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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

    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.

  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

    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)

  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

    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

    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.)

  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 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)

  6. 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)

  7. 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)

  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. 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,

  10. 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),

  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. 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

  12. 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...

  13. 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...

  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. 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.

  16. 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...

  17. 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)

  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. 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...

  18. 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

  19. 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...

  20. 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

  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. 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...

  5. 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

  6. 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.

  7. 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

  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. 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.

  10. 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...

  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. 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.

  14. 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

  15. 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.

  16. 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...

  17. [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

  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. [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

  2. 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

  3. 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...

  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. 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.)

  9. 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)

  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. 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.

  13. 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)

  14. 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…

  15. 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

  16. 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

  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. 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

  19. 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

  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. 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.

  3. 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

  4. 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...

  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. 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

  13. 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

  14. 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)

  15. 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)

  16. 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.

  17. 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

  18. 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

  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. 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.)

  11. 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

  12. 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

  13. 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...

  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. 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.

  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. 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...

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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+.

  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. 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

  5. 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.

  6. 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)

  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. 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

  9. 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.

  10. 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...

  11. 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...

  12. 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...

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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...

  2. 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.)

  3. 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.

  4. 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.

  5. 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...

  6. 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 (§...

  7. 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

  8. [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

  9. 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

  10. 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)

  11. 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.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  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. 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)

  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. Reducing tube bundle deposition with alternative amines

    Particle deposition rates have been 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 an order of magnitude 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 two-phase forced convection through a thin film. (author)

  9. ITO deposited by pyrosol for photovoltaic applications

    The goal of this work is to investigate morphology, electrical and optical properties of indium-tin-oxide (ITO) deposited by pyrosol on glass and Si substrates at different temperatures and to implement such layers for the processing of Si-based solar cells. The influence of the methanol/H2O ratio on general properties of ITO was investigated. Atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission spectra, ellipsometry and resistivity measurements were used for the analysis. It is shown that properties of ITO layers depend dramatically on the substrate used. It is shown that the resistivity of ITO layers deposited on a glass substrate is higher up to 2.5 times, compared to that of ITO layers deposited on a Si substrate at the same conditions, but in both cases decreases if the deposition temperature increases. Moreover, ITO layers deposited on a glass substrate are more flat and their refractive indexes are always lower for all deposition temperatures. An increase of the H2O concentration in a film-forming solution leads to a decrease of the ITO film resistivity and to a slight increase of the roughness. An application of pyrosol deposited ITO films as the top transparent electrodes for the (p+nn+)Si and heterojunction ITO/n-Si solar cells is demonstrated

  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.

  11. 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.

  12. 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.

  13. TEOS-based oxides: deposition dependent properties

    This paper reports the effects of three important parameters, deposition temperature, TEOS concentration and RF power in the plasma enhanced CVD of TEOS-based oxides on the resulting film characteristics such as impurity incorporation, film density, moisture absorption, intrinsic and thermal stresses. Ion-bombardment induced desorption of reactive precursor species is suggested to occur under certain conditions. Further, it is shown that the film properties continue to evolve until the film thickness exceeds 3000A. For 1 μm films deposited using typical settings of deposition parameters, the average TCE is estimated to be 0.9 ppm/ C using the stress-temperature characteristics. (orig.)

  14. Magnetoresistive multilayers deposited on the AAO membranes

    Malkinski, Leszek M. [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States)]. E-mail: lmalkins@uno.edu; Chalastaras, Athanasios [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States); Vovk, Andriy [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States); Jung, Jin-Seung [Department of Chemistry, Kangnung National University, Kangnung 210702 (Korea, Republic of) ; Kim, Eun-Mee [Department of Chemistry, Kangnung National University, Kangnung 210702 (Korea, Republic of) ; Jun, Jong-Ho [Department of Applied Chemistry, Kunkuk University, Chungju 151747 (Korea, Republic of) ; Ventrice, Carl A. [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States)

    2005-02-01

    Silicon and GaAs wafers are the most commonly used substrates for deposition of giant magnetoresistive (GMR) multilayers. We explored a new type of a substrate, prepared electrochemically by anodization of aluminum sheets, for deposition of GMR multilayers. The surface of this AAO substrate consists of nanosized hemispheres organized in a regular hexagonal array. The current applied along the substrate surface intersects many magnetic layers in the multilayered structure, which results in enhancement of giant magnetoresistance effect. The GMR effect in uncoupled Co/Cu multilayers was significantly larger than the magnetoresistance of similar structures deposited on Si.

  15. Geochemistry and deposit exploration of uranium

    On the basis of genetically simplified earth crust profiles and a mining synoptic table the broad outlines of the enrichment processes are shown, from geochemical dilution to workable deposits for the major uranium ore deposits. Characteristics are offered of the physical-chemical data of different genetic environments, the tectonic preconditions for ready mobilisation of uranium in the form of uranyl complexes with U6+ and the preferred fixing of U4+ minerals in reducing facies; these cover both intracrustal deposit formations, surface circulation and metamorphesis. (orig.)

  16. Thermodynamic analysis and deposition of refractory materials

    This article does not pretend to be an exhaustive review of all publications in which a thermodynamic analysis has been used to analyse the chemical vapour deposition of refractory materials. It simply covers a certain number of experiments in which the present authors made use of various aspects of this method: overall or partial optimization of a process, determination of the deposition material most suited to fulfilling a given role and approach to mechanisms governing the chemical deposition reaction. A thermodynamic analysis is presented here from a more unusual angle, by examples of localized and varied intervention, in order to demonstrate the multiple uses of the method. (orig.)

  17. Residual stresses in tungsten vapor deposits

    Using circular specimens values and distribution of peripheral residual stresses in deposits of gaseous tungsten of different thickness on a graphite substrate were determined by the Davidenkov method during electrolytic re oval of metal layers. It is established that the thinner is the deposit the lower is the level of arisnng stresses. After annealing at 750 deg C the stresses decrease by approximately 30 %, and annealing at 1500 deg C results in minimum values. It is assumed that the decrease of the stresses after nnealing at 1500 deg C results from the variations in deposit substructure typical for polygonization processes

  18. Deposition of thin films of multicomponent materials

    Thakoor, Sarita (Inventor)

    1993-01-01

    Composite films of multicomponent materials, such as oxides and nitrides, e.g., lead zirconate titanate, are deposited by dc magnetron sputtering, employing a rotating substrate holder, which rotates relative to a plurality of targets, one target for each metal element of the multicomponent material. The sputtering is carried out in a reactive atmosphere. The substrates on which the layers are deposited are at ambient temperature. Following deposition of the composite film, the film is heated to a temperature sufficient to initiate a solid state reaction and form the final product, which is substantially single phase and substantially homogeneous.

  19. Deposition and microstructure of pyrolytic carbon

    Two kinds of experiment concerning pyrolytic carbon deposition have been carried out. In one experiment, an attempt was made to coat alumina particles as well as buffer-coated UO2 particle with pyrolytic carbon of laminar structure by means of a fluidized bed technique. Benzene was used as the carbon source and the temperature was 10000C. In the other experiment, carbon deposition was made on graphite surface. Possibility was tested to obtain uniform coating along the direction of gas stream. Carbon source, in this case, was mainly n-hexane and the temperature ranged 750 -- 8500C. Microstructure of the deposit was studied in both experiments. (author)

  20. Hybrid fall deposits in the Bishop Tuff, California: A novel pyroclastic depositional mechanism

    Wilson, Colin J. N.; Hildreth, Wes

    1998-01-01

    Hybrid fall deposits in the Bishop Tuff show features common to both archetypal fall and surge deposits. Like normal-fall deposits, they have an overall plane-parallel bedding and flat-lying pumice clasts but also, like surge deposits, they show variable development of cross-bedding, some crystal and pumice sorting, and some rounding of pumice clasts. All variations exist from normal-fall deposits, through streaky material with incipient development of cross-bedding, to the hybrid fall deposits with well-developed cross-bedding. The streaky and hybrid deposits are interpreted as fall material contemporaneously redeposited by strong (up to 40 m/s) swirling winds, comparable to firestorm whirlwinds, generated by air currents associated with coeval emplacement of pyroclastic flows. Recognition of hybrid fall deposits is important in interpreting the dynamics of explosive eruptions and correctly assessing volcanic hazards. However, although such deposits may be commonly produced by explosive eruptions, especially where pyroclastic flows accompany fall activity, they are likely to be overlooked, or wrongly interpreted as surge deposits or secondary, reworked material.

  1. Platinum-ruthenium bimetallic clusters on graphite: a comparison of vapor deposition and electroless deposition methods.

    Galhenage, Randima P; Xie, Kangmin; Diao, Weijian; Tengco, John Meynard M; Seuser, Grant S; Monnier, John R; Chen, Donna A

    2015-11-14

    Bimetallic Pt-Ru clusters have been grown on highly ordered pyrolytic graphite (HOPG) surfaces by vapor deposition and by electroless deposition. These studies help to bridge the material gap between well-characterized vapor deposited clusters and electrolessly deposited clusters, which are better suited for industrial catalyst preparation. In the vapor deposition experiments, bimetallic clusters were formed by the sequential deposition of Pt on Ru or Ru on Pt. Seed clusters of the first metal were grown on HOPG surfaces that were sputtered with Ar(+) to introduce defects, which act as nucleation sites for Pt or Ru. On the unmodified HOPG surface, both Pt and Ru clusters preferentially nucleated at the step edges, whereas on the sputtered surface, clusters with relatively uniform sizes and spatial distributions were formed. Low energy ion scattering experiments showed that the surface compositions of the bimetallic clusters are Pt-rich, regardless of the order of deposition, indicating that the interdiffusion of metals within the clusters is facile at room temperature. Bimetallic clusters on sputtered HOPG were prepared by the electroless deposition of Pt on Ru seed clusters from a Pt(+2) solution using dimethylamine borane as the reducing agent at pH 11 and 40 °C. After exposure to the electroless deposition bath, Pt was selectively deposited on Ru, as demonstrated by the detection of Pt on the surface by XPS, and the increase in the average cluster height without an increase in the number of clusters, indicating that Pt atoms are incorporated into the Ru seed clusters. Electroless deposition of Ru on Pt seed clusters was also achieved, but it should be noted that this deposition method is extremely sensitive to the presence of other metal ions in solution that have a higher reduction potential than the metal ion targeted for deposition. PMID:26018140

  2. Properties of carbon deposits on tungsten nano-structure

    C deposition characteristics on W nano-structure by two different deposition methods are investigated to study C deposition mechanisms on W nano-structure and its characteristics. The two methods were as follows: irradiation by mixed D and C ion beam, and deposition by magnetron sputtering. Differences on deposition condition such as deposition temperature, incident species and energy affected properties of C deposits. Structure of C deposits was investigated by SEM and Raman spectroscopy. D retention properties were investigated by thermal desorption spectroscopy. It was found that C deposits on nano-structured surface have low internal stress and porous structure compared with C deposits on flat surfaces. Increase of CD4 release from C deposition layers on nano-structured surface was investigated by TDS. These results showed the effects of nano-structure on structure and thermal desorption properties of C deposits

  3. The neutron characteristics of coal deposits

    The neutron parameters of coal vs. its hydrogen content are calculated. The strong dependences observed point the possibilities of neutron analytical methods for determining hydrogen content in coal deposits. (author)

  4. Contacting cadmium deposition from spent industrial solutions

    Cadmium metal deposition from spent industrial solutions by cadmium (2) reduction with dispersed aluminium is studied. The influence of temperature, reagent concentration and the presence of complexing agents on the yield and purity of isolated cadmium metal is examined

  5. Porphyry copper deposits of the world

    U.S. Geological Survey, Department of the Interior — Information on porphyry copper deposits from around the world with grade and tonnage models, a general classification based on geologic setting, mineralogy, with...

  6. ROE Wet Nitrate Deposition 1989-1991

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  7. ROE Wet Sulfate Deposition 2009-2011

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  8. Oscillations in Electrochemical Deposition of Zinc

    Wang, Sheng; Zhang, Ke-Qin; Xu, Qing-Yu; Wang, Mu; Peng, Ru-Wen; Zhang, Ze; Ming, Nai-ben

    2003-06-01

    In this article we report the systematic studies on the oscillation of contrast in front of a growing zinc dendrite in electrochemical deposition observed with interference contrast microscopy. The dependence of the oscillation frequency on the experimental conditions, such as the electric current, the resistance of ion transfer, pH of the electrolyte and the tilting of the electrodeposition cell, etc., has been investigated. The microstructures of the electrodeposits are analyzed with transmission electron microscopy. We conclude that the contrast oscillation in front of the zinc deposit is indeed associated with the concentration oscillation, and is synchronized with the electric voltage/current signals. Although the oscillation can be affected by mass transport in the system, we suggest that it roots from the alternating deposition of zinc and zinc hydroxide on the deposit-electrolyte interface.

  9. Rare earth element mines, deposits, and occurrences

    U.S. Geological Survey, Department of the Interior — This dataset contains location, geologic and mineral economic data for world rare earth mines, deposits, and occurrences. The data in this compilation were derived...

  10. NOAA/WDC Global Tsunami Deposits Database

    National Oceanic and Atmospheric Administration, Department of Commerce — Discover where, when and how severely tsunamis affected Earth in geologic history. Information regarding Tsunami Deposits and Proxies for Tsunami Events complements...

  11. ROE Total Nitrogen Deposition 1989-1991

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of nitrogen in kilograms per hectare from 1989 to 1991 at a set of point locations across the...

  12. DLC films deposited by DC PACVD method

    In this paper the deposition of DLC coating by direct current PACVD (DC PACVD) is presented. DLC films were deposited on silicon (111) and steel substrates. The steel substrate consists of 0.9 % - C, 4.14% - Cr, 6.1% - W, 5% - Mo, 2.02% - V. These samples were polished up to a mirror finish using series of standard metallurgical polishing steps. The apparatus for plasma assisted chemical vapor deposition consisted of vacuum chamber, diffusion pump, two parallel electrodes and generator of DC discharge plasma. We deposited DLC films on our substrates with the same parameters, but one, which was changed. The microhardness of the coated materials is higher than the base material about 13 GPa at the load 50 mN and bias voltage -900 V. (Authors)

  13. Stability of nanocrystalline electrochemically deposited layers

    Pantleon, Karen; Somers, Marcel A. J.

    2009-01-01

    The technological demand for manufacturing components with complex geometries of micrometer or sub-micrometer dimensions and ambitions for ongoing miniaturization have attracted particular attention to electrochemical deposition methods. Thin layers of electrochemically deposited metals and alloys...... have different microstructure and properties compared to bulk materials and the thermodynamic non-equilibrium state of as-deposited layers frequently results in changes of the microstructure as a function of time and/or temperature. The evolving microstructure affects the functionality and reliability...... of electrodeposited components, which can be beneficial, as for the electrical conductivity of copper interconnect lines, or detrimental, as for reduced strength of nickel in MEMS applications. The present work reports on in-situ studies of the microstructure stability of as-deposited nanocrystalline...

  14. ROE Total Nitrogen Deposition 2011-2013

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of nitrogen in kilograms per hectare from 2011 to 2013 at a set of point locations across the...

  15. ROE Total Sulfur Deposition 1989-1991

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of sulfur in kilograms per hectare from 1989 to 1991 at a set of point locations across the...

  16. Dikes and mineralization in uraniferous apatite deposits

    The problem of the age relationships between dike bodies and the mineralization in deposits of uraniferous apatites in carbonate rocks is reconsidered. The post-ore history of apatite mineralization reveals a combination of polygenic mineral associations

  17. Major mineral deposits of the world

    U.S. Geological Survey, Department of the Interior — Regional locations and general geologic setting of known deposits of major nonfuel mineral commodities. Originally compiled in five parts by diverse authors,...

  18. Hard carbon films: Deposition and diagnostics

    Frgala Zdeněk; Kudrle Vít; Janča Jan; Meško Marcel; Eliáš Marek; Buršík Jiří

    2003-01-01

    We studied the growth of microcrystalline diamond films on pre-treated Si and WC-Co substrates by microwave plasma chemical vapour deposition (MPCVD). The pre-treatment was varied and its effect on diamond film was studied.

  19. Perovskite Thin Films via Atomic Layer Deposition

    Sutherland, Brandon R.

    2014-10-30

    © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

  20. Fabrication of Micro Components by Electrochemical Deposition

    Tang, Peter Torben

    The main issue of this thesis is the combination of electrochemical deposition of metals and micro machining. Processes for electroplating and electroless plating of nickel and nickel alloys have been developed and optimised for compatibility with microelectronics and silicon based micromechanics...... of electrochemical machining and traditional machining is compared to micro machining techniques as performed in the field of microelectronics. Various practical solutions and equipment for electrochemical deposition of micro components are demonstrated, as well as the use and experience obtained...

  1. Making Lightweight Structures By Vapor Deposition

    Goela, Jitendra S.; Pickering, Michael A.; Taylor, Raymond L.

    1990-01-01

    Technique developed for fabrication of stiff, strong, lightweight structures of silicon carbide or other materials by any of several deposition processes. Structures made by method can have complicated shapes. Ability to manufacture complex shape from pure deposited SiC useful and leads to new products in several fields. These lightweight structures used as backup structures for optical components, as structural components in automotive, aerospace, and outer space applications, and as lightweight parts of furniture for outer space.

  2. A Game Theory Approach of Deposit Insurance

    JIANG Hong-xun; QIU Wan-hua; MING Ming

    2002-01-01

    This paper presents a dynamic game theory approach for deposit insurance. We formulate a deposit insurance problem as an incomplete information game theory model, which deduces the expression of Capital Charge Ratio for national central bank. The main contribution of the paper however is that we then extrapolate the declared value of the bank in best its policy. Finally a numerical example is used to illustrate the approach proposed in this paper.

  3. Removal of External Deposits on Boiler Tubes

    C. P. De

    1970-07-01

    Full Text Available The superheater tubes in Port and Starboard boilers were found to have completely clogged by heavy deposits, which on analysis mainly vanadium pentoxide and sodium sulphmatter. The cleaning of the deposits was accomplished by alternate spraying with 15-20 per cent hydrogen peroxide and washing with hot water jets. Over the past two years, since the date of cleaning, the IN ship is operating without any trouble in the boilers.

  4. Selective Electroless Silver Deposition on Graphene Edges

    Durhuus, D.; Larsen, M. V.; Andryieuski, Andrei;

    2015-01-01

    We demonstrate a method of electroless selective silver deposition on graphene edges or between graphene islands without covering the surface of graphene. Modifications of the deposition recipe allow for decoration of graphene edges with silver nanoparticles or filling holes in damaged graphene...... on silica substrate and thus potentially restoring electric connectivity with minimal influence on the overall graphene electrical and optical properties. The presented technique could find applications in graphene based transparent conductors as well as selective edge functionalization and can be extended...

  5. Theoretical and Economic Aspects of Deposit Insurance

    Zbyněk Revenda

    2013-01-01

    The paper deals with deposit insurance schemes as an integral part of the present system of the banking regulation. Insurance premiums, limits and the rates of compensation and consequences of deposit insurance are then discussed from the theoretical and practical points of view. The moral hazard of banks and depositors and adverse selection are the main undesirable accompanying effects, which are directly connected with the scale of insurance protection in banks. The European Union unifi es ...

  6. Study on pulsed excimer laser deposited films

    Liu Jing Ru; Li Tie Jun; Yao Dong Sheng; Wang Li Ge; Yuan Xiao; Wang Sheng; Ye Xi Sheng

    2002-01-01

    Pulsed lasers of two different durations (30 ns, 500 fs) are used to deposit Hydrogen-free Diamond Like Carbon (DLC) films over large areas. Analysis of DLC films shows remarkable mechanical, optical, electrical, and chemical properties that are close to those of diamond. By optical emission spectroscopy and ion probe, the effects of plasma characteristic on DLC film are on experimentally studied. Amorphous silicon films deposited by PLD are also experimentally studied

  7. Thin film deposition with time varying temperature

    de Assis, T. A.; Reis, F. D. A. A.

    2013-01-01

    We study the effects of time-dependent substrate/film temperature in the deposition of a mesoscopically thick film using a statistical model that accounts for diffusion of adatoms without lateral neighbors whose coefficients depend on an activation energy and temperature. Dynamic scaling with fixed temperature is extended to predict conditions in which the temperature variation significantly affects surface roughness scaling. It agrees with computer simulation results for deposition of up to ...

  8. IMMUNOGLOBULIN DEPOSITIONS IN PERIPHERAL NERVES IN POLYMYOSITIS

    李越星; 陈清棠; 吴丽娟; 贾钟; 张秋荣; 左越焕

    1995-01-01

    An immunocytochemical study was performed in 6 peripheral nerve specimens from 6 cases of polymyositis.The results revealed that depositions of IgG,IgM,IgA and C3 were found in the epineurium,perineurium and the walls of capillaries.These findings demonstrated that depositions of immonoglobulins and the complement-mediated immunoreaction may play an important role in pathogenesis of polymyositis with peripheral nerfve involvements.

  9. Modelling The Dynamic Distribution Of Spray Deposits

    Lebeau, Frédéric

    2004-01-01

    A mathematical model to estimate the spray distribution of phytopharmaceutical deposits under a spray boom is proposed. It focuses on the need to take account of the dynamic effects of the forward movement of the boom. These are related both to the horizontal and vertical boom movement and to the influence of aerodynamic factors on the nozzle spray distribution. The distribution of the spray deposits is computed by multiplying the nozzle spray pattern by the time needed to m...

  10. Deposition and Characterisation of Crystalline Silicon

    Rachow, Thomas

    2014-01-01

    In this thesis, crystalline silicon thin films by atmospheric pressure chemical vapour deposition have been studied. These silicon films can be deposited on silicon wafers or transferred to various substrates for photovoltaic applications. One of the main advantages is the flexibility in thickness and doping concentration which allows the application of the silicon thin films in various solar cell concepts. The combination of these films with an industrial solar cell fabrication process has a...

  11. Impact of sludge deposition on biodiversity.

    Manzetti, Sergio; van der Spoel, David

    2015-11-01

    Sludge deposition in the environment is carried out in several countries. It encompasses the dispersion of treated or untreated sludge in forests, marsh lands, open waters as well as estuarine systems resulting in the gradual accumulation of toxins and persistent organic compounds in the environment. Studies on the life cycle of compounds from sludge deposition and the consequences of deposition are few. Most reports focus rather on treatment-methods and approaches, legislative aspects as well as analytical evaluations of the chemical profiles of sludge. This paper reviews recent as well as some older studies on sludge deposition in forests and other ecosystems. From the literature covered it can be concluded that sludge deposition induces two detrimental effects on the environment: (1) raising of the levels of persistent toxins in soil, vegetation and wild life and (2) slow and long-termed biodiversity-reduction through the fertilizing nutrient pollution operating on the vegetation. Since recent studies show that eutrophication of the environment is a major threat to global biodiversity supplying additional nutrients through sludge-based fertilization seems imprudent. Toxins that accumulate in the vegetation are transferred to feeding herbivores and their predators, resulting in a reduced long-term survival chance of exposed species. We briefly review current legislation for sludge deposition and suggest alternative routes to handling this difficult class of waste. PMID:26318179

  12. Modeling sediment deposition from marine outfall jets.

    Terfous, Abdelali; Chiban, Samia; Ghenaim, Abdellah

    2016-08-01

    This paper presents a two-dimensional model to study the sediment deposition from marine outfall jets. The introduced unidirectional coupling (fluid-sediment) is an appropriate choice in the case of low-concentrated particle-laden jets such as municipal wastewater discharge, where the concentration of particles is small enough and does not affect the hydrodynamic development of the jet in the nearfield. The sedimentation model takes advantage of the preferential concentration phenomenon. The deposition criterion states that the deposition of sediments begins when the vertical component of the entrainment velocity becomes smaller than the settling velocity. Once the deposition process begins, it is controlled by the settling velocity, entrainment velocity, volume flux, and sediment concentration. The deposition along the jet trajectory is expressed by an ordinary differential equation coupled with the liquid phase equations. Experiments of Lane-Serff and Moran [Sedimentation from Buoyant jets. J Hyd Eng. 2005;131(3):166-174], Cuthbertson and Davies [Deposition from particle-laden, round, turbulent, horizontal, buoyant jets in stationary and coflowing receiving fluids. J Hydr Eng. 2008;134(4):390-402], and Lee [Mixing of horizontal sediment laden jets [dissertation]. Hong Kong: University of Hong Kong; 2010], chosen from bibliography, are used to validate the model. These experiments cover the cases of horizontal and inclined buoyant jets in stationary ambient, horizontal buoyant jets in co-flow current and nonbuoyant horizontal jets in stationary ambient. Good agreement between the experiments and the obtained simulations is revealed. PMID:26732467

  13. Crud deposition on fuel in WWER reactors

    Reliability of nuclear fuel and radiation fields surrounding primary systems are important aspects of overall nuclear reactor safety. Corrosion product (crud) deposition on fuel surfaces has implications for fuel performance through heat transfer and local chemistry modifications. Crud is currently one of the key industry issues and has been implicated in several recent cases of crud-related fuel failures and core plugging. Activated crud is deposited on out-of-core surfaces, mainly steam generators, resulting in high radiation fields and high doses of plant staff. Due to radiation build-up in primary circuit systems, decontamination of primary systems components and steam generators is used. Several issues involving decontamination were observed in some cases. After decontamination higher corrosion product release occurs followed by subsequent crud deposition on fuel surfaces. The paper summarizes experience with water chemistry and decontamination that can influence crud deposition on fuel surfaces. The following areas are discussed: 1) Experience with crud deposition, primary water chemistry and decontamination under operating conditions; 2) The behaviour of organic compounds in primary coolant and on fuel surfaces; 3) A proposed experimental programme to study crud deposition. (authors)

  14. Atmospheric deposition fluxes to Monetary Bay

    Gray, E.; Paytan, A.; Ryan, J.

