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Sample records for acid-mediated callose deposition

  1. Dynamics of callose deposition and B-1,3-glucanase expression during reproductive events in sexual and apomictic Hieracium

    Tucker, M.R.; Paech, N.A.; Willemse, M.T.M.; Koltunow, A.M.G.

    2001-01-01

    Callose accumulates in the walls of cells undergoing megasporogenesis during embryo sac formation in angiosperm ovules. Deficiencies in callose deposition have been observed in apomictic plants and causal linkages between altered callose deposition and apomictic initiation proposed. In apomictic Hie

  2. Callose deposition during gravitropism of Zea mays and Pisum sativum and its inhibition by 2-deoxy-D-glucose

    Jaffe, M. J.; Leopold, A. C.

    1984-01-01

    In etiolated corn (Zea mays L.) and etiolated pea (Pisum sativum L.) seedlings, a gravitropic stimulation induces the deposition of callose. In the corn coleoptiles this occurs within 5 min of gravity stimulation, and prior to the beginning of curvature. Both gravitropic curvature and callose deposition reach their maxima by 12 h. Within the first 2 h more callose is deposited on the upper (concave) side, but after 2-3 h, this deposition pattern is reversed. An inhibitor of protein glycosylation, 2-deoxy-D-glucose (DDG), inhibits callose production and considerably retards gravitropic bending in both species of plants. Mannose can relieve the inhibition of gravitropic bending by DDG. The pea mutant "Ageotropum", which does not respond to gravity when etiolated, also fails to produce callose in response to a gravitic stimulus. These correlations indicate that callose deposition may be a biochemical component of gravitropism in plant shoots.

  3. The enhanced callose deposition in barley with ml-o powdery mildew resistance genes

    Skou, Jens-Peder

    1985-01-01

    Carborundum treatment of barley leaves induced a callose deposition which was detected as diffuse blotches in the epidermal cells of susceptible barleys and as deeply stained tracks along the scratches in barleys with the ml-o powdery mildew resistance gene. Subsequent inoculation with powdery...... mildew resulted in appositions that enlarged inversely to their size in the respective varieties when inoculated without carborundum treatment. Aphids sucking the leaves resulted in rows of callose containing spots along the anticlinal cell walls. The spots were larger in the ml-o mutant than...... in the mother variety. Callose was deposited in connection with the pleiotropic necrotic spotting in barleys with the ml-o gene. Modification of the necrotic spotting by crossing the ml-o gene into other gene backgrounds did not result in any change in the size of appositions upon inoculation with powdery...

  4. The enhanced callose deposition in barley with ml-o powdery mildew resistance genes

    Skou, Jens-Peder

    1985-01-01

    Carborundum treatment of barley leaves induced a callose deposition which was detected as diffuse blotches in the epidermal cells of susceptible barleys and as deeply stained tracks along the scratches in barleys with the ml-o powdery mildew resistance gene. Subsequent inoculation with powdery...

  5. Altered callose deposition during embryo sac formation of multi-pistil mutant (mp1) in Medicago sativa.

    Zhou, H C; Jin, L; Li, J; Wang, X J

    2016-01-01

    Whether callose deposition is the cause or result of ovule sterility in Medicago sativa remains controversial, because it is unclear when and where changes in callose deposition and dissolution occur during fertile and sterile embryo sac formation. Here, alfalfa spontaneous multi-pistil mutant (mp1) and wild-type plants were used to compare the dynamics of callose deposition during embryo sac formation using microscopy. The results showed that both mutant and wild-type plants experienced megasporogenesis and megagametogenesis, and there was no significant difference during megasporogenesis. In contrast to the wild-type plants, in which the mature embryo sac was observed after three continuous cycles of mitosis, functional megaspores of mutant plants developed abnormally after the second round of mitosis, leading to degeneration of synergid, central, and antipodal cells. Callose deposition in both mutant and wild-type plants was first observed in the walls of megasporocytes, and then in the megaspore tetrad walls. After meiosis, the callose wall began to degrade as the functional megaspore underwent mitosis, and almost no callose was observed in the mature embryo sac in wild-type plants. However, callose deposition was observed in mp1 plants around the synergid, and increased with the development of the embryo sac, and was mainly deposited at the micropylar end. Our results indicate that synergid, central, and antipodal cells, which are surrounded by callose, may degrade owing to lack of nutrition. Callose accumulation around the synergid and at the micropylar end may hinder signals required for the pollen tube to enter the embryo sac, leading to abortion. PMID:27323128

  6. Iron-dependent callose deposition adjusts root meristem maintenance to phosphate availability.

    Müller, Jens; Toev, Theresa; Heisters, Marcus; Teller, Janine; Moore, Katie L; Hause, Gerd; Dinesh, Dhurvas Chandrasekaran; Bürstenbinder, Katharina; Abel, Steffen

    2015-04-20

    Plant root development is informed by numerous edaphic cues. Phosphate (Pi) availability impacts the root system architecture by adjusting meristem activity. However, the sensory mechanisms monitoring external Pi status are elusive. Two functionally interacting Arabidopsis genes, LPR1 (ferroxidase) and PDR2 (P5-type ATPase), are key players in root Pi sensing, which is modified by iron (Fe) availability. We show that the LPR1-PDR2 module facilitates, upon Pi limitation, cell-specific apoplastic Fe and callose deposition in the meristem and elongation zone of primary roots. Expression of cell-wall-targeted LPR1 determines the sites of Fe accumulation as well as callose production, which interferes with symplastic communication in the stem cell niche, as demonstrated by impaired SHORT-ROOT movement. Antagonistic interactions of Pi and Fe availability control primary root growth via meristem-specific callose formation, likely triggered by LPR1-dependent redox signaling. Our results link callose-regulated cell-to-cell signaling in root meristems to the perception of an abiotic cue. PMID:25898169

  7. Sr36- and Sr5-Mediated Resistance Response to Puccinia graminis f. sp. tritici Is Associated with Callose Deposition in Wheat Guard Cells.

    Wang, X; McCallum, B D; Fetch, T; Bakkeren, G; Saville, B J

    2015-06-01

    Race-specific resistance of wheat to Puccinia graminis f. sp. tritici is primarily posthaustorial and often involves the induction of a hypersensitive response (HR). The aim of this study was to investigate host defense responses induced in interactions between P. graminis f. sp. tritici races and wheat lines carrying different race-specific stem rust resistance (Sr) genes. In incompatible interactions between wheat lines carrying Sr36 in three genetic backgrounds (LMPG, Prelude, or W2691) and avirulent P. graminis f. sp. tritici races MCCFC or RCCDM, callose accumulated within 24 h in wheat guard cells contacted by a P. graminis f. sp. tritici appressorium, and P. graminis f. sp. tritici ingress was inhibited following appressorium formation. Accordingly, the expression of transcripts encoding a callose synthase increased in the incompatible interaction between LMPG-Sr36 and avirulent P. graminis f. sp. tritici race MCCFC. Furthermore, the inhibition of callose synthesis through the infiltration of 2-deoxy-D-glucose (DDG) increased the ability of P. graminis f. sp. tritici race MCCFC to infect LMPG-Sr36. A similar induction of callose deposition in wheat guard cells was also observed within 24 h after inoculation (hai) with avirulent P. graminis f. sp. tritici race HKCJC on LMPG-Sr5 plants. In contrast, this defense response was not induced in incompatible interactions involving Sr6, Sr24, or Sr30. Instead, the induction of an HR and cellular lignification were noted. The manifestation of the HR and cellular lignification was induced earlier (24 hai) and was more extensive in the resistance response mediated by Sr6 compared with those mediated by Sr24 or Sr30. These results indicate that the resistance mediated by Sr36 is similar to that mediated by Sr5 but different from those triggered by Sr6, Sr24, or Sr30. Resistance responses mediated by Sr5 and Sr36 are prehaustorial, and are a result of very rapid recognition of molecules derived from avirulent isolates of

  8. An Arabidopsis callose synthase

    Ostergaard, Lars; Petersen, Morten; Mattsson, Ole;

    2002-01-01

    unclear whether callose synthases can also produce cellulose and whether plant cellulose synthases may also produce beta-1,3-glucans. We describe here an Arabidopsis gene, AtGsl5, encoding a plasma membrane-localized protein homologous to yeast beta-1,3-glucan synthase whose expression partially......Beta-1,3-glucan polymers are major structural components of fungal cell walls, while cellulosic beta-1,4-glucan is the predominant polysaccharide in plant cell walls. Plant beta-1,3-glucan, called callose, is produced in pollen and in response to pathogen attack and wounding, but it has been...

  9. Isolated complete corpus callosal agenesis

    Jaiganesh S, Venkateshwaran A, Naresh Kumar C, Rajasekhar KV

    2014-11-01

    Full Text Available Isolated complete corpus callosal agenesis is a rare entity. Usually this condition will be an associated finding in other syndromes. 3 month old male child came with complaints of deformed foot on both sides, not having a social smile and neck holding. Patient referred to the Radiology department for MRI brain which showed complete absence of corpus callosum, widely separated and parallely placed lateral ventricles, colpocephaly, high riding of 3rd ventricle and absence of cingulate gyrus and radial arrangement of gyri along the interhemispheric fissure. Hence it was reported as isolated complete corpus callosal agenesis and this article describes the Embryogenesis, anatomy, developmental anomalies and its clinical manifestations & prognosis.

  10. Callosal alterations in pyridoxine-dependent epilepsy

    Friedman, S.D.; Ishak, G.E.; Poliachik, S.L.; Poliakov, A.V.; Otto, R.K.; Shaw, D.W.; Willemsen, M.A.A.P.; Bok, L.A.; Gospe, S.M., Jr.

    2014-01-01

    AIM: While there have been isolated reports of callosal morphology differences in pyridoxine-dependent epilepsy (PDE), a rare autosomal disorder caused by ALDH7A1 gene mutations, no study has systematically evaluated callosal features in a large sample of patients. This study sought to overcome this

  11. PNA-based DNA assay with attomolar detection limit based on polygalacturonic acid mediated in-situ deposition of metallic silver on a gold electrode

    An electrochemical method is described for the ultrasensitive determination of sequence-specific DNA by using polysaccharide-mediated in-situ deposition of metallic silver on a gold electrode. Specifically, a thiolated peptide nucleic acid (PNA) is immobilized on the gold electrode via formation of a self-assembled monolayer. Following hybridization between PNA and target single-stranded DNA (ssDNA), polygalacturonic acid (PGUA) is introduced to the PNA/DNA heteroduplexes via phosphate-zirconium-carboxylate coordination interaction. Next, the vicinal hydroxy groups of the polysaccharide backbone are cleaved and oxidized into aldehyde groups. These act as reductants and convert added silver ions into metallic silver which in-situ deposits on the gold electrode, and then is stripped off electrochemically into a solution of KCl where it is accurately determined by differential pulse voltammetry. Under optimal conditions, this assay exhibits a wide linear response range in that the stripping current is related to the logarithm of the concentration of target ssDNA in the 0.1 fM to 10 pM range, with a detection limit as low as 2.5 aM. The method displays excellent specificity in clearly differentiating mismatched oligonucleotide fragments. We therefore believe that this method has a large potential in terms of genotyping of single-nucleotide polymorphism. Moreover, this kind of signal amplification possesses a very large capability with respect to ultrasensitive quantitation of low-abundant biomarkers. (author)

  12. Role of callose synthases in transfer cell wall development in tocopherol deficient Arabidopsis mutants

    Hiroshi eMaeda

    2014-02-01

    Full Text Available Tocopherols (vitamin E are lipid-soluble antioxidants produced by all plants and algae, and many cyanobacteria, yet their functions in these photosynthetic organisms are still not fully understood. We have previously reported that the vitamin E deficient 2 (vte2 mutant of Arabidopsis thaliana is sensitive to low temperature (LT due to impaired transfer cell wall (TCW development and photoassimilate export, associated with massive callose deposition in transfer cells of the phloem. To further understand the role of tocopherols in LT induced TCW development we compared global transcript profiles of vte2 and wild type leaves during LT treatment. Tocopherol deficiency had no impact on global gene expression in permissive conditions, but affected expression of 77 genes after 48 hours of LT treatment. In vte2 relative to wild type, genes related with solute transport were repressed, while those involved in various pathogen responses and cell wall modifications, such as GLUCAN SYNTHASE LIKE genes (GSL4 and GSL11, were induced. However, introduction of gsl4 or gsl11 mutations into the vte2 background did not suppress callose deposition or the overall LT-induced phenotypes of vte2. Intriguingly, introduction of a mutation of GSL5, the major GSL responsible for pathogen-induced callose deposition, into vte2 substantially reduced vascular callose deposition at LT, but again had no effect on the photoassimilate export phenotype of LT-treated vte2. These results suggest that GSL5 plays a major role in TCW callose deposition in LT-treated vte2 but that this GSL5-dependent callose deposition is not the primary cause of the impaired photoassimilate export phenotype.

  13. Distinctive patterns of callose deposition provide an early sign of ovule abortion1 in the andromonoecious shrub Caesalpinia gilliesii Patrones distintivos de deposición de calosa proveen evidencia temprana de aborto de óvulos en el arbusto andromonoico Caesalpinia gilliesii

    A. Calviño

    2009-07-01

    Full Text Available Ovule abortion may lead to the partial or complete reduction of the number of functional ovules in the ovary and then is the primary factor that determines the sexual expression of the plant. In different species, ovule abortion was associated with the presence of callose in advanced ovules. Based on these observations, we studied the pattern of ovule development and callose deposition in both perfect and staminate flowers of the andromonoecious shrub Caesalpinia gilliesii. The obtained results showed that all ovules reached the 8-nucleate stage of embryo sac development and exhibited callose deposition at advanced stages. Nevertheless, from the 2-nucleate stage, a distinct spatial pattern of callose deposition within the ovule was observed between perfect and staminate flowers. Differences in callose deposition suggest that not callose per se but its distribution pattern in the ovule tissues is the main factor that triggers ovule isolation and abortion and leads to flowers with non-functional pistils in this species. Furthermore, previous observed differential growth rates between perfect and staminate flowers support for resource depletion as the likely underlying mechanism of ovule fate in C. gilliesii.El aborto de óvulos puede llevar a la reducción parcial o completa de óvulos fértiles en el ovario, pudiendo ser entonces un factor primario que determine la expresión sexual de toda la planta. En diferentes especies de plantas, el aborto de los óvulos ha sido asociado con la presencia de calosa en estadios avanzados del desarrollo de los óvulos. Basado en estas observaciones, se estudiaron el desarrollo de los óvulos y el patrón de deposición de calosa tanto en flores perfectas como estaminadas en el arbusto andromonoico C. gilliesii. Los resultados obtenidos muestran que los sacos embrionarios alcanzan el estadio de desarrollo 8-nucleado en todos los óvulos, y que presentan deposición de calosa en los estadios avanzados. Sin

  14. Conflict of intentions due to callosal disconnection

    Nishikawa, T.; Okuda, J; MIZUTA, I; Ohno, K.; Jamshidi, J; Tokunaga, H.; Ikejiri, Y; Nakagawa, Y.; Yoshimine, T.; Tanabe, H; Takeda, M.

    2001-01-01

    OBJECTIVES—Three patients with callosal syndrome manifested a peculiar symptom in that they were unable to perform intended whole body actions because another intention emerged in competition with the original one. Attempts were made to clarify the symptomatology of this manifestation and its possible mechanism is discussed.
METHODS—The three patients are described and previous reports on patients with callosal damage were reviewed. Four additional patients with similar s...

  15. Callosal Disconnection Syndrome Associated with Relapsing Polychondritis.

    Baba, Toru; Kanno, Shigenori; Shijo, Tomomi; Nishio, Yoshiyuki; Iizuka, Osamu; Kamimura, Naoto; Ishii, Tomonori; Mori, Etsuro

    2016-01-01

    Relapsing polychondritis (RP) is a rare inflammatory disorder of the cartilagenous structures, and it sometimes involves the central nervous system. Encephalitis associated with RP causes a wide variety of symptoms according to the affected sites. We herein report the first case of 72-year-old right-handed man who developed acute meningoencephalitis associated with RP involving the corpus callous. After immunosuppressive therapy, his symptoms dramatically improved, but difficulty in performing bimanual movements with occasional diagonistic dyspraxia in his right hand remained. Because callosal signs are easily missed, especially in acute settings, it would be useful to know that RP can sometimes cause callosal disconnection syndrome. PMID:27150878

  16. Selective serotonergic excitation of callosal projection neurons

    Daniel eAvesar

    2012-03-01

    Full Text Available Serotonin (5-HT acting as a neurotransmitter in the cerebral cortex is critical for cognitive function, yet how 5-HT regulates information processing in cortical circuits is not well understood. We tested the serotonergic responsiveness of layer 5 pyramidal neurons (L5PNs of the mouse medial prefrontal cortex (mPFC, and found 3 distinct response types: long-lasting 5-HT1A (1A receptor-dependent inhibitory responses (84% of L5PNs, 5-HT2A (2A receptor-dependent excitatory responses (9%, and biphasic responses in which 2A-dependent excitation followed brief inhibition (5%. Relative to 5-HT-inhibited neurons, those excited by 5-HT had physiological properties characteristic of callosal/commissural (COM neurons that project to the contralateral cortex. We tested whether serotonergic responses in cortical pyramidal neurons are correlated with their axonal projection pattern using retrograde fluorescent labeling of COM and corticopontine-projecting (CPn neurons. 5-HT generated excitatory or biphasic responses in all 5-HT-responsive layer 5 COM neurons. Conversely, CPn neurons were universally inhibited by 5-HT. Serotonergic excitation of COM neurons was blocked by the 2A antagonist MDL 11939, while serotonergic inhibition of CPn neurons was blocked by the 1A antagonist WAY 100635, confirming a role for these two receptor subtypes in regulating pyramidal neuron activity. Selective serotonergic excitation of COM neurons was not layer-specific, as COM neurons in layer 2/3 were also selectively excited by 5-HT relative to their non-labeled pyramidal neuron neighbors. Because neocortical 2A receptors are implicated in the etiology and pathophysiology of schizophrenia, we propose that COM neurons may represent a novel cellular target for intervention in psychiatric disease.

  17. Callose Synthase Family Genes Involved in the Grapevine Defense Response to Downy Mildew Disease.

    Yu, Ying; Jiao, Li; Fu, Shufang; Yin, Ling; Zhang, Yali; Lu, Jiang

    2016-01-01

    The deposition of callose is a common plant defense response to intruding pathogens and part of the plant's innate immunity. In this study, eight grapevine callose synthase (CalS) genes were identified and characterized. To investigate biological function of CalS in grapevine against the infection of Plasmopara viticola, expression patterns of grapevine CalS family genes were analyzed among resistant/susceptible cultivars. After P. viticola infection, expression of CalS1, 3, 7, 8, 9, 10, and 11 were significantly modified among the grapevine cultivars. For example, the expression of CalS1 and CalS10 were greatly increased in downy mildew (DM)-immune Muscadinia rotundifolia 'Carlos' and 'Noble'. Transient expression assay with promoters of the CalS1 and CalS10 genes confirmed that they were regulated by the oomycete pathogen P. viticola. CalS1 promoter activity was also significantly up-regulated by ABA in DM-immune M. rotundifolia 'Noble', but down-regulated in DM-susceptible Vitis vinifera 'Chardonnay'. The CalS1 promoter, however, was also down-regulated by GA in 'Chardonnay', but not affected in 'Noble'. The promoter activity of CalS10 was significantly up-regulated by GA in 'Chardonnay', but not regulated by ABA at all. It is proposed that CalS1 and CalS10 were involved in grapevine defense against DM disease. PMID:26474330

  18. Electrophysiological Correlates of Morphological Neuroplasticity in Human Callosal Dysgenesis

    Lazarev, Vladimir V.; de Carvalho Monteiro, Myriam; Vianna-Barbosa, Rodrigo; deAzevedo, Leonardo C.; Lent, Roberto; Tovar-Moll, Fernanda

    2016-01-01

    In search for the functional counterpart of the alternative Probst and sigmoid bundles, considered as morphological evidence of neuroplasticity in callosal dysgenesis, electroencephalographic (EEG) coherence analysis was combined with high resolution and diffusion tensor magnetic resonance imaging. Data of two patients with callosal agenesis, plus two with typical partial dysgenesis with a remnant genu, and one atypical patient with a substantially reduced genu were compared to those of fifteen neurotypic controls. The interhemispheric EEG coherence between homologous nontemporal brain regions corresponded to absence or partial presence of callosal connections. A generalized coherence reduction was observed in complete acallosal patients, as well as coherence preservation in the anterior areas of the two patients with a remnant genu. jThe sigmoid bundles found in three patients with partial dysgenesis correlated with augmented EEG coherence between anterior regions of one hemisphere and posterior regions of the other. These heterologous (crossed) interhemispheric connections were asymmetric in both imaging and EEG patterns, with predominance of the right-anterior-to-left-posterior connections over the mirror ones. The Probst bundles correlated with higher intrahemispheric long-distance coherence in all patients. The significant correlations observed for the delta, theta and alpha bands indicate that these alternative pathways are functional, although the neuropsychological nature of this function is still unknown. PMID:27055255

  19. Comparative Studies on Callose Formation in Powdery Mildew Compatible and Incompatible Barley

    Skou, Jens-Peder; Jørgensen, Jørgen Helms; Lilholt, Ulla

    1984-01-01

    Callose formation in barley mutants, lines and varieties with different genes for resistance to powdery mildew in seven different loci was compared. Only barley with resistance genes in the ml-o locus showed so early a callose formation passing off at such a high rate that it prevented fungal pen...

  20. Diffusion Weighted Callosal Integrity Reflects Interhemispheric Communication Efficiency in Multiple Sclerosis

    Warlop, Nele P.; Achten, Eric; Debruyne, Jan; Vingerhoets, Guy

    2008-01-01

    We aimed to investigate the relation between damage in the corpus callosum and the performance on an interhemispheric communication task in patients with multiple sclerosis (MS). Relative callosal lesion load defined as the ratio between callosal area and the total lesion load in the total corpus callosum, and the diffusion tensor imaging (DTI)…

  1. Callosal lesions and behavior: history and modern concepts.

    Devinsky, Orrin; Laff, Rachel

    2003-12-01

    Callosotomy has played a unique role in the treatment of epilepsy and in the understanding of human brain function. The pioneering work of Dejerine and Liepmann presenting the first findings of callosal lesion pathology at the turn of the 20th century was accepted but then quickly forgotten. Two schools resurrected the phoenix of callosal syndromes: Roger Sperry and Michael Gazzaniga leading in experimental neuroscience, and Norman Geschwind leading in clinical neurology. Callosotomy remains an effective technique to treat atonic, tonic, and tonic-clonic seizures, especially in patients with symptomatic generalized epilepsies such as Lennox-Gastaut syndrome. Neurologic, cognitive, and behavioral complications limit its use given that precise characterization of these complications as well as their frequency is difficult. The high frequencies of developmental delays, severe seizures, head injuries, antiepileptic drug burden, and other factors limit the ability to attribute a specific change to surgical intervention, since surgery can change multiple factors. For example, subtle behavioral changes in executive function and personality are difficult to delineate in a population with preexisting neurologic and psychiatric disorders. Despite this, a clearer picture of the effects of callosotomy, as defined by clinical neurology and neuropsychology as well as cognitive neuroscience, is emerging. PMID:14698693

  2. Motor callosal disconnection in early relapsing-remitting multiple sclerosis.

    Wahl, Mathias; Hübers, Annemarie; Lauterbach-Soon, Birgit; Hattingen, Elke; Jung, Patrick; Cohen, Leonardo G; Ziemann, Ulf

    2011-06-01

    In relapsing-remitting multiple sclerosis (RRMS) the corpus callosum (CC) is often and early affected by macroscopic lesions when investigated by conventional MRI. We sought to determine to which extent microstructural and effective disconnection of the CC are already present in RRMS patients at the earliest stages of the disease prior to evidence of macroscopic CC lesion. We compared 16 very early RRMS patients (median expanded disability status scale (EDSS), 1.5; range, 0-2.0) to an age-matched group of healthy controls and focused analysis to the motor CC, i.e. that part of the CC relaying interhemispheric motor information. A combined functional magnetic resonance imaging/diffusion tensor imaging fiber-tracking procedure was applied to identify the callosal motor fibers (CMFs) connecting the hand areas of the primary motor cortices of the two hemispheres. Fractional anisotropy (FA) within the motor CC (FA-CC) assessed the CMF microstructural integrity. Bifocal paired transcranial magnetic stimulation (TMS) tested short-interval interhemispheric inhibition (S-IHI), an established measure of CMF effective connectivity. FA-CC and S-IHI were significantly reduced in early RRMS compared to healthy controls. Furthermore, a significant linear correlation between microstructure (FA-CC) and function (S-IHI) in the controls was broken down in the patients. These abnormalities were obtained in the absence of macroscopic CMF lesion in conventional MRI, and whilst motor hand/arm function in the nine-hole-peg test and corticospinal conduction time were normal. Findings suggest that reductions in FA and S-IHI may serve as surrogate markers of motor callosal disconnection at the earliest stages of RRMS prior to development of macroscopic lesion. PMID:21495114

  3. A family of conserved bacterial effectors inhibits salicylic acid-mediated basal immunity and promotes disease necrosis in plants.

