "In-bore diagnostics of drag forces in the electrothermal launcher SIRENS." In International Conference on Plasma Sciences (ICOPS). IEEE, 1993. http://dx.doi.org/10.1109/plasma.1993.593635.
10
Abdu, M. A., P. Muralikrishna, J. H. A. Sobral, S. Domingos, and K. I. Oyama. "Plasma Probe: Estudo de Bolhas de Plasma a Bordo do Primeiro Micro Satelite Cientifico Brasileiro." In 4th International Congress of the Brazilian Geophysical Society. European Association of Geoscientists & Engineers, 1995. http://dx.doi.org/10.3997/2214-4609-pdb.313.38.
Звіти організацій з теми "Plasma du borde":
1
Chang, J. J., C. D. Boley, W. A. Molander, B. E. Warner, and M. W. Martinez. Beam characteristics of a large-bore copper laser with a radiatively cooled plasma. Office of Scientific and Technical Information (OSTI), January 1994. http://dx.doi.org/10.2172/10167204.
2
Lindow, Steven, Isaac Barash, and Shulamit Manulis. Relationship of Genes Conferring Epiphytic Fitness and Internal Multiplication in Plants in Erwinia herbicola. United States Department of Agriculture, July 2000. http://dx.doi.org/10.32747/2000.7573065.bard.
Анотація:
Most bacterial plant pathogens colonize the surface of healthy plants as epiphytes before colonizing internally and initiating disease. The epiphytic phase of these pathogens is thus an important aspect of their epidemiology and a stage at which chemical and biological control is aimed. However, little is known of the genes and phenotypes that contribute to the ability of bacteria to grow on leaves and survive the variable physical environment in this habitat. In addition, while genes such as hrp awr and others which confer pathogenicity and in planta growth ability have been described, their contribution to other aspects of bacterial epidemiology such as epiphytic fitness have not been addressed. We hypothesized that bacterial genes conferring virulence or pathogenicity to plants also contribute to the epiphytic fitness of these bacteria and that many of these genes are preferentially located on plasmids. We addressed these hypotheses by independently identifying genes that contribute to epiphytic fitness, in planta growth, virulence and pathogenicity in the phytopathogenic bacterium Erwinia herbicola pv gypsophilae which causes gall formation on gypsophila. This species is highly epiphytically fit and has acquired a plasmid (pPATH) that contains numerous pathogenicity and virulence determinants, which we have found to also contribute to epiphytic fitness. We performed saturation transposon mutagenesis on pPATH as well as of the chromosome of E.h. gypsophilae, and identified mutants with reduced ability to grow in plants and/or cause disease symptoms, and through a novel competition assay, identified mutants less able to grow or survive on leaves. The number and identity of plasmid-borne hrp genes required for virulence was determined from an analysis of pPATH mutants, and the functional role of these genes in virulence was demonstrated. Likewise, other pPATH-encoded genes involved in IAA and cytokinin biosynthesis were characterized and their pattern of transcriptional activity was determined in planta. In both cases these genes involved in virulence were found to be induced in plant apoplasts. About half of avirulent mutants in pPATH were also epiphytically unfit whereas only about 10% of chromosomal mutants that were avirulent also had reduced epiphytic fitness. About 18% of random mutants in pPATH were avirulent in contrast to only 2.5% of random chromosomal mutants. Importantly, as many as 28% of pPATH mutants had lower epiphytic fitness while only about 10% of random chromosomal mutants had lower epiphytic fitness. These results support both of our original hypotheses, and indicate that genes important in a variety of interactions with plant have been enriched on mobile plasmids such as pPATH. The results also suggest that the ability of bacteria to colonize the surface of plants and to initiate infections in the interior of plants involves many of the same traits. These traits also appear to be under strong regulatory control, being expressed in response to the plant environment in many cases. It may be possible to alter the pattern of expression of such genes by altering the chemical environment of plants either by genetic means or by additional or chemical antagonists of the plant signals. The many novel bacterial genes identified in this study that are involved in plant interactions should be useful in further understanding of bacterial plant interactions.
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Kim, Kyekyoon. Development of small-bore, high-current-density railgun as testbed for study of plasma-materials interaction. Progress report for October 16,2000 - May 13, 2003. Office of Scientific and Technical Information (OSTI), May 2003. http://dx.doi.org/10.2172/818929.
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Rasmussen, D. A., and R. L. Freeman. THE DESIGN OF AN RF ANTENNA FOR A LARGE-BORE, HIGH POWER, STEADY STATE PLASMA PROCESSING CHAMBER FOR MATERIAL SEPARATION - CRADA FINAL REPORT for CRADA Number ORNL00-0585. Office of Scientific and Technical Information (OSTI), November 2001. http://dx.doi.org/10.2172/1134263.