    2008-12-01

    Atmospheric deposition has been widely recognized as a source of pollutants and nutrients to coastal ecosystems. Specifically, deposition includes nitrogen compounds, sulfur compounds, mercury, pesticides, phosphate, trace metals and other toxic compounds that can travel great distances. Sources of these components include both natural (volcanoes, mineral dust, forest fires) and anthropogenic (fossil fuels, chemical byproducts, incineration of waste) sources, which may contribute to harmful health and environmental impacts such as eutrophication, contaminated fish and harmful algal blooms. This study looks at the flux of aerosol deposition (TSP - total suspended particle load) to Monterey Bay, California. Samples are collected on a cascade impactor aerosol sampler (size fractions PM 2.5 and PM 10) every 48 hours continuously. Preliminary results indicate that the TSP for PM 10 ranged from 0.026 to 0.104 mg m-3 of air and for PM 2.5 from 0.014 to 0.046 mg m-3 of air. Using a deposition velocity of 2 cm s-1 for the large fraction (PM10 - PM 2.5) and a deposition velocity of 0.7 cm s-1 for the fine fraction (PM 2.5) deposition rates are 13 and 86 mg m-2 d-1 respectively.

  15. Deposition uniformity inspection in IC wafer surface

    This paper focuses on the task of automatic visual inspection of color uniformity on the surface of integrated circuits (IC) wafers arising from the layering process. The oxide thickness uniformity within a given wafer with a desired target thickness is of great importance for modern semiconductor circuits with small oxide thickness. The non-uniform chemical vapor deposition (CVD) on a wafer surface will proceed to fail testing in Wafer Acceptance Test (WAT). Early detection of non-uniform deposition in a wafer surface can reduce material waste and improve production yields. The fastest and most low-priced inspection method is a machine vision-based inspection system. In this paper, the proposed visual inspection system is based on the color representations which were reflected from wafer surface. The regions of non-uniform deposition present different colors from the uniform background in a wafer surface. The proposed inspection technique first learns the color data via color space transformation from uniform deposition of normal wafer surfaces. The individual small region statistical comparison scheme then proceeds to the testing wafers. Experimental results show that the proposed method can effectively detect the non-uniform deposition regions on the wafer surface. The inspection time of the deposited wafers is quite compatible with the atmospheric pressure CVD time

  16. Plasma deposited fluorinated films on porous membranes

    Gancarz, Irena [Department of Polymer and Carbon Materials, Wrocław University of Technology, 50-370 Wrocław (Poland); Bryjak, Marek, E-mail: marek.bryjak@pwr.edu.pl [Department of Polymer and Carbon Materials, Wrocław University of Technology, 50-370 Wrocław (Poland); Kujawski, Jan; Wolska, Joanna [Department of Polymer and Carbon Materials, Wrocław University of Technology, 50-370 Wrocław (Poland); Kujawa, Joanna; Kujawski, Wojciech [Nicolaus Copernicus University, Faculty of Chemistry, 7 Gagarina St., 87-100 Torun (Poland)

    2015-02-01

    75 KHz plasma was used to modify track etched poly(ethylene terephthalate) membranes and deposit on them flouropolymers. Two fluorine bearing monomers were used: perflourohexane and hexafluorobenzene. The modified surfaces were analyzed by means of attenuated total reflection infra-red spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy and wettability. It was detected that hexaflourobenxene deposited to the larger extent than perflourohaxane did. The roughness of surfaces decreased when more fluoropolymer was deposited. The hydrophobic character of surface slightly disappeared during 20-days storage of hexaflourobenzene modified membrane. Perfluorohexane modified membrane did not change its character within 120 days after modification. It was expected that this phenomenon resulted from post-reactions of oxygen with radicals in polymer deposits. The obtained membranes could be used for membrane distillation of juices. - Highlights: • Plasma deposited hydrophobic layer of flouropolymers. • Deposition degree affects the surface properties. • Hydrohilization of surface due to reaction of oxygen with entrapped radicals. • Possibility to use modified porous membrane for water distillation and apple juice concentration.

  17. Quantitative analysis of diamond deposition reactor efficiency

    Graphical abstract: Surface H atom densities in a diamond deposition plasma reactor and the highest predicted value (black line). A 350 μm diamond crystal grown at 70 μm/h. Highlights: ► Electron temperature measurement at high pressure in diamond deposition reactor. ► H-atom density measurements at high pressure and high power in diamond deposition reactor. ► Surface H-atom density measurements at high pressure and high power in diamond deposition reactor. ► Microwave cavity based reactor efficiency compared to others reactors. - Abstract: Optical emission spectroscopy has been used to characterize diamond deposition microwave chemical vapour deposition (MWCVD) plasmas operating at high power density. Electron temperature has been deduced from H atom emission lines while H-atom mole fraction variations have been estimated using actinometry technique, for a wide range of working conditions: pressure 25–400 hPa and MW power 600–4000 W. An increase of the pressure from 14 hPa to 400 hPa with a simultaneous increase in power causes an electron temperature decrease from 17,000 K to 10,000 K and a H atom mole fraction increase from 0.1 to up to 0.6. This last value however must be considered as an upper estimate due to some assumptions made as well as experimental uncertainties.

  18. As-grown magnesium diboride superconducting thin films deposited by pulsed laser deposition

    Grassano, G.; Ramadan, W.; Ferrando, V.; Bellingeri, E.; Marre, D.; Ferdeghini, C.; Grasso, G.; Putti, M.; Chincarini, A. [INFM, Dipartimento di Fisica, Genoa (Italy); Manfrinetti, P.; Palenzona, A. [INFM, Dipartimento di Chimica e Chimica Industriale, Genoa (Italy)

    2001-09-01

    As-grown superconducting MgB{sub 2} thin films were deposited by pulsed laser deposition on magnesium oxide and sapphire substrates. Starting from a non-stoichiometric, Mg and B mixed-powder target, we were able to grow the superconducting phase during the film deposition, without any further annealing process. So far, samples grown in the temperature range of 400-450 deg. C, and at an argon buffer pressure of the order of 10{sup -2} mbar turned out to be superconducting with an onset temperature of the resistive transition at about 25 K. Even if the deposition process still needs to be fully optimized, we have demonstrated that this method allows us to achieve in situ deposition of as-grown superconducting thin films. This procedure could therefore be promising for the deposition of high-quality epitaxial MgB{sub 2} thin films. (author)

  19. Hybrid inorganic–organic superlattice structures with atomic layer deposition/molecular layer deposition

    Tynell, Tommi; Yamauchi, Hisao; Karppinen, Maarit

    2014-01-01

    A combination of the atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques is successfully employed to fabricate thin films incorporating superlattice structures that consist of single layers of organic molecules between thicker layers of ZnO. Diethyl zinc and water are used as precursors for the deposition of ZnO by ALD, while three different organic precursors are investigated for the MLD part: hydroquinone, 4-aminophenol and 4,4′-oxydianiline. The successful superla...

  20. Evaluation of neodymium doped fluoride glass films deposited by pulsed laser deposition

    Harwood, D.W.J.; Eason, R. W.; Taylor, E. R.

    1997-01-01

    Pulsed laser deposition (PLD) has been evaluated as a technique for the realisation of neodymium doped fluoride glass waveguides. In contrast to other high energy techniques such as sputtering and molecular beam epitaxy, pulsed laser deposition appears to reliably reproduce the bulk stoichiometry of the doped glass in thin film form. However, characteristically for this deposition technique, the film topography is dominated by micron size particulates generated during fabrication. Film unifor...

  1. The deposit operations of commercial banks of Ukraine, their organization and deposit policy

    Bobyl, V. V.; Kornilenko, M. S.

    2015-01-01

    The purpose. The work is devoted to the nature of the Deposit activity of the Bank, to highlight the features of the Deposit policy of the Bank and ways of increase of efficiency of management of the Deposit operations of the Bank. The basic problems faced by banks in implementing their Deposit activity, in particular: lack of active-passive operations of banks, the lack of resources accumulated by banking institutions to ensure the financial needs of the economy. The main ways to improve Dep...

  2. Ultrafast deposition of silicon nitride and semiconductor silicon thin films by Hot Wire Chemical Vapor Deposition

    Schropp, R.E.I.; van der Werf, C.H.M.; Verlaan, V.; J.K. Rath; Li, H. B. T.

    2009-01-01

    The technology of Hot Wire Chemical Vapor Deposition (HWCVD) or Catalytic Chemical Vapor Deposition (Cat-CVD) has made great progress during the last couple of years. This review discusses examples of significant progress. Specifically, silicon nitride deposition by HWCVD (HW-SiNx) is highlighted, as well as thin film silicon single junction and multijunction junction solar cells. The application of HW-SiNx at a deposition rate of 3 nm/s to polycrystalline Si wafer solar cells has led to cell...

  3. Electrophoretic deposition of titania nanoparticles: Wet density of deposits during EPD

    Morteza Farrokhi-Rad; Taghi Shahrabi; Shirin Khanmohammadi

    2014-08-01

    Electrophoretic deposition (EPD) of titania nanoparticles was performed at different voltages and times. The wet density of deposits was calculated according to the Archimedes’ principle. The wet density as well as the electric field over the deposits increased with time and attained the plateau at longer times. The velocity at which particles attach to the deposit, strongly influences its wet density at initial times. However, the effect of electro-osmotic flow is dominant at longer times. The coating with higher wet density had the higher corrosion resistance in Ringer’s solution at 37.5 °C due to its closely packed and crack free microstructure.

  4. Uranium deposits in magmatic and metamorphic rocks

    The association of uranium with certain types of magmatic and metamorphic rocks is well known. They have consequently been explored and studied quite extensively. In recent years interest in them has been eclipsed by the discovery of larger, lower cost deposits in other geological environments. Nonetheless, magmatic and metamorphic rocks continue to be important sources of uranium and large areas of the Earth's crust with such rocks are prospective locations for additional discoveries. As future exploration and development could be more difficult the full importance of individual deposits may not be recognized until after many years of investigation and experience. In addition to being important host rocks, magmatic and metamorphic rocks have been of considerable interest to uranium geologists as they are considered to be important source rocks for uranium and thus can lead to deposits nearby in other environments. Furthermore, these rocks provide important information on the geochemical cycle of uranium in the Earth's crust and mantle. Such information can lead to identification of uranium provinces and districts and to a basic understanding of processes of formation of uranium deposits. The International Atomic Energy Agency convened a Technical Committee Meeting on Uranium Deposits in Magmatic and Metamorphic Rocks. The meeting was held in Salamanca, Spain, from 29 September to 3 October 1986. It was followed by a two day field trip to uranium deposits in the Ciudad Rodrigo and Don Benito areas. The meeting was attended by 48 participants from 22 countries. Two panels were organized for discussion of the following topics: (1) ore deposit genesis and characterization and (2) exploration and resource assessment. The technical papers together with the panel reports form this publication. The scope and variety of the papers included and the panel reports provide a good coverage of current knowledge and thinking on uranium in magmatic and metamorphic rocks

  5. Dispersion, deposition and resuspension of atmospheric contaminants

    The following topics are discussed: dry deposition, oil shale fugitive air emissions, particle resuspension and translocation, theoretical studies and applications, and processing of emissions by clouds and precipitation. The concentration of contaminant species in air is governed by the rate of input from sources, the rate of dilution or dispersion as a result of air turbulence, and the rate of removal to the surface by wet and dry deposition processes. Once on the surface, contaminants also may be resuspended, depending on meteorological and surface conditions. An understanding of these processes is necessary for accurate prediction of exposures of hazardous or harmful contaminants to humans, animals, and crops. In the field, plume dispersion and plume depletion by dry deposition were studied by the use of tracers. Dry deposition was investigated for particles of both respiration and inhalation interest. Complementary dry deposition studies of particles to rock canopies were conducted under controlled conditions in a wind tunnel. Because of increasing concern about hazardous, organic gases in the atmosphere some limited investigations of the dry deposition of nitrobenzene to a lichen mat were conducted in a stirred chamber. Resuspension was also studied using tracers and contaminated surfaces and in the wind tunnel. The objective of the resuspension studies was to develop and verify models for predicting the airborne concentrations of contaminants over areas with surface contamination, develop resuspension rate predictors for downwind transport, and develop predictors for resuspension input to the food chain. These models will be of particular relevance to the evaluation of deposition and resuspension of both radionuclides and chemical contaminants

  6. Chemical characteristics of some major uranium deposits in western USA

    Multi-element chemical analyses of several thousand samples were retrieved from the US Geological Survey's computerized Rock Analysis Storage System and used to estimate the average abundances of various elements in each of several types of uranium deposits, in altered rocks associated with some of these deposits, and in unmineralized parts of the various host rocks. Deposits for which results are presented include the tabular deposits in the Morrison Formation, Ambrosia Lake district, New Mexico; secondary deposits in the Ambrosia Lake district; tabular deposits in the Morrison Formation of the Henry Mountains, Utah; tabular deposits in the Chinle Formation in Utah and Colorado; roll-type deposits in Tertiary rocks from the Texas Gulf district; roll-type deposits in the Tertiary basins of Wyoming; tabular deposits in the Entrada Sandstone in Colorado; and a vein-type deposit in crystalline rocks of the Front Range of Colorado. Statistical treatment of the data identified elements that were notably more or less abundant in the deposits and altered rocks than in the unmineralized parts of the host rocks. Comparisons of the mean abundances of elements in the deposits show that the chemical composition of roll-type deposits varies greatly even among deposits in the same district. By contrast, the chemical characteristics of tabular deposits display little variation; the Ambrosia Lake tabular deposits and those of the Henry Mountains district are particularly similar. The data place some constraints on the geochemical aspects of genetic models and suggest certain elements as potential prospecting guides

  7. Rocky Mountain Carbonate Spring Deposit development

    Rainey, Dustin Kyle

    Relict Holocene carbonate spring deposits containing diverse biotic and abiotic depositional textures are present at Fall Creek cold sulphur springs, Alberta, Fairmont Hot Springs, British Columbia, and Hot Creek cold springs, British Columbia. The relict deposits are formed mainly of low-magnesium crystalline calcite contained in laterally continuous strata. Paleo-flow regimes were characterized by extensive sheet flow that increased the surface area of spring water exposed to the atmosphere. Calcite precipitated inorganically from spring water that attained CaCO3 supersaturation through agitation-induced CO2 degassing that was facilitated by elevated flow rates and a large surface area as spring water flowed down-slope. Thus, the deposits contain only minor amounts of detrital, mechanically deposited, and biogenic carbonate. Evaporation was only a minor contributor to CaCO3 supersaturation, mainly in quiescent environments. Photosynthetic CO2 removal did not measurably contribute to CaCO3 supersaturation. Calcite crystals precipitated in biotic facies formed from low to moderately supersaturated spring water, whereas abiotic dendrite crystals formed rapidly from highly supersaturated spring water. Calcite passively nucleated on cyanobacteria, bryophytes and macrophytes, and was probably facilitated by cyanobacterial extracellular polymeric substances. Cyanobacterial filaments and stromatolites are integral parts of all three deposits, whereas bryophytes were restricted to the Fall Creek and Hot Creek deposits. Diagenetic microbial degradation of crystalline calcite was common to all three deposits, but recrystallization was limited to the Fall Creek deposit. The amount and location of calcite precipitation relative to the vents was controlled by the concentrations of Ca2+ and HCO3- in solution, and discharge volume fluctuations. Spring water with high [Ca2+] and [HCO 3-] precipitated large amounts of calcite proximal to the vents (e.g. Fairmont), whereas spring

  8. Global Tsunami Deposits Database, a demonstration

    Brocko, V. R.; Dunbar, P. K.

    2008-12-01

    A result of collaboration between NOAA's National Geophysical Data Center (NGDC) and the Cooperative Institute for Research in the Environmental Sciences (CIRES), the Global Tsunami Database includes instrumental records, human observations, and now, information inferred from the geologic record. Historical reports, tide gauge data, Deep Ocean Assessment and Reporting of Tsunamis (DART) data, and information gleaned from published tsunami deposit research build a multi-faceted view of tsunami hazards and their history around the world. Tsunami history provides clues to what might happen in the future, including frequency of occurrence and maximum wave heights. However, instrumental and written records commonly span too little time to reveal the full range of a region's tsunami hazard. The sedimentary deposits of tsunamis, identified with the aid of modern analogs, increasingly complement instrumental and human observations. By adding the component of tsunamis inferred from the geologic record, the database extends the record of tsunamis backward in time. Deposit locations, their estimated age and descriptions of the deposits themselves fill in the tsunami record. Tsunamis inferred from proxies, such as evidence for coseismic subsidence, are included to estimate recurrence intervals, but are flagged to highlight the absence of a physical deposit. NGDC and CIRES welcome contributions and suggestions to improve the content and presentation of the database. Authors may submit their own descriptions and upload digital versions of publications. The data and information may be searched and viewed using tools designed to extract and display data from the Oracle database (selection forms, Web Map Services, and Web Feature Services). For example, users may select or sort by many fields, including event, location, region, age of deposit, author, publication type, grain size, composition, presence/absence of plant material. They may find tsunami deposit references for a given

  9. Pulsed laser deposition of pepsin thin films

    Kecskemeti, G. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary)]. E-mail: kega@physx.u-szeged.hu; Kresz, N. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Smausz, T. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Hopp, B. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Nogradi, A. [Department of Ophthalmology, University of Szeged, H-6720, Szeged, Koranyi fasor 10-11 (Hungary)

    2005-07-15

    Pulsed laser deposition (PLD) of organic and biological thin films has been extensively studied due to its importance in medical applications among others. Our investigations and results on PLD of a digestion catalyzing enzyme, pepsin, are presented. Targets pressed from pepsin powder were ablated with pulses of an ArF excimer laser ({lambda} = 193 nm, FWHM = 30 ns), the applied fluence was varied between 0.24 and 5.1 J/cm{sup 2}. The pressure in the PLD chamber was 2.7 x 10{sup -3} Pa. The thin layers were deposited onto glass and KBr substrates. Our IR spectroscopic measurements proved that the chemical composition of deposited thin films is similar to that of the target material deposited at 0.5 and 1.3 J/cm{sup 2}. The protein digesting capacity of the transferred pepsin was tested by adapting a modified 'protein cube' method. Dissolution of the ovalbumin sections proved that the deposited layers consisted of catalytically active pepsin.

  10. Pharmacological approach to evaluate aerosol pulmonary deposition.

    Girodet, Pierre-Olivier; Molimard, Mathieu

    2005-01-01

    Drug delivery to the lung in vivo may be assessed using pharmacokinetic or pharmacodynamic techniques. The choice of method depends on drug class specificities. Pharmacokinetic determination of deposition to the lung for drugs without hepatic first-pass effect, such as short acting beta2-agonists, has to be done shortly after inhalation to minimize the effect of gastrointestinal absorption. For medication undergoing important hepatic first-pass metabolisation, such as inhaled corticosteroid, plasma concentration indirectly reflects bronchial deposition. The pharmacodynamic profile should be assessed through clinical effects and adverse events induced by inhaled drugs. Dose ranking of lung deposition for bronchodilators requires patient selection with sufficient bronchial obstruction to maintain room for improvement after the first dose. To assess dose effect relationship between inhaled corticosteroid, the Finney parallel line bioassay is the reference method with a study period of at least 6 weeks. Analysis of side effects with high doses of beta2-agonists or inhaled corticosteroids may also be used to compare lung deposition. Finally, pharmacological evaluation of lung deposition provides complementary information to scintigraphic studies, based on their clinical relevance. PMID:15966772

  11. Definition and classification of surficial uranium deposits

    Uraniferous surficial deposits may be broadly defined as uraniferous sediments or soils, usually of Tertiary to Recent age, that have not been subjected to deep burial and may or may not have been cemented to some degree. Evaluation of the available literature shows that confusion has arisen as to the use of the term ''calcrete'' when describing fluviatile sediments that have been calcified to a greater or lesser degree. It is felt that a useful purpose would be served by proposing a classification system which may go some way towards a redefinition of the applicable terminology. Unfortunately the terms ''calcrete'' or ''valley calcrete'' have been used to define Tertiary to Recent sediments ranging from boulder beds to silts which, in some Namibian examples, contain between 5 and 50% CaCO3 and as much as 90% total carbonate in some Australian surficial uranium deposits. It is proposed that the detrital material constituting the sediments be prefixed with the terms calcareous, dolomitic, gypsiferous, halitiferous or ferruginous (e.g. calcareous grit) rather than the terms calcrete, dolocrete, gypcrete, and ferricrete, all of which have genetic connotations. The latter group of terms are preferably used for the pedogenic uranium deposits only. This will have the effect of placing these deposits in categories of their own and not confusing the issue with the overprint of pedogenic calcrete or duricrustal deposits which may or may not be present. This view is not shared by some authorities notably Butt and Carlisle (see this volume). (author)

  12. Percolation and structural properties of particle deposits

    We investigate the percolation properties of configurations of spherical particles deposited by a generalized ballistic deposition model. In this model, a tuning parameter a is introduced for controlling the relative efficiency of two mechanisms: direct deposition and deposition by following the path of steepest descent on previously deposited particles. Any particle that is trapped in an elevated position after rolling is rejected. Exact critical exponents are obtained for the (1+1)-dimensional version of the model. We performed computer simulations of the (2+1)-dimensional version and by studying the percolative behavior both for fixed values of a, as a function of the surface coverage θ, and along the saturation curve θ(a,∞), we construct the percolation phase diagram of the model. Below a threshold value, ac congruent 3.05, there is no percolation transition, but we give some evidence for a ''virtual percolation line.'' The critical exponents β,γ,ν are determined by finite-size scaling and Monte Carlo renormalization group techniques, and are shown to be consistent with those of ordinary two-dimensional lattice percolation. Finally, changes of structure with a are illustrated through the pair distribution function and the pair connectedness function

  13. Dry deposition to vegetated surfaces: parametric dependencies

    The dry deposition velocity of airborne pollutants to vegetated surfaces depends on the physico-chemical form of the pollutant, on meteorological conditions (windspeed, atmospheric stability) and on characteristics of the surface cover. This report examines these dependencies, drawing on experimental data and on information from theoretical analyses. A canopy model is outlined which uses first-order closure of the equations for turbulent transport of momentum (or matter), with losses of momentum (or matter) to individual canopy elements parameterised in terms of the mean windspeed: the model has previously been tested against experimental data on an artificial 'grass' canopy. The model is used to elucidate the features of the dependence of deposition velocity on windspeed and on whether the pollutant is in gaseous or particulate form: in the former case, the dependence on the molecular diffusivity of the gas is shown; in the latter case, dependencies on particle diameter and density are deduced. The predictions are related to available measurements. Additional hypotheses are introduced to treat the influence of atmospheric stability on deposition, and the analysis is used to shed light on the somewhat confusing picture that has emerged from past experimental studies. In considering the dependence of deposition velocity on the structural properties of the vegetation, it is established that more parameters than the single one conventionally used -aerodynamic roughness length - are needed to characterise the surface cover. Some indications of the extent of variation in deposition velocity from one type of vegetation to another are elicited from the model. (author)

  14. Palladium clusters deposited on the heterogeneous substrates

    Wang, Kun; Liu, Juanfang; Chen, Qinghua

    2016-07-01

    To improve the performance of the Pd composite membrane prepared by the cold spraying technology, it is extremely essential to give insights into the deposition process of the cluster and the heterogeneous deposition of the big Pd cluster at the different incident velocities on the atomic level. The deposition behavior, morphologies, energetic and interfacial configuration were examined by the molecular dynamic simulation and characterized by the cluster flattening ratio, the substrate maximum local temperature, the atom-embedded layer number and the surface-alloy formation. According to the morphology evolution, three deposition stages and the corresponding structural and energy evolution were clearly identified. The cluster deformation and penetrating depth increased with the enhancement of the incident velocity, but the increase degree also depended on the substrate hardness. The interfacial interaction between the cluster and the substrate can be improved by the higher substrate local temperature. Furthermore, it is found that the surface alloys were formed by exchanging sites between the cluster and substrate atoms, and the cluster atoms rearranged following as the substrate lattice arrangement from bottom to up in the deposition course. The ability and scope of the structural reconstruction are largely determined by both the size and incident energy of the impacted cluster.