    DebRoy, Sruti; Thilmony, Roger; Kwack, Yong-Bum; Nomura, Kinya; He, Sheng Yang

    2004-06-29

    Salicylic acid (SA)-mediated host immunity plays a central role in combating microbial pathogens in plants. Inactivation of SA-mediated immunity, therefore, would be a critical step in the evolution of a successful plant pathogen. It is known that mutations in conserved effector loci (CEL) in the plant pathogens Pseudomonas syringae (the Delta CEL mutation), Erwinia amylovora (the dspA/E mutation), and Pantoea stewartii subsp. stewartii (the wtsE mutation) exert particularly strong negative effects on bacterial virulence in their host plants by unknown mechanisms. We found that the loss of virulence in Delta CEL and dspA/E mutants was linked to their inability to suppress cell wall-based defenses and to cause normal disease necrosis in Arabidopsis and apple host plants. The Delta CEL mutant activated SA-dependent callose deposition in wild-type Arabidopsis but failed to elicit high levels of callose-associated defense in Arabidopsis plants blocked in SA accumulation or synthesis. This mutant also multiplied more aggressively in SA-deficient plants than in wild-type plants. The hopPtoM and avrE genes in the CEL of P. syringae were found to encode suppressors of this SA-dependent basal defense. The widespread conservation of the HopPtoM and AvrE families of effectors in various bacteria suggests that suppression of SA-dependent basal immunity and promotion of host cell death are important virulence strategies for bacterial infection of plants. PMID:15210989

  4. Why Size Matters: Differences in Brain Volume Account for Apparent Sex Differences in Callosal Anatomy

    Luders, Eileen; Toga, Arthur W.; Thompson, Paul M.

    2013-01-01

    Numerous studies have demonstrated a sexual dimorphism of the human corpus callosum. However, the question remains if sex differences in brain size, which typically is larger in men than in women, or biological sex per se account for the apparent sex differences in callosal morphology. Comparing callosal dimensions between men and women matched for overall brain size may clarify the true contribution of biological sex, as any observed group difference should indicate pure sex effects. We thus...

  5. Tannic acid-mediated green synthesis of antibacterial silver nanoparticles.

    Kim, Tae Yoon; Cha, Song-Hyun; Cho, Seonho; Park, Youmie

    2016-04-01

    The search for novel antibacterial agents is necessary to combat microbial resistance to current antibiotics. Silver nanoparticles (AgNPs) have been reported to be effective antibacterial agents. Tannic acid is a polyphenol compound from plants with antioxidant and antibacterial activities. In this report, AgNPs were prepared from silver ions by tannic acid-mediated green synthesis (TA-AgNPs). The reaction process was facile and involved mixing both silver ions and tannic acid. The absorbance at 423 nm in the UV-Visible spectra demonstrated that tannic acid underwent a reduction reaction to produce TA-AgNPs from silver ions. The synthetic yield of TA-AgNPs was 90.5 % based on inductively coupled plasma mass spectrometry analysis. High-resolution transmission electron microscopy and atomic force microscopy images indicated that spherical-shaped TA-AgNPs with a mean particle size of 27.7-46.7 nm were obtained. Powder high-resolution X-ray diffraction analysis indicated that the TA-AgNP structure was face-centered cubic with a zeta potential of -27.56 mV. The hydroxyl functional groups of tannic acid contributed to the synthesis of TA-AgNPs, which was confirmed by Fourier transform infrared spectroscopy. The in vitro antibacterial activity was measured using the minimum inhibitory concentration (MIC) method. The TA-AgNPs were more effective against Gram-negative bacteria than Gram-positive bacteria. The MIC for the TA-AgNPs in all of the tested strains was in a silver concentration range of 6.74-13.48 μg/mL. The tannic acid-mediated synthesis of AgNPs afforded biocompatible nanocomposites for antibacterial applications. PMID:26895244

  6. New insight into silica deposition in horsetail (Equisetum arvense

    Exley Christopher

    2011-07-01

    Full Text Available Abstract Background The horsetails (Equisetum sp are known biosilicifiers though the mechanism underlying silica deposition in these plants remains largely unknown. Tissue extracts from horsetails grown hydroponically and also collected from the wild were acid-digested in a microwave oven and their silica 'skeletons' visualised using the fluor, PDMPO, and fluorescence microscopy. Results Silica deposits were observed in all plant regions from the rhizome through to the stem, leaf and spores. Numerous structures were silicified including cell walls, cell plates, plasmodesmata, and guard cells and stomata at varying stages of differentiation. All of the major sites of silica deposition in horsetail mimicked sites and structures where the hemicellulose, callose is known to be found and these serendipitous observations of the coincidence of silica and callose raised the possibility that callose might be templating silica deposition in horsetail. Hydroponic culture of horsetail in the absence of silicic acid resulted in normal healthy plants which, following acid digestion, showed no deposition of silica anywhere in their tissues. To test the hypothesis that callose might be templating silica deposition in horsetail commercially available callose was mixed with undersaturated and saturated solutions of silicic acid and the formation of silica was demonstrated by fluorimetry and fluorescence microscopy. Conclusions The initiation of silica formation by callose is the first example whereby any biomolecule has been shown to induce, as compared to catalyse, the formation of silica in an undersaturated solution of silicic acid. This novel discovery allowed us to speculate that callose and its associated biochemical machinery could be a missing link in our understanding of biosilicification.

  7. Persistent activation of microglia is associated with neuronal dysfunction of callosal projecting pathways and multiple sclerosis-like lesions in relapsing--remitting experimental autoimmune encephalomyelitis

    Rasmussen, Stine; Wang, Yue; Kivisäkk, Pia;

    2007-01-01

    Cortical pathology, callosal atrophy and axonal loss are substrates of progression in multiple sclerosis (MS). Here we describe cortical, periventricular subcortical lesions and callosal demyelination in relapsing-remitting experimental autoimmune encephalomyelitis in SJL mice that are similar to...

  8. Distribution of callose synthase, cellulose synthase, and sucrose synthase in tobacco pollen tube is controlled in dissimilar ways by actin filaments and microtubules

    Cai, G.; Faleri, C.; Casino, C.; Emons, A.M.C.; Cresti, M.

    2011-01-01

    Callose and cellulose are fundamental components of the cell wall of pollen tubes and are probably synthesized by distinct enzymes, callose synthase and cellulose synthase, respectively. We examined the distribution of callose synthase and cellulose synthase in tobacco (Nicotiana tabacum) pollen tub

  9. Cetalox and analogues: synthesis via acid-mediated polyene cyclizations.

    Snowden, Roger L

    2008-06-01

    Using a novel, acid-mediated cyclization methodology, a direct access to Cetalox ((+/-)-1; a commercially important ambergris-type odorant) and various structurally related didehydro (i.e., 19, 26, and 30) and tetradehydro (i.e., 28 and 37/38) analogues is described. Treatment of either (E,E)-14 or (E)-15 with an excess of FSO(3)H in 2-nitropropane at -90 degrees stereospecifically afforded (+/-)-1 in 40 and 42% yield, respectively. Under similar conditions, cyclization of (E)-18 or 20 furnished 19 in 60 and 64% yield, respectively. Analogously, using an excess of ClSO(3)H in CH(2)Cl(2) at -80 degrees, 26 is formed with high stereoselectivity by cyclization of either (E)-24 or (Z)-25 (52 and 31% yield, resp.); in the same manner, 28 was prepared from 27 (22% yield). The same principle was applied to the synthesis of racemic Superambrox (30), via cyclization of 35, but only with poor selectivity (22%) and low yield (7%). Another approach via cyclization of (E)-40 under solvolysis conditions (excess TFA in CH(2)Cl(2) at -10 degrees) gave a higher yield (15%) with improved selectivity (43%). Finally, cyclization of 34 (1:1 diastereoisomer mixture) afforded 37/38 (10:1) in 27% yield. The qualitative organoleptic properties of 19, 26, 28, 30, and 37/38 (10:1) are briefly discussed. PMID:18618391

  10. The PTI1-like kinase ZmPti1a from maize (Zea mays L. co-localizes with callose at the plasma membrane of pollen and facilitates a competitive advantage to the male gametophyte

    Wienand Udo

    2006-10-01

    Full Text Available Abstract Background The tomato kinase Pto confers resistance to bacterial speck disease caused by Pseudomonas syringae pv. tomato in a gene for gene manner. Upon recognition of specific avirulence factors the Pto kinase activates multiple signal transduction pathways culminating in induction of pathogen defense. The soluble cytoplasmic serine/threonine kinase Pti1 is one target of Pto phosphorylation and is involved in the hypersensitive response (HR reaction. However, a clear role of Pti1 in plant pathogen resistance is uncertain. So far, no Pti1 homologues from monocotyledonous species have been studied. Results Here we report the identification and molecular analysis of four Pti1-like kinases from maize (ZmPti1a, -b, -c, -d. These kinase genes showed tissue-specific expression and their corresponding proteins were targeted to different cellular compartments. Sequence similarity, expression pattern and cellular localization of ZmPti1b suggested that this gene is a putative orthologue of Pti1 from tomato. In contrast, ZmPti1a was specifically expressed in pollen and sequestered to the plasma membrane, evidently owing to N-terminal modification by myristoylation and/or S-acylation. The ZmPti1a:GFP fusion protein was not evenly distributed at the pollen plasma membrane but accumulated as an annulus-like structure which co-localized with callose (1,3-β-glucan deposition. In addition, co-localization of ZmPti1a and callose was observed during stages of pollen mitosis I and pollen tube germination. Maize plants in which ZmPti1a expression was silenced by RNA interference (RNAi produced pollen with decreased competitive ability. Hence, our data provide evidence that ZmPti1a plays an important part in a signalling pathway that accelerates pollen performance and male fitness. Conclusion ZmPti1a from maize is involved in pollen-specific processes during the progamic phase of reproduction, probably in crucial signalling processes associated with regions

  11. Perinatal testosterone exposure and cerebral lateralisation in adult males: evidence for the callosal hypothesis.

    Hollier, Lauren P; Maybery, Murray T; Keelan, Jeffrey A; Hickey, Martha; Whitehouse, Andrew J O

    2014-12-01

    Two competing theories address the influence of foetal testosterone on cerebral laterality: one proposing exposure to high foetal testosterone concentrations is related to atypical lateralisation (Geschwind-Galaburda hypothesis), the other that high foetal testosterone concentrations exaggerate typical lateralisation (callosal hypothesis). The current study examined the relationship between cord testosterone concentrations and cerebral laterality for language and spatial memory in adulthood. Male participants with high (>0.15nmol) and low (lateralisation of language was more common in the high-testosterone group than in the low-testosterone group, χ(2)=4.50, df=1, p=034. Spatial memory laterality was unrelated to cord testosterone level. Our findings indicate that foetal testosterone exposure is related to language laterality in a direction that supports the callosal hypothesis. PMID:25148786

  12. Relation of callosal structure to cognitive abilities in temporal lobe epilepsy

    Christine eSchneider

    2014-02-01

    Full Text Available The main objective of this paper is to analyse the influence of mesial temporal lobe epilepsy (TLE on the morphology of the corpus callosum (CC and its relation to cognitive abilities. More specifically, we investigated correlations between intellectual abilities and callosal morphology, while additionally exploring the modulating impact of (a side of seizure onset (b age of disease onset.For this reason a large representative sample of patients with hippocampal sclerosis (n=79; 35 males; 44 females; age: 18-63 years with disease onset ranging from 0 to 50 years of age, and consisting of 46 left and 33 right TLE patients was recruited. Intelligence was measured using the Wechsler Adult Intelligence Scale Revised (WAIS-R.To get localizations of correlations with high anatomic precision, callosal morphology was examined using computational mesh-based modeling methods, applied to anatomical brain MRI scans.Intellectual performance was positively associated with callosal thickness in anterior and midcallosal callosal regions, with anterior parts being slightly more affected by age of disease onset and side of seizure onset than posterior parts. Earlier age at onset of epilepsy was associated with lower thickness in anterior and midcallosal regions. In addition, laterality of seizure onset had a significant influence on anterior CC morphology, with left hemispheric origin having stronger effects.We found that in TLE, anterior and midcallosal CC morphology are related to cognitive performance. The findings support recent findings of detrimental effects of early onset mTLE on anterior brain regions and of a distinct effect particularly of left TLE on frontal lobe functioning and structure. The causal nature of the relationship remains an open question, i.e., whether CC morphology impacts IQ development or whether IQ development impacts CC morphology, or both.

  13. Developmental evolution of flowering plant pollen tube cell walls: callose synthase (CalS gene expression patterns

    Abercrombie Jason M

    2011-07-01

    Full Text Available Abstract Background A number of innovations underlie the origin of rapid reproductive cycles in angiosperms. A critical early step involved the modification of an ancestrally short and slow-growing pollen tube for faster and longer distance transport of sperm to egg. Associated with this shift are the predominantly callose (1,3-β-glucan walls and septae (callose plugs of angiosperm pollen tubes. Callose synthesis is mediated by callose synthase (CalS. Of 12 CalS gene family members in Arabidopsis, only one (CalS5 has been directly linked to pollen tube callose. CalS5 orthologues are present in several monocot and eudicot genomes, but little is known about the evolutionary origin of CalS5 or what its ancestral function may have been. Results We investigated expression of CalS in pollen and pollen tubes of selected non-flowering seed plants (gymnosperms and angiosperms within lineages that diverged below the monocot/eudicot node. First, we determined the nearly full length coding sequence of a CalS5 orthologue from Cabomba caroliniana (CcCalS5 (Nymphaeales. Semi-quantitative RT-PCR demonstrated low CcCalS5 expression within several vegetative tissues, but strong expression in mature pollen. CalS transcripts were detected in pollen tubes of several species within Nymphaeales and Austrobaileyales, and comparative analyses with a phylogenetically diverse group of sequenced genomes indicated homology to CalS5. We also report in silico evidence of a putative CalS5 orthologue from Amborella. Among gymnosperms, CalS5 transcripts were recovered from germinating pollen of Gnetum and Ginkgo, but a novel CalS paralog was instead amplified from germinating pollen of Pinus taeda. Conclusion The finding that CalS5 is the predominant callose synthase in pollen tubes of both early-diverging and model system angiosperms is an indicator of the homology of their novel callosic pollen tube walls and callose plugs. The data suggest that CalS5 had transient expression

  14. Plasmodesmata without callose and calreticulin in higher plants - open channels for fast symplastic transport?

    Kirill N. Demchenko

    2014-03-01

    Full Text Available Plasmodesmata (PD represent membrane-lined channels that link adjacent plant cells across the cell wall. PD of higher plants contain a central tube of endoplasmic reticulum called desmotubule. Membrane and lumen proteins seem to be able to move through the desmotubule, but most transport processes through PD occur through the cytoplasmic annulus (Brunkard et al., 2013. Calreticulin (CRT, a highly conserved Ca2+-binding protein found in all multi-cellular eukaryotes, predominantly located in the ER, was shown to localize to PD, though not all PD accumulate CRT. In nitrogen fixing actinorhizal root nodules of the Australian tree Casuarina glauca, the primary walls of infected cells containing the microsymbiont become lignified upon infection. TEM analysis of these nodules showed that during the differentiation of infected cells, PD connecting infected cells, and connecting infected and adjacent uninfected cells, were reduced in number as well as diameter (Schubert et al., 2013. In contrast with PD connecting young infected cells, and most PD connecting mature infected and adjacent uninfected cells, PD connecting mature infected cells did not accumulate CRT. Furthermore, as shown here, these PD were not associated with callose, and based on their diameter, they probably had lost their desmotubules. We speculate that either this is a slow path to PD degradation, or that the loss of callose accumulation and presumably also desmotubules leads to the PD becoming open channels and improves metabolite exchange between cells.

  15. Characterization and partial purification of beta-1,3-D-glucan (callose) synthase from barley (Hordeum vulgare) leaves

    Pedersen, L.H.; Jacobsen, S.; Hejgaard, J.;

    1993-01-01

    was inhibited by UDP and uridine 5' triphosphate (UTP). Glucanase digestion of the in vitro product showed that it was a beta-1,3-linked polysaccharide. Two different procedures were used for further enrichment of polypeptides involved in callose synthase activity. Sucrose gradient centrifugation with...

  16. A new sign of callosal disconnection syndrome: agonistic dyspraxia. A case study.

    Lavados, Manuel; Carrasco, Ximena; Peña, Marcela; Zaidel, Eran; Zaidel, Dahlia; Aboitiz, Francisco

    2002-01-01

    We report a patient with callosal haemorrhage and no extracallosal involvement who developed a unique form of intermanual conflict. In the acute phase the patient showed a mild speech disturbance and right hemiparesis, and in her right hand, a grasp reflex and compulsive manipulation of tools, all attributable to transient frontal involvement. In the chronic phase there was intermanual conflict occasionally associated with the sensation of a second left hand. The patient also presented a sign consisting of compulsive, automatic execution of orders by one hand (the left or the right) when the patient was specifically asked to perform the movement with the other hand (the right or the left, respectively). There was no left-right confusion in this patient. We call this condition agonistic dyspraxia. In contrast with diagonistic dyspraxia, this consists of the agonistic behaviour of the other hand under conditions in which the hand that has been instructed to respond cannot execute the request. PMID:12529456

  17. Reactive amyloidosis associated with ischial callosititis: a report with histology of ischial callosities in rhesus macaques (Macaca mulatta)

    Liu, David X.; Gilbert, Margaret H; Wang, Xiaolei; Didier, Peter J.; Veazey, Ronald S.

    2012-01-01

    Ischial callosities have received little attention in veterinary medicine even though they are distinguishing anatomic organs. The organs are characterized by a pair of hairless pads of thickened epidermis, located bilaterally in the gluteal region, which overlay the tuberosities of the ischia of all Old World monkeys, gibbons, and siamangs. The current report describes a case of reactive amyloidosis associated with ischial callosititis in a rhesus macaque (Macaca mulatta). Amyloid A (AA) pro...

  18. Deafferentation-Induced Plasticity of Visual Callosal Connections: Predicting Critical Periods and Analyzing Cortical Abnormalities Using Diffusion Tensor Imaging

    Jaime F. Olavarria

    2012-01-01

    Full Text Available Callosal connections form elaborate patterns that bear close association with striate and extrastriate visual areas. Although it is known that retinal input is required for normal callosal development, there is little information regarding the period during which the retina is critically needed and whether this period correlates with the same developmental stage across species. Here we review the timing of this critical period, identified in rodents and ferrets by the effects that timed enucleations have on mature callosal connections, and compare it to other developmental milestones in these species. Subsequently, we compare these events to diffusion tensor imaging (DTI measurements of water diffusion anisotropy within developing cerebral cortex. We observed that the relationship between the timing of the critical period and the DTI-characterized developmental trajectory is strikingly similar in rodents and ferrets, which opens the possibility of using cortical DTI trajectories for predicting the critical period in species, such as humans, in which this period likely occurs prenatally. Last, we discuss the potential of utilizing DTI to distinguish normal from abnormal cerebral cortical development, both within the context of aberrant connectivity induced by early retinal deafferentation, and more generally as a potential tool for detecting abnormalities associated with neurodevelopmental disorders.

  19. Age Differences in Interhemispheric Interactions: Callosal Structure, Physiological Function, and Behavior

    Brett W Fling

    2011-03-01

    Full Text Available There is a fundamental gap in understanding how brain structural and functional network connectivity are interrelated, how they change with age, and how such changes contribute to older adults’ sensorimotor deficits. Recent neuroimaging approaches including resting state functional connectivity MRI (fcMRI and diffusion tensor imaging (DTI have been used to assess brain functional (fcMRI and structural (DTI network connectivity, allowing for more integrative assessments of distributed neural systems than in the past. Declines in corpus callosum size and microstructure with advancing age have been well documented, but their contributions to age deficits in unimanual and bimanual function are not well defined. Our recent work implicates age-related declines in callosal size and integrity as a key contributor to unimanual and bimanual control deficits. Moreover, our data provide evidence for a fundamental shift in the balance of excitatory and inhibitory interhemispheric processes that occurs with age, resulting in age differences in the relationship between functional and structural network connectivity. Training studies suggest that the balance of interhemispheric interactions can be shifted with experience, making this a viable target for future interventions.

  20. Distinct roles of neuropilin 1 signaling for radial and tangential extension of callosal axons.

    Hatanaka, Yumiko; Matsumoto, Tomoko; Yanagawa, Yuchio; Fujisawa, Hajime; Murakami, Fujio; Masu, Masayuki

    2009-05-20

    Cortical excitatory neurons migrate from their origin in the ventricular zone (VZ) toward the pial surface. During migration, these neurons exhibit a stellate shape in the intermediate zone (IZ), transform into bipolar cells, and then initiate radial migration, extending a trailing process, which may lead to an axon. Here we examined the role of neuropilin 1 (NRP1) in these developmental events. Both NRP1 mRNA and protein were highly expressed in the IZ, where stellate-shaped cells were located. DiI labeling experiments showed that neuronal migration occurred normally in Nrp1 mutant mice up to embryonic day (E) 14.5, the latest day to which the mutant survives, with only subtle axonal defasciculation. However, interference with Nrp1 signaling at a later stage caused pathfinding errors: when a dominant negative form of Nrp1 was electroporated into the cortical VZ cells at E12.5 or E15.5 and examined perinatally, guidance errors were found in tangential axonal extension toward the midline. In contrast, no significant effect was noted on the migration of cortical excitatory neurons. These findings indicate that NRP1 plays an important role in the guidance of callosal axons originating from cortical excitatory neurons but does not support a role in their migration. Moreover, insofar as radial axonal extension within the cortical plate was unaffected, the present findings imply that molecular mechanisms for the axonal extension of excitatory neurons within the cortical plate are distinct from those in the white matter. PMID:19296474

  1. Poly(methacrylic acid)-mediated morphosynthesis of PbWO4 micro-crystals

    PbWO4 crystals with various morphologies were fabricated via a facile poly(methacrylic acid)-mediated hydrothermal route. Novel microsized PbWO4 single crystals with a needle-like shape as well as other morphologies, such as a fishbone, dendrite, sphere, spindle, ellipsoid, rod, and dumbbell with two dandelion-like heads, could be produced. The presence of PMAA, [Pb2+]/[WO42-] molar ratio (R), and aging temperature played key roles in the formation of the PbWO4 needle-like structures. Between temperatures of 60 to 150 C, the length and photoluminescence intensities of the PbWO4 micro needles significantly increased with aging temperature, while the diameter did not change remarkably. Time-dependent experiments revealed that the formation of PbWO4 microneedles involved an unusual growth process, involving nucleation, oriented assembly and controlled mesoscale restructuring of nanoparticle building blocks. (orig.)

  2. Small RNA Derived from the Virulence Modulating Region of the Potato spindle tuber viroid Silences callose synthase Genes of Tomato Plants.

    Adkar-Purushothama, Charith Raj; Brosseau, Chantal; Giguère, Tamara; Sano, Teruo; Moffett, Peter; Perreault, Jean-Pierre

    2015-08-01

    The tomato (Solanum lycopersicum) callose synthase genes CalS11-like and CalS12-like encode proteins that are essential for the formation of callose, a major component of pollen mother cell walls; these enzymes also function in callose formation during pathogen infection. This article describes the targeting of these callose synthase mRNAs by a small RNA derived from the virulence modulating region of two Potato spindle tuber viroid variants. More specifically, viroid infection of tomato plants resulted in the suppression of the target mRNAs up to 1.5-fold, depending on the viroid variant used and the gene targeted. The targeting of these mRNAs by RNA silencing was validated by artificial microRNA experiments in a transient expression system and by RNA ligase-mediated rapid amplification of cDNA ends. Viroid mutants incapable of targeting callose synthase mRNAs failed to induce typical infection phenotypes, whereas a chimeric viroid obtained by swapping the virulence modulating regions of a mild and a severe variant of Potato spindle tuber viroid greatly affected the accumulation of viroids and the severity of disease symptoms. These data provide evidence of the silencing of multiple genes by a single small RNA derived from a viroid. PMID:26290537

  3. Small RNA Derived from the Virulence Modulating Region of the Potato spindle tuber viroid Silences callose synthase Genes of Tomato Plants[OPEN

    Adkar-Purushothama, Charith Raj; Brosseau, Chantal; Giguère, Tamara; Sano, Teruo; Moffett, Peter; Perreault, Jean-Pierre

    2015-01-01

    The tomato (Solanum lycopersicum) callose synthase genes CalS11-like and CalS12-like encode proteins that are essential for the formation of callose, a major component of pollen mother cell walls; these enzymes also function in callose formation during pathogen infection. This article describes the targeting of these callose synthase mRNAs by a small RNA derived from the virulence modulating region of two Potato spindle tuber viroid variants. More specifically, viroid infection of tomato plants resulted in the suppression of the target mRNAs up to 1.5-fold, depending on the viroid variant used and the gene targeted. The targeting of these mRNAs by RNA silencing was validated by artificial microRNA experiments in a transient expression system and by RNA ligase-mediated rapid amplification of cDNA ends. Viroid mutants incapable of targeting callose synthase mRNAs failed to induce typical infection phenotypes, whereas a chimeric viroid obtained by swapping the virulence modulating regions of a mild and a severe variant of Potato spindle tuber viroid greatly affected the accumulation of viroids and the severity of disease symptoms. These data provide evidence of the silencing of multiple genes by a single small RNA derived from a viroid. PMID:26290537

  4. MRI in callosal apraxia and agraphia due to a traumatic lesion in the posterior trunk of the corpus callosum

    We discussed functional topography of the corpus callosum in a case with ideo-motor apraxia and agraphia of the left hand due to a traumatic callosal hematoma confirmed by MRI. The patient was a 35-year-old right-handed woman with head injury in a traffic accident. On admission she was semi-comatose with left oculomotor palsy and her left upper limb showed a decorticate rigidity by noxious stimuli, however, she became alert within 14 days. X-ray CT showed an abnormal high density area in the posterior part of the trunk of the corpus callosum on admission. MRI (inversion recovery technique) on the 60th hospital day showed a low intensity area extending for about 2 cm posteriorly from the center of the trunk. Sequential neuropsychological examinations for the callosal disconnection syndrome were performed. The patient showed ideo-motor apraxia and agraphia in her left hand only. Her response to verbal commands were all parapraxic except for correct use of a comb and a tooth brush. Her writings with her left hand were those of scrawls due to apraxia. These apraxia and agraphia of the left hand were transient and recovered completely within 80 days of onset. Transient impairement of bimanual coordination movement was also observed. Ataxie optique, callosal pseudoneglect, left hand tactile anomia, difficulty of somesthetic transfer or diagonistic dyspraxia was not observed. Based on the neuropsychological and the MRI findings we suggest that the lesion in the posterior part of the trunk of the corpus callosum is important for causing ideo-motor apraxia and agraphia of the left hand. (author)

  5. Normal centrolineal myelination of the callosal splenium reflects the development of the cortical origin and size of its commissural fibers

    Commissural white matter fibers comprising the callosal splenium are diverse. Subsections of the splenium myelinate at different times, in a centrolineal manner. The aims of this study are to depict the normal callosal splenium myelination pattern and to distinguish the transient age-related mid splenium hypointensity from pathology. We reviewed 131 consecutive brain MRIs in patients between ages 3 and 6 months from a single academic children's hospital. Patients that were preterm, hydrocephalic, and/or had volume loss were excluded. Fifty total MR exams that included T1-weighted MR imaging (T1WI), T2-weighted MR imaging (T2WI), and diffusion tensor imaging (DTI) were reviewed. Regions of callosal splenium myelination manifested by T1 and T2 shortening were evaluated. Tractography was performed with seeds placed over the posterior, mid, and anterior splenium to define the origin, destination, and course of traversing fibers. Splenium signal varied significantly from 3 to 6 months, with distinct age-related trends. On T1WI, the splenium was hypointense at 3 months (12/13), centrally hypointense/peripherally hyperintense at 4 months (15/16), and hyperintense at 6 months (10/11). Tractography revealed three distinct white matter tract populations: medial occipital (posterior); precuneus, posterior cingulate, and medial temporal (middle); and postcentral gyri (anterior). Specific commissural fiber components of the splenium myelinate at different times. The transient developmental mid splenium hypointensity on T1WI corresponds to tracts from the associative cortex, principally the precuneus. Heterogeneous splenium signal alteration in patients ages 3-6 months is a normal developmental phenomenon that should not be confused with pathologic lesions. (orig.)

