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Evaluating program integration and the rise in collaboration: case study of a palliative care network.

PubMed

Bainbridge, Daryl; Brazil, Kevin; Krueger, Paul; Ploeg, Jenny; Taniguchi, Alan; Darnay, Julie

2011-01-01

There is increasing global interest in using regional palliative care networks (PCNs) to integrate care and create systems that are more cost-effective and responsive. We examined a PCN that used a community development approach to build capacity for palliative care in each distinct community in a region of southern Ontario, Canada, with the goal of achieving a competent integrated system. Using a case study methodology, we examined a PCN at the structural level through a document review, a survey of 20 organizational administrators, and an interview with the network director. The PCN identified 14 distinct communities at different stages of development within the region. Despite the lack of some key features that would facilitate efficient palliative care delivery across these communities, administrators largely viewed the network partnership as beneficial and collaborative. The PCN has attempted to recognize specific needs in each local area. Change is gradual but participatory. There remain structural issues that may negatively affect the functioning of the PCN.
Impact of Paracoccin Gene Silencing on Paracoccidioides brasiliensis Virulence.

PubMed

Fernandes, Fabrício F; Oliveira, Aline F; Landgraf, Taise N; Cunha, Cristina; Carvalho, Agostinho; Vendruscolo, Patrícia E; Gonçales, Relber A; Almeida, Fausto; da Silva, Thiago A; Rodrigues, Fernando; Roque-Barreira, Maria Cristina

2017-07-18

Among the endemic deep mycoses in Latin America, paracoccidioidomycosis (PCM), caused by thermodimorphic fungi of the Paracoccidioides genus, is a major cause of morbidity. Disease development and its manifestations are associated with both host and fungal factors. Concerning the latter, several recent studies have employed the methodology of gene modulation in P. brasiliensis using antisense RNA (AsRNA) and Agrobacterium tumefaciens -mediated transformation (ATMT) to identify proteins that influence fungus virulence. Our previous observations suggested that paracoccin (PCN), a multidomain fungal protein with both lectin and enzymatic activities, may be a potential P. brasiliensis virulence factor. To explore this, we used AsRNA and ATMT methodology to obtain three independent PCN-silenced P. brasiliensis yeast strains (As PCN1 , As PCN2 , and As PCN3 ) and characterized them with regard to P. brasiliensis biology and pathogenicity. As PCN1 , As PCN2 , and As PCN3 showed relative PCN expression levels that were 60%, 40%, and 60% of that of the wild-type (WT) strain, respectively. PCN silencing led to the aggregation of fungal cells, blocked the morphological yeast-to-mycelium transition, and rendered the yeast less resistant to macrophage fungicidal activity. In addition, mice infected with As PCN1 , As PCN2 , and As PCN3 showed a reduction in fungal burden of approximately 96% compared with those inoculated with the WT strain, which displayed a more extensive destruction of lung tissue. Finally, mice infected with the PCN-silenced yeast strains had lower mortality than those infected with the WT strain. These data demonstrate that PCN acts as a P. brasiliensis contributory virulence factor directly affecting fungal pathogenesis. IMPORTANCE The nonexistence of efficient genetic transformation systems has hampered studies in the dimorphic fungus Paracoccidioides brasiliensis , the etiological agent of the most frequent systemic mycosis in Latin America. The recent development of a method for gene expression knockdown by antisense RNA technology, associated with an Agrobacterium tumefaciens -mediated transformation system, provides new strategies for studying P. brasiliensis Through this technology, we generated yeasts that were silenced for paracoccin (PCN), a P. brasiliensis component that has lectin and enzymatic properties. By comparing the phenotypes of PCN-silenced and wild-type strains of P. brasiliensis , we identified PCN as a virulence factor whose absence renders the yeasts unable to undergo the transition to mycelium and causes a milder pulmonary disease in mice, with a lower mortality rate. Our report highlights the importance of the technology used for P. brasiliensis transformation and demonstrates that paracoccin is a virulence factor acting on fungal biology and pathogenesis. Copyright © 2017 Fernandes et al.
A Spatial Analysis of the Potato Cyst Nematode Globodera pallida in Idaho.

PubMed

Dandurand, Louise-Marie; Contina, Jean Bertrand; Knudsen, Guy R

2018-03-13

The potato cyst nematode (PCN), Globodera pallida, is a globally regulated and quarantine potato pest. It was detected for the first time in the U.S. in the state of Idaho in 2006. A spatial analysis was performed to: (i) understand the spatial arrangement of PCN infested fields in southern Idaho using spatial point pattern analysis; and (ii) evaluate the potential threat of PCN for entry to new areas using spatial interpolation techniques. Data point locations, cyst numbers and egg viability values for each infested field were collected by USDA-APHIS during 2006-2014. Results showed the presence of spatially clustered PCN infested fields (P = 0.003). We determined that the spread of PCN grew in diameter from the original center of infestation toward the southwest as an ellipsoidal-shaped cluster. Based on the aggregated spatial pattern of distribution and the low extent level of PCN infested fields in southern Idaho, we determined that PCN spread followed a contagion effect scenario, where nearby infested fields contributed to the infestation of new fields, probably through soil contaminated agricultural equipment or tubers. We determined that the recent PCN presence in southern Idaho is unlikely to be associated with new PCN entry from outside the state of Idaho. The relative aggregation of PCN infested fields, the low number of cysts recovered, and the low values in egg viability facilitate quarantine activities and confine this pest to a small area, which, in 2017, is estimated to be 1,233 hectares. The tools and methods provided in this study should facilitate comprehensive approaches to improve PCN control and eradication programs as well as to raise public awareness about this economically important potato pest.
Effect of a drug allergy educational program and antibiotic prescribing guideline on inpatient clinical providers' antibiotic prescribing knowledge.

PubMed

Blumenthal, Kimberly G; Shenoy, Erica S; Hurwitz, Shelley; Varughese, Christy A; Hooper, David C; Banerji, Aleena

2014-01-01

Inpatient providers have varying levels of knowledge in managing patients with drug and/or penicillin (PCN) allergy. Our objectives were (1) to survey inpatient providers to ascertain their baseline drug allergy knowledge and preparedness in caring for patients with PCN allergy, and (2) to assess the impact of an educational program paired with the implementation of a hospital-based clinical guideline. We electronically surveyed 521 inpatient providers at a tertiary care medical center at baseline and again 6 weeks after an educational initiative paired with clinical guideline implementation. The guideline informed providers on drug allergy history taking and antibiotic prescribing for inpatients with PCN or cephalosporin allergy. Of 323 unique responders, 42% (95% CI, 37-48%) reported no prior education in drug allergy. When considering those who responded to both surveys (n = 213), we observed a significant increase in knowledge about PCN skin testing (35% vs 54%; P < .001) and loss of PCN allergy over time (54% vs 80%; P < .0001). Among those who reported attending an educational session (n = 62), preparedness to determine if an allergy was severe significantly improved (77% vs 92%; P = .03). Other areas, including understanding absolute contraindications to receiving a drug again and PCN cross-reactivity with other antimicrobials, did not improve significantly. Inpatient providers have drug allergy knowledge deficits but are interested in tools to help them care for inpatients with drug allergies. Our educational initiative and hospital guideline implementation were associated with increased PCN allergy knowledge in several crucial areas. To improve care of inpatients with drug allergy, more research is needed to evaluate hospital policies and sustainable educational tools. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
iTRAQ-based quantitative proteomic analysis reveals potential factors associated with the enhancement of phenazine-1-carboxamide production in Pseudomonas chlororaphis P3

PubMed Central

Jin, Xue-Jie; Peng, Hua-Song; Hu, Hong-Bo; Huang, Xian-Qing; Wang, Wei; Zhang, Xue-Hong

2016-01-01

Phenazine-1-carboxamide (PCN), a phenazine derivative, is strongly antagonistic to fungal phytopathogens. Pseudomonas chlororaphis HT66 is a PCN-producing, non-pathogenic biocontrol strain, and we obtained the mutant P. chlororaphis P3, which produces 4.7 times more PCN than the wild-type HT66 strain. To reveal the cause of PCN production enhancement in P3 and find potential factors related to PCN biosynthesis, an iTRAQ-based quantitative proteomic analysis was used to study the expression changes between the two strains. Of the 452 differentially expressed proteins, most were functionally mapped into PCN biosynthesis pathway or other related metabolisms. The upregulation of proteins, including PhzA/B, PhzD, PhzF, PhzG, and PhzH, involved in PCN biosynthesis was in agreement with the efficient production of PCN in P3. A number of proteins that function primarily in energy production, amino acid metabolism, and secondary metabolism played important roles in PCN biosynthesis. Notably, proteins involved in the uptake and conversion of phosphate, inorganic nitrogen sources, and iron improved the PCN production. Furthermore, the type VI secretion system may participate in the secretion or/and indirect biosynthetic regulation of PCN in P. chlororaphis. This study provides valuable clues to better understand the biosynthesis, excretion and regulation of PCN in Pseudomonas and also provides potential gene targets for further engineering high-yield strains. PMID:27273243
Tuning the Formations of Metal-Organic Frameworks by Modification of Ratio of Reactant, Acidity of Reaction System, and Use of a Secondary Ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Q; Xie, YB; Li, JR

2012-01-01

Four porous coordination networks (PCNs), {[Zn3O(H2O)(3)(adc)(3)]center dot 2(C2H6NH2)center dot 2(DMF)center dot 3(H2O)}(n) (PCN-131), Zn-2(DMA)(2)(adc)(2)]center dot 2(DMA)}(n) (PCN-132), {[Zn3O(DMF)(adc)(3)(4,4'-bpy)]center dot 2(C2H6NH2)center dot S}(n) (PCN-131'), and {[Zn(adc)(4,4'-bpy)(0.5)]center dot S}(n) (PCN-132'), have been synthesized by the assembly of anthrancene-9,10-dicarboxylic acid (H(2)adc) with Zn(II) under different reaction conditions, including modifications of reactant ratio, acidity variations, and the use of a secondary ligand. Single-crystal X-ray diffraction studies reveal that PCN-131, obtained from the dimethylformamide (DMF) solution under acid condition, has a three-dimentional (3D) framework structure with one-dimensional (1D) honeycomb channels. PCN-132 isolated from dimethylacetamide (DMA) solution without adding acid in synthesis is a two-dimensional (2D)more » layer compound. By employing 4,4'-bipyridyl (4,4'-bpy) as a secondary ligand, PCN-131' and PCN-132' were synchronously synthesized as a mixture outcome with more PCN-131' than PCN-132'. In PCN-131', 4,4'-bpy acting as a secondary ligand is arranged inside the honeycomb channel of the 3D PCN-131, resulting in an effective improvement of thermal stability of the network, while in PCN-132', 4,4'-bpy ligands link 2D layers of PCN-132 to form a pillared-layer 3D framework Gas adsorption has been performed for selected materials. The results show that the framework of PCN-131 is thermally unstable after removing the solvent molecules coordinated to their metal sites. While PCN-131' is stable for gas uptake, with an evaluated Langmuir surface area of 199.04 m(2) g(-1), it shows a selective adsorption of CO2 over CH4.« less
Copy number variability of expression plasmids determined by cell sorting and Droplet Digital PCR.

PubMed

Jahn, Michael; Vorpahl, Carsten; Hübschmann, Thomas; Harms, Hauke; Müller, Susann

2016-12-19

Plasmids are widely used for molecular cloning or production of proteins in laboratory and industrial settings. Constant modification has brought forth countless plasmid vectors whose characteristics in terms of average plasmid copy number (PCN) and stability are rarely known. The crucial factor determining the PCN is the replication system; most replication systems in use today belong to a small number of different classes and are available through repositories like the Standard European Vector Architecture (SEVA). In this study, the PCN was determined in a set of seven SEVA-based expression plasmids only differing in the replication system. The average PCN for all constructs was determined by Droplet Digital PCR and ranged between 2 and 40 per chromosome in the host organism Escherichia coli. Furthermore, a plasmid-encoded EGFP reporter protein served as a means to assess variability in reporter gene expression on the single cell level. Only cells with one type of plasmid (RSF1010 replication system) showed a high degree of heterogeneity with a clear bimodal distribution of EGFP intensity while the others showed a normal distribution. The heterogeneous RSF1010-carrying cell population and one normally distributed population (ColE1 replication system) were further analyzed by sorting cells of sub-populations selected according to EGFP intensity. For both plasmids, low and highly fluorescent sub-populations showed a remarkable difference in PCN, ranging from 9.2 to 123.4 for ColE1 and from 0.5 to 11.8 for RSF1010, respectively. The average PCN determined here for a set of standardized plasmids was generally at the lower end of previously reported ranges and not related to the degree of heterogeneity. Further characterization of a heterogeneous and a homogeneous population demonstrated considerable differences in the PCN of sub-populations. We therefore present direct molecular evidence that the average PCN does not represent the true number of plasmid molecules in individual cells.
Use of chronic disease management programs for diabetes: in Alberta's primary care networks.

PubMed

Campbell, David J T; Sargious, Peter; Lewanczuk, Richard; McBrien, Kerry; Tonelli, Marcello; Hemmelgarn, Brenda; Manns, Braden

2013-02-01

To determine the types of chronic disease management (CDM) programs offered for patients with diabetes in Alberta's primary care networks (PCNs). A survey was administered to PCNs to determine the types of CDM programs offered for patients with diabetes; CDM programs were organized into categories by their resource intensity and effectiveness. Results of the survey were reported using frequencies and percentages. Alberta has recently created PCNs-groups of family physicians who receive additional funds to enable them to support activities that fall outside the typical physician-based fee-for-service model, but which address specified objectives including CDM. It is currently unknown what additional programs are being provided through the PCN supplemental funding. A survey was administered to the individual responsible for CDM in each PCN. This included executive directors, chronic disease managers, and CDM nurses. We determined the CDM strategies used in each PCN to care for patients with diabetes, whether they were available to all patients, and whether the services were provided exclusively by the PCN or in conjunction with other agencies. There was considerable variation across PCNs with respect to the CDM programs offered for people with diabetes. Nearly all PCNs used multidisciplinary teams (which could include nurses, dietitians, and pharmacists) and patient education. Fewer than half of the PCNs permitted personnel other than the primary physician to write or alter prescriptions for medications. Alberta's PCNs have successfully established many different types of CDM programs. Multidisciplinary care teams, which are among the most effective CDM strategies, are currently being used by most of Alberta's PCNs.
Use of chronic disease management programs for diabetes

PubMed Central

Campbell, David J.T.; Sargious, Peter; Lewanczuk, Richard; McBrien, Kerry; Tonelli, Marcello; Hemmelgarn, Brenda; Manns, Braden

2013-01-01

Objective To determine the types of chronic disease management (CDM) programs offered for patients with diabetes in Alberta's primary care networks (PCNs). Design A survey was administered to PCNs to determine the types of CDM programs offered for patients with diabetes; CDM programs were organized into categories by their resource intensity and effectiveness. Results of the survey were reported using frequencies and percentages. Setting Alberta has recently created PCNs—groups of family physicians who receive additional funds to enable them to support activities that fall outside the typical physician-based fee-for-service model, but which address specified objectives including CDM. It is currently unknown what additional programs are being provided through the PCN supplemental funding. Participants A survey was administered to the individual responsible for CDM in each PCN. This included executive directors, chronic disease managers, and CDM nurses. Main outcome measures We determined the CDM strategies used in each PCN to care for patients with diabetes, whether they were available to all patients, and whether the services were provided exclusively by the PCN or in conjunction with other agencies. Results There was considerable variation across PCNs with respect to the CDM programs offered for people with diabetes. Nearly all PCNs used multidisciplinary teams (which could include nurses, dietitians, and pharmacists) and patient education. Fewer than half of the PCNs permitted personnel other than the primary physician to write or alter prescriptions for medications. Conclusion Alberta's PCNs have successfully established many different types of CDM programs. Multidisciplinary care teams, which are among the most effective CDM strategies, are currently being used by most of Alberta's PCNs. PMID:23418263
Cell cycle accumulation of the proliferating cell nuclear antigen PCN-1 transitions from continuous in the adult germline to intermittent in the early embryo of C. elegans.

PubMed

Kocsisova, Zuzana; Kornfeld, Kerry; Schedl, Tim

2018-05-30

The proliferating cell nuclear antigen (PCNA or PCN-1 in C. elegans), an essential processivity factor for DNA polymerase δ, has been widely used as a marker of S-phase. In C. elegans early embryos, PCN-1 accumulation is cyclic, localizing to the nucleus during S-phase and the cytoplasm during the rest of the cell cycle. The C. elegans larval and adult germline is an important model systems for studying cell cycle regulation, and it was observed that the cell cycle regulator cyclin E (CYE-1 in C. elegans) displays a non-cyclic, continuous accumulation pattern in this tissue. The accumulation pattern of PCN-1 has not been well defined in the larval and adult germline, and the objective of this study was to determine if the accumulation pattern is cyclic, as in other cells and organisms, or continuous, similar to cyclin E. To study the larval and adult germline accumulation of PCN-1 expressed from its native locus, we used CRISPR/Cas9 technology to engineer a novel allele of pcn-1 that encodes an epitope-tagged protein. S-phase nuclei were labeled using EdU nucleotide incorporation, and FLAG::PCN-1 was detected by antibody staining. All progenitor zone nuclei, including those that were not in S-phase (as they were negative for EdU staining) showed PCN-1 accumulation, indicating that PCN-1 accumulated during all cell cycle phases in the germline progenitor zone. The same result was observed with a GFP::PCN-1 fusion protein expressed from a transgene. pcn-1 loss-of-function mutations were analyzed, and pcn-1 was necessary for robust fertility and embryonic development. In the C. elegans early embryo as well as other organisms, PCN-1 accumulates in nuclei only during S-phase. By contrast, in the progenitor zone of the germline of C. elegans, PCN-1 accumulated in nuclei during all cell cycle stages. This pattern is similar to accumulation pattern of cyclin E. These observations support the model that mitotic cell cycle regulation in the germline stem and progenitor cells is distinct from somatic cells, as it does not heavily rely on cyclic accumulation of classic cell cycle proteins.
Engineering and systems-level analysis of Pseudomonas chlororaphis for production of phenazine-1-carboxamide using glycerol as the cost-effective carbon source.

PubMed

Yao, Ruilian; Pan, Keli; Peng, Huasong; Feng, Lei; Hu, Hongbo; Zhang, Xuehong

2018-01-01

Glycerol, an inevitable byproduct of biodiesel, has become an attractive feedstock for the production of value-added chemicals due to its availability and low price. Pseudomonas chlororaphis HT66 can use glycerol to synthesize phenazine-1-carboxamide (PCN), a phenazine derivative, which is strongly antagonistic to fungal phytopathogens. A systematic understanding of underlying mechanisms for the PCN overproduction will be important for the further improvement and industrialization. We constructed a PCN-overproducing strain (HT66LSP) through knocking out three negative regulatory genes, lon , parS , and prsA in HT66. The strain HT66LSP produced 4.10 g/L of PCN with a yield of 0.23 (g/g) from glycerol, which was of the highest titer and the yield obtained among PCN-producing strains. We studied gene expression, metabolomics, and dynamic 13 C tracer in HT66 and HT66LSP. In response to the phenotype changes, the transcript levels of phz biosynthetic genes, which are responsible for PCN biosynthesis, were all upregulated in HT66LSP. Central carbon was rerouted to the shikimate pathway, which was shown by the modulation of specific genes involved in the lower glycolysis, the TCA cycle, and the shikimate pathway, as well as changes in abundances of intracellular metabolites and flux distribution to increase the precursor availability for PCN biosynthesis. Moreover, dynamic 13 C-labeling experiments revealed that the presence of metabolite channeling of 3-phosphoglyceric acid to phosphoenolpyruvate and shikimate to trans-2,3-dihydro-3-hydroxyanthranilic acid in HT66LSP could enable high-yielding synthesis of PCN. The integrated analysis of gene expression, metabolomics, and dynamic 13 C tracer enabled us to gain a more in-depth insight into complex mechanisms for the PCN overproduction. This study provides important basis for further engineering P . chlororaphis for high PCN production and efficient glycerol conversion.
High-throughput diagnosis of potato cyst nematodes in soil samples.

PubMed

Reid, Alex; Evans, Fiona; Mulholland, Vincent; Cole, Yvonne; Pickup, Jon

2015-01-01

Potato cyst nematode (PCN) is a damaging soilborne pest of potatoes which can cause major crop losses. In 2010, a new European Union directive (2007/33/EC) on the control of PCN came into force. Under the new directive, seed potatoes can only be planted on land which has been found to be free from PCN infestation following an official soil test. A major consequence of the new directive was the introduction of a new harmonized soil sampling rate resulting in a threefold increase in the number of samples requiring testing. To manage this increase with the same staffing resources, we have replaced the traditional diagnostic methods. A system has been developed for the processing of soil samples, extraction of DNA from float material, and detection of PCN by high-throughput real-time PCR. Approximately 17,000 samples are analyzed each year using this method. This chapter describes the high-throughput processes for the production of float material from soil samples, DNA extraction from the entire float, and subsequent detection and identification of PCN within these samples.
Attenuation of the Atmospheric Migration Ability of Polychlorinated Naphthalenes (PCN-2) Based on Three-dimensional QSAR Models with Full Factor Experimental Design.

PubMed

Gu, Wenwen; Chen, Ying; Li, Yu

2017-08-01

Based on the experimental subcooled liquid vapor pressures (P L ) of 17 polychlorinated naphthalene (PCN) congeners, one type of three-dimensional quantitative structure-activity relationship (3D-QSAR) models, comparative molecular similarity indices analysis (CoMSIA), was constructed with Sybyl software. Full factor experimental design was used to obtain the final regulation scheme for PCN, and then carry out modification of PCN-2 to significantly lower its P L . The contour maps of CoMSIA model showed that the migration ability of PCN decreases when the Cl atoms at the 2-, 3-, 4-, 5-, 6-, 7- and 8-positions of PCNs are replaced by electropositive groups. After modification of PCN-2, 12 types of new modified PCN-2 compounds were obtained with lnP L values two orders of magnitude lower than that of PCN-2. In addition, there are significant differences between the calculated total energies and energy gaps of the new modified compounds and those of PCN-2.
A porphyrin-based metal–organic framework as a pH-responsive drug carrier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Wenxin; Hu, Quan; Jiang, Ke

A low cytotoxic porphyrin-based metal–organic framework (MOF) PCN-221, which exhibited high PC12 cell viability via 3-(4,5-dimethylthiazol-2-yl)−2,5-diphenyl tetrazolium (MTT) assay, was selected as an oral drug carrier. Methotrexate (MTX) was chosen as the model drug molecule which was absorbed into inner pores and channels of MOFs by diffusion. PCN-221 showed high drug loading and sustained release behavior under physiological environment without “burst effect”. The controlled pH-responsive release of drugs by PCN-221 revealed its promising application in oral drug delivery. - Graphical abstract: The porous crystals PCN-221 with pore openings (MOF) PCN-221 was prepared exhibiting low cytotoxicity. PCN-221 showed high drug Methotrexatemore » loading and controlled pH-responsive release of Methotrexate. - Highlights: • A porphyrin-based metal–organic framework (MOF) PCN-221 was prepared showing low cytotoxicity. • PCN-221 showed high drug Methotrexate loading. • PCN-221 showed controlled pH-responsive release of Methotrexate.« less
Control Effect and Possible Mechanism of the Natural Compound Phenazine-1-Carboxamide against Botrytis cinerea

PubMed Central

Su, Pin; Liao, Xiaolan

2015-01-01

To develop new agents against strawberry grey mould and to aid in the development of biological pesticides, we investigated the inhibitory effect of a natural compound, phenazine-1-carboxamide (PCN), against Botrytis cinerea using a growth rate assay. Additionally, indoor toxicity and the in vitro control effect of PCN were further studied to determine its potential mechanisms of action on B. cinerea. PCN was inhibitory against B. cinerea with a 50% effective concentration (EC50) of 108.12 μg/mL; the toxicity of PCN was equivalent to that of carbendazim (CBM). The best in vitro control effect of PCN against grey mould in strawberry (fruit) reached 75.32%, which was slightly higher than that of CBM. The field control effect of PCN against grey mould reached a maximum of 72.31% at a PCN concentration of 700 μg/mL, which was 1.02 times higher than that of CBM. Fungistatic activity was observed at low concentrations of PCN, while high concentrations of PCN resulted in fungicidal activity against B. cinerea. This natural compound strongly inhibited both spore and sclerotium germination of B. cinerea, with the best relative inhibition rates of 77.03% and 82.11%, respectively. The inhibitory effect of PCN on mycelial growth of B. cinerea was significant and reached levels of 87.32%. Scanning electron microscopy observations revealed that after 48 h of PCN treatment, the mycelia appeared loose, locally twisted, and folded, with exudation of contents; the mycelia was withered and twisted, with edge burrs, deformations, ruptures and a sheet-like structure. Transmission electron microscopy observations revealed that after 48 h of PCN treatment, the structure of the cell nucleus was unclear and the vacuoles had ruptured; additionally, various organelles exhibited disordered structures, there were substantial non-membrane transparent inclusions, the cells were plasmolysed, the cell walls were collapsed in some cases, and the hyphal tissue was essentially necrotic. A PCN dosage of 35–140 μg/mL had no effect on the cell membrane permeability of the mycelia, while a PCN dosage of 700 μg/mL resulted in significant permeability. PCN inhibited B. cinerea toxin; the mycotoxin level was approximately 0.41 of the value recorded for the control at a PCN dosage of 700 μg/mL. PCN affected the activity of pectin methylgalacturonase (PMG), polygalacturonase (PG), cellulase (Cx) and β-glucosidase (BG); the lowest activities of PMG, PG, BG and Cx reached 0.3 U/mg, 0.62 U/mg, 0.64 U/mg, and 0.79 U/mg, respectively, after treatment with 700 μg/mL PCN. PMID:26460973
Final Project Report for DOE/EERE High-Capacity and Low-Cost Hydrogen-Storage Sorbents for Automotive Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Hong-Cai; Liu, Di-Jia

This report provides a review of the objectives, progress, and milestones of the research conducted during this project on the topic of developing innovative metal-organic frameworks (MOFs) and porous organic polymers (POPs) for high-capacity and low-cost hydrogen-storage sorbents in automotive applications.1 The objectives of the proposed research were to develop new materials as next-generation hydrogen storage sorbents that meet or exceed DOE’s 2017 performance targets of gravimetric capacity of 0.055 kg H 2/kg system and volumetric capacity of 0.040 kg H 2/L system at a cost of $400/kg H 2 stored. Texas A&M University (TAMU) and Argonne National Laboratory (ANL)more » collaborated in developing low-cost and high-capacity hydrogen-storage sorbents with appropriate stability, sorption kinetics, and thermal conductivity. The research scope and methods developed to achieve the project’s goals include the following: Advanced ligand design and synthesis to construct MOF sorbents with optimal hydrogen storage capacities, low cost and high stability; Substantially improve the hydrogen uptake capacity and chemical stability of MOF-based sorbents by incorporating high valent metal ions during synthesis or through the post-synthetic metal metathesis oxidation approach; Enhance sorbent storage capacity through material engineering and characterization; Generate a better understanding of the H 2-sorbent interaction through advanced characterization and simulation. Over the course of the project 5 different MOFs were developed and studied: PCN-250, PCN-12, PCN-12’, PCN-608 and PCN-609.2-3 Two different samples were submitted to the National Renewable Energy Laboratory (NREL) in order to validate their hydrogen adsorption capacity, PCN-250 and PCN-12. Neither of these samples reached the project’s Go/No-Go requirements but the data obtained did further prove the hypothesis that the presence of open metal sites oriented towards MOF pores help to surpass the predicted hydrogen uptakes described by Chahine’s rule.4 These observations are believed to have a major impact on the hydrogen storage community, and may potentially lead to the development of a material that could meet the DOE goals for hydrogen storage systems for automotive applications.« less
Usefulness of real-time three-dimensional ultrasonography in percutaneous nephrostomy: an animal study.

PubMed

Hongzhang, Hong; Xiaojuan, Qin; Shengwei, Zhang; Feixiang, Xiang; Yujie, Xu; Haibing, Xiao; Gallina, Kazobinka; Wen, Ju; Fuqing, Zeng; Xiaoping, Zhang; Mingyue, Ding; Huageng, Liang; Xuming, Zhang

2018-05-17

To evaluate the effect of real-time three-dimensional (3D) ultrasonography (US) in guiding percutaneous nephrostomy (PCN). A hydronephrosis model was devised in which the ureters of 16 beagles were obstructed. The beagles were divided equally into groups 1 and 2. In group 1, the PCN was performed using real-time 3D US guidance, while in group 2 the PCN was guided using two-dimensional (2D) US. Visualization of the needle tract, length of puncture time and number of puncture times were recorded for the two groups. In group 1, score for visualization of the needle tract, length of puncture time and number of puncture times were 3, 7.3 ± 3.1 s and one time, respectively. In group 2, the respective results were 1.4 ± 0.5, 21.4 ± 5.8 s and 2.1 ± 0.6 times. The visualization of needle tract in group 1 was superior to that in group 2, and length of puncture time and number of puncture times were both lower in group 1 than in group 2. Real-time 3D US-guided PCN is superior to 2D US-guided PCN in terms of visualization of needle tract and the targeted pelvicalyceal system, leading to quick puncture. Real-time 3D US-guided puncture of the kidney holds great promise for clinical implementation in PCN. © 2018 The Authors BJU International © 2018 BJU International Published by John Wiley & Sons Ltd.
Clinical implications of acute pelvicaliceal hematoma formation during percutaneous catheter nephrostomy insertion.

PubMed

Stewart, Jessica K; Smith, Tony P; Kim, Charles Y

To determine the clinical implications of acute pelvicaliceal hematoma formation during percutaneous catheter nephrostomy (PCN) insertion. Collecting system hematoma burden was retrospectively assessed for 694 PCN insertions in 502 patients. Pelvicaliceal hematoma formation occurred in 146 kidneys (21%) in 136 patients. Clinically significant blood loss occurred in 3 patients with hematomas within one week compared to 4 patients without hematomas (p=0.39). Twenty-four patients with hematomas underwent catheter exchange within one week, compared to 55 patients without hematomas (p=0.49). Pelvicaliceal hematoma formation after PCN insertion is not uncommon and is associated with very rare clinical sequelae. Copyright © 2017 Elsevier Inc. All rights reserved.
Comparison of Polar Cap (PC) index calculations.

NASA Astrophysics Data System (ADS)

Stauning, P.

2012-04-01

The Polar Cap (PC) index introduced by Troshichev and Andrezen (1985) is derived from polar magnetic variations and is mainly a measure of the intensity of the transpolar ionospheric currents. These currents relate to the polar cap antisunward ionospheric plasma convection driven by the dawn-dusk electric field, which in turn is generated by the interaction of the solar wind with the Earth's magnetosphere. Coefficients to calculate PCN and PCS index values from polar magnetic variations recorded at Thule and Vostok, respectively, have been derived by several different procedures in the past. The first published set of coefficients for Thule was derived by Vennerstrøm, 1991 and is still in use for calculations of PCN index values by DTU Space. Errors in the program used to calculate index values were corrected in 1999 and again in 2001. In 2005 DMI adopted a unified procedure proposed by Troshichev for calculations of the PCN index. Thus there exists 4 different series of PCN index values. Similarly, at AARI three different sets of coefficients have been used to calculate PCS indices in the past. The presentation discusses the principal differences between the various PC index procedures and provides comparisons between index values derived from the same magnetic data sets using the different procedures. Examples from published papers are examined to illustrate the differences.
Techniques for characterization and eradication of potato cyst nematode: a review.

PubMed

Bairwa, Aarti; Venkatasalam, E P; Sudha, R; Umamaheswari, R; Singh, B P

2017-09-01

Correct identification of species and pathotypes is must for eradication of potato cyst nematodes (PCN). The identification of PCN species after completing the life cycle is very difficult because it is based on morphological and morphometrical characteristics. Genetically different populations of PCN are morphologically same and differentiated based on the host differential study. Later on these traditional techniques have been replaced by biochemical techniques viz, one and two dimensional gel electrophoresis, capillary gel electrophoresis, isozymes, dot blot hybridization and isoelectric focusing etc. to distinguish both the species. One and two dimensional gel electrophoresis has used to examine inter- and intra-specific differences in proteins of Globodera rostochiensis and G. pallida . Now application of PCR and DNA based characterization techniques like RAPD, AFLP and RFLP are the important tools for differentiating inter- and intra specific variation in PCN and has given opportunities to accurate identification of PCN. For managing the PCN, till now we are following integrated pest management (IPM) strategies, however these strategies are not effective to eradicate the PCN. Therefore to eradicate the PCN we need noval management practices like RNAi (RNA interference) or Gene silencing.

POPCORN functions in the auxin pathway to regulate embryonic body plan and meristem organization in Arabidopsis.

PubMed

Xiang, Daoquan; Yang, Hui; Venglat, Prakash; Cao, Yongguo; Wen, Rui; Ren, Maozhi; Stone, Sandra; Wang, Edwin; Wang, Hong; Xiao, Wei; Weijers, Dolf; Berleth, Thomas; Laux, Thomas; Selvaraj, Gopalan; Datla, Raju

2011-12-01

The shoot and root apical meristems (SAM and RAM) formed during embryogenesis are crucial for postembryonic plant development. We report the identification of POPCORN (PCN), a gene required for embryo development and meristem organization in Arabidopsis thaliana. Map-based cloning revealed that PCN encodes a WD-40 protein expressed both during embryo development and postembryonically in the SAM and RAM. The two pcn alleles identified in this study are temperature sensitive, showing defective embryo development when grown at 22°C that is rescued when grown at 29°C. In pcn mutants, meristem-specific expression of WUSCHEL (WUS), CLAVATA3, and WUSCHEL-RELATED HOMEOBOX5 is not maintained; SHOOTMERISTEMLESS, BODENLOS (BDL) and MONOPTEROS (MP) are misexpressed. Several findings link PCN to auxin signaling and meristem function: ectopic expression of DR5(rev):green fluorescent protein (GFP), pBDL:BDL-GFP, and pMP:MP-β-glucuronidase in the meristem; altered polarity and expression of pPIN1:PIN1-GFP in the apical domain of the developing embryo; and resistance to auxin in the pcn mutants. The bdl mutation rescued embryo lethality of pcn, suggesting that improper auxin response is involved in pcn defects. Furthermore, WUS, PINFORMED1, PINOID, and TOPLESS are dosage sensitive in pcn, suggesting functional interaction. Together, our results suggest that PCN functions in the auxin pathway, integrating auxin signaling in the organization and maintenance of the SAM and RAM.
POPCORN Functions in the Auxin Pathway to Regulate Embryonic Body Plan and Meristem Organization in Arabidopsis[W][OA

PubMed Central

Xiang, Daoquan; Yang, Hui; Venglat, Prakash; Cao, Yongguo; Wen, Rui; Ren, Maozhi; Stone, Sandra; Wang, Edwin; Wang, Hong; Xiao, Wei; Weijers, Dolf; Berleth, Thomas; Laux, Thomas; Selvaraj, Gopalan; Datla, Raju

2011-01-01

The shoot and root apical meristems (SAM and RAM) formed during embryogenesis are crucial for postembryonic plant development. We report the identification of POPCORN (PCN), a gene required for embryo development and meristem organization in Arabidopsis thaliana. Map-based cloning revealed that PCN encodes a WD-40 protein expressed both during embryo development and postembryonically in the SAM and RAM. The two pcn alleles identified in this study are temperature sensitive, showing defective embryo development when grown at 22°C that is rescued when grown at 29°C. In pcn mutants, meristem-specific expression of WUSCHEL (WUS), CLAVATA3, and WUSCHEL-RELATED HOMEOBOX5 is not maintained; SHOOTMERISTEMLESS, BODENLOS (BDL) and MONOPTEROS (MP) are misexpressed. Several findings link PCN to auxin signaling and meristem function: ectopic expression of DR5rev:green fluorescent protein (GFP), pBDL:BDL-GFP, and pMP:MP-β-glucuronidase in the meristem; altered polarity and expression of pPIN1:PIN1-GFP in the apical domain of the developing embryo; and resistance to auxin in the pcn mutants. The bdl mutation rescued embryo lethality of pcn, suggesting that improper auxin response is involved in pcn defects. Furthermore, WUS, PINFORMED1, PINOID, and TOPLESS are dosage sensitive in pcn, suggesting functional interaction. Together, our results suggest that PCN functions in the auxin pathway, integrating auxin signaling in the organization and maintenance of the SAM and RAM. PMID:22158464
Determination of temperature dependent Henry's law constants of polychlorinated naphthalenes: Application to air-sea exchange in Izmir Bay, Turkey

NASA Astrophysics Data System (ADS)

Odabasi, Mustafa; Adali, Mutlu

2016-12-01

The Henry's law constant (H) is a crucial variable to investigate the air-water exchange of persistent organic pollutants. H values for 32 polychlorinated naphthalene (PCN) congeners were measured using an inert gas-stripping technique at five temperatures ranging between 5 and 35 °C. H values in deionized water (at 25 °C) varied between 0.28 ± 0.08 Pa m3 mol-1 (PCN-73) and 18.01 ± 0.69 Pa m3 mol-1 (PCN-42). The agreement between the measured and estimated H values from the octanol-water and octanol-air partition coefficients was good (measured/estimated ratio = 1.00 ± 0.41, average ± SD). The calculated phase change enthalpies (ΔHH) were within the interval previously determined for other several semivolatile organic compounds (42.0-106.4 kJ mol-1). Measured H values, paired atmospheric and aqueous concentrations and meteorological variables were also used to reveal the level and direction of air-sea exchange fluxes of PCNs at the coast of Izmir Bay, Turkey. The net PCN air-sea exchange flux varied from -0.55 (volatilization, PCN-24/14) to 2.05 (deposition, PCN-23) ng m-2 day-1. PCN-19, PCN-24/14, PCN-42, and PCN-33/34/37 were mainly volatilized from seawater while the remaining congeners were mainly deposited. The overall number of the cases showing deposition was higher (67.9%) compared to volatilization (21.4%) and near equilibrium (10.7%).
Selective inhibition by chloramphenicol of pregnenolone-16. cap alpha. -carbonitrile-inducible rat liver cytochrome P-450 isozymes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graves, P.E.; Kaminsky, L.S.; Halpert, J.

