Metabolome Integrated Analysis of High-Temperature Response in Pinus radiata

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Mónica Escandón

2018-04-01

Full Text Available The integrative omics approach is crucial to identify the molecular mechanisms underlying high-temperature response in non-model species. Based on future scenarios of heat increase, Pinus radiata plants were exposed to a temperature of 40°C for a period of 5 days, including recovered plants (30 days after last exposure to 40°C in the analysis. The analysis of the metabolome using complementary mass spectrometry techniques (GC-MS and LC-Orbitrap-MS allowed the reliable quantification of 2,287 metabolites. The analysis of identified metabolites and highlighter metabolic pathways across heat time exposure reveal the dynamism of the metabolome in relation to high-temperature response in P. radiata, identifying the existence of a turning point (on day 3 at which P. radiata plants changed from an initial stress response program (shorter-term response to an acclimation one (longer-term response. Furthermore, the integration of metabolome and physiological measurements, which cover from the photosynthetic state to hormonal profile, suggests a complex metabolic pathway interaction network related to heat-stress response. Cytokinins (CKs, fatty acid metabolism and flavonoid and terpenoid biosynthesis were revealed as the most important pathways involved in heat-stress response in P. radiata, with zeatin riboside (ZR and isopentenyl adenosine (iPA as the key hormones coordinating these multiple and complex interactions. On the other hand, the integrative approach allowed elucidation of crucial metabolic mechanisms involved in heat response in P. radiata, as well as the identification of thermotolerance metabolic biomarkers (L-phenylalanine, hexadecanoic acid, and dihydromyricetin, crucial metabolites which can reschedule the metabolic strategy to adapt to high temperature.

Male sterile mutant in Vigna radiata

International Nuclear Information System (INIS)

Pande, Kalpana; Raghuvanshi, S.S.

1987-01-01

Single and combined treatment of γ-rays and 0.25 per cent EMS were tried on Vigna radiata variety K851. A male sterile mutant was isolated in M 2 generation. Experiments indicated male sterility to be recessive and monogenic in nature. 6 figures. (author)

Abnormal white matter integrity as a structural endophenotype for bipolar disorder.

Science.gov (United States)

Sarıçiçek, A; Zorlu, N; Yalın, N; Hıdıroğlu, C; Çavuşoğlu, B; Ceylan, D; Ada, E; Tunca, Z; Özerdem, A

2016-05-01

Several lines of evidence suggest that bipolar disorder (BD) is associated with white matter (WM) pathology. Investigation of unaffected first-degree relatives of BD patients may help to distinguish structural biomarkers of genetic risk without the confounding effects of burden of illness, medication or clinical state. In the present study, we applied tract-based spatial statistics to study WM changes in patients with BD, unaffected siblings and controls. A total of 27 euthymic patients with BD type I, 20 unaffected siblings of bipolar patients and 29 healthy controls who did not have any current or past diagnosis of Axis I psychiatric disorders were enrolled in the study. Fractional anisotropy (FA) was significantly lower in BD patients than in the control group in the corpus callosum, fornix, bilateral superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, anterior thalamic radiation, posterior thalamic radiation, cingulum, uncinate fasciculus, superior corona radiata, anterior corona radiata and left external capsule. In region-of-interest (ROI) analyses, we found that both unaffected siblings and bipolar patients had significantly reduced FA in the left posterior thalamic radiation, the left sagittal stratum, and the fornix compared with healthy controls. Average FA for unaffected siblings was intermediate between the healthy controls and bipolar patients within these ROIs. Decreased FA in the fornix, left posterior thalamic radiation and left sagittal stratum in both bipolar patients and unaffected siblings may represent a potential structural endophenotype or a trait-based marker for BD.

Potential biochemical markers for selection of disease resistance in Vigna radiata

International Nuclear Information System (INIS)

Badere, R.S.; Koche, D.K.; Choudhary, A.D.; Pawar, S.E.

2001-01-01

The Vigna radiata (L.) Wilczek (Green gram), a major pulse crop is prone to damaging diseases caused by Erysiphe polygoni, Cercospora canescens and Rhizoctonia sp. Therefore, the development of multiple resistance is a major breeding objective in green gram. Resistance to powdery mildew has already been developed, however, there are no reports on the development of resistance to Cercospora in green gram. Owing to limitation of conventional screening methods, the improvement for multiple disease resistance is inadequate, in this crop. It needs an efficient and quick selection method, for screening the plant population at an early stage. It is well established that the resistant interaction, in plants, involves accumulation of antibiotic compound phytoalexin (Genestein in Vigna radiata) and induction of enzymes such as β-1,3 gulcanase and Chitinases. These compounds are not only induced by pathogens but also pathogen-derived elicitors. These biochemical compounds can be used as resistance indicative biochemical markers for screening the natural or mutagen induced genetic diversity in populations of Vigna radiata in non-destructive manner. It, however, needs a systematic study of plant defense response. This paper deals with the response of resistant and susceptible cultivars of vigna radiata to Cercospora elicitor and development of non-destructive selection method for disease resistance. (author)

Characteristics of a corona discharge with a hot corona electrode

International Nuclear Information System (INIS)

Kulumbaev, E. B.; Lelevkin, V. M.; Niyazaliev, I. A.; Tokarev, A. V.

2011-01-01

The effect of the temperature of the corona electrode on the electrical characteristics of a corona discharge was studied experimentally. A modified Townsend formula for the current-voltage characteristic of a one-dimensional corona is proposed. Gasdynamic and thermal characteristics of a positive corona discharge in a coaxial electrode system are calculated. The calculated results are compared with the experimental data.

Bioactive phenolic acids from Scorzonera radiata Fisch.

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N Tsevegsuren

2014-09-01

Full Text Available Chromatographic separation of the crude extract obtained from the aerial parts of the Mongolian medicinal plant Scorzonera radiata yielded five new dihydrostilbenes [4], two new flavonoids, one new quinic acid derivative, as well as twenty known compounds including eight quinic acid derivatives, four flavonoids, two coumarins, five simple benzoic acids, and one monoterpene glycoside. We present here results on isolation and structural identification some active phenolic compounds from the Scorzonera radiata - eight quinic acid derivatives (quinic acid, 4,5-dicaffeoylquinic acid, 4,5-dicaffeoyl-epi-quinic acid, 3,5-dicaffeoylquinic acid, 3,5-dicaffeoyl-epi-quinic acid, chlorogenic acid, 5-p-coumaroylquinic acid (trans, 5-p-coumaroylquinic acid (cis. Quinic acid derivatives exhibited antioxidative activity.DOI: http://dx.doi.org/10.5564/mjc.v12i0.177 Mongolian Journal of Chemistry Vol.12 2011: 78-84

Descomposición de hojarasca de Pinus radiata y tres especies arbóreas nativas Decomposition of leaf litter of Pinus radiata and three native tree species

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CHRISTOPHER H. LUSK

2001-09-01

Full Text Available En el centro-sur de Chile, las últimas décadas han sido testigo de una conversión masiva de bosques, matorrales y tierras agrícolas a plantaciones de árboles exóticos. Aunque se ha estudiado la influencia de dichos cambios sobre el balance hídrico, los posibles efectos sobre otros procesos ecosistémicos han recibido poca atención. En esta breve comunicación se presentan datos de un estudio de la descomposición de hojarasca de Pinus radiata y tres especies arbóreas nativas, llevado a cabo con el fin de explorar los posibles efectos del reemplazo de bosque nativo por plantaciones exóticas sobre el ciclaje de nutrientes. Se incubaron muestras de las cuatro especies en dos ambientes distintos en sitios colindantes: bajo un bosque nativo secundario, y bajo un rodal de P. radiata. Se registró la pérdida de peso seco después de dos meses y seis meses. Las tasas diarias de descomposición fueron mucho mayores durante los primeros dos meses de incubación que durante los cuatro meses subsiguientes. En ambas fechas hubo diferencias significativas entre las especies y entre los sitios: todas las especies presentaron mayores tasas de descomposición bajo P. radiata que bajo el bosque nativo. No hubo evidencia de interacción entre sitio y especie. Después de seis meses, el orden de pérdida de peso seco fue Nothofagus obliqua > P. radiata > Peumus boldus > Cryptocarya alba. La variación interespecífica en la tasa de descomposición presentó más relación con el área foliar específica que con el contenido de nitrógeno en la hojarasca. Dado que la hojarasca de P. radiata se descompuso más lentamente que la de la especie caducifolia N. obliqua, pero más rápidamente que las especies esclerófilas, los efectos de la sustitución o invasión sobre descomposición dependerían de la composición original del bosque nativo en cuestiónRecent decades have seen widespread conversion of native forests, shrublands and farmland in south

Discovering and verifying DNA polymorphisms in a mung bean [V. radiata (L. R. Wilczek] collection by EcoTILLING and sequencing

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Dean Rob E

2008-06-01

Full Text Available Abstract Background Vigna radiata, which is classified in the family Fabaceae, is an important economic crop and a dietary staple in many developing countries. The species radiata can be further subdivided into varieties of which the variety sublobata is currently acknowledged as the putative progenitor of radiata. EcoTILLING was employed to identify single nucleotide polymorphisms (SNPs and small insertions/deletions (INDELS in a collection of Vigna radiata accessions. Findings A total of 157 DNA polymorphisms in the collection were produced from ten primer sets when using V. radiata var. sublobata as the reference. The majority of polymorphisms detected were found in putative introns. The banding patterns varied from simple to complex as the number of DNA polymorphisms between two pooled samples increased. Numerous SNPs and INDELS ranging from 4–24 and 1–6, respectively, were detected in all fragments when pooling V. radiata var. sublobata with V. radiata var. radiata. On the other hand, when accessions of V. radiata var. radiata were mixed together and digested with CEL I relatively few SNPs and no INDELS were detected. Conclusion EcoTILLING was utilized to identify polymorphisms in a collection of mung bean, which previously showed limited molecular genetic diversity and limited morphological diversity in the flowers and pod descriptors. Overall, EcoTILLING proved to be a powerful genetic analysis tool providing the rapid identification of naturally occurring variation.

Evaluación estética de seis tipos de coronas para dientes primarios

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Héctor Alejandro Ramírez Peña

2017-03-01

Full Text Available Objetivo: Evaluar las preferencias estéticas en relación con el color y la forma de coronas primarias utilizadas para dientes incisivos superiores primarios, mediante la realización de una encuesta a miembros de la Academia Mexicana de Odontología Pediatrica (AMOP. Material y Métodos: Se establecieron seis grupos de estudio con seis coronas diferentes: grupo 1, coronas de zirconia EZ-Pedo; grupo 2, coronas de zirconia NuSmile Zr; grupo 3, coronas estéticas hechas en el consultorio; grupo 4, coronas de fundas de celuloide; grupo 5, coronas estéticas prefabricadas NuSmile signature; y grupo 6, coronas estéticas fenestradas. Se llevaron a cabo encuestas con la finalidad de conocer las preferencias estéticas de estas diferentes coronas, con la finalidad de conocer cuál es la mejor opción para su uso en el consultorio dental. Resultados: Noventa miembros de la AMOP realizaron una encuesta válida, y se determinó que el grupo 4 fue el mejor evaluado, seguido de los grupos 2, 5, 1, 6 y 3. Se identificaron diferencias significativas entre los diferentes grupos. Conclusiones: Las coronas de fundas de celuloide fueron seleccionadas como mejor alternativa de uso en los dientes primarios anteriores, por parte de los miembros de la AMOP; asimismo, se consideró a las coronas de zirconia como una buena opción terapéutica. Es recomendable que se implemente el tratamiento estético en dientes primarios, para realizar un tratamiento integral.

90SR uptake by Pinus ponderosa and Pinus radiata seedlings inoculated with ectomycorrhizal fungi

International Nuclear Information System (INIS)

Entry, J.A.; Emmingham, W.H.; Rygiewicz, P.T.

1994-01-01

Strontium-90 ( 90 Sr) is a radionuclide characteristic of fallout from nuclear reactor accidents and nuclear weapons testing. Prior studies have shown that Pinus ponderosa and P. radiata seedlings can remove appreciable quantities of 90 Sr from soil and store it in plant tissue. In this study, we inoculated P. ponderosa and P. radiata seedlings with one of five isolates of ectomycorrhizal fungi. Inoculated and noninoculated (control) seedlings were compared for their ability to remove 90 Sr from an organic growth medium. Ectomycorrhizal P. ponderosa and P. radiata seedlings are able to remove 3-5 times more 90 Sr from contaminated soil than seedlings without ectomycorrhizae. (Author)

Corticospinal tract degeneration and possible pathogenesis in ALS evaluated by MR diffusion tensor imaging

DEFF Research Database (Denmark)

Karlsborg, Merete; Rosenbaum, Sverre; Wiegell, Mette R.

2004-01-01

BACKGROUND: MR diffusion tensor imaging (DTI) appears to be a powerful method to investigate the neuronal and axonal fibre distribution in the human brain. Changes in diffusion characteristics of water molecules in the white matter can be estimated as the apparent diffusion coefficient (ADC...... significance. ADC was unchanged at the level of the corona radiata. FA was significantly reduced at the lowest level (pons), only tended to be reduced in the internal capsule, but was also unchanged in the corona radiata. CONCLUSIONS: Segmentation of the CST into three regions supports the hypothesis...

Immunolocalization of IAA and ABA in roots and needles of radiata pine (Pinus radiata) during drought and rewatering.

Science.gov (United States)

De Diego, N; Rodríguez, J L; Dodd, I C; Pérez-Alfocea, F; Moncaleán, P; Lacuesta, M

2013-05-01

Anatomical, physiological and phytohormonal changes involved in drought tolerance were examined in different Pinus radiata D. Don breeds subjected to soil drying and rewatering. Breeds with the smallest stomatal chamber size had the lowest transpiration rate and the highest intrinsic water-use efficiency. Xylem cell size was positively correlated with leaf hydraulic conductance and needle indole-3-acetic acid (IAA) concentrations, whereas transpiration rate was negatively correlated with needle abscisic acid (ABA) levels. Since these two phytohormones seem important in regulating the P. radiata drought response, they were simultaneously immunolocalized in roots and needles of the most tolerant breed (P. radiata var. radiata × var. cedrosensis) during two sequential drought cycles and after rewatering. During drought, IAA was unequally distributed into the pointed area of the needle cross-section and mainly located in mesophyll and vascular tissue cells of needles, possibly inducing needle epinasty, whereas ABA was principally located in guard cells, presumably to elicit stomata closure. In the roots, at the end of the first drought cycle, while strong IAA accumulation was observed in the cortex, ABA levels decreased probably due to translocation to the leaves. Rewatering modified the distribution of both IAA and ABA in the needles, causing an accumulation principally in vascular tissue, with residual concentrations in mesophyll, likely favouring the acclimatization of the plants for further drought cycles. Contrarily, in the roots IAA and ABA were located in the exodermis, a natural barrier that regulates the phytohormone translocation to other plant tissues and hormone losses to the soil solution after rewatering. These results confirm that immunolocalization is an efficient tool to understand the translocation of IAA and ABA in plants subjected to different water stress situations, and clarify their role in regulating physiological responses such as stomata

Development of an Automated MRI-Based Diagnostic Protocol for Amyotrophic Lateral Sclerosis Using Disease-Specific Pathognomonic Features: A Quantitative Disease-State Classification Study.

Science.gov (United States)

Schuster, Christina; Hardiman, Orla; Bede, Peter

2016-01-01

Despite significant advances in quantitative neuroimaging, the diagnosis of ALS remains clinical and MRI-based biomarkers are not currently used to aid the diagnosis. The objective of this study is to develop a robust, disease-specific, multimodal classification protocol and validate its diagnostic accuracy in independent, early-stage and follow-up data sets. 147 participants (81 ALS patients and 66 healthy controls) were divided into a training sample and a validation sample. Patients in the validation sample underwent follow-up imaging longitudinally. After removing age-related variability, indices of grey and white matter integrity in ALS-specific pathognomonic brain regions were included in a cross-validated binary logistic regression model to determine the probability of individual scans indicating ALS. The following anatomical regions were assessed for diagnostic classification: average grey matter density of the left and right precentral gyrus, the average fractional anisotropy and radial diffusivity of the left and right superior corona radiata, inferior corona radiata, internal capsule, mesencephalic crus of the cerebral peduncles, pontine segment of the corticospinal tract, and the average diffusivity values of the genu, corpus and splenium of the corpus callosum. Using a 50% probability cut-off value of suffering from ALS, the model was able to discriminate ALS patients and HC with good sensitivity (80.0%) and moderate accuracy (70.0%) in the training sample and superior sensitivity (85.7%) and accuracy (78.4%) in the independent validation sample. This diagnostic classification study endeavours to advance ALS biomarker research towards pragmatic clinical applications by providing an approach of automated individual-data interpretation based on group-level observations.

Diffusion tensor imaging of Parkinson's disease, multiple system atrophy and progressive supranuclear palsy: a tract-based spatial statistics study.

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Amanda Worker

Full Text Available Although often clinically indistinguishable in the early stages, Parkinson's disease (PD, Multiple System Atrophy (MSA and Progressive Supranuclear Palsy (PSP have distinct neuropathological changes. The aim of the current study was to identify white matter tract neurodegeneration characteristic of each of the three syndromes. Tract-based spatial statistics (TBSS was used to perform a whole-brain automated analysis of diffusion tensor imaging (DTI data to compare differences in fractional anisotropy (FA and mean diffusivity (MD between the three clinical groups and healthy control subjects. Further analyses were conducted to assess the relationship between these putative indices of white matter microstructure and clinical measures of disease severity and symptoms. In PSP, relative to controls, changes in DTI indices consistent with white matter tract degeneration were identified in the corpus callosum, corona radiata, corticospinal tract, superior longitudinal fasciculus, anterior thalamic radiation, superior cerebellar peduncle, medial lemniscus, retrolenticular and anterior limb of the internal capsule, cerebral peduncle and external capsule bilaterally, as well as the left posterior limb of the internal capsule and the right posterior thalamic radiation. MSA patients also displayed differences in the body of the corpus callosum corticospinal tract, cerebellar peduncle, medial lemniscus, anterior and superior corona radiata, posterior limb of the internal capsule external capsule and cerebral peduncle bilaterally, as well as the left anterior limb of the internal capsule and the left anterior thalamic radiation. No significant white matter abnormalities were observed in the PD group. Across groups, MD correlated positively with disease severity in all major white matter tracts. These results show widespread changes in white matter tracts in both PSP and MSA patients, even at a mid-point in the disease process, which are not found in patients

Primer Registro de Tamarixia radiata (Waterston, 1922 (Hymenoptera: Eulophidae en Colombia Record of Tamarixia radiata (Waterston, 1922 (Hymenoptera: Eulophidae in Colombia

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Everth Emilio Ebratt Ravelo

2011-12-01

Full Text Available Tamarixia radiata es un ectoparasitoide idiobionte de Diaphorina citri Kuwayama (Hemiptera: Psyllidae; la especie fue descrita a partir de material recogido en la India. Ha sido introducida en muchas regiones intencional o accidentalmente para el control biológico de D. citri, incluyendo algunos países asiáticos. Se sabe de su presencia en el sur de África y las Américas. En Suramérica, se reportó en Brasil, Argentina y ahora en Colombia.Tamarixia radiata is an ectoparasitoid idiobionte of Diaphorina citri Kuwayama (Hemiptera: Psyllidae; the species was described from material collected in India. It has been introduced in many regions intentionally or accidentally, to biological control of D. citri, including some Asian countries. It is know about its presence in southern Africa and the Americas. In South America, it is present in Brazil, Argentina and now in Colombia.

Ethanol production from Lycoris radiata Herbert (Amarylllidaceae) residues as a new resource

International Nuclear Information System (INIS)

Liu, Shuangping; Ding, Zhongyang; Zhang, Liang; Gu, Zhenghua; Wang, Xiaolan; Sun, Xiaojun; Shi, Guiyang

2012-01-01

The large quantities of Lycoris radiata Herbert (Amarylllidaceae) residues, left after the extraction of alkaloids from the bulbs, could threaten the environment if not properly disposed. Therefore, the aim of this research is to investigate the feasibility of bioconversion of L. radiata Herbert residues to ethanol through batch fermentation. In L. radiata Herbert residues, the average contents (g kg −1 ) of non-structural carbohydrates, crude fiber, crude protein, ash, and lignin are 485.1, 177.3, 124.7, 108.9, and 91.0, respectively. Five commercial enzymes (β-glucanase, pectinase, xylanase, phytase and cellulase) were employed in pretreatment process and ethanol bioconversion was evaluated with three yeasts (Saccharomyces cerevisiae, osmotolerant S. cerevisiae and genetically engineered S. cerevisiae constructed to use cellobiose). The results showed that pretreament by β-glucanase successfully facilitated the penetration of α-amylase into ground material. After residues pretreatment by 10 g kg −1 of β-glucanase for 14 h at 50 °C, the viscosity decreased from 1135 to 59 Pa·s which was equivalent to that obtained by the combined whole five enzymes. Further experiments proved that osmotolerant S. cerevisiae was desirable for ethanol production from Lycoris radiate Herbert residues. The results are helpful to develop non-grain bioethanol production. -- Highlights: ► The residuals from Lycoris radiata Herbert bulbs were able to generate 55% ethanol concentrations by yeast fermentation. ► Treatment with xylanase significantly reduced the viscosity more than 10-fold and improved fermentable sugars by ∼35%. ► An osmotolerant Saccharomyces cerevisiae strain that showed improved fermentation rates was identified.

Physiological response to drought in radiata pine: phytohormone implication at leaf level.

Science.gov (United States)

De Diego, N; Pérez-Alfocea, F; Cantero, E; Lacuesta, M; Moncaleán, P

2012-04-01

Pinus radiata D. Don is one of the most abundant species in the north of Spain. Knowledge of drought response mechanisms is essential to guarantee plantation survival under reduced water supply as predicted in the future. Tolerance mechanisms are being studied in breeding programs, because information on such mechanisms can be used for genotype selection. In this paper, we analyze the changes of leaf water potential, hydraulic conductance (K(leaf)), stomatal conductance and phytohormones under drought in P. radiata breeds (O1, O2, O3, O4, O5 and O6) from different climatology areas, hypothesizing that they could show variable drought tolerance. As a primary signal, drought decreased cytokinin (zeatin and zeatin riboside-Z + ZR) levels in needles parallel to K(leaf) and gas exchange. When Z + ZR decreased by 65%, indole-3-acetic acid (IAA) and abscisic acid (ABA) accumulation started as a second signal and increments were higher for IAA than for ABA. When plants decreased by 80%, Z + ZR and K(leaf) doubled their ABA and IAA levels, the photosystem II yield decreased and the electrolyte leakage increased. At the end of the drought period, less tolerant breeds increased IAA over 10-fold compared with controls. External damage also induced jasmonic acid accumulation in all breeds except in O5 (P. radiata var. radiata × var. cedrosensis), which accumulated salicylic acid as a defense mechanism. After rewatering, only the most tolerant plants recovered their K(leaf,) perhaps due to an IAA decrease and 1-aminocyclopropane-1-carboxylic acid maintenance. From all phytohormones, IAA was the most representative 'water deficit signal' in P. radiata.

Corona SDK hotshot

CERN Document Server

Flanagan, Nevin

2013-01-01

Using a project based approach you will learn the coolest aspects of Corona SDK development. Each project contains step bystep explanations, diagrams, screenshots, and downloadable materials.This book is for users who already have completed at least one simple app using Corona and are familiar with mobile development using another platform and have done Lua programming in another context. Knowledge of the basic functions of Corona routines, as well as an understanding of the Lua programming language's syntax and common libraries, is assumed throughout.

IDENTIFICACION DEL CILINDRO NUDOSO EN IMÁGENES TC DE TROZAS PODADAS DE PINUS RADIATA UTILIZANDO REDES NEURONALES ARTIFICIALES

OpenAIRE

Rojas Espinoza,Gerson; Ortiz Irribarren,Oscar

2010-01-01

La factibilidad de identificar el cilindro nudoso en imágenes de tomografía computarizada de rayos X (TC) de trozas podadas de pino radiata (Pinus radiata D. Don), fue evaluada utilizando un método de clasificación supervisada basado en Redes Neuronales Artificiales (RNA). El proceso de clasificación consideró también la identificación de la zona libre de defectos y nudos. Treinta trozas podadas de pino radiata fueron escaneadas en un escáner médico multi-slice de rayos X, donde las imágenes ...

Corona helps curb losses

Energy Technology Data Exchange (ETDEWEB)

Laasonen, M.; Lahtinen, M.; Lustre, L.

1996-11-01

The greatest power losses in electricity transmission arise through a phenomenon called load losses. Corona losses caused by the surface discharge of electricity also constitute a considerable cost item. IVS, the nationwide network company, is investigating corona- induced losses, and has also commissioned similar research from IVO International, the Technical Research Centre of Finland (VTT) and from Tampere University of Technology. The research work strives to gain more in-depth knowledge on the phenomenon of frosting and its impact on corona losses. The correct prediction of frost helps reduce corona losses, while also cutting costs considerably. (orig.)

Disease specific protein corona

Science.gov (United States)

Rahman, M.; Mahmoudi, M.

2015-03-01

It is now well accepted that upon their entrance into the biological environments, the surface of nanomaterials would be covered by various biomacromolecules (e.g., proteins and lipids). The absorption of these biomolecules, so called `protein corona', onto the surface of (nano)biomaterials confers them a new `biological identity'. Although the formation of protein coronas on the surface of nanoparticles has been widely investigated, there are few reports on the effect of various diseases on the biological identity of nanoparticles. As the type of diseases may tremendously changes the composition of the protein source (e.g., human plasma/serum), one can expect that amount and composition of associated proteins in the corona composition may be varied, in disease type manner. Here, we show that corona coated silica and polystyrene nanoparticles (after interaction with in the plasma of the healthy individuals) could induce unfolding of fibrinogen, which promotes release of the inflammatory cytokines. However, no considerable releases of inflammatory cytokines were observed for corona coated graphene sheets. In contrast, the obtained corona coated silica and polystyrene nanoparticles from the hypofibrinogenemia patients could not induce inflammatory cytokine release where graphene sheets do. Therefore, one can expect that disease-specific protein coronas can provide a novel approach for applying nanomedicine to personalized medicine, improving diagnosis and treatment of different diseases tailored to the specific conditions and circumstances.

Measurement and analysis of time-domain characteristics of corona-generated radio interference from a single positive corona source

Science.gov (United States)

Li, Xuebao; Li, Dayong; Chen, Bo; Cui, Xiang; Lu, Tiebing; Li, Yinfei

2018-04-01

The corona-generated electromagnetic interference commonly known as radio interference (RI) has become a limiting factor for the design of high voltage direct current transmission lines. In this paper, a time-domain measurement system is developed to measure the time-domain characteristics of corona-generated RI from a single corona source under a positive corona source. In the experiments, the corona current pulses are synchronously measured through coupling capacitors. The one-to-one relationship between the corona current pulse and measured RI voltage pulse is observed. The statistical characteristics of pulse parameters are analyzed, and the correlations between the corona current pulse and RI voltage pulse in the time-domain and frequency-domain are analyzed. Depending on the measured corona current pulses, the time-domain waveform of corona-generated RI is calculated on the basis of the propagation model of corona current on the conductor, the dipolar model for electric field calculation, and the antenna model for inducing voltage calculation. The well matched results between measured and simulated waveforms of RI voltage can show the validity of the measurement and calculation method presented in this paper, which also further show the close correlation between corona current and corona-generated RI.

PHYSIOLOGICAL RESPONSES OF ECKLONIA RADIATA (LAMINARIALES) TO A LATITUDINAL GRADIENT IN OCEAN TEMPERATURE

DEFF Research Database (Denmark)

Stæhr, Peter Anton; Wernberg, Thomas

2009-01-01

We tested the ability of sporophytes of a small kelp, Ecklonia radiata (C. Agardh) J. Agardh, to adjust their photosynthesis, respiration, and cellular processes to increasingly warm ocean climates along a latitudinal gradient in ocean temperature (~4°C). Tissue concentrations of pigment and nutr......We tested the ability of sporophytes of a small kelp, Ecklonia radiata (C. Agardh) J. Agardh, to adjust their photosynthesis, respiration, and cellular processes to increasingly warm ocean climates along a latitudinal gradient in ocean temperature (~4°C). Tissue concentrations of pigment...... and nutrients decreased with increasing ocean temperature. Concurrently, a number of gradual changes in the metabolic balance of E. radiata took place along the latitudinal gradient. Warm-acclimatized kelps had 50% lower photosynthetic rates and 90% lower respiration rates at the optimum temperature than did...... cool-acclimatized kelps. A reduction in temperature sensitivity was also observed as a reduction in Q10-values from cool- to warm-acclimatized kelps for gross photosynthesis (Q10: 3.35 to 1.45) and respiration (Q10: 3.82 to 1.65). Respiration rates were more sensitive to increasing experimental...

Defect core detection in radiata pine logs

International Nuclear Information System (INIS)

Wallace, G.

1993-01-01

Internal defect cores in Pinus radiata logs arise primarily from the practice in New Zealand of pruning trees to increase the amount of clear wood. Realising the benefits of this practice when milling the logs is hampered by the lack of a practical method for detecting the defect cores. This report attempts to establish industry requirements for detections and examine techniques which may be suitable. Some trials of a novel technique are described. (author) 19 refs.; 11 figs

Visual Grading and Structural Properties Assessment of Large Cross-Section Pinus radiata D. Don Timber

Directory of Open Access Journals (Sweden)

Eva Hermoso Prieto

2016-04-01

Full Text Available The use of large cross-section timber for structural purposes has increased in Spain, and knowledge of its properties is strategically necessary. The Spanish visual strength-grading standard UNE 56544 (2011 efficiency applied to large cross-section structural timber was analyzed using a sample of 363 specimens of radiata pine (Pinus radiata D. Don. from the Basque Country and Catalonia, Spain. Different sizes were tested (80 × 120 × 2400 mm3, 150 × 250 × 5600 mm3, 150 × 250 × 4300 mm3, and 200 × 250 × 5000 mm3. Bending strength, modulus of elasticity, and density were obtained, and characteristic values were determined in order to assign strength class according to European standard EN 338 (2010. Knots and twists were the most relevant singularities for visual strength grading. It was concluded that large cross-section Spanish radiata pine timber was suitable for structures, and it was assigned to the C20 strength class.

Thermal hygrometric requirements for the rearing and release of Tamarixia radiata (Waterston (Hymenoptera, Eulophidae

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Mariuxi Lorena Gómez-Torres

2014-09-01

Full Text Available Thermal hygrometric requirements for the rearing and release of Tamarixia radiata (Waterston (Hymenoptera, Eulophidae. Tamarixia radiata is the main agent for the biological control of Diaphorina citri in Brazil with a parasitism rate ranging from 20 to 80%. This study investigated the influence of temperature on the development, fecundity and longevity of adults of T. radiata and the effect of relative humidity (RH on their parasitism capacity and survival rate in the pre-imaginal period. The effect of temperature was assessed in the range between 15 and 35 ± 1ºC, 70 ± 10% RH, and a 14-h photophase. The RH effect was evaluated in the range from 30 to 90 ± 10%, temperature at 25 ± 1ºC, and photophase of 14-h. At 25ºC, circa 166.7 nymphs were parasitized, the highest parasitism capacity observed compared to other treatments. The longest longevity of females was observed at 25ºC, although the rate did not differ in the 20-30ºC temperature range. The threshold temperature (TT was 7.2ºC, and 188.7 degrees-day were required for the development (egg-to-adult period. The parasitism rate and longevity were higher at 50 and 70% of RH. This shows that temperature and RH may affect the parasitism capacity of T. radiata on nymphs of D. citri, which can explain the great parasitism variation for D. citri observed in citrus groves in São Paulo State, Brazil.

Generation and analysis of expressed sequence tags from six developing xylem libraries in Pinus radiata D. Don

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Dillon Shannon K

2009-01-01

Full Text Available Abstract Background Wood is a major renewable natural resource for the timber, fibre and bioenergy industry. Pinus radiata D. Don is the most important commercial plantation tree species in Australia and several other countries; however, genomic resources for this species are very limited in public databases. Our primary objective was to sequence a large number of expressed sequence tags (ESTs from genes involved in wood formation in radiata pine. Results Six developing xylem cDNA libraries were constructed from earlywood and latewood tissues sampled at juvenile (7 yrs, transition (11 yrs and mature (30 yrs ages, respectively. These xylem tissues represent six typical development stages in a rotation period of radiata pine. A total of 6,389 high quality ESTs were collected from 5,952 cDNA clones. Assembly of 5,952 ESTs from 5' end sequences generated 3,304 unigenes including 952 contigs and 2,352 singletons. About 97.0% of the 5,952 ESTs and 96.1% of the unigenes have matches in the UniProt and TIGR databases. Of the 3,174 unigenes with matches, 42.9% were not assigned GO (Gene Ontology terms and their functions are unknown or unclassified. More than half (52.1% of the 5,952 ESTs have matches in the Pfam database and represent 772 known protein families. About 18.0% of the 5,952 ESTs matched cell wall related genes in the MAIZEWALL database, representing all 18 categories, 91 of all 174 families and possibly 557 genes. Fifteen cell wall-related genes are ranked in the 30 most abundant genes, including CesA, tubulin, AGP, SAMS, actin, laccase, CCoAMT, MetE, phytocyanin, pectate lyase, cellulase, SuSy, expansin, chitinase and UDP-glucose dehydrogenase. Based on the PlantTFDB database 41 of the 64 transcription factor families in the poplar genome were identified as being involved in radiata pine wood formation. Comparative analysis of GO term abundance revealed a distinct transcriptome in juvenile earlywood formation compared to other stages of

Above-ground biomass equations for Pinus radiata D. Don in Asturias

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E. Canga

2013-12-01

Full Text Available Aim of the study: The aim of this study was to develop a model for above-ground biomass estimation for Pinus radiata D. Don in Asturias.Area of study: Asturias (NE of Spain.Material and methods: Different models were fitted for the different above-ground components and weighted regression was used to correct heteroscedasticity. Finally, all the models were refitted simultaneously by use of Nonlinear Seemingly Unrelated Regressions (NSUR to ensure the additivity of biomass equations.Research highlights: A system of four biomass equations (wood, bark, crown and total biomass was develop, such that the sum of the estimations of the three biomass components is equal to the estimate of total biomass. Total and stem biomass equations explained more than 92% of observed variability, while crown and bark biomass equations explained 77% and 89% respectively.Keywords: radiata pine; plantations; biomass.

A preliminary diffusional kurtosis imaging study of Parkinson disease: comparison with conventional diffusion tensor imaging

Energy Technology Data Exchange (ETDEWEB)

Kamagata, Koji; Kamiya, Kouhei; Suzuki, Michimasa; Hori, Masaaki; Yoshida, Mariko; Aoki, Shigeki [Juntendo University School of Medicine, Department of Radiology, Bunkyo-ku, Tokyo (Japan); Tomiyama, Hiroyuki; Hatano, Taku; Motoi, Yumiko; Hattori, Nobutaka [Juntendo University School of Medicine, Department of Neurology, Tokyo (Japan); Abe, Osamu [Nihon University School of Medicine, Department of Radiology, Tokyo (Japan); Shimoji, Keigo [National Center of Neurology and Psychiatry Hospital, Department of Radiology, Tokyo (Japan)

2014-03-15

Diffusional kurtosis imaging (DKI) is a more sensitive technique than conventional diffusion tensor imaging (DTI) for assessing tissue microstructure. In particular, it quantifies the microstructural integrity of white matter, even in the presence of crossing fibers. The aim of this preliminary study was to compare how DKI and DTI show white matter alterations in Parkinson disease (PD). DKI scans were obtained with a 3-T magnetic resonance imager from 12 patients with PD and 10 healthy controls matched by age and sex. Tract-based spatial statistics were used to compare the mean kurtosis (MK), mean diffusivity (MD), and fractional anisotropy (FA) maps of the PD patient group and the control group. In addition, a region-of-interest analysis was performed for the area of the posterior corona radiata and superior longitudinal fasciculus (SLF) fiber crossing. FA values in the frontal white matter were significantly lower in PD patients than in healthy controls. Reductions in MK occurred more extensively throughout the brain: in addition to frontal white matter, MK was lower in the parietal, occipital, and right temporal white matter. The MK value of the area of the posterior corona radiata and SLF fiber crossing was also lower in the PD group. DKI detects changes in the cerebral white matter of PD patients more sensitively than conventional DTI. In addition, DKI is useful for evaluating crossing fibers. By providing a sensitive index of brain pathology in PD, DKI may enable improved monitoring of disease progression. (orig.)

[Embolic stroke immediately after initial administration of intravitreal aflibercept].

Science.gov (United States)

Mizutani, Hironori; Inatomi, Yuichiro; Singu, Takaomi; Nakajima, Makoto; Yonehara, Toshiro; Ando, Yukio

2018-04-28

A 72-year-old man was admitted to our hospital because of right upper limb monoplegia 8 hours after the initial intravitreal injection of aflibercept, which is an inhibitor of vascular endothelial growth factor. Magnetic resonance diffusion-weighted images showed recent ischemic lesions in the left corona radiata and the right superior frontal gyrus. Laboratory findings showed mild hyperfibrinolysis. A patent foramen ovale was diagnosed on transesophageal echocardiography; however, lower-extremity ultrasonography did not detect deep vein thrombosis. The source of embolism remained unknown. A possible mechanism of cerebral emboli in the present case was a rapidly induced hypercoagulative state due to transfer of aflibercept from the vitreous body to the systemic circulation.

Proanthocyanidin-rich Pinus radiata bark extract inhibits mast cell-mediated anaphylaxis-like reactions.

Science.gov (United States)

Choi, Yun Ho; Song, Chang Ho; Mun, Sung Phil

2018-02-01

Mast cells play a critical role in the effector phase of immediate hypersensitivity and allergic reactions. Pinus radiata bark extract exerts multiple biological effects and exhibits immunomodulatory and antioxidant properties. However, its role in mast cell-mediated anaphylactic reactions has not been thoroughly investigated. In this study, we examined the effects of proanthocyanidin-rich water extract (PAWE) isolated from P. radiata bark on compound 48/80-induced or antidinitrophenyl (DNP) immunoglobulin E (IgE)-mediated anaphylaxis-like reactions in vivo. In addition, we evaluated the mechanism underlying the inhibitory effect of PAWE on mast cell activation, with a specific focus on histamine release, using rat peritoneal mast cells. PAWE attenuated compound 48/80-induced or anti-DNP IgE-mediated passive cutaneous anaphylaxis-like reactions in mice, and it inhibited histamine release triggered by compound 48/80, ionophore A23187, or anti-DNP IgE in rat peritoneal mast cells in vitro. Moreover, PAWE suppressed compound 48/80-elicited calcium uptake in a concentration-dependent manner and promoted a transient increase in intracellular cyclic adenosine-3',5'-monophosphate levels. Together, these results suggest that proanthocyanidin-rich P. radiata bark extract effectively inhibits anaphylaxis-like reactions. Copyright © 2017 John Wiley & Sons, Ltd.

Diaphorina citri (Kuwayama, 1907 and Tamarixia radiata (Waterson, 1922 in citrus crops of Cundinamarca, Colombia

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Ebratt Ravelo Everth Emilio

2011-12-01

Full Text Available

The presence of Diaphorina citri Kuwayama (Hemiptera: Psyllidae and Tamarixia radiata (Waterston (Hymenoptera: Eulophidae was recorded in citrus crops of Cundinamarca, Colombia. This work is to know the geographic distribution of D. citri and an initial record of the parasitoid T. radiata in citrus producing areas of this department.

Selection and evaluation of Rhizobial strains of Vigna radiata L ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... Selection and evaluation of Rhizobial strains of Vigna radiata L. beneficial to ... This study aimed to select suitable strains that can be used as inoculants to enhance legume production and simultaneously reduce the use of ... contributor to natural or biological N2 fixation and allows legumes to grow in the ...

Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage

Energy Technology Data Exchange (ETDEWEB)

Li, Xuebao, E-mail: lxb08357x@ncepu.edu.cn; Cui, Xiang, E-mail: x.cui@ncepu.edu.cn; Ma, Wenzuo; Bian, Xingming; Wang, Donglai [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206 (China); Lu, Tiebing, E-mail: tiebinglu@ncepu.edu.cn [Beijing Key Laboratory of High Voltage and EMC, North China Electric Power University, Beijing 102206 (China); Hiziroglu, Huseyin [Department of Electrical and Computer Engineering, Kettering University, Flint, Michigan 48504 (United States)

2016-03-15

The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.

Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage

Science.gov (United States)

Li, Xuebao; Cui, Xiang; Lu, Tiebing; Ma, Wenzuo; Bian, Xingming; Wang, Donglai; Hiziroglu, Huseyin

2016-03-01

The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.

Lethal and Sublethal Impacts of Acaricides on Tamarixia radiata (Hemiptera: Eulophidae), an Important Ectoparasitoid of Diaphorina citri (Hemiptera: Liviidae).

Science.gov (United States)

Lira, A C S; Zanardi, O Z; Beloti, V H; Bordini, G P; Yamamoto, P T; Parra, J R P; Carvalho, G A

2015-10-01

The use of synthetic acaricides for management of pest mites may alter the efficacy of the ectoparasitoid Tamarixia radiata (Waterston) in biological control of Diaphorina citri Kuwayama, the vector of the bacteria associated with huanglongbing (HLB) in citrus orchards. We evaluated the toxicity of 16 acaricides that are recommended for the control of citrus-pest mites to T. radiata. Acrinathrin, bifenthrin, carbosulfan, and fenpropathrin caused high acute toxicity and were considered harmful (mortality >77%) to T. radiata. Abamectin, diflubenzuron, etoxazole, fenbutatin oxide, fenpyroximate, flufenoxuron, hexythiazox, propargite, spirodiclofen, and sulfur caused low acute toxicity and affected the parasitism rate and emergence rate of adults (F1 generation), and were considered slightly harmful to T. radiata. Dicofol and pyridaben did not affect the survival and action of the ectoparasitoid, and were considered harmless. In addition to its acute toxicity, carbosulfan caused mortality higher than 25% for >30 d after application, and was considered persistent. Acrinathrin, bifenthrin, fenpropathrin, fenpyroximate, propargite, and sulfur caused mortalities over 25% until 24 d after application and were considered moderately persistent; abamectin was slightly persistent, and fenbutatin oxide was short lived. Our results suggest that most acaricides used to control pest mites in citrus affect the density and efficacy of T. radiata in the biological control of D. citri. However, further evaluations are needed in order to determine the effect of these products on this ectoparasitoid under field conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

TESIS experiment on study of solar corona in EUV spectral range (CORONAS-PHOTON project)

International Nuclear Information System (INIS)

Kuzin, S.V.; Zhitnik, I.A.; Ignat'ev, A.P.; Mitrofanov, A.V.; Pertsov, A.A.; Bugaenko, O.I.

2005-01-01

A new orbital station, namely: the CORONAS-PHOTON one (to be launched in 2006) equipped with systems to explore Sun at the intensification period of the solar activity 24-th cycle and at its peak is being designed within the framework of the CORONAS National Sun Space Exploration Program. The station equipment consists of systems to observe Sun within the spectral soft X-ray and vacuum ultraviolet bands. Paper lists and describes the TESIS experiment tools designed for the CORONAS-PHOTON Project to ensure the Sun atmospheric research within short-wave band [ru

Improvement of non-key traits in radiata pine breeding programme when long-term economic importance is uncertain.

Science.gov (United States)

Li, Yongjun; Dungey, Heidi; Yanchuk, Alvin; Apiolaza, Luis A

2017-01-01

Diameter at breast height (DBH), wood density (DEN) and predicted modulus of elasticity (PME) are considered as 'key traits' (KT) in the improvement in radiata pine breeding programmes in New Zealand. Any other traits which are also of interest to radiata pine breeders and forest growers are called 'non-key traits' (NKTs). External resin bleeding (ERB), internal checking (IC), number of heartwood rings (NHR) are three such non-key traits which affect wood quality of radiata pine timber. Economic importance of the KTs and NKTs is hard to define in radiata pine breeding programmes due to long rotation period. Desired-gain index (DGIs) and robust selection were proposed to incorporate NKTs into radiata pine breeding programme in order to deal with the uncertainty of economic importance. Four desired-gain indices A-D were proposed in this study. The desired-gain index A (DGI-A) emphasized growth and led to small decrease in ERB and small increase in IC and NHR. The expected genetic gains of all traits in the desired-gain index B (DGI-B) were in the favourable directions (positive genetic gains in the key traits and negative genetic gains in the non-key traits). The desired-gain index C (DGI-C) placed emphasis on wood density, leading to favourable genetic gain in the NKTs but reduced genetic gains for DBH and PME. The desired-gain index D (DGI-D) exerted a bit more emphasis on the non-key traits, leading large favourable reduction in the non-key traits and lower increase in the key traits compared with the other DGIs. When selecting both the key traits and the non-key traits, the average EBVs of six traits were all in the same directions as the expected genetic gains except for DBH in the DGI-D. When the key traits were measured and selected, internal checking always had a negative (favourable) genetic gain but ERB and NHR had unfavourable genetic gain in the most of time. After removing some individuals with high sensitivity to the change of economic weights, robust

Improvement of non-key traits in radiata pine breeding programme when long-term economic importance is uncertain.

Directory of Open Access Journals (Sweden)

Yongjun Li

Full Text Available Diameter at breast height (DBH, wood density (DEN and predicted modulus of elasticity (PME are considered as 'key traits' (KT in the improvement in radiata pine breeding programmes in New Zealand. Any other traits which are also of interest to radiata pine breeders and forest growers are called 'non-key traits' (NKTs. External resin bleeding (ERB, internal checking (IC, number of heartwood rings (NHR are three such non-key traits which affect wood quality of radiata pine timber. Economic importance of the KTs and NKTs is hard to define in radiata pine breeding programmes due to long rotation period. Desired-gain index (DGIs and robust selection were proposed to incorporate NKTs into radiata pine breeding programme in order to deal with the uncertainty of economic importance. Four desired-gain indices A-D were proposed in this study. The desired-gain index A (DGI-A emphasized growth and led to small decrease in ERB and small increase in IC and NHR. The expected genetic gains of all traits in the desired-gain index B (DGI-B were in the favourable directions (positive genetic gains in the key traits and negative genetic gains in the non-key traits. The desired-gain index C (DGI-C placed emphasis on wood density, leading to favourable genetic gain in the NKTs but reduced genetic gains for DBH and PME. The desired-gain index D (DGI-D exerted a bit more emphasis on the non-key traits, leading large favourable reduction in the non-key traits and lower increase in the key traits compared with the other DGIs. When selecting both the key traits and the non-key traits, the average EBVs of six traits were all in the same directions as the expected genetic gains except for DBH in the DGI-D. When the key traits were measured and selected, internal checking always had a negative (favourable genetic gain but ERB and NHR had unfavourable genetic gain in the most of time. After removing some individuals with high sensitivity to the change of economic weights

Evaluation of Trichoderma spp. and Clonostachys spp. Strains to Control Fusarium circinatum in Pinus radiata Seedlings Evaluación de Cepas de Trichoderma spp. y Clonostachys spp. para Controlar Fusarium circinatum en Plántulas de Pinus radiata

Directory of Open Access Journals (Sweden)

Priscila Moraga-Suazo

2011-09-01

Full Text Available The fungus Fusarium circinatum Nirenberg & O’Donnell causes pine pitch canker, an important disease for conifers worldwide. F. circinatum was first detected in Chile in 2001 and to date is present in nurseries and clonal hedges from Libertador General Bernardo O’Higgins Region to Los Rios Region. The purpose of this study was to evaluate the potential of Trichoderma spp. and Clonostachys spp. strains to control F. circinatum in Pinus radiata D. Don seedlings in the absence of other effective control methods. Eighty-one Trichoderma spp. and Clonostachys spp. strains were evaluated through in vitro assays to determine their ability to act as antagonists of F. circinatum and 21 strains were tested for their ability to reduce post-emergence mortality and increase P. radiata survival under greenhouse conditions. During in vitro experiments, 15 strains of Trichoderma inhibited mycelial growth of the pathogen by more than 60% and one strain of Clonostachys showed parasitism of F. circinatum hyphae. Greenhouse experiments showed no control of the disease when the antagonists were added to substrate after the pathogen. However, when the antagonists were added before the pathogen, four strains (Clonostachys UDC-32 and UDC-222 and Trichoderma UDC-23 and UDC-408 reduced post-emergence mortality between 80 and 100%. Among these strains, only Clonostachys UDC-222 significantly increased the survival of P. radiata seedlings. These results showed that Clonostachys UDC-222 has the potential to be used as a biocontrol agent against F. circinatum in the production of P. radiata plants.Fusarium circinatum Nirenberg & O’Donnell es el hongo que causa el cancro resinoso del pino, una enfermedad de importancia mundial en coníferas. En Chile, F. cicirnatum fue detectado por primera vez el año 2001 y a la fecha se encuentra presente en algunos viveros y huertos clonales desde la Región del Libertador General Bernardo O’Higgins hasta la Región de Los R�

INFLUENCIA DE LA MADERA JUVENIL DE PINO RADIATA SOBRE LAS PROPIEDADES MECÁNICAS DE TABLEROS OSB

OpenAIRE

PECHO,Robert; ANANIAS,Rubén A; BALLERINI,Aldo; CLOUTIER,Alain

2004-01-01

En este trabajo se estudia la influencia de la madera juvenil de pino radiata (Pinus radiata D. Don) sobre las propiedades mecánicas de tableros de hojuelas orientadas OSB. La madera para los ensayos es recogida de 10 árboles en pié de 26 años creciendo en plantaciones manejadas de la Octava región, Chile. La determinación de madera juvenil se realiza observando la variación radial de los anillos de crecimiento de la madera, usando un analizador de anillos en base a rayos X. Los detalles de l...

Susceptibility of Diaphorina citri (Hemiptera: Liviidae) and Its Parasitoid Tamarixia radiata (Hymenoptera: Eulophidae) to Entomopathogenic Fungi under Laboratory Conditions.

Science.gov (United States)

Ibarra-Cortés, K H; Guzmán-Franco, A W; González-Hernández, H; Ortega-Arenas, L D; Villanueva-Jiménez, J A; Robles-Bermúdez, A

2018-02-01

Diaphorina citri (Kuwayama) is a global pest of citrus that transmits the bacteria associated with the disease, Huanglongbing. Entomopathogenic fungi and the parasitoid Tamarixia radiata (Waterston) are important biological control agents of this pest and likely to interact in D. citri populations. As a basis for interaction studies, we determined the susceptibility of nymphs and adults of D. citri and adults of the parasitoid T. radiata to six fungal isolates from the species Beauveria bassiana s.l. (Bals.-Criv.) Vuill. (isolates B1 and B3), Metarhizium anisopliae s.s. (Metsch.) (Ma129 and Ma65) and Isaria fumosorosea Wize (I2 and Pae). We conducted experiments evaluating infection levels in all three insect groups following inoculation with a series of conidial concentrations (1 × 10 4 -1 × 10 8 conidia mL -1 ). Results showed that D. citri nymphs and T. radiata were more susceptible to fungal isolates than D. citri adults. Overall, B. bassiana and M. anisopliae isolates caused the greatest infection compared with I. fumosorosea isolates in all three groups of insects. Isolates B1 (B. bassiana) and Ma129 (M. anisopliae) infected a greater proportion of adults and nymphs of D. citri, respectively. Both isolates of B. bassiana caused greater infection in T. radiata compared with isolates of the other fungal species. We propose that isolates B1 and Ma129 are the strongest candidates for control of D. citri. Our results represent the first report of entomopathogenic fungi infecting T. radiata, and the basis for future studies to design a biological control programme that uses both agents more efficiently against D. citri populations.

Large-scale volcanism associated with coronae on Venus

Science.gov (United States)

Roberts, K. Magee; Head, James W.

1993-01-01

The formation and evolution of coronae on Venus are thought to be the result of mantle upwellings against the crust and lithosphere and subsequent gravitational relaxation. A variety of other features on Venus have been linked to processes associated with mantle upwelling, including shield volcanoes on large regional rises such as Beta, Atla and Western Eistla Regiones and extensive flow fields such as Mylitta and Kaiwan Fluctus near the Lada Terra/Lavinia Planitia boundary. Of these features, coronae appear to possess the smallest amounts of associated volcanism, although volcanism associated with coronae has only been qualitatively examined. An initial survey of coronae based on recent Magellan data indicated that only 9 percent of all coronae are associated with substantial amounts of volcanism, including interior calderas or edifices greater than 50 km in diameter and extensive, exterior radial flow fields. Sixty-eight percent of all coronae were found to have lesser amounts of volcanism, including interior flooding and associated volcanic domes and small shields; the remaining coronae were considered deficient in associated volcanism. It is possible that coronae are related to mantle plumes or diapirs that are lower in volume or in partial melt than those associated with the large shields or flow fields. Regional tectonics or variations in local crustal and thermal structure may also be significant in determining the amount of volcanism produced from an upwelling. It is also possible that flow fields associated with some coronae are sheet-like in nature and may not be readily identified. If coronae are associated with volcanic flow fields, then they may be a significant contributor to plains formation on Venus, as they number over 300 and are widely distributed across the planet. As a continuation of our analysis of large-scale volcanism on Venus, we have reexamined the known population of coronae and assessed quantitatively the scale of volcanism associated

Relationship between fiber porosity and cellulose digestibility in steam-exploded Pinus radiata

Energy Technology Data Exchange (ETDEWEB)

Wong, K.K.Y.; Deverell, K.F.; Mackie, K.L.; Clark, T.A.; Donaldson, L.A.

1988-04-05

The use of lignocellulosic materials in bioconversion processes may be improved if the critical factors limiting conversion are better understood. Steam explosion after sulfur dioxide impregnation of wood chips is an effective method for improving the enzymatic digestibility of cellulose in the softwood Pinus radiata. Digestibility of pretreated fiber was progressively increased by altering the conditions of steam explosion. With increasing digestibility, there was an observed increase in fiber porosity as measured by the solute exclusion technique. Accessible pore volume and accessible surface area to a 5-nm dextran probe positively correlated with both 2- and 24-h digestion yields from pretreated fiber. The increase in accessibility was probably the result of hemicellulose extraction and lignin redistribution. A subsequent loss in accessibility, brought about by structural collapse or further lignin redistribution, resulted in a corresponding loss in digestibility. It appears that steam explosion increases cellulose digestibility in P. radiata by increasing fiber porosity.

Limbic-thalamo-cortical projections and reward-related circuitry integrity affects eating behavior: A longitudinal DTI study in adolescents with restrictive eating disorders.

Directory of Open Access Journals (Sweden)

Gaia Olivo

Full Text Available Few studies have used diffusion tensor imaging (DTI to investigate the micro-structural alterations of WM in patients with restrictive eating disorders (rED, and longitudinal data are lacking. Twelve patients with rED were scanned at diagnosis and after one year of family-based treatment, and compared to twenty-four healthy controls (HCs through DTI analysis. A tract-based spatial statistics procedure was used to investigate diffusivity parameters: fractional anisotropy (FA and mean, radial and axial diffusivities (MD, RD and AD, respectively. Reduced FA and increased RD were found in patients at baseline in the corpus callosum, corona radiata and posterior thalamic radiation compared with controls. However, no differences were found between follow-up patients and controls, suggesting a partial normalization of the diffusivity parameters. In patients, trends for a negative correlation were found between the baseline FA of the right anterior corona radiata and the Eating Disorder Examination Questionnaire total score, while a positive trend was found between the baseline FA in the splenium of corpus callosum and the weight loss occurred between maximal documented weight and time of admission. A positive trend for correlation was also found between baseline FA in the right anterior corona radiata and the decrease in the Obsessive-Compulsive Inventory Revised total score over time. Our results suggest that the integrity of the limbic-thalamo-cortical projections and the reward-related circuitry are important for cognitive control processes and reward responsiveness in regulating eating behavior.

Joint Soviet-French studies of the solar corona. II - Photometry of the solar corona on June 30, 1973

Science.gov (United States)

Vsekhsvyatsky, S. K.; Dzyubenko, N. I.; Ivanchuk, V. I.; Popov, O. S.; Rubo, G. A.; Koutchmy, S.; Koutchmy, O.; Shtelmacher, G.

1981-04-01

Results are presented of a study of negatives obtained on June 30, 1973 during the total solar eclipse in Africa; the study was part of a joint Soviet-French experiment on white corona dynamics, carried out by expeditions of Kiev University (Atar, Mauritania) and the Paris Astrophysical Institute (Moussoro, Chad). The distribution of total corona brightness up to 4.5 solar radii and its K and F corona components for east and north directions were found on the basis of novel methods of photometry and colorimetry using star images up to 8.5m as the photometry standards. Neither the color effect nor flattening is found in the inner part (less than 2.5 solar radii) of the F corona. Integral corona brightness in the standard zone of 1.03-6.00 solar radii was found to be 0.64 x 10 to the -6th solar-E.

Ions mobilities in corona discharge

International Nuclear Information System (INIS)

Bakhtaev, Sh. A.; Bochkareva, G. V.; Sydykova, G. K.

2000-01-01

Ion mobility in unipolar corona at small inter-electron distances (up to 0.01 m) when as coroning element serves micro-wire is consider. Experimental data of ion mobility in corona discharge external zone in atmospheric air are obtained and its comparative analysis with known data is worked out. (author)

Chaotic characteristics of corona discharges in atmospheric air

International Nuclear Information System (INIS)

Tan Xiangyu; Zhang Qiaogen; Wang Xiuhuan; Sun Fu; Zha Wei; Jia Zhijie

2008-01-01

A point-plane electrode system in atmospheric air is established to investigate the mechanism of the corona discharge. By using this system, the current pulses of the corona discharges under the 50 Hz ac voltage are measured using partial discharge (PD) measurement instrument and constitute the point-plane voltage-current (V-I) characteristic equation together with the voltage. Then, this paper constructs the nonlinear circuit model and differential equations of the system in an attempt to give the underlying dynamic mechanism based on the nonlinear V-I characteristics of the point-plane corona discharges. The results show that the chaotic phenomenon is found in the corona circuit by the experimental study and nonlinear dynamic analysis. The basic dynamic characteristics, including the Lyapunov exponent, the existence of the strange attractors, and the equilibrium points, are also found and analyzed in the development process of the corona circuit. Moreover, the time series of the corona current pulses obtained in the experiment is used to demonstrate the chaotic characteristics of the corona current based on the nonlinear dynamic circuit theory and the experimental basis. It is pointed out that the corona phenomenon is not a purely stochastic phenomenon but a short term deterministic chaotic activity

Characteristics of pulse corona discharge over water surface

Science.gov (United States)

Fujii, Tomio; Arao, Yasushi; Rea, Massimo

2008-12-01

Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed more ozone production than the negative one both in the DC and in the pulse corona.

Characteristics of pulse corona discharge over water surface

International Nuclear Information System (INIS)

Fujii, Tomio; Arao, Yasushi; Rea, Massimo

2008-01-01

Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO 2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed more ozone production than the negative one both in the DC and in the pulse corona.

EFFECTIVENESS OF A SUPERFICIAL TREATMENT USING BIFENTHRIN TO PROTECT RADIATA PINE FRAMING FROM DAMAGE BY SUBTERRANEAN AND DRYWOOD TERMITES IN INDONESIA

OpenAIRE

Paimin Sukartana; Jim W. Creffield; Agus Ismanto; Neo E. Lelana; Rusti Rushelia

2010-01-01

Various experimental testing procedures were undertaken in Indonesia to determine the effectiveness of a patented superficial (envelope) treatment using bifenthrin to protect radiata pine framing material from damage by two species of subterranean termites (Macrotermes gilvus and Coptotermes curvignathus) and one species of drywood termite (Cryptotermes cynocephalus). Lengths of framing material (Pinus radiata sapwood) were commercially treated to the targeted retention of 0.02% m/m of bifent...

The nanoparticle biomolecule corona: lessons learned - challenge accepted?

Science.gov (United States)

Docter, D; Westmeier, D; Markiewicz, M; Stolte, S; Knauer, S K; Stauber, R H

2015-10-07

Besides the wide use of engineered nanomaterials (NMs) in technical products, their applications are not only increasing in biotechnology and biomedicine, but also in the environmental field. While the physico-chemical properties and behaviour of NMs can be characterized accurately under idealized conditions, this is no longer the case in complex physiological or natural environments. Herein, proteins and other biomolecules rapidly bind to NMs, forming a protein/biomolecule corona that critically affects the NMs' (patho)biological and technical identities. As the corona impacts the in vitro and/or in vivo NM applications in humans and ecosystems, a mechanistic understanding of its relevance and of the biophysical forces regulating corona formation is mandatory. Based on recent insights, we here critically review and present an updated concept of corona formation and evolution. We comment on how corona signatures may be linked to effects at the nano-bio interface in physiological and environmental systems. In order to comprehensively analyse corona profiles and to mechanistically understand the coronas' biological/ecological impact, we present a tiered multidisciplinary approach. To stimulate progress in this field, we introduce the potential impact of the corona for NM-microbiome-(human)host interactions and the novel concept of 'nanologicals', i.e., the nanomaterial-specific targeting of molecular machines. We conclude by discussing the relevant challenges that still need to be resolved in this field.

Altered Brain Microstructure Assessed by Diffusion Tensor Imaging in Patients With Diabetes Mellitus and Gastrointestinal Symptoms

DEFF Research Database (Denmark)

Frøkjær, Jens Brøndum; Andersen, Lars Wiuff; Brock, Christina

2012-01-01

= 0.002) insula. No difference was found in corpus callosum (P > 0.05). The microstructural changes in some areas correlated with clinical parameters such as bloating (anterior insula), mental well-being (anterior insula, prefrontal cortex, and mid-cingulated and corona radiata), autonomic function...

Progress towards initiation of somatic embryogenesis from differentiated tissues of radiata pine (Pinus radiata D. Don) using cotyledonary embryos

DEFF Research Database (Denmark)

Find, Jens Iver; Hargreaves, Cathy L.; Reeves, Catherine B.

2014-01-01

of dissected embryos and a modified Litvay medium, Glitz, was best. This combination gave the highest rate of initiation, and it was possible to initiate somatic embryogenesis (SE) from differentiated cells in the epicotyledonary region of postcotyledonary zygotic embryos from the two tested families...... with an average initiation rate of approximately 24% and 7% from stage five and six embryos, respectively. This is different from established initiation protocols of embryogenic cultures in radiata pine, which has traditionally been based on embryo rescue and continued proliferation of immature zygotic embryos....... A further implication of initiation of SE from excised post-cotyledonary embryos was that the period of initiation of embryogenic cultures was extended from 4 to 12 wk....

Equilibrium moisture content of radiata pine at elevated temperature and pressure reveals measurement challenges

DEFF Research Database (Denmark)

Pearson, Hamish; Gabbitas, Brian; Ormarsson, Sigurdur

2012-01-01

moisture contents were attributed to condensation of liquid water on the specimen with subsequent evaporation at a rate that was too slow for the moisture content to reach equilibrium before it was measured. Reliable EMC data at elevated temperatures require (1) tight process control of experimental......Relatively few studies have been performed on the equilibrium moisture content (EMC) of wood under conditions of elevated temperature and pressure. Eight studies indicated that EMC near saturation decreased between 100 and 150 °C, whilst five studies indicated that EMC increased. The aim...... of this study was to identify the likely source of the disagreement using radiata pine (Pinus radiata D. Don) sapwood which was conditioned to a moisture content of around 3 % and then exposed for 1 h at 150 °C and relative humidities of either 50, 70 or 90 %. Mean values of EMC, obtained through in situ...

Alargamiento de corona clínica por erupción pasiva alterada

OpenAIRE

Reyes Doimi, Juan; Cervantes Yabar, Priscilla; Noriega Castañeda, Jorge

2011-01-01

Caso clínico Las alteraciones en la erupción pasiva en las que la corona anatómica del diente se ve cubierta por un exceso de tejido blando son situaciones que se presentan muy a menudo. Son en ocasiones difíciles de diagnosticar y hoy en día están adquiriendo relevancia clínica debido al aumento de la demanda de tratamientos de odontología estética. El exceso de encía al sonreír depende de muchos factores, como la excesiva dimensión vertical del maxilar superior y las malposicion...

A guide to the solar corona

CERN Document Server

Billings, Donald E

1966-01-01

A Guide to the Solar Corona is specifically directed to the space scientist or engineer who is not a specialist in solar physics, but whose work requires a fairly detailed knowledge of the corona. It is hoped that the material may prove useful to most graduate students in astrophysics, while solar physicists may find some topics of interest and value to them. The book contains 12 chapters and begins with three descriptive chapters that provide the casual reader with a concept of the corona as it is evident through more or less direct observation. Topics covered include the development of coron

Lack of genetic variation in tree ring delta13C suggests a uniform, stomatally-driven response to drought stress across Pinus radiata genotypes.

Science.gov (United States)

Rowell, Douglas M; Ades, Peter K; Tausz, Michael; Arndt, Stefan K; Adams, Mark A

2009-02-01

We assessed the variation in delta(13)C signatures of Pinus radiata D. Don stemwood taken from three genetic trials in southern Australia. We sought to determine the potential of using delta(13)C signatures as selection criteria for drought tolerance. Increment cores were taken from P. radiata and were used to determine the basal area increment and the delta(13)C signature of extracted cellulose. Both growth increment and cellulose delta(13)C were affected by water availability. Growth increment and delta(13)C were negatively correlated suggesting that growth was water-limited. While there was significant genetic variation in growth, there was no significant genetic variation in cellulose delta(13)C of tree rings. This suggests that different genotypes of P. radiata display significant differences in growth and yet respond similarly to drought stress. The delta(13)C response to drought stress was more due to changes in stomatal conductance than to the variation in photosynthetic capacity, and this may explain the lack of genetic variation in delta(13)C. The lack of genetic variation in cellulose delta(13)C of tree rings precludes its use as a selection criterion for drought tolerance among P. radiata genotypes.

The Safe Area in the Parieto-Occipital Lobe in the Human Brain: Diffusion Tensor Tractography.