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Ehrlich, Marcelo, John S. Parker, and Terence S. Dermody. Development of a Plasmid-Based Reverse Genetics System for the Bluetongue and Epizootic Hemorrhagic Disease Viruses to Allow a Comparative Characterization of the Function of the NS3 Viroporin in Viral Egress. United States Department of Agriculture, September 2013. http://dx.doi.org/10.32747/2013.7699840.bard.
Анотація:
Project Title: "Development of a plasmid-based reverse genetics system for the Bluetongue and Epizootic Hemorrhagic Disease viruses to allow comparative characterization of the function of the NS3 viroporin in viral egress". Project details: No - IS-4192-09; Participants – Ehrlich M. (Tel Aviv University), Parker J.S. (Cornell University), DermodyT.S. (Vanderbilt University); Period - 2009-2013. Orbiviruses are insect-borne infectious agents of ruminants that cause diseases with considerable economical impact in Israel and the United States. The recent outbreaks of BTV in Europe and of Epizootic Hemorrhagic Disease Virus (EHDV) in Israel, underscore the need for: (i) a better comprehension of the infection process of orbiviruses, (ii) the identification of unique vs. common traits among different orbiviruses, (iii) the development of novel diagnosis and treatment techniques and approaches; all aimed at the achievement of more effective control and treatment measures. It is the context of these broad goals that the present project was carried out. To fulfill our long-term goal of identifying specific viral determinants of virulence, growth, and transmission of the orbiviruses, we proposed to: (i) develop reverse genetics systems for BTV and EHDV2-Ibaraki; and (ii) identify the molecular determinants of the NS3 nonstructural protein related to viroporin/viral egress activities. The first objective was pursued with a two-pronged approach: (i) development of a plasmid-based reverse genetics system for BTV-17, and (ii) development of an "in-vitro" transcription-based reverse genetics system for EHDV2-Ibaraki. Both approaches encountered technical problems that hampered their achievement. However, dissection of the possible causes of the failure to achieve viral spread of EHDV2-Ibaraki, following the transfection of in-vitro transcribed genomic segments of the virus, revealed a novel characteristic of EHDV2-Ibaraki infection: an uncharacteristically low fold increase in titer upon infection of different cell models. To address the function and regulation of NS3 we employed the following approaches: (i) development (together with Anima Cell Metrology) of a novel technique (based on the transfection of fluorescently-labeledtRNAs) that allows for the detection of the levels of synthesis of individual viral proteins (i.e. NS3) in single cells; (ii) development of a siRNA-mediated knockdown approach for the reduction in levels of expression of NS3 in EHDV2-Ibaraki infected cells; (iii) biochemical and microscopy-based analysis of the localization, levels and post-translational modifications of NS3 in infected cells. In addition, we identified the altered regulation and spatial compartmentalization of protein synthesis in cells infected with EHDV2-Ibaraki or the mammalian reovirus. In EHDV2-Ibaraki-infected cells such altered regulation in protein synthesis occurs in the context of a cell stress reponse that includes the induction of apoptosis, autophagy and activation of the stressrelated kinase c-Jun N-terminal Kinase (JNK). Interestingly, inhibition of such stress-related cellular processes diminishes the production of infectious virions, suggesting that EHDV usurps these responses for the benefit of efficient infection. Taken together, while the present project fell short of the generation of novel reverse genetics systems for orbiviruses, the development of novel experimental approaches and techniques, and their employment in the analysis of EHDV-infected cells, yielded novel insights in the interactions of orbiviruses with mammalian cells.
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Manulis, Shulamit, Christine D. Smart, Isaac Barash, Guido Sessa, and Harvey C. Hoch. Molecular Interactions of Clavibacter michiganensis subsp. michiganensis with Tomato. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7697113.bard.