Pregnenolone-16 ..cap alpha..-carbonitrile (PCN) has been shown to induce, in male rats, cytochrome P-450 isozymes responsible for the formation of R-10-hydroxywarfarin and R-dehydrowarfarin. Antibodies to the major PCN-inducible isozyme (PB/PCN-E) inhibit both activities in microsomal preparations. Recently the authors have shown that PCN treatment of female rats also induces the formation of both R-warfarin metabolites. However, in both sexes chloramphenicol (CAP) treatment selectively inhibits only the rate of formation of the R-dehydrowarfarin. A decrease in microsomal P-450 content occurs after in vivo administration of CAP to PCN-treated rats of both sexes. This is in contrast to the lack of effectmore » of CAP on P-450 levels in phenobarbital-treated rats. Covalent binding of /sup 14/C-CAP to microsomal protein in vitro was increased 3 to 4-fold following PCN treatment. Chromatographic evidences suggests the presence of at least two PCN-induced isozymes of similar molecular weights in both male and female rat liver microsomes. These data are consistent with the multiplicity of PCN-inducible P-450 in rat liver.« less
The test characteristics of head circumference measurements for pathology associated with head enlargement: a retrospective cohort study

PubMed Central

2012-01-01

Background The test characteristics of head circumference (HC) measurement percentile criteria for the identification of previously undetected pathology associated with head enlargement in primary care are unknown. Methods Electronic patient records were reviewed to identify children age 3 days to 3 years with new diagnoses of intracranial expansive conditions (IEC) and metabolic and genetic conditions associated with macrocephaly (MGCM). We tested the following HC percentile threshold criteria: ever above the 95th, 97th, or 99.6th percentile and ever crossing 2, 4, or 6 increasing major percentile lines. The Centers for Disease Control and World Health Organization growth curves were used, as well as the primary care network (PCN) curves previously derived from this cohort. Results Among 74,428 subjects, 85 (0.11%) had a new diagnosis of IEC (n = 56) or MGCM (n = 29), and between these 2 groups, 24 received intervention. The 99.6th percentile of the PCN curve was the only threshold with a PPV over 1% (PPV 1.8%); the sensitivity of this threshold was only 15%. Test characteristics for the 95th percentiles were: sensitivity (CDC: 46%; WHO: 55%; PCN: 40%), positive predictive value (PPV: CDC: 0.3%; WHO: 0.3%; PCN: 0.4%), and likelihood ratios positive (LR+: CDC: 2.8; WHO: 2.2; PCN: 3.9). Test characteristics for the 97th percentiles were: sensitivity (CDC: 40%; WHO: 48%; PCN: 34%), PPV (CDC: 0.4%; WHO: 0.3%; PCN: 0.6%), and LR+ (CDC: 3.6; WHO: 2.7; PCN: 5.6). Test characteristics for crossing 2 increasing major percentile lines were: sensitivity (CDC: 60%; WHO: 40%; PCN: 31%), PPV (CDC: 0.2%; WHO: 0.1%; PCN: 0.2%), and LR+ (CDC: 1.3; WHO: 1.1; PCN: 1.5). Conclusions Commonly used HC percentile thresholds had low sensitivity and low positive predictive value for diagnosing new pathology associated with head enlargement in children in a primary care network. PMID:22269214
The effect of linalool on second-stage juveniles of the potato cyst nematodes Globodera rostochiensis and G. pallida.

PubMed

Būda, Vincas; Cepulytė-Rakauskienė, Rasa

2011-09-01

Linalool is either a toxic compound to a few species of plant parasitic nematodes or attractive to entomopathogenic nematodes. This compound is produced and emitted by several host plants of Globodera rostochiensis and G. pallida, the potato cyst nematodes (PCN). With the aim to reveal the effect of linalool on PCN, laboratory assays were carried out. Survival of PCN second-stage juveniles (J2s) in water + linalool control did not differ; thus, proving linalool to be nontoxic to PCN. Behavioral assays carried out in Petri dishes revealed attractiveness in the form of positive response of J2s of both PCN species towards linalool. Based on these behavioral assays, sensitivity to linalool of G. rostochiensis J2s was higher compared with that of G. pallida J2s. Linalool is the first compound of plant origin to elicit positive response in both PCN species.
Basic dynamics from a pulse-coupled network of autonomous integrate-and-fire chaotic circuits.

PubMed

Nakano, H; Saito, T

2002-01-01

This paper studies basic dynamics from a novel pulse-coupled network (PCN). The unit element of the PCN is an integrate-and-fire circuit (IFC) that exhibits chaos. We an give an iff condition for the chaos generation. Using two IFC, we construct a master-slave PCN. It exhibits interesting chaos synchronous phenomena and their breakdown phenomena. We give basic classification of the phenomena and their existence regions can be elucidated in the parameter space. We then construct a ring-type PCN and elucidate that the PCN exhibits interesting grouping phenomena based on the chaos synchronization patterns. Using a simple test circuit, some of typical phenomena can be verified in the laboratory.
Triptycene-Based Microporous Cyanate Resins for Adsorption/Separations of Benzene/Cyclohexane and Carbon Dioxide Gas.

PubMed

Deng, Gaoyang; Wang, Zhonggang

2017-11-29

Triptycene-based cyanate monomers 2,6,14-tricyanatotriptycene (TPC) and 2,6,14-tris(4-cyanatophenyl)triptycene (TPPC) that contain different numbers of benzene rings per molecule were synthesized, from which two microporous cyanate resins PCN-TPC and PCN-TPPC were prepared. Of interest is the observation that the two polymers have very similar porosity parameters, but PCN-TPPC uptakes considerably higher benzene (77.8 wt %) than PCN-TPC (17.6 wt %) at room temperature since the higher concentration of phenyl groups in PCN-TPPC enhances the π-π interaction with benzene molecules. Besides, the adsorption capacity of benzene in PCN-TPPC is dramatically 7 times as high as that of cyclohexane. Contrary to the adsorption of organic vapors, at 273 K and 1.0 bar, PCN-TPC with more heteroatoms in the network skeleton displays larger uptake of CO 2 and higher CO 2 /N 2 selectivity (16.4 wt %, 60) than those of PCN-TPPC (14.0 wt %, 39). The excellent and unique adsorption properties exhibit potential applications in the purification of small molecular organic hydrocarbons, e.g., separation of benzene from benzene/cyclohexane mixture as well as CO 2 capture from flue gas. Moreover, the results are helpful for deeply understanding the effect of porous and chemical structures on the adsorption properties of organic hydrocarbons and CO 2 gas.
Biofumigation with Brassica juncea, Raphanus sativus and Eruca sativa for the management of field populations of the potato cyst nematode Globodera pallida.

PubMed

Ngala, Bruno M; Haydock, Patrick P J; Woods, Simon; Back, Matthew A

2015-05-01

The viability of potato cyst nematode (PCN) populations (Globodera pallida) was evaluated in three field experiments using Brassica juncea, Raphanus sativus and Eruca sativa amendments. These species were summer cultivated and autumn incorporated in experiment 1; in experiment 2, overwintered brassicaceous cover crops were spring incorporated. Experiment 3 involved determination of effects of metconazole application on biomass/glucosinolate production by B. juncea and R. sativus and on PCN pre- and post-incorporation. Glucosinolate contents were determined before incorporation. Following cover crop incorporation, field plots were planted with susceptible potatoes to evaluate the biofumigation effects on PCN reproduction. In experiment 1, PCN population post-potato harvest was reduced (P = 0.03) in B. juncea-treated plots, while R. sativus prevented further multiplication, but in experiment 2 there were no significant effects on PCN reproduction. In experiment 3, B. juncea or R. sativus either untreated or treated with metconazole reduced PCN populations. Glucosinolate concentrations varied significantly between different plant regions and cultivation seasons. Metconazole application increased the sinigrin concentration in B. juncea tissues. Glucosinolate concentrations correlated positively with PCN mortality for summer-cultivated brassicaceous plants. The results demonstrated that B. juncea and R. sativus green manures can play an important role in PCN management, particularly if included in an integrated pest management scheme. © 2014 Society of Chemical Industry.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Yagci, Cemil, E-mail: cemil.yagci@medicine.ankara.edu.tr; Ustuner, Evren, E-mail: evrenustuner@hotmail.com; Atman, Ebru Dusunceli, E-mail: ebrumd2001@yahoo.com

Percutaneous nephrostomy (PCN) in a nondilated pelvicaliceal system is technically challenging. We describe an effective method to achieve transient dilatation of the pelvicaliceal system via induction of diuresis using infusion of a diuretic agent in normal saline, therefore allowing easier access to the pelvicaliceal system. Under real-time ultrasound guidance, the technique had been tested in 22 nephrostomies with nondilated system (a total of 20 patients with 2 patients having bilateral nephrostomies) during a 5-year period. Patients were given 40 mg of furosemide in 250 ml of normal saline solution intravenously by rapid infusion. As soon as maximum calyceal dilatation ofmore » more than 5 mm was observed, which is usually 15 min later after the end of rapid infusion, patients were positioned obliquely, and PCN procedure under ultrasound guidance was performed. The procedure was successful in 19 of the nephrostomies in 17 patients with a success rate of 86.36 % per procedure and 85 % per patient in nondilated pelvicaliceal systems. No major nephrostomy-, drug-, or technique-related complications were encountered. The technique failed to work in three patients due to the presence of double J catheters and preexisting calyceal perforation which avoided transient dilation of the pelvicaliceal system with diuresis. Diuretic infusion in saline is a feasible and effective method for PCN in nondilated pelvicaliceal systems.« less
Dysmegakaryocytopoiesis and maintaining platelet count in patients with plasma cell neoplasm.

PubMed

Mair, Yasmin; Zheng, Yan; Cai, Donghong

2013-05-01

Dysmegakaryocytopoiesis in patients with the plasma cell neoplasm (PCN) is rarely discussed in the literature. The puzzling phenomenon, which PCN patients maintaining normal platelet count even when the marrow is mostly replaced by plasma cells, is hardly explored. This study was aimed to determine the frequency of dysmegakaryocytopoiesis in PCN and the relationships between bone marrow (BM) plasma cell percentage, plasma cell immunomarkers, the severity of dysmegakaryocytopoiesis, and peripheral blood platelet count in PCN. We randomly selected 16 cases of PCN, among which 4 were with monoclonal gammopathy of undetermined significance and 12 were with plasma cell myeloma. OUR STUDY SHOWED THAT: (1) Dysmegakaryocytopoiesis was present in all the selected cases of PCN and its severity was not correlated with the percentage of the plasma cells in BM; (2) almost all patients maintained normal platelet count even when BM was mostly replaced by plasma cells; (3) immunomarkers of the neoplastic plasma cells were not associated with dysmegakaryocytopoiesis or maintaining of platelet count. The possible mechanisms behind dysmegakaryocytopoiesis and maintaining of platelet count were also discussed. Despite the universal presence of dysmegakaryocytopoiesis in PCN, the platelet count is maintained at normal range.
Coating polymeric carbon nitride photoanodes on conductive Y:ZnO nanorod arrays for overall water splitting.

PubMed

Fang, Yuanxing; Xu, Yuntao; Li, Xiaochun; Ma, Yiwen; Wang, Xinchen

2018-06-14

Solar-to-fuel conversion via photoelectrochemical (PEC) water splitting has the potential to ease current energy and environmental concerns. In pursuit of sustainability, polymeric carbon nitride (PCN) photosensitizers are receiving increasing attention as replacements for their inorganic counterparts. However, intense charge recombination, primarily because of the numerous surface defects, limits the use of PCN in PEC systems. Herein, photoanodes are designed by coating PCN films onto highly conductive yttrium (Y) doped zinc oxide (ZnO) nanorods (NRs) serving as charge collectors. The generation of charge carriers can therefore be promoted by this type II heterostructure. Accordingly, the charge collectors would be kept nearby for charge separation and transport to be used in the interfacial redox reactions. As such, the photocurrent density of the polymer electrode is improved to an exceptional value of 0.4 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) in a Na2SO4 electrolyte solution under AM 1.5 illumination. The result reveals a more than 50-fold enhancement over the PCN films achieved by powder, and the efficiency can be preserved at ca. 95% for 160 minutes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Pip, a Novel Activator of Phenazine Biosynthesis in Pseudomonas chlororaphis PCL1391▿ †

PubMed Central

Girard, Geneviève; Barends, Sharief; Rigali, Sébastien; van Rij, E. Tjeerd; Lugtenberg, Ben J. J.; Bloemberg, Guido V.

2006-01-01

Secondary metabolites are important factors for interactions between bacteria and other organisms. Pseudomonas chlororaphis PCL1391 produces the antifungal secondary metabolite phenazine-1-carboxamide (PCN) that inhibits growth of Fusarium oxysporum f. sp. radius lycopersici the causative agent of tomato foot and root rot. Our previous work unraveled a cascade of genes regulating the PCN biosynthesis operon, phzABCDEFGH. Via a genetic screen, we identify in this study a novel TetR/AcrR regulator, named Pip (phenazine inducing protein), which is essential for PCN biosynthesis. A combination of a phenotypical characterization of a pip mutant, in trans complementation assays of various mutant strains, and electrophoretic mobility shift assays identified Pip as the fifth DNA-binding protein so far involved in regulation of PCN biosynthesis. In this regulatory pathway, Pip is positioned downstream of PsrA (Pseudomonas sigma factor regulator) and the stationary-phase sigma factor RpoS, while it is upstream of the quorum-sensing system PhzI/PhzR. These findings provide further evidence that the path leading to the expression of secondary metabolism gene clusters in Pseudomonas species is highly complex. PMID:16997957
A Base-Resistant Metalloporphyrin Metal–Organic Framework for C–H Bond Halogenation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lv, Xiu-Liang; Wang, Kecheng; Wang, Bin

A base-resistant porphyrin metal–organic framework (MOF), namely PCN-602 has been constructed with 12-connected [Ni 8(OH) 4(H 2O) 2Pz 12] (Pz = pyrazolate) cluster and a newly designed pyrazolate-based porphyrin ligand, 5,10,15,20-tetrakis(4-(pyrazolate-4-yl)phenyl)porphyrin under the guidance of the reticular synthesis strategy. Besides its robustness in hydroxide solution, PCN-602 also shows excellent stability in aqueous solutions of F –, CO 3 2–, and PO 4 3– ions. Interestingly, the Mn 3+-porphyrinic PCN-602, as a recyclable MOF catalyst, presents high catalytic activity for the C–H bond halogenation reaction in a basic system, significantly outperforming its homogeneous counterpart. For the first time, a porphyrinic MOFmore » was thus used as an efficient catalyst in a basic solution with coordinating anions, to the best of our knowledge.« less
75 FR 11111 - Pale Cyst Nematode; Update of Quarantined Areas

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

...: Background The pale cyst nematode (PCN, Globodera pallida) is a major pest of potato crops in cool.... The PCN is thought to have originated in Peru and is now widely distributed in many potato-growing regions of the world. PCN infestations may be expressed as patches of poor growth. Affected potato plants...
Identification and preliminary evaluation of polychlorinated naphthalene emissions from hot dip galvanizing plants.

PubMed

Liu, Guorui; Lv, Pu; Jiang, Xiaoxu; Nie, Zhiqiang; Liu, Wenbin; Zheng, Minghui

2015-01-01

Hot dip galvanizing (HDG) processes are sources of polychlorinated-p-dioxins and dibenzofurans (PCDD/Fs). Close correlations have been found between the concentration of PCDD/Fs and polychlorinated naphthalenes (PCNs) that are produced and released during industrial thermal processes. We speculated, therefore, that HDG plants are potential PCN sources. In this preliminary study, PCNs were analyzed in solid residues, ash and precipitate from three HDG plants of different sizes. The total PCN concentrations (∑2-8PCNs) in the residue samples ranged from 60.3 to 226pgg(-1). The PCN emission factors for the combined ash and precipitate residues from the HDG plants ranged from 75 to 178ngt(-1) for the dichlorinated and octachlorinated naphthalenes. The preliminary results suggested that the HDG industry might not currently be a significant source of PCN emissions. The trichloronaphthalenes were the dominant homologs followed by the dichloronaphthalenes and the tetrachloronaphthalenes. The PCN congeners CN37/33/34, CN52/60, CN66/67, and CN73 dominated the tetrachlorinated, pentachlorinated, hexachlorinated, and heptachlorinated naphthalene homologs, respectively. The PCNs emitted from the HDG plants had similar homolog distributions and congener profiles to the PCNs emitted from combustion plants and other metallurgical processes. The identification and preliminary evaluation of PCN emissions from HDG plants presented here will help in the prioritization of measures for controlling PCN emissions from industrial sources. Copyright © 2014 Elsevier Ltd. All rights reserved.
Ultrasound-Guided Percutaneous Nephrostomy Performed on Neonates and Infants Using a "14-4" (Trocar and Cannula) Technique.

PubMed

Bas, Ahmet; Gülşen, Fatih; Emre, Senol; Samanci, Cesur; Uzunlu, Osman; Cantasdemir, Murat; Emir, Haluk; Numan, Furuzan

2015-12-01

Percutaneous nephrostomy (PCN) catheters are placed under combined ultrasound and fluoroscopic guidance in the interventional radiology suite and present unique challenges in neonates and infants. The purpose of this study was to demonstrate feasibility of PCN using a "14-4" (trocar and cannula) technique on neonates and infants. Between September 2009 and June 2014, data for 27 kidneys from consecutive 22 neonates or infants who underwent PCN catheter placement using the "14-4" technique were retrospectively analyzed. The median age at the time of placement of the PCN catheters was 11 days (range 5-300 days). There were 18 males and 4 females. All procedures were performed in the interventional radiology suite but without using fluoroscopy. Unilateral PCN was performed on 17 out of 22 patients, while bilateral drainage was performed on five patients. The technical success rate was 100%. The median duration of PCN catheter was 75 days (range 10-138 days). Minor macroscopic hematuria not requiring blood transfusion was present in two of the patients in which the hematuria lasted in 2 days. Placement of PCN catheters using a "14-4" technique with ultrasound as the sole imaging modality is a technically feasible and desirable option for neonates or infants. The technique obviates the need for ionizing radiation and potentially could be performed in the ultrasound room or even at the bedside.
Top-down dimensional weight set determines the capture of visual attention: evidence from the PCN component.

PubMed

Töllner, Thomas; Müller, Hermann J; Zehetleitner, Michael

2012-07-01

Visual search for feature singletons is slowed when a task-irrelevant, but more salient distracter singleton is concurrently presented. While there is a consensus that this distracter interference effect can be influenced by internal system settings, it remains controversial at what stage of processing this influence starts to affect visual coding. Advocates of the "stimulus-driven" view maintain that the initial sweep of visual processing is entirely driven by physical stimulus attributes and that top-down settings can bias visual processing only after selection of the most salient item. By contrast, opponents argue that top-down expectancies can alter the initial selection priority, so that focal attention is "not automatically" shifted to the location exhibiting the highest feature contrast. To precisely trace the allocation of focal attention, we analyzed the Posterior-Contralateral-Negativity (PCN) in a task in which the likelihood (expectancy) with which a distracter occurred was systematically varied. Our results show that both high (vs. low) distracter expectancy and experiencing a distracter on the previous trial speed up the timing of the target-elicited PCN. Importantly, there was no distracter-elicited PCN, indicating that participants did not shift attention to the distracter before selecting the target. This pattern unambiguously demonstrates that preattentive vision is top-down modifiable.
International Intelligence Forum 2002

DTIC Science & Technology

2002-01-01

International Intelligence Forum 2002 PCN 46737 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection...Intelligence Forum 2002 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...Std Z39-18 INTERNATIONAL INTELLIGENCE FORUM -3 The Joint Military Intelligence College created the International Intelligence Fellows Program
Xenon Recovery at Room Temperature using Metal-Organic Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elsaidi, Sameh K.; Ongari, Daniele; Xu, Wenqian

2017-07-24

Xenon is known to be a very efficient anesthetic gas but its cost prohibits the wider use in medical industry and other potential applications. It has been shown that Xe recovery and recycle from anesthetic gas mixture can significantly reduce its cost as anesthetic. The current technology uses series of adsorbent columns followed by low temperature distillation to recover Xe, which is expensive to use in medical facilities. Herein, we propose much efficient and simpler system to recover and recycle Xe from simulant exhale anesthetic gas mixture at room temperature using metal organic frameworks. Among the MOFs tested, PCN-12 exhibitsmore » unprecedented performance with high Xe capacity, Xe/O2, Xe/N2 and Xe/CO2 selectivity at room temperature. The in-situ synchrotron measurements suggest the Xe is occupied in the small pockets of PCN-12 compared to unsaturated metal centers (UMCs). Computational modeling of adsorption further supports our experimental observation of Xe binding sites in PCN-12.« less

Xenon Recovery at Room Temperature using Metal-Organic Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elsaidi, Sameh K.; Ongari, Daniele; Xu, Wenqian

2017-07-24

Xenon is known to be a very efficient anesthetic gas but its cost prohibits the wider use in medical industry and other potential applications. It has been shown that Xe recovery and recycle from anesthetic gas mixture can significantly reduce its cost as anesthetic. The current technology uses series of adsorbent columns followed by low temperature distillation to recover Xe, which is expensive to use in medical facilities. Herein, we propose much efficient and simpler system to recover and recycle Xe from simulant exhale anesthetic gas mixture at room temperature using metal organic frameworks. Among the MOFs tested, PCN-12 exhibitsmore » unprecedented performance with high Xe capacity, Xe/N2 and Xe/O2 selectivity at room temperature. The in-situ synchrotron measurements suggest the Xe is occupied in the small pockets of PCN-12 compared to unsaturated metal centers (UMCs). Computational modeling of adsorption further supports our experimental observation of Xe binding sites in PCN-12.« less
Lead-free piezoelectrics based on potassium-sodium niobate with giant d(33).

PubMed

Zhang, Binyu; Wu, Jiagang; Cheng, Xiaojing; Wang, Xiaopeng; Xiao, Dingquan; Zhu, Jianguo; Wang, Xiangjian; Lou, Xiaojie

2013-08-28

High-performance lead-free piezoelectrics (d33 > 400 pC/N) based on 0.96(K0.5Na0.5)0.95Li0.05Nb1-xSbxO3-0.04BaZrO3 with the rhombohedral-tetragonal (R-T) phase boundary have been designed and prepared. The R-T phase boundary lies the composition range of 0.04 ≤ x ≤ 0.07, and the dielectric and piezoelectric properties of the ceramics with the compositions near the phase boundary are significantly enhanced. In addition, the ceramic with x = 0.07 has a giant d33 of ~425 pC/N, which is comparable to that (~416 pC/N) of textured KNN-based ceramics (Saito, Y.; Takao, H.; Tani, T.; Nonoyama, T.; Takatori, K.; Homma, T.; Nagaya, T.; Nakamura, M. Nature 2004, 432, 84). The underlying physical mechanisms for enhanced piezoelectric properties are addressed. We believe that the material system is the most promising lead-free piezoelectric candidates for the practical applications.
Giant piezoelectricity in potassium-sodium niobate lead-free ceramics.

PubMed

Wang, Xiaopeng; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo; Cheng, Xiaojing; Zheng, Ting; Zhang, Binyu; Lou, Xiaojie; Wang, Xiangjian

2014-02-19

Environment protection and human health concern is the driving force to eliminate the lead from commercial piezoelectric materials. In 2004, Saito et al. [ Saito et al., Nature , 2004 , 432 , 84 . ] developed an alkali niobate-based perovskite solid solution with a peak piezoelectric constant d33 of 416 pC/N when prepared in the textured polycrystalline form, intriguing the enthusiasm of developing high-performance lead-free piezoceramics. Although much attention has been paid on the alkali niobate-based system in the past ten years, no significant breakthrough in its d33 has yet been attained. Here, we report an alkali niobate-based lead-free piezoceramic with the largest d33 of ∼490 pC/N ever reported so far using conventional solid-state method. In addition, this material system also exhibits excellent integrated performance with d33∼390-490 pC/N and TC∼217-304 °C by optimizing the compositions. This giant d33 of the alkali niobate-based lead-free piezoceramics is ascribed to not only the construction of a new rhombohedral-tetragonal phase boundary but also enhanced dielectric and ferroelectric properties. Our finding may pave the way for "lead-free at last".
Photocatalytic CO2 conversion by polymeric carbon nitrides.

PubMed

Fang, Yuanxing; Wang, Xinchen

2018-05-10

CO2 is a vital compond for life, and its concentration significantly affects the living environment of the Earth. Extensive effort has been devoted to balance its concentration. Among the developed approaches, photocatalytic CO2 conversion is considered as an ideal option. Previous reports suggest polymeric carbon nitride (PCN) can be effectively used as a metal-free photocatalyst to convert CO2. Herein, the recent developments of PCN and the related photocatalysts for CO2 conversion are summarized from the fundamental of using PCN, and their extended applications through molecular modification and physical/chemical coupling with other substances. The concluding remarks finally indicate the future challenges of using PCN materials for relevant solar-driven applications.
A comprehensive Network Security Risk Model for process control networks.

PubMed

Henry, Matthew H; Haimes, Yacov Y

2009-02-01

The risk of cyber attacks on process control networks (PCN) is receiving significant attention due to the potentially catastrophic extent to which PCN failures can damage the infrastructures and commodity flows that they support. Risk management addresses the coupled problems of (1) reducing the likelihood that cyber attacks would succeed in disrupting PCN operation and (2) reducing the severity of consequences in the event of PCN failure or manipulation. The Network Security Risk Model (NSRM) developed in this article provides a means of evaluating the efficacy of candidate risk management policies by modeling the baseline risk and assessing expectations of risk after the implementation of candidate measures. Where existing risk models fall short of providing adequate insight into the efficacy of candidate risk management policies due to shortcomings in their structure or formulation, the NSRM provides model structure and an associated modeling methodology that captures the relevant dynamics of cyber attacks on PCN for risk analysis. This article develops the NSRM in detail in the context of an illustrative example.
Selective Adsorption of Ethane over Ethylene in PCN-245: Impacts of Interpenetrated Adsorbent.

PubMed

Lv, Daofei; Shi, Renfeng; Chen, Yongwei; Wu, Ying; Wu, Houxiao; Xi, Hongxia; Xia, Qibin; Li, Zhong

2018-03-07

The separation of ethane from ethylene using cryogenic distillation is an energy-intensive process in the industry. With lower energetic consumption, the adsorption technology provides the opportunities for developing the industry with economic sustainability. We report an iron-based metal-organic framework PCN-245 with interpenetrated structures as an ethane-selective adsorbent for ethylene/ethane separation. The material maintains stability up to 625 K, even after exposure to 80% humid atmosphere for 20 days. Adsorptive separation experiments on PCN-245 at 100 kPa and 298 K indicated that ethane and ethylene uptakes of PCN-245 were 3.27 and 2.39 mmol, respectively, and the selectivity of ethane over ethylene was up to 1.9. Metropolis Monte Carlo calculations suggested that the interpenetrated structure of PCN-245 created greater interaction affinity for ethane than ethylene through the crossing organic linkers, which is consistent with the experimental results. This work highlights the potential application of adsorbents with the interpenetrated structure for ethane separation from ethylene.
Crystal engineering on superpolyhedral building blocks in metal-organic frameworks applied in gas adsorption.

PubMed

Chen, Ying Pin; Liu, Tian Fu; Fordham, Stephen; Zhou, Hong Cai

2015-12-01

Two metal-organic frameworks [PCN-426(Ni) and PCN-427(Cu)] have been designed and synthesized to investigate the structure predictability using a SBB (supermolecular building blocks) approach. Tetratopic ligands featuring 120° angular carboxylate moieties were coordinated with a [Ni3(μ3-O)] cluster and a [Cu2O2] unit, respectively. As topologically predicted, 4-connected networks with square coordination adopted the nbo net for the Ni-MOF and ssb net for the Cu-MOF. PCN-426(Ni) was augmented with 12-connected octahedral SBBs, while PCN-427(Cu) was constructed with tetragonal open channels. After a CO2 supercritical drying procedure, the PCN-426(Ni) possessed a Brunauer-Emmett-Teller (BET) surface area as high as 3935 m(2) g(-1) and impressively high N2 uptake of 1500 cm(3) g(-1). This work demonstrates the generalization of the SBB strategy, finding an alternative to inconvenient synthetic processes to achieve the desired structural features.
Fano resonances in photonic crystal nanobeams side-coupled with nanobeam cavities

NASA Astrophysics Data System (ADS)

Meng, Zi-Ming; Liang, Anhui; Li, Zhi-Yuan

2017-05-01

Fano resonances usually arise when a narrow resonance or discrete state and a broad resonance or continuum state are coupled. In this paper, we theoretically and numerically study asymmetric Fano line shape realized in a photonic crystal nanobeam (PCN) side-coupled with a photonic crystal nanobeam cavity (PCNC). Asymmetric transmission profiles with a transmission peak and a transmission valley are obtained for a low index concentrated cavity mode. The transmission valley, associated with the destructive interference, of our PCN-PCNC structures is deeper than that of a waveguide or Fabry-Perot resonator side-coupled with a PCNC structure. Through changing the position of the photonic band gap (PBG) of the PCN, we can utilize the high or low frequency band edge modes and the Fano transmission profiles can be further controlled. The transmission spectra of our PCN-PCNC structures can be well fitted by the Fano resonance formula and agree qualitatively with the prediction made by the temporal coupled mode theory. By using the band edge modes of the PCN as the continuum state instead of a usual broad resonance, we have demonstrated a new way to generate a prominent Fano resonance. Our PCN-PCNC structures are compact and feasible to achieve large-scale high-performance integrated photonic devices, such as optical modulators or switches.
For reliable urine cultures in the detection of complicated urinary tract infection, do we use urine specimens obtained with urethral catheter or a nephrostomy tube?

PubMed

Dede, Gülay; Deveci, Özcan; Dede, Onur; Utanğac, Mazhar; Dağgulli, Mansur; Penbegül, Necmettin; Hatipoğlu, Namık Kemal

2016-12-01

The aim of this study was to compare the results of urine cultures obtained either from urethral, and percutaneous nephrostomy (PCN) catheters. This study included 328 consecutive patients that underwent PCN at our institution with complicated urinary tract infections (UTIs) between July 2010 and April 2015. Results of urine cultures obtained from the urethral and nephrostomy catheters were compared. This study included 152 male and 176 female patients. Mean age of the patients was 46.2±24.3 years. The main indications were obstructive uropathy due to urolithiasis complicated with pyonephrosis 145 (44%), malignant disease (n=87; 26%), pregnancy (n=26; 8%), and anatomical abnormality (n=23; 7%). One hundred and twenty three patients had diabetes mellitus. The most common causative organisms were Escherichia coli , Klebsiella pneumoniae , and Pseudomonas aeruginosa . Blood cultures showed the same results for the PCN and bladder urine cultures. The bladder urine culture was positive in 304 patients, while the PCN urine culture in 314 patients. PCN is an important treatment for the management of pyonephrosis. Cultures from the PCN yield valuable information that is not available from urethral urine cultures, and is a guiding tool for antibiotic therapy selection.
The bacterial pigment pyocyanin inhibits the NLRP3 inflammasome through intracellular reactive oxygen and nitrogen species

PubMed Central

Virreira Winter, Sebastian; Zychlinsky, Arturo

2018-01-01

Inflammasomes are cytosolic complexes that mature and secrete the inflammatory cytokines interleukin 1β (IL-1β) and IL-18 and induce pyroptosis. The NLRP3 (NACHT, LRR, and PYD domains–containing protein 3) inflammasome detects many pathogen- and danger-associated molecular patterns, and reactive oxygen species (ROS)/reactive nitrogen species (RNS) have been implicated in its activation. The phenazine pyocyanin (PCN) is a virulence factor of Pseudomonas aeruginosa and generates superoxide in cells. Here we report that PCN inhibits IL-1β and IL-18 release and pyroptosis upon NLRP3 inflammasome activation in macrophages by preventing speck formation and Caspase-1 maturation. Of note, PCN did not regulate the AIM2 (absent in melanoma 2) or NLRC4 inflammasomes or tumor necrosis factor (TNF) secretion. Imaging of the fluorescent glutathione redox potential sensor Grx1-roGFP2 indicated that PCN provokes cytosolic and nuclear but not mitochondrial redox changes. PCN-induced intracellular ROS/RNS inhibited the NLRP3 inflammasome posttranslationally, and hydrogen peroxide or peroxynitrite alone were sufficient to block its activation. We propose that cytosolic ROS/RNS inhibit the NLRP3 inflammasome and that PCN's anti-inflammatory activity may help P. aeruginosa evade immune recognition. PMID:29414783
Factors influencing trends of polychlorinated naphthalenes and other dioxin-like compounds in lake trout (Salvelinus namaycush) from Lake Ontario, North America (1979-2004).

PubMed

Gewurtz, Sarah B; Lega, Rocsana; Crozier, Patrick W; Whittle, D Michael; Fayez, Laila; Reiner, Eric J; Helm, Paul A; Marvin, Chris H; Tomy, Gregg T

2009-05-01

Concentrations of polychlorinated naphthalenes (PCNs) were determined in archived lake trout (Salvelinus namaycush) from Lake Ontario, North America, collected between 1979 and 2004 to evaluate their temporal trends and the factors influencing their trends. Concentrations of PCNs, as well as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and non- and mono-ortho-substituted polychlorinated biphenyls (DL-PCBs), which were measured for comparative purposes, declined by eight-, seven-, and fivefold, respectively, between 1979 and 2004. Apparent elimination rate constants (k2) were calculated as the slopes of the regression lines of concentration versus time for PCN, DL-PCB, and PCDD/F congeners to compare the rate of decrease among congeners within and between compound classes. The k2 values for PCNs that had two pairs or three adjacent carbons unsubstituted with chlorine (congeners that can be biotransformed by vertebrates) were not significantly different from zero, indicating no decline in fish. For PCN congeners having no adjacent carbons unsubstituted with chlorine, the k2 values generally increased with hydrophobicity and degree of chlorination. This pattern differed from that of PCDD/Fs and DL-PCBs and from previous findings for non-DL-PCBs, for which the rate of contaminant decline decreased with hydrophobicity, and the pattern also differed from expectations based on thermodynamics. Differences in the rate of decline of PCN congeners may be caused by changes in source or mixture formulations over time and/or metabolic dechlorination of the less stable, higher-chlorinated PCNs 73, 74, and 75 to lower-chlorinated congeners. Based on suggested dioxin toxic equivalency factors, PCN concentrations in these whole lake trout may be sufficient to trigger consumption restrictions in Ontario, Canada, and our results suggest that PCNs merit incorporation into monitoring and assessment programs.
PCNs (polychlorinated napthalenes): dietary exposure via cereal crops, distribution and screening-level risk assessment in wheat, rice, soil and air along two tributaries of the River Chenab, Pakistan.

PubMed

Mahmood, Adeel; Malik, Riffat Naseem; Li, Jun; Zhang, Gan; Jones, Kevin C

2014-05-15

There is a lack of scientific literature regarding the bioaccumulation, dietary and toxicity exposure of PCN via food crops. The current study presents the information of dietary intake, distribution pattern and screening level risk assessment of PCN in wheat, rice, soil and air along upstream feeding tributaries of the River Chenab, Punjab Province, Pakistan. A total six air and twenty eight of soil, wheat and rice samples were collected during Jan, 2013 to June, 2013 to analyze the thirty nine PCN congeners. ∑39PCN concentrations were ranged between 0.02 and 0.21 ng g(-1) dw, 0.02-1.21 ng g(-1) dw, 24.6-233 ng g(-1) dw and 1,222-5,052 pg m(-3) in wheat, rice, soil and air samples, respectively. In this study soil exhibited higher TEQ values while in case of air, wheat and rice TEQ concentrations were in accordance with the previously reported pattern from other parts of the world. Estimated daily intake (EDI) of ∑39PCN through consumption of wheat and rice was estimated as 0.21 ng kg(-1) (body weight)day(-1) and 0.03 ng kg(-1) (body weight)day(-1), respectively. This is the first report of PCN dietary intake and screening-level risk assessment by consumption of cereal crops from Pakistan. The results of dietary and toxicity exposure of PCN warrant auxiliary devotion in future, to this group of contaminant. Copyright © 2014 Elsevier B.V. All rights reserved.
Identification of indicator congeners and evaluation of emission pattern of polychlorinated naphthalenes in industrial stack gas emissions by statistical analyses.

PubMed

Liu, Guorui; Cai, Zongwei; Zheng, Minghui; Jiang, Xiaoxu; Nie, Zhiqiang; Wang, Mei

2015-01-01

Identifying marker congeners of unintentionally produced polychlorinated naphthalenes (PCNs) from industrial thermal sources might be useful for predicting total PCN (∑2-8PCN) emissions by the determination of only indicator congeners. In this study, potential indicator congeners were identified based on the PCN data in 122 stack gas samples from over 60 plants involved in more than ten industrial thermal sources reported in our previous case studies. Linear regression analyses identified that the concentrations of CN27/30, CN52/60, and CN66/67 correlated significantly with ∑2-8PCN (R(2)=0.77, 0.80, and 0.58, respectively; n=122, p<0.05), which might be good candidates for indicator congeners. Equations describing relationships between indicators and ∑2-8PCN were established. The linear regression analyses involving 122 samples showed that the relationships between the indicator congeners and ∑2-8PCN were not significantly affected by factors such as industry types, raw materials used, or operating conditions. Hierarchical cluster analysis and similarity calculations for the 122 stack gas samples were adopted to group those samples and evaluating their similarity and difference based on the PCN homolog distributions from different industrial thermal sources. Generally, the fractions of less chlorinated homologs comprised of di-, tri-, and tetra-homologs were much higher than that of more chlorinated homologs for up to 111 stack gas samples contained in group 1 and 2, which indicating the dominance of lower chlorinated homologs in stack gas from industrial thermal sources. Copyright © 2014 Elsevier Ltd. All rights reserved.
Head-circumference distribution in a large primary care network differs from CDC and WHO curves.

PubMed

Daymont, Carrie; Hwang, Wei-Ting; Feudtner, Chris; Rubin, David

2010-10-01

To compare currently available head-circumference growth curves to curves constructed from clinical measurements from patients in a large US primary care network (PCN). We performed a retrospective cohort study of 75 412 patients in an urban-suburban PCN. Patients with a birth weight of <1500 g or gestational age of <33 weeks at birth were excluded. We compared percentile values and the proportion of head-circumference observations above the 95th percentile and below the 5th percentile for the existing and PCN curves. The PCN curves were most similar to the National Center for Health Statistics (NCHS) curves and were substantially different from the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) curves. The overall proportion of observations above the 95th percentile was 4.9% (PCN), 6.2% (NCHS), 8.6% (CDC), and 14.0% (WHO). The proportion below the 5th percentile was 4.4% (PCN), 5.1% (NCHS), 2.9% (CDC), and 2.3% (WHO). When using the CDC curves, the proportion above the 95th percentile increased from 0.2% for children younger than 2 weeks to 11.8% for children 12 months old. When using the WHO curves, the proportion above the 95th percentile was >5% at all ages, with a maximum of 18.0% for children older than 24 months. The CDC and WHO head-circumference curves describe different distributions than the clinical measurements in our PCN population, especially for children with larger heads. The resulting percentile misclassification may delay diagnosis in children with intracranial pathology in very young infants and spur unnecessary evaluation of healthy children older than 6 months.
Quantification of penicillin G during labor and delivery by capillary electrophoresis.

PubMed

Thomas, Andrea; Ukpoma, Omon K; Inman, Jennifer A; Kaul, Anil K; Beeson, James H; Roberts, Kenneth P

2008-04-24

In this study, a capillary electrophoresis (CE) method was developed as a means to measure levels of penicillin G (PCN G) in Group B Streptococcus (GBS) positive pregnant women during labor and delivery. Volunteers for this developmental study were administered five million units of PCN G at the onset of labor. Urine, blood, and amniotic fluid samples were collected during labor and post delivery. Samples were semi-purified by solid-phase extraction (SPE) using Waters tC18 SepPak 3cc cartridges with a sodium phosphate/methanol step gradient for elution. Capillary electrophoresis or reversed-phase high-performance liquid chromatography (RP-HPLC) with diode-array absorbance detection were used to separate the samples in less than 30 min. Quantification was accomplished by establishing a calibration curve with a linear dynamic range. The tC18 SPE methodology provided substantial sample clean-up with high recovery yields of PCN G ( approximately 90%). It was found that SPE was critical for maintaining the integrity of the separation column when using RP-HPLC, but was not necessary for sample analysis by CE where no stationary phase is present. Quantification results ranged from millimolar concentrations of PCN G in maternal urine to micromolar concentrations in amniotic fluid. Serum and cord blood levels of PCN G were below quantification limits, which is likely due to the prolonged delay in sample collection after antibiotic administration. These results show that CE can serve as a simple and effective means to characterize the pharmacokinetic distribution of PCN G from mother to unborn fetus during labor and delivery. It is anticipated that similar methodologies have the potential to provide a quick, simple, and cost-effective means of monitoring the clinical efficacy of PCN G and other drugs during pregnancy.
FMRFamide-related peptides in potato cyst nematodes.