  6. Normal centrolineal myelination of the callosal splenium reflects the development of the cortical origin and size of its commissural fibers

    Whitehead, Matthew T. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Children' s National Medical Center, Department of Radiology, Washington, DC (United States); Raju, Anand; Choudhri, Asim F. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States)

    2014-04-15

    Commissural white matter fibers comprising the callosal splenium are diverse. Subsections of the splenium myelinate at different times, in a centrolineal manner. The aims of this study are to depict the normal callosal splenium myelination pattern and to distinguish the transient age-related mid splenium hypointensity from pathology. We reviewed 131 consecutive brain MRIs in patients between ages 3 and 6 months from a single academic children's hospital. Patients that were preterm, hydrocephalic, and/or had volume loss were excluded. Fifty total MR exams that included T1-weighted MR imaging (T1WI), T2-weighted MR imaging (T2WI), and diffusion tensor imaging (DTI) were reviewed. Regions of callosal splenium myelination manifested by T1 and T2 shortening were evaluated. Tractography was performed with seeds placed over the posterior, mid, and anterior splenium to define the origin, destination, and course of traversing fibers. Splenium signal varied significantly from 3 to 6 months, with distinct age-related trends. On T1WI, the splenium was hypointense at 3 months (12/13), centrally hypointense/peripherally hyperintense at 4 months (15/16), and hyperintense at 6 months (10/11). Tractography revealed three distinct white matter tract populations: medial occipital (posterior); precuneus, posterior cingulate, and medial temporal (middle); and postcentral gyri (anterior). Specific commissural fiber components of the splenium myelinate at different times. The transient developmental mid splenium hypointensity on T1WI corresponds to tracts from the associative cortex, principally the precuneus. Heterogeneous splenium signal alteration in patients ages 3-6 months is a normal developmental phenomenon that should not be confused with pathologic lesions. (orig.)

  7. MRI in callosal apraxia and agraphia due to a traumatic lesion in the posterior trunk of the corpus callosum

    Yasumura, Shuichi; Ito, Naoki; Terunuma, Hiroshi; Matsuzaki, Takayuki; Iwabuchi, Reiko

    1987-08-01

    We discussed functional topography of the corpus callosum in a case with ideo-motor apraxia and agraphia of the left hand due to a traumatic callosal hematoma confirmed by MRI. The patient was a 35-year-old right-handed woman with head injury in a traffic accident. On admission she was semi-comatose with left oculomotor palsy and her left upper limb showed a decorticate rigidity by noxious stimuli, however, she became alert within 14 days. X-ray CT showed an abnormal high density area in the posterior part of the trunk of the corpus callosum on admission. MRI (inversion recovery technique) on the 60th hospital day showed a low intensity area extending for about 2 cm posteriorly from the center of the trunk. Sequential neuropsychological examinations for the callosal disconnection syndrome were performed. The patient showed ideo-motor apraxia and agraphia in her left hand only. Her response to verbal commands were all parapraxic except for correct use of a comb and a tooth brush. Her writings with her left hand were those of scrawls due to apraxia. These apraxia and agraphia of the left hand were transient and recovered completely within 80 days of onset. Transient impairement of bimanual coordination movement was also observed. Ataxie optique, callosal pseudoneglect, left hand tactile anomia, difficulty of somesthetic transfer or diagonistic dyspraxia was not observed. Based on the neuropsychological and the MRI findings we suggest that the lesion in the posterior part of the trunk of the corpus callosum is important for causing ideo-motor apraxia and agraphia of the left hand.

  8. Tumour–stromal interactions in acid-mediated invasion: A mathematical model

    Martin, Natasha K.

    2010-12-01

    It is well established that the tumour microenvironment can both promote and suppress tumour growth and invasion, however, most mathematical models of invasion view the normal tissue as inhibiting tumour progression via immune modulation or spatial constraint. In particular, the production of acid by tumour cells and the subsequent creation of a low extracellular pH environment has been explored in several \\'acid-mediated tumour invasion\\' models where the acidic environment facilitates normal cell death and permits tumour invasion. In this paper, we extend the acid-invasion model developed by Gatenby and Gawlinski (1996) to include both the competitive and cooperative interactions between tumour and normal cells, by incorporating the influence of extracellular matrix and protease production at the tumour-stroma interface. Our model predicts an optimal level of tumour acidity which produces both cell death and matrix degradation. Additionally, very aggressive tumours prevent protease production and matrix degradation by excessive normal cell destruction, leading to an acellular (but matrix filled) gap between the tumour and normal tissue, a feature seen in encapsulated tumours. These results suggest, counterintuitively, that increasing tumour acidity may, in some cases, prevent tumour invasion.

  9. Poly(methacrylic acid)-mediated morphosynthesis of PbWO{sub 4} micro-crystals

    Yu, J.G.; Zhao, X.F.; Liu, S.W. [Wuhan University of Technology, State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan (China); Li, M.; Mann, S. [University of Bristol, School of Chemistry, Bristol (United Kingdom); Ng, D.H.L. [The Chinese University of Hong Kong, Department of Physics, Hong Kong (China)

    2007-04-15

    PbWO{sub 4} crystals with various morphologies were fabricated via a facile poly(methacrylic acid)-mediated hydrothermal route. Novel microsized PbWO{sub 4} single crystals with a needle-like shape as well as other morphologies, such as a fishbone, dendrite, sphere, spindle, ellipsoid, rod, and dumbbell with two dandelion-like heads, could be produced. The presence of PMAA, [Pb{sup 2+}]/[WO{sub 4} {sup 2-}] molar ratio (R), and aging temperature played key roles in the formation of the PbWO{sub 4} needle-like structures. Between temperatures of 60 to 150 C, the length and photoluminescence intensities of the PbWO{sub 4} micro needles significantly increased with aging temperature, while the diameter did not change remarkably. Time-dependent experiments revealed that the formation of PbWO{sub 4} microneedles involved an unusual growth process, involving nucleation, oriented assembly and controlled mesoscale restructuring of nanoparticle building blocks. (orig.)

  10. Cell Wall Maturation of Arabidopsis Trichomes Is Dependent on Exocyst Subunit EXO70H4 and Involves Callose Deposition

    Kulich, I.; Vojtíková, Z.; Glanc, M.; Ortmannová, Jitka; Rasmann, S.; Žárský, Viktor

    2015-01-01

    Roč. 168, č. 1 (2015), s. 120-131. ISSN 0032-0889 Institutional support: RVO:61389030 Keywords : PLASMA-MEMBRANE * MICRO- PIXE * PLANT Subject RIV: EA - Cell Biology Impact factor: 6.841, year: 2014

  11. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  12. Analysis of YFP(J16)-R6/2 reporter mice and postmortem brains reveals early pathology and increased vulnerability of callosal axons in Huntington's disease.

    Gatto, Rodolfo G; Chu, Yaping; Ye, Allen Q; Price, Steven D; Tavassoli, Ehsan; Buenaventura, Andrea; Brady, Scott T; Magin, Richard L; Kordower, Jeffrey H; Morfini, Gerardo A

    2015-09-15

    Cumulative evidence indicates that the onset and severity of Huntington's disease (HD) symptoms correlate with connectivity deficits involving specific neuronal populations within cortical and basal ganglia circuits. Brain imaging studies and pathological reports further associated these deficits with alterations in cerebral white matter structure and axonal pathology. However, whether axonopathy represents an early pathogenic event or an epiphenomenon in HD remains unknown, nor is clear the identity of specific neuronal populations affected. To directly evaluate early axonal abnormalities in the context of HD in vivo, we bred transgenic YFP(J16) with R6/2 mice, a widely used HD model. Diffusion tensor imaging and fluorescence microscopy studies revealed a marked degeneration of callosal axons long before the onset of motor symptoms. Accordingly, a significant fraction of YFP-positive cortical neurons in YFP(J16) mice cortex were identified as callosal projection neurons. Callosal axon pathology progressively worsened with age and was influenced by polyglutamine tract length in mutant huntingtin (mhtt). Degenerating axons were dissociated from microscopically visible mhtt aggregates and did not result from loss of cortical neurons. Interestingly, other axonal populations were mildly or not affected, suggesting differential vulnerability to mhtt toxicity. Validating these results, increased vulnerability of callosal axons was documented in the brains of HD patients. Observations here provide a structural basis for the alterations in cerebral white matter structure widely reported in HD patients. Collectively, our data demonstrate a dying-back pattern of degeneration for cortical projection neurons affected in HD, suggesting that axons represent an early and potentially critical target for mhtt toxicity. PMID:26123489

  13. Callose-mediated resistance to pathogenic intruders in plant defense-related papillae

    Voigt, Christian A.

    2014-01-01

    Plants are exposed to a wide range of potential pathogens, which derive from diverse phyla. Therefore, plants have developed successful defense mechanisms during co-evolution with different pathogens. Besides many specialized defense mechanisms, the plant cell wall represents a first line of defense. It is actively reinforced through the deposition of cell wall appositions, so-called papillae, at sites of interaction with intruding microbial pathogens. The papilla is a complex structure that ...

  14. Microstructural callosal abnormalities in normal-appearing brain of children with developmental delay detected with diffusion tensor imaging

    Ding, Xiao-Qi [Hannover Medical School, Institute of Diagnostic and Interventional Neuroradiology, Hannover (Germany); University Medical Center Hamburg-Eppendorf, Department of Neuroradiology, Hamburg (Germany); Sun, Yimeng; Illies, Till; Zeumer, Hermann; Fiehler, Jens [University Medical Center Hamburg-Eppendorf, Department of Neuroradiology, Hamburg (Germany); Kruse, Bernd [University Medical Center Hamburg-Eppendorf, Department of Pediatrics, Hamburg (Germany); Lanfermann, Heinrich [Hannover Medical School, Institute of Diagnostic and Interventional Neuroradiology, Hannover (Germany)

    2009-06-15

    Callosal fibres play an important role in psychomotor and cognitive functions. The purpose of this study was to investigate possible microstructural abnormalities of the corpus callosum in children with developmental delay, who have normal conventional brain MR imaging results. Seventeen pediatric patients (aged 1-9 years) with developmental delay were studied. Quantitative T2 and fractional anisotropy (FA) values were measured at the genu and splenium of the corpus callosum (CC). Fibre tracking, volumetric determination, as well as fibre density calculations of the CC were also carried out. The results were compared with those of the age-matched healthy subjects. A general elevation of T2 relaxation times (105 ms in patients vs. 95 ms in controls) and reduction of the FA values (0.66 in patients vs. 0.74 in controls) at the genu of the CC were found in patients. Reductions of the fibre numbers (5,464 in patients vs. 8,886 in controls) and volumes (3,415 ml in patients vs. 5,235 ml in controls) of the CC were found only in patients older than 5 years. The study indicates that despite their inconspicuous findings in conventional MRI microstructural brain abnormalities are evident in these pediatric patients suffering from developmental delay. (orig.)

  15. Microstructural callosal abnormalities in normal-appearing brain of children with developmental delay detected with diffusion tensor imaging

    Callosal fibres play an important role in psychomotor and cognitive functions. The purpose of this study was to investigate possible microstructural abnormalities of the corpus callosum in children with developmental delay, who have normal conventional brain MR imaging results. Seventeen pediatric patients (aged 1-9 years) with developmental delay were studied. Quantitative T2 and fractional anisotropy (FA) values were measured at the genu and splenium of the corpus callosum (CC). Fibre tracking, volumetric determination, as well as fibre density calculations of the CC were also carried out. The results were compared with those of the age-matched healthy subjects. A general elevation of T2 relaxation times (105 ms in patients vs. 95 ms in controls) and reduction of the FA values (0.66 in patients vs. 0.74 in controls) at the genu of the CC were found in patients. Reductions of the fibre numbers (5,464 in patients vs. 8,886 in controls) and volumes (3,415 ml in patients vs. 5,235 ml in controls) of the CC were found only in patients older than 5 years. The study indicates that despite their inconspicuous findings in conventional MRI microstructural brain abnormalities are evident in these pediatric patients suffering from developmental delay. (orig.)

  16. Nonlinear stability of a heterogeneous state in a PDE-ODE model for acid-mediated tumor invasion.

    Tao, Youshan; Tello, J Ignacio

    2016-02-01

    This work studies a general reaction-diffusion model for acid-mediated tumor invasion, where tumor cells produce excess acid that primarily kills healthy cells, and thereby invade the microenvironment. The acid diffuses and could be cleared by vasculature, and the healthy and tumor cells are viewed as two species following logistic growth with mutual competition. A key feature of this model is the density-limited diffusion for tumor cells, reflecting that a healthy tissue will spatially constrain a tumor unless shrunk. Under appropriate assumptions on model parameters and on initial data, it is shown that the unique heterogeneous state is nonlinearly stable, which implies a long-term coexistence of the healthy and tumor cells in certain parameter space. Our theoretical result suggests that acidity may play a significant role in heterogeneous tumor progression. PMID:26776259

  17. Acid-mediated reactions under microfluidic conditions: A new strategy for practical synthesis of biofunctional natural products

    Katsunori Tanaka

    2009-08-01

    Full Text Available Microfluidic conditions were applied to acid-mediated reactions, namely, glycosylation, reductive opening of the benzylidene acetal groups, and dehydration, which are the keys to the practical synthesis of N-glycans and the immunostimulating natural product, pristane. A distinctly different reactivity from that in conventional batch stirring was found; the vigorous micromixing of the reactants with the concentrated acids is critical especially for the “fast” reactions to be successful. Such a common feature might be due to the integration of all favorable aspects of microfluidic conditions, i.e., efficient mixing, precise temperature control, and the easy handling of the reactive intermediate by controlling the residence time. The microfluidic reactions cited in this review indicate the need to reinvestigate the traditional or imaginary reactions which have so far been performed and evaluated only in batch apparatus, and therefore they could be recognized as a new strategy in synthesizing natural products of prominent biological activity in a “practical” and a “industrial” manner.

  18. Insight into 2α-Chloro-2′(2′,6′)-(Di)Halogenopicropodophyllotoxins Reacting with Carboxylic Acids Mediated by BF3·Et2O

    Lingling Fan; Xiaoyan Zhi; Zhiping Che; Hui Xu

    2015-01-01

    Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2′(2′,6′)-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5–31 h, the resulting compounds were all transformed into the unusual C-ring aromatization products. Additionally, it demonstrated that BF3·Et2O and reaction tempera...

  19. Subthreshold receptive fields and baseline excitability of "silent" S1 callosal neurons in awake rabbits: contributions of AMPA/kainate and NMDA receptors.

    Swadlow, H A; Hicks, T P

    1997-07-01

    The contribution of NMDA and non-NMDA receptors to excitatory subthreshold receptive fields was examined in callosal efferent neurons (CC neurons) in primary somatosensory cortex of the fully awake rabbit. Only neurons showing no traditional (suprathreshold) receptive fields were examined. Subthreshold responses were examined by monitoring the thresholds of efferent neurons to juxtasomal current pulses (JSCPs) delivered through the recording microelectrode. Changes in threshold following a peripheral conditioning stimulus signify a subthreshold response. Using this method, excitatory postsynaptic potentials and inhibitory postsynaptic potentials are manifested as decreases and increases in JSCP threshold, respectively. NMDA and non-NMDA agonists and antagonists were administered iontophoretically via a multibarrel micropipette assembly attached to the recording/stimulating microelectrode. Receptor-selective doses of both AMPA/kainate and NMDA antagonists decreased the excitability of CC neurons in the absence of any peripheral stimulation. Threshold to JSCPs rose by a mean of 20% for both classes of antagonist. Despite the similar effects of NMDA and non-NMDA antagonists on baseline excitability, these antagonists had dramatically different effects on the subthreshold excitatory response to activation of the receptive field. Whereas receptor-selective doses of AMPA/kainate antagonists either eliminated or severely attenuated the subthreshold excitatory responses to peripheral stimulation, NMDA antagonists had little or no effect on the subthreshold evoked response. PMID:9262195

  20. Severe form of radiculo - myelo - neuropathy with meningo - encephalitis secondary to Angiostrongylus cantonensis infection: unusual corpus callosal lesions and serial magnetic resonance imaging findings.

    Nalini, Atchayaram; Ramakrishna, Anil; Dekumoy, Paron; Kumar, Raju Ravi; Pakdee, Wallop; Saini, Jitender; Hegde, Vinay S

    2013-01-01

    A 43-year-old man presented with the symptoms of recurrent lower abdominal pain, malaise and loss of appetite of 3-week duration, followed by acute onset of generalized paresthesias, fever and headache which progressed over few days to quadriparesis, altered sensorium, urinary and fecal incontinence. He had consumed raw tongue, liver, gall bladder and testicles of monitor lizard (Varanus bengalensis). Blood picture showed eosinophilia and cerebrospinal fluid (CSF) analysis revealed elevated protein and eosinophilia. Serum and CSF serology was positive for angiostrongyliasis. Magnetic resonance imaging showed focal hyperintense lesions in the corpus callosum and brainstem and an enhancing lesion in the cerebellum. Post-contrast T1-weighted axial images of spine showed evidence of cervical cord hyperintense lesions and root enhancement. Susceptibility weighted images/phase images showed unusual feature of multiple hemorrhagic lesions in the posterior fossa and supratentorial areas. Diffusion showed no restriction of corpus callosal lesions. Patient was treated with the high dose parenteral steroids with albendazole and at 6-month follow-up and had a remarkable recovery. PMID:24005735

  1. [Case of callosal disconnection syndrome with a chief complaint of right-hand disability, despite presence of left-hand diagonistic dyspraxia].

    Okamoto, Yoko; Saida, Hisako; Yamamoto, Toru

    2009-04-01

    e report the case of 48-year-old right-handed male patient with an infarction affecting most part of the body and the splenium of the left half of the corpus callosum. Neuropsychological examination revealed typical signs of callosal disconnection including left-sided apraxia, diagonistic dyspraxia, left-sided agraphia, left-hand tactile anomia, left hemialexia, and right-sided constructional disability. Moreover, he complained of impairment in activities involving the right hand disability and agraphia. He could not stop behaving with his right hand when he had a vague idea. For example, he involuntarily picked up a tea bottle with his right hand when he had a desire to drink, although the action was not appropriate to that occasion. The imitation and utilization behavior did not imply this case, because his right hand behaviors were not exaggerated in response to external stimuli, such as the gestures of the examiner or the subjects in front of the patient. Unexpectedly, he complained about impairment of the activity of his right hand and was unaware of left hand apraxia or diagonistic dyspraxia; this trend continued for 6 months, at the time of this writing. We argue that the patient may have been subconsciouly aware of the symptoms of his left hand but had not verbalized them. PMID:19378819

  2. Insight into 2α-Chloro-2‧(2‧,6‧)-(Di)Halogenopicropodophyllotoxins Reacting with Carboxylic Acids Mediated by BF3·Et2O

    Fan, Lingling; Zhi, Xiaoyan; Che, Zhiping; Xu, Hui

    2015-11-01

    Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2‧(2‧,6‧)-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5-31 h, the resulting compounds were all transformed into the unusual C-ring aromatization products. Additionally, it demonstrated that BF3·Et2O and reaction temperature were the important factors for C-ring aromatization, and AlCl3 could be substituted for BF3·Et2O as a lewis acid for C-ring aromatization. Halogenation of E-ring of 2β-chloropodophyllotoxins with NCS or NBS also led to the same C-ring aromatization compounds. Especially compounds 5c, 6g and 7b exhibited insecticidal activity equal to that of toosendanin.

  3. Insight into 2α-Chloro-2'(2',6')-(Di)Halogenopicropodophyllotoxins Reacting with Carboxylic Acids Mediated by BF3·Et2O.

    Fan, Lingling; Zhi, Xiaoyan; Che, Zhiping; Xu, Hui

    2015-01-01

    Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2'(2',6')-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5-31 h, the resulting compounds were all transformed into the unusual C-ring aromatization products. Additionally, it demonstrated that BF3·Et2O and reaction temperature were the important factors for C-ring aromatization, and AlCl3 could be substituted for BF3·Et2O as a lewis acid for C-ring aromatization. Halogenation of E-ring of 2β-chloropodophyllotoxins with NCS or NBS also led to the same C-ring aromatization compounds. Especially compounds 5c, 6g and 7b exhibited insecticidal activity equal to that of toosendanin. PMID:26573374

  4. Acid-Mediated N-H/α,β-C(sp(3))-H Trifunctionalization of Pyrrolidine: Intermolecular [3 + 2] Cycloaddition for the Construction of 2,3-Dihydro-1H-Pyrrolizine Derivatives.