Science.gov (United States)

Jang, Sung Ho; Kim, Seong Ho; Kwon, Hyeok Gyu

2015-06-01

A recent study reported on the relatively safe area in the frontal lobe for performance of neurological interventions; however, no study on the posterior safe area has been reported. In this study, using diffusion tensor tractography, we attempted to identify the safe area in the parieto-occipital lobe in healthy subjects. A total of 47 healthy subjects were recruited for this study. Eleven neural tracts were reconstructed in and around the parieto-occipital area of the brain using diffusion tensor tractography. The safe area, which is free from any trajectory of 10 neural tracts, was measured anteriorly and medially from the line of the most posterior and lateral margin of the brain at 5 axial levels (from the cerebral cortex to the corona radiata). The anterior boundaries of the safe area in the upper cerebral cortex, lower cerebral cortex, centrum semiovale, upper corona radiata, and lower corona radiata levels were located at 31.0, 32.6, 32.7, 35.1, and 35.2 mm anteriorly from the line of the most posterior margin of the brain, respectively, and the medial boundaries were located at an average of 34.7, 38.1, 39.2, 36.1, and 33.6 mm medially from the line of the most lateral margin of the brain, respectively. According to our findings, the safe area was located in the posterolateral portion of the parieto-occipital lobe in the shape of a triangle. However, we found no safe area in the deep white matter around the lateral ventricle. Copyright © 2015 Elsevier Inc. All rights reserved.

Modeling of Trichel pulses in negative corona

International Nuclear Information System (INIS)

Napartovich, A.P.; Akishev, Yu. S.; Deryugin, A.A.; Kochetov, I.V.; Pan'kin, M.V.; Trushkin, N.I.

1998-01-01

Results are reported of detailed numerical studies of Trichel pulse formation for dry air in short-gap coronas. Continuity equations for electrons, positive and negative ions, and the Poisson equation averaged over the current cross section were solved numerically with appropriate boundary conditions. The results of numerical simulation make it possible to analyze in detail the trailing edge of the Trichel pulse and the inter-pulse pause determining the period between pulses. In particular, the variations of the total number of negative ions in the corona spacing occurring under typical conditions of a pulsating corona, proved to be quite insignificant. A comparison with experiments demonstrated a reasonable agreement both for the shape of the pulse and for the average characteristics of the negative corona. (J.U.)

Pulsed Corona Discharge Generated By Marx Generator

Science.gov (United States)

Sretenovic, G. B.; Obradovic, B. M.; Kovacevic, V. V.; Kuraica, M. M.; Puric J.

2010-07-01

The pulsed plasma has a significant role in new environmental protection technologies. As a part of a pulsed corona system for pollution control applications, Marx type repetitive pulse generator was constructed and tested in arrangement with wire-plate corona reactor. We performed electrical measurements, and obtained voltage and current signals, and also power and energy delivered per pulse. Ozone formation by streamer plasma in air was chosen to monitor chemical activity of the pulsed corona discharge.

Polyamine levels during the development of zygotic and somatic embryos of Pinus radiata

Science.gov (United States)

Rakesh Minocha; Dale R. Smith; Cathie Reeves; Kevin D. Steele; Subhash C. Minocha

1999-01-01

Changes in the cellular content of three polyamines (putrescine, spermidine and spermine) were compared at different stages of development in zygotic and somatic embryos of Pinus radiata D. Don. During embryo development, both the zygotic and the somatic embryos showed a steady increase in spermidine content, with either a small decrease or no...

Mechanism of Resistance in Mungbean [Vigna radiata (L. R. Wilczek var. radiata] to bruchids, Callosobruchus spp. (Coleoptera: Bruchidae

Directory of Open Access Journals (Sweden)

Abdul R. War

2017-06-01

Full Text Available Mungbean [Vigna radiata (L. R. Wilczek var. radiata] is an important pulse crop in Asia, and is consumed as dry seeds and as bean sprouts. It is an excellent source of digestible protein. Bruchids [Callosobruchus chinensis (L. and Callosobruchus maculatus (F.] are the important pests of mungbean and cause damage in the field and in storage. Bruchid infestation reduces the nutritional and market value of the grain and renders seeds unfit for human consumption, agricultural and commercial uses. These pests are controlled mainly by fumigation with highly toxic chemicals such as carbon disulfide, phosphene, and methyl bromide, or by dusting with several other insecticides, which leave residues on the grain, thus, threatening food safety. Some plant-based extracts have been found useful in controlling bruchids, but are not fully successful due to their short-term activity, rapid degradability, and potentially negative effect on seed germination. Although some wild sources of bruchid resistance in mungbean have been reported, which have been used to develop bruchid- resistant lines, undesirable genetic linkages threaten the proper exploitation of genetic diversity from wild germplasm into commercial cultivars. Further, biotype variation in bruchids has rendered some mungbean lines susceptible that otherwise would have been resistant to the pest. Host plant resistance is a cost-effective and a safe alternative to control bruchids in mungbean and is associated with morphological, biochemical, and molecular traits. These traits affect insect growth and development, thereby, reduce the yield losses by the pests. Understanding the defense mechanisms against insect pests could be utilized in exploiting these traits in crop breeding. This review discusses different traits in mungbean involved in defense against bruchids and their utility in pest management. We also highlight the breeding constraints for developing bruchid-resistant mungbean and how can these

Corona Associations and Their Implications for Venus

Science.gov (United States)

Chapman, M.G.; Zimbelman, J.R.

1998-01-01

Geologic mapping principles were applied to determine genetic relations between coronae and surrounding geomorphologic features within two study areas in order to better understand venusian coronae. The study areas contain coronae in a cluster versus a contrasting chain and are (1) directly west of Phoebe Regio (quadrangle V-40; centered at latitude 15??S, longitude 250??) and (2) west of Asteria and Beta Regiones (between latitude 23??N, longitude 239?? and latitude 43??N, longitude 275??). Results of this research indicate two groups of coronae on Venus: (1) those that are older and nearly coeval with regional plains, and occur globally; and (2) those that are younger and occur between Beta, Atla, and Themis Regiones or along extensional rifts elsewhere, sometimes showing systematic age progressions. Mapping relations and Earth analogs suggest that older plains coronae may be related to a near-global resurfacing event perhaps initiated by a mantle superplume or plumes. Younger coronae of this study that show age progression may be related to (1) a tectonic junction of connecting rifts resulting from local mantle upwelling and spread of a quasi-stationary hotspot plume, and (2) localized spread of post-plains volcanism. We postulate that on Venus most of the young, post-resurfacing coronal plumes may be concentrated within an area defined by the bounds of Beta, Atla, and Themis Regiones. ?? 1998 Academic Press.

Host range testing of Tamarixia radiata (Hymenoptera: Eulophidae) sourced from the Punjab of Pakistan for classical biological control of Diaphorina citri (Hemiptera: Liviidae: Euphyllurinae: Diaphorinini) in California.

Science.gov (United States)

Hoddle, Mark S; Pandey, Raju

2014-02-01

ABSTRACT Tests evaluating the host range of Tamarixia radiata (Waterson) (Hymenoptera: Eulophidae), a parasitoid of the pestiferous Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), sourced from the Punjab of Pakistan, were conducted in quarantine at the University of California, Riverside, CA. Seven nontarget psyllid species (five native and two self-introduced species) representing five families were exposed to T radiata under the following three different exposure scenarios: 1) sequential no-choice tests, 2) static no-choice tests, and 3) choice tests. Nontarget species were selected for testing based on the following criteria: 1) taxonomic relatedness to the target, D. citri; 2) native psyllids inhabiting native host plants related to citrus that could release volatiles attractive to T. radiata; 3) native psyllids with a high probability of occurrence in native vegetation surrounding commercial citrus groves that could be encountered by T. radiata emigrating from D. citri-infested citrus orchards; 4) a common native pest psyllid species; and 5) a beneficial psyllid attacking a noxious weed. The results of host range testing were unambiguous; T radiata exhibited a narrow host range and high host specificity, with just one species of nontarget psyllid, the abundant native pest Bactericera cockerelli Sulc, being parasitized at low levels (citri poses negligible environmental risk.

Identification of Bradyrhizobium elkanii Genes Involved in Incompatibility with Vigna radiata

Directory of Open Access Journals (Sweden)

Hien P. Nguyen

2017-12-01

Full Text Available The establishment of a root nodule symbiosis between a leguminous plant and a rhizobium requires complex molecular interactions between the two partners. Compatible interactions lead to the formation of nitrogen-fixing nodules, however, some legumes exhibit incompatibility with specific rhizobial strains and restrict nodulation by the strains. Bradyrhizobium elkanii USDA61 is incompatible with mung bean (Vigna radiata cv. KPS1 and soybean cultivars carrying the Rj4 allele. Here, we explored genetic loci in USDA61 that determine incompatibility with V. radiata KPS1. We identified five novel B. elkanii genes that contribute to this incompatibility. Four of these genes also control incompatibility with soybean cultivars carrying the Rj4 allele, suggesting that a common mechanism underlies nodulation restriction in both legumes. The fifth gene encodes a hypothetical protein that contains a tts box in its promoter region. The tts box is conserved in genes encoding the type III secretion system (T3SS, which is known for its delivery of virulence effectors by pathogenic bacteria. These findings revealed both common and unique genes that are involved in the incompatibility of B. elkanii with mung bean and soybean. Of particular interest is the novel T3SS-related gene, which causes incompatibility specifically with mung bean cv. KPS1.

Bark polyflavonoids from Pinus radiata as functional building-blocks for polylactic acid (PLA-based green composites

Directory of Open Access Journals (Sweden)

D. E. Garcia

2016-10-01

Full Text Available Polylactic acid (PLA was melt-blended with Pinus radiata unmodified and modified (hydroxypropyled bark polyflavonoids in order to use such polyphenolic building-blocks as functional additives for envisaged applications. Rheological, morphological, molecular, thermal, and flexural properties were studied. Polyflavonoids improved blend processability in terms of short-time mixing. Furthermore, hydroxypropylated polyflavonoids improve miscibility in binary and ternary blends. Blend-composition affects crystallization-, melting-, and glass transition-temperature of PLA, as well as thermal resistance, and flexural properties of the blends. Polyflavonoids induced PLA-crystallization, and polymer-chain decomposition. Modified and unmodified bark polyflavonoids from radiata pine can be used successfully in PLA-based green composites beyond the food-packaging applications. The high compatibility between PLA and hydroxypropyled polyflavonoids highlights the potential of such phenolic derivatives for PLA-based material design.

Effect of Pinus radiata derived biochars on soil sorption and desorption of phenanthrene

International Nuclear Information System (INIS)

Zhang Honghua; Lin Kunde; Wang Hailong; Gan, Jay

2010-01-01

Biochars are anthropogenic carbonaceous sorbent and their influences on the sorption of environmental contaminants need to be characterized. Here we evaluated the effect of Pinus radiata derived biochars on soil sorption and desorption of phenanthrene. Two biochars separately produced at 350 o C and 700 o C and three soils were tested. Biochar amendment generally enhanced the soil sorption of phenanthrene. The biochar produced at 700 o C generally showed a greater ability at enhancing a soil's sorption ability than that prepared at 350 o C. The single-step desorption measurement showed an apparent hysteresis in biochar-amended soils. After 28 d equilibration, the sorptive capacity of biochar-amended soil (with an organic carbon content of 0.16%) significantly decreased. This study clearly suggested that biochar application enhanced soil sorption of hydrophobic organic compounds, but the magnitude of enhancement depended on the preparation of biochars, the indigenous soil organic carbon levels, and the contact time between soil and biochar. - Pinus radiata derived biochars influence soil sorption and desorption of phenanthrene.

Pulsed corona demonstrator for semi-industrial scale air purification

NARCIS (Netherlands)

Beckers, F.J.C.M.; Hoeben, W.F.L.M.; Huiskamp, T.; Pemen, A.J.M.; Heesch, van E.J.M.

2013-01-01

Although pulsed corona technology for air purification is widely investigated by the lab experiments, large-scale application has yet to be proven. Industrial systems require large flow handling and thus, high corona power. An autonomous semi-industrial scale pilot wire-cylinder type corona reactor

Role of cumulus cells during vitrification and fertilization of mature bovine oocytes

NARCIS (Netherlands)

Ortiz-Escribano, N.; Smits, K.; Piepers, S.; Abbeel, Van den E.; Woelders, H.; Soom, Van A.

2016-01-01

This study was designed to determine the role of cumulus cells during vitrification of bovine oocytes. Mature cumulus-oocyte complexes (COCs) with many layers of cumulus cells, corona radiata oocytes (CRs), with a few layers of cumulus cells, and denuded oocytes (DOs) without cumulus cells were

Natural parasitism of Diaphorina citri Kuwayama (Hemiptera, Psyllidae nymphs by Tamarixia radiata Waterston (Hymenoptera, Eulophidae in São Paulo orange groves Parasitismo natural de ninfas de Diaphorina citri Kuwayama (Hemiptera, Psyllidae por Tamarixia radiata Waterston (Hymenoptera, Eulophidae em pomares de laranja em São Paulo

Directory of Open Access Journals (Sweden)

Paulo Eduardo Branco Paiva

2012-12-01

Full Text Available The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922 in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72% of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March, with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.O psilídeo Diaphorina citri Kuwayama 1908 tornou-se a principal praga dos citros no estado de São Paulo após a introdução do huanglongbing ou grenning dos citros. Este estudo avaliou as proporções de ninfas de terceiro a quinto ínstares de D. citri parasitadas por Tamarixia radiata (Waterston, 1922 em pomares de laranja submetidos a pulverizações constantes de inseticidas em dez regiões produtoras, Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins e São João da Boa Vista. Foram coletadas 69 amostras de ramos jovens infestados com ninfas de D. citri obtidas entre 2005 e 2008 em pomares de 1 a 20 anos de idade, das cultivares Hamilin, Pera, Valencia e Natal. O parasitóide T. radiata encontra-se amplamente distribuído em pomares de São Paulo, tendo sido observado em 50 amostras (72%, com taxa média de

Ocean acidification reverses the positive effects of seawater pH fluctuations on growth and photosynthesis of the habitat-forming kelp, Ecklonia radiata.

Science.gov (United States)

Britton, Damon; Cornwall, Christopher E; Revill, Andrew T; Hurd, Catriona L; Johnson, Craig R

2016-05-27

Ocean acidification (OA) is the reduction in seawater pH due to the absorption of human-released CO2 by the world's oceans. The average surface oceanic pH is predicted to decline by 0.4 units by 2100. However, kelp metabolically modifies seawater pH via photosynthesis and respiration in some temperate coastal systems, resulting in daily pH fluctuations of up to ±0.45 units. It is unknown how these fluctuations in pH influence the growth and physiology of the kelp, or how this might change with OA. In laboratory experiments that mimicked the most extreme pH fluctuations measured within beds of the canopy-forming kelp Ecklonia radiata in Tasmania, the growth and photosynthetic rates of juvenile E. radiata were greater under fluctuating pH (8.4 in the day, 7.8 at night) than in static pH treatments (8.4, 8.1, 7.8). However, pH fluctuations had no effect on growth rates and a negative effect on photosynthesis when the mean pH of each treatment was reduced by 0.3 units. Currently, pH fluctuations have a positive effect on E. radiata but this effect could be reversed in the future under OA, which is likely to impact the future ecological dynamics and productivity of habitats dominated by E. radiata.

Off-limb EUV observations of the solar corona and transients with the CORONAS-F/SPIRIT telescope-coronagraph

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V. Slemzin

2008-10-01

Full Text Available The SPIRIT telescope aboard the CORONAS-F satellite (in orbit from 26 July 2001 to 5 December 2005, observed the off-limb solar corona in the 175 Å (Fe IX, X and XI lines and 304 Å (He II and Si XI lines bands. In the coronagraphic mode the mirror was tilted to image the corona at the distance of 1.1...5 R_sun from the solar center, the outer occulter blocked the disk radiation and the detector sensitivity was enhanced. This intermediate region between the fields of view of ordinary extreme-ultraviolet (EUV telescopes and most of the white-light (WL coronagraphs is responsible for forming the streamer belt, acceleration of ejected matter and emergence of slow and fast solar wind. We present here the results of continuous coronagraphic EUV observations of the solar corona carried out during two weeks in June and December 2002. The images showed a "diffuse" (unresolved component of the corona seen in both bands, and non-radial, ray-like structures seen only in the 175 Å band, which can be associated with a streamer base. The correlations between latitudinal distributions of the EUV brightness in the corona and at the limb were found to be high in 304 Å at all distances and in 175 Å only below 1.5 R_sun. The temporal correlation of the coronal brightness along the west radial line, with the brightness at the underlying limb region was significant in both bands, independent of the distance. On 2 February 2003 SPIRIT observed an expansion of a transient associated with a prominence eruption seen only in the 304 Å band. The SPIRIT data have been compared with the corresponding data of the SOHO LASCO, EIT and UVCS instruments.

Characterization of seasonal reproductive and stress steroid hormones in wild Radiated Tortoises, Astrochelys radiata.

Science.gov (United States)

Currylow, Andrea F T; Rafeliarisoa, Tsilavo H; Louis, Edward E; Stanford, Craig B; Randrianjafizanaka, Soary T; Chinn, Sarah M; Crocker, Daniel E

2017-11-01

The critically endangered Radiated Tortoise (Astrochelys radiata) is endemic to the southern coastlines of Madagascar. Once common, wild populations of this tortoise have undergone dramatic declines in recent years. Although there have been studies documenting reproductive activities, reproductive physiological parameters are unknown yet may be crucial in the recovery of the species. Over four research seasons in remote field locations native to A. radiata, we surveyed for, radio-tracked, and sampled wild, free ranging tortoises. We sampled and measured stress and reproductive parameters (corticosterone [CORT], testosterone [T], estradiol-17β [E2], and progesterone [P]) in 311 plasma samples from 203 wild A. radiata, capturing their active period. Generally, hormone concentrations were associated with body condition, temperature, and humidity. There was wide variation in CORT that varied monthly and by group. Juvenile tortoises maintained more than twice the mean basal CORT concentrations than either adult sex, with the most dramatic distinctions in the middle of the wet season. For adult sex hormones, the last months of the dry season and into the wet season when ground humidities are low and just begin to rise prior to temperature declines, male T concentrations gradually increased to a peak before returning to near undetectable values into the dry season. We had limited data for T concentrations in females, but found average T concentrations were much lower than in males and positively correlated with larger female home range sizes. For female hormone cycles, E2 also peaked in the early 1/3 of the wet season along with male T, and was followed by an uptick in P which correlates to the putative ovulatory cycle. Females tracked over four years showed variation in patterns of P, indicating that number and frequency of clutches vary. Our results suggest that 1) there is high species plasticity in response to stress; 2) A. radiata reproductive cycling is somewhat

Enhancing Growth of Vigna radiata in the Presence of Pseudomonas aeruginosa Biopolymer and Metarhizium anisopliae Spores

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Bhagwan N. Rekadwad

2016-01-01

Full Text Available Exopolysaccharide producing Pseudomonas aeruginosa NCIM 2945 (PANCL belonging to gamma-proteobacterium and entomopathogenic fungus Metarhizium anisopliae MCC 1129 (MAMCC belonging to Ascomycota were studied for their morphological features biochemical characteristics and plant growth promotion ability. Optimum growth of PANCL was recorded after 24 h at temperature 30°C and pH 7.0. Gram-negative PANCL appeared as white in color, one mm size, circular, opaque, and nonconsistent elevated colonies with entire margin. It has utilized dextrose, fructose, maltose, and sorbitol as carbon source and produced acid in the medium. PANCL was sensitive to Polymyxin B (300 µgm/disc followed by Neomycin (30 µgm/disc, Gentamycin (10 µgm/disc, and Chloramphenicol (30 µgm/disc. PANCL has secreted extracellular lipase, amylase, protease, and exopolysaccharides (EPS. Another fungal strain MAMCC sporulated after 168 h at temperature 30°C and pH 7.0. MAMCC has septate-white mycelium and bears dirty green colored spores. Growth of MAMCC was enhanced in the presence of Neem and Karela-Amla oil (0.1 mL each. Extracellular polysaccharide produced by PANCL and spores of MAMCC promoted growth of dicotyledon Vigna radiata (Mung individually as well as in consortium. Considerable increase in dry weight of Vigna radiata was recorded. Thus, reported PANCL and MAMCC strains have promoted growth Vigna radiata and may be a solution for sustainable agriculture.

Admittance Survey of Type 1 Coronae on Venus: Implications for Elastic Thickness

Science.gov (United States)

Hoogenboom, T.; Smrekar, S. E.; Anderson, F. S.; Houseman, G.

2003-01-01

Coronae are volcano-tectonic features on Venus which range from 60km to 2600km and are defined by their nearly circular patterns of fractures. Type 1 (regular) coronae are classified as having >50% complete fracture annuli. Previous work has examined the factors controlling the morphology, size, and fracture pattern of coronae, using lithospheric properties, loading signature and geologic characteristics. However, these studies have been limited to Type 2 (topographic) coronae (e.g. coronaes with <50% fracture annuli), and the factors controlling the formation of Type 1 coronae remain poorly understood. In this study, we apply the methodology of to survey the admittance signature for Type 1 coronae to determine the controlling parameters which govern Type 1 coronae formation.

Productivity and cost of harvesting a stemwood biomass product from integrated cut-to-length harvest operations in Australian Pinus radiata plantations

International Nuclear Information System (INIS)

Walsh, D.; Strandgard, M.

2014-01-01

Significant quantities of woody biomass from the tops of trees and larger woody ‘waste’ pieces that fall outside existing sawlog and pulpwood specifications are left on site post final harvest in Australian radiata Pinus radiata (D. Don) (radiata pine) plantations. Woody biomass is a potential product for pulp making or energy generation. Commercial use of woody biomass from radiata pine plantations would add extra value to the Australian plantation estate through improved resource utilisation, and potentially reduced post-harvesting silvicultural costs. This study investigated the productivity and cost impact of the harvest and extraction to roadside of woody biomass in an integrated harvest operation in a typical Australian two machine (harvester/processor and forwarder), cut-to-length, clearfall operation in a mature, thinned radiata pine plantation. The harvest operation yielded 23 GMt/ha (5% of the total yield) of woody biomass (known as ‘fibreplus’), 443 GMt/ha of sawlogs and 28 GMt/ha of pulpwood. The mean quantity of biomass left on site was 128 GMt/ha, mainly consisting of branches and needles, sufficient to minimise nutrient loss and protect the soil from erosion. Woodchips derived from the fibreplus product were suitable for kraft pulp making, (when blended in small amounts with clean de-barked roundwood woodchips), and for energy generation. The method trialed with the fibreplus product being produced did not impact harvesting and processing productivity and costs, but extraction was 14% less productive. Through analysis of the productivities of each phase and development of a cost model the harvest and extraction of the fibreplus product was estimated to increase total unit costs by ∼4.9%. - Highlights: • Study of the productivity and cost impact of producing a woody biomass product. • We compared two scenarios – harvesting with and without the biomass product. • An additional 23 GMt/ha (5% of the total yield) of woody biomass

Contrasting Effects of Aqueous Tissue Extracts from an Invasive Plant, Bidens pilosa L. var. radiata, on the Performance of Its Sympatric Plant Species

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Hsiao-Mei Hsu

2009-09-01

Full Text Available Bidens pilosa L. var. radiata Sch. Bip., a common weed in lowland Taiwan, is listed as one of the twenty most noxious invasive plants in Taiwan. In this study, we examined the effect of aqueous extracts of leaves, stems and roots of the invasive plant on germination and growth of seedlings (estimated by measuring the elongation of hypocotyls and radicals of the same species and two other sympatric species, B. bipinnata and Ageraturem conyzoides. The objective of this study was to understand whether the aqueous tissue extracts affected the performance of the target species and whether these effects varied among tissue types and among target species. We found that the germination percentage of seeds of B. bipinnata was significantly reduced by root and leaf extracts, that of B. pilosa var. radiata was also significantly reduced by the application of root extract, while that of A. conyzoides was not affected by any of the three tissue extracts. The application of stem and leaf extracts inhibited the elongation of radicals of B. pilosa var. radiata, consequently, the growth of seedlings of this species was decreased in these two treatments. Though the elongation of hypocotyls was stimulated by leaf extract, the overall growth of seedlings of B. bipinnata was not affected by any tissue extract. In contrast, all three extracts stimulated the elongation of hypocotyls and radicals of A. conyzoides, consequently, the overall growth of seedlings of this plant was promoted by all three extracts. These results revealed that aqueous extracts from tissue of B. pilosa var. radiata had differential effect on the emergence and seedling growth of the three target species. The inhibition effect of its root and leaf extracts on the germination of B. bipinnata may partially explain the overwhelming dominance of B. pilosa var. radiata over B. bipinnata when they are sympatric.

Double streamer phenomena in atmospheric pressure low frequency corona plasma

International Nuclear Information System (INIS)

Kim, Dan Bee; Jung, H.; Gweon, B.; Choe, Wonho

2010-01-01

Time-resolved images of an atmospheric pressure corona discharge, generated at 50 kHz in a single pin electrode source, show unique positive and negative corona discharge features: a streamer for the positive period and a glow for the negative period. However, unlike in previous reports of dc pulse and low frequency corona discharges, multistreamers were observed at the initial time stage of the positive corona. A possible physical mechanism for the multistreamers is suggested.

Acoustic waves in M dwarfs: Maintaining a corona

Science.gov (United States)

Mullan, D. J.; Cheng, Q. Q.

1994-01-01

We use a time-dependent hydrodynamics code to follow the propagation of acoustic waves into the corona of an M dwarf star. An important qualitative difference between M dwarfs and stars such as the Sun is that the acoustic spectrum in M dwarfs is expected to peak at periods close to the acoustic cutoff P(sub A): this allows more effective penetration of waves into the corona. In our code, radiative losses in the photosphere, chromosphere, and corona are computed using Rosseland mean opacities, Mg II kappa and Ly alpha emission, and optically thin emissivities respectively. We find that acoustic heating can maintain a corona with a temperature of order 0.7-1 x 10(exp 6) K and a surface X-ray flux as large as 10(exp 5)ergs/sq cm/s. In a recent survey of X-rays from M dwarfs, some (20%-30%) of the stars lie at or below this limiting X-ray flux: we suggest that such stars may be candidates for acoustically maintained coronae.

Acute Toxicity of Fresh and Aged Residues of Pesticides to the Parasitoid Tamarixia radiata and to the HLB-Bacteria Vector Diaphorina citri.

Science.gov (United States)

Beloti, V H; Alves, G R; Moral, R A; Demétrio, C G B; Yamamoto, P T

2018-06-01

One method for controlling the Asian citrus psyllid (ACP) Diaphorina citri Kuwayama, the vector of the putative causal agent of Huanglongbing, uses the parasitoid Tamarixia radiata (Waterston). However, the general intensive use of insecticides has reduced the numbers of this parasitoid. This study evaluated the effect of the residual action of 24 insecticides on T. radiata and also determined the differential toxicity of insecticides to D. citri and T. radiata, using three bioassays. In the first, when adults of the parasitoid were exposed to residues of the 24 insecticides, ten were considered short-life (class 1), six slightly persistent (class 2), five moderately persistent (class 3), and three insecticides were considered persistent (class 4), under the IOBC/WPRS classification system. The second bioassay evaluated the sublethal concentrations of the persistent insecticides (formetanate, dimethoate, spinosad). Increasing the concentrations of the insecticides increased the number that were classified as persistent. In the third bioassay, evaluation of the differential toxicity of eight insecticides to the ACP and the parasitoid showed that chlorpyrifos and bifenthrin were more harmful to T. radiata. Therefore, these two insecticides are not recommended for application at the time of parasitoid release. Cypermethrin, imidacloprid, and dimethoate caused higher mortality of D. citri and are most often recommended in IPM programs. The choice of an insecticide for the control of citrus pests must be made with care, aiming to preserve the natural enemies in the ecosystem, and thereby contribute to the success of biological control.

Lactarius deliciosus and Pinus radiata in New Zealand: towards the development of innovative gourmet mushroom orchards.

Science.gov (United States)

Guerin-Laguette, Alexis; Cummings, Nicholas; Butler, Ruth Catherine; Willows, Anna; Hesom-Williams, Nina; Li, Shuhong; Wang, Yun

2014-10-01

The cultivation of Lactarius deliciosus (saffron milk cap) in New Zealand began in 2002 when fruiting bodies were produced in an Otago plantation of Pinus radiata seedlings artificially mycorrhized by L. deliciosus. In 2007, 42 P. radiata seedlings mycorrhized by L. deliciosus under controlled conditions were planted in a grass field at Plant and Food Research (Lincoln, Canterbury). The effects of pine bark mulch application and initial degree of mycorrhization of seedlings were examined to determine their influence on tree growth, development of mycorrhizae (i.e. their multiplication on the root system and their degree of branching) and fruiting body production. Mulch application increased tree growth significantly over 4 years. High initial mycorrhization slightly stimulated tree growth over 2 years. The initial degree of mycorrhization was positively, but not strongly, related to the persistence and development of L. deliciosus mycorrhizae and rhizomorphs based on root sample analyses 2 years after planting. However, mulching strongly reduced the proportion of highly branched L. deliciosus mycorrhizae compared with poorly ramified ones. A positive correlation was observed between the fruiting of L. deliciosus and the development of mycorrhizae. Mulching delayed the onset of fruiting body production. In 2010, fruiting bodies were produced only from non-mulched trees with eight of these (38 %) producing a total of 12 fruiting bodies. In 2011, 19 non-mulched trees (90 %) and 9 mulched trees (45 %) produced 143 and 47 fruiting bodies, respectively, totalling 190 fruiting bodies. By 2012, 19 non-mulched trees (90 %) and 13 mulched trees (65 %) produced 333 and 236 fruiting bodies, respectively, totalling 569 fruiting bodies (c. 30 kg). This study presents new information on factors influencing the onset of fruiting and the development of yields in a plantation of P. radiata mycorrhized by L. deliciosus. Projected yields as high as c. 300 kg/ha from the

Proteomic analysis of Pinus radiata needles: 2-DE map and protein identification by LC/MS/MS and substitution-tolerant database searching.

Science.gov (United States)

Valledor, Luis; Castillejo, Maria A; Lenz, Christof; Rodríguez, Roberto; Cañal, Maria J; Jorrín, Jesús

2008-07-01

Pinus radiata is one of the most economically important forest tree species, with a worldwide production of around 370 million m (3) of wood per year. Current selection of elite trees to be used in conservation and breeding programes requires the physiological and molecular characterization of available populations. To identify key proteins related to tree growth, productivity and responses to environmental factors, a proteomic approach is being utilized. In this paper, we present the first report of the 2-DE protein reference map of physiologically mature P. radiata needles, as a basis for subsequent differential expression proteomic studies related to growth, development, biomass production and responses to stresses. After TCA/acetone protein extraction of needle tissue, 549 +/- 21 well-resolved spots were detected in Coommassie-stained gels within the 5-8 pH and 10-100 kDa M(r) ranges. The analytical and biological variance determined for 450 spots were of 31 and 42%, respectively. After LC/MS/MS analysis of in-gel tryptic digested spots, proteins were identified by using the novel Paragon algorithm that tolerates amino acid substitution in the first-pass search. It allowed the confident identification of 115 out of the 150 protein spots subjected to MS, quite unusual high percentage for a poor sequence database, as is the case of P. radiata. Proteins were classified into 12 or 18 groups based on their corresponding cell component or biological process/pathway categories, respectively. Carbohydrate metabolism and photosynthetic enzymes predominate in the 2-DE protein profile of P. radiata needles.

Response in water yield to the thinning of Pinus radiata, Pinus patula and Eucalyptus grandis plantations

CSIR Research Space (South Africa)

Lesch, W

1997-12-15

Full Text Available . radiata plantation in the Biesievlei catchment, annual stream flow increased by between 10 and 71% (19-99 mm). These increases persisted for three and two years after the thinning, respectively. A final thinning in the same catchment removed only 22...

Properties of minimum-flux coronae in dwarfs and giants

International Nuclear Information System (INIS)

Mullan, D.J.

1976-01-01

Using a method due to Hearn, we examine the properties of minimum-flux coronae in dwarfs and giants. If the fraction phi of the total stellar luminosity which is used to heat the corona is equal to the solar value phi/sub s/, then red dwarfs must have coronae that are cooler than the solar corona: in UV Ceti, for example, the coronal temperature is a factor 3 less than in the Sun. This is consistent with an independent estimate of coronal temperature in a flare star. If phi=phi/sub s/, main-sequence stars hotter than the Sun have coronae which are hotter than the solar corona. Soft X-rays from Sirius suggest that the coronal temperature in Sirius is indeed hotter than the Sun by a factor of about 40 percent. Giants show an even more marked decrease in coronal temperature at later spectral type than do the dwarfs. We suggest that the reason for the presence of O V emission in β Gem and O VI emission in α Aur, and the absence of O V emission in α Boo and α Tau, is that the coronae in the latter two stars are cooler (rather than hotter, as McClintock et al. have suggested) than in the former two. Our results explain why it is more likely that mass loss has been detected in α Aur and α Boo, but not in α Tau or β Gem. Using a simple flare model, we show that flares in both a dwarf star (UV Ceti) and a giant (α Aur) were initiated not in the corona, but in the transition region

Study of the effects of gamma sterilization on a bio material potential bone substitute: the nacre of Pinctada radiata (Leach, 1814)

International Nuclear Information System (INIS)

Ben Ammar, Rim

2010-01-01

In this work, we studied the effects of gamma irradiation at a dose of 25 kGy on physico-chemical properties of the nacre of the pearl oyster P. radiata Tunisian coast. The aim of our work is, after sterilizing the shell to gamma radiation, the study of its crystal structure, behavior and thermodynamics of the qualitative and quantitative composition of organic and inorganic matrices and compare them with those of the non-irradiated pearl . In addition, there has been interest in developing the method of sterilization with gamma irradiation to 25 kGy of the nacre of the pearl oyster Pinctada radiata.

Equitable Colorings Of Corona Multiproducts Of Graphs

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Furmánczyk Hanna

2017-11-01

Full Text Available A graph is equitably k-colorable if its vertices can be partitioned into k independent sets in such a way that the numbers of vertices in any two sets differ by at most one. The smallest k for which such a coloring exists is known as the equitable chromatic number of G and denoted by =(G. It is known that the problem of computation of =(G is NP-hard in general and remains so for corona graphs. In this paper we consider the same model of coloring in the case of corona multiproducts of graphs. In particular, we obtain some results regarding the equitable chromatic number for the l-corona product G ◦l H, where G is an equitably 3- or 4-colorable graph and H is an r-partite graph, a cycle or a complete graph. Our proofs are mostly constructive in that they lead to polynomial algorithms for equitable coloring of such graph products provided that there is given an equitable coloring of G. Moreover, we confirm the Equitable Coloring Conjecture for corona products of such graphs. This paper extends the results from [H. Furmánczyk, K. Kaliraj, M. Kubale and V.J. Vivin, Equitable coloring of corona products of graphs, Adv. Appl. Discrete Math. 11 (2013 103–120].

Implante transalveolar en sustitución de una corona espiga de pronóstico dudoso*

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Josefina Fajardo Puig

Full Text Available La sustitución de los dientes perdidos en la región estética presenta un complejo desafío debido a la dificultad en la reforma de la apariencia natural y de la anatomía papilar. Se Presenta un caso clínico donde se sustituyó un diente con corona espiga de pronóstico dudoso, por un implante inmediato Avanza. Se trata de una paciente de 24 años de edad atendida en la consulta multidisciplinaria de Implantología de la Clínica Docente de Prótesis de Marianao. Tenía una corona espiga en el incisivo central superior derecho, con cambio de coloración que le afectaba su estética. Además se le caía constantemente y estaba ligeramente inflamada por vestibular, lo cual le producía dolor. Después de una evaluación multidisciplinaria y el consentimiento de la paciente, se procede a la retirada de la corona espiga y exodoncia de la raíz del 11 mediante la técnica de colgajo. Inmediatamente se colocó el implante Avanza y se rehabilitó con una prótesis parcial acrílica removible por razones estéticas. Con este tratamiento, la paciente mantuvo el contorno de los tejidos blandos y la altura ósea de la zona intervenida, necesarios para alcanzar excelentes resultados estéticos.

Soviet-France cooperative study of the solar corona

International Nuclear Information System (INIS)

Vsekhvsyatskij, S.K.; Dzyubenko, N.I.; Ivanchuk, V.I.; Popov, O.S.; Rubo, G.A.; Kuchmij, S.; Kuchmij, O.; Shtel'makher, G.

1981-01-01

The study continues the investigations on the solar corona performed according to the program of the Soviet-France experiment ''The white corona dynamics'' during total solar eclipses on July 10 1972 and June 30, 1973 by the expeditions of Kiev University and Paris Astrophysical Institute. The results of the study of eclipse negatives obtained on June 30 1973 in Africa are given. On the basis of new methods of photometry and colorimetry using star images up to 8.5sup(m) as the photometry standards it has been found with high accuracy the distribution of the total corona brightness up to r approximately equal to 4.5 Rsub(S) and its K- and F-corona components for E and N directions. Neither color effect nor flattening is found in the dust component (r -6 Esub(S)

CORONA project -contribution to VVER nuclear education and training

International Nuclear Information System (INIS)

Ilieva, M.; Miteva, R.; Takov, T.

2016-01-01

CORONA Project is established to stimulate the transnational mobility and lifelong learning amongst VVER end users. The project aims to provide a special purpose structure for training of specialists and to maintain the nuclear expertise by gathering the existing and generating new knowledge in the VVER area. CORONA Project consists of two parts: CORONA I (2011-2014) ''Establishment of a regional center of competence for VVER technology and Nuclear Applications'', co-financed by the Framework Program 7 of the European Union (EU) and CORONA II (2015-2018) ''Enhancement of training capabilities in VVER technology through establishment of VVER training academy'', co-financed by HORIZON 2020, EURATOM 2014-2015. The selected form of the CORONA Academy, together with the online availability of the training opportunities will allow trainees from different locations to access the needed knowledge on demand. The project will target also new-comers in VVER community like Vietnam, Turkey, Belarus, etc. (authors)

The TESIS experiment on the CORONAS-PHOTON spacecraft

Science.gov (United States)

Kuzin, S. V.; Zhitnik, I. A.; Shestov, S. V.; Bogachev, S. A.; Bugaenko, O. I.; Ignat'ev, A. P.; Pertsov, A. A.; Ulyanov, A. S.; Reva, A. A.; Slemzin, V. A.; Sukhodrev, N. K.; Ivanov, Yu. S.; Goncharov, L. A.; Mitrofanov, A. V.; Popov, S. G.; Shergina, T. A.; Solov'ev, V. A.; Oparin, S. N.; Zykov, A. M.

2011-04-01

On February 26, 2009, the first data was obtained in the TESIS experiment on the research of the solar corona using imaging spectroscopy. The TESIS is a part of the scientific equipment of the CORONAS-PHO-TON spacecraft and is designed for imaging the solar corona in soft X-ray and extreme ultraviolet regions of the spectrum with high spatial, spectral, and temporal resolutions at altitudes from the transition region to three solar radii. The article describes the main characteristics of the instrumentation, management features, and operation modes.

Pulsed corona generation using a diode-based pulsed power generator

Science.gov (United States)

Pemen, A. J. M.; Grekhov, I. V.; van Heesch, E. J. M.; Yan, K.; Nair, S. A.; Korotkov, S. V.

2003-10-01

Pulsed plasma techniques serve a wide range of unconventional processes, such as gas and water processing, hydrogen production, and nanotechnology. Extending research on promising applications, such as pulsed corona processing, depends to a great extent on the availability of reliable, efficient and repetitive high-voltage pulsed power technology. Heavy-duty opening switches are the most critical components in high-voltage pulsed power systems with inductive energy storage. At the Ioffe Institute, an unconventional switching mechanism has been found, based on the fast recovery process in a diode. This article discusses the application of such a "drift-step-recovery-diode" for pulsed corona plasma generation. The principle of the diode-based nanosecond high-voltage generator will be discussed. The generator will be coupled to a corona reactor via a transmission-line transformer. The advantages of this concept, such as easy voltage transformation, load matching, switch protection and easy coupling with a dc bias voltage, will be discussed. The developed circuit is tested at both a resistive load and various corona reactors. Methods to optimize the energy transfer to a corona reactor have been evaluated. The impedance matching between the pulse generator and corona reactor can be significantly improved by using a dc bias voltage. At good matching, the corona energy increases and less energy reflects back to the generator. Matching can also be slightly improved by increasing the temperature in the corona reactor. More effective is to reduce the reactor pressure.

Calculation of single phase AC and monopolar DC hybrid corona effects

International Nuclear Information System (INIS)

Zhao, T.; Sebo, S.A.; Kasten, D.G.

1996-01-01

Operating a hybrid HVac and HVdc line is an option for increasing the efficiency of power transmission and overcoming the difficulties in obtaining a new right-of-way. This paper proposes a new calculation method for the study of hybrid line corona. The proposed method can be used to calculate dc corona losses and corona currents in dc or ac conductors for single phase ac and monopolar dc hybrid lines. Profiles of electric field strength and ion current density at ground level can be estimated. The effects of the presence of an energized ac conductor on dc conductor corona and dc voltage on ac conductor corona are included in the method. Full-scale and reduced-scale experiments were utilized to investigate the hybrid line corona effects. Verification of the proposed calculation method is given

Interdependence of plant water status with photosynthetic performance and root defense responses in Vigna radiata (L.) Wilczek under progressive drought stress and recovery.

Science.gov (United States)

Sengupta, Debashree; Guha, Anirban; Reddy, Attipalli Ramachandra

2013-10-05

The present study investigates the interdependence of plant water status with foliar and root responses in Vigna radiata L.Wilczek under progressive drought. Vegetatively-mature V. radiata plants were subjected to water withdrawal for 3 and 6days (D3 and D6, respectively) and then re-watered subsequently for 6days (6R) for stress-recovery. Changes in plant water status were expressed in terms of leaf and root moisture contents (LMC and RMC, respectively) and leaf relative water content (LRWC). Progressive drought caused apparent decrease in LRWC, LMC and RMC depicting significant level of dehydration of leaf and root tissues. Stomatal limitation alone could not account for the observed decrease in net CO2 assimilation rates (Pn) due to comparatively less decrease in sub-stomatal CO2 (Ci) concentrations with respect to other gas exchange parameters indicating possible involvement of non-stomatal limitations. Analysis of polyphasic chl a fluorescence kinetics during progressive drought showed decreased energy connectivity among PSII units as defined by a positive L-band with highest amplitude during D6. Efficiency of electron flux from OEC towards PSII acceptor side was not significantly affected during drought conditions as evidenced by the absence of a positive K-band. Increasing root-level water-limitation enforced a gradual oxidative stress through H2O2 accumulation and membrane lipid peroxidation in V. radiata roots exhibiting drastic enhancement of proline content and a significant but gradual increase in ascorbic acid content as well as guaiacol peroxidase activity under progressive drought. Expression analysis of Δ(1) pyrroline-5-carboxylate synthetase (P5CS) through real time PCR and enzyme activity studies showed a strong positive correlation between VrP5CS gene expression, enzyme activity and proline accumulation in the roots of V. radiata under progressive drought and recovery. Drought-induced changes in root moisture content (RMC) showed positive linear

Corona development and floral nectaries of Asclepiadeae (Asclepiadoideae, Apocynaceae

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Mariana Maciel Monteiro

Full Text Available ABSTRACT Flowers of Asclepiadoideae are notable for possessing numerous nectaries and elaborate coronas, where nectar can accumulate but is not necessarily produced. Given the complexity and importance of these structures for reproduction, this study aimed to analyze the ontogeny of the corona, the structure and position of nectaries and the histochemistry of the nectar of species of Asclepiadeae. Two types of coronas were observed: androecial [C(is] and corolline (Ca. The development of the C(is-type of corona initiates opposite the stamens in all species examined with the exception of Matelea in which it begins to develop as a ring around the filament tube. Despite their morphological variation, coronas typically originate from the androecium. A notable difference among the studied species was the location of the nectaries. Primarily, they are located in the stigmatic chamber, where nectar composed of carbohydrates and lipids is produced. A secondary location of nectaries found in species of Peplonia and Matelea is within the corona, where nectar is produced and stored, composed of carbohydrates and lipids in Peplonia and only carbohydrates in Matelea. The functional role of nectar is related to the location of its production since it is a resource for pollinators and inducers of pollen germination.

Population structure and historical demography of the thorny skate (Amblyraja radiata, Rajidae) in the North Atlantic

NARCIS (Netherlands)

Chevolot, M.; Wolfs, P.H.J.; Palsson, J.; Rijnsdorp, A.D.; Stam, W.T.; Olsen, J.L.

2007-01-01

Population genetic structure of the thorny skate (Amblyraja radiata) was surveyed in >300 individuals sampled from Newfoundland, Iceland, Norway, the Kattegat and the central North Sea. A 290-bp fragment of the mt cytochrome-b gene was first screened by SSCP. Sequences of SSCP haplotypes revealed

Population structure and historical demography of the thorny skate (Amblyraja radiata, Rajidae) in the North Atlantic

NARCIS (Netherlands)

Chevolot, Malia; Wolfs, Peter H. J.; Palsson, Jonbjorn; Rijnsdorp, Adriaan D.; Stam, Wytze T.; Olsen, Jeanine L.; Palson, J.

Population genetic structure of the thorny skate (Amblyraja radiata) was surveyed in > 300 individuals sampled from Newfoundland, Iceland, Norway, the Kattegat and the central North Sea. A 290-bp fragment of the mt cytochrome-b gene was first screened by SSCP. Sequences of SSCP haplotypes revealed

Biochemical Changes under Chromium Stress on Germinating Seedlings of Vigna radiata

Directory of Open Access Journals (Sweden)

Bhavin SUTHAR

2014-03-01

Full Text Available Hexavalant chromium is considered the most toxic form because of its high solubility in water. Cr is known to induce production of elevated concentration of reactive oxygen species (ROS resulted in macromolecule damage. Plants are having unique mechanisms to overcome ROS induced damage by accumulation of proline, ascorbate and glutathione and increasing the activities of antioxidant enzymes such as superoxide dismutase (SOD, catalase (CAT, glutathione reductase (GR, and ascorbate peroxidaes (APX, peroxidise (POX. In the present investigation effects of chromium on seed germination of Mung bean (Vigna radiata 'Gujarat Mung-4’ were studied. Seeds were treated with different Cr concentrations (50, 100, 150 and 200 4M for seven days. On 7th day root and shoot length was measured and activities of antioxidant enzyme SOD, APX, POX, CAT and GR were checked along with protein, proline and lipid peroxidation. It was observed that there is gradual decrease in shoot and root length with respect to the increase in Cr concentration. Level of lipid peroxidation significantly increased along with proline and antioxidant enzyme activity at higher Cr concentration. Lipid peroxidation is an indication of membrane damage due to elevated production of reactive oxygen species (ROS. To combat oxidative damage by ROS antioxidant enzyme activity increased significantly, which indicates that antioxidant enzymes (SOD, CAT, APX and GR play a crucial role during Cr stress during germination of V. radiata.

Direct observation of a single nanoparticle-ubiquitin corona formation

Science.gov (United States)

Ding, Feng; Radic, Slaven; Chen, Ran; Chen, Pengyu; Geitner, Nicholas K.; Brown, Jared M.; Ke, Pu Chun

2013-09-01

The advancement of nanomedicine and the increasing applications of nanoparticles in consumer products have led to administered biological exposure and unintentional environmental accumulation of nanoparticles, causing concerns over the biocompatibility and sustainability of nanotechnology. Upon entering physiological environments, nanoparticles readily assume the form of a nanoparticle-protein corona that dictates their biological identity. Consequently, understanding the structure and dynamics of a nanoparticle-protein corona is essential for predicting the fate, transport, and toxicity of nanomaterials in living systems and for enabling the vast applications of nanomedicine. Here we combined multiscale molecular dynamics simulations and complementary experiments to characterize the silver nanoparticle-ubiquitin corona formation. Notably, ubiquitins competed with citrates for the nanoparticle surface, governed by specific electrostatic interactions. Under a high protein/nanoparticle stoichiometry, ubiquitins formed a multi-layer corona on the particle surface. The binding exhibited an unusual stretched-exponential behavior, suggesting a rich binding kinetics. Furthermore, the binding destabilized the α-helices while increasing the β-sheet content of the proteins. This study revealed the atomic and molecular details of the structural and dynamic characteristics of nanoparticle-protein corona formation.The advancement of nanomedicine and the increasing applications of nanoparticles in consumer products have led to administered biological exposure and unintentional environmental accumulation of nanoparticles, causing concerns over the biocompatibility and sustainability of nanotechnology. Upon entering physiological environments, nanoparticles readily assume the form of a nanoparticle-protein corona that dictates their biological identity. Consequently, understanding the structure and dynamics of a nanoparticle-protein corona is essential for predicting the fate

Natural parasitism of Diaphorina citri Kuwayama (Hemiptera, Psyllidae nymphs by Tamarixia radiata Waterston (Hymenoptera, Eulophidae in São Paulo orange groves

Directory of Open Access Journals (Sweden)

Paulo Eduardo Branco Paiva

2012-12-01

Full Text Available The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922 in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72% of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March, with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.

Elastic Thickness Estimates for Coronae Associated with Chasmata on Venus

Science.gov (United States)

Hoogenboom, T.; Martin, P.; Housean, G. A.

2005-01-01

Coronae are large-scale circular tectonic features surrounded by annular ridges. They are generally considered unique to Venus and may offer insights into the differences in lithospheric structure or mantle convective pattern between Venus and Earth. 68% of all coronae are associated with chasmata or fracture belts. The remaining 32% are located at volcanic rises or in the plains. Chasmata are linear to arcuate troughs, with trough parallel fractures and faults which extend for 1000 s of kilometers. Estimates of the elastic thickness of the lithosphere (T(sub e)) have been calculated in a number of gravity/topography studies of Venus and for coronae specifically. None of these studies, however, have explored the dependence of T(sub e) on the tectonic history of the region, as implied from the interpretation of relative timing relationships between coronae and surrounding features. We examine the relationship between the local T(sub e) and the relative ages of coronae and chasmata with the aim of further constraining the origin and evolution of coronae and chasmata systems.

Novel ssDNA Viruses Detected in the Virome of Bleached, Habitat-Forming Kelp Ecklonia radiata

Directory of Open Access Journals (Sweden)

Douglas T. Beattie

2018-01-01

Full Text Available Kelp forests provide essential habitats for organisms in temperate rocky shores. Loss of kelp forests has occurred over large areas in a number of temperate regions, including in Australia, where the dominant kelp Ecklonia radiata has been lost from substantial areas of the shoreline. Loss of E. radiata has been associated with environmental stressors, including increased temperature and anthropogenic contaminants, as well as biological factors, such as herbivory. Disease may also play a role, but there is little information on the role of disease in the loss of kelp from coastal ecosystems or on the potential role of pathogenic microorganisms, such as viruses. E. radiata across much of its distribution in Australia can develop a “bleached” phenotype, which may be a disease. To investigate whether the phenotype was associated with a potential viral agent, we shotgun sequenced viral particles that were isolated from kelp with normal (healthy and bleached phenotypes. Each virome consisted of ~380,000 reads, of which ~25% were similar to known viruses. All samples were dominated by bacteriophages, but novel ssDNA virus sequences were detected that were almost exclusively in viromes from the bleached kelp phenotype. These ssDNA viruses are covered by 11 contigs that contained complete capsids and characteristic rep genes that were 30–60% similar to those of circular, Rep-encoding ssDNA viruses (CRESS-DNA viruses. CRESS-DNA viruses have not previously been described from macroalgae, and the rep genes were similar to CRESS-DNA viruses from marine water samples, snails, crabs, anemones, but also dragonflies. This raises the interesting possibility that the kelp could be a vector of the CRESS-DNA viruses to other organisms that are associated with the bleached state.

Spatial Mapping and Quantification of Soft and Hard Protein Coronas at Silver Nanocubes

DEFF Research Database (Denmark)

Miclaus, Teodora; Bochenkov, Vladimir; Ogaki, Ryosuke

2014-01-01

kinetics of the corona-formation at cube edges/corners versus facets at short incubation times, where the polymer stabilization agent delayed corona hardening. The soft corona contained more protein than the hard corona at all time-points (8-fold difference with 10% serum conditions).......Protein coronas around silver nanocubes were quantified in serum-containing media using localized surface plasmon resonances. Both soft and hard coronas showed exposure-time and concentration-dependent changes in protein surface density with time-dependent hardening. We observed spatially dependent...

Corona Borealis

Science.gov (United States)

Murdin, P.

2000-11-01

(the Northern Crown; abbrev. CrB, gen. Coronae Borealis; area 179 sq. deg.) A northern constellation which lies between Boötes and Hercules, and culminates at midnight in mid-May. It represents the crown that in Greek mythology was made by Hephaestus, god of fire, and worn by Princess Ariadne of Crete. Its brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest....

Are All Flare Ribbons Simply Connected to the Corona?

Energy Technology Data Exchange (ETDEWEB)

Judge, Philip G. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Paraschiv, Alin; Lacatus, Daniela; Donea, Alina [Monash Center for Astrophysics, School of Mathematical Science, Monash University, Victoria 3800 (Australia); Lindsey, Charlie, E-mail: judge@ucar.edu, E-mail: alina.donea@monash.edu, E-mail: alin.paraschiv@monash.edu, E-mail: daniela.lacatus@monash.edu, E-mail: indsey@cora.nwra.com [Northwest Research Associates, 3380 Mitchell Lane, Boulder, CO 80301 (United States)

2017-04-01

We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode , Solar Dynamics Observatory , and IRIS missions. While most ribbons appear connected to the corona and overlie regions of significant vertical magnetic field, we examine one ribbon with no clear evidence for such connections. Evolving horizontal magnetic fields seen with Hinode suggest that reconnection with preexisting fields below the corona can explain the data. The identification of just one, albeit small, ribbon, with no apparent connection to the corona, leads us to conclude that at least two mechanisms are responsible for the heating that leads to flare ribbon emission.

Core-Shell-Corona Micelles with a Responsive Shell.

Science.gov (United States)

Gohy, Jean-François; Willet, Nicolas; Varshney, Sunil; Zhang, Jian-Xin; Jérôme, Robert

2001-09-03

A reactor for the synthesis of gold nanoparticles is one of the uses of a poly(styrene)-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) triblock copolymer (PS-b-P2VP-b-PEO) which forms core-shell-corona micelles in water. Very low polydispersity spherical micelles are observed that consist of a PS core surrounded by a pH-sensitive P2VP shell and a corona of PEO chains end-capped by a hydroxyl group. The corona can act as a site for attaching responsive or sensing molecules. © 2001 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.

Characterization of moisture in acetylated and propionylated radiata pine using low-field nuclear magnetic resonance (LFNMR) relaxometry

DEFF Research Database (Denmark)

Beck, Greeley; Thybring, Emil Engelund; Thygesen, Lisbeth Garbrecht

2018-01-01

. A possible explanation is the counteracting effects of decreased hydrophilicity and reduced moisture content (MC) of these water populations at higher levels of acetylation. The evaluation of propionylation on WCW T2 data was complicated by peak splitting in the relaxation spectrum. Constant T2 values......Moisture in radiata pine (Pinus radiata D. Don) earlywood (EW), which was acetylated or propionylated to various degrees, was measured by low-field nuclear magnetic resonance (LFNMR) relaxometry. Spin-spin relaxation times (T2) were determined for fully saturated samples at 22 and -18°C. T2 values...... for EW lumen water increased with increasing acetylation weight percentage gain (WPG), perhaps caused by the less hydrophilic acetylated wood (AcW) surface. Cell wall water (WCW) and the water in pits and small voids also showed increasing T2 values as a function of WPG but with a weaker tendency...

The Faraday rotation experiment. [solar corona

Science.gov (United States)

Volland, H.; Levy, G. S.; Bird, M. K.; Stelzried, C. T.; Seidel, B. L.

1984-01-01

The magnetized plasma of the solar corona was remotely sounded using the Faraday rotation effect. The solar magnetic field together with the electrons of the coronal plasma cause a measurable Faraday rotation effect, since the radio waves of Helios are linearly polarized. The measurement is performed at the ground stations. Alfven waves traveling from the Sun's surface through the corona into interplanetary space are observed. Helios 2 signals penetrating through a region where coronal mass is ejected show wavelike structures.

Simultaneous Observation of High Temperature Plasma of Solar Corona By TESIS CORONAS-PHOTON and XRT Hinode.

Science.gov (United States)

Reva, A.; Kuzin, S.; Bogachev, S.; Shestov, S.

2012-05-01

The Mg XII spectroheliograph is a part of instrumentation complex TESIS (satellite CORONAS-PHOTON). This instrument builds monochromatic images of hot plasma of the solar corona (λ = 8.42 Å, T>5 MK). The Mg XII spectroheliograph observed hot plasma in the non-flaring active-region NOAA 11019 during nine days. We reconstructed DEM of this active region with the help of genetic algorithm (we used data of the Mg XII spectroheliograph, XRT and EIT). Emission measure of the hot component amounts 1 % of the emission measure of the cool component.

Galactic absorption line coronae

International Nuclear Information System (INIS)

Bregman, J.N.

1981-01-01

We have investigated whether gaseous coronae around galaxies rise to the absorption systems seen in quasar spectra. In our model, gas originally located in the disk is heated to the million degree range and rises to surround the galaxy; the gas remains bound to the galaxy. Optically thin radiative cooling drives a thermal instability in the hot gas which causes cool clouds (T 4 K) to condense out of the corona. These clouds, which follow ballistic trajectories back to the disk, are the absorption sites. A two-dimensional hydrodynamic code with radiative cooling was used to study the dynamics and thermodynamics of the corona as well as the position rate at which clouds form. Coupled to the code is a galaxy with two mass components, a disk (approx.10 11 M/sub sun/) and a dark halo (approx.10 12 M/sub sun/). In a model where the temperature at the base of the corona (in the disk) is 3 x 10 6 K, absorbing gas of column density NL> or approx. =10 18 cm 2 extends radially to 100 kpc (face-on orientation) and vertically to 60 Kpc (edge-on orientation). The total mass of gas required here (coronal plus cloud gas) is 1.4 x 10 10 M/sub sun/, while the minimum supernova heating rate is one supernova per 27 years. In two other models (base coronal temperatures of 0.50 x 10 6 K and 1 x 10 6 K), coronal gas rises from an extended gaseous disk (in the previous model, the gas comes from a typical gaseous disk approximately 15 kpc in extent). Here, column densities of 10 19 cm -2 out to a radius of 70 kpc (face-on orientation) are achieved with a total gas mass of 1.7 x 10 9 M/sub direct-product/ and 2.0 x 10 9 M/sub sun/ and minimum heating rates of approximately one supernova per 170 years and one supernova per 60 years

Lacunar infarction in brain tumor patients. Chronic stage complication after radiation therapy

International Nuclear Information System (INIS)

Nakazaki, Kiyoshi; Titoku, Shirou; Ota, Shinzou; Sato, Mitiyoshi; Kobanawa, Satoshi; Tutida, Kazuyuki; Tanaka, Yasue; Goto, Katsuya; Ota, Taisei

2007-01-01

The authors reported two relatively young adults with lacunar infarction that took place many years after radiation therapy. The first case was that of a 41-year-old male presenting with a slight decrease in consciousness and right hemiparesis of sudden occurrence. MRI revealed a lacunar infarction in the left internal capsule. This patient had received radiation therapy and chemotherapy for a right basal ganglia germinoma when he was 24 years old. The tumor completely disappeared and he was able to return to work. The second case was a 24-year-old female presenting with dysesthesia in the right upper extremity and nausea of sudden occurrence. MRI disclosed a lacunar infarct in the right corona radiata. The patient had received radiation therapy for a suprasellar tumor when she was 11 years old. The tumor considerably decreased in size and the patient conducted normal social life thereafter. MRI showed a lacunar infarction in the right corona radiata. Review of the literature was made and the possibility of radiation therapy as a causative factor of the lacunar infarction in relatively young adults was discussed. (author)

Cerebral atrophy in elderly with subjective memory complaints.

Science.gov (United States)

Palm, Walter M; Ferrarini, Luca; van der Flier, Wiesje M; Westendorp, Rudi G J; Bollen, Eduard L E M; Middelkoop, Huub A M; Milles, Julien R; van der Grond, Jeroen; van Buchem, Mark A

2013-08-01

To evaluate ventricular shape differences along the complete surface of the lateral and third ventricles of persons with subjective memory complaints (MC). We included 28 controls and 21 persons with MC. FLAIR, T2, and PD-weighted brain MRI scans were acquired at 1.5 Tesla, followed by semi-automated segmentation of the lateral and third ventricles, and local shape difference analysis based on growing and adaptive meshes. Ventricular meshes were used to highlight local areas with significant differences between controls and persons with MC, determined by permutation tests with a predefined threshold (P = 0.01). Compared with control subjects, relevant differences were found in the shape of the ventricular surface adjacent to the thalamus and corona radiata in persons with MC. Before correction for multiple comparisons, relevant differences were also found in the shape of the ventricular surface adjacent to the corpus callosum, hippocampus, and amydala. Our findings suggest the presence of localized structural brain differences in patients with subjective memory complaints in the thalamus and the corona radiata. Copyright © 2013 Wiley Periodicals, Inc.

The somatotopic localisation of the descending cortical tract in the cerebral peduncle: a study using MRI of changes following Wallerian degeneration in the cerebral peduncle after a supratentorial vascular lesion

International Nuclear Information System (INIS)

Waragai, M.; Watanabe, H.; Iwabuchi, S.

1994-01-01

We studied the effects of Wallerian degeneration in the cerebral peduncle shown by magnetic resonance imaging (MRI) following a supratentorial vascular lesion, to identify the somatotopic localisation of the descending cortical tracts. Patients with a lesion involving a large area of a cerebral hemisphere has an area of abnormal signal intensity in the whole cerebral peduncle, suggesting Wallerian degeneration of all the whole descending cortical tracts. With a small lesion confined to the precentral gyrus, corona radiata, or posterior limb of the internal capsule there was an abnormal signal at the centre of the peduncle, suggesting degeneration of the precentrospinal tract. Those with a small lesion confined to the paracentral gyrus had an abnormal area slightly lateral to the centre of the peduncle, suggesting degeneration of the parietospinal tract. Patients with a lesion of the parietal or temporal lobes, not including the paracentral or precentral gyri, corona radiata, or the posterior limb of the internal capsule, had an abnormal area laterally in the peduncle, suggesting degeneration of the parietopontine or temporopontine tract. (orig.)

Pulsed Corona for Sustainable Technology

International Nuclear Information System (INIS)

Heesch, E.J.M. van; Pemen, A.J.M.; Yan, K.; Blom, P.P.M.; Huijbrechts, P.A.H.J.; Der Laan, P.C.T. van

2000-01-01

Highly active coronas with a peak power of up to 25 MW p/m corona wire and kJ/liter energy densities in the streamer channels can be produced by pulsed power. Since the voltage pulses are short, full breakdown does not occur even though the discharge currents are hundreds of Amperes. A matched pulsed power source can deposit up to 80% of its electrical energy into such a controlled discharge. Reliable and efficient sources characterized by 100 kV,150 ns wide pulses at 1000 Hz have passed 400 hours of operation. The area of applications is growing: VOC control, hot gas cleanup, water and air purification and sterilization. (author)

Numerical modelling of ozone production in a wire-cylinder corona discharge and comparison with a wire-plate corona discharge

International Nuclear Information System (INIS)

Wang Pengxiang; Chen Junhong

2009-01-01

The effect of electrode configuration on ozone production in the direct-current corona discharge of dry and humid air is studied by a numerical model that combines the electron distribution in the corona plasma, plasma chemistry and transport phenomena. Two electrode configurations are considered: wire-cylinder discharge with air flowing along the wire axis and wire-plate discharge with air flowing transverse to the wire. The ozone distributions in both types of discharges are compared. For both electrode configurations, the ozone production rate is higher in the negative corona than in the positive corona and it decreases with an increase in relative humidity. More importantly, the detailed ozone distribution in the neighbourhood of the discharge wire, together with the ozone kinetics, reveals the possible difference in the ozone production from the two discharges. With the same operating conditions and sufficiently short flow residence time, the ozone production rate is nearly the same for both electrode configurations. When the flow residence time is longer than the characteristic time for homogeneous ozone destruction, the net ozone production is higher in the wire-cylinder discharge than in the wire-plate discharge due to relatively less ozone destruction.

Numerical modelling of ozone production in a wire-cylinder corona discharge and comparison with a wire-plate corona discharge

Science.gov (United States)

Wang, Pengxiang; Chen, Junhong

2009-02-01

The effect of electrode configuration on ozone production in the direct-current corona discharge of dry and humid air is studied by a numerical model that combines the electron distribution in the corona plasma, plasma chemistry and transport phenomena. Two electrode configurations are considered: wire-cylinder discharge with air flowing along the wire axis and wire-plate discharge with air flowing transverse to the wire. The ozone distributions in both types of discharges are compared. For both electrode configurations, the ozone production rate is higher in the negative corona than in the positive corona and it decreases with an increase in relative humidity. More importantly, the detailed ozone distribution in the neighbourhood of the discharge wire, together with the ozone kinetics, reveals the possible difference in the ozone production from the two discharges. With the same operating conditions and sufficiently short flow residence time, the ozone production rate is nearly the same for both electrode configurations. When the flow residence time is longer than the characteristic time for homogeneous ozone destruction, the net ozone production is higher in the wire-cylinder discharge than in the wire-plate discharge due to relatively less ozone destruction.

Determination of the Corona model parameters with artificial neural networks

International Nuclear Information System (INIS)

Ahmet, Nayir; Bekir, Karlik; Arif, Hashimov

2005-01-01

Full text : The aim of this study is to calculate new model parameters taking into account the corona of electrical transmission line wires. For this purpose, a neural network modeling proposed for the corona frequent characteristics modeling. Then this model was compared with the other model developed at the Polytechnic Institute of Saint Petersburg. The results of development of the specified corona model for calculation of its influence on the wave processes in multi-wires line and determination of its parameters are submitted. Results of obtained calculation equations are brought for electrical transmission line with allowance for superficial effect in the ground and wires with reference to developed corona model

Nanoparticles-cell association predicted by protein corona fingerprints

Science.gov (United States)

Palchetti, S.; Digiacomo, L.; Pozzi, D.; Peruzzi, G.; Micarelli, E.; Mahmoudi, M.; Caracciolo, G.