Анотація:
Clavibacter michiganensis subsp. michiganensis (Cmm), the causal agent of bacterial wilt and canker of tomato, is the most destructive bacterial disease of tomato causing substantial economic losses in Israel, the U.S.A. and worldwide. The molecular strategies that allow Cmm, a Gram-positive bacterium, to develop a successful infection in tomato plants are largely unknown. The goal of the project was to elucidate the molecular interactions between Cmmand tomato. The first objective was to analyze gene expression profiles of susceptible tomato plants infected with pathogenic and endophytic Cmmstrains. Microarray analysis identified 122 genes that were differentially expressed during early stages of infection. Cmm activated typical basal defense responses in the host including induction of defense-related genes, production of scavenging of free oxygen radicals, enhanced protein turnover and hormone synthesis. Proteomic investigation of the Cmm-tomato interaction was performed with Multi-Dimensional Protein Identification Technology (MudPIT) and mass spectroscopy. A wide range of enzymes secreted by Cmm382, including cell-wall degrading enzymes and a large group of serine proteases from different families were identified in the xylem sap of infected tomato. Based on proteomic results, the expression pattern of selected bacterial virulence genes and plant defense genes were examined by qRT-PCR. Expression of the plasmid-borne cellulase (celA), serine protease (pat-1) and serine proteases residing on the chp/tomA pathogenicity island (chpCandppaA), were significantly induced within 96 hr after inoculation. Transcription of chromosomal genes involved in cell wall degradation (i.e., pelA1, celB, xysA and xysB) was also induced in early infection stages. The second objective was to identify by VIGS technology host genes affecting Cmm multiplication and appearance of disease symptoms in plant. VIGS screening showed that out of 160 tomato genes, which could be involved in defense-related signaling, suppression of 14 genes led to increase host susceptibility. Noteworthy are the genes Snakin-2 (inhibitor of Cmm growth) and extensin-like protein (ELP) involved in cell wall fortification. To further test the significance of Snakin -2 and ELP in resistance towards Cmm, transgenic tomato plants over-expressing the two genes were generated. These plants showed partial resistance to Cmm resulting in a significant delay of the wilt symptoms and reduction in size of canker lesion compared to control. Furthermore, colonization of the transgenic plants was significantly lower. The third objective was to assess the involvement of ethylene (ET), jasmonate (JA) and salicylic acid (SA) in Cmm infection. Microarray and proteomic studies showed the induction of enzymes involved in ET and JA biosynthesis. Cmm promoted ET production 8 days after inoculation and SIACO, a key enzyme of ET biosynthesis, was upregulated. Inoculation of the tomato mutants Never ripe (Nr) impaired in ET perception and transgenic plants with reduced ET synthesis significantly delayed wilt symptoms as compared to the wild-type plants. The retarded wilting in Nr plants was shown to be a specific effect of ET insensitivity and was not due to altered expression of defense related genes, reduced bacterial population or decrease in ethylene biosynthesis . In contrast, infection of various tomato mutants impaired in JA biosynthesis (e.g., def1, acx1) and JA insensitive mutant (jai1) yielded unequivocal results. The fourth objective was to determine the role of cell wall degrading enzymes produced by Cmm in xylem colonization and symptoms development. A significance increase (2 to 7 fold) in expression of cellulases (CelA, CelB), pectate lyases (PelA1, PelA2), polygalacturonase and xylanases (XylA, XylB) was detected by qRT-PCR and by proteomic analysis of the xylem sap. However, with the exception of CelA, whose inactivation led to reduced wilt symptoms, inactivation of any of the other cell wall degrading enzymes did not lead to reduced virulence. Results achieved emphasized the complexity involved in Cmm-tomato interactions. Nevertheless they provide the basis for additional research which will unravel the mechanism of Cmm pathogenicity and formulating disease control measures.
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Necesidades y atención en salud sexual y reproductiva de mujeres migrantes en México: Un estudio desde Ciudad Juárez—Volumen 1. Population Council, 2021. http://dx.doi.org/10.31899/sbsr2021.1060.
Анотація:
El estudio retoma las voces de mujeres migrantes en la frontera norte de México (Ciudad Juárez) y explora sus diversas necesidades de salud sexual y reproductiva durante el tránsito por este país. Retoma experiencias de preparación para el viaje migratorio y acceso a la atención durante su estancia en Ciudad Juárez. El reporte presenta por separado los resultados descriptivos de los componentes del estudio: cuantitativo y cualitativo. Se planea realizar un análisis más profundo de estos datos en el futuro próximo. --- Elevating the voices of migrant women in the northern border of Mexico (Ciudad Juárez), the study explores the various sexual and reproductive health needs that in-transit migrant women have on their migration journey through this country. Information on their journey prep as well as access to health services in Ciudad Juárez is also explored. The reports present, separately, the descriptive findings of the qualitative and quantitative components of the research. Further analysis of these data is forthcoming.
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Economía circular en São Paulo, produciendo biodisel para evitar la escasez de agua. Banco Interamericano de Desarrollo, September 2023. http://dx.doi.org/10.18235/0004954.
Анотація:
Pasaron 84 años para que São Paulo sintiera de nuevo los efectos de la sequía prolongada. En 2015 más de la mitad de los pobladores de la urbe más grande de Brasil sufrieron interrupciones del servicio de agua 12 horas al día entre 4 y 5 días a la semana. La recolección de agua de lluvia en recipientes caseros derivó en una plaga de mosquitos que dejó a la ciudad al borde del caos. Gobierno y población lo tenían claro, crisis como esta no pueden ocurrir de nuevo. Fue en ese contexto que nació el proyecto de Proadapt “Economía circular y reciclaje de aceite de cocina”. El estudio del Programa de Gestión Ambiental, realizado por la consultora ATVOS en 2012, determinó que uno de los principales contaminantes del agua potable es el óleo descartado que corre por las tuberías de la ciudad, costándole millones de reales brasileños al Estado en programas de saneamiento. El desafío para el proyecto era intervenir en dos partes críticas del proceso de descarte de aceite. Primero se debía concientizar a la población sobre la importancia de separar el aceite sobrante y depositarlo en los puntos de recolección; y segundo, se debía construir una estructura eficiente de recogida a través de cooperativas que pudieran darle un destino correcto al óleo usado y devolverlo al sector productivo.