PubMed

Kimber, M J; Fleming, C C; Bjourson, A J; Halton, D W; Maule, A G

2001-09-03

This study presents data demonstrating the presence of FMRFamide-related peptides (FaRPs) in potato cyst nematodes (PCN). Five transcripts of FaRP encoding genes, designated gpflp-1 to gpflp-5, were characterised using RACE. In terms of ORFs, gpflp-1 was 444 base pairs (bp) long and coded for four copies of the FaRP, PF3 (KSAYMRFamide) whilst gpflp-2 was 309 bp long and encoded one copy of the peptide, KNKFEFIRFamide. gpflp-3 (420 bp) Encoded two copies of KHEYLRFamide (AF2) and the genes gpflp-4 and gpflp-5 encoded a total of 11 FaRPs, most of which are novel to PCN. FMRFamide-related peptide (FaRP)-like immunoreactivity was observed in both PCN species, Globodera pallida and Globodera rostochiensis, using an antiserum raised against the invertebrate peptide, FMRFamide. Immunopositive neurones were found throughout the central nervous system in the ventral and dorsal nerve cords and the circumpharyngeal and perianal nerve rings. Reactive neurones were also present peripherally, innervating the highly muscular pharynx with a nerve net and ring-like structures. Positive immunostaining was also observed in neurones running toward the stylet protractor muscles and/or the anterior sensory apparatus. This study implicates a role for FaRPs in feeding, host penetration and sensory function of PCN. This is the first study to characterise FaRP encoding genes from a plant-parasitic nematode using a targeted PCR based RACE approach and further underlines the importance and diversity of this neuropeptide group in the phylum Nematoda.
Site-specific management of nematodes pitfalls and practicalities.

PubMed

Evans, Ken; Webster, Richard M; Halford, Paul D; Barker, Anthony D; Russell, Michael D

2002-09-01

The greatest constraint to potato production in the United Kingdom (UK) is damage by the potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis. Management of PCN depends heavily on nematicides, which are costly. Of all the inputs in UK agriculture, nematicides offer the largest potential cost savings from spatially variable application, and these savings would be accompanied by environmental benefits. We mapped PCN infestations in potato fields and monitored the changes in population density and distribution that occurred when susceptible potato crops were grown. The inverse relationship between population density before planting and multiplication rate of PCN makes it difficult to devise reliable spatial nematicide application procedures, especially when the pre-planting population density is just less than the detection threshold. Also, the spatial dependence found suggests that the coarse sampling grids used commercially are likely to produce misleading distribution maps.
Phenazines and Other Redox-Active Antibiotics Promote Microbial Mineral Reduction

PubMed Central

Hernandez, Maria E.; Kappler, Andreas; Newman, Dianne K.

2004-01-01

Natural products with important therapeutic properties are known to be produced by a variety of soil bacteria, yet the ecological function of these compounds is not well understood. Here we show that phenazines and other redox-active antibiotics can promote microbial mineral reduction. Pseudomonas chlororaphis PCL1391, a root isolate that produces phenazine-1-carboxamide (PCN), is able to reductively dissolve poorly crystalline iron and manganese oxides, whereas a strain carrying a mutation in one of the phenazine-biosynthetic genes (phzB) is not; the addition of purified PCN restores this ability to the mutant strain. The small amount of PCN produced relative to the large amount of ferric iron reduced in cultures of P. chlororaphis implies that PCN is recycled multiple times; moreover, poorly crystalline iron (hydr)oxide can be reduced abiotically by reduced PCN. This ability suggests that PCN functions as an electron shuttle rather than an iron chelator, a finding that is consistent with the observation that dissolved ferric iron is undetectable in culture fluids. Multiple phenazines and the glycopeptidic antibiotic bleomycin can also stimulate mineral reduction by the dissimilatory iron-reducing bacterium Shewanella oneidensis MR1. Because diverse bacterial strains that cannot grow on iron can reduce phenazines, and because thermodynamic calculations suggest that phenazines have lower redox potentials than those of poorly crystalline iron (hydr)oxides in a range of relevant environmental pH (5 to 9), we suggest that natural products like phenazines may promote microbial mineral reduction in the environment. PMID:14766572
A Highly Stable Porphyrinic Zirconium Metal–Organic Framework with shp-a Topology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Dawei; Gu, Zhi-Yuan; Chen, Ying-Pin

2014-12-24

Through a kinetically controlled synthetic process, we synthesized PCN-223, a new porphyrinic Zr-MOF constructed from the newly reported hexagonal prismatic 12-connected Zr6 cluster through an unusual disordered arrangement, giving rise to the first example of the shp-a network in MOFs. With its extremely high connectivity, PCN-223 shows high stability in aqueous solutions with a wide range of pH. Cationic PCN-223(Fe) formed by postsynthetic treatment is an excellent recyclable heterogeneous catalyst for the hetero-Diels–Alder reaction.
Healthy eating and active living for diabetes in primary care networks (HEALD-PCN): rationale, design, and evaluation of a pragmatic controlled trial for adults with type 2 diabetes

PubMed Central

2012-01-01

Background While strong and consistent evidence supports the role of lifestyle modification in the prevention and management of type 2 diabetes (T2DM), the best strategies for program implementation to support lifestyle modification within primary care remain to be determined. The objective of the study is to evaluate the implementation of an evidence-based self- management program for patients with T2DM within a newly established primary care network (PCN) environment. Method Using a non-randomized design, participants (total N = 110 per group) will be consecutively allocated in bi-monthly blocks to either a 6-month self-management program lead by an Exercise Specialist or to usual care. Our primary outcome is self-reported physical activity and pedometer steps. Discussion The present study will assess whether a diabetes self-management program lead by an Exercise Specialist provided within a newly emerging model of primary care and linked to available community-based resources, can lead to positive changes in self-management behaviours for adults with T2DM. Ultimately, our work will serve as a platform upon which an emerging model of primary care can incorporate effective and efficient chronic disease management practices that are sustainable through partnerships with local community partners. Clinical Trials Registration ClinicalTrials.gov identifier: NCT00991380 PMID:22712881

Pressure-induced polymerization of P(CN) 3

DOE PAGES

Gou, Huiyang; Yonke, Brendan L.; Epshteyn, Albert; ...

2015-05-21

Motivated to explore the formation of novel extended carbon-nitrogen solids via well-defined molecular precursor pathways, we studied the chemical reactivity of highly pure phosphorous tricyanide, P(CN) 3, under conditions of high pressure at room temperature. Raman and infrared (IR) spectroscopic measurements reveal a series of phase transformations below 10 GPa, and several low-frequency vibrational modes are reported for the first time. Synchrotron powder Xray diffraction (PXRD) measurements taken during compression show that molecular P(CN) 3 is highly compressible with a bulk modulus of 10.0±0.3 GPa and polymerizes into an amorphous solid above ~10.0 GPa. Raman and infrared (IR) spectra, togethermore » with first-principles molecular-dynamics simulations, show that the amorphization transition is associated with polymerization of the cyanide groups into CN bonds with predominantly sp 2 character, similar to known carbon nitrides, resulting in a novel PCN polymeric phase, which is recoverable to ambient pressure.« less
Draft transcriptome of Globodera ellingtonae

USDA-ARS?s Scientific Manuscript database

The recently described cyst nematode species, Globodera ellingtonae, is a phylogenetic intermediary between the potato cyst nematodes (PCN), G. rotochiensis and G. pallida, and as such provides a new avenue for understanding the evolution and biology of PCN. Given that assembled genomes and transcri...
A porphyrin-based metal-organic framework as a pH-responsive drug carrier

NASA Astrophysics Data System (ADS)

Lin, Wenxin; Hu, Quan; Jiang, Ke; Yang, Yanyu; Yang, Yu; Cui, Yuanjing; Qian, Guodong

2016-05-01

A low cytotoxic porphyrin-based metal-organic framework (MOF) PCN-221, which exhibited high PC12 cell viability via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay, was selected as an oral drug carrier. Methotrexate (MTX) was chosen as the model drug molecule which was absorbed into inner pores and channels of MOFs by diffusion. PCN-221 showed high drug loading and sustained release behavior under physiological environment without "burst effect". The controlled pH-responsive release of drugs by PCN-221 revealed its promising application in oral drug delivery.
Control of Fano resonances in photonic crystal nanobeams side-coupled with nanobeam cavities and their applications to refractive index sensing

NASA Astrophysics Data System (ADS)

Meng, Zi-Ming; Li, Zhi-Yuan

2018-03-01

We study the control of Fano resonances in a 2D photonic crystal nanobeam (PCN) side-coupled with a photonic crystal nanobeam cavity (PCNC) by choosing different cavity modes, the position of the photonic bandgap of PCNs and the displacement between PCNs and PCNCs. By increasing the refractive index of the holes and the surrounding medium, it is found that the air mode cavity with even mirror-reflection symmetry holds the highest sensitivity (538 nm/RIU RIU, refractive index unit) and maximal figure of merit (FOM = 516). Our results can be extended to a practical 3D configuration, where an air-suspended silicon PCN is side-coupled with a PCNC. Although the sensitivity is only 192 nm/RIU for our 3D structures, the maximal FOM is as large as 2095 due to the deep transmission valley. The sensitivity of our PCN-PCNC structures can be further improved by designing PCNCs with electric field concentrated in the air region as much as possible. Our PCN-PCNC structures do not require ultrahigh Q and can be fabricated on the silicon-on-insulator platform, which is compatible with CMOS processing. Therefore, our proposed PCN-PCNC structures provide feasible solutions for realizing label-free sensitive integrated refractive index sensors.
Economic impact from unrestricted spread of potato cyst nematodes in australia.

PubMed

Hodda, M; Cook, D C

2009-12-01

ABSTRACT Potato cyst nematodes (PCN) (Globodera spp.) are quarantine pests with serious potential economic consequences. Recent new detections in Australia, Canada, and the United States have focussed attention on the consequences of spread and economic justifications for alternative responses. Here, a full assessment of the economic impact of PCN spread from a small initial incursion is presented. Models linking spread, population growth, and economic impact are combined to estimate costs of spread without restriction in Australia. Because the characteristics of the Australian PCN populations are currently unknown, the known ranges of parameters were used to obtain cost scenarios, an approach which makes the model predictions applicable generally. Our analysis indicates that mean annual costs associated with spread of PCN would increase rapidly initially, associated with increased testing. Costs would then increase more slowly to peak at over AUD$20 million per year approximately 10 years into the future. Afterward, this annual cost would decrease slightly due to discounting factors. Mean annual costs over 20 years were $18.7 million, with a 90% confidence interval between AUD$11.9 million and AUD$27.0 million. Thus, cumulative losses to Australian agriculture over 20 years may exceed $370 million without action to prevent spread of PCN and entry to new areas.
Reinforcement for percutaneous nephrostomy tubes with a new technique.

PubMed

Zhou, Tie; Gao, Xiaofeng; Yang, Cheng; Peng, Yonghan; Xiao, Liang; Xu, Chuanliang; Wang, Linhui; Hou, Jianguo; Sun, Yinghao

2011-01-01

Percutaneous nephrostomy (PCN) still plays a significant role in decompressing the renal collecting system. Percutaneous nephrostomy tubes (PNTs), however, which are flexible and may not be protected well by patients, are vulnerable to mechanical drag, although they are carefully fixed to the skin with silk suture. We developed a simple method to reinforce the nephrostomy tube against dislodgement from the skin. A total of 133 adult patients underwent ultrasonography-guided PCN; 85 patients received a conventional method to fix the tubes, while the other 48 patients received a new one. We used a rubber drainage tube, about 2 cm long, sheared longitudinally, as the outer tube to encase the nephrostomy tube, and then sutured the cutting edges together with the skin suture to reinforce the nephrostomy tube. Compared with the 85 patients who received the conventional method, there was not any tube dislodgement after PCN in the 48 patients who received the new one at the end of 2 weeks (0 vs 7, P=0.049) and 4 weeks (0 vs 10, P=0.014) follow-up. This is a simple, effective, and inexpensive method that can significantly decrease the dislodgement incidence of PNTs and keep them fixed well after surgery.
Inclusion of Astronomy Themes in an Inovative Approach of Informal Physics Teaching for High School Students. (Spanish Title: Inclusión de Temas Astronómicos en Uma Abordaje Innovadora de la Enseñanza Informal de Física Para Estudiantes de Secumdaria.) Inclusão de Temas Astronômicos Numa Abordagem Inovadora do Ensino Informal de Física Para Estudantes do Ensino Médio

NASA Astrophysics Data System (ADS)

Tiara Mota, Aline; de Morais Bonomini, Iracema Ariel; Meloni Martins Rosado, Ricardo

2009-12-01

The current work reports on an experience on Astronomy education at the Federal University of Itajubá through an extra-curricular course offered for High School students. This initiative was motivated by the low attention paid to the Astronomy subjects at this stage of the Brazilian Formal Education, in spite that the National Curricular Parameters (PCN and PCN+, in Brazil) point out the importance of their inclusion Este artículo relata una experiencia en la enseñanza de la astronomía efectuada en la Universidad Federal de Itajubá en la forma de un curso de extensión orientado para los estudiantes del colegio secundario. Esta iniciativa surgió de constatar la poca atención dada a la Astronomía en esta etapa de la Educación formal brasileña, a pesar que los Parámetros Curriculares Nacionales (PCN y PCN+, en Brasil) destacan la importancia de su inclusión. Este artigo relata uma experiência em ensino de Astronomia realizada na Universidade Federal de Itajubá na forma de um curso de extensão voltado para alunos do Ensino Médio. Esta iniciativa surgiu da pouca atenção que se dá à Astronomia nesta etapa da Educação embora os Parâmetros Curriculares Nacionais (PCN e PCN+) apontem a importância de sua inclusão.
PCN-index derivation at World Data Center for Geomagnetism, Copenhagen, DTU Space

NASA Astrophysics Data System (ADS)

Stolle, C.; Matzka, J.

2012-04-01

The Polar Cap North (PCN) index is based on a correlation between geomagnetic disturbances at the Qaanaaq geomagnetic observatory (IAGA code THL) and the merging electric field derived from solar wind parameters. The index is therefore meant to provide a fast ground based single station indicator for variations in the merging electric field without being dependent on satellite observations. The PC index will be subject to an IAGA endorsement process during IAGA Scientific Assembly 2013. Actually the WDC provides near real time PC-indices and post-processed final PC-indices based on former developed algorithms. However, the coefficients used for calculating the PCN distributed by the WDC Copenhagen are presently not reproducible. In the frame of the IAGA endorsement, DTU Space tests new coefficients mainly based on published algorithms. This presentation will report on activities at the WDC Copenhagen and on the current status at DTU Space with respect to the preparation for the IAGA endorsement process of the PCN-index.
Conventional and two step sintering of PZT-PCN ceramics

NASA Astrophysics Data System (ADS)

Keshavarzi, Mostafa; Rahmani, Hooman; Nemati, Ali; Hashemi, Mahdieh

2018-02-01

In this study, PZT-PCN ceramic was made via sol-gel seeding method and effects of conventional sintering (CS) as well as two-step sintering (TSS) were investigated on microstructure, phase formation, density, dielectric and piezoelectric properties. First, high quality powder was achieved by seeding method in which the mixture of Co3O4 and Nb2O5 powder was added to the prepared PZT sol to form PZT-PCN gel. After drying and calcination, pyrochlore free PZT-PCN powder was synthesized. Second, CS and TSS were applied to achieve dense ceramic. The optimum temperature used for 2 h of conventional sintering was obtained at 1150 °C; finally, undesired ZrO2 phase formed in CS procedure was removed successfully with TSS procedure and dielectric and piezoelectric properties were improved compared to the CS procedure. The best electrical properties obtained for the sample sintered by TSS in the initial temperature of T 1 = 1200 °C and secondary temperature of T 2 = 1000 °C for 12 h.
Ionothermal Synthesis of Triazine-Heptazine Based Co-frameworks with Apparent Quantum Yields of 60 % at 420 nm for Solar Hydrogen Production from "Sea Water".

PubMed

Zhang, Guigang; Lin, Lihua; Li, Guosheng; Zhang, Yongfan; Savateev, Aleksandr; Wang, Xinchen; Antonietti, Markus

2018-05-31

Polymeric carbon nitride (PCN), either in triazine or heptazine forms, has been regarded as promising metal-free, environmental benign and sustainable photocatalysts for solar hydrogen production. However, PCN in most cases only exhibits moderate activities due to the inherent properties such as rapid charge carrier recombination. Here we present a triazine-heptazine copolymer synthesized from simple post-calcination of PCN in eutectic salts, i.e. NaCl/KCl, to modulate the polymerization process and optimize the structure. The construction of internal triazine-heptazine donor-acceptor (D-A) heterostructures is affirmed to significantly accelerate the charge transfer (CT) and thus corporately boost the photocatalytic activity (AQY= 60 % at 420 nm). This study highlights the construction of intermolecular D-A copolymers in NaCl/KCl molten salts with higher melting points but absence of lithium to modulate the polymerization process and chemical structure of PCN. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Molecular variation in the potato cyst nematode, Globodera pallida, in relation to virulence.

PubMed

Blok, V C; Pylypenko, L; Phillips, M S

2006-01-01

The potato cyst nematode Globodera pallida poses a challenge for potato growers. The potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida cause damage valued at over pounds 50m per annum in the U.K. and problems in controlling PCN are growing due to the increase in populations and spread of G. pallida, the lack of many commercially attractive cultivars with resistance to this species and the pressure to reduce nematicide use. Over 60% of potato fields in the U.K. are infected with G. pallida (Minnis et al. 2000). The Scottish Agricultural Science Agency (SASA) figures show that the incidence of both species of PCN on Scottish seed potato land, though low, has been increasing. The proportion of potato land in ware production in Scotland is also increasing and now represents 50% of the potato growing area. This situation potentially increases the risk of the spread of PCN unless it is very carefully monitored and managed.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Kecheng; Feng, Dawei; Liu, Tian-Fu

A series of mesoporous metalloporphyrin Fe-MOFs, namely PCN-600(M) (M = Mn, Fe, Co, Ni, Cu), have been synthesized using the preassembled [Fe3O(OOCCH3)6] building block. PCN-600 exhibits a one-dimensional channel as large as 3.1 nm and the highest experimental pore volume of 1.80 cm3g–1 among all the reported porphyrinic MOFs. It also shows very high stability in aqueous solutions with pH values ranging from 2–11 and is to our knowledge the only mesoporous porphyrinic MOF stable under basic aqueous conditions. PCN-600(Fe) has been demonstrated as an effective peroxidase mimic to catalyze the co-oxidation reaction.
Weed hosts Globodera pallida from Idaho

USDA-ARS?s Scientific Manuscript database

The potato cyst nematode, Globodera pallida (PCN), a restricted pest in the USA, was first reported in Bingham and Bonneville counties of Idaho in 2006. The US government and Idaho State Department of Agriculture hope to eradicate it from infested fields. Eradicating PCN will require depriving the n...
Novel determination of polychlorinated naphthalenes in water by liquid chromatography-mass spectrometry with atmospheric pressure photoionization.

PubMed

Moukas, Athanasios I; Thomaidis, Nikolaos S; Calokerinos, Antony C

2016-01-01

This study presents the development, optimization, and validation of a novel method for the determination of polychlorinated naphthalenes (PCNs) by liquid chromatography-atmospheric pressure photoionization (APPI), using toluene as dopant. The mass spectra of PCN 52, 54, 66, 67, 73, and 75 were recorded in negative ionization. The base ions corresponded to [M-Cl+O](-), where M is the analyte molecule. A strategy, which includes designs of experiments, for the development, the evaluation, and the optimization of the LC-APPI-MS/MS methods is also described. Finally, a highly sensitive method with low instrumental limits of detection (LoDs), ranging from 0.8 pg for PCN 75 to 16 pg for PCN 54 on column, was validated. A Thermo Hypersil Green PAH (100 mm × 2.1 mm, 3 μm) column was used with acetonitrile/water/methanol as mobile phase. The method was applied for the determination of the selected PCNs in surface and tap water samples. A simple liquid-liquid extraction method for the extraction of PCNs from water samples was used. Method LoQs ranged from 29 ng L(-1), for PCN 73, to 63 ng L(-1), for PCN 54, and the recoveries ranged from 97 to 99%, for all congeners. This is the first LC-APPI-MS/MS method for the determination of PCNs in water samples.
Novel RNA viruses within plant parasitic cyst nematodes

PubMed Central

Ruark, Casey L.; Gardner, Michael; Mitchum, Melissa G.; Davis, Eric L.

2018-01-01

The study of invertebrate–and particularly nematode–viruses is emerging with the advancement of transcriptome sequencing. Five single-stranded RNA viruses have now been confirmed within the economically important soybean cyst nematode (SCN; Heterodera glycines). From previous research, we know these viruses to be widespread in greenhouse and field populations of SCN. Several of the SCN viruses were also confirmed within clover (H. trifolii) and beet (H. schachtii) cyst nematodes. In the presented study, we sequenced the transcriptomes of several inbred SCN populations and identified two previously undiscovered viral-like genomes. Both of these proposed viruses are negative-sense RNA viruses and have been named SCN nyami-like virus (NLV) and SCN bunya-like virus (BLV). Finally, we analyzed publicly available transcriptome data of two potato cyst nematode (PCN) species, Globodera pallida and G. rostochiensis. From these data, a third potential virus was discovered and called PCN picorna-like virus (PLV). PCN PLV is a positive-sense RNA virus, and to the best of our knowledge, is the first virus described within PCN. The presence of these novel viruses was confirmed via qRT-PCR, endpoint PCR, and Sanger sequencing with the exception of PCN PLV due to quarantine restrictions on the nematode host. While much work needs to be done to understand the biological and evolutionary significance of these viruses, they offer insight into nematode ecology and the possibility of novel nematode management strategies. PMID:29509804
Novel RNA viruses within plant parasitic cyst nematodes.

PubMed

Ruark, Casey L; Gardner, Michael; Mitchum, Melissa G; Davis, Eric L; Sit, Tim L

2018-01-01

The study of invertebrate-and particularly nematode-viruses is emerging with the advancement of transcriptome sequencing. Five single-stranded RNA viruses have now been confirmed within the economically important soybean cyst nematode (SCN; Heterodera glycines). From previous research, we know these viruses to be widespread in greenhouse and field populations of SCN. Several of the SCN viruses were also confirmed within clover (H. trifolii) and beet (H. schachtii) cyst nematodes. In the presented study, we sequenced the transcriptomes of several inbred SCN populations and identified two previously undiscovered viral-like genomes. Both of these proposed viruses are negative-sense RNA viruses and have been named SCN nyami-like virus (NLV) and SCN bunya-like virus (BLV). Finally, we analyzed publicly available transcriptome data of two potato cyst nematode (PCN) species, Globodera pallida and G. rostochiensis. From these data, a third potential virus was discovered and called PCN picorna-like virus (PLV). PCN PLV is a positive-sense RNA virus, and to the best of our knowledge, is the first virus described within PCN. The presence of these novel viruses was confirmed via qRT-PCR, endpoint PCR, and Sanger sequencing with the exception of PCN PLV due to quarantine restrictions on the nematode host. While much work needs to be done to understand the biological and evolutionary significance of these viruses, they offer insight into nematode ecology and the possibility of novel nematode management strategies.
Comparison of the hepatic and thyroid gland effects of sodium phenobarbital in wild type and constitutive androstane receptor (CAR) knockout rats and pregnenolone-16α-carbonitrile in wild type and pregnane X receptor (PXR) knockout rats.

PubMed

Haines, Corinne; Chatham, Lynsey R; Vardy, Audrey; Elcombe, Clifford R; Foster, John R; Lake, Brian G

2018-05-01

A number of chemicals produce liver and thyroid gland tumours in rodents by nongenotoxic modes of action (MOAs). In this study the hepatic and thyroid gland effects of the constitutive androstane receptor (CAR) activator sodium phenobarbital (NaPB) were examined in male Sprague-Dawley wild type (WT) rats and in CAR knockout (CAR KO) rats and the effects of the pregnane X receptor (PXR) activator pregnenolone-16α-carbonitrile (PCN) were examined in WT and PXR knockout (PXR KO) rats. Rats were either fed diets containing 0 (control) or 500 ppm NaPB or were dosed with 0 (control) or 100 mg/kg/day PCN orally for 7 days. The treatment of WT rats with NaPB and PCN for 7 days resulted in increased relative liver weight, increased hepatocyte replicative DNA synthesis (RDS) and the induction of cytochrome P450 CYP2B and CYP3A subfamily enzyme, mRNA and protein levels. In marked contrast, the treatment of CAR KO rats with NaPB and PXR KO rats with PCN did not result in any increases in liver weight and induction of CYP2B and CYP3A enzymes. The treatment of CAR KO rats with NaPB had no effect on hepatocyte RDS, while PCN produced only a small increase in hepatocyte RDS in PXR KO rats. Treatment with NaPB had no effect on thyroid gland weight in WT and CAR KO rats, whereas treatment with PCN resulted in an increase in relative thyroid gland weight in WT, but not in PXR KO, rats. Thyroid gland follicular cell RDS was increased by the treatment of WT rats with NaPB and PCN, with NaPB also producing a small increase in thyroid gland follicular cell RDS in CAR KO rats. Overall, the present study with CAR KO rats demonstrates that a functional CAR is required for NaPB-mediated increases in liver weight, stimulation of hepatocyte RDS and induction of hepatic CYP enzymes. The studies with PXR KO rats demonstrate that a functional PXR is required for PCN-mediated increases in liver weight and induction of hepatic CYP enzymes; with induction of hepatocyte RDS also being largely mediated through PXR. The hepatic effects of NaPB in CAR KO rats and of PCN in PXR KO rats are in agreement with those observed in other recent literature studies. These results suggest that CAR KO and PXR KO rats are useful experimental models for liver MOA studies with rodent CAR and PXR activators and may also be useful for thyroid gland MOA studies. Copyright © 2018 Elsevier B.V. All rights reserved.
75 FR 54592 - Pale Cyst Nematode; Update of Quarantined Areas

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

... nematode (PCN, Globodera pallida) is a major pest of potato crops in cool-temperature areas. Other... originated in Peru and is now widely distributed in many potato-growing regions of the world. PCN infestations may be expressed as patches of poor growth. Affected potato plants may exhibit yellowing, wilting...
47 CFR 27.1170 - Payment Issues.

Code of Federal Regulations, 2011 CFR

2011-10-01

... initiating operations for a newly constructed site or modified existing site, an AWS entity or MSS/ATC entity... prior coordination notice (PCN) under § 101.103(d) of this chapter is prepared, AWS entities can satisfy the site-data filing requirement by submitting a copy of their PCN to the clearinghouse. AWS entities...
Validation of the PCN Concept: Mobility, Traffic Flow Confidentiality and Protection Against Directed Attacks

DTIC Science & Technology

2010-11-01

peer, racoon (IKE-daemon) will start authenticating using certificates. After a successful authentication, IPSec security associations will be set up...colour had credentials from one CA. Racoon and ipsec-tools are open-source software, implementing IKE and IPSec. Validation of the PCN Concept; Mobility

Ureteric stents vs percutaneous nephrostomy for initial urinary drainage in children with obstructive anuria and acute renal failure due to ureteric calculi: a prospective, randomised study.

PubMed

ElSheemy, Mohammed S; Shouman, Ahmed M; Shoukry, Ahmed I; ElShenoufy, Ahmed; Aboulela, Waseem; Daw, Kareem; Hussein, Ahmed A; Morsi, Hany A; Badawy, Hesham

2015-03-01

To compare percutaneous nephrostomy (PCN) tube vs JJ ureteric stenting as the initial urinary drainage method in children with obstructive calcular anuria (OCA) and post-renal acute renal failure (ARF) due to bilateral ureteric calculi, to identify the selection criteria for the initial urinary drainage method that will improve urinary drainage, decrease complications and facilitate the subsequent definitive clearance of stones, as this comparison is lacking in the literature. A series of 90 children aged ≤12 years presenting with OCA and ARF due to bilateral ureteric calculi were included from March 2011 to September 2013 at Cairo University Pediatric Hospital in this randomised comparative study. Patients with grade 0-1 hydronephrosis, fever or pyonephrosis were excluded. No patient had any contraindication for either method of drainage. Stable patients (or patients stabilised by dialysis) were randomised (non-blinded, block randomisation, sealed envelope method) into PCN-tube or bilateral JJ-stent groups (45 patients for each group). Initial urinary drainage was performed under general anaesthesia and fluoroscopic guidance. We used 4.8-6 F JJ stents or 6-8 F PCN tubes. The primary outcomes were the safety and efficacy of both groups for the recovery of renal functions. Both groups were compared for operative and imaging times, complications, and the period required for a return to normal serum creatinine levels. The secondary outcomes included the number of subsequent interventions needed for clearance of stones. Additional analysis was done for factors affecting outcome within each group. All presented patients completed the study with intention-to-treat analysis. There was no significant difference between the PCN-tube and JJ-stent groups for the operative and imaging times, period for return to a normal creatinine level and failure of insertion. There were significantly more complications in the PCN-tube group. The stone size (>2 cm) was the only factor affecting the rates of mucosal complications, operative time and failure of insertion in the JJ-stent group. The degree of hydronephrosis significantly affected the operative time for PCN-tube insertion. Grade 2 hydronephrosis was associated with all cases of insertion failure in the PCN-tube group. The total number of subsequent interventions needed to clear stones was significantly higher in the PCN-tube group, especially in patients with bilateral stones destined for chemolytic dissolution (alkalinisation) or extracorporeal shockwave lithotripsy (ESWL). We recommend the use of JJ stents for initial urinary drainage for stones that will be subsequently treated with chemolytic dissolution or ESWL, as this will lower the total number of subsequent interventions needed to clear the stones. This is also true for stones destined for ureteroscopy (URS), as JJ-stent insertion will facilitate subsequent URS due to previous ureteric stenting. Mild hydronephrosis will prolong the operative time for PCN-tube insertion and may increase the incidence of insertion failure. We recommend the use of PCN tube if the stone size is >2 cm, as there was a greater risk of possible iatrogenic ureteric injury during stenting with these larger ureteric stones in addition to prolongation of operative time with an increased incidence of failure. © 2014 The Authors. BJU International © 2014 BJU International.
Molecular diagnostics of potato cyst nematodes (PCN) from the national survey

USDA-ARS?s Scientific Manuscript database

The potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida are regulated pathogens of potato, a crop worth nearly $3.9 billion in the United States. Since the initial discovery of G. pallida in Idaho in 2006, extensive surveys of the major potato growing acreage have been carried out, to...
47 CFR 24.249 - Payment issues.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SERVICES Broadband PCS Policies Governing Microwave Relocation from the 1850-1990 Mhz Band § 24.249 Payment issues. (a) Timing. On the day that a PCS entity files its prior coordination notice (PCN) in accordance with § 101.103(d) of this chapter, it must file a copy of the PCN with the clearinghouse. The...
Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

PubMed Central

Xu, Fei; Zhang, Ruiming; Li, Yunfeng; Zhang, Qingzhu; Wang, Wenxing

2015-01-01

Polychlorinated naphthalenes (PCNs) are dioxins-like compounds and are formed along with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in thermal and combustion procedures. Chlorophenols (CPs) are the most important forerunners of PCNs. A comprehensive comprehension of PCN formation procedure from CPs is a precondition for reducing the discharge of PCNs. Experiments on the formation of PCNs from CPs have been hindered by PCN toxicity and short of precise detection methods for active intermediate radicals. In this work, PCN formation mechanism in gas-phase condition from 2-chlorophenol (2-CP) as forerunner was studied by quantum chemistry calculations. Numbers of energetically advantaged formation routes were proposed. The rate constants of key elementary steps were calculated over 600–1200 K using canonical variational transition-state theory (CVT) with small curvature tunneling contribution (SCT) method. This study illustrates formation of PCNs with one chlorine atom loss from 2-CP is preferred over that without chlorine atom loss. In comparison with formation of PCDFs from 2-CP, PCN products are less chlorinated and have lower formation potential. PMID:26516839
Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner.

PubMed

Xu, Fei; Zhang, Ruiming; Li, Yunfeng; Zhang, Qingzhu; Wang, Wenxing

2015-10-26

Polychlorinated naphthalenes (PCNs) are dioxins-like compounds and are formed along with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in thermal and combustion procedures. Chlorophenols (CPs) are the most important forerunners of PCNs. A comprehensive comprehension of PCN formation procedure from CPs is a precondition for reducing the discharge of PCNs. Experiments on the formation of PCNs from CPs have been hindered by PCN toxicity and short of precise detection methods for active intermediate radicals. In this work, PCN formation mechanism in gas-phase condition from 2-chlorophenol (2-CP) as forerunner was studied by quantum chemistry calculations. Numbers of energetically advantaged formation routes were proposed. The rate constants of key elementary steps were calculated over 600-1200 K using canonical variational transition-state theory (CVT) with small curvature tunneling contribution (SCT) method. This study illustrates formation of PCNs with one chlorine atom loss from 2-CP is preferred over that without chlorine atom loss. In comparison with formation of PCDFs from 2-CP, PCN products are less chlorinated and have lower formation potential.
Concentrations and trophic magnification of polychlorinated naphthalenes (PCNs) in marine fish from the Bohai coastal area, China.

PubMed

Cui, Lili; Wang, Shasha; Gao, Lirong; Huang, Huiting; Xia, Dan; Qiao, Lin; Liu, Wenbin

2018-03-01

Polychlorinated naphthalenes (PCNs) have been found widely in the aquatic environment and can be transferred through food chains, which can magnify or dilute their toxic effects on humans. In this study, PCNs were analyzed in samples of 17 species of fish with different dietary habits collected in the Bohai coastal area in China. Dichloronaphthalenes, which have rarely been quantified in previous studies, were determined. The total PCN concentrations were from 7.3 to 214 pg/g wet weight, and the highest concentration was found in ditrema. The trichloronaphthalenes were the most abundant PCNs, followed by the dichloronaphthalenes and pentachloronaphthalenes. The relatively high contributions of the less-chlorinated homologs to the total PCN concentrations indicated that the main PCN sources around the Bohai were industrial thermal process emissions rather than technical PCN formulations. The trophic magnification factors of the PCN homologs were from 3.1 to 9.9, indicating that PCNs were biomagnified by fish. The trophic magnification factor of dichloronaphthalene and trichloronaphthalenes was 5.8 and 6.4, respectively, indicating for the first time that dichloronaphthalene and trichloronaphthalenes can undergo trophic magnification by fish. The two highest trophic magnification factors were for the pentachloronaphthalenes and hexachloronaphthalenes, probably because these PCNs having fewer vicinal carbon atoms without chlorine atoms attached are less easily biotransformed than the other homologs. The dioxin-like toxicities of the PCNs in the samples, expressed as potential toxic equivalences (TEQs), were assessed. The highest total TEQ was 0.0090 pg/g ww, in Pacific herring, and the hexachloronaphthalenes were the dominant contributors to the total TEQs in the fish samples. The PCN TEQs were much lower than the polychlorinated dibenzo-p-dioxin and dibenzofuran and dioxin-like polychlorinated biphenyl TEQs found in fish from the Bohai in previous studies, and made marginal contributions to overall human exposure to dioxin-like TEQs, suggesting that PCNs pose no toxicological concerns. Copyright © 2017 Elsevier Ltd. All rights reserved.
Percutaneous Cervical Nucleoplasty vs. Pulsed Radio Frequency of the Dorsal Root Ganglion in Patients with Contained Cervical Disk Herniation; A Prospective, Randomized Controlled Trial.

PubMed

Halim, Willy; van der Weegen, Walter; Lim, Toine; Wullems, Jorgen Antonin; Vissers, Kris Christiaan

2017-07-01

Cervical neck pain is often caused by cervical disk pathology and may cause severe symptoms and disability. Surgeons and patients are increasingly aware of postsurgery-related complications. This stimulated the clinical usage of minimally invasive treatments such as percutaneous nucleoplasty (PCN) and pulsed radio frequency (PRF). However, scientific evidence on both treatments is limited. Our objective was to evaluate the efficacy of PCN compared to PRF in patients with contained cervical disk herniation. A prospective randomized clinical trial was conducted including 34 patients with radicular pain due to a single contained cervical disk herniation who were treated with either PCN or PRF. Demographic data were collected, and the Medical Outcomes Study 12-Item Short Form (SF-12) Health Survey, visual analog scale (VAS), and the Neck Disability Index (NDI) were completed 1, 2, and 3 months after treatment. Treatment satisfaction and complications were recorded. In the PCN group (n = 17, mean age 52.4 years, 10 female/7 male), patients were treated at C5 to C6 (8 cases) or C6 to C7 (9 cases). In the PRF group (n = 17, mean age 49.5 years, 8 female/9 male), patients were treated at C3 to C4 (1 case), C5 to C6 (10 cases), or C6 to C7 (6 cases). At 3 months, mean pain VAS improved significantly from baseline in the PCN group (mean improvement: 43.4 points) and in the PRF group (34.0 points). However, improvement in 1 group was not superior compared to the other group (P = 0.48). No serious complications were reported. Within 3 months, both PCN and PRF show significant pain improvement in patients with contained cervical disk herniation, but none is superior to the other. Both treatment options appear to be effective and safe in regular clinical practice. © 2016 World Institute of Pain.
Uncertainties and understanding of experimental and theoretical results regarding reactions forming heavy and superheavy nuclei

NASA Astrophysics Data System (ADS)

Giardina, G.; Mandaglio, G.; Nasirov, A. K.; Anastasi, A.; Curciarello, F.; Fazio, G.

2018-02-01

Experimental and theoretical results of the PCN fusion probability of reactants in the entrance channel and the Wsur survival probability against fission at deexcitation of the compound nucleus formed in heavy-ion collisions are discussed. The theoretical results for a set of nuclear reactions leading to formation of compound nuclei (CNs) with the charge number Z = 102- 122 reveal a strong sensitivity of PCN to the characteristics of colliding nuclei in the entrance channel, dynamics of the reaction mechanism, and excitation energy of the system. We discuss the validity of assumptions and procedures for analysis of experimental data, and also the limits of validity of theoretical results obtained by the use of phenomenological models. The comparison of results obtained in many investigated reactions reveals serious limits of validity of the data analysis and calculation procedures.
Strong piezoelectric anisotropy d15/d33 in ⟨111⟩ textured Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 ceramics

NASA Astrophysics Data System (ADS)

Yan, Yongke; Priya, Shashank

2015-08-01

The shear mode piezoelectric properties of Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMN-PZT) ceramic with 72% ⟨111⟩ texture were investigated. The piezoelectric anisotropic factor d15/d33 was as high as 8.5 in ⟨111⟩ textured ceramic as compared to 2.0 in random counterpart. The high d15/d33 indicates the "rotator" ferroelectric characteristics of PMN-PZT system and suggests that the large shear piezoelectric response contributes towards the high longitudinal piezoelectric response (d33) in non-polar direction (d33 = 1100 pC/N in ⟨001⟩ textured ceramic vs. d33 = 112 pC/N in ⟨111⟩ textured ceramic).
Identification, synthesis and regulatory function of the N-acylated homoserine lactone signals produced by Pseudomonas chlororaphis HT66.

PubMed

Peng, Huasong; Ouyang, Yi; Bilal, Muhammad; Wang, Wei; Hu, Hongbo; Zhang, Xuehong

2018-01-22

Pseudomonas chlororaphis HT66 isolated from the rice rhizosphere is an important plant growth-promoting rhizobacteria that produce phenazine-1-carboxamide (PCN) in high yield. Phenazine production is regulated by a quorum sensing (QS) system that involves the N-acylated homoserine lactones (AHLs)-a prevalent type of QS molecule. Three QS signals were detected by thin layer chromatography (TLC) and high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS), which identified to be N-(3-hydroxy hexanoyl)-L-homoserine lactone (3-OH-C6-HSL), N-(3-hydroxy octanoyl)-L-homoserine lactone (3-OH-C8-HSL) and N-(3-hydroxy decanoyl)-L-homoserine lactone (3-OH-C10-HSL). The signal types and methods of synthesis were different from that in other phenazine-producing Pseudomonas strains. By non-scar deletion and heterologous expression techniques, the biosynthesis of the AHL-signals was confirmed to be only catalyzed by PhzI, while other AHLs synthases i.e., CsaI and HdtS were not involved in strain HT66. In comparison to wild-type HT66, PCN production was 2.3-folds improved by over-expression of phzI, however, phzI or phzR mutant did not produce PCN. The cell growth of HT66∆phzI mutant was significantly decreased, and the biofilm formation in phzI or phzR inactivated strains of HT66 decreased to various extents. In conclusion, the results demonstrate that PhzI-PhzR system plays a critical role in numerous biological processes including phenazine production.
Induction of cytochrome P450 3A by paclitaxel in mice: pivotal role of the nuclear xenobiotic receptor, pregnane X receptor.