2016-06-01

In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells.In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface

Aerobic fitness is associated with greater white matter integrity in children

Directory of Open Access Journals (Sweden)

Laura eChaddock-Heyman

2014-08-01

Full Text Available Aerobic fitness has been found to play a positive role in brain and cognitive health of children. Yet, many of the neural biomarkers related to aerobic fitness remain unknown. Here, using diffusion tensor imaging (DTI, we demonstrated that higher aerobic fitness was related to greater estimates of white matter microstructure in children. Higher fit 9- and 10-year-old children showed greater fractional anisotropy (FA in sections of the corpus callosum, corona radiata, and superior longitudinal fasciculus, compared to lower fit children. The FA effects were primarily characterized by aerobic fitness differences in radial diffusivity (RD, thereby raising the possibility that estimates of myelination may vary as a function of individual differences in fitness during childhood. White matter structure may be another potential neural mechanism of aerobic fitness that assists in efficient communication between gray matter regions as well as the integration of regions into networks.

Soviet Union-France cooperative study of the solar corona. 1. The structure singularities and photometry of the corona on July 10, 1972

International Nuclear Information System (INIS)

Vsekhsvyatskij, S.K.; Dzyubenko, N.I.; Nesmyanovich, A.T.; Popov, O.S.; Kuchmij, S.; Centre National de la Recherche Scientifique, 75 - Paris

1975-01-01

The results of the study of the eclipse negatives obtained by the expedition of the astronomy division of the Kiev University on 10 July 1972 in accordance with the program of the Soviet-France experiment ''Thynamics of white corona'' are given. New formations - ''voids'' and sharp boundary are obtained side by side with the usual coronal structure details: -polar ray systems, large coronal beams; arch systems. A great number of extended thin streamers in the south-west square and a helical beam over bright condensation are registered. Photometry of one of the negatives exibited a considerable heterogeneity of the corona. Mean values of the K-corona brightness are in agreement with the brightness of a maximum corona according to Van de Hulst model within the range of p < 2R. The coronal gifts are registered near the N-pole and in the south-west region are registered

Efficacy of insecticides against army worm (spodoptera mauritia) on mung bean (vigna radiata l.) under arid climate

International Nuclear Information System (INIS)

Abbas, G.; Aslam, M.; Khokhar, M.B.; Khattak, J.Z.K.; Malik, A.U.

2011-01-01

Influence of Bifenthrine (Talstar) at the rate 375 ml ha/sup -1/, Deltaphos 10+350 EC at the rate 500 ml ha/sup -1/, Lorsban 40 EC at the rate 850 ml ha/sup -1/, Triazofos (20/400 EC) at the rate 750 ml ha/sup -1/and Karate 5 EC at the rate 1250 ml ha/sup -1/ was studied on mung bean (Vigna radiata L.) yield under arid climate at Adaptive Research Farm, Karor during two kharif seasons of 2007 and 2008. Experiments were laid out in randomized complete block design with six a test variety. All the chemicals showed significant impact on mung crop as compared to that in control treatments. AZRI- 2006, a promising variety of mung bean (Vigna radiata L.) for arid climate was used as plots, but the treatment of Deltaphos 10+350 EC at the rate 350 ml ha/sup -1/consistently proved better than other treatments. (author)

Ecological impacts of long-term application of biosolids to a radiata pine plantation

International Nuclear Information System (INIS)

Xue, Jianming; Kimberley, Mark O.; Ross, Craig; Gielen, Gerty; Tremblay, Louis A.; Champeau, Olivier; Horswell, Jacqui; Wang, Hailong

2015-01-01

Assessment of the ecological impact of applying biosolids is important for determining both the risks and benefits. This study investigated the impact on soil physical, chemical and biological properties, tree nutrition and growth of long-term biosolids applications to a radiata pine (Pinus radiata D. Don) plantation growing on a Sandy Raw Soil in New Zealand. Biosolids were applied to the trial site every 3 years from tree age 6 to 19 years at three application rates: 0 (Control), 300 (Standard) and 600 (High) kg nitrogen (N) ha −1 , equivalent to 0, 3 and 6 Mg ha −1 of dry biosolids, respectively. Tree nutrition status and growth have been monitored annually. Soil samples were collected 13 years after the first biosolids application to assess the soil properties and functioning. Both the Standard and High biosolids treatments significantly increased soil (0–50 cm depth) total carbon (C), N, and phosphorus (P), Olsen P and cation exchange capacity (CEC), reduced soil pH, but had no significant effects on soil (0–20 cm depth) physical properties including bulk density, total porosity and unsaturated hydraulic conductivity. The High biosolids treatment also increased concentrations of soil total cadmium (Cd), chromium (Cr), copper (Cu) and lead (Pb) at 25–50 cm depth, but these concentrations were still considered very low for a soil. Ecotoxicological assessment showed no significant adverse effects of biosolids application on either the reproduction of springtails (Folsomia candida) or substrate utilisation ability of the soil microbial community, indicating no negative ecological impact of bisolids-derived heavy metals or triclosan. This study demonstrated that repeated application of biosolids to a plantation forest on a poor sandy soil could significantly improve soil fertility, tree nutrition and pine productivity. However, the long-term fate of biosolids-derived N, P and litter-retained heavy metals needs to be further monitored in the receiving

High-tension corona controlled ozone generator for environment protection

International Nuclear Information System (INIS)

Vijayan, T; Patil, Jagadish G

2010-01-01

Engineering details of a high voltage driven corona-plasma ozone generator are described. The plasma diode of generator has coaxial cylindrical geometry with cathode located inside anode. Cathode is made of a large number of radial gas nozzles arranged on central tubular mast which admits oxygen gas. The sharp endings of the nozzles along with a set of corona rings create the high electric field at the cathode required for formation of dense corona plume responsible for O 3 evolution. A model of coronal plasma generation and ozone production is presented. The plasma formation is strongly dependent on the electric field and temperature in side diode where a high electron density in a low temperature negative corona is suited for high ozone yields. These are established by suitable regulation of A-K gap, voltage, oxygen pressure, and cathode-nozzle population.

Ion-impact secondary emission in negative corona with photoionization

Directory of Open Access Journals (Sweden)

B. X. Lu

2017-03-01

Full Text Available A corona discharge measurement system and simulation model are presented to investigate the effects of photoionization and ion-impact secondary emission process in negative corona discharge. The simulation results obtained is shown good agreement with experimental observations. Distribution of electron density along the symmetry axis at three critical moments is shown and the role of photoionization in negative corona discharge is clearly explained. Moreover, the current pulses are also presented under different secondary emission coefficients and the effect of the secondary emission coefficient is discussed.

Comparison of traditional field retting and Phlebia radiata Cel 26 retting of hemp fibres for fibre-reinforced composites

DEFF Research Database (Denmark)

Liu, Ming; Ale, Marcel Tutor; Kołaczkowski, Bartłomiej

2017-01-01

Classical field retting and controlled fungal retting of hemp using Phlebia radiata Cel 26 (a mutant with low cellulose degrading ability) were compared with pure pectinase treatment with regard to mechanical properties of the produced fibre/epoxy composites. For field retting a classification...

Application of gamma radiation to the nodes detection in Pinus Radiata (D.Don) wood pieces; Aplicacion de la radiacion gamma en la deteccion de nudos en piezas de madera de Pino Radiata (D.Don)

Energy Technology Data Exchange (ETDEWEB)

Morales, J R; Dinator, Maria I [Chile Univ., Santiago (Chile). Dept. de Fisica; Karsulovic C, Jose T; Leon G, Adolfo [Chile Univ., Santiago (Chile). Dept. de Tecnologia de la Madera

1997-12-31

Attenuation of 59.5 KeV photons provided by an Am-241 source, has been used to detect knots in lumber pieces from Pinus Radiata (D.Don). It is shown that the linear attenuation coefficient is a sensitive parameter to detect singularities in the structure of this material. The scanning of the piece provides profiles which define the position and extension of the singularity. (author). 7 refs.

Skylab investigations of solar corona

International Nuclear Information System (INIS)

Krivsky, L.

1976-01-01

The findings are reported obtained by the observation of the Sun and its corona from Skylab. The most important findings include the discovery of explosive loop structures induced by eruptive phenomena below the corona, in the chromosphere. The front edge of the explosive loop structure was observed at a distance of 1,700,000 to 2,800,000 km from the Sun. The rate of prominence was around 500 km/s. The loop structure disturbed the original shape of the corona above the solar disk edge. A graph was plotted of the variation of the release of the expanding loop structure from the solar surface in millions of kilometers with time. The graph aided in refuting the erroneous assumption that the prominence was not associated with radio bursts similar to those induced by plasma shock waves. It was also shown that a prominent shock wave is present in the vicinity of the expanding structure front which, at lower levels, got released from the eruptive flare above the solar ''surface''. The knowledge obtained does not involve the Sun alone but is also valuable from the point of view of the prognosis of consequent magnetic anomalies in the interstellar space and geomagnetic disturbances on the Earth. (Z.S.)

Personalized disease-specific protein corona influences the therapeutic impact of graphene oxide

Science.gov (United States)

Hajipour, Mohammad Javad; Raheb, Jamshid; Akhavan, Omid; Arjmand, Sareh; Mashinchian, Omid; Rahman, Masoud; Abdolahad, Mohammad; Serpooshan, Vahid; Laurent, Sophie; Mahmoudi, Morteza

2015-05-01

The hard corona, the protein shell that is strongly attached to the surface of nano-objects in biological fluids, is recognized as the first layer that interacts with biological objects (e.g., cells and tissues). The decoration of the hard corona (i.e., the type, amount, and conformation of the attached proteins) can define the biological fate of the nanomaterial. Recent developments have revealed that corona decoration strongly depends on the type of disease in human patients from which the plasma is obtained as a protein source for corona formation (referred to as the `personalized protein corona'). In this study, we demonstrate that graphene oxide (GO) sheets can trigger different biological responses in the presence of coronas obtained from various types of diseases. GO sheets were incubated with plasma from human subjects with different diseases/conditions, including hypofibrinogenemia, blood cancer, thalassemia major, thalassemia minor, rheumatism, fauvism, hypercholesterolemia, diabetes, and pregnancy. Identical sheets coated with varying protein corona decorations exhibited significantly different cellular toxicity, apoptosis, and uptake, reactive oxygen species production, lipid peroxidation and nitrogen oxide levels. The results of this report will help researchers design efficient and safe, patient-specific nano biomaterials in a disease type-specific manner for clinical and biological applications.The hard corona, the protein shell that is strongly attached to the surface of nano-objects in biological fluids, is recognized as the first layer that interacts with biological objects (e.g., cells and tissues). The decoration of the hard corona (i.e., the type, amount, and conformation of the attached proteins) can define the biological fate of the nanomaterial. Recent developments have revealed that corona decoration strongly depends on the type of disease in human patients from which the plasma is obtained as a protein source for corona formation (referred

Nanoparticles formation and deposition in the trichel pulse corona

International Nuclear Information System (INIS)

Amirov, R H; Samoylov, I S; Petrov, A A

2013-01-01

Cathode erosion in the negative corona discharge has been studied in the point-to-plane electrode configuration with Cu cathodes in the Trichel pulse regime. Redeposition of erosion products has been found on the cathode surface in form of agglomerates of 10-nm nanoparticles. Nanocraters and nanoparticles formation in the negative corona discharge has been considered in frames of electro-explosive mechanism of cathode erosion. According to this mechanism the cathode erosion is performed as a consequence of elementary erosion events each of which is caused by a Trichel pulse. A 1-dimentional model of corona-produced nanoparticles dynamics in the gap was elaborated. According to results of the simulation, the redeposition is explained by charging of the nanoparticles due to positive ions adsorption and thermionic emission. The size, temperature and initial velocity of the aerosol nanoparticles have the decisive action on redeposition in the negative corona discharge.

The coronas-F space mission key results for solar terrestrial physics

CERN Document Server

2014-01-01

This volume is the updated and extended translation of the Russian original. It presents the results of observations of solar activity and its effects in the Earth space environment carried out from July 2001 to December 2005 on board the CORONAS-F space mission. The general characteristics of the CORONAS-F scientific payload are provided with a description of the principal experiments. The main results focus on the global oscillations of the Sun (p-modes), solar corona, solar flares, solar cosmic rays, Earth’s radiation belts, and upper atmosphere. The book will be welcomed by students, post-graduates, and scientists working in the field of solar and solar-terrestrial physics. This English edition is supplemented by sections presenting new results of the SPIRIT and TESIS experiments under the CORONAS solar program, as well as from the SONG experiment onboard the CORONAS-F satellite.

CORONA DISCHARGE IGNITION FOR ADVANCED STATIONARY NATURAL GAS ENGINES

Energy Technology Data Exchange (ETDEWEB)

Dr. Paul D. Ronney

2003-09-12

An ignition source was constructed that is capable of producing a pulsed corona discharge for the purpose of igniting mixtures in a test chamber. This corona generator is adaptable for use as the ignition source for one cylinder on a test engine. The first tests were performed in a cylindrical shaped chamber to study the characteristics of the corona and analyze various electrode geometries. Next a test chamber was constructed that closely represented the dimensions of the combustion chamber of the test engine at USC. Combustion tests were performed in this chamber and various electrode diameters and geometries were tested. The data acquisition and control system hardware for the USC engine lab was updated with new equipment. New software was also developed to perform the engine control and data acquisition functions. Work is underway to design a corona electrode that will fit in the new test engine and be capable igniting the mixture in one cylinder at first and eventually in all four cylinders. A test engine was purchased for the project that has two spark plug ports per cylinder. With this configuration it will be possible to switch between corona ignition and conventional spark plug ignition without making any mechanical modifications.

Application of gamma radiation to the nodes detection in Pinus Radiata (D.Don) wood pieces

International Nuclear Information System (INIS)

Morales, J.R.; Dinator, Maria I; Karsulovic C, Jose T.; Leon G, Adolfo

1996-01-01

Attenuation of 59.5 KeV photons provided by an Am-241 source, has been used to detect knots in lumber pieces from Pinus Radiata (D.Don). It is shown that the linear attenuation coefficient is a sensitive parameter to detect singularities in the structure of this material. The scanning of the piece provides profiles which define the position and extension of the singularity. (author)

Influence of corona charging in cellular polyethylene film

International Nuclear Information System (INIS)

Ortega Brana, Gustavo; Magraner, Francisco; Quijano, Alfredo; Llovera Segovia, Pedro

2011-01-01

Cellular polymers have recently attracted attention for their property of exhibiting a piezoelectric constant when they are electrically charged. The electrostatic charge generated in the voids by the internal discharges creates and internal macrodipole which is responsible for the piezoelectric effect. Charging by corona discharge is the most used method for cellular polymers. Many works has been published on polypropylene and polyethylene films mainly focused on the required expansion process or on the results obtained for raw cellular materials electrically activated. Our work is based on commercial polyethylene cellular films which have been physically characterized and electrically activated. The effect of thermal treatment, physical uniaxial or biaxial stretching and corona charging was investigated. The new method of corona charging improved the piezoelectric constant under other activation conditions.

Influence of corona charging in cellular polyethylene film

Energy Technology Data Exchange (ETDEWEB)

Ortega Brana, Gustavo; Magraner, Francisco; Quijano, Alfredo [Instituto Tecnologico de la Energia (ITE), Av. Juan de la Cierva 24, Parque Tecnologico de Valencia, 46980 Paterna-Valencia (Spain); Llovera Segovia, Pedro, E-mail: gustavo.ortega@ite.es [Instituto de TecnologIa Electrica - Universitat Politecnica de Valencia, Camino de Vera s/n 46022-Valencia (Spain)

2011-06-23

Cellular polymers have recently attracted attention for their property of exhibiting a piezoelectric constant when they are electrically charged. The electrostatic charge generated in the voids by the internal discharges creates and internal macrodipole which is responsible for the piezoelectric effect. Charging by corona discharge is the most used method for cellular polymers. Many works has been published on polypropylene and polyethylene films mainly focused on the required expansion process or on the results obtained for raw cellular materials electrically activated. Our work is based on commercial polyethylene cellular films which have been physically characterized and electrically activated. The effect of thermal treatment, physical uniaxial or biaxial stretching and corona charging was investigated. The new method of corona charging improved the piezoelectric constant under other activation conditions.

The heating of the solar corona. Pt. 2

International Nuclear Information System (INIS)

McWhirter, R.W.P.; Thonemann, P.C.; Wilson, R.

1975-01-01

The density and temperature distribution of the solar corona is calculated assuming an energy balance between thermal conduction and radiated power loss with the primary heating of the corona by the dissipation of sound-waves propagated upwards from below the sun's surface. A sharp transition region is found and the calculated results are compared with observations. A detailed model atmosphere for the transition region and corona is derived using the Harvard Smithsonian Reference Atmosphere (for the chromosphere) as starting point. Hydrostatic equilibrium is assumed in the calculations but it is also shown that a pressure arises because of the sound-waves which is of comparable magnitude to hydrostatic pressure. The inclusion of this pressure introduces difficulties that are discussed. (orig.) [de

Protein Corona Analysis of Silver Nanoparticles Links to Their Cellular Effects.

Science.gov (United States)

Juling, Sabine; Niedzwiecka, Alicia; Böhmert, Linda; Lichtenstein, Dajana; Selve, Sören; Braeuning, Albert; Thünemann, Andreas F; Krause, Eberhard; Lampen, Alfonso

2017-11-03

The breadth of applications of nanoparticles and the access to food-associated consumer products containing nanosized materials lead to oral human exposure to such particles. In biological fluids nanoparticles dynamically interact with biomolecules and form a protein corona. Knowledge about the protein corona is of great interest for understanding the molecular effects of particles as well as their fate inside the human body. We used a mass spectrometry-based toxicoproteomics approach to elucidate mechanisms of toxicity of silver nanoparticles and to comprehensively characterize the protein corona formed around silver nanoparticles in Caco-2 human intestinal epithelial cells. Results were compared with respect to the cellular function of proteins either affected by exposure to nanoparticles or present in the protein corona. A transcriptomic data set was included in the analyses in order to obtain a combined multiomics view of nanoparticle-affected cellular processes. A relationship between corona proteins and the proteomic or transcriptomic responses was revealed, showing that differentially regulated proteins or transcripts were engaged in the same cellular signaling pathways. Protein corona analyses of nanoparticles in cells might therefore help in obtaining information about the molecular consequences of nanoparticle treatment.

Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona

Energy Technology Data Exchange (ETDEWEB)

Brandenburg, Axel; Ashurova, Mohira B. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); Jabbari, Sarah, E-mail: brandenb@nordita.org [School of Mathematical Sciences and Monash Centre for Astrophysics, Monash University, Clayton, VIC 3800 (Australia)

2017-08-20

A turbulent dynamo in spherical geometry with an outer corona is simulated to study the sign of magnetic helicity in the outer parts. In agreement with earlier studies, the sign in the outer corona is found to be opposite to that inside the dynamo. Line-of-sight observations of polarized emission are synthesized to explore the feasibility of using the local reduction of Faraday depolarization to infer the sign of helicity of magnetic fields in the solar corona. This approach was previously identified as an observational diagnostic in the context of galactic magnetic fields. Based on our simulations, we show that this method can be successful in the solar context if sufficient statistics are gathered by using averages over ring segments in the corona separately for the regions north and south of the solar equator.

Meteoric ions in the corona and solar wind

International Nuclear Information System (INIS)

Lemaire, J.

1990-01-01

The total mass of refractory material of interplanetary origin penetrating and evaporated in the meltosphere surrounding the sun has been inferred from observations of meteoroids and fireballs falling in earth's atmosphere. The amount of iron atoms deposited this way in the solar corona is of the order of 3000 t/s or larger. The measured flux of outflowing solar wind iron ions is equal to 2200 t/s. The close agreement of both fluxes is evidence that a significant fraction of iron ions observed in the solar wind and in the corona must be of meteoric origin. A similar accord is also obtained for silicon ions. The mean velocity of meteoroid ions formed in the solar corona is equal to the free-fall velocity: i.e., independent of their atomic mass as the thermal speed of heavy ion measured in low-density solar wind streams at 1 AU. Furthermore, the heavy ions of meteoric origin escape out of the corona with a larger bulk velocity than the protons which are mainly of solar origin. These differences of heavy ion and proton bulk velocities are also observed in the solar wind. 52 refs

Effects of corona discharge treatment on some properties of wool ...

African Journals Online (AJOL)

Yomi

2011-12-21

Dec 21, 2011 ... Corona discharge after operation worsted water absorption property increased and the ... finally conditioned with atmospheric air (20°C, relative humidity ... For corona treatment, a glow discharge generator was used with a.

The energy and pressure balance in the corona

International Nuclear Information System (INIS)

McWhirter, R.W.P.; Wilson, R.

1976-01-01

This paper reviews theoretical models for the solar corona based on energy and pressure calculations. Processes included in these calculations are: (a) heating of the outer corona by mechanical waves; (b) convective out-flow of gas giving rise to the solar wind; (c) thermal conductions; (d) radiated power loss. Possible observations to help answer some of the outstanding questions about the energy balance are suggested. (author)

Results of Spectral Corona Observations in Solar Activity Cycles 17-24

Science.gov (United States)

Aliev, A. Kh.; Guseva, S. A.; Tlatov, A. G.

2017-12-01

The results of the work of the global observation network are considered, and a comparative analysis of the data of various coronal observatories is performed. The coronal activity index has been reconstructed for the period 1939-2016 based on the data of various observatories in Kislovodsk system. For this purpose, the corona daily intensity maps from the Sacramento Peak and Lomnický Štít observatories according to the Solar-Geophysical Data journal have been digitized; they supplement the data of other observatories. The homogeneity and continuity of the corona observations at the Kislovodsk station, including activity cycle 24, is confirmed. Unfortunately, the only observatory at present that continues observation of the spectral corona in Fe XIV 5303 Å and Fe XIV 6374 Å lines is the Kislovodsk astronomical station Mountain Astronomical Station (MAS) of the Central Astronomical Observatory, Russian Academy of Sciences (Pulkovo). The data on the combined corona in 5303 Å line are analyzed. It is shown that there is a high correlation of the intensity index of green corona with solar radiation measurements in the vacuum UV region. Data on the beginning of the new 25th activity cycle in the corona at high latitudes are presented.

Cánula rígida, alternativa en el tratamiento estético-funcional de la apicoformación por fractura complicada de corona

Directory of Open Access Journals (Sweden)

Javier Alvarez Rodríguez

Full Text Available Las edades más afectadas, por la presencia de fracturas complicadas de corona, son la niñez y la adolescencia. En la mayoría de los pacientes se afectan los incisivos centrales superiores permanentes de incompleta formación apical. Esto implica una disminución de las capacidades de masticación, dicción y trae consigo implicaciones psicológicas en la adolescencia. El tratamiento consiste en la aplicación de una técnica de apicoformación que dificulta lograr al unísono la resolución de la afección estética. Nuestro propósito es describir un caso de apicoformación en incisivo central superior izquierdo, con cementación de cánula rígida, conformación de muñón y restauración estético-funcional definitiva. Un paciente de 8 años, masculino acude a consulta tras sufrir traumatismo dentoalveolar consistente en fractura complicada de corona. Los rayos X muestran ligero ensanchamiento periodontal y ápice inmaduro. Se le aplicó anestesia local, se realizó la extirpación pulpar total del diente afectado, y se colocó medicamento intraconducto. La culminación del tratamiento de restauración total coronaria se realizó con la cementación con ionómero de vidrio tipo II de una cánula rígida No. 22 hasta las dos terceras partes de la longitud de trabajo; alrededor de esta se conformó un muñón y corona de nano composite híbrido fotopolimerizable. Se controló evolución cada 24 días, durante tres meses para comprobar el estado de maduración apical. La cementación de la cánula rígida, consituye una alternativa para el tratamiento funcional de la apicoformación por fractura complicada de corona. Supone una rápida recuperación de las funciones bucodentales y psicológico-sociales integrales del paciente.

Ecological impacts of long-term application of biosolids to a radiata pine plantation

Energy Technology Data Exchange (ETDEWEB)

Xue, Jianming, E-mail: jianming.xue@scionresearch.com [Scion, Private Bag 29237, Christchurch (New Zealand); Kimberley, Mark O., E-mail: mark.kimberley@scionresearch.com [Scion, Private Bag 3020, Rotorua (New Zealand); Ross, Craig, E-mail: rossc@landcareresearch.co.nz [Landcare, Private Bag 11052, Palmerston North (New Zealand); Gielen, Gerty, E-mail: gerty.gielen@scionresearch.com [Scion, Private Bag 3020, Rotorua (New Zealand); Tremblay, Louis A., E-mail: louis.tremblay@cawthron.org.nz [Cawthron Institute, Private Bag 2, Nelson (New Zealand); School of Biological Sciences, University of Auckland, PO Box 92019, Auckland 1142 (New Zealand); Champeau, Olivier, E-mail: olivier.champeau@cawthron.org.nz [Cawthron Institute, Private Bag 2, Nelson (New Zealand); Horswell, Jacqui, E-mail: jacqui.horswell@esr.cri.nz [ESR, P O Box 50-348, Porirua (New Zealand); Wang, Hailong, E-mail: hailong@zafu.edu.cn [Scion, Private Bag 3020, Rotorua (New Zealand); Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang Agricultural and Forestry University, Lin' an, Hangzhou, Zhejiang Province 311300 (China)

2015-10-15

Assessment of the ecological impact of applying biosolids is important for determining both the risks and benefits. This study investigated the impact on soil physical, chemical and biological properties, tree nutrition and growth of long-term biosolids applications to a radiata pine (Pinus radiata D. Don) plantation growing on a Sandy Raw Soil in New Zealand. Biosolids were applied to the trial site every 3 years from tree age 6 to 19 years at three application rates: 0 (Control), 300 (Standard) and 600 (High) kg nitrogen (N) ha{sup −1}, equivalent to 0, 3 and 6 Mg ha{sup −1} of dry biosolids, respectively. Tree nutrition status and growth have been monitored annually. Soil samples were collected 13 years after the first biosolids application to assess the soil properties and functioning. Both the Standard and High biosolids treatments significantly increased soil (0–50 cm depth) total carbon (C), N, and phosphorus (P), Olsen P and cation exchange capacity (CEC), reduced soil pH, but had no significant effects on soil (0–20 cm depth) physical properties including bulk density, total porosity and unsaturated hydraulic conductivity. The High biosolids treatment also increased concentrations of soil total cadmium (Cd), chromium (Cr), copper (Cu) and lead (Pb) at 25–50 cm depth, but these concentrations were still considered very low for a soil. Ecotoxicological assessment showed no significant adverse effects of biosolids application on either the reproduction of springtails (Folsomia candida) or substrate utilisation ability of the soil microbial community, indicating no negative ecological impact of bisolids-derived heavy metals or triclosan. This study demonstrated that repeated application of biosolids to a plantation forest on a poor sandy soil could significantly improve soil fertility, tree nutrition and pine productivity. However, the long-term fate of biosolids-derived N, P and litter-retained heavy metals needs to be further monitored in the

Preliminary protein corona formation stabilizes gold nanoparticles and improves deposition efficiency

Science.gov (United States)

Luby, Alexandra O.; Breitner, Emily K.; Comfort, Kristen K.

2016-08-01

Due to their advantageous characteristics, gold nanoparticles (AuNPs) are being increasingly utilized in a vast array of biomedical applications. However, the efficacy of these procedures are highly dependent upon strong interactions between AuNPs and the surrounding environment. While the field of nanotechnology has grown exponentially, there is still much to be discovered with regards to the complex interactions between NPs and biological systems. One area of particular interest is the generation of a protein corona, which instantaneously forms when NPs encounter a protein-rich environment. Currently, the corona is viewed as an obstacle and has been identified as the cause for loss of application efficiency in physiological systems. To date, however, no study has explored if the protein corona could be designed and advantageously utilized to improve both NP behavior and application efficacy. Therefore, we sought to identify if the formation of a preliminary protein corona could modify both AuNP characteristics and association with the HaCaT cell model. In this study, a corona comprised solely of epidermal growth factor (EGF) was successfully formed around 10-nm AuNPs. These EGF-AuNPs demonstrated augmented particle stability, a modified corona composition, and increased deposition over stock AuNPs, while remaining biocompatible. Analysis of AuNP dosimetry was repeated under dynamic conditions, with lateral flow significantly disrupting deposition and the nano-cellular interface. Taken together, this study demonstrated the plausibility and potential of utilizing the protein corona as a means to influence NP behavior; however, fluid dynamics remains a major challenge to progressing NP dosimetry.

Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

Directory of Open Access Journals (Sweden)

Antonio Rigueiro-Rodríguez

2012-02-01

Full Text Available Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener and beta (Jaccard and Magurran biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing. Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

Family-site interaction in Pinus radiata: implications for progeny testing strategy and regionalised breeding in New Zealand.

Science.gov (United States)

G.R. Johnson; R.D. Brudon

1990-01-01

A progeny test of 170 open-pollinated families from second-generation plus trees of Pinus radiata was established on four sites in New Zealand in 1981. Two test sites were on volcanic purnice soils in the Central North Island region and two were on phosphate-retentive clay soils in the Northland region.Assessments of volume growth, stem straightness, mal-...

Semi-analytical modelling of positive corona discharge in air

Science.gov (United States)

Pontiga, Francisco; Yanallah, Khelifa; Chen, Junhong

2013-09-01

Semianalytical approximate solutions of the spatial distribution of electric field and electron and ion densities have been obtained by solving Poisson's equations and the continuity equations for the charged species along the Laplacian field lines. The need to iterate for the correct value of space charge on the corona electrode has been eliminated by using the corona current distribution over the grounded plane derived by Deutsch, which predicts a cos m θ law similar to Warburg's law. Based on the results of the approximated model, a parametric study of the influence of gas pressure, the corona wire radius, and the inter-electrode wire-plate separation has been carried out. Also, the approximate solutions of the electron number density has been combined with a simplified plasma chemistry model in order to compute the ozone density generated by the corona discharge in the presence of a gas flow. This work was supported by the Consejeria de Innovacion, Ciencia y Empresa (Junta de Andalucia) and by the Ministerio de Ciencia e Innovacion, Spain, within the European Regional Development Fund contracts FQM-4983 and FIS2011-25161.

Dynamic characteristics of corona discharge generated under rainfall condition on AC charged conductors

Science.gov (United States)

Xu, Pengfei; Zhang, Bo; Wang, Zezhong; Chen, Shuiming; He, Jinliang

2017-12-01

By synchronous measurement of corona current and the water droplet deformation process on a conductor surface, different types of corona discharge are visualized when AC voltage is applied on a line-ground electrode system. The corona characteristics are closely related to the applied voltage and water supply rate. With the increase of AC voltage, the positive Taylor cone discharge firstly appears and then disappears, replaced by the dripping and crashing discharge. Furthermore, the number of pulses in each pulse train increases with the increase of applied voltage. The mechanism of the transfer from the positive Taylor cone discharge to the dripping and crashing discharge is found to be related to the oscillation process of the water droplet. The water supply rate also has a great influence on the characteristics of corona currents. The number of positive pulse trains increases linearly when the water supply rate gets larger, leading to a higher audible noise and radio interference level from the AC corona, which is quite different from that of the DC corona. The difference between the AC and DC coronas under rainfall conditions is analyzed finally.

MASC: Magnetic Activity of the Solar Corona

Science.gov (United States)

Auchere, Frederic; Fineschi, Silvano; Gan, Weiqun; Peter, Hardi; Vial, Jean-Claude; Zhukov, Andrei; Parenti, Susanna; Li, Hui; Romoli, Marco

We present MASC, an innovative payload designed to explore the magnetic activity of the solar corona. It is composed of three complementary instruments: a Hard-X-ray spectrometer, a UV / EUV imager, and a Visible Light / UV polarimetric coronagraph able to measure the coronal magnetic field. The solar corona is structured in magnetically closed and open structures from which slow and fast solar winds are respectively released. In spite of much progress brought by two decades of almost uninterrupted observations from several space missions, the sources and acceleration mechanisms of both types are still not understood. This continuous expansion of the solar atmosphere is disturbed by sporadic but frequent and violent events. Coronal mass ejections (CMEs) are large-scale massive eruptions of magnetic structures out of the corona, while solar flares trace the sudden heating of coronal plasma and the acceleration of electrons and ions to high, sometimes relativistic, energies. Both phenomena are most probably driven by instabilities of the magnetic field in the corona. The relations between flares and CMEs are still not understood in terms of initiation and energy partition between large-scale motions, small-scale heating and particle acceleration. The initiation is probably related to magnetic reconnection which itself results magnetic topological changes due to e.g. flux emergence, footpoints motions, etc. Acceleration and heating are also strongly coupled since the atmospheric heating is thought to result from the impact of accelerated particles. The measurement of both physical processes and their outputs is consequently of major importance. However, despite its fundamental importance as a driver for the physics of the Sun and of the heliosphere, the magnetic field of our star’s outer atmosphere remains poorly understood. This is due in large part to the fact that the magnetic field is a very difficult quantity to measure. Our knowledge of its strength and

Multiscale simulation of DC corona discharge and ozone generation from nanostructures

Science.gov (United States)

Wang, Pengxiang

Atmospheric direct current (dc) corona discharge from micro-sized objects has been widely used as an ion source in many devices, such as photocopiers, laser printers, and electronic air cleaners. Shrinking the size of the discharge electrode to the nanometer range (e.g., through the use of carbon nanotubes or CNTs) is expected to lead to a significant reduction in power consumption and detrimental ozone production in these devices. The objectives of this study are to unveil the fundamental physics of the nanoscale corona discharge and to evaluate its performance and ozone production through numerical models. The extremely small size of CNTs presents considerable complexity and challenges in modeling CNT corona discharges. A hybrid multiscale model, which combines a kinetic particle-in-cell plus Monte Carlo collision (PIC-MCC) model and a continuum model, is developed to simulate the corona discharge from nanostructures. The multiscale model is developed in several steps. First, a pure PIC-MCC model is developed and PIC-MCC simulations of corona plasma from micro-sized electrode with same boundary conditions as prior model are performed to validate the PIC-MCC scheme. The agreement between the PIC-MCC model and the prior continuum model indicates the validity of the PIC-MCC scheme. The validated PIC-MCC scheme is then coupled with a continuum model to simulate the corona discharge from a micro-sized electrode. Unlike the prior continuum model which only predicts the corona plasma region, the hybrid model successfully predicts the self-consistent discharge process in the entire corona discharge gap that includes both corona plasma region and unipolar ion region. The voltage-current density curves obtained by the hybrid model agree well with analytical prediction and experimental results. The hybrid modeling approach, which combines the accuracy of a kinetic model and the efficiency of a continuum model, is thus validated for modeling dc corona discharges. For

The effects of corona on current surges induced on conducting lines by EMP: A comparison of experiment data with results of analytic corona models

Science.gov (United States)

Blanchard, J. P.; Tesche, F. M.; McConnell, B. W.

1987-09-01

An experiment to determine the interaction of an intense electromagnetic pulse (EMP), such as that produced by a nuclear detonation above the Earth's atmosphere, was performed in March, 1986 at Kirtland Air Force Base near Albuquerque, New Mexico. The results of that experiment have been published without analysis. Following an introduction of the corona phenomenon, the reason for interest in it, and a review of the experiment, this paper discusses five different analytic corona models that may model corona formation on a conducting line subjected to EMP. The results predicted by these models are compared with measured data acquired during the experiment to determine the strengths and weaknesses of each model.

Analysis of counter flow of corona wind for heat transfer enhancement

Science.gov (United States)

Shin, Dong Ho; Baek, Soo Hong; Ko, Han Seo

2018-03-01

A heat sink for cooling devices using the counter flow of a corona wind was developed in this study. Detailed information about the numerical investigations of forced convection using the corona wind was presented. The fins of the heat sink using the counter flow of a corona wind were also investigated. The corona wind generator with a wire-to-plate electrode arrangement was used for generating the counter flow to the fin. The compact and simple geometric characteristics of the corona wind generator facilitate the application of the heat sink using the counter flow, demonstrating the heat sink is effective for cooling electronic devices. Parametric studies were performed to analyze the effect of the counter flow on the fins. Also, the velocity and temperature were measured experimentally for the test mock-up of the heat sink with the corona wind generator to verify the numerical results. From a numerical study, the type of fin and its optimal height, length, and pitch were suggested for various heat fluxes. In addition, the correlations to calculate the mass of the developed heat sink and its cooling performance in terms of the heat transfer coefficient were derived. Finally, the cooling efficiencies corresponding to the mass, applied power, total size, and noise of the devices were compared with the existing commercial central processing unit (CPU) cooling devices with rotor fans. As a result, it was confirmed that the heat sink using the counter flow of the corona wind showed appropriate efficiencies for cooling electronic devices, and is a suitable replacement for the existing cooling device for high power electronics.

Micro Corona Ionizer as an Ozone Source for Bacterial Cell Lysis

Science.gov (United States)

Lee, Eun-Hee; Lim, Hyun Jeong; Chua, Beelee; Son, Ahjeong

2015-04-01

DNA extraction is a critical process of DNA assays including polymerase chain reaction (PCR), microarrays, molecular cloning, and DNA hybridization which has been well established and can be implemented by commercial kits. DNA extraction involves cell lysis, precipitation, and purification through the combination of physical and chemical processes. Cell lysis is essential to high DNA recovery yield which can be achieved via a variety of physical, chemical, and enzymatic methods. However, these methods were originally developed for bioassays that were labor intensive, time consuming, and vulnerable to contamination and inhibition. Here, we proposed to employ a micro corona ionizer as an ozone source to lyse bacterial cells. Ozone has been well known and used as a disinfectant which allows cell lysis and DNA extraction. Previously, we have shown that a micro corona ionizer is capable of generating a significant amount of ozone. In this study, we employed the micro corona ionizer for the bacterial cell lysis which consists of a 50 μm diameter cantilever wire as the discharge cathode and a 50 μm thick copper foil as anode. Applied voltages varied from 1900 to 2200 V with corresponding corona currents from 16 to 28 μA. The resultant ozone (concentration > 0.14 ppm) generated from the micro corona ionizer was bubbled into the sample via a miniature pump. We demonstrated the cell lysis of Pseudomonas putida as the target bacterium using the micro corona ionizer. At a flow rate of 38 ml/min and applied corona voltage of 2000 V, 98.5 ± 0.2% lysis (normalized to sonication result) was achieved after 10 min. In comparison, untreated and air-treated samples showed normalized % lysis of 11.9 ± 2.4 and 36.1 ± 1.7%, respectively. We also showed that the cell lysis efficiency could be significantly increased by increasing the flow rate and the applied corona voltage. By comparing the experimental results for continuous and pulsed treatment, we verified that the percentage of

EFFECTIVENESS OF A SUPERFICIAL TREATMENT USING BIFENTHRIN TO PROTECT RADIATA PINE FRAMING FROM DAMAGE BY SUBTERRANEAN AND DRYWOOD TERMITES IN INDONESIA

Directory of Open Access Journals (Sweden)

Paimin Sukartana

2010-06-01

Full Text Available Various experimental testing procedures were undertaken in Indonesia to determine the effectiveness of a patented superficial (envelope treatment using bifenthrin to protect radiata pine framing material from damage by two species of subterranean termites (Macrotermes gilvus and Coptotermes curvignathus and one species of drywood termite (Cryptotermes cynocephalus. Lengths of framing material (Pinus radiata sapwood were commercially treated to the targeted retention of 0.02% m/m of bifenthrin in the outer 2 mm depth penetration zone of the material. The treated and untreated materials were subsequently cut into test specimens and exposed to M. gilvus in the field and a semi-laboratory trial, to C. curvignathus in the laboratory and a semi-laboratory trial and to C. cynocephalus in a laboratory trial. No supplementary treatment was performed on the exposed cut ends of the treated test specimens. The results from the trials clearly demonstrated that the superficial treatment of bifenthrin seemed effective in protecting test specimens of radiata pine framing material from significant damage by Indonesia’s most notorious termite species that often causes serious economic loss to the timbers. Termites were unable to damage any of the bifenthrin-treated surfaces of test specimens. Any obser ved damage by termites, albeit minor, was in all cases confined to the exposed cut ends of test specimens. In contrast, attack by termites on the untreated control test specimens caused damage of the samples ranging from light to heavy.

Co-existence of two plasma phases in solar and AGN coronas

Directory of Open Access Journals (Sweden)

Kubičela A.

1998-01-01

Full Text Available Here we have juxtaposed two distant cosmic locations of the Sun and AGN where neutral hydrogen appears in a close connection with hot coronas. Besides the solar photosphere, chromosphere and prominences where the presence of neutral hydrogen is well established, its emission quite high in hot solar corona is still puzzling. Some of earlier observations where Hα emission in solar corona was detected in eclipse and in daily coronagraphic observations are reviewed. A proper theoretical explanation of this cold chromospheric-type emission in the hot corona does not exist yet. On the other side, a similar emission of hydrogen lines is present in Active Galactic Nuclei (AGNs. Much research work is currently being done in this field. We outline some of the concepts of the AGN structure prevailing in the astrophysics today.

Why the negative corona current in air decreases?

International Nuclear Information System (INIS)

Pavlik, M.; Skalny, J.D.; Strelle, D.

1996-01-01

The time dependence of negative corona current I, called by Gagarin like 'relaxing of CV-characteristics', is a observed phenomena. The observed phenomena was explained by two theoretical models considering the ion-molecule and chemical reactions in the negative corona discharges in air, especially the ozone production. In the presented paper the discrepancies of above mentioned models, re-examination the earlier experimental data and presumptions used in models in a light the latest experimentally confirmed facts are discussed

Are X-ray emitting coronae around supermassive black holes outflowing?

Energy Technology Data Exchange (ETDEWEB)

Liu, Teng; Wang, Jun-Xian; Yang, Huan; Zhu, Fei-Fan; Zhou, You-Yuan, E-mail: liuteng@ustc.edu.cn, E-mail: jxw@ustc.edu.cn [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-03-10

Hard X-ray emission in radio-quiet active galactic nuclei (AGNs) is believed to be produced via inverse Compton scattering by hot and compact coronae near the supermassive black hole. However, the origin and physical properties of the coronae, including geometry, kinematics, and dynamics, remain poorly known. In this work, taking [O IV] 25.89 μm emission line as an isotropic indicator of AGNs' intrinsic luminosity, we compare the intrinsic corona X-ray emission between Seyfert 1 and Compton-thin Seyfert 2 galaxies, which are viewed at different inclinations according to the unification scheme. We compile a sample of 130 Compton-thin Seyfert galaxies with both [O IV] 25.89 μm line luminosities measured with the Spitzer Infrared Spectrometer and X-ray spectra observed by XMM-Newton, Chandra, Suzaku, or Swift. Known radio-loud sources are excluded. We fit the X-ray spectra to obtain the absorption-corrected 2-10 keV continuum luminosities. We find that Seyfert 1 galaxies are intrinsically brighter in intrinsic 2-10 keV emission by a factor of 2.8{sub −0.4}{sup +0.5} (2.2{sub −0.3}{sup +0.9} in Swift Burst Alert Telescope 14-195 keV emission), compared with Compton-thin Seyfert 2 galaxies. The Seyfert 1 and Compton-thin Seyfert 2 galaxies follow a statistically identical correlation between the absorption-corrected 2-10 keV luminosity and the 14-195 keV luminosity, indicating that our absorption correction to the 2-10 keV flux is sufficient. The difference in X-ray emission between the two populations is thus unlikely to be due to X-ray absorption, and instead implies an intrinsic anisotropy in the corona X-ray emission. This striking anisotropy of X-ray emission can be explained by a bipolar outflowing corona with a bulk velocity of ∼0.3-0.5c. This would provide a natural link between the so-called coronae and weak jets in these systems. Other consequences of outflowing coronae are also discussed.

The effect of water availability on plastic responses and biomass allocation in early growth traits of Pinus radiata D. Don

Energy Technology Data Exchange (ETDEWEB)

Espinoza, S. E.; Magni, C. R.; Martinez, V. A.; Ivkovic, M.

2013-05-01

Aim of study: The aim of the study was to assess the effect of water availability on plastic responses and biomass allocation in early growth traits of Pinus radiata D. Don. Area of study: Seedlings of 69 families of P. radiata belonging to five different sites in Central Chile, ranging from coastal range to fothills of the Andes, were grown in controlled conditions to evaluate differences in response to watering. Material and methods: The seedlings were subjected to two watering regimes: well-watered treatment, in which seedlings were watered daily, and water stress treatment in which seedlings were subjected to three cyclic water deficits by watering to container capacity on 12 days cycles each. After twenty-eight weeks root collar diameter, height, shoot dry weight (stem + needles), root dry weight, total dry weight, height/diameter ratio and root/shoot ratio were recorded. Patterns and amounts of phenotypic changes, including changes in biomass allocation, were analyzed. Main results: Families from coastal sites presented high divergence for phenotypic changes, allocating more biomass to shoots, and those families from interior sites presented low phenotypic plasticity, allocating more biomass to roots at the expense of shoots. These changes are interpreted as a plastic response and leads to the conclusion that the local land race of P. radiata in Chile originating from contrasting environments possess distinct morphological responses to water deficit which in turn leads to phenotypic plasticity. Research highlights: Families belonging to sandy soil sites must be considered for tree breeding in dry areas, selecting those with high root: shoot ratio. (Author) 46 refs.

Propagation characteristics of audible noise generated by single corona source under positive DC voltage

Directory of Open Access Journals (Sweden)

Xuebao Li

2017-10-01

Full Text Available The directivity and lateral profile of corona-generated audible noise (AN from a single corona source are measured through experiments carried out in the semi-anechoic laboratory. The experimental results show that the waveform of corona-generated AN consists of a series of random sound pressure pulses whose pulse amplitudes decrease with the increase of measurement distance. A single corona source can be regarded as a non-directional AN source, and the A-weighted SPL (sound pressure level decreases 6 dB(A as doubling the measurement distance. Then, qualitative explanations for the rationality of treating the single corona source as a point source are given on the basis of the Ingard’s theory for sound generation in corona discharge. Furthermore, we take into consideration of the ground reflection and the air attenuation to reconstruct the propagation features of AN from the single corona source. The calculated results agree with the measurement well, which validates the propagation model. Finally, the influence of the ground reflection on the SPL is presented in the paper.

The effect of atmospheric corona treatment on AA1050 aluminium

DEFF Research Database (Denmark)

Jariyaboon, Manthana; Møller, Per; Dunin-Borkowski, Rafal E.

2010-01-01

The effect of atmospheric corona discharge on AM 050 aluminium surface was investigated using electrochemical polarization, SEM-EDX, FIB-SEM. and XPS. The corona treatment was performed with varying time (1, 5, and 15 min) in atmospheric air. A 200 nm oxide layer was generated on AA1050 after...

Inception behaviour of pulsed positive corona in several gases

International Nuclear Information System (INIS)

Veldhuizen, E M van; Rutgers, W R

2003-01-01

The inception probability and the streamer length of pulsed positive corona discharges is determined in argon, nitrogen, oxygen and air. This study is performed in a 25 mm point-plane gap at a pressure of 1 bar. The lowest voltage at which a discharge in argon starts is 3 kV but only with an inception probability of 1%. At 5 kV the corona discharge in argon transforms into a spark with a probability close to 100%. The inception probability of corona discharges in all molecular gases used here as a function of the voltage is identical, starting with 1% at 4 kV and going up to 100% at 9 kV. The streamer lengths are quite different for these gases, nitrogen requiring the lowest voltage for streamers to cross the gap and oxygen the highest. This is probably due to electron attachment in oxygen. A remarkable result is that in air streamers bridge the gap at 8 kV, but spark breakdown occurs only above 26 kV. This property makes it relatively easy to obtain powerful pulsed corona discharges in air

Inception behaviour of pulsed positive corona in several gases

Energy Technology Data Exchange (ETDEWEB)

Veldhuizen, E M van; Rutgers, W R [Technische Universiteit Eindhoven, PO Box 513, 5600 MB Eindhoven (Netherlands)

2003-11-07

The inception probability and the streamer length of pulsed positive corona discharges is determined in argon, nitrogen, oxygen and air. This study is performed in a 25 mm point-plane gap at a pressure of 1 bar. The lowest voltage at which a discharge in argon starts is 3 kV but only with an inception probability of 1%. At 5 kV the corona discharge in argon transforms into a spark with a probability close to 100%. The inception probability of corona discharges in all molecular gases used here as a function of the voltage is identical, starting with 1% at 4 kV and going up to 100% at 9 kV. The streamer lengths are quite different for these gases, nitrogen requiring the lowest voltage for streamers to cross the gap and oxygen the highest. This is probably due to electron attachment in oxygen. A remarkable result is that in air streamers bridge the gap at 8 kV, but spark breakdown occurs only above 26 kV. This property makes it relatively easy to obtain powerful pulsed corona discharges in air.

Leaf area index, biomass carbon and growth rate of radiata pine genetic types and relationships with LiDAR

Science.gov (United States)

Peter N. Beets; Stephen Reutebuch; Mark O. Kimberley; Graeme R. Oliver; Stephen H. Pearce; Robert J. McGaughey

2011-01-01

Relationships between discrete-return light detection and ranging (LiDAR) data and radiata pine leaf area index (LAI), stem volume, above ground carbon, and carbon sequestration were developed using 10 plots with directly measured biomass and leaf area data, and 36 plots with modelled carbon data. The plots included a range of genetic types established on north- and...

Ionizing radiation induced changes in phenotype, photosynthetic pigments and free polyamine levels in Vigna radiata (L.) Wilczek

International Nuclear Information System (INIS)

Sengupta, Mandar; Chakraborty, Anindita; Raychaudhuri, Sarmistha Sen

2013-01-01

Effects of gamma rays on the free polyamine (PA) levels were studied in Vigna radiata (L.) Wilczek. Seeds exposed to different doses of gamma rays were checked for damage on phenotype, germination frequency and alteration in photosynthetic pigments. Free polyamine levels were estimated from seeds irradiated in dry and water imbibed conditions. Polyamine levels of seedlings grown from irradiated seeds, and irradiated seedlings from unexposed seeds were also measured. Damage caused by gamma irradiation resulted in decrease in final germination percentage and seedling height. Photosynthetic pigments decreased in a dose dependent manner as marker of stress. Polyamines decreased in irradiated dry seeds and in seedlings grown from irradiated seeds. Radiation stress induced increase in free polyamines was seen in irradiated imbibed seeds and irradiated seedlings. Response of polyamines towards gamma rays is dependent on the stage of the life cycle of the plant. - Highlights: ► Gamma irradiation of Vigna radiata (L.) Wilczek seeds and seedlings. ► Decrease in germination frequency. ► Increase in seedling injury with increased dosage of gamma rays. ► Decrease in chlorophyll and carotenoid pigments. ► Change in free polyamine levels

Impedance-stabilized positive corona discharge and its decontamination properties

Energy Technology Data Exchange (ETDEWEB)

Horak, P; Khun, J, E-mail: pavel.horak@vscht.c [Department of Physics and Measurements, Faculty of Chemical Engineering, Institute of Chemical Technology, Technicka 5, 166 28 Praha 6 (Czech Republic)

2010-04-01

The point-to-plane DC corona discharge in air at atmospheric pressure was stabilized by a serially connected ballast impedance. The ballast impedance was implemented by a resistor-capacitor group connected in parallel. In the case of connecting the serial impedance into the electric circuit of a negative corona, the transition into a spark takes place at parameters similar to those of a non-stabilized discharge. In contrast, in the case of a positive corona, the discharge does not undergo a transition into a spark, but rather into a mode of periodic streamers. We measured the bactericidal effect of the stabilized discharge. The experiments showed that after a 2-minute exposure the quantity of surviving bacteria decreased from 95% for a non-stabilized discharge down to 5% for a stabilized one.

Impedance-stabilized positive corona discharge and its decontamination properties

International Nuclear Information System (INIS)

Horak, P; Khun, J

2010-01-01

The point-to-plane DC corona discharge in air at atmospheric pressure was stabilized by a serially connected ballast impedance. The ballast impedance was implemented by a resistor-capacitor group connected in parallel. In the case of connecting the serial impedance into the electric circuit of a negative corona, the transition into a spark takes place at parameters similar to those of a non-stabilized discharge. In contrast, in the case of a positive corona, the discharge does not undergo a transition into a spark, but rather into a mode of periodic streamers. We measured the bactericidal effect of the stabilized discharge. The experiments showed that after a 2-minute exposure the quantity of surviving bacteria decreased from 95% for a non-stabilized discharge down to 5% for a stabilized one.

Triggering Excimer Lasers by Photoionization from Corona Discharges

Science.gov (United States)

Xiong, Zhongmin; Duffey, Thomas; Brown, Daniel; Kushner, Mark

2009-10-01

High repetition rate ArF (192 nm) excimer lasers are used for photolithography sources in microelectronics fabrication. In highly attaching gas mixtures, preionization is critical to obtaining stable, reproducible glow discharges. Photoionization from a separate corona discharge is one technique for preionization which triggers the subsequent electron avalanche between the main electrodes. Photoionization triggering of an ArF excimer laser sustained in multi-atmosphere Ne/Ar/F2/Xe gas mixtures has been investigated using a 2-dimensional plasma hydrodynamics model including radiation transport. Continuity equations for charged and neutral species, and Poisson's equation are solved coincident with the electron temperature with transport coefficients obtained from solutions of Boltzmann's equation. Photoionizing radiation is produced by a surface discharge which propagates along a corona-bar located adjacent to the discharge electrodes. The consequences of pulse power waveform, corona bar location, capacitance and gas mixture on uniformity, symmetry and gain of the avalanche discharge will be discussed.

Joint Soviet--French investigations of the solar corona. 2. Photometry of solar corona of June 30, 1973

International Nuclear Information System (INIS)

Vsekhsvyatskii, S.; Dzyubenko, N.; Ivanchuk, V.; Popov, O.; Rubo, G.; Koutchmy, S.; Koutchmy, O.; Stellmacher, G.

1981-01-01

The results are presented on a study of eclipse negative obtained on June 30, 1973, in Africa in the program of the Soviet--French experiment ''Dynamics of the White Corona'' by expeditions of Kiev University (Atar, Mauritania) and the Paris Astropysical Institute (Moussoro, Chad). The distributions of the total brightness of the corona out to rapprox. =4.5 R/sub sun/ and of its K and F components for the E and N directions are found with high accuracy on the basis of a new method of photometry and colorimetry using the images of stars down to 8.5/sup m/ as photometric standards. Neither reddening nor flattening of the dusty F component were detected at r -6 E/sub sun/

Madera de compresión en Pinus radiata III: propiedades de pulpas kraft

OpenAIRE

Diaz-vaz,J.E; Ananias,R. A; Valenzuela,L; Torres,M; Rodriguez,S

2012-01-01

Estudios anteriores en estos mismos árboles de Pinus radiata con fustes levemente inclinados, demostraron que la madera de compresión leve que ellos exhibían presentaba: traqueidas más cortas, mayor densidad, mayor proporción de lignina, mayor proporción de extraíbles en etanol tolueno y menor proporción de alfa celulosa que la madera opuesta y que la madera de árboles sin madera de compresión. En el presente estudio se analiza las propiedades pulpables de la madera de compresión y la de sus ...

Equilibrium plasma corona surfaces

International Nuclear Information System (INIS)

Ensley, D.L.

1979-07-01

The distribution of charge of one sign when the opposite charge density is given is determined. Poisson's equation is solved in plane geometry for a simple specified ion density. This automatically gives the inverse solution for a given electron density, by reversing the sign of the potential. Some solutions can approximate a microwave confined corona, for very over dense cases

Effect of chronic administration of Tamoxifen on fertility in male bonnet monkeys (Macaca radiata).

Science.gov (United States)

Rao, A J; Ramachandra, S G; Ramesh, V; Krishnamurthy, H N; Jayaraman, S; Gopalakrishnan, K; Juneja, H S

1998-01-01

Administration of Tamoxifen via the Alzet pump at a rate of 50 micrograms hr-1 for 90 days in the adult male bonnet monkeys Macaca radiata had no effect on the serum testosterone concentration determined at 10 AM and 10 PM as well as total sperm count determined at 15-day intervals over a period of 260 days. However, a significant reduction in sperm motility was observed beyond 90 days up until the 225th day. Breeding studies conducted from day 90 to 260 revealed that these males were infertile.

Radiation magnetohydrodynamic simulations of the formation of hot accretion disk coronae

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yan-Fei [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Stone, James M. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Davis, Shane W. [Canadian Institute for Theoretical Astrophysics. Toronto, ON M5S3H4 (Canada)

2014-04-01

A new mechanism to form a magnetic pressure supported, high temperature corona above the photosphere of an accretion disk is explored using three dimensional radiation magnetohydrodynamic (MHD) simulations. The thermal properties of the disk are calculated self-consistently by balancing radiative cooling through the surfaces of the disk with heating due to dissipation of turbulence driven by magneto-rotational instability (MRI). As has been noted in previous work, we find the dissipation rate per unit mass increases dramatically with height above the mid-plane, in stark contrast to the α-disk model which assumes this quantity is a constant. Thus, we find that in simulations with a low surface density (and therefore a shallow photosphere), the fraction of energy dissipated above the photosphere is significant (about 3.4% in our lowest surface density model), and this fraction increases as surface density decreases. When a significant fraction of the accretion energy is dissipated in the optically thin photosphere, the gas temperature increases substantially and a high temperature, magnetic pressure supported corona is formed. The volume-averaged temperature in the disk corona is more than 10 times larger than at the disk mid-plane. Moreover, gas temperature in the corona is strongly anti-correlated with gas density, which implies the corona formed by MRI turbulence is patchy. This mechanism to form an accretion disk corona may help explain the observed relation between the spectral index and luminosity from active galactic nucleus (AGNs), and the soft X-ray excess from some AGNs. It may also be relevant to spectral state changes in X-ray binaries.

Influencia de la poda en el desarrollo de masas de Pinus radiata D. Don y Pinus pinaster Aiton en Asturias

OpenAIRE

Hevia Cabal, Andrea

2013-01-01

Esta tesis evaluó la influencia de diferentes intensidades de poda sobre el crecimiento, desarrollo y persistencia de masas regulares jóvenes de Pinus radiata D. Don y Pinus pinaster Aiton en Asturias, dentro de una selvicultura sostenible enfocada a la producción de madera de calidad.

Loeb's and streamer-based mechanism for negative corona current pulses

International Nuclear Information System (INIS)

Vagnerova, L.; Skalny, J.D.; Cermak, M.

1998-01-01

The negative point-to-plane corona discharge in electronegative gaseous mixtures is studied experimentally and the basic mechanisms controlling the corona phenomena are discussed. The typical shapes of the current pulse waveforms observed in experiments with the nitrogen-freon mixtures are explained in terms of the theory by Loeb and of the positive-streamer-based model. (J.U.)

Prominence-corona interface compared with the chromosphere-corona transition region

Energy Technology Data Exchange (ETDEWEB)

Orrall, F Q; Schmahl, E J [Harvard Coll. Observatory, Cambridge, Mass. (USA)

1976-11-01

The intensities of 52 EUV emission lines from each of 9 hedgerow prominences observed at the limb with the Harvard experiment on ATM-Skylab have been compared with intensities from the interior of network cells at the center of the disk, in order to compare the prominence-corona (P-C) interface with the chromosphere-corona (C-C) transition region. The intensity ratio Isub(cell)/Isub(prominence) for each line varies systematically (in all of the prominences observed), with the temperature of formation of the line as approximately Tsup(-0.6). The density sensitive C III (formed at T approximately 9x10/sup 4/ K) line ratio Isub(lambda1175)/Isub(lambda977) implies an average density 1.3x10/sup 9/ electrons cm/sup -3/ in the P-C interface and approximately 4 times this value in the C-C transition of the cells. The total optical thickness at the head of the Lyman continuum is < approximately 10 in most of the prominences studied; in two of the prominences, however, the possibility that tau/sub 0/ is large cannot be rejected. Methods of analysis of these EUV data are developed assuming both a resolved and an unresolved internal prominence structure. Although the systematic differences between the P-C interface and the C-C transition are stressed, the similarities are probably more remarkable and may be a result of fine structure in the C-C transition.

DC negative corona discharge in atmospheric pressure helium: transition from the corona to the ‘normal’ glow regime

International Nuclear Information System (INIS)

Hasan, Nusair; Farouk, Bakhtier; Antao, Dion S

2014-01-01

Direct current (dc) negative corona discharges in atmospheric pressure helium are simulated via detailed numerical modeling. Simulations are conducted to characterize the discharges in atmospheric helium for a pin plate electrode configuration. A self-consistent two-dimensional hybrid model is developed to simulate the discharges and the model predictions are validated with experimental measurements. The discharge model considered consists of momentum and energy conservation equations for a multi-component (electrons, ions, excited species and neutrals) gas mixture, conservation equations for each component of the mixture and state relations. A drift–diffusion approximation for the electron and the ion fluxes is used. A model for the external circuit driving the discharge is also considered and solved along with the discharge model. Many of the key features of a negative corona discharge, namely non-linear current–voltage characteristics, spatially flat cathode current density and glow-like discharge in the high current regime are displayed in the predictions. A transition to the ‘normal’ glow discharge from the corona discharge regime is also observed. The transition is identified from the calculated current–voltage characteristic curve and is characterized by the radial growth of the negative glow and the engulfment of the cathode wire. (paper)

Nanoparticle-protein corona in invertebrate in vitro testing

DEFF Research Database (Denmark)

Hayashi, Yuya; Miclaus, Teodora; Scavenius, Carsten

2013-01-01

, and the primary cells were thus exposed to silver nanoparticles with pre-formed corona of serum albumin (a major serum protein). Here we have profiled proteins forming the hard corona around silver nanoparticles (OECD reference materials, 15 nm and 75 nm) using gel electrophoresis techniques to identify proteins...... that strongly interact with the nanoparticles. This study was accompanied by multi-parametric flow-cytometry analysis of the cellular responses, in particular nanoparticle accumulation and cytotoxicity. The formation of and differential cellular responses to nanoparticle-protein complexes underscore the need...

Fabrication of corona-free nanoparticles with tunable hydrophobicity.

Science.gov (United States)

Moyano, Daniel F; Saha, Krishnendu; Prakash, Gyan; Yan, Bo; Kong, Hao; Yazdani, Mahdieh; Rotello, Vincent M

2014-07-22

A protein corona is formed at the surface of nanoparticles in the presence of biological fluids, masking the surface properties of the particle and complicating the relationship between chemical functionality and biological effects. We present here a series of zwitterionic NPs of variable hydrophobicity that do not adsorb proteins at moderate levels of serum protein and do not form hard coronas at physiological serum concentrations. These particles provide platforms to evaluate nanobiological behavior such as cell uptake and hemolysis dictated directly by chemical motifs at the nanoparticle surface.

The concept of bio-corona in modulating the toxicity of engineered nanomaterials (ENM)

International Nuclear Information System (INIS)

Westmeier, Dana; Stauber, Roland H.; Docter, Dominic

2016-01-01

Besides the wide use of engineered nanomaterials (ENM) in technical products, their application spectrum in biotechnology and biomedicine is steadily increasing. In complex physiological environments the physico-chemical properties and the behavior of nanoparticles (NPs) are challenging to characterize. Biomolecules rapidly adsorb to the nanomaterial, leading to the formation of the protein/biomolecule corona, which critically affects the nanomaterials' (patho)biological and technical identities. This formation can trigger an immune response and affect nanoparticles' toxicity and targeting capabilities. In this review, we provide a survey of recent findings on the (protein)corona-nanoparticle interaction and discuss how the corona modulates both cytotoxicity and the immune response as well as to improve the efficacy of targeted delivery of nanocarriers. - Highlights: • “Nanotoxicology” has emerged an autonomous field with an explosive growth. • Nanomaterials adsorb (bio)molecules forming the so-called (bio)molecule corona. • (Fine-)tune of the corona composition could enable new possibilities in nanomedicine.

Modeling the time evolution of the nanoparticle-protein corona in a body fluid.

Directory of Open Access Journals (Sweden)

Daniele Dell'Orco

Full Text Available BACKGROUND: Nanoparticles in contact with biological fluids interact with proteins and other biomolecules, thus forming a dynamic corona whose composition varies over time due to continuous protein association and dissociation events. Eventually equilibrium is reached, at which point the continued exchange will not affect the composition of the corona. RESULTS: We developed a simple and effective dynamic model of the nanoparticle protein corona in a body fluid, namely human plasma. The model predicts the time evolution and equilibrium composition of the corona based on affinities, stoichiometries and rate constants. An application to the interaction of human serum albumin, high density lipoprotein (HDL and fibrinogen with 70 nm N-iso-propylacrylamide/N-tert-butylacrylamide copolymer nanoparticles is presented, including novel experimental data for HDL. CONCLUSIONS: The simple model presented here can easily be modified to mimic the interaction of the nanoparticle protein corona with a novel biological fluid or compartment once new data will be available, thus opening novel applications in nanotoxicity and nanomedicine.

The concept of bio-corona in modulating the toxicity of engineered nanomaterials (ENM)

Energy Technology Data Exchange (ETDEWEB)

Westmeier, Dana; Stauber, Roland H.; Docter, Dominic, E-mail: docter@uni-mainz.de

2016-05-15

Besides the wide use of engineered nanomaterials (ENM) in technical products, their application spectrum in biotechnology and biomedicine is steadily increasing. In complex physiological environments the physico-chemical properties and the behavior of nanoparticles (NPs) are challenging to characterize. Biomolecules rapidly adsorb to the nanomaterial, leading to the formation of the protein/biomolecule corona, which critically affects the nanomaterials' (patho)biological and technical identities. This formation can trigger an immune response and affect nanoparticles' toxicity and targeting capabilities. In this review, we provide a survey of recent findings on the (protein)corona-nanoparticle interaction and discuss how the corona modulates both cytotoxicity and the immune response as well as to improve the efficacy of targeted delivery of nanocarriers. - Highlights: • “Nanotoxicology” has emerged an autonomous field with an explosive growth. • Nanomaterials adsorb (bio)molecules forming the so-called (bio)molecule corona. • (Fine-)tune of the corona composition could enable new possibilities in nanomedicine.