  15. Model boiler studies on deposition and corrosion

    Deposit formation was studied in a model boiler, with sea-water injections to simulate the in-leakage which could occur from sea-water cooled condensers. When All Volatile Treatment (AVT) was used for chemistry control the deposits consisted of the sea-water salts and corrosion products. With sodium phosphate added to the boiler water, the deposits also contained the phosphates derived from the sea-water salts. The deposits were formed in layers of differing compositions. There was no significant corrosion of the Fe-Ni-Cr alloy boiler tube under deposits, either on the open area of the tube or in crevices. However, carbon steel that formed a crevice around the tube was corroded severely when the boiler water did not contain phosphate. The observed corrosion of carbon steel was caused by the presence of acidic, highly concentrated chloride solution produced from the sea-water within the crevice. Results of theoretical calculations of the composition of the concentrated solution are presented. (author)

  16. THE WATERSHED DEPOSITION TOOL: A MEANS TO LINK ATMOSPHERIC DEPOSITION TO WATERSHEDS

    The potential for atmospheric deposition reductions to contribute to water quality management is not being included in many planning exercises. This is because often the water quality scientists do not know where to get and how to use projections of atmospheric deposition reducti...

  17. Controllable deposition of gadolinium doped ceria electrolyte films by magnetic-field-assisted electrostatic spray deposition

    This paper describes a simple and low-temperature approach to fabrication of dense and crack-free gadolinium doped ceria (GDC) thin films with controllable deposition by a magnetic-field-assisted electrostatic spray deposition technique. The influences of external permanent magnets on the deposition of GDC films were investigated. The coating area deposited using two magnets with the same pole arrangement decreased in comparison with the case of no magnets, whereas the largest deposition area was obtained in the system of the opposite poles. Analysis of as-deposited films at 450 °C indicated the formation of uniform, smooth and dense thin films with a single-phase fluorite structure. The films produced in the system using same poles were thicker, smaller in crystallite size and smoother than those fabricated under other conditions. Additionally, the GDC film deposited using the same pole arrangement showed the maximum in electrical conductivity of about 2.5 × 10−2 S/cm at a low operating temperature of 500 °C. - Highlights: • Magnetic-field-assisted electrostatic spray allows a controllable coating. • Dense, crack-free thin films were obtained at low process temperature of 450 °C. • Control of deposition, thickness and uniformity is easy to achieve simultaneously. • Films from the same pole were thicker, smaller in crystal size and smoother. • The maximum conductivity of doped ceria film was 2.5 × 10−2 S/cm at 500 °C

  18. The uranium ore deposits in Ciudad Rodrigo Phyllites. about the possibility of new deposits

    The main features of the genesis of uranium deposits of the Fe mine type, are discussed in this paper. Pitchblende ore is related with phyllites bearing organic material and with geomorphological level, fossilized by eocene sediments. As a result, new uranium ore deposits are possible under Ciudad Rodrigo tertiary basin, tertiary cover depth being little more than three hundred feet. (Author)

  19. Alternate slicing and deposition strategies for fused deposition modelling of light curved parts

    B. Huang

    2012-12-01

    Full Text Available Fused deposition modeling (FDM, as one of the additive manufacturing (AM techniques, has been widely used in the manufacturing industry from the 1990s. It is relatively cheaper than other AM methods and there are other advantages such as being able to process a variety of other polymers. Currently, FDM is more likely to be suitable for direct production of the terminal-use parts, in some cases challenging traditional process such as injection molding. Research evidences indicate that change of road and layer structure would have significant influence on the meso-structure and thus impact the mechanical properties of the resulting polymer parts. Adaptive flat layer deposition and curved layer deposition have been introduced to improve the mechanical properties of terminal-use product. It is necessary that an appropriate deposition scheme is essential to ensure the best interroad and inter-layer connectivity. Uninterrupted connections are likely to result in a continuous network of polymer chains, as in the case of the conventional processes. The current research proposes conventional flat layer deposition, adaptive flat layer deposition and curved layer deposition for FDM. In particular for curved parts, curved layer deposition in expected to ensure fiber continuity and better meso-structure. Mathematical models are developed for curved slicing, practically implemented to print physical parts and test results suggest marked improvement in the mechanical characteristics of curved parts.

  20. Spatial atomic layer deposition: a route towards further industrialization of atomic layer deposition

    Poodt, P.W.G.; Cameron, D.C.; Dickey, E.; George, S.M.; Kuznetsov, V.; Parsons, G.N.; Roozeboom, F.; Sundaram, G.; Vermeer, A.

    2012-01-01

    Atomic layer deposition (ALD) is a technique capable of producing ultrathin conformal films with atomic level control over thickness. A major drawback of ALD is its low deposition rate, making ALD less attractive for applications that require high throughput processing. An approach to overcome this

  1. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    H. Guan

    2010-05-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

  2. Deposition of Thin Film Electrolyte by Pulsed Laser Deposition (PLD) for micro-SOFC Development

    Krogstad, Hedda Nordby

    2012-01-01

    Optimalization of PLD deposition of YSZ for micr-SOFC electrolyte applications by varying deposition pressure and target-substrate distance.Substrate used was Si-based chips and wafers (large area PLD), and the substrate temperature was held at 600. Dense films were obtained at 20 mTorr.

  3. Ash Deposition Trials at Three Power Stations in Denmark

    Laursen, Karin; Frandsen, Flemming; Larsen, Ole Hede

    1998-01-01

    the probe temperature did influence the composition of deposits for coals with medium ash deposition propensities. These results may indicate that coals with medium to high ash deposition propensities in existing boilers may cause increasing ash deposit formation in future boilers with higher steam...

  4. The Principles of Efficient Banking Deposit Insurance System ABSTRACT

    Petr Dvořák

    2008-01-01

    The subject of article consists in banking deposit insurance system and in international experiences set the principles of efficient banking deposit insurance system for modern banking systems in global financial market. The recommended design of deposit insurance system is explicit insurance with broad client’s protection, which is comparable with systems in other countries where clients can easy transfer their deposit.

  5. 7 CFR 27.92 - Method of payment; advance deposit.

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Method of payment; advance deposit. 27.92 Section 27... Micronaire § 27.92 Method of payment; advance deposit. Any payment or advance deposit under this subpart...,” and may not be made in cash except in cases where the total payment or deposit does not exceed...

  6. Influence of deposition time on the properties of chemical bath deposited manganese sulfide thin films

    Anuar Kassim

    2010-12-01

    Full Text Available Manganese sulfide thin films were chemically deposited from an aqueous solution containing manganese sulfate, sodium thiosulfate and sodium tartrate. The influence of deposition time (2, 3, 6 and 8 days on the properties of thin films was investigated. The structure and surface morphology of the thin films were studied by X-ray diffraction and atomic force microscopy, respectively. In addition, in order to investigate the optical properties of the thin films, the UV-visible spectrophotometry was used. The XRD results indicated that the deposited MnS2 thin films exhibited a polycrystalline cubic structure. The number of MnS2 peaks on the XRD patterns initially increased from three to six peaks and then decreased to five peaks, as the deposition time was increased from 2 to 8 days. From the AFM measurements, the film thickness and surface roughness were found to be dependent on the deposition time.

  7. Effect of deposition pressure and post deposition annealing on SmCo thin film properties

    In this article we report on the effect of the deposition pressure and the post deposition annealing conditions on the structural and magnetic properties of SmCo thin films deposited on Si(100) wafers employing Ta buffer and capping layers. The films were deposited by DC magnetron sputtering and annealed in vacuum at various temperatures. The films under investigation were isotropic with high remanence magnetization, maximum coercive field of 8 kOe and a squareness ratio of coercivity higher than 0.9. It was found that the Ar pressure during the deposition is a key factor in controlling the stoichiometry and the structural and magnetic properties of the SmCo films, while the effect of the annealing temperature is crucial in optimizing the magnetic properties of the films. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Uranium and thorium deposits of Northern Ontario

    This, the second edition of the uranium-thorium deposit inventory, describes briefly the deposits of uranium and/or thorium in northern Ontario, which for the purposes of this circular is defined as that part of Ontario lying north and west of the Grenville Front. The most significant of the deposits described are fossil placers lying at or near the base of the Middle Precambrian Huronian Supergroup. These include the producing and past-producing mines of the Elliot Lake - Agnew Lake area. Also included are the pitchblende veins spatially associated with Late Precambrian (Keweenawan) diabase dikes of the Theano Point - Montreal River area. Miscellaneous Early Precambrian pegmatite, pitchblende-coffinite-sulphide occurrences near the Middle-Early Precambrian unconformity fringing the Lake Superior basin, and disseminations in diabase, granitic rocks, alkalic complexes and breccias scattered throughout northern Ontario make up the rest of the occurrences

  9. Measurements of surface deposition from seeded flames

    In the work reported here, the authors used Raman scattering from a surface deposit to determine its composition and thickness. Surface deposits of B2O3 are obtained by doping a CH4/H2/air flame with BCl3. The dependence of deposit growth and loss rates on surface temperature and the water and boron seed level in the combustion gases are discussed. At temperatures more than 200 K below the dew point, the observed growth and loss rate are explained by a near-constant arrival rate of boron at the surface with an enhanced volatilization at lower temperatures due to the formation of H3BO3 and (HBO2)3

  10. Worldwide deposition of strontium-90 through 1990

    Strontium-90 results from the Environmental Measurements Laboratory's (EML) Global Fallout Program (GFP) are presented for the years 1987 through 1990. Quarterly 90Sr deposition results for the 66 sampling locations of EML's GFP were generally low, indicating that there was no significant release of fission products into the atmosphere during this period. The global 90Sr deposition during these 4 years was lower than it has been for any similar period since this program began in 1958. Since there was no major atmospheric source of 90Sr during this period, the global cumulative deposit of 90Sr continued to decrease by radioactive decay to a 27 year low of 311.4 Pbq

  11. Patterned deposition at moving contact lines

    Thiele, Uwe

    2013-01-01

    When a simple or complex liquid recedes from a smooth solid substrate it often leaves a homogeneous or structured deposit behind. In the case of a receding non-volatile pure liquid the deposit might be a liquid film or an arrangement of droplets depending on the receding speed of the meniscus and the wetting properties of the system. For complex liquids with volatile components as, e.g., polymer solutions and particle or surfactant suspensions, the deposit might be a homogeneous or structured layer of solute - with structures ranging from line patterns that can be orthogonal or parallel to the receding contact line via hexagonal or square arrangements of drops to complicated hierarchical structures. We review a number of recent experiments and modelling approaches with a particular focus on mesoscopic hydrodynamic long-wave models. The conclusion highlights open question and speculates about future developments.

  12. Crud deposition modeling on BWR fuel rods

    Deposition of boiling water reactor (BWR) system corrosion products (crud) on operating fuel rods has resulted in performance-limiting conditions in a number of plants. The operational impact of performance-limiting conditions involving crud deposition can be detrimental to a BWR operator, resulting in unplanned or increased frequency of fuel inspections, fuel failure and associated radiological consequences, operational restrictions including core power derate and/or forced shutdowns to remove failed fuel, premature discharge of individual bundles or entire reloads, and/or undesirable core design restrictions. To facilitate improved management of crud-related fuel performance risks, EPRI has developed the CORAL (Crud DepOsition Risk Assessment ModeL) tool. This paper presents a summary of the CORAL elements and benchmarking results. Applications of CORAL as a tool for fuel performance risk assessment are also discussed. (author)

  13. Plant responses to insect egg deposition.

    Hilker, Monika; Fatouros, Nina E

    2015-01-01

    Plants can respond to insect egg deposition and thus resist attack by herbivorous insects from the beginning of the attack, egg deposition. We review ecological effects of plant responses to insect eggs and differentiate between egg-induced plant defenses that directly harm the eggs and indirect defenses that involve egg parasitoids. Furthermore, we discuss the ability of plants to take insect eggs as warning signals; the eggs indicate future larval feeding damage and trigger plant changes that either directly impair larval performance or attract enemies of the larvae. We address the questions of how egg-associated cues elicit plant defenses, how the information that eggs have been laid is transmitted within a plant, and which molecular and chemical plant responses are induced by egg deposition. Finally, we highlight evolutionary aspects of the interactions between plants and insect eggs and ask how the herbivorous insect copes with egg-induced plant defenses and may avoid them by counteradaptations. PMID:25341089

  14. Model calculations to formation of salt deposits

    The present work is a contribution from the geophysical side and its target is to explain the formation of long stretched salt deposits - salt walls - in a better manner than has been done sofar using model calculations. A few works have already been dedicated to this subject (they are treated in chapter 5). They all have the disadvantage however in not being able to represent the time sequence of the salt deposit generations. Precisely the latter is achieved in this work by including assumed initial interference. The values for the salt wall distance and its growth rate are improved upon. The Schleswig-Holstein salt deposit is taken as example. The model calculations are supported by model experiments. (orig.)

  15. Washout and dry deposition of atmospheric aerosols

    The deposition velocities onto different rough surfaces and the washout coefficients of simulated rain droplets for submicron aerosols were studied in a wind channel. The influence of particle size and electric charge upon the collection efficiencies of simulated rain droplets was measured. The deposition velocity of the particles was determined as a function of aerosol size, wind velocity and roughness of the surface. The experiments were carried out with monodisperse, radioactive particles with sizes which were varied from 0.03 and 5 μm. Using the measured values, the activity flux of the long lived radon decay product (RaD), the mass flux of the atmospheric aerosol and the activity flux near a stack of a nuclear power plant onto the ground surface were calculated considering washout, rainout and dry deposition in the atmosphere. (author)

  16. Deposit control in process cooling water systems

    In order to achieve efficient heat transfer in cooling water systems, it is essential to control the fouling of heat exchanger surfaces. Solubilities of scale forming salts, their growth into crystals, and the nature of the surfaces play important roles in the deposition phenomenon. Condensed phosphates, organic polymers and compounds like phosphates are effective in controlling deposition of scale forming salts. The surface active agents inhibit crystal growth and modify the crystals of the scale forming salts, and thus prevent deposition of dense, uniformly structured crystalline mass on the heat transfer surface. Understanding the mechanism of biofouling is essential to control it by surface active agents. Certain measures taken in the plant, such as back flushing, to control scaling, sometimes may not be effective and can be detrimental to the system itself. (author)

  17. MOCVD deposition of YSZ on stainless steels

    Chevalier, S.; Kilo, M.; Borchardt, G.; Larpin, J. P.

    2003-01-01

    Yttria stabilized zirconia was deposited on stainless steel using the metal-organic chemical vapor deposition (MOCVD) technique, from β-diketonate precursors. The variation of the evaporation temperatures of yttrium and zirconium precursor allowed to control the level of Y within the film. Over the temperature range 125-150 °C, the Y content increased from 2.5 to 17.6 at.%. X-ray diffraction (XRD) analyses evidenced tetragonal phase of zirconia when the Y content was below 8 at.%, and cubic phase for higher concentration. Sputtered neutral mass spectrometry (SNMS) profiles confirmed that the control and stability of Y precursor temperature were of major importance to guarantee the homogeneity of the deposited films.

  18. Multi-Constituent Simulation of Thrombus Deposition

    Wu, Wei-Tao; Massoudi, Mehrdad; Wagner, William R; Antaki, James F

    2016-01-01

    Based on the transport model of Sorensen et al. (1999), an improved mathematical model describing the process of thrombus deposition and growth was developed. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus phase. The transport and reactions of 10 chemical and biological species are modeled using a system of coupled convection-reaction-diffusion (CRD) equations. These represent three main processes: initiation, propagation and stabilization. Computational fluid dynamic (CFD) simulations using the libraries of OpenFOAM were performed for two illustrative benchmark problems: mural thrombus growth in an injured blood vessel and thrombus deposition in a small (125 x 95 micros) crevice observed in vitro. For both problems, the simulated thrombus deposition agreed very well with experimental observations, both spatially and temporally. These promising results encourage further simulations to investigate clinical conditions and design factors that affect the risk of t...

  19. Sputtering. [as deposition technique in mechanical engineering

    Spalvins, T.

    1976-01-01

    This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

  20. Simulation of Indoor Fine Suspension Particle Deposition

    Li, K. Q.; Gong, G. C.; Zou, S. H.

    In this paper, the migration and deposition of particles are simulated using the Moment Dynamic Equation (MDE). Indoor fine suspension particle depositions and particle distribution function are obtained. Gas phase flow is simulated by v 2 - f model. The simulated results of particle concentration profiles show that a uniform concentration exists in the middle region of the room with a low supplying speed. At the same time, the total number of partciels deposited is also obtained using Gradient diffusion model. Through the comparison of velocity predictions among several CFD k-ɛ models and v 2 -f model and experimental data, it is concluded that the results obtained by v 2 -f model more accurately approximate the experimental data. So that the MDE combined v 2 -f model will gain in popularity amongst building engineers and it will gradually be adopted as an attractive alternative tool to predict contaminant particle dispersion and distribution.

  1. Atomic-layer deposition of silicon nitride

    Yokoyama, S; Ooba, K

    1999-01-01

    Atomic-layer deposition (ALD) of silicon nitride has been investigated by means of plasma ALD in which a NH sub 3 plasma is used, catalytic ALD in which NH sub 3 is dissociated by thermal catalytic reaction on a W filament, and temperature-controlled ALD in which only a thermal reaction on the substrate is employed. The NH sub 3 and the silicon source gases (SiH sub 2 Cl sub 2 or SiCl sub 4) were alternately supplied. For all these methods, the film thickness per cycle was saturated at a certain value for a wide range of deposition conditions. In the catalytic ALD, the selective deposition of silicon nitride on hydrogen-terminated Si was achieved, but, it was limited to only a thin (2SiO (evaporative).

  2. Deposition of caesium to surfaces of buildings

    Outdoor surfaces of several different types of building material have been analysed for 134Cs and 137Cs and the results used to estimate deposition velocities using integrated air doses. The Chernobyl reactor accident would have been the only significant source of 134Cs and, for materials unlikely to have intercepted precipitation during the passage of the main plume, dry deposition velocities have been inferred. Substantial amounts of 137Cs on the older building materials would have been due to nuclear weapons fall-out. For brick walls, 134Cs levels were below the limits of analytical detection and upper limits of dry deposition velocity have been estimated. Values have also been inferred for roofing felt and flat clay and corrugated concrete roof tiles. 137Cs levels on older roofing materials indicate significant weathering of weapons fall-out. (author)

  3. Dry deposition of pan to grassland vegetation

    Doskey, P.V.; Wesely, M.L.; Cook, D.R.; Gao, W.

    1994-01-01

    Peroxyacetyl nitrate or PAN (CH{sub 3}C(O)OONO{sub 2}) is formed in the lower troposphere via photochemical reactions involving nitrogen oxides (NO{sub x}) and non-methane hydrocarbons (NMHCs). PAN has a lifetime in the free troposphere of about three months and is removed by photolysis or reaction with OH. Dry deposition will decrease its lifetime, although the few measurements that have been made indicate that this process is slow. Measurements of the uptake of PAN by alfalfa in growth chambers indicated that the dry deposition velocity (downward flux divided by concentration at a specified height) was 0.75 cm s{sup {minus}1}. Garland and Penkett measured a dry deposition velocity of 0.25 cm s{sup {minus}1} for PAN to grass and soil in a return-flow wind tunnel. Shepson et al. (1992) analyzed trends of PAN and O{sub 3} concentrations in the stable nocturnal boundary layer over mixed deciduous/coniferous forests at night, when leaf stomata were closed, and concluded that the deposition velocity for PAN was at least 0.5 cm s{sup {minus}1}. We measured the dry deposition velocity of PAN to a grassland site in the midwestern United States with a modified Bowen ratio technique. Experiments were conducted on selected days during September, October, and November of 1990. An energy balance Bowen ratio station was used to observe the differences in air temperature and water vapor content between heights of 3.0 and 0.92 m and to evaluate the surface energy balance. Air samples collected at the same two heights in Teflon {reg_sign} bags were analyzed for PAN by a gas chromatographic technique. We present an example of the variations of PAN concentrations and gradients observed during the day and compare measurements of the dry deposition velocity to expectations based on the physicochemical properties of PAN.

  4. Transport and Deposition of Electrosprayed Nanoparticles

    Brown, Nicholas; Chiarot, Paul

    2015-11-01

    In an electrospray, high electric potentials are utilized to generate a fine aerosol of a conductive solvent. For this study, the solvent consisted of nanoparticles dispersed in alcohol. The nanoparticle suspensions act as printable nanoparticle inks. In this process, a glass capillary tube is held as a high electric potential relative to a grounded reference plate located below the tip. Droplets are ejected from the tube and are directed towards the ground plate. If the solvent is sufficiently volatile, it will rapidly evaporate while the droplets are in flight (due to the high surface area to volume ratio) leaving behind dry, highly charged nanoparticles. The droplets/nanoparticles are deposited onto a target substrate that is place onto the grounded plate. The transport of any individual droplet/nanoparticle from the emitter tip to the target substrate is a stochastic process. This transport can be modeled using a Monte Carlo simulation. The probability of an individual particle being deposited at a given location on the target substrate is directly related to the electric potential at that location. In other words, the probability function that determines the deposition is directly related to the electric potential at the substrate. The total potential is comprised of the applied electric potential required to generate the electrospray, the induced charge on the surface of the target dielectric, and the charge on the individual particles themselves. We report on the structure of droplet/nanoparticle deposits printed using electrospray. The evolution of the deposit is investigated over time using experimental studies and Monte Carlo simulations. The deposit structure passes through four distinct regimes that are characterized by repeatable bulk features.

  5. Texture of atomic layer deposited ruthenium

    Musschoot, J.; Xie, Q; Deduytsche, D.; De Keyser, K; Longrie, D.; Haemers, J.; Van den Berghe, S.; Van Meirhaeghe, R. L.; D'Haen, Jan; Detavernier, C

    2010-01-01

    Ruthenium films were grown by plasma enhanced atomic layer deposition (ALD) on Si(1 0 0) and ALD TiN. X-ray diffraction (XRD) showed that the as-deposited films on Si(1 0 0) were polycrystalline, on TiN they were (0 0 2) oriented. After annealing at 800 degrees C for 60 s, all Ru films were strongly (0 0 2) textured and very smooth. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) demonstrated that the lateral grain size of the annealed films was several 100 ...

  6. Solid Organic Deposition During Gas Injection Studies

    Dandekar, Abhijit Y.; Andersen, Simon Ivar; Stenby, Erling Halfdan

    also evident as oil fractions expelled from the top to bottom of the PVT cell were observed to vary in density, molecular weight, as well as darkness of color. The change in stability of the oil samples before and after the contact with gas was analyzed using flocculation threshold titration. The...... asphaltene content of the different oil samples were determined by the TP 143 method. The standard asphaltenes and the solid organic deposit recovered from the swelling tests were analyzed using FTIR, HPLC-SEC and H-1 NMR. The aim of these analyses is to reveal the molecular nature of the deposits formed...

  7. Diamond deposition on siliconized stainless steel

    Silicon diffusion layers in AISI 304 and AISI 316 type stainless steels were investigated as an alternative to surface barrier coatings for diamond film growth. Uniform 2 μm thick silicon rich interlayers were obtained by coating the surface of the steels with silicon and performing diffusion treatments at 800 deg. C. Adherent diamond films with low sp2 carbon content were deposited on the diffused silicon layers by a modified hot filament assisted chemical vapor deposition (HFCVD) method. Characterization of as-siliconized layers and diamond coatings was performed by energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction and Raman spectroscopy.

  8. Polymer-assisted deposition of films

    McCleskey,Thomas M.; Burrell,Anthony K.; Jia,Quanxi; Lin,Yuan

    2012-02-28

    A polymer assisted deposition process for deposition of metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be conformal on a variety of substrates including non-planar substrates. In some instances, the films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  9. Reactive sputter deposition of boron nitride

    The preparation of fully dense, boron targets for use in planar magnetron sources has lead to the synthesis of Boron Nitride (BN) films by reactive rf sputtering. The deposition parameters of gas pressure, flow and composition are varied along with substrate temperature and applied bias. The films are characterized for composition using Auger electron spectroscopy, for chemical bonding using Raman spectroscopy and for crystalline structure using transmission electron microscopy. The deposition conditions are established which lead to the growth of crystalline BN phases. In particular, the growth of an adherent cubic BN coating requires 400--500 C substrate heating and an applied -300 V dc bias

  10. Bioactive surfaces with atomic layer deposition

    Kvalvik, Julie Nitsche

    2015-01-01

    The overall goal of this work has been to make bioactive surfaces with atomic layer deposition (ALD). To do this, a new ALD system with titanium tetraisopropoxide (TTIP) and lysine as precursors was developed with emphasis on studying the effects of pulsing times and deposition temperatures. TTIP was chosen as titanium is regarded to be biocompatible and lysine was chosen as poly-L-lysine is a part of the extra-cellular matrix (ECM) and hence affects cell adhesion. The effect of a water pulse...

  11. Treating paraffin deposits in producing oil wells

    Noll, L.