    Zheng, Kai-Lu; Shu, Wen-Ming; Ma, Jun-Rui; Wu, Yan-Dong; Wu, An-Xin

    2016-08-01

    A one-pot acid-mediated reaction has been developed for the N-H/α,β-C(sp(3))-H trifunctionalization of pyrrolidine without any metallic reagents or external oxidants. This reaction involves the intermolecular [3 + 2] cycloaddition of in situ-generated azomethine ylides with acrylic esters to provide facile access to 2,3-dihydro-1H-pyrrolizine derivatives in high yields under mild conditions. PMID:27396906

  5. Deposited radionuclides

    The measurements presented here were carried out for determination of the fallout levels of radionuclides throughout the country, including the areas surrounding the nuclear power plants at Loviisa and Olkiluoto. The 90Sr, 137Cs and 3H contents of deposition were determined and the results are given as a follow-up to the previous results. 89Sr and other gammaradionuclides in addition to 137Cs were measured from wet and dry deposition. Also 89-90Sr, 239-240Pu, 137Cs and other gammaradionuclides deposited in soil were measured. The radiochemical separation technique was used to determine 89Sr, 90Sr, 137Cs and 239-240Pu. Tritium contents were determined by liquid scintillation counting after electrolytic enrichment. Gammaradionuclides were measured by Ge(Li) spectrometry. In 1977 the contents of the long-lived radionuclides 90Sr and 137Cs in deposition increased to almost the same level as in the early '70s. This is due to the high-yield atmospheric nuclear weapon tests carried out by China. A slight increase in 3H deposition can also be noticed in 1977. The results of soil sample measurements indicate that practically all the activity is found in the top 20 cm layer. (author)

  6. Deposited radionuclides

    Measurements were carried out to determine the fall-out levels of radionuclides in Finland including those from the surroundings of the nuclear power plants at Loviisa and Olkiluoto. Deposition samples were analysed for their 3H, 89Sr and 90Sr as well as 137Cs and other gamma radionuclide contents. 90Sr, 239,240Pu, as well as 137Cs and other gamma radionuclides deposited in soil were also measured. The 90Sr and 137Cs levels in deposition in 1978 remained at almost the same level as in 1977. The slightly increasing trend in 3H concentrations continued in 1978. The mean annual deposition of tritium at different sampling stations varied from 120 nCi/m2 (4.4 kBq/m2) to 200 nCi/m2 (7.4 kBq/m2). The total annual deposits of various fission product radionuclides during 1978 were smaller than during 1977. No increase in radioactivity originating from nuclear power plants could be observed. (author)

  7. Deposited radionuclides

    The results presented are from the nationwide programme to survey the fall-out levels of radionuclides in Finland. This programme includes results from the vicinities of the nuclear power plants at Loviisa and Olkiluoto. Analysis of deposition samples for their 3H, 89Sr and 90Sr, as well as 137Cs and other gamma radionuclide contents was continued. The results are given as a follow-up to the previous results. The cumulative deposition of long-lived radionuclides retained in soil was measured near the Finnish nuclear power stations. The 90Sr and 137Cs levels in deposition in 1979 were lower than in the previous two years, and no 89Sr was detected. The trend to slightly increasing 3H concentrations of previous years was reversed in 1979. The mean annual deposition of tritium at different sampling stations varied from 85 nCi/m2 (3.1 kBq/m2) to 180 nCi/m2 (6.7 kBq/m2). The total annual deposits of various fission product radionuclides have decreased continuously since the maximum in 1977. No short-lived radionuclides originating from either nuclear explosions or nuclear power plants were observed in 1979. (author)

  8. METALS DEPOSITS

    2011-01-01

    <正>20111705 An Junbo(Team 603,Bureau of Nonferrous Metals Geological Exploration of Jilin Province,Hunchun 133300,China);Xu Renjie Geological Features and Ore Genesis of Baishilazi Scheelite Deposit in Yanbian Area(Jilin Geology,ISSN1001-2427,CN22-1099/P,29(3),2010,p.39-43,2 illus.,2 tables,7 refs.)Key words:tungsten ores,Jilin ProvinceThe Baishilazi scheelite deposit is located in contacting zone between the marble of the Late Palaeozoic Qinglongcun Group and the Hercynian biotite granite.The vein and lenticular major ore body is obviously controlled by NE-extending faults and con

  9. NONMETALS DEPOSITS

    2013-01-01

    <正>20131601 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550003,China);Yang Ruidong Hydrothermal Venting-Flowing Sedimentation Characteristics of Devonian Barite Deposits from Leji,Zhenning County,Guizhou Province(Acta Sedimentologica Sinica,ISSN1000-0550,CN62-1038/P,30(3),

  10. METALS DEPOSITS

    2015-01-01

    20150904An Fang(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China);Wang Juli Skarn Mineral Assemblage in Representative Ore Districts of Sayak Copper Orefield,Kazakhstan,and Its Genetic Implications(Mineral Deposits,ISSN0258-7106,CN11-1965/P,33(3),2014,p.521-540,

  11. Study on the distribution of callose and β-1,3-D-glucanase in Chenopodium quinoa by immuno-gold labeling%免疫胶体金标记定位昆诺藜中的胼胝质和胼胝质降解酶

    李云琴; 王华; 谢礼; 洪健

    2014-01-01

    运用免疫胶体金技术研究了感染蚕豆萎蔫病毒2号以及健康昆诺藜细胞中胼胝质和胼胝质降解酶的分布情况。电镜观察发现胶体金特异性标记在含有VP37小管的胞间运动通道周围,其余区域感病和健康细胞的胼胝质及胼胝质降解酶分布差别不大,胼胝质主要分布于细胞间隙的大块电子致密物质以及细胞壁结构发生较大变化的区域,胼胝质降解酶主要分布于筛板、维管束细胞紧贴细胞壁区域的大块电子致密物质上,在细胞壁结构发生较大改变的区域也有胼胝质降解酶的分布。推测胼胝质在昆诺藜细胞中的积累和降解可能与细胞壁结构成分改变有关。%The distribution of callose and β⁃1,3⁃D⁃glucanase in the Broad bean wilt virus 2 ( BBWV 2 ) infected and the healthy Chenopodium quinoa was investigated by using immuno⁃gold labeling with the antibody against callose and β⁃1, 3⁃D⁃glucanase, respectively. The results show that, except for the VP37 intercellular moving cell wall pathways, there is no obvious difference on the distribution of callose and β⁃1,3⁃D⁃glucanase between the infected and healthy cells. Callose is mainly distributed on the regions as bellow:the electron condensed material which located in the intercellular space, the structural altered region of cell wall and the cell wall broken region. Glucanase is mainly distributed on the regions as bellow:the sieve plate, the electron condensed material attached to cell wall in the vascular bundle and the structural altered region of cell wall. From these results, it can be deduced that the accumulation and degradation of callose in C. quinoa is related to the cell wall structural and component alteration.

  12. Deposit insurance and international bank deposits

    Harry Huizinga; Gaëtan Nicodème

    2003-01-01

    This paper examines how international depositors respond to national deposit insurance policies. Countries with explicit deposit insurance are found to be relatively attractive to international non-bank depositors. Deposit schemes characterized by co-insurance, a private administration, and a low deposit insurance premium appear to be particularly favored by these depositors. The sensitivity of non-bank deposits to deposit insurance policies opens up the possibility of international regulator...

  13. NONMETALS DEPOSITS

    2011-01-01

    <正>20111761 Chen Hua(115 Geological Party,Guizhou Bureau of Geology and Mineral Exploration & Development,Guiyang 551400,China);Deng Chao Analysis on the Metallogenic Environment of Maochang Bauxite in Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(3),2010,p.198-201,2 illus.,1 table,8 refs.)Key words:bauxite deposit,Guizhou Province By long time physical and chemical process,the carbonate rock after Central Guizhou uplidft,becomes red clay,after further weathering,the red clay decomposed into the oxide,hydroxide of Al and Fe,in the dissolution hole and depression,it concentrates primary fragmentary tight and earthy karst bauxite ore.Because the variation of landform,it decomposes and cracks again,affords the material source

  14. Genetic effects in callose content in root apex of inbred resistant and susceptible corn lines to acid soils Efectos genéticos de la formación de calosa en ápices radicales de líneas de maíz resistentes y susceptibles a suelos ácidos

    Arcos Alba Lucía

    2007-12-01

    Full Text Available

    The main objective of this work was to identify genetic parameters that are related to callose accumulation using tropical inbreeds corn. Fourteen inbreed lines selected for different levels of tolerance to acid soils were chosen and a diallel among them was generated. The seeds were grown under controlled environmental conditions in a growth chamber and transferred to a nutrient solution at pH 4.3. After 12 hours of 25 µM Al (AlCl3 treatment was applied, callose contents of 1 cm root apex were determined with fluorescence spectrophotometer. Significant differences were found for parents, crosses and parents vs crosses. Average callose content varied from 0.746 to 2.035 (µg PE/cm root apex. Heterosis varied from –21.2% to 276.3%. General combining ability (GCA and specific combining ability (SCA were highly significant indicating that both, additive and non–additive gene effects were important for callose inheritance. SCA and GCA sum of squares accounted for 54% and 46%, respectively of crosses of squares sum. Correlation coefficient between callose content and corn grain yield in the field was negative but not significant (r = –0.38.

    Key words: Zea mays; callose; inheritance; diallel; heterosis; acid soils.

    El objetivo de este trabajo fue estudiar la herencia de la producción de calosa utilizando líneas endogámicas de maíz. Seleccionando 14 líneas (7 tolerantes y 7 susceptibles a suelos ácidos se formó un dialelo que fue probado en campo y en invernadero. Se determinó el contenido de calosa en los 91 cruzamientos resultantes y los 14 progenitores. Para ello se colocaron las semillas en cámara de crecimiento en condiciones controladas. Después de 4–5 días las plántulas fueron transferidas a cubetas que contenían solución nutritiva con aireación constante. Luego de 48 horas se adicionaron 25 µM de aluminio (AlCl3 a cada una de las cubetas y se mantuvieron por 12 horas. Se cortaron tres ápices radicales de

  15. Lead deposited in the cell wall of Funaria hygrometrica protonemata is not stable - A remobilization can occur

    The hypothesis that lead (Pb) can be uptake or remobilized from the cell wall (CW) by internalization withlow-esterified pectins (up to 40% - JIM5-P), was studied in tip-growing apical cell of Funaria hygrometrica protonemata. Treatment 4 h with 1 mM PbCl2 caused marked vesicular traffic intensification and the common internalization of JIM5-P from the CW. Lead bound to JIM5-P was internalized from the CW, together with this compound and entered the protoplast. It showed that Pb deposited in CW is not as safe for plant cell as previously believed. However, pulse-chase experiments (recovering 4 h and 24 h) indicated that CW and its thickenings can function as the final sequestration compartments. In Pb deposition sites, a callose layer occurred. It was localized from the protoplast site, next to Pb deposits separating sequestrated to CW and its thickenings Pb from plasma membrane almost certainly protecting the plant cell from its returning into the protoplast. - Lead bound to low-esterified pectins in cell wall can be uptake or remobilized by endocytosis together with this pectin epitope.

  16. Lead deposited in the cell wall of Funaria hygrometrica protonemata is not stable - A remobilization can occur

    Krzeslowska, Magdalena, E-mail: magdak@amu.edu.p [Laboratory of General Botany, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan (Poland); Lenartowska, Marta [Laboratory of Developmental Biology, Institute of General and Molecular Biology, Nicolaus Copernicus University, Gagarina 2, 87-100 Torun (Poland); Samardakiewicz, Slawomir [Laboratory of Electron and Confocal Microscopy, Adam Mickiewicz University, Umultowska street 89, 61-614 Poznan (Poland); Bilski, Henryk [Laboratory of Electron Microscopy, Nencki Institute of Experimental Biology, Pasteur Street 3, 02-093 Warszawa (Poland); Wozny, Adam [Laboratory of General Botany, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan (Poland)

    2010-01-15

    The hypothesis that lead (Pb) can be uptake or remobilized from the cell wall (CW) by internalization withlow-esterified pectins (up to 40% - JIM5-P), was studied in tip-growing apical cell of Funaria hygrometrica protonemata. Treatment 4 h with 1 mM PbCl{sub 2} caused marked vesicular traffic intensification and the common internalization of JIM5-P from the CW. Lead bound to JIM5-P was internalized from the CW, together with this compound and entered the protoplast. It showed that Pb deposited in CW is not as safe for plant cell as previously believed. However, pulse-chase experiments (recovering 4 h and 24 h) indicated that CW and its thickenings can function as the final sequestration compartments. In Pb deposition sites, a callose layer occurred. It was localized from the protoplast site, next to Pb deposits separating sequestrated to CW and its thickenings Pb from plasma membrane almost certainly protecting the plant cell from its returning into the protoplast. - Lead bound to low-esterified pectins in cell wall can be uptake or remobilized by endocytosis together with this pectin epitope.

  17. Efectos genéticos de la formación de calosa en ápices radicales de líneas de maíz resistentes y susceptibles a suelos ácidos Genetic effects in callose content in root apex of inbred resistant and susceptible corn lines to acid soils

    Alba Lucía Arcos

    2007-01-01

    Full Text Available El objetivo de este trabajo fue estudiar la herencia de la producción de calosa utilizando líneas endogámicas de maíz. Seleccionando 14 líneas (7 tolerantes y 7 susceptibles a suelos ácidos se formó un dialelo que fue probado en campo y en invernadero. Se determinó el contenido de calosa en los 91 cruzamientos resultantes y los 14 progenitores. Para ello se colocaron las semillas en cámara de crecimiento en condiciones controladas. Después de 4-5 días las plántulas fueron transferidas a cubetas que contenían solución nutritiva con aireación constante. Luego de 48 horas se adicionaron 25 µM de aluminio (AlCl3 a cada una de las cubetas y se mantuvieron por 12 horas. Se cortaron tres ápices radicales de cada genotipo y se mantuvieron en etanol 96%. Para medir el contenido de calosa se utilizó Methyl blue como colorante, este forma un complejo con la calosa llamado Siruflúor-calosa, que es medido con el espectrofotómetro de fluorescencia. Se encontraron diferencias significativas para los progenitores, los cruzamientos y los progenitores Vs cruzamientos. El contenido de calosa de los progenitores varió de 0.746 a 2.035 µg PE/cm ápice de raíz. La heterosis varió desde -21.2% a 276.3%. La Habilidad Combinatoria General (HCG y la Habilidad Combinatoria Específica (HCE fueron altamente significativas, lo que indica que tanto los efectos genéticos aditivos y no aditivos fueron importantes en la herencia de calosa. El 46% de SC entre cruzamientos correspondió a la HCG y el 54% a la HCE. El coeficiente de correlación entre el contenido de calosa y la producción de grano del maíz en el campo fue negativo aunque no significativo (r = -0.38.The main objective of this work was to identify genetic parameters that are related to callose accumulation using tropical inbreeds corn. Fourteen inbreed lines selected for different levels of tolerance to acid soils were chosen and a diallel among them was generated. The seeds were grown

  18. Electro-Deposition Laboratory

    Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

  19. Calcium Pyrophosphate Deposition (CPPD)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  20. Selection of bentonite deposits

    The selection of bentonite deposits is to offer a supply base of backfill/buffer materials for high-level radioactive waste repository in China. In this paper the comprehensive evaluation criteria were discussed first, then a comprehensive comment on bentonite deposits in China was given. The properties of geographic distribution, origin, reserves and ore quality of bentonite deposits were also discussed. The comprehensive comparison studies on 12 large-sized bentonite deposits was presented. Based on the results obtained Gaomiaozi bentonite deposit, Inner Mongolia, was recommended as the first choice of backfill/buffer materials for repository in China. (author)

  1. Acid Deposition Phenomena

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO2) and nitrogen oxides (NOx). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H2SO4) and nitric acids (HNO3), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  2. HT deposition to snow

    A series of exposure chamber measurements of the deposition of HT to snow were conducted at a field site. These experiments indicate that deposition velocities for conversion of HT to HTO are likely 10-6 m s-1 or less, which is approximately two to three orders of magnitude slower than deposition to soils under growing season conditions. Previous measurements of deposition to soil under freezing or near-freezing conditions also indicated very low deposition velocities. Deposition under winder conditions is thus likely to be much slower than deposition to soil under growing season conditions. It is concluded that exposure to HTO formed by the conversion of HT to HTO during a winter release of HT over snow or frozen ground is likely to be small compared to the dose from the HT plume itself. (4 tabs., 5 figs., 14 refs.)

  3. Airfoil deposition model

    Kohl, F. J.

    1982-01-01

    The methodology to predict deposit evolution (deposition rate and subsequent flow of liquid deposits) as a function of fuel and air impurity content and relevant aerodynamic parameters for turbine airfoils is developed in this research. The spectrum of deposition conditions encountered in gas turbine operations includes the mechanisms of vapor deposition, small particle deposition with thermophoresis, and larger particle deposition with inertial effects. The focus is on using a simplified version of the comprehensive multicomponent vapor diffusion formalism to make deposition predictions for: (1) simple geometry collectors; and (2) gas turbine blade shapes, including both developing laminar and turbulent boundary layers. For the gas turbine blade the insights developed in previous programs are being combined with heat and mass transfer coefficient calculations using the STAN 5 boundary layer code to predict vapor deposition rates and corresponding liquid layer thicknesses on turbine blades. A computer program is being written which utilizes the local values of the calculated deposition rate and skin friction to calculate the increment in liquid condensate layer growth along a collector surface.

  4. Shedding of ash deposits

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt;

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  5. The Imouraren deposit, Niger

    Imouraren deposit has been discovered in the late sixties. It is located South of Arlit where two mines are mined, one open pit and one underground. The grades of reduced Imouraren Uranium ore are lesser than these of Arlit and Akouta. Imouraren deposit is owned by COGEMA (France): 70% and ONAREM (Niger): 30%. The concession area is about 45 square kilometers. The thickness of the deposit is between 50 and 60 meters and its depth reaches 110 to 170 meters. (author)

  6. Deposits and relationship lending

    Mitchell Berlin; Mester, Loretta J.

    1998-01-01

    The authors empirically examine the hypothesis that access to deposits with inelastic rates (core deposits) permits a bank to make contractual agreements with borrowers that are infeasible if the bank must pay market rates for its funds. Access to core deposits insulates a bank's costs of funds from exogenous shocks, allowing the bank to insulate its borrowers against exogenous credit shocks. Using a large sample of loans from the Survey of the Terms of Bank Lending, the authors find that whe...

  7. Uraniferous surficial deposits

    As a result of the discovery of uranium in surficial deposits of Tertiary to Recent age, in Australia and Southern Africa, increasing attention is being paid to the location and understanding of the genesis of these deposits. The paper discusses the definitions and terminology currently in use and a classification of these deposits is presented. It is concluded that in order to obtain a measure of clarity, the terms calcrete, gypcrete and dolocrete should not be used to describe the uraniferous valley-fill deposits of Southern Africa and Australia

  8. Deposition patterns with Turbuhaler.

    Borgström, L

    1994-01-01

    The degree of lung deposition is an important factor in the evaluation of different inhalation flow driven dry powder inhalers. A number of studies using radioactive and non-radioactive methods have been performed with Turbuhaler to assess lung deposition under different conditions. Mean total lung deposition of terbutaline sulfate or budesonide via Turbuhaler in healthy volunteers ranged from 21-32% of the dose when a normal inhalation flow (60L/min) was used. At a low flow (30L/min) a mean 15% of the dose was deposited in the lungs, a similar value as for a well-performed inhalation via a pressurized metered dose inhaler. Regional deposition of inhaled drug can be expressed as the ratio between the amount of drug deposited in the more peripheral parts of the lung relative to the more central parts. In a comparative study, budesonide and terbutaline sulfate were given by inhalation via Turbuhaler to healthy volunteers. The ratio of peripheral to central deposition was 2.03 for terbutaline and 1.72 for budesonide. Thus, both the water-soluble terbutaline sulfate and the non-water soluble budesonide seemed to behave in the same way when inhaled via Turbuhaler. In conclusion, Turbuhaler delivers over 20% of a metered dose to the lungs when inhaled at a normal inhalation flow rate. The regional deposition pattern in the lungs was the same for terbutaline sulfate and budesonide, in spite of differences in water solubility. PMID:10147081

  9. MAPLE deposition of nanomaterials

    Caricato, A.P., E-mail: annapaola.caricato@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Arima, V.; Catalano, M. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Cesaria, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Cozzoli, P.D. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Martino, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Taurino, A.; Rella, R. [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, I-73100 Lecce (Italy); Scarfiello, R. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Tunno, T. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Zacheo, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy)

    2014-05-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  10. Biomimetic thin film deposition

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  11. Speleothem (Cave Deposit) Data

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, and other aspects of climate derived from mineral deposits found in caves. Parameter keywords describe what was measured...

  12. Modeled Wet Nitrate Deposition

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  13. Uranium hydrothermal deposits

    René, Miloš

    New York : Nova Science Publishers, 2012 - (Vasiliev, A.; Sidorov, M.), s. 211-244 ISBN 978-1-62081-207-5 Institutional research plan: CEZ:AV0Z30460519 Keywords : uranium * hydrothermal deposits * uraninite Subject RIV: DB - Geology ; Mineralogy

  14. Uranium deposit research, 1983

    Research on uranium deposits in Canada, conducted as a prerequisite for assessment of the Estimated Additional Resources of uranium, revealed that (a) the uranium-gold association in rudites of the Huronian Supergroup preferably occurs in the carbon layers; (b) chloritized ore at the Panel mine, Elliot Lake, Ontario, occurs locally in tectonically disturbed areas in the vicinity of diabase dykes; (c) mineralization in the Black Sturgeon Lake area, Ontario, formed from solutions in structural and lithological traps; (d) the Cigar Lake deposit, Saskatchewan, has two phases of mineralization: monomineralic and polymetallic; (e) mineralization of the JEB (Canoxy Ltd.) deposit is similar to that at McClean Lake; (f) the uranium-carbon assemblage was identified in the Claude deposit, Carswell Structure; and (g) the Otish Mountains area, Quebec, should be considered as a significant uranium-polymetallic metallogenic province

  15. Automatic Payroll Deposit System.

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  16. Podiform chromite deposits

    U.S. Geological Survey, Department of the Interior — Location and characteristics of 1,124 individual mineral deposits of this type, with grade and tonnage models for chromium as well as several related elements.

  17. Alluvial Deposits in Iowa

    Iowa State University GIS Support and Research Facility — This coverage maps alluvial deposits throughout Iowa. This generally would include areas of alluvial soils associated with modern streams that are identified on...

  18. Metallic mineral deposits

    Crow, M J; van Leeuwen, T.M.

    2005-01-01

    This account concentrates on the the primary metallic mineral deposits and occurrences in Sumatra, in particular the recent discoveries of gold, tin and base metals. The residual and placer deposits are given less emphasis, as no significant discoveries have been made in recent years. The history of mineral exploration and discovery in Indonesia has been reviewed recently by van Leeuwen (1993, 1994), documenting the change in emphasis of mineral-based activities from western to eastern I...

  19. Uranium deposits in Africa

    Africa is not only known for its spectacular diamond, gold, copper, chromium, platinum and phosphorus deposits but also for its uranium deposits. At least two uranium provinces can be distinguished - the southern, with the equatorial sub-province; and the south Saharan province. Uranium deposits are distributed either in cratons or in mobile belts, the first of sandstone and quartz-pebble conglomerate type, while those located in mobile belts are predominantly of vein and similar (disseminated) type. Uranium deposits occur within Precambrian rocks or in younger platform sediments, but close to the exposed Precambrian basement. The Proterozoic host rocks consist of sediments, metamorphics or granitoids. In contrast to Phanerozoic continental uranium-bearing sediments, those in the Precambrian are in marginal marine facies but they do contain organic material. The geology of Africa is briefly reviewed with the emphasis on those features which might control the distribution of uranium. The evolution of the African Platform is considered as a progressive reduction of its craton area which has been affected by three major Precambrian tectonic events. A short survey on the geology of known uranium deposits is made. However, some deposits and occurrences for which little published material is available are treated in more detail. (author)

  20. Vein type uranium deposits

    Veins are tabular- or sheet-like masses of minerals occupying or following a fracture or a set of fractures in the enclosing rock. They have been formed later than the country rock and fractures, either by filling of the open spaces or by partial or complete replacement of the adjoining rock or most commonly by both of these processes combined. This volume begins with the occurrences and deposits known from old shield areas and the sedimentary belts surrounding them. They are followed by papers describing the European deposits mostly of Variscan age, and by similar deposits known from China being of Jurassic age. The volume is completed by two papers which do not fit exactly in the given scheme. A separate abstract was prepared for each of the 25 papers in this report

  1. "Total Deposition (TDEP) Maps"

    The presentation provides an update on the use of a hybrid methodology that relies on measured values from national monitoring networks and modeled values from CMAQ to produce of maps of total deposition for use in critical loads and other ecological assessments. Additionally, c...

  2. Thorium ore deposits

    The main occurences of the thorium minerals of the Argentine Republic which have not been exploited, due to their reduced volume, are described. The thoriferous deposits have three genetic types: pegmatitic, hydrothermal and detritic, being the most common minerals: monazite, thorite and thorogummite. The most important thorium accumulations are located in Salta, being of less importance those of Cordoba, Jujuy and San Juan. (M.E.L.)

  3. Uranium deposits of Brazil

    Brazil is a country of vast natural resources, including numerous uranium deposits. In support of the country's nuclear power program, Brazil has developed the most active uranium industry in South America. Brazil has one operating reactor (Angra 1, a 626-MWe PWR), and two under construction. The country's economic challenges have slowed the progress of its nuclear program. At present, the Pocos de Caldas district is the only active uranium production. In 1990, the Cercado open-pit mine produced approximately 45 metric tons (MT) U3O8 (100 thousand pounds). Brazil's state-owned uranium production and processing company, Uranio do Brasil, announced it has decided to begin shifting its production from the high-cost and nearly depleted deposits at Pocos de Caldas, to lower-cost reserves at Lagoa Real. Production at Lagoa Real is schedules to begin by 1993. In addition to these two districts, Brazil has many other known uranium deposits, and as a whole, it is estimated that Brazil has over 275,000 MT U3O8 (600 million pounds U3O8) in reserves

  4. Intricately Rippled Sand Deposits

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for Intricately Rippled Sand Deposits (QTVR) NASA's Mars Exploration Rover Spirit welcomed the beginning of 2006 on Earth by taking this striking panorama of intricately rippled sand deposits in Gusev Crater on Mars. This is an approximate true-color rendering of the 'El Dorado' ripple field provided by Spirit over the New Year's holiday weekend. The view spans about 160 degrees in azimuth from left to right and consists of images acquired by Spirit's panoramic camera on Spirit's 708th and 710th Martian days, or sols, (Dec. 30, 2005 and Jan. 1, 2006). Spirit used the Pancam's 750-nanometer, 530-nanometer and 430-nanometer filters to capture the colors on Mars. Scientists have eliminated seams between individual frames in the sky portion of the mosaic to better simulate the vista a person standing on Mars would see. Spirit spent several days acquiring images, spectral data, and compositional and mineralogical information about these large sand deposits before continuing downhill toward 'Home Plate.'

  5. The classification of minerals deposits

    In this part of book author present the classification of minerals deposits. Deposit formation take place as a result of complicated and long geology processes in the wide temperature intervals (from 1500 digC to usual) and pressures (from usual and to tens kilobars). Deposits of minerals as other investigation objects require in definite systematization on the base of definite characteristics

  6. HEDL sodium vapor deposit experience

    Sodium vapor deposits can affect reactor component operation and maintenance. Recorded cases include plugged cover gas lines and cementation of rotating components or sliding surfaces. Deposits found on plant scale components after testing in sodium were measured. Laboratory tests show the effect of Na pool temperature and condenser geometry on deposit accumulation rates and viewport fogging

  7. Limited Deposit Insurance Coverage and Bank Competition

    Shy, Oz; Stenbacka, Rune; Yankov, Vladimir

    2014-01-01

    Deposit insurance designs in many countries place a limit on the coverage of deposits in each bank. However, no limits are placed on the number of accounts held with different banks. Therefore, under limited deposit insurance, some consumers open accounts with different banks to achieve higher or full deposit insurance coverage. We compare three regimes of deposit insurance: No deposit insurance, unlimited deposit insurance, and limited deposit insurance. We show that limited deposit insuranc...

  8. Función de OCP3 en la resistencia de Arabidopsis frente a hongos necrotrofos.

    García-Andrade Serrano, Javier

    2016-01-01

    [EN] ocp3 mutant plants exhibit an accelerated and intensified callose deposition in response to infection by Botrytis cinerea or Plectosphaerella cucumerina. After phenotypic analysis of a series of double mutants ocp3 we observed that both, the increase callose deposition and resistance, require PMR4 callose synthase and hormone abscisic acid (ABA). In wild plants after infection with any of these necrotrophic fungi, ABA synthesis increases, this increase is even higher in ocp3. The greater...