Models of the plasma corona formation and stratification of exploding micro-wires

International Nuclear Information System (INIS)

Volkov, N.B.; Sarkisov, G.S.; Struve, K.W.; McDaniel, D.H.

2005-01-01

There are proposed the models pf plasma corona formation and stratification of a gas-plasma core of exploding micro-wire. The opportunity of use for the description of physical processes in a formed plasma corona of an electronic magnetohydrodynamics is generalized in view of change of particle number as a result of evaporation, ionization and a leaving of electrons on a wire surface. Necessity of the account of influence of a hot plasma corona on stratification of a gas-plasma core was grounded [ru

Comments on the 'minimum flux corona' concept

International Nuclear Information System (INIS)

Antiochos, S.K.; Underwood, J.H.

1978-01-01

Hearn's (1975) models of the energy balance and mass loss of stellar coronae, based on a 'minimum flux corona' concept, are critically examined. First, it is shown that the neglect of the relevant length scales for coronal temperature variation leads to an inconsistent computation of the total energy flux F. The stability arguments upon which the minimum flux concept is based are shown to be fallacious. Errors in the computation of the stellar wind contribution to the energy budget are identified. Finally we criticize Hearn's (1977) suggestion that the model, with a value of the thermal conductivity modified by the magnetic field, can explain the difference between solar coronal holes and quiet coronal regions. (orig.) 891 WL [de

Comparison of toluene removal in air at atmospheric conditions by different corona discharges.

Science.gov (United States)

Schiorlin, Milko; Marotta, Ester; Rea, Massimo; Paradisi, Cristina

2009-12-15

Different types of corona discharges, produced by DC of either polarity (+/-DC) and positive pulsed (+pulsed) high voltages, were applied to the removal of toluene via oxidation in air at room temperature and atmospheric pressure. Mechanistic insight was obtained through comparison of the three different corona regimes with regard to process efficiency, products, response to the presence of humidity and, for DC coronas, current/voltage characteristics coupled with ion analysis. Process efficiency increases in the order +DC toluene conversion and product selectivity were achieved, CO(2) and CO accounting for about 90% of all reacted carbon. Ion analysis, performed by APCI-MS (Atmospheric Pressure Chemical Ionization-Mass Spectrometry), provides a powerful rationale for interpreting current/voltage characteristics of DC coronas. All experimental findings are consistent with the proposal that in the case of +DC corona toluene oxidation is initiated by reactions with ions (O(2)(+*), H(3)O(+) and their hydrates, NO(+)) both in dry as well as in humid air. In contrast, with -DC no evidence is found for any significant reaction of toluene with negative ions. It is also concluded that in humid air OH radicals are involved in the initial stage of toluene oxidation induced both by -DC and +pulsed corona.

Core–corona PSt/P(BA–AA) composite particles by two-stage emulsion polymerization

Energy Technology Data Exchange (ETDEWEB)

Xie, Delong; Ren, Xiaolin; Zhang, Xinya, E-mail: cexyzh@scut.edu.cn; Liao, Shijun [South China University of Technology, School of Chemistry and Chemical Engineering (China)

2016-03-15

Raspberry-shaped composite particles with polystyrene (PSt) as core and poly(n-butyl acrylate-co-acrylic acid) (P(BA–AA)) as corona were synthesized via emulsion polymerization. The random copolymer, P(BA–AA), was pre-prepared and used as a polymeric surfactant, its emulsifying properties adjusted by changing the mass ratio of BA and AA. The morphology of the resulting core–corona composite particles, P(St/P(BA–AA)), could be regulated and controlled by varying the concentrations of P(BA–AA) or the mass ratio of BA:AA in P(BA–AA). The experimental results indicate that 3.0–6.0 wt% of P(BA–AA) is required to obtain stable composite emulsions, and P(BA–AA) with a mass ratio of BA:AA = 1:2 is able to generate distinct core–corona structures. A mechanism of composite particle formation is proposed based on the high affinity between the PSt core and the hydrophobic segments of P(BA–A). The regular morphology of the colloidal film is expected to facilitate potential application of core–corona particles in the field of light scattering. Furthermore, the diversity of core–corona particles can be expanded by replacing P(BA–AA) corona particles with other amphiphilic particles.

Breakdown of methylene blue and methyl orange by pulsed corona discharge

NARCIS (Netherlands)

Grabowski, L.R.; Veldhuizen, van E.M.; Pemen, A.J.M.; Rutgers, W.R.

2007-01-01

The recently developed corona above water technique is applied to water containing 10 mg l-1 methylene blue (MB) or methyl orange (MO). The corona discharge pulses are created with a spark gap switched capacitor followed by a transmission line transformer. The pulse amplitude is 40 kV; its duration

Corona ignition system for highly efficient gasoline engines; Corona-Zuendsystem fuer hocheffiziente Ottomotoren

Energy Technology Data Exchange (ETDEWEB)

Burrows, John [Federal-Mogul Limited, Manchester (United Kingdom); Lykowski, Jim; Mixell, Kristapher [Federal-Mogul, Plymouth, MI (United States)

2013-06-01

Many future gasoline engines will require higher air/fuel ratios and higher mean effective pressures to further improve fuel efficiency. Federal-Mogul has taken up this challenge and has developed the Advanced Corona Ignition System (ACIS) as a new solution to reliably ignite a mix with high AFR/EGR and high MEP. During engine tests ACIS enabled a direct fuel economy improvement of up to 10 %. (orig.)

Energy distribution of nanoflares in the quiet solar corona

Science.gov (United States)

Ulyanov, Artyom

2012-07-01

We present a detailed statistical analysis of flare-like events in low layer of solar corona detected with TESIS instrument onboard CORONAS-PHOTON satellite in 171 {Å} during high-cadence (5 sec) time-series. The estimated thermal energies of these small events amount to 10^{23} - 10^{26} erg. According to modern classification flare-like events with such energies are usually referred to as nanoflares. The big number of registered events (above 2000) allowed us to obtain precise distributions of geometric and physical parameters of nanoflares, the most intriguing being energy distribution. Following Aschwanden et al. (2000) and other authors we approximated the calculated energy distribution with a single power law slope: N(E)dE ˜ N^{-α}dE. The power law index was derived to be α = 2.4 ± 0.2, which is very close to the value reported by Krucker & Benz (1998): α ≈ 2.3 - 2.4. The total energy input from registered events constitute about 10^4 erg \\cdot cm^{-2} \\cdot s^{-1}, which is well beyond net losses in quiet corona (3 \\cdot 10^5 erg \\cdot cm^{-2} \\cdot s^{-1}). However, the value of α > 2 indicates that nanoflares with lower energies dominate over nanoflares with bigger energies and could contribute considerably to quiet corona heating.

Ground-based observation of emission lines from the corona of a red-dwarf star.

Science.gov (United States)

Schmitt, J H; Wichmann, R

2001-08-02

All 'solar-like' stars are surrounded by coronae, which contain magnetically confined plasma at temperatures above 106 K. (Until now, only the Sun's corona could be observed in the optical-as a shimmering envelope during a total solar eclipse.) As the underlying stellar 'surfaces'-the photospheres-are much cooler, some non-radiative process must be responsible for heating the coronae. The heating mechanism is generally thought to be magnetic in origin, but is not yet understood even for the case of the Sun. Ultraviolet emission lines first led to the discovery of the enormous temperature of the Sun's corona, but thermal emission from the coronae of other stars has hitherto been detectable only from space, at X-ray wavelengths. Here we report the detection of emission from highly ionized iron (Fe XIII at 3,388.1 A) in the corona of the red-dwarf star CN Leonis, using a ground-based telescope. The X-ray flux inferred from our data is consistent with previously measured X-ray fluxes, and the non-thermal line width of 18.4 km s-1 indicates great similarities between solar and stellar coronal heating mechanisms. The accessibility and spectral resolution (45,000) of the ground-based instrument are much better than those of X-ray satellites, so a new window to the study of stellar coronae has been opened.

In silico genome-wide identification and characterization of the glutathione S-transferase gene family in Vigna radiata.

Science.gov (United States)

Vaish, Swati; Awasthi, Praveen; Tiwari, Siddharth; Tiwari, Shailesh Kumar; Gupta, Divya; Basantani, Mahesh Kumar

2018-05-01

Plant glutathione S-transferases (GSTs) are integral to normal plant metabolism and biotic and abiotic stress tolerance. The GST gene family has been characterized in diverse plant species using molecular biology and bioinformatics approaches. In the current study, in silico analysis identified 44 GSTs in Vigna radiata. Of the total 44 GSTs identified, chromosomal locations of 31 GSTs were confirmed. The pI value of GST proteins ranged from 5.10 to 9.40. The predicted molecular weights ranged from 13.12 to 50 kDa. Subcellular localization analysis revealed that all GSTs were predominantly localized in the cytoplasm. The active site amino acids were confirmed to be serine in tau, phi, theta, zeta, and TCHQD; cysteine in lambda, DHAR, and omega; and tyrosine in EF1G. The gene architecture conformed to the two-exon/one-intron and three-exon/two-intron organization in the case of tau and phi classes, respectively. MEME analysis identified 10 significantly conserved motifs with the width of 8-50 amino acids. The motifs identified were either specific to a specific GST class or were shared by multiple GST classes. The results of the current study will be of potential importance in the characterization of the GST gene family in V. radiata, an economically important leguminous crop.

A review on functional and structural brain connectivity in numerical cognition

Directory of Open Access Journals (Sweden)

Korbinian eMoeller

2015-05-01

Full Text Available Only recently has the complex anatomo-functional system underlying numerical cognition become accessible to evaluation in the living brain. We identified 26 studies investigating brain connectivity in numerical cognition. Despite considerable heterogeneity regarding methodological approaches, populations investigated, and assessment procedures implemented, the results provided largely converging evidence regarding the underlying brain connectivity involved in numerical cognition. Analyses of both functional/effective as well as structural connectivity have consistently corroborated the assumption that numerical cognition is subserved by a fronto-parietal network including (intraparietal as well as (prefrontal cortex sites. Evaluation of structural connectivity has indicated the involvement of fronto-parietal association fibers encompassing the superior longitudinal fasciculus dorsally and the external capsule/extreme capsule system ventrally. Additionally, commissural fibers seem to connect the bilateral intraparietal sulci when number magnitude information is processed. Finally, the identification of projection fibers such as the superior corona radiata indicates connections between cortex and basal ganglia as well as the thalamus in numerical cognition. Studies on functional/effective connectivity further indicated a specific role of the hippocampus. These specifications of brain connectivity augment the triple-code model of number processing and calculation with respect to how grey matter areas associated with specific number-related representations may work together.

Differences in integrity of white matter and changes with training in spelling impaired children: a diffusion tensor imaging study.

Science.gov (United States)

Gebauer, D; Fink, A; Filippini, N; Johansen-Berg, H; Reishofer, G; Koschutnig, K; Kargl, R; Purgstaller, C; Fazekas, F; Enzinger, C

2012-07-01

While the functional correlates of spelling impairment have been rarely investigated, to our knowledge no study exists regarding the structural characteristics of spelling impairment and potential changes with interventions. Using diffusion tensor imaging at 3.0 T, we here therefore sought to investigate (a) differences between children with poor spelling abilities (training group and waiting group) and controls, and (b) the effects of a morpheme-based spelling intervention in children with poor spelling abilities on DTI parameters. A baseline comparison of white matter indices revealed significant differences between controls and spelling-impaired children, mainly located in the right hemisphere (superior corona radiata (SCR), posterior limb of internal capsule, superior longitudinal fasciculus). After 5 weeks of training, spelling ability improved in the training group, along with increases in fractional anisotropy and decreases of radial diffusivity in the right hemisphere compared to controls. In addition, significantly higher decreases of mean diffusivity in the right SCR for the spelling-impaired training group compared to the waiting group were observed. Our results suggest that spelling impairment is associated with differences in white-matter integrity in the right hemisphere. We also provide first indications that white matter changes occur during successful training, but this needs to be more specifically addressed in future research.

Diffusion tensor imaging in children with tuberous sclerosis complex: tract-based spatial statistics assessment of brain microstructural changes.

Science.gov (United States)

Zikou, Anastasia K; Xydis, Vasileios G; Astrakas, Loukas G; Nakou, Iliada; Tzarouchi, Loukia C; Tzoufi, Meropi; Argyropoulou, Maria I

2016-07-01

There is evidence of microstructural changes in normal-appearing white matter of patients with tuberous sclerosis complex. To evaluate major white matter tracts in children with tuberous sclerosis complex using tract-based spatial statistics diffusion tensor imaging (DTI) analysis. Eight children (mean age ± standard deviation: 8.5 ± 5.5 years) with an established diagnosis of tuberous sclerosis complex and 8 age-matched controls were studied. The imaging protocol consisted of T1-weighted high-resolution 3-D spoiled gradient-echo sequence and a spin-echo, echo-planar diffusion-weighted sequence. Differences in the diffusion indices were evaluated using tract-based spatial statistics. Tract-based spatial statistics showed increased axial diffusivity in the children with tuberous sclerosis complex in the superior and anterior corona radiata, the superior longitudinal fascicle, the inferior fronto-occipital fascicle, the uncinate fascicle and the anterior thalamic radiation. No significant differences were observed in fractional anisotropy, mean diffusivity and radial diffusivity between patients and control subjects. No difference was found in the diffusion indices between the baseline and follow-up examination in the patient group. Patients with tuberous sclerosis complex have increased axial diffusivity in major white matter tracts, probably related to reduced axonal integrity.

Diffusion tensor imaging in children with tuberous sclerosis complex: tract-based spatial statistics assessment of brain microstructural changes

International Nuclear Information System (INIS)

Zikou, Anastasia K.; Xydis, Vasileios G.; Tzarouchi, Loukia C.; Argyropoulou, Maria I.; Astrakas, Loukas G.; Nakou, Iliada; Tzoufi, Meropi

2016-01-01

There is evidence of microstructural changes in normal-appearing white matter of patients with tuberous sclerosis complex. To evaluate major white matter tracts in children with tuberous sclerosis complex using tract-based spatial statistics diffusion tensor imaging (DTI) analysis. Eight children (mean age ± standard deviation: 8.5 ± 5.5 years) with an established diagnosis of tuberous sclerosis complex and 8 age-matched controls were studied. The imaging protocol consisted of T1-weighted high-resolution 3-D spoiled gradient-echo sequence and a spin-echo, echo-planar diffusion-weighted sequence. Differences in the diffusion indices were evaluated using tract-based spatial statistics. Tract-based spatial statistics showed increased axial diffusivity in the children with tuberous sclerosis complex in the superior and anterior corona radiata, the superior longitudinal fascicle, the inferior fronto-occipital fascicle, the uncinate fascicle and the anterior thalamic radiation. No significant differences were observed in fractional anisotropy, mean diffusivity and radial diffusivity between patients and control subjects. No difference was found in the diffusion indices between the baseline and follow-up examination in the patient group. Patients with tuberous sclerosis complex have increased axial diffusivity in major white matter tracts, probably related to reduced axonal integrity. (orig.)

28-Homobrassinolide mitigates boron induced toxicity through enhanced antioxidant system in Vigna radiata plants.

Science.gov (United States)

Yusuf, Mohammad; Fariduddin, Qazi; Ahmad, Aqil

2011-11-01

The objective of this study was to establish relationship between boron induced oxidative stress and antioxidant system in Vigna radiata plants and also to investigate whether brassinosteroids will enhance the level of antioxidant system that could confer tolerance to the plants from the boron induced oxidative stress. The mung bean (V. radiata cv. T-44) plants were administered with 0.50, 1.0 and 2.0 mM boron at 6 d stage for 7 d along with nutrient solution. At 13 d stage, the seedlings were sprayed with deionized water (control) or 10(-8) M of 28-homobrassinolide and plants were harvested at 21 d stage to assess growth, leaf gas-exchange traits and biochemical parameters. The boron treatments diminished growth, water relations and photosynthetic attributes along with nitrate reductase and carbonic anhydrase activity in the concentration dependent manner whereas, it enhanced lipid peroxidation, electrolyte leakage, accumulation of H(2)O(2) as well as proline, and various antioxidant enzymes in the leaves of mung bean which were more pronounced at higher concentrations of boron. However, the follow-up application of 28-homobrassinolide to the boron stressed plants improved growth, water relations and photosynthesis and further enhanced the various antioxidant enzymes viz. catalase, peroxidase and superoxide dismutase and content of proline. The elevated level of antioxidant enzymes as well as proline could have conferred tolerance to the B-stressed plants resulting in improved growth, water relations and photosynthetic attributes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Genomic DNA methylation-demethylation during aging and reinvigoration of Pinus radiata.

Science.gov (United States)

Fraga, Mario F; Rodríguez, Roberto; Cañal, Maria Jesús

2002-08-01

In animals, DNA methylation is related to gene silencing during ontogenic development. Little is known about DNA methylation in plants, although occasional changes in the DNA methylation state of specific gene promoters have been reported in angiosperms during some developmental processes. We found large differences in the extent of DNA methylation between meristematic areas of juvenile and mature Pinus radiata D. Don. trees, whereas differences in the extent of DNA methylation between differentiated tissues of juvenile and mature trees were small. In meristematic areas, there was a gradual decrease in extent of DNA methylation as the degree of reinvigoration increased. The observed changes in extent of DNA methylation during aging and reinvigoration indicate that reinvigoration could be a consequence of epigenetic modifications opposite in direction to those that occur during aging.

Salt and drought stress and ABA responses related to bZIP genes from V. radiata and V. angularis.

Science.gov (United States)

Wang, Lanfen; Zhu, Jifeng; Li, Xiaoming; Wang, Shumin; Wu, Jing

2018-04-20

Mung bean and adzuki bean are warm-season legumes widely cultivated in China. However, bean production in major producing regions is limited by biotic and abiotic stress, such as drought and salt stress. Basic leucine zipper (bZIP) genes play key roles in responses to various biotic and abiotic stresses. However, only several bZIP genes involved in drought and salt stress in legumes, especially Vigna radiata and Vigna angularis, have been identified. In this study, we identified 54 and 50 bZIP proteins from whole-genome sequences of V. radiata and V. angularis, respectively. First, we comprehensively surveyed the characteristics of all bZIP genes, including their gene structure, chromosome distribution and motif composition. Phylogenetic trees showed that VrbZIP and VabZIP proteins were divided into ten clades comprising nine known and one unknown subgroup. The results of the nucleotide substitution rate of the orthologous gene pairs showed that bZIP proteins have undergone strong purifying selection: V. radiata and V. angularis diverged 1.25 million years ago (mya) to 9.20 mya (average of 4.95 mya). We also found that many cis-acting regulatory elements (CAREs) involved in abiotic stress and plant hormone responses were detected in the putative promoter regions of the bZIP genes. Finally, using the quantitative real-time PCR (qRT-PCR) method, we performed expression profiling of the bZIP genes in response to drought, salt and abscisic acid (ABA). We identified several bZIP genes that may be involved in drought and salt responses. Generally, our results provided useful and rich resources of VrbZIP and VabZIP genes for the functional characterization and understanding of bZIP transcription factors (TFs) in warm-season legumes. In addition, our results revealed important and interesting data - a subset of VrbZIP and VabZIP gene expression profiles in response to drought, salt and ABA stress. These results provide gene expression evidence for the selection of

Induction of chlorophyll chimeras and chlorophyll mutations in mungbean (Vigna radiata) cv. T44

International Nuclear Information System (INIS)

Singh, V.P.; Yadav, R.D.S.

1993-01-01

Uniform and healthy seeds of mungbean (Vigna radiata) cv. T44 were exposed to varying doses of gamma rays, ethyl methane sulphonate (EMS) and combination treatment of gamma rays with EMS. The data were recorded for seed germination, plant survival, frequency and spectrum of chlorophyll chimeras in M 1 and chlorophyll mutations in M 2 generation. Among all, the combination treatments were found most effective for inducing chlorophyll chimeras and chlorophyll mutations than the gamma rays or EMS alone. Of the mutants under reference, the albino, xantha and chlorina showed monogenic recessive while viridis exhibited digenic recessive inheritance. (author). 8 refs., 2 tabs

The detailed characteristics of positive corona current pulses in the line-to-plane electrodes

Science.gov (United States)

Xuebao, LI; Dayong, LI; Qian, ZHANG; Yinfei, LI; Xiang, CUI; Tiebing, LU

2018-05-01

The corona current pulses generated by corona discharge are the sources of the radio interference from transmission lines and the detailed characteristics of the corona current pulses from conductor should be investigated in order to reveal their generation mechanism. In this paper, the line-to-plane electrodes are designed to measure and analyze the characteristics of corona current pulses from positive corona discharges. The influences of inter-electrode gap and line diameters on the detail characteristics of corona current pulses, such as pulse amplitude, rise time, duration time and repetition frequency, are carefully analyzed. The obtained results show that the pulse amplitude and the repetition frequency increase with the diameter of line electrode when the electric fields on the surface of line electrodes are same. With the increase of inter-electrode gap, the pulse amplitude and the repetition frequency first decrease and then turn to be stable, while the rise time first increases and finally turns to be stable. The distributions of electric field and space charges under the line electrodes are calculated, and the influences of inter-electrode gap and line electrode diameter on the experimental results are qualitatively explained.

Formation of post-fire water-repellent layers in Monterrey pine (Pinus radiata D. Don) plantations in south-central Chile

Science.gov (United States)

P. Garcia-Chevesich; R. Pizarro; C. L. Stropki; P. Ramirez de Arellano; P. F. Ffolliott; L. F. DeBano; Dan Neary; D. C. Slack

2010-01-01

A wildfire burned about 15,000 ha of Monterrey Pine (Pinus radiata D. Don) plantations near Yungay, Chile, in January of 2007. Post-fire water repellency (hydrophobicity) was measured using the water-drop-penetration-time (WDPT) method at depths of 0, 5, and 10 mm from the soil surface. These measurements were collected on burned sites of both young (4-years old) and...

The corona problem connections between operator theory, function theory, and geometry

CERN Document Server

Krantz, Steven; Sawyer, Eric; Treil, Sergei; Wick, Brett

2014-01-01

The purpose of the corona workshop was to consider the corona problem in both one and several complex variables, both in the context of function theory and harmonic analysis as well as the context of operator theory and functional analysis. It was held in June 2012 at the Fields Institute in Toronto, and attended by about fifty mathematicians. This volume validates and commemorates the workshop, and records some of the ideas that were developed within. The corona problem dates back to 1941. It has exerted a powerful influence over mathematical analysis for nearly 75 years. There is material to help bring people up to speed in the latest ideas of the subject, as well as historical material to provide background. Particularly noteworthy is a history of the corona problem, authored by the five organizers, that provides a unique glimpse at how the problem and its many different solutions have developed. There has never been a meeting of this kind, and there has never been a volume of this kind. Mathematicians—...

Research on the correlation between corona current spectrum and audible noise spectrum of HVDC transmission line

Science.gov (United States)

Liu, Yingyi; Zhou, Lijuan; Liu, Yuanqing; Yuan, Haiwen; Ji, Liang

2017-11-01

Audible noise is closely related to corona current on a high voltage direct current (HVDC) transmission line. In this paper, we measured a large amount of audible noise and corona current waveforms simultaneously based on the largest outdoor HVDC corona cage all over the world. By analyzing the experimental data, the related statistical regularities between a corona current spectrum and an audible noise spectrum were obtained. Furthermore, the generation mechanism of audible noise was analyzed theoretically, and the related mathematical expression between the audible noise spectrum and the corona current spectrum, which is suitable for all of these measuring points in the space, has been established based on the electro-acoustic conversion theory. Finally, combined with the obtained mathematical relation, the internal reasons for these statistical regularities appearing in measured corona current and audible noise data were explained. The results of this paper not only present the statistical association regularities between the corona current spectrum and the audible noise spectrum on a HVDC transmission line, but also reveal the inherent reasons of these associated rules.

FTIR study of decomposition of carbon dioxide in dc corona discharges

International Nuclear Information System (INIS)

Horvath, G; Skalny, J D; Mason, N J

2008-01-01

The decomposition rate of carbon dioxide and the generation of ozone and carbon monoxide in coaxial corona discharges fed by pure CO 2 has been investigated in a dc corona discharge operated in both positive and negative polarities using FTIR spectroscopy. The degree of CO 2 decomposition is found to be dependent on the voltage, U, with a maximum CO 2 decomposition of nearly 10% found in a negative corona discharge for U = 7.5 kV. In all cases the amount of CO 2 decomposition was lower in positive polarity discharges than in negative polarity discharges operated under same conditions. CO and ozone were found to be the main products observed in the discharges.

FTIR study of decomposition of carbon dioxide in dc corona discharges

Energy Technology Data Exchange (ETDEWEB)

Horvath, G; Skalny, J D [Department of Experimental Physics, Comenius University, Mlynska dolina F-2, 842 48, Bratislava (Slovakia); Mason, N J [Open University, Department of Physics and Astronomy, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

2008-11-21

The decomposition rate of carbon dioxide and the generation of ozone and carbon monoxide in coaxial corona discharges fed by pure CO{sub 2} has been investigated in a dc corona discharge operated in both positive and negative polarities using FTIR spectroscopy. The degree of CO{sub 2} decomposition is found to be dependent on the voltage, U, with a maximum CO{sub 2} decomposition of nearly 10% found in a negative corona discharge for U = 7.5 kV. In all cases the amount of CO{sub 2} decomposition was lower in positive polarity discharges than in negative polarity discharges operated under same conditions. CO and ozone were found to be the main products observed in the discharges.

Viking solar corona experiment

International Nuclear Information System (INIS)

Tyler, G.L.; Brenkle, J.P.; Komarek, T.A.; Zygielbaum, A.I.

1977-01-01

The 1976 Mars solar conjunction resulted in complete occulations of the Viking spacecraft by the sun at solar minimum. During the conjunction period, coherent 3.5- and 13-cm wavelength radio waves from the orbiters passed through the solar corona and were received with the 64-m antennas of the NASA Deep Space Network. Data were obtained within at least 0.3 and 0.8 R/sub s/ of the photosphere at the 3.5- and 13-cm wavelengths, respectively. The data can be used to determine the plasma density integrated along the radio path, the velocity of density irregularities in the coronal plasma, and the spectrum of the density fluctuations in the plasma. Observations of integrated plasma density near the south pole of the sun generally agree with a model of the corona which has an 8:1 decrease in plasma density from the equator to the pole. Power spectra of the 3.5- and 13-cm signals at a heliocentric radial distance of about 2 R/sub s/ have a 1/2-power width of several hundred hertz and vary sharply with proximate geometric miss distance. Spectral broadening indicates a marked progressive increase in plasma irregularities with decreasing ray altitude at scales between about 1 and 100 km

INDUCED SCATTERING LIMITS ON FAST RADIO BURSTS FROM STELLAR CORONAE

Energy Technology Data Exchange (ETDEWEB)

Lyubarsky, Yuri [Physics Department, Ben-Gurion University, P.O.B. 653, Beer-Sheva 84105 (Israel); Ostrovska, Sofiya [Department of Mathematics, Atilim University, Incek 06836, Ankara (Turkey)

2016-02-10

The origin of fast radio bursts remains a puzzle. Suggestions have been made that they are produced within the Earth’s atmosphere, in stellar coronae, in other galaxies, or at cosmological distances. If they are extraterrestrial, the implied brightness temperature is very high, and therefore the induced scattering places constraints on possible models. In this paper, constraints are obtained on flares from coronae of nearby stars. It is shown that the radio pulses with the observed power could not be generated if the plasma density within and in the nearest vicinity of the source is as high as is necessary to provide the observed dispersion measure. However, one cannot exclude the possibility that the pulses are generated within a bubble with a very low density and pass through the dense plasma only in the outer corona.

Silver nanoparticle-human hemoglobin interface: time evolution of the corona formation and interaction phenomenon

Science.gov (United States)

Bhunia, A. K.; Kamilya, T.; Saha, S.

2017-10-01

In this paper, we have used spectroscopic and electron microscopic analysis to monitor the time evolution of the silver nanoparticles (Ag NP)-human hemoglobin (Hb) corona formation and to characterize the interaction of the Ag NPs with Hb. The time constants for surface plasmon resonance binding and reorganization are found to be 9.51 and 118.48 min, respectively. The drop of surface charge and the increase of the hydrodynamic diameter indicated the corona of Hb on the Ag NP surface. The auto correlation function is found to broaden with the increasing time of the corona formation. Surface zeta potential revealed that positively charged Hb interact electrostatically with negatively charged Ag NP surfaces. The change in α helix and β sheet depends on the corona formation time. The visualization of the Hb corona from HRTEM showed large number of Hb domains aggregate containing essentially Ag NPs and without Ag NPs. Emission study showed the tertiary deformation, energy transfer, nature of interaction and quenching under three different temperatures.

Mineralización del nitrógeno, carbono y actividad enzimática del suelo en un bosque de Nothofagus obliqua (Mirb Oerst y una plantación de Pinus radiata D. Don. del centro-sur de Chile Nitrogen and carbon mineralization and enzyme activity in soils of Nothofagus obliqua (Mirb Oerst stands and Pinus radiata D. Don plantation in south-central Chile

Directory of Open Access Journals (Sweden)

YESSICA RIVAS

2009-03-01

Full Text Available En Chile, el establecimiento de plantaciones comerciales de rápido crecimiento ha sido sostenido en las últimas décadas mediante la sustitución de bosques nativos y conversión de suelos agrícolas. Pinus radiata D. Don es la principal especie productiva, debido a su crecimiento acelerado y adaptabilidad al clima y los suelos. En el presente estudio se plantea que la actividad biológica del suelo es variable a través del año, en respuesta a variaciones de precipitación, temperatura y contenido de humedad de suelo y que el cambio de uso de suelo desde un bosque templado de Nothofagus obliqua (Mirb Oerst a una plantación con coniferas exóticas, modifica la química del suelo y consecuentemente los procesos de N-min, C-min y la actividad biológica del suelo. Esta hipótesis fue examinada en un bosque de N. obliqua y una plantación de P. radiata del centro-sur de Chile (40°07' S, 72° O. Se evaluó mensualmente la tasa mineralización de nitrógeno (N-min, cabono (C-min y la actividad enzimática potencial del suelo (ureasa, proteasa e hidrólisis de la fluoresceína diacetato entre septiembre 2003 y mayo 2005. Los resultados demuestran que los niveles de las variables de actividad biológica del suelo fueron significativamente diferentes entre las parcelas de bosque y plantación (Lambda de Wilk = 0,022; F 5,80 = 733; P In Chile, commercial forests plantations have increased during the last decades due in part to replacement of native forests and conversion of agricultural soils. Pinus radiata D. Don has been the main tree planted, due to its rapid growth and adaptability. In the present study we proposed that biological activity varies along the year due to changes of precipitation, temperature and soil water content and mainly because the conversion of native forest to exotic P. radiata plantations alters the soil chemistry, N and C mineralization and the potential enzymatic activity in these soils. This hypothesis was examined in a

The Substructure of the Solar Corona Observed in the Hi-C Telescope

Science.gov (United States)

Winebarger, A.; Cirtain, J.; Golub, L.; DeLuca, E.; Savage, S.; Alexander, C.; Schuler, T.

2014-01-01

In the summer of 2012, the High-resolution Coronal Imager (Hi-C) flew aboard a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore calculate how the intensity scales from a low-resolution (AIA) pixels to high-resolution (Hi-C) pixels for both the dynamic events and "background" emission (meaning, the steady emission over the 5 minutes of data acquisition time). We find there is no evidence of substructure in the background corona; the intensity scales smoothly from low-resolution to high-resolution Hi-C pixels. In transient events, however, the intensity observed with Hi-C is, on average, 2.6 times larger than observed with AIA. This increase in intensity suggests that AIA is not resolving these events. This result suggests a finely structured dynamic corona embedded in a smoothly varying background.

Anatomical aspects of the male reproductive system in the bonnet monkey (Macaca radiata).

Science.gov (United States)

Prakash, S; Suresh, S; Prithiviraj, E

2009-04-01

The normal anatomy of the male reproductive system in Macaca radiata is presented here. The external genitalia consist of a triangular button-shaped glans penis. The corpus cavernosum, and spongiosum form the vascular component of the penis and the baculum or os penis forms the non-vascular erectile component. The baculum is one of the longest in the genus macaques. The scrotal sac is non-pigmented, slightly pendulous, with scattered hairs, faintly corrugated, and does not reach the ischial callosities in the sitting posture. The testicles are ovoid in shape without appendix. Right and left testicular arteries originate at the level of the inter-vertebral disc between T12-L1 and L2-L3, respectively. Seminiferous tubules present mixed stages of spermatogenesis, i.e. single/multistage. The epididymis is crescent shaped, attached to the postero-lateral border of the testis without an appendix. Light microscopic observation revealed a characteristic high columnar epithelium with stereocilia. Clear cells or light cells are seen in the caudal region. The ductus deferens display a lumen lined by pseudo-stratified columnar epithelium separated by concentric layers of smooth muscle cells covered by serosa. The seminal vesicles are pyramidal in shape, prominently projecting above the urinary bladder, and are the largest of the accessory glands, typical of polyandrous primate genera. The prostate is conical in shape. Its base is in contact with the trigone of the bladder. Its posterior surface shows a transverse cleft separating an upper quarter, the cranial lobe, from the lower three-quarters of the gland. Compared with other macaques there are many distinguishing features in M. radiata. Excellent adaptability and spermatogenic efficiency in the laboratory environment makes this animal a good primate model for andrological research.

Effect of dc and pulsed corona discharge on DNA and proteins

International Nuclear Information System (INIS)

Shvedchikov, A.P.; Polyakova, A.V.; Belousova, E.V.; Ponizovskii, A.Z.; Goncharov, V.A.

1993-01-01

The authors have investigated the effect of a d.c. and pulsed corona discharge in air and nitrogen on DNA and albumin films in the temperature range 77-298 K. The authors have shown that upon exposure to a corona discharge and O 3 , the biopolymers are degraded. With a reduction in temperature, the extent of degradation of DNA drops

THE ALLELOPATHIC EFFECT OF SHREDDED LEAVES OF ARTOCARPUS HETEROPHYLLUS AND A. ALTILIS ON VIGNA RADIATA L

OpenAIRE

Romilly Margaret Mendez* & Glaxy Ezekel.V

2017-01-01

In the present study, an attempt has been made to study the effect of Artocarpus heterophyllus Lam. and Artocarpus altilis (Parkinson) Fosberg on seed germination, seedling growth and total phenolic content of Vigna radiata L. The objective of this study is to assess the rate of germination, growth of the seedlings and the chlorophyll content of the cultivar seeds exposed to four concentrations (10 ppm, 1 ppm, 0.1 ppm and 0.01 ppm) of the leaf extracts of A. heterophyllus and A. altilis. I...

A semi-analytical study of positive corona discharge in wire–plane electrode configuration

International Nuclear Information System (INIS)

Yanallah, K; Pontiga, F; Chen, J H

2013-01-01

Wire-to-plane positive corona discharge in air has been studied using an analytical model of two species (electrons and positive ions). The spatial distributions of electric field and charged species are obtained by integrating Gauss's law and the continuity equations of species along the Laplacian field lines. The experimental values of corona current intensity and applied voltage, together with Warburg's law, have been used to formulate the boundary condition for the electron density on the corona wire. To test the accuracy of the model, the approximate electric field distribution has been compared with the exact numerical solution obtained from a finite element analysis. A parametrical study of wire-to-plane corona discharge has then been undertaken using the approximate semi-analytical solutions. Thus, the spatial distributions of electric field and charged particles have been computed for different values of the gas pressure, wire radius and electrode separation. Also, the two dimensional distribution of ozone density has been obtained using a simplified plasma chemistry model. The approximate semi-analytical solutions can be evaluated in a negligible computational time, yet provide precise estimates of corona discharge variables. (paper)

A semi-analytical study of positive corona discharge in wire-plane electrode configuration

Science.gov (United States)

Yanallah, K.; Pontiga, F.; Chen, J. H.

2013-08-01

Wire-to-plane positive corona discharge in air has been studied using an analytical model of two species (electrons and positive ions). The spatial distributions of electric field and charged species are obtained by integrating Gauss's law and the continuity equations of species along the Laplacian field lines. The experimental values of corona current intensity and applied voltage, together with Warburg's law, have been used to formulate the boundary condition for the electron density on the corona wire. To test the accuracy of the model, the approximate electric field distribution has been compared with the exact numerical solution obtained from a finite element analysis. A parametrical study of wire-to-plane corona discharge has then been undertaken using the approximate semi-analytical solutions. Thus, the spatial distributions of electric field and charged particles have been computed for different values of the gas pressure, wire radius and electrode separation. Also, the two dimensional distribution of ozone density has been obtained using a simplified plasma chemistry model. The approximate semi-analytical solutions can be evaluated in a negligible computational time, yet provide precise estimates of corona discharge variables.

Nontarget effects of chemical pesticides and biological pesticide on rhizospheric microbial community structure and function in Vigna radiata.

Science.gov (United States)

Singh, Sunil; Gupta, Rashi; Kumari, Madhu; Sharma, Shilpi

2015-08-01

Intensive agriculture has resulted in an indiscriminate use of pesticides, which demands in-depth analysis of their impact on indigenous rhizospheric microbial community structure and function. Hence, the objective of the present work was to study the impact of two chemical pesticides (chlorpyrifos and cypermethrin) and one biological pesticide (azadirachtin) at two dosages on the microbial community structure using cultivation-dependent approach and on rhizospheric bacterial communities involved in nitrogen cycle in Vigna radiata rhizosphere through cultivation-independent technique of real-time PCR. Cultivation-dependent study highlighted the adverse effects of both chemical pesticide and biopesticide on rhizospheric bacterial and fungal communities at different plant growth stages. Also, an adverse effect on number of genes and transcripts of nifH (nitrogen fixation); amoA (nitrification); and narG, nirK, and nirS (denitrification) was observed. The results from the present study highlighted two points, firstly that nontarget effects of pesticides are significantly detrimental to soil microflora, and despite being of biological origin, azadirachtin exerted negative impact on rhizospheric microbial community of V. radiata behaving similar to chemical pesticides. Hence, such nontarget effects of chemical pesticide and biopesticide in plants' rhizosphere, which bring out the larger picture in terms of their ecotoxicological effect, demand a proper risk assessment before application of pesticides as agricultural amendments.

Sulphur dioxide (SO2) electrotransfer in electric field generated by corona discharge

International Nuclear Information System (INIS)

Wang, Zu-wu; Guo, Jia; Zeng, Han-cai; Ge, Chun-liang; Yu, Jiang

2007-01-01

The mechanism of the forming SO 2 negative ions and their electrotransfer in the corona discharge electric field was investigated in this paper. The experimental results showed that SO 2 electrotransfer occurred in the electric field with corona discharge, which had potential applications in removal of SO 2 of the flue gas from coal-fired power plants by electrotransfer. SO 2 electrotransfer was enhanced by higher electric-field intensity or a larger discharging area. Assistant uniform electric field after the corona discharge electric field would improve SO 2 electrotransfer. The increment of the desulphurization efficiency by SO 2 electrotransfer might reach as high as 50%. (author)

The role of the right inferior frontal gyrus in the pathogenesis of post-stroke psychosis.

Science.gov (United States)

Devine, Michael J; Bentley, Paul; Jones, Brynmor; Hotton, Gary; Greenwood, Richard J; Jenkins, I Harri; Joyce, Eileen M; Malhotra, Paresh A

2014-03-01

Psychotic symptoms have previously been reported following right hemisphere brain injury. We sought to identify the specific neuroanatomical basis of delusions following stroke by studying a series of patients with post-stroke psychosis. Lesion overlap analysis was conducted on three individuals with delusions following right hemisphere stroke. These cases were compared with a control group of patients with similar anatomical damage. The main outcome measures were presence of delusions and presence of behavioural susceptibility. The right inferior frontal gyrus and underlying white matter, including the superior longitudinal fasciculus and anterior corona radiata, were involved in all three cases. All three had a preexisting untreated psychiatric disorder. In contrast, only one of nine control cases with equivalent lesions had evidence of previous psychiatric disorder (p = 0.0182, Fisher's exact test), and this was being treated at the time of stroke. We provide clinical evidence from patients with structural brain lesions implicating damage to the right inferior frontal lobe in the generation of persistent psychosis following stroke. We suggest that preexisting psychiatric disease provided a behavioural susceptibility to develop delusions in these individuals.

Corona SDK application design

CERN Document Server

Williams, Daniel

2013-01-01

A step by step tutorial that focuses on everything from setup to deployment of basic apps.Have you ever wanted to create your own app? Then this book is for you. You will learn how to create apps using Corona SDK and how to publish your app so others can get a glimpse of your creation. This book is aimed at both Android and iOS app developers. The reader must have basic knowledge of app development.

Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata.

Science.gov (United States)

Beloti, Vitor Hugo; Alves, Gustavo Rodrigues; Araújo, Diogo Feliciano Dias; Picoli, Mateus Manara; Moral, Rafael de Andrade; Demétrio, Clarice Garcia Borges; Yamamoto, Pedro Takao

2015-01-01

Huanglongbing (HLB) is a disease associated with the bacteria "Candidatus Liberibacter spp." and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston), the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1), 12% as slightly harmful (Class 2), 12% as moderately harmful (Class 3) and 56% as harmful (Class 4), according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful) were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless) were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases.

Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata.

Directory of Open Access Journals (Sweden)

Vitor Hugo Beloti

Full Text Available Huanglongbing (HLB is a disease associated with the bacteria "Candidatus Liberibacter spp." and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston, the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1, 12% as slightly harmful (Class 2, 12% as moderately harmful (Class 3 and 56% as harmful (Class 4, according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases.

''Relaxing phenomena'' in negative corona discharge in air: new aspects

International Nuclear Information System (INIS)

Strelle, D.; Pavlik, M.; Skalny, J.D.

1998-01-01

Several conspicuous differences between the positive and the negative corona discharges in air observed in small discharge gaps have been explained by two recent theoretical models considering the ion-molecule and chemical reactions in the negative corona discharge in air. In the present paper the discrepancies of these models are discussed, and the earlier experimental data and the presumptions used in the models are re-examined in the light of the latest experimentally confirmed facts. (J.U.)

Low-level NOx removal in ambient air by pulsed corona technology

International Nuclear Information System (INIS)

Beckers, F J C M; Hoeben, W F L M; Pemen, A J M; Van Heesch, E J M

2013-01-01

Although removal of NO x by (pulsed) corona discharges has been thoroughly investigated for high concentrations of NO x in flue gas, removal of low levels in ambient air proves to be a difficult task. (Sub) ppm NO x levels exist in traffic tunnels due to accumulation of exhaust gases. The application of pulsed corona technology for purification of traffic tunnel air is studied during a series of lab and field experiments. An industrial pilot scale wire-cylinder type corona reactor has been utilized. Lab tests have been carried out using a diesel generator as NO x source. NO x conversion levels have been determined by applying two Recordum Airpointers (chemiluminescence-based detection). The detector appeared to be cross-sensitive for HNO 3 and high levels of O 3 . NO x removal rates of 60–80% were obtained for inlet levels of 2–10 ppm. The SIE value of 10 ppm NO x removal is 7 J l −1 . The corona discharges produce ppm level NO x at high energy densities. This intrinsic NO x production limits removal of inlet levels due to equilibrium between production and oxidation. (paper)

HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

Energy Technology Data Exchange (ETDEWEB)

Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

2013-08-01

Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

Simulation of the AC corona phenomenon with experimental validation

International Nuclear Information System (INIS)

Villa, Andrea; Barbieri, Luca; Marco, Gondola; Malgesini, Roberto; Leon-Garzon, Andres R

2017-01-01

The corona effect, and in particular the Trichel phenomenon, is an important aspect of plasma physics with many technical applications, such as pollution reduction, surface and medical treatments. This phenomenon is also associated with components used in the power industry where it is, in many cases, the source of electro-magnetic disturbance, noise and production of undesired chemically active species. Despite the power industry to date using mainly alternating current (AC) transmission, most of the studies related to the corona effect have been carried out with direct current (DC) sources. Therefore, there is technical interest in validating numerical codes capable of simulating the AC phenomenon. In this work we describe a set of partial differential equations that are comprehensive enough to reproduce the distinctive features of the corona in an AC regime. The model embeds some selectable chemical databases, comprising tens of chemical species and hundreds of reactions, the thermal dynamics of neutral species and photoionization. A large set of parameters—deduced from experiments and numerical estimations—are compared, to assess the effectiveness of the proposed approach. (paper)

Corona initiated from grounded objects under thunderstorm conditions and its influence on lightning attachment

International Nuclear Information System (INIS)

Bazelyan, E M; Raizer, Yu P; Aleksandrov, N L

2008-01-01

Lightning attachment to grounded structures due to the initiation of an upward connecting leader from them is considered taking into account the effect of corona space charge near the structures. It is shown that the corona space charge strongly affects the initiation and development of the connecting leader. Specific features of a non-stationary corona are analysed analytically and numerically for one-dimensional electrode geometries and for a grounded rod coronating in a slowly varying thundercloud electric field that can be enhanced by the charge of an approaching downward lightning leader. Initiation and development of an upward connecting leader or upward lightning from high ground objects are investigated. Prospects of using the effect of coronae to control downward lightning discharges are discussed.

Comparison of reconnection in magnetosphere and solar corona

Science.gov (United States)

Imada, Shinsuke; Hirai, Mariko; Isobe, Hiroaki; Oka, Mitsuo; Watanabe, Kyoko; Minoshima, Takashi

One of the most famous rapid energy conversion mechanisms in space is a magnetic reconnec-tion. The general concept of a magnetic reconnection is that the rapid energy conversion from magnetic field energy to thermal energy, kinetic energy or non-thermal particle energy. The understanding of rapid energy conversion rates from magnetic field energy to other energy is the fundamental and essential problem in the space physics. One of the important goals for studying magnetic reconnection is to answer what plasma condition/parameter controls the energy conversion rates. Earth's magnetotail has been paid much attention to discuss a mag-netic reconnection, because we can discuss magnetic reconnection characteristics in detail with direct in-situ observation. Recently, solar atmosphere has been focused as a space laboratory for magnetic reconnection because of its variety in plasma condition. So far considerable effort has been devoted toward understanding the energy conversion rates of magnetic reconnection, and various typical features associated with magnetic reconnection have been observed in the Earth's magnetotail and the solar corona. In this talk, we first introduce the variety of plasma condition/parameter in solar corona and Earth's magnetotail. Later, we discuss what plasma condition/parameter controls the energy conversion from magnetic field to especially non-thermal particle. To compare non-thermal electron and ion acceleration in magnetic reconnection, we used Hard X-ray (electron) /Neu-tron monitor (ion) for solar corona and Geotail in-situ measurement (electron and ion) for magnetoatil. We found both of electron and ion accelerations are roughly controlled by re-connection electric field (reconnection rate). However, some detail points are different in ion and electron acceleration. Further, we will discuss what is the major difference between solar corona and Earth's magnetotail for particle acceleration.

Threaded-Field-Line Model for the Transition Region and Solar Corona

Science.gov (United States)

Sokolov, I.; van der Holst, B.; Gombosi, T. I.

2014-12-01

In numerical simulations of the solar corona, both for the ambient state and especially for dynamical processes the most computational resources are spent for maintaining the numerical solution in the Low Solar Corona and in the transition region, where the temperature gradients are very sharp and the magnetic field has a complicated topology. The degraded computational efficiency is caused by the need in a highest resolution as well as the use of the fully three-dimensional implicit solver for electron heat conduction. On the other hand, the physical nature of the processes involved is rather simple (which still does not facilitate the numerical methods) as long as the heat fluxes as well as slow plasma motional velocities are aligned with the magnetic field. The Alfven wave turbulence, which is often believed to be the main driver of the solar wind and the main source of the coronal heating, is characterized by the Poynting flux of the waves, which is also aligned with the magnetic field. Therefore, the plasma state in any point of the three-dimensional grid in the Low Solar Corona can be found by solving a set of one-dimensional equations for the magnetic field line ("thread"), which passes through this point and connects it to the chromosphere and to the global Solar Corona. In the present paper we describe an innovative computational technology based upon the use of the magnetic-field-line-threads to forlmulate the boundary condition for the global solar corona model which traces the connection of each boundary point to the cromosphere along the threads.

Analysis of disconnected diallel mating designs II: results from a third generation progeny test of the New Zealand radiata pine improvement programme.

Science.gov (United States)

J.N. King; M.J. Carson; G.R. Johnson

1998-01-01

Genetic parameters from a second generation (F2) disconnected diallel progeny test of the New Zealand radiata pine improvement programme are presented. Heritability estimates of growth and yield traits of 0.2 are similar to progeny test results of the previous generation (F1) generation tests. A trend of declining dominance...

MADERA DE COMPRESIÓN EN PINUS RADIATA D. DON: I, CARACTERÍSTICAS ANATÓMICAS

OpenAIRE

Diaz-vaz,J.E; Fernandez,A; Valenzuela,L; Torres,M

2007-01-01

Se caracterizó la madera de compresión en 10 árboles de Pinus radiata D.Don con inclinaciones menores a 10 º en dos sitios.          Los diámetros de traqueidas de los árboles del sitio Arena húmeda resultaron estadísticamente mayores que los del sitio Arcilla; pero no resultaron diferentes al comparar madera juvenil y madura o al compara madera de compresión con madera opuesta.          Diferencias significativas se determinaron en el largo de traqueida entre sitios (Arena húmeda-Arcilla), t...

Flight Dynamics and Abundance of Ips sexdentatus (Coleoptera: Curculionidae: Scolytinae in Different Sawmills from Northern Spain: Differences between Local Pinus radiata (Pinales: Pinaceae and Southern France Incoming P. pinaster Timber

Directory of Open Access Journals (Sweden)

Sergio López

2012-01-01

Full Text Available In January 2009, the windstorm “Klaus” struck the southern part of France, affecting 37.9 million m3 of maritime pine Pinus pinaster Aiton (Pinales: Pinaceae. This breeding plant material favored the outbreak of Ips sexdentatus (Börner (Coleoptera: Curculionidae: Scolytinae. As much of this timber is imported to the Basque Country (northern Spain, a potential risk to conifer stands is generated, due to the emergence of the incoming beetles. Thus, flight dynamics and beetle abundance were compared in different sawmills, according to the timber species (either local P. radiata D. Don or imported P. pinaster. A maximum flight peak of I. sexdentatus was observed in mid-June in P. pinaster importing sawmills, whereas a second lighter peak occurred in September. In contrast, only a maximum peak in mid-June was observed in P. radiata inhabiting beetles, being significantly smaller than in local P. pinaster trading sawmills. In addition, significant differences were found between imported P. pinaster and P. radiata regarding the number of insects beneath the bark. The development of IPM strategies for controlling I. sexdentatus populations is recommended, due to the insect abundance found in P. pinaster imported timber.

Block copolymer micelle coronas as quasi-two-dimensional dilute or semidilute polymer solutions

DEFF Research Database (Denmark)

Svaneborg, C.; Pedersen, J.S.

2001-01-01

Chain-chain interactions in a corona of polymers tethered to a spherical core under good solvent conditions are studied using Monte Carlo simulations. The total scattering function of the corona as well as different partial contributions are sampled. By combining the different contributions...

On ion-cyclotron-resonance heating of the corona and solar wind

Directory of Open Access Journals (Sweden)

E. Marsch

2003-01-01

Full Text Available This paper concisely summarizes and critically reviews recent work by the authors on models of the heating of the solar corona by resonance of ions with high-frequency waves (up to the proton cyclotron frequency. The quasi-linear theory of pitch angle diffusion is presented in connection with relevant solar wind proton observations. Hybrid fluid-kinetic model equations, which include wave-particle interactions and collisions, are derived. Numerical solutions are discussed, representative of the inner corona and near-Sun solar wind. A semi-kinetic model for reduced velocity distributions is presented, yielding kinetic results for heavy ions in the solar corona. It is concluded that a self-consistent treatment of particle distributions and wave spectra is required, in order to adequately describe coronal physics and to obtain agreement with observations.

Radio and television interference caused by corona discharges from high-voltage transmission lines

International Nuclear Information System (INIS)

Sarmadi, M.

1996-01-01

Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions and generally increases by 10 to 30 dB in foul weather

Transformation of soybean Gy3 gene into Artemisaarenaria mediated by corona discharge

International Nuclear Information System (INIS)

Chao, Lu-meng; Na, Ri; Xue, Dan; Xu, Yongze; Liu, Teng

2013-01-01

In order to improve the protein content of desert plant, a method of genetic transformation mediated by corona discharge was established. Artemisia seeds were processed in corona electric field for 120 min at 12 kV, and then soaked in 0.1 SSC media that contained Soybean Gy3 gene DNA to incubate for 12 h at 26 °C. Finally the seeds were inoculated on the differentiation medium. Polymerase Chain Reaction (PCR) and Reverse Transcription Polymerase Chain Reaction (RT-PCR) detection showed that the Soybean Gy3 gene had been successfully introduced into genomic DNA of the regenerated plants of Artemisaarenaria. The study provided a new way for corona discharge in plant genetic modification.

Hi-C Observations of an Active Region Corona, and Investigation of the Underlying Magnetic Structure

Science.gov (United States)

Tiwari, S. K.; Alexander, C. E.; Winebarger, A.; Moore, R. L.

2014-01-01

The solar corona is much hotter (>=10(exp 6) K) than its surface (approx 6000 K), puzzling astrophysicists for several decades. Active region (AR) corona is again hotter than the quiet Sun (QS) corona by a factor of 4-10. The most widely accepted mechanism that could heat the active region corona is the energy release by current dissipation via reconnection of braided magnetic field structure, first proposed by E. N. Parker three decades ago. The first observational evidence for this mechanism has only recently been presented by Cirtain et al. by using High-resolution Coronal Imager (Hi-C) observations of an AR corona at a spatial resolution of 0.2 arcsec, which is required to resolve the coronal loops, and was not available before the rocket flight of Hi-C in July 2012. The Hi-C project is led by NASA/MSFC. In the case of the QS, work done by convection/granulation on the inter-granular feet of the coronal field lines translates into the heat observed in the corona. In the case of the AR, as here, there could be flux emergence, cancellation/submergence, or shear flows generating large stress and tension in coronal field loops which is released as heat in the corona. We are currently investigating the changes taking place in photospheric feet of the magnetic field involved with brightenings in the Hi-C AR corona. For this purpose, we are also using SDO/AIA data of +/- 2 hours around the 5 minutes Hi-C flight. In the present talk, I will first summarize some of the results of the Hi-C observations and then present some results from our recent analysis on what photospheric processes feed the magnetic energy that dissipates into heat in coronal loops.

Improving initiation, genotype capture, and family representation in somatic embryogenesis of Pinus radiata by a combination of zygotic embryo maturity, media, and explant preparation

DEFF Research Database (Denmark)

Hargreaves, Cathy; Find, Jens; Reeves, Cathie

2009-01-01

The principal aim of this investigation was to improve somatic embryogenesis initiation and to enhance representation of families and genotypes within those families of Pinus radiata D. Don. A total of 19 open-pollinated seed families, many with unrelated and weakly related parents, were tested...

Sub-Compartment Variation in Tree Height, Stem Diameter and Stocking in a Pinus radiata D. Don Plantation Examined Using Airborne LiDAR Data

Directory of Open Access Journals (Sweden)

Hanieh Saremi

2014-08-01

Full Text Available Better information regarding the spatial variability of height, Diameter at Breast Height (DBH and stocking could improve inventory estimates at the operational Planning Unit since these parameters are used extensively in allometric equations, including stem volume, biomass and carbon calculations. In this study, the influence of stand stocking on height and DBH of two even aged radiata pine (Pinus radiata D. Don stands were investigated using airborne Light Detection and Ranging (LiDAR data at a study site in New South Wales, Australia. Both stands were characterized by irregular stocking due to patchy establishment and self-thinning in the absence of any silvicultural thinning events. For the purpose of this study, a total of 34 plots from a 34 year old site and 43 plots from a nine year old site were established, from which a total of 447 trees were sampled. Within these plots, DBH and height measurements were measured and their relationships with stocking were evaluated. LiDAR was used for height estimation as well as stem counts in fixed plots (stocking. The results showed a significant relationship between stem DBH and stocking. At both locations, trees with larger diameters were found on lower stocking sites. Height values were also significantly correlated with stocking, with taller trees associated with high stocking. These results were further verified of additional tree samples, with independent field surveys for DBH and LiDAR-derived metrics for height analysis. This study confirmed the relationship between P. radiata tree heights and stem diameter with stocking and demonstrated the capacity of LiDAR to capture sub-compartment variation in these tree-level attributes.

Transcriptional Slippage and RNA Editing Increase the Diversity of Transcripts in Chloroplasts: Insight from Deep Sequencing of Vigna radiata Genome and Transcriptome.

Directory of Open Access Journals (Sweden)

Ching-Ping Lin

Full Text Available We performed deep sequencing of the nuclear and organellar genomes of three mungbean genotypes: Vigna radiata ssp. sublobata TC1966, V. radiata var. radiata NM92 and the recombinant inbred line RIL59 derived from a cross between TC1966 and NM92. Moreover, we performed deep sequencing of the RIL59 transcriptome to investigate transcript variability. The mungbean chloroplast genome has a quadripartite structure including a pair of inverted repeats separated by two single copy regions. A total of 213 simple sequence repeats were identified in the chloroplast genomes of NM92 and RIL59; 78 single nucleotide variants and nine indels were discovered in comparing the chloroplast genomes of TC1966 and NM92. Analysis of the mungbean chloroplast transcriptome revealed mRNAs that were affected by transcriptional slippage and RNA editing. Transcriptional slippage frequency was positively correlated with the length of simple sequence repeats of the mungbean chloroplast genome (R2=0.9911. In total, 41 C-to-U editing sites were found in 23 chloroplast genes and in one intergenic spacer. No editing site that swapped U to C was found. A combination of bioinformatics and experimental methods revealed that the plastid-encoded RNA polymerase-transcribed genes psbF and ndhA are affected by transcriptional slippage in mungbean and in main lineages of land plants, including three dicots (Glycine max, Brassica rapa, and Nicotiana tabacum, two monocots (Oryza sativa and Zea mays, two gymnosperms (Pinus taeda and Ginkgo biloba and one moss (Physcomitrella patens. Transcript analysis of the rps2 gene showed that transcriptional slippage could affect transcripts at single sequence repeat regions with poly-A runs. It showed that transcriptional slippage together with incomplete RNA editing may cause sequence diversity of transcripts in chloroplasts of land plants.

Signatures of Lithospheric Flexure and Elevated Heat Flow in Stereo Topography at Coronae on Venus

Science.gov (United States)

O'Rourke, Joseph G.; Smrekar, Suzanne E.

2018-02-01

Signatures of lithospheric flexure were previously identified at a dozen or more large coronae on Venus. Thin plate models fit to topographic profiles return elastic parameters, allowing derivation of mechanical thickness and surface heat flows given an assumed yield strength envelope. However, the low resolution of altimetry data from the NASA Magellan mission has hindered studying the vast majority of coronae, particularly those less than a few hundred kilometers in diameter. Here we search for flexural signatures around 99 coronae over ˜20% of the surface in Magellan altimetry data and stereo-derived topography that was recently assembled from synthetic aperture radar images. We derive elastic thicknesses of ˜2 to 30 km (mostly ˜5 to 15 km) with Cartesian and axisymmetric models at 19 coronae. We discuss the implications of low values that were also noted in earlier gravity studies. Most mechanical thicknesses are estimated as 24 K km-1. Implied surface heat flows >95 mW m-2—twice the global average in many thermal evolution models—imply that coronae are major contributors to the total heat budget or Venus is cooling faster than expected. Binomial statistics show that "Type 2" coronae with incomplete fracture annuli are significantly less likely to host flexural signatures than "Type 1" coronae with largely complete annuli. Stress calculations predict extensional faulting where nearly all profiles intersect concentric fractures. We failed to identify systematic variations in flexural parameters based on type, geologic setting, or morphologic class. Obtaining quality, high-resolution topography from a planetwide survey is vital to verifying our conclusions.

Catastrophic cooling and cessation of heating in the solar corona

Science.gov (United States)

Peter, H.; Bingert, S.; Kamio, S.

2012-01-01

Context. Condensations in the more than 106 K hot corona of the Sun are commonly observed in the extreme ultraviolet (EUV). While their contribution to the total solar EUV radiation is still a matter of debate, these condensations certainly provide a valuable tool for studying the dynamic response of the corona to the heating processes. Aims: We investigate different distributions of energy input in time and space to investigate which process is most relevant for understanding these coronal condensations. Methods: For a comparison to observations we synthesize EUV emission from a time-dependent, one-dimensional model for coronal loops, where we employ two heating scenarios: simply shutting down the heating and a model where the heating is very concentrated at the loop footpoints, while keeping the total heat input constant. Results: The heating off/on model does not lead to significant EUV count rates that one observes with SDO/AIA. In contrast, the concentration of the heating near the footpoints leads to thermal non-equilibrium near the loop top resulting in the well-known catastrophic cooling. This process gives a good match to observations of coronal condensations. Conclusions: This shows that the corona needs a steady supply of energy to support the coronal plasma, even during coronal condensations. Otherwise the corona would drain very fast, too fast to even form a condensation. Movies are available in electronic form at http://www.aanda.org

Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

Directory of Open Access Journals (Sweden)

J. W. Zhang

2017-10-01

Full Text Available As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC. In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

Science.gov (United States)

Zhang, J. W.; Zhou, T. C.; Wang, J. X.; Yang, X. F.; Zhu, F.; Tian, L. M.; Liu, R. T.

2017-10-01

As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC). In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

Oviposition behavior and survival of Tamarixia radiata (Hymenoptera: Eulophidae), an ectoparasitoid of the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), on hosts exposed to an entomopathogenic fungus

Science.gov (United States)

Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 isolate of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae) could disrupt biological control of the Asian citrus psyllid, Diaphorina ...

High-cadence observations of CME initiation and plasma dynamics in the corona with TESIS on board CORONAS-Photon

Science.gov (United States)

Bogachev, Sergey; Kuzin, Sergey; Zhitnik, I. A.; Bugaenko, O. I.; Goncharov, A. L.; Ignatyev, A. P.; Krutov, V. V.; Lomkova, V. M.; Mitrofanov, A. V.; Nasonkina, T. P.; Oparin, S. N.; Petzov, A. A.; Shestov, S. V.; Slemzin, V. A.; Soloviev, V. A.; Suhodrev, N. K.; Shergina, T. A.

The TESIS is an ensemble of space instruments designed in Lebedev Institute of Russian Academy of Sciences for spectroscopic and imaging investigation of the Sun in EUV and soft X-ray spectral range with high spatial, temporal and spectral resolution. From 2009 January, when TESIS was launched onboard the Coronas-Photon satellite, it provided about 200 000 new images and spectra of the Sun, obtained during one of the deepest solar minimum in last century. Because of the wide field of view (4 solar radii) and high sensitivity, TESIS provided high-quality data on the origin and dynamics of eruptive prominences and CMEs in the low and intermediate solar corona. TESIS is also the first EUV instrument which provided high-cadence observations of coronal bright points and solar spicules with temporal resolution of a few seconds. We present first results of TESIS observations and discuss them from a scientific point of view.

Dielectric fluid directional spreading under the action of corona discharge

Science.gov (United States)

Zhou, Shangru; Liu, Jie; Hu, Qun; Jiang, Teng; Yang, Jinchu; Liu, Sheng; Zheng, Huai

2018-01-01

Liquid spreading is a very common nature phenomenon and of significant importance for a broad range of applications. In this study, a dielectric fluid directional spreading phenomenon is presented. Under the action of corona discharge, a dielectric fluid, here a typical silicone directionally spreads along conductive patterns on conductive/nonconductive substrates. Directional spreading behaviors of silicone were experimentally observed on different conductive patterns in detail. Spreading speeds were analyzed at different driving voltages, which induced the corona discharge. The presented phenomenon may be useful to inspire several techniques of manipulating liquid transportation and fabricating micropatterns.

Create 2D mobile games with Corona SDK for iOS and Android

CERN Document Server

Mekersa, David

2015-01-01

Corona SDK is one of the most powerful tools used to create games and apps for mobile devices.The market requires speed; new developers need to operate quickly and efficiently. Create 2D Mobile Games with Corona SDK gives you the tools needed to master Corona - even within the framework of professional constraints. A must-read guide, this book gives you fast, accurate tips to learn the programming language necessary to create games. Read it sequentially or as an FAQ and you will have the tools you need to create any base game before moving on to advanced topics. The tutorial-based format:Conta

Density determination in Pino Radiata (D.Don) samples using 59.5 keV gamma radiation attenuation; Determinacion de densidad en muestras de Pino Radiata (D. Don) mediante atenuacion de radiacion gamma de 59.5 KeV

Energy Technology Data Exchange (ETDEWEB)

Dinator, Maria I; Morales, Jose R; Aliaga, Nelson [Chile Univ., Santiago (Chile). Dept. de Fisica; Karsulovic, Jose T; Sanchez, Jaime; Leon, Adolfo [Chile Univ., Santiago (Chile). Dept. de Tecnologia de la Madera

1997-12-31

A non destructive method to determine wood samples density is presented. The photon mass attenuation coefficient in samples of Pino radiata (D.Don) was measured at 59.5 keV with a radioactive source of Am-241. The value of 0.192 {+-} 0.002 cm{sup 2}/g was obtained with a gamma spectroscopy system and later used on the determination of the mass density in sixteen samples of the same species. Comparison of these results with those of gravimetric method through a linear regression showed a slope of 1.001 and a correlation factor of 0.94. (author). 3 refs., 4 figs.

EFFECT OF THE REACTION CONDITIONS OVER THE YIELD AND PROPERTIES OF METHYLCELLULOSE OBTAINED FROM PINUS RADIATA KRAFT BLEACHED CELLULOSE

OpenAIRE

TAPIA, C.; SAPAG-HAGAR, J.; ANDRADE, C.T.; HASSÓN, J.; VALENZUELA, F.; BASUALTO, C.