    1992-01-01

    Paraffin deposition has been a problem for operators in many areas since the beginning of petroleum production from wells. An extensive literature search on paraffin problems and methods of control has been carried out, and contact was made with companies which provide chemicals to aid in the treatment of paraffin problems. A discussion of the nature of paraffins and the mechanisms of this deposition is presented. The methods of prevention and treatment of paraffin problems are summarized. Suggested procedures for handling paraffin problems are provided. Suggestions for areas of further research testing are given.

  12. Shanxi Finding Another Large Bauxite Deposit

    2007-01-01

    <正>According to Department of Resources of Shanxi,a new breakthrough has been made on the prospecting in the province.The preliminary result shows that another large bauxite mine has been found in Shiqie River in Baode County with a deposit height of 0.81- 8.01m and an estimate reserve of 140 million tons.Meanwhile 3 large-and 3 medium-size bauxite deposits have also been found in the northwest part of Shanxi including Hejiaqianhe of Xin County with an estimate reserve of 37.1 million tons and Beiguli of Jiaokou County.

  13. Risk Adjusted Deposit Insurance for Japanese Banks

    Ryuzo Sato; Rama V. Ramachandran; Bohyong Kang

    1990-01-01

    The purpose of this paper is to evaluate the Japanese deposit insurance scheme by contrasting the flat insurance rate with a market-determined risk-adjusted rate. The model used to calculate the risk-adjusted rate is that of Ronn and Verrna (1986) . It utilizes the notion of Merton(1977) that the deposit insurance can be based on a one-to-one relation between it and the put option; this permits the application of Black and Scholes(1973) model for the calculation of the insurance rate. The ris...

  14. XRF analysis of depth profiled thin depositions

    The main information about atmospheric and water pollutants is obtained from analysis of thin depositions on filters. Due its high sensitivity for a large number of elements, the XRF analysis based on X-ray tube as source of excitation, is a very advantageous method to measure samples of this kind. However, due to very large absorption photon cross sections in this energy range, the deposition profile can play an important role in analysis. Neglecting it might lead in some cases to wrong results. Assuming a normalized exponentially decaying profile as a realistic approximation of the deposition profile of a given element as ρ(x) = mkme-kmx/(1- e-kmD), where ρ(x) is element density at depth x, m - its surface density, km - deposition parameter and D - sample thickness, the yield, Y(km), of a characteristic X-line measured on a side of the sample is given as a function of Φ(E) - incident X-ray flux at energy E, σf(E) - photoelectric absorption cross section of the element, χ(E) - total X-ray absorption coefficient in sample considering both incidence and emergence path. Measuring the sample on the opposite side, the yield will be Y(-km), while from the ratio Y(-km)/Y(km) can be determined numerically. Since y(km) = Y(km)/m is independent of m, the deposition superficial mass is calculated using a thick standard as m = Y(s)S(x)/y(km)S(s), where S(x) (S(s)) is the X-line intensity measured in sample (standard) and theoretical yield in standard Y(s) is calculated using the formulas of Shiraiwa and Fujino. A computer code based on this formalism was written. Many samples of wet soil and aerosols deposition on filters, previously measured by other methods, were used to check the correctness of the present analysis procedure and a very good agreement is found between our results and the measurements taken as reference. A table is given with the results of the IAEA soil standard SOIL-7, deposited wet on a thin filter and measured after drying. The soil deposition was 3

  15. Wax deposition in crude oil pipelines

    Assuncao, Pablo Morelato; Rodrigues, Lorennzo Marrochi Nolding [Universidade Federal do Espirito Santo, Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Engenharia de Petroleo; Romero, Mao Ilich [University of Wyoming, Laramie, WY (United States). Enhanced Oil Recovery Institute], e-mail: mromerov@uwyo.edu

    2010-07-01

    Crude oil is a complex mixture of hydrocarbons which consists of aromatics, paraffins, naphthenics, resins asphaltenes, etc. When the temperature of crude oil is reduced, the heavy components, like paraffin, will precipitate and deposit on the pipe internal wall in the form of a wax-oil gel. The gel deposit consists of wax crystals that trap some amount of oil. As the temperature gets cooler, more wax will precipitate and the thickness of the wax gel will increase, causing gradual solidification of the crude and eventually the oil stop moving inside the offshore pipeline. Crude oil may not be able to be re-mobilized during re-startup. The effective diameter will be reduced with wax deposition, resulting in several problems, for example, higher pressure drop which means additional pumping energy costs, poor oil quality, use of chemical components like precipitation inhibitors or flowing facilitators, equipment failure, risk of leakage, clogging of the ducts and process equipment. Wax deposition problems can become so sever that the whole pipeline can be completely blocked. It would cost millions of dollars to remediate an offshore pipeline that is blocked by wax. Wax solubility decreases drastically with decreasing temperature. At low temperatures, as encountered in deep water production, is easy to wax precipitate. The highest temperature below which the paraffins begins to precipitate as wax crystals is defined as wax appearance temperature (WAT). Deposition process is a complex free surface problem involving thermodynamics, fluid dynamics, mass and heat transfer. In this work, a numerical analysis of wax deposition by molecular diffusion and shear dispersion mechanisms in crude oil pipeline is studied. Diffusion flux of wax toward the wall is estimated by Fick's law of diffusion, in similar way the shear dispersion; wax concentration gradient at the solid-liquid interface is obtained by the volume fraction conservation equation; and since the wax deposition

  16. Distribution And Mineralogy Of The Clay Deposits In Saudi Arabia

    Al Mohandis, Ahmed A. [احمد عبد القادر المهندس

    1993-01-01

    The main goal of this paper is to characterize the mineral clay deposits in Saudi Arabia; especially their mineral composition, deposit size, geological setting and possible uses. Different published reports and papers on clay deposits of Saudi Arabia have been reviewed. Three major clay deposits have been studied by XRD, DTA and chemical analyses. Saudi clay deposits consist generally of kaolinite as a major mineral, and small amounts other clay minerals, such as montmorillonite and illite. ...

  17. Dual ion beam assisted deposition of biaxially textured template layers

    Groves, James R.; Arendt, Paul N.; Hammond, Robert H.

    2005-05-31

    The present invention is directed towards a process and apparatus for epitaxial deposition of a material, e.g., a layer of MgO, onto a substrate such as a flexible metal substrate, using dual ion beams for the ion beam assisted deposition whereby thick layers can be deposited without degradation of the desired properties by the material. The ability to deposit thicker layers without loss of properties provides a significantly broader deposition window for the process.

  18. Deposit Insurance Without Commitment: Wall St. Versus Main St

    2011-01-01

    This paper studies the provision of deposit insurance without commitment in an economy with heterogenous households. When households are identical, deposit insurance will be provided ex post to reap insurance gains. But the ex post provision of deposit insurance redistributes consumption when households differ in their claims on the banking system as well as in their tax obligations to finance the deposit insurance. Deposit insurance will not be provided ex post if it requires a (socially) un...

  19. 12 CFR 347.203 - Deposit insurance required for all branches of foreign banks engaged in domestic retail deposit...

    2010-01-01

    ... foreign banks engaged in domestic retail deposit activity in the same State. 347.203 Section 347.203 Banks... engaged in domestic retail deposit activity in the same State. The FDIC will not insure deposits in any... foreign bank in the same state that engages in domestic retail deposit activity will be an insured branch....

  20. State-of-the-art Pb photocathodes deposited by pulsed laser deposition

    In this article we present and discuss the current status of thin film Pb photocathodes deposited by pulsed laser deposition (PLD) with different laser parameters, such as laser fluence, wavelength or pulse duration. The PLD technique appears very efficient for the fabrication of pure Pb photocathodes, providing good adherence and respectable quantum efficiency. The films deposited on the picosecond and subpicosecond regimes are practically free of big droplets and fragments, whereas in the nanosecond regime their presence cannot be neglected. All the films present a granular structure and polycrystalline character with preferential orientation along the (111) crystalline planes, irrespective of the laser pulse duration or wavelength. The main results obtained from the photoemission performance of Pb thin films deposited by PLD demonstrate their chemical stability under vacuum conditions and respectable quantum efficiency with a maximum of 7.3×10−5 for films deposited on the subpicosecond regime. The photoemission properties confirm that Pb thin films deposited by PLD are a notable alternative for the fabrication of photocathodes for superconductive radio-frequency electron guns. - Highlights: • Lead samples were grown by Pulsed Laser Deposition at different laser parameters • All films present a granular morphology • Lead films grow preferentially along the 111 crystalline planes of the cubic net • A maximum quantum efficiency of 7.3 × 10-5 has been found

  1. Atomic layer deposition of nanoporous biomaterials.

    Narayan, R. J.; Adiga, S. P.; Pellin, M. J.; Curtiss, L. A.; Stafslien, S.; Chisholm, B.; Monteiro-Riviere, N. A.; Brigmon, R. L.; Elam, J. W.; Univ. of North Carolina; North Carolina State Univ.; Eastman Kodak Co.; North Dakota State Univ.; SRL

    2010-03-01

    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. Nanoporous alumina, also known as anodic aluminum oxide (AAO), is a nanomaterial that exhibits several unusual properties, including high pore densities, straight pores, small pore sizes, and uniform pore sizes. In 1953, Keller et al. showed that anodizing aluminum in acid electrolytes results in a thick layer of nearly cylindrical pores, which are arranged in a close-packed hexagonal cell structure. More recently, Matsuda & Fukuda demonstrated preparation of highly ordered platinum and gold nanohole arrays using a replication process. In this study, a negative structure of nanoporous alumina was initially fabricated and a positive structure of a nanoporous metal was subsequently fabricated. Over the past fifteen years, nanoporous alumina membranes have been used as templates for growth of a variety of nanostructured materials, including nanotubes, nanowires, nanorods, and nanoporous membranes.

  2. Kinetic modeling of BN deposition by PECVD

    We present kinetic modeling of BN deposition by PECVD in the system B-N-H-X where X represents the gases F, Cl, Br or O, respectively. In the first step the thermodynamic data as well as kinetic coefficients are collected from literature and compared with each others. The kinetic coefficients also include the most important plasma reactions. With data set up selected calculations were performed in the program ''CHEMKIN''. Kinetic modeling was executed with the perfectly stirred reactor model. This model requires modeling of volume reactions as well as reactions on the surface. The rate coefficients for the surface reactions are investigated through parameter studies. Results of these parameter studies are compared with data known from experiments to obtain the probably way of reaction mechanisms. Data from kinetic modeling are also compared with results from calculations in thermodynamic equilibrium. Results of kinetic and equilibrium modeling show that the range where BN can be deposited is very sensitive to the mole fraction of the species X which is used. Using oxygen as well as fluorine there exist only few parameter compositions to deposit BN. These parameter sets are very important in relation to possible etching effects in PECVD of c-BN deposition

  3. Deposition of grids on plastic detectors

    Birabeau, J P; Mendola, Onofrio

    1972-01-01

    In order to facilitate the locating of tracks of charged particles in cellulose-nitrate and polycarbonate (Makrofol, Lexan) foils, a method has been developed for the photo-deposition of translucent coordinate grids on these materials. The grids are resistant to the strongly caustic solutions used in developing tracks in plastic foils. (9 refs) .

  4. Panel 1 - comparative evaluation of deposition technologies

    Fenske, G.R.; Stodolsky, F. [Argonne National Lab., IL (United States); Benson, D.K.; Pitts, R.J. [National Renewable Energy Lab., Golden, CO (United States); Bhat, D.G. [GTE Valenite Corp., Troy, MI (United States); Yulin Chen [Allison Gas Turbine Division, GM, Indianapolis, IN (United States); Gat, R.; Sunkara, M.K. [Case Western Reserve Univ., Cleveland, OH (United States); Kelly, M. [Stanford Univ., CA (United States); Lawler, J.E. [Univ. of Wisconsin, Madison (United States); Nagle, D.C. [Martin Marietta Labs., Baltimore, MD (United States); Outka, D. [Sandia National Laboratories, Livermore, CA (United States); Revankar, G.S. [Deere & Co., Moline, IL (United States); Subramaniam, V.V. [Ohio State Univ., Columbus (United States); Wilbur, P.J. [Colorado State Univ., Fort Collins (United States); Mingshow Wong [Northwestern Univ., Evanston, IL (United States); Woolam, W.E. [Southwest Research Inst., Arlington, VA (United States)

    1993-01-01

    This working group attempted to evaluate/compare the different types of deposition techniques currently under investigation for depositing diamond and diamond-like carbon films. A table lists the broad types of techniques that were considered for depositing diamond and diamond-like carbon films. After some discussion, it was agreed that any evaluation of the various techniques would be dependent on the end application. Thus the next action was to list the different areas where diamond and DLC films could find applications in transportation. These application areas are listed in a table. The table intentionally does not go into great detail on applications because that subject is dealt with specifically by Panel No. 4 - Applications To Transportation. The next action concentrated on identifying critical issues or limitations that need to be considered in evaluating the different processes. An attempt was then made to rank different broad categories of deposition techniques currently available or under development based on the four application areas and the limitations. These rankings/evaluations are given for diamond and DLC techniques. Finally, the working group tried to identify critical development and research issues that need to be incorporated into developing a long-term program that focuses on diamond/DLC coatings for transportation needs. 5 tabs.

  5. New Mexico Known Mineral Deposit Areas

    Earth Data Analysis Center, University of New Mexico — This dataset contains all Known Mineral Deposit Areas in the state of New Mexico. It is in a vector digital structure digitized from a 1:500,000 scale map of the...

  6. Deposition Diagnostics for Next-step Devices

    C.H. Skinner; A.L. Roquemore; the NSTX team; A. Bader; W.R. Wampler

    2004-06-15

    The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX.

  7. Deposition of biopolymer films on micromechanical sensors

    Keller, Stephan Sylvest; Gammelgaard, Lene; Jensen, Marie P.;

    2011-01-01

    The influence of various parameters on the spray-coating of thin films of poly(l-lactide) (PLLA) was investigated. The optimized processing conditions were used for deposition of the biodegradable polymer on arrays of SU-8 microcantilevers. The resonance frequency of the cantilevers before and af...

  8. 20 CFR 901.46 - Depositions.

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Depositions. 901.46 Section 901.46 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES REGULATIONS GOVERNING THE PERFORMANCE OF ACTUARIAL SERVICES UNDER THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974 Suspension or Termination of...

  9. A literature review on wet deposition

    The literature on wet deposition or precipitation scavenging have been reviewed with special reference to predicting the radiological consequences of accidental contamination. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIAF-423-DK(SD). (author)

  10. Deposition Diagnostics for Next-step Devices

    The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX

  11. 31 CFR 223.4 - Deposits.

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Deposits. 223.4 Section 223.4 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE SURETY COMPANIES DOING BUSINESS WITH THE UNITED...

  12. Atmosfærisk deposition 2000

    Ellermann, T.; Hertel, O.; Hovmand, M. F.;

    Denne rapport sammenfatter de vigtigste konklusioner fra dette års rapportering af atmosfæredelen af NOVA 2003 og opsummerer ovedresultaterne vedrørende måling og beregning af koncentrationer af atmosfæriske kvælstof-, fosfor-, svovlforbindelser og tungmetaller samt deposition til danske hav- og...... den største kvælstofdeposition, som hidtil er blevet rapporteret og ca. 20% højere end rapporteret for 1999 (Ellermann et al. 2000). For begge år viser de nyeste beregninger en tydeligt højere deposition til de danske farvande end hidtil rapporteret. Opdatering af model Det er vigtigt at bemærke, at...... den samlede deposition til de danske farvande, og dels højere kvælstofkoncentrationer i nedbøren. Denne forklaring underbygges af målingerne, som viser en svag stigning i våddepositionen fra 1999 til 2000 på trods af, at nedbørsmængden er lidt mindre i 2000 end 1999. Deposition opdelt på de...

  13. Crystal modified deposition of hydrated metal oxide

    Richardson, E.A.; Herce, J.A.

    1976-12-14

    A treating liquid for depositing a coating of hydrated metal oxide on a remotely located material (such as a subterranean sand mass to be consolidated) is improved by a crystal modifier. The treating liquid consists of an aqueous alkaline solution of an amphoteric metal compound, a pH-reducing reactant, and a hydroxyorganic crystal modifier. (4 claims)

  14. Solid Organic Deposition During Gas Injection Studies

    Dandekar, Abhijit Y.; Andersen, Simon Ivar; Stenby, Erling Halfdan

    2000-01-01

    Recently a series of first contact miscibility (swelling) experiments have been performed on undersaturated light and heavy oils using LPG rich and methane rich injection gases, in which solid organic deposition was observed. A compositional gradient in the oils during the gas injection process w...

  15. Absolute determination of bremsstrahlung deposition (Hydra)

    A technique developed to measure electron energy deposition in metals has been applied to the determination of bremsstrahlung deposition. In this method a square-wave beam modulation is employed and the time-derivative of a calorimeter temperature is used to obtain the energy deposited. This paper presents the results of bremsstrahlung deposition measurements in gold and aluminum. Data are presented for dose to a material as a function of converter material, converter thickness, and angle of electron incidence for electron energies in the range from 0.2 to 1.0 MeV. In addition, measurements of dose as a function of calorimeter position as it was moved both laterally and axially with respect to the beam axis are reported. Utilizing the facility and technique developed to make these measurements, a thorough study of the bremsstrahlung measuring calorimeters used with the pulsed electron beam machine Hydra was accomplished. The goal of this study was to determine accurately the correction factor for the loading effect of the thermocouple wires. The loading correction factor was measured to be 1.72 with an uncertainty of +- 5 percent. This value should be used when determining true dose to gold with the standard Hydra calorimeters instead of the value of 1.5 obtained from data on Hydra, since there is a larger uncertainty in the latter value. (U.S.)

  16. Low temperature CVD deposition of silicon carbide

    The coating of graphite on silicon carbide from the gaseous phase in a hot-well, open flow reactor at 1150degC is described. This study constitutes the first part of an investigation of the process for the coating of nuclear fuel by chemical vapor deposition (CVD)

  17. CVD diamond deposition onto dental burs

    A hot-filament chemical vapor deposition (HFCVD) system has been modified to enable non-planar substrates, such as metallic wires and dental burs, to be uniformly coated with thin polycrystalline diamond films. Initially, diamond deposition was carried out on titanium and tantalum wires in order to test and optimize the system. High growth rates of the order of approx. 8 /hr were obtained when depositing diamond on titanium wires using the vertical filament arrangement. However, lower growth rates of the order of 4-5meu m/hr were obtained with diamond deposition on tantalum wires. To extend the work towards a practical biomedical application tungsten carbide dental burs were coated with diamond films. The as-grown films were found to be polycrystalline and uniform over the cutting tip. Finally, the costs relating to diamond CVD onto dental burs have been presented in this paper. The costs relating to coating different number of burs at a time and the effect of film thickness on costs have been included in this investigation. (author)

  18. Generalized ballistic deposition of small buoyant particles

    Csúcs, G.; Ramsden, J. J.

    1998-07-01

    The adsorption kinetics of the protein bee venom phospholipase A2 to a smooth, planar metal oxide surface has been measured under controlled hydrodynamic conditions using optical waveguide lightmode spectroscopy (OWLS). Adsorption follows the generalized ballistic deposition (GBD) model, except at low bulk protein concentrations, where Langmuir kinetics are observed.

  19. Lifetime obtained by ion beam assisted deposition

    We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ion beam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H2O and O2. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances

  20. Iron and manganese deposits in Uruguay

    This report is the results of the study carried out for the United Nations expert which the main object was: the study of the information available about iron and manganese formation in Uruguay, as well as the main researching deposit to determinate economical possibilities in the exportation.

  1. Local plasma deposition on polymer components

    Bolt, P.J.; Theelen, M.J.; Habets, D.; Winands, G.J.J.; Staemmler, L.

    2011-01-01

    For the modification of the surface energy of polymers, organosilicon coatings provide good optical and mechanical properties and are excellent candidates for the modification of the surface energy of polymers. These coatings can be deposited by plasma polymerization of hexamethyldisiloxane (HMDSO)

  2. Contaminant transport at a waste residue deposit

    Engesgaard, Peter Knudegaard; Traberg, Rikke

    1996-01-01

    Contaminant transport in an aquifer at an incinerator waste residue deposit in Denmark is simulated. A two-dimensional, geochemical transport code is developed for this purpose and tested by comparison to results from another code, The code is applied to a column experiment and to the field site...

  3. Uniform reflective films deposited on large surfaces

    1966-01-01

    Specially designed baffle which intercepts varying amounts of the vapor stream from an evaporant source, vacuum deposits films of uniform thickness on large substrates, using a single small area evaporation source. A mirror coated by this method will have a reflectance as high as 82 percent at 1216 angstroms with a variation of only plus/minus 2 percent over the surface.

  4. World Distribution of Uranium Deposits (UDEPO) with uranium deposit classification. 2009 ed

    The World Distribution of Uranium Deposits (UDEPO) database provides general, technical and geological information, including references, about the worldwide uranium deposits. UDEPO has been published on the internet which allows the users to register freely and to work with datasets (http://www-nfcis.iaea.org). The UDEPO web site is designed to allow users to retrieve data sets on a variety of deposit related topics ranging from specific information on individual uranium deposits to statistical information on uranium deposits worldwide. The basic building blocks for the UDEPO database are the more than 900 individual deposits for which information is available in the database. The database is arranged in a relational database format which has one main table and a number of associated tables. Structured nature of the database allows filtering and querying the database in more systematic way. The web site provides filtering and navigation to the data from the database. It has also a statistical tool which provides summary information on number of deposits and uranium resources by type and status, and by country and status. In this respect and with regard to the data presented, the UDEPO database is a unique database which provides freely accessible information on worldwide uranium deposits. Although a great effort is spent to have complete and accurate database, the users should take into consideration that there still might be missing or outdated data for individual deposits due to the rapid changes in the uranium industry due to the new exploration works which are ongoing everyday. This document and its supplementary CD-ROM represent a snapshot of the status of the database as of the end of 2008. However, the database is being continuously updated and the latest updates and additions can be accessed from the database web site (http://wwwnfcis.iaea.org)

  5. Athabasca basin unconformity-type uranium deposits. A special class of sandstone-type deposits

    Two major episodes of uranium metallogenesis are recognized in Northern Saskatchewan. The first is of late-Hudsonian age and gave rise to metamorphic-hydrothermal pitchblende deposits of simple mineralogy at Beaverlodge (primary mineralization: 1780+-20 m.y.). The second and more important episode of approximately Grenvillian age rendered unconformity-type deposits in the Athabasca Basin (primary mineralization: 1000-1300 m.y.). The late-Hudsonian deposits at Beaverlodge were overprinted by this second event and new deposits of complex mineralogy were formed in that area. The metallogenetic importance of a third and much later episode which gave rise to mineralization within the Athabasca Formation is uncertain at the moment. With regards to metallogenesis of the unconformity-type deposits, presently available evidence favours a diagenetic-hydrothermal rather than a near-surface supergene or a magmatic/metamorphic hydrothermal model. The diagenetic-hydrothermal model relates uranium mineralization to 'red bed-type' diagenetic processes in the Athabasca Formation involving post-depositional oxidation and leaching, which continued for several hundred million years after deposition. Ore deposits were formed by interaction, under conditions of deep burial at elevated temperatures and pressures, of a uraniferous oxidizing Athabasca aquifer with reducing, graphite-bearing, metamorphic rocks of the basin floor. The large-scale convection required for such interaction may have been induced by mafic magmatic activity coeval with the episode of mineralization. The diagenetic-hydrothermal model displays close similarities with metallogenetic models developed for certain sandstone-type deposits. (author)

  6. Comparison of mineralization geologic character of interlayer oxidized zone sandstone type uranium deposit and 2082 paleovalley sandstone type uranium deposit

    On the basis of analyzing mineralization geologic character of of interlayer oxidized zone sandstone type uranium deposit and 2082 paleovalley sandstone type uranium deposit, we compared the similarities and differences on the lithology and lithofacies of host structure, paleoclimate background on formation of uranium deposit, the way and period of oxidization (mineralization), orebody shape and space distribution character of both deposits. Then to conclude mineralization geologic character of both deposits and hope to cause the attention of the experts

  7. Integrated Historical Tsunami Event and Deposit Database

    Dunbar, P. K.; McCullough, H. L.