  9. Deposition of carbon dioxide

    In Norway, there is currently a debate about whether or not to build gas power stations. To meet the possibility of reduced emission quotas for carbon dioxide in the future, current interest focuses on the incorporation of large-scale separation and deposition of carbon dioxide when such plants are planned. A group of experts concludes that this technology will become self-financing by means of environmental taxes. From the environmental point of view, taxes upon production are to be preferred over taxes on consumption

  10. Uranium ore deposits

    The main uranium deposits and occurrences in the Argentine Republic are described, considering, in principle, their geologic setting, the kind of 'model' of the mineralization and its possible origin, and describing the ore species present in each case. The main uraniferous accumulations of the country include the models of 'sandstong type', veintype and impregnation type. There are also other kinds of accumulations, as in calcrete, etc. The main uranium production has been registered in the provinces of Mendoza, Salta, La Rioja, Chubut, Cordoba and San Luis. In each case, the minerals present are mentioned, having been recognized 37 different species all over the country (M.E.L.)

  11. Sandstone-type uranium deposits

    Three overall factors are necessary for formation of uranium deposits in sandstone: a source of uranium, host rocks capable of transmitting uranium-bearing solutions, and a precipitant. Possible sources of uranium in sandstone-type deposits include groundwaters emanating from granitic highlands, arkosic sediments, tuffaceous material within or overlying the host rocks, connate fluids, and overlying black shales. The first three sources are considered the most likely. Host rocks are generally immature sandstones deposited in alluvial-fan, intermontane-basin or marginal-marine environments, but uranium deposits do occur in well-winnowed barrier-bar or eolian sands. Host rocks for uranium deposits generally show coefficients of permeability on the order of 1 to 100 gal/day/ft2. Precipitants are normally agents capable of reducing uranium from the uranyl to the uranous state. The association of uranium with organic matter is unequivocal; H2S, a powerful reductant, may have been present at the time of formation of some deposits but may go unnoticed today. Vanadium can serve to preserve the tabular characteristics of some deposits in the near-surface environment, but is considered an unlikely primary precipitant for uranium. Uranium deposits in sandstone are divided into two overall types: peneconcordant deposits, which occur in locally reducing environments in otherwise oxidized sandstones; and roll-type deposits, which occur at the margin of an area where an oxidized groundwater has permeated an otherwise reduced sandstone. Uranium deposits are further broken down into four subclasses; these are described

  12. FDIC Summary of Deposits (SOD) Download File

    Federal Deposit Insurance Corporation — The FDIC's Summary of Deposits (SOD) download file contains deposit data for branches and offices of all FDIC-insured institutions. The Federal Deposit Insurance...

  13. Lunar western limb pyroclastic deposits

    Coombs, Cassandra R.; Hawke, B. Ray

    1991-01-01

    It has become increasingly evident that the lunar pyroclastic volcanism played an important role in the formation and resurfacing of many areas of the Moon. On-going analysis of lunar Orbiter and Apollo photographs continues to locate and identify pyroclastic deposits and suggests that they just may be more ubiquitous than once thought. Located near mare/highland boundaries, many of these deposits formed contemporaneously with effusive mare volcanism. The mantling deposits formed as products of fire-fountaining. Probable source vents for these deposits include irregular depressions at the head of associated sinuous rilles and/or along irregular fractures in the floors of ancient craters. Here, researchers provide a brief synopsis of the nature of the dark mantling deposits and briefly discuss several newly identified deposits on the western limb.

  14. A remote coal deposit revisited

    Bojesen-Kofoed, Jørgen A.; Kalkreuth, Wolfgang; Petersen, Henrik I.;

    2012-01-01

    In 1908, members of the “Danmark Expedition” discovered a coal deposit in a very remote area in western Germania Land, close to the margin of the inland ice in northeast Greenland. The deposit was, however, neither sampled nor described, and was revisited in 2009 for the first time since its...... discovery. The outcrops found in 2009 amount to approximately 8 m of sediment including a coal seam of 2 m thickness. More outcrops and additional coal deposits most certainly are to be found, pending further fieldwork. The deposits are Middle Jurassic, Callovian, in age and were deposited in a floodplain...... environment related to meandering river channels. Spores and pollen in the lower fluvial deposits reflect abundant vegetation of ferns along the river banks. In contrast, a sparse spore and pollen flora in the coals show a mixed vegetation of ferns and gymnosperms. Based on proximate and petrographic analyses...

  15. Momentum Deposition in Curvilinear Coordinates

    Cleveland, Mathew Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lowrie, Robert Byron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rockefeller, Gabriel M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thompson, Kelly Glen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wollaber, Allan Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-03

    The momentum imparted into a material by thermal radiation deposition is an important physical process in astrophysics and inertial confinement fusion (ICF) simulations. In recent work we presented a new method of evaluating momentum deposition that relies on the combination of a time-averaged approximation and a numerical integration scheme. This approach robustly and efficiently evaluates the momentum deposition in spherical geometry. Future work will look to extend this approach to 2D cylindrical geometries.

  16. Enhanced nitrogen deposition over China

    Liu, Xuejun; Zhang, Ying; Han, Wenxuan; Tang, Aohan; Shen, Jianlin; Cui, Zhenling; Christie, Peter; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Vitousek, Peter [Department of Biology, Stanford University, Stanford, California 94305 (United States); Erisman, Jan Willem [VU University Amsterdam, 1081 HV Amsterdam (Netherlands); Goulding, Keith [The Sustainable Soils and Grassland Systems Department, Rothamsted Research, Harpenden AL5 2JQ (United Kingdom); Fangmeier, Andreas [Institute of Landscape and Plant Ecology, University of Hohenheim, 70593 Stuttgart (Germany)

    2013-02-28

    China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4+) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3-), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

  17. NURE uranium deposit model studies

    The National Uranium Resource Evaluation (NURE) Program has sponsored uranium deposit model studies by Bendix Field Engineering Corporation (Bendix), the US Geological Survey (USGS), and numerous subcontractors. This paper deals only with models from the following six reports prepared by Samuel S. Adams and Associates: GJBX-1(81) - Geology and Recognition Criteria for Roll-Type Uranium Deposits in Continental Sandstones; GJBX-2(81) - Geology and Recognition Criteria for Uraniferous Humate Deposits, Grants Uranium Region, New Mexico; GJBX-3(81) - Geology and Recognition Criteria for Uranium Deposits of the Quartz-Pebble Conglomerate Type; GJBX-4(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits in Mixed Fluvial-Shallow Marine Sedimentary Sequences, South Texas; GJBX-5(81) - Geology and Recognition Criteria for Veinlike Uranium Deposits of the Lower to Middle Proterozoic Unconformity and Strata-Related Types; GJBX-6(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits of the Salt Wash Type, Colorado Plateau Province. A unique feature of these models is the development of recognition criteria in a systematic fashion, with a method for quantifying the various items. The recognition-criteria networks are used in this paper to illustrate the various types of deposits

  18. Liquefier Dynamics in Fused Deposition

    Bellini, Anna; Guceri, Selcuk; Bertoldi, Maurizio

    2004-01-01

    Layered manufacturing (LM) is an evolution of rapid prototyping (RP) technology whereby a part is built in layers. Fused deposition modeling (FDM) is a particular LM technique in which each section is fabricated through vector style deposition of building blocks, called roads, which are then...

  19. Sandstone-type uranium deposits

    World-class sandstone-type uranium deposits are defined as epigenetic concentrations of uranium minerals occurring as uneven impregnations and minor massive replacements primarily in fluvial, lacustrine, and deltaic sandstone formations. The main purpose of this introductory paper is to define, classify, and introduce to the general geologic setting for sandstone-type uranium deposits

  20. Deposition and Resuspension of Particles

    Lengweiler, P.; Nielsen, Peter V.; Moser, A.;

    A new experimental set-up to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airBorne dust concentration considerably. As a basis for developing methods to eliminate dust related problems in rooms, there is a...

  1. Laser deposition of HTSC films

    Studies of the high-temperature superconducting (HTSC) films fabrication by the laser deposition are reviewed. Physical and chemical processes taking place during laser deposition are considered, such as the target evaporation, the material transport from the target to the substrate, the film growth on the substrate, thermochemical reactions and mass transfer within the HTSC films and their stability. The experimental results on the laser deposition of different HTSC ceramics and their properties investigations are given. The major technological issues are discussed including the deposition schemes, the oxygen supply, the target compositions and structure, the substrates and interface layers selection, the deposition regimes and their impact on the HTSC films properties. 169 refs.; 6 figs.; 2 tabs

  2. TULSA UNIVERSITY PARAFFIN DEPOSITION PROJECTS

    Michael Volk; Cem Sarica

    2003-10-01

    As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multiphase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines. The following deliverables are scheduled during the first three projects of the program: (1) Single-Phase Studies, with three different black oils, which will yield an enhanced computer code for predicting paraffin deposition in deepwater and surface pipelines. (2) Two

  3. Atmospheric deposition 2000. NOVA 2003; Atmosfaerisk deposition 2000. NOVA 2003

    Ellermann, T.; Hertel, O.; Hovmand, M.F.; Kemp, K.; Skjoeth, C.A.

    2001-11-01

    This report presents measurements and calculations from the atmospheric part of NOVA 2003 and covers results for 2000. It summarises the main results concerning concentrations and depositions of nitrogen, phosphorus and sulphur compounds related to eutrophication and acidification. Depositions of atmospheric compounds to Danish marine waters as well as land surface are presented. Measurements: In 2000 the monitoring program consisted of eight stations where wet deposition of ammonium, nitrate, phosphate (semi quantitatively) and sulphate were measured using bulk precipitation samplers. Six of the stations had in addition measurements of atmospheric content of A, nitrogen, phosphorus, and sulphur compounds in gas and particulate phase carried out by use of filter pack samplers. Filters were analysed at the National Environmental Research Institute. Furthermore nitrogen dioxide were measured using nitrogen dioxide filter samplers and monitors. Model calculations: The measurements in the monitoring program were supplemented with model calculations of concentrations and depositions of nitrogen and sulphur compounds to Danish land surface, marine waters, fjords and bays using the ACDEP model (Atmospheric Chemistry and Deposition). The model is a so-called trajectory model and simulates the physical and chemical processes in the atmosphere using meteorological and emission data as input. The advantage of combining measurements with model calculations is that the strengths of both methods is obtained. Conclusions concerning: 1) actual concentration levels at the monitoring stations, 2) deposition at the monitoring stations, 3) seasonal variations and 4) long term trends in concentrations and depositions are mainly based on the direct measurements. These are furthermore used to validate the results of the model calculations. Calculations and conclusions concerning: 1) depositions to land surface and to the individual marine water, 2) contributions from different emission

  4. Acid Deposition Maps in Spain

    Animal and monthly deposition velocity and total sulfur deposition maps have been performed for the peninsular Spain for 1992 by using the inferential method. To do this, updated databases with high space and time resolution, for land uses (CORINE) and meteorological information from analysis modelling for the same year, have been utilized. The final result are deposition maps in a 5x5 Km2 grid which allow to assess the methodology used in Europe to obtain the maps of excedances over the critical loads of pollutants. (Author) 32 refs

  5. Reforming deposit insurance and FDICIA

    Robert A. Eisenbeis; Larry D. Wall

    2002-01-01

    Current discussions about deposit insurance reform center on issues such as the size of insurance premiums, the size of the fund, and the size of the coverage limits-all issues that reflect a concern with how to allocate the losses arising from bank failures. The authors of this article argue that such issues, while important, do not affect the performance of the deposit insurance system nor should they be the focus of deposit insurance reform. They suggest that reform efforts should be direc...

  6. Particle deposition in ventilation ducts

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on

  7. Plasma Deposition of Amorphous Silicon

    Calcote, H. F.

    1982-01-01

    Strongly adhering films of silicon are deposited directly on such materials as Pyrex and Vycor (or equivalent materials) and aluminum by a non-equilibrium plasma jet. Amorphous silicon films are formed by decomposition of silicon tetrachloride or trichlorosilane in the plasma. Plasma-jet technique can also be used to deposit an adherent silicon film on aluminum from silane and to dope such films with phosphorus. Ability to deposit silicon films on such readily available, inexpensive substrates could eventually lead to lower cost photovoltaic cells.

  8. Ferroelectric thin films deposited by pulsed laser deposition

    Dinu, Raluca; Vrejoiu, I.; Verardi, P.; Craciun, F.; Dinescu, Maria

    2001-06-01

    Influence of substrate and electrode on the properties of PbZr0.53Ti0.47O3 (PZT) thin films grown by pulsed laser deposition technique (1060 nm wavelength Nd:YAG laser light, 10 ns pulse duration, 10 Hz repetition rate, 0.35 J/pulse, 25 J/cm2 laser fluence, deposition rate about 1 angstrom/pulse) was studied. The substrate temperatures were in the range 380 degree(s)C-400 degree(s)C. Oriented crystalline PZT layers with 1-3 micrometers thickness were deposited on glass substrates plated with Au/Pt/NiCr electrodes, from a PZT commercial target in oxygen reactive atmosphere. The deposited PZT films with perovskite structure were preferentially oriented along the (111) direction as revealed from XRD spectra. Piezoelectric d33 coefficients up to 30 pC/N were obtained on as deposited films. Ferroelectric hysteresis loops at 100 Hz revealed a remanent polarization of 15 (mu) C/cm2 and a coercive field of 100 kV/cm. A comparison with properties of PZT films deposited using a KrF laser and with SrBi2Ta2O9 (SBT) films is reported.

  9. Hereditary iron and copper deposition

    Aaseth, Jan; Flaten, Trond Peder; Andersen, Ole

    2007-01-01

    Hereditary deposition of iron (primary haemochromatosis) or copper (Wilson's disease) are autosomal recessive metabolic disease characterized by progressive liver pathology and subsequent involvement of various other organs. The prevalence of primary haemochromatosis is approximately 0.5%, about...

  10. Cathodoluminescence in Quaternary carbonate deposits

    Braithwaite, Colin J. R.

    2016-05-01

    The cathodoluminescent oscillatory and sectoral growth zones common in crystals formed in ancient limestone successions in a variety of putative environments appear to be rare or absent from Recent and Pleistocene marine carbonate sequences. The factors controlling cathodoluminescence and reasons for this disparity are examined. The cathodoluminescent zones in the cements of ancient rocks have been interpreted as responses to variations in the redox potential of formative pore waters during crystal growth; although similar cathodoluminescent behaviour is recorded from some deposits, including travertines and Quaternary speleothems, formed in what are thought to have been strongly oxidizing environments. The apparent absence of cathodoluminescence in the most Recent and Pleistocene marine deposits, that presumably reflect deposition and diagenesis in environments that are also characteristically oxidized, therefore seems anomalous. The controlling influences on cathodoluminescence are reviewed, together with evidence relating to observations of Pleistocene marine deposits and likely conditions of formation but, where it is present, the mechanism(s) for its development remain elusive.

  11. Gasoline from Kumkol deposit petroleum

    Samples of gasoline from petroleum of Kumkol deposit are investigated by chromatographic analysis. It is found, that gasoline is characterizing by increased content of iso-paraffin hydrocarbons. (author)

  12. Language and development in FG syndrome with callosal agenesis.

    McCardle, P; Wilson, B

    1993-06-01

    The FG syndrome is characterized by unusual facies, sudden infant death, developmental delay, and abnormalities of the cardiac, gastrointestinal, and central nervous systems. No longitudinal data on development in surviving patients are currently available. Serial evaluations of a patient with FG syndrome, whose sole central nervous system anomaly was agenesis of the corpus callosum, showed a consistent pattern over time. Specific language impairments in syntactic and pragmatic-semantic areas are emerging. These findings represent the first detailed data on which expectations for children with the FG syndrome can be based. The findings also fit theoretical constructs on the function of the corpus callosum and may therefore be generalized to provide expectations for other patients with isolated agenesis of the corpus callosum. Given the information gained from this case, it is clear that language intervention/consultation should be a pivotal service for such children, and that the speech-language pathologist should play a role in the development of an integrated educational services plan. PMID:7688382

  13. Uranium deposits in volcanic rocks

    Twenty-eight papers were presented at the meeting and two additional papers were provided. Three panels were organized to consider the specific aspects of the genesis of uranium deposits in volcanic rocks, recognition criteria for the characterization of such deposits, and approaches to exploration. The papers presented and the findings of the panels are included in the Proceedings. Separate abstracts were prepared for each of these papers

  14. Vapor deposition of hardened niobium

    Blocher, Jr., John M.; Veigel, Neil D.; Landrigan, Richard B.

    1983-04-19

    A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.

  15. Composition for preventing salt depositing

    Mikhaylov, S.A.; Balakin, V.M.; Lezhenin, V.V.; Litvinets, Yu.I.; Marinin, N.S.; Talankin, V.S.; Yaryshev, G.M.

    1982-01-01

    A composition is proposed for preventing salt depositing which includes polyethylene-polyamine-N-methyl phosphonic acid or its salt and water. It is distinguished by the fact that in order to improve the degree of prevention of the salt depositing under low temperature conditions, it additionally contains ethylene glycol with the following ratio of components (% by mass): polyethylene polyamine-N-methylphosphonic acid or its salt 5-12; ethylene glycol 30-50; water--the rest.

  16. [Free fatty acids: mediators of insulin resistance and atherosclerosis].

    Castro Cabezas, M; Erkelens, D W; van Dijk, H

    2002-01-19

    Free fatty acids (FFAs) are involved in the transportation of energy; in the postprandial phase to the peripheral tissues and in the postabsorptive phase from the adipose tissue to the liver. In the postprandial phase, FFAs are mainly derived from hydrolysis of triglyceride-rich particles like chylomicrons and very low-density lipoproteins (VLDL). The flux of FFAs is directed to peripheral cells such as adipocytes and muscle cells. In the postabsorptive period, FFAs are transported to the liver after being released from intracellular storage in the adipocytes. Complement component 3 (C3) plays an important role in the uptake of free fatty acids by the peripheral cells and their esterification to triglycerides. Since C3 is also involved in the pathogenesis of the insulin resistance syndrome, and since a deviant FFA metabolism with an increased FFA flux to the liver may induce insulin resistance, it is hypothesized that C3 may form the missing link between FFA metabolism and insulin resistance. In addition, recent studies have increasingly indicated that atherosclerosis is in fact an inflammation-based process involving complement-dependent responses, in which FFAs seem to play a role in the complement-dependent pathway. It has recently become apparent that FFAs have a regulatory function in the transcription of DNA, in relation to lipoprotein metabolism. This is where PPAR-gamma and PPAR-alpha agonists ('glitazones' and fibrates respectively) are active (PPAR is an abbreviation for peroxisome proliferation activating receptor). Glitazons may play an important role in the treatment of insulin resistance and related disorders. Acquiring more knowledge about the relationship between complement and FFA metabolism may increase our understanding of these processes and provide openings for the development of new antiatherogenic strategies. PMID:11826668

  17. Fulvic Acid Mediated Photolysis of Ibuprofen in Water.

    Photolysis of the nonsteroidal anti-inflammatory drug ibuprofen was studied in solutions of fulvic acid (FA) isolated from Pony Lake, Antarctica; Suwannee River, GA, USA; and Old Woman Creek, OH, USA. At an initial concentration of 10 µM ibuprofen degrades by direct photolysis...

  18. Retinoic Acid-mediated Nuclear Receptor Activation and Hepatocyte Proliferation

    Bushue, Nathan; Wan, Yu-Jui Yvonne

    2016-01-01

    Due to their well-known differentiation and apoptosis-inducing abilities, retinoic acid (RA) and its analogs have strong anti-cancer efficacy in human cancers. However, in vivo RA is a liver mitogen. While speculation has persisted that RA-mediated signaling is likely involved in hepatocyte proliferation during liver regeneration, direct evidence is still required. Findings in support of this proposition include observations that a release of retinyl palmitate (the precursor of RA) occurs in liver stellate cells following liver injury. Nevertheless, the biological action of this released vitamin A is virtually unknown. More likely is that the released vitamin A is converted to RA, the biological form, and then bound to a specific receptor (retinoid x receptor; RXRα), which is most abundantly expressed in the liver. Considering the mitogenic effects of RA, the RA-activated RXRα would likely then influence hepatocyte proliferation and liver tissue repair. At present, the mechanism by which RA stimulates hepatocyte proliferation is largely unknown. This review summarizes the activation of nuclear receptors (peroxisome proliferator activated receptor-α, pregnane x receptor, constitutive androstane receptor, and farnesoid x receptor) in an RXRα dependent manner to induce hepatocyte proliferation, providing a link between RA and its proliferative role.

  19. New insights into the acid mediated disproportionation of pentavalent uranyl

    Mougel, Victor; Biswas, Biplab; Pecaut, Jacques; Mazzanti, Marinella [Laboratoire de Reconnaissance Ionique et Chimie de Coordination, SCIB, UMR-E 3 CEA-UJF FRE 3200 CNRS, INAC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 09 (France)

    2010-07-01

    The reaction of benzoic acid with the uranyl(V) complex [(UO{sub 2}Py{sub 5})(KI{sub 2}Py{sub 2})] in pyridine leads to immediate disproportionation with formation of a hexa-nuclear U(IV) benzoate cluster, a bis-benzoate complex of uranyl(VI) and water. (authors)

  20. Felsic magmatism and uranium deposits

    The strongly incompatible behaviour of uranium in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behavior, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth, which crystallized uraninite, dated at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: per-alkaline, high-K met-aluminous calc-alkaline, L-type peraluminous and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass of their volcanic equivalents represent the best U source. Per-alkaline granites or syenites are associated with the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction under the present economic conditions and make them unfavorable U sources for other deposit types. By contrast, felsic per-alkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals (U-thorite, allanite, Nb oxides) become metamict. The volcanic rocks of the same geochemistry may be

  1. A Radon Progeny Deposition Model

    Guiseppe, V E; Hime, A; Rielage, K; Westerdale, S

    2011-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly Rn-222) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of Pb-210 on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to depos...

  2. [Calcium pyrophosphate dihydrate deposition disease].

    Koitschev, C; Kaiserling, E; Koitschev, A

    2003-08-01

    Calcium pyrophosphate dihydrate deposition disease (CPPD) of the temporomandibular joint is rare. The disorder is characterized by the presence of crystal deposits within the affected joint. The deposition of crystals in adjacent soft tissue may lead to the formation of pseudotumors. This form of the disease is called tophaceous pseudogout and typically affects the temporomandibular joint. It is difficult to differentiate the disease, particularly from malignant tumors, on the clinical and radiographic findings alone. The diagnosis is based on histological identification of the calcium pyrophosphate crystals. We present an unusually advanced case of tophaceous pseudogout of the temporomandibular joint. The etiology, clinical and diagnostic criteria as well as treatment options are discussed on the basis of our own experience and a review of the literature. PMID:12942180

  3. Kalan uranium deposit profitability expectation

    The aims of this paper were to reevaluate the chance for uranium deposit at Kalan to be profitable to mine. For that reasons, it is necessary to calculate not only the expenses, but also to give and estimation of the value of the uranium to be produced. Mining and milling considerations had been made for Eko-Hi tam and Rirang-Tanah Merah deposits. It is sugested that feasibility study is needed for determination of the most suitable mining method to be applied for those deposits. It was also suggested that an upgrade of milling feed is needed for ore processing. The use of Knelson concentrator was introduced for ore sorting. (author); 4 refs; 3 figs

  4. Sub-aerial tailings deposition

    The sub-aerial technique involves the systematic deposition of tailings in thin layers and allowing each layer to settle, drain and partially air dry prior to covering with a further layer. Underdrainage produces densities in excess of those achieved by sub-aqueous deposition and any air-drying serves to preconsolidate each layer with a resulting further increase in density. The low permeability of the tailings surface resulting from this deposition technique results in high runoff coefficients and, by decanting the runoff component of direct precipitation, a net evaporation condition can be achieved even in high rainfall areas. An underdrainage system prevents the build-up of excess pore-pressures within the tailings mass and at decommissioning the tailings are fully consolidated and drained thereby eliminating the possibility of any long term seepage. This paper presents a general description of these design concepts, and details of two projects where the concepts have been applied

  5. TULSA UNIVERSITY PARAFFIN DEPOSITION PROJECTS

    Cem Sarica; Michael Volk

    2004-06-01

    As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multi-phase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines, because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines.

  6. 78 FR 56583 - Deposit Insurance Regulations; Definition of Insured Deposit

    2013-09-13

    ... exposure, but argued that it would adversely affect public relations. The commenter suggested that foreign... changes. \\15\\ 78 FR 11604 (February 19, 2013). II. Statutory Framework A. Definition of ``Insured Deposit....C. 1820(g); see, e.g., Unlimited Coverage for Noninterest- Bearing Transaction Accounts, 75 FR...

  7. Nanofriction properties of molecular deposition films

    王强斌; 高芒来; 张嗣伟

    2000-01-01

    The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that ( i ) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ii) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (iii) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (iv) the relat

  8. Sandstone-type uranium deposits

    Sandstone deposits represent a large part of the world's uranium deposits, and are particularly common in the United States of America. Orebodies of this type tend to exhibit many of the following features: (1) tabular or roll shape; (2) cross-bedded grey or green sandstone host rock, generally of Silurian or younger age; (3) a certain minimum thickness of sandstone; (4) mudstone interbedded with the sandstone; and (5) abundant organic matter and pyrite. The orebodies contain mainly uraninite and coffinite, with carnotite and other secondary minerals, and are commonly clustered along mineral trends. (author)

  9. Tumoral calcium pyrophosphate deposition disease

    A report of two patients in which a soft tissue mass, initially regarded as a malignant tumor, was shown to be the result of calcium pyrophosphate deposition disease. The first case, a woman aged 71 years, presented with a mass involving the right fifth finger. In the second case, also a women aged 71 years, the lesion involved the tissues adjacent to the right hip. Each lesion consisted of a mass of highly cellular tissue containing deposits of calcium pyrophosphate dihydrate crystals. The clinical, radiological, and pathological features of the two cases are compared with those of seven similar cases reported in the literature. (orig.)