2002-01-01

Kraft bleached cellulose from Pinus radiata was submitted to methylation reactions in heterogeneous media. After activation with 29% (w/w) NaOH solution, methylation reactions were carried out both with dimethyl sulfate (DMS) and methyl iodide (MI). The effects of the pressing ratio, reaction time and type of methylation agent were studied. The better yields were obtained with dimethylsulphate and the pressing ratio and reaction time were not signficant over the yield. Methylcellulose (MC) of...

Dynamic development of the protein corona on silica nanoparticles: composition and role in toxicity

Science.gov (United States)

Mortensen, Ninell P.; Hurst, Gregory B.; Wang, Wei; Foster, Carmen M.; Nallathamby, Prakash D.; Retterer, Scott T.

2013-06-01

The formation and composition of the protein corona on silica (SiO2) nanoparticles (NP) with different surface chemistries was evaluated over time. Native SiO2, amine (-NH2) and carboxy (-COO-) modified NP were examined following incubation in mammalian growth media containing fetal bovine serum (FBS) for 1, 4, 24 and 48 hours. The protein corona transition from its early dynamic state to the later more stable corona was evaluated using mass spectrometry. The NP diameter was 22.4 +/- 2.2 nm measured by scanning transmission electron microscopy (STEM). Changes in hydrodynamic diameter and agglomeration kinetics were studied using dynamic light scattering (DLS). The initial surface chemistry of the NP played an important role in the development and final composition of the protein corona, impacting agglomeration kinetics and NP toxicity. Particle toxicity, indicated by changes in membrane integrity and mitochondrial activity, was measured by lactate dehydrogenase (LDH) release and tetrazolium reduction (MTT), respectively, in mouse alveolar macrophages (RAW264.7) and mouse lung epithelial cells (C10). SiO2-COO- NP had a slower agglomeration rate, formed smaller aggregates, and exhibited lower cytotoxicity compared to SiO2 and SiO2-NH2. Composition of the protein corona for each of the three NP was unique, indicating a strong dependence of corona development on NP surface chemistry. This work underscores the need to understand all aspects of NP toxicity, particularly the influence of agglomeration on effective dose and particle size. Furthermore, the interplay between materials and local biological environment is emphasized and highlights the need to conduct toxicity profiling under physiologically relevant conditions that provide an appropriate estimation of material modifications that occur during exposure in natural environments.The formation and composition of the protein corona on silica (SiO2) nanoparticles (NP) with different surface chemistries was evaluated

Metabolites and hormones are involved in the intraspecific variability of drought hardening in radiata pine.

Science.gov (United States)

De Diego, N; Saiz-Fernández, I; Rodríguez, J L; Pérez-Alfocea, P; Sampedro, M C; Barrio, R J; Lacuesta, M; Moncaleán, P

2015-09-01

Studies of metabolic and physiological bases of plant tolerance and hardening against drought are essential to improve genetic breeding programs, especially in productive species such as Pinus radiata. The exposure to different drought cycles is a highly effective tool that improves plant conditioning, but limited information is available about the mechanisms that modulate this process. To clarify this issue, six P. radiata breeds with well-known differences in drought tolerance were analyzed after two consecutive drought cycles. Survival rate, concentration of several metabolites such as free soluble amino acids and polyamines, and main plant hormones varied between them after drought hardening, while relative growth ratio and water potential at both predawn and dawn did not. Hardening induced a strong increase in total soluble amino acids in all breeds, accumulating mainly those implicated in the glutamate metabolism (GM), especially L-proline, in the most tolerant breeds. Other amino acids from GM such as γ-aminobutyric acid (GABA) and L-arginine (Arg) were also strongly increased. GABA pathway could improve the response against drought, whereas Arg acts as precursor for the synthesis of spermidine. This polyamine showed a positive relationship with the survival capacity, probably due to its role as antioxidant under stress conditions. Finally, drought hardening also induced changes in phytohormone content, showing each breed a different profile. Although all of them accumulated indole-3-acetic acid and jasmonic acid and reduced zeatin content in needles, significant differences were observed regarding abscisic acid, salicylic acid and mainly zeatin riboside. These results confirm that hardening is not only species-dependent but also an intraspecific processes controlled through metabolite changes. Copyright © 2015 Elsevier GmbH. All rights reserved.

Effect of the protein corona on nanoparticles for modulating cytotoxicity and immunotoxicity

Directory of Open Access Journals (Sweden)

Lee YK

2014-12-01

Full Text Available Yeon Kyung Lee,1,* Eun-Ju Choi,2,* Thomas J Webster,3 Sang-Hyun Kim,4 Dongwoo Khang1 1Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, South Korea; 2Division of Sport Science, College of Science and Technology, Konkuk University, Chungju, South Korea; 3Department of Chemical Engineering and Program in Bioengineering, Northeastern University, Boston, MA, USA; 4Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, South Korea *These authors contributed equally to this work Abstract: Although the cytotoxicity of nanoparticles (NPs is greatly influenced by their interactions with blood proteins, toxic effects resulting from blood interactions are often ignored in the development and use of nanostructured biomaterials for in vivo applications. Protein coronas created during the initial reaction with NPs can determine the subsequent immunological cascade, and protein coronas formed on NPs can either stimulate or mitigate the immune response. Along these lines, the understanding of NP-protein corona formation in terms of physiochemical surface properties of the NPs and NP interactions with the immune system components in blood is an essential step for evaluating NP toxicity for in vivo therapeutics. This article reviews the most recent developments in NP-based protein coronas through the modification of NP surface properties and discusses the associated immune responses. Keywords: nanostructured biomaterials, blood response, cytotoxicity, immunotoxicity, protein corona

Observational capabilities of solar satellite "Coronas-Photon"

Science.gov (United States)

Kotov, Yu.

Coronas-Photon mission is the third satellite of the Russian Coronas program on solar activity observation The main goal of the Coronas-Photon is the study of solar hard electromagnetic radiation in the wide energy range from UV up to high energy gamma-radiation sim 2000MeV Scientific payload for solar radiation observation consists of three type of instruments 1 monitors Natalya-2M Konus-RF RT-2 Penguin-M BRM Phoka Sphin-X Sokol for spectral and timing measurements of full solar disk radiation with timing in flare burst mode up to one msec Instruments Natalya-2M Konus-RF RT-2 will cover the wide energy range of hard X-rays and soft Gamma rays 15keV to 2000MeV and will together constitute the largest area detectors ever used for solar observations Detectors of gamma-ray monitors are based on structured inorganic scintillators with energy resolution sim 5 for nuclear gamma-line band to 35 for GeV-band PSD analysis is used for gamma neutron separation for solar neutron registration T 30MeV Penguin-M has capability to measure linear polarization of hard X-rays using azimuth are measured by Compton scattering asymmetry in case of polarization of an incident flux For X-ray and EUV monitors the scintillation phoswich detectors gas proportional counter CZT assembly and Filter-covered Si-diodes are used 2 Telescope-spectrometer TESIS for imaging solar spectroscopy in X-rays with angular resolution up to 1 in three spectral lines and RT-2 CZT assembly of CZT

The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona

Directory of Open Access Journals (Sweden)

Robitaille P.-M.

2013-07-01

Full Text Available The K-corona, a significant portion of the solar atmosphere, displays a continuous spectrum which closely parallels photospheric emission, though without the presence of overlying Fraunhofer lines. The E-corona exists in the same region and is characterized by weak emission lines from highly ionized atoms. For instance, the famous green emission line from coronium (FeXIV is part of the E-corona. The F-corona exists beyond the K/E-corona and, like the photospheric spectrum, is characterized by Fraunhofer lines. The F-corona represents photospheric light scattered by dust particles in the interplanetary medium. Within the gaseous models of the Sun, the K-corona is viewed as photospheric radiation which has been scattered by relativistic electrons. This scattering is thought to broaden the Fraunhofer lines of the solar spectrum such that they can no longer be detected in the K-corona. Thus, the gaseous models of the Sun account for the appearance of the K-corona by distorting photospheric light, since they are unable to have recourse to condensed matter to directly produce such radiation. Conversely, it is now advanced that the continuous emission of the K-corona and associated emission lines from the E-corona must be interpreted as manifestations of the same phenomenon: condensed matter exists in the corona. It is well-known that the Sun expels large amounts of material from its surface in the form of flares and coronal mass ejections. Given a liquid metallic hydrogen model of the Sun, it is logical to assume that such matter, which exists in the condensed state on the solar surface, continues to manifest its nature once expelled into the corona. Therefore, the continuous spectrum of the K-corona provides the twenty-seventh line of evidence that the Sun is composed of condensed matter.

Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

Directory of Open Access Journals (Sweden)

Fuangpian Phanupong

2016-01-01

Full Text Available Nowadays, using of High Voltage Direct Current (HVDC transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage should be investigated. In this work, the effect of DC polarity and Alternating Current (AC field stress on corona inception voltage and corona discharge is investigated on various test objects, such as High Voltage (HV needle, needle at ground plane, internal defect, surface discharge, underground cable without cable termination, cable termination with simulated defect and bare overhead conductor. The corona discharge is measured by partial discharge measurement device with high-frequency current transformer. Finally, the relationship between supply voltage and discharge intensity on each DC polarity and AC field stress can be successfully determined.

Executive deficits, not processing speed relates to abnormalities in distinct prefrontal tracts in amyotrophic lateral sclerosis.

Science.gov (United States)

Pettit, Lewis D; Bastin, Mark E; Smith, Colin; Bak, Thomas H; Gillingwater, Thomas H; Abrahams, Sharon

2013-11-01

, uncinate fasciculus and hippocampal portion of the cingulum bundles. Significant differences also emerged in the anterior corona radiata as well as in white matter underlying the superior, medial and inferior frontal gyri and the temporal gyri. Dual-task performance significantly correlated with fractional anisotropy measures in the middle frontal gyrus white matter and anterior corona radiata. Letter fluency indices significantly correlated with fractional anisotropy measures of the inferior frontal gyrus white matter and corpus callosum in addition to the corticospinal tracts and mean diffusivity measures in the white matter of the superior frontal gyrus. The current study demonstrates that cognitive impairment in amyotrophic lateral sclerosis is not due to generic slowing of processing speed. Moreover, different executive deficits are related to distinct prefrontal tract involvement in amyotrophic lateral sclerosis with dual-task impairment associating with dorsolateral prefrontal dysfunction and letter fluency showing greater dependence on inferolateral prefrontal dysfunction.

The Growth Potential of Corona Discharges from Aircraft Flying in Precipitation.

Science.gov (United States)

1987-11-12

required for corona onset. However, it turns out that the fields required to generate corona from ’ce and water particles of the anticipated size are...still significantly larger than those commonly encountered in a thundercloud. The exception here is the long water filament drawn out when water drop...trial and error had 300 cone-angle, with a tip of radius -20Im (measured with a travelling microscope). It was necessary to electrolyse the tip in

Abnormal white matter integrity in chronic users of codeine-containing cough syrups: a tract-based spatial statistics study.

Science.gov (United States)

Qiu, Y-W; Su, H-H; Lv, X-F; Jiang, G-H

2015-01-01

Codeine-containing cough syrups have become one of the most popular drugs of abuse in young people in the world. Chronic codeine-containing cough syrup abuse is related to impairments in a broad range of cognitive functions. However, the potential brain white matter impairment caused by chronic codeine-containing cough syrup abuse has not been reported previously. Our aim was to investigate abnormalities in the microstructure of brain white matter in chronic users of codeine-containing syrups and to determine whether these WM abnormalities are related to the duration of the use these syrups and clinical impulsivity. Thirty chronic codeine-containing syrup users and 30 matched controls were evaluated. Diffusion tensor imaging was performed by using a single-shot spin-echo-planar sequence. Whole-brain voxelwise analysis of fractional anisotropy was performed by using tract-based spatial statistics to localize abnormal WM regions. The Barratt Impulsiveness Scale 11 was surveyed to assess participants' impulsivity. Volume-of-interest analysis was used to detect changes of diffusivity indices in regions with fractional anisotropy abnormalities. Abnormal fractional anisotropy was extracted and correlated with clinical impulsivity and the duration of codeine-containing syrup use. Chronic codeine-containing syrup users had significantly lower fractional anisotropy in the inferior fronto-occipital fasciculus of the bilateral temporo-occipital regions, right frontal region, and the right corona radiata WM than controls. There were significant negative correlations among fractional anisotropy values of the right frontal region of the inferior fronto-occipital fasciculus and the right superior corona radiata WM and Barratt Impulsiveness Scale total scores, and between the right frontal region of the inferior fronto-occipital fasciculus and nonplan impulsivity scores in chronic codeine-containing syrup users. There was also a significant negative correlation between fractional

Transfer of electrical space charge from corona between ground and thundercloud: Measurements and modeling

Science.gov (United States)

Soula, Serge

1994-01-01

The evolution of the vertical electric field profile deduced from simultaneous field measurements at several levels below a thundercloud shows the development of a space charge layer at least up to 600 m. The average charge density in the whole layer from 0 m to 600 m can reach about 1 nC m(exp -3). The ions are generated at the ground by corona effect and the production rate is evaluated with a new method from the comparison of field evolutions at the ground and at altitude after a lightning flash. The modeling of the relevant processes shows tht ground corona accounts for the observed field evolutions and that the aerosol particles concentration has a very large effect on the evolution of corona ions. However, with a realistic value for this concentration a large amount of ground corona ions reach the level of 600 m.

River water remediation using pulsed corona, pulsed spark or ozonation

Energy Technology Data Exchange (ETDEWEB)

Izdebski, T.; Dors, M. [Polish Academy of Sciences, Szewalski Inst. of Fluid Flow Machiney, Fiszera (Poland). Centre for Plasma and Laser Engineering; Mizeraczyk, J. [Polish Academy of Sciences, Szewalski Inst. of Fluid Flow Machiney, Fiszera (Poland). Centre for Plasma and Laser Engineering; Gdynia Maritime Univ., Morska (Poland). Dept. of Marine Electronics

2010-07-01

The most common reason for epidemic formation is the pollution of surface and drinking water by wastewater bacteria. Pathogenic microorganisms that form the largest part of this are fecal bacteria, such as escherichia coli (E. coli). Wastewater treatment plants reduce the amount of the fecal bacteria by 1-3 orders of magnitude, depending on the initial number of bacteria. There is a lack of data on waste and drinking water purification by the electrohydraulic discharges method, which causes the destruction and inactivation of viruses, yeast, and bacteria. This paper investigated river water cleaning from microorganisms using pulsed corona, spark discharge and ozonization. The paper discussed the experimental setup and results. It was concluded that ozonization is the most efficient method of water disinfection as compared with pulsed spark and pulsed corona discharges. The pulsed spark discharge in water was capable of killing all microorganism similarly to ozonization, but with much lower energy efficiency. The pulsed corona discharge was found to be the less effective method of water disinfection. 21 refs., 4 figs.

Diagnostics of the solar corona from comparison between Faraday rotation measurements and magnetohydrodynamic simulations

International Nuclear Information System (INIS)

Le Chat, G.; Cohen, O.; Kasper, J. C.; Spangler, S. R.

2014-01-01

Polarized natural radio sources passing behind the Sun experience Faraday rotation as a consequence of the electron density and magnetic field strength in coronal plasma. Since Faraday rotation is proportional to the product of the density and the component of the magnetic field along the line of sight of the observer, a model is required to interpret the observations and infer coronal structures. Faraday rotation observations have been compared with relatively ad hoc models of the corona. Here for the first time we compare these observations with magnetohydrodynamic (MHD) models of the solar corona driven by measurements of the photospheric magnetic field. We use observations made with the NRAO Very Large Array of 34 polarized radio sources occulted by the solar corona between 5 and 14 solar radii. The measurements were made during 1997 May, and 2005 March and April. We compare the observed Faraday rotation values with values extracted from MHD steady-state simulations of the solar corona. We find that (1) using a synoptic map of the solar magnetic field just one Carrington rotation off produces poorer agreements, meaning that the outer corona changes in the course of one month, even in solar minimum; (2) global MHD models of the solar corona driven by photospheric magnetic field measurements are generally able to reproduce Faraday rotation observations; and (3) some sources show significant disagreement between the model and the observations, which appears to be a function of the proximity of the line of sight to the large-scale heliospheric current sheet.

Density determination in Pino Radiata (D.Don) samples using 59.5 keV gamma radiation attenuation

International Nuclear Information System (INIS)

Dinator, Maria I.; Morales, Jose R.; Aliaga, Nelson; Karsulovic, Jose T.; Sanchez, Jaime; Leon, Adolfo

1996-01-01

A non destructive method to determine wood samples density is presented. The photon mass attenuation coefficient in samples of Pino radiata (D.Don) was measured at 59.5 keV with a radioactive source of Am-241. The value of 0.192 ± 0.002 cm 2 /g was obtained with a gamma spectroscopy system and later used on the determination of the mass density in sixteen samples of the same species. Comparison of these results with those of gravimetric method through a linear regression showed a slope of 1.001 and a correlation factor of 0.94. (author)

Current Sheets in the Corona and the Complexity of Slow Wind

Science.gov (United States)

Antiochos, Spiro

2010-01-01

The origin of the slow solar wind has long been one of the most important problems in solar/heliospheric physics. Two observational constraints make this problem especially challenging. First, the slow wind has the composition of the closed-field corona, unlike the fast wind that originates on open field lines. Second, the slow wind has substantial angular extent, of order 30 degrees, which is much larger than the widths observed for streamer stalks or the widths expected theoretically for a dynamic heliospheric current sheet. We propose that the slow wind originates from an intricate network of narrow (possibly singular) open-field corridors that emanate from the polar coronal hole regions. Using topological arguments, we show that these corridors must be ubiquitous in the solar corona. The total solar eclipse in August 2008, near the lowest point of cycle 23 affords an ideal opportunity to test this theory by using the ultra-high resolution Predictive Science's (PSI) eclipse model for the corona and wind. Analysis of the PSI eclipse model demonstrates that the extent and scales of the open-field corridors can account for both the angular width of the slow wind and its closed-field composition. We discuss the implications of our slow wind theory for the structure of the corona and heliosphere at solar minimum and describe further observational and theoretical tests.

The colour of the solar corona and dust grains in it

International Nuclear Information System (INIS)

Ajmanov, A.K.; Nikolsky, G.M.

1980-01-01

The photometry of coronal negatives is carried out. The films were obtained at the March 7, 1970 and July 10, 1972 eclipses. A distribution of the coronal brightness in the red (635 mm), green (545 nm), and blue (455 nm) wavelength intervals up to distances of (6-7)Rsub(sun) is deduced (Figure 1). Colour indexes of the corona (the emission ratio red/blue-Csub(rb) and green/blue-Csub(gb)) have been obtained. We assume Csub(rb) = Csub(gb) = 1 in the inner corona ( = 1 μm. RED brightness is evaluated to be 4 x 10 -10 anti Bsub(sun). There is 1 grain of dust in the elementary volume with cross section of 1 cm 2 along the line of sight. The intensity of dust emission in wavelength interval 10 μm deduced by the authors is approximately 1 μ W cm -2 sm -1 . That is in agreement with Mankin et al. (1974) and Lena et al. (1974) observations. The whole dust mass of RED is -11 cm -3 . Determination of the colour of the solar corona have been made by a number of scientists (Tikhov, 1940, 1957; Allen, 1946; Blackwell, 1952; Michard, 1956; Sharonov, 1958; Nay et al. 1961). The corona colour was found to be somewhat redder than the Sun's. However this question is not finally settled to date. (orig.)

Profundidad del surco gingival en dientes primarios restaurados con coronas de acero cromo

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Rubén Muñoz Delgado

2015-01-01

Full Text Available Objetivo: Evaluar la relación entre el ajuste marginal y la profundidad del surco gingival en dientes primarios restaurados con coronas de acero cromo. Métodos: Se midió la profundidad del surco gingival de 114 dientes primarios restaurados con coronas de acero cromo en 67 niños, ambos sexos, de 3 a 6 años de edad de la clínica de Estomatología Pediátrica de la UATx, México. La población en estudio fue dividida en tres grupos: a experimental (n=30, b control (n=8, y c control negativo (n=29. Previo consentimiento informado se tomaron los índices de placa (LöeSilness 1967 e índice gingival en seis superficies; se midió el surco gingival con sonda periodontal y las coronas de acero cromo fueron evaluadas clínica y radiográficamente según su ajuste marginal y longitud cervical. Resultados: Los índices de placa y gingival no mostraron diferencias significativas para los grupos experimental y control negativo. El 34% de las coronas mostraron buen ajuste marginal, 33% un mal ajuste, 10.5% cortas, 7.9% largas y el 14% otro tipo de mal ajuste. La profundidad del surco gingival fue estadísticamente significativa para el primer y segundo molar inferior derechos y en los caninos inferiores (p >0.05; la superficie disto-vestibular presentó la mayor profundidad del surco gingival (2.34 mm, siendo estadísticamente significativa (p>0.05. Conclusiones: La profundidad del surco gingival fue mayor en los dientes rehabilitados con coronas de acero cromo mal ajustadas y sobre contorneadas (largas. La presencia de placa bacteriana y gingivitis estuvo relacionada con las coronas de acero cromo mal ajustadas.

A semi-analytical stationary model of a point-to-plane corona discharge

International Nuclear Information System (INIS)

Yanallah, K; Pontiga, F

2012-01-01

A semi-analytical model of a dc corona discharge is formulated to determine the spatial distribution of charged particles (electrons, negative ions and positive ions) and the electric field in pure oxygen using a point-to-plane electrode system. A key point in the modeling is the integration of Gauss' law and the continuity equation of charged species along the electric field lines, and the use of Warburg's law and the corona current–voltage characteristics as input data in the boundary conditions. The electric field distribution predicted by the model is compared with the numerical solution obtained using a finite-element technique. The semi-analytical solutions are obtained at a negligible computational cost, and provide useful information to characterize and control the corona discharge in different technological applications. (paper)

Novel modulator topology for corona plasma generation

NARCIS (Netherlands)

Ariaans, T.H.P.; Pemen, A.J.M.; Winands, G.J.J.; Liu, Z.; Heesch, van E.J.M.

2009-01-01

Gas cleaning using plasma technology is slowly introduced into industry nowadays. Several challenges still have to be overcome: increasing the scale, safety, life time and reducing costs. In 2006 we demonstrated a 20 kW nanosecond pulsed corona system. The electrical efficiency was > 90%. O-radical

Processing method of images obtained during the TESIS/CORONAS-PHOTON experiment

Science.gov (United States)

Kuzin, S. V.; Shestov, S. V.; Bogachev, S. A.; Pertsov, A. A.; Ulyanov, A. S.; Reva, A. A.

2011-04-01

In January 2009, the CORONAS-PHOTON spacecraft was successfully launched. It includes a set of telescopes and spectroheliometers—TESIS—designed to image the solar corona in soft X-ray and EUV spectral ranges. Due to features of the reading system, to obtain physical information from these images, it is necessary to preprocess them, i.e., to remove the background, correct the white field, level, and clean. The paper discusses the algorithms and software developed and used for the preprocessing of images.

Extração e caracterização de hemiceluloses de Pinus radiata e sua viabilidade para a produção de bioetanol Extraction and characterization of hemicelluloses from Pinus radiata and its feasibility for bioethanol production

Directory of Open Access Journals (Sweden)

Pablo Reyes

2013-02-01

Full Text Available As galactoglucomananas são as principais frações de hemiceluloses presentes nas madeiras moles e contêm, principalmente, as hexoses galactose, glicose e manose. O isolamento eficiente e seletivo dessas hemiceluloses é um obstáculo crítico a superar para sua utilização. Os objetivos deste trabalho foram extrair e caracterizar soluções aquosas ácidas e neutras de hemiceluloses de cavacos de madeira de Pinus radiata, bem como avaliar sua viabilidade para a produção de bioetanol. As hemiceluloses em P. radiata representam 26 g/100 g de madeira (base seca, e as hexoses são responsáveis por aproximadamente 64% dessa quantidade. De acordo com as diferentes condições de extração, cerca de 50% da fração hemicelulósica foi solubilizada e recuperada depois de uma precipitação com etanol. As frações recuperadas de hemiceluloses estavam na forma de oligômeros com peso molecular médio (Mw variando entre 4x10³ e 4x10(5 g/mol. Os oligômeros hemicelulósicos foram hidrolisados com ácido sulfúrico diluído e os hidrolisados concentrados até aproximadamente 70 g/L hexosas e fermentados pela levedura Saccharomyces cerevisiae. Os resultados de fermentação indicaram que os açúcares obtidos dos extratos ácidos e neutros foram fermentados com rendimentos máximos de etanol de 63% e 54% (22 g/L e 19 g/L, respectivamente. A conversão de hemiceluloses da madeira em etanol é viável, porém seu baixo rendimento faz que o processo não seja economicamente atrativo, razão por que melhorias no processo ou usos alternativos das hemiceluloses devem ser avaliados.Galactoglucomannans are the major hemicellulosic fraction present in softwoods, and is mainly composed by the hexoses: galactose, glucose and mannose. The efficient and selective isolation of these hemicelluloses is regarded as one of the most critical obstacles to overcome for their utilization. The objective of the current work was to extract and characterize acidic and

Kinetic Physics of the Solar Corona and Solar Wind

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Marsch Eckart

2006-07-01

Full Text Available Kinetic plasma physics of the solar corona and solar wind are reviewed with emphasis on the theoretical understanding of the in situ measurements of solar wind particles and waves, as well as on the remote-sensing observations of the solar corona made by means of ultraviolet spectroscopy and imaging. In order to explain coronal and interplanetary heating, the microphysics of the dissipation of various forms of mechanical, electric and magnetic energy at small scales (e.g., contained in plasma waves, turbulences or non-uniform flows must be addressed. We therefore scrutinise the basic assumptions underlying the classical transport theory and the related collisional heating rates, and also describe alternatives associated with wave-particle interactions. We elucidate the kinetic aspects of heating the solar corona and interplanetary plasma through Landau- and cyclotron-resonant damping of plasma waves, and analyse in detail wave absorption and micro instabilities. Important aspects (virtues and limitations of fluid models, either single- and multi-species or magnetohydrodynamic and multi-moment models, for coronal heating and solar wind acceleration are critically discussed. Also, kinetic model results which were recently obtained by numerically solving the Vlasov–Boltzmann equation in a coronal funnel and hole are presented. Promising areas and perspectives for future research are outlined finally.

The Mechanism for Energy Buildup in the Solar Corona

Science.gov (United States)

Antiochos, Spiro; Knizhnik, Kalman; DeVore, Richard

2017-10-01

Magnetic reconnection and helicity conservation are two of the most important basic processes determining the structure and dynamics of laboratory and space plasmas. The most energetic dynamics in the solar system are the giant CMEs/flares that produce the most dangerous space weather at Earth, yet may also have been essential for the origin of life. The origin of these explosions is that the lowest-lying magnetic flux in the Sun's corona undergoes the continual buildup of stress and free energy that can be released only through explosive ejection. We perform MHD simulations of a coronal volume driven by quasi-random boundary flows designed to model the processes by which the solar interior drives the corona. Our simulations are uniquely accurate in preserving magnetic helicity. We show that even though small-scale stress is injected randomly throughout the corona, the net result of magnetic reconnection is a coherent stressing of the lowest-lying field lines. This highly counter-intuitive result - magnetic stress builds up locally rather than spreading out to a minimum energy state - is the fundamental mechanism responsible for the Sun's magnetic explosions. It is likely to be a mechanism that is ubiquitous throughout laboratory and space plasmas. This work was supported by the NASA LWS and SR Programs.

Water purification by corona-above-water treatment

NARCIS (Netherlands)

Pemen, A.J.M.; Heesch, van E.J.M.; Hoeben, W.F.L.M.

2012-01-01

Advanced oxidation technologies (AOT), such as non-thermal plasmas, are considered to be very promising for the purpose of water treatment. The goal of this study is to test the feasibility of "Corona-above-water" technology for the treatment of drinking water. Experiments have been performed on the

Nanoflare heating model for collisionless solar corona

Indian Academy of Sciences (India)

Magnetic reconnection plays a significant role in heating the solar corona. When two oppositely directed magnetic fields come closer to form a current sheet, the current density of the plasma increases due to which magnetic reconnection and conversion of magnetic energy into thermal energy takes place. The present ...

Performance evaluation of oxygen adsorbents using negative corona discharge–ion mobility spectrometry

Energy Technology Data Exchange (ETDEWEB)

Azadkish, Kamal; Jafari, Mohammad T., E-mail: jafari@cc.iut.ac.ir; Ghaziaskar, Hassan S.

2017-02-08

Trace amounts of oxygen was determined using negative corona discharge as an ionization source for ion mobility spectrometry. A point-in-cylinder geometry with novel design was used to establish the corona discharge without interferences of negative ions such as NO{sub X}{sup −}. The desirable background spectrum shows only electrons peak, providing the instrument capable of trace analysis of oxygen in gaseous samples. The limit of detection and linear dynamic range with high coefficient of determination (r{sup 2} = 0.9997), were obtained for oxygen as 8.5 and 28–14204 ppm, respectively. The relative standard deviations of the method for intraday and interday were obtained 4 and 11%, respectively. The satisfactory results revealed the ability of the negative corona discharge ion mobility spectrometry for investigating the performance of synthesized oxygen adsorbents in nitrogen streams. Two oxygen scavengers of MnO and Cu powder were prepared and the optimum temperature of the reactor containing MnO and Cu powder were obtained as 180 and 230 °C, respectively. Due to higher lifetime of copper powder, it was selected as the oxygen scavenger and some parameters such as: the type of adsorbent support, the size of adsorbent particles, and the amount of copper were studied for preparation of more efficient oxygen adsorbent. - Highlights: • Analysis of oxygen using negative corona discharge-ion mobility spectrometry was investigated for the first time. • Novel designed point-in-cylinder geometry was used to establish the corona discharge without interferences of negative ions. • The method was utilized to evaluate the performance of some synthesized oxygen scavengers.

The Combined Intervention with Germinated Vigna radiata and Aerobic Interval Training Protocol Is an Effective Strategy for the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD) and Other Alterations Related to the Metabolic Syndrome in Zucker Rats.

Science.gov (United States)

Kapravelou, Garyfallia; Martínez, Rosario; Nebot, Elena; López-Jurado, María; Aranda, Pilar; Arrebola, Francisco; Cantarero, Samuel; Galisteo, Milagros; Porres, Jesus M

2017-07-19

Metabolic syndrome (MetS) is a group of related metabolic alterations that increase the risk of developing non-alcoholic fatty liver disease (NAFLD). Several lifestyle interventions based on dietary treatment with functional ingredients and physical activity are being studied as alternative or reinforcement treatments to the pharmacological ones actually in use. In the present experiment, the combined treatment with mung bean ( Vigna radiata ), a widely used legume with promising nutritional and health benefits that was included in the experimental diet as raw or 4 day-germinated seed flour, and aerobic interval training protocol (65-85% VO₂ max) has been tested in lean and obese Zucker rats following a 2 × 2 × 2 (2 phenotypes, 2 dietary interventions, 2 lifestyles) factorial ANOVA (Analysis of Variance) statistical analysis. Germination of V. radiata over a period of four days originated a significant protein hydrolysis leading to the appearance of low molecular weight peptides. The combination of 4 day-germinated V. radiata and aerobic interval training was more efficient compared to raw V. radiata at improving the aerobic capacity and physical performance, hepatic histology and functionality, and plasma lipid parameters as well as reverting the insulin resistance characteristic of the obese Zucker rat model. In conclusion, the joint intervention with legume sprouts and aerobic interval training protocol is an efficient treatment to improve the alterations of glucose and lipid metabolism as well as hepatic histology and functionality related to the development of NAFLD and the MetS.

Core/corona modeling of diode-imploded annular loads

Science.gov (United States)

Terry, R. E.; Guillory, J. U.

1980-11-01

The effects of a tenuous exterior plasma corona with anomalous resistivity on the compression and heating of a hollow, collisional aluminum z-pinch plasma are predicted by a one-dimensional code. As the interior ("core") plasma is imploded by its axial current, the energy exchange between core and corona determines the current partition. Under the conditions of rapid core heating and compression, the increase in coronal current provides a trade-off between radial acceleration and compression, which reduces the implosion forces and softens the pitch. Combined with a heuristic account of energy and momentum transport in the strongly coupled core plasma and an approximate radiative loss calculation including Al line, recombination and Bremsstrahlung emission, the current model can provide a reasonably accurate description of imploding annular plasma loads that remain azimuthally symmetric. The implications for optimization of generator load coupling are examined.

Phase-change related epigenetic and physiological changes in Pinus radiata D. Don.

Science.gov (United States)

Fraga, Mario F; Cañal, Maria Jesús; Rodríguez, Roberto

2002-08-01

DNA methylation and polyamine levels were analysed before and after Pinus radiata D. Don. phase change in order to identify possible molecular and physiological phase markers. Juvenile individuals (without reproductive ability) were characterised by a degree of DNA methylation of 30-35% and a ratio of free polyamines to perchloric acid-soluble polyamine conjugates greater than 1, while mature trees (with reproductive ability) had 60% 5-methylcytosine and a ratio of free polyamines to perchloric acid-soluble polyamine conjugates of less than 1. Results obtained with trees that attained reproductive capacity during the experimental period confirmed that changes in the degree of DNA methylation and polyamine concentrations found among juvenile and mature states come about immediately after the phase change. We suggest that both indicators may be associated with the loss of morphogenic ability during ageing, particularly after phase change, through a number of molecular interactions, which are subsequently discussed.

Magnetorelaxometry in the Presence of a DC Bias Field of Ferromagnetic Nanoparticles Bearing a Viscoelastic Corona

Directory of Open Access Journals (Sweden)

Victor Rusakov

2018-05-01

Full Text Available With allowance for orientational Brownian motion, the magnetorelaxometry (MRX signal, i.e., the decay of magnetization generated by an ensemble of ferromagnet nanoparticles, each of which bears a macromolecular corona (a loose layer of polymer gel is studied. The rheology of corona is modelled by the Jeffreys scheme. The latter, although comprising only three phenomenological parameters, enables one to describe a wide spectrum of viscoelastic media: from linearly viscous liquids to weakly-fluent gels. The “transverse” configuration of MRX is considered where the system is subjected to a DC (constant bias field, whereas the probing field is applied perpendicularly to the bias one. The analysis shows that the rate of magnetization decay strongly depends on the state of corona and slows down with enhancement of the corona elasticity. In addition, for the case of “transverse” MRX, we consider the integral time, i.e., the characteristic that is applicable to relaxation processes with an arbitrary number of decay modes. Expressions for the dependence of the integral time on the corona elasticity parameter and temperature are derived.

Corona discharge induced snow formation in a cloud chamber.

Science.gov (United States)

Ju, Jingjing; Wang, Tie-Jun; Li, Ruxin; Du, Shengzhe; Sun, Haiyi; Liu, Yonghong; Tian, Ye; Bai, Yafeng; Liu, Yaoxiang; Chen, Na; Wang, Jingwei; Wang, Cheng; Liu, Jiansheng; Chin, S L; Xu, Zhizhan

2017-09-18

Artificial rainmaking is in strong demand especially in arid regions. Traditional methods of seeding various Cloud Condensation Nuclei (CCN) into the clouds are costly and not environment friendly. Possible solutions based on ionization were proposed more than 100 years ago but there is still a lack of convincing verification or evidence. In this report, we demonstrated for the first time the condensation and precipitation (or snowfall) induced by a corona discharge inside a cloud chamber. Ionic wind was found to have played a more significant role than ions as extra CCN. In comparison with another newly emerging femtosecond laser filamentation ionization method, the snow precipitation induced by the corona discharge has about 4 orders of magnitude higher wall-plug efficiency under similar conditions.

A Covert Disruptive Technology: Test and Development of the Corona Satellite

Science.gov (United States)

Peebles, Curtis

2008-01-01

The launching by the Soviet Union of the Sputnik satellite in 19457 was an impetuous to the United States. The Intercontinental ballistic Missile (ICBM) that launched the Earth's first satellite, could have been armed with a nuclear warhead, that could destroy an American city. The primary intelligence requirement that the US had was to determine the actual size of the Soviet missile program. To this end, a covert, high-risk photoreconnaissance satellite was developed. The code name of this program was "Corona." This article describes the trials and eventual successes of the Corona program.

Hot Coronae in Local AGN: Present Status and Future Perspectives

Directory of Open Access Journals (Sweden)

Andrea Marinucci

2018-04-01

Full Text Available The nuclear X-ray emission in radio-quiet Active Galactic Nuclei (AGN is commonly believed to be due to inverse Compton scattering of soft UV photons in a hot corona. The radiation is expected to be polarized, the polarization degree depending mainly on the geometry and optical depth of the corona. Nuclear Spectroscopic Telescope Array (NuSTAR observations are providing for the first time high quality measurements of the coronal physical parameters—temperature and optical depth. We hereby review the NuSTAR results on the coronal physical parameters (temperature and optical depth and discuss their implications for future X-ray polarimetric studies.

SWAP OBSERVATIONS OF THE LONG-TERM, LARGE-SCALE EVOLUTION OF THE EXTREME-ULTRAVIOLET SOLAR CORONA

Energy Technology Data Exchange (ETDEWEB)

Seaton, Daniel B.; De Groof, Anik; Berghmans, David; Nicula, Bogdan [Royal Observatory of Belgium-SIDC, Avenue Circulaire 3, B-1180 Brussels (Belgium); Shearer, Paul [Department of Mathematics, 2074 East Hall, University of Michigan, 530 Church Street, Ann Arbor, MI 48109-1043 (United States)

2013-11-01

The Sun Watcher with Active Pixels and Image Processing (SWAP) EUV solar telescope on board the Project for On-Board Autonomy 2 spacecraft has been regularly observing the solar corona in a bandpass near 17.4 nm since 2010 February. With a field of view of 54 × 54 arcmin, SWAP provides the widest-field images of the EUV corona available from the perspective of the Earth. By carefully processing and combining multiple SWAP images, it is possible to produce low-noise composites that reveal the structure of the EUV corona to relatively large heights. A particularly important step in this processing was to remove instrumental stray light from the images by determining and deconvolving SWAP's point-spread function from the observations. In this paper, we use the resulting images to conduct the first-ever study of the evolution of the large-scale structure of the corona observed in the EUV over a three year period that includes the complete rise phase of solar cycle 24. Of particular note is the persistence over many solar rotations of bright, diffuse features composed of open magnetic fields that overlie polar crown filaments and extend to large heights above the solar surface. These features appear to be related to coronal fans, which have previously been observed in white-light coronagraph images and, at low heights, in the EUV. We also discuss the evolution of the corona at different heights above the solar surface and the evolution of the corona over the course of the solar cycle by hemisphere.

Experimental determination of the effect of temperature and humidity on the development of colour in Pinus radiata

Directory of Open Access Journals (Sweden)

M. McCurdy

2005-06-01

Full Text Available Experiments were undertaken to determine the effects of drying conditions (temperature and humidity on the development of kiln brown stain in radiata pine during drying. Eight schedules were tested with temperatures ranging from 50°C to 120°C and relative humidity from 14% to 67%. The variables measured were moisture content, color expressed using the CIELab color space, and nitrogen content. The experiments have shown that the kiln brown stain is influenced by drying temperature and drying time. The recommendation is therefore that low-temperature and low-humidity schedules be developed for controlling color development.

Electrical and optical analysis of fast transient discharges in a pulsed corona pilot unit

NARCIS (Netherlands)

Blom, P.P.M.; Smulders, H.W.M.; Heesch, van E.J.M.; Laan, van der P.C.T.

1997-01-01

We give a detailed analysis of intense pulsed corona dis charges. CCD movies and current, voltage and energy in put measurements are the basis of the description. The discharges are generated in a 1.5 kW pilot unit, which cre ates pulsed corona discharges energized by 100 kV pulses of 200 us width,

La Corona: un acercamiento a las políticas del reino Kaan desde un centro secundario del noroeste del Petén La Corona: an approach to politics in the kingdom of Kaan from a secondary center in Norwest Petén

Directory of Open Access Journals (Sweden)

Marcello A. Canuto

2011-01-01

Full Text Available El Proyecto Regional Arqueológico La Corona estudia la región del noroeste de Petén, Guatemala, donde se localiza la antigua ciudad maya de La Corona, que recientemente fue identificada como el Sitio Q. La investigación ha incluido las excavaciones de arquitectura monumental, asentamientos, la elaboración de mapas, el uso de sensores remotos y la realización de estudios paleoclimatológicos y ecológicos. Desde el punto de vista de los modelos de la organización política, las investigaciones en La Corona presentan una oportunidad para estudiar la naturaleza y las relaciones políticas de los sitios secundarios. Los datos epigráficos relatan una afiliación directa entre La Corona y la dinastía gobernante en Calakmul, por lo que el primer centro seguramente fungió como punto clave para las estrategias de expansión de Calakmul por las Tierras Bajas Mayas durante los siglos VI y VII d.C. Aquí se presentan algunos resultados obtenidos en las investigaciones llevadas al cabo entre 2005 y 2009.The La Corona Regional Archaeological Project is studying the northwestern Peten region (Guatemala, where the ancient Maya city of La Corona is located. This site has been recently identified as the unknown Site Q. The research at La Corona has included excavations of monumental and settlement architecture, mapping, use of remote sensing and ecological and paleo-climate studies. Viewed from the political organization models, investigations at La Corona present an opportunity to study the nature and political relations of secondary sites. Epigraphic data show a direct affiliation between La Corona and the ruling dynasty of Calakmul, suggesting that La Corona could have been a key center for the expansionistic strategies of Calakmul during the sixth and seventh centuries A.D. In this paper we present some of the results obtained in the investigations carried out between 2005 and 2009.

Pulsed power corona discharges for air pollution control

NARCIS (Netherlands)

Smulders, H.W.M.; Heesch, van E.J.M.; Paasen, van S.V.B.

1998-01-01

Successful introduction of pulsed corona for industrial purposes very much depends on the reliability of high-voltage and pulsed power technology and on the efficiency of energy transfer. In addition, it is of the utmost importance that adequate electromagnetic compatibility (EMC) is achieved

Tomographic Validation of the AWSoM Model of the Inner Corona During Solar Minima

Science.gov (United States)

Manchester, W.; Vásquez, A. M.; Lloveras, D. G.; Mac Cormack, C.; Nuevo, F.; Lopez-Fuentes, M.; Frazin, R. A.; van der Holst, B.; Landi, E.; Gombosi, T. I.

2017-12-01

Continuous improvement of MHD three-dimensional (3D) models of the global solar corona, such as the Alfven Wave Solar Model (AWSoM) of the Space Weather Modeling Framework (SWMF), requires testing their ability to reproduce observational constraints at a global scale. To that end, solar rotational tomography based on EUV image time-series can be used to reconstruct the 3D distribution of the electron density and temperature in the inner solar corona (r used to validate steady-state 3D MHD simulations of the inner corona using the latest version of the AWSoM model. We perform the study for selected rotations representative of solar minimum conditions, when the global structure of the corona is more axisymmetric. We analyse in particular the ability of the MHD simulation to match the tomographic results across the boundary region between the equatorial streamer belt and the surrounding coronal holes. The region is of particular interest as the plasma flow from that zone is thought to be related to the origin of the slow component of the solar wind.

The Intracellular Destiny of the Protein Corona: A Study on its Cellular Internalization and Evolution.

Science.gov (United States)

Bertoli, Filippo; Garry, David; Monopoli, Marco P; Salvati, Anna; Dawson, Kenneth A

2016-11-22

It has been well established that the early stages of nanoparticle-cell interactions are governed, at least in part, by the layer of proteins and other biomolecules adsorbed and slowly exchanged with the surrounding biological media (biomolecular corona). Subsequent to membrane interactions, nanoparticles are typically internalized into the cell and trafficked along defined pathways such as, in many cases, the endolysosomal pathway. Indeed, if the original corona is partially retained on the nanoparticle surface, the biomolecules in this layer may play an important role in determining subsequent cellular processing. In this work, using a combination of organelle separation and fluorescence labeling of the initial extracellular corona, we clarify its intracellular evolution as nanoparticles travel within the cell. We show that specific proteins present in the original protein corona are retained on the nanoparticles until they accumulate in lysosomes, and, once there, they are degraded. We also report on how different bare surfaces (amino and carboxyl modified) affect the details of this evolution. One overarching discovery is that the same serum proteins can exhibit different intracellular processing when carried inside cells by nanoparticles, as components of their corona, compared to what is observed when they are transported freely from the extracellular medium.

Tuning complement activation and pathway through controlled molecular architecture of dextran chains in nanoparticle corona.

Science.gov (United States)

Coty, Jean-Baptiste; Eleamen Oliveira, Elquio; Vauthier, Christine

2017-11-05

The understanding of complement activation by nanomaterials is a key to a rational design of safe and efficient nanomedicines. This work proposed a systematic study investigating how molecular design of nanoparticle coronas made of dextran impacts on mechanisms that trigger complement activation. The nanoparticles used for this work consisted of dextran-coated poly(isobutylcyanoacrylate) (PIBCA) nanoparticles have already been thoroughly characterized. Their different capacity to trigger complement activation established on the cleavage of the protein C3 was also already described making these nanoparticles good models to investigate the relation between the molecular feature of their corona and the mechanism by which they triggered complement activation. Results of this new study show that complement activation pathways can be selected by distinct architectures formed by dextran chains composing the nanoparticle corona. Assumptions that explain the relation between complement activation mechanisms triggered by the nanoparticles and the nanoparticle corona molecular feature were proposed. These results are of interest to better understand how the design of dextran-coated nanomaterials will impact interactions with the complement system. It can open perspectives with regard to the selection of a preferential complement activation pathway or prevent the nanoparticles to activate the complement system, based on a rational choice of the corona configuration. Copyright © 2017 Elsevier B.V. All rights reserved.

Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

International Nuclear Information System (INIS)

Malik, Muhammad Arif; Ubaid-ur-Rehman; Ghaffar, Abdul; Ahmed, Kurshid

2002-01-01

The effect of O 2 and O 3 bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 MΩ resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l -1 methylene blue in distilled water was decolourized in 120 min. Bubbling O 2 at 10 ml min -1 through the discharge region reduced the decolourization time to 25 min. Bubbling O 2 containing 1500 μmol O 3 l -1 at 10 ml min -1 reduced the decolourization time to 8 min. The O 3 was produced by fractionating input energy between a water treatment reactor and a O 3 generator, i.e. no additional energy was consumed for O 3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in 30 min by corona discharge with O 2 bubbling, and in 11 min by corona discharge with bubbling of O 2 containing 1500 μmol O 3 l -1

First report of shoot blight and dieback caused by Diplodia pinea on Pinus pinaster and P. radiata trees in Tunisia

Directory of Open Access Journals (Sweden)

B.T. Linaldeddu

2009-01-01

Full Text Available Damage caused by Diplodia pinea on Pinus pinaster and P. radiata forests are reported for the fi rst time in Tunisia. The affected plants show shoot blight, canker and branch dieback. On decaying and dead branches pycnidia of D. pinea are observed. The fungus was repeatedly isolated from the bark of symptomatic branches. The results of pathogenicity tests confirm the virulence of D. pinea and the susceptibility of both Pinus species to infection.

Spicular downflows in late-type giant coronae

International Nuclear Information System (INIS)

Wallenhorst, S.G.

1980-01-01

Models of the coronae of late-type stars are considered, under the assumption that the dominant coronal energy loss is not conduction, as is usually assumed, but rather the losses due to hot spicular material falling back onto the chromosphere. This assumption is used to estimated the increase in stellar mass-loss rate which should occur when stars evolve across the so-called Supersonic Transition Locus (STL). For a constant downward number flux, this increase is estimate to be about one order of magnitude. Energy-balance models are then considered for spicule-dominated coronae, under the additional assumption that the energy input flux to the corona is constant over a star's post-main sequence evolution; this assumption is found to be consistent with observed red giant mass-loss rates. A sequence of models is constructed which enables the various coronal parameters to be estimated for different masses and radii. The models yield results similar to those of the minimum flux coronal theory of A.G. Hearn; these similarities, along with the validity of the minimum flux technique, are discussed. It is shown that several criticisms of the minimum flux method, due to Antiochos and Underwood (1978) and Van Tend (1979), are valid for minimum flux models in which spicular downflow is neglected, but are satisfied by the models considered below. Solutions which precisely satisfy the constant-flux assumption are not found to exist for solar mass stars. Under the assumption that the minimum flux theory is correct, and using a downflow number flux derived from the energy-balance model, the jump in mass-loss rate at the STL is reevaluated. In this more rigorous case, the jump is found to be only about a factor of three. It is concluded that large increases in mass-loss rate are not to be expected as stars evolve across this transition locus

Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

Science.gov (United States)

Patil, Jagadish G.; Vijayan, T.

2010-02-01

Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over μA) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 102-106 m-3 are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

Energy Technology Data Exchange (ETDEWEB)

Patil, Jagadish G; Vijayan, T, E-mail: jagdishlove@gmail.co [Mahatma Education Society' s ' Pillai' s Institute of Information Technology, Engineering, Media Studies and Research' Dr. K M Vasudevan Pillai' s Campus, Sector 16, New Panvel, Navi Mumbai - 410 206 (India)

2010-02-01

Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over {mu}A) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 10{sup 2}-10{sup 6} m{sup -3} are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

International Nuclear Information System (INIS)

Patil, Jagadish G; Vijayan, T

2010-01-01

Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over μA) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 10 2 -10 6 m -3 are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

Structural modifications of the brain in acclimatization to high-altitude.

Directory of Open Access Journals (Sweden)

Jiaxing Zhang

Full Text Available Adaptive changes in respiratory and cardiovascular responses at high altitude (HA have been well clarified. However, the central mechanisms underlying HA acclimatization remain unclear. Using voxel-based morphometry (VBM and diffusion tensor imaging (DTI with fractional anisotropy (FA calculation, we investigated 28 Han immigrant residents (17-22 yr born and raised at HA of 2616-4200 m in Qinghai-Tibetan Plateau for at least 17 years and who currently attended college at sea-level (SL. Their family migrated from SL to HA 2-3 generations ago and has resided at HA ever since. Control subjects were matched SL residents. HA residents (vs. SL showed decreased grey matter volume in the bilateral anterior insula, right anterior cingulate cortex, bilateral prefrontal cortex, left precentral cortex, and right lingual cortex. HA residents (vs. SL had significantly higher FA mainly in the bilateral anterior limb of internal capsule, bilateral superior and inferior longitudinal fasciculus, corpus callosum, bilateral superior corona radiata, bilateral anterior external capsule, right posterior cingulum, and right corticospinal tract. Higher FA values in those regions were associated with decreased or unchanged radial diffusivity coinciding with no change of longitudinal diffusivity in HA vs. SL group. Conversely, HA residents had lower FA in the left optic radiation and left superior longitudinal fasciculus. Our data demonstrates that HA acclimatization is associated with brain structural modifications, including the loss of regional cortical grey matter accompanied by changes in the white matter, which may underlie the physiological adaptation of residents at HA.

Phenotype- and genotype-specific structural alterations in spasmodic dysphonia.

Science.gov (United States)

Bianchi, Serena; Battistella, Giovanni; Huddleston, Hailey; Scharf, Rebecca; Fleysher, Lazar; Rumbach, Anna F; Frucht, Steven J; Blitzer, Andrew; Ozelius, Laurie J; Simonyan, Kristina

2017-04-01

Spasmodic dysphonia is a focal dystonia characterized by involuntary spasms in the laryngeal muscles that occur selectively during speaking. Although hereditary trends have been reported in up to 16% of patients, the causative etiology of spasmodic dysphonia is unclear, and the influences of various phenotypes and genotypes on disorder pathophysiology are poorly understood. In this study, we examined structural alterations in cortical gray matter and white matter integrity in relationship to different phenotypes and putative genotypes of spasmodic dysphonia to elucidate the structural component of its complex pathophysiology. Eighty-nine patients with spasmodic dysphonia underwent high-resolution magnetic resonance imaging and diffusion-weighted imaging to examine cortical thickness and white matter fractional anisotropy in adductor versus abductor forms (distinct phenotypes) and in sporadic versus familial cases (distinct genotypes). Phenotype-specific abnormalities were localized in the left sensorimotor cortex and angular gyrus and the white matter bundle of the right superior corona radiata. Genotype-specific alterations were found in the left superior temporal gyrus, supplementary motor area, and the arcuate portion of the left superior longitudinal fasciculus. Our findings suggest that phenotypic differences in spasmodic dysphonia arise at the level of the primary and associative areas of motor control, whereas genotype-related pathophysiological mechanisms may be associated with dysfunction of regions regulating phonological and sensory processing. Identification of structural alterations specific to disorder phenotype and putative genotype provides an important step toward future delineation of imaging markers and potential targets for novel therapeutic interventions for spasmodic dysphonia. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

Combined corona discharge and UV photoionization source for ion mobility spectrometry.

Science.gov (United States)

Bahrami, Hamed; Tabrizchi, Mahmoud

2012-08-15

An ion mobility spectrometer is described which is equipped with two non-radioactive ion sources, namely an atmospheric pressure photoionization and a corona discharge ionization source. The two sources cannot only run individually but are additionally capable of operating simultaneously. For photoionization, a UV lamp was mounted parallel to the axis of the ion mobility cell. The corona discharge electrode was mounted perpendicular to the UV radiation. The total ion current from the photoionization source was verified as a function of lamp current, sample flow rate, and drift field. Simultaneous operation of the two ionization sources was investigated by recording ion mobility spectra of selected samples. The design allows one to observe peaks from either the corona discharge or photoionization individually or simultaneously. This makes it possible to accurately compare peaks in the ion mobility spectra from each individual source. Finally, the instrument's capability for discriminating two peaks appearing in approximately identical drift times using each individual ionization source is demonstrated. Copyright © 2012 Elsevier B.V. All rights reserved.

Alkali ion migration between stacked glass plates by corona discharge treatment

Energy Technology Data Exchange (ETDEWEB)

Kawaguchi, Keiga [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan); Suzuki, Toshio [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Ikeda, Hiroshi [Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Sakai, Daisuke [Department of Electrical and Electronic Engineering, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Funatsu, Shiro; Uraji, Keiichiro [Production Technology Center, Asahi Glass Co., Ltd., 1-1 Suehiro-cyo, Tsurumiku, Yokohama, Kanagawa 230-0045 (Japan); Yamamoto, Kiyoshi [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Harada, Kenji [Department of Computer Science, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Nishii, Junji, E-mail: nishii@es.hokudai.ac.jp [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan)

2015-05-30

Highlights: • Two stacked glass plates with a 1 mm gap were treated by corona discharge. • Spatial migration of alkali ion over the gap was demonstrated. • Hydrogen gas was necessary for uniform migration. • Surface modification was done with this process without high temperature or vacuum. - Abstract: Corona discharge reflects the spatial migration of alkali ions over a gap between two glass plates. This study examined stacked glass plates containing different alkali ions treated with the corona discharge plasma generated by applied voltage of 4.5 kV at 200 °C. Protons generated at the anode electrode penetrate into the potassium-ion-containing upper glass plate, which is located 5 mm below the anode electrode. Potassium ions intruded into the lower glass plate containing sodium ions placed on the cathode electrode, even over a 1 mm gap separating the plates. Finally, the sodium ion discharged on the cathode electrode. The hydrogen atmosphere was effective at inhibiting the potassium ion reaction with ambient gases during the spatial migration between the two glass plates.

CORONA ACADEMY, Opportunities for Enhancement of Training Capabilities in VVER Technology

International Nuclear Information System (INIS)

Ilieva, M.; Dieguez Porras, P.; Klepakova, A.

2016-01-01

Full text: The general objective of the project CORONA II is to enhance the safety of nuclear installations through further improvement of the training capabilities for providing the necessary personnel competencies in VVER area. More specific objective of the project is to continue the development of a state-of-the-art regional training network for VVER competence called CORONA Academia. The project aims at continuation of the European cooperation and support in this area for preservation and further development of expertise in the nuclear field by improvement of higher education and training. The consortium is focusing its effort on using the most advanced ways of providing training to the trainees, saving cost and time–distance learning and e-learning approaches which will be tested in CORONA II Project. The knowledge management portal will integrate the information on VVER web into a single communication system and develop and implement a semantic web structure to achieve mutual recognition of authentication information with other databases. That will enable the partners to share the materials available in each specific training center. (author

THE STRUCTURE AND SPECTRAL FEATURES OF A THIN DISK AND EVAPORATION-FED CORONA IN HIGH-LUMINOSITY ACTIVE GALACTIC NUCLEI

International Nuclear Information System (INIS)

Liu, J. Y.; Liu, B. F.; Qiao, E. L.; Mineshige, S.

2012-01-01

We investigate the accretion process in high-luminosity active galactic nuclei (HLAGNs) in the scenario of the disk evaporation model. Based on this model, the thin disk can extend down to the innermost stable circular orbit (ISCO) at accretion rates higher than 0.02 M-dot Edd while the corona is weak since part of the coronal gas is cooled by strong inverse Compton scattering of the disk photons. This implies that the corona cannot produce as strong X-ray radiation as observed in HLAGNs with large Eddington ratio. In addition to the viscous heating, other heating to the corona is necessary to interpret HLAGN. In this paper, we assume that a part of accretion energy released in the disk is transported into the corona, heating up the electrons, and is thereby radiated away. For the first time, we compute the corona structure with additional heating, fully taking into account the mass supply to the corona, and find that the corona could indeed survive at higher accretion rates and that its radiation power increases. The spectra composed of bremsstrahlung and Compton radiation are also calculated. Our calculations show that the Compton-dominated spectrum becomes harder with the increase of energy fraction (f) liberating in the corona, and the photon index for hard X-ray (2-10 keV) is 2.2 bol /L 2-10keV ) increases with increasing accretion rate for f < 8/35, which is roughly consistent with the observational results.

Greener corona discharge for enhanced wind generation with a simple dip-coated carbon nanotube decoration

Science.gov (United States)

Wu, Yishan; Li, Jun; Ye, Jianchun; Chen, Xiaohong; Li, Huili; Huang, Sumei; Zhao, Ran; Ou-Yang, Wei

2017-10-01

Corona discharge-induced wind (CDIW) has been widely utilized in production lines in the food and semiconductor industries and in indoor devices such as electrostatic precipitators. Some ozone is inevitably emitted, posing serious health risks to respiratory system and lung function of a human being. In this work, a greener corona discharge with enhanced wind generation for a needle-to-cylinder discharge structure is demonstrated using a simple dip-coating method to attach carbon nanotubes (CNTs) to the discharge electrode of a stainless steel needle. Compared with a conventional discharge electrode without CNT decoration, the velocity of the CDIW is greatly enhanced, the onset voltage is lowered, the energy conversion efficiency is greatly improved and the concentration of generated ozone is much reduced, making this easy method of CNT decoration a promising candidate for greener corona discharge systems. In addition, several impact factors for improved performance are discussed mathematically and phenomenologically, providing an insight into the corona discharge and wind generation.

Greener corona discharge for enhanced wind generation with a simple dip-coated carbon nanotube decoration

International Nuclear Information System (INIS)

Wu, Yishan; Ye, Jianchun; Chen, Xiaohong; Li, Huili; Huang, Sumei; Zhao, Ran; Ou-Yang, Wei; Li, Jun

2017-01-01

Corona discharge-induced wind (CDIW) has been widely utilized in production lines in the food and semiconductor industries and in indoor devices such as electrostatic precipitators. Some ozone is inevitably emitted, posing serious health risks to respiratory system and lung function of a human being. In this work, a greener corona discharge with enhanced wind generation for a needle-to-cylinder discharge structure is demonstrated using a simple dip-coating method to attach carbon nanotubes (CNTs) to the discharge electrode of a stainless steel needle. Compared with a conventional discharge electrode without CNT decoration, the velocity of the CDIW is greatly enhanced, the onset voltage is lowered, the energy conversion efficiency is greatly improved and the concentration of generated ozone is much reduced, making this easy method of CNT decoration a promising candidate for greener corona discharge systems. In addition, several impact factors for improved performance are discussed mathematically and phenomenologically, providing an insight into the corona discharge and wind generation. (paper)

The Combined Intervention with Germinated Vigna radiata and Aerobic Interval Training Protocol Is an Effective Strategy for the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD and Other Alterations Related to the Metabolic Syndrome in Zucker Rats

Directory of Open Access Journals (Sweden)

Garyfallia Kapravelou

2017-07-01

Full Text Available Metabolic syndrome (MetS is a group of related metabolic alterations that increase the risk of developing non-alcoholic fatty liver disease (NAFLD. Several lifestyle interventions based on dietary treatment with functional ingredients and physical activity are being studied as alternative or reinforcement treatments to the pharmacological ones actually in use. In the present experiment, the combined treatment with mung bean (Vigna radiata, a widely used legume with promising nutritional and health benefits that was included in the experimental diet as raw or 4 day-germinated seed flour, and aerobic interval training protocol (65–85% VO2 max has been tested in lean and obese Zucker rats following a 2 × 2 × 2 (2 phenotypes, 2 dietary interventions, 2 lifestyles factorial ANOVA (Analysis of Variance statistical analysis. Germination of V. radiata over a period of four days originated a significant protein hydrolysis leading to the appearance of low molecular weight peptides. The combination of 4 day-germinated V. radiata and aerobic interval training was more efficient compared to raw V. radiata at improving the aerobic capacity and physical performance, hepatic histology and functionality, and plasma lipid parameters as well as reverting the insulin resistance characteristic of the obese Zucker rat model. In conclusion, the joint intervention with legume sprouts and aerobic interval training protocol is an efficient treatment to improve the alterations of glucose and lipid metabolism as well as hepatic histology and functionality related to the development of NAFLD and the MetS.

Fast imaging of intermittent electrospraying of water with positive corona discharge

International Nuclear Information System (INIS)

Pongrác, B; Janda, M; Martišovitš, V; Machala, Z; Kim, H H

2014-01-01

The effect of the electrospraying of water in combination with a positive direct current (dc) streamer corona discharge generated in air was investigated in this paper. We employed high-speed camera visualizations and oscilloscopic discharge current measurements in combination with an intensified charge-coupled device camera for fast time-resolved imaging. The repetitive process of Taylor cone formation and droplet formation from the mass fragments of water during the electrospray was visualized. Depending on the applied voltage, the following intermittent modes of electrospraying typical for water were observed: dripping mode, spindle mode, and oscillating-spindle mode. The observed electrospraying modes were repetitive with a frequency of a few hundreds of Hz, as measured from the fast image sequences. This frequency agreed well with the frequency of the measured streamer current pulses. The presence of filamentary streamer discharges at relatively low voltages probably prevented the establishment of a continuous electrospray in the cone–jet mode. After each streamer, a positive glow corona discharge was established on the water filament tip, and it propagated from the stressed electrode along with the water filament elongation. The results show a reciprocal character of intermittent electrospraying of water, and the presence of corona discharge, where both the electrospray and the discharge affect each other. The generation of a corona discharge from the water cone depended on the repetitive process of the cone formation. Also, the propagation and curvature of the water filament were influenced by the discharge and its resultant space charge. Furthermore, these phenomena were partially influenced by the water conductivity. (paper)

Intermittent heating of the solar corona by MHD turbulence

Directory of Open Access Journals (Sweden)

É. Buchlin

2007-10-01

Full Text Available As the dissipation mechanisms considered for the heating of the solar corona would be sufficiently efficient only in the presence of small scales, turbulence is thought to be a key player in the coronal heating processes: it allows indeed to transfer energy from the large scales to these small scales. While Direct numerical simulations which have been performed to investigate the properties of magnetohydrodynamic turbulence in the corona have provided interesting results, they are limited to small Reynolds numbers. We present here a model of coronal loop turbulence involving shell-models and Alfvén waves propagation, allowing the much faster computation of spectra and turbulence statistics at higher Reynolds numbers. We also present first results of the forward-modelling of spectroscopic observables in the UV.

Two-zone model of coronal hole structure in the high corona

International Nuclear Information System (INIS)

Wang, Z.; Kundu, M.R.; Yoshimura, H.

1988-01-01

The two-zone coronal hole structure model presently proposed for the high corona at 1.5-1.7 solar radii emerges from a comparison of computation results for the potential magnetic fields of the corona and meter-decameter radio observations. The two zones of a coronal hole are defined by the configuration of magnetic field lines around a coronal hole: (1) the central hole of an open diverging magnetic field line system; and (2) the boundary zone between the central zone of the open field line system and the closed field line system or systems surrounding the open field line system. 19 references

Repeatability and variation of region-of-interest methods using quantitative diffusion tensor MR imaging of the brain

International Nuclear Information System (INIS)

Hakulinen, Ullamari; Brander, Antti; Ryymin, Pertti; Öhman, Juha; Soimakallio, Seppo; Helminen, Mika; Dastidar, Prasun; Eskola, Hannu

2012-01-01

Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain’s white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain’s parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10 -3 mm 2 /s with the CM and 0.747 ×10 -3 mm 2 /s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate

Physical conditions in the corona for a bipolar magnetic region

International Nuclear Information System (INIS)

Vorpahl, J.A.

1978-01-01

The S-056 X-ray data from Skylab has been used to determine quantitative values for the coronal conditions characterizing a new bipolar magnetic region (BMR). In particular, the author includes (a) the time variation of the total soft X-ray flux from the BMR as a function of time; (b) the temporal and spatial variation of the temperature and emission measure; (c) the variation with time of thermal energy density; (d) the (calculated) magnetic field configuration and magnetic flux density in the corona; and (e) the temporal variation of the magnetic field energy in the corona. Detailed comparisons are made between the configuration of X-ray features and the magnetic field topology. (Auth.)

Absolute photometry of the corona of July 10, 1972 total solar eclipse

Energy Technology Data Exchange (ETDEWEB)

Khetsuriani, Ts.S.; Tetruashvili, Eh.I.

1985-01-01

The observations were carried out by the Abastumani astrophysical observatory expedition at July 10.1972 total solar eclipse from a site of the Chukotka Peninsula. The photometry of the corona images is performed by the equidensity method having expressed the intensities in absolute units. The F and K components of the corona are separated on the basis of photometric and polarisation data. The variations of the electron concentration with the distance from the centre of the Sun and tempeatures at various distances are calculated.