    2010-12-01

    The National Geophysical Data Center (NGDC) provides integrated access to historical tsunami event, deposit, and proxy data. The NGDC tsunami archive initially listed tsunami sources and locations with observed tsunami effects. Tsunami frequency and intensity are important for understanding tsunami hazards. Unfortunately, tsunami recurrence intervals often exceed the historic record. As a result, NGDC expanded the archive to include the Global Tsunami Deposits Database (GTD_DB). Tsunami deposits are the physical evidence left behind when a tsunami impacts a shoreline or affects submarine sediments. Proxies include co-seismic subsidence, turbidite deposits, changes in biota following an influx of marine water in a freshwater environment, etc. By adding past tsunami data inferred from the geologic record, the GTD_DB extends the record of tsunamis backward in time. Although the best methods for identifying tsunami deposits and proxies in the geologic record remain under discussion, developing an overall picture of where tsunamis have affected coasts, calculating recurrence intervals, and approximating runup height and inundation distance provides a better estimate of a region’s true tsunami hazard. Tsunami deposit and proxy descriptions in the GTD_DB were compiled from published data found in journal articles, conference proceedings, theses, books, conference abstracts, posters, web sites, etc. The database now includes over 1,200 descriptions compiled from over 1,100 citations. Each record in the GTD_DB is linked to its bibliographic citation where more information on the deposit can be found. The GTD_DB includes data for over 50 variables such as: event description (e.g., 2010 Chile Tsunami), geologic time period, year, deposit location name, latitude, longitude, country, associated body of water, setting during the event (e.g., beach, lake, river, deep sea), upper and lower contacts, underlying and overlying material, etc. If known, the tsunami source mechanism

  8. Deposition of diamond and boron nitride films by plasma chemical vapour deposition

    Albella, J.M. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Gomez-Aleixandre, C. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Sanchez-Garrido, O. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Vazquez, L. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Martinez-Duart, J.M. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.

    1995-01-01

    The deposition problems of diamond and cubic boron nitride (c-BN) by chemical vapour deposition techniques are reviewed, with major emphasis on the nucleation and reaction mechanisms. A discussion is made of the main deposition parameters (i.e. gas mixture, substrate conditioning, plasma discharges etc.) which favour the formation of the cubic phase. Most of the work is devoted to diamond owing to the large progress attained in this material. In fact, the use of diamond as a hard protective coating is now on a commercial scale. By contrast, the preparation of c-BN layers with good characteristics still needs of further research. ((orig.))

  9. Atmospheric Deposition of Phosphorus to the Everglades: Concepts, Constraints, and Published Deposition Rates for Ecosystem Management

    Garth W. Redfield

    2002-01-01

    Full Text Available This paper summarizes concepts underlying the atmospheric input of phosphorus (P to ecosystems, published rates of P deposition, measurement methods, and approaches to future monitoring and research. P conveyed through the atmosphere can be a significant nutrient source for some freshwater and marine ecosystems. Particle sources and sinks at the land-air interface produce variation in P deposition from the atmosphere across temporal and spatial scales. Natural plant canopies can affect deposition rates by changing the physical environment and surface area for particle deposition. Land-use patterns can alter P deposition rates by changing particle concentrations in the atmosphere. The vast majority of P in dry atmospheric deposition is conveyed by coarse (2.5 to 10 μm and giant (10 to 100 μm particles, and yet these size fractions represent a challenge for long-term atmospheric monitoring in the absence of accepted methods for routine sampling. Most information on P deposition is from bulk precipitation collectors and wet/dry bucket sampling, both with questionable precision and accuracy. Most published annual rates of P deposition are gross estimates derived from bulk precipitation sampling in locations around the globe and range from about 5 to well over 100 mg P m–2 year–1, although most inland ecosystems receive between 20 and 80 mg P m–2 year–1. Rates below 30 mg P m–2 year–1 are found in remote areas and near coastlines. Intermediate rates of 30 to 50 mg P m–2 year–1 are associated with forests or mixed land use, and rates of 50 to 100 mg P m–2 year–1 or more are often recorded from urban or agricultural settings. Comparison with other methods suggests that these bulk precipitation estimates provide crude boundaries around actual P deposition rates for various land uses. However, data screening cannot remove all positive bias caused by contamination of bucket or bulk collectors. As a consequence, continued sampling

  10. The Nopal 1 Uranium Deposit: an Overview

    Calas, G.; Allard, T.; Galoisy, L.

    2007-05-01

    The Nopal 1 natural analogue is located in the Pena Blanca uranium district, about 50 kms north of Chihuahua City, Mexico. The deposit is hosted in tertiary ignimbritic ash-flow tuffs, dated at 44 Ma (Nopal and Colorados formations), and overlying the Pozos conglomerate formation and a sequence of Cretaceous carbonate rocks. The deposit is exposed at the ground surface and consists of a near vertical zone extending over about 100 m with a diameter of 40 m. An interesting characteristic is that the primary mineralization has been exposed above the water table, as a result of the uplift of the Sierra Pena Blanca, and subsequently oxidized with a remobilization of hexavalent uranium. The primary mineralization has been explained by various genetic models. It is associated to an extensive hydrothermal alteration of the volcanic tuffs, locally associated to pyrite and preserved by an intense silicification. Several kaolinite parageneses occur in fissure fillings and feldspar pseudomorphs, within the mineralized breccia pipe and the barren surrounding rhyolitic tuffs. Smectites are mainly developed in the underlying weakly welded tuffs. Several radiation-induced defect centers have been found in these kaolinites providing a unique picture of the dynamics of uranium mobilization (see Allard et al., this session). Another evidence of this mobilization is given by the spectroscopy of uranium-bearing opals, which show characteristic fluorescence spectra of uranyl groups sorbed at the surface of silica. By comparison with the other uranium deposits of the Sierra Pena Blanca and the nearby Sierra de Gomez, the Nopal 1 deposit is original, as it is one of the few deposits hving retained a reduced uranium mineralization.

  11. Emission reductions to meet deposition criteria

    Smith, F. B.

    The paper assumes Governments are willing and able to reduce national emissions of pollution to protect the environment. Sulphur dioxide is examined as an important example. Although not necessarily true at the present time, it further assumes: (i) that the cost of reducing these emissions from different industries (and other source types) are known, and that these costs include the secondary consequences of emission control (for example, possible resulting unemployment); (ii) that maximum deposition criteria ( mdc) have been established on some appropriate grid (above which undesirable environmental damage will occur) and that in some gridsquares these mdc are currently being exceeded; and (iii) that priorities for reducing the deposition may be ascribed for each gridsquare. The highest priority may reflect concern over excessive levels of heavy metals in drinking water drawn from wells used by remote homesteads, for example. Gridsquares where more gradual, and hopefully reversible, damage is taking place would be given a rather lower priority. The paper seeks to establish maximum levels of emission in each gridsquare which will result in depositions nowhere exceeding the mdc (on the scale of a gridsquare). It also offers a means of selecting an optimum staged reduction strategy whereby emissions are reduced gradually towards the ultimate maximum levels, and at each stage of the reduction, gives the maximum benefit for the capital outlay consistent with the priorities and costs outlined above. The paper utilizes a very simple analytical model of the deposition field resulting from a single emission. The model is tuned to give the best comparison with the 1985 sulphur deposition field obtained using the much more complex EMEP MSC-W Lagrangian model used operationally for acid-rain analyses in Europe.

  12. Uranium deposits: northern Denver Julesburg basin, Colorado

    The Fox Hills Sandstone and the Laramie Formation (Upper Cretaceous) are the host rocks for uranium deposits in Weld County, northern Denver Julesburg basin, Colorado. The uranium deposits discovered in the Grover and Sand Creek areas occur in well-defined north--south trending channel sandstones of the Laramie Formation whereas the sandstone channel in the upper part of the Fox Hills Sandstone trends east--west. Mineralization was localized where the lithology was favorable for uranium accumulation. Exploration was guided by log interpretation methods similar to those proposed by Bruce Rubin for the Powder River basin, Wyoming, because alteration could not be readily identified in drilling samples. The uranium host rocks consist of medium- to fine-grained carbonaceous, feldspathic fluvial channel sandstones. The uranium deposits consist of simple to stacked roll fronts. Reserve estimates for the deposits are: (1) Grover 1,007,000 lbs with an average grade of 0.14 percent eU3O8,2) Sand Creek 154,000 lbs with an average grade of 0.08 percent eU3O8, and 3) The Pawnee deposit 1,060,000 lbs with an average grade of 0.07 percent eU3O8. The configuration of the geochemical cells in the Grover and Sand Creek sandstones indicate that uraniferous fluids moved northward whereas in the Pawnee sandstone of the Fox Hills uraniferous fluids moved southward. Precipitation of uranium in the frontal zone probably was caused by downdip migration of oxygcnated groundwater high in uranium content moving through a favorable highly carbonaceous and pyritic host sandstone

  13. Mississippi Valley-Type Lead-Zinc Deposit Model

    Leach, David L.; Taylor, Ryan D.

    2009-01-01

    Mississippi Valley-type (MVT) lead-zinc (Pb+Zn) deposits are found throughout the world, and these deposits are characteristically distributed over hundreds of square kilometers that define individual ore districts. The median size of individual MVT deposits is 7.0 million tonnes with grades of about 7.9 percent Pb+Zn metal. However, MVT deposits usually occur in extensive districts consisting of several to as many as 400 deposits. Nearly one-quarter of the world's sedimentary and volcanic rock-hosted Pb+Zn resources are found in these deposits, with by-product commodities including silver (Ag), copper (Cu), and indium (In) for some deposits. Environmentally, MVT deposits are less of a concern than other types of mineral deposits since the carbonate-host rocks mitigate many environmental concerns.

  14. Litterfall mercury dry deposition in the eastern USA

    Mercury (Hg) in autumn litterfall from predominately deciduous forests was measured in 3 years of samples from 23 Mercury Deposition Network sites in 15 states across the eastern USA. Annual litterfall Hg dry deposition was significantly higher (median 12.3 micrograms per square meter (μg/m2), range 3.5–23.4 μg/m2) than annual Hg wet deposition (median 9.6 μg/m2, range 4.4–19.7 μg/m2). The mean ratio of dry to wet Hg deposition was 1.3–1. The sum of dry and wet Hg deposition averaged 21 μg/m2 per year and 55% was litterfall dry deposition. Methylmercury was a median 0.8% of Hg in litterfall and ranged from 0.6 to 1.5%. Annual litterfall Hg and wet Hg deposition rates differed significantly and were weakly correlated. Litterfall Hg dry deposition differed among forest-cover types. This study demonstrated how annual litterfall Hg dry deposition rates approximate the lower bound of annual Hg dry fluxes. - Highlights: ► Annual litterfall mercury dry deposition was significantly higher than wet deposition. ► The mean ratio of dry to wet mercury deposition was 1.3–1. ► The sum of dry and wet mercury deposition averaged 55% litterfall dry deposition. ► Litterfall mercury deposition was highest in the oak-hickory forest-cover type. ► Methylmercury was a median 0.8% of mercury in litterfall and ranged to 1.5%. - A multi-year study of Mercury Deposition Network sites found that annual mercury dry deposition from litterfall in predominately deciduous forests exceeded annual mercury wet deposition in the eastern USA.

  15. Cobalt cluster-assembled thin films deposited by low energy cluster beam deposition: Structural and magnetic investigations of deposited layers

    Cobalt cluster-assembled thin films were deposited on amorphous-carbon-coated copper grids and on silicon substrates at room temperature by low energy cluster beam deposition. Characterizations using high-resolution transmission electronic microscopy and atomic force microscopy reveal randomly stacked agglomerates of 9-11 nm diameter, which are themselves composed of small 3.6 nm diameter fcc cobalt clusters. The films are ferromagnetic up to room temperature and above, which implies that the clusters are exchange coupled. The approach to saturation is analyzed within the random anisotropy model. The values of the exchange coefficient A and the anisotropy constant K then derived are discussed. The temperature dependence of the coercivity below 100 K is discussed in terms of thermal activation effects. All results indicate that the fundamental entity governing the magnetic behaviors is constituted by the 9-11 nm diameter agglomerates rather than by the clusters themselves

  16. Electrochemical deposition and characterization of zinc–nickel alloys deposited by direct and reverse current

    JELENA B. BAJAT

    2005-12-01

    Full Text Available Zn–Ni alloys electrochemically deposited on steel under various deposition conditions were investigated. The alloys were deposited on a rotating disc electrode and on a steel panel from chloride solutions by direct and reverse current. The influence of reverse plating variables (cathodic and anodic current densities and their time duration on the composition, phase structure and corrosion properties were investigated. The chemical content and phase composition affect the anticorrosive properties of Zn–Ni alloys during exposure to a corrosive agent (3 % NaCl solution. It was shown that the Zn–Ni alloy electrodeposited by reverse current with a full period T = 1 s and r = 0.2 exhibits the best corrosion properties of all the investigated alloys deposited by reverse current.

  17. Indomethacin nanoparticles directly deposited on the fluidized particulate excipient by pulsed laser deposition

    Nanoparticles of indomethacin (IM), a sparingly soluble drug in water, were prepared by pulsed laser deposition with Nd: YAG laser at 1064 nm. Variation of the deposition rate (DR) with various experimental conditions, such as species and pressure of the background gas, and laser fluence, was discussed. We obtained highest DR, 2.7 μg/cm2min, under He at 100 Pa with the laser fluence of 25 J/cm2. In the deposited solid product, no trace of drug decomposition was observed by HPLC. Deposition of IM nanoparticles was achieved on the fluidized excipient, potato starch particles of 20 μm regime. By TEM observation and zeta potential distribution measurement, we confirmed that surface of excipient particles was fully covered by nanoparticles of IM. Thus, the present method enables us a new method of one-step preparation of drug-excipient nanocomposites to eliminate tedious problems associated with nanoparticles handling

  18. Indomethacin nanoparticles directly deposited on the fluidized particulate excipient by pulsed laser deposition

    Nagare, Sanshiro [Nara Machinery Co., Ltd. (Japan)], E-mail: nagare@nara-m.co.jp; Senna, Mamoru [Keio University, Faculty of Science and Technology (Japan)

    2004-12-15

    Nanoparticles of indomethacin (IM), a sparingly soluble drug in water, were prepared by pulsed laser deposition with Nd: YAG laser at 1064 nm. Variation of the deposition rate (DR) with various experimental conditions, such as species and pressure of the background gas, and laser fluence, was discussed. We obtained highest DR, 2.7 {mu}g/cm{sup 2}min, under He at 100 Pa with the laser fluence of 25 J/cm{sup 2}. In the deposited solid product, no trace of drug decomposition was observed by HPLC. Deposition of IM nanoparticles was achieved on the fluidized excipient, potato starch particles of 20 {mu}m regime. By TEM observation and zeta potential distribution measurement, we confirmed that surface of excipient particles was fully covered by nanoparticles of IM. Thus, the present method enables us a new method of one-step preparation of drug-excipient nanocomposites to eliminate tedious problems associated with nanoparticles handling.

  19. Atomic layer deposition and post-deposition annealing of PbTiO3 thin films

    Lead titanate thin films were deposited by atomic layer deposition on Si(100) using Ph4Pb and Ti(O-i-Pr)4 as metal precursors and O3 and H2O as oxygen sources. The influence of the Ti : Pb precursor pulsing ratio on the film growth, stoichiometry and quality was studied at two different temperatures, i.e. 250 and 300 deg. C. Uniform and stoichiometric films were obtained using a Ti : Pb precursor pulsing ratio of 1 : 10 at 250 deg. C or 1 : 28 at 300 deg. C. The as-deposited films were amorphous but the crystalline PbTiO3 phase was obtained by rapid thermal annealing at 600-900 deg. C both in N2 and O2 ambient. Thin PbTiO3 films were visually uniform and roughness values for as-deposited and annealed films were observed by atomic force microscopy

  20. Advance in research on aerosol deposition simulation methods

    A comprehensive analysis of the health effects of inhaled toxic aerosols requires exact data on airway deposition. A knowledge of the effect of inhaled drugs is essential to the optimization of aerosol drug delivery. Sophisticated analytical deposition models can be used for the computation of total, regional and generation specific deposition efficiencies. The continuously enhancing computer seem to allow us to study the particle transport and deposition in more and more realistic airway geometries with the help of computational fluid dynamics (CFD) simulation method. In this article, the trends in aerosol deposition models and lung models, and the methods for achievement of deposition simulations are also reviewed. (authors)

  1. Modelling of stomatal conductance and ozone deposition flux of Norway Spruce using deposition model

    Zapletal, M.; Chroust, P.; Večeřa, Zbyněk; Mikuška, Pavel; Cudlín, Pavel; Urban, Otmar; Pokorný, Radek; Czerný, Radek; Janouš, Dalibor; Taufarová, Klára

    2009-01-01

    Roč. 12, 2-3 (2009), s. 75-81. ISSN 1335-339X R&D Projects: GA MŽP SP/1B7/189/07 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z40310501 Keywords : ozone concentration * ozone deposition * stomatal conductance * deposition velocity * resistance model * tropo-spheric ozone Subject RIV: DG - Athmosphere Sciences, Meteorology

  2. Uranium deposits of Gabon and Oklo reactors. Metallogenic model for rich deposits of the lower proterozoic

    The geology of the Franceville basin (Gabon) is examined: stratigraphy, tectonics and geodynamics. The mobile zone of the Ogooue is specially studied: lithology, metamorphism and tectonics, isotopic geochronologic data are given. The different uranium deposits are described. A whole chapter is devoted to the study of Oklo natural nuclear reactor. A metallogenic model is proposed evidencing conditions required for deposit genesis. Tectonics, microstructures sedimentology, organic matter, diagenesis and uraniferous mineralizations are examined

  3. Development of a Parafin Wax deposition Unit for Fused Deposition Modelling (FDM)

    D'Angelo, Greta; Hansen, Hans Nørgaard; Pedersen, David Bue

    2014-01-01

    During the last decade Additive Manufacturing (AM) witnessed a big development in terms of technologies, processes and possibilities. However of materials and their use still represents a big challenge. In fact availability of materials is rather limited if compared to conventional manufacturing. This project illustrates the redesign of an extrusion unit for the deposition of paraffin wax in Fused Deposition Modelling (FDM) instead of the conventional polymeric materials. Among the benefits a...

  4. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construc...

  5. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this st...

  6. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    H. Guan

    2009-09-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many coastal areas of Australia, may have perturbed catchment chloride balance conditions for appropriate use in CMB applications. In order to deal with these issues, a high resolution chloride deposition map in the coastal region is needed. In this study, we examined geographic, orographic, and atmospheric factors influencing chloride deposition in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia, using partial correlation and regression analyses. The results indicate that coastal distance, and terrain aspect and slope are two most significant factors controlling chloride deposition. Coastal distance accounts for 65% spatial variability in chloride deposition, with terrain aspect and slope for 8%. The deposition gradient is about 0.08 gm-2 year-1 km-1 as one progresses inland. The results are incorporated into a published de-trended residual kriging approach (ASOADeK to produce a 1 km×1 km resolution annual chloride deposition map and a bulk precipitation chloride concentration map. The average uncertainty of the deposition map is about 30% in the western MLR, and over 50% in the eastern MLR. The maps will form a very useful basis for examining catchment chloride balances for use in the CMB application in the study area.

  7. Deposition of metal oxide films and nanostructures by methods derived from photochemical metal organic deposition

    Xin ZHANG

    2009-01-01

    In this research, methods for the deposition of patterned films and nanostructures were developed from photochemical metal organic deposition (PMOD). Positive lithographic PMOD was demonstrated with films of titanium (IV) di-n-butoxide bis(2-ethylhexanoate) (Ti(OBun)2(eh)2), titanium (IV) diisopropoxide bis(2,4-pentanedionate), and zirconium (IV) di-n-butoxide bis(2,4-pentanedionate). The photochemistry of these complexes in films was studied by FTIR, AES, and XRD. Photo-induced reactivity an...

  8. Seismic stratigraphy and depositional history of late Quaternary deposits in the Yellow Sea.

    Lee, Gwang-Soo; Yoo, Dong Geun; Bae, Sungho; Choul Kim, Dae; Yi, Hi-Il

    2016-04-01

    To identify the seismic stratigraphy and depositional history of late Quaternary deposits in the Yellow Sea, approximately 52,600 line-km of Chirp seismic profiles and 5,060 line-km of Sparker seismic profiles were analyzed. The Yellow Sea are correspond to three sedimentary environments: (1) a various scale sand ridges/waves and mud belt (the western inner-shelf of the Korean Peninsula), (2) recent- and paleo-channels, erosional and broad surface (the center of the Yellow Sea), and (3) prodelta mud patch (the eastern offshore of China). Based on the seismic stratigraphic analysis of seismic profiles, the late Quaternary deposits in the Yellow Sea are divided into five distinctive seismic units (units CY1~5), consisting of two depositional sequences that can be defined as erosional and disconformable strata. Each unit show different seismic facies and geometry, and is clearly separated by each bounding surface. The major depositional processes and sediment dispersal systems during the late Quaternary in the Yellow Sea are: (1) regressive estuarine/deltaic deposits (unit CY1), (2) transgressive incised channel fill (unit CY2), (3) transgressive sand sheet (unit CY3), (4) transgressive sand ridges (unit CY4), and (5) prodelta/recent mud (unit CY5). The depositional sequences follow the general concepts of sequence stratigraphy very well. Lower sequence (DI) correspond to the falling stage systems tract regarded as regressive estuarine or deltaic deposits (unit CY1), whereas upper sequence (DII) consists of a set of the transgressive (units CY2, CY3, and CY4) and highstand systems tract (unit CY5) formed since the last-glacial period.

  9. Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

    Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef;

    2010-01-01

    We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi...... increased the barrier property of the modified low-density polyethylene, polyethylene terephthalate, and polylactide by 96.48%, 99.69%, and 99.25%, respectively....

  10. Atmospheric Deposition of Phosphorus to the Everglades: Concepts, Constraints, and Published Deposition Rates for Ecosystem Management

    Redfield, Garth W.

    2002-01-01

    This paper summarizes concepts underlying the atmospheric input of phosphorus (P) to ecosystems, published rates of P deposition, measurement methods, and approaches to future monitoring and research. P conveyed through the atmosphere can be a significant nutrient source for some freshwater and marine ecosystems. Particle sources and sinks at the land-air interface produce variation in P deposition from the atmosphere across temporal and spatial scales. Natural plant canopies can affect depos...

  11. Heavy metal deposition mapping: concentrations and deposition of heavy metals in rural areas of the UK

    Malcolm, Heath; Fowler, David; Crossley, Alan; Kentisbeer, John; Hallsworth, Steve; Lawlor, Alan; Rowland, Phil; Guyatt, Hayley; Beith, Sarah; Thacker, Sarah; Halford, Alan; ROGERS Stuart; Cape, J. Neil; Leeson, Sarah; Harmens, Harry

    2012-01-01

    CEH has been monitoring the concentrations of a range of heavy metals in rural locations across the UK since 2004. This report presents the annual average concentrations and deposition of heavy metals in air and rainfall samples collected from rural locations during 2011 and it reviews the temporal and spatial trends in heavy metal concentrations and deposition between 2004 and 2011. The monitoring network was established to measure the background concentration of a range of heavy meta...

  12. Experimental measurements of the thermal conductivity of ash deposits: Part 2. Effects of sintering and deposit microstructure

    A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

    2000-04-01

    The authors report results from an experimental study that examines the influence of sintering and microstructure on ash deposit thermal conductivity. The measurements are made using a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. The technique is designed to minimize the disturbance of the natural deposit microstructure. The initial stages of sintering and densification are accompanied by an increase in deposit thermal conductivity. Subsequent sintering continues to densify the deposit, but has little effect on deposit thermal conductivity. SEM analyses indicates that sintering creates a layered deposit structure with a relatively unsintered innermost layer. They hypothesize that this unsintered layer largely determines the overall deposit thermal conductivity. A theoretical model that treats a deposit as a two-layered material predicts the observed trends in thermal conductivity.

  13. Deposition from wax-solvent mixtures under turbulent flow : effects of shear rate and time on deposit properties

    Tiwary, R.; Mehrotra, A.K. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering

    2008-07-01

    The effects of deposition time and shear rate on the deposition of solids was investigated under turbulent flow, for solutions of a multi-component wax in a paraffinic solvent. The deposition experiments were performed in a bench-scale flow-loop apparatus, incorporating a co-current double-pipe heat exchanger. The experiment involved 2 mixture compositions (10 and 15 mass per cent wax) at Reynolds numbers between 9000 and 27000 over a range of deposition times from 30 min to 24 h. The study showed that the deposit mass decreased with an increase in the Reynolds number, but it increased asymptotically with the deposition time. The deposit mass and density data were analyzed using a pseudo-steady-state heat transfer model to study the variation in the deposit-layer thickness and thermal conductivity with shear rate and deposition time. According to the GC analysis of deposit samples, there were noticeable changes in the carbon-number-distribution with shear rate and time. The variations in deposit properties were also assessed using a recently proposed model involving one-dimensional cubical-cage deformation. These study results provide evidence that deposition from waxy crude oils is mainly a thermally-driven process, in which the shear stress and the deposition time play significant roles by influencing the deposit properties. 4 refs.