  10. Deposition of diamondlike carbon films

    Mirtich, M. J.; Sovey, J. S.; Banks, B. A. (Inventor)

    1984-01-01

    A diamondlike carbon film is deposited in the surface of a substrate by exposing the surface to an argon ion beam containing a hydrocarbon. The current density in the ion beam is low during initial deposition of the film. Subsequent to this initial low current condition, the ion beam is increased to full power. At the same time, a second argon ion beam is directed toward the surface of the substrate. The second ion beam has an energy level much greater than that of the ion beam containing the hydrocarbon. This addition of energy to the system increases mobility of the condensing atoms and serves to remove lesser bound atoms.

  11. Advanced deposition model for thermal activated chemical vapor deposition

    Cai, Dang

    Thermal Activated Chemical Vapor Deposition (TACVD) is defined as the formation of a stable solid product on a heated substrate surface from chemical reactions and/or dissociation of gaseous reactants in an activated environment. It has become an essential process for producing solid film, bulk material, coating, fibers, powders and monolithic components. Global market of CVD products has reached multi billions dollars for each year. In the recent years CVD process has been extensively used to manufacture semiconductors and other electronic components such as polysilicon, AlN and GaN. Extensive research effort has been directed to improve deposition quality and throughput. To obtain fast and high quality deposition, operational conditions such as temperature, pressure, fluid velocity and species concentration and geometry conditions such as source-substrate distance need to be well controlled in a CVD system. This thesis will focus on design of CVD processes through understanding the transport and reaction phenomena in the growth reactor. Since the in situ monitor is almost impossible for CVD reactor, many industrial resources have been expended to determine the optimum design by semi-empirical methods and trial-and-error procedures. This approach has allowed the achievement of improvements in the deposition sequence, but begins to show its limitations, as this method cannot always fulfill the more and more stringent specifications of the industry. To resolve this problem, numerical simulation is widely used in studying the growth techniques. The difficulty of numerical simulation of TACVD crystal growth process lies in the simulation of gas phase and surface reactions, especially the latter one, due to the fact that very limited kinetic information is available in the open literature. In this thesis, an advanced deposition model was developed to study the multi-component fluid flow, homogeneous gas phase reactions inside the reactor chamber, heterogeneous surface

  12. Large cooling tower drift deposition

    A model for the determination of drift deposition around natural-draft cooling towers is presented. An application of the model in actual operating conditions indicates the effect of drift rate at the cooling tower outlet and weather conditions on the size and shape of wetted area. (author)

  13. Simple Chemical Vapor Deposition Experiment

    Pedersen, Henrik

    2014-01-01

    Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

  14. ECONOMIC GEOLOGY (2)NONMETALS DEPOSITS

    2008-01-01

    <正>20082329 Chen Wang(China University of Geosciences,Beijing 100083,China) Control Factors on Distribution of Carboniferous Bauxite Deposits in Western Henan Province (Geotectonica et Metallogenia,ISSN1001—1552,CN44—1595/P,31(4),2007,p.452—456,1 illus.,10 refs.) Key words:bauxite,mineralization con- trols,Henan Province

  15. The uranium deposits of Ontario

    The principal types of uranium deposits in Ontario are carbonatites and fenites, alkalic volcanic rocks, pegiatites, calc-silicate rocks, pyritic quartz-pebble conglomerates, polymictic conglomerates and some pelitic rocks, and various 'pitchblende' deposits including late Precambrian unconformities, possibly late Precambrian diabase dikes, and other unconformities: carbonates, sandstones, lignites, and semi-pelitic rocks of middle and upper Precambrian age. Only red unzoned pegmatite and the pyritic quartz-pebble conglomerate have supported production. Ontario reasonably assured and estimated resources in the economic and subeconomic categories in 1977 amounted to 553 000 tonnes U, and 1977 production was 4000 tonnes U. Measured, indicated, and inferred resources in the Elliot Lake - Agnew Lake area are at least 400 000 tonnes U. The latter deposits are also a significant thorium resource. Geological features reflecting major changes in physics and chemistry are prime controls on distribution of uranium deposits. Geological province and subprovince boundaries, major faults, higher metamorphic grades, domain boundaries related to quartz monzonite batholiths, alkalic complexes, and the distribution of carbonate rocks are examples of such geological features

  16. Electro-spark deposition technology

    Johnson, R.N. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-12-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The ESD process was developed to produce coatings for use in severe environments where most other coatings fail. Because of the exceptional damage resistance of these coatings, and the versatility of the process to apply a wide variety of alloys, intermetallics, and cermets to metal surfaces, the ESD process has been designated critical to the life and economy of the advanced fossil energy systems as the higher temperatures and corrosive environments exceed the limits of known structural materials to accommodate the service conditions. Developments include producing iron aluminide-based coatings with triple the corrosion resistance of the best previous Fe{sub 3}Al coatings, coatings with refractory metal diffusion barriers and multi layer coatings for achieving functionally gradient properties between the substrate and the surface. A new development is the demonstration of advanced aluminide-based ESD coatings for erosion and wear applications. One of the most significant breakthroughs to occur in the last dozen years is the discovery of a process regime that yields an order of magnitude increase in deposition rates and achievable coating thicknesses. Achieving this regime has required the development of advanced ESD electronic capabilities. Development is now focused on further improvements in deposition rates, system reliability when operating at process extremes, and economic competitiveness.

  17. Deposition and Resuspension of Particles

    Lengweiler, P.; Nielsen, Peter V.; Moser, A.;

    To investigate the physical process of deposition and resuspension of particles in the indoor environment, scale experiments are used and a sampling method is established. The influences of surface orientation and turbulence and velocity of the air on the dust load on a surface are analysed....

  18. Effect of 5-aminolevulinic acid-mediated photodynamic therapy on human gastric cancer xenografts in nude mice in vivo%5-氨基乙酰丙酸介导的光动力学对裸鼠人胃癌移植瘤的治疗作用

    周广军; 黄宗海; 俞金龙; 厉周; 丁涟沭

    2008-01-01

    Objective To investigate the effect of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) on human gastric cancer xenografts in vivo and to explore its potential tumoreidal mechanism. Methods Cultured MGC-803 human gastric cancer cells were injected below the skins of the nude mice to develop the tumor model. The tumor-bearing nude mice were examined under the Leica LT-9MACIMSYSPULS to detect the fluorescence. The tumor volume of day 1, 3, 7, 14, 21 after treatment were measured, and its histological changes were also studied. The tissues of the tumors in nude mice of the control group, light group, 5-ALA group and PDT group were examined with the electron microscope and apoptosis was detected by TUNEL assay. Results The tumor model was successfully developed. The tumor in the nude mice emited the red fluorescence under the Leica LT-9MACIMSYSPULS. The tumor volumes were (0.189±0.010)cm3, (0.183±0.011)cm3, (0.185±0.019) cm3, (0.182±0.015)cm3 for the control group, light group, 5-ALA group, PDT group, respectively at day 1 after treatment, while at day 3, (0.294±0.010)cm3, (0.280±0.013)cm3, (0.278±0.016)cm3, (0.183±0.014)cm3;at day 7, (0.409±0.016)cm3, (0.411±0.009)cm3, (0.407±0.015)cm3, (0.221±0.008)cm3;at day 14, (0.970±0.055)cm3 (0.976±0.054)cm3, (0.981±0.032)cm3, (0.318±0.005)cm3;at day 21, (1.495±0.059)cm3, (1.513±0.057)cm3, ( 1.524±0.063)cm3, (0.446±0.042)cm3(F=1003.086, P=0.000). The histology demonstrated that most tumor blood vessels were congested and necrosis developed after PDT while not in the control group, light group and 5-ALA group. Necrosis and apoptosis were observed in the cells of the tumors of the PDT group examined by TUNEL and electron microscope while not in the cells of the tumors of the other groups. Conclusions 5-aminolevulinic acid-mediated photodynamic therapy (PDT) can induce injury to human gastric cancer xenografts and inhibit the tumor growth while light only and 5-ALA only can not. 5-aminolevulinic

  19. Vapor deposition of tantalum and tantalum compounds

    Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

  20. Computational study of wax deposition in pipeline

    Duan, Jimiao; Gong, Jing; Liu, Huishu

    2013-07-01

    Wax deposition in subsea pipelines is one of the flow assurance problems for oil and gas production. In contrast to many studies about single phase wax deposition, gas-oil wax deposition studies are very limited. The wax deposition mechanism and model prediction are restricted by many factors such as hydrodynamic and thermal when multiphase flow is involved. Wax deposition modeling becomes complicated under multiphase flowing conditions. wax deposition is depended by the flow pattern. The stratified flow is one of the most common flow patterns in the actual subsea gas-oil flowing conditions. In this work, numerical methods are used to study wax deposition in oil-gas stratified flow through a pipe. Based on the flow analysis about stratified flow, the non-isothermal heat and mass transfer is calculated. The temperature profile of the oil and the concentration profile of wax in oil are obtained. The change of the oil-gas interface i.e. the liquid holdup throughout the pipe must be taken into the heat and mass balance. The valid wax deposition surface must be taken into the wax deposition modeling by establishing function of the liquid holdup and the wetted area by oil. The molecular diffusion is as the deposition mechanism. The increase of the wax fraction in the deposit as a function of time depends on the mass flux from the oil deposit interface into the gel and the growth of the deposit thickness depends on the difference between the mass flux from the bulk oil to the oil deposit interface and the mass flux from the interface into the deposit. In addition, the growth of the wax deposit as a function of time along with the effect oil flow rate, gas flow rate and the inlet temperature are discussed. The presence of gas significantly reduces the severity of wax deposition by altering the heat and mass transfer characteristics.

  1. Atmosfærisk deposition

    Ellermann, T.; Hertel, O.; Kemp, K.;

    Kvælstofdepositionen til danske havområder, fjorde, vige og bugte er for 2001 blevet beregnet til 118 ktons N, hvilket er ca. 20 % lavere end i 2000. Tilsvarende er depositionen til landområderne beregnet til 87 ktons N, hvilket svarer til deposition i 2000. Den primære årsag til den højere...... deposition for 1999-2001, i forhold til tidligere år, er ændringer i beregningsmetoden. Den samlede kvælstofdeposition til farvandene er faldet svagt i perioden 1989-2001. Depositionen til landoverflader skønnes ikke ændret betydeligt. Depositionen af svovlforbindelser til danske landområder er for 2001...

  2. Electrochemical Depositions in Ionic Liquids

    De Vreese, Peter

    2013-01-01

    In this PhD thesis, several aspects of the electrodeposition of metals and alloys in ionic liquids were investigated. First, the deposition of brass from choline acetate was studied. Secondly, the electrodeposition of pure molybdenum from ionic liquids based on phosphonium chloride and zinc chloride was treated. In each case, the influence of water, either as a main constituent of the electrolyte or an impurity, was investigated. When comparing electrochemical processes such as electrodeposit...

  3. Electro-spark deposition technology

    Johnson, R.N. [Pacific Northwest Lab., WA (United States)

    1996-08-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The ESD process was developed to produce coatings for use in severe environments where most other coatings fail. Because of the exceptional damage resistance of these coatings, and the versatility of the process to apply a wide variety of alloys, intermetallics, and cermets to metal surfaces, the ESD process has been designated as one of the enabling technologies for advanced energy systems. Developments include producing iron aluminide-based coatings with triple the corrosion resistance of the best previous Fe{sub 3}Al coatings, coatings with refractory metal diffusion barriers and multi layer coatings for achieving functionally gradient properties between the substrate and the surface. One of the most significant breakthroughs to occur in the last dozen years is the discovery of a process regime that promises an order of magnitude increase in deposition rates and achievable coating thicknesses. Since this regime borders on and exceeds the normal operating limits of existing ESD electronic equipment, development is in progress to produce equipment that can consistently and reliably achieve these conditions for a broad range of materials. Progress so far has resulted in a consistent 500% increase in deposition rates, and greater rates still are anticipated. Technology transfer activities are a significant portion of the ESD program effort. Notable successes now include the start-up of a new business to commercialize the ESD technology, the incorporation of the process into the operations of a major gas turbine manufacturer, major new applications in gas turbine blade and steam turbine blade protection and repair, and in military, medical, metal-working, and recreational equipment applications.

  4. Complexing and hydrothermal ore deposition

    Helgeson, Harold C

    1964-01-01

    Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

  5. CTD_DATABASE - Cascadia tsunami deposit database

    U.S. Geological Survey, Department of the Interior — The Cascadia Tsunami Deposit Database contains data on the location and sedimentological properties of tsunami deposits found along the Cascadia margin. Data have...

  6. Are international deposits tax-driven?

    Huizinga, H.P.; Nicodeme, G.

    2004-01-01

    This paper investigates the impact of tax policy on international depositing. Non-bank international deposits are shown to be positively related to interest income and wealth taxes and to the presence of domestic bank interest reporting. This suggests that international deposits are in part intended to facilitate tax evasion. The tax sensitivity of international deposits is estimated to be higher in 1999 than before. At present, only part of international interest flow are covered by either n...

  7. Adhesion Strength of Biomass Ash Deposits

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2015-01-01

    This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...

  8. 75 FR 6348 - Deposit of Biological Materials

    2010-02-09

    ... Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection; comment request....Fawcett@uspto.gov . Include ``0651-0022 Deposit of Biological Materials comment'' in the subject line of....Hanlon@uspto.gov . SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part...

  9. Silicidation of Niobium Deposited on Silicon by Physical Vapor Deposition

    Coumba Ndoye, Kandabara Tapily, Marius Orlowski, Helmut Baumgart, Diefeng Gu

    2011-07-01

    Niobium was deposited by physical vapor deposition (PVD) using e-beam evaporation on bare (100) silicon substrates and SiO2 surfaces. The formation of niobium silicide was investigated by annealing PVD Nb films in the temperatures range 400–1000°C. At all elevated annealing temperatures the resistivity of Nb silicide is substantially higher than that of Nb. The Nb silicidation as a function of temperature has been investigated and different NbXSiy compounds have been characterized. It has been observed that the annealing of the Nb film on Si is accompanied by a strong volume expansion of about 2.5 of the resulting reacted film. The films' structural properties were studied using X-Ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM), which was not previously presented in the context of the extant NbSi literature. The X-Ray diffraction characterization of the Nb on Si sample annealed at 1000°C, showed the presence of hexagonal Nb5Si3 phases, with a dominant peak at the (200) plane, and NbSi2 phases. Fractal dimension calculations indicate a distinct transition from Stranski-Krastanov to Volmer-Weber film growth for NbSi formation at the annealing temperature of 600°C and above.

  10. Deposition station for selenium isotopes

    Complete text of publication follows. Isotopic tracing of nanoparticles mostly involved in environmental and metabolic processes, industrial, and agricultural technologies, attracts an increasing attention nowadays. As an experimental goal, for proposed tracing studies selenium was chosen, which is an essential trace element for the nutrition of almost all living organisms, since it plays a crucial role in the antioxidant activity of seleno-enzymes. Selenium in forms of nanoparticles being synthesized by wet chemical or microbial dissimilatory processes, turned out to possess new functionality as examplified in affecting semiconductor properties, toxicity, and growth factors, which are important for both nutritional supplements and potential cancer therapy agents. Stable isotope tracing of selenium nanoparticles under in vivo conditions would then yield relevant information on biodistributions, efficiency and safety issues of applications. A prototype version of a deposition station for enrichment of stable selenium isotopes was constructed and installed downstream to the sector magnet of the DiSP isotope separator. The deposition of the isotopic beam particles was carried out with the use of selfsputtering technique. The beam with a kinetic energy of 25-30 keV was first guided through electrostatic elements, where it was focused and decelerated to 300-500 eV (Fig. 1). The geometry of the electrostatic lenses was designed with the simulation code SIMION 8. The outcoming beam impinged upon the surface of a tungsten disc, on which recombination and selfsputtering of selenium ions occurred. Sputtering yields and efficiencies were measured as a function of beam intensities. It was concluded that emission of the selenium atoms can be predominantly attributed to heat spike mechanism due to large differences in evaporation characteristics of selenium and tungsten. The selenium atoms were then deposited as a thin film on a polypropylene (PP) surface with a conical geometry

  11. Adhesion Strength of Biomass Ash Deposits

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2016-01-01

    Ash deposition on boiler surfaces is a major problem encountered during biomass combustion. Ash deposition adversely influences the boiler efficiency, may corrode heat transfer surfaces, and may even completely block flue gas channels in severe cases, causing expensive unscheduled boiler shutdowns....... Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...

  12. Towards a genetic classification of uranium deposits

    As the IAEA's uranium deposit classification is based on the deposit nature and morphology, some deposits which have been formed by very different genetic processes and located in very different geological environments, are grouped according to this classification. In order to build up a reliable genetic classification based on the mechanism at the origin of the formation of the deposit, the author presents the five main categories according to which uranium deposits can be classified: magmatic, hydrothermal, evapotranspiration, syn-sedimentary, and infiltration of meteoric water

  13. Particle deposition in granular media: Progress report

    Tien, Chi

    1987-01-01

    This paper discusses topics on particle deposition in granular media. The six topics discussed are: experimental determination of initial collection efficiency in granular beds - an assessment of the effect of instrument sensitivity and the extent of particle bounce-off; deposition of polydispersed aerosols in granular media; in situ observation of aerosol deposition in a two-dimensional model filter; solid velocity in cross-flow granular moving bed; aerosol deposition in granular moving bed; and aerosol deposition in a magnetically stabilized fluidized bed. (LSP)

  14. Impulse Plasma Deposition (IPD) of Compound powder

    Different powder materials have been deposited by Impulse plasma Deposition(IPD) using coaxial plasma accelerator. Commercial compound powder is placed at the breach of the plasma accelerator. For discharge energy of 208 Joule, the deposited layer thickness was 3 nm/pulse. Analyses showed that the deposited layer consists of the different materials in the powder compound. Plasma current sheath carried the powder ions has been studied experimentally and theoretically. The grain size distribution for the deposited materials showed that most of the grain size is 2 um with Maxwellian distribution

  15. Carbonate Deposition on Antarctic Shelves

    Frank, T. D.; James, N. P.; Malcolm, I.

    2011-12-01

    Limestones associated with glaciomarine deposits occur throughout the geologic record but remain poorly understood. The best-described examples formed during major ice ages of the Neoproterozoic and Late Paleozoic. Quaternary analogs on Antarctic shelves have received comparatively little study. Here, we report on the composition, spatial distribution, and stratigraphic context of carbonate sediments contained in piston cores from the Ross Sea. The goals of this work are to (1) document the nature and distribution of carbonate sediments on the Ross Sea continental shelf and (2) examine temporal relationships to Quaternary glaciation. Results will be used to develop criteria that will improve understanding of analogous deposits in the ancient record. All carbonate-rich intervals in piston cores from the Ross Rea, now housed at the Antarctic Marine Geology Research Facility at Florida State University, were examined and described in detail. Sediment samples were disaggregated and sieved into size fractions before description with paleontological analysis carried out on the coarsest size fraction (>250 microns). Carbonate-rich sediments are concentrated in the northwestern Ross Sea, along the distal margins of Mawson and Pennell Banks. Calcareous facies include a spectrum of lithologies that range from fossiliferous mud, sand, and gravel to skeletal floatstone-rudstone and bafflestone. Floatstone-rudstone and bafflestone is most abundant along western-facing slopes in areas protected from the Antarctic Coastal Current. Sand-prone facies dominate the tops of banks and mud-prone, often spicultic, facies occur in deeper areas. The carbonate factory is characterized by a low-diversity, heterozoan assemblage that is dominated by stylasterine hydrocorals, barnacles, and bryozoans. Molluscs and echinoids are present but not abundant. Planktic and benthic foraminifera are ubiquitous components of the sediment matrix, which is locally very rich in sponge spicules. Biota rarely

  16. Minerals deposited as thin films

    Free matrix effects are due to thin film deposits. Thus, it was decided to investigate this technique as a possibility to use pure oxide of the desired element, extrapolating its concentration from analytical curves made with avoiding, at the same time, mathematical corrections. The proposed method was employed to determine iron and titanium concentrations in geological samples. The range studied was 0.1-5%m/m for titanium and 5-20%m/m for iron. For both elements the reproducibility was about 7% and differences between this method and other chemical determinations were 15% for titanium and 7% for iron. (Author)

  17. Metal deposition using seed layers

    Feng, Hsein-Ping; Chen, Gang; Bo, Yu; Ren, Zhifeng; Chen, Shuo; Poudel, Bed

    2013-11-12

    Methods of forming a conductive metal layers on substrates are disclosed which employ a seed layer to enhance bonding, especially to smooth, low-roughness or hydrophobic substrates. In one aspect of the invention, the seed layer can be formed by applying nanoparticles onto a surface of the substrate; and the metallization is achieved by electroplating an electrically conducting metal onto the seed layer, whereby the nanoparticles serve as nucleation sites for metal deposition. In another approach, the seed layer can be formed by a self-assembling linker material, such as a sulfur-containing silane material.

  18. Valorization of small uranium deposits

    For the valorization of small uranium deposits, the Total Mining Co. has developed an original leaching process in immersed live stalls, allied to the treatment of uraniferous liquors on ion exchanger resins. This technology was put in operation at Saint-Pierre (Cantal) in 1976, at La Ribiere (Creuse) in 1982 and in Bertholene (Aveyron) in 1985. In the last mentioned installation, 75 t of uranium can be produced per year on the basis of 60 000 t of ore containing 1.5 kg of uranium per ton. The investments per kg of uranium have thus been reduced to a quarter of their value in a conventional plant

  19. Cluster Implantation and Deposition Apparatus

    Hanif, Muhammad; Popok, Vladimir

    In the current report, a design and capabilities of a cluster implantation and deposition apparatus (CIDA) involving two different cluster sources are described. The clusters produced from gas precursors (Ar, N etc.) by PuCluS-2 can be used to study cluster ion implantation in order to develop...... contributions to the theory of cluster stopping in matter as well as for practical applications requiring ultra-shallow implantation and modification of surfaces on the nanoscale. Metal clusters from the magnetron cluster source are of interest for the production of optical sensors to detect specific biological...

  20. Directional material probe for deposition layer studies

    A simple new tool for deposition layer studies, a directional material probe, is proposed. The probe, which examines the directionality of deposition layer formation, consists of a flat disk and pin. If deposits have directionality, a shadow of the pin is formed on the deposition layer on the disk. If no shadow appears on the deposition layer, this suggests that the deposition layer was formed isotropically. The probe can be applied to plasma-wall interaction studies in fusion devices and laboratory plasma devices such as linear divertor simulators to reveal the material migration mechanisms in such devices. The directional material probe method has been applied to plasma-wall interaction studies in the Large Helical Device (LHD), and a position-dependent variation in the directionality of deposition layer formation was found. (author)

  1. Remediation of spent block in Uvanas deposit

    In 2007 by 'Kazatomprom' and 'Mining company' board decision, the branch of 'Mining company', 'Steppe ore management body' is reorganized in structure subdivision, the basic activity of which is organization and carrying out remediation works on spent blocks of PSV uranium deposit. In 2002 works are completed on OVOS for operating deposits Uvanas, Kanjugan, Northern Karamurun and Eastern Minkuduk. The results of present work were reported in IAEA conference. The working project 'Remediation of spent blocks of PSV uranium deposit PV-17 polygon of Steppe ore management body' approved in 2005 was developed for carrying out the remediation works. Works funding were carried out from liquidation fund of the current deposit established in accordance with the Republic of Kazakhstan law 'About interior and interior use'. Deposits remediation is the part of deposit operation life cycle which obliges to operate deposits with minimum expenditures for remediation.

  2. Energetic deposition of thin metal films

    Al-Busaidy, M S K

    2001-01-01

    deposited films. The primary aim of this thesis was to study the physical effect of energetic deposition metal thin films. The secondary aim is to enhance the quality of the films produced to a desired quality. Grazing incidence X-ray reflectivity (GIXR) measurements from a high-energy synchrotron radiation source were carried out to study and characterise the samples. Optical Profilers Interferometery, Atomic Force Microscope (AFM), Auger electron spectroscopy (AES), Medium energy ion spectroscopy (MEIS), and the Electron microscope studies were the other main structural characterisation tools used. AI/Fe trilayers, as well as multilayers were deposited using a Nordico planar D.C. magnetron deposition system at different voltage biases and pressures. The films were calibrated and investigated. The relation between energetic deposition variation and structural properties was intensely researched. Energetic deposition refers to the method in which the deposited species possess higher kinetic energy and impact ...

  3. Depositing Materials on the Micro- and Nanoscale

    Mar, Mikkel Dysseholm; Herstrøm, Berit; Shkondin, Evgeniy;

    2014-01-01

    that can be used separately or in combination to give the micro/nano system the properties needed. These techniques and film properties are presented. ALD (Atomic Layer Deposition) is good for very thin films (down to monolayers) with extremely good stepcoverage and extremely good control of the layer...... good for high quality thin film metal deposition e.g. for electrical leads or surfaceplasmonic devices. MVD (Molecular Vapor Deposition) is used for making anti stiction coating. Below is shown an example of Atomic Layer Deposition which is a self-terminating chemical vapor deposition technique based......, layers with specific optical properties in optical sensors, piezoelectric thin films or insulating layers in many other applications. These different materials and properties impose a demand for different kind of deposition techniques. At DTU Danchip we have a large variety of these deposition techniques...