Oxidation of sulfur and nitrogen oxides by pulse corona discharge

International Nuclear Information System (INIS)

Amirov, R.H.; Desiaterik, Yu.N.; Filimonova, E.A.; Zhelezniak, M.B.; Chae, J.O.

1996-01-01

The NO x and SO 2 removal efficiency of the corona reactor has been measured both with and without ammonia addition to the gas stream. Experimental conditions are described. The dependence of NO and SO 2 removal efficiency from flow rate and initial pollutant concentrations were measured. One test with fixed amount of the inputted energy per the unit of SO 2 but with different initial concentration have been made. It is found that increasing of the initial concentration from 200 ppm to 700 ppm can enlarge the removal efficiency by factor 2.5. Some tests were carried out with both pollutant gases SO 2 and NO simultaneously. An efficiency on the SO 2 removal of 96% and on the NO removal 70% in pulse corona have been achieved with ammonia addition when SO 2 initial concentration was 480 ppm and the NO initial concentration was 230 ppm. A numerical model for NO and SO 2 oxidation in homogeneous gas flow has been developed. The flow contains cold (T = 300-400 K) background components N 2 , CO 2 , H 2 O, O 2 and impurities SO 2 , NO x , CO. A source of chemically active species is an electrical streamer discharge of corona type. (authors)

Assessment of environmental impact of HVDC power lines in terms of corona currents

International Nuclear Information System (INIS)

Tikhodeev, N.N.

1997-01-01

Corona loss measurements were made on a HVDC power transmission line to evaluate current density. Ion currents were obtained from unipolar and bipolar 400 to 1000 kV DC test lines. A numerical solution was proposed for assessing the maximum current density of unipolar corona currents near the lines. A larger ground clearance of line conductors was proposed as being the most effective way of lowering the current density. 11 refs., 2 tabs., 4 figs

First record of the genus .i.Bloszykiella./i. in Kenya with the description of .i.Bloszykiella tertia./i. sp n. (Acari: Uropodidae) from a .i.Pinus radiata./i. D. Don plantation

Czech Academy of Sciences Publication Activity Database

Kontschán, J.; Starý, Josef

2015-01-01

Roč. 56, č. 3 (2015), s. 629-635 ISSN 1681-5556 Institutional support: RVO:60077344 Keywords : Acari * new species * Pinus radiata plantation * Kenya Subject RIV: EG - Zoology Impact factor: 0.708, year: 2015

Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

Energy Technology Data Exchange (ETDEWEB)

Malik, Muhammad Arif [Applied Chemistry Division, PINSTECH, PO Nilore, Islamabad (Pakistan); Ubaid-ur-Rehman [Applied Chemistry Division, PINSTECH, PO Nilore, Islamabad (Pakistan); Ghaffar, Abdul; Ahmed, Kurshid [Electronics Division, PINSTECH, PO Nilore, Islamabad (Pakistan)

2002-08-01

The effect of O{sub 2} and O{sub 3} bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 M{omega} resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l{sup -1} methylene blue in distilled water was decolourized in 120 min. Bubbling O{sub 2} at 10 ml min{sup -1} through the discharge region reduced the decolourization time to 25 min. Bubbling O{sub 2} containing 1500 {mu}mol O{sub 3} l{sup -1} at 10 ml min{sup -1} reduced the decolourization time to 8 min. The O{sub 3} was produced by fractionating input energy between a water treatment reactor and a O{sub 3} generator, i.e. no additional energy was consumed for O{sub 3} production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in 30 min by corona discharge with O{sub 2} bubbling, and in 11 min by corona discharge with bubbling of O{sub 2} containing 1500 {mu}mol O{sub 3} l{sup -1}.

Biogenic synthesis and spatial distribution of silver nanoparticles in the legume mungbean plant (Vigna radiata L.).

Science.gov (United States)

Kumari, Rima; Singh, Jay Shankar; Singh, Devendra Pratap

2017-01-01

The present investigation aimed to study the in vivo synthesis of silver nanoparticles (AgNPs) in the legume Vigna radiata. The level of plant metabolites such as total phenolics, lipid, terpenoids, alkaloids and amino acid increased by 65%, 133%, 19%, 67% and 35%, respectively, in AgNO 3 (100 mg L -1 ) treated plants compared to control. Whereas protein and sugar contents in the treated plants were reduced by 38% and 27%, respectively. FTIR analysis of AgNO 3 (20-100 mg L -1 ) treated plants exhibited changes in the IR regions between 3297 and 3363 cm -1 , 1635-1619 cm -1 , 1249-1266 cm -1 and that corresponded to alterations in OH groups of carbohydrates, OH and NH groups of amide I and II regions of protein, when compared with the control. Transmission electron micrographs showed the spatial distribution of AgNPs in the chloroplast, cytoplasmic spaces, vacuolar and nucleolar plant regions. Metal quantification in different tissues of plants exposed to 20-100 mg L -1 AgNO 3 showed about a 22 fold accumulation of Ag in roots as compared to shoots. The phytotoxic parameters such as percent seed germination and shoot elongation remained almost unaltered at low AgNO 3 doses (20-50 mg L -1 ). However, at higher levels of exposure (100 mg L -1 ), the percent seed germination as well as root and shoot elongation exhibited concentration dependent decline. In conclusion, synthesis of AgNPs in V. radiata particularly at lower doses of AgNO 3 , could be used as a sustainable and environmentally safe technology for large scale production of metal nanoparticles. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Design of the corona current measurement sensor with wide bandwidth under dc ultra-high-voltage environment

International Nuclear Information System (INIS)

Liu, Yingyi; Yuan, Haiwen; Yang, Qinghua; Cui, Yong

2011-01-01

The research in the field of corona discharge, which is one of the key technologies, can help us to realize ultra-high-voltage (UHV) power transmission. This paper proposes a new sampling resistance sensor to measure the dc UHV corona current in a wide band. By designing the structural and distributed parameters of the sensor, the UHV dielectric breakdown performance and the wide-band measuring characteristics of the sensor are satisfied. A high-voltage discharge test shows that the designed sensor can work under a 1200 kV dc environment without the occurrence of corona discharge. A frequency characteristic test shows that the measuring bandwidth of the sensor can be improved from the current 4.5 to 20 MHz. The test results in an actual dc UHV transmission line demonstrate that the sensor can accurately measure the corona current under the dc UHV environment

Halopriming of seeds imparts tolerance to NaCl and PEG induced stress in Vigna radiata (L.) Wilczek varieties.

Science.gov (United States)

Jisha, K C; Puthur, Jos T

2014-07-01

The investigation was carried out to study the effect of halopriming on NaCl and polyethylene glycol-6000 (PEG-6000) induced stress tolerance potential of three Vigna radiata (L.) Wilczek varieties, with varied abiotic stress tolerance potential. Halopriming is a seed priming technique in which the seeds were soaked in various salt solutions (in this study NaCl was used). The results of the study indicated that the application of stresses (both NaCl and PEG) induced retardation of growth attributes (measured in terms of shoot length, fresh weight, dry weight) and decrease in physiological attributes like total chlorophyll content, metabolites, photosynthetic and mitochondrial activity of the seedlings in all three V. radiata (L.) varieties. However, halopriming of the seeds could reduce the extent of decrease in these biological attributes. NaCl and PEG stress also caused increase in MDA content (a product of membrane lipid peroxidation) in all the varieties studied and this increase was significantly minimized under halopriming. From the present investigation it was evident that among the green gram varieties studied, Pusa Vishal, a NaCl tolerant variety showed enhanced tolerance to NaCl and PEG induced stress, when the seeds were subjected to halopriming followed by Pusa Ratna (stress sensitive variety). Pusa 9531 (drought tolerant variety) also showed positive halopriming effects but it was less significant when compared to other two varieties. It could be concluded that halopriming improved the drought and salinity stress tolerance potential of all varieties and it was significantly higher in the Pusa Vishal as compared to Pusa 9531 and Pusa Ratna.

Structure of the solar transition region and inner corona

International Nuclear Information System (INIS)

Mariska, J.T.

1977-01-01

Emission gradient curves for extreme ultraviolet (EUV) resonance lines of lithium-like ions were constructed from spectroheliograms of quiet limb regions and a north polar coronal hole observed with the Harvard experiment on Skylab. The observations are interpreted with simple coronal models. Comparison of the theoretical and observed emission gradients for quiet regions indicates that for these areas the temperature rises throughout the inner corona (1.03 less than or equal to r less than or equal to 1.20 R/sub mass/). In the coronal hole the temperature rises in a manner consistent with a constant conductive flux to an isothermal corona at a temperature of 1.1 x 10 6 K at 1.08/sub mass/. The geometry of the coronal hole boundary is also determined. The boundary geometry and density distribution are combined with typical solar wind parameters at the north to determine an outflow velocity of 15 km s -1 at 1.08 R/sub mass/. The energy balance implications of the models are examined. It was found that in the transition region both conduction and radiation are important in determining the energy balance in network regions in both quiet areas and coronal holes. Additional energy sources are required in the network in coronal holes. In the corona it is found that, to within the errors of the determination, the energy losses, and hence the requirements for mechanical heating, are the same in quiet regions and coronal holes

Reticulated Vitreous Carbon Electrodes for Gas Phase Pulsed Corona Reactors

National Research Council Canada - National Science Library

Locke, B

1998-01-01

A new design for gas phase pulsed corona reactors incorporating reticulated vitreous carbon electrodes is demonstrated to be effective for the removal of nitrogen oxides from synthetic air mixtures...

Reticulated Vitreous Carbon Electrodes for Gas Phase Pulsed Corona Reactors

National Research Council Canada - National Science Library

LOCKE, B

1999-01-01

A new design for gas phase pulsed corona reactors incorporating reticulated vitreous carbon electrodes is demonstrated to be effective for the removal of nitrogen oxides from synthetic air mixtures...

Gill tissue reactions in walleye Stizostedion vitreum vitreum and common carp Cyprinus carpio to glochidia of the freshwater mussel Lampsilis radiata siliquoidea

Science.gov (United States)

Waller, D.L.; Mitchell, L.G.

1989-01-01

The glochidia of many freshwater mussels, which are obligate parasites on the gills, fins, and other body parts of specific fishes, attach to a suitable host, become encapsulated, and develop to the free-living juvenile stage. Using light and electron microscopy we compared gill tissue reactions in a suitable host (walleye Stizostedion vitreum vitreum) and unsuitable host (common carp Cyprinus carpio) infected with Lampsilis radiata siliquoidea. Encapsulation of glochidia on walleye gills was completed by 6 h post-infection at 20 to 22°C. Capsular formation and compaction were accompanied by a general increase in epithelioid cells. Fibrotic material appeared in capsules at about 48 h and virtually filled capsular cells from about Day 5 to Day 11 post-infection. Liberation of juvenile mussels was accompanied by thinning of the capsule from about Day 11 to Day l7. Although glochidia attached to the gills of common carp, few became encapsulated. By 48 h post-infection, preliminary capsular growth was evident and necrotic cells and cellular debris appeared at the edges of the growth. However, all glochidia were sloughed from carp gills by 60 h. Host specificity of L. radiata siliquoidea apparently depended on a combination of the attachment response of glochidia, differences in the encapsulation process, and tissue reactions in the fish.

Protein corona: a new approach for nanomedicine design

Directory of Open Access Journals (Sweden)

Nguyen VH

2017-04-01

Full Text Available Van Hong Nguyen, Beom-Jin Lee Department of Pharmacy, Bioavailability Control Laboratory, College of Pharmacy, Ajou University, Suwon, Republic of Korea Abstract: After administration of nanoparticle (NP into biological fluids, an NP–protein complex is formed, which represents the “true identity” of NP in our body. Hence, protein–NP interaction should be carefully investigated to predict and control the fate of NPs or drug-loaded NPs, including systemic circulation, biodistribution, and bioavailability. In this review, we mainly focus on the formation of protein corona and its potential applications in pharmaceutical sciences such as prediction modeling based on NP-adsorbed proteins, usage of active proteins for modifying NP to achieve toxicity reduction, circulation time enhancement, and targeting effect. Validated correlative models for NP biological responses mainly based on protein corona fingerprints of NPs are more highly accurate than the models solely set up from NP properties. Based on these models, effectiveness as well as the toxicity of NPs can be predicted without in vivo tests, while novel cell receptors could be identified from prominent proteins which play important key roles in the models. The ungoverned protein adsorption onto NPs may have generally negative effects such as rapid clearance from the bloodstream, hindrance of targeting capacity, and induction of toxicity. In contrast, controlling protein adsorption by modifying NPs with diverse functional proteins or tailoring appropriate NPs which favor selective endogenous peptides and proteins will bring promising therapeutic benefits in drug delivery and targeted cancer treatment. Keywords: protein-nanoparticle interaction, protein corona, exchange of adsorbed protein, toxicity reduction, predictive modeling, targeting drug delivery

Photometric intensity and polarization measurements of the solar corona.

Science.gov (United States)

Mcdougal, D. S.

1971-01-01

Use of a satellite photometric observatory (SPO) to measure the solar corona from Miahuatlan, Mexico during the Mar. 7, 1970, total eclipse of the sun. The SPO is equipped with a 24-in. Cassegrainian telescope, a four-channel photoelectric photometer, a Wollaston prism, and a rotating half-wave plate. Simultaneous measurements were made of the two orthogonal components of coronal light in the B and R bands of the UBVRI system. A 1-minute arc aperture was scanned from the lunar disk center out to five solar radii in a series of spirals of gradually increasing radius. For the first time, simultaneous multicolor intensity, degree, and angle of polarization profiles are computed from photoelectric measurements. Comparison of the variations of the measurements for each spiral scan yield a detailed picture of the intensity and polarization features in the K corona.

STEREO OBSERVATIONS OF FAST MAGNETOSONIC WAVES IN THE EXTENDED SOLAR CORONA ASSOCIATED WITH EIT/EUV WAVES

International Nuclear Information System (INIS)

Kwon, Ryun-Young; Ofman, Leon; Kramar, Maxim; Olmedo, Oscar; Davila, Joseph M.; Thompson, Barbara J.; Cho, Kyung-Suk

2013-01-01

We report white-light observations of a fast magnetosonic wave associated with a coronal mass ejection observed by STEREO/SECCHI/COR1 inner coronagraphs on 2011 August 4. The wave front is observed in the form of density compression passing through various coronal regions such as quiet/active corona, coronal holes, and streamers. Together with measured electron densities determined with STEREO COR1 and Extreme UltraViolet Imager (EUVI) data, we use our kinematic measurements of the wave front to calculate coronal magnetic fields and find that the measured speeds are consistent with characteristic fast magnetosonic speeds in the corona. In addition, the wave front turns out to be the upper coronal counterpart of the EIT wave observed by STEREO EUVI traveling against the solar coronal disk; moreover, stationary fronts of the EIT wave are found to be located at the footpoints of deflected streamers and boundaries of coronal holes, after the wave front in the upper solar corona passes through open magnetic field lines in the streamers. Our findings suggest that the observed EIT wave should be in fact a fast magnetosonic shock/wave traveling in the inhomogeneous solar corona, as part of the fast magnetosonic wave propagating in the extended solar corona.

Are coronae of late type stars made of solar-like structures? The Fx-HR diagram and the pressure-temperature correlation

OpenAIRE

Peres, G.; Orlando, S.; Reale, F.

2004-01-01

We show that stellar coronae can be composed of X-ray emitting structures like those in the solar corona, using a large set of ROSAT/PSPC observations of late-type-stars, and a large set of solar X-ray data collected with Yohkoh/SXT. We have considered data on the solar corona at various phases of the cycle and various kinds of X-ray coronal structures, from flares to the background corona. The surface flux (F_x) vs. spectral hardness ratio (HR) diagram is a fundamental tool for our study. We...

Ataxic Hemiparesis Associated with Cortical Infarct Localized in the Postcentral Gyrus.

Science.gov (United States)

Kinjo, Yoshino; Suda, Satoshi; Sakamoto, Yuki; Okubo, Seiji; Kimura, Kazumi

2017-09-15

Ataxic hemiparesis (AH) is a classic lacunar syndrome associated with localized damage to the pons, internal capsule, thalamus, or corona radiata. A depression of metabolic activity known as crossed cerebellar diaschisis (CCD) is frequently observed in the cerebellar hemisphere contralateral to the site of the lesion in patients with AH. Though small cortical or subcortical lesions may result in AH, such occurrences are rare. The current report details the case of a patient with AH resulting from acute infarction associated with localized lesions of the postcentral gyrus who presented without CCD.

Conventional and Diffusion-Weighted MRI in the Evaluation of Methanol Poisoning. A case report

International Nuclear Information System (INIS)

Server, A.; Nakstad, P.Hj.; Dullerud, R.; Haakonsen, M.; Hovda, K.E.; Jacobsen, D.

2003-01-01

Cerebral lesions were studied in 2 methanol-poisoned patients using conventional magnetic resonance imaging (MRI). In 1 patient, diffusion-weighted MRI (DWI) was also performed. In this patient, conventional MRI showed symmetrical, bilateral increased signal in the lentiform nuclei, involving predominantly putamina, but also extending into the corona radiata, centrum semiovale and subcortical white matter. DWI showed decreased diffusion, which most probably reflects cytotoxic edema. In the other patient, fluid attenuated-inversion recovery (FLAIR) and T2-weighted images showed hyperintensity in the putamina, characteristic of post-necrotic changes

NO removal characteristics of a corona radical shower system under DC and AC/DC superimposed operations

NARCIS (Netherlands)

Yan, K.; Yamamoto, T.; Kanazawa, S.; Ohkubo, T.; Nomoto, Y.; Chang, Jen-Shih

2001-01-01

In this paper, the effects of the applied voltage modes on the positive corona discharge morphology and NO removal characteristics from air streams are experimentally investigated. By using a DC superimposed high frequency AC power supply (10-60 kHz), a uniform streamer corona can be generated,

Reconstructing Historical Land Cover Type and Complexity by Synergistic Use of Landsat Multispectral Scanner and CORONA

Directory of Open Access Journals (Sweden)

Amir Reza Shahtahmassebi

2017-07-01

Full Text Available Survey data describing land cover information such as type and diversity over several decades are scarce. Therefore, our capacity to reconstruct historical land cover using field data and archived remotely sensed data over large areas and long periods of time is somewhat limited. This study explores the relationship between CORONA texture—a surrogate for actual land cover type and complexity—with spectral vegetation indices and texture variables derived from Landsat MSS under the Spectral Variation Hypothesis (SVH such as to reconstruct historical continuous land cover type and complexity. Image texture of CORONA was calculated using a mean occurrence measure while image textures of Landsat MSS were calculated by occurrence and co-occurrence measures. The relationship between these variables was evaluated using correlation and regression techniques. The reconstruction procedure was undertaken through regression kriging. The results showed that, as expected, texture based on the visible bands and corresponding indices indicated larger correlation with CORONA texture, a surrogate of land cover (correlation >0.65. In terms of prediction, the combination of the first-order mean of band green, second-order measure of tasseled cap brightness, second-order mean of Normalized Visible Index (NVI and second-order entropy of NIR yielded the best model with respect to Akaike’s Information Criterion (AIC, r-square, and variance inflation factors (VIF. The regression model was then used in regression kriging to map historical continuous land cover. The resultant maps indicated the type and degree of complexity in land cover. Moreover, the proposed methodology minimized the impacts of topographic shadow in the region. The performance of this approach was compared with two conventional classification methods: hard classifiers and continuous classifiers. In contrast to conventional techniques, the technique could clearly quantify land cover complexity and

The effect of polycarboxylate shell of magnetite nanoparticles on protein corona formation in blood plasma

Energy Technology Data Exchange (ETDEWEB)

Szekeres, Márta, E-mail: szekeres@chem.u-szeged.hu [Department of Physical Chemistry and Materials Sciences, University of Szeged, Hungary, 1 Aradi vt, 6720 Szeged (Hungary); Tóth, Ildikó Y. [Department of Physical Chemistry and Materials Sciences, University of Szeged, Hungary, 1 Aradi vt, 6720 Szeged (Hungary); Turcu, R. [National Institute R& D for Isotopic and Molecular Technology, Cluj-Napoca 400293 (Romania); Tombácz, Etelka [Department of Physical Chemistry and Materials Sciences, University of Szeged, Hungary, 1 Aradi vt, 6720 Szeged (Hungary)

2017-04-01

The development of protein corona around nanoparticles upon administration to the human body is responsible in a large part for their biodistribution, cell-internalization and toxicity or biocompatibility. We studied the influence of the chemical composition of polyelectrolyte shells (citric acid (CA) and poly(acrylic-co-maleic acid) (PAM)) of core-shell magnetite nanoparticles (MNPs) on the evolution of protein corona in human plasma (HP). The aggregation state and zeta potential of the particles were measured in the range of HP concentration between 1 and 80 (v/v)% 3 min and 20 h after dispersing the particles in HP diluted with Tris buffered saline. Naked MNPs aggregated in HP solution, but the carboxylated MNPs became stabilized colloidally at higher plasma concentrations. Significant differences were observed at low plasma concentration. CA@MNPs aggregated instantly while the hydrodynamic diameter of PAM@MNP increased only slightly at 1–3 v/v % HP concentrations. The observed differences in protein corona formation can be explained by the differences in the steric effects of the polycarboxylate shells. It is interesting that relatively small but systematic changes in zeta potential alter the aggregation state significantly. - Highlights: • Human plasma protein corona cannot stabilize naked and citrate-coated magnetite nanoparticles. • Polycarboxylic acid (PAM) coated MNPs are well stabilized with HP protein corona. • Stability pattern of naked, CA and PAM-coated MNPs is not predicted by zeta potential.

Corona Onset Characteristics of Bundle Conductors in UHV AC Power Lines at 2200 m Altitude

Directory of Open Access Journals (Sweden)

Shilong Huang

2018-04-01

Full Text Available The corona onset characteristic of bundle conductors is an important limiting factor for the design of UHV AC power lines in high-altitude areas. An experimental study on the corona characteristics of 8 × LGJ630, 6 × LGJ720, 8 × LGJ720 and 10 × LGJ720 bundle conductors commonly used in UHV power lines under dry and wet conductor conditions, as well as artificial moderate and heavy rain conditions, was conducted in Ping’an County, Xining City (elevation 2200 m. By using the tangent line method, the corona onset voltages and onset electric field of four types of conductors at high altitudes are obtained for the first time. In addition, the calculation model of corona onset voltage considering the outer strands’ effect on the electric field and the geometric factor in the corona cage in high altitude areas is established. The comparison of the calculation results and experimental results under dry conditions verifies the model’s correctness. Based on the results, an optimal selection scheme for high altitudes is proposed. The roughness coefficient was also calculated and analysed: the roughness coefficient of bundled conductors was between 0.59 and 0.77, and the roughness coefficient of the wet conductor was between the dry and rainy conditions. Both the experimental data and the calculation model can provide a reference for conductor selection for UHV AC power lines for use in high-altitude areas.

Removal of iodomethane from air using a plot-scale corona discharge scrubber

International Nuclear Information System (INIS)

Dickson, L.W.; Toft-Hall, A.; Torgerson, D.F.

1985-12-01

This report presents the results of a study of the removal of iodomethane from air using a pilot-scale corona discharge scrubber. The removal was measured in the following parameter ranges: bulk air flow, 30 to 350 m 3 /h; initial CH 3 I concentration, 6 to 230 μmol/m 3 ; and discharge current, 0 to 75 mA DC (negative polarity). Approximately five to ten moles of iodomethane are removed per mole of electrons added to the air stream at a discharge voltage of ∼ 10 kV. This removal efficiency suggests that both ion-molecule and radical-molecule reactions may be important in the removal of iodomethane from air in a corona discharge. The results of this pilot-scale demonstration indicate that a corona discharge scrubber would be suitable for removing iodine species from air as part of the emergency filtered-air discharge system of a nuclear reactor. The application of this technology to the control of nitrogen oxide, sulfur dioxide and hydrogen sulfide emissions is being investigated. 15 refs

Method for measuring the stochastic properties of corona and partial-discharge pulses

International Nuclear Information System (INIS)

Van Brunt, R.J.; Kulkarni, S.V.

1989-01-01

A new method is described for measuring the stochastic behavior of corona and partial-discharge pulses which utilizes a pulse selection and sorting circuit in conjunction with a computer-controlled multichannel analyzer to directly measure various conditional and unconditional pulse-height and pulse-time-separation distributions. From these measured distributions it is possible to determine the degree of correlation between successive discharge pulses. Examples are given of results obtained from measurements on negative, point-to-plane (Trichel-type) corona pulses in a N 2 /O 2 gas mixture which clearly demonstrate that the phenomenon is inherently stochastic in the sense that development of a discharge pulse is significantly affected by the amplitude of and time separation from the preceding pulse. It is found, for example, that corona discharge pulse amplitude and time separation from an earlier pulse are not independent random variables. Discussions are given about the limitations of the method, sources of error, and data analysis procedures required to determine self-consistency of the various measured distributions

A morphological study of the changes in the ultrastructure of a bacterial biofilm disrupted by an ac corona discharge in air

International Nuclear Information System (INIS)

Stepanova, Olga; Astafiev, Alexander; Kudryavtsev, Anatoly; Rybalchenko, Oksana; Orlova, Olga; Kapustina, Valentina

2016-01-01

The morphology of bacterial cells and biofilms subjected to a low frequency (∼10"5 Hz) ac (∼10"−"1 A) corona discharge was investigated using electron microscopy. A low-frequency ac corona discharge in air is shown to have a bactericidal and bacteriostatic effect on Escherichia coli M17 culture at both the cellular and population levels. Corona exposure inhibits the formation of a microbial community and results in the destruction of formed biofilms. This paper presents data on changes in the ultrastructure of cells and biofilms after corona treatment. Our results suggest that the E. coli M17 cells inside biofilms are affected with results similar to sub-lethal and lethal thermal exposure. Some of the biological aspects of colony and biofilm cells death are evaluated. Morphological changes in the ultrastructure of the biofilms under corona treatment are described. Our results indicate that the heating effect is the main factor responsible for the corona-induced inactivation of bacteria.

A morphological study of the changes in the ultrastructure of a bacterial biofilm disrupted by an ac corona discharge in air

Energy Technology Data Exchange (ETDEWEB)

Stepanova, Olga, E-mail: o.m.stepanova@spbu.ru; Astafiev, Alexander; Kudryavtsev, Anatoly [Physical Faculty, Saint Petersburg State University, St. Petersburg (Russian Federation); Rybalchenko, Oksana; Orlova, Olga; Kapustina, Valentina [Faculty of Medicine, Saint Petersburg State University, St. Petersburg (Russian Federation)

2016-08-14

The morphology of bacterial cells and biofilms subjected to a low frequency (∼10{sup 5} Hz) ac (∼10{sup −1} A) corona discharge was investigated using electron microscopy. A low-frequency ac corona discharge in air is shown to have a bactericidal and bacteriostatic effect on Escherichia coli M17 culture at both the cellular and population levels. Corona exposure inhibits the formation of a microbial community and results in the destruction of formed biofilms. This paper presents data on changes in the ultrastructure of cells and biofilms after corona treatment. Our results suggest that the E. coli M17 cells inside biofilms are affected with results similar to sub-lethal and lethal thermal exposure. Some of the biological aspects of colony and biofilm cells death are evaluated. Morphological changes in the ultrastructure of the biofilms under corona treatment are described. Our results indicate that the heating effect is the main factor responsible for the corona-induced inactivation of bacteria.

Adaptación de una corona metal cerámica como pilar de una prótesis parcial removible preexistente

OpenAIRE

Torres Herbozo, Melissa; Quintana del Solar, Martin; Castillo Andamayo, Diana

2016-01-01

El presente artículo muestra el reporte de un caso clínico donde se confeccionó una corona metal cerámica que fue adaptada a una prótesis parcial removible pre existente. Por lo general el tratamiento para estos casos es la confección de una nueva prótesis parcial removible adaptada a la nueva corona, lo cual implica mayor tiempo de trabajo y costo para el paciente. Diversos materiales y técnicas pueden ser utilizados para la realización de la corona como por ejemplo coronas de aleaciones met...

Wood formation from the base to the crown in Pinus radiata: gradients of tracheid wall thickness, wood density, radial growth rate and gene expression

Science.gov (United States)

Sheree Cato; Lisa McMillan; Lloyd Donaldson; Thomas Richardson; Craig Echt; Richard Gardner

2006-01-01

Wood formation was investigated at five heights along the bole for two unrelated trees of Pinus radiataBoth trees showed clear gradients in wood properties from the base to the crown. Cambial cells at the base of the tree were dividing 3.3-fold slower than those at the crown, while the average thickness of cell walls in wood was highest at the base....

Corona discharge secondary ionization of laser desorbed neutral molecules from a liquid matrix at atmospheric pressure

Energy Technology Data Exchange (ETDEWEB)

Turney, Kevin [Department of Chemistry, University of Florida, Gainesville, Florida 32611 (United States); Harrison, W.W. [Department of Chemistry, University of Florida, Gainesville, Florida 32611 (United States)]. E-mail: harrison@chem.ufl.edu

2006-06-15

Matrix assisted laser desorption/ionization (MALDI) is studied at atmospheric pressure using liquid sampling methods. A time-of-flight mass spectrometer couples to an open sample stage accessed by a UV laser for desorption and ionization. Also coupled to the sampling state is a corona discharge for auxiliary ionization of desorbed neutral molecules. The interaction of the laser desorption and corona ionization is studied for a range of desorption conditions, showing enhanced analyte ionization, but the effect is analytically advantageous only at low desorption rates. The effect of corona discharge voltage was also explored. The decoupling of neutral molecule formation and subsequent ionization provides an opportunity to study each process separately.

Corona discharge secondary ionization of laser desorbed neutral molecules from a liquid matrix at atmospheric pressure

International Nuclear Information System (INIS)

Turney, Kevin; Harrison, W.W.

2006-01-01

Matrix assisted laser desorption/ionization (MALDI) is studied at atmospheric pressure using liquid sampling methods. A time-of-flight mass spectrometer couples to an open sample stage accessed by a UV laser for desorption and ionization. Also coupled to the sampling state is a corona discharge for auxiliary ionization of desorbed neutral molecules. The interaction of the laser desorption and corona ionization is studied for a range of desorption conditions, showing enhanced analyte ionization, but the effect is analytically advantageous only at low desorption rates. The effect of corona discharge voltage was also explored. The decoupling of neutral molecule formation and subsequent ionization provides an opportunity to study each process separately

The CORONAS-Photon/TESIS experiment on EUV imaging spectroscopy of the Sun

Science.gov (United States)

Kuzin, S.; Zhitnik, I.; Bogachev, S.; Bugaenko, O.; Ignat'ev, A.; Mitrofanov, A.; Perzov, A.; Shestov, S.; Slemzin, V.; Suhodrev, N.

The new experiment TESIS is developent for russian CORONAS-Photon mission launch is planned on the end of 2007 The experiment is aimed on the study of activity of the Sun in the phases of minimum rise and maximum of 24 th cycle of Solar activity by the method of XUV imaging spectroscopy The method is based on the registration full-Sun monochromatic images with high spatial and temporal resolution The scientific tasks of the experiment are i Investigation dynamic processes in corona flares CME etc with high spatial up to 1 and temporal up to 1 second resolution ii determination of the main plasma parameters like plasma electron and ion density and temperature differential emission measure etc iii study of the processes of appearance and development large scale long-life magnetic structures in the solar corona study of the fluency of this structures on the global activity of the corona iv study of the mechanisms of energy accumulation and release in the solar flares and mechanisms of transformation of this energy into the heating of the plasma and kinematics energy To get the information for this studies the TESIS will register full-Sun images in narrow spectral intervals and the monochromatic lines of HeII SiXI FeXXI-FeXXIII MgXII ions The instrument includes 5 independent channels 2 telescopes for 304 and 132 A wide-field 2 5 degrees coronograph 280-330A and 8 42 A spectroheliographs The detailed description of the TESIS experiment and the instrument is presented

Protein corona as a proteome fingerprint: The example of hidden biomarkers for cow mastitis.

Science.gov (United States)

Miotto, Giovanni; Magro, Massimiliano; Terzo, Milo; Zaccarin, Mattia; Da Dalt, Laura; Bonaiuto, Emanuela; Baratella, Davide; Gabai, Gianfranco; Vianello, Fabio

2016-04-01

Proteome modifications in a biological fluid can potentially indicate the occurrence of pathologies, even if the identification of a proteome fingerprint correlated to a specific disease represents a very difficult task. When a nanomaterial is introduced into a biological fluid, macromolecules compete to form a protein corona on the nanoparticle surface, and depending on the specific proteome, different patterns of proteins will form the final protein corona shell depending on their affinity for the nanoparticle surface. Novel surface active maghemite nanoparticles (SAMNs) display a remarkable selectivity toward protein corona formation, and they are able to concentrate proteins and peptides presenting high affinities for their surface even if they are present in very low amounts. Thus, SAMNs may confer visibility to hidden biomarkers correlated to the occurrence of a pathology. In the present report, SAMNs were introduced into milk samples from healthy cows and from animals affected by mastitis, and the selectively bound protein corona shell was easily analyzed and quantified by gel electrophoresis and characterized by mass spectrometry. Upon incubation in mastitic milk, SAMNs were able to selectively bind αs2-casein fragments containing the FALPQYLK sequence, as part of the larger casocidin-1 peptide with strong antibacterial activity, which were not present in healthy samples. Thus, SAMNs can be used as a future candidate for the rapid diagnosis of mastitis in bovine milk. The present report proposes protein competition for SAMN protein corona formation as a means of mirroring proteome modifications. Thus, the selected protein shell on the nanoparticles results in a fingerprint of the specific pathology. Copyright © 2015 Elsevier B.V. All rights reserved.

Air trichloroethylene oxidation in a corona plasma-catalytic reactor

Science.gov (United States)

Masoomi-Godarzi, S.; Ranji-Burachaloo, H.; Khodadadi, A. A.; Vesali-Naseh, M.; Mortazavi, Y.

2014-08-01

The oxidative decomposition of trichloroethylene (TCE; 300 ppm) by non-thermal corona plasma was investigated in dry air at atmospheric pressure and room temperature, both in the absence and presence of catalysts including MnOx, CoOx. The catalysts were synthesized by a co-precipitation method. The morphology and structure of the catalysts were characterized by BET surface area measurement and Fourier Transform Infrared (FTIR) methods. Decomposition of TCE and distribution of products were evaluated by a gas chromatograph (GC) and an FTIR. In the absence of the catalyst, TCE removal is increased with increases in the applied voltage and current intensity. Higher TCE removal and CO2 selectivity is observed in presence of the corona and catalysts, as compared to those with the plasma alone. The results show that MnOx and CoOx catalysts can dissociate the in-plasma produced ozone to oxygen radicals, which enhances the TCE decomposition.

Stellar winds and coronae of low-mass Population II/III stars

Science.gov (United States)

Suzuki, Takeru K.

2018-06-01

We investigated stellar winds from zero-/low-metallicity low-mass stars by magnetohydrodynamical simulations for stellar winds driven by Alfvén waves from stars with mass M = (0.6-0.8) M⊙ and metallicity Z = (0-1) Z⊙, where M⊙ and Z⊙ are the solar mass and metallicity, respectively. Alfvénic waves, which are excited by the surface convection, travel upward from the photosphere and heat up the corona by their dissipation. For lower Z, denser gas can be heated up to the coronal temperature because of the inefficient radiation cooling. The coronal density of Population II/III stars with Z ≤ 0.01 Z⊙ is one to two orders of magnitude larger than that of a solar-metallicity star with the same mass, and as a result, the mass loss rate, \\dot{M}, is 4.5-20 times larger. This indicates that metal accretion on low-mass Pop. III stars is negligible. The soft X-ray flux of the Pop. II/III stars is also expected to be ˜1-30 times larger than that of a solar-metallicity counterpart owing to the larger coronal density, even though the radiation cooling efficiency is smaller. A larger fraction of the input Alfvénic wave energy is transmitted to the corona in low-Z stars because they avoid severe reflection owing to the smaller density difference between the photosphere and the corona. Therefore, a larger fraction is converted to the thermal energy of the corona and the kinetic energy of the stellar wind. From this energetics argument, we finally derived a scaling of \\dot{M} as \\dot{M}∝ L R_{\\star }^{11/9} M_{\\star }^{-10/9} T_eff^{11/2}[\\max (Z/Z_{⊙},0.01)]^{-1/5}, where L, R⋆, and Teff are the stellar luminosity, radius, and effective temperature, respectively.

Stellar winds and coronae of low-mass Population II/III stars

Science.gov (United States)

Suzuki, Takeru K.

2018-04-01

We investigated stellar winds from zero-/low-metallicity low-mass stars by magnetohydrodynamical simulations for stellar winds driven by Alfvén waves from stars with mass M = (0.6-0.8) M⊙ and metallicity Z = (0-1) Z⊙, where M⊙ and Z⊙ are the solar mass and metallicity, respectively. Alfvénic waves, which are excited by the surface convection, travel upward from the photosphere and heat up the corona by their dissipation. For lower Z, denser gas can be heated up to the coronal temperature because of the inefficient radiation cooling. The coronal density of Population II/III stars with Z ≤ 0.01 Z⊙ is one to two orders of magnitude larger than that of a solar-metallicity star with the same mass, and as a result, the mass loss rate, \\dot{M}, is 4.5-20 times larger. This indicates that metal accretion on low-mass Pop. III stars is negligible. The soft X-ray flux of the Pop. II/III stars is also expected to be ˜1-30 times larger than that of a solar-metallicity counterpart owing to the larger coronal density, even though the radiation cooling efficiency is smaller. A larger fraction of the input Alfvénic wave energy is transmitted to the corona in low-Z stars because they avoid severe reflection owing to the smaller density difference between the photosphere and the corona. Therefore, a larger fraction is converted to the thermal energy of the corona and the kinetic energy of the stellar wind. From this energetics argument, we finally derived a scaling of \\dot{M} as \\dot{M}∝ L R_{\\star }^{11/9} M_{\\star }^{-10/9} T_eff^{11/2}[\\max (Z/Z_{⊙},0.01)]^{-1/5}, where L, R⋆, and Teff are the stellar luminosity, radius, and effective temperature, respectively.

Yield and Quality of Mung Bean (Vigna radiata (l. R. Wilczek Seeds Produced in Poland

Directory of Open Access Journals (Sweden)

Kamil MISIAK

2017-11-01

Full Text Available The aim of the experiment was to do field and laboratory assessments of yield and quality of mung bean (Vigna radiata (L. R. Wilczek seeds cultivated in Western Poland. Mean yield of seeds per plant was higher for common bean (Phaseolus vulgaris L. than for mung one: 13.1 g and 2.58 g, respectively. The mean 1000 mung seeds weight was 50.9 g and their germination – 78 %. Germination capacities of seeds of both beans in the field were similar. Mung beans, compared to common bean, had much smaller seeds, started to bloom later and produced mature seeds later than the latter. Mung bean seeds had more total proteins and Magnesium and Copper than common bean seeds. In Western Poland, production of high quality mung bean seeds was possible.

The Effect of a Corona Discharge on a Lightning Attachment

International Nuclear Information System (INIS)

Aleksandrov, N.L.; Bazelyan, E.M.; Raizer, Yu.P.

2005-01-01

The interaction between the lightning leader and the space charge accumulated near the top of a ground object in the atmospheric electric field is considered using analytical and numerical models developed earlier to describe spark discharges in long laboratory gaps. The specific features of a nonstationary corona discharge that develops in the electric field of a thundercloud and a downward lightning leader are analyzed. Conditions for the development of an upward lightning discharge from a ground object and for the propagation of an upward-connecting leader from the object toward a downward lightning leader (the process determining the point of strike to the ground) are investigated. Possible mechanisms for the interaction of the corona space charge with an upward leader and prospects of using it to control downward lightning discharges are analyzed

Expanding the repertoire of microsatellite markers for polymorphism studies in Indian accessions of mung bean (Vigna radiata L. Wilczek).

Science.gov (United States)

Shrivastava, Divya; Verma, Priyanka; Bhatia, Sabhyata

2014-09-01

Limited availability of validated, polymorphic microsatellite markers in mung bean (Vigna radiata), an important food legume of India, has been a major hurdle towards its improvement and higher yield. The present study was undertaken in order to develop a new set of microsatellite markers and utilize them for the analysis of genetic diversity within mung bean accessions from India. A GA/CT enriched library was constructed from V. radiata which resulted in 1,250 putative recombinant clones of which 850 were sequenced. SSR motifs were identified and their flanking sequences were utilized to design 328 SSR primer pairs. Of these, 48 SSR markers were employed for assessing genetic diversity among 76 mung bean accessions from various geographical locations in India. Two hundred and thirty four alleles with an average of 4.85 alleles per locus were detected at 48 loci. The polymorphic information content (PIC) per locus varied from 0.1 to 0.88 (average: 0.49 per locus). The observed and expected heterozygosities ranged from 0.40 to 0.95 and 0.40 to 0.81 respectively. Based on Jaccard's similarity matrix, a dendrogram was constructed using the unweighted pair-group method with arithmetic averages (UPGMA) analysis which revealed that one accession from Bundi, Rajasthan was clustered out separately while remaining accessions were grouped into two major clusters. The markers generated in this study will help in expanding the repertoire of the available SSR markers thereby facilitating analysis of genetic diversity, molecular mapping and ultimately broadening the scope for genetic improvement of this legume.

AC/DC/pulsed-power modulator for corona-plasma generation

NARCIS (Netherlands)

Ariaans, T.H.P.; Pemen, A.J.M.; Winands, G.J.J.; Heesch, van E.J.M.; Liu, Z.

2009-01-01

Gas-cleaning techniques using nonthermal plasma are slowly introduced into industry nowadays. In this paper, we present a novel power modulator for the efficient generation of large-volume corona plasma. No expensive high-voltage components are required. Switching is done at an intermediate voltage

Cytotoxic and Antimalarial Amaryllidaceae Alkaloids from the Bulbs of Lycoris radiata

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Bin Hao

2013-02-01

Full Text Available Phytochemical investigation of the 80% ethanol extract of the bulbs of Lycoris radiata resulted in the isolation of five new Amaryllidaceae alkaloids: (+-5,6-dehydrolycorine (1, (+-3α,6β-diacetyl-bulbispermine (2, (+-3α-hydroxy-6β-acetyl- bulbispermine (3, (+-8,9-methylenedioxylhomolycorine-N-oxide (5, and 5,6-dihydro-5- methyl-2-hydroxyphenanthridine (7, together with two known compounds, (+-3α-methoxy- 6β-acetylbulbispermine (4 and (+-homolycorine- N-oxide (6. Structural elucidation of all the compounds were performed by spectral methods such as 1D and 2D (1H-1H COSY, HMQC, and HMBC NMR spectroscopy, in addition to high resolution mass spectrometry. Alkaloid 1 showed potent cytotoxicity against astrocytoma and glioma cell lines (CCF-STTG1, CHG-5, SHG-44, and U251, as well as HL-60, SMMC-7721, and W480 cell lines with IC50 values of 9.4–11.6 μM. Additonally, compound 1 exhibited antimalarial activity with IC50 values of 2.3 μM for D-6 strain and 1.9 μM for W-2 strain of Plasmodium falciparum.

Corona-induced graft polymerization for surface modification of porous polyethersulfone membranes

International Nuclear Information System (INIS)

Zhu Liping; Zhu Baoku; Xu Li; Feng Yongxiang; Liu Fu; Xu Youyi

2007-01-01

Graft polymerization of acrylic acid (AA) onto porous polyethersulfone (PES) membrane surfaces was developed using corona discharge in atmospheric ambience as an activation process followed by polymerization of AA in aqueous solution. The effects of the corona parameters and graft polymerization conditions on grafting yield (GY) of AA were investigated. The grafting of AA on the PES membranes was confirmed by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) analysis. Porosimetry measurements indicate the average pore diameters and porosities of the modified membranes decrease with the increase of the GY. The hydrophilicity and surface wetting properties of the original and modified membranes were evaluated by observing the dynamic changes of water contact angles. It is found that the grafting of AA occurs not only on the membrane surfaces, but also on the pore walls of the cells inside the membrane. The permeability experiments of protein solution reveal that the grafting of PAA endows the modified membranes with enhanced fluxes and anti-fouling properties. The optimized GY of AA is in the range of 150-200 μg/cm 2 . In addition, the tensile experiments show the corona discharge treatment with the power lower than 150 W yields little damage to the mechanical strength of the membranes

Degradation of methylparaben in water by corona plasma coupled with ozonation.

Science.gov (United States)

Dobrin, D; Magureanu, M; Bradu, C; Mandache, N B; Ionita, P; Parvulescu, V I

2014-11-01

The degradation of methylparaben (MeP) in water was investigated using a pulsed corona discharge generated in oxygen, above the liquid. A comparison was made between results obtained in semi-batch corona (SBC) configuration (stationary solution, continuous gas flow) and results obtained in a semi-batch corona with recirculation combined with ozonation (SBCR + O3), where the liquid is continuously circulated between a solution reservoir and the plasma reactor and the effluent gas containing ozone is bubbled through the solution in the reservoir. It was found that MeP was completely degraded after 10-15 min of treatment in both configurations. Oxidation by ozone alone, in the absence of plasma, was a slower process. The energy efficiency for MeP removal (Y MeP) and for mineralization (Y TOC) was significantly higher in the SBCR + O3 configuration (Y MeP = 7.1 g/kWh at 90 % MeP removal and Y TOC = 0.41 g/kWh at 50 % total organic carbon (TOC) removal) than in the SBC configuration (Y MeP = 0.6 g/kWh at 90 % MeP removal and Y TOC = 0.11 g/kWh at 50 % TOC removal).

Magnetic Untwisting in Solar Jets that Go into the Outer Corona in Polar Coronal Holes

Science.gov (United States)

Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A.

2014-01-01

We present results from 14 exceptionally high-reaching large solar jets observed in the polar coronal holes. EUV movies from SDO/AIA show that each jet is similar to many other similar-size and smaller jets that erupt in coronal holes, but each is exceptional in that it goes higher than most other jets, so high that it is observed in the outer corona beyond 2.2 R(sub Sun) in images from the SOHO/LASCO/C2 coronagraph. For these high-reaching jets, we find: (1) the front of the jet transits the corona below 2.2 R(sub Sun) at a speed typically several times the sound speed; (2) each jet displays an exceptionally large amount of spin as it erupts; (3) in the outer corona, most jets display oscillatory swaying having an amplitude of a few degrees and a period of order 1 hour. We conclude that these jets are magnetically driven, propose that the driver is a magnetic-untwisting wave that is grossly a large-amplitude (i.e., nonlinear) torsional Alfven wave that is put into the reconnected open magnetic field in the jet by interchange reconnection as the jet erupts, and estimate from the measured spinning and swaying that the magnetic-untwisting wave loses most of its energy in the inner corona below 2.2 R(sub Sun). From these results for these big jets, we reason that the torsional magnetic waves observed in Type-II spicules should dissipate in the corona in the same way and could thereby power much of the coronal heating in coronal holes.

Discovery of Finely Structured Dynamic Solar Corona Observed in the Hi-C Telescope

Science.gov (United States)

Winebarger, A.; Cirtain, J.; Golub, L.; DeLuca, E.; Savage, S.; Alexander, C.; Schuler, T.

2014-01-01

In the summer of 2012, the High-resolution Coronal Imager (Hi-C) flew aboard a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore examine how the intensity scales from AIA resolution to Hi-C resolution. For each low-resolution pixel, we calculate the standard deviation in the contributing high-resolution pixel intensities and compare that to the expected standard deviation calculated from the noise. If these numbers are approximately equal, the corona can be assumed to be smoothly varying, i.e. have no evidence of substructure in the Hi-C image to within Hi-C's ability to measure it given its throughput and readout noise. A standard deviation much larger than the noise value indicates the presence of substructure. We calculate these values for each low-resolution pixel for each frame of the Hi-C data. On average, 70 percent of the pixels in each Hi-C image show no evidence of substructure. The locations where substructure is prevalent is in the moss regions and in regions of sheared magnetic field. We also find that the level of substructure varies significantly over the roughly 160 s of the Hi-C data analyzed here. This result indicates that the finely structured corona is concentrated in regions of heating and is highly time dependent.

DISCOVERY OF FINELY STRUCTURED DYNAMIC SOLAR CORONA OBSERVED IN THE Hi-C TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Winebarger, Amy R.; Cirtain, Jonathan; Savage, Sabrina; Alexander, Caroline [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Golub, Leon; DeLuca, Edward [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Schuler, Timothy, E-mail: amy.r.winebarger@nasa.gov [State University of New York College at Buffalo, 1300 Elmwood Avenue, Buffalo, NY 14222 (United States)

2014-05-20

In the Summer of 2012, the High-resolution Coronal Imager (Hi-C) flew on board a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore examine how the intensity scales from AIA resolution to Hi-C resolution. For each low-resolution pixel, we calculate the standard deviation in the contributing high-resolution pixel intensities and compare that to the expected standard deviation calculated from the noise. If these numbers are approximately equal, the corona can be assumed to be smoothly varying, i.e., have no evidence of substructure in the Hi-C image to within Hi-C's ability to measure it given its throughput and readout noise. A standard deviation much larger than the noise value indicates the presence of substructure. We calculate these values for each low-resolution pixel for each frame of the Hi-C data. On average, 70% of the pixels in each Hi-C image show no evidence of substructure. The locations where substructure is prevalent is in the moss regions and in regions of sheared magnetic field. We also find that the level of substructure varies significantly over the roughly 160 s of the Hi-C data analyzed here. This result indicates that the finely structured corona is concentrated in regions of heating and is highly time dependent.

DISCOVERY OF FINELY STRUCTURED DYNAMIC SOLAR CORONA OBSERVED IN THE Hi-C TELESCOPE

International Nuclear Information System (INIS)

Winebarger, Amy R.; Cirtain, Jonathan; Savage, Sabrina; Alexander, Caroline; Golub, Leon; DeLuca, Edward; Schuler, Timothy

2014-01-01

In the Summer of 2012, the High-resolution Coronal Imager (Hi-C) flew on board a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore examine how the intensity scales from AIA resolution to Hi-C resolution. For each low-resolution pixel, we calculate the standard deviation in the contributing high-resolution pixel intensities and compare that to the expected standard deviation calculated from the noise. If these numbers are approximately equal, the corona can be assumed to be smoothly varying, i.e., have no evidence of substructure in the Hi-C image to within Hi-C's ability to measure it given its throughput and readout noise. A standard deviation much larger than the noise value indicates the presence of substructure. We calculate these values for each low-resolution pixel for each frame of the Hi-C data. On average, 70% of the pixels in each Hi-C image show no evidence of substructure. The locations where substructure is prevalent is in the moss regions and in regions of sheared magnetic field. We also find that the level of substructure varies significantly over the roughly 160 s of the Hi-C data analyzed here. This result indicates that the finely structured corona is concentrated in regions of heating and is highly time dependent

Modelación matemática del funcionamiento de las coronas de molinos considerando la flotación de la maza superior // An equivalent mechanism for the kinetic and dynamic analysis of the sugar cane mill gears

Directory of Open Access Journals (Sweden)

Mario Javier Cabello-Ulloa

2011-08-01

Full Text Available ResumenEn este trabajo se propone un mecanismo equivalente para modelar el funcionamiento de lascoronas de los molinos de caña de azúcar, que permite tomar en cuenta la forma real del perfil de losdientes trazados por arcos de círculos y la variación de la distancia entre centros durante sufuncionamiento. Aplicando el método grafo-analítico al modelo propuesto se obtiene una funcióncinemática que define la posición angular instantánea de la corona conducida con dependencia de ladistancia entre ejes de las ruedas y la posición angular de la corona conductora. Aplicando métodosparamétricos se obtienen ecuaciones para la velocidad y aceleración que son generales paracualquier tipo de perfil de dientes en engranajes que trabajan con variación de distancia entrecentros. Finalmente se grafican estos parámetros para el funcionamiento de las coronas de unmolino real concluyéndose que estas tienen relación de transmisión instantánea variable y que por elsolo hecho de la forma del perfil se producen aceleraciones.Palabras claves: corona de molino, engranaje, mecanismo plano, modelación, cinemática del molino.______________________________________________________________________AbstractEquivalent mechanism is proposed for modeling sugar cane mills gears, which allows to take intoaccount the shape of the tooth profile formed by circular arcs and the variation of the distancebetween centers for operation. Applying the graph-analytical method to the proposed model isobtained a function to define the instantaneous angular position of the sugar cane mill gear in relationwith the instantaneous angular position of driver gear and the center distance of gears. Generalequations for the velocity and acceleration for any type of gear tooth profile with variable distancebetween centers are proposed through parametric method. Plotted these parameters for real sugarcane mill gear and it is concluded that the instantaneous speed ratio is variable

Ozone generation by negative direct current corona discharges in dry air fed coaxial wire-cylinder reactors

International Nuclear Information System (INIS)

Yehia, Ashraf; Mizuno, Akira

2013-01-01

An analytical study was made in this paper for calculating the ozone generation by negative dc corona discharges. The corona discharges were formed in a coaxial wire-cylinder reactor. The reactor was fed by dry air flowing with constant rates at atmospheric pressure and room temperature, and stressed by a negative dc voltage. The current-voltage characteristics of the negative dc corona discharges formed inside the reactor were measured in parallel with concentration of the generated ozone under different operating conditions. An empirical equation was derived from the experimental results for calculating the ozone concentration generated inside the reactor. The results, that have been recalculated by using the derived equation, have agreed with the experimental results over the whole range of the investigated parameters, except in the saturation range for the ozone concentration. Therefore, the derived equation represents a suitable criterion for expecting the ozone concentration generated by negative dc corona discharges in dry air fed coaxial wire-cylinder reactors under any operating conditions in range of the investigated parameters.

Second harmonic generation from corona-poled polymer thin films ...

Indian Academy of Sciences (India)

2014-02-09

Feb 9, 2014 ... We characterize thermal stability of second harmonic generation (SHG) properties of four different Y-type polymers poled using corona poling method. These polymers are based on donor–acceptor–donor-type repeating unit with different aromatic moieties acting as donors and dicyanomethylene acting as ...

Air trichloroethylene oxidation in a corona plasma-catalytic reactor

International Nuclear Information System (INIS)

Masoomi-Godarzi, S.; Ranji-Burachaloo, H.; Khodadadi, A.A.; Vesali-Naseh, M.; Mortazavi, Y.

2014-01-01

The oxidative decomposition of trichloroethylene (TCE; 300 ppm) by non-thermal corona plasma was investigated in dry air at atmospheric pressure and room temperature, both in the absence and presence of catalysts including MnO x , CoO x . The catalysts were synthesized by a co-precipitation method. The morphology and structure of the catalysts were characterized by BET surface area measurement and Fourier Transform Infrared (FTIR) methods. Decomposition of TCE and distribution of products were evaluated by a gas chromatograph (GC) and an FTIR. In the absence of the catalyst, TCE removal is increased with increases in the applied voltage and current intensity. Higher TCE removal and CO 2 selectivity is observed in presence of the corona and catalysts, as compared to those with the plasma alone. The results show that MnO x and CoO x catalysts can dissociate the in-plasma produced ozone to oxygen radicals, which enhances the TCE decomposition. (author)

Negative corona discharges modelling. Application to the electrostatic precipitation

International Nuclear Information System (INIS)

Gaychet, S.

2010-01-01

Electrostatic precipitation presents many advantages from the nuclear wastes treatment's point of view. Indeed, this kind of process can capture submicron particles without producing secondary wastes (no filter media) and without pressure looses in the exhaust circuit. The work presented in this thesis concerns the study of negative corona discharges in air at atmospheric pressure occurring in an electrostatic precipitator (ESP) developed by the CEA (Atomic Energy Committee). The aim of this study is to determine how the electrostatic precipitation dedicated phenomena, especially the specific high voltage generator, the gas temperature and the fact that particles are flowing through the gap then collapsing on the electrodes, modify the discharge to improve the efficiency of ESPs. This work is based on a fundamental experimental study of the negative corona discharge and on numerical simulations of this discharge under conditions close to those of the lab scale ESP developed by the CEA. (author) [fr

The protein corona protects against size- and dose-dependent toxicity of amorphous silica nanoparticles

Directory of Open Access Journals (Sweden)

Dominic Docter

2014-08-01

Full Text Available Besides the lung and skin, the gastrointestinal (GI tract is one of the main targets for accidental exposure or biomedical applications of nanoparticles (NP. Biological responses to NP, including nanotoxicology, are caused by the interaction of the NP with cellular membranes and/or cellular entry. Here, the physico-chemical characteristics of NP are widely discussed as critical determinants, albeit the exact mechanisms remain to be resolved. Moreover, proteins associate with NP in physiological fluids, forming the protein corona potentially transforming the biological identity of the particle and thus, adding an additional level of complexity for the bio–nano responses.Here, we employed amorphous silica nanoparticles (ASP and epithelial GI tract Caco-2 cells as a model to study the biological impact of particle size as well as of the protein corona. Caco-2 or mucus-producing HT-29 cells were exposed to thoroughly characterized, negatively charged ASP of different size in the absence or presence of proteins. Comprehensive experimental approaches, such as quantifying cellular metabolic activity, microscopic observation of cell morphology, and high-throughput cell analysis revealed a dose- and time-dependent toxicity primarily upon exposure with ASP30 (Ø = 30 nm. Albeit smaller (ASP20, Ø = 20 nm or larger particles (ASP100; Ø = 100 nm showed a similar zeta potential, they both displayed only low toxicity. Importantly, the adverse effects triggered by ASP30/ASP30L were significantly ameliorated upon formation of the protein corona, which we found was efficiently established on all ASP studied. As a potential explanation, corona formation reduced ASP30 cellular uptake, which was however not significantly affected by ASP surface charge in our model. Collectively, our study uncovers an impact of ASP size as well as of the protein corona on cellular toxicity, which might be relevant for processes at the nano–bio interface in general.

Influence of the airflow speed along transmission lines on the DC corona discharge loss, using finite element approach

Energy Technology Data Exchange (ETDEWEB)

Shemshadi, A.; Akbari, A. [Electric Department, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Niayesh, K. [Electric Engineering Department, Tehran University, Tehran (Iran, Islamic Republic of)

2012-07-15

Corona discharge is of great interest from the physical point of view and due to its numerous practical applications in industry and especially one of the most important sources of loss in the high voltage transmission lines. This paper provides guidelines for the amount of electric loss caused by corona phenomenon occurred around a DC high voltage wire placed between two flat plates and influence of wind speed rate on the amount of corona loss using COMSOL Multiphysics. So electric potential distribution patterns and charge density diffusion around the wire are studied in this article.

The influence of the breakdown electric field in the configuration of lightning corona sheath on charge distribution in the channel

Science.gov (United States)

Ignjatovic, Milan; Cvetic, Jovan; Heidler, Fridolin; Markovic, Slavoljub; Djuric, Radivoje

2014-11-01

A model of corona sheath that surrounds the thin core of the lightning channel has been investigated by using a generalized traveling current source return stroke model. The lightning channel is modeled by a charged corona sheath that stretches around a highly conductive central core through which the main current flows. The channel core with the negatively charged outer channel sheath forms a strong electric field, with an overall radial orientation. The return stroke process is modeled as the negative leader charge in the corona sheath being discharged by the positive charge coming from the channel core. Expressions that describe how the corona sheath radius evolves during the return stroke are obtained from the corona sheath model, which predicts charge motion within the sheath. The corona sheath model, set forth by Maslowski and Rakov (2006), Tausanovic et al. (2010), Marjanovic and Cvetic (2009), Cvetic et al. (2011) and Cvetic et al. (2012), divides the sheath onto three zones: zone 1 (surrounding the channel core with net positive charge), zone 2 (surrounding zone 1 with negative charge) and zone 3 (the outer zone, representing uncharged virgin air). In the present study, we have assumed a constant electric field inside zone 1, as suggested by experimental research of corona discharges in coaxial geometry conducted by Cooray (2000). The present investigation builds upon previous studies by Tausanovic et al. (2010) and Cvetic et al. (2012) in several ways. The value of the breakdown electric field has been varied for probing its effect on channel charge distribution prior and during the return stroke. With the aim of investigating initial space charge distribution along the channel, total electric field at the outer surface of the channel corona sheath, just before the return stroke, is calculated and compared for various return stroke models. A self-consistent algorithm is applied to the generalized traveling current source return stroke model, so that the

Multimodal magnetic resonance imaging study of treatment-naïve adults with attention-deficit/hyperactivity disorder.

Directory of Open Access Journals (Sweden)

Tiffany M Chaim

Full Text Available BACKGROUND: Attention-Deficit/Hiperactivity Disorder (ADHD is a prevalent disorder, but its neuroanatomical circuitry is still relatively understudied, especially in the adult population. The few morphometric magnetic resonance imaging (MRI and diffusion tensor imaging (DTI studies available to date have found heterogeneous results. This may be at least partly attributable to some well-known technical limitations of the conventional voxel-based methods usually employed to analyze such neuroimaging data. Moreover, there is a great paucity of imaging studies of adult ADHD to date that have excluded patients with history of use of stimulant medication. METHODS: A newly validated method named optimally-discriminative voxel-based analysis (ODVBA was applied to multimodal (structural and DTI MRI data acquired from 22 treatment-naïve ADHD adults and 19 age- and gender-matched healthy controls (HC. RESULTS: Regarding DTI data, we found higher fractional anisotropy in ADHD relative to HC encompassing the white matter (WM of the bilateral superior frontal gyrus, right middle frontal left gyrus, left postcentral gyrus, bilateral cingulate gyrus, bilateral middle temporal gyrus and right superior temporal gyrus; reductions in trace (a measure of diffusivity in ADHD relative to HC were also found in fronto-striatal-parieto-occipital circuits, including the right superior frontal gyrus and bilateral middle frontal gyrus, right precentral gyrus, left middle occipital gyrus and bilateral cingulate gyrus, as well as the left body and right splenium of the corpus callosum, right superior corona radiata, and right superior longitudinal and fronto-occipital fasciculi. Volumetric abnormalities in ADHD subjects were found only at a trend level of significance, including reduced gray matter (GM in the right angular gyrus, and increased GM in the right supplementary motor area and superior frontal gyrus. CONCLUSIONS: Our results suggest that adult ADHD is associated

Multimodal Magnetic Resonance Imaging Study of Treatment-Naïve Adults with Attention-Deficit/Hyperactivity Disorder

Science.gov (United States)

Chaim, Tiffany M.; Zhang, Tianhao; Zanetti, Marcus V.; da Silva, Maria Aparecida; Louzã, Mário R.; Doshi, Jimit; Serpa, Mauricio H.; Duran, Fabio L. S.; Caetano, Sheila C.; Davatzikos, Christos; Busatto, Geraldo F.

2014-01-01

Background Attention-Deficit/Hiperactivity Disorder (ADHD) is a prevalent disorder, but its neuroanatomical circuitry is still relatively understudied, especially in the adult population. The few morphometric magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) studies available to date have found heterogeneous results. This may be at least partly attributable to some well-known technical limitations of the conventional voxel-based methods usually employed to analyze such neuroimaging data. Moreover, there is a great paucity of imaging studies of adult ADHD to date that have excluded patients with history of use of stimulant medication. Methods A newly validated method named optimally-discriminative voxel-based analysis (ODVBA) was applied to multimodal (structural and DTI) MRI data acquired from 22 treatment-naïve ADHD adults and 19 age- and gender-matched healthy controls (HC). Results Regarding DTI data, we found higher fractional anisotropy in ADHD relative to HC encompassing the white matter (WM) of the bilateral superior frontal gyrus, right middle frontal left gyrus, left postcentral gyrus, bilateral cingulate gyrus, bilateral middle temporal gyrus and right superior temporal gyrus; reductions in trace (a measure of diffusivity) in ADHD relative to HC were also found in fronto-striatal-parieto-occipital circuits, including the right superior frontal gyrus and bilateral middle frontal gyrus, right precentral gyrus, left middle occipital gyrus and bilateral cingulate gyrus, as well as the left body and right splenium of the corpus callosum, right superior corona radiata, and right superior longitudinal and fronto-occipital fasciculi. Volumetric abnormalities in ADHD subjects were found only at a trend level of significance, including reduced gray matter (GM) in the right angular gyrus, and increased GM in the right supplementary motor area and superior frontal gyrus. Conclusions Our results suggest that adult ADHD is associated with

Mass and energy flows between the Solar chromosphere, transition region, and corona

Science.gov (United States)

Hansteen, V. H.

2017-12-01

A number of increasingly sophisticated numerical simulations spanning the convection zone to corona have shed considerable insight into the role of the magnetic field in the structure and energetics of the Sun's outer atmosphere. This development is strengthened by the wealth of observational data now coming on-line from both ground based and space borne observatories. We discuss what numerical models can tell us about the mass and energy flows in the region of the upper chromosphere and lower corona, using a variety of tools, including the direct comparison with data and the use of passive tracer particles (so-called 'corks') inserted into the simulated flows.

New Views of the Solar Corona from STEREO and SDO

Science.gov (United States)

Vourlidas, A.

2012-01-01

In the last few years, we have been treated to an unusual visual feast of solar observations of the corona in EUV wavelengths. The observations from the two vantage points of STEREO/SECCHI are now capturing the entire solar atmosphere simultaneously in four wavelengths. The SDO/AIA images provide us with arcsecond resolution images of the full visible disk in ten wavelengths. All these data are captured with cadences of a few seconds to a few minutes. In this talk, I review some intriguing results from our first attempts to deal with these observations which touch upon the problems of coronal mass ejection initiation and solar wind generation. I will also discuss data processing techniques that may help us recover even more information from the images. The talk will contain a generous portion of beautiful EUV images and movies of the solar corona.

Characteristics of shocks in the solar corona, as inferred from radio, optical, and theoretical investigations

Science.gov (United States)

Maxwell, A.; Dryer, M.

1982-01-01

Solar radio bursts of spectral type II provide one of the chief diagnostics for the propagation of shocks through the solar corona. Radio data on the shocks are compared with computer models for propagation of fast-mode MHD shocks through the solar corona. Data on coronal shocks and high-velocity ejecta from solar flares are then discussed in terms of a general model consisting of three main velocity regimes.