PubMed

Nallani, Srikanth C; Goodwin, Bryan; Maglich, Jodi M; Buckley, Donna J; Buckley, Arthur R; Desai, Pankaj B

2003-05-01

Paclitaxel, a taxane anti-microtubule agent, is known to induce CYP3A in rat and human hepatocytes. Recent studies suggest that a member of the nuclear receptor family, pregnane X Receptor (PXR), is a key regulator of the expression of CYP3A in different species. We investigated the role of PXR activation, in vitro and in vivo, in mediating Cyp3a induction by paclitaxel. Pregnenolone 16 alpha-carbonitrile (PCN), an antiglucocorticoid, was employed as a positive control for mouse PXR (mPXR) activation in vitro, and Cyp3a induction in vivo. In cell based reporter gene assays paclitaxel and PCN activated mPXR with an EC(50) of 5.6 and 0.27 microM, respectively. Employing PXR wild-type and transgenic mice lacking functional PXR (-/-), we evaluated the expression and activity of CYP3A following treatment with paclitaxel and PCN. Paclitaxel significantly induced CYP3A11 mRNA and immunoreactive CYP3A protein in PXR wild-type mice. Consistent with kinetics of CYP3A induction, the V(max) of testosterone 6 beta-hydroxylation in microsomal fraction increased 15- and 30-fold in paclitaxel- and PCN-treated mice, respectively. The Cyp3a induction response was completely abolished in paclitaxel- and PCN-treated PXR-null mice. This suggests that paclitaxel-mediated CYP3A induction in vivo requires an intact PXR-signaling mechanism. Our study validates the use of PXR activation assays in screening newer taxanes for potential drug interactions that may be related to PXR-target gene induction.
Current evidence of percutaneous nucleoplasty for the cervical herniated disk: a systematic review.

PubMed

Wullems, Jorgen A; Halim, Willy; van der Weegen, Walter

2014-07-01

Although percutaneous cervical nucleoplasty (PCN) has been shown to be both safe and effective, its application is still debated. PCN applied in disk herniation has not been systematically reviewed before, resulting in a limited insight into its effectiveness and safety, and the quality of available evidence. Therefore, we systematically reviewed the evidence on the efficacy and safety of PCN in patients with a (contained) herniated disk. MEDLINE, EMBASE, and the Cochrane Library (Central Register of Controlled Trials) were searched for randomized controlled trials (RCTs) and nonrandomized studies using the following keywords: "Nucleoplasty," "Cervical," "Hernia," "Herniation," "Prolapse," "Protrusion," "Intervertebral disk," and "Percutaneous disk decompression." First, all articles were appraised for methodological quality, and then, RCTs were graded for the level of evidence according a best-evidence synthesis, because a meta-analysis was not possible. Finally, the RCTs' applicability and clinical relevance also was assessed. Of 75 identified abstracts, 10 full-text articles were included (3 RCTs and 7 nonrandomized studies). These studies represented a total of 1021 patients: 823 patients (≥ 892 disks) were treated by PCN. All studies showed low methodological quality, except for two. The level of evidence of the RCTs was graded as moderate, with low to moderate applicability and clinical relevance. All included studies showed PCN to be an effective and safe procedure in the treatment of (contained) herniated disks at short-, mid-, and long-term follow-up. However, the level of evidence is moderate and shows only low to moderate applicability and clinical relevance. © 2013 World Institute of Pain.
Metal-Organic Framework-Templated Porous Carbon for Highly Efficient Catalysis: The Critical Role of Pyrrolic Nitrogen Species.

PubMed

Huang, Gang; Yang, Li; Ma, Xiao; Jiang, Jun; Yu, Shu-Hong; Jiang, Hai-Long

2016-03-01

Metal-free catalysts are of great importance and alternative candidates to conventional metal-based catalysts for many reactions. Herein, several types of metal-organic frameworks have been exploited as templates/precursors to afford porous carbon materials with various nitrogen dopant forms and contents, degrees of graphitization, porosities, and surface areas. Amongst these materials, the PCN-224-templated porous carbon material optimized by pyrolysis at 700 °C (denoted as PCN-224-700) is composed of amorphous carbon coated with well-defined graphene layers, offering a high surface area, hierarchical pores, and high nitrogen content (mainly, pyrrolic nitrogen species). Remarkably, as a metal-free catalyst, PCN-224-700 exhibits a low activation energy and superior activity to most metallic catalysts in the catalytic reduction of 4-nitrophenol to 4-aminophenol. Theoretical investigations suggest that the content and type of the nitrogen dopant play crucial roles in determining the catalytic performance and that the pyrrolic nitrogen species makes the dominant contribution to this activity, which explains the excellent efficiency of the PCN-224-700 catalyst well. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Characterization of resistance to Globodera rostochiensis pathotype Ro1 in cultivated and wild potato species accessions from the Vavilov Institute of Plant Industry

USDA-ARS?s Scientific Manuscript database

Potato cyst nematodes (PCN) in Russia are represented by only Globodera rostochiensis pathotype Ro1. It is a quarantine pathogen with losses in yield in susceptible cultivars which can reach 50-90%. The aims of our study were to verify the species and pathotype composition of natural PCN populations...
Levels, patterns, trends and significance of polychlorinated naphthalenes (PCNs) in Great Lakes fish.

PubMed

Gewurtz, Sarah B; Gandhi, Nilima; Drouillard, Ken G; Kolic, Terry; MacPherson, Karen; Reiner, Eric J; Bhavsar, Satyendra P

2018-05-15

Polychlorinated naphthalenes (PCNs) were introduced to market about a century ago and their production is thought to have ceased by the early 1980s. However, relatively limited knowledge exists on their abundance in the edible portion of a variety of Great Lakes fish to aid in understanding their potential risk to human consumers. We studied levels, patterns, trends and significance of PCNs in a total 470 fillet samples of 18 fish species collected from the Canadian waters of the Great Lakes between 2006 and 2013. A limited comparison of fillet and wholebody concentrations in Carp and Bullhead was also conducted. The ∑PCN ranged from 0.006-6.7ng/g wet weight (ww) and 0.15-190ng/g lipid weight (lw) with the dominant congeners being PCN-52/60 (34%), -42 (21%) and -66/67 (15%). The concentrations spatially varied in the order of the Detroit River>Lakes Erie>Ontario>Huron>Superior. PCN-66/67 was the dominating congener contributing on average 76-80% of toxic equivalent concentration (TEQ PCN ). Contribution of TEQ PCN to TEQ Total (TEQ Dioxins+Furans+dioxin-likePCBs+PCNs ) was mostly <15%, especially at higher TEQ Total, and PCB-126 remains the major congener contributing to TEQ Total . The congener pattern suggests that impurities in PCB formulations and thereby historical PCB contamination, instead of unintentional releases from industrial thermal processes, could be an important source of PCNs in Great Lakes fish. A limited temporal change analysis indicated declines in the levels of PCN-66/67 between 2006 and 2012, complemented by previously reported decrease in PCNs in Lake Ontario Lake Trout between 1979 and 2004. The whole body concentrations were 1.4-3.2 fold higher than the corresponding fillets of Carp and Bullhead. Overall, the study results suggest that only targeted monitoring of PCNs in Great Lakes fish, especially at the Detroit River, Lake Erie and Lake Ontario, is necessary to assess continued future improvements of this group of contaminants of concern. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.
Impact of Clean-Label Antimicrobials and Nitrite Derived from Natural Sources on the Outgrowth of Clostridium perfringens during Cooling of Deli-Style Turkey Breast.

PubMed

King, Amanda M; Glass, Kathleen A; Milkowski, Andrew L; Sindelar, Jeffrey J

2015-05-01

Organic acids and sodium nitrite have long been shown to provide antimicrobial activity during chilling of cured meat products. However, neither purified organic acids nor NaNO2 is permitted in products labeled natural and both are generally avoided in clean-label formulations; efficacy of their replacement is not well understood. Natural and clean-label antimicrobial alternatives were evaluated in both uncured and in alternative cured (a process that uses natural sources of nitrite) deli-style turkey breast to determine inhibition of Clostridium perfringens outgrowth during 15 h of chilling. Ten treatments of ground turkey breast (76% moisture, 1.2% salt) included a control and four antimicrobials: 1.0% tropical fruit extract, 0.7% dried vinegar, 1.0% cultured sugar-vinegar blend, and 2.0% lemon-vinegar blend. Each treatment was formulated without (uncured) and with nitrite (PCN; 50 ppm of NaNO2 from cultured celery juice powder). Treatments were inoculated with C. perfringens spores (three-strain mixture) to yield 2.5 log CFU/g. Individual 50-g portions were vacuum packaged, cooked to 71.1°C, and chilled from 54.4 to 26.7°C in 5 h and from 26.7 to 7.2°C in an additional 10 h. Triplicate samples were assayed for growth of C. perfringens at predetermined intervals by plating on tryptose-sulfite-cycloserine agar. Uncured control and PCN-only treatments allowed for 4.6- and 4.2-log increases at 15 h, respectively, and although all antimicrobial treatments allowed less outgrowth than uncured and PCN, the degree of inhibition varied. The 1.0% fruit extract and 1.0% cultured sugar-vinegar blend were effective at controlling populations at or below initial levels, whether or not PCN was included. Without PCN, 0.7% dried vinegar and 2.0% lemon-vinegar blend allowed for 2.0- and 2.5-log increases, respectively, and ∼1.5-log increases with PCN. Results suggest using clean-label antimicrobials can provide for safe cooling following the study parameters, and greater inhibition of C. perfringens may exist when antimicrobials are used with nitrite.
Seasonal and spatial distributions of atmospheric polychlorinated naphthalenes in Shanghai, China.

PubMed

Die, Qingqi; Nie, Zhiqiang; Fang, Yanyan; Yang, Yufei; Gao, Xingbao; Tian, Yajun; He, Jie; Liu, Feng; Huang, Qifei; Tian, Shulei

2016-02-01

Air samples were collected in Shanghai during summer and winter 2013, and the gas and particulate concentrations of polychlorinated naphthalenes (PCNs) were measured. All 75 congeners were quantified and the corresponding toxic equivalents (TEQs) were calculated. PCN concentrations were higher in summer than winter, at 8.22-102 pg/m(3) (average of 61.3 pg/m(3)) in summer and 16.5-61.1 pg/m(3) (average of 37.7 pg/m(3)) in winter. Their seasonal TEQ values were in contrast, at 1.35-7.31 fg/m(3) (average of 3.84 fg/m(3)) in summer and 4.08-23.3 fg/m(3) (average of 8.80 fg/m(3)) in winter, because of the seasonal change in congener profiles. Tri-CNs were the predominant homologs in both the summer and winter samples. However, the major congeners in summer were PCNs containing less chlorine, but these decreased over winter. Air mass back trajectories suggested that wind direction over various sites was similar in the summer and winter seasons, yet there were clear seasonal variations in atmospheric PCN concentrations. Ratios of several characteristic congeners were calculated and the results indicated that the ratios varied only to a limited extent with PCN emissions profile from industrial thermal sources, but varied strongly with profiles of technical PCN and PCN contaminants in polychlorinated biphenyl mixtures. The results of principal component analysis suggest that local industrial thermal emissions (thermal processes containing waste incineration and secondary metal smelting processes) still play a considerable role in influencing the atmospheric PCNs in Shanghai. Copyright © 2015 Elsevier Ltd. All rights reserved.
Role of UDP-Glucuronosyltransferase (UGT) 2B2 in Metabolism of Triiodothyronine: Effect of Microsomal Enzyme Inducers in Sprague Dawley and UGT2B2-Deficient Fischer 344 Rats

PubMed Central

Richardson, Terrilyn A.; Klaassen, Curtis D.

2010-01-01

Microsomal enzyme inducers (MEI) that increase UDP-glucuronosyltransferases (UGTs) can impact thyroid hormone homeostasis in rodents. Increased glucuronidation can result in reduction of serum thyroid hormone and a concomitant increase in thyroid-stimulating hormone (TSH). UGT2B2 is thought to glucuronidate triiodothyronine (T3). The purposes of this study were to determine the role of UGT2B2 in T3 glucuronidation and whether increased T3 glucuronidation mediates the increased TSH observed after MEI treatment. Sprague Dawley (SD) and UGT2B2-deficient Fischer 344 (F344) rats were fed a control diet or diet containing pregnenolone-16α-carbonitrile (PCN; 800 ppm), 3-methylcholanthrene (3-MC; 200 ppm), or Aroclor 1254 (PCB; 100 ppm) for 7 days. Serum thyroxine (T4), T3, and TSH concentrations, hepatic androsterone/T4/T3 glucuronidation, and thyroid follicular cell proliferation were determined. In both SD and F344 rats, MEI treatments decreased serum T4, whereas serum T3 was maintained (except with PCB treatment). Hepatic T4 glucuronidation increased significantly after MEI in both rat strains. Compared with the other MEI, only PCN treatment significantly increased T3 glucuronidation (281 and 497%) in both SD and UGT2B2-deficient F344 rats, respectively, and increased both serum TSH and thyroid follicular cell proliferation. These data demonstrate an association among increases in T3 glucuronidation, TSH, and follicular cell proliferation after PCN treatment, suggesting that T3 is glucuronidated by other PCN-inducible UGTs in addition to UGT2B2. These data also suggest that PCN (rather than 3-MC or PCB) promotes thyroid tumors through excessive TSH stimulation of the thyroid gland. PMID:20421340
A Large-Surface-Area Boracite-Network-Topology Porous MOF Constructed from a Conjugated Ligand Exhibiting a High Hydrogen Uptake Capacity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xi-Sen; Ma, Shengqian; Yuan, Daqiang

2009-01-01

A new porous metal-organic framework, PCN-20 with a twisted boracite net topology, was constructed based on a highly conjugated planar tricarboxylate ligand; PCN-20 possesses a large Langmuir surface area of over 4200 m(2)/g as well as demonstrates a high hydrogen uptake capacity of 6.2 wt % at 77 K and 50 bar.
European evidence-based guidelines on pancreatic cystic neoplasms

PubMed Central

Del Chiaro, Marco

2018-01-01

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. This guideline is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy. It replaces the 2013 European consensus statement guidelines on PCN. European and non-European experts performed systematic reviews and used GRADE methodology to answer relevant clinical questions on nine topics (biomarkers, radiology, endoscopy, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystic neoplasm, rare cysts, (neo)adjuvant treatment, and pathology). Recommendations include conservative management, relative and absolute indications for surgery. A conservative approach is recommended for asymptomatic MCN and IPMN measuring <40 mm without an enhancing nodule. Relative indications for surgery in IPMN include a main pancreatic duct (MPD) diameter between 5 and 9.9 mm or a cyst diameter ≥40 mm. Absolute indications for surgery in IPMN, due to the high-risk of malignant transformation, include jaundice, an enhancing mural nodule >5 mm, and MPD diameter >10 mm. Lifelong follow-up of IPMN is recommended in patients who are fit for surgery. The European evidence-based guidelines on PCN aim to improve the diagnosis and management of PCN. PMID:29574408

Dual-Emitting Fluorescent Metal-Organic Framework Nanocomposites as a Broad-Range pH Sensor for Fluorescence Imaging.

PubMed

Chen, Haiyong; Wang, Jing; Shan, Duoliang; Chen, Jing; Zhang, Shouting; Lu, Xiaoquan

2018-05-15

pH plays an important role in understanding physiological/pathologic processes, and abnormal pH is a symbol of many common diseases such as cancer, stroke, and Alzheimer's disease. In this work, an effective dual-emission fluorescent metal-organic framework nanocomposite probe (denoted as RB-PCN) has been constructed for sensitive and broad-range detection of pH. RB-PCN was prepared by encapsulating the DBI-PEG-NH 2 -functionalized Fe 3 O 4 into Zr-MOFs and then further reacting it with rhodamine B isothiocyanates (RBITC). In RB-PCN, RBITC is capable of sensing changes in pH in acidic solutions. Zr-MOFs not only enrich the target analyte but also exhibit a fluorescence response to pH changes in alkaline solutions. Based on the above structural and compositional features, RB-PCN could detect a wide range of pH changes. Importantly, such a nanoprobe could "see" the intracellular pH changes by fluorescence confocal imaging as well as "measure" the wider range of pH in actual samples by fluorescence spectroscopy. To the best of our knowledge, this is the first time a MOF-based dual-emitting fluorescent nanoprobe has been used for a wide range of pH detection.
Direct evidence of charge separation in a metal-organic framework: efficient and selective photocatalytic oxidative coupling of amines via charge and energy transfer.

PubMed

Xu, Caiyun; Liu, Hang; Li, Dandan; Su, Ji-Hu; Jiang, Hai-Long

2018-03-28

The selective aerobic oxidative coupling of amines under mild conditions is an important laboratory and commercial procedure yet a great challenge. In this work, a porphyrinic metal-organic framework, PCN-222, was employed to catalyze the reaction. Upon visible light irradiation, the semiconductor-like behavior of PCN-222 initiates charge separation, evidently generating oxygen-centered active sites in Zr-oxo clusters indicated by enhanced porphyrin π-cation radical signals. The photogenerated electrons and holes further activate oxygen and amines, respectively, to give the corresponding redox products, both of which have been detected for the first time. The porphyrin motifs generate singlet oxygen based on energy transfer to further promote the reaction. As a result, PCN-222 exhibits excellent photocatalytic activity, selectivity and recyclability, far superior to its organic counterpart, for the reaction under ambient conditions via combined energy and charge transfer.
Reaction dynamics near the barrier

NASA Astrophysics Data System (ADS)

Loveland, W.

2011-10-01

The availability of modest intensity (103-107 p/s) radioactive nuclear beams has had a significant impact on the study of nuclear reactions near the interaction barrier. The role of isospin in capture reactions is a case in point. Using heavy elements as a laboratory to explore these effects, we note that the cross section for producing an evaporation residue is σEVR(Ec . m .) = ∑ J = 0 JmaxσCN(Ec . m . , J) Wsur(Ec . m . , J) where σCN is the complete fusion cross section and Wsur is the survival probability of the completely fused system. The complete fusion cross section can be written as, σCN(Ec . m .) = ∑ J = 0 Jmaxσcapture(Ec . m .) PCN(Ec . m . , J) where σcapture(Ec.m.,J) is the ``capture'' cross section at center-of mass energy Ec.m. and spin J and PCN is the probability that the projectile-target system will evolve inside the fission saddle point to form a completely fused system rather than re-separating (quasi-fission). The systematics of the isospin dependence of the capture cross sections has been developed and the deduced interaction barriers for all known studies of capture cross sections with radioactive beams are in good agreement with recent predictions of an improved QMD model and semi-empirical models. The deduced barriers for these n-rich systems are lower than one would expect from the Bass or proximity potentials. In addition to the barrier lowering, there is an enhanced sub-barrier cross section in these n-rich systems that is of advantage in the synthesis of new heavy nuclei. Recent studies of the ``inverse fission'' of uranium (124,132Sn + 100Mo) have yielded unexpectedly low upper limits for this process due apparently to low values of the fusion probability, PCN. The fusion of halo nuclei, like 11Li with heavy nuclei, like 208Pb, promises to give new information about these and related nuclei and has led/may lead to unusual reaction mechanisms. This work was sponsored, in part, by the USDOE Office of Nuclear Physics.
Emission of Polychlorinated Naphthalenes during Thermal Related Processes

NASA Astrophysics Data System (ADS)

Liu, Guorui; Zheng, Minghui; Du, Bing; Liu, Wenbin; Zhang, Bing; Xiao, Ke

2010-05-01

Due to the structural similarity of polychlorinated naphthalenes (PCNs) to those of dioxins, PCNs exhibit toxicological properties similar to dioxins (Olivero-Verbel et al., 2004). Based on their high toxicity, persistence, bioaccumulation, and long-distance transmission, PCNs were also selected as a candidate POP for the UN-ECE (United Nations Economic Commission for Europe) POP protocol (Lerche et al., 2002). In addition, some studies suggested that PCNs contributed a greater proportion of the dioxin-like activity than polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) contributed in some locations (Kannan et al., 1998). However, the identification and quantitation for PCN sources are very scarce compared with PCDD/Fs. Understanding the emission levels and developing the emission inventory of PCNs is important for regulatory and source reduction purposes. In this study, several potential sources were preliminarily investigated for PCN release. Coking process (CP), iron ore sintering (IOS), and electric arc furnace steel making units (AF) were selected due to their huge activity level of industrial production in China. Municipal solid waste incineration (MSWI) and medical waste incineration (MWI) were also investigated because of the possible high concentration of PCNs in stack gas. Two plants were investigated for each thermal related process, except for MWI with one incinerator was investigated. The stack gas samples were collected by automatic isokinetic sampling system (Isostack Basic, TCR TECORA, Milan Italy). Isotope dilution high resolution gas chromatography coupled with high resolution mass spectrometry (HRGC/HRMS) technique was used for the identification and quantitation of PCN congeners. The concentrations of PCNs from the selected thermal processes were determined in this study. The average concentrations of total PCNs were 26 ng Nm-3 for CP, 65 ng Nm-3 for IOS, 720 ng Nm-3 for AF, 443 ng Nm-3 for MSWI, and 45 ng Nm-3 for MWI. The emission factors of PCNs were derived, and the average values were 6 μg tonne-1 for CP, 42 μg tonne-1 for IOS, 2980 μg tonne-1 for AF, 1354 μg tonne-1 for MSWI, and 937 μg tonne-1 for MWI, which could be helpful for estimating the annual emission amounts of PCNs from the investigated sources. However, since the investigated plant numbers for each process are limited, there might be large uncertainties when developing the PCN emission inventory. From the obtained data in the preliminary investigation, it could be seen that these investigated sources are worthy of further concerns for PCN emission. Further investigation on PCN release from thermal related process is still in process. References Kannan, K., Imagawa, T., Blankenship, A.L., et al., 1998. Isomer-specific analysis and toxic evaluation of polychlorinated naphthalenes in soil, sediment, and biota collected near the site of a former chlor-alkali plant. Environ Sci Technol 32, 2507-2514. Lerche, D., van de Plassche, E., Schwegler, A., et al., 2002. Selecting chemical substances for the UN-ECE POP protocol. Chemosphere 47, 617-630. Olivero-Verbel, J., Vivas-Reyes, R., Pacheco-Londono, et al., 2004. Discriminant analysis for activation of the aryl hydrocarbon receptor by polychlorinated naphthalenes. J Mol Struc-Theochem 678, 157-161.
A single crystalline porphyrinic titanium metal–organic framework

DOE PAGES

Yuan, Shuai; Liu, Tian -Fu; Feng, Dawei; ...

2015-04-28

We successfully assembled the photocatalytic titanium-oxo cluster and photosensitizing porphyrinic linker into a metal–organic framework (MOF), namely PCN-22. A preformed titanium-oxo carboxylate cluster is adopted as the starting material to judiciously control the MOF growth process to afford single crystals. This synthetic method is useful to obtain highly crystalline titanium MOFs, which has been a daunting challenge in this field. Moreover, PCN-22 demonstrated permanent porosity and photocatalytic activities toward alcohol oxidation.
Polychlorinated naphthalenes and polychlorinated biphenyls in fishes from Michigan waters including the Great Lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kannan, K.; Yamashita, N.; Imagawa, Takashi

2000-02-15

Polychlorinated naphthalene (PCN) and polychlorinated biphenyl (PCB) congeners were measured in while body and fillet of fishes collected from Michigan waters, including the Great Lakes, during 1996--1997. PCNs were found in all the fishes analyzed including those from Siskiwit Lake, a remote lake located near the southern shoreline of Isle Royale National park in Lake Superior. Concentration of total PCNs in fishes ranged from 19 to 31 400 pg/g, wet wt, and varied depending on sampling location and species. Fishes from the Detroit River contained the greatest concentrations of both PCNs and PCBs. Concentrations of total PCNs in fishes frommore » Michigan waters were significantly correlated with the concentrations of PCBs. As with total PCN concentrations, the profiles of PCN isomer/congener distribution in fishes varied among sampling locations and species. Fishes from the Detroit River contained PCN profile similar to that of Halowax 1014, whereas those from Siskiwit Lake and lake Superior contained greater proportions of congeners which have great bioaccumulative potential. Estimated concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) of PCNs ranged from 0.007 to 11 pg/g, wet wt. PCN congeners 66/67 and 69 accounted for greater than 80% of the TEQs contributed by PCNs. TEQs contributed by PCBs, estimated based on H411E bioassay-derived TEFs, were in the range of 0.06--11 pg/g, wet wt, which were similar to those contributed by PCNs. When international TEFs (1-TEFs) for coplanar PCBs were applied, estimated PCB-TEQs ranged from 0.46 to 79 pg/g, wet wt, which were 5--10 times greater than those that were estimated from H411E TEFs. PCB congener 126 contributed greater than 50% of the TEQs contributed by PCBs in all the fishes. Overall, when similarly derived TEFs were used. PCNs contributed 2--57% of the sum of TEQs of PCNs and PCBs.« less
Study of Electrocatalytic Properties of Metal–Organic Framework PCN-223 for the Oxygen Reduction Reaction

DOE PAGES

Usov, Pavel M.; Huffman, Brittany; Epley, Charity C.; ...

2017-03-27

Here, a highly robust metal–organic framework (MOF) constructed from Zr 6 oxo clusters and Fe(III) porphyrin linkers, PCN-223-Fe was investigated as a heterogeneous catalyst for oxygen reduction reaction (ORR). Films of the framework were grown on a conductive FTO substrate and showed a high catalytic current upon application of cathodic potentials and achieved high H 2O/H 2O 2 selectivity. In addition, the effect of the proton source on the catalytic performance was also investigated.
Interactions between nematophagous fungi and consequences for their potential as biological agents for the control of potato cyst nematodes.

PubMed

Jacobs, Helen; Gray, Simon N; Crump, David H

2003-01-01

The efficacies of three nematophagous fungi, Paecilomyces lilacinus, Plectosphaerella cucumerina and Pochonia chlamydosporia, for controlling potato cyst nematodes (PCN) as part of an Integrated Pest Management (IPM) regime were studied. The compatibility of the nematophagous fungi with commonly used chemical pesticides and their ability to compete with the soil fungi Rhizoctonia solani, Chaetomium globosum, Fusarium oxysporum, Penicillium bilaii and Trichoderma harzianum were tested in vitro. Paecilomyces lilacinus was the most successful competitor when the ability to grow and inhibit growth of an opposing colony at both 10 and 20 degrees C was considered. P. lilacinus also showed potential for control of the soil-borne fungal pathogen R. solani, releasing a diffusable substance in vitro which inhibited its growth and caused morphological abnormalities in its hyphae. Pochonia chlamydosporia was least susceptible to growth inhibition by other fungi at 20 degrees in vitro, but the isolate tested did not grow at 10 degrees. Plectosphaerella cucumerina was a poor saprophytic competitor. Radial growth of Paecilomyces lilacinus and Plectosphaerella cucumerina was slowed, but not prevented, when grown on potato dextrose agar incorporating the fungicides fenpiclonil and tolclofos-methyl, and was not inhibited by the addition of pencycuron or the nematicide oxamyl. Radial growth of Pochonia chlamydosporia was partially inhibited by all the chemical pesticides tested. The efficacy of Paecilomyces lilacinus as a control agent for R. solani was further investigated in situ. Treatment with P. lilacinus significantly reduced the symptoms of Rhizoctonia disease on potato stems in a pot trial. The effectiveness of P. lilacinus and P. cucumerina against PCN was also tested in situ. Three application methods were compared; incorporating the fungi into alginate pellets, Terra-Green inoculated with the fungi and applying conidia directly to the tubers. Both formulations containing P. lilacinus and formulation mixtures alone, particularly alginate pellets, significantly reduced multiplication of PCN in soil. We conclude that P. lilacinus showed the greatest potential for use in combination with selected fungicides and nematicides as part of an IPM programme for the control of PCN, but further work is required to confirm whether it is effective against PCN in soil.
Neural correlates of finger gnosis.

PubMed

Rusconi, Elena; Tamè, Luigi; Furlan, Michele; Haggard, Patrick; Demarchi, Gianpaolo; Adriani, Michela; Ferrari, Paolo; Braun, Christoph; Schwarzbach, Jens

2014-07-02

Neuropsychological studies have described patients with a selective impairment of finger identification in association with posterior parietal lesions. However, evidence of the role of these areas in finger gnosis from studies of the healthy human brain is still scarce. Here we used functional magnetic resonance imaging to identify the brain network engaged in a novel finger gnosis task, the intermanual in-between task (IIBT), in healthy participants. Several brain regions exhibited a stronger blood oxygenation level-dependent (BOLD) response in IIBT than in a control task that did not explicitly rely on finger gnosis but used identical stimuli and motor responses as the IIBT. The IIBT involved stronger signal in the left inferior parietal lobule (IPL), bilateral precuneus (PCN), bilateral premotor cortex, and left inferior frontal gyrus. In all regions, stimulation of nonhomologous fingers of the two hands elicited higher BOLD signal than stimulation of homologous fingers. Only in the left anteromedial IPL (a-mIPL) and left PCN did signal strength decrease parametrically from nonhomology, through partial homology, to total homology with stimulation delivered synchronously to the two hands. With asynchronous stimulation, the signal was stronger in the left a-mIPL than in any other region, possibly indicating retention of task-relevant information. We suggest that the left PCN may contribute a supporting visuospatial representation via its functional connection to the right PCN. The a-mIPL may instead provide the core substrate of an explicit bilateral body structure representation for the fingers that when disrupted can produce the typical symptoms of finger agnosia. Copyright © 2014 the authors 0270-6474/14/339012-12$15.00/0.
Induction of lead-binding phytochelatins in vetiver grass [Vetiveria zizanioides (L.)].

PubMed

Andra, Syam S; Datta, Rupali; Sarkar, Dibyendu; Makris, Konstantinos C; Mullens, Conor P; Sahi, Shivendra V; Bach, Stephan B H

2009-01-01

Elevated lead (Pb) concentrations in residential houseyards around house walls painted with Pb-based pigments pose serious human health risks, especially to children. Vetiver grass (Vetiveria zizanioides L.) has shown promise for use in in situ Pb phytoremediation efforts. However, little is known about the biochemical mechanisms responsible for the observed high Pb tolerance by vetiver. We hypothesized that vetiver exposure to Pb induced the synthesis of phytochelatins (PC(n)) and the formation of Pb-PC(n) complexes, alleviating the phytotoxic effects of free Pb ions. Our main objective was to identify PC(n) and Pb-PC(n) complexes in root and shoot compartments of vetiver grass using high-performance liquid chromatography coupled to electrospray mass spectrometry (HPLC-ES-MS). After 7 d of exposure to Pb, vetiver accumulated up to 3000 mg Pb kg(-1) in shoot tissues, but much higher Pb concentrations were measured in root ( approximately 20,000 mg kg(-1)), without phytotoxic symptoms. Scanning electron micrographs showed Pb deposition in the vascular tissues of root and shoot, suggesting Pb translocation to shoot. Collision-induced dissociation analyses in MS/ MS mode during HPLC-ES-MS analysis allowed for the confirmation of four unique PC(n) (n = 1-4) based on their respective amino acid sequence. The high tolerance of vetiver grass to Pb was attributed to the formation of PC(n) and Pb-PC(n) complexes within the plant tissues, using ES-MS and Pb mass isotopic patterns. These data illustrate the mechanism of high Pb tolerance by vetiver grass, suggesting its potential usefulness for the remediation of Pb-contaminated residential sites.
Preparation of mesoporous carbon nitride structure by the dealloying of Ni/a-CN nanocomposite films

NASA Astrophysics Data System (ADS)

Zhou, Han; Shen, Yongqing; Huang, Jie; Liao, Bin; Wu, Xianying; Zhang, Xu

2018-05-01

The preparation of mesoporous carbon nitride (p-CN) structure by the selective dealloying process of Ni/a-CN nanocomposite films is investigated. The composition and structure of the Ni/a-CN nanocomposite films and porous carbon nitride (p-CN) films are determined by scan electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Phase separated structure including nickel carbide phase and the surrounding amorphous carbon nitride (a-CN) matrix are detected for the as-deposited films. Though the bulk diffusion is introduced in the film during the annealing process, the grain sizes for the post-annealed films are around 10 nm and change little comparing with the ones of the as-deposited films, which is associated with the thermostability of the CN surrounding in the film. The p-CN skeleton with its pore size around 12.5 nm is formed by etching the post-annealed films, indicative of the stability of the phase separated structure during the annealing process.
A self-assembled 2D/2D-type protonated carbon nitride-modified graphene oxide nanocomposite with improved photocatalytic activity

NASA Astrophysics Data System (ADS)

Xie, Linfang; Ni, Jie; Tang, Bo; He, Guangyu; Chen, Haiqun

2018-03-01

A surface charge modified g-C3N4 was successfully prepared by protonation of nitric acid. Combination of the protonated g-C3N4 (pCN) and graphene oxide (GO) layers created a 2D/2D-type composite (pCN/GO) under the synergistic effect of sonication-exfoliation and self-assembly. The obtained 2D nanostructure of pCN/GO was explored by electron microscopy analysis. The photocatalytic degradation of rhodamine B (RhB) and ciprofloxacin (CIP) showed a distinctly high efficiency of pCN/GO-5% with excellent stability, which is superior not only to that of g-C3N4, pCN and g-C3N4/GO-5% nanocomposites we prepared, but also to what was reported previously. The optimized combination of GO and pCN afforded the pCN/GO composite intimate interfacial contact within the heterojunction, which promoted the separation of photogenerated electron-hole pairs as evidenced by zeta potential, photoluminescence and photocurrent measurements. A visible-light photocatalytic degradation mechanism associated with pCN/GO nanocomposites was also proposed.
Special role of corn flour as an ideal carbon source for aerobic denitrification with minimized nitrous oxide emission.

PubMed

Zhu, Shuangyue; Zheng, Maosheng; Li, Can; Gui, Mengyao; Chen, Qian; Ni, Jinren

2015-06-01

Much effort has been made for reducing nitrous oxide (N2O) emission in wastewater treatment processes. This paper presents an interesting way to minimize N2O in aerobic denitrification by strain Pseudomonas stutzeri PCN-1 with help of corn flour as cheaper additional carbon source. Experimental results showed that maximal N2O accumulation by strain PCN-1 was only 0.02% of removed nitrogen if corn flour was used as sole carbon source, which was significantly reduced by 52.07-99.81% comparing with others such as succinate, glucose, acetate and citrate. Sustained release of reducing sugar from starch and continuous expression of nosZ coding for N2O reductase contributed to the special role of corn flour as the ideal carbon source for strain PCN-1. Further experiments in sequencing batch reactors (SBRs) demonstrated similarly efficient nitrogen removal with much less N2O emission due to synergy of the novel strain and activated sludge, which was then confirmed by quantitative PCR analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.
CAR/PXR provide directives for Cyp3a41 gene regulation differently from Cyp3a11.

PubMed

Anakk, S; Kalsotra, A; Kikuta, Y; Huang, W; Zhang, J; Staudinger, J L; Moore, D D; Strobel, H W

2004-01-01

This study reports that Cyp3a41 gene contains 13 exons and is localized on the chromosome 5. CYP3A41 is a female-specific isoform that is predominantly expressed in the liver. Estrogen signaling is not responsible for its female specificity. CYP3A41 expression in kidney and brain is observed only in 50% of mice examined. PXR mediates dexamethasone-dependent suppression of CYP3A41. In contrast to CYP3A11, CYP3A41 expression is not induced by pregnenolone-16alpha-carbonitrile (PCN) in wild-type mice, but is significantly suppressed by PCN in PXR(-/-) mice. Phenobarbital and TCPOBOP induce CYP3A11 expression only in the presence of CAR, but have no effect on CYP3A41 expression. Immunoblot and erythromycin demethylase activity analysis reveal robust CYP3A induction after PCN treatment, which is poorly correlated to CYP3A41. These findings suggest a differential role for CAR/PXR in regulating individual CYP3A isoforms by previously characterized CYP3A inducers.
Core network infrastructure supporting the VLT at ESO Paranal in Chile

NASA Astrophysics Data System (ADS)

Reay, Harold

2000-06-01

In October 1997 a number of projects were started at ESO's Paranal Observatory at Cerro Paranal in Chile to upgrade the communications infrastructure in place at the time. The planned upgrades were to internal systems such as computer data networks and telephone installations and also data links connecting Paranal to other ESO sites. This paper details the installation work carried out on the Paranal Core Network (PCN) during the period of October 1997 to December 1999. These installations were to provide both short term solutions to the requirement for reliable high bandwidth network connectivity between Paranal and ESO HQ in Garching, Germany in time for UTI (Antu) first light and perhaps more importantly, to provide the core systems necessary for a site moving towards operational status. This paper explains the reasons for using particular cable types, network topology, and fiber backbone design and implementation. We explain why it was decided to install the PCN in two distinct stages and how equipment used in temporary installations was re-used in the Very Large Telescope networks. Finally we describe the tools used to monitor network and satellite link performance and will discuss whether network backbone bandwidth meets the expected utilization and how this bandwidth can easily be increased in the future should there be a requirement.
Management of obstructive calcular anuria with acute renal failure in children less than 4 years in age: a protocol for initial urinary drainage in relation to planned definitive stone management.

PubMed

ElSheemy, Mohammed S; Shoukry, Ahmed I; Shouman, Ahmed M; ElShenoufy, Ahmed; Aboulela, Waseem; Daw, Kareem; Hussein, Ahmed A; Morsi, Hany A

2014-12-01

To describe and evaluate our protocol for management of children≤4years old with obstructive calcular anuria (OCA) and acute renal failure (ARF) to improve selection of initial urinary drainage (ID) method and to facilitate subsequent definitive stone management (DSM) as studies discussing this special group of patients are still few. Patients with a contraindication to any method of ID were excluded. Decision (percutaneous nephrostomy (PCN) or double J (JJ) stent) was based on degree of hydronephrosis and planned DSM. We used 4.8-5Fr JJ or 6-8Fr PCN under general anesthesia and fluoroscopic guidance. According to our protocol, JJ is inserted for hydronephrosis≤grade 1. When the hydronephrosis is >grade 1, patients with radiolucent stones were treated by JJ whatever the site of the stone. When the stones were radiopaque, PCN was reserved for stones in a solitary functioning kidney and bilateral ureteric stones prepared for subsequent bilateral ureterolithotomy (or stone prepared for ureterolithotomy in a solitary kidney). After normalization of renal functions, DSM was staged attacking only one side before discharge. Both sides were cleared at the same session in cases with bilateral ureterolithotomy. Renal or ureteric stones suitable for SWL in a solitary kidney were treated with percutaneous nephrolithotripsy (PNL) or ureteroscopy. This was followed also in patients with bilateral stones suitable for SWL by clearing one side using ureteroscopy or PNL before discharge. Open surgery (OS) was reserved for cases with failed ureteroscopy or PNL, for ureteric stones>2.5 cm in size or very large volume complex renal stones. Stone free rate (SFR) was evaluated by CT. Our protocol was evaluated as regard recovery of renal functions, complications, and number of interventions to clear stones. This study included 62 boys and 22 girls presented with anuria for 1-4 days. JJ and PCN were inserted in 105 and 30 ureterorenal units (URU), respectively. Creatinine returns normal within 72 h. JJ insertion formed a part of DSM in 78/159 (49%) URU (stones prepared for extracorporeal shockwave lithotripsy or oral chemolytic dissolution therapy). PCN was the ideal tract for subsequent PNL in 11/159 (6.9%) URU. Accordingly, ID participated by 55.97% in DSM. Both operative and imaging times were slightly longer with PCN than JJ. There was no statistically significant difference in the insertion success or mean period to return to normal chemistry. Complications of both methods were mild and without any significant difference. Endourologic procedures constituted the majority of our interventions. Open surgical and endoscopic interventions for clearance of stones (including ID, treatment conversion and 2ry procedures) were done once for 25 patients, twice for 43 patients while it was needed three times for 16 patients. Total number of interventions was 149 procedures. SFR was 94%. Our protocol ensures adequate ID with minimal complications when using our selection criteria in children≤4 years in age with OCA and ARF. It also minimizes number of subsequent procedures to clear stones. Complications and success in insertion and drainage were equivalent in PCN and JJ groups. Copyright © 2014 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Improving Clinical Outcomes in Patients With Methicillin-Sensitive Staphylococcus aureus Bacteremia and Reported Penicillin Allergy

PubMed Central

Blumenthal, Kimberly G.; Parker, Robert A.; Shenoy, Erica S.; Walensky, Rochelle P.