  4. Legal Deposit of Digital Materials

    Erik Oltmans

    2003-09-01

    Full Text Available Digital publishing is causing a real paradigm shift for research institutions and publishers, as well as for libraries. As a consequence these institutions have to develop new policies, new business models and new infrastructures and techniques. A major problem is that, at the same rate at which our world is becoming digital, the digital information is threatened. New types of hardware, computer applications and file formats supersede each other, making our recorded digital information inaccessible in the long-term. In the past years libraries and archives have undertaken several actions and studies on digital preservation issues. For instance the Koninklijke Bibliotheek (KB has jointly with IBM developed a standard-based deposit system: Digital Information Archiving System ( DIAS. Using DIAS the KB realised in 2002 an electronic deposit (the e-Depot and signed archiving agreements with major science publishers for permanent keeping of their digital materials. In this paper I will discuss the fully operational e-Depot at the KB. I will focus on the data flow of processing the digital publications, and I will address the issue of digital preservation in detail.

  5. Digital electrospray for controlled deposition.

    Deng, Weiwei; Waits, C Mike; Gomez, Alessandro

    2010-03-01

    Many novel functional structures are now fabricated by controlled deposition as a maskless, bottom-up fabrication technique. These applications require rapid and precise deposition of minute amounts of solutions/suspensions or their ultimate particle products in predefined patterns. The electrospray is a promising alternative to the commonly used inkjet printing because it can easily handle highly viscous liquid, avoid high shear rates, and has low risk of clogging. We demonstrate a proof-of-concept digital electrospray. This system consists of a 61-nozzle array microfabricated in silicon and a 61-element digital extractor fabricated using flexible polyimide substrates. "Digital" refers to the state of each electrospray source that can be tuned either on or off independently and responsively. We showed a resolution of 675 mum and a response frequency up to 100 Hz. With similar design and industry standard fabrication procedures, it is feasible to scale up the system to O(1000) sources with spatial resolution better than 250 mum and a O(kHz) response frequency. The latter is controlled by the viscous damping time. PMID:20370220

  6. Nanofriction properties of molecular deposition films

    2000-01-01

    The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that (ⅰ) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ⅱ) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (ⅲ) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (ⅳ) the relative humidity affects the frictional force; the higher the RH, the lower the frictional force.

  7. Oil shales, evaporites and ore deposits

    Eugster, Hans P.

    1985-03-01

    The relationships between oil shales, evaporites and sedimentary ore deposits can be classified in terms of stratigraphic and geochemical coherence. Oil shale and black shale deposition commonly follows continental red beds and is in turn followed by evaporite deposition. This transgressive-regressive sequence represents an orderly succession of depositional environments in space and time and results in stratigraphic coherence. The amount of organic carbon of a sediment depends on productivity and preservation, both of which are enhanced by saline environments. Work on Great Salt Lake. Utah, allows us to estimate that only 5% of TOC originally deposited is preserved. Inorganic carbonate production is similar to TOC production, but preservation is much higher. Oil shales and black shales commonly are enriched in heavy metals through scavenging by biogenic particles and complexation by organic matter. Ore deposits are formed from such rocks through secondary enrichment processes, establishing a geochemical coherence between oil shales and ore deposits. The Permian Kupferschiefer of N. Europe is used as an example to define a Kupferschiefer type (KST) deposit. Here oxygenated brines in contact with red beds become acidified through mineral precipitation and acquire metals by dissolving oxide coatings. Oxidation of the black shale leads to further acid production and metal acquisition and eventually to sulfide deposition along a reducing front. In order to form ore bodies, the stratigraphic coherence of the red bed-black shale-evaporite succession must be joined by the geochemical coherence of the ore body-evaporite-black shale association. The Cretaceous Cu-Zn deposits of Angola, the Zambian Copperbelt as well as the Creta, Oklahoma, deposits are other KST examples. In the Zambian Copperbelt, evaporites are indicated by the carbonate lenticles thought to be pseudomorphs after gypsum-anhydrite nodules. MVT deposits are also deposited by acid brines, but at more

  8. Particle deposition in turbulent flow

    Ranegger, G.; Schaflinger, U. [Technical Univ. Graz (Austria). CD-Lab. of Continuous Casting Processes

    2001-07-01

    During continuous casting processes impurities like deoxidation products in the melt deposit at the walls of the tundish nozzle and the stopper. This phenomenon, termed clogging, causes obstruction of the flow and decreases the quality of the casted metal. A knowledge of the flow pattern within the tundish nozzle-stopper region is very important for the design of the nozzle and the stopper. The transport of the particles will be calculated by using a Lagrangian approach. To simulate the turbulent fluctuations in the Lagrangian formulation, a stochastic procedure (Random Walk Model) will be employed. A new design for the nozzle and stopper region reduces turbulence, prevents recirculation and permits only a very limited lateral particle transport. (orig.)

  9. Analysing the Cenozoic depositional record

    Goledowski, Bartosz; Clausen, O.R.; Nielsen, S.B.

    between the global climate record (oxygen isotopes) and lithology variations on the Eocene-Oligocene transition in the eastern North Sea. Due to the strongly limited time resolution of low temperature thermochronology, the Cenozoic sedimentary record potentially provides the most detailed history of...... lower limit to erosion rate in source areas of the respective sedimentary bodies. The lower limit arises because some erosional products are transported out of the mapped area, and some erosion is caused by chemical dissolution. The development of the source areas will be modelled using surface process...... models. The matrix mass deposition history will be compared with the paleoclimate record (e.g. oxygen isotope curves) to see if the previously observed correlation in the eastern North Sea can be extended to other ages and locations.  ...

  10. Iron-sulfide crystals in probe deposits

    Laursen, Karin; Frandsen, Flemming

    1998-01-01

    Iron-sulfides were observed in deposits collected on a probe inserted at the top of the furnace of a coal-fired power station in Denmark. The chemical composition of the iron-sulfides is equivalent to pyrrhotite (FeS). The pyrrhotites are present as crystals and, based on the shape of the crystals......, it was deduced that they were not deposited but instead grew within the deposit. The presence of unburned char particles within the deposits supports the concept that a reducing environment existed in the deposits. Two processes are proposed for explaining the existence of pyrrhotite crystals within...... a deposit: (1) impact of low viscous droplets of iron sulfide; and (2) sulfur diffusion. Previous research on the influence of pyrite on slagging focused on the decomposition of pyrite into pyrrhotite and especially on the oxidation stage of this product during impact on the heat transfer surfaces...

  11. Modeling particle deposition on HVAC heat exchangers

    Fouling of fin-and-tube heat exchangers by particle deposition leads to diminished effectiveness in supplying ventilation and air conditioning. This paper explores mechanisms that cause particle deposition on heat exchanger surfaces. We present a model that accounts for impaction, diffusion, gravitational settling, and turbulence. Simulation results suggest that some submicron particles deposit in the heat exchanger core, but do not cause significant performance impacts. Particles between 1 and 10(micro)m deposit with probabilities ranging from 1-20% with fin edge impaction representing the dominant mechanism. Particles larger than 10(micro)m deposit by impaction on refrigerant tubes, gravitational settling on fin corrugations, and mechanisms associated with turbulent airflow. The model results agree reasonably well with experimental data, but the deposition of larger particles at high velocities is underpredicted. Geometric factors, such as discontinuities in the fins, are hypothesized to be responsible for the discrepancy

  12. UFOMOD - atmospheric dispersion and deposition

    The report gives an introduction into the modelling of atmospheric dispersion and deposition which has been implemented in the new program system UFOMOD for assessing the consequences after nuclear accidents. According to the new structure of UFOMOD, different trajectory models with ranges of validity near to the site and at far distances are applied. Emphasis is laid on the description of the segmented plume model MUSEMET and its affilated submodels, being the removal of activity from the cloud by dry and wet deposition, and special effects like plume rise and the behaviour of plumes released into building wakes. In addition, the evaluation of γ-dose correction factors to take account of the finite extent of the radioactive plume in the near range (up to about 20 km) are described. Only brief introductions are given into the principles of the other models available: the puff model RIMPUFF, the long-range puff model MESOS, and the special straight-line Gaussian model ISOLA which are used if low-level long-duration releases are considered. To define starting times of weather sequences and the probabilities of occurrence of these sequences, it is convenient to perform stratified sampling. Therefore, the preprocessing program package METSAM has been developed to perform for generic ACAs a random sampling of weather sequences out off a population of classified weather conditions. The sampling procedure and a detailed input/output (I/O) description is presented and an additional appendix, respectively. A general overview on the I/O structure of MUSEMET as well as a brief user guide to run the KfK version of the MESOS code are also given in the appendix. (orig.)

  13. Update on calcium pyrophosphate deposition.

    Abhishek, Abhishek; Doherty, Michael

    2016-01-01

    Calcium pyrophosphate crystal deposition (CPPD) associates with ageing, osteoarthritis (OA), uncommon metabolic diseases, mutations and polymorphisms in the ankylosis human gene (ANKH). CPPD is frequently polyarticular, occurs due to a generalised articular predisposition, and the association between CPPD and OA is joint specific, for example CPPD associates with knee OA, but not with hip OA. Other recently identified associations include knee malalignment (knee CC), low cortical BMD and soft-tissue calcification. CPPD is generally asymptomatic. A recent study reported that knees with OA plus CC at the index joint, or at distant joints (in absence of index joint CC), were more likely to have attrition. CPPD can cause acute CPP crystal arthritis, chronic CPP crystal inflammatory arthritis, and is frequently present in joints with OA. Joint aspiration remains the gold standard for diagnosing CPPD, although other promising techniques are emerging. Patients with polyarticular or young onset CPPD should be screened for underlying metabolic abnormalities, however, such testing can be unrewarding. The treatment of CPPD is symptomatic. Acute CPP crystal arthritis is treated with rest, local application of ice-packs, joint aspiration, colchicine and/or intra-articular corticosteroid injection (once infection is excluded). Colchicine, low-dose corticosteroids, hydroxychloroquine and radiosynovectomy are recommended for the treatment of chronic or recurrent acute CPP crystal arthritis. Recent RCTs did not confirm any benefit from methotrexate, and although there is increasing interest in the use of anti-IL1 agents for acute or chronic CPP crystal arthritis, their efficacy has not been formally examined. Unlike gout, currently there are no treatments to eliminate CPP crystal deposits. PMID:27586801

  14. Laboratory Deposition Apparatus to Study the Effects of Wax Deposition on Pipe Magnetic Field Leakage Signals

    Karim Mohd Fauzi Abd

    2014-07-01

    Full Text Available Accurate technique for wax deposition detection and severity measurement on cold pipe wall is important for pipeline cleaning program. Usually these techniques are validated by conventional techniques on laboratory scale wax deposition flow loop. However conventional techniques inherent limitations and it is difficult to reproduce a predetermine wax deposit profile and hardness at designated location in flow loop. An alternative wax deposition system which integrates modified pour casting method and cold finger method is presented. This system is suitable to reproduce high volume of medium hard wax deposit in pipe with better control of wax deposit profile and hardness.

  15. Vapor wall deposition in Teflon chambers

    Zhang, X; R. H. Schwantes; R. C. McVay; H Lignell; M. M. Coggon; Flagan, R C; Seinfeld, J.H.

    2014-01-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, α-pinene, and dodecan...

  16. FTIR analysis of aviation fuel deposits

    Helmick, L. S.; Seng, G. T.

    1984-01-01

    Five modes of operation of the Nicolet 7199 Fourier Transform Infrared Spectrophotometer have been evaluated for application in analysis of the chemical structure of accelerated storage/thermal deposits produced by jet fuels. Using primarily the absorption and emission modes, the effects of fuel type, stress temperature, stress time, type of spiking agent, spiking agent concentration, fuel flow, and post-depositional treatment on the chemical nature of fuel deposits have been determined.

  17. Review of cooling tower drift deposition models

    Chen, N.C.J.

    1977-05-04

    The behavior, basic assumptions, and limitations of ten different models for calculating the drift deposition rate from wet cooling towers are reviewed and then their predicted results for such deposition with a common set of input parameters are compared. The predicted maximum deposition differs among the models by two orders of magnitude with a wide range in peak location. Comments and suggestions to improve the models are included.

  18. Boron deposition from fused salts. Final report

    A partial evaluation of the feasibility of a process to electrodeposit pure coherent coatings of elemental boron from molten fluorides has been performed. The deposit produced was powdery and acicular, unless the fluoride melt was purified to have very low oxygen concentration. When the oxygen activity was reduced in the melt by addition of crystalline elemental boron, dense, amorphous boron deposit was produced. The boron deposits produced had cracks but were otherwise pure and dense and ranged up to 0.35 mm thick. Information derived during this project suggests that similar deposits might be obtained crack-free up to 1.00 mm thick by process modifications and improvements

  19. Structural characterization of MAPLE deposited lipase biofilm

    Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase

  20. Kaolinite influence on calcareous deposit formation

    This study investigate the influence of kaolinite, introduced in electrolytes solutions, on the calcareous deposit formation, which is monitored by chronoamperometric measurements coupled with chemical impedance spectroscopy analyses. The deposits formed are observed by scanning electron microscopy and analysed by Raman spectroscopy and X-ray diffraction analyses. In presence of Mg2+ ions, kaolinite delay the deposit formation, preventing the reduction of energy required for an efficient cathodic protection. Whereas no influence of this clay was noticed on the CaCO3 deposit when the electrolyte was totally exempt of Mg2+.

  1. Low-fluorine Stockwork Molybdenite Deposits

    Ludington, Steve; Hammarstrom, Jane; Piatak, Nadine M.

    2009-01-01

    Low-fluorine stockwork molybdenite deposits are closely related to porphyry copper deposits, being similar in their tectonic setting (continental volcanic arc) and the petrology (calc-alkaline) of associated igneous rock types. They are mainly restricted to the Cordillera of western Canada and the northwest United States, and their distribution elsewhere in the world may be limited. The deposits consist of stockwork bodies of molybdenite-bearing quartz veinlets that are present in and around the upper parts of intermediate to felsic intrusions. The deposits are relatively low grade (0.05 to 0.2 percent Mo), but relatively large, commonly >50 million tons. The source plutons for these deposits range from granodiorite to granite in composition; the deposits primarily form in continental margin subduction-related magmatic arcs, often concurrent with formation of nearby porphyry copper deposits. Oxidation of pyrite in unmined deposits or in tailings and waste rock during weathering can lead to development of acid-rock drainage and limonite-rich gossans. Waters associated with low-fluorine stockwork molybdenite deposits tend to be nearly neutral in pH; variable in concentrations of molybdenum (10,000 ug/L); below regulatory guidelines for copper, iron, lead, zinc, and mercury; and locally may exceed guidelines for arsenic, cadmium, and selenium.

  2. Structural characterization of MAPLE deposited lipase biofilm

    Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Ausanio, Giovanni; Bloisi, Francesco [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Calabria, Raffaela [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Califano, Valeria, E-mail: v.califano@im.cnr.it [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Massoli, Patrizio [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Vicari, Luciano R.M. [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy)

    2014-11-30

    Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase.

  3. Atomic layer deposition of nanoporous biomaterials

    Roger J Narayan

    2010-03-01

    Full Text Available Due to its chemical stability, uniform pore size, and high pore density, nanoporous alumina is being investigated for use in biosensing, drug delivery, hemodialysis, and other medical applications. In recent work, we have examined the use of atomic layer deposition for coating the surfaces of nanoporous alumina membranes. Zinc oxide coatings were deposited on nanoporous alumina membranes using atomic layer deposition. The zinc oxide-coated nanoporous alumina membranes demonstrated antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. These results suggest that atomic layer deposition is an attractive technique for modifying the surfaces of nanoporous alumina membranes and other nanostructured biomaterials.

  4. Hideout in steam generator tube deposits

    Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m2, corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 103. Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

  5. Regional aerosol deposition in human upper airways

    During the report period significant progress on the quantitative understanding of regional upper airway deposition of airborne particle has been realized. Replicate models of the human upper airways obtained from post-mortem casting of the nasal, oral, pharyngeal, laryngeal and upper tracheal regions and in vivo magnetic resonance imaging (MRI) of the same regions of adults and children have been employed to determine the overall and local deposition characteristics of aerosols in the ultrafine (1--100 μm diameter) and fine (0.8--12 μm diameter) region. Studies have been carried out for both nasal and oral breathing during inspiratory and expiratory flow at constant flow rates representative of rest and states of exercise. The results of these investigations indicate that particles in the size range of ''unattached'' radon progeny (1--3 nm) are deposited in both the nasal and oral passages with high efficiency (60--80%) for both inspiration and expiration, with the nasal deposition being somewhat greater (5--10%) than oral deposition. The effect of flow rate on upper airway deposition for both pathways is not great; data analysis indicates that the deposition for all flow rates from 4--50 liters/minute can be grouped by plotting deposition vs Q-1/8, where Q is flow rate, a far weaker dependency than observed for inertial deposition. Diffusional transport is the primary mechanism of deposition, and size dependence can be accounted for by plotting, deposition percent vs Dn where D is particle diffusion coefficient and n ranges from 0.5--0.66. 2 refs

  6. Predicting particle deposition on HVAC heat exchangers

    Siegel, Jeffrey A.; Nazaroff, William W.

    Particles in indoor environments may deposit on the surfaces of heat exchangers that are used in heating, ventilation and air conditioning (HVAC) systems. Such deposits can lead to performance degradation and indoor air quality problems. We present a model of fin-and-tube heat-exchanger fouling that deterministically simulates particle impaction, gravitational settling, and Brownian diffusion and uses a Monte Carlo simulation to account for impaction due to air turbulence. The model predicts that heat exchangers with air flows and fin spacings that are typical of HVAC systems. For supermicron particles, deposition increases with particle size. The dominant deposition mechanism for 1-10 μm particles is impaction on fin edges. Gravitational settling, impaction, and air turbulence contribute to deposition for particles larger than 10 μm. Gravitational settling is the dominant deposition mechanism for lower air velocities, and impaction on refrigerant tubes is dominant for higher velocities. We measured deposition fractions for 1-16 μm particles at three characteristic air velocities. On average, the measured results show more deposition than the model predicts for an air speed of 1.5 m s -1. The amount that the model underpredicts the measured data increases at higher velocities and especially for larger particles, although the model shows good qualitative agreement with the measured deposition fractions. Discontinuities in the heat-exchanger fins are hypothesized to be responsible for the increase in measured deposition. The model and experiments reported here are for isothermal conditions and do not address the potentially important effects of heat transfer and water phase change on deposition.

  7. Yangshan Gold Deposit: The Largest Carlin and Carlin-like Type Gold Deposit in China

    YAN Fengzeng; LI Qiangzhi

    2008-01-01

    Gold Headquarter of the CAPF has discovered the Yangshan super large-scale gold depositin Gansu Province, which is a great breakthrough of gold exploration and prospecting in WesternQiniing Mountains of China. The gold resources of this deposit achieved 308 tons with increasingpotentials. Preliminary geological investigations indicate that the Yangshan gold deposit is located inthe intra-continental collision orogenic belt; and the deposit was formed during the continent-continentcollision orogenic processes. The geological characteristics of the deposit are similar to that of thetypical Carlin-type gold deposits, while differences still exist. The ore-forming background is notablydifferent from the Carlin gold deposit province in the United States; and the ore-forming fluids aresimilar with that of the orogenic-type gold deposit. Accordingly, the Yangshan gold deposit is atransitional type between the Carlin-type and the orogenic type gold deposits. At present, the Yangshangold deposit is the largest Carlin and Carlin-like type gold deposit that is ever discovered in China.Researches on metaliogeny, metaliogenic model and ore-enrichment regularities of the Yangshan golddeposit are crucial to meet the pressing needs of the current geological investigation and oreexploration of the deposit.

  8. 24 CFR 891.775 - Security deposits.

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Security deposits. 891.775 Section 891.775 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... Individuals-Section 162 Assistance § 891.775 Security deposits. The general requirements for security...

  9. 37 CFR 1.25 - Deposit accounts.

    2010-07-01

    ... over the Office's Internet Web site (www.uspto.gov). (3) A payment to replenish a deposit account may... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES General Provisions Fees and Payment of Money § 1.25... the Patent and Trademark Office upon payment of the fee for establishing a deposit account (§...

  10. Large Nonferrous Metals Deposits Found in Yunnan

    2012-01-01

    <正>According to the Department of Land and Resources of Yunnan, Yunnan has made great achievements since implementation of the geological prospecting action plan. 5 ultra-large deposits and several large deposits have been found, and a group of key areas with favorable ore-forming prospect have been pinpointed.

  11. Uranium deposits of Australia to 1975

    This bibliography provides a retrospective account of Australian uranium deposits, particularly the unpublished materials in the Australian Capital Territory. Some abstracts are included. Occurrences, mineralogy, ore genesis, structural controls and the eonomic geology of uranium deposits are covered but the mining of uranium, exploration reports, surveys, environmental aspects and controversial materials are not

  12. Time Resolved Deposition Measurements in NSTX

    C.H. Skinner; H. Kugel; A.L. Roquemore; J. Hogan; W.R. Wampler; the NSTX team

    2004-08-03

    Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 {micro}g/cm{sup 2} of deposition, however surprisingly, 15.9 {micro}g/cm{sup 2} of material loss occurred at 7 discharges. The net deposited mass of 13.3 {micro}g/cm{sup 2} matched the mass of 13.5 {micro}g/cm{sup 2} measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition.

  13. Time Resolved Deposition Measurements in NSTX

    Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 (micro)g/cm2 of deposition, however surprisingly, 15.9 (micro)g/cm2 of material loss occurred at 7 discharges. The net deposited mass of 13.3 (micro)g/cm2 matched the mass of 13.5 (micro)g/cm2 measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition

  14. Atmospheric deposition maps for the Rocky Mountains

    Nanus, L.; Campbell, D.H.; Ingersoll, G.P.; Clow, D.W.; Mast, M.A.

    2003-01-01

    Variability in atmospheric deposition across the Rocky Mountains is influenced by elevation, slope, aspect, and precipitation amount and by regional and local sources of air pollution. To improve estimates of deposition in mountainous regions, maps of average annual atmospheric deposition loadings of nitrate, sulfate, and acidity were developed for the Rocky Mountains by using spatial statistics. A parameter-elevation regressions on independent slopes model (PRISM) was incorporated to account for variations in precipitation amount over mountainous regions. Chemical data were obtained from the National Atmospheric Deposition Program/National Trends Network and from annual snowpack surveys conducted by the US Geological Survey and National Park Service, in cooperation with other Federal, State and local agencies. Surface concentration maps were created by ordinary kriging in a geographic information system, using a local trend and mathematical model to estimate the spatial variance. Atmospheric-deposition maps were constructed at 1-km resolution by multiplying surface concentrations from the kriged grid and estimates of precipitation amount from the PRISM model. Maps indicate an increasing spatial trend in concentration and deposition of the modeled constituents, particularly nitrate and sulfate, from north to south throughout the Rocky Mountains and identify hot-spots of atmospheric deposition that result from combined local and regional sources of air pollution. Highest nitrate (2.5-3.0kg/ha N) and sulfate (10.0-12.0kg/ha SO4) deposition is found in northern Colorado.

  15. Plasma Deposition of Doped Amorphous Silicon

    Calcote, H. F.

    1985-01-01

    Pair of reports present further experimental details of investigation of plasma deposition of films of phosphorous-doped amosphous silicon. Probe measurements of electrical resistance of deposited films indicated films not uniform. In general, it appeared that resistance decreased with film thickness.

  16. Uranium deposits of the Czech Republic

    The existing uranium production in the Czech Republic has a long tradition for about 100 years. The unimportant production of uranium ores used in the glass and ceramic industries and medicine was replaced after World War II by an intense evolution of uranium ore exploration, mining and processing activities. This whole period is characterized by a steadily increasing level, of exploration work and of linked research activities in a few stages. A substantial reduction in the volume of geological exploratory works aimed at the detection and development of new deposits occurred as a result of the contraction programme of the uranium industry, pronounced in 1989. There are only two regions with prospective uranium deposits at present time. The first one is in northern Bohemia with the Hamr and the Straz deposits in production. These deposits are connected with basal Cretaceous sediments (sandstones). The other one is in western Moravia (Moldanubian) with the Rozna and the Brzkov deposits. These deposits are connected with metamorphosed rocks of the Moldanubian. All the exploration, extraction and processing activities were operated by the state for approximately 50 years. Nowadays the only uranium producer in the Czech Republic is the DIAMO state enterprise, based in Straz pod Ralskem. The continuation of extraction is planned at the Rozna and the Hamr deposits in the near future. The ISL-production of uranium is planned at the Straz deposit during the restoration activities. (author). 4 figs, 3 tabs

  17. Goudafzettingen in Suriname (Gold deposits in Surinam)

    Brinck, J.W.

    1956-01-01

    THE GOLD DEPOSITS IN SURINAM AND THE DISTRIBUTION OF CONCESSIONS THROUGH THE COUNTRY The fieldwork on the occurrence of primary and secondary gold deposits in Surinam on which this thesis is based was carried out by order of the Welfare Fund Surinam (Welvaarts Fonds Suriname) during the periods Dece

  18. Resource assessment of copper deposits in China

    ZHANG Qin-li; GU De-sheng; T. Shoji; H. Kaneda

    2005-01-01

    Copper-bearing deposits of China are statistically analyzed in terms of ore grade, metal amount and ore tonnage. Each of grade and metal amount shows more or less a lognormal distribution. Analysis gives 10 copper metallogenic districts, each having specific densities of deposit numbers and copper reserves larger than 3. Based on the ratio of copper in ore value (Rcu), Chinese copper deposits are classified into two groups: mainly copper-producing deposits (MC: Rcu≥0.5) and accessorily copper-producing deposits (AC: Rcu<0. 5). The grade-tonnage relation of MC deposits can be combined by two exponential functions approximating high grade (> 3.0 %) and low grade (<2.0%) parts. The critical copper grade, which is obtained from the low grade part of the relation, is 0. 34 %. Chinese copper resources are concluded to become pessimistic, because some mines are working with grades close to this critical value. Taking account of the fact that many copper deposits are actually polymetallic, Cu-equivalent grades, which are converted from ratios of metal prices to the copper price, are also introduced. The critical Cu-equivalent grade of MC deposits (0. 43 % ) also suggests that Chinese copper resources are pessimistic.