Serrated leaf mutant in mungbean (Vigna radiata (L) Wilczek)

International Nuclear Information System (INIS)

Malik, I.A.; Ghulam, Sarwar; Yousaf, Ali; Saleem, M.

1988-01-01

Dry dormant seeds of mungbean (Vigna radiata (L) Wilczek) were treated with gamma rays (15, 30 and 60 kR). The serrated leaf mutation was noticed in M 2 of cultivar Pak 32 treated with 60 kR. Cf 14 plants, 3 showed the altered leaf structure and the others were normal. The feature of this mutant was the deep serration of leaflet margins. The mutant had large thick leaflets with prominent venation. The mutant bred true in the M 3 and successive generation. Details of the morphological characteristics of the mutant are presented. The mutant exhibited slower growth particularly during the early stages of development, flowered later and attained shorter height. There was an increase in the number of pods, in seed weight and in seed protein content, but number of seed per pod was considerably reduced. The seed coat colour showed a change from green to yellowish green. In the mutant's flowers the stamina were placed much below the stigma level and the stigma sometimes protruded the corolla. Outcrossing of 4% recorded in some of the mutant lines revealed a reduced cleistogamy. The low number of seeds per pod in the mutant could be due to reduced pollen fertility. The mutant behaved as monogenic recessive. The symbols SL/sl are proposed for this allelic pair. The mutant may have use as a green manure crop because of its large foliage and for the breeders as a genetic marker

Dynamics of a lightning corona sheath—A constant field approach using the generalized traveling current source return stroke model

Science.gov (United States)

Cvetic, Jovan; Heidler, Fridolin; Markovic, Slavoljub; Radosavljevic, Radovan; Osmokrovic, Predrag

2012-11-01

A generalized lightning traveling current source return stroke model has been used to examine the characteristics of the lightning channel corona sheath surrounding a thin channel core. A model of the lightning channel consisting of a charged corona sheath and a narrow, highly conducting central core that conducts the main current flow is assumed. Strong electric field, with a predominant radial direction, has been created during the return stroke between the channel core and the outer channel sheath containing the negative charge. The return stroke process is modeled with the positive charge coming from the channel core discharging the negative leader charge in the corona sheath. The corona sheath model that predicts the charge motion in the sheath is used to derive the expressions of the sheath radius vs. time during the return stroke. According to the corona sheath model proposed earlier by Maslowski and Rakov (2006) and Maslowski et al. (2009), it consists of three zones, zone 1 (surrounding channel core with net positive charge), zone 2 (surrounding zone 1 with negative charge) and zone 3 (outer zone representing the virgin air without charges). We adopted the assumption of a constant electric field inside zone 1 of the corona sheath observed in the experimental research of corona discharges in a coaxial geometry by Cooray (2000). This assumption seems to be more realistic than the assumption of a uniform corona space charge density used previously in the study of Maslowski and Rakov (2006), Marjanovic and Cvetic (2009), and Tausanovic et al. (2010). Applying the Gauss' law on the infinitesimally small cylindrical section of the channel the expressions for time-dependence of the radii of zones 1 and 2 during the return stroke are derived. The calculations have shown that the overall channel dynamics concerning electrical discharge is roughly 50% slower and the maximum radius of zone 1 is about 33% smaller compared to the corresponding values calculated in the

The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere V. On the Nature of the Corona

Directory of Open Access Journals (Sweden)

Robitaille P.-M.

2013-07-01

Full Text Available The E-corona is the site of numerous emission lines associated with high ionization states (i.e. FeXIV-FeXXV. Modern gaseous models of the Sun require that these states are produced by atomic irradiation, requiring the sequential removal of electrons to infinity, without an associated electron acceptor. This can lead to computed temperatures in the corona which are unrealistic (i.e. ∼30–100 MK contrasted to solar core values of ∼16 MK. In order to understand the emission lines of the E-corona, it is vital to recognize that they are superimposed upon the K-corona, which produces a continuous spectrum, devoid of Fraunhofer lines, arising from this same region of the Sun. It has been advanced that the K-corona harbors self-luminous condensed matter (Robitaille P.M. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona. Progr. Phys., 2013, v. 3, L8–L10; Robitaille P.M. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere III. Importance of Continuous Emission Spectra from Flares, Coronal Mass Ejections, Prominences, and Other Coronal Structures. Progr. Phys., 2013, v. 3, L11–L14. Condensed matter can possess elevated electron affinities which may strip nearby atoms of their electrons. Such a scenario accounts for the high ionization states observed in the corona: condensed matter acts to harness electrons, ensuring the electrical neutrality of the Sun, despite the flow of electrons and ions in the solar winds. Elevated ionization states reflect the presence of materials with high electron affinities in the corona, which is likely to be a form of metallic hydrogen, and does not translate into elevated temperatures in this region of the solar atmosphere. As a result, the many mechanisms advanced to account for coronal heating in the gaseous models of the Sun

Middle longitudinal fasciculus delineation within language pathways: A diffusion tensor imaging study in human

Energy Technology Data Exchange (ETDEWEB)

Menjot de Champfleur, Nicolas, E-mail: nicolasdechampfleur@orange.fr [Department of Neuroradiology, University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Team “Plasticity of Central Nervous System, Stem Cells and Glial Tumors,” Institut National de la Santé et de la Recherche Médicale Unité 1051, Institut of Neurosciences of Montpellier, Saint Eloi Hospital, Montpellier (France); Lima Maldonado, Igor [Department of Neuroradiology, University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Team “Plasticity of Central Nervous System, Stem Cells and Glial Tumors,” Institut National de la Santé et de la Recherche Médicale Unité 1051, Institut of Neurosciences of Montpellier, Saint Eloi Hospital, Montpellier (France); Divisão de Neurologia e Epidemiologia (CPPHO), Complexo Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, Salvador-Bahia (Brazil); Moritz-Gasser, Sylvie [Department of Neuroradiology, University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Department of Neurology, University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Machi, Paolo [Department of Neuroradiology, University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); and others

2013-01-15

Introduction: The existence in the human brain of the middle longitudinal fasciculus (MdLF), initially described in the macaque monkey, is supported by diffusion tensor imaging studies. In the present work, we aim (1) to confirm that this fascicle is found constantly in control subjects with the use of DTI techniques and (2) to delineate the MdLF from the other fiber bundles that constitute the language pathways. Materials and methods: Tractography was realized in four right-handed healthy volunteers for the arcuate fascicle, uncinate fascicle, inferior fronto-occipital fascicle, inferior longitudinal fascicle and the middle longitudinal fascicle. The fiber tracts were characterized for their size, mean fractional anisotropy (FA), for their length, number of streamlines, and lateralization indices were calculated. Results: The MdLF is found constantly and it is clearly delineated from the other fascicles that constitute the language pathways, especially the ventral pathway. It runs within the superior temporal gyrus white matter from the temporal pole, then it extends caudally in the upper part of the sagittal stratum and the posterior part of the corona radiata, to reach the inferior parietal lobule (angular gyrus). We found a leftward asymmetry for all fiber tracts when considering the mean FA. Discussion: Using DTI methods, we confirm that the MdLF connects the angular gyrus and the superior temporal gyrus. On the basis of these findings, the role of the MdLF is discussed. Conclusion: The middle longitudinal fasciculus, connects the angular gyrus and the superior temporal gyrus and its course can be systematically differenciated from those of other fascicles composing both ventral and dorsal routes (IFOF, IFL, AF and UF)

Pre-surgical integration of FMRI and DTI of the sensorimotor system in transcortical resection of a high-grade insular astrocytoma

Directory of Open Access Journals (Sweden)

Chelsea eEkstrand

2016-03-01

Full Text Available Herein we report on a patient with a WHO Grade III astrocytoma in the right insular region in close proximity to the internal capsule who underwent a right frontotemporal craniotomy. Total gross resection of insular gliomas remains surgically challenging based on the possibility of damage to the corticospinal tracts. However, maximizing the extent of resection has been shown to decrease future adverse outcomes. Thus, the goal of such surgeries should focus on maximizing extent of resection while minimizing possible adverse outcomes. In this case, pre-surgical planning included integration of functional magnetic resonance imaging (fMRI and diffusion tensor imaging (DTI, to localize motor and sensory pathways. Novel fMRI tasks were individually developed for the patient to maximize both somatosensory and motor activation simultaneously in areas in close proximity to the tumor. Information obtained was used to optimize resection trajectory and extent, facilitating gross total resection of the astrocytoma. Across all three motor-sensory tasks administered, fMRI revealed an area of interest just superior and lateral to the astrocytoma. Further, DTI analyses showed displacement of the corona radiata around the superior dorsal surface of the astrocytoma, extending in the direction of the activation found using fMRI. Taking into account these results, a transcortical superior temporal gyrus surgical approach was chosen in order to avoid the area of interest identified by fMRI and DTI. Total gross resection was achieved and minor post-surgical motor and sensory deficits were temporary. This case highlights the utility of comprehensive pre-surgical planning, including fMRI and DTI, to maximize surgical outcomes on a case-by-case basis.

Middle longitudinal fasciculus delineation within language pathways: A diffusion tensor imaging study in human

International Nuclear Information System (INIS)

Menjot de Champfleur, Nicolas; Lima Maldonado, Igor; Moritz-Gasser, Sylvie; Machi, Paolo

2013-01-01

Introduction: The existence in the human brain of the middle longitudinal fasciculus (MdLF), initially described in the macaque monkey, is supported by diffusion tensor imaging studies. In the present work, we aim (1) to confirm that this fascicle is found constantly in control subjects with the use of DTI techniques and (2) to delineate the MdLF from the other fiber bundles that constitute the language pathways. Materials and methods: Tractography was realized in four right-handed healthy volunteers for the arcuate fascicle, uncinate fascicle, inferior fronto-occipital fascicle, inferior longitudinal fascicle and the middle longitudinal fascicle. The fiber tracts were characterized for their size, mean fractional anisotropy (FA), for their length, number of streamlines, and lateralization indices were calculated. Results: The MdLF is found constantly and it is clearly delineated from the other fascicles that constitute the language pathways, especially the ventral pathway. It runs within the superior temporal gyrus white matter from the temporal pole, then it extends caudally in the upper part of the sagittal stratum and the posterior part of the corona radiata, to reach the inferior parietal lobule (angular gyrus). We found a leftward asymmetry for all fiber tracts when considering the mean FA. Discussion: Using DTI methods, we confirm that the MdLF connects the angular gyrus and the superior temporal gyrus. On the basis of these findings, the role of the MdLF is discussed. Conclusion: The middle longitudinal fasciculus, connects the angular gyrus and the superior temporal gyrus and its course can be systematically differenciated from those of other fascicles composing both ventral and dorsal routes (IFOF, IFL, AF and UF)

Flare-induced MHD disturbances in the corona--Moreton waves and type II shocks

International Nuclear Information System (INIS)

Uchida, Y.

1972-01-01

The propagation in the corona of the magnetohydrodynamic (MHD) disturbance possibly emitted at the explosive stage in the initial phase of a flare is considered. The behavior of the MHD fast-mode wavefront, whose source is located at the flare, is calculated by using eiconal-characteristic method in the High Altitude Observatory (HAO) realistic models of coronal magnetic field and density for the days of some particular flare events. It is shown as the result that the peculiar behavior of Moreton' s surface wave and the peculiar appearance in the shape and position of the type II burst sources can be consistently understood by considering the refraction, focussing, and fermation of shocks of MHD fast-mode disturbance in the actual distribution of Alfven velocity in the corona. Based on some comparison of the positions of low-Alfven-velocity regions in the corona with observed positions of type II burst sources, it is proposed that the type II burst sources may be identified with such low-Alfven-velocity regions ''illuminated'' by thus enhanced shocks. (U.S.)

A study on the electrical characteristics of corona discharges for flue gas treatment

International Nuclear Information System (INIS)

Jung, Suk Won

2000-02-01

A wire- cylinder reactor and wire- plate reactor were designed and constructed for generating the corona discharges to be applied to the dissociation of NOx and SOx in the flue gases of combustion engines and power plants. Experiments for the characterization of the corona discharges in air were carried out. To obtain the pulsed voltage shape, a rotary spark gap switch was formed with a DC motor. A discharge circuit was constructed with a resistor (50kΩ ), DC high voltage power supply, a rotary spark gap switch. Two electric probes and voltage probe were installed in order to measure the total current, displacement current, conduction current and applied voltage. The charges, power, and energy in the two reactors were calculated from the measured voltage and current. Also, to find the frequency dependence of the corona discharge, the high frequency (20kHz) and high voltage power supply was used in the wire- cylinder reactor. The each obtained and calculated value from the probes in both reactor cases (high frequency, low frequency ) were compared each other

Novel dielectric reduces corona breakdown in ac capacitors

Science.gov (United States)

Loehner, J. L.

1972-01-01

Dielectric system was developed which consists of two layers of 25-gage paper separated by one layer of 50-gage polypropylene to reduce corona breakdown in ac capacitors. System can be used in any alternating current application where constant voltage does not exceed 400 V rms. With a little research it could probably be increased to 700 to 800 V rms.

DBD-Corona Discharge for Degradation of Toxic Gases

International Nuclear Information System (INIS)

Pacheco-Pacheco, M.; Pacheco-Sotelo, J.; Moreno-Saavedra, H.; Diaz-Gomez, J. A.; Mercado-Cabrera, A.; Yousfi, M.

2007-01-01

The non-thermal plasma technology is a promising technique to treat SO 2 and NO x . Chemical radicals produced with this technology can remove several pollutants at atmospheric pressure in a very short period of time simultaneously. Both theoretical and experimental study on SO 2 and NO x removal, by a dielectric barrier discharge (DBD) with corona effect, is presented

A precise measurement of the magnetic field in the corona of the black hole binary V404 Cygni.

Science.gov (United States)

Dallilar, Yigit; Eikenberry, Stephen S; Garner, Alan; Stelter, Richard D; Gottlieb, Amy; Gandhi, Poshak; Casella, Piergiorgio; Dhillon, Vik S; Marsh, Tom R; Littlefair, Stuart P; Hardy, Liam; Fender, Rob; Mooley, Kunal; Walton, Dominic J; Fuerst, Felix; Bachetti, Matteo; Castro-Tirado, A J; Charcos, Miguel; Edwards, Michelle L; Lasso-Cabrera, Nestor M; Marin-Franch, Antonio; Raines, S Nicholas; Ackley, Kendall; Bennett, John G; Cenarro, A Javier; Chinn, Brian; Donoso, H Veronica; Frommeyer, Raymond; Hanna, Kevin; Herlevich, Michael D; Julian, Jeff; Miller, Paola; Mullin, Scott; Murphey, Charles H; Packham, Chris; Varosi, Frank; Vega, Claudia; Warner, Craig; Ramaprakash, A N; Burse, Mahesh; Punnadi, Sujit; Chordia, Pravin; Gerarts, Andreas; de Paz Martín, Héctor; Calero, María Martín; Scarpa, Riccardo; Acosta, Sergio Fernandez; Hernández Sánchez, William Miguel; Siegel, Benjamin; Pérez, Francisco Francisco; Viera Martín, Himar D; Rodríguez Losada, José A; Nuñez, Agustín; Tejero, Álvaro; Martín González, Carlos E; Rodríguez, César Cabrera; Molgó, Jordi; Rodriguez, J Esteban; Cáceres, J Israel Fernández; Rodríguez García, Luis A; Lopez, Manuel Huertas; Dominguez, Raul; Gaggstatter, Tim; Lavers, Antonio Cabrera; Geier, Stefan; Pessev, Peter; Sarajedini, Ata

2017-12-08

Observations of binary stars containing an accreting black hole or neutron star often show x-ray emission extending to high energies (>10 kilo--electron volts), which is ascribed to an accretion disk corona of energetic particles akin to those seen in the solar corona. Despite their ubiquity, the physical conditions in accretion disk coronae remain poorly constrained. Using simultaneous infrared, optical, x-ray, and radio observations of the Galactic black hole system V404 Cygni, showing a rapid synchrotron cooling event in its 2015 outburst, we present a precise 461 ± 12 gauss magnetic field measurement in the corona. This measurement is substantially lower than previous estimates for such systems, providing constraints on physical models of accretion physics in black hole and neutron star binary systems. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

The effect of coronae on leader initiation and development under thunderstorm conditions and in long air gaps

International Nuclear Information System (INIS)

Aleksandrov, N.L.; Bazelyan, E.M.; Carpenter Jr, R.B.; Drabkin, M.M.; Raizer, Yu P.

2001-01-01

The initiation and development of a leader is theoretically studied by considering an electrode which is embedded in a cloud of space charge injected by a corona discharge. The focus is on the initiation of upward lightning from a stationary grounded object in a thundercloud electric field. The main results are also applicable to the leader process in long laboratory air gaps at direct voltage. Simple physical models of non-stationary coronae developing in free space near a solitary stressed sphere and of a leader propagating in the space charge cloud of coronae are suggested. It is shown that the electric field redistribution due to the space charge released by the long corona discharge near the top of a high object hinders the initiation and development of an upward leader from the object in a thundercloud electric field. The conditions for the formation of corona streamers that are required to initiate a leader are derived. The criteria are obtained for a leader to be initiated and propagate in the space charge cloud. A hypothesis is proposed that the streamers are never initiated near the top of a high object under thunderstorm conditions if at ground level there is only a slowly-varying electric field of the thundercloud. The streamers may be induced by the fast-rising electric field of distant downward leaders or intracloud discharges. (author)

Regional cerebral blood flow in pure dysarthria. A 3D-SSP study

International Nuclear Information System (INIS)

Okamoto, Kensho; Kamogawa, Kenji; Okuda, Bungo; Kawabata, Keita; Tachibana, Hisao

2007-01-01

Pure dysarthria from brain infarction is a rare condition, and its pathophysiology remains unclear. To clarify the underlying mechanism of pure dysarthria, we investigated the lesion sites and regional cerebral blood flow in patients with pure dysarthria. We examined 18 consecutive patients with pure dysarthria (9 men and 9 women; mean age, 71 years) who underwent MRI and cerebral blood flow studies. To visualize the regional cerebral blood flow, we generated Z score images using the three-dimensional stereotactic surface projection (3D-SSP) method with single-photon emission computed tomography (SPECT) and N-isopropyl-p [ 123 I]iodoamphetamine. Data on the brain surface perfusion extracted by the 3D-SSP analysis were compared between the pure dysarthria (PD) patients and 9 control subjects. MRI revealed multiple lacunar infarctions involving the internal capsule and/or corona radiata in 11 patients, left internal capsule-corona radiata infarction in 4 patients, and pontine infarction in 3 patients. SPECT with 3D-SSP demonstrated bilateral frontal cortical hypoperfusion in all patients, particularly in the anterior opercular region. Based on intergroup comparisons, the PD group exhibited pronounced cortical hypoperfusion in the opercular and medial frontal regions, left more than right. In conclusion, pure dysarthria is considered to originate from frontal cortical hypoperfusion, mainly in the anterior opercular and medial frontal regions, which is probably due to interruption of the corticosubcortical neural networks relevant to speech expression and articulation. In addition, it is suggested that left hemispheric lesions may make a greater contribution to the development of pure dysarthria than do right ones. (author)

Texture analysis of MR images of patients with Mild Traumatic Brain Injury

International Nuclear Information System (INIS)

Holli, Kirsi K; Harrison, Lara; Dastidar, Prasun; Wäljas, Minna; Liimatainen, Suvi; Luukkaala, Tiina; Öhman, Juha; Soimakallio, Seppo; Eskola, Hannu

2010-01-01

Our objective was to study the effect of trauma on texture features in cerebral tissue in mild traumatic brain injury (MTBI). Our hypothesis was that a mild trauma may cause microstructural changes, which are not necessarily perceptible by visual inspection but could be detected with texture analysis (TA). We imaged 42 MTBI patients by using 1.5 T MRI within three weeks of onset of trauma. TA was performed on the area of mesencephalon, cerebral white matter at the levels of mesencephalon, corona radiata and centrum semiovale and in different segments of corpus callosum (CC) which have been found to be sensitive to damage. The same procedure was carried out on a control group of ten healthy volunteers. Patients' TA data was compared with the TA results of the control group comparing the amount of statistically significantly differing TA parameters between the left and right sides of the cerebral tissue and comparing the most discriminative parameters. There were statistically significant differences especially in several co-occurrence and run-length matrix based parameters between left and right side in the area of mesencephalon, in cerebral white matter at the level of corona radiata and in the segments of CC in patients. Considerably less difference was observed in the healthy controls. TA revealed significant changes in texture parameters of cerebral tissue between hemispheres and CC segments in TBI patients. TA may serve as a novel additional tool for detecting the conventionally invisible changes in cerebral tissue in MTBI and help the clinicians to make an early diagnosis

Removal of NO and SO2 in Corona Discharge Plasma Reactor with Water Film

Institute of Scientific and Technical Information of China (English)

贺元吉; 董丽敏; 杨嘉祥

2004-01-01

In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water,and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NOx removal under suitable conditions is obtained in our experiments.

Constant-current corona triode adapted and optimized for the characterization of thin dielectric films

Science.gov (United States)

Giacometti, José A.

2018-05-01

This work describes an enhanced corona triode with constant current adapted to characterize the electrical properties of thin dielectric films used in organic electronic devices. A metallic grid with a high ionic transparency is employed to charge thin films (100 s of nm thick) with a large enough charging current. The determination of the surface potential is based on the grid voltage measurement, but using a more sophisticated procedure than the previous corona triode. Controlling the charging current to zero, which is the open-circuit condition, the potential decay can be measured without using a vibrating grid. In addition, the electric capacitance and the characteristic curves of current versus the stationary surface potential can also be determined. To demonstrate the use of the constant current corona triode, we have characterized poly(methyl methacrylate) thin films with films with thicknesses in the range from 300 to 500 nm, frequently used as gate dielectric in organic field-effect transistors.

El comercio de productos alimentarios entre las Coronas de Castilla y Aragón en los siglos XIV y XV

Directory of Open Access Journals (Sweden)

Diago Hernando, Máximo

2001-12-01

Full Text Available The author analyses in this article the export trade of foodstuffs between the territories of the Crown of Castile and those of the Crown of Aragón during the fourteenth and fifteenth centuries, taking into account the overland traffic as well as the maritime one. He gives account of the importance attained by the export of cattle, fish and corn from Castile to Aragón. And on the other side he proves that foodstuffss played a minor role in the exports from the Crown of Aragón to the Crown of Castile, though spices, wine and oil, among other foodstuffs, were exported to Castile from the territories of the Crown of Aragón.

En este artículo el autor analiza el comercio de exportación de los productos alimentarios entre los territorios de la Corona de Castilla y los de la Corona de Aragón, durante los siglos XIV y XV, tanto por vía terrestre como por vía marítima. Subraya la importancia que alcanzó la exportación de ganado, pescado y cereales desde la Corona de Castilla a la Corona de Aragón. Como contrapartida, el autor demuestra que los productos de alimentación no tenían tanta importancia dentro de las exportaciones efectuadas desde la Corona de Aragón a la Corona de Castilla, si bien las especias, el vino y el aceite fueron objeto de exportación desde la Corona de Aragón a Castilla.

The potential of L. scoparium, K. robusta and P. radiata to mitigate N-losses in silvopastural systems.

Science.gov (United States)

Esperschuetz, J; Balaine, N; Clough, T; Bulman, S; Dickinson, N M; Horswell, J; Robinson, B H

2017-06-01

Silvopastoral systems aim to enhance economic, cultural and social principles by sustainably combining forest management with agriculture. In these typically high-nitrogen (N) environments, plant species selection can profoundly influence N fluxes. For grazed pastures, plants may be exposed to urine patches that have received the equivalent of up to 1000 kg N ha -1 . We aimed to determine the growth and N fluxes in three potential trees that may be used in silvopastoral systems: L. scoparium, K. robusta and P. radiata. Plants were grown in a greenhouse lysimeter experiment, with controlled irrigation and temperature and exposed to N at rates of 200 kg ha -1 equiv. for 15 weeks, followed by the addition of 800 kg ha -1 N equiv, to simulate a urine patch. Urea produced a positive growth response of all plant species. Treatments containing L. scoparium and K. robusta leached lower amounts of nitrate (NO 3 - ) (2 kg ha -1 NO 3 - ) compared to P. radiata (53 kg ha -1 ). Measurements of N 2 O over 20 days after the application of 800 kg N ha -1 indicated an inhibitory effect of L. scoparium and K. robusta on denitrification, hence loss of N via N 2 O. Both L. scoparium and K. robusta demonstrated that they have potential to reduce N-losses in silvopastural systems, while producing valuable biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study on law of negative corona discharge in microparticle-air two-phase flow media

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Bo He

2016-03-01

Full Text Available To study the basic law of negative corona discharge in solid particle-air two-phase flow, corona discharge experiments in a needle-plate electrode system at different voltage levels and different wind speed were carried out in the wind tunnel. In this paper, the change law of average current and current waveform were analyzed, and the observed phenomena were systematically explained from the perspectives of airflow, particle charging, and particle motion with the help of PIV (particle image velocity measurements and ultraviolet observations.

JET PROPERTIES OF GeV-SELECTED RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES AND POSSIBLE CONNECTION TO THEIR DISK AND CORONA

Energy Technology Data Exchange (ETDEWEB)

Sun, Xiao-Na; Lin, Da-Bin; Liang, En-Wei [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Zhang, Jin [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Xue, Zi-Wei; Zhang, Shuang-Nan, E-mail: zhang.jin@hotmail.com [Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 (China)

2015-01-01

The observed spectral energy distributions of five GeV-selected narrow-line Seyfert 1 (NLS1) galaxies are fitted with a model including the radiation ingredients from the relativistic jet, the accretion disk, and the corona. We compare the properties of these GeV NLS1 galaxies with flat spectrum radio quasars (FSRQs), BL Lacertae objects (BL Lacs), and radio-quiet (RQ) Seyfert galaxies, and explore possible hints for jet-disk/corona connection. Our results show that the radiation physics and the jet properties of the GeV NLS1 galaxies resemble that of FSRQs. The luminosity variations of PMN J0948+0022 and 1H 0323+342 at the GeV band is tightly correlated with the beaming factor (δ), similar to that observed in FSRQ 3C 279. The accretion disk luminosities and the jet powers of the GeV NLS1 galaxies cover both the ranges of FSRQs and BL Lacs. With the detection of bright corona emission in 1H 0323+342, we show that the ratio of the corona luminosity (L {sub corona}) to the accretion disk luminosity (L {sub d}) is marginally within the high end of this ratio distribution for an RQ Seyfert galaxy sample, and the variation of jet luminosity may connect with L {sub corona}. However, it is still unclear whether a system with a high L {sub corona}/L {sub d} ratio prefers to power a jet.

Pulsed corona generation using a diode-based pulsed power generator

NARCIS (Netherlands)

Pemen, A.J.M.; Grekhov, I.V.; Heesch, van E.J.M.; Yan, K.; Nair, S.A.; Korotkov, S.V.

2003-01-01

Pulsed plasma techniques serve a wide range of unconventional processes, such as gas and water processing, hydrogen production, and nanotechnology. Extending research on promising applications, such as pulsed corona processing, depends to a great extent on the availability of reliable, efficient and

A high-voltage pulse generator for corona plasma generation

NARCIS (Netherlands)

Yan, K.; Heesch, van E.J.M.; Pemen, A.J.M.; Huijbrechts, P.A.H.J.; Gompel, van F.M.; Leuken, van H.E.M.; Matyas, Z.

2002-01-01

This paper discusses a high-voltage pulse generator for producing corona plasma. The generator consists of three resonant charging circuits, a transmission line transformer, and a triggered spark-gap switch. Voltage pulses in the order of 30-100 kV with a rise time of 10-20 ns, a pulse duration of

Filamentation of diamond nanoparticles treated in underwater corona discharge

Czech Academy of Sciences Publication Activity Database

Jirásek, Vít; Lukeš, Petr; Kozak, Halyna; Artemenko, Anna; Člupek, Martin; Čermák, Jan; Rezek, Bohuslav; Kromka, Alexander

2016-01-01

Roč. 6, č. 3 (2016), 2352-2360 ISSN 2046-2069 R&D Projects: GA ČR GA15-01687S; GA MŠk(CZ) LD14011 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : nanodiamonds * pulsed streamer corona discharge * filamentation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.108, year: 2016

Reduction in flatulence factors in mung beans (Vigna radiata) using low-dose gamma-irradiation

International Nuclear Information System (INIS)

Machaiah, J.P.; Pednekar, M.D.; Thomas, P.

1999-01-01

Mungbeans (Vigna radiata), control and gamma-irradiated at insect disinfestation dose levels (0.25 and 0.75 kGy) were germinated (0-6 Bays) and the qualitative and quantitative changes in soluble carbohydrates were studied in detail. The key flatulence-producing raffinose family oligosaccharides inmungbeans were degraded in the irradiated samples at the onset of the germination (0-2 days) compared to the control where it occurred much later (>4days). However, the reducing sugars, mainly glucose, fructose and galactose, which are metabolised easily, were enhanced in the irradiated samples. At low dose (0.25 kGy), irradiation had no effect on germination and sprout length, indicating that irradiated beans are suitable for use as sprouted beans. These observations clearly indicate that gamma-irradiation at insect disinfestation dose levels improved the digestibility and nutritional quality of mung beans by reducing the content of oligosaccharides responsible for intestinal gas production. (C) 1999 Society of Chemical Industry

Double elevator weakening for unilateral congenital superior oblique palsy with ipsilateral superior rectus contracture and lax superior oblique tendon.

Science.gov (United States)

Khan, Arif O

2012-06-01

In unilateral congenital superior oblique palsy, a large hypertropia is sometimes associated with ipsilateral contracture of the superior rectus muscle and apparent overaction of the contralateral superior oblique. Ipsilateral double elevator weakening is one surgical approach; however, this procedure could compromise supraduction. We report a series of three consecutive patients who underwent ipsilateral superior rectus and inferior oblique recessions for unilateral superior oblique palsy. Intraoperatively, all three patients were found to have a lax ipsilateral superior oblique tendon. Postoperatively, all three patients had satisfactory correction of the hypertropia and abnormal head position with minimal supraduction defect. This procedure seems to be an acceptable initial surgical option for treating congenital superior oblique muscle palsy with ipsilateral contracture of the superior rectus muscle, even when the ipsilateral superior oblique tendon is lax. Copyright © 2012 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

An analytical theory of corona discharge plasmas

International Nuclear Information System (INIS)

Uhm, H.S.; Lee, W.M.

1997-01-01

In this paper we describe an analytical investigation of corona discharge systems. Electrical charge and the energy transfer mechanism are investigated based on the circuit analysis. Efficient delivery of electrical energy from the external circuit to the reactor chamber is a major issue in design studies. The optimum condition obtained in this paper ensures 100% energy transfer. Second-order coupled differential equations are numerically solved. All the analytical results agree remarkably well with numerical data. The reactor capacitor plays a pivotal role in circuit performance. The voltage profile is dominated by the reactor capacitor. Corona discharge properties in the reactor chamber are also investigated, assuming that a specified voltage profile V(t) is fed through the inner conductor. The analytical description is based on the electron moment equation. Defining the plasma breakdown parameter u=V/R c p, plasma is generated for a high-voltage pulse satisfying u>u c , where u c is the critical breakdown parameter defined by geometrical configuration. Here, u is in units of a million volts per m per atm, and R c is the outer conductor radius. It is found that the plasma density profile generated inside the reactor chamber depends very sensitively on the system parameters. A small change of a physical parameter can easily lead to a density change in one order of magnitude

Magnetic Untwisting in Jets that Go into the Outer Solar Corona in Polar Coronal Holes

Science.gov (United States)

Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David

2014-06-01

We present results from a study of 14 jets that were observed in SDO/AIA EUV movies to erupt in the Sun’s polar coronal holes. These jets were similar to the many other jets that erupt in coronal holes, but reached higher than the vast majority, high enough to be observed in the outer corona beyond 2 solar radii from Sun center by the SOHO/LASCO/C2 coronagraph. We illustrate the characteristic structure and motion of these high-reaching jets by showing observations of two representative jets. We find that (1) the speed of the jet front from the base of the corona out to 2-3 solar radii is typically several times the sound speed in jets in coronal holes, (2) each high-reaching jet displays unusually large rotation about its axis (spin) as it erupts, and (3) in the outer corona, many jets display lateral swaying and bending of the jet axis with an amplitude of a few degrees and a period of order 1 hour. From these observations we infer that these jets are magnetically driven, propose that the driver is a magnetic-untwisting wave that is basically a large-amplitude (non-linear) torsional Alfven wave that is put into the open magnetic field in the jet by interchange reconnection as the jet erupts, and estimate that the magnetic-untwisting wave loses most of its energy before reaching the outer corona. These observations of high-reaching coronal jets suggest that the torsional magnetic waves observed in Type-II spicules can similarly dissipate in the corona and thereby power much of the coronal heating in coronal holes and quiet regions. This work is funded by the NASA/SMD Heliophysics Division’s Living With a Star Targeted Research & Technology Program.

Introduction to investigations of the negative corona and EHD flow in gaseous two-phase fluids

Science.gov (United States)

Jerzy, MIZERACZYK; Artur, BERENDT

2018-05-01

Research interests have recently been directed towards electrical discharges in multi-phase environments. Natural electrical discharges, such as lightning and coronas, occur in the Earth’s atmosphere, which is actually a mixture of gaseous phase (air) and suspended solid and liquid particulate matters (PMs). An example of an anthropogenic gaseous multi-phase environment is the flow of flue gas through electrostatic precipitators (ESPs), which are generally regarded as a mixture of a post-combustion gas with solid PM and microdroplets suspended in it. Electrical discharges in multi-phase environments, the knowledge of which is scarce, are becoming an attractive research subject, offering a wide variety of possible discharges and multi-phase environments to be studied. This paper is an introduction to electrical discharges in multi-phase environments. It is focused on DC negative coronas and accompanying electrohydrodynamic (EHD) flows in a gaseous two-phase fluid formed by air (a gaseous phase) and solid PM (a solid phase), run under laboratory conditions. The introduction is based on a review of the relevant literature. Two cases will be considered: the first case is of a gaseous two-phase fluid, initially motionless in a closed chamber before being subjected to a negative corona (with the needle-to-plate electrode arrangement), which afterwards induces an EHD flow in the chamber, and the second, of a gaseous two-phase fluid flowing transversely with respect to the needle-to-plate electrode axis along a chamber with a corona discharge running between the electrodes. This review-based introductory paper should be of interest to theoretical researchers and modellers in the field of negative corona discharges in single- or two-phase fluids, and for engineers who work on designing EHD devices (such as ESPs, EHD pumps, and smoke detectors).

A cone-like enhancement of polar solar corona plasma and its influence on heliospheric particles

Science.gov (United States)

Grzedzielski, Stan; Sokół, Justyna M.

2017-04-01

We will present results of the study of the properties of the solar wind plasma due to rotation of the polar solar corona. We focus in our study on the solar minimum conditions, when the polar coronal holes are well formed and the magnetic field in the solar polar corona exhibit almost regular "ray-like" structure. The solar rotation twists the magnetic field lines of the expanding fast polar solar wind and the resulting toroidal component of the field induces a force directed towards the rotation axis. This phenomenon is tantamount to a (weak) zeta pinch, known also in other astrophysical contexts (e.g. like in AGN jets). The pinch compresses the polar solar corona plasma and forms a cone-like enhancement of the solar wind density aligned with the rotation axis in the spherically symmetric case. The effect is likely very dynamic due to fast changing conditions in the solar corona, however in the study presented here, we assume a time independent description to get an order-of-magnitude estimate. The weak pinch is treated as a first-order perturbation to the zeroth-order radial flow. Following the assumptions based on the available knowledge about the plasma properties in the polar solar corona we estimated the most typical density enhancements. The cone like structure may extend as far from the Sun as tens of AU and thus will influence the heliospheric particles inside the heliosphere. An increase of the solar wind density in the polar region may be related with a decrease of the solar wind speed. Such changes of the solar wind plasma at high latitudes may modify the charge-exchange and electron impact ionization rates of heliospheric particles in interplanetary space. We will present their influence on the interstellar neutral gas and energetic neutral atoms observed by IBEX.

Interaction of single and multi-layer graphene oxide with fetal bovine serum: assessing the protein corona formation

Energy Technology Data Exchange (ETDEWEB)

Franqui, Lidiane Silva; Farias, Marcelo Alexandre de; Portugal, Rodrigo Villares; Costa, Carlos Alberto; Leme, Adriana Franco Paes; Martinez, Diego Stefani Teodoro, E-mail: lidiane.franqui@pos.ft.unicamp.br [Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP (Brazil); Coluci, Vitor Rafael [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

2016-07-01

Full text: When in contact with biological systems, nanomaterials surface adsorbs biomolecules present in the biological medium, mainly proteins, yielding a molecular coating 'protein corona' which affects the biological response and toxicity of the nanomaterials. Several factors can influence the protein corona formation, such as nanomaterial physicochemical properties and the nature of biological medium. In this work, we have performed a comparative study between the single and multi-layer graphene oxide nanomaterials (SL-GO and ML-GO, respectively) after their interaction with DMEM cell culture medium containing fetal bovine serum (FBS). Bare GOs and FBS protein corona-coated GOs were characterized using dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), atomic force microscopy (AFM), cryogenic transmission electron microscopy (Cryo-TEM) and X-ray photoelectron spectroscopy (XPS). The protein corona composition was characterized by gel electrophoresis (SDS-PAGE) and mass spectrometry (LC-MS/MS). Our results showed that, after interaction with FBS, GO particle size increased due to the protein corona formation. Besides, the presence of proteins also has significantly increased the dispersion stability of SLGO and ML-GO over time. Whereas the main proteins have been identified in both SL-GO and ML-GO, SL-GO has adsorbed larger amounts of proteins than ML-GO. Finally, the number of GO layers influences its interactions with FBS proteins and dispersion stability in DMEM medium. These results point out implications for in vitro cytotoxicity assessment and biomedical applications of these promising carbon nanomaterials. (author)

Interaction of single and multi-layer graphene oxide with fetal bovine serum: assessing the protein corona formation

International Nuclear Information System (INIS)

Franqui, Lidiane Silva; Farias, Marcelo Alexandre de; Portugal, Rodrigo Villares; Costa, Carlos Alberto; Leme, Adriana Franco Paes; Martinez, Diego Stefani Teodoro; Coluci, Vitor Rafael

2016-01-01

Full text: When in contact with biological systems, nanomaterials surface adsorbs biomolecules present in the biological medium, mainly proteins, yielding a molecular coating 'protein corona' which affects the biological response and toxicity of the nanomaterials. Several factors can influence the protein corona formation, such as nanomaterial physicochemical properties and the nature of biological medium. In this work, we have performed a comparative study between the single and multi-layer graphene oxide nanomaterials (SL-GO and ML-GO, respectively) after their interaction with DMEM cell culture medium containing fetal bovine serum (FBS). Bare GOs and FBS protein corona-coated GOs were characterized using dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), atomic force microscopy (AFM), cryogenic transmission electron microscopy (Cryo-TEM) and X-ray photoelectron spectroscopy (XPS). The protein corona composition was characterized by gel electrophoresis (SDS-PAGE) and mass spectrometry (LC-MS/MS). Our results showed that, after interaction with FBS, GO particle size increased due to the protein corona formation. Besides, the presence of proteins also has significantly increased the dispersion stability of SLGO and ML-GO over time. Whereas the main proteins have been identified in both SL-GO and ML-GO, SL-GO has adsorbed larger amounts of proteins than ML-GO. Finally, the number of GO layers influences its interactions with FBS proteins and dispersion stability in DMEM medium. These results point out implications for in vitro cytotoxicity assessment and biomedical applications of these promising carbon nanomaterials. (author)

Accretion Disks and Coronae in the X-Ray Flashlight

Science.gov (United States)

Degenaar, Nathalie; Ballantyne, David R.; Belloni, Tomaso; Chakraborty, Manoneeta; Chen, Yu-Peng; Ji, Long; Kretschmar, Peter; Kuulkers, Erik; Li, Jian; Maccarone, Thomas J.; Malzac, Julien; Zhang, Shu; Zhang, Shuang-Nan

2018-02-01

Plasma accreted onto the surface of a neutron star can ignite due to unstable thermonuclear burning and produce a bright flash of X-ray emission called a Type-I X-ray burst. Such events are very common; thousands have been observed to date from over a hundred accreting neutron stars. The intense, often Eddington-limited, radiation generated in these thermonuclear explosions can have a discernible effect on the surrounding accretion flow that consists of an accretion disk and a hot electron corona. Type-I X-ray bursts can therefore serve as direct, repeating probes of the internal dynamics of the accretion process. In this work we review and interpret the observational evidence for the impact that Type-I X-ray bursts have on accretion disks and coronae. We also provide an outlook of how to make further progress in this research field with prospective experiments and analysis techniques, and by exploiting the technical capabilities of the new and concept X-ray missions ASTROSAT, NICER, Insight-HXMT, eXTP, and STROBE-X.

Secreted protein eco-corona mediates uptake and impacts of polystyrene nanoparticles on Daphnia magna.

Science.gov (United States)

Nasser, Fatima; Lynch, Iseult

2016-03-30

Nanoparticles (NPs) are defined as having at least one external dimension between 1 and 100 nm. Due to their small size, NPs have a large surface area to volume ratio giving them unique characteristics that differ from bulk material of the same chemical composition. As a result these novel materials have found numerous applications in medical and industrial fields with the result that environmental exposure to NPs is increasingly likely. Similarly, increased reliance on plastic, which degrades extremely slowly in the environment, is resulting in increased accumulation of micro-/nano-plastics in fresh and marine waters, whose ecotoxicological impacts are as yet poorly understood. Although NPs are well known to adsorb macromolecules from their environment, forming a biomolecule corona which changes the NP identity and how it interacts with organisms, significantly less research has been performed on the ecological corona (eco-corona). Secretion of biomolecules is a well established predator-prey response in aquatic food chains, raising the question of whether NPs interact with secreted proteins, and the impact of such interaction on NP uptake and ecotoxicity. We report here initial studies, including optimisation of protocols using carboxylic-acid and amino modified spherical polystyrene NPs, to assess interaction of NPs with biomolecules secreted by Daphnia magna and the impact of these interactions on NP uptake, retention and toxicity towards Daphnia magna. Daphnia magna are an important environmental indicator species who may be especially sensitive to nanoparticles (NPs) as a result of being filter-feeders. This paper demonstrates for the first time that proteins released by Daphnia magna create an eco-corona around polystyrene NPs which causes heightened uptake of the NPs and consequently increases toxicity. The secreted protein eco-corona also causes the NPs to be less efficiently removed from the gut of D. magna and NPs remaining in the gut of D. magna

Utilization of Diamine Oxidase Enzyme from Mung Bean Sprouts (Vigna radiata L) for Histamine biosensors

Science.gov (United States)

Karim, Abdul; Wahab, A. W.; Raya, I.; Natsir, H.; Arif, A. R.

2018-03-01

This research is aimed to utilize the diamine oxidase enzyme (DAO) which isolated from mung bean sprouts (Vigna radiata L) to develop histamine biosensors based on electode enzyme with the amperometric method (cyclic voltammetry).The DAO enzyme is trapped inside the membrane of chitin-cellulose acetate 2:1 and glutaraldehyde which super imposed on a Pt electrode. Histamine will be oxidized by DAO enzyme to produce aldehydes and H2O2 that acting as electron transfer mediators.The performance of biosensors will be measured at various concentrations of glutaraldehyde, temperature changes and different range of pH. Recently, it has been found that the optimal conditions obtained from the paramaters as follows; at 25% of glutaraldehyde, temperature of 37°C and pH of 7.4. Eventually, the results provided an expectation for applying histamine biosensors in determining the freshness and safety of fish specifically skombroidae families.

Influences of the pulsed power supply on corona streamer appearance

NARCIS (Netherlands)

Veldhuizen, van E.M.; Briels, T.M.P.; Grabowski, L.R.; Pemen, A.J.M.; Ebert, U.M.

2005-01-01

Pulsed positive corona streamers in air are studied by images obtained with an intensified CCD camera. Using a switched capacitor power supply, thin streamers are observed that branch. A power supply consisting of a 4-stage transmission line transformer gives pulses of much higher current to the

A search for the origins of a possible coronal mass ejection in the low corona

Science.gov (United States)

Neupert, Werner M.

1988-01-01

Evidence for coronal and chromospheric precursors of a hypothesized coronal mass ejection is sought in OSO-7 observations of a filament eruption and the subsequent flare. Large-scale changes in the corona above the active region were clearly present for at least several minutes before the flare, culminating in the activation and eruption of two widely separated filaments; the eruption of one of the preexisting filaments initiated magnetic reconnections and energy releases in the low corona, generating the observed chromospheric flare.

The influence of electrohydrodynamic flow on the distribution of chemical species in positive corona

Science.gov (United States)

Pontiga, Francisco; Yanallah, Khelifa; Bouazza, R.; Chen, Junhong

2015-09-01

A numerical simulation of positive corona discharge in air, including the effect of electrohydrodynamic (EHD) motion of the gas, has been carried out. Air flow is assumed to be confined between two parallel plates, and corona discharge is produced around a thin wire, midway between the plates. Therefore, fluid dynamics equations, including electrical forces, have been solved together with the continuity equation of each neutral species. The plasma chemical model included 24 chemical reactions and ten neutral species, in addition to electrons and positive ions. The results of the simulation have shown that the influence of EHD flow on the spatial distributions of the species is quite different depending on the species. Hence, reactive species like atomic oxygen and atomic nitrogen are confined to the vicinity of the wire, and they are weakly affected by the EHD gas motion. In contrast, nitrogen oxides and ozone are efficiently dragged outside the active region of the corona discharge by the EHD flow. This work was supported by the Spanish Government Agency ``Ministerio de Ciencia e Innovación'' under Contract No. FIS2011-25161.

Venus - 3D Perspective View of Latona Corona and Dali Chasma

Science.gov (United States)

1992-01-01

This computer-generated perspective view of Latona Corona and Dali Chasma on Venus shows Magellan radar data superimposed on topography. The view is from the northeast and vertical exaggeration is 10 times. Exaggeration of relief is a common tool scientists use to detect relationships between structure (i.e. faults and fractures) and topography. Latona Corona, a circular feature approximately 1,000 kilometers (620 miles) in diameter whose eastern half is shown at the left of the image, has a relatively smooth, radar-bright raised rim. Bright lines or fractures within the corona appear to radiate away from its center toward the rim. The rest of the bright fractures in the area are associated with the relatively deep (approximately 3 kilometers or 1.9 miles) troughs of Dali Chasma. The Dali and Diana Chasma system consist of deep troughs that extend for 7,400 kilometers (4,588 miles) and are very distinct features on Venus. Those chasma connect the Ovda and Thetis highlands with the large volcanoes at Atla Regio and thus are considered to be the 'Scorpion Tail' of Aphrodite Terra. The broad, curving scarp resembles some of Earth's subduction zones where crustal plates are pushed over each other. The radar-bright surface at the highest elevation along the scarp is similar to surfaces in other elevated regions where some metallic mineral such as pyrite (fool's gold) may occur on the surface.

Faraday rotation fluctuations of MESSENGER radio signals through the equatorial lower corona near solar minimum

Science.gov (United States)

Wexler, D. B.; Jensen, E. A.; Hollweg, J. V.; Heiles, C.; Efimov, A. I.; Vierinen, J.; Coster, A. J.

2017-02-01

Faraday rotation (FR) of transcoronal radio transmissions from spacecraft near superior conjunction enables study of the temporal variations in coronal plasma density, velocity, and magnetic field. The MESSENGER spacecraft 8.4 GHz radio, transmitting through the corona with closest line-of-sight approach 1.63-1.89 solar radii and near-equatorial heliolatitudes, was recorded soon after the deep solar minimum of solar cycle 23. During egress from superior conjunction, FR gradually decreased, and an overlay of wave-like FR fluctuations (FRFs) with periods of hundreds to thousands of seconds was found. The FRF power spectrum was characterized by a power law relation, with the baseline spectral index being -2.64. A transient power increase showed relative flattening of the spectrum and bands of enhanced spectral power at 3.3 mHz and 6.1 mHz. Our results confirm the presence of coronal FRF similar to those described previously at greater solar offset. Interpreted as Alfvén waves crossing the line of sight radially near the proximate point, low-frequency FRF convey an energy flux density higher than that of the background solar wind kinetic energy, but only a fraction of that required to accelerate the solar wind. Even so, this fraction is quite variable and potentially escalates to energetically significant values with relatively modest changes in estimated magnetic field strength and electron concentration. Given the uncertainties in these key parameters, as well as in solar wind properties close to the Sun at low heliolatitudes, we cannot yet confidently assign the quantitative role for Alfvén wave energy from this region in driving the slow solar wind.

The Plasticity of Brain Gray Matter and White Matter following Lower Limb Amputation

Directory of Open Access Journals (Sweden)

Guangyao Jiang

2015-01-01

Full Text Available Accumulating evidence has indicated that amputation induces functional reorganization in the sensory and motor cortices. However, the extent of structural changes after lower limb amputation in patients without phantom pain remains uncertain. We studied 17 adult patients with right lower limb amputation and 18 healthy control subjects using T1-weighted magnetic resonance imaging and diffusion tensor imaging. Cortical thickness and fractional anisotropy (FA of white matter (WM were investigated. In amputees, a thinning trend was seen in the left premotor cortex (PMC. Smaller clusters were also noted in the visual-to-motor regions. In addition, the amputees also exhibited a decreased FA in the right superior corona radiata and WM regions underlying the right temporal lobe and left PMC. Fiber tractography from these WM regions showed microstructural changes in the commissural fibers connecting the bilateral premotor cortices, compatible with the hypothesis that amputation can lead to a change in interhemispheric interactions. Finally, the lower limb amputees also displayed significant FA reduction in the right inferior frontooccipital fasciculus, which is negatively correlated with the time since amputation. In conclusion, our findings indicate that the amputation of lower limb could induce changes in the cortical representation of the missing limb and the underlying WM connections.

EFFECTS OF FIELD-LINE TOPOLOGY ON ENERGY PROPAGATION IN THE CORONA

Energy Technology Data Exchange (ETDEWEB)

Candelaresi, S.; Pontin, D. I.; Hornig, G. [Division of Mathematics, University of Dundee, Dundee, DD1 4HN (United Kingdom)

2016-12-01

We study the effect of photospheric footpoint motions on magnetic field structures containing magnetic nulls. The footpoint motions are prescribed on the photospheric boundary as a velocity field that entangles the magnetic field. We investigate the propagation of the injected energy, the conversion of energy, emergence of current layers, and other consequences of the nontrivial magnetic field topology in this situation. These boundary motions lead initially to an increase in magnetic and kinetic energy. Following this, the energy input from the photosphere is partially dissipated and partially transported out of the domain through the Poynting flux. The presence of separatrix layers and magnetic null points fundamentally alters the propagation behavior of disturbances from the photosphere into the corona. Depending on the field-line topology close to the photosphere, the energy is either trapped or free to propagate into the corona.

Experimental investigation and numerical modelling of positive corona discharge: ozone generation

Energy Technology Data Exchange (ETDEWEB)

Yanallah, K; Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla (Spain); Pontiga, F; Fernandez-Rueda, A [Departamento de FIsica Aplicada II, Universidad de Sevilla (Spain)

2009-03-21

The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

Experimental investigation and numerical modelling of positive corona discharge: ozone generation

International Nuclear Information System (INIS)

Yanallah, K; Castellanos, A; Pontiga, F; Fernandez-Rueda, A

2009-01-01

The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

Power-Law Statistics of Driven Reconnection in the Magnetically Closed Corona

Science.gov (United States)

Klimchuk, J. A.; DeVore, C. R.; Knizhnik, K. J.; Uritskiy, V. M.

2018-01-01

Numerous observations have revealed that power-law distributions are ubiquitous in energetic solar processes. Hard X-rays, soft X-rays, extreme ultraviolet radiation, and radio waves all display power-law frequency distributions. Since magnetic reconnection is the driving mechanism for many energetic solar phenomena, it is likely that reconnection events themselves display such power-law distributions. In this work, we perform numerical simulations of the solar corona driven by simple convective motions at the photospheric level. Using temperature changes, current distributions, and Poynting fluxes as proxies for heating, we demonstrate that energetic events occurring in our simulation display power-law frequency distributions, with slopes in good agreement with observations. We suggest that the braiding-associated reconnection in the corona can be understood in terms of a self-organized criticality model driven by convective rotational motions similar to those observed at the photosphere.

Power-law Statistics of Driven Reconnection in the Magnetically Closed Corona

Science.gov (United States)

Knizhnik, K. J.; Uritsky, V. M.; Klimchuk, J. A.; DeVore, C. R.

2018-01-01

Numerous observations have revealed that power-law distributions are ubiquitous in energetic solar processes. Hard X-rays, soft X-rays, extreme ultraviolet radiation, and radio waves all display power-law frequency distributions. Since magnetic reconnection is the driving mechanism for many energetic solar phenomena, it is likely that reconnection events themselves display such power-law distributions. In this work, we perform numerical simulations of the solar corona driven by simple convective motions at the photospheric level. Using temperature changes, current distributions, and Poynting fluxes as proxies for heating, we demonstrate that energetic events occurring in our simulation display power-law frequency distributions, with slopes in good agreement with observations. We suggest that the braiding-associated reconnection in the corona can be understood in terms of a self-organized criticality model driven by convective rotational motions similar to those observed at the photosphere.

Ozone generation by negative corona discharge: the effect of Joule heating

International Nuclear Information System (INIS)

Yanallah, K; Castellanos, A; Pontiga, F; Fernandez-Rueda, A; Belasri, A

2008-01-01

Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poisson's equation, and the current-voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage

Experimental investigation and numerical modelling of positive corona discharge: ozone generation

Science.gov (United States)

Yanallah, K; Pontiga, F; Fernández-Rueda, A; Castellanos, A

2009-03-01

The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

Ozone generation by negative corona discharge: the effect of Joule heating

Science.gov (United States)

Yanallah, K.; Pontiga, F.; Fernández-Rueda, A.; Castellanos, A.; Belasri, A.

2008-10-01

Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poisson's equation, and the current-voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage.

A study on the influence of corona on currents and electromagnetic fields predicted by a nonlinear lightning return-stroke model

Science.gov (United States)

De Conti, Alberto; Silveira, Fernando H.; Visacro, Silvério

2014-05-01

This paper investigates the influence of corona on currents and electromagnetic fields predicted by a return-stroke model that represents the lightning channel as a nonuniform transmission line with time-varying (nonlinear) resistance. The corona model used in this paper allows the calculation of corona currents as a function of the radial electric field in the vicinity of the channel. A parametric study is presented to investigate the influence of corona parameters, such as the breakdown electric field and the critical electric field for the stable propagation of streamers, on predicted currents and electromagnetic fields. The results show that, regardless of the assumed corona parameters, the incorporation of corona into the nonuniform and nonlinear transmission line model under investigation modifies the model predictions so that they consistently reproduce most of the typical features of experimentally observed lightning electromagnetic fields and return-stroke speed profiles. In particular, it is shown that the proposed model leads to close vertical electric fields presenting waveforms, amplitudes, and decay with distance in good agreement with dart leader electric field changes measured in triggered lightning experiments. A comparison with popular engineering return-stroke models further confirms the model's ability to predict consistent electric field waveforms in the close vicinity of the channel. Some differences observed in the field amplitudes calculated with the different models can be related to the fact that current distortion, while present in the proposed model, is ultimately neglected in the considered engineering return-stroke models.

Preliminary experiments on the growth of plants exposed to DC corona discharge in a hydroponics. Chokuryu corona hodenkadeno suiko sanbaini yoru shokubutsu seiikuno yobiteki kento

Energy Technology Data Exchange (ETDEWEB)

Shigemitsu, Tsukasa; Watanabe, Yasunori

1988-01-01

For the purpose of utilizing electrical phenomena to agriculture fields, preliminary experiments were carried out hydroponically to evaluate especially the effects of ion by DC corona discharge on the growth of plants such as lettuce or radish. The influences of various shapes of discharge electrodes on a water evaporation rate, ozone production rate and ion current change were studied, and the indirect stimulation effects on plants by more water evaporation under discharge, and the direct stimulation effects on plants with discharge by the electrode fixed 45cm above plants were studied. As a result, the water evaporation rate was 2 or 3 times more than that of control plots by positive or negative corona discharge, however, for the growth of plants, no remarkable direct or indirect stimulation effects by discharge were observed. As subjects, the clarification of water behavior change under discharge and of effects on plants in cellular level were pointed out to be necessary. (14 figs, 12 tabs, 12 refs)

Ignition method of corona discharge with modulation of the field in ion source of ion mobility spectrometer

International Nuclear Information System (INIS)

Gromov, Evgeniy

2011-01-01

The new method for the ignition of the corona discharge has been developed, which improves the stability of the ion mobility spectrometer and the resolution of the instrument. The system of forming a corona discharge without additional electrodes, which are used in a number of known structures for the pre-ionization, has been developed. This simplifies the design of the proposed source and an electronic control circuit. IMS technology is widely used in different civil and military fields for vapor-phase detection of explosive, narcotics, chemical warfare agents, biology molecules and so on. There are set of methods whose are used for the ionization of molecules under analysis. They are the following: radioactive ionization, ultraviolet photoionization, laser ionization, electric field ionization, corona spray ionization, electro spray ionization, roentgen ionization, and surface ionization. All these methods has their own advantages and disadvantages. A comparing of ion mobility spectra of non-polar hydrocarbons for photoionization, corona discharge ionization and 63 Ni ionization, had carried in. In our work we have investigated four types of IMS spectrometers whose use different sources for molecules under analysis ionization. They use radioactive ionization, ultraviolet photoionization, laser ionization, and roentgen ionization. The traditional explosives had investigated in experiments. In electricity, a corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor, which occurs when the potential gradient (the strength of the electric field) exceeds a certain value, but conditions are insufficient to cause complete electrical breakdown or arcing.

Waves and Turbulence in the Solar Corona: A Surplus of Sources and Sinks

Science.gov (United States)

Cranmer, Steven R.

2018-06-01

The Sun's corona is a hot, dynamic, and highly stochastic plasma environment, and we still do not yet understand how it is heated. Both the loop-filled coronal base and the extended acceleration region of the solar wind appear to be filled with waves and turbulent eddies. Models that invoke the dissipation of these magnetohydrodynamic (MHD) fluctuations have had some success in explaining the heating. In this presentation I will review some new insights about the different ways these waves are thought to be created and destroyed. For example: (1) Intergranular bright points in the photosphere are believed to extend upwards as coronal flux tubes, and their transverse oscillations are driven by the underlying convection. New high-resolution MHD simulations predict the kinetic energy spectra of the resulting coronal waves and serve as predictions for upcoming DKIST observations. (2) Magnetic reconnection in the supergranular network of the low corona can also generate MHD waves, and new Monte Carlo models of the resulting power spectra will be presented. The total integrated power in these waves is typically small in comparison to that of photosphere-driven waves, but they dominate the total spectrum at periods longer than about 30 minutes. (3) Because each magnetic field line in the corona is tied to at least one specific chromospheric footpoint (each with its own base pressure), the corona also plays host to field-aligned "density striations." These fluctuations vary with the supergranular network on timescales of roughly a day, but they also act as a spatially varying background through which the higher-frequency waves propagate. These multiple sources of space/time variability must be taken into account to properly understand off-limb measurements from CoMP and EIS/Hinode, as well as in-situ measurements from Parker Solar Probe.

Ozone production by corona discharges during a convective event in DISCOVER-AQ Houston

Science.gov (United States)

Kotsakis, Alexander; Morris, Gary A.; Lefer, Barry; Jeon, Wonbae; Roy, Anirban; Minschwaner, Ken; Thompson, Anne M.; Choi, Yunsoo

2017-07-01

An ozonesonde launched near electrically active convection in Houston, TX on 5 September 2013 during the NASA DISCOVER-AQ project measured a large enhancement of ozone throughout the troposphere. A separate ozonesonde was launched from Smith Point, TX (∼58 km southeast of the Houston site) at approximately the same time as the launch from Houston and did not measure that enhancement. Furthermore, ozone profiles for the descent of both sondes agreed well with the ascending Smith Point profile, suggesting a highly localized event in both space and time in which an anomalously large enhancement of 70-100 ppbv appeared in the ascending Houston ozonesonde data. Compared to literature values, such an enhancement appears to be the largest observed to date. Potential sources of the localized ozone enhancement such as entrainment of urban or biomass burning emissions, downward transport from the stratosphere, photochemical production from lightning NOx, and direct ozone production from corona discharges were investigated using model simulations. We conclude that the most likely explanation for the large ozone enhancement is direct ozone production by corona discharges. Integrating the enhancement seen in the Houston ozone profile and using the number of electrical discharges detected by the NLDN (or HLMA), we estimate a production of 2.48 × 1028 molecules of ozone per flash which falls within the range of previously recorded values (9.89 × 1026-9.82 × 1028 molecules of ozone per flash). Since there is currently no parameterization for the direct production of ozone from corona discharges we propose the implementation of an equation into a chemical transport model. Ultimately, additional work is needed to further understand the occurrence and impact of corona discharges on tropospheric chemistry on short and long timescales.

Diffusion models for corona formation in metagabbros from the Western Grenville Province, Canada

Science.gov (United States)

Grant, Shona M.

1988-01-01

Metagabbro bodies in SW Grenville Province display a variety of disequilibrium corona textures between spinel-clouded plagioclase and primary olivine or opaque oxide. Textural evidence favours a single-stage, subsolidus origin for the olivine coronas and diffusive mass transfer is believed to have been the rate-controlling process. Irreversible thermodynamics have been used to model two different garnet symplectite-bearing corona sequences in terms of steady state diffusion. In the models the flux of each component is related to the chemical potential gradients of all diffusing species by the Onsager or L-coefficients for diffusion. These coefficients are analogous to experimentally determined diffusion coefficients ( d), but relate the flux of components to chemical potential rather than concentration gradients. The major constraint on the relative values of Onsager coefficients comes from the observed mole fraction, X, of garnet in the symplectites; in (amph-gt) symplectites X {Gt/Sym}˜0.80, compared with ˜0.75 in (cpx-gt) symplectites. Several models using simple oxide components, and two different modifications of the reactant plagioclase composition, give the following qualitative results: the very low mobility of aluminium appears to control the rate of corona formation. Mg and Fe have similar mobility, and Mg can be up to 6 8 times more mobile than sodium. Determination of calcium mobility is problematical because of a proposed interaction with cross-coefficient terms reflecting “uphill” Ca-diffusion, i.e., calcium diffusing up its own chemical potential gradient. If these terms are not introduced, it is difficult to generate the required proportions of garnet in the symplectite. However, at moderate values of the cross-coefficient ratios, Mg can be up to 4 6 times more mobile than calcium ( L MgMg/LCaCaCaCa/LAlAl>3).

Pulsed positive corona streamer propagation and branching

International Nuclear Information System (INIS)

Veldhuizen, E.M. van; Rutgers, W.R.

2002-01-01

The propagation and branching of pulsed positive corona streamers in a short gap is observed with high resolution in space and time. The appearance of the pre-breakdown phenomena can be controlled by the electrode configuration, the gas composition and the impedance of the pulsed power circuit. In a point-wire gap the positive corona shows much more branching than in the parallel plane gap with a protrusion. In air, the branching is more pronounced than in argon. The pulsed power circuit appears to operate in two modes, either as an inductive circuit creating a lower number of thick streamers or as a resistive circuit giving a higher number of thin streamers. A possible cause for branching is electrostatic repulsion of two parts of the streamer head. The electric field at the streamer head is limited, the maximum values found are ∼170 kV cm -1 in air and ∼100 kV cm -1 in argon. At these maximum field strengths, the electrons have 5-10 eV energy, so the ionization is dominated by two-step processes. Differences between argon and ambient air in the field strength at which streamers propagate are ascribed to the difference in de-excitation processes in noble and molecular gases. The fact that the pulsed power circuit can control the streamer structure is important for applications, but this effect must also be taken into account in fundamental studies of streamer propagation and branching. (author)

Pulsed positive corona streamer propagation and branching

Energy Technology Data Exchange (ETDEWEB)

Veldhuizen, E.M. van [Department of Physics, Technische Universiteit Eindhoven, Eindhoven (Netherlands)]. E-mail: e.m.v.veldhuizen@tue.nl; Rutgers, W.R. [Department of Physics, Technische Universiteit Eindhoven, Eindhoven (Netherlands)

2002-09-07

The propagation and branching of pulsed positive corona streamers in a short gap is observed with high resolution in space and time. The appearance of the pre-breakdown phenomena can be controlled by the electrode configuration, the gas composition and the impedance of the pulsed power circuit. In a point-wire gap the positive corona shows much more branching than in the parallel plane gap with a protrusion. In air, the branching is more pronounced than in argon. The pulsed power circuit appears to operate in two modes, either as an inductive circuit creating a lower number of thick streamers or as a resistive circuit giving a higher number of thin streamers. A possible cause for branching is electrostatic repulsion of two parts of the streamer head. The electric field at the streamer head is limited, the maximum values found are {approx}170 kV cm{sup -1} in air and {approx}100 kV cm{sup -1} in argon. At these maximum field strengths, the electrons have 5-10 eV energy, so the ionization is dominated by two-step processes. Differences between argon and ambient air in the field strength at which streamers propagate are ascribed to the difference in de-excitation processes in noble and molecular gases. The fact that the pulsed power circuit can control the streamer structure is important for applications, but this effect must also be taken into account in fundamental studies of streamer propagation and branching. (author)

Changes in some biophysical and biochemical parameters of mungbean [vigna radiata (L.) wilczek] grown on chromium-contaminated soils treated with solid tea wastage

International Nuclear Information System (INIS)

Azmat, R.; Akhtar, H.