2015-01-01

Background. Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection. First-line MSSA therapies (nafcillin, oxacillin, cefazolin) are generally avoided in the 10% of patients reporting penicillin (PCN) allergy, but most of these patients are not truly allergic. We used a decision tree with sensitivity analyses to determine the optimal evaluation and treatment for patients with MSSA bacteremia and reported PCN allergy. Methods. Our model simulates 3 strategies: (1) no allergy evaluation, give vancomycin (Vanc); (2) allergy history–guided treatment: if history excludes anaphylactic features, give cefazolin (Hx-Cefaz); and (3) complete allergy evaluation with history-appropriate PCN skin testing: if skin test negative, give cefazolin (ST-Cefaz). Model outcomes included 12-week MSSA cure, recurrence, and death; allergic reactions including major, minor, and potentially iatrogenic; and adverse drug reactions. Results. Vanc results in the fewest patients achieving MSSA cure and the highest rate of recurrence (67.3%/14.8% vs 83.4%/9.3% for Hx-Cefaz and 84.5%/8.9% for ST-Cefaz) as well as the greatest frequency of allergic reactions (3.0% vs 2.4% for Hx-Cefaz and 1.7% for ST-Cefaz) and highest rates of adverse drug reactions (5.2% vs 4.6% for Hx-Cefaz and 4.7% for ST-Cefaz). Even in a “best case for Vanc” scenario, Vanc yields the poorest outcomes. ST-Cefaz is preferred to Hx-Cefaz although sensitive to input variations. Conclusions. Patients with MSSA bacteremia and a reported PCN allergy should have the allergy addressed for optimal treatment. Full allergy evaluation with skin testing seems to be preferred, although more data are needed. PMID:25991471
Improving Clinical Outcomes in Patients With Methicillin-Sensitive Staphylococcus aureus Bacteremia and Reported Penicillin Allergy.

PubMed

Blumenthal, Kimberly G; Parker, Robert A; Shenoy, Erica S; Walensky, Rochelle P

2015-09-01

Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection. First-line MSSA therapies (nafcillin, oxacillin, cefazolin) are generally avoided in the 10% of patients reporting penicillin (PCN) allergy, but most of these patients are not truly allergic. We used a decision tree with sensitivity analyses to determine the optimal evaluation and treatment for patients with MSSA bacteremia and reported PCN allergy. Our model simulates 3 strategies: (1) no allergy evaluation, give vancomycin (Vanc); (2) allergy history-guided treatment: if history excludes anaphylactic features, give cefazolin (Hx-Cefaz); and (3) complete allergy evaluation with history-appropriate PCN skin testing: if skin test negative, give cefazolin (ST-Cefaz). Model outcomes included 12-week MSSA cure, recurrence, and death; allergic reactions including major, minor, and potentially iatrogenic; and adverse drug reactions. Vanc results in the fewest patients achieving MSSA cure and the highest rate of recurrence (67.3%/14.8% vs 83.4%/9.3% for Hx-Cefaz and 84.5%/8.9% for ST-Cefaz) as well as the greatest frequency of allergic reactions (3.0% vs 2.4% for Hx-Cefaz and 1.7% for ST-Cefaz) and highest rates of adverse drug reactions (5.2% vs 4.6% for Hx-Cefaz and 4.7% for ST-Cefaz). Even in a "best case for Vanc" scenario, Vanc yields the poorest outcomes. ST-Cefaz is preferred to Hx-Cefaz although sensitive to input variations. Patients with MSSA bacteremia and a reported PCN allergy should have the allergy addressed for optimal treatment. Full allergy evaluation with skin testing seems to be preferred, although more data are needed. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
The Speed of Visual Attention and Motor-Response Decisions in Adult Attention-Deficit/Hyperactivity Disorder.

PubMed

Cross-Villasana, Fernando; Finke, Kathrin; Hennig-Fast, Kristina; Kilian, Beate; Wiegand, Iris; Müller, Hermann Joseph; Möller, Hans-Jürgen; Töllner, Thomas

2015-07-15

Adults with attention-deficit/hyperactivity disorder (ADHD) exhibit slowed reaction times (RTs) in various attention tasks. The exact origins of this slowing, however, have not been established. Potential candidates are early sensory processes mediating the deployment of focal attention, stimulus response translation processes deciding upon the appropriate motor response, and motor processes generating the response. We combined mental chronometry (RT) measures of adult ADHD (n = 15) and healthy control (n = 15) participants with their lateralized event-related potentials during the performance of a visual search task to differentiate potential sources of slowing at separable levels of processing: the posterior contralateral negativity (PCN) was used to index focal-attentional selection times, while the lateralized readiness potentials synchronized to stimulus and response events were used to index the times taken for response selection and production, respectively. To assess the clinical relevance of event-related potentials, a correlation analysis between neural measures and subjective current and retrospective ADHD symptom ratings was performed. ADHD patients exhibited slower RTs than control participants, which were accompanied by prolonged PCN and lateralized readiness potentials synchronized to stimulus, but not lateralized readiness potentials synchronized to response events, latencies. Moreover, the PCN timing was positively correlated with ADHD symptom ratings. The behavioral RT slowing of adult ADHD patients was based on a summation of internal processing delays arising at perceptual and response selection stages; motor response production, by contrast, was not impaired. The correlation between PCN times and ADHD symptom ratings suggests that this brain signal may serve as a potential candidate for a neurocognitive endophenotype of ADHD. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
Purification, crystal structure and antimicrobial activity of phenazine-1-carboxamide produced by a growth-promoting biocontrol bacterium, Pseudomonas aeruginosa MML2212.

PubMed

Shanmugaiah, V; Mathivanan, N; Varghese, B

2010-02-01

To purify and characterize an antimicrobial compound produced by a biocontrol bacterium, Pseudomonas aeruginosa MML2212, and evaluate its activity against rice pathogens, Rhizoctonia solani and Xanthomonas oryzae pv. oryzae. Pseudomonas aeruginosa strain MML2212 isolated from the rice rhizosphere with wide-spectrum antimicrobial activity was cultured in Kings'B broth using a fermentor for 36 h. The extracellular metabolites were isolated from the fermented broth using ethyl acetate extraction and purified by two-step silica-gel column chromatography. Three fractions were separated, of which a major compound was obtained in pure state as yellow needles. It was crystallized after dissolving with chloroform followed by slow evaporation. It is odourless with a melting point of 220-222 degrees C. It was soluble in most of the organic solvents and poorly soluble in water. The molecular mass of purified compound was estimated as 223.3 by mass spectral analysis. Further, it was characterized by IR, (1)H and (13)C NMR spectral analyses. The crystal structure of the compound was elucidated for the first time by X-ray diffraction study and deposited in the Cambridge Crystallographic Data Centre (http://www.ccde.com.ac.uk) with the accession no. CCDC 617344. The crystal compound was undoubtedly identified as phenazine-1-carboxamide (PCN) with the empirical formula of C(13)H(9)N(3)O. As this is the first report on the crystal structure of PCN, it provides additional information to the structural chemistry. Furthermore, the present study reports the antimicrobial activity of purified PCN on major rice pathogens, R. solani and X. oryzae pv. oryzae. Therefore, the PCN can be developed as an ideal agrochemical candidate for the control of both sheath blight and bacterial leaf blight diseases of rice.

Temperature Dependent Electrical Properties of PZT Wafer

NASA Astrophysics Data System (ADS)

Basu, T.; Sen, S.; Seal, A.; Sen, A.

2016-04-01

The electrical and electromechanical properties of lead zirconate titanate (PZT) wafers were investigated and compared with PZT bulk. PZT wafers were prepared by tape casting technique. The transition temperature of both the PZT forms remained the same. The transition from an asymmetric to a symmetric shape was observed for PZT wafers at higher temperature. The piezoelectric coefficient (d 33) values obtained were 560 pc/N and 234 pc/N, and the electromechanical coupling coefficient (k p) values were 0.68 and 0.49 for bulk and wafer, respectively. The reduction in polarization after fatigue was only ~3% in case of PZT bulk and ~7% for PZT wafer.
Relationship between focal penicillin spikes and cortical spindles in the cerveau isolé cat.

PubMed

McLachlan, R S; Kaibara, M; Girvin, J P

1983-01-01

Using the unanesthetized, cerveau isolé preparation in the cat, the association between artificially induced penicillin (PCN) spikes and spontaneously occurring electrocorticographic (ECoG) spindles was investigated. Spikes were elicited by surface application of small pledgets of PCN. After the application of PCN, there was a decrease in spindle amplitude but no change in frequency, duration, or spindle wave frequency in the area of the focus. Examination of the times of occurrence of the spikes and spindles disclosed that in the majority of cases, within a few minutes of the initiation of the foci, there was very high simultaneity, usually 100% between the occurrences of these two events. Examination of the times of occurrence of the spikes within the ECoG spindles failed to disclose any compelling evidence which would favor either the hypothesis that spikes "trigger" spindles or the hypothesis that spindles predispose to focal spikes. Thus, whether spikes trigger spindles, or spikes simply occur in a nonspecific manner during the occurrence of the spindle, or whether it is a combination of both these explanations, must remain an open question on the basis of the data available.
Composite Piezoelectric Rubber Band for Energy Harvesting from Breathing and Limb Motion

NASA Astrophysics Data System (ADS)

Wang, Jhih-Jhe; Su, Huan-Jan; Hsu, Chang-I.; Su, Yu-Chuan

2014-11-01

We have successfully demonstrated the design and microfabrication of piezoelectric rubber bands and their application in energy harvesting from human motions. Composite polymeric and metallic microstructures with embedded bipolar charges are employed to realize the desired stretchability and electromechanical sensitivity. In the prototype demonstration, multilayer PDMS cellular structures coated with PTFE films and stretchable gold electrodes are fabricated and implanted with bipolar charges. The composite structures show elasticity of 300~600 kPa and extreme piezoelectricity of d33 >2000 pC/N and d31 >200 pC/N. For a working volume of 2.5cm×2.5cm×0.3mm, 10% (or 2.5mm) stretch results in effective d31 of >17000 pC/N. It is estimated that electric charge of >0.2 μC can be collected and stored per breath (or 2.5cm deformation). As such, the composite piezoelectric rubber bands (with spring constants of ~200 N/m) can be mounted on elastic waistbands to harvest the circumferential stretch during breathing, or on pads around joints to harvest the elongation during limb motion. Furthermore, the wearable piezoelectric structures can be spread, stacked and connected to charge energy storages and power micro devices.
A study of physician collaborations through social network and exponential random graph

PubMed Central

2013-01-01

Background Physician collaboration, which evolves among physicians during the course of providing healthcare services to hospitalised patients, has been seen crucial to effective patient outcomes in healthcare organisations and hospitals. This study aims to explore physician collaborations using measures of social network analysis (SNA) and exponential random graph (ERG) model. Methods Based on the underlying assumption that collaborations evolve among physicians when they visit a common hospitalised patient, this study first proposes an approach to map collaboration network among physicians from the details of their visits to patients. This paper terms this network as physician collaboration network (PCN). Second, SNA measures of degree centralisation, betweenness centralisation and density are used to examine the impact of SNA measures on hospitalisation cost and readmission rate. As a control variable, the impact of patient age on the relation between network measures (i.e. degree centralisation, betweenness centralisation and density) and hospital outcome variables (i.e. hospitalisation cost and readmission rate) are also explored. Finally, ERG models are developed to identify micro-level structural properties of (i) high-cost versus low-cost PCN; and (ii) high-readmission rate versus low-readmission rate PCN. An electronic health insurance claim dataset of a very large Australian health insurance organisation is utilised to construct and explore PCN in this study. Results It is revealed that the density of PCN is positively correlated with hospitalisation cost and readmission rate. In contrast, betweenness centralisation is found negatively correlated with hospitalisation cost and readmission rate. Degree centralisation shows a negative correlation with readmission rate, but does not show any correlation with hospitalisation cost. Patient age does not have any impact for the relation of SNA measures with hospitalisation cost and hospital readmission rate. The 2-star parameter of ERG model has significant impact on hospitalisation cost. Furthermore, it is found that alternative-k-star and alternative-k-two-path parameters of ERG model have impact on readmission rate. Conclusions Collaboration structures among physicians affect hospitalisation cost and hospital readmission rate. The implications of the findings of this study in terms of their potentiality in developing guidelines to improve the performance of collaborative environments among healthcare professionals within healthcare organisations are discussed in this paper. PMID:23803165
Breeding of a new potato variety 'Nagasaki Kogane' with high eating quality, high carotenoid content, and resistance to diseases and pests.

PubMed

Sakamoto, Yu; Mori, Kazuyuki; Matsuo, Yuuki; Mukojima, Nobuhiro; Watanabe, Wataru; Sobaru, Norio; Tamiya, Seiji; Nakao, Takashi; Hayashi, Kazuya; Watanuki, Hitomi; Nara, Kazuhiro; Yamazaki, Kaoru; Chaya, Masataka

2017-06-01

'Nagasaki Kogane' is a new potato variety bred from a cross between 'Saikai 35' as a female parent and 'Saikai 33' as a male. 'Saikai 35' is resistant to bacterial wilt, contains the H1 and Ry chc genes for resistance to the potato cyst nematode (PCN) and potato virus Y (PVY), respectively, and has high carotenoid content, while 'Saikai 33' has large and high-yielding tubers and is resistant to both bacterial wilt and PCN. The carotenoid content of 'Nagasaki Kogane' is higher than that of 'Dejima', a common double cropping variety. The taste quality of steamed 'Nagasaki Kogane' is comparable to that of 'Inca-no-mezame' tubers, which has high levels of carotenoid, and superior to 'Nishiyutaka', another popular double cropping variety. 'Nagasaki Kogane' is suitable for French fries, because its tuber has high starch content. The marketable yield of 'Nagasaki Kogane' was higher than that of 'Inca-no-mezame' in spring cropping, although it was lower than that of 'Nishiyutaka' in double cropping regions. 'Nagasaki Kogane' tubers are larger on average than 'Inca-no-mezame' tubers in spring cropping. Moreover, the 'Nagasaki Kogane' variety is resistant to PCN and PVY, and exhibits a high level of resistance to bacterial wilt.
'Peripheric' pancreatic cysts: performance of CT scan, MRI and endoscopy according to final pathological examination.

PubMed

Duconseil, P; Turrini, O; Ewald, J; Soussan, J; Sarran, A; Gasmi, M; Moutardier, V; Delpero, J R

2015-06-01

To assess the accuracy of pre-operative staging in patients with peripheral pancreatic cystic neoplasms (pPCNs). From 2005 to 2011, 148 patients underwent a pancreatectomy for pPCNs. The pre-operative examination methods of computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) were compared for their ability to predict the suggested diagnosis accurately, and the definitive diagnosis was affirmed by pathological examination. A mural nodule was detected in 34 patients (23%): only 1 patient (3%) had an invasive pPCN at the final histological examination. A biopsy was performed in 79 patients (53%) during EUS: in 55 patients (70%), the biopsy could not conclude a diagnosis; the biopsy provided the correct and wrong diagnosis in 19 patients (24%) and 5 patients (6%), respectively. A correct diagnosis was affirmed by CT, EUS and pancreatic MRI in 60 (41%), 103 (74%) and 80 (86%) patients (when comparing EUS and MRI; P = 0.03), respectively. The positive predictive values (PPVs) of CT, EUS and MRI were 70%, 75% and 87%, respectively. Pancreatic MRI appears to be the most appropriate examination to diagnose pPCNs accurately. EUS alone had a poor PPV. Mural nodules in a PCN should not be considered an indisputable sign of pPCN invasiveness. © 2015 International Hepato-Pancreato-Biliary Association.
Roles of Long and Short Replication Initiation Proteins in the Fate of IncP-1 Plasmids

PubMed Central

Yano, Hirokazu; Deckert, Gail E.; Rogers, Linda M.

2012-01-01

Broad-host-range IncP-1 plasmids generally encode two replication initiation proteins, TrfA1 and TrfA2. TrfA2 is produced from an internal translational start site within trfA1. While TrfA1 was previously shown to be essential for replication in Pseudomonas aeruginosa, its role in other bacteria within its broad host range has not been established. To address the role of TrfA1 and TrfA2 in other hosts, efficiency of transformation, plasmid copy number (PCN), and plasmid stability were first compared between a mini-IncP-1β plasmid and its trfA1 frameshift variant in four phylogenetically distant hosts: Escherichia coli, Pseudomonas putida, Sphingobium japonicum, and Cupriavidus necator. TrfA2 was sufficient for replication in these hosts, but the presence of TrfA1 enhanced transformation efficiency and PCN. However, TrfA1 did not contribute to, and even negatively affected, long-term plasmid persistence. When trfA genes were cloned under a constitutive promoter in the chromosomes of the four hosts, strains expressing either both TrfA1 and TrfA2 or TrfA1 alone, again, generally elicited a higher PCN of an IncP1-β replicon than strains expressing TrfA2 alone. When a single species of TrfA was produced at different concentrations in E. coli cells, TrfA1 maintained a 3- to 4-fold higher PCN than TrfA2 at the same TrfA concentrations, indicating that replication mediated by TrfA1 is more efficient than that by TrfA2. These results suggest that the broad-host-range properties of IncP-1 plasmids are essentially conferred by TrfA2 and the intact replication origin alone but that TrfA1 is nonetheless important to efficiently establish plasmid replication upon transfer into a broad range of hosts. PMID:22228734
Structure and expression of the rat CYP3A1 gene: isolation of the gene (P450/6betaB) and characterization of the recombinant protein.

PubMed

Nagata, K; Ogino, M; Shimada, M; Miyata, M; Gonzalez, F J; Yamazoe, Y

1999-02-15

A P450 gene (P450/6betaB) of the CYP3A subfamily was isolated from a rat genomic library. Nucleotide sequencing of the exons revealed a high similarity with P450PCN1 cDNA (Gonzalez et al. (1985), J. Biol. Chem. 260, 7345-7441), but differed in 41 nucleotides, resulting in 11 changes and 2 deletions of amino acid residues. The P450/6betaB spanned about 30 kbp and consisted of 13 exons, and was in exon number and size identical with CYP3A2 gene except in the 6th exon, which was shorter than that of CYP3A2. 6beta-B mRNA, which may be transcribed from P450/6betaB, was detected on Northern blotting and by reverse transcription-polymerase chain reaction (RT-PCR). Profiles of the developmental change and induction by a treatment with several chemicals were very similar to those of P450PCN1 mRNA reported previously. P450PCN1 mRNA and gene, however, were not detected by PCR in rats. To determine whether P450/6betaB encodes an active protein, a cDNA was isolated and expressed. Expression of 6beta-B cDNA in COS-1 cells was carried out and revealed that the recombinant protein comigrated with purified P4506beta-4 previously identified as CYP3A1. The recombinant 6beta-B protein showed similar turnover rate and regioselectivity for testosterone with purified P4506beta-4 by the simultaneous addition of NADPH-cytochrome P450 reductase and cytochrome b5. These data suggest that P450/6betaB encodes an active P450 form corresponding to CYP3A1 and P450PCN1 reported previously does not exist in rats. Copyright 1999 Academic Press.
Thermal destruction of wastes containing polychlorinated naphthalenes in an industrial waste incinerator.

PubMed

Yamamoto, Takashi; Noma, Yukio; Sakai, Shin-Ichi

2016-07-02

A series of verification tests were carried out in order to confirm that polychlorinated naphthalenes (PCNs) contained in synthetic rubber products (Neoprene FB products) and aerosol adhesives, which were accidentally imported into Japan, could be thermally destroyed using an industrial waste incinerator. In the verification tests, Neoprene FB products containing PCNs at a concentration of 2800 mg/kg were added to industrial wastes at a ratio of 600 mg Neoprene FB product/kg-waste, and then incinerated at an average temperature of 985 °C. Total PCN concentrations were 14 ng/m 3 N in stack gas, 5.7 ng/g in bottom ash, 0.98 ng/g in boiler dust, and 1.2 ng/g in fly ash. Destruction efficiency (DE) and destruction removal efficiency (DRE) of congener No. 38/40, which is considered an input marker congener, were 99.9974 and 99.9995 %, respectively. The following dioxin concentrations were found: 0.11 ng-TEQ/m 3 N for the stack gas, 0.096 ng-TEQ/g for the bottom ash, 0.010 ng-TEQ/g for the boiler dust, and 0.072 ng-TEQ/g for the fly ash. Since the PCN levels in the PCN destruction test were even at slightly lower concentrations than in the baseline test without PCN addition, the detected PCNs are to a large degree unintentionally produced PCNs and does not mainly stem from input material. Also, the dioxin levels did not change. From these results, we confirmed that PCNs contained in Neoprene FB products and aerosol adhesives could be destroyed to a high degree by high-temperature incineration. Therefore, all recalled Neoprene FB products and aerosol adhesives containing PCNs were successfully treated under the same conditions as the verification tests.
Percutaneous Nephrostomy: Technical Aspects and Indications

PubMed Central

Dagli, Mandeep; Ramchandani, Parvati

2011-01-01

First described in 1955 by Goodwin et al as a minimally invasive treatment for urinary obstruction causing marked hydronephrosis, percutaneous nephrostomy (PCN) placement quickly found use in a wide variety of clinical indications in both dilated and nondilated systems. Although the advancement of modern endourological techniques has led to a decline in the indications for primary nephrostomy placement, PCNs still play an important role in the treatment of multiple urologic conditions. In this article, the indications, placement, and postprocedure management of percutaneous nephrostomy drainage are described. PMID:23204641
Synthesis, growth, structural, thermal and optical studies of pyrrolidinium-2-carboxylate-4-nitrophenol single crystals.

PubMed

Swarna Sowmya, N; Sampathkrishnan, S; Vidyalakshmi, Y; Sudhahar, S; Mohan Kumar, R

2015-06-15

Organic nonlinear optical material, pyrrolidinium-2-carboxylate-4-nitrophenol (PCN) was synthesized and single crystals were grown by slow evaporation solution growth method. Single crystal X-ray diffraction analysis confirmed the structure and lattice parameters of PCN crystals. Infrared, Raman and NMR spectral analyses were used to elucidate the functional groups present in the compound. The thermal behavior of synthesized compound was studied by thermogravimetric and differential scanning calorimetry (TG-DSC) analyses. The photoluminescence property was studied by exciting the crystal at 360 nm. The relative second harmonic generation (SHG) efficiency of grown crystal was estimated by using Nd:YAG laser with fundamental wavelength of 1,064 nm. Copyright © 2015 Elsevier B.V. All rights reserved.
High Performance Piezoelectric Thin Films for Shape Control in Large Inflatable Structures

NASA Technical Reports Server (NTRS)

Neurgaonkar, R. R.; Nelson, J. G.

1999-01-01

The objective of this research and development program was to develop PbZr(1-x)Ti(x)O3 (PZT) and Pb(1-x)Ba(x)Nb2O6 (PBN) materials with large piezoelectric response which are suitable for shape control in large inflatable structures. Two approaches were to be considered: (1) direct deposition of PZT and PBN films on flexible plastic or thin metal foil substrates, and (2) deposition on Si followed by fabrication of hybrid structures on mylar or kapton. Testing in shape control concepts was carried out at JPL and based on their results, the required modifications were made in the final film compositions and deposition techniques. The program objective was to identify and then optimize piezoelectric materials for NASA shape control applications. This involved the bulk piezoelectric and photovoltaic responses and the compatibility of the thin films with appropriate substrate structures. Within the PZT system, Rockwell has achieved the highest reported piezoelectric coefficient (d(sub 33) greater than 100 pC/N) of any ceramic composition. We used this experience in piezoelectric technology to establish compositions that can effectively address the issues of this program. The performance of piezoelectric thin films depends directly on d(sub ij) and Epsilon. The challenge was to find PZT compositions that maintained high d(sub ij) and Epsilon, while also exhibiting a large photovoltaic effect and integrate thin films of this composition into the system structure necessary to meet shape control applications. During the course of this program, several PZT and PLZT compositions were identified that meet these requirements. Two such compositions were successfully used in electrical and optical actuation studies of thin film structures.
High Performance Piezoelectric Thin Films for Shape Control in Large Inflatable Structures

NASA Technical Reports Server (NTRS)

Neurgaonkar, R. R.; Nelson, J. G.

1999-01-01

The objective of this research and development program was to develop PbZr(1-x)Ti(x)O3 (PZT) and Pb(1-x)Ba(x)Nb2O6 (PBN) materials with large piezoelectric response which are suitable for shape control in large inflatable structures. Two approaches were to be considered: (1) direct deposition of PZT and PBN films on flexible plastic or thin metal foil substrates, and (2) deposition on Si followed by fabrication of hybrid structures on mylar or kapton. Testing in shape control concepts was carried out at JPL and based on their results, the required modifications were made in the final film compositions and deposition techniques. The program objective was to identify and then optimize piezoelectric materials for NASA shape control applications. This involved the bulk piezoelectric and photovoltaic responses and the compatibility of the thin films with appropriate substrate structures. Within the PZT system, Rockwell has achieved the highest reported piezoelectric coefficient (d(sub 33) greater than 100 pC/N) of any ceramic composition. We used this experience in piezoelectric technology to establish compositions that can effectively address the issues of this program. The performance of piezoelectric thin films depends directly on d(sub ij) and epsilin. The challenge was to find PZT compositions that maintained high d(sub ij) and epsilon, while also exhibiting a large photovoltaic effect and integrate thin films of this composition into the system structure necessary to meet shape control applications. During the course of this program, several PZT and PLZT compositions were identified that meet these requirements. Two such compositions were successfully used in electrical and optical actuation studies of thin film structures.
New potassium-sodium niobate lead-free piezoceramic: Giant-d33 vs. sintering temperature

NASA Astrophysics Data System (ADS)

Wu, Jiagang; Wang, Xiaopeng; Cheng, Xiaojing; Zheng, Ting; Zhang, Binyu; Xiao, Dingquan; Zhu, Jianguo; Lou, Xiaojie

2014-03-01

The objective of this work is to achieve a giant piezoelectric constant in (K,Na)NbO3-based lead-free ceramics, and then 0.96K0.46Na0.54Nb0.95Sb0.05O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 lead-free piezoceramics were designed and prepared by optimizing the sintering temperature (TS). The rhombohedral-tetragonal phase boundary is found in the ceramics sintered at 1070 ˜ 1105 °C and is suppressed when sintered at low TS of 1060 ˜ 1065 °C. The threshold for TS is 1070 °C in terms of their ferroelectric and piezoelectric properties owing to the difference in the phase boundary and the microstructure, and a large d33 of 388 ˜ 465 pC/N could be attained in a wide TS range of 1070 ˜ 1105 °C, benefiting their practical applications because of broad TS. More interestingly, the ceramic sintered at 1075 °C has a giant d33 of ˜465 pC/N. We think that such a giant d33 of this material system can benefit the development of (K,Na)NbO3-based piezoceramics.
Ziegler-Natta Catalyst Based on MgCl₂/Clay/ID/TiCl₄ for the Synthesis of Spherical Particles of Polypropylene Nanocomposites.

PubMed

Cardoso, Renata da Silva; Oliveira, Jaqueline da Silva; Ramis, Luciana Bortolin; Marques, Maria de Fátima V

2018-07-01

In the present work, we have designed MgCl2/clay/internal donor (ID)/TiCl4 based bisupported Ziegler-Natta catalysts containing varying amounts of organoclay (montmorillonite) in order to synthesize spherical particles of polypropylene/clay nanocomposites (PCN). The organoclay was introduced into the catalyst support formulation and PCN was obtained using the in situ polymerization technique. Decreasing the reaction time, it was possible to obtain nanocomposites with high concentrations of clay (masterbatches). Micrographs of SEM confirmed the spherical morphology of the catalysts. In addition, XRD patterns show that the active sites for polymerization were inserted in the clay galleries. The catalytic performance was evaluated in slurry propylene polymerization using triethylaluminium as cocatalyst and silane as external electron donor at 70 °C, 4 bar, and different reaction times. The PCNs obtained containing different clay amounts were characterized by X-ray diffraction, thermal analyses, transmission electronic microscopy, and extractables in heptane. The results revealed that the synthesized PP/clay particles were also spherical showing that the morphological control is possible even using catalysts containing high amounts of clay. The PCN presented high degradation temperature (459 °C). The XRD peak related to the clay interlamellar distance has shifted to lower angles, and TEM images confirmed the formation of exfoliated/intercalated clay on the PP matrix and absence of microparticles of clay.
Breeding of a new potato variety ‘Nagasaki Kogane’ with high eating quality, high carotenoid content, and resistance to diseases and pests

PubMed Central

Sakamoto, Yu; Mori, Kazuyuki; Matsuo, Yuuki; Mukojima, Nobuhiro; Watanabe, Wataru; Sobaru, Norio; Tamiya, Seiji; Nakao, Takashi; Hayashi, Kazuya; Watanuki, Hitomi; Nara, Kazuhiro; Yamazaki, Kaoru; Chaya, Masataka

2017-01-01

‘Nagasaki Kogane’ is a new potato variety bred from a cross between ‘Saikai 35’ as a female parent and ‘Saikai 33’ as a male. ‘Saikai 35’ is resistant to bacterial wilt, contains the H1 and Rychc genes for resistance to the potato cyst nematode (PCN) and potato virus Y (PVY), respectively, and has high carotenoid content, while ‘Saikai 33’ has large and high-yielding tubers and is resistant to both bacterial wilt and PCN. The carotenoid content of ‘Nagasaki Kogane’ is higher than that of ‘Dejima’, a common double cropping variety. The taste quality of steamed ‘Nagasaki Kogane’ is comparable to that of ‘Inca-no-mezame’ tubers, which has high levels of carotenoid, and superior to ‘Nishiyutaka’, another popular double cropping variety. ‘Nagasaki Kogane’ is suitable for French fries, because its tuber has high starch content. The marketable yield of ‘Nagasaki Kogane’ was higher than that of ‘Inca-no-mezame’ in spring cropping, although it was lower than that of ‘Nishiyutaka’ in double cropping regions. ‘Nagasaki Kogane’ tubers are larger on average than ‘Inca-no-mezame’ tubers in spring cropping. Moreover, the ‘Nagasaki Kogane’ variety is resistant to PCN and PVY, and exhibits a high level of resistance to bacterial wilt. PMID:28744186
Acute toxicity of some synthetic cyanogens in rats: time-dependent cyanide generation and cytochrome oxidase inhibition in soft tissues after sub-lethal oral intoxication.

PubMed

Rao, Pooja; Singh, Poonam; Yadav, Shiv Kumar; Gujar, Niranjan L; Bhattacharya, Rahul

2013-09-01

Cyanogens include complex nitrile-containing compounds that can generate free cyanide of toxicological significance. Acute toxicity, time-dependent cyanide generation and cytochrome oxidase (CYTOX) inhibition in soft tissues, and urinary thiocyanate levels were measured after acute cyanogen intoxication in rats. Order of cyanogens in terms of LD₅₀ was: malononitrile (MCN)>propionitrile (PCN)≈sodium nitroprusside (SNP)>acrylonitrile (ACN)>succinonitrile (SCN)>acetonitrile (ATCN) for oral, and SNP>MCN>ACN>PCN>SCN>ATCN for intraperitoneal and subcutaneous routes. MCN was most toxic by oral (LD₅₀=66.4 mg/kg) and SNP by intraperitoneal (LD₅₀=16.7 mg/kg) and subcutaneous (LD₅₀=11.9 mg/kg) routes. Minimum survival time (25 min) was recorded after 4.0 LD₅₀ ATCN. Order of cyanogens (0.75 LD₅₀; oral) on the basis of maximum blood cyanide and time of peak cyanide generation were: ATCN>SNP>SCN>PCN>MCN>ACN, and MCN (30 min)
[Health education as a transversal proposal: an analysis of the national curriculum guidelines and certain teaching conceptions].

PubMed

Marinho, Julio Cesar Bresolin; da Silva, João Alberto; Ferreira, Maira

2015-01-01

Starting from the assumption that transversality is conceived as a proposal for change in education, the article outlines certain inferences on the subject. The analysis is founded on the transversal subject of "health" in the national curriculum guidelines (PCN), on semi-structured interviews and on reports resulting from conversations with teachers. It reveals that, in Brazil, the notion of transversality gained importance during the 1990s, when the PCN were established, which listed "transversal themes." In the view of the teachers interviewed, health education appears as something apart, on the margins of the curriculum. The authors believe that this is the case owing to the consolidation of the subject fields at school and the curricular structure in teacher training courses.
[Effect of the soil contamination with a potato cyst-forming nematode on the community structure of soil-inhabiting nematodes].

PubMed

Gruzdeva, L I; Suzhchuk, A A

2008-01-01

Nematode community structure of the potato fields with different infection levels of potato cyst-forming nematode (PCN) such as 10, 30 and 214 cysts per 100 g of soil has been investigated. The influence of specialized parasite on nematode fauna and dominance character of different ecological-trophic groups were described. Parasitic nematode genera in natural meadow biocenosis and agrocenoses without PCN are Paratylenchus, Tylenchorhynchus, and Helicotylenchus. It is established, that Paratylenchus nanus was the prevalent species among plant parasites at low infection level. Larvae of Globodera prevailed in the soil with middle and high infection levels and substituted individuals of other genera of parasitic nematodes. The fact of increase in number of hyphal-feeding nematode Aphelenchus avenae was revealed.
On an adaptive preconditioned Crank-Nicolson MCMC algorithm for infinite dimensional Bayesian inference

NASA Astrophysics Data System (ADS)

Hu, Zixi; Yao, Zhewei; Li, Jinglai

2017-03-01

Many scientific and engineering problems require to perform Bayesian inference for unknowns of infinite dimension. In such problems, many standard Markov Chain Monte Carlo (MCMC) algorithms become arbitrary slow under the mesh refinement, which is referred to as being dimension dependent. To this end, a family of dimensional independent MCMC algorithms, known as the preconditioned Crank-Nicolson (pCN) methods, were proposed to sample the infinite dimensional parameters. In this work we develop an adaptive version of the pCN algorithm, where the covariance operator of the proposal distribution is adjusted based on sampling history to improve the simulation efficiency. We show that the proposed algorithm satisfies an important ergodicity condition under some mild assumptions. Finally we provide numerical examples to demonstrate the performance of the proposed method.

Dynamic Nuclear Polarization NMR Spectroscopy of Polymeric Carbon Nitride Photocatalysts: Insights into Structural Defects and Reactivity.

PubMed

Li, Xiaobo; Sergeyev, Ivan V; Aussenac, Fabien; Masters, Anthony F; Maschmeyer, Thomas; Hook, James M

2018-06-04

Metal-free polymeric carbon nitrides (PCNs) are promising photocatalysts for solar hydrogen production, but their structure-photoactivity relationship remains elusive. Two PCNs were characterized by dynamic-nuclear-polarization-enhanced solid-state NMR spectroscopy, which circumvented the need for specific labeling with either 13 C- or 15 N-enriched precursors. Rapid 1D and 2D data acquisition was possible, providing insights into the structural contrasts between the PCNs. Compared to PCN_B with lower performance, PCN_P is a more porous and more active photocatalyst that is richer in terminal N-H bonds not associated with interpolymer chains. It is proposed that terminal N-H groups act as efficient carrier traps and reaction sites. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Survival-mediated capture and fusion cross sections for heavy-element synthesis

NASA Astrophysics Data System (ADS)

Yao, L.; Loveland, W.

2018-01-01

The cross section for producing a heavy evaporation residue σEVR in a fusion reaction can be written as a product of three nonseparable factors, i.e., the capture cross section, the fusion probability PCN, and the survival probability Wsur. Each of these factors is dependent on the spin. However, one must remember that the Wsur term is zero or very small for higher spin values, thus effectively limiting the capture and fusion terms. For a series of ˜287 reactions leading to heavy evaporation residues with ZCN≤110 , we point out the implications of this fact for capture cross sections for heavy element formation reactions. From a comparison of calculated and measured evaporation residue cross sections we deduce values of the fusion probability PCN for some of these reactions.
RNA-Seq reveals common and unique PXR- and CAR-target gene signatures in the mouse liver transcriptome.

PubMed

Cui, Julia Yue; Klaassen, Curtis D

2016-09-01

The pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are well-known xenobiotic-sensing nuclear receptors with overlapping functions. However, there lacks a quantitative characterization to distinguish between the PXR and CAR target genes and signaling pathways in the liver. The present study performed a transcriptomic comparison of the PXR- and CAR-targets using RNA-Seq in livers of adult wild-type mice that were treated with the prototypical PXR ligand PCN (200mg/kg, i.p. once daily for 4days in corn oil) or the prototypical CAR ligand TCPOBOP (3mg/kg, i.p., once daily for 4days in corn oil). At the given doses, TCPOBOP differentially regulated many more genes (2125) than PCN (212), and 147 of the same genes were differentially regulated by both chemicals. As expected, the top pathways differentially regulated by both PCN and TCPOBOP were involved in xenobiotic metabolism, and they also up-regulated genes involved in retinoid metabolism, but down-regulated genes involved in inflammation and iron homeostasis. Regarding unique pathways, PXR activation appeared to overlap with the aryl hydrocarbon receptor signaling, whereas CAR activation appeared to overlap with the farnesoid X receptor signaling, acute-phase response, and mitochondrial dysfunction. The mRNAs of differentially regulated drug-processing genes (DPGs) partitioned into three patterns, namely TCPOBOP-induced, PCN-induced, as well as TCPOBOP-suppressed gene clusters. The cumulative mRNAs of the differentially regulated DPGs, phase-I and -II enzymes, as well as efflux transporters were all up-regulated by both PCN and TCPOBOPOP, whereas the cumulative mRNAs of the uptake transporters were down-regulated only by TCPOBOP. The absolute mRNA abundance in control and receptor-activated conditions was examined in each DPG category to predict the contribution of specific DPG genes in the PXR/CAR-mediated pharmacokinetic responses. The preferable differential regulation by TCPOBOP in the entire hepatic transcriptome correlated with a marked change in the expression of many DNA and histone epigenetic modifiers. In conclusion, the present study has revealed known and novel, as well as common and unique targets of PXR and CAR in mouse liver following pharmacological activation using their prototypical ligands. Results from this study will further support the role of these receptors in regulating the homeostasis of xenobiotic and intermediary metabolism in the liver, and aid in distinguishing between PXR and CAR signaling at various physiological and pathophysiological conditions. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie. Copyright © 2016 Elsevier B.V. All rights reserved.
Crystal growth, piezoelectric, non-linear optical and mechanical properties of lithium hydrogen oxalate monohydrate single crystal

NASA Astrophysics Data System (ADS)

Chandran, Senthilkumar; Paulraj, Rajesh; Ramasamy, P.

2017-05-01

Semi-organic lithium hydrogen oxalate monohydrate non-linear optical single crystals have been grown by slow evaporation solution growth technique at 35 °C. Single crystal X-ray diffraction study showed that the grown crystal belongs to the triclinic system with space group P1. The mechanical strength decreases with increasing load. The piezoelectric coefficient is found to be 1.41 pC/N. The nonlinear optical property was measured using Kurtz Perry powder technique and SHG efficiency was almost equal to that of KDP.
Structure and electrical properties of <001> textured (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 lead-free piezoelectric ceramics

NASA Astrophysics Data System (ADS)

Ye, S. K.; Fuh, J. Y. H.; Lu, L.