  14. Deposition of Cu seed layer film by supercritical fluid deposition for advanced interconnects

    The deposition of a Cu seed layer film is investigated by supercritical fluid deposition (SCFD) using H2 as a reducing agent for Bis(2,2,6,6-tetramethyl-3,5- heptanedionato) copper in supercritical CO2 (scCO2). The effects of deposition temperature, precursor, and H2 concentration are investigated to optimize Cu deposition. Continuous metallic Cu films are deposited on Ru substrates at 190 °C when a 0.002 mol/L Cu precursor is introduced with 0.75 mol/L H2. A Cu precursor concentration higher than 0.002 mol/L is found to have negative effects on the surface qualities of Cu films. For a H2 concentration above 0.56 mol/L, the root-mean-square (RMS) roughness of a Cu film decreases as the H2 concentration increases. Finally, a 20-nm thick Cu film with a smooth surface, which is required as a seed layer in advanced interconnects, is successfully deposited at a high H2 concentration (0.75 mol/L)

  15. Metallogenic evolution of uranium deposits in the Middle East and North Africa deposits

    Howari, Fares; Goodell, Philip; Salman, Abdulaty

    2016-02-01

    This paper is briefly involved in classification and distributions of the Middle East and North Africa (MENA) uranium deposits. The study of these mineral systems can significantly contribute to our further understanding of the metallogeny of known and poorly explored deposits. This provides contribution to, and further enhancement of, current classifications and metallogenic models of uranium systems, allowing researchers to emphasize on unknown or poorly studied mineral systems found in MENA. The present study identified eight metallogenic types of uranium associated with: 1) the Archean rocks and intra-cratonic basins, 2) the Pan-African granites and rhyolites which are characterized by igneous activity, 3) Phanerozoic (Paleozoic) clastics, these deposits are the sedimentological response to Pan African magmatism, 4) Mesozoic (basal) clastics type e.g. Nubia sandstones which are characterized by uranium minerals, 5) regional sedimentary phosphate deposits which are categorized as geosynclinal, or continental margin deposits, on the shelf of the Tethys Ocean, 6) Cenozoic Intracratonic Felsic Magmatism of the Tibesti and Hoggar, and the sandstone U deposits of adjoining Niger. These are similar to the Pan-African magmatism metallogenic, 7) Calcretes, and 8) Resistate minerals which are often enriched in rare earth elements, sometimes including uranium. They are thus sometimes considered as U resources but poorly explored in the MENA region. These metallogenic types are described and discussed in the current paper.

  16. Deposition of Cu seed layer film by supercritical fluid deposition for advanced interconnects

    Zhao Bin; Zhao Ming-Tao; Zhang Yan-Fei; Yang Jun-He

    2013-01-01

    The deposition of a Cu seed layer film is investigated by supercritical fluid deposition (SCFD) using H2 as a reducing agent for Bis(2,2,6,6-tetramethyl-3,5-heptanedionato) copper in supercritical CO2 (scCO2).The effects of deposition temperature,precursor,and H2 concentration are investigated to optimize Cu deposition.Continuous metallic Cu films are deposited on Ru substrates at 190 ℃ when a 0.002 mol/L Cu precursor is introduced with 0.75 mol/L H2.A Cu precursor concentration higher than 0.002 mol/L is found to have negative effects on the surface qualities of Cu films.For a H2concentration above 0.56 mol/L,the root-mean-square (RMS) roughness of a Cu film decreases as the H2 concentration increases.Finally,a 20-nm thick Cu film with a smooth surface,which is required as a seed layer in advanced interconnects,is successfully deposited at a high H2 concentration (0.75 mol/L).

  17. Paraffin wax deposits and chemical inhibitors

    Mendell, J.L.

    1970-01-01

    Solutions to this problem becomes necessary with the advent of extremely deep production, offshore production, and the probability of ocean-floor completions. The reasons for paraffin-wax accumulations are many and difficult to pinpoint. Inhibition of these paraffin deposits appears to be the best solution. Paraffin solvents and inhibitors are as follows: solvents, wetting agents, dispersants, and crystal modifiers. Solvents are effective, but can harm a refinery catalyst and create health hazards. Wetting agents and dispersants comprise the majority of chemicals used as paraffin wax inhibitors. Crystal modifiers are relatively new and may provide the most efficient means of reducing deposition. Evaluations of chemical paraffin inhibitors are outlined. Field test results which consider the various chemicals tested may give satisfactory results in determining which particular chemical can solve the problem of the particular situation. (38 refs.)

  18. Fluidized bed silicon deposition from silane

    Hsu, George (Inventor); Levin, Harry (Inventor); Hogle, Richard A. (Inventor); Praturi, Ananda (Inventor); Lutwack, Ralph (Inventor)

    1984-01-01

    A process and apparatus for thermally decomposing silicon containing gas for deposition on fluidized nucleating silicon seed particles is disclosed. Silicon seed particles are produced in a secondary fluidized reactor by thermal decomposition of a silicon containing gas. The thermally produced silicon seed particles are then introduced into a primary fluidized bed reactor to form a fludized bed. Silicon containing gas is introduced into the primary reactor where it is thermally decomposed and deposited on the fluidized silicon seed particles. Silicon seed particles having the desired amount of thermally decomposed silicon product thereon are removed from the primary fluidized reactor as ultra pure silicon product. An apparatus for carrying out this process is also disclosed.

  19. Designing leaching fields in Straz deposit

    The deposit contains several types of ores differing in permeability and leachability. A network of survey bores offers basic design information. Using the data obtained, the description is produced of the geotechnological structure of the deposit. Kinetic functions of sulfuric acid reaction with ore are determined for each layer. The design also requires information on tectonics, hydraulic conditions in the whole area and on economic parameters. The results of the calculations can provide information on the quality of the leachate, production, acid consumption; using prices and other economic data, costs for different seasons and years elapsing from the beginning of the leaching process can be calculated. The model is demonstrated on an example of optimization of one mining field. (M.D.). 10 figs., 10 refs

  20. Electrochemical Behaviour of Sputtering Deposited DLC Films

    LIUErjia; ZENGA; LIULX

    2003-01-01

    Diamondlike carbon (DLC) films were deposited via magnetron sputtering process. The energetic ion hombardment on the surface of growing film is one of the major parameters that control the atom mobility on the flirt1 surface and further the physical and chemical characteristics of the films. In this study, the energy of carbon ions was monitored by changing sputtering powerdensity, and its effect on the electrochemical performance of the films was investigated. For the deposition at a higher sputtering power density, a higher sp3 content in the DLC films was achieved with denser structure and increased film-substrate adhesion. The impedance at the interface of Si substrate/sulfufic acid solution was significantly enhanced, and at the same time higher film resistance, lower capacitance, higher breakdown potential and longer breakdown time were observed, which were related to the significant sp3 content of the DLC films.

  1. Electrochemical Behaviour of Sputtering Deposited DLC Films

    LIU Erjia; ZENG A,LIU L X

    2003-01-01

    Diamondlike carbon (DLC) films were deposited via magnetron sputtering process. The energetic ion bombardment on the surface of growing film is one of the major parameters that control the atom mobility on the film surface and further the physical and chemical characteristics of the films. In this study, the energy of carbon ions was monitored by changing sputtering power density, and its effect on the electrochemical performance of the films was investigated. For the deposition at a higher sputtering power density, a higher sp3 content in the DLC films was achieved with denser structure and increased film-substrate adhesion. The impedance at the interface of Si substrate/sulfuric acid solution was significantly enhanced, and at the same time higher film resistance, lower capacitance, higher breakdown potential and longer breakdown time were observed, which were related to the significant sp3 content of the DLC films.

  2. Electrophoretically-deposited solid film lubricants

    Dugger, M.T.; Panitz, J.K.J.; Vanecek, C.W.

    1995-04-01

    An aqueous-based process that uses electrophoresis to attract powdered lubricant in suspension to a charged target was developed. The deposition process yields coatings with low friction, complies with environmental safety regulations, requires minimal equipment, and has several advantages over processes involving organic binders or vacuum techniques. This work focuses on development of the deposition process, includes an analysis of the friction coefficient of the material in sliding contact with stainless steel under a range of conditions, and a functional evaluation of coating performance in a precision mechanical device application. Results show that solid lubricant films with friction coefficients as low as 0.03 can be produced. A 0.03 friction coefficient is superior to solid lubricants with binder systems and is comparable to friction coefficients generated with more costly vacuum techniques.

  3. Problems and prospects of Kumkol deposit development

    Kumkol deposit's petroleum balance supply situated in Southern-Turgaj depression makes up 153.2 million tones, extracted supply by C1 category includes 89.4 million tones. Petroleum of cretaceous and sediments by its physico-chemical content are light (density 0.835 g/sm3), high-paraffin (12-15 %), low-sulphur content one (0,5 %). Content of light fractions under temperature 300 deg C is up to 45 %, gasoline one is up to 25 %. Gas content of stratum petroleum and saturation pressure substantially is changing by productive horizons. Rational system of Kumkol deposit development with sustaining of reservoir pressure for increase of petroleum extraction rate from bed and increase its output is presented. Technological and economical parameters of the Yuzhneftgas Joint Stock Company operation in condition of market economy and urgent problems on increase of petroleum production are considered

  4. Deposited low temperature silicon GHz modulator

    Lee, Yoon Ho Daniel; Lipson, Michal

    2013-01-01

    The majority of silicon photonics is built on silicon-on-insulator (SOI) wafers while the majority of electronics, including CPUs and memory, are built on bulk silicon wafers, limiting broader acceptance of silicon photonics. This discrepancy is a result of silicon photonics's requirement for a single-crystalline silicon (c-Si) layer and a thick undercladding for optical guiding that bulk silicon wafers to not provide. While the undercladding problem can be partially addressed by substrate removal techniques, the complexity of co-integrating photonics with state-of-the-art transistors and real estate competition between electronics and photonics remain problematic. We show here a platform for deposited GHz silicon photonics based on polycrystalline silicon with high optical quality suitable for high performance electro-optic devices. We demonstrate 3 Gbps polysilicon electro-optic modulator fabricated on a deposited polysilicon layer fully compatible with CMOS backend integration. These results open up an arr...

  5. Role of iron sulfides in uranium deposition

    The role of iron mono- and disulfides in uranium infiltrated orogenesis is considered on the basis of the results of experimental and mineral-geochemical investigations. it is shown that pyrrhotite decomposing in a weak-acid medium with hydrogen sulfide and hydrogen emission precipitates actively uranium from oxygen-containing waters. Pyrrhotite in oxygen-free medium - when hydrogoethite is absent (probably due to partial proportionalization of Fe2+, SO42- and H2S and electron release causes Eh decrease at the mineral solution boundary up to values - 250 mV and correspondingly recovery uranium deposition. Regions of near-the fracture and over-the-break rock pyritization are of great importance when forecasting and prospecting infiltrated uranium deposits

  6. Chemical Vapour Deposition of Large Area Graphene

    Larsen, Martin Benjamin Barbour Spanget

    Chemical Vapor Deposition (CVD) is a viable technique for fabrication of large areas of graphene. CVD fabrication is the most prominent and common way of fabricating graphene in industry. In this thesis I have attempted to optimize a growth recipe and catalyst layer for CVD fabrication of uniform......, single layer, and high carrier mobility large area graphene. The main goals of this work are; (1) explore the graphene growth mechanics in a low pressure cold-wall CVD system on a copper substrate, and (2) optimize the process of growing high quality graphene in terms of carrier mobility, and crystal...... structure. Optimization of a process for graphene growth on commercially available copper foil is limited by the number of aluminium oxide particles on the surface of the catalyst. By replacing the copper foil with a thin deposited copper film on a SiO2/Si or c-plane sapphire wafer the particles can...

  7. Protein Data Bank Depositions from Synchrotron Sources

    A survey and analysis of Protein Data Bank (PDB) depositions from international synchrotron radiation facilities, based on the latest released PDB entries, are reported. The results () show that worldwide, every year since 1999, more than 50% of the deposited X-ray structures have used synchrotron facilities, reaching 75% by 2003. In this web-based database, all PDB entries among individual synchrotron beamlines are archived, synchronized with the weekly PDB release. Statistics regarding the quality of experimental data and the refined model for all structures are presented, and these are analysed to reflect the impact of synchrotron sources. The results confirm the common impression that synchrotron sources extend the size of structures that can be solved with equivalent or better quality than home sources

  8. Strategic metal deposits of the Arctic Zone

    Bortnikov, N. S.; Lobanov, K. V.; Volkov, A. V.; Galyamov, A. L.; Vikent'ev, I. V.; Tarasov, N. N.; Distler, V. V.; Lalomov, A. V.; Aristov, V. V.; Murashov, K. Yu.; Chizhova, I. A.; Chefranov, R. M.

    2015-11-01

    Mineral commodities rank high in the economies of Arctic countries, and the status of mineral resources and the dynamics of their development are of great importance. The growing tendency to develop strategic metal resources in the Circumarctic Zone is outlined in a global perspective. The Russian Arctic Zone is the leading purveyor of these metals to domestic and foreign markets. The comparative analysis of tendencies in development of strategic metal resources of the Arctic Zone in Russia and other countries is crucial for the elaboration of trends of geological exploration and research engineering. This paper provides insight into the development of Arctic strategic metal resources in global perspective. It is shown that the mineral resource potential of the Arctic circumpolar metallogenic belt is primarily controlled by large and unique deposits of nonferrous, noble, and rare metals. The prospective types of economic strategic metal deposits in the Russian Arctic Zone are shown.

  9. Controlled Deposition and Alignment of Carbon Nanotubes

    Smits, Jan M. (Inventor); Wincheski, Russell A. (Inventor); Patry, JoAnne L. (Inventor); Watkins, Anthony Neal (Inventor); Jordan, Jeffrey D. (Inventor)

    2012-01-01

    A carbon nanotube (CNT) attraction material is deposited on a substrate in the gap region between two electrodes on the substrate. An electric potential is applied to the two electrodes. The CNT attraction material is wetted with a solution defined by a carrier liquid having carbon nanotubes (CNTs) suspended therein. A portion of the CNTs align with the electric field and adhere to the CNT attraction material. The carrier liquid and any CNTs not adhered to the CNT attraction material are then removed.

  10. Australia's experience with the variable deposit requirement

    Australian Treasury

    1999-01-01

    This article examines the implementation of the Variable Deposit Requirement (VDR) capital control scheme in Australia in the 1970s. It notes that while capital controls can play a role in certain circumstances, they should not be used as a substitute for addressing underlying policy needs or financial sector reforms of an economy. The scheme was short-term in nature, and depended on subjective judgements about what level of capital inflow was appropriate at the time, and was unrelated to lon...

  11. Post deposition purification of PTCDA thin films

    The decomposition of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules during evaporation of unpurified raw material in ultra high vacuum was studied. The fragments were identified by mass spectrometry and the influence of these fragments and further contaminations of the raw material on the electronic structure of PTCDA thin films was measured by photoemission spectroscopy. Annealing of contaminated PTCDA films was tested as cheap and easy to perform method for (partial) post deposition purification of the contaminated films

  12. Gem corundum deposits of Madagascar : a review

    Rakotondrazafy, A. F. M.; Giuliani, Gaston; Ohnenstetter, D.; Fallick, A.E.; Rakotosamizanany, S.; Andriamamonjy, A.; Ralantoarison, T.; Razanatseheno, M.; Offant, Y.; Garnier, Virginie; H. Maluski; Dunaigre, C.; Schwarz, D.; Ratrimo, V.

    2008-01-01

    Madagascar is one of the most important gem-producing countries in the world, including ruby and sapphires. Gem corundum deposits formed at different stages in the geological evolution of the island and in contrasting environments. Four main settings are identified: (I) Gem corundum formed in the Precambrian basement within the Neoproterozoic terranes of southern Madagascar. and in the volcano-sedimentary series of Beforona, north of Antananarivo. In the South, high-temperature (700 to 800 de...

  13. Trail formation based on directed pheromone deposition

    Boissard, Emmanuel; Degond, Pierre; Motsch, Sébastien

    2011-01-01

    We propose an Individual-Based Model of ant-trail formation. The ants are modeled as self-propelled particles which deposit directed pheromones and interact with them through alignment interaction. The directed pheromones intend to model pieces of trails, while the alignment interaction translates the tendency for an ant to follow a trail when it meets it. Thanks to adequate quantitative descriptors of the trail patterns, the existence of a phase transition as the ant-pheromone interaction fr...

  14. Isotope targets prepared by vapor deposition

    As the state of the art for producing thin films has developed, the parameters set by the experiments have in turn become more stringent. Often these targets must be of high purity, extremely thin, self-supporting, and of accurately determined thickness. In addition, the target material may be an expensive isotope which must be reduced to elemental form at the time of vapor deposition. Methods of producing some of these targets will be discussed with such examples as calcium, magnesium and boron

  15. Electrostatic force assisted deposition of graphene

    Liang, Xiaogan

    2011-11-15

    An embodiment of a method of depositing graphene includes bringing a stamp into contact with a substrate over a contact area. The stamp has at least a few layers of the graphene covering the contact area. An electric field is developed over the contact area. The stamp is removed from the vicinity of the substrate which leaves at least a layer of the graphene substantially covering the contact area.

  16. Pulsed laser deposition of rare earth compounds

    Magnetostrictive thin films have been deposited using various techniques such as sputtering and evaporation but the use of laser deposition has been limited. This research presents the results from pulsed laser deposition (PLD) of TbFe2, DyFe2 and Terfenol-D thin films using an infra red Transversely Excited Atmospheric (TEA) CO2 laser at λ ∼10.6 μm and an ultra violet Argon-Fluoride (ArF) excimer laser at λ ∼ 193 nm. Results have showed that the TEA CO2 laser under the range of conditions studied is not suitable for the production of magnetostrictive films. The problems experienced are a mixture of mostly fracture debris at low fluences (F ∼ 20 Jcm-2) and melt droplets at high fluences (F∼ 60 Jcm-2). In all cases the destruction of the target is a major problem, with the Terfenol-D targets being the worst affected. Thin films produced were all iron rich. The use of an excimer laser has proved more successful in providing stoichiometric transfer of the target material, although this is only true under certain conditions. When a rotating target was used the growth of stoichiometric films was difficult due to a process related to the high photon energy of the excimer laser. The use of single spot irradiation did provide films of near stoichiometric composition over a wide range of fluences. Magnetostrictions for both TbFe2 and DyFe2 were found to be quite similar λ// ∼ 280 ppm at an applied field of 980 kAm-1. The results for Terfenol-D films were quite low with λ// ∼ 190 ppm at 980 kAm-1 but these showed signs of being adversely affected by stresses created during deposition. (author)

  17. Determination of electroless deposition by chemical nickeling

    Badida, M.; M. Gombár; L. Sobotová; J. Kmec

    2013-01-01

    Increasing of technical level and reliability of machine products in compliance with the economical and ecological terms belongs to the main trends of the industrial development. During the utilisation of these products there arise their each other contacts and the interaction with the environment. That is the reason for their surface degradation by wear effect, corrosion and other influences. The chemical nickel-plating allows autocatalytic deposition of nickel from water solutions in the fo...

  18. Surface free energy and microarray deposition technology

    McHale, Glen

    2007-01-01

    Microarray techniques use a combinatorial approach to assess complex biochemical interactions. The fundamental goal is simultaneous, large-scale experimentation analogous to the automation achieved in the semiconductor industry. However, microarray deposition inherently involves liquids contacting solid substrates. Liquid droplet shapes are determined by surface and interfacial tension forces, and flows during drying. This article looks at how surface free energy and wetting considerations ma...

  19. Chemical Vapour Deposition of Large Area Graphene

    Larsen, Martin Benjamin Barbour Spanget; Bøggild, Peter; Booth, Tim; Jørgensen, Anders Michael

    2015-01-01

    Chemical Vapor Deposition (CVD) is a viable technique for fabrication of large areas of graphene. CVD fabrication is the most prominent and common way of fabricating graphene in industry. In this thesis I have attempted to optimize a growth recipe and catalyst layer for CVD fabrication of uniform, single layer, and high carrier mobility large area graphene. The main goals of this work are; (1) explore the graphene growth mechanics in a low pressure cold-wall CVD system on a copper substrate, ...

  20. Flowslide Early Warning System in pyroclastic deposits

    Olivares, Lucio; Damiano, Emila; De Cristofaro, Martina; Roberto, Greco; Mollo, Luigi; Netti, Nadia; Capparelli, Giovanna

    2015-04-01

    Most of the mountains of Campania are covered by airfall pyroclastic deposits in primary deposition generally in unsaturated conditions. These deposits are periodically subjected to rainfall induced landslides that may evolve into catastrophic flowslides. To protect towns EWS can be implemented in order to correctly and promptly predict the trigger. In the paper we detect some 'essential ingredients' for effective EWSs which are new with respect to those already employed and essentially based on pluviometric thresholds (Greco et. Al., 2013) and extremely simplified models not able to correctly follow the physical phenomena which are responsible of flowslides generation (Olivares et Al. 2009). Complex models, able to correctly simulate those physical phenomena such as infiltration processes and the effects of partial saturated conditions on shear strength contain the 'essential ingredients' that we discuss in the paper. A particular attention is devoted to define the relation between suction and shear strength and the water retention curve obtained from different techniques to assess a reliable hydro-geotechnical model to analyze the slope response of loose unsaturated pyroclastic deposits. An EWS that contains these elements can provide many advantages. In fact, catastrophic flowslides but even false alarms about such events, produce negative technological and productive shocks that strongly reduce the actual and prospective value added of investment in the areas at risk suggesting the opportunity of their shrinking and postponement. Of course this severely compromises the economic development of those areas. In the paper we propose to examine this subject in the Dixit e Pindyck framework of the Real Option Valuation Approach in order to explain the socio-economic value of effective EWS. In fact, such EWSs will embed valuable new real options in the investment opportunities in the areas at risk increasing their actual and prospective values. Keywords: slope

  1. Quality study of a fedspar deposit

    Taboada, J.; Vaamonde, A.; Saavedra, A.; Argüelles, A.

    2000-01-01

    This work describes a pegmatite mineral deposit composed by some veins of a length between 50 and 800 meters and a width of almost 15 meters. With the purpose to evaluate the potential exploitation, we have characterized the quality of the selling product, through a sampling procedure, granulometric classification, magnetic separation, flotation process and mineralogical analysis. In order to establish the more able flotation process, we have tested different methods, that we also include her...

  2. Deposition and Coating Properties on CVD Tungsten

    DU Ji-hong; LI Zheng-xiang; LIU Gao-jian; ZHOU Hui-Huang; CHUN liang

    2004-01-01

    Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.

  3. Niobium sputter deposition on quarter wave resonators

    Viswanadham, C; Jayaprakash, D; Mishra, R L

    2003-01-01

    Niobium sputter deposition on quarter wave copper R.F resonators, have been taken up in our laboratory, An ultra high vacuum system was made for this purpose. Niobium exhibits superconducting properties at liquid Helium temperature. A uniform coating of about 1.5 mu m of niobium on the internal surfaces of the copper resonant cavities is desired. Power dissipation in the resonators can be greatly reduced by making the internal surfaces of the R.F cavity super conducting. (author)

  4. High-deposition-rate ceramics synthesis

    Allendorf, M.D.; Osterheld, T.H.; Outka, D.A. [Sandia National Laboratories, Livermore, CA (United States)] [and others

    1995-05-01

    Parallel experimental and computational investigations are conducted in this project to develop validated numerical models of ceramic synthesis processes. Experiments are conducted in the High-Temperature Materials Synthesis Laboratory in Sandia`s Combustion Research Facility. A high-temperature flow reactor that can accommodate small preforms (1-3 cm diameter) generates conditions under which deposition can be observed, with flexibility to vary both deposition temperature (up to 1500 K) and pressure (as low as 10 torr). Both mass spectrometric and laser diagnostic probes are available to provide measurements of gas-phase compositions. Experiments using surface analytical techniques are also applied to characterize important processes occuring on the deposit surface. Computational tools developed through extensive research in the combustion field are employed to simulate the chemically reacting flows present in typical industrial reactors. These include the CHEMKIN and Surface-CHEMKIN suites of codes, which permit facile development of complex reaction mechanisms and vastly simplify the implementation of multi-component transport and thermodynamics. Quantum chemistry codes are also used to estimate thermodynamic and kinetic data for species and reactions for which this information is unavailable.

  5. A Personal Nanoparticle Respiratory Deposition (NRD) Sampler

    Cena, Lorenzo G.; Anthony, T. Renée; Peters, Thomas M.

    2016-01-01

    A lightweight (60 g), personal nanoparticle respiratory deposition (NRD) sampler was developed to selectively collect particles smaller than 300 nm similar to their typical deposition in the respiratory tract. The sampler operates at 2.5 Lpm and consists of a respirable cyclone fitted with an impactor and a diffusion stage containing mesh screens. The cut-point diameter of the impactor was determined to be 300 nm with a sharpness σ = 1.53. The diffusion stage screens collect particles with an efficiency that matches the deposition efficiency of particles smaller than 300 nm in the respiratory tract. Impactor separation performance was unaffected by loading at typical workplace levels (p-value = 0.26). With chemical analysis of the diffusion media, the NRD sampler can be used to directly assess exposures to nanoparticles of a specific composition apart from other airborne particles. The pressure drop of the NRD sampler is sufficiently low to permit its operation with conventional, belt-mounted sampling pumps. PMID:21718022

  6. Deposited sediment settlement and consolidation mechanisms

    Shuai-jie Guo

    2015-10-01

    Full Text Available In order to study deposited sediment settlement and consolidation mechanisms, sediment settlement experiments were conducted using a settlement column. Based on the experimental results, sediment settlement stage definition, excessive pore pressure (EPP dissipation, and consolidation constitutive equations are discussed. Three stages, including the free settlement, hindered settlement, and self-weight consolidation settlement stages, are defined. The results of this study show that sediment settlement is mainly affected by the initial sediment concentration and initial settlement height, and the interface settlement rate is attenuated linearly with time on bilogarithmic scales during the hindered settlement and self-weight consolidation settlement stages. Moreover, the deposited sediment layer in the self-weight consolidation settlement stage experiences large strains, and the settlement amount in this stage is about 32% to 59% of the initial height of deposited sediment. EPP is nonlinearly distributed in the settlement direction, and consolidation settlement is faster than EPP dissipation in the self-weight consolidation settlement stage. Consolidation constitutive equations for the hydraulic conductivity and effective stress, applicable to large-strain consolidation calculation, were also determined and fitted in the power function form.