2010-01-01

The success of solid tea wastage treatment technology in remediating chromium (111) contamination in the soil has been demonstrated on growth of Vigna radiata. The present research was designed to study the effect of chromium (Cr3/sup +/) on plant growth, potassium (K), phosphorus (P), protease activity and proline profile of Vigna radiata as a bio indicator in the presence and absence of the solid tea surface as a bio sorbent to control the mobility of Cr3/sup +/ in the soil. Results showed toxic effects of Cr3/ sup +/ on plant growth and development, which include high protease activity with prominent proline and decreased potassium and phosphorus contents at elevated concentration of metal. Proline content is the only amino acid that accumulates to a greater extent in the leaves of plants under stress. An increase in proline contents in leaves, stem and root with high concentration of Cr3/s sup +/ gets reduced in a solid tea wastage amended plants. Metabolic alteration by Cr3/ sup +/exposure and their control by solid tea wastage already described in the first report, showed direct effect on enzymes or other metabolites or by its ability to generate reactive oxygen species which may cause oxidative stress. It is suggested that the plant can grow under chromium stress if some suitable adsorbent (like tea wastage) is mixed with the soil which can protect the plants from the phyto toxicity of Cr 3/sup +/ by altering various metabolic processes. (author)

Integrated 3D printing and corona poling process of PVDF piezoelectric films for pressure sensor application

Science.gov (United States)

Kim, Hoejin; Torres, Fernando; Wu, Yanyu; Villagran, Dino; Lin, Yirong; Tseng, Tzu-Liang(Bill

2017-08-01

This paper presents a novel process to fabricate piezoelectric films from polyvinylidene fluoride (PVDF) polymer using integrated fused deposition modeling (FDM) 3D printing and corona poling technique. Corona poling is one of many effective poling processes that has received attention to activate PVDF as a piezoelectric responsive material. The corona poling process occurs when a PVDF polymer is exposed to a high electric field created and controlled through an electrically charged needle and a grid electrode under heating environment. FDM 3D printing has seen extensive progress in fabricating thermoplastic materials and structures, including PVDF. However, post processing techniques such as poling is needed to align the dipoles in order to gain piezoelectric properties. To further simplify the piezoelectric sensors and structures fabrication process, this paper proposes an integrated 3D printing process with corona poling to fabricate piezoelectric PVDF sensors without post poling process. This proposed process, named ‘Integrated 3D Printing and Corona poling process’ (IPC), uses the 3D printer’s nozzle and heating bed as anode and cathode, respectively, to create poling electric fields in a controlled heating environment. The nozzle travels along the programmed path with fixed distance between nozzle tip and sample’s top surface. Simultaneously, the electric field between the nozzle and bottom heating pad promotes the alignment of dipole moment of PVDF molecular chains. The crystalline phase transformation and output current generated by printed samples under different electric fields in this process were characterized by a Fourier transform infrared spectroscopy and through fatigue load frame. It is demonstrated that piezoelectric PVDF films with enhanced β-phase percentage can be fabricated using the IPC process. In addition, mechanical properties of printed PVDF was investigated by tensile testing. It is expected to expand the use of additive

Destruction of Sun-Grazing Comet C-2011 N3 (SOHO) Within the Low Solar Corona

Science.gov (United States)

Schrijver, C. J.; Brown, J. C.; Battams, K.; Saint-Hilaire, P.; Liu, W.; Hudson, H.; Pesnell, W. D.

2012-01-01

Observations of comets in Sun-grazing orbits that survive solar insolation long enough to penetrate into the Suns inner corona provide information on the solar atmosphere and magnetic field as well as on the makeup of the comet. On 6 July 2011, the Solar Dynamics Observatory (SDO) observed the demise of comet C2011 N3 (SOHO) within the low solar corona in five wavelength bands in the extreme ultraviolet (EUV). The comet penetrated to within 0.146 solarradius (100,000 kilometers) of the solar surface before its EUV signal disappeared.

Increased antioxidant activity and polyphenol metabolites in methyl jasmonate treated mung bean (Vigna radiata sprouts

Directory of Open Access Journals (Sweden)

Li LI

Full Text Available Abstract Mung bean sprouts are a popular health food both in China and worldwide. We determined the optimal concentration of exogenous methyl jasmonate (MeJA for the promotion of the sprouting in mung beans (Vigna radiata. The 1,1-diphenyl-2- picrylhydrazyl radical (DPPH scavenging test showed that MeJA application resulted in significantly improved antioxidant capacity in the sprouts 72 h later. Measurement of total polyphenols in MeJA-treated beans from 0 to 168 h, using Folin–Ciocalteu colorimetry, showed that the polyphenols changing was significantly correlated with antioxidant activity. The main polyphenols isovitexin, kaempferol-3-O-rutinoside, daidzein, genistein, isoquercitrin, p-coumaric acid, and caffeic acid were quantified using high-performance liquid chromatography (HPLC/QqQ MS and partial least squares discriminant analysis (PLS-DA. MeJA promoted the production of polyphenols, metabolites, and antioxidants in the sprouts; therefore, its use may allow sprouts to be prepared more quickly or increase their nutritional value.

Addiction as an Attachment Disorder: White Matter Impairment Is Linked to Increased Negative Affective States in Poly-Drug Use

Directory of Open Access Journals (Sweden)

Eva Z. Reininghaus

2017-04-01

Full Text Available Substance use disorders (SUD have been shown to be linked to various neuronal and behavioral impairments. In this study, we investigate whether there is a connection between the integrity of white matter (WM and attachment styles as well as different affective states including spirituality in a group of patients diagnosed for poly-drug use disorder (PUD in comparison to non-clinical controls. A total sample of 59 right-handed men, comprising the groups of patients with PUD (n = 19, recreational drug-using individuals (RUC; n = 20 as well as non-drug using controls were recruited (NUC; n = 20. For the behavioral assessment, we applied the Adult Attachment-Scale, the Affective Neuroscience Personality-Scale (short version and the Multidimensional Inventory for Religious/Spiritual Well-Being. Diffusion Tensor Imaging was used to investigate differences in WM neural connectivity. Analyses revealed decreased Fractional Anisotropy and decreased Mean Diffusivity in PUD patients as compared to RUC and NUC. No differences were found between RUC and NUC. Additional ROI analyses suggested that WM impairment in the superior longitudinal fasciculus (SLF and the superior corona radiata (SCR was linked to more insecure attachment as well as to more negative affectivity. No substantial correlation was observed with spirituality. These findings are mainly limited by the cross-sectional design of the study. However, our preliminary results support the idea of addiction as an attachment disorder, both at neuronal and behavioral levels. Further research might be focused on the changes of insecure attachment patterns in SUD treatment and their correlation with changes in the brain.

Evaluation of white matter integrity in systemic lupus erythematosus by diffusion tensor magnetic resonance imaging: a study using tract-based spatial statistics

Energy Technology Data Exchange (ETDEWEB)

Goulart Correa, Diogo; Ventura, Nina; Gasparetto, Emerson Leandro [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Zimmermann, Nicolle; Paz Fonseca, Rochele [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Pontifical Catholic University of Rio Grande do Sul, Department of Psychology, Porto Alegre, RS (Brazil); Batista Pereira, Denis; Netto, Tania Maria [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Doring, Thomas M. [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)

2016-08-15

The aim of this study was to evaluate the white matter integrity in brains of patients with systemic lupus erythematosus (SLE) using a voxel-based analyses of diffusion tensor imaging (DTI) data. Fifty-seven patients with SLE were compared to 36 control patients who were matched by gender, age, education, and Mini Mental State Examination score. DTI was performed along 30 noncollinear directions in a 1.5 Tesla scanner. For tract-based spatial statistics (TBSS), a white matter skeleton was created, and a permutation-based inference with 5000 permutations and a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean (MD), radial (RD), and axial diffusivities (AD) were also projected onto the mean FA skeleton. We found a significant decrease of global FA in SLE patients compared to controls. The areas of reduced FA included the right superior corona radiata, the right superior longitudinal fasciculus, the body of the corpus callosum, the right inferior fronto-occipital fasciculus, the right thalamic radiation, and the right uncinate fasciculus. Patients with SLE also had increased AD and RD in several areas. Substantial overlap of areas with increased AD and RD occurred and were spatially much more extensive than the areas of reduced FA. Significant increases of AD values were concordant to those of RD and MD and more extensive than FA changes. Analyzing all diffusivity parameters, using TBSS, can detect more white matter microstructural changes in patients with SLE than analyzing FA alone. (orig.)

Evaluation of white matter integrity in systemic lupus erythematosus by diffusion tensor magnetic resonance imaging: a study using tract-based spatial statistics

International Nuclear Information System (INIS)

Goulart Correa, Diogo; Ventura, Nina; Gasparetto, Emerson Leandro; Zimmermann, Nicolle; Paz Fonseca, Rochele; Batista Pereira, Denis; Netto, Tania Maria; Doring, Thomas M.

2016-01-01

The aim of this study was to evaluate the white matter integrity in brains of patients with systemic lupus erythematosus (SLE) using a voxel-based analyses of diffusion tensor imaging (DTI) data. Fifty-seven patients with SLE were compared to 36 control patients who were matched by gender, age, education, and Mini Mental State Examination score. DTI was performed along 30 noncollinear directions in a 1.5 Tesla scanner. For tract-based spatial statistics (TBSS), a white matter skeleton was created, and a permutation-based inference with 5000 permutations and a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean (MD), radial (RD), and axial diffusivities (AD) were also projected onto the mean FA skeleton. We found a significant decrease of global FA in SLE patients compared to controls. The areas of reduced FA included the right superior corona radiata, the right superior longitudinal fasciculus, the body of the corpus callosum, the right inferior fronto-occipital fasciculus, the right thalamic radiation, and the right uncinate fasciculus. Patients with SLE also had increased AD and RD in several areas. Substantial overlap of areas with increased AD and RD occurred and were spatially much more extensive than the areas of reduced FA. Significant increases of AD values were concordant to those of RD and MD and more extensive than FA changes. Analyzing all diffusivity parameters, using TBSS, can detect more white matter microstructural changes in patients with SLE than analyzing FA alone. (orig.)

Ozone generation by negative corona discharge: the effect of Joule heating

Energy Technology Data Exchange (ETDEWEB)

Yanallah, K; Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla (Spain); Pontiga, F; Fernandez-Rueda, A [Departamento de Fisica Aplicada II, Universidad de Sevilla (Spain); Belasri, A [Laboratoire de Physique des Plasmas, des Materiaux Conducteur et Leurs Applications, Universite d' Oran (Algeria)

2008-10-07

Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poisson's equation, and the current-voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage.

The nonuniform magnetohydrodynamic nature of the solar corona. III. Cylindrical geometry

International Nuclear Information System (INIS)

De ville, A.; Priest, E.R.

1989-01-01

The method developed by Priest in 1988 for modeling steady MHD disturbances in the solar corona is extended to a cylindrical geometry, which is more realistic for three-dimensional structures, such as plumes and coronal holes, which are observed in the corona. Both axial symmetric and nonaxial magnetic fields are treated. The basic characteristics of the axisymmetric solutions are found to be similar to the previous Cartesian case. Quantitatively, the interactions are stronger in the central region and weaker at the outer boundary. Pressure gradients are also found to be smaller. Solutions dependent on all three spatial variables exhibit an asymmetry because of the angular dependence. They depend upon the azimuthal magnetic field imposed at the coronal base. The solutions found in this paper may be useful in interpreting the physics of MHD interactions observed in numerical experiments and also in the solar atmosphere

Magnetic tornadoes as energy channels into the solar corona.

Science.gov (United States)

Wedemeyer-Böhm, Sven; Scullion, Eamon; Steiner, Oskar; van der Voort, Luc Rouppe; de la Cruz Rodriguez, Jaime; Fedun, Viktor; Erdélyi, Robert

2012-06-27

Heating the outer layers of the magnetically quiet solar atmosphere to more than one million kelvin and accelerating the solar wind requires an energy flux of approximately 100 to 300 watts per square metre, but how this energy is transferred and dissipated there is a puzzle and several alternative solutions have been proposed. Braiding and twisting of magnetic field structures, which is caused by the convective flows at the solar surface, was suggested as an efficient mechanism for atmospheric heating. Convectively driven vortex flows that harbour magnetic fields are observed to be abundant in the photosphere (the visible surface of the Sun). Recently, corresponding swirling motions have been discovered in the chromosphere, the atmospheric layer sandwiched between the photosphere and the corona. Here we report the imprints of these chromospheric swirls in the transition region and low corona, and identify them as observational signatures of rapidly rotating magnetic structures. These ubiquitous structures, which resemble super-tornadoes under solar conditions, reach from the convection zone into the upper solar atmosphere and provide an alternative mechanism for channelling energy from the lower into the upper solar atmosphere.

New Techniques Used in Modeling the 2017 Total Solar Eclipse: Energizing and Heating the Large-Scale Corona

Science.gov (United States)

Downs, Cooper; Mikic, Zoran; Linker, Jon A.; Caplan, Ronald M.; Lionello, Roberto; Torok, Tibor; Titov, Viacheslav; Riley, Pete; Mackay, Duncan; Upton, Lisa

2017-08-01

Over the past two decades, our group has used a magnetohydrodynamic (MHD) model of the corona to predict the appearance of total solar eclipses. In this presentation we detail recent innovations and new techniques applied to our prediction model for the August 21, 2017 total solar eclipse. First, we have developed a method for capturing the large-scale energized fields typical of the corona, namely the sheared/twisted fields built up through long-term processes of differential rotation and flux-emergence/cancellation. Using inferences of the location and chirality of filament channels (deduced from a magnetofrictional model driven by the evolving photospheric field produced by the Advective Flux Transport model), we tailor a customized boundary electric field profile that will emerge shear along the desired portions of polarity inversion lines (PILs) and cancel flux to create long twisted flux systems low in the corona. This method has the potential to improve the morphological shape of streamers in the low solar corona. Second, we apply, for the first time in our eclipse prediction simulations, a new wave-turbulence-dissipation (WTD) based model for coronal heating. This model has substantially fewer free parameters than previous empirical heating models, but is inherently sensitive to the 3D geometry and connectivity of the coronal field---a key property for modeling/predicting the thermal-magnetic structure of the solar corona. Overall, we will examine the effect of these considerations on white-light and EUV observables from the simulations, and present them in the context of our final 2017 eclipse prediction model.Research supported by NASA's Heliophysics Supporting Research and Living With a Star Programs.

Dynamics of the transition corona

International Nuclear Information System (INIS)

Masson, Sophie; McCauley, Patrick; Golub, Leon; Reeves, Katharine K.; DeLuca, Edward E.

2014-01-01

Magnetic reconnection between the open and closed magnetic fields in the corona is believed to play a crucial role in the corona/heliosphere coupling. At large scale, the exchange of open/closed connectivity is expected to occur in pseudo-streamer (PS) structures. However, there is neither clear observational evidence of how such coupling occurs in PSs, nor evidence for how the magnetic reconnection evolves. Using a newly developed technique, we enhance the off-limb magnetic fine structures observed with the Atmospheric Imaging Assembly and identify a PS-like feature located close to the northern coronal hole. We first identify that the magnetic topology associated with the observation is a PS, null-point (NP) related topology bounded by the open field. By comparing the magnetic field configuration with the EUV emission regions, we determined that most of the magnetic flux associated with plasma emission are small loops below the PS basic NP and open field bounding the PS topology. In order to interpret the evolution of the PS, we referred to a three-dimensional MHD interchange reconnection modeling the exchange of connectivity between small closed loops and the open field. The observed PS fine structures follow the dynamics of the magnetic field before and after reconnecting at the NP obtained by the interchange model. Moreover, the pattern of the EUV plasma emission is the same as the shape of the expected plasma emission location derived from the simulation. These morphological and dynamical similarities between the PS observations and the results from the simulation strongly suggest that the evolution of the PS, and in particular the opening/closing of the field, occurs via interchange/slipping reconnection at the basic NP of the PS. Besides identifying the mechanism at work in the large-scale coupling between the open and closed fields, our results highlight that interchange reconnection in PSs is a gradual physical process that differs from the impulsive

Analysis of euv limb-brightening observations from ATM. I. Model for the transition layer and the corona

Energy Technology Data Exchange (ETDEWEB)

Mariska, J T; Withbroe, G L [Harvard Coll. Observatory, Cambridge, Mass. (USA)

1975-09-01

Limb-brightening curves for euv resonance lines of O VI and Mg X have been constructed from spectroheliograms (5 sec resolution) of quiet limb regions observed with the Harvard experiment on Skylab. The observations are interpreted with a simple model for the transition layer and the corona. A comparison of theoretical and observed limb-brightening curves indicates that the lower boundary of the corona, where T/sub e/ = 10/sup 6/K, is at a height of about 8000 km in typical quiet areas. For 1.01 R(sun) approximately = to or < r < 1.25(sun), the corona can be represented by a homogeneous model in hydrostatic equilibrium with a temperature of 10/sup 6/K for 1.01 R(sun) approximately = to or < r < 1.1 R(sun) and 1.1x10/sup 6/K for r > approximately = to 1.1 R(sun). The model for the transition layer is inhomogeneous, with the temperature gradient a factor of 3 shallower in the network than in the intranetwork regions. It appears that spicules should be included in the model in order to account for the penetration into the corona of cool (T/sub e/ < 10/sup 6/K) euv-emitting material to heights up to 20000 km above the limb.

Electrons in the solar corona. Pt. 3. Coronal streamers analysis from balloon-borne coronagraph

Energy Technology Data Exchange (ETDEWEB)

Dollfus, A; Mouradian, Z [Observatoire de Paris, Section de Meudon, 92 (France)

1981-03-01

During a balloon flight in France on September 13, 1971, at altitude 32 000 m, the solar corona was cinematographed from 2 to 5 Rsub(sun) during 5 hr, with an externally occulted coronagraph. Motions in coronal features, when they occur, exhibit deformations of structures with velocities not exceeding a few 10 km s/sup -1/; several streamers were often involved simultaneously; these variations are compatible with magnetic changes or sudden reorganizations of lines of forces. Intensity and polarization measurements give the electron density with height in the quiet corona above the equator. Electron density gradient for one of the streamers gives a temperature of 1.6 x 10/sup 6/ K and comparisons with the on-board Apollo 16 coronal observation of 31 July, 1971 are compatible with the extension of this temperature up to 25 Rsub(sun). Three-dimensional structures and localizations of the streamers are deduced from combined photometry, polarimetry and ground-based K coronametry. Three of the four coronal streamers analysed have their axis bent with height towards the direction of the solar rotation, as if the upper corona has a rotation slightly faster than the chromosphere.

A high-current rail-type gas switch with preionization by an additional corona discharge

Energy Technology Data Exchange (ETDEWEB)

Antipov, E. I.; Belozerov, O. S.; Krastelev, E. G., E-mail: ekrastelev@yandex.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

2016-12-15

The characteristics of a high-current rail-type gas switch with preionization of the gas (air) in a spark gap by an additional corona discharge are investigated. The experiments were performed in a voltage range of 10–45 kV using a two-electrode switch consisting of two cylindrical electrodes with a diameter of 22 mm and a length of 100 mm and a set of laterally located corona-discharge needles. The requirements for the position and size of the needles are defined for which a corona discharge is ignited before a breakdown of the main gap and does not change to a sparking form, and the entire length of the rail electrodes is efficiently used. The fulfillment of these requirements ensures stable operation of the switch with a small variation of the pulse breakdown voltage, which is not more than 1% for a fixed voltage-pulse rise time in the range from 150 ns to 3.5 μs. A short delay time of the switch breakdown makes it possible to control the two-electrode switch by an overvoltage pulse of nanosecond duration.

A high-current rail-type gas switch with preionization by an additional corona discharge

International Nuclear Information System (INIS)

Antipov, E. I.; Belozerov, O. S.; Krastelev, E. G.

2016-01-01

The characteristics of a high-current rail-type gas switch with preionization of the gas (air) in a spark gap by an additional corona discharge are investigated. The experiments were performed in a voltage range of 10–45 kV using a two-electrode switch consisting of two cylindrical electrodes with a diameter of 22 mm and a length of 100 mm and a set of laterally located corona-discharge needles. The requirements for the position and size of the needles are defined for which a corona discharge is ignited before a breakdown of the main gap and does not change to a sparking form, and the entire length of the rail electrodes is efficiently used. The fulfillment of these requirements ensures stable operation of the switch with a small variation of the pulse breakdown voltage, which is not more than 1% for a fixed voltage-pulse rise time in the range from 150 ns to 3.5 μs. A short delay time of the switch breakdown makes it possible to control the two-electrode switch by an overvoltage pulse of nanosecond duration.

Wallerian degeneration of the corticodescending tract in the cerebral peduncle following a supratentorial cerebrovascular lesion detected by MRI; The relationship between Wallerian degeneration at the center of the cerebral peduncle and functional recovery of paresis

Energy Technology Data Exchange (ETDEWEB)

Waragai, Masaaki; Iwabuchi, Sadamu (Nanasawa Rehabilitation Hospital, Kanagawa (Japan))

1993-11-01

We studied Wallerian degeneration of the corticodescending tract in the cerebral peduncle following a supratentorial cerebrovascular lesion by MRI. A total of 57 patients with palsy following a supratenotorial cerebrovascular lesion were prospectively studied. Wallerian degeneration was detected as a high signal intensity (HSI) in 37 patients between 70 days and 100 days after the onset, but not detected in the remaining 27 patients. Patient with as HSI in all areas of the cerebral peduncle had a large lesion involving the hemisphere. Patient with an HSI at the center of the cerebral peduncle had a lesion confined to the paracentral gyrus, precentral gyrus, corona radiata or posterior limb of the internal capsule. Patient with an HSI at the lateral side of the cerebral peduncle had a lesion of parietal lobe or temporal lobe which spares the corticospinal tract originating from the paracentral gyrus, precentral gyrus, corona radiata or posterior limb of the internal capsule. These findings suggest that as HSI at the center of the cerebral peduncle may reveal Wallerian degeneration of the corticospinal tract, and an HSI at the lateral side of the cerebral peduncle may show Wallerian degeneration of the corticopontine tract. The functional recovery of paresis was poor in all patients with an HSI at the center of the cerebral peduncle, while it was good in all patients without an HSI in that region. Our data suggested that somatotopical localization of the corticodescending tract in the cerebral peduncle may be identified by detecting Wallerian degeneration following a supratentorial lesion, and the functional recovery of patients with paresis could be predicted according to presence or absence of Wallerian degeneration at the center of the cerebral peduncle. (author).

Voxel-based analysis of fractional anisotropy in post-stroke apathy.

Directory of Open Access Journals (Sweden)

Song-ran Yang

Full Text Available To explore the structural basis of post-stroke apathy by using voxel-based analysis (VBA of fractional anisotropy (FA maps.We enrolled 54 consecutive patients with ischemic stroke during convalescence, and divided them into apathy (n = 31 and non-apathy (n = 23 groups. We obtained magnetic resonance images of their brains, including T1, T2 and DTI sequences. Age, sex, education level, Hamilton Depression Scale (HAMD scores, Mini-Mental State Examination (MMSE scores, National Institutes of Health Stroke Scale (NIHSS scores, and infarct locations for the two groups were compared. Finally, to investigate the structural basis of post-stroke apathy, VBA of FA maps was performed in which we included the variables that a univariate analysis determined had P-values less than 0.20 as covariates.HAMD (P = 0.01 and MMSE (P<0.01 scores differed significantly between the apathy and non-apathy groups. After controlling for age, education level, HAMD scores, and MMSE scores, significant FA reduction was detected in four clusters with peak voxels at the genu of the corpus callosum (X = -16, Y = 30, Z = 8, left anterior corona radiata (-22, 30, 10, splenium of the corpus callosum (-24, -56, 18, and right inferior frontal gyrus white matter (52, 24, 18, after family-wise error correction for multiple comparisons.Post-stroke apathy is related to depression and cognitive decline. Damage to the genu of the corpus callosum, left anterior corona radiata, splenium of the corpus callosum, and white matter in the right inferior frontal gyrus may lead to apathy after ischemic stroke.

Assessment of white matter abnormalities in paranoid schizophrenia and bipolar mania patients.

Science.gov (United States)

Cui, Liqian; Chen, Zhuangfei; Deng, Wei; Huang, Xiaoqi; Li, Mingli; Ma, Xiaohong; Huang, Chaohua; Jiang, Lijun; Wang, Yingcheng; Wang, Qiang; Collier, David A; Gong, Qiyong; Li, Tao

2011-12-30

White matter abnormalities have been repeatedly reported in both schizophrenia and bipolar disorder (BD) in diffusion tensor imaging (DTI) studies, but the empirical evidence about the diagnostic specificity of white matter abnormalities in these disorders is still limited. This study sought to investigate the alterations in fractional anisotropy (FA) in white matter throughout the entire brain of patients from Chengdu, China with paranoid schizophrenia and bipolar mania. For this purpose, DTI was used to assess white matter integrity in patients with paranoid schizophrenia (n=25) and psychotic bipolar mania (n=18) who had been treated with standard pharmacotherapy for fewer than 5 days at the time of study, as well as in normal controls (n=30). The differences in FA were measured by use of voxel-based analysis. The results show that reduced FA was found in the left posterior corona radiata (PCR) in patients with psychotic bipolar mania and paranoid schizophrenia compared to the controls. Patients with psychotic bipolar mania also showed a significant reduction in FA in right posterior corona radiata and in right anterior thalamic radiation (ATR). A direct comparison between the two patient groups found no significant differences in any regions, and none of the findings were associated with illness duration. Correlation analysis indicated that FA values showed a significant negative correlation with positive symptom scores on the Positive and Negative Syndrome Scale in the left frontal-parietal lobe in the paranoid schizophrenia. It was concluded that common abnormalities in the left PCR might imply an overlap in white matter pathology in the two disorders and might be related to shared risk factors for the two disorders. 2011 Elsevier Ireland Ltd. All rights reserved.

Wallerian degeneration of the corticodescending tract in the cerebral peduncle following a supratentorial cerebrovascular lesion detected by MRI

International Nuclear Information System (INIS)

Waragai, Masaaki; Iwabuchi, Sadamu

1993-01-01

We studied Wallerian degeneration of the corticodescending tract in the cerebral peduncle following a supratentorial cerebrovascular lesion by MRI. A total of 57 patients with palsy following a supratenotorial cerebrovascular lesion were prospectively studied. Wallerian degeneration was detected as a high signal intensity (HSI) in 37 patients between 70 days and 100 days after the onset, but not detected in the remaining 27 patients. Patient with as HSI in all areas of the cerebral peduncle had a large lesion involving the hemisphere. Patient with an HSI at the center of the cerebral peduncle had a lesion confined to the paracentral gyrus, precentral gyrus, corona radiata or posterior limb of the internal capsule. Patient with an HSI at the lateral side of the cerebral peduncle had a lesion of parietal lobe or temporal lobe which spares the corticospinal tract originating from the paracentral gyrus, precentral gyrus, corona radiata or posterior limb of the internal capsule. These findings suggest that as HSI at the center of the cerebral peduncle may reveal Wallerian degeneration of the corticospinal tract, and an HSI at the lateral side of the cerebral peduncle may show Wallerian degeneration of the corticopontine tract. The functional recovery of paresis was poor in all patients with an HSI at the center of the cerebral peduncle, while it was good in all patients without an HSI in that region. Our data suggested that somatotopical localization of the corticodescending tract in the cerebral peduncle may be identified by detecting Wallerian degeneration following a supratentorial lesion, and the functional recovery of patients with paresis could be predicted according to presence or absence of Wallerian degeneration at the center of the cerebral peduncle. (author)

Interpretation of zircon coronae textures from metapelitic granulites of the Ivrea–Verbano Zone, northern Italy: two-stage decomposition of Fe–Ti oxides

Directory of Open Access Journals (Sweden)

E. Kovaleva

2017-07-01

Full Text Available In this study, we report the occurrence of zircon coronae textures in metapelitic granulites of the Ivrea–Verbano Zone. Unusual zircon textures are spatially associated with Fe–Ti oxides and occur as (1 vermicular-shaped aggregates 50–200 µm long and 5–20 µm thick and as (2 zircon coronae and fine-grained chains, hundreds of micrometers long and ≤ 1 µm thick, spatially associated with the larger zircon grains. Formation of such textures is a result of zircon precipitation during cooling after peak metamorphic conditions, which involved: (1 decomposition of Zr-rich ilmenite to Zr-bearing rutile, and formation of the vermicular-shaped zircon during retrograde metamorphism and hydration; and (2 recrystallization of Zr-bearing rutile to Zr-depleted rutile intergrown with quartz, and precipitation of the submicron-thick zircon coronae during further exhumation and cooling. We also observed hat-shaped grains that are composed of preexisting zircon overgrown by zircon coronae during stage (2. Formation of vermicular zircon (1 preceded ductile and brittle deformation of the host rock, as vermicular zircon is found both plastically and cataclastically deformed. Formation of thin zircon coronae (2 was coeval with, or immediately after, brittle deformation as coronae are found to fill fractures in the host rock. The latter is evidence of local, fluid-aided mobility of Zr. This study demonstrates that metamorphic zircon can nucleate and grow as a result of hydration reactions and mineral breakdown during cooling after granulite-facies metamorphism. Zircon coronae textures indicate metamorphic reactions in the host rock and establish the direction of the reaction front.

Enhanced stiffness of silk-like fibers by loop formation in the corona leads to stronger gels.

Science.gov (United States)

Rombouts, Wolf H; Domeradzka, Natalia E; Werten, Marc W T; Leermakers, Frans A M; de Vries, Renko J; de Wolf, Frits A; van der Gucht, Jasper

2016-11-01

We study the self-assembly of protein polymers consisting of a silk-like block flanked by two hydrophilic blocks, with a cysteine residue attached to the C-terminal end. The silk blocks self-assemble to form fibers while the hydrophilic blocks form a stabilizing corona. Entanglement of the fibers leads to the formation of hydrogels. Under oxidizing conditions the cysteine residues form disulfide bridges, effectively connecting two corona chains at their ends to form a loop. We find that this leads to a significant increase in the elastic modulus of the gels. Using atomic force microscopy, we show that this stiffening is due to an increase of the persistence length of the fibers. Self-consistent-field calculations indicate a slight decrease of the lateral pressure in the corona upon loop formation. We argue that this small decrease in the repulsive interactions affects the stacking of the silk-like blocks in the core, resulting in a more rigid fiber. © 2016 Wiley Periodicals, Inc.

A Spectroscopic Study of the Energy Deposition in the Low Corona: Connecting Global Modeling to Observations

Science.gov (United States)

Szente, J.; Landi, E.; Toth, G.; Manchester, W.; van der Holst, B.; Gombosi, T. I.

2017-12-01

We are looking for signatures of coronal heating process using a physically consistent 3D MHD model of the global corona. Our approach is based on the Alfvén Wave Solar atmosphere Model (AWSoM), with a domain ranging from the upper chromosphere (50,000K) to the outer corona, and the solar wind is self-consistently heated and accelerated by the dissipation of low-frequency Alfvén waves. Taking into account separate electron and anisotropic proton heating, we model the coronal plasma at the same time and location as observed by Hinode/EIS, and calculate the synthetic spectra that we compare with the observations. With the obtained synthetic spectra, we are able to directly calculate line intensities, line width, thermal and nonthermal motions, line centroids, Doppler shift distributions and compare our predictions to real measurements. Our results directly test the extent to which Alfvénic heating is present in the low corona.

Temporal and spatial evolution of EHD particle flow onset in air in a needle-to-plate negative DC corona discharge

International Nuclear Information System (INIS)

Mizeraczyk, J; Berendt, A; Podlinski, J

2016-01-01

In this paper we present images showing the temporal and spatial evolution of the electrohydrodynamic (EHD) flow of dust particles (cigarette smoke) suspended in still air in a needle-to-plate negative DC corona discharge arrangement just after the corona onset, i.e. in the first stage of development of the EHD particle flow. The experimental apparatus for our study of the EHD flow onset consisted of a needle-to-plate electrode arrangement, high voltage power supply and time-resolved EHD imaging system based on 2D time-resolved particle image velocimetry equipment. The time-resolved flow images clearly show the formation of a ball-like flow structure at the needle tip just after the corona discharge onset, and its evolution into a mushroom-like object moving to the collecting electrode. After a certain time, when the mushroom-like object is still present in the interelectrode gap a second mushroom-like object forms near the needle electrode and starts to move towards the collecting electrode. Before the first mushroom-like object reaches the collecting electrode several similar mushroom-like objects can be formed and presented simultaneously in the interelectrode gap. They look like a series of mushroom-like minijets shot from the needle electrode vicinity towards the collecting electrode. The simultaneous presence of mushroom-like minijets in the interelectrode gap in the corona discharge in particle-seeded air resembles the negative-ion-charged ‘clouds’ (induced by the Trichel pulses) traversing simultaneously the interelectrode gap of the corona discharge in air, predicted a long time ago by Loeb, and Lama and Gallo and recently by Dordizadeh et al . Analysing the time behaviours of the mushroom-like minijets and current waveform in the corona discharge in particle-seeded air, we found that the Trichel pulse trains, formed just after the corona onset initiates the mushroom-like minijets. The first stage of development of the EHD particle flow, the area of

Numerical and Experimental Study of Amplitude Modulated Positive Corona Discharge

Directory of Open Access Journals (Sweden)

Pablo Martín GOMEZ

2014-12-01

Full Text Available The electrical behavior of a modulated positive corona discharge loudspeaker was studied. A coaxial transducer in air was built using a central copper wire of 75 mm radius (inner electrode and a perforated tube of 11 mm (outer electrode. A high voltage DC supply provided the bias current and a sinusoidal signal was superimposed to measure the discharge admittance. The experimental results could not be matched to previously reported equivalent circuits with fixed components. Using the basic equations that describe the ion motion, a numerical model was proposed. The computed values matched well the experimental data and suggested an equivalent circuit composed of frequency dependent conductance and capacitance. This dependence is closely related to the ion travel time between electrodes (transit time. Simulations carried out at several inter-electrode distances could be synthesized in a single plot where the different results overlap and further emphasize the role of the transit time. This numerical model proved to be an efficient tool to simulate and design modulated corona transducers.

Green corona, geomagnetic activity and radar meteor rates

International Nuclear Information System (INIS)

Prikryl, P.

1979-01-01

The short-term dependence of radar meteor rates on geomagnetic activity and/or central meridian passage (CMP) of bright or faint green corona regions is studied. A superimposed-epoch analysis was applied to radar meteor observations from the Ottawa patrol radar (Springhill, Ont.) and Ksub(p)-indices of geomagnetic activity for the period 1963 to 1967. During the minimum of solar activity (1963 to 1965) the CMP of bright coronal regions was followed by the maximum in the daily rates of persistent meteor echoes (>=4s), and the minimum in the daily sums of Ksub(p)-indices whereas the minimum or the maximum, respectively, occurs after the CMP of faint coronal regions. The time delay between the CMP of coronal structures and the corresponding maxima or minima is found to be 3 to 4 days. However, for the period immediately after the minimum of solar activity (1966 to 1967) the above correlation with the green corona is void both for the geomagnetic activity and radar meteor rates. An inverse correlation was found between the radar meteor rates and the geomagnetic activity irrespective of the solar activity. The observed effect can be ascribed to the solar-wind-induced ''geomagnetic'' heating of the upper atmosphere and to the subsequent change in the density gradient in the meteor zone. (author)

Plasma chemical and electrical modelling of a negative DC corona in pure oxygen

Energy Technology Data Exchange (ETDEWEB)

Soria, C [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla (Spain); Pontiga, F [Departamento de FIsica Aplicada II, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla (Spain); Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla (Spain)

2004-02-01

A complex plasma chemical and electrical model of a negative stationary wire-to-cylinder corona discharge in pure oxygen is presented. The corona discharge is assumed to have axial and azimuthal symmetry. The experimental current-voltage characteristic is required as input data, but there are no other adjustable or empirical parameters. The experimental validation of the results of the model comes from its prediction of the ozone concentration. The role played by different reactions and species is analysed in detail using the results of the simulation. The effect of the gas temperature and of the decomposition of ozone at the electrodes is also investigated. The agreement between the model and the experiments is excellent when the effect of ozone decomposition at the electrodes is taken into account.

Plasma chemical and electrical modelling of a negative DC corona in pure oxygen

International Nuclear Information System (INIS)

Soria, C; Pontiga, F; Castellanos, A

2004-01-01

A complex plasma chemical and electrical model of a negative stationary wire-to-cylinder corona discharge in pure oxygen is presented. The corona discharge is assumed to have axial and azimuthal symmetry. The experimental current-voltage characteristic is required as input data, but there are no other adjustable or empirical parameters. The experimental validation of the results of the model comes from its prediction of the ozone concentration. The role played by different reactions and species is analysed in detail using the results of the simulation. The effect of the gas temperature and of the decomposition of ozone at the electrodes is also investigated. The agreement between the model and the experiments is excellent when the effect of ozone decomposition at the electrodes is taken into account

Nanoparticle electrostatic loss within corona needle charger during particle-charging process

International Nuclear Information System (INIS)

Huang Chenghsiung; Alonso, Manuel

2011-01-01

A numerical investigation has been carried out to examine the electrostatic loss of nanoparticles in a corona needle charger. Two-dimensional flow field, electric field, particle charge, and particle trajectory were simulated to obtain the electrostatic deposition loss at different conditions. Simulation of particle trajectories shows that the number of charges per particle during the charging process depends on the particle diameter, radial position from the symmetry axis, applied voltage, Reynolds number, and axial distance along the charger. The numerical results of nanoparticle electrostatic loss agreed fairly well with available experimental data. The results reveal that the electrostatic loss of nanoparticles increases with increasing applied voltage and electrical mobility of particles; and with decreasing particle diameter and Reynolds number. A regression equation closely fitted the obtained numerical results for different conditions. The equation is useful for directly calculating the electrostatic loss of nanoparticles in the corona needle charger during particle-charging process.

Pulsed Corona Plasma Technology for Treating VOC Emissions from Pulp Mills

International Nuclear Information System (INIS)

Fridman, Alexander A.; Gutsol, Alexander; Kennedy, Lawrence A.; Saveliev, Alexei V.; Korobtsev, Sergey V.; Shiryaevsky, Valery L.; Medvedev, Dmitry

2004-01-01

Under the DOE Office of Industrial Technologies Forest Products program various plasma technologies were evaluated under project FWP 49885 ''Experimental Assessment of Low-Temperature Plasma Technologies for Treating Volatile Organic Compound Emissions from Pulp Mills and Wood Products Plants''. The heterogeneous pulsed corona discharge was chosen as the best non-equilibrium plasma technology for control of the vent emissions from HVLC Brownstock Washers. The technology for removal of Volatile Organic Compounds (VOCs) from gas emissions with conditions typical of the exhausts of the paper industry by means of pulsed corona plasma techniques presented in this work. For the compounds of interest in this study (methanol, acetone, dimethyl sulfide and ? -pinene), high removal efficiencies were obtained with power levels competitive with the present technologies for the VOCs removal. Laboratory experiments were made using installation with the average power up to 20 W. Pilot plant prepared for on-site test has average plasma power up to 6.4 kW. The model of the Pilot Plant operation is presented

Ozone formation by gaseous corona discharge generated above aqueous solution

Czech Academy of Sciences Publication Activity Database

Lukeš, Petr; Člupek, Martin; Babický, Václav; Šunka, Pavel

2004-01-01

Roč. 54, suppl. C (2004), C909-C913 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21st/. Praha, 14.06.2004-17.06.2004] R&D Projects: GA ČR GA202/02/1026 Keywords : corona discharg, ozone Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

Periodicities in the X-ray Emission from the Solar Corona: SphinX and SOXS Observations

Science.gov (United States)

Steślicki, M.; Awasthi, A. K.; Gryciuk, M.; Jain, R.

The structure and evolution of the solar magnetic field is driven by a magnetohydrodynamic dynamo operating in the solar interior, which induces various solar activities that exhibit periodic variations on different timescales. Therefore, probing the periodic nature of emission originating from the solar corona may provide insights of the convection-zone-photosphere-corona coupling processes. We present the study of the mid-range periodicities, between rotation period (˜27 days) and the Schwabe cycle period (˜11 yr), in the solar soft X-ray emission, based on the data obtained by two instruments: SphinX and SOXS in various energy bands.

Effect of (/sup 60/cobalt) gamma rays on growth and root rot diseases in mungbean (vigna radiata L.)

International Nuclear Information System (INIS)

Ikram, N.; Dawar, S.; Zaki, M.J.; Abass, Z.

2010-01-01

Present investigation showed that gamma rays influences suppressive effect on root rot fungi such as Macrophomina phaseolina (Tassi) Goid, Rhizoctonia solani Kuhn and Fusarium spp., and inducive effect on growth parameters of mung bean (Vigna radiata L.). Seeds of mung bean were treated with gamma rays (/sup 60/Cobalt) at time periods of 0 and 4 minutes and stored for 90 days at room temperature to determine its effect on growth parameters and infection of root infecting fungi. All treatments of gamma rays enhanced the growth parameters as compared to untreated plants. Infection of M. phaseolina, R. solani and Fusarium spp., were significantly decreased on mung bean seeds treated with gamma rays. Gamma rays significantly increased the growth parameters and controlled the root rot fungi up to 90 days of storage of seeds. (author)

NEOCE: a new external occulting coronagraph experiment for ultimate observations of the chromosphere, corona and interface

Science.gov (United States)

Damé, Luc; Fineschi, Silvano; Kuzin, Sergey; Von Fay-Siebenburgen, Erdélyi Robert

Several ground facilities and space missions are currently dedicated to the study of the Sun at high resolution and of the solar corona in particular. However, and despite significant progress with the advent of space missions and UV, EUV and XUV direct observations of the hot chromosphere and million-degrees coronal plasma, much is yet to be achieved in the understanding of these high temperatures, fine dynamic dissipative structures and of the coronal heating in general. Recent missions have shown the definite role of a wide range of waves and of the magnetic field deep in the inner corona, at the chromosphere-corona interface, where dramatic and physically fundamental changes occur. The dynamics of the chromosphere and corona is controlled and governed by the emerging magnetic field. Accordingly, the direct measurement of the chromospheric and coronal magnetic fields is of prime importance. The solar corona consists of many localised loop-like structures or threads with the plasmas brightening and fading independently. The plasma evolution in each thread is believed to be related to the formation of filaments, each one being dynamic, in a non-equilibrium state. The mechanism sustaining this dynamics, oscillations or waves (Alfvén or other magneto-plasma waves), requires both very high-cadence, multi-spectral observations, and high resolution and coronal magnetometry. This is foreseen in the future Space Mission NEOCE (New External Occulting Coronagraph Experiment), the ultimate new generation high-resolution coronagraphic heliospheric mission, to be proposed for ESA M4. NEOCE, an evolution of the HiRISE mission, is ideally placed at the L5 Lagrangian point (for a better follow-up of CMEs), and provides FUV imaging and spectro-imaging, EUV and XUV imaging and spectroscopy, and ultimate coronagraphy by a remote external occulter (two satellites in formation flying 375 m apart minimizing scattered light) allowing to characterize temperature, densities and

Nonlinearity and instability in stellar coronae

International Nuclear Information System (INIS)

Martens, P.C.H.

1983-01-01

This thesis is mainly concerned with time dependent processes occurring in the hot and teneous plasma - about 1 million degrees and higher and less than 10 10 cm density - that forms the outer envelopes of many stars including the sun. These envelopes - coronae - emit X-rays and indirectly in the ultraviolet and are therefore mainly observed by satellite techniques. Part I consists of a general introduction to the work and an overview of the non-linear methods that are used in the following. Part II and part III are concerned with respectively open and closed coronal structures. There is great similarity in the physics of these two systems, but the open structures are somewhat more complicated. (Auth.)

Mathieu functions for fermions generated in magnetar’s corona

Science.gov (United States)

Dariescu, Marina-Aura; Dariescu, Ciprian

2017-10-01

This work deals with the behavior of fermions in a configuration supposed to exist in magnetar’s corona. For a static magnetic induction parallel to a time-harmonic electric field, the solution to the U(1)-gauge invariant Dirac equation is expressed in terms of Laguerre polynomials and Mathieu’s functions of complex parameter. Using the Fourier series valid before the branching point, we are computing the conserved current density components.

Comparison of pulsed corona plasma and pulsed electric fields for the decontamination of water containing Legionella pneumophila as model organism.

Science.gov (United States)

Banaschik, Robert; Burchhardt, Gerhard; Zocher, Katja; Hammerschmidt, Sven; Kolb, Juergen F; Weltmann, Klaus-Dieter

2016-12-01

Pulsed corona plasma and pulsed electric fields were assessed for their capacity to kill Legionella pneumophila in water. Electrical parameters such as in particular dissipated energy were equal for both treatments. This was accomplished by changing the polarity of the applied high voltage pulses in a coaxial electrode geometry resulting in the generation of corona plasma or an electric field. For corona plasma, generated by high voltage pulses with peak voltages of +80kV, Legionella were completely killed, corresponding to a log-reduction of 5.4 (CFU/ml) after a treatment time of 12.5min. For the application of pulsed electric fields from peak voltages of -80kV a survival of log 2.54 (CFU/ml) was still detectable after this treatment time. Scanning electron microscopy images of L. pneumophila showed rupture of cells after plasma treatment. In contrast, the morphology of bacteria seems to be intact after application of pulsed electric fields. The more efficient killing for the same energy input observed for pulsed corona plasma is likely due to induced chemical processes and the generation of reactive species as indicated by the evolution of hydrogen peroxide. This suggests that the higher efficacy and efficiency of pulsed corona plasma is primarily associated with the combined effect of the applied electric fields and the promoted reaction chemistry. Copyright © 2016 Elsevier B.V. All rights reserved.

Low-level NOx removal in ambient air by pulsed corona technology

NARCIS (Netherlands)

Beckers, F.J.C.M.; Hoeben, W.F.L.M.; Pemen, A.J.M.; Heesch, van E.J.M.

2013-01-01

Although removal of NOx by (pulsed) corona discharges has been thoroughly investigated for high concentrations of NOx in flue gas, removal of low levels in ambient air proves to be a difficult task. (Sub) ppm NOx levels exist in traffic tunnels due to accumulation of exhaust gases. The application

NOx removal characteristics of corona radical shower with ammonia and methylamine radical injections

Energy Technology Data Exchange (ETDEWEB)

Urashima, K.; Ara, M.; Chang, J.S. [McMaster Univ., Hamilton, ON (Canada). Dept. of Engineering Physics; Uchida, Y. [Aichi Inst. of Technology, (Japan). Dept. of Engineering

2010-07-01

Air pollutants such as nitrogen oxides (NOx) and sulfur oxides (SOx) are the major cause of acid rain. There are different types of NOx and SOx conversion techniques such as wet scrubber, selective catalytic reactor, sorbent injection, and low NOx burner. Non-thermal plasma techniques have also been utilized in commercial plants, but the energy efficiency of the non-thermal plasma reactors have not yet been optimized. The direct plasma treatments of flue gases including, the electron beam, barrier discharge and pulsed corona reactors, may lose input energy to activate unwanted components of flue gases such as carbon dioxide (CO{sub 2}) and nitrogen (N{sub 2}). The corona discharge ammonia radical shower system has demonstrated significant NOx removal with higher energy efficiency for large bench scale and pilot plant tests for combustion exhausts. An experiment has also demonstrated that methane can replace ammonia as an injection gas with less NOx removal efficiency. This paper presented an experimental investigation that compared methylamine radical injection with traditional ammonia and methane radical injections. The paper discussed the bench scale test facilities and corona radical shower plasma reactor. It was concluded that the processes to form ammonium nitrate could be observed from trace white solid particles deposited on the reactor wall as observed by scanning electron microscopy pictures. 10 refs., 5 figs., 2 appendices.

Signatures of Slow Solar Wind Streams from Active Regions in the Inner Corona

Science.gov (United States)

Slemzin, V.; Harra, L.; Urnov, A.; Kuzin, S.; Goryaev, F.; Berghmans, D.

2013-08-01

The identification of solar-wind sources is an important question in solar physics. The existing solar-wind models ( e.g., the Wang-Sheeley-Arge model) provide the approximate locations of the solar wind sources based on magnetic field extrapolations. It has been suggested recently that plasma outflows observed at the edges of active regions may be a source of the slow solar wind. To explore this we analyze an isolated active region (AR) adjacent to small coronal hole (CH) in July/August 2009. On 1 August, Hinode/EUV Imaging Spectrometer observations showed two compact outflow regions in the corona. Coronal rays were observed above the active-region coronal hole (ARCH) region on the eastern limb on 31 July by STEREO-A/EUVI and at the western limb on 7 August by CORONAS- Photon/TESIS telescopes. In both cases the coronal rays were co-aligned with open magnetic-field lines given by the potential field source surface model, which expanded into the streamer. The solar-wind parameters measured by STEREO-B, ACE, Wind, and STEREO-A confirmed the identification of the ARCH as a source region of the slow solar wind. The results of the study support the suggestion that coronal rays can represent signatures of outflows from ARs propagating in the inner corona along open field lines into the heliosphere.

Empirical models of the Solar Wind : Extrapolations from the Helios & Ulysses observations back to the corona

Science.gov (United States)

Maksimovic, M.; Zaslavsky, A.

2017-12-01

We will present extrapolation of the HELIOS & Ulysses proton density, temperature & bulk velocities back to the corona. Using simple mass flux conservations we show a very good agreement between these extrapolations and the current state knowledge of these parameters in the corona, based on SOHO mesurements. These simple extrapolations could potentially be very useful for the science planning of both the Parker Solar Probe and Solar Orbiter missions. Finally will also present some modelling considerations, based on simple energy balance equations which arise from these empirical observationnal models.

Electrical and spectroscopic analysis of mono- and multi-tip pulsed corona discharges in air at atmospheric pressure

Science.gov (United States)

Mraihi, A.; Merbahi, N.; Yousfi, M.; Abahazem, A.; Eichwald, O.

2011-12-01

This work is devoted to the analysis of experimental results obtained in dry air at atmospheric pressure in a positive point-to-plane corona discharge under a pulsed applied voltage in the cases of anodic mono- and multi-tips. In the mono-tip case, the peak corona current is analysed as a function of several experimental parameters such as magnitude, frequency and duration of pulsed voltage and gap distance. The variation of the corona discharge current is correlated with the ozone production. Then in the multi-tip case, the electrical behaviour is analysed as a function of the distance between two contiguous tips and the tip number in order to highlight the region of creation active species for the lowest dissipated power. Intensified charge-coupled device pictures and electric field calculations as a function of inter-tip distance are performed to analyse the mutual effect between two contiguous tips. The optical emission spectra are measured in the UV-visible-NIR wavelength range between 200 nm and 800 nm, in order to identify the main excited species formed in an air corona discharge such as the usual first and second positive systems with first negative systems of molecular nitrogen. The identification of atomic species (O triplet and N) and the quenching of NOγ emission bands are also emphasized.

Electrical and spectroscopic analysis of mono- and multi-tip pulsed corona discharges in air at atmospheric pressure

International Nuclear Information System (INIS)

Mraihi, A; Merbahi, N; Yousfi, M; Abahazem, A; Eichwald, O

2011-01-01

This work is devoted to the analysis of experimental results obtained in dry air at atmospheric pressure in a positive point-to-plane corona discharge under a pulsed applied voltage in the cases of anodic mono- and multi-tips. In the mono-tip case, the peak corona current is analysed as a function of several experimental parameters such as magnitude, frequency and duration of pulsed voltage and gap distance. The variation of the corona discharge current is correlated with the ozone production. Then in the multi-tip case, the electrical behaviour is analysed as a function of the distance between two contiguous tips and the tip number in order to highlight the region of creation active species for the lowest dissipated power. Intensified charge-coupled device pictures and electric field calculations as a function of inter-tip distance are performed to analyse the mutual effect between two contiguous tips. The optical emission spectra are measured in the UV–visible–NIR wavelength range between 200 nm and 800 nm, in order to identify the main excited species formed in an air corona discharge such as the usual first and second positive systems with first negative systems of molecular nitrogen. The identification of atomic species (O triplet and N) and the quenching of NOγ emission bands are also emphasized.

Warm gas towards young stellar objects in Corona Australis

DEFF Research Database (Denmark)

Lindberg, Johan; Jørgensen, Jes Kristian; D. Green, Joel

2014-01-01

The effects of external irradiation on the chemistry and physics in the protostellar envelope around low-mass young stellar objects are poorly understood. The Corona Australis star-forming region contains the R CrA dark cloud, comprising several low-mass protostellar cores irradiated by an interm......The effects of external irradiation on the chemistry and physics in the protostellar envelope around low-mass young stellar objects are poorly understood. The Corona Australis star-forming region contains the R CrA dark cloud, comprising several low-mass protostellar cores irradiated...... by an intermediate-mass young star. We study the effects on the warm gas and dust in a group of low-mass young stellar objects from the irradiation by the young luminous Herbig Be star R CrA. Herschel/PACS far-infrared datacubes of two low-mass star-forming regions in the R CrA dark cloud are presented...... Be star R CrA. Our results show that a nearby luminous star does not increase the molecular excitation temperatures in the warm gas around a young stellar object (YSO). However, the emission from photodissociation products of H2O, such as OH and O, is enhanced in the warm gas associated...

Mass ejections from the solar corona into interplanetary space

International Nuclear Information System (INIS)

Hildner, E.

1977-01-01

Mass ejections from the corona are common occurrances, as observations with the High Altitude Observatory's white light coronagraph aboard Skylab showed. During 227 days of operation in 1973 and 1974 at least 77 mass ejections were observed and as many more probably occurred unobserved. It is suggested that the frequency of ejections varies with the solar cycle and that ejections may contribute 10 percent or more of the total solar mass efflux to the interplanetary medium at solar maximum. Since ejections are confined to relatively low latitudes, their fractional mass flux contribution is greater near the ecliptic than far from it. From the behavior of ejecta, we can estimate the magnitude of the force driving them through the corona. It is also suggested that loop-shaped ejection - the largest fraction of ejections - are driven, primarily, by magnetic forces. By comparison, gas pressure forces are negligible, and forces due to wave pressure are completely inadequate. That magnetic forces are important is consistent with observation that ejections seem to come, primarily, from regions where the magnetic field is more intense and more complex than elsewhere. Indeed, ejections are associated with phenomena (flares and eruptive prominences) which occur over lines separating regions of opposite polarities. (Auth.)

Corona-producing ice clouds: A case study of a cold mid-latitude cirrus layer

International Nuclear Information System (INIS)

Sassen, K.; Mace, G.G.; Hallett, J.; Poellot, M.R.

1998-01-01

A high (14.0-km), cold (-71.0thinsp degree C) cirrus cloud was studied by ground-based polarization lidar and millimeter radar and aircraft probes on the night of 19 April 1994 from the Cloud and Radiation Testbed site in northern Oklahoma. A rare cirrus cloud lunar corona was generated by this 1 - 2-km-deep cloud, thus providing an opportunity to measure the composition in situ, which had previously been assumed only on the basis of lidar depolarization data and simple diffraction theory for spheres. In this case, corona ring analysis indicated an effective particle diameter of ∼22 μm. A variety of in situ data corroborates the approximate ice-particle size derived from the passive retrieval method, especially near the cloud top, where impacted cloud samples show simple solid crystals. The homogeneous freezing of sulfuric acid droplets of stratospheric origin is assumed to be the dominant ice-particle nucleation mode acting in corona-producing cirrus clouds. It is speculated that this process results in a previously unrecognized mode of acid-contaminated ice-particle growth and that such small-particle cold cirrus clouds are potentially a radiatively distinct type of cloud. copyright 1998 Optical Society of America

Skylab and solar exploration. [chromosphere-corona structure, energy production and heat transport processes

Science.gov (United States)

Von Puttkamer, J.

1973-01-01

Review of some of the findings concerning solar structure, energy production, and heat transport obtained with the aid of the manned Skylab space station observatory launched on May 14, 1973. Among the topics discussed are the observation of thermonuclear fusion processes which cannot be simulated on earth, the observation of short-wave solar radiation not visible to observers on earth, and the investigation of energy-transport processes occurring in the photosphere, chromosphere, and corona. An apparent paradox is noted in that the cooler chromosphere is heating the hotter corona, seemingly in defiance of the second law of thermodynamics, thus suggesting that a nonthermal mechanism underlies the energy transport. Understanding of this nonthermal mechanism is regarded as an indispensable prerequisite for future development of plasma systems for terrestrial applications.

Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

CERN Document Server

Malik, M A; Ghaffar, A; Ahmed, K

2002-01-01

The effect of O sub 2 and O sub 3 bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 M OMEGA resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l sup - sup 1 methylene blue in distilled water was decolourized in 120 min. Bubbling O sub 2 at 10 ml min sup - sup 1 through the discharge region reduced the decolourization time to 25 min. Bubbling O sub 2 containing 1500 mu mol O sub 3 l sup - sup 1 at 10 ml min sup - sup 1 reduced the decolourization time to 8 min. The O sub 3 was produced by fractionating input energy between a water treatment reactor and a O sub 3 generator, i.e. no additional energy was consumed for O sub 3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in...

Synchronized observations of bright points from the solar photosphere to the corona

Science.gov (United States)

Tavabi, Ehsan

2018-05-01

One of the most important features in the solar atmosphere is the magnetic network and its relationship to the transition region (TR) and coronal brightness. It is important to understand how energy is transported into the corona and how it travels along the magnetic field lines between the deep photosphere and chromosphere through the TR and corona. An excellent proxy for transportation is the Interface Region Imaging Spectrograph (IRIS) raster scans and imaging observations in near-ultraviolet (NUV) and far-ultraviolet (FUV) emission channels, which have high time, spectral and spatial resolutions. In this study, we focus on the quiet Sun as observed with IRIS. The data with a high signal-to-noise ratio in the Si IV, C II and Mg II k lines and with strong emission intensities show a high correlation with TR bright network points. The results of the IRIS intensity maps and dopplergrams are compared with those of the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) instruments onboard the Solar Dynamical Observatory (SDO). The average network intensity profiles show a strong correlation with AIA coronal channels. Furthermore, we applied simultaneous observations of the magnetic network from HMI and found a strong relationship between the network bright points in all levels of the solar atmosphere. These features in the network elements exhibited regions of high Doppler velocity and strong magnetic signatures. Plenty of corona bright points emission, accompanied by the magnetic origins in the photosphere, suggest that magnetic field concentrations in the network rosettes could help to couple the inner and outer solar atmosphere.

Synoptic, Global Mhd Model For The Solar Corona

Science.gov (United States)

Cohen, Ofer; Sokolov, I. V.; Roussev, I. I.; Gombosi, T. I.

2007-05-01

The common techniques for mimic the solar corona heating and the solar wind acceleration in global MHD models are as follow. 1) Additional terms in the momentum and energy equations derived from the WKB approximation for the Alfv’en wave turbulence; 2) some empirical heat source in the energy equation; 3) a non-uniform distribution of the polytropic index, γ, used in the energy equation. In our model, we choose the latter approach. However, in order to get a more realistic distribution of γ, we use the empirical Wang-Sheeley-Arge (WSA) model to constrain the MHD solution. The WSA model provides the distribution of the asymptotic solar wind speed from the potential field approximation; therefore it also provides the distribution of the kinetic energy. Assuming that far from the Sun the total energy is dominated by the energy of the bulk motion and assuming the conservation of the Bernoulli integral, we can trace the total energy along a magnetic field line to the solar surface. On the surface the gravity is known and the kinetic energy is negligible. Therefore, we can get the surface distribution of γ as a function of the final speed originating from this point. By interpolation γ to spherically uniform value on the source surface, we use this spatial distribution of γ in the energy equation to obtain a self-consistent, steady state MHD solution for the solar corona. We present the model result for different Carrington Rotations.

Biofertilizing efficiency of Sargassum polycystum extract on growth and biochemical composition of Vigna radiata and Vigna mungo

Directory of Open Access Journals (Sweden)

B Bharath

2018-01-01

Full Text Available Objective: To evaluate the effect of marine brown alga Sargassum polycystum extract on growth and biochemical parameters of Vigna radiata and Vigna mungo.Methods: Different concentrations of algal extracts (0.5%, 1.0%, 2.0%, 3.0%, 4.0%, and 5.0% were prepared and applied to the crops at every 10-day intervals under natural conditions. After 30 d, the plants were harvested to evaluate the growth and biochemical parameters.Results: Seaweed liquid fertilizers treated seedlings showed maximum growth in 3.0% concentration when compared to the untreated seedlings. Similarly, biochemical parameters such as photosynthetic pigments, protein, reducing sugar, total sugar and amino acids exhibited increases in 3.0% concentration seaweed extract. Decreases in growth and biochemical parameters were noticed in concentrations higher than 3.0%.Conclusions: Presence of micronutrients and growth regulating substances in the liquid extract help healthier and faster productivity of the crop.

Corona magnetic field over sunspots estimated by m-wave observation

International Nuclear Information System (INIS)

Kurihara, Masahiro

1974-01-01

The shape of the magnetic field in corona was estimated from the observation of the type I storm occurred in the last decade of August, 1971. It was found from the observation with a 160 MHz interferometer at Mt. Nobeyama that at most three storm sources, which are called radio wave source, were produced. The radio wave sources were fixed above sunspots. The height of the radio wave sources was estimated to be 0.45 R from the photosphere. The sunspots under the radio wave sources can be classified to four sub-groups. Weakening of the magnetic field on the photosphere was found from the reduction of the area of some sub-group. The relation between the activity of type I storm and the intensity of the magnetic field of sunspots is qualitatively suggested. It is considered that the radio wave sources and the sunspots were connected by common magnetic force lines. The probable magnetic field in corona was presumed and is shown in a figure. An interesting point is that the direction of magnetic force lines inclined by about 30 0 outward to the vertical line to the photosphere surface. (Kato, T.)

Anomalous energy transport in hot plasmas: solar corona and Tokamak

International Nuclear Information System (INIS)

Beaufume, P.

1992-04-01

Anomalous energy transport is studied in two hot plasmas and appears to be associated with a heating of the solar corona and with a plasma deconfining process in tokamaks. The magnetic structure is shown to play a fundamental role in this phenomenon through small scale instabilities which are modelized by means of a nonlinear dynamical system: the Beasts' Model. Four behavior classes are found for this system, which are automatically classified in the parameter space thanks to a neural network. We use a compilation of experimental results relative to the solar corona to discuss current-based heating processes. We find that a simple Joule effect cannot provide the required heating rates, and therefore propose a dimensional model involving a resistive reconnective instability which leads to an efficient and discontinuous heating mechanism. Results are in good agreement with the observations. We give an analytical expression for a diffusion coefficient in tokamaks when magnetic turbulence is perturbing the topology, which we validate thanks to the standard mapping. A realistic version of the Beasts' Model allows to test a candidate to anomalous transport: the thermal filamentation instability

Gamma rays in L-B coordinates at CORONAS-I altitude

Directory of Open Access Journals (Sweden)

I. N. Myagkova

2005-09-01

Full Text Available We present here observations of gamma rays in the energy range between 3.0 and 8.3 MeV gathered by the SONG instrument aboard low-altitude polar-orbiting satellite CORONAS-I throughout the period March-June 1994. We concentrate on the emissions related to the trapped particles and organize CORONAS-I measurements in the magnetic L–B coordinate system. The spatial distribution of the average gamma-ray counts reveals that the most intense fluxes were observed under the inner radiation belt, at L<2, and that they are exclusively confined into the region of stably trapped particles, where daughter gamma rays could result from the interactions within the spacecraft and instrumental matter. In the outer radiation zone (L~4, the enhanced gamma radiation, also detected outside the stably trapping region, shows pronounced longitudinal variations. The observed eastward increase in the gamma-ray count rate suggests quasi-traped energetic (megavolt electrons as a source of the gamma rays both in the upper atmosphere and in the satellite matter, most likely, through the bremsstrahlung process in the studied energy domain. Keywords. Magnetospheric physics (Energetic particles, precipitating; Energetic particles, trapped; Magnetosphereionosphere interactions

Ionization and Corona Discharges from Stressed Rocks

Science.gov (United States)

Winnick, M. J.; Kulahci, I.; Cyr, G.; Tregloan-Reed, J.; Freund, F. T.

2008-12-01

Pre-earthquake signals have long been observed and documented, though they have not been adequately explained scientifically. These signals include air ionization, occasional flashes of light from the ground, radio frequency emissions, and effects on the ionosphere that occur hours or even days before large earthquakes. The theory that rocks function as p-type semiconductors when deviatoric stresses are applied offers a mechanism for this group of earthquake precursors. When an igneous or high-grade metamorphic rock is subjected to deviatoric stresses, peroxy bonds that exist in the rock's minerals as point defects dissociate, releasing positive hole charge carriers. The positive holes travel by phonon-assisted electron hopping from the stressed into and through the unstressed rock volume and build up a positive surface charge. At sufficiently large electric fields, especially along edges and sharp points of the rock, air molecules become field-ionized, loosing an electron to the rock surface and turning into airborne positive ions. This in turn can lead to corona discharges, which manifest themselves by flashes of light and radio frequency emissions. We applied concentrated stresses to one end of a block of gabbro, 30 x 15 x 10 cm3, inside a shielded Faraday cage and observed positive ion currents through an air gap about 25 cm from the place where the stresses were applied, punctuated by short bursts, accompanied by flashes of light and radio frequency emissions characteristic of a corona discharge. These observations may serve to explain a range of pre-earthquake signals, in particular changes in air conductivity, luminous phenomena, radio frequency noise, and ionospheric perturbations.

The role of photoionization in negative corona discharge

Directory of Open Access Journals (Sweden)

B. X. Lu

2016-09-01

Full Text Available The effect of photoionization on the negative corona discharge was simulated based on the needle to plane air gaps. The Trichel pulse, pulse train, electron density and the distribution of electric field will be discussed in this manuscript. Effect of photoionization on the magnitude and interval of the first pulse will be discussed for different applied voltages. It is demonstrated that the peak of the first pulse current could be weakened by photoionization and a critical voltage of the first pulse interval influenced by photoionization was given.

An alternative mass model for galactic dark coronae

Directory of Open Access Journals (Sweden)

Ninković S.

2001-01-01

Full Text Available A spherically symmetric mass distribution with two scale parameters for the dark corona of a (spiral galaxy as an alternative to the usually applied quasi-isothermal sphere is considered. Examinations of the rotation curve produced by this distribution over a limited interval of the distance to the rotation axis show that it can be a successful alternative to the usual approximation of the quasiisothermal sphere. This is important taking into account that the potential formula considered in the present paper can be easily generalized towards axial symmetry.