2012-06-01

<001> textured (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ) lead-free piezoelectric ceramics were prepared by templated-grain growth method using BaTiO3 as template. The degree of orientation and the microstructure of the ceramics with different amount of template were investigated. The electrical properties of the textured-ceramics in the optimized condition were dramatically enhanced compared with randomly-oriented BCTZ ceramics. The textured BCTZ ceramics showed high piezoelectric constants d33 = 470 pC/N and d31 = -170 pC/N, and high electromechanical coupling factors kp = 44% and k31 = 22%. In addition, the Curie point of the textured ceramics revealed an increase with the template content.
Management of the potato cyst nematode (Globodera pallida) with bio-fumigants/stimulants.

PubMed

Martin, T J G; Turner, S J; Fleming, C C

2007-01-01

Field trials evaluated the effect of four plant-based bio-fumigants/stimulants on population levels of G. pallida and the resulting potato yields and quality. Three formulations contained seaweed biostimulants (Algifol, Nutridip and Metastim) and one bio-fumigant containing mustard and chilli pepper extracts (Dazitol). These were compared with the fumigant nematicide Nemathorin and untreated control plots. The effect of G. pallida on growing potato crops was assessed by recording haulm characteristics which indicated that the nematicide treatment gave most protection. Levels of PCN juveniles and migratory nematodes were assessed during the trial. Plots treated with Nemathorin and Dazitol had fewest PCN, whilst the highest number of migratory nematodes occurred in fallow plots. Sixteen weeks after planting the nematicide treatment produced highest yield and tuber numbers. Dazitol treatment produced a lower yield but the largest tubers.
The growth and investigations of electromechanical properties of Fresnoite Ba2Si2TiO8 crystal as a function of orientation

NASA Astrophysics Data System (ADS)

Shen, Chuanying; Wang, Duanliang; Zhang, Jinyue; Zhang, Huaijin; Wang, Jiyang; Boughton, Robert I.

2018-04-01

Large sized Fresnoite Ba2TiSi2O8 single crystals were grown by the Czochralski method. Using coordinate transformation methods, the relative dielectric, piezoelectric and elastic constants of Fresnoite Ba2TiSi2O8 as a function of orientation were investigated, and their two- and three-dimensional spatial distributions are presented. From them, the maximum values of the piezoelectric coefficients and the corresponding rotation angle can be obtained. The maximum values of coefficients d22∗, d23∗, d24∗, d32∗, d33∗ and d34∗ were achieved for rotation angles of 40°, 32°, 0°, 58°, 50° and 90°, respectively, and are on the order of 8.7, -4.7, 17.5, 4.7, 8.7 and 17.5 pC/N, respectively. Furthermore, the validity of the electromechanical properties investigation as a function of orientation was verified. The relative dielectric permittivity, elastic constant and piezoelectric coefficient of a ZXl50o cut rod were calculated and found to be 14.1, 8.7 pC/N and 11.2 pm2/N, respectively, in good agreement with the experimental values of 12.7, 9.1 pC/N and 11.7 pm2/N. This investigation is important in providing direction for theoretical research and device design of piezoelectric Ba2TiSi2O8 crystals.
Determination of metals in lubricating oils by flame atomic absorption spectrometry using a single-bore high-pressure pneumatic nebulizer.

PubMed

Mora, J; Todolí, J L; Sempere, F J; Canals, A; Hernandis, V

2000-12-01

The behaviour of a single-bore high-pressure pneumatic nebulizer (SBHPPN) as a tool for the analysis of lubricating oils by flame atomic absorption spectrometry (FAAS) was investigated. The effects of the sample oil content [from 10% to 100% (w/w) oil in 4-methylpentan-2-one, IBMK] and the carrier nature (IBMK and methanol) on the characteristics of the aerosols generated, on the analyte transport efficiency and on the analytical figures of merit in FAAS were studied. A pneumatic concentric nebulizer (PCN) was used for comparison. Increasing the oil content increases the viscosity of the sample. With the PCN this gives rise to coarser aerosols, making it impossible to nebulize samples with an oil content higher than 70% (w/w). Using the SBHPPN, the viscosity of the sample scarcely affects the characteristics of the primary aerosols. Hence, the SBHPPN is able, by using the appropriate carrier, to nebulize pure lubricating oils. Among the carriers tested, IBMK is the most advisable because it is fully miscible with all the oil samples. The SBHPPN provides higher sensitivities and lower limits of detection than the PCN. Compared with a method based on organic dilution, the use of the SBHPPN for the direct analysis of lubricating oils by FAAS makes it possible, in addition to increasing the analysis throughput, to detect elements at lower concentrations. Moreover, the SBHPPN provides similar results to those obtained using a previous acid digestion step.
Multi-station basis for Polar Cap (PC) indices: ensuring credibility and operational reliability

NASA Astrophysics Data System (ADS)

Stauning, Peter

2018-02-01

The Polar Cap (PC) indices, PCN (North) and PCS (South) are based on polar geomagnetic observations from Qaanaaq (Thule) and Vostok, respectively, processed to measure the transpolar plasma convection that may seriously affect space weather conditions. To establish reliable space weather forecasts based on PC indices, and also to ensure credibility of their use for scientific analyses of solar wind-magnetosphere interactions, additional sources of data for the PC indices are investigated. In the search for alternative index sources, objective quality criteria are established here to be used for the selection among potential candidates. These criteria are applied to existing PC index series to establish a quality scale. In the Canadian region, the data from Resolute Bay magnetometer are shown to provide alternative PCN indices of adequate quality. In Antarctica, the data from Concordia Dome-C observatory are shown to provide basis for alternative PCS indices. In examples to document the usefulness of these alternative index sources it is shown that PCN indices in a real-time version based on magnetometer data from Resolute Bay could have given 6 h of early warning, of which the last 2 h were "red alert", up to the onset of the strong substorm event on 13 March 1989 that caused power outage in Quebec. The alternative PCS indices based on data from Dome-C have helped to disclose that presently available Vostok-based PCS index values are corrupted throughout most of 2011.
Population PKPD modeling of BACE1 inhibitor-induced reduction in Aβ levels in vivo and correlation to in vitro potency in primary cortical neurons from mouse and guinea pig.

PubMed

Janson, Juliette; Eketjäll, Susanna; Tunblad, Karin; Jeppsson, Fredrik; Von Berg, Stefan; Niva, Camilla; Radesäter, Ann-Cathrin; Fälting, Johanna; Visser, Sandra A G

2014-03-01

The aims were to quantify the in vivo time-course between the oral dose, the plasma and brain exposure and the inhibitory effect on Amyloid β (Aβ) in brain and cerebrospinal fluid, and to establish the correlation between in vitro and in vivo potency of novel β-secretase (BACE1) inhibitors. BACE1-mediated inhibition of Aβ was quantified in in vivo dose- and/or time-response studies and in vitro in SH-SY5Y cells, N2A cells, and primary cortical neurons (PCN). An indirect response model with inhibition on Aβ production rate was used to estimate unbound in vivo IC 50 in a population pharmacokinetic-pharmacodynamic modeling approach. Estimated in vivo inhibitory potencies varied between 1 and 1,000 nM. The turnover half-life of Aβ40 in brain was predicted to be 0.5 h in mouse and 1 h in guinea pig. An excellent correlation between PCN and in vivo potency was observed. Moreover, a strong correlation in potency was found between human SH-SY5Y cells and mouse PCN, being 4.5-fold larger in SH-SY5Y cells. The strong in vivo-in vitro correlation increased the confidence in using human cell lines for screening and optimization of BACE1 inhibitors. This can optimize the design and reduce the number of preclinical in vivo effect studies.
Percutaneous nephrolithotomy in ectopically located kidneys and in patients with musculoskeletal deformities.

PubMed

Srivastava, A; Gupta, P; Chaturvedi, S; Singh, P; Kapoor, R; Dubey, D; Kumar, A

2010-01-01

To assess the feasibility, safety and results of percutaneous nephrolithotomy (PNL) in ectopically located kidneys and in patients with musculoskeletal deformities. Thirteen such patients underwent PNL between June 2005 and May 2008. Mean stone size was 27.4 mm (16-37 mm). Six patients had severe kyphoscoliosis, 2 patients each had achondroplasia, cross-fused ectopia and pelvic ectopic kidney, and 1 patient had thoracic kidney. All had a preoperative CT scan of the abdomen. Preoperative ultrasound- or CT-guided percutaneous nephrostomy (PCN) was done in 10 patients. Three patients underwent laparoscopic-assisted PNL. All underwent standard PNL. The stone-free rate, complication rate and need for secondary intervention were evaluated. PNL was successfully completed in all. A second ultrasound-guided intraoperative puncture was required in 2 patients. Re-look PNL was required in 1 patient and the same patient later required shock wave lithotripsy for complete stone clearance. The remaining 12 patients (92.3%) were rendered stone-free in a single sitting. PNL is a feasible and effective modality in anomalous kidneys. Preoperative planning with CT and image-guided PCN is helpful in these situations. Laparoscopic-assisted PNL can be safely performed in patients where access to a renal collecting system by fluoroscopy or image-guided assistance (ultrasound or CT scan) is not possible. Copyright (c) 2010 S. Karger AG, Basel.
Effect of (Li,Ce) doping in Aurivillius phase material Na0.25K0.25Bi2.5Nb2O9

NASA Astrophysics Data System (ADS)

Gai, Zhi-Gang; Wang, Jin-Feng; Wang, Chun-Ming

2007-01-01

The effect of (Li,Ce) substitution for A site on the properties of Na0.25K0.25Bi2.5Nb2O9-based ceramics was investigated. The piezoelectric activity of Na0.25K0.25Bi2.5Nb2O9-based ceramics is significantly improved by the modification of lithium and cerium. The Curie temperature (TC) gradually increases from 668to684°C with increasing the (Li,Ce) modification. The piezoelectric coefficient d33 of the [(Na0.5K0.5)Bi]0.44(LiCe)0.03[]0.03Bi2Nb2O9 ceramic was found to be 28pC/N, the highest value among the Na0.25K0.25Bi2.5Nb2O9-based ceramics and also almost 50% higher than the reported d33 values of other bismuth layer-structured ferroelectric systems (˜5-19pC/N). The planar coupling factors kp and kt were found to be 8.0% and 23.0%, together with the high TC (˜670°C) and stable piezoelectric properties, demonstrating that the (Li,Ce) modified Na0.25K0.25Bi2.5Nb2O9-based material a promising candidate for high temperature applications.
Materials Data on P(CN)3 (SG:122) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-04

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
Sequential Linker Installation: Precise Placement of Functional Groups in Multivariate Metal-Organic Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, S; Lu, WG; Chen, YP

2015-03-11

A unique strategy, sequential linker installation (SLI), has been developed to construct multivariate MOFs with functional groups precisely positioned. PCN-700, a Zr-MOF with eight-connected Zr6O4(OH)(8)(H2O)(4) clusters, has been judiciously designed; the Zr-6 clusters in this MOF are arranged in such a fashion that, by replacement of terminal OH-/H2O ligands, subsequent insertion of linear dicarboxylate linkers is achieved. We demonstrate that linkers with distinct lengths and functionalities can be sequentially installed into PCN-700. Single-crystal to single-crystal transformation is realized so that the positions of the subsequently installed linkers are pinpointed via single-crystal X-ray diffraction analyses. This methodology provides a powerful toolmore » to construct multivariate MOFs with precisely positioned functionalities in the desired proximity, which would otherwise be difficult to achieve.« less
Electromechanical behavior of [001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics

NASA Astrophysics Data System (ADS)

Yan, Yongke; Wang, Yu. U.; Priya, Shashank

2012-05-01

[001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) ceramics were synthesized by using templated grain growth method. Significantly high [001] texture degree corresponding to 0.98 Lotgering factor was achieved at 1 vol. % BaTiO3 template. Electromechanical properties for [001]-textured PMN-PT ceramics with 1 vol. % BaTiO3 were found to be d33 = 1000 pC/N, d31 = 371 pC/N, ɛr = 2591, and tanδ = ˜0.6%. Elastoelectric composite based modeling results showed that higher volume fraction of template reduces the overall dielectric constant and thus has adverse effect on the piezoelectric response. Clamping effect was modeled by deriving the changes in free energy as a function of applied electric field and microstructural boundary condition.
Enhancing Piezoelectric Performance of CaBi2Nb2O9 Ceramics Through Microstructure Control

NASA Astrophysics Data System (ADS)

Chen, Huanbei; Zhai, Jiwei

2012-08-01

Calcium bismuth niobate (CaBi2Nb2O9, CBN) is a high-Curie-temperature ( T C) piezoelectric material with relatively poor piezoelectric performance. Attempts were made to enhance the piezoelectric and direct-current (DC) resistive properties of CBN ceramics by increasing their density and controlling their microstructural texture, which were achieved by combining the templated grain growth and hot pressing methods. The modified CBN ceramics with 97.5% relative density and 90.5% Lotgering factor had much higher piezoelectric constant ( d 33 = 20 pC/N) than those prepared by the normal sintering process ( d 33 = 6 pC/N). High-temperature alternating-current (AC) impedance spectroscopy of the CBN ceramics was measured by using an impedance/gain-phase analyzer. Their electrical resistivity was approximately 6.5 × 104 Ω cm at 600°C. Therefore, CBN ceramics can be used for high-temperature piezoelectric applications.
Stable metal-organic frameworks containing single-molecule traps for enzyme encapsulation.

PubMed

Feng, Dawei; Liu, Tian-Fu; Su, Jie; Bosch, Mathieu; Wei, Zhangwen; Wan, Wei; Yuan, Daqiang; Chen, Ying-Pin; Wang, Xuan; Wang, Kecheng; Lian, Xizhen; Gu, Zhi-Yuan; Park, Jihye; Zou, Xiaodong; Zhou, Hong-Cai

2015-01-19

Enzymatic catalytic processes possess great potential in chemical manufacturing, including pharmaceuticals, fuel production and food processing. However, the engineering of enzymes is severely hampered due to their low operational stability and difficulty of reuse. Here, we develop a series of stable metal-organic frameworks with rationally designed ultra-large mesoporous cages as single-molecule traps (SMTs) for enzyme encapsulation. With a high concentration of mesoporous cages as SMTs, PCN-333(Al) encapsulates three enzymes with record-high loadings and recyclability. Immobilized enzymes that most likely undergo single-enzyme encapsulation (SEE) show smaller Km than free enzymes while maintaining comparable catalytic efficiency. Under harsh conditions, the enzyme in SEE exhibits better performance than free enzyme, showing the effectiveness of SEE in preventing enzyme aggregation or denaturation. With extraordinarily large pore size and excellent chemical stability, PCN-333 may be of interest not only for enzyme encapsulation, but also for entrapment of other nanoscaled functional moieties.
Stable metal-organic frameworks containing single-molecule traps for enzyme encapsulation

NASA Astrophysics Data System (ADS)

Feng, Dawei; Liu, Tian-Fu; Su, Jie; Bosch, Mathieu; Wei, Zhangwen; Wan, Wei; Yuan, Daqiang; Chen, Ying-Pin; Wang, Xuan; Wang, Kecheng; Lian, Xizhen; Gu, Zhi-Yuan; Park, Jihye; Zou, Xiaodong; Zhou, Hong-Cai

2015-01-01

Enzymatic catalytic processes possess great potential in chemical manufacturing, including pharmaceuticals, fuel production and food processing. However, the engineering of enzymes is severely hampered due to their low operational stability and difficulty of reuse. Here, we develop a series of stable metal-organic frameworks with rationally designed ultra-large mesoporous cages as single-molecule traps (SMTs) for enzyme encapsulation. With a high concentration of mesoporous cages as SMTs, PCN-333(Al) encapsulates three enzymes with record-high loadings and recyclability. Immobilized enzymes that most likely undergo single-enzyme encapsulation (SEE) show smaller Km than free enzymes while maintaining comparable catalytic efficiency. Under harsh conditions, the enzyme in SEE exhibits better performance than free enzyme, showing the effectiveness of SEE in preventing enzyme aggregation or denaturation. With extraordinarily large pore size and excellent chemical stability, PCN-333 may be of interest not only for enzyme encapsulation, but also for entrapment of other nanoscaled functional moieties.
Source identification, spatio-temporal distribution and ecological risk of persistent organic pollutants in sediments from the upper Danube catchment.

PubMed

Kukučka, Petr; Audy, Ondřej; Kohoutek, Jiří; Holt, Eva; Kalábová, Tereza; Holoubek, Ivan; Klánová, Jana

2015-11-01

Riverine sediments, collected on a monthly basis during a period of one year, from five sites in a mixed land use region of the Czech Republic were analysed for chlorinated and brominated persistent organic pollutants (POPs). The region is located in the upper catchment of the Danube River. The POPs concentrations were as follows: 11-930 pg g(-1) polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs), 170-980 pg g(-1) dioxin-like polychlorinated biphenyls (dl-PCBs), 34-13,700 pg g(-1) polychlorinated naphthalenes (PCNs), 5.7-29,200 pg g(-1) polybrominated diphenylethers (PBDEs) and 0.21-351 ng g(-1) hexabromocyclododecanes (HBCDs). Concentrations expressed as toxic equivalents (TEQs), for PCDD/F+dl-PCB+PCN (TEQPCDD/F+dl-PCB+PCN) ranged from 0.37 to 19 pg g(-1). The results revealed a clear spatial separation between sites based on concentration and congener profile. There were also some obvious temporal patterns of selected POPs, which were related to river flow (seasonality) and organic carbon (TOC) of the sediment. Potential sources of POPs include local municipalities (flame retardants), some diffuse sources (PCNs and PCDDs/Fs) and potential point sources (PBDEs). Risk assessment based on risk quotients (RQ) revealed limited to medium ecological risk from PBDEs. TEQPCDD/F+dl-PCB+PCN were low relative to other European rivers, hence the risk to aquatic organisms was considered to be low. PCNs contributed significantly to overall TEQ in several cases. Copyright © 2015 Elsevier Ltd. All rights reserved.
A Pest of Importance

USDA-ARS?s Scientific Manuscript database

Potato cyst nematodes (PCN), G. rostochiensis and G. pallida, are internationally-recognized quarantine pests and considered the most devastating pests of potatoes worldwide. PCNs continue to spread throughout North America and were recently detected in Idaho (G. pallida) and Quebec and Alberta, Can...

Design and implementation of a versatile and variable-frequency piezoelectric coefficient measurement system.

PubMed

Wu, J S; Huang, Y K; Wu, F L; Lin, D Y

2012-08-01

We present a simple but versatile piezoelectric coefficient measurement system, which can measure the longitudinal and transverse piezoelectric coefficients in the pressing and bending modes, respectively, at different applied forces and a wide range of frequencies. The functionality of this measurement system has been demonstrated on three samples, including a PbZr(0.52)Ti(0.48)O(3) (PZT) piezoelectric ceramic bulk, a ZnO thin film, and a laminated piezoelectric film sensor. The static longitudinal piezoelectric coefficients of the PZT bulk and the ZnO film are estimated to be around 210 and 8.1 pC/N, respectively. The static transverse piezoelectric coefficients of the ZnO film and the piezoelectric film sensor are determined to be, respectively, -0.284 and -0.031 C/m(2).
CORRELATION OF POLYCHLORINATED NAPHTHALENES WITH POLYCHLORINATED DIBENZOFURANS FORMED FROM WASTE INCINERATION

EPA Science Inventory

Isomer composition of polychlorinated naphthalenes (PCNs) was measured for municipal waste incinerator fly ash samples,and for emission samples produced from soot and copper deposit experiments conducted at EPA. Two types of PCN isomer patterns were identified. One pattern cxonta...
Cooperative electrochemical water oxidation by Zr nodes and Ni–porphyrin linkers of a PCN-224 MOF thin film

DOE PAGES

Usov, P. M.; Ahrenholtz, S. R.; Maza, W. A.; ...

2016-10-06

In this paper, we demonstrate a new strategy for cooperative catalysis and proton abstraction via the incorporation of independent species competent in the desired reactivity into a metal–organic framework (MOF) thin film.
Organic halogenated contaminants in mother-fetus pairs of harbor seals (Phoca vitulina richardii) from Alaska, 2000-2002

USDA-ARS?s Scientific Manuscript database

Environmental stressors may interfere with foraging, survival and reproduction of marine mammals resulting in marine mammal population decline. In this study, organic halogenated pollutants [OHs, including organochlorine pesticides, polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCN...
Polytetramethylene glycol-modified polycyanurate matrices reinforced with nanoclays: synthesis and thermomechanical performance

NASA Astrophysics Data System (ADS)

Anthoulis, G. I.; Kontou, E.; Fainleib, A.; Bei, I.

2009-03-01

The outstanding improvement in the physical properties of cyanate esters (CEs) compared with those of competitor resins, such as epoxies, has attracted appreciable attention recently. Cyanate esters undergo thermal polycyclotrimerization to give polycyanurates (PCNs). However, like most thermo setting resins, the main draw back of CEs is brittleness. To over come this disadvan tage, CEs can be toughened by the introduction of polytetramethylene glycol (PTMG), a hydroxyl-terminated polyether. How ever, PTMG has a detrimental impact on Young's modulus. To simultaneously enhance both the ductility and the stiffness of CE, we added PTMG and an organoclay (mont morillonite, MMT) to it. A series of PCN/PTMG/MMT nanocomposites with a constant PTMG weight ratio was pre pared, and the resulting nanophase morphology, i.e., the degree of filler dispersion and distribution in the composite and the thermomechanical properties, in terms of glass-transition behaviour, Young's modulus, tensile strength, and elongation at break, were examined using the scanning elec tron micros copy (SEM), a dynamic mechanical analysis (DMA), and stress-strain measurements, re spectively. It was found that, at a content of MMT below 2 wt.%, MMT nanoparticles were distributed uniformly in the matrix, suggesting a lower degree of agglomeration for these materials. In the glassy state, the significant increase in the storage modulus revealed a great stiffening effect of MMT due to its high Young's modulus. The modification with PTMG led to a 233% greater elongation at break compared with that of neat PCN. The nanocomposites exhibited an invariably higher Young's modulus than PCN/PTMG for all the volume factors of organoclay examined, with the 2 wt.% material displaying the most pronounced in crease in the modulus, in agreement with micros copy results.
Congener-specific analysis of polychlorinated naphthalenes (PCNs) in the major Chinese technical PCB formulation from a stored Chinese electrical capacitor.

PubMed

Huang, Jun; Yu, Gang; Yamauchi, Makoto; Matsumura, Toru; Yamazaki, Norimasa; Weber, Roland

2015-10-01

Impurity of polychlorinated naphthalenes (PCNs) in commercial polychlorinated biphenyl (PCB) formulations has been recognized as a relevant source of PCNs in the environment. Congener-specific analysis of most main PCB formulations has been accomplished previously, excluding the Chinese product. The insulating oil in a stored Chinese electric capacitor containing the major Chinese technical formulation "PCB3" was sampled and tested by isotope dilution technology using high-resolution gas chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS). The detected concentration of PCNs in the Chinese PCB oil sample was 1,307.5 μg/g and therefore significantly higher than that reported in PCB formulations from other countries, as well as that in the transformer oil (ASKAREL Nr 1740) additionally tested in the present study for comparison. Based on the measurement, the total amount of PCNs in Chinese PCB3 oil is estimated to be 7.8 t, which would mean only 0.005 % of global production of PCNs of 150,000 t. The homolog profile is similar to those of PCN in Aroclor 1262 and Clophen A40, where the contributions from hexa-CNs and hepta-CNs are predominant and accounted for similar proportions. The Toxic Equivalent Quantity (TEQ) concentration of dioxin-like PCN congeners is 0.47 μg TEQ/g, with the dominant contributors of CN-73 and CN-66/67. This TEQ content from PCN is higher than that in most other PCB formulations with the exemption of the Russian Sovol formulation. The total TEQ in the historic 6,000 t of the Chinese PCB3 formulation is estimated to be 2.8 kg TEQ.
Suicide inactivation of cytochrome P-450 by methoxsalen. Evidence for the covalent binding of a reactive intermediate to the protein moiety

DOE Office of Scientific and Technical Information (OSTI.GOV)

Labbe, G.; Descatoire, V.; Beaune, P.

Incubation of rat liver microsomes with (3H)methoxsalen and NADPH resulted in the covalent binding of a methoxsalen intermediate to proteins comigrating with cytochromes P-450 UT-A, PB-B/D, ISF-G and PCN-E. Binding was increased by pretreatments with phenobarbital, beta-naphthoflavone (beta NF) and dexamethasone. Such pretreatments also increased the loss of CO-binding capacity either after administration of methoxsalen, or after incubation of hepatic microsomes with methoxsalen and NADPH. Immunoprecipitation of the methoxsalen metabolite-protein adducts in phenobarbital-induced microsomes was moderate with anti-UT-A antibodies, but marked with anti-PB-B/D and anti-PCN-E antibodies. Immunoprecipitation was observed also with anti-ISF-G (anti-beta NF-B) antibodies in beta NF-induced microsomes. Methoxsalenmore » (0.25 mM) inhibited markedly the benzphetamine demethylase activity of phenobarbital-induced microsomes and the erythromycin demethylase activity of dexamethasone-induced microsomes. Whereas methoxsalen itself did not produce any binding spectrum, in contrast either in vivo administration of methoxsalen or incubation in vitro with methoxsalen and NADPH resulted in a low-to-high spin conversion of cytochrome P-450 as suggested by the appearance of a spectrum analogous to a type I binding spectrum. This low-to-high spin conversion was apparently due to a methoxsalen intermediate (probably, covalently bound to the protein and preventing partial sixth ligation of the iron). We conclude that suicide inactivation of cytochrome P-450 by methoxsalen is related to the covalent binding of a methoxsalen intermediate to the protein moiety of several cytochrome P-450 isoenzymes (including UT-A, PB-B/D, PCN-E as well as ISF-G and/or beta NF-B).« less
A metagenetic approach to determine the diversity and distribution of cyst nematodes at the level of the country, the field and the individual.

PubMed

Eves-van den Akker, Sebastian; Lilley, Catherine J; Reid, Alex; Pickup, Jon; Anderson, Eric; Cock, Peter J A; Blaxter, Mark; Urwin, Peter E; Jones, John T; Blok, Vivian C

2015-12-01

Distinct populations of the potato cyst nematode (PCN) Globodera pallida exist in the UK that differ in their ability to overcome various sources of resistance. An efficient method for distinguishing between populations would enable pathogen-informed cultivar choice in the field. Science and Advice for Scottish Agriculture (SASA) annually undertake national DNA diagnostic tests to determine the presence of PCN in potato seed and ware land by extracting DNA from soil floats. These DNA samples provide a unique resource for monitoring the distribution of PCN and further interrogation of the diversity within species. We identify a region of mitochondrial DNA descriptive of three main groups of G. pallida present in the UK and adopt a metagenetic approach to the sequencing and analysis of all SASA samples simultaneously. Using this approach, we describe the distribution of G. pallida mitotypes across Scotland with field-scale resolution. Most fields contain a single mitotype, one-fifth contain a mix of mitotypes, and less than 3% contain all three mitotypes. Within mixed fields, we were able to quantify the relative abundance of each mitotype across an order of magnitude. Local areas within mixed fields are dominated by certain mitotypes and indicate towards a complex underlying 'pathoscape'. Finally, we assess mitotype distribution at the level of the individual cyst and provide evidence of 'hybrids'. This study provides a method for accurate, quantitative and high-throughput typing of up to one thousand fields simultaneously, while revealing novel insights into the national genetic variability of an economically important plant parasite. © 2015 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.
Piezoelectric properties of nonstoichiometric Sr1-xBi2+2x/3Ta2O9 ceramics

NASA Astrophysics Data System (ADS)

Jain, Rajni; Chauhan, Arun Kumar Singh; Gupta, Vinay; Sreenivas, K.

2005-06-01

The effect of poling on the structural, dielectric, and piezoelectric properties has been investigated for sol-gel-derived strontium bismuth tantalate (SBT) [Sr1-xBi2+2x/3Ta2O9] ceramics with x =0.0,0.15,0.30,0.45. The dielectric and ferroelectric properties are found to improve with increase in x up to 0.3. Beyond x >0.3 the properties are found to degrade due to the limited solid solubility and the presence of a mixed phase of bismuth tantalate (BiTaO4) is detected with x =0.45. Poling treatment reduces the dielectric dispersion and dielectric loss in the frequency range (0.1-100kHz). The resonance and antiresonance frequencies increase with increase in x (x=0-0.30), and the corresponding minimum impedance decreases. The measured coupling coefficients (kp) are small (0.0967-0.1) for x =0-0.30, and the electromechanical quality factor (Qm=915) is a maximum for the Sr0.7Bi2.2Ta2O9 composition (x=0.30). The estimated piezoelectric charge coefficient (d31) and piezoelectric voltage coefficient (g31) are 5.2pC/N and 5.8×10-3Vm/N, respectively. The positive values of d31 and g31 and the low dielectric permittivity of SBT yield a high value for the hydrostatic coefficients, despite the low charge coefficient of d33=24pC/N. The maximum values of charge coefficient (dh=34pC/N) and voltage coefficient (gh=39×10-3Vm/N) are obtained for Sr0.7Bi2.2Ta2O9 composition, and the estimated hydrostatic figure of merit (dhgh×10-15=1215m2/N) is high.
Long-Term Outcomes of Double-Layered Polytetrafluoroethylene Membrane-Covered Self-Expandable Segmental Metallic Stents (Uventa) in Patients with Chronic Ureteral Obstructions: Is It Really Safe?

PubMed

Kim, Myong; Hong, Bumsik; Park, Hyung Keun

2016-12-01

To evaluate the long-term clinical efficacy and safety of double-layered polytetrafluoroethylene membrane-covered self-expandable segmental metallic stents (Uventa) in patients with chronic ureteral obstruction. In a retrospective study, a total of 50 ureter units (44 patients) with chronic obstructions were included from July 2010 to May 2015. Indications for Uventa placement were primary stenting for malignant ureteral obstruction, failed conventional polymeric Double-J stent (PS), or percutaneous nephrostomy (PCN) technique, with comorbidities or fears limiting PS/PCN changes, or with irritation or pain due to PS/PCN. Patients underwent Uventa stent placement using the antegrade or retrograde approach. There were no immediate procedure-related complications, and all stents were placed in the proper sites. During the median follow-up of 30.9 (interquartile range [IQR], 8.1-49.0) months, the primary (no obstruction and no additional intervention) and overall success (no obstruction and no additional intervention except supplementary Uventa) was 30.0% and 34.0%, respectively. Moreover, 14 of 50 ureter units (28.0%) experienced major complications (≥Clavien-Dindo class IIIb), such as ureteroarterial fistula (three cases, 6.0%), ureteroenteric fistula (three, 6.0%), ureterovaginal fistula (one, 2.0%), ureter perforation (one, 2.0%), uncontrollable bleeding (one, 2.0%), and complete obstruction (five, 10.0%). On univariate analysis, major complications were associated with female (odds ratio [OR] = 6.000), cervical cancer (OR = 4.667), ureteral stricture length (≥6.0 cm, OR = 4.583), and placement duration (≥24.0 months, OR = 20.429; all p < 0.05). In long-term follow-up, the Uventa stent demonstrated poor treatment outcomes with frequent major complications in patients with chronic ureteral obstructions.
The effects of fuel composition and ammonium sulfate addition on PCDD, PCDF, PCN and PCB concentrations during the combustion of biomass and paper production residuals.

PubMed

Lundin, Lisa; Jansson, Stina

2014-01-01

The use of waste wood as an energy carrier has increased during the last decade. However, the higher levels of alkali metals and chlorine in waste wood compared to virgin biomass can promote the formation of deposits and organic pollutants. Here, the effect of fuel composition and the inhibitory effects of ammonium sulfate, (NH4)2SO4, on the concentrations of persistent organic pollutants (POPs) in the flue gas of a lab-scale combustor was investigated. Ammonium sulfate is often used as a corrosion-preventing additive and may also inhibit formation of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). In addition to PCDDs and PCDFs, polychlorinated naphthalenes (PCN) and biphenyls (PCB) were also analyzed. It was found that the flue gas composition changed dramatically when (NH4)2SO4 was added: CO, SO2, and NH3 levels increased, while those of HCl decreased to almost zero. However, the additive's effects on POP formation were less pronounced. When (NH4)2SO4 was added to give an S:Cl ratio of 3, only the PCDF concentration was reduced, indicating that this ratio was not sufficient to achieve a general reduction in POP emissions. Conversely, at an S:Cl ratio of 6, significant reductions in the WHO-TEQ value and the PCDD and PCDF contents of the flue gas were observed. The effect on the PCDF concentration was especially pronounced. PCN formation seemed to be promoted by the elevated CO concentrations caused by adding (NH4)2SO4. Copyright © 2013. Published by Elsevier Ltd.
Characterization of susceptibility and resistance responses to potato cyst nematode (Globodera spp.) infection of tomato lines in the absence and presence of the broad-spectrum nematode resistance Hero gene.

PubMed

Sobczak, Miroslaw; Avrova, Anna; Jupowicz, Justyna; Phillips, Mark S; Ernst, Karin; Kumar, Amar

2005-02-01

The tomato Hero A gene is the only member of a multigene family that confers a high level (>80%) of resistance to all the economically important pathotypes of potato cyst nematode (PCN) species Globodera rostochiensis and G. pallida. Although the resistance levels of transgenic tomato lines were similar to those of the tomato line LA1792 containing the introgressed Hero multigene family, transgenic potato plants expressing the tomato Hero A gene are not resistant to PCNs. Comparative microscopy studies of in vitro infected roots of PCN-susceptible tomato cv. Money Maker, the resistant breeding line LA1792, and transgenic line L10 with Ro1 pathotype have revealed no statistically significant difference in the number of juveniles invading roots. However, syncytia (specialized feeding cells) induced in LA1792 and L10 roots mostly were found to have degenerated a few days after their induction, and a few surviving syncytia were able to support only the development of males rather than females. Thus, the ratio between males and females was biased towards males on LA1792 and L10 roots. A series of changes occur in resistant plants leading to formation of a layer of necrotic cells separating the syncytium from stellar conductive tissues and this is followed by degradation of the syncytium. Although the Hero A gene is expressed in all tissues, including roots, stems, leaves, and flower buds, its expression is upregulated in roots in response to PCN infection. Moreover, the expression profiles of the Hero A correlates with the timing of death of the syncytium.
In Planta Processing and Glycosylation of a Nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-Like Effector and Its Interaction with a Host CLAVATA2-Like Receptor to Promote Parasitism1[OPEN

PubMed Central

Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S.; Mitchum, Melissa G.

2015-01-01

Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. PMID:25416475
Detection and quantification of Plectosphaerella cucumerina, a potential biological control agent of potato cyst nematodes, by using conventional PCR, real-time PCR, selective media, and baiting.

PubMed

Atkins, S D; Clark, I M; Sosnowska, D; Hirsch, P R; Kerry, B R

2003-08-01

Potato cyst nematodes (PCN) are serious pests in commercial potato production, causing yield losses valued at approximately $300 million in the European Community. The nematophagous fungus Plectosphaerella cucumerina has demonstrated its potential as a biological control agent against PCN populations by reducing field populations by up to 60% in trials. The use of biological control agents in the field requires the development of specific techniques to monitor the release, population size, spread or decline, and pathogenicity against its host. A range of methods have therefore been developed to monitor P. cucumerina. A species-specific PCR primer set (PcCF1-PcCR1) was designed that was able to detect the presence of P. cucumerina in soil, root, and nematode samples. PCR was combined with a bait method to identify P. cucumerina from infected nematode eggs, confirming the parasitic ability of the fungus. A selective medium was adapted to isolate the fungus from root and soil samples and was used to quantify the fungus from field sites. A second P. cucumerina-specific primer set (PcRTF1-PcRTR1) and a Taqman probe (PcRTP1) were designed for real-time PCR quantification of the fungus and provided a very sensitive means of detecting the fungus from soil. PCR, bait, and culture methods were combined to investigate the presence and abundance of P. cucumerina from two field sites in the United Kingdom where PCN populations were naturally declining. All methods enabled differences in the activity of P. cucumerina to be detected, and the results demonstrated the importance of using a combination of methods to investigate population size and activity of fungi.
Mobile user environment and satellite diversity for NGSO S-PCN's

NASA Technical Reports Server (NTRS)

Werner, Markus; Bischl, Hermann; Lutz, Erich

1995-01-01

The performance of satellite diversity under the influence of the mobile user environment is analyzed. To this end, a digital channel model is presented which takes into account the elevation angle as well as the user mobility in a given environment. For different LEO and MEO systems and for varying mobile user environments, some crucial benefits and drawbacks of satellite diversity are discussed. Specifically, the important GW service area concept is introduced. The conclusions are validated by numerical results from computer simulations. Globalstar (LEO) and Inmarsat (MEO) are compared in terms of visibility, service availability and equivalent handover complexity for different environments and user mobility.
Orthorhombic-tetragonal phase coexistence and enhanced piezo-response at room temperature in Zr, Sn, and Hf modified BaTiO{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalyani, Ajay Kumar; Brajesh, Kumar; Ranjan, Rajeev, E-mail: rajeev@materials.iisc.ernet.in

2014-06-23

The effect of Zr, Hf, and Sn in BaTiO{sub 3} has been investigated at close composition intervals in the dilute concentration limit. Detailed structural analysis by x-ray and neutron powder diffraction revealed that merely 2 mol. % of Zr, Sn, and Hf stabilizes a coexistence of orthorhombic (Amm2) and tetragonal (P4mm) phases at room temperature. As a consequence, all the three systems show substantial enhancement in the longitudinal piezoelectric coefficient (d{sub 33}), with Sn modification exhibiting the highest value ∼425 pC/N.
The Shock and Vibration Bulletin. Part 3. Analytical Methods, Dynamic Analysis, Vehicle Systems

DTIC Science & Technology

1981-05-01

1 Strnge Spcingramtr Fig 3% aito fma qaedslcmn ihsrne pcn 654 12 100 0 0 0 4 0 s 0 2 Distance along peal edge in - - Fig. 4 - Variation of...7 ~ ! v’j 4 pq -1 iijiL - -bp(C) I bpp ’ (24) L V* ki k2K 2 + (1 (ZT~~ - !I + !- 2) Y(IJ) and the value of bpp ’ can be tabulated as in 101 L .’blel1I...mI Table It. Values of bpp in Equation (24) The assembling of equations for a gun dynamics problem is more involved. The basic r1 procedures
47 CFR 27.1170 - Payment Issues.

Code of Federal Regulations, 2010 CFR

2010-10-01

... is required to file a notice containing site-specific data with the clearinghouse. The notice... name of the transmitting base station, the geographic coordinates corresponding to that base station... the site-data filing requirement by submitting a copy of their PCN to the clearinghouse. AWS entities...
Potato cyst nematodes: pests of national importance

USDA-ARS?s Scientific Manuscript database

Potato cyst nematodes (PCN; G. rostochiensis and G. pallida) are internationally-recognized quarantine pests and considered the most devastating pests of potatoes due to annual worldwide yield losses estimated at 12.2%. PCNs continue to spread throughout North America and were recently detected in I...
A case report on buccal mucosa graft for upper ureteral stricture repair.