  7. Atmospheric transport, diffusion, and deposition of radioactivity

    From a meteorological standpoint there are two types of initial sources for atmospheric diffusion from Plowshare applications. One is the continuous point-source plume - a slow, small leak from an underground engineering application. The other is the large cloud produced almost instantaneously from a cratering application. For the purposes of this paper the effluent from neither type has significant fall speed. Both are carried by the prevailing wind, but the statistics of diffusion for each type are different. The use of constant altitude, isobaric and isentropic techniques for predicting the mean path of the effluent is briefly discussed. Limited data are used to assess the accuracy of current trajectory forecast techniques. Diffusion of continuous point-source plumes has been widely studied; only a brief review is given of the technique used and the variability of their results with wind speed and atmospheric stability. A numerical model is presented for computing the diffusion of the 'instantaneously-produced' large clouds. This model accounts for vertical and diurnal changes in atmospheric turbulence, wet and dry deposition, and radioactivity decay. Airborne concentrations, cloud size, and deposition on the ground are calculated. Pre- and post-shot calculations of cloud center, ground level concentration of gross radioactivity, and dry and wet deposition of iodine-131 are compared with measurements on Cabriolet and Buggy. (author)

  8. Air Laya coal deposit - South Sumatra, Indonesia

    Schwarzenberg, T. von

    1986-11-01

    In southern Sumatra geological coal reserves of about 6 billion tons were proven during the past twenty years. These reserves consist mainly of hard brown coals. Only locally is the coal of higher rank and reaches anthracitic quality in the immediate vicinity of andesite intrusions. The coals are of paralic origin and were deposited during the Miocene and Pliocene in a large foreland deep east of the Barisan Mountain range. From 1974 onwards extensive geological exploration programmes were carried out. In 1980 and 1982, two of these programmes were conducted by geologists of Rheinbraun-Consulting GmbH, Cologne, in order to obtain more detailed data on the geological structure of the deposit, the coal quality and geomechanical parameters. Parallel to this field work, numerous mining and equipment variants were investigated which finally led to the decision to install a modern system of bucket wheel excavator operation with belt conveyors and spreaders. The mineable coal reserves of the deposit amount to 112 Mt coal.

  9. Alkylphenols in atmospheric depositions and urban runoff.

    Bressy, A; Gromaire, M-C; Lorgeoux, C; Chebbo, G

    2011-01-01

    A sampling campaign was conducted in order to determine alkylphenol (AP) concentrations in stormwater as well as potential AP sources in suburban environments. An analytical procedure was developed to quantify APs in bulk atmospheric deposition, building runoff, road runoff and stormwater. Both nonylphenols and octylphenols could be quantified in each sample. Median stormwater concentrations amounted to: 470 ng/l for nonylphenols, and 36 ng/l for octylphenols. These concentrations are 3 times higher than those found in atmospheric deposition, thus proving that local human activity constitutes a significant source of contamination. The contributions of the various sources to stormwater have been assessed from mass balances at the catchment scale. 70% of AP mass in stormwater originates from building and road emissions. Annual AP fluxes have been extrapolated from the total AP mass measured over our sampling periods for atmospheric depositions (44 to 84 µgNP/m(2)/yr) and stormwater (100 to 190 µgNP/m(2)/yr). Moreover, since APs were mainly found in the dissolved fraction, runoff treatment devices based on settling are unlikely to be very efficient. PMID:21330713

  10. Plasma deposition of amorphous metal alloys

    Rapid solidification, sputtering and electroless chemical deposition have been used to produce amorphous metal alloys which possess excellent corrosion and abrasion resistance. This paper discusses a new technique for obtaining amorphous metal alloy coatings. Plasma decomposition of Ni(CO)4 and PH3 in argon and hydrogen carrier gases [Ni(CO4/PH3--8/1] yielded films that were black and silver, respectively, in appearance. Both films were amorphous as determined by transmission electron microscopy. Films deposited using a hydrogen carrier gas were three orders of magnitude more conductive than those deposited using an argon carrier gas. Analysis of both films using electron microprobe analysis and inductively-coupled plasma spectroscopy showed an enrichment of P in the films over the P content in the plasma gas mixtures. Reducing the P content of the plasma gas mixture [Ni(CO)4/PH3--17/11 yielded crystalline films with no P enrichment. The grain size in these films was --60Δ as determined by x-ray line-broadening

  11. Characterization of radioactive deposits in primary circuits

    Reduction of the dose rate that results from crud deposits in various systems of nuclear power plants, seems to be one of the most efficient steps to reduce collective operations doses recived by personnel working in these plants. At present, various processes are being applied tending to minimize those phonemena that lead to the generation of these radiation fields. For this reason, a great emphasis is attached to providing a procedure to follow-up the evolution of contamination levels produced in each system, and to asses the effects achieved by aplying corrective measures. At the Santa Maria de Garona nuclear plant, a device has been designed together with a procedure, to allow for gamma spectrometry tests to be performed on lines and other components as well as to quantify the specific activity of each of the isotopes presents in crud deposits. This method has been applied to measure the isotopes deposited in the Reactor Recirculation System lines, resulting that 76,8% of the total dose rate is due to Co''60 and 83.6% comes from both C0''60 and C0''58 put together. Smaller shares are attributable to Mn''54(10,6%), Fe(2,9%), Zn''65(1,4%) and Sb''124(1,4%)

  12. The genesis of surficial uranium deposits

    Surficial uranium deposits can form in such diverse environments as calcareous-dolomitic-gypsiferous fluvial and aeolian valley sediments in hot arid and semi-arid regions, oxidizing and reducing alkaline and saline playas, highly organic and/or clay-rich wetland areas, calcareous regoliths in arid terranes, laterites, lake sediments, and highly fractured zones in igneous and metamorphic basement complexes. Formation of ore is governed by the interrelationships between source of ore-forming elements, mechanisms of migration, environment of deposition, climate, preservation, tectonic history and structural framework. The principal factors controlling mobilization of ore-forming elements from source to site of deposition are the availability of elements in source rocks, presence of complexing agents, climate, nature of source rock regolith and structure of source rock terrane. The major processes governing precipitation of uranium in the surficial environment are reduction mechanisms, sorption processes, dissociation of uranyl complexes, change in redox states of ore-forming constituents, evaporation of surface and groundwaters, change in partial pressure of dissolved carbon dioxide, changes in pH, colloidal precipitation, and mixing of two or more surface and groundwaters. One or a number of these processes may be actively involved in ore formation. (author)

  13. Radioactive disequilibrium in mound spring deposits

    The problem to be resolved was the age of the mound spring sediments on the margin of the Great Artesian Basin to the south and southwest of Lake Eyre. Nine samples from six springs and two from neighbouring dune fields were collected. The parent and daughter nuclides for the uranium and thorium decay chains have been comprehensively measured by a variety of techniques: DNA, thick-source alpha particle counting, field scintillometry, high resolution gamma spectrometry and high resolution alpha spectrometry. Gross radioactive disequilibrium in the uranium chain is found for the spring samples. The activity, in Bq kg-1, for the uranium chain at and below radium, compared with the parent uranium and its immediate daughters, ranges from an excess factor of two to a factor of six, depending on the age of the spring mound deposit. This is interpreted as evidence that radium is being carried up into the springs with artesian groundwater and deposited in the spring mound sediments. There is also evidence for a small excess of thorium. The ages of the spring mound deposits have been successfully found by thermoluminescence. They range from about 20 ka to 500 ka. The disequilibrium suggests why attempts to use uranium series dating have not been successful

  14. Pulsed laser deposition of rare earth compounds

    Stone, L A

    2001-01-01

    Magnetostrictive thin films have been deposited using various techniques such as sputtering and evaporation but the use of laser deposition has been limited. This research presents the results from pulsed laser deposition (PLD) of TbFe sub 2 , DyFe sub 2 and Terfenol-D thin films using an infra red Transversely Excited Atmospheric (TEA) CO sub 2 laser at lambda approx 10.6 mu m and an ultra violet Argon-Fluoride (ArF) excimer laser at lambda approx 193 nm. Results have showed that the TEA CO sub 2 laser under the range of conditions studied is not suitable for the production of magnetostrictive films. The problems experienced are a mixture of mostly fracture debris at low fluences (F approx 20 Jcm sup - sup 2) and melt droplets at high fluences (F approx 60 Jcm sup - sup 2). In all cases the destruction of the target is a major problem, with the Terfenol-D targets being the worst affected. Thin films produced were all iron rich. The use of an excimer laser has proved more successful in providing stoichiometri...

  15. Tree Leaf Biomarkers for Atmospheric Nitrogen Deposition

    The aim of this paper was to investigate the effects of nitrogen (N) deposition on tree N cycling and identify potential biomarkers for N deposition. Between April and October 2002 extensive fieldwork was undertaken at Mardley Heath in Hertfordshire. This woodland, located adjacent to the A1(M) motorway, is exposed to high levels of atmospheric nitrogen oxides from the traffic. Measurements of δ15N, in vivo nitrate reductase (NR) activity, tissue, xylem and surface nitrate concentrations as well as N concentration and growth were made along a 700-m transect at 90o to the motorway. The δ15N data show that oxidised N from the road traffic is taken up by nearby trees and is incorporated into plant tissues. Our measurements of NR activities suggest elevated rates close to the motorway. However, xylem sap, leaf tissue and leaf surface nitrate concentrations showed no differences between the roadside location and the most distant sampling point from the motorway. Taken together the δ15N and nitrate reductase data suggest uptake and assimilation of N through the foliage. We conclude that for this lowland deciduous woodland, tissue, xylem and surface measurements of nitrate are unreliable biomarkers for N deposition whereas δ15N, growth measurements and integrated seasonal NR might be useful. The results also point to the benefit of roadside tree planting to screen pollution from motor vehicles

  16. Tree leaf biomarkers for atmospheric nitrogen deposition

    The aim of this paper was to investigate the effects of nitrogen (N) deposition on tree N cycling and identify potential biomarkers for N deposition. Between April and October 2002 extensive fieldwork was undertaken at Mardley Heath in Hertfordshire. This woodland, located adjacent to the A1(M) motorway, is exposed to high levels of atmospheric nitrogen oxides from the traffic. Measurements of δ15N, in vivo nitrate reductase (NR) activity, tissue, xylem and surface nitrate concentrations as well as N concentration and growth were made along a 700-m transect at 90o to the motorway. The δ15N data show that oxidised N from the road traffic is taken up by nearby trees and is incorporated into plant tissues. Our measurements of NR activities suggest elevated rates close to the motorway. However, xylem sap, leaf tissue and leaf surface nitrate concentrations showed no differences between the roadside location and the most distant sampling point from the motorway. Taken together the δ15N and nitrate reductase data suggest uptake and assimilation of N through the foliage.We conclude that for this lowland deciduous woodland, tissue, xylem and surface measurements of nitrate are unreliable biomarkers for N deposition whereas δ15N, growth measurements and integrated seasonal NR might be useful. The results also point to the benefit of roadside tree planting to screen pollution from motor vehicles

  17. Supersonic Flow Control Using Combined Energy Deposition

    O. A. Azarova

    2015-03-01

    Full Text Available Drag force control via energy deposition in an oncoming flow is a wide area of interest in aerospace sciences. Recently, investigations on the effect of combining energy sources have been conducted. The possibility of coupling microwave (MW discharges or MW and laser energy deposition is discussed. In the present work, the flow details accompanying the interaction of a combined energy release and an aerodynamic body in a supersonic flow are considered numerically on the base of the Euler equations. Comparison with non-combined energy deposition is analyzed. The effect of introducing the internal part to the energy release on the drag force reduction is examined. The flows for blunt cylinder, hemisphere-cylinder and pointed body are considered for a wide class of the combined energy source characteristics. Freestream Mach number is varied from 1.89 to 3.45. Complicated unsteady vortex structures caused by the Richtmyer–Meshkov instabilities are shown to be the reason for the reduction in drag. The unsteady double vortex mechanism of the frontal drag force reduction and mechanism of the constantly acting vortices at the steady flow are described. Suppression of shear layer instability and large scaled flow pulsations as the result of the combined energy release effect is established. Complex conservative difference schemes are used in the simulations.

  18. GYPSUM DEPOSITS IN THE REPUBLIC OF CROATIA

    Anto Gabrić

    2002-12-01

    Full Text Available The occurences and deposits of gypsum can be found in big karst poljes (Sinjsko, Vrličko, Petrovo, Kosovo and Kninsko as well as in tectonnically predestined river valleys of Zrmanja, Butišnica and Una. There also appear spatially localized occurences on the island of Vis and in the vicinity of Samobor. Evaporites (gypsum and anhydrite with adjoining overlying clastic rocks (red sandstones, siltites and pelites, carbonate rocks (dolomites and limestones and porous carbonate breccias (Rauhwackes were deposited during the period of Upper Permian. The recent position of the Upper Permian beds is a result of complex tectonic, particularly neotectonic, movements and diapiric displacements. Evaporites were deposited in marginal areas of the epicontinental marine basin, in a period of favourable conditions for the sabkha and playa sedimentation due to the continuous shoreline progradation. The Upper Permian age of these sediments in Dalmatio is proved by the characteristic mineral paragenesis and palinological determinations in elastics rocks, as well as by isotope analyses of sulphure in gypsum. Gypsum is a significant ore mineral resource in building, cement production, as well as in a number of tehnological processes used in chemical industry and elsewhere. According to the recent investigations gypsum is predestined to serve as an ore mineral resource of significant perspectives (the paper is published in Croatian.

  19. Source Molecular Effect on Amorphous Carbon Film Deposition

    Kawazoe, Hiroki; Inayoshi, Takanori; Shinohara, Masanori; Matsuda, Yoshinobu; Fujiyama, Hiroshi; Nitta, Yuki; Nakatani, Tatsuyuki

    2009-01-01

    We investigated deposition process of amorphous carbon films using acetylene and methane as a source molecule, by using infrared spectroscopy in multiple internal reflection geometry (MIR-IRAS). We found that deposited film structures were different due to source molecules.

  20. Properties of weld deposit for butt weldings of reactor components

    Mechanical properties of weld deposit type MnNiMo from submerged arc- and manual shielded arc weldings for reactor components, influence of chemical composition and heat treatment condition, proposal for the testing of mechanical properties for weld deposit. (orig.)

  1. Uranium deposits, their geochronology and general features of location

    Main types of uranium deposits are considered. Attention is paid to uranium provinces in the hierarchy of metallogenic parts and to general features of their location. Problems of geochronology are considered. All known at present uranium deposits are shown to belong to four genetic types: endogenic, exogenetic, metamorphogenetic and poligenic. Three groups of deposits, which are connected with alkaline-ultrabasic alkaline and acid magmatism are distinguished among endogenic ones. Two groups of deposits: sedimentary-diagenetic (syngenetic) and infiltrated (epigenetic), represent exogenic ones. Metamorphosed and ultrametamorphic deposits are formed a metamorphogenic group. Deposits formed mainly during oxidation of primary uranium concentrations of different origin are distinguished in a polygenic group. All major uranium deposits are formed in 12 main metallogenic periods. ''Deposition'' of uranium provinces occurred in four important periods of geologic history of mainlands: in the period between Late Archean and Early Proterozoic, of Early Proterozoic and Ripheic, of Paleozoic and Mezozoic, of Jurassic and Cretaceous period

  2. Point locations and characteristics of evaporite-related potash deposits

    U.S. Geological Survey, Department of the Interior — This spatial database of evaporite-related potash deposits and occurrences provides location and descriptive information for 981 deposits and occurrences that are...

  3. Ash Deposition Trials at Three Power Stations in Denmark

    Laursen, Karin; Frandsen, Flemming; Larsen, Ole Hede

    1998-01-01

    Six full-scale trials were conducted at three power stations in Denmark: Ensted, Funen, and Vendsyssel power stations. During these trials, pulverized coal, bottom ash, fly ash, and deposits from cooled probes were sampled and analyzed with various techniques. On the basis of SEM analyses, the...... deposits can be grouped into five textural types, which all possess distinct textural and chemical characteristics. Likewise, the deposition mechanisms for these five types are characteristic and they may be used for constructing a model for the buildup and maturation of an ash deposit. The deposits...... collected on the probes were thin (maximum 2 mm after 9 h) and the influence of operational parameters and probe temperatures on the magnitude of the deposits were minor. The probe temperatures had no influence on the composition of the ash deposits for coals with low ash deposition propensities, whereas...

  4. Mineral deposits research in Uruguay. Technical economic part

    Technical researches, mineralogical and chemical analysis were carried out in Zapucay and Iman deposit located in Uruguay south America, as a result of that, researchers was described the mineral adherences of the deposits.

  5. Multiwalled Carbon Nanotube Deposition on Model Environmental Surfaces

    Deposition of multiwalled carbon nanotubes (MWNTs) on model environmental surfaces was investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D). Deposition behaviors of MWNTs on positively and negatively charged surfaces were in good agreement with Der...

  6. Influence of deposit architecture on intrastratal deformation, slope deposits of the Tres Pasos Formation, Chile

    Auchter, Neal C.; Romans, Brian W.; Hubbard, Stephen M.

    2016-07-01

    Slope sediments on passive and active margins deform and fail across a broad range of scales ranging from loading and sediment remobilization near the sediment-water interface to submarine landslides and mass movements that incorporate significant volumes of slope deposits. Deformational styles are characterized by updip extension and downdip compressional features that occur above a detachment surface. Conditions for failure and deformation include the presence of weak layer(s) that serve as a detachment surface, competency contrasts that allow for detachment and downslope movement, deformation above a detachment surface, and a triggering mechanism(s) that initiates failure. Slope failure processes and products are well documented at scales resolvable by seismic-reflection surveys and in instances of extensive downslope failure, but the processes and products associated with intermediate-scale slope deformation are poorly understood. Intrastratal deformation is defined as stratigraphically isolated zones of deformation bounded above and below by concordant and undeformed strata. In this study, outcrop examples of intrastratal deformation from the Upper Cretaceous Tres Pasos Formation are used to elucidate the influence of depositional architecture on slope deformation. The facies distribution associated with compensational stacking of lobe deposits is shown to have a first-order control on the location and style of deformation. Detachment planes that form in mudstone deposits associated with lobe fringe and interlobe deposits are spatially limited and deformation is restricted to interbedded sandstone and mudstone associated with off-axial lobe positions. Downslope translation was arrested by stratigraphic buttresses associated with more sandstone-prone axial deposits. Emplacement of a regionally extensive mass transport deposit is interpreted as the triggering mechanism for contemporaneous intrastratal deformation of > 60 m of underlying stratigraphy. A vertical

  7. In Situ Electrochemical Deposition of Microscopic Wires

    Yun, Minhee; Myung, Nosang; Vasquez, Richard

    2005-01-01

    A method of fabrication of wires having micron and submicron dimensions is built around electrochemical deposition of the wires in their final positions between electrodes in integrated circuits or other devices in which the wires are to be used. Heretofore, nanowires have been fabricated by a variety of techniques characterized by low degrees of controllability and low throughput rates, and it has been necessary to align and electrically connect the wires in their final positions by use of sophisticated equipment in expensive and tedious post-growth assembly processes. The present method is more economical, offers higher yields, enables control of wire widths, and eliminates the need for post-growth assembly. The wires fabricated by this method could be used as simple electrical conductors or as transducers in sensors. Depending upon electrodeposition conditions and the compositions of the electroplating solutions in specific applications, the wires could be made of metals, alloys, metal oxides, semiconductors, or electrically conductive polymers. In this method, one uses fabrication processes that are standard in the semiconductor industry. These include cleaning, dry etching, low-pressure chemical vapor deposition, lithography, dielectric deposition, electron-beam lithography, and metallization processes as well as the electrochemical deposition process used to form the wires. In a typical case of fabrication of a circuit that includes electrodes between which microscopic wires are to be formed on a silicon substrate, the fabrication processes follow a standard sequence until just before the fabrication of the microscopic wires. Then, by use of a thermal SiO-deposition technique, the electrodes and the substrate surface areas in the gaps between them are covered with SiO. Next, the SiO is electron-beam patterned, then reactive-ion etched to form channels having specified widths (typically about 1 m or less) that define the widths of the wires to be formed. Drops

  8. Imbalanced phosphorus and nitrogen deposition in China's forests

    Du, Enzai; de Vries, Wim; Han, Wenxuan; Liu, Xuejun; Yan, Zhengbing; Jiang, Yuan

    2016-07-01

    Acceleration of anthropogenic emissions in China has substantially increased nitrogen (N) deposition during the last 3 decades and may result in an imbalance of atmospheric N and phosphorus (P) inputs in terrestrial ecosystems. However, the status of P deposition in China is poorly understood. This study synthesized data on total P and total N concentrations in bulk precipitation and throughfall from published literature to assess the characteristics of P deposition, N deposition and N : P deposition ratio in China's forests. Our results show relatively high mean rates of bulk P deposition (0.38 kg P ha-1 yr-1) and total P deposition (0.69 kg P ha-1 yr-1), but they were accompanied by even more elevated N inputs via bulk deposition (16.5 kg N ha-1 yr-1) and total deposition (21.6 kg N ha-1 yr-1), resulting in high N : P ratios in bulk deposition (44.4) and total deposition (32.8). Based on the difference between total deposition and bulk deposition, canopy-captured dry P and N deposition was estimated to be 0.31 kg P ha-1 yr-1 and 5.1 kg N ha-1 yr-1, respectively. We found significantly higher P deposition and lower N : P ratios at sites nearby than those far from semiarid regions. The estimated bulk and total deposition of P and N both showed a significant power-law increase with decreasing distance to the nearest large cities either in the areas nearby or far from semiarid regions. Our results suggest an anthropogenic alternation of regional P and N cycling, which may shift large areas of China's forests towards human-induced P limitation especially in southern China.

  9. Deposition of manganese in a drinking water distribution system.

    Sly, L I; M.C. Hodgkinson; Arunpairojana, V

    1990-01-01

    The deposition of manganese in a water distribution system with manganese-related "dirty water" problems was studied over a 1-year period. Four monitoring laboratories with Robbins biofilm sampling devices fitted to the water mains were used to correlate the relationship among manganese deposition, the level of manganese in the water, and the chlorination conditions. Manganese deposition occurred by both chemical and microbial processes. Chemical deposition occurred when Mn(II) not removed du...

  10. Pulsed laser ablation and deposition of niobium carbide

    Sansone, M.; De Bonis, A.; Santagata, A.; Rau, J. V.; Galasso, A.; Teghil, R.

    2016-06-01

    NbC crystalline films have been deposited in vacuum by ultra-short pulsed laser deposition technique. The films have been characterized by transmission and scanning electron microscopies and by X-ray diffraction. To clarify the ablation-deposition mechanism, the plasma produced by the ablation process has been characterized by optical emission spectroscopy and fast imaging. A comparison of the results with those obtained by ns pulsed deposition of the same target has been carried out.

  11. Uranium deposits: Main types and concepts for detection

    This paper presents a classification of uranium deposits as a basis for developing an optimal exploration strategy for discovering deposits with favorable characteristics for low production cost. The classification is based on endogenic and exogenic sub-classes both of which are subdivided to synegenetic and epigenetic groups. The tectonic setting is also taken into consideration. Following description of the economic and geological types of deposits, the factors governing the formation of the deposits is given. (author). 2 figs, 2 tabs

  12. High Energy Radial Deposition of Diamond-Like Carbon Coatings

    Konrad Suschke; René Hübner; Peter Paul Murmu; Prasanth Gupta; John Futter; Andreas Markwitz

    2015-01-01

    Diamond-like carbon (DLC) coatings were deposited with a new direct ion deposition system using a novel 360 degree ion source operating at acceleration voltage between 4 and 8 kV. Cross-sectional TEM images show that the coatings have a three layered structure which originates from changes in the deposition parameters taking into account ion source condition, ion current density, deposition angles, ion sputtering and ion source movement. Varying structural growth conditions can be achieved by...