  19. 10 CFR 2.1019 - Depositions.

    2010-01-01

    ... Applicable to Proceedings for the Issuance of Licenses for the Receipt of High-Level Radioactive Waste at a... take the testimony of any person by deposition on oral examination shall, without leave of the... place of taking the deposition; the name and address of each person to be examined, if known, or if...

  20. 49 CFR 1114.24 - Depositions; procedures.

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Depositions; procedures. 1114.24 Section 1114.24... OF TRANSPORTATION RULES OF PRACTICE EVIDENCE; DISCOVERY Discovery § 1114.24 Depositions; procedures... provided in § 1114.21(c). If the order made terminates the examination, it should be resumed...

  1. 49 CFR 1114.22 - Deposition.

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Deposition. 1114.22 Section 1114.22 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE EVIDENCE; DISCOVERY Discovery § 1114.22 Deposition. (a) Purpose. The...

  2. Assessment of Global Mercury Deposition through Litterfall.

    Wang, Xun; Bao, Zhengduo; Lin, Che-Jen; Yuan, Wei; Feng, Xinbin

    2016-08-16

    There is a large uncertainty in the estimate of global dry deposition of atmospheric mercury (Hg). Hg deposition through litterfall represents an important input to terrestrial forest ecosystems via cumulative uptake of atmospheric Hg (most Hg(0)) to foliage. In this study, we estimate the quantity of global Hg deposition through litterfall using statistical modeling (Monte Carlo simulation) of published data sets of litterfall biomass production, tree density, and Hg concentration in litter samples. On the basis of the model results, the global annual Hg deposition through litterfall is estimated to be 1180 ± 710 Mg yr(-1), more than two times greater than the estimate by GEOS-Chem. Spatial distribution of Hg deposition through litterfall suggests that deposition flux decreases spatially from tropical to temperate and boreal regions. Approximately 70% of global Hg(0) dry deposition occurs in the tropical and subtropical regions. A major source of uncertainty in this study is the heterogeneous geospatial distribution of available data. More observational data in regions (Southeast Asia, Africa, and South America) where few data sets exist will greatly improve the accuracy of the current estimate. Given that the quantity of global Hg deposition via litterfall is typically 2-6 times higher than Hg(0) evasion from forest floor, global forest ecosystems represent a strong Hg(0) sink. PMID:27418119

  3. [Glomerulopathies with organized monoclonal immunoglobulin deposits].

    Touchard, Guy; Bridoux, Frank; Goujon, Jean-Michel

    2016-02-01

    The spectrum of glomerular disorders with organized immunoglobulin (Ig) deposits is heterogeneous. It encompasses 2 mains categories: glomerulopathies with fibrillary deposits are mostly represented by immunoglobulinic amyloidosis (most commonly AL amyloidosis, characterized by monoclonal light chain deposits often of the lambda isotype), and pseudo-amyloid fibrillary glomerulonephritis in which deposits predominantly contain polyclonal IgG4. Glomerulopathies with microtubular deposits include cryoglobulinemic glomerulonephritis (type I and type II, with or without detectable serum cryoglobulin) and glomerulonephritis with organized microtubular monoclonal Ig deposits (GOMMID) also referred to as immunotactoid glomerulopathy. Pathological diagnosis requires meticulous studies by light microscopy (with systematic Congo red staining), immunofluorescence with specific conjugates, and electron microscopy. Ultrastructural studies are required to differentiate amyloid fibrils (8 to 10 nm in external diameter), pseudo-amyloid fibrils (15-20 nm) and microtubules (10 to 50 nm in external diameter, with a central hollow core). Glomerular deposits in type I cryoglobulinemic glomerulonephritis are arranged into parallel straight microtubules similar to those observed in GOMMID, but with different topography that allows distinction between the two entities. Glomerular substructures composed of circulating Igs should be distinguished from collagen fibrils that are commonly observed in glomerular disorders with or without deposition of monoclonal or polyclonal Igs. PMID:26810049

  4. Genetic types of uranium deposits of Ukraine

    There are three genetic classes of uranium deposits in Ukraine. Eight types of uranium deposits are described with reference to their genesis, age and geological position. The attributes of uranium concentration in Precambrian and Proterozoic periods of activization are shown. (author). 1 fig., 1 tab

  5. Ion plating technique improves thin film deposition

    Mattox, D. M.

    1968-01-01

    Ion plating technique keeps the substrate surface clean until the film is deposited, allows extensive diffusion and chemical reaction, and joins insoluble or incompatible materials. The technique involves the deposition of ions on the substrate surface while it is being bombarded with inert gas ions.

  6. Microwave-enhanced thin-film deposition

    Chitre, S.

    1984-01-01

    The deposition of semiconducting and insulating thin films at low temperatures using microwave technology was explored. The method of plasma formations, selection of a power source, the design of the microwave plasma cavity, the microwave circuitry, impedance matching, plasma diagnostics, the deposition chamber and the vacuum system were studied.

  7. Deposition of contaminant aerosol on human skin

    Andersson, Kasper Grann; Roed, Jørn; Byrne, M.A.;

    2006-01-01

    Over recent years, it has been established that deposition of various types of pollutant aerosols (e.g., radioactive) on human skin can have serious deleterious effects on health. However. only few investigations in the past have been devoted to measurement of deposition velocities on skin...

  8. Energy deposition in NSRR test fuels

    Interpretation of fuel performance data collected during inpile testing in the NSRR requires a knowledge of the energy deposition or enthalpy increase in each sample tested. The report describes the results of absolute measurement of fission products and contents of uranium in irradiated test fuels which were performed to determine the energy deposition. (auth.)

  9. Polymetallic uranium-copper deposits

    The present report is an addendum to the final report, dated June 30, 1988, on the research program 'Polymetallic uranium-copper deposits' and is concerned with investigations carried out in the Palaeozoic/Mesozoic basins of the Hessian Depression, FRG, in the first half of 1988. The investigations comprised the further compilation of literature data and limited field work; they were related to three objectives and yielded the following results: 1. Additional data were obtained on the geochemistry (in particular U) of the stratiform, polymetallic Cu mineralization of the Kupferschiefer type. The new data confirm the conclusions reached previously within the present research program. 2. The radiometric scanning of samples and of surface exposures and dumps from the historic mining of the 'Ruecken' veins (barite ± Co-Ni-As) in the Richelsdorfer Gebirge area yielded negative results. Follow-up investigations are not justified. 3. The occurrence of collapse structure ('Erdfaelle'), in one case combined with tensional tectonics and possible diapiric phenomena (Sontra graben structure) led to the speculation that some of these structures may host epigenetic polymetallic mineralization. Results have been negative, respectively inconclusive; a direct proof requires deeper drilling. However, based on the lack of any positive indication, follow-up investigations are not justified. (orig./RB)

  10. The geomicrobiology of bauxite deposits

    Xiluo Hao; Kwunlun Leung; Rucheng Wang; Weidong Sun; Yiliang Li

    2010-01-01

    Bauxite deposits are studied because of their economic value and because they play an important role in the study of paleoclimate and paleogeography of continents. They provide a rare record of the weathering and evolution of continental surfaces. Geomicrobiological analysis makes it possible to verify that microorganisms have played a critical role during the formation of bauxite with the possibility already intimated in previous studies. Ambient temperature, abundance of water, organic carbon and bioavailable iron and other metal substrates provide a suitable environment for microbes to inhabit. Thiobacillus, Leptospirilum, Thermophilic bacteria and Heterotrophs have been shown to be able to oxidize ferrous iron and to reduce sulfate-generating sulfuric acid, which can accelerate the weathering of aluminosilicates and precipitation of iron oxyhydroxides. Microorganisms referred to the genus Bacillus can mediate the release of alkaline metals. Although the dissimilatory iron-reducing and sulfate-reducing bacteria in bauxites have not yet been identified, some recorded authigenic carbonates and "bacteriopyrites" that appear to be unique in morphology and grain size might record microbial activity. Typical bauxite minerals such as gibbsite, kaolinite, covellite, galena, pyrite, zircon, calcium ptagioclase, orthoclase, and albite have been investigated as part of an analysis of microbial mediation. The paleoecologyof such bauxitic microorganisms inhabiting continental (sub) surfaces, revealed through geomicrobiological analysis, will add a further dimension to paleoclimatic and paleoenvironmental studies.

  11. Geological classification of uranium deposits

    The worst of times for the uranium producer may be over and a new episode in the tale of uranium is starting to unfold. In this next episode, trade restrictions, civilian inventories, and even HEU are drifting slowly backstage. With the changing scene-uranium prices having finally crossed the $13 per pound U3O8 threshold, and with expectations of continued strengthening-the uranium producer is once again assuming the role protagonist. The price gap that was opened with restrictions on CIS-origin uranium is now closing as this lower-priced supply appears to be scarce. Even matched sales may lose their appeal to both producer and utility. HEU and other inventories, once thought to be able to flood the market, are now turning out to be mostly pomp, with little circumstance. Meanwhile, industry participants, especially utilities, sit on the edge of their seats, already wondering if a soliloquy by the uranium producer can keep their undivided attention. The question in 1996 and through the turn of the century will be whether uranium producers are capable of mining enough uranium to satisfy utility requirements. If so, at what prices? And for how long? Where will 150 million pounds per year of uranium come from? Producers are already gearing up exploration crews in almost every continent in an effort to increase minable reserves. Some are even exploring in new areas, hopeful that lower-cost reserves will be found in addition to their discovered deposits

  12. A Complexity View of Acid Deposition

    朱建林; 方见树

    2003-01-01

    We show that acid deposition is analogous to complex systems composed of a series of interconnected components.Frequency-size distributions of weekly hydrogen deposition (WHD) of precipitation are consistent with double power-law in two different regimes separated by a crossover WHD. The distribution of variations in acid deposition over a week interval is remarkably symmetrical, with long tail extending over eight orders of magnitude. The acid deposition fluctuations exhibit fractal Brown motion with two different temporal scaling regimes and long-range correlation exists in the series. The power-laws in the acid deposition dynamics are considered to be indicators of seff-organization of atmosphere under environmental pollution stress.

  13. Thin Film Deposition Using Energetic Ions

    Stephan Mändl

    2010-07-01

    Full Text Available One important recent trend in deposition technology is the continuous expansion of available processes towards higher ion assistance with the subsequent beneficial effects to film properties. Nowadays, a multitude of processes, including laser ablation and deposition, vacuum arc deposition, ion assisted deposition, high power impulse magnetron sputtering and plasma immersion ion implantation, are available. However, there are obstacles to overcome in all technologies, including line-of-sight processes, particle contaminations and low growth rates, which lead to ongoing process refinements and development of new methods. Concerning the deposited thin films, control of energetic ion bombardment leads to improved adhesion, reduced substrate temperatures, control of intrinsic stress within the films as well as adjustment of surface texture, phase formation and nanotopography. This review illustrates recent trends for both areas; plasma process and solid state surface processes.

  14. Tax evasion and Swiss bank deposits

    Johannesen, Niels

    2014-01-01

    Bank deposits in offshore financial centers may be used to evade taxes on interest income. A recent EU reform limits the scope for this type of tax evasion by introducing a withholding tax on interest income earned by EU households in Switzerland and several other offshore centers. This paper...... estimates the impact of the withholding tax on Swiss bank deposits held by EU residents while using non-EU residents who were not subject to the tax as a comparison group. We present evidence that Swiss bank deposits owned by EU residents declined by 30–40% relative to other Swiss bank deposits in two...... quarters immediately before and after the tax was introduced. We also present evidence suggesting that the drop in Swiss bank deposits was driven by behavioral responses aiming to escape the tax - such as the transfer of funds to bank accounts in other offshore centers and the transfer of formal ownership...

  15. Diamond deposition on thin cylindrical substrates

    GORDANA S. RISTIĆ

    2011-03-01

    Full Text Available Diamond coatings were deposited onto different cylindrical substrates (Cu, SiC, W and Mo by the hot filament chemical vapor deposition (CVD method. Continuous, adhered and well-faceted crystalline coatings of diamond were obtained on Cu-wire using a special pretreatment with a mixture of diamond and metal powders as well as carefully controlled deposition at lower power. Diamond deposition on SiC-fiber gave continuous and uniform coatings when only the filament power was properly selected. Uniform, homogeneous, euchedral diamond coatings on W- and Mo-wires, attained at a higher filament power, confirmed once more the convenience of refractory metals as substrates for diamond deposition by the CVD technique. Characterization of the obtained coatings was realized using scanning electron microscopy (SEM. The obtained results are compared with the literature data. Differences are discussed with regard to the chemical nature of the substrates as well as their thermophysical characteristics.

  16. Biosensor Applications of MAPLE Deposited Lipase

    Valeria Califano

    2014-10-01

    Full Text Available Matrix Assisted Pulsed Laser Evaporation (MAPLE is a thin film deposition technique derived from Pulsed Laser Deposition (PLD for deposition of delicate (polymers, complex biological molecules, etc. materials in undamaged form. The main difference of MAPLE technique with respect to PLD is the target: it is a frozen solution or suspension of the (guest molecules to be deposited in a volatile substance (matrix. Since laser beam energy is mainly absorbed by the matrix, damages to the delicate guest molecules are avoided, or at least reduced. Lipase, an enzyme catalyzing reactions borne by triglycerides, has been used in biosensors for detection of β-hydroxyacid esters and triglycerides in blood serum. Enzymes immobilization on a substrate is therefore required. In this paper we show that it is possible, using MAPLE technique, to deposit lipase on a substrate, as shown by AFM observation, preserving its conformational structure, as shown by FTIR analysis.

  17. Sediment-hosted stratabound copper deposit model: Chapter M in Mineral deposit model for resource assessment

    Hayes, Timothy S.; Cox, Dennis P.; Bliss, James D.; Piatak, Nadine M.; Seal, Robert R., II

    2015-01-01

    This report contains a descriptive model of sediment-hosted stratabound copper (SSC) deposits that supersedes the model of Cox and others (2003). This model is for use in assessments of mineral resource potential. SSC deposits are the second most important sources of copper in the world behind porphyry copper deposits. Around 20 percent of the copper in the world is produced from this class of deposits. They are also the most important sources of cobalt in the world, and they are fourth among classes of ore deposits in production of silver. SSC deposits are the basis of the economies of three countries: Democratic Republic of Congo, Poland, and Zambia. This report provides a description of the key features of SSC deposits; it identifies their tectonic-sedimentary environments; it illustrates geochemical, geophysical, and geoenvironmental characteristics of SSC deposits; it reviews and evaluates hypotheses on how these deposits formed; it presents exploration and assessment guides; and it lists some gaps in our knowledge about the SSC deposits. A summary follows that provides overviews of many subjects concerning SSC deposits.

  18. Effects of deposition time in chemically deposited ZnS films in acidic solution

    Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

    2015-08-31

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

  19. Effects of deposition time in chemically deposited ZnS films in acidic solution

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h

  20. Research on depositing Ni45 alloy on titanium alloy surface by electrospark deposition

    You Tao; Zhang Chunhui; Su Guiqiao; Yan Ping

    2008-01-01

    Taking Ni45 bar as electrode, a strengthened layer of thickness up to 50 pm was built up on BT20 titanium alloy matrix by means of electrospark deposition. Results of phase analysis by using of X-ray diffraction confirmed that the deposition layer was composed mostly of three phases, NiTi, NiTi2layer was up to 910 HV0.05, about 2.7 times as high as that of the matrix. The hardness at the cross-section of the entire deposition layer showed a gradient distribution. The effects of capacitance and deposition time on thickness of deposition layer were also studied, and results showed that with relatively low capacity and short deposition time the deposition layer without cracks can be obtained.

  1. The effect of fog on radionuclide deposition velocities

    Current nuclear power station release models do not evaluate deposition under foggy atmospheric conditions. Deposition velocities and scavenging coefficients of radioactive particles entrained in fog are presented for the Point Lepreau area of the Bay of Fundy coast. It is recommended to calculate deposition based on fog deposition velocities. The deposition velocities can be calculated from common meteorological data. The range of deposition velocities is approximately 1 - 100 cm/s. Fog deposition is surface roughness dependent with forests having larger deposition and deposition velocities than soil or grasses. (author)

  2. Dust deposits on Mars: The 'parna' analog

    Greeley, Ronald; Williams, Steven H.

    1994-07-01

    Parna is an Australian aboriginal word meaning 'sandy dust'. It has been applied to deposits of clay, silt, and sand which were initially transported by the wind as aggregates, or pellets, of sand size. Parna is distinguished by its silt and clay content, which in some cases exceeds 85% of the total volume of the deposit. Much of the fine-grained playa silt and clay is incorporated into the parna as sand-sized aggregates, which greatly facilitate their transportation and reworking by the wind. Rain following aggregate emplacement can cause their disintegration, rendering the parna immobile by the wind, yet some pellets can survive several wetting/drying episodes. Parna deposits on Earth occur both as dune forms and as sheet deposits which mantle older terrains. In both cases the deposits are typically derived from lacustrine (lake) beds, such as playas. There is substantial evidence to suggest that bodies of water existed on Mars in the past. Thus, the potential is high for lacustrine deposits and the formation of parna on Mars. Although no parna dunes have been identified, it is suggested that the deposits derived from White Rock (-8 deg, 335 deg W), near Mamers Valles (34 deg, 343 deg W), and elsewhere on Mars may represent sheet parna. Data obtained from Mars-94/96 missions and potential landed spacecraft may provide additional evidence for the existence of parna on Mars.

  3. Regional and Localized Deposits on the Moon

    Coombs, Cassandra R.

    1996-01-01

    Earth-based telescopic remote sensing studies have provided important information concerning lunar pyroclastic deposits. Combined with the returned lunar sample studies and analyses of lunar photography, we have learned a great deal about the nature and origin of these explosive volcanic materials. Lunar pyroclastic deposits are more numerous, extensive, and widely distributed than previously thought. Two generic classes of lunar pyroclastics have been identified, regional and localized. From the former, two separate spectral compositional groups have been identified; one is dominated by Fe(2+)-bearing glasses, the other is composed of ilmenite-rich black spheres. Comparatively, three separate spectral groups have been identified among the localized deposits: highlands-rich, olivine-rich, and mare-rich. Returned sample studies and the recently collected Galileo and Clementine data also corroborate these findings. Albedo data and multispectral imagery suggest that the thicker core deposits of the regional dark mantle deposits (RDMD) are surrounded by pyroclastic debris and subjacent highlands material. The presence of a major component of pyroclastic debris in the regolith surrounding the core regional deposits has important implications for the resource potential of these materials. Both telescopic and orbital spectra indicate that the regional pyroclastic deposits are rich in iron, titanium and oxygen-bearing minerals. Particle shapes vary from simple glass spheres to compound droplets with quench crystallized textures. Their small grain size and friability make them ideal indigenous feedstock. Compared to other resource feedstock sources on the Moon, these pyroclastic materials may be the best oxygen resource on the Moon.

  4. Reducing tube bundle deposition using alternative amines

    Particle deposition rates were measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled, using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates 10 times greater than those measured for magnetite although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) : ammonia (0.51) dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat-transfer mechanism from nucleate boiling to 2-phase forced-convection through a thin film. (author)

  5. Deposition of large particles in human lung

    Twenty-four nonsmoking males, all without history of pulmonary disease, were randomly divided into four groups of six subjects each. The subjects in each group inhaled monodisperse Teflon particles labelled with 111In (half-life 2.83 days); 8.2, 11.5, 13.7 and 16.4 micron aerodynamic diameter, respectively. Radioactivity in head and throat, lung and stomach was determined after 0, 3 and 24 hrs using a profile scanner. For some subjects radioactivity was also determined using a whole-body scanner at 3.5 and 24 hrs. After the 24-hr determination the subjects inhaled labelled Teflon particles again, this time with a filter in front of the mouth. Average values for total deposition in the body, obtained using a profile scanner, whole-body scanner and filter measurements, agreed fairly well. Lung retention values obtained by whole-body and profile scanning also agreed well. The average deposition in the lung, expressed as a percentage of total deposition, was 49, 31, 21 and 13% for the four particle sizes (8.2-16.4 micron). Alveolar deposition, determined as retention at 24 hrs and expressed in percent of total deposition, was 15, 4, 4 and 1%. For the smallest particle sizes the deposition values agreed with earlier investigations. However, for the larger particles the two deposition values were higher than expected when compared to earlier studies

  6. Deposition of large particles in human lung.

    Svartengren, M; Falk, R; Linnman, L; Philipson, K; Camner, P

    1987-01-01

    Twenty-four nonsmoking males, all without history of pulmonary disease, were randomly divided into four groups of six subjects each. The subjects in each group inhaled monodisperse Teflon particles labelled with 111In (half-life 2.83 days); 8.2, 11.5, 13.7 and 16.4 micron aerodynamic diameter, respectively. Radioactivity in head and throat, lung and stomach was determined after 0, 3 and 24 hrs using a profile scanner. For some subjects radioactivity was also determined using a whole-body scanner at 3.5 and 24 hrs. After the 24-hr determination the subjects inhaled labelled Teflon particles again, this time with a filter in front of the mouth. Average values for total deposition in the body, obtained using a profile scanner, whole-body scanner and filter measurements, agreed fairly well. Lung retention values obtained by whole-body and profile scanning also agreed well. The average deposition in the lung, expressed as a percentage of total deposition, was 49, 31, 21 and 13% for the four particle sizes (8.2-16.4 micron). Alveolar deposition, determined as retention at 24 hrs and expressed in percent of total deposition, was 15, 4, 4 and 1%. For the smallest particle sizes the deposition values agreed with earlier investigations. However, for the larger particles the two deposition values were higher than expected when compared to earlier studies. PMID:3102217

  7. Deposition of large particles in human lung

    Svartengren, M.; Falk, R.; Linnman, L.; Philipson, K.; Camner, P.

    1987-01-01

    Twenty-four nonsmoking males, all without history of pulmonary disease, were randomly divided into four groups of six subjects each. The subjects in each group inhaled monodisperse Teflon particles labelled with /sup 111/In (half-life 2.83 days); 8.2, 11.5, 13.7 and 16.4 micron aerodynamic diameter, respectively. Radioactivity in head and throat, lung and stomach was determined after 0, 3 and 24 hrs using a profile scanner. For some subjects radioactivity was also determined using a whole-body scanner at 3.5 and 24 hrs. After the 24-hr determination the subjects inhaled labelled Teflon particles again, this time with a filter in front of the mouth. Average values for total deposition in the body, obtained using a profile scanner, whole-body scanner and filter measurements, agreed fairly well. Lung retention values obtained by whole-body and profile scanning also agreed well. The average deposition in the lung, expressed as a percentage of total deposition, was 49, 31, 21 and 13% for the four particle sizes (8.2-16.4 micron). Alveolar deposition, determined as retention at 24 hrs and expressed in percent of total deposition, was 15, 4, 4 and 1%. For the smallest particle sizes the deposition values agreed with earlier investigations. However, for the larger particles the two deposition values were higher than expected when compared to earlier studies.

  8. Structural characterization of MAPLE deposited lipase biofilm

    Aronne, Antonio; Ausanio, Giovanni; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Fanelli, Esther; Massoli, Patrizio; Vicari, Luciano R. M.

    2014-11-01

    Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography-mass spectrometry gave results consistent with undamaged deposition of lipase.

  9. Industrial types of uranium deposits in Kazakhstan

    The main industrial uranium deposits of Kazakhstan that can be commercially mined, are located in two ore regions and are represented by two types of the uranium deposits. The first region is named Chu-Syrdarya (75.6% of total resources of Kazakhstan) and is located in the South of Kazakhstan and this one is the largest in the world among the regions of the deposits connected with the bed oxidation zone, localized in the permeable sediments and amenable for in-situ leach mining. The second region is named Kokshetau (16% of total resources) and is located in the North of Kazakhstan at the north edge of Kazak Shield and is characterized by the vein-stockwork type of deposit. Other industrial deposits (8.4% of total resources) are grouped in two regions that have been determined and are retained as reserves for economical and ecological reasons. These are: Pricaspian region with the organic phosphate type of uranium deposits; and Ili-Balkhash region with mainly the coal-uranium type. There are 44 industrial uranium deposits with resources ranging from 1000 t to 100000 t U and more in each of them, in all, in Kazakhstan. Seven of them are completely mined now. Total uranium resources in Kazakhstan are determined at 1670000 t U. (author)

  10. Dust deposits on Mars: The 'parna' analog

    Greeley, Ronald; Williams, Steven H.

    1994-01-01

    Parna is an Autralian aboriginal word meaning 'sandy dust'. It has been applied to deposits of clay, silt, and sand which were initially transported by the wind as aggregates, or pellets, of sand size. Parna is distinguished by its silt and clay content, which in some cases exceeds 85% of the total volume of the deposit. Much of the fine-grained playa silt and clay is incorporated into the parna as sand-sized aggregates, which greatly facilitate their transportation and reworking by the wind. Rain following aggregate emplacement can cause their disintegration, rendering the parna immobile by the wind, yet some pellets can survive several wetting/drying episodes. Parna deposits on Earth occur both as dune forms and as sheet deposits which mantle older terrains. In both cases the deposits are typically derived from lacustrine (lake) beds, such as playas. There is substantial evidence to suggest that bodies of water existed on Mars in the past. Thus, the potential is high for lacustrine deposits and the formation of parna on Mars. Although no parna dunes have been identified, it is suggested that the deposits derived from White Rock (-8 deg, 335 deg W), near Mamers Valles (34 deg, 343 deg W), and elsewhere on Mars may represent sheet parna. Data obtained from Mars-94/96 missions and potential landed spacecraft may provide additional evidence for the existence of parna on Mars.