PubMed

Sabale, Vilas Pandurang; Thakur, Naveen; Kankalia, Sharad Kumar; Satav, Vikram Pramod

2016-01-01

Management of ureteric stricture especially long length upper one-third poses a challenging job for most urologists. With the successful use of buccal mucosa graft (BMG) for stricture urethra leads the foundation for its use in ureteric stricture also. A 35-year-old male diagnosedcase of left upper ureteric stricture, postureteroscopy with left percutaneous nephrostomy (PCN) in situ . Cysto-retrograde pyelography and nephrostogram done simultaneously suggestive of left upper ureteric stricture of 3 cm at L3 level. On exploration, diseased ureteral segment exposed, BMG harvested and sutured as onlay patch graft with supportive omental wrap. The treatment choice for upper ureteric long length stricture is inferior nephropexy, autotransplantation, or bowel interposition. With PCN in situ , inferior nephropexy becomes technically difficult, other two are morbid procedures. Use of BMG in this situation is technically better choice with all the advantages of buccal mucosa. Onlay BMG for ureteral stricture is technically easy, less morbid procedure and can be important choice in future.

Polychlorinated naphthalenes (PCNs) in riverine and marine sediments of the Laizhou Bay area, North China.

PubMed

Pan, Xiaohui; Tang, Jianhui; Chen, Yingjun; Li, Jun; Zhang, Gan

2011-12-01

PCN congeners were analyzed in marine and riverine sediments of the Laizhou Bay area, North China. Concentrations of PCNs ranged from 0.12 to 5.1 ng g(-)(1) dry weight (dw) with a mean value of 1.1 ng g(-)(1) dw. The levels of PCNs varied largely, with industrial group approximately ten folds higher than those of the rural in riverine sediment. A strong impact by direct discharge from local factories was suggested. Similar compositional profiles were found within groups. High resemblance of compositional profiles between industrial samples and Halowax 1014 was observed. It was indicated that PCNs in riverine sediments were mainly from release of industrial usage, with additional contributions from industrial thermal process at certain sites. In marine sediments, it was suggested that PCNs along the coast of Laizhou Bay were mainly controlled by riverine input. While in the central bay, PCN distributions were possibly impacted by combined multiple factors. Copyright © 2011 Elsevier Ltd. All rights reserved.
(K, Na, Li)(Nb, Ta)O3:Mn lead-free single crystal with high piezoelectric properties

PubMed Central

Huo, Xiaoqing; Zhang, Rui; Zheng, Limei; Zhang, Shujun; Wang, Rui; Wang, Junjun; Sang, Shijing; Yang, Bin; Cao, Wenwu

2016-01-01

Lead-free single crystal, (K, Na, Li)(Nb, Ta)O3:Mn, was successfully grown using top-seeded solution growth method. Complete matrix of dielectric, piezoelectric and elastic constants for [001]C poled single crystal was determined. The piezoelectric coefficient d33 measured by the resonance method was 545 pC/N, which is almost three times that of its ceramic counterpart. The values measured by the Berlincourt meter ( d33∗=630pC/N) and strain-field curve ( d33∗∗=870pm/V) were even higher. The differences were assumed to relate with the different extrinsic contributions of domain wall vibration and domain wall translation during the measurements by different approaches, where the intrinsic contribution (on the order of 539 pm/V) was supposed to be the same. The crystal has ultrahigh electromechanical coupling factor (k33 ~ 95%) and high ultrasound velocity, which make it promising for high frequency medical transducer applications. PMID:27594704
HEPATIC ENZYME INDUCERS INCREASE THYROXINE (T4) CATABOLISM IN HUMAN AND RAT HEPATOCYTES

EPA Science Inventory

Nuclear receptor agonists such as 3-methylcholantrene (3-MC), phenobarbital (PB), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), and, pregnenolone-16a-carbonitrile (PCN) decrease serum thyroxine (T4) concentrations in rats. It appears that this decrease occurs through the induction...
Host resistance in potato to three Globodera species

USDA-ARS?s Scientific Manuscript database

Potato cyst nematodes (PCN) under quarantine in the U.S. and Canada are the pale cyst nematode (Globodera pallida) and the golden cyst nematode (G. rostochiensis). A new species, G. ellingtonae was discovered in Oregon and Idaho in 2008 and is not currently a quarantine pest. In 2006 detection of ...
47 CFR 27.1170 - Payment issues.

Code of Federal Regulations, 2014 CFR

2014-10-01

... emission designator. If a prior coordination notice (PCN) under § 101.103(d) of this chapter is prepared... Bands Cost-Sharing Policies Governing Microwave Relocation from the 2110-2150 Mhz and 2160-2200 Mhz Bands § 27.1170 Payment issues. Prior to initiating operations for a newly constructed site or modified...
Phytonutrient analysis of Solanum sisymbriifolium Lam. berries

USDA-ARS?s Scientific Manuscript database

Solanum sisymbriifolium Lam. (Litchi tomato) is grown ornamentally, and in Europe it is used as a trap crop for management of the potato cyst nematode (PCN). Its berries are edible, but little is known about their nutritional content. If more was known about their nutritional value this could provid...
Functionality of resistance gene Hero, which controls plant root-infecting potato cyst nematodes, in leaves of tomato.

PubMed

Poch, H L Cabrera; López, R H Manzanilla; Kanyuka, K

2006-07-01

The expression of host genomes is modified locally by root endoparasitic nematode secretions to induce the development of complex cellular structures referred as feeding sites. In compatible interactions, the feeding sites provide the environment and nutrients for the completion of the nematode's life cycle, whereas in an incompatible (resistant) interaction, the host immune system triggers a plant cell death programme, often in the form of a hypersensitive reaction, which restricts nematode reproduction. These processes have been studied in great detail in organ tissues normally infected by these nematodes: the roots. Here we show that host leaves can support a similar set of programmed developmental events in the potato cyst nematode Globodera rostochiensis life cycle that are typical of the root-invading nematodes. We also show that a gene-for-gene type specific disease resistance that is effective against potato cyst nematodes (PCN) in roots also operates in leaves: the expression of the resistance (R) gene Hero and members of its gene family in leaves correlates with the elicitation of a hypersensitive response only during the incompatible interaction. These findings, and the ability to isolate RNA from relevant parasitic stages of the nematode, may have significant implications for the identification of nematode factors involved in incompatible interactions.
A new chorismate mutase gene identified from Globodera ellingtonae and its utility as a molecular diagnostic marker

USDA-ARS?s Scientific Manuscript database

Globodera ellingtonae, a new cyst nematode species recently detected in Oregon and confirmed of reproduction on potato, shares key morphological features with the two species of potato cyst nematode (PCN; G. rostochiensis and G. pallida) of quarantine concern. Currently no methods are available for ...
THYROXINE (T4) CATABOLISM IN HUMAN AND RAT HEPATOCYTES INCREASES FOLLOWING EXPOSURE TO PROTOTYPICAL HEPATIC ENZYME INDUCERS

EPA Science Inventory

Nuclear receptor agonists such as phenobarbital (PB), 3-methylcholantrene (3MC), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), and, pregnenolone-16a-carbonitrile (PCN) decrease serum thyroxine (T4) concentrations in rats. This decrease is thought to occur through the induction of ...
THYROXINE (T4) CATABOLISM IN HUMAN AND RAT HEPATOCYTES INCREASES FOLLOWING EXPOSURE TO HEPATIC ENZYME INDUCERS

EPA Science Inventory

Nuclear receptor agonists phenobarbital (PB), 3-methylcholanthrene (3MC), pregnenolone-16a-carbonitrile (PCN), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), and 2,2' ,4,4'-tetrabromodiphenyl ether (BDE 47) decrease serum thyroxine (T4) in rats. This decrease is thought to occur th...
Development of Methods for Sampling and Analysis of Polychlorinated Naphthalenes in Ambient Air

ERIC Educational Resources Information Center

Erickson, Mitchell D.; And Others

1978-01-01

The procedure and sampler described permits detection of less than 50pg of one polychlorinated naphthalene (PCN) isomer. The method uses gas chromatography-mass spectrometry. The PCNs are collected on a glass fiber filter and two polyurethane foam plugs and extracted with toluene at 25 degrees Celsius. (BB)
Multiplex real-time PCR assays for the identification of the potato cyst and tobacco cyst nematodes

USDA-ARS?s Scientific Manuscript database

TaqMan primer-probe sets were developed for the detection and identification of potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis using two-tube, multiplex real-time PCR. One tube contained a primer-probe set specific for G. pallida (pale cyst nematode) multiplexed with another prim...
PCR detection of potato cyst nematode.

PubMed

Reid, Alex

2009-01-01

Potato cyst nematode (PCN) is responsible for losses in potato production totalling millions of euros every year in the EC. It is important for growers to know which species is present in their land as this determines its subsequent use. The two species Globodera pallida and Globodera rostochiensis can be differentiated using an allele-specific PCR.
Pyrolytic Carbon Nanosheets for Ultrafast and Ultrastable Sodium-Ion Storage.

PubMed

Cho, Se Youn; Kang, Minjee; Choi, Jaewon; Lee, Min Eui; Yoon, Hyeon Ji; Kim, Hae Jin; Leal, Cecilia; Lee, Sungho; Jin, Hyoung-Joon; Yun, Young Soo

2018-04-01

Na-ion cointercalation in the graphite host structure in a glyme-based electrolyte represents a new possibility for using carbon-based materials (CMs) as anodes for Na-ion storage. However, local microstructures and nanoscale morphological features in CMs affect their electrochemical performances; they require intensive studies to achieve high levels of Na-ion storage performances. Here, pyrolytic carbon nanosheets (PCNs) composed of multitudinous graphitic nanocrystals are prepared from renewable bioresources by heating. In particular, PCN-2800 prepared by heating at 2800 °C has a distinctive sp 2 carbon bonding nature, crystalline domain size of ≈44.2 Å, and high electrical conductivity of ≈320 S cm -1 , presenting significantly high rate capability at 600 C (60 A g -1 ) and stable cycling behaviors over 40 000 cycles as an anode for Na-ion storage. The results of this study show the unusual graphitization behaviors of a char-type carbon precursor and exceptionally high rate and cycling performances of the resulting graphitic material, PCN-2800, even surpassing those of supercapacitors. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Lead-Free KNbO3:xZnO Composite Ceramics.

PubMed

Lv, Xiang; Li, Zhuoyun; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo

2016-11-09

It is a tough issue to develop dense and water resistant KNbO 3 ceramics due to high evaporation and hygroscopicity of K 2 O. Here, KNbO 3 :xZnO composite ceramics were used to successfully solve this problem, where ZnO particles were randomly distributed into a KNbO 3 matrix. The addition of ZnO hardly affects the phase structure of KNbO 3 , and moreover, the enhancement of electrical properties, thermal stability, and aging characteristics was observed in KNbO 3 :xZnO composite ceramics. The composites possessed the maximum d 33 of 120 ± 5 pC/N, which is superior to that of pure KNbO 3 (d 33 = 80 pC/N). More importantly, a strong water resistance and an aging-free characteristic were observed in KNbO 3 :0.4ZnO. This is the first time for KNbO 3 ceramics to simultaneously improve electrical properties and resolve the water-absorbing properties. We believe that these composite ceramics are promising for practical applications.
Fabrication of Biocompatible Potassium Sodium Niobate Piezoelectric Ceramic as an Electroactive Implant

PubMed Central

Chen, Wei; Yu, Zunxiong; Pang, Jinshan; Yu, Peng; Tan, Guoxin; Ning, Chengyun

2017-01-01

The discovery of piezoelectricity in natural bone has attracted extensive research in emulating biological electricity for various tissue regeneration. Here, we carried out experiments to build biocompatible potassium sodium niobate (KNN) ceramics. Then, influence substrate surface charges on bovine serum albumin (BSA) protein adsorption and cell proliferation on KNN ceramics surfaces was investigated. KNN ceramics with piezoelectric constant of ~93 pC/N and relative density of ~93% were fabricated. The adsorption of protein on the positive surfaces (Ps) and negative surfaces (Ns) of KNN ceramics with piezoelectric constant of ~93 pC/N showed greater protein adsorption capacity than that on non-polarized surfaces (NPs). Biocompatibility of KNN ceramics was verified through cell culturing and live/dead cell staining of MC3T3. The cells experiment showed enhanced cell growth on the positive surfaces (Ps) and negative surfaces (Ns) compared to non-polarized surfaces (NPs). These results revealed that KNN ceramics had great potential to be used to understand the effect of surface potential on cells processes and would benefit future research in designing piezoelectric materials for tissue regeneration. PMID:28772704
PMN-PT based quaternary piezoceramics with enhanced piezoelectricity and temperature stability

NASA Astrophysics Data System (ADS)

Luo, Nengneng; Zhang, Shujun; Li, Qiang; Yan, Qingfeng; He, Wenhui; Zhang, Yiling; Shrout, Thomas R.

2014-05-01

The phase structure, piezoelectric, dielectric, and ferroelectric properties of (0.80 - x)PMN-0.10PFN-0.10PZ-xPT were investigated systematically. The morphotropic phase boundary (MPB) was confirmed to be 0.30 < x < 0.34. Both MPB compositions of x = 0.32 and x = 0.33 exhibit high piezoelectric coefficients d33 = 640 pC/N and 580 pC/N, electromechanical couplings kp of 0.53 and 0.52, respectively. Of particular importance is that the composition with x = 0.33 was found to process high field-induced piezoelectric strain coefficient d33* of 680 pm/V, exhibiting a minimal temperature-dependent behavior, being less than 8% in the temperature range of 25-165 °C, which can be further confirmed by d31, with a variation of less than 9%. The temperature-insensitive d33* values can be explained by the counterbalance of the ascending dielectric permittivity and descending polarization with increasing temperature. These features make the PMN-PT based quaternary MPB compositions promising for actuator applications demanding high temperature stability.
Fabrication of Biocompatible Potassium Sodium Niobate Piezoelectric Ceramic as an Electroactive Implant.

PubMed

Chen, Wei; Yu, Zunxiong; Pang, Jinshan; Yu, Peng; Tan, Guoxin; Ning, Chengyun

2017-03-26

The discovery of piezoelectricity in natural bone has attracted extensive research in emulating biological electricity for various tissue regeneration. Here, we carried out experiments to build biocompatible potassium sodium niobate (KNN) ceramics. Then, influence substrate surface charges on bovine serum albumin (BSA) protein adsorption and cell proliferation on KNN ceramics surfaces was investigated. KNN ceramics with piezoelectric constant of ~93 pC/N and relative density of ~93% were fabricated. The adsorption of protein on the positive surfaces (Ps) and negative surfaces (Ns) of KNN ceramics with piezoelectric constant of ~93 pC/N showed greater protein adsorption capacity than that on non-polarized surfaces (NPs). Biocompatibility of KNN ceramics was verified through cell culturing and live/dead cell staining of MC3T3. The cells experiment showed enhanced cell growth on the positive surfaces (Ps) and negative surfaces (Ns) compared to non-polarized surfaces (NPs). These results revealed that KNN ceramics had great potential to be used to understand the effect of surface potential on cells processes and would benefit future research in designing piezoelectric materials for tissue regeneration.
Influence of silencing soluble epoxide hydrolase with RNA interference on cardiomyocytes apoptosis induced by doxorubicin.

PubMed

Du, Guangsheng; Lv, Jiagao; He, Li; Ma, Yexin

2011-06-01

In order to investigate the influence of silencing soluble epoxide hydrolase (sEH) with double-stranded small interfering RNA (siRNA) on cardiomyocytes apoptosis induced by doxorubicin (DOX), two plasmids containing siRNA sequences specific to sEH were constructed and transfected into the primary cultured cardiomyocytes by using FuGENE HD transfection agents. The mRNA and protein expression levels of sEH were detected by semiquantitative RT-PCR and Western blotting respectively, and the plasmids that silenced sEH most significantly were selected, and renamed EH-R. The plasmids carrying a nonspecific siRNA coding sequence (PCN) served as the negative control. Cardiomyocytes were divided into four groups: control group, DOX group, PCN+DOX group, and EH-R+DOX group. Apoptosis of cardiomyocytes was induced by DOX at a concentration of 1 μmol/L. Apoptosis rate of cardiomyocytes was determined by flow cytometery. The protein expression levels of Bcl-2 and Bax were detected by Western blotting. The results showed that the expression of sEH was down-regulated by EH-R plasmid. The expression levels of sEH mRNA and protein in the EH-R+DOX group were significantly decreased as compared with other groups (P<0.01). As compared with the control group, the apoptosis rate of cardiomyocytes in three DOX-treated groups was obviously increased, the expression levels of Bax increased, and those of Bcl-2 decreased (P<0.01). However, the expression levels of Bax were decreased, those of Bcl-2 increased and the apoptosis rate of cardiomyocytes obviously decreased in EH-R+DOX group when compared with those in the DOX group and the PCN+DOX group (P<0.01 for each). It was concluded that the recombinant plasmids could be successfully constructed, and transfected into the primary cultured cardiomyocytes. They could ameliorate the DOX-induced cardiomyocytes apoptosis by selectively inhibiting the expression of sEH with RNAi and increasing the expression of Bcl-2.
Enhanced Fluorescent Siderophore Biosynthesis and Loss of Phenazine-1-Carboxamide in Phenotypic Variant of Pseudomonas chlororaphis HT66.

PubMed

Liu, Yang; Wang, Zheng; Bilal, Muhammad; Hu, Hongbo; Wang, Wei; Huang, Xianqing; Peng, Huasong; Zhang, Xuehong

2018-01-01

Pseudomonas chlororaphis HT66 is a plant-beneficial bacterium that exhibits wider antagonistic spectrum against a variety of plant pathogenic fungi due to its main secondary metabolite, i.e., phenazine-1-carboxamide (PCN). In the present study, a spontaneous phenotypic variant designated as HT66-FLUO was isolated from the fermentation process of wild-type HT66 strain. The newly isolated phenotypic variant was morphologically distinct from the wild-type strain such as larger cell size, semi-transparent, non-production of PCN (Green or yellow crystals) and enhanced fluorescence under UV light. The whole-genome, RNA-sequencing, and phenotypic assays were performed to identify the reason of phenotypic variation in HT66-FLUO as compared to the HT66. Transcriptomic analysis revealed that 1,418 genes, representing approximately 22% of the 6393 open reading frames (ORFs) had undergone substantial reprogramming of gene expression in the HT66-FLUO. The whole-genome sequence indicated no gene alteration in HT66-FLUO as compared to HT66 according to the known reference sequence. The levels of global regulatory factor gacA and gacS expression were not significantly different between HT66 and HT66-FLUO. It was observed that overexpressing gacS rather than gacA in HT66-FLUO can recover switching of the variant to HT66. The β-galactosidase ( LacZ ) activity and qRT-PCR results indicate the downregulated expression of rsmX, rsmY , and rsmZ in HT66-FLUO as compared to HT66. Overexpressing three small RNAs in HT66-FLUO can revert switching of colony phenotype toward wild-type HT66 up to a certain degree, restore partial PCN production and reduces the fluorescent siderophores yield. However, the origin of the spontaneous phenotypic variant was difficult to be determined. In conclusion, this study helps to understand the gene regulatory effect in the spontaneous phenotypic variant.

Construction and analysis of experimental DNA vaccines against megalocytivirus.

PubMed

Zhang, Min; Hu, Yong-Hua; Xiao, Zhi-Zhong; Sun, Yun; Sun, Li

2012-11-01

Iridoviruses are large double-stranded DNA viruses with icosahedral capsid. The Iridoviridae family contains five genera, one of which is Megalocytivirus. Megalocytivirus has emerged in recent years as an important pathogen to a wide range of marine and freshwater fish. In this study, we aimed at developing effective genetic vaccines against megalocytivirus affecting farmed fish in China. For this purpose, we constructed seven DNA vaccines based on seven genes of rock bream iridovirus isolate 1 from China (RBIV-C1), a megalocytivirus with a host range that includes Japanese flounder (Paralichthys olivaceus) and turbot (Scophthalmus maximus). The protective potentials of these vaccines were examined in a turbot model. The results showed that after vaccination via intramuscular injection, the vaccine plasmids were distributed in spleen, kidney, muscle, and liver, and transcription of the vaccine genes and production of the vaccine proteins were detected in these tissues. Following challenge with a lethal-dose of RBIV-C1, fish vaccinated with four of the seven DNA vaccines exhibited significantly higher levels of survival compared to control fish. Of these four protective DNA vaccines, pCN86, which is a plasmid that expresses an 86-residue viral protein, induced the highest protection. Immunological analysis showed that pCN86 was able to (i) stimulate the respiratory burst of head kidney macrophages at 14 d, 21 d, and 28 d post-vaccination, (ii) upregulate the expression of immune relevant genes involved in innate and adaptive immunity, and (iii) induce production of serum antibodies that, when incubated with RBIV-C1 before infection, significantly reduced viral loads in kidney and spleen following viral infection of turbot. Taken together, these results indicate that pCN86 is an effective DNA vaccine that may be used in the control of megalocytivirus-associated diseases in aquaculture. Copyright © 2012 Elsevier Ltd. All rights reserved.
Niaspan increases axonal remodeling after stroke in type 1 diabetes rats✩

PubMed Central

Yan, Tao; Chopp, Michael; Ye, Xinchun; Liu, Zhongwu; Zacharek, Alex; Cui, Yisheng; Roberts, Cynthia; Buller, Ben; Chen, Jieli

2012-01-01

Background and objective We investigated axonal plasticity in the bilateral motor cortices and the long term therapeutic effect of Niaspan on axonal remodeling after stroke in type-1 diabetic (T1DM) rats. Experimental approaches T1DM was induced in young adult male Wistar rats via injection of streptozotocin. T1DM rats were subjected to 2 h transient middle cerebral artery occlusion (MCAo) and were treated with 40 mg/kg Niaspan or saline starting 24 h after MCAo and daily for 28 days. Anterograde tracing using biotinylated dextran amine (BDA) injected into the contralateral motor cortex was performed to assess axonal sprouting in the ipsilateral motor cortex area. Functional outcome, SMI-31 (a pan-axonal microfilament marker), Bielschowsky silver and synaptophysin expression were measured. In vitro studies using primary cortical neuron (PCN) cultures and in vivo BDA injection into the brain to anterogradely label axons and terminals were employed. Results Niaspan treatment of stroke in T1DM–MCAo rats significantly improved functional outcome after stroke and increased SMI-31, Bielschowsky silver and synaptophysin expression in the ischemic brain compared to saline treated T1DM–MCAo rats (p<0.05). Using BDA to anterograde label axons and terminals, Niaspan treatment significantly increased axonal density in ipsilateral motor cortex in T1DM–MCAo rats (p<0.05, n=7/group). Niacin treatment of PCN significantly increased Ang1 expression under high glucose condition. Niacin and Ang1 significantly increased neurite outgrowth, and anti-Ang1 antibody marginally attenuated Niacin induced neurite outgrowth (p=0.06, n=6/group) in cultured PCN under high glucose condition. Conclusion Niaspan treatment increased ischemic brain Ang1 expression and promoted axonal remodeling in the ischemic brain as well as improved functional outcome after stroke. Ang1 may partially contribute to Niaspan-induced axonal remodeling after stroke in T1DM-rats. PMID:22266016
Enhanced Fluorescent Siderophore Biosynthesis and Loss of Phenazine-1-Carboxamide in Phenotypic Variant of Pseudomonas chlororaphis HT66

PubMed Central

Liu, Yang; Wang, Zheng; Bilal, Muhammad; Hu, Hongbo; Wang, Wei; Huang, Xianqing; Peng, Huasong; Zhang, Xuehong

2018-01-01

Pseudomonas chlororaphis HT66 is a plant-beneficial bacterium that exhibits wider antagonistic spectrum against a variety of plant pathogenic fungi due to its main secondary metabolite, i.e., phenazine-1-carboxamide (PCN). In the present study, a spontaneous phenotypic variant designated as HT66-FLUO was isolated from the fermentation process of wild-type HT66 strain. The newly isolated phenotypic variant was morphologically distinct from the wild-type strain such as larger cell size, semi-transparent, non-production of PCN (Green or yellow crystals) and enhanced fluorescence under UV light. The whole-genome, RNA-sequencing, and phenotypic assays were performed to identify the reason of phenotypic variation in HT66-FLUO as compared to the HT66. Transcriptomic analysis revealed that 1,418 genes, representing approximately 22% of the 6393 open reading frames (ORFs) had undergone substantial reprogramming of gene expression in the HT66-FLUO. The whole-genome sequence indicated no gene alteration in HT66-FLUO as compared to HT66 according to the known reference sequence. The levels of global regulatory factor gacA and gacS expression were not significantly different between HT66 and HT66-FLUO. It was observed that overexpressing gacS rather than gacA in HT66-FLUO can recover switching of the variant to HT66. The β-galactosidase (LacZ) activity and qRT-PCR results indicate the downregulated expression of rsmX, rsmY, and rsmZ in HT66-FLUO as compared to HT66. Overexpressing three small RNAs in HT66-FLUO can revert switching of colony phenotype toward wild-type HT66 up to a certain degree, restore partial PCN production and reduces the fluorescent siderophores yield. However, the origin of the spontaneous phenotypic variant was difficult to be determined. In conclusion, this study helps to understand the gene regulatory effect in the spontaneous phenotypic variant. PMID:29740409
In planta processing and glycosylation of a nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-like effector and its interaction with a host CLAVATA2-like receptor to promote parasitism.

PubMed

Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S; Mitchum, Melissa G; Wang, Xiaohong

2015-01-01

Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. © 2015 American Society of Plant Biologists. All Rights Reserved.
A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

NASA Technical Reports Server (NTRS)

Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

2011-01-01

Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (< 10(exp 4) pC/N). For instance, more than 80% of PEHT related papers are on transverse "31" mode cantilever beam type PEHTs (CBPEHTs) having piezoelectric coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective piezoelectric coefficient structures enable PEHTs to harvest more electrical energy from mechanical vibrations or motions, suggesting an effective design for high-performance low-footprint PEHTs with potential applications in military, aerospace, and portable electronics. In addition, this study provides a route for using piezoelectric multilayer stacks for active or semi-active adaptive control to damp, harvest or transform unwanted dynamic vibrations into useful electrical energy.
In planta processing and glycosylation of a nematode CLE effector and its interaction with a CLV2-like receptor to promote parasitism

USDA-ARS?s Scientific Manuscript database

Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ESR (CLE)-like proteins have been identified in several cyst nematodes including the potato cyst nematode (PCN); however, th...
Growth, piezoelectric study and particle size dependent SHG of an 80 mm long SR grown imidazolium l-tartrate single crystals

NASA Astrophysics Data System (ADS)

Jauhar, RO MU; Era, Paavai; Murugakoothan, P.

2018-05-01

Single crystal of imidazolium l-tartrate (IMLT), an organic nonlinear optical material, was successfully grown by slow evaporation solution growth technique (SEST) and Sankaranarayanan - Ramasamy (SR) method. The crystal structure and its lattice parameters were confirmed by single crystal X-ray diffraction study. The IMLT crystal belongs to monoclinic crystal system having a = 7.579(6) Å, b = 6.911(4) Å, c = 8.9281(5) Å, β = 101.45(8)°, volume, V = 458.33 Å3. The d33 coefficient found from the the piezoelectric study is 23 pC/N. The relative second harmonic generation efficiency of IMLT was found to be 3.16 times that of reference KDP material.
Piezoelectric performance enhancement of Pb(Mg1/3Nb2/3)O3-0.25PbTiO3 crystals by alternating current polarization for ultrasonic transducer

NASA Astrophysics Data System (ADS)

Xu, Jialin; Deng, Hao; Zeng, Zhou; Zhang, Zhang; Zhao, Kunyu; Chen, Jianwei; Nakamori, Nami; Wang, Feifei; Ma, Jinpeng; Li, Xiaobing; Luo, Haosu

2018-04-01

The [001]-oriented Pb(Mg1/3Nb2/3)O3-0.25PbTiO3(PMN-0.25PT) single crystal has been poled by alternating current polarization (ACP). The piezoelectric, dielectric, and electromechanical properties of PMN-0.25PT crystals were investigated with the variations of the electric field, polarization frequency, and cycles. For the piezoelectric performance of the PMN-0.25PT crystal, the optimum ACP condition was obtained under the electric field of 12-18 kV/cm in the frequency range of 20-40 Hz and after 20 cycles. It gives the crystals an increase by 40% from 1220 pC/N to 1730 pC/N in the piezoelectric coefficient compared with traditional direct current polarization. The patterns of the periodic stripe nanodomains under different polarization conditions were revealed by piezoresponse force microscopy. The enhancement of the piezoelectric performance is attributed to the high density of these domain walls. This work indicates that ACP is an effective way to modify the piezoelectric performance of PMN-0.25PT crystals and make it a promising candidate for sensors and transducers.
Growth and piezoelectric properties of Ca3Nb(Al0.5Ga0.5)3Si2O14 crystals with langasite structure

NASA Astrophysics Data System (ADS)

Xiong, Kainan; Zheng, Yanqing; Tu, Xiaoniu; Jiang, Bohan; Cao, Shuoliang; Shi, Erwei

2017-06-01

Piezoelectric crystals Ca3Nb(Al0.5Ga0.5)3Si2O14 (CNAGS) with langasite structure have been successfully grown by Czochralski method. In this work, the crystal structure, quality, chemical composition, piezoelectric properties, electric resistivity and optical properties of the as-grown crystals were characterized. The full width at half-maximum (FWHM) of the rocking curve of CNAGS was found to be 23″. The chemical compositions of CNAGS crystals are very close to that of initial compositions. At room temperature, the piezoelectric coefficients d11 and d14 of CNAGS crystals are 4.12 pC/N and -5.03 pC/N, and the electromechanical coupling coefficients k12 and k26 are also determined as 11.6% and 18.3%, respectively. The electric resistivity of as-growth crystal was found to be on the order of 2×108 Ω cm at 500 °C and 1×106 Ω cm at 800 °C. And the transmittances of CNAGS crystals were found to be over 80% in the wavelength range of 700-2700 nm.
[An approach regarding the use of medication in biology textbooks as a strategy for health promotion].

PubMed

Corrêa, Anderson Domingues; Caminha, Juliana dos Reis; de Souza, Cristina Alves Magalhães; Alves, Luiz Anastacio

2013-10-01

The inappropriate use of medication represents a major threat to public health and drugs rank first among the agents causing intoxication in Brazil, ahead of poisons for rodents and insects, illegal drugs, pesticides, cleaning products and spoiled food. The National Curriculum of Secondary Education Parameters (PCN+) give major emphasis to health, since the reference to Drugs is mentioned repeatedly in the text. The scope of this research was to study the approaches to drug use in textbooks. For this purpose, eleven biology textbooks were analyzed, namely six single volumes and five with three volumes each, i.e. a total of twenty-one volumes. The rational use of medication should be considered an important topic for the promotion of health which affects all sectors of society and should be emphasized in basic education. In line with this idea and based on the results obtained, it is suggested that the textbooks analyzed should be adapted to the new legislation and content that addresses Rational Drug Use, thus meeting the recommendations of PCN+. In this context, the books should concisely address the following topics: self-medication, adherence to drug treatment, advertisements and reports on drugs, among others.
Magnetron sputtering in the creation of photonic nanostructures derived from Sasakia Charonda Formosana-butterfly wings for applied in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Niu, Haihong; Zhou, Ru; Cheng, Cong; Zhang, Gonghai; Hu, Yu; Huang, Bin; Zhang, Shouwei; Shang, Xin; Xia, Mei; Xu, Jinzhang

2016-09-01

Creating new functional materials derived from the structures seen on butterfly wings has achieved interest in a variety of research topics. However, there need a concision approach could result in a high-quality, precise, and convenient process for the fabrication of complex nanostructures replication with unique functionalities based on the butterfly wings. Here we developed a pithy approach based on a magnetron sputtering metal Ti process for biotemplating used to refine hierarchically porous titanium dioxide photonic crystal nanostructures (TiO2sbnd PCN), themselves derived from nanostructures present on the wings of Sasakia Charonda Formosana (S. Charonda) butterflies. For the first time, the TiO2sbnd PCN were deposited on the top of the P25 active layer and were used to fabricate DSSCs as the light-scattering layers of photoanodes with power conversion efficiencies of up to 8.7%. Remarkably, a much enhanced photocurrent density and a prominent photoelectrochemical conversion capability have been achieved, which are exceeding most of the previously reported photoanodes as well as a similar butterflies replication-based device structure. Our study suggests many exciting opportunities of developing artificially engineered butterfly wing-based solar-to-fuel conversion.
Launch Complex 39 Observation Gantry Area (SWMU# 107) Annual Long-Term Monitoring Report (Year 1) Kennedy Space Center, Florida

NASA Technical Reports Server (NTRS)

Johnson, Jill W.; Towns, Crystal

2015-01-01

This document has been prepared by Geosyntec Consultants, Inc. (Geosyntec) to present and discuss the findings of the 2014 and 2015 Long-Term Monitoring (LTM) activities that were completed at the Launch Complex 39 (LC39) Observation Gantry Area (OGA) located at the John F. Kennedy Space Center (KSC), Florida (Site). The remainder of this report includes: (i) a description of the Site location; (ii) summary of Site background and previous investigations; (iii) description of field activities completed as part of the annual LTM program at the Site; (iv) groundwater flow evaluation; (v) presentation and discussion of field and analytical results; and (vi) conclusions and recommendations. Applicable KSC Remediation Team (KSCRT) Meeting minutes are included in Attachment A. This Annual LTM Letter Report was prepared by Geosyntec Consultants (Geosyntec) for NASA under contract number NNK12CA13B, Delivery Order NNK13CA39T project number PCN ENV2188.
DESTINY

DOE Office of Scientific and Technical Information (OSTI.GOV)

2015-03-10

DESTINY is a comprehensive tool for modeling 3D and 2D cache designs using SRAM,embedded DRAM (eDRAM), spin transfer torque RAM (STT-RAM), resistive RAM (ReRAM), and phase change RAM (PCN). In its purpose, it is similar to CACTI, CACTI-3DD or NVSim. DESTINY is very useful for performing design-space exploration across several dimensions, such as optimizing for a target (e.g. latency, area or energy-delay product) for agiven memory technology, choosing the suitable memory technology or fabrication method (i.e. 2D v/s 3D) for a given optimization target, etc. DESTINY has been validated against several cache prototypes. DESTINY is expected to boost studies ofmore » next-generation memory architectures used in systems ranging from mobile devices to extreme-scale supercomputers.« less
Adaptive Processing Experiment (APE) Phase II

DTIC Science & Technology

1976-05-01

P*T*~--- - ~ q ~ IPY , U.S. DEPARTMENT OF COMMERCE National Technical Information Service t AD/A-027 071 ADAPTIVE PROCESSING EXPERIMENT (APE...4 newsletter service covering the most recentik" research findings in 25 areas of industrial, The weekly w•Nsletter series will keep you...and professional informa- wish. Please request NTIS-PR-186/PCN for tion service provided by NTIS in the Weekly more information. Government Abstracts
Surface morphology and electrochemical studies on polyaniline/CuO nano composites

NASA Astrophysics Data System (ADS)

Ashokkumar, S. P.; Vijeth, H.; Yesappa, L.; Niranjana, M.; Vandana, M.; Basappa, M.; Devendrappa, H.

2018-05-01

An electrochemically synthesized Polyaniline (PANI) and Polyaniline/copper oxide (PCN) nano composite have studied the morphology and electrochemical properties. The composite is characterized by X-ray diffraction (XRD) and surface morphology was studied using FESEM and electrochemical behavior is studied using cyclic voltammetry (CV) technique. The CV curves shows rectangular shaped curve and they have contribution to electrical double layer capacitance (EDCL).
Transition From NASA Space Communication Systems to Commerical Communication Products

NASA Technical Reports Server (NTRS)

Ghazvinian, Farzad; Lindsey, William C.

1994-01-01

Transitioning from twenty-five years of space communication system architecting, engineering and development to creating and marketing of commercial communication system hardware and software products is no simple task for small, high-tech system engineering companies whose major source of revenue has been the U.S. Government. Yet, many small businesses are faced with this onerous and perplexing task. The purpose of this talk/paper is to present one small business (LinCom) approach to taking advantage of the systems engineering expertise and knowledge captured in physical neural networks and simulation software by supporting numerous National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD) projects, e.g., Space Shuttle, TDRSS, Space Station, DCSC, Milstar, etc. The innovative ingredients needed for a systems house to transition to a wireless communication system products house that supports personal communication services and networks (PCS and PCN) development in a global economy will be discussed. Efficient methods for using past government sponsored space system research and development to transition to VLSI communication chip set products will be presented along with notions of how synergy between government and industry can be maintained to benefit both parties.
Template-based fluoroethylenepropylene piezoelectrets with tubular channels for transducer applications

NASA Astrophysics Data System (ADS)

Altafim, Ruy Alberto Pisani; Qiu, Xunlin; Wirges, Werner; Gerhard, Reimund; Altafim, Ruy Alberto Corrêa; Basso, Heitor Cury; Jenninger, Werner; Wagner, Joachim

2009-07-01

We describe the concept, the fabrication, and the most relevant properties of a piezoelectric-polymer system: Two fluoroethylenepropylene (FEP) films with good electret properties are laminated around a specifically designed and prepared polytetrafluoroethylene (PTFE) template at 300 °C. After removing the PTFE template, a two-layer FEP film with open tubular channels is obtained. For electric charging, the two-layer FEP system is subjected to a high electric field. The resulting dielectric barrier discharges inside the tubular channels yield a ferroelectret with high piezoelectricity. d33 coefficients of up to 160 pC/N have already been achieved on the ferroelectret films. After charging at suitable elevated temperatures, the piezoelectricity is stable at temperatures of at least 130 °C. Advantages of the transducer films include ease of fabrication at laboratory or industrial scales, a wide range of possible geometrical and processing parameters, straightforward control of the uniformity of the polymer system, flexibility, and versatility of the soft ferroelectrets, and a large potential for device applications e.g., in the areas of biomedicine, communications, production engineering, sensor systems, environmental monitoring, etc.
Racial Disparities in Palliative Care for Prostate Cancer

DTIC Science & Technology

2013-10-01

obstruction from prostate cancer metastases, evaluating the placement of stents or percutaneous nephrostomy; and assessment of radiation therapy use among...placement of retrograde ureteral stent (RUS) or percutaneous nephrostomy (PCN) to palliate symptoms associated with obstructive uropathy and/or...CI) 1.03-2.13] than Whites, but equally likely to receive a stent . Subjects of >80 years were less likely to undergo RUS (ages 80-84, 0.41, 95 % CI
A Single Crystalline Porphyrinic Titanium MetalOrganic Framework

DTIC Science & Technology

2015-04-28

22, which was synthesized from preformed titanium -oxo carboxylate clusters and porphyrinic ligands. PCN-22 possesses high porosity and photocatalytic...DOI: 10.1039/c5sc00916b www.rsc.org/chemicalscience 3926 | Chem. Sci., 2015, 6, 3926–3930e porphyrinic titanium metal– organic framework† Shuai Yuan...Scott J. Dalgarnoc and Hong-Cai Zhou*a We successfully assembled the photocatalytic titanium -oxo cluster and photosensitizing porphyrinic linker into a
Defense Technical Information Center Cataloging, Abstracting and Indexing Guidelines

DTIC Science & Technology

2008-05-01

APPEARS AS: ENTER AS: General Electric Co., Daytona Beach , Florida. Apollo Support Dept. General Electric Co Daytona Beach FL Apollo Support Dept...OMAN OM PAKISTAN PK PALAU PW PANAMA PA PAPUA NEW GUINEA PG PARAGUAY PY PERU PE PHILIPPINES PH PITCAIRN PN POLAND PL PORTUGAL PT PUERTO...OMN PAKISTAN PAK PALAU PLW PANAMA PAN PAPUA NEW GUINEA PNG PARAGUAY PRY PERU PER PHILIPPINES PHL PITCAIRN PCN POLAND POL PORTUGAL PRT

Piezoelectric Response of Aligned Electrospun Polyvinylidene Fluoride/Carbon Nanotube Nanofibrous Membranes.