  13. Sandstone type uranium deposits in NW China

    Northwest China named here indicates the territory of China north of Kunlun-Qilian-Qingling mountain systems and west of Great Higgan Range, containing most of the significant sandstone type uranium deposits in China. The territory, some 2500 km long, in average 650 km wide and about 2.86x106km2 in area, comprises seven Mesozoic-Cenozoic basin-forming domains: the Tianshan-Junggar, the Tarimu, the Altun, the Alxan-Corridor, the Qaidam, the Eren-Hailar and the Ordos. Most domains include several sub-domains, but the Tarimu, the Qaidam and the Ordos domains contain one sub-dome only. Known deposits are mainly distributed in the Tianshan sub-domain of the Tianshan-Junggar domain and the Eren sub-domain of the Eren-Hailar domain. Besides, Dongsheng uranium mineralized has been discovered in the Ordos domain in latest years with a considerable amount of uranium resources/ reserves (Chen Anping et al., 2004). The host sandstones deposited in four different environments: 1) the cratonic basin, open and wide, characterised with shallow water depth and low subsidence rate, such as Junggar, Tarimu and Ordos basins; 2) the intra-continental down-faulted basin, usually divided by uplifts into second depressions and third order sags, characterised with deeper water depth and higher subsidence rate, exemplified by the basins in Eren-Hailar domain; 3) the compressive intermountain flexural basin, mostly of medium/small in size and narrowelongated in shape, occupying the intermediate position between previous two in water depth and subsidence rate, such as inter-mountain basins in Tianshan sub-domain; and 4) the erosive gully, formed on the hillside fields in stream head area and wide spread along the piedmont slope of Yingshan Mountains and the second uplifts within the range of the Eren basin. Meanwhile, uranium ore deposits/fields formed under three quite distinct tectonic regimes: the slight arching regime, characterized by the deformation mainly in shape of dome with vertical

  14. Imparting passivity to vapor deposited magnesium alloys

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  15. 24 CFR 291.535 - Earnest money deposit.

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Earnest money deposit. 291.535... Next Door Sales Program § 291.535 Earnest money deposit. (a) General. The earnest money deposit is the sum of money that must be paid by the law enforcement officer, teacher, or...

  16. Grade-Tonnage Model of Porphyry Copper Deposits of China

    Wang Xueping; Wei Min; Yang Lipei; Zhao Jingman

    2003-01-01

    A grade-tonnage model is established according to the analysis of 72 porphyry copper deposits recorded in "The Mineral Resources Data Base of China". Based on the analysis of frequency histogram, the cumulative frequency distributing graph and the theoretical model with double logarithmic coordinates of copper deposits, the typical mathematical characteristics of grade-tonnage model of porphyry copper deposits are clarified.

  17. 16 CFR 1025.35 - Depositions upon oral examination.

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Depositions upon oral examination. 1025.35... ADJUDICATIVE PROCEEDINGS Discovery, Compulsory Process § 1025.35 Depositions upon oral examination. (a) When... where the examination is held. No deposition shall be taken before a person who is a relative,...

  18. Resonant infrared pulsed laser deposition of thin biodegradable polymer films

    Bubb, D.M.; Toftmann, B.; Haglund Jr., R.F.;

    2002-01-01

    Thin films of the biodegradable polymer poly(DL-lactide-co-glycolide) (PLGA) were deposited using resonant infrared pulsed laser deposition (RIR-PLD). The output of a free-electron laser was focused onto a solid target of the polymer, and the films were deposited using 2.90 (resonant with O...

  19. Process and machinery description of equipment for deposition of canisters in medium-long deposition holes

    In this report twelve methods are presented to deposit a canister with spent nuclear fuel in a horizontal hole, several canisters per hole (MLH). These methods are part of the KBS-3 system. They have been developed successively, after an analysis of weak points and strong points in previously described methods. In conformance with the guidelines for Project JADE, a choices of system has been considered during the development work. This is whether canister and bentonite buffer should be deposited 'in parts', i.e. at different occasions, but shortly after each other or 'in a package', i.e. together in a single package. The other choice in the guidelines for the JADE project, whether the canister should be placed in a radiation shield or not during transport in the secondary tunnels, was not relevant to MLR. The basic technical problem is depositing heavy objects, the canister and the buffer components, in an horizontal hole which is approximately 200 m deep. Two methods for depositing of the bentonite barrier and the canisters in separate processes have been studied. For depositing of the bentonite barrier and the canister 'in a package', four alternative techniques have been studied: a metallic sleeve around the package, a loading scoop that is rotated, a fork carriage and rails. The repeated transports in a hole, a consequence of depositing several canisters in the same hole, could lead to the rock being crushed. The mutual impact of machines, load and rock wall has therefore been particularly considered. In several methods, the use of a gangway has been proposed (steel plates or layer of ice). A failure mode and effect analysis has been performed for one of the twelve methods. When comparing with a method to deposit one canister per hole using the same technique, the need for equipment and resources is far larger for this MLH method if incidents should occur during depositing. The development work reported here has not yet yielded a definitive method for placing

  20. Prediction of wall deposition behaviour in a pilot-scale spray dryer using deposition correlations for pipe flows

    KOTA K.; LANGRISH T.A.G.

    2007-01-01

    The particle deposition behaviour of skim milk, water and maltodextrin in the conical section of a pilot-scale spray dryer was predicted using simple correlations for particle depositions in pipes. The predicted particle deposition fluxes of these materials were then compared with the measured deposition fluxes. The predicted particle deposition regimes of the spray dryer were expected to be in the diffusional and mixed (diffusional and inertial) regimes, but the experimental results suggested that the particle deposition was mainly in the inertial regime. Therefore, using the pipe correlations for predicting deposition in a pilot-scale spray dryer suggests that they do not sufficiently represent the actual deposition behaviour. This outcome indicates that a further study of particle flow patterns needs to be carried out using numerical simulations (computational fluid dynamics,CFD) in view of the additional geometrical complexity of the spray dryer.

  1. Routine estimation and reporting of dry deposition for the U.S.A. Dry-Deposition Network

    A National Dry Deposition Network (NDDN) was established in the United States during 1986 to document the magnitude, spatial variability, and trends in dry deposition of ozone and acidic particles and gases. Currently, the network consists of 50 stations: 41 in the eastern United States and 9 in the western United States. Dry deposition is not measured directly in the NDDN, but is estimated by an inferential approach, i.e., fluxes are calculated as the product of measured ambient concentration and modeled deposition velocity. The temporal resolution for the dry deposition calculations is weekly. Chemical species include ozone, sulfate, nitrate, ammonium, sulfur dioxide and nitric acid. Preliminary dry deposition calculations yielded the following observations: (1) calculated values of dry deposition for colocated sites are in good agreement suggesting good network precision, and (2) spatial patterns of SO2 and HNO3 dry deposition are consistent with emission patterns

  2. In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

    Avila-Avendano, Jesus

    2016-04-09

    In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

  3. Experimental study of porosity reduction in high deposition-rate Laser Material Deposition

    Zhong, Chongliang; Gasser, Andres; Schopphoven, Thomas; Poprawe, Reinhart

    2015-12-01

    For several years, the interest in Additive Manufacturing (AM) is continuously expanding, owing to the paradigm shift that new production processes, such as Laser Material Deposition (LMD), provide over conventional manufacturing technologies. With LMD, three-dimensional, complex components out of a wide range of materials can be manufactured consecutively layer-by-layer. Despite the technological advantages of the LMD process, currently achieved deposition-rates of approx. 0.5 kg/h for Inconel 718 (IN 718) remain a major concern in regards to processing times and economic feasibility. Moreover, processing conditions need to be chosen carefully or else material defects can be systematically formed either at the interface separating two adjacent clad layers, at the bonding zone or within the bulk of the layer. In this respect, the effects of powder humidity, laser power, nominal powder particle size, powder morphology and shielding gas flow rate on the porosity in laser deposited single tracks at an increased deposition-rate of approx. 2 kg/h was investigated through experiments. Based on experimental results, several approaches of reducing porosity in high deposition-rate LMD are proposed in this paper.

  4. Matrix shaped pulsed laser deposition: New approach to large area and homogeneous deposition

    Pulsed laser deposition (PLD) is one of the well-established physical vapor deposition methods used for synthesis of ultra-thin layers. Especially PLD is suitable for the preparation of thin films of complex alloys and ceramics where the conservation of the stoichiometry is critical. Beside several advantages of PLD, inhomogeneity in thickness limits use of PLD in some applications. There are several approaches such as rotation of the substrate or scanning of the laser beam over the target to achieve homogenous layers. On the other hand movement and transition create further complexity in process parameters. Here we present a new approach which we call Matrix Shaped PLD to control the thickness and homogeneity of deposited layers precisely. This new approach is based on shaping of the incoming laser beam by a microlens array and a Fourier lens. The beam is split into much smaller multi-beam array over the target and this leads to a homogenous plasma formation. The uniform intensity distribution over the target yields a very uniform deposit on the substrate. This approach is used to deposit carbide and oxide thin films for biomedical applications. As a case study coating of a stent which has a complex geometry is presented briefly.

  5. Matrix shaped pulsed laser deposition: New approach to large area and homogeneous deposition

    Akkan, C.K.; May, A. [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany); Hammadeh, M. [Department for Obstetrics, Gynecology and Reproductive Medicine, IVF Laboratory, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Abdul-Khaliq, H. [Clinic for Pediatric Cardiology, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Aktas, O.C., E-mail: cenk.aktas@inm-gmbh.de [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany)

    2014-05-01

    Pulsed laser deposition (PLD) is one of the well-established physical vapor deposition methods used for synthesis of ultra-thin layers. Especially PLD is suitable for the preparation of thin films of complex alloys and ceramics where the conservation of the stoichiometry is critical. Beside several advantages of PLD, inhomogeneity in thickness limits use of PLD in some applications. There are several approaches such as rotation of the substrate or scanning of the laser beam over the target to achieve homogenous layers. On the other hand movement and transition create further complexity in process parameters. Here we present a new approach which we call Matrix Shaped PLD to control the thickness and homogeneity of deposited layers precisely. This new approach is based on shaping of the incoming laser beam by a microlens array and a Fourier lens. The beam is split into much smaller multi-beam array over the target and this leads to a homogenous plasma formation. The uniform intensity distribution over the target yields a very uniform deposit on the substrate. This approach is used to deposit carbide and oxide thin films for biomedical applications. As a case study coating of a stent which has a complex geometry is presented briefly.

  6. Initial deposition of calcium phosphate ceramic on polystyrene and polytetrafluoroethylene by rf magnetron sputtering deposition

    Calcium phosphate (CaP) coatings can be applied to improve the biological performance of polymeric medical implants. A strong interfacial bond between ceramic and polymer is required for clinical applications. Because the chemical structure of an interface plays an important role in the adhesion of a coating, we studied the formation of the interface between CaP and polystyrene (PS) and polytetrafluoroethylene (PTFE). The coating was deposited in a radio frequency (rf) magnetron sputtering deposition system. Prior to the deposition, some samples received an oxygen plasma pretreatment. We found that the two substrates show a strongly different reactivity towards CaP. On PS a phosphorus and oxygen enrichment is present at the interface. This is understood from POx complexes that are able to bind to the PS. The effects of the plasma pretreatment are overruled by the deposition process itself. On PTFE, a calcium enrichment and an absence of phosphorus is found at the interface. The former is the result of CaF2-like material being formed at the interface. The latter may be the result of phosphorus reacting with escaping fluorine to a PF3 molecule, which than escapes from the material as a gas molecule. We found that the final structure of the interface is mostly controlled by the bombardment of energetic particles escaping either from the plasma or from the sputtering target. The work described here can be used to understand and improve the adhesion of CaP coatings deposited on medical substrates

  7. Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

    The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10−1 to 104 Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 1019 to 1013 cm−3 and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm2/V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 1019 to 1013 cm−3. • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied

  8. Effects of Ar plasma treatment for deposition of ruthenium film by remote plasma atomic layer deposition

    Ruthenium thin films were deposited on argon plasma-treated SiO2 and untreated SiO2 substrates by remote plasma atomic layer deposition using bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a Ru precursor and ammonia plasma as a reactant. The results of in situ Auger electron spectroscopy (AES) analysis indicate that the initial transient region of Ru deposition was decreased by Ar plasma treatment at 400 deg. C, but did not change significantly at 300 deg. C The deposition rate exhibited linearity after continuous film formation and the deposition rates were about 1.7 A/cycle and 0.4 A/cycle at 400 deg. C and 300 deg. C, respectively. Changes of surface energy and polar and dispersive components were measured by the sessile drop test. The quantity of surface amine groups was measured from the surface nitrogen concentration with AES. Furthermore, the Ar plasma-treated SiO2 contained more amine groups and less hydroxyl groups on the surface than on untreated SiO2. Auger spectra exhibited chemical shifts by Ru-O bonding, and larger shifts were observed on untreated substrates due to the strong adhesion of Ru films.

  9. Selective deposition contact patterning using atomic layer deposition for the fabrication of crystalline silicon solar cells

    Selective deposition contact (SDC) patterning was applied to fabricate the rear side passivation of crystalline silicon (Si) solar cells. By this method, using screen printing for contact patterning and atomic layer deposition for the passivation of Si solar cells with Al2O3, we produced local contacts without photolithography or any laser-based processes. Passivated emitter and rear-contact solar cells passivated with ozone-based Al2O3 showed, for the SDC process, an up-to-0.7% absolute conversion-efficiency improvement. The results of this experiment indicate that the proposed method is feasible for conversion-efficiency improvement of industrial crystalline Si solar cells. - Highlights: • We propose a local contact formation process. • Local contact forms a screen print and an atomic layer deposited-Al2O3 film. • Ozone-based Al2O3 thin film was selectively deposited onto patterned silicon. • Selective deposition contact patterning method can increase cell-efficiency by 0.7%

  10. Characterisation of TiO 2 deposited by photo-induced chemical vapour deposition

    Kaliwoh, Never; Zhang, Jun-Ying; Boyd, Ian W.

    2002-01-01

    We report the deposition of thin TiO 2 films on crystalline Si and quartz by photo-induced chemical vapour deposition (CVD) using UV excimer lamps employing a dielectric barrier discharge in krypton chloride (KrCl ∗) to provide intense narrow band radiation at λ=222 nm. The precursor used was titanium isopropoxide (TTIP). Films from around 20-510 nm in thickness with refractive indices from 2.20 to 2.54 were grown at temperatures between 50 and 350 °C. The higher refractive index values compare favourably with the value of 2.58 recorded for the bulk material. The measured deposition rate was around 50 nm/min at 350 °C. Fourier transform infrared spectroscopy (FTIR) revealed the presence of TiO 2 through the observation of a Ti-O absorption peak and the absence of OH in films deposited at 250-350 °C indicated relatively good quality films. The phase of films deposited at 200-350 °C was anatase as determined by X-ray diffraction.

  11. A new pulsed laser deposition technique: scanning multi-component pulsed laser deposition method.

    Fischer, D; de la Fuente, G F; Jansen, M

    2012-04-01

    The scanning multi-component pulsed laser deposition (PLD) method realizes uniform depositions of desired coatings by a modified pulsed laser deposition process, preferably with a femto-second laser-system. Multi-component coatings (single or multilayered) are thus deposited onto substrates via laser induced ablation of segmented targets. This is achieved via horizontal line-scanning of a focused laser beam over a uniformly moving target's surface. This process allows to deposit the desired composition of the coating simultaneously, starting from the different segments of the target and adjusting the scan line as a function of target geometry. The sequence and thickness of multilayers can easily be adjusted by target architecture and motion, enabling inter/intra layer concentration gradients and thus functional gradient coatings. This new, simple PLD method enables the achievement of uniform, large-area coatings. Case studies were performed with segmented targets containing aluminum, titanium, and niobium. Under the laser irradiation conditions applied, all three metals were uniformly ablated. The elemental composition within the rough coatings obtained was fixed by the scanned area to Ti-Al-Nb = 1:1:1. Crystalline aluminum, titanium, and niobium were found to coexist side by side at room temperature within the substrate, without alloy formation up to 600 °C. PMID:22559543

  12. Estimated variability of National Atmospheric Deposition Program/Mercury Deposition Network measurements using collocated samplers

    Wetherbee, G.A.; Gay, D.A.; Brunette, R.C.; Sweet, C.W.

    2007-01-01

    The National Atmospheric Deposition Program/Mercury Deposition Network (MDN) provides long-term, quality-assured records of mercury in wet deposition in the USA and Canada. Interpretation of spatial and temporal trends in the MDN data requires quantification of the variability of the MDN measurements. Variability is quantified for MDN data from collocated samplers at MDN sites in two states, one in Illinois and one in Washington. Median absolute differences in the collocated sampler data for total mercury concentration are approximately 11% of the median mercury concentration for all valid 1999-2004 MDN data. Median absolute differences are between 3.0% and 14% of the median MDN value for collector catch (sample volume) and between 6.0% and 15% of the median MDN value for mercury wet deposition. The overall measurement errors are sufficiently low to resolve between NADP/MDN measurements by ??2 ng??l-1 and ??2 ????m-2?? year-1, which are the contour intervals used to display the data on NADP isopleths maps for concentration and deposition, respectively. ?? Springer Science+Business Media B.V. 2007.

  13. Differences in the deposition of radionuclides to leafy vegetables

    To quantify the variability in deposition to several species, the dry deposition of gaseous elemental radio-iodine and particulate radio-caesium on mature leafy vegetables was studied inside a deposition chamber by comparative experiments. The simultaneous exposition of endive, head lettuce, red oak leaf lettuce, curly kale, white cabbage and spinach was performed under homogeneous and controlled conditions (131 vertical stroke 2-portion, particle median, stomata opening, air humidity and temperature). Significant differences were observed for the 131 vertical stroke deposition on spring vegetables: the deposition on spinach was roughly 3times that on leaf lettuce, 4times that on endive and 9times that on head lettuce. For 134Cs, there was no significant difference between spinach and leaf lettuce, about twice the amount was deposited on both species as on endive and 3times as on head lettuce. All summer vegetables showed differences in deposition. For Iodine, the deposition on spinach was roughly 3times (6times) that on curly kale and 35times (100times) that on white cabbage in the 2 experiments. For Caesium, the deposition to curly kale was highest, about twice that on spinach and 35times (80times) that on white cabbage. The deposition was always the lowest on the closed heads of white cabbage and head lettuce. The many open stomata of spinach increased the efficiency of gaseous deposition. In addition, rough and crimpy leafs increased the particle deposition efficiency. The estimation of the deposition velocity showed that dry deposition was in average about 8times higher for 131 vertical stroke than for 134Cs. The influence of the particle size on the deposition velocity was small in the considered size range. Washing could reduce the contamination by about 10% for 131 vertical stroke and 45% for 134Cs. (orig.)

  14. Atmospheric Sulfur Deposition on Farmland in East China

    WANG Ti-Jian; YANG Hao-Ming; GAO Li-Jie; ZHANG Yan; HU Zheng-Yi; XU Cheng-Kai

    2005-01-01

    Atmospheric sulfur deposition onto typical farmland in East China was investigated using both field measurements and numerical modeling. The field measurements were conducted at the Experiment Station of Red Soil Ecology, Chinese Academy of Sciences, 10 km from Yingtan, Jiangxi Province, East China, between November 1998 and October 1999, and at the Changshu Ecological Experiment Station, Chinese Academy of Sciences, in a rapidly developing region of Jiangsu Province, East China, between April 2001 and March 2002. The regional acid deposition model system (RegADMS), in which the dry deposition velocities of SO2 and sulfate aerosols (SO42-) were estimated using a big-leaf resistance analogy model, was applied to simulate air sulfur deposition over East China and sulfur deposition onto lands of different use types in East China. The wet scavenging coefficients were parameterized in terms of precipitation rate, and the effect of sub-grid processes due to inhomogeneous land use on dry deposition velocity was also included. Results of the field measurements showed that over 83% of the total sulfur deposition at the Yingtan site was dry deposition, while at the Changshu site42% was dry deposition. The total sulfur deposition was much larger at the Yingtan site than at the Changshu site, which suggested contrasting air pollution and meteorological situations. The modeling results revealed that the total annual sulfur deposition over East China was 1.88 Mt, of which 72.8% was deposited onto farmland, and dry deposition accounted for 43% of the total sulfur deposited. The modeling results were generally in agreement with those from the observations.Overall, this study suggested that atmospheric sulfur deposition played an important role in the soil sulfur balance, which could have a significant effect on agricultural ecosystems in the study region.

  15. Hybrid inorganic–organic superlattice structures with atomic layer deposition/molecular layer deposition

    Tynell, Tommi; Yamauchi, Hisao; Karppinen, Maarit, E-mail: maarit.karppinen@aalto.fi [Department of Chemistry, Aalto University, FI-00076 Aalto (Finland)

    2014-01-15

    A combination of the atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques is successfully employed to fabricate thin films incorporating superlattice structures that consist of single layers of organic molecules between thicker layers of ZnO. Diethyl zinc and water are used as precursors for the deposition of ZnO by ALD, while three different organic precursors are investigated for the MLD part: hydroquinone, 4-aminophenol and 4,4′-oxydianiline. The successful superlattice formation with all the organic precursors is verified through x-ray reflectivity studies. The effects of the interspersed organic layers/superlattice structure on the electrical and thermoelectric properties of ZnO are investigated through resistivity and Seebeck coefficient measurements at room temperature. The results suggest an increase in carrier concentration for small concentrations of organic layers, while higher concentrations seem to lead to rather large reductions in carrier concentration.

  16. Hybrid inorganic–organic superlattice structures with atomic layer deposition/molecular layer deposition

    A combination of the atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques is successfully employed to fabricate thin films incorporating superlattice structures that consist of single layers of organic molecules between thicker layers of ZnO. Diethyl zinc and water are used as precursors for the deposition of ZnO by ALD, while three different organic precursors are investigated for the MLD part: hydroquinone, 4-aminophenol and 4,4′-oxydianiline. The successful superlattice formation with all the organic precursors is verified through x-ray reflectivity studies. The effects of the interspersed organic layers/superlattice structure on the electrical and thermoelectric properties of ZnO are investigated through resistivity and Seebeck coefficient measurements at room temperature. The results suggest an increase in carrier concentration for small concentrations of organic layers, while higher concentrations seem to lead to rather large reductions in carrier concentration

  17. Deposition of indium tin oxide by atmospheric pressure chemical vapour deposition

    We report the deposition of indium tin oxide (ITO) by atmospheric pressure chemical vapour deposition (APCVD). This process is potentially scalable for high throughput, large area production. We utilised a previously unreported precursor combination; dimethylindium acetylacetonate, [Me2In(acac)] and monobutyltintrichloride, MBTC. [Me2In(acac)] is a volatile solid. It is more stable and easier to handle than traditional indium oxide precursors such as pyrophoric trialkylindium compounds. Monobutyltintrichloride (MBTC) is also easily handled and can be readily vaporised. It is compatible with the process conditions required for using [Me2In(acac)]. Cubic ITO was deposited at a substrate temperature of 550 °C with growth rates exceeding 15 nm/s and growth efficiencies of between 20 and 30%. Resistivity was 3.5 × 10−4 Ω cm and transmission for a 200 nm film was > 85% with less than 2% haze.

  18. Deposition of fluorine doped indium oxide by atmospheric pressure chemical vapour deposition

    We report the deposition of fluorine doped indium oxide by atmospheric pressure chemical vapour deposition (APCVD) using a previously unreported precursor combination; dimethylindium acetylacetonate, [Me2In(acac)] and trifluoroacetic acid (TFA). This process is potentially scalable for high throughput, large area production. [Me2In(acac)] is a volatile solid. It is more stable and easier to handle than traditional indium oxide precursors such as pyrophoric trialkylindium compounds. Cubic fluorine doped indium oxide (F.In2O3) was deposited at a substrate temperature of 550 °C with growth rates exceeding 8 nm/s. Resistivity was 8 × 10−4 Ω cm and transmission for a 200 nm film was > 80% with less than 1% haze.

  19. The power source effect on SiOx coating deposition by plasma enhanced chemical vapor deposition

    SiOx coatings were prepared by capacitively coupled plasma enhanced chemical vapor deposition on polyethyleneterephtalate substrates in 23 kHz middle-frequency and radio frequency power supplies, respectively, where hexamethyldisiloxane was used as gas source. The influences of discharge conditions on gas phase intermediate species and active radicals for SiOx formation was investigated by mass spectrometry as real-time in-situ diagnosis. The deposited SiOx coating chemical structures were also analyzed by Fourier transform infrared spectroscopy. Meanwhile, the film barrier property, oxygen transmission rate, was measured at 23 oC and 50% humidity circumstance. The better barrier property was obtained in the MF power source depositing SiOx coated PET.

  20. ZnS thin film deposited with chemical bath deposition process directed by different stirring speeds

    In this combined film thickness, scanning electron microscopy (SEM), X-ray diffraction and optical properties study, we explore the effects of different stirring speeds on the growth and optical properties of ZnS film deposited by CBD method. From the disclosed changes of thickness of ZnS film, we conclude that film thickness is independent of the stirring speeds in the heterogeneous process (deposition time less than 40 min), but increases with the stirring speeds and/or deposition time increasing in the homogeneous process. Grazing incident X-ray diffraction (GIXRD) and the study of optical properties disclosed that the ZnS films grown with different stirring speeds show partially crystallized film and exhibit good transmittance (70-88% in the visible region), but the stirring speeds cannot give much effects on the structure and optical properties in the homogeneous process.