PubMed

Wu, Chang-Mou; Chou, Min-Hui; Zeng, Wun-Yuan

2018-06-10

Polyvinylidene fluoride (PVDF) shows piezoelectricity related to its β-phase content and mechanical and electrical properties influenced by its morphology and crystallinity. Electrospinning (ES) can produce ultrafine and well-aligned PVDF nanofibers. In this study, the effects of the presence of carbon nanotubes (CNT) and optimized ES parameters on the crystal structures and piezoelectric properties of aligned PVDF/CNT nanofibrous membranes were examined. The optimal β content and piezoelectric coefficient (d 33 ) of the aligned electrospun PVDF reached 88% and 27.4 pC/N; CNT addition increased the β-phase content to 89% and d 33 to 31.3 pC/N. The output voltages of piezoelectric units with aligned electrospun PVDF/CNT membranes increased linearly with applied loading and showed good stability during cyclic dynamic compression and tension. The sensitivities of the piezoelectric units with the membranes under dynamic compression and tension were 2.26 mV/N and 4.29 mV/%, respectively. In bending tests, the output voltage increased nonlinearly with bending angle because complicated forces were involved. The output of the aligned membrane-based piezoelectric unit with CNT was 1.89 V at the bending angle of 100°. The high electric outputs indicate that the aligned electrospun PVDF/CNT membranes are potentially effective for flexible wearable sensor application with high sensitivity.
A rapid, sensitive, and cost-efficient assay to estimate viability of potato cyst nematodes.

PubMed

van den Elsen, Sven; Ave, Maaike; Schoenmakers, Niels; Landeweert, Renske; Bakker, Jaap; Helder, Johannes

2012-02-01

Potato cyst nematodes (PCNs) are quarantine organisms, and they belong to the economically most relevant pathogens of potato worldwide. Methodologies to assess the viability of their cysts, which can contain 200 to 500 eggs protected by the hardened cuticle of a dead female, are either time and labor intensive or lack robustness. We present a robust and cost-efficient viability assay based on loss of membrane integrity upon death. This assay uses trehalose, a disaccharide present at a high concentration in the perivitelline fluid of PCN eggs, as a viability marker. Although this assay can detect a single viable egg, the limit of detection for regular field samples was higher, ≈10 viable eggs, due to background signals produced by other soil components. On the basis of 30 nonviable PCN samples from The Netherlands, a threshold level was defined (ΔA(trehalose) = 0.0094) below which the presence of >10 viable eggs is highly unlikely (true for ≈99.7% of the observations). This assay can easily be combined with a subsequent DNA-based species determination. The presence of trehalose is a general phenomenon among cyst nematodes; therefore, this method can probably be used for (for example) soybean, sugar beet, and cereal cyst nematodes as well.
Piezoelectric Motion of Multilayer Film with Alternate Rows of Optical Isomers of Chiral Polymer Film

NASA Astrophysics Data System (ADS)

Yoshida, Tetsuo; Imoto, Kenji; Nakai, Takaaki; Uwami, Ryouta; Kataoka, Takuya; Inoue, Masataka; Fukumoto, Takahiro; Kamimura, Yuuki; Kato, Atsuko; Tajitsu, Yoshiro

2011-09-01

We realized a multilayer film laminated alternately with poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) films in order to improve the piezoelectric performance of the PLLA film. In the fabrication processes, the thicknesses of PLLA and PDLA films were reduced to improve the effective electric field, and a multilayer composed of more than 100 layers (PDLA/PLLA multilayer film) was realized to improve the piezoelectric performance. In general, a single PLLA film has a piezoelectric constant of about 5 pC/N, and it is difficult to observe the piezoelectric resonance in this film of centimeter-order size using a commercial impedance analyzer because of its small Q-value. In contrast, the PDLA/PLLA multilayer film of centimeter-order size has a piezoelectric performance equivalent to that of the piezoelectric material with a piezoelectric constant of 100 pC/N, and also, the piezoelectric resonance can be observed in this film. On the basis of these results, we confirmed that even an object of 259 g mass is made to vibrate under the piezoelectric resonance vibration of this PDLA/PLLA multilayer film. In other words, necessary quantities for actual work as an actuator could be obtained in the PDLA/PLLA multilayer film.
Effect of Ag nanoparticle concentration on the electrical and ferroelectric properties of Ag/P(VDF-TrFE) composite films

DOE PAGES

Paik, Haemin; Choi, Yoon -Young; Hong, Seungbum; ...

2015-09-04

Here, we investigated the effect of the Ag nanoparticles on the ferroelectric and piezoelectric properties of Ag/poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) composite films. We found that the remanent polarization and direct piezoelectric coefficient increased up to 12.14 μC/cm 2 and 20.23 pC/N when the Ag concentration increased up to 0.005 volume percent (v%) and decreased down to 9.38 μC/cm 2 and 13.45 pC/N when it increased up to 0.01 v%. Further increase in Ag concentration resulted in precipitation of Ag phase and significant leakage current that hindered any meaningful measurement of the ferroelectric and piezoelectric properties. 46% increase of the remanent polarization valuemore » and 27% increase of the direct piezoelectric coefficient were observed in the film with the 0.005 v% of the Ag nanoparticles added without significant changes to the crystalline structure confirmed by both X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) experiments. The enhancements of both the ferroelectric and piezoelectric properties are attributed to the increase in the effective electric field induced by the reduction in the effective volume of P(VDF-TrFE) that results in more aligned dipoles.« less
Survival Mediated Heavy Element Capture Cross Sections

NASA Astrophysics Data System (ADS)

Loveland, Walter; Yao, Larry

2017-11-01

Formally, the cross section for producing a heavy evaporation residue, σEVR, in a fusion reaction can be written as where E is the center of mass energy, and T is the probability of the colliding nuclei to overcome the potential barrier in the entrance channel and reach the contact point. PCN is the probability that the projectile-target system will evolve from the contact point to the compound nucleus. Wsur is the probability that the compound nucleus will decay to produce an evaporation residue rather than fissioning. However, one must remember that the Wsur term effectively sets the allowed values of the spin, which in turn, restricts the values of the capture and fusion cross sections. We point out the implications of this fact for capture cross sections for heavy element formation reactions.
Comparative Study of Ferroelectric and Piezoelectric Properties of BNT-BKT-BT Ceramics near the Phase Transition Zone

PubMed Central

Fernandez-Benavides, David Andres; Gutierrez-Perez, Aixa Ibeth; Benitez-Castro, Angelica Maria; Ayala-Ayala, Maria Teresa; Moreno-Murguia, Barbara

2018-01-01

We report a comprehensive comparative study of ferroelectric and piezoelectric properties of BNT-BKT-BT ceramics through the MPB (morphotropic phase boundary) zone, from the rhombohedral to the tetragonal phases in the system (97.5−x)(Bi0.5Na0.5)TiO3 + x(Bi0.5K0.5)TiO3 + 2.5(BaTiO3), where x = 0 to 24.5 mol %. The structural transitions were studied by XRD patterns and Raman spectra. The MPB was confirmed between x = 10 and 12.5 mol % BKT. The dielectric/ferroelectric/piezoelectric properties of the BNT-BKT-BT system are maximized in the MPB region exhibiting a dielectric constant of 1506, a remanent polarization of 34.4 μC/cm2, a coercive field = 36.9 kV/cm, and piezoelectric values of d33 = 109 pC/N, kt = 0.52, and kp = 0.24. Changes in microstructure as a function of BKT content are also presented and discussed. PMID:29494486
Racial Disparities in Palliative Care for Prostate Cancer

DTIC Science & Technology

2016-01-01

analysis is complete. The manuscript reporting the results of the spinal cord compression study is published ( Spencer BA, Shim JJ, Hershman DL...to ureteral obstruction ( Spencer BA, Insel BJ, Hershman DL, Benson MC, Neugut AI. 2013. Racial disparities in the use of palliative therapy for...and men who received a PCN were 55% more likely to die than those who were untreated for ureteral obstruction. See Table 3 (page 20-21) in Spencer
The Location of Stress in Clothing

DTIC Science & Technology

1984-12-01

BUTON STATEMEN A Akppwood ttx public wlesE LI. Dlabuutiof Unlimite~d : DEFENCE RESEARCH ESTABLISHMENT OTTAWA REPORT 911 December 1984 Canadgi Ottawa 85 5...Protective Sciences Division * IV a., .4 DEFENCE RESEARCH ESTABLISHMENT OTTAWA , REPORT 011 : - PCN December 1984 ", . 14B0M Ottawa - ’,o , , .; • -,,..- ’ t...seams. RESUME Cet exposi porte sur les r~sultats deune 6tude ayant pour but de * diterminer quelles positions imposent les plus grandes contraintes sur
Sierra Army Depot, Phase 1, Remedial Investigation/Feasibility Study, Lassen County, California. Appendices G-Q

DTIC Science & Technology

1991-10-01

concentrations in the liquid phase. The role of the distribution coefficient in mitigating chemical migration is given in an approximation of nonuniform ...0.110 USA 60.0 12r- 990 1.11111 1219CN 0.230 USA 70.0 12-nor-199 Lull 12E1CM 0.240 UsA 80.0 12-spr-1990 LAIR 121PCN 0.260 USA 35.0 ?2-spr-I99 LOSl 121Cm
Challenges and New Trends for Piezoelectric Actuators

NASA Technical Reports Server (NTRS)

Sehirlioglu, Alp

2008-01-01

BiScO3-PbTiO3 ceramics with TC greater than 400 C has been successfully processed. Despite the increase in TC, excess Pb addition increases both the bulk conductivity and the grain boundary contribution to conductivity at elevated temperatures. Conductivity at elevated temperatures, that limits the operating temperature for actuators, has been greatly reduced by excess Bi additions. Excess Bi doping improves poling conditions resulting in enhanced piezoelectric coefficient (d(sub 33) = 408 pC/N).
Pseudomonas aeruginosa manipulates redox and iron homeostasis of its microbiota partner Aspergillus fumigatus via phenazines

PubMed Central

Briard, Benoit; Bomme, Perrine; Lechner, Beatrix E.; Mislin, Gaëtan L. A.; Lair, Virginie; Prévost, Marie-Christine; Latgé, Jean-Paul; Haas, Hubertus; Beauvais, Anne

2015-01-01

The opportunistic fungal pathogen Aspergillus fumigatus is increasingly found as a coinfecting agent along with Pseudomonas aeruginosa in cystic fibrosis patients. Amongst the numerous molecules secreted by P. aeruginosa during its growth, phenazines constitute a major class. P. aeruginosa usually secreted four phenazines, pyocyanin (PYO), phenazine-1-carboxamide (PCN), 1-hydroxyphenazine (1-HP) and phenazine-1-carboxylic acid (PCA). These phenazines inhibited the growth of A. fumigatus but the underlying mechanisms and the impact of these four phenazines on A. fumigatus biology were not known. In the present study, we analyzed the functions of the four phenazines and their mode of action on A. fumigatus. All four phenazines showed A. fumigatus growth inhibitory effects by inducing production of reactive oxygen species (ROS), specifically O2·−, and reactive nitrogen species (RNS), ONOO−. A. fumigatus Sod2p was the major factor involved in resistance against the ROS and RNS induced by phenazines. Sub-inhibitory concentrations of PYO, PCA and PCN promote A. fumigatus growth by an independent iron-uptake acquisition. Of the four phenazines 1-HP had a redox-independent function; being able to chelate metal ions 1-HP induced A. fumigatus iron starvation. Our data show the fine-interactions existing between A. fumigatus and P. aeruginosa, which can lead to stimulatory or antagonistic effects. PMID:25665925
Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xiaoqing; Institute for Telecommunications Technology, Merckstrasse 25, 64283 Darmstadt; Wu, Liming

Piezoelectret films are prepared by modification of the microstructure of polypropylene foam sheets cross-linked by electronic irradiation (IXPP), followed by proper corona charging. Young’s modulus, relative permittivity, and electromechanical coupling coefficient of the fabricated films, determined by dielectric resonance spectra, are about 0.7 MPa, 1.6, and 0.08, respectively. Dynamic piezoelectric d{sub 33} coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d{sub 33} ⋅ g{sub 33}) for a more typical d{sub 33} value of 400 pC/N is about 11.2 GPa{sup −1}. Vibration-based energy harvesting with one-layer and two-layer stacks of these films is investigatedmore » at various frequencies and load resistances. At an optimum load resistance of 9 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, referred to the acceleration g due to gravity, is obtained for an energy harvester consisting of a one-layer IXPP film with an area of 3.14 cm{sup 2} and a seismic mass of 33.7 g. The output power can be further improved by using two-layer stacks of IXPP films in electric series. IXPP energy harvesters could be used to energize low-power electronic devices, such as wireless sensors and LED lights.« less
Fabrication and in vitro biological properties of piezoelectric bioceramics for bone regeneration

PubMed Central

Tang, Yufei; Wu, Cong; Wu, Zixiang; Hu, Long; Zhang, Wei; Zhao, Kang

2017-01-01

The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO3) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d33 of HA/BaTiO3 piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO3 content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO3 piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO3 promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO3 piezoelectric ceramics. PMID:28240268
Fabrication and in vitro biological properties of piezoelectric bioceramics for bone regeneration.

PubMed

Tang, Yufei; Wu, Cong; Wu, Zixiang; Hu, Long; Zhang, Wei; Zhao, Kang

2017-02-27

The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO 3 ) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d 33 of HA/BaTiO 3 piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO 3 content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO 3 piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO 3 promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO 3 piezoelectric ceramics.
Structural stability, enhanced magnetic, piezoelectric, and transport properties in (1-x)BiFeO3-(x)Ba0.70Sr0.30TiO3 nanoparticles

NASA Astrophysics Data System (ADS)

Sharma, Subhash; Singh, Vikash; Anshul, Avneesh; Siqueiros, J. M.; Dwivedi, R. K.

2018-05-01

Multiferroic samples with composition (1-x)BiFeO3-(x)(Ba0.70Sr0.30)TiO3 (BFO-BST) were synthesized using a sol-gel route to study the effect of BST doping on structural, transport, and magnetic properties in BiFeO3 (BFO). X-ray diffraction studies with Rietveld analysis revealed that a phase transition occurred from rhombohedral (R3c) (0.0 ≤ × ≤ 0.15) to tetragonal (P4 mm) for x = 0.20 and nanocrystalline nature confirmed by transmission electron microscopy measurements. Piezoelectric properties improved as x increased from x = 0.0 (58 pC/N) to x = 0.20 (112 pC/N) increasing distortion in the crystal structure as evinced by Williamson-Hall analysis. Ferromagnetism was observed in doped BFO, different from the antiferromagnetic ordering in bulk BFO, indicating the noteworthy size effects and Fe-O-Fe bond angle variations in the magnetic ordering of BFO. An improvement in ferroelectric properties is observed with doping of BST compared to pristine BFO. Thermally activated conduction behavior occurred at low and high temperature regions as revealed by temperature dependent dc resistivity measurement. Effective improvements in dielectric response, meaning high dielectric constant with a low dielectric loss, were found in the doped samples.
Effect of ZnO Nanoparticles on the Sintering Behavior and Physical Properties of Bi0.5(Na0.8K0.2)0.5TiO3 Lead-Free Ceramics

NASA Astrophysics Data System (ADS)

Vuong, Le Dai; Truong-Tho, Nguyen

2017-11-01

Sintered Bi0.5(Na0.8K0.2)0.5TiO3 + x wt.% ZnO nanoparticle (BNKT- xZnOn) ceramics have been fabricated by conventional annealing with the aid of ultrasound waves for preliminary milling. Because of the presence of the liquid Bi2O3-ZnO phase at the eutectic point of 738°C, the sintering temperature decreased from 1150°C to 1000°C, and the morphology phase boundary of BNKT- xZnOn ceramics can be clarified by two separated peaks at (002)T and (200)T of 2 θ in the x-ray diffraction (XRD) patterns. The improvement of ferroelectric properties has been obtained for BNZT-0.2 wt.% ZnOn ceramics by the increase of remanent polarization up to 20.4 μC/cm2 and a decrease of electric coercive field down to 14.2 kV/cm. The piezoelectric parameters of the ceramic included a piezoelectric charge constant of d 31 = 78 pC/N; electromechanical coupling factors k p = 0.31 and k t = 0.34, larger than the values of 42 pC/N, 0.12 and 0.13, respectively, were obtained for the BNKT ceramics.
Crystal Structure, Piezoelectric and Dielectric Properties of (Li, Ce)4+, Nb5+ and Mn2+ Co-doped CaBi4Ti4O15 High-Temperature Ceramics

NASA Astrophysics Data System (ADS)

Xin, Deqiong; Chen, Qiang; Wu, Jiagang; Bao, Shaoming; Zhang, Wen; Xiao, Dingquan; Zhu, Jianguo

2016-07-01

Bismuth-layered structured ceramics Ca0.85(Li,Ce)0.075Bi4Ti4- x Nb x O15-0.01MnCO3 were prepared by the conventional solid-state reaction method. The evolution of microstructure and corresponding electrical properties were studied. All the samples presented a single bismuth layered-structural phase with m = 4, indicating that (Li, Ce)4+, Nb5+ and Mn2+ adequately enter into the pseudo-perovskite structure and form solid solutions. It was found that Ca0.85(Li,Ce)0.075Bi4Ti3.98Nb0.02O15-0.01MnCO3 (CBTLCM-0.02Nb) ceramics possess the optimum electrical properties. The piezoelectric coefficient d 33, dielectric constant ɛ r, loss tan δ, planar electromechanical coupling factor k p and Curie-temperature T C of CBTLCM-0.02Nb ceramics were found to be ˜19.6 pC/N, 160, 0.16%, 8.1% and 767°C, respectively. Furthermore, the thermal depoling behavior demonstrates that the d 33 value of x = 0.02 content remains at 16.8 pC/N after annealing at 500°C. These results suggest that the (Li, Ce)4+-, Nb5+- and Mn2+-doped CBT-based ceramics are promising candidates for high-temperature piezoelectric applications.
Fabrication and in vitro biological properties of piezoelectric bioceramics for bone regeneration

NASA Astrophysics Data System (ADS)

Tang, Yufei; Wu, Cong; Wu, Zixiang; Hu, Long; Zhang, Wei; Zhao, Kang

2017-02-01

The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO3) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d33 of HA/BaTiO3 piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO3 content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO3 piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO3 promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO3 piezoelectric ceramics.
Growth and characterization of new semiorganic nonlinear optical and piezoelectric lithium sulfate monohydrate oxalate single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadav, Harsh; Sinha, Nidhi; Kumar, Binay, E-mail: b3kumar69@yahoo.co.in

2015-04-15

Highlights: • A new semiorganic single crystal of LSO grown by slow evaporation technique. • Morphological studies of the LSO crystal deduced by BFDH law. • In the UV–vis spectrum wide transparent region and large band gap were found. • SHG is equal to KDP crystal and d{sub 33} was found to be equal to 6pC/N. • Grown crystal belongs to softer category. - Abstract: New semiorganic crystal of lithium sulfate monohydrate oxalate (LSO) for nonlinear application was synthesized by controlled slow evaporation method. The growth rate of various planes of the grown crystal was estimated by morphological study. Singlemore » crystal XRD analysis confirmed that the crystal belongs to triclinic lattice with space group P1. High transparency (∼95%) with large band gap (4.57 eV) was analyzed by UV–vis studies. FTIR and Raman spectroscopy were used to identify various functional groups present in the LSO crystal. SHG efficiency was found to be equal to the KDP crystal. Thermal stability (up to 117.54 °C) and melting point (242 °C) of the crystal were studied by TG-DTA. In dielectric measurements, the value of dielectric constant decreases with increase in frequency. Hardness studies confirmed soft nature of crystals. The piezoelectric coefficient was found to be 6pC/N along [0 0 1].« less
Design of a Film-Cooled Entraining Diffuser.

DTIC Science & Technology

1980-04-01

AD-A783 951 DEFENCE RESEARCH ESTABLISHMENT SUFFIELD RALSTON (ALBERTA) FIG 20/4 NL3 DESIGN OF A FILM-COOLED ENTRAINING DIFFUSER. 1U) APR 80 S B MURRAY...S.B. Murray C PCN 27C01 April 1980 80 4 29 004 DEFENCE RESEARCH ESTABLISHMENT SUFFIELD: RALSTON: ALBERTA WARNING rht ... , i. to - °aton is per lle...ulje(f to -ogoltio • IIl proprieh’~ra~r ind wtent it hh , i j l - UNCLASS I FI ED Li m DEFENCE RESEARCH ESTABLISHMENT SUFFIELD RALSTON ALBERTA

Giant Electric Field Control of Magnetism and Narrow Ferromagnetic Resonance Linewidth in FeCoSiB/Si/SiO2/PMN PT Multiferroic Heterostructures (Open Access Author’s Manuscript)

DTIC Science & Technology

2016-06-06

the widely used lead zirconate titanate ceramics which have a typical piezoelectric coefficient d31 of ~- 200pC/N, PMN-PT single crystals used in...substrate clamping effect, therefore, a relatively giant tunability can be obtained. However, the normally large roughness of piezoelectric layer...is the saturation magnetostriction constant, Y the Young’s modulus of the magnetic film, deff the effective piezoelectric coefficient, E
Production of continuous piezoelectric ceramic fibers for smart materials and active control devices

NASA Astrophysics Data System (ADS)

French, Jonathan D.; Weitz, Gregory E.; Luke, John E.; Cass, Richard B.; Jadidian, Bahram; Bhargava, Parag; Safari, Ahmad

1997-05-01

Advanced Cerametrics Inc. has conceived of and developed the Viscous-Suspension-Spinning Process (VSSP) to produce continuous fine filaments of nearly any powdered ceramic materials. VSSP lead zirconate titanate (PZT) fiber tows with 100 and 790 filaments have been spun in continuous lengths exceeding 1700 meters. Sintered PZT filaments typically are 10 - 25 microns in diameter and have moderate flexibility. Prior to carrier burnout and sintering, VSSP PZT fibers can be formed into 2D and 3D shapes using conventional textile and composite forming processes. While the extension of PZT is on the order of 20 microns per linear inch, a woven, wound or braided structure can contain very long lengths of PZT fiber and generate comparatively large output strokes from relatively small volumes. These structures are intended for applications such as bipolar actuators for fiber optic assembly and repair, vibration and noise damping for aircraft, rotorcraft, automobiles and home applications, vibration generators and ultrasonic transducers for medical and industrial imaging. Fiber and component cost savings over current technologies, such as the `dice-and-fill' method for transducer production, and the range of unique structures possible with continuous VSSP PZT fiber are discussed. Recent results have yielded 1-3 type composites (25 vol% PZT) with d33 equals 340 pC/N, K equals 470, and g33 equals 80 mV/N, kt equals 0.54, kp equals 0.19, dh equals 50.1pC/N and gh equals 13 mV/N.
Enhanced performance of ferroelectric materials under hydrostatic pressure

NASA Astrophysics Data System (ADS)

Chauhan, Aditya; Patel, Satyanarayan; Wang, Shuai; Novak, Nikola; Xu, Bai-Xiang; Lv, Peng; Vaish, Rahul; Lynch, Christopher S.

2017-12-01

Mechanical confinement or restricted degrees of freedom have been explored for its potential to enhance the performance of ferroelectric devices. It presents an easy and reversible method to tune the response for specific applications. However, such studies have been mainly limited to uni- or bi-axial stress. This study investigates the effect of hydrostatic pressure on the ferroelectric behavior of bulk polycrystalline Pb0.99Nb0.02(Zr0.95Ti0.05)0.98O3. Polarization versus electric field hysteresis plots were generated as a function of hydrostatic pressure for a range of operating temperatures (298-398 K). The application of hydrostatic pressure was observed to induce anti-ferroelectric like double hysteresis loops. This in turn enhances the piezoelectric, energy storage, energy harvesting, and electrocaloric effects. The hydrostatic piezoelectric coefficient (dh) was increased from 50 pCN-1 (0 MPa) to ˜900 pC N-1 (265 MPa) and ˜3200 pCN-1 (330 MPa) at 298 K. Energy storage density was observed to improve by more than 4 times under pressure, in the whole temperature range. The relative change in entropy was also observed to shift from ˜0 to 4.8 J kg-1 K-1 under an applied pressure of 325 MPa. This behavior can be attributed to the evolution of pinched hysteresis loops that have been explained using a phenomenological model. All values represent an improvement of several hundred percent compared to unbiased performance, indicating the potential benefits of the proposed methodology.
Efficacy of preparation solutions and cleansing techniques on contamination of the skin in foot and ankle surgery: A systematic review and meta-analysis.

PubMed

Yammine, K; Harvey, A

2013-04-01

We report a systematic review and meta-analysis of published randomised and quasi-randomised trials evaluating the efficacy of pre-operative skin antisepsis and cleansing techniques in reducing foot and ankle skin flora. The post-preparation culture number (Post-PCN) was the primary outcome. The data were evaluated using a modified version of the Cochrane Collaboration’s tool. We identified eight trials (560 participants, 716 feet) that met the inclusion criteria. There was a significant difference in the proportions of Post-PCN between hallux nailfold (HNF) and toe web spaces (TWS) sites: 0.47 vs 0.22, respectively (95% confidence interval (CI) 0.182937 to 0.304097; p < 0.0001). Meta-analyses showed that alcoholic chlorhexidine had better efficacy than alcoholic povidone-iodine (PI) at HNF sites (risk difference 0.19 (95% CI 0.08 to 0.30); p = 0.0005); a two-step intervention using PI scrub and paint (S&P) followed by alcohol showed significantly better efficacy over PI (S&P) alone at TWS sites (risk difference 0.13 (95% CI 0.02 to 0.24); p = 0.0169); and a two-step intervention using chlorhexidine scrub followed by alcohol showed significantly better efficacy over PI (S&P) alone at the combined (HNF with TWS) sites (risk difference 0.27 (95% CI 0.13 to 0.40); p < 0.0001). No significant difference was found between cleansing techniques.
Polychlorinated naphthalenes in Great Lakes air: assessing spatial trends and combustion inputs using PUF disk passive air samplers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tom Harner; Mahiba Shoeib; Todd Gouin

2006-09-01

Passive air samplers made from polyurethane foam (PUF) disks housed in stainless steel chambers were deployed over four seasons during 2002-2003, at 15 sites in the Laurentian Great lakes, to assess spatial and temporal trends of polychlorinated naphthalenes (PCNs). Sampling rates, determined using depuration compounds pre-spiked into the PUF disk prior to exposure, were, on average, 2.9 {+-} 1.1 m{sup 3} d{sup -1}, consistent with previous studies employing these samplers. PCN air concentrations exhibited strong urban-rural differences - typically a few pg m{sup 3} at rural sites and an order of magnitude higher at urban sites (Toronto, 12-31 pg m{supmore » -3} and Chicago, 13-52 pg m{sup -3}). The high concentrations at urban sites were attributed to continued emissions of historically used technical PCN. Contributions from combustion-derived PCNs seemed to be more important at rural locations where congeners 24 and 50, associated with wood and coal burning, were elevated. Congener 66/67, associated with incineration and other industrial thermal processes, was elevated at two sites and explained by nearby and/or upwind sources. Probability density maps were constructed for each site and for every integration period were shown to be a useful complement to seasonally integrated passive sampling data to resolve source-receptor relationship for PCNs and other pollutants. 25 refs., 7 figs., 1 tabs.« less
Levels and spatial distribution of gaseous polychlorinated biphenyls and polychlorinated naphthalenes in the air over the northern South China Sea

NASA Astrophysics Data System (ADS)

Li, Qilu; Xu, Yue; Li, Jun; Pan, Xiaohui; Liu, Xiang; Zhang, Gan

2012-09-01

Monitoring marine persistent organic pollutants (POPs) is important because oceans play a significant role in the cycling of POPs. The South China Sea (SCS) is surrounded by developing countries in Southeast Asia which are centers of e-waste recycling and the ship dismantling industry. In this study, shipboard air samples collected over the SCS between September 6 and 22, 2005 were analyzed for polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). The levels of ∑12PCBs ranged from 32.3 to 167 pg m-3, with a mean value of 98.4 ± 36.0 pg m-3. Tetra-CBs were the predominant congeners. The concentrations of ∑18PCNs ranged from N.D. to 26.0 pg m-3, with a mean value of 10.5 ± 7.16 pg m-3, and tri-CNs were predominant. The gaseous concentrations of PCBs and PCNs over the SCS were consistent with those over other seas and oceans. Compared with previous studies, it was found that the concentrations of PCBs exhibited an obviously declining trend. The measured PCB and PCN concentrations in the atmosphere over the SCS were influenced by their proximity to source regions and air mass origins. The highest gaseous PCB and PCN concentrations were found at sampling sites adjacent to the continental South China. E-waste recycling, ship dismantling and combustion in South China and some Southeast Asian countries might contribute PCBs and PCNs to the atmosphere of the SCS.
Enzymatic Degradation of Phenazines Can Generate Energy and Protect Sensitive Organisms from Toxicity

PubMed Central

Costa, Kyle C.; Bergkessel, Megan; Saunders, Scott; Korlach, Jonas

2015-01-01

ABSTRACT Diverse bacteria, including several Pseudomonas species, produce a class of redox-active metabolites called phenazines that impact different cell types in nature and disease. Phenazines can affect microbial communities in both positive and negative ways, where their presence is correlated with decreased species richness and diversity. However, little is known about how the concentration of phenazines is modulated in situ and what this may mean for the fitness of members of the community. Through culturing of phenazine-degrading mycobacteria, genome sequencing, comparative genomics, and molecular analysis, we identified several conserved genes that are important for the degradation of three Pseudomonas-derived phenazines: phenazine-1-carboxylic acid (PCA), phenazine-1-carboxamide (PCN), and pyocyanin (PYO). PCA can be used as the sole carbon source for growth by these organisms. Deletion of several genes in Mycobacterium fortuitum abolishes the degradation phenotype, and expression of two genes in a heterologous host confers the ability to degrade PCN and PYO. In cocultures with phenazine producers, phenazine degraders alter the abundance of different phenazine types. Not only does degradation support mycobacterial catabolism, but also it provides protection to bacteria that would otherwise be inhibited by the toxicity of PYO. Collectively, these results serve as a reminder that microbial metabolites can be actively modified and degraded and that these turnover processes must be considered when the fate and impact of such compounds in any environment are being assessed. PMID:26507234
Unusual pi-donating effects of pi-accepting substituents on the stabilities of benzylic cations: a theoretical study.

PubMed

Kim, Chang Kon; Han, In Suk; Ryu, Wang Sun; Lee, Hai Whang; Lee, Bon-Su; Kim, Chan Kyung

2006-02-23

The pi-donating effects of pi-accepting X-substituents in substituted benzylic cations, X-C(6)H(5)-CHR(+) where R = CF(3), H and OCH(3), and X = p-NH(2), p-OCH(3), p-CH(3), H, p-F, p-Cl, p-CHO, m-CN, p-CN, m-NO(2) or p-NO(2), have been studied theoretically by using isodesmic hydride transfer reactions at various levels of theory. It might be difficult to determine the pi-donating effects of pi-acceptors using the simple Hammett-type linear equation, because it is not sensitive enough to include small pi-donating effects. Therefore, this effect was estimated using the NBO deletion energy (DeltaE(D)) of the second-order charge-transfer interaction (DeltaE(ct)) between the pi-orbitals (or lone pair orbitals) of the X-substituent and the pi-orbitals of phenyl ring. The extents of pi-donating effects increased in the order X = p-NO(2) < p-CHO < p-CN < p-Cl for both neutral and cationic species, and these effects were found to be more important for para- than for meta-substituents. Moreover, this could represent a general trend for pi-donation by pi-acceptors. On the other hand, the effects of R-substituents on this pi-donating effect were found to be in the order R = OCH(3) < H congruent with CF(3), as predicted by natural resonance theory (NRT) analyses.
Insertion of Astronomy as a High School Subject. (Spanish Title: Inserción de Astronomia Como Materia del Ciclo Secundario.) Inserção da Astronomia Como Disciplina Curricular do Ensino Médio

NASA Astrophysics Data System (ADS)

Dias, Claudio André C. M.; Santa Rita, Josué R.

2008-12-01

Astronomy is considered among the first sciences that man dominated, however, the basic skills for the construction of knowledge, relatively to the contents "Earth and the Universe" are not being developed properly for the majority of students concluding the high school level. The students are concluding this teaching cycle without proper knowledge of several subjects in the area of Astronomy, which are mandatory in the national Curricular National Parameters (PCN). Because of this discrepancy, this work stresses the need of the incorporation of a specific subject of Astronomy in the high school, in order to reduce the gap between what is taught and which should be taught. La Astronomía es considerada una de las primeras ciencias que el hombre dominó. Sin embargo, las habilidades básicas para la construcción del conocimento, relativo al eje temático "Tierra y Universo", no vienen siendo trabajadas adecuadamente con la mayoría de los alumnos que concluyen el ciclo escolar medio. Los alumnos están concluyendo este nivel de enseñanza sin conocimentos de varios temas en el área de Astronomía, que son obligatorios según los Parámetros Curriculares Nacionales (PCN). En virtud de esta discrepancia, este trabajo enfatiza la necesidad de incorporar una disciplina específica de Astronomía em el ciclo medio, em pro de la reducción de las distorsiones entre lo que es enseñado y lo que se debe enseñar. A Astronomia é considerada uma das primeiras ciências que o homem dominou, porém as competências básicas para a construção do conhecimento, relativo ao eixo temático "Terra e Universo", não vêm sendo trabalhadas a contento com a maioria dos alunos que concluem o ensino médio. Os alunos estão concluindo este nível de ensino sem conhecimento de vários temas na área de Astronomia, que são obrigatórios nos Parâmetros Curriculares Nacionais (PCN). Em virtude desta discrepância, este trabalho vem evidenciar a necessidade da incorporação de uma disciplina específica de Astronomia, no ensino médio, em prol da redução das distorções entre o que é ensinado e o que se deve ensinar.
Interaction of Bacterial Phenazines with Colistimethate in Bronchial Epithelial Cells.

PubMed

Mossine, Valeri V; Chance, Deborah L; Waters, James K; Mawhinney, Thomas P

2018-05-21

Multidrug-resistant bacterial infections are being increasingly treated in clinics with polymyxins, a class of antibiotics associated with adverse effects in the kidney, nervous system, or airways of a significant proportion of human and animal patients. Although many of the resistant pathogens display enhanced virulence, a hazard of cytotoxic interactions between polymyxin antibiotics and bacterial virulence factors (VFs) has not been assessed, to date. We report here on testing paired combinations of four Pseudomonas aeruginosa VF phenazine toxins, pyocyanin (PYO), 1-hydroxyphenazine (1-HP), phenazine-1-carboxylic acid (PCA), phenazine-1-carboxamide (PCN), and two commonly prescribed polymyxin drugs, colistimethate (CMS)/colistin and polymyxin B, in three human airway cell lines, BEAS-2B, HBE-1, and CFT-1. Cytotoxicities of individual antibiotics, toxins, and their combinations were evaluated by simultaneous measurement of mitochondrial metabolic, total transcriptional/translational, and the Nrf2 stress response regulator activities in treated cells. Two phenazines, PYO and 1-HP, were cytotoxic at clinically relevant concentrations (100-150 μM) and prompted a significant increase in the oxidative stress-induced transcriptional activity in surviving cells. The polymyxin antibiotics arrested the cell proliferation at clinically achievable (< 1 mM) concentrations, as well, with CMS displaying a surprisingly high cytotoxicity (ED 50 = 180 μM) in BEAS-2B. The dose-response curves were probed by the median-effect analysis which established a synergistically enhanced cytotoxicity of the PYO/CMS combination in all three airway cell lines; a particularly strong effect was observed in the BEAS-2B cells, with the combination index (CI) = 0.27 at ED 50 PCA, PCN, and 1-HP potentiated CMS cytotoxicity to a smaller extent. The cytotoxicity of CMS could be reduced with 10 mM N -acetyl-cysteine. Iron chelators, while ineffective against the polymyxins, could rescue all three bronchial epithelial cell lines treated with lethal PYO or CMS/PYO doses. These findings suggest further evaluations of CMS safety are needed, along with a search for means to moderate the potentially cytotoxic interactions. Copyright © 2018 Mossine et al.
Design Calculation Procedure for Passive Solar Houses at Navy Installations in Regions with Cold Climate. Volume I.

DTIC Science & Technology

1981-10-01

8217.nd So,,,g.YPFREO T1 PRO CVRC Design Calculation Procedure for Passive Preliminary Solar Houses at Navy Installations in Apr zO STpiPOR NUBE Regions...unlimited I7 DISTRIBUTION STATEMENT (of the WAtract ente~red InI 81-1, 20, it diferent from Report) 18 SUPPLEMENTARY NOTES 19P KEY WORDS ( Con ,,nUe on~df -1...agl Figure ~ ~ 5. Deiiino ybl sdi Swot pcn aclto 59/ condition) for oorthern latitudes and different times of da are listed in .11 lable 5.4
Satellite diversity and its implications on the RAKE receiver architecture for CDMA-based S-PCN's

NASA Technical Reports Server (NTRS)

Taaghol, P.; Sammut, A.; Tafazolli, R.; Evans, B. G.

1995-01-01

In this paper we examine the applicability of RAKE receivers in a mobile LEO satellite channel and identify the potential problem areas. We then proceed to investigate the possibility of a coherent combining architecture (downlink) in the presence of satellite diversity. We closely examine the path delay difference statistics of a diversity channel and propose a delay compensation scheme for the downlink in order to reduce the complexity of the user terminal. Finally, the required modifications to the conventional RAKE receiver are proposed and discussed.
Giant increase in piezoelectric coefficient of AlN by Mg-Nb simultaneous addition and multiple chemical states of Nb

NASA Astrophysics Data System (ADS)

Uehara, Masato; Shigemoto, Hokuto; Fujio, Yuki; Nagase, Toshimi; Aida, Yasuhiro; Umeda, Keiichi; Akiyama, Morito

2017-09-01

Aluminum nitride (AlN) is one of piezoelectric materials, which are eagerly anticipated for use in microelectromechanical systems (MEMS) applications such as communication resonators, sensors, and energy harvesters. AlN is particularly excellent in generated voltage characteristics for the MEMS rather than oxide piezoelectric materials such as lead zirconium titanate Pb(Zr, Ti)O3. However, it is necessary to improve the piezoelectric properties of AlN in order to advance the performance of the MEMS. We dramatically increased the piezoelectric coefficient d33 of AlN films by simultaneously adding magnesium (Mg) and niobium (Nb). The d33 of Mg39.3Nb25.0Al35.7N is 22 pC/N, which is about four times that of AlN. The d33 is increased by Mg and Nb simultaneous addition, and is not increased by Mg or Nb single addition. Interestingly, the Nb has multiple chemical states, and which are influenced by the Mg concentration.
Effect of poling process on piezoelectric properties of BCZT - 0.08 wt.% CeO{sub 2} lead-free ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandrakala, E.; Praveen, J. Paul; Das, Dibakar, E-mail: ddse@uohyd.ernet.in

2016-05-06

The properties of lead free piezoelectric materials can be tuned by suitable doping in the A and B sites of the perovskite structure. In the present study, cerium has been identified as a dopant to investigate the piezoelectric properties of lead-free BCZT system. BCZT – 0.08 wt.%CeO{sub 2} lead-free ceramics have been synthesized using sol-gel technique and the effects of CeO{sub 2} dopant on their phase structure and piezoelectric properties were investigated systematically. Poling conditions, such as temperature, electric field, and poling time have been optimized to get enhanced piezoelectric response. The optimized poling conditions (50°C, 3Ec and 30min) resultedmore » in high piezoelectric charge coefficient d{sub 33} ~ 670pC/N, high electromechanical coupling coefficient k{sub p} ~ 60% and piezoelectric voltage coefficient g{sub 33} ~ 14 mV.m/N for BCZT – 0.08wt.% CeO{sub 2} ceramics.« less
Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K0.5Bi0.5TiO3-BaTiO3-Na0.5Bi0.5TiO3 piezoelectric materials

PubMed Central

Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

2015-01-01

We synthesized grain-oriented lead-free piezoelectric materials in (K0.5Bi0.5TiO3-BaTiO3-xNa0.5Bi0.5TiO3 (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d33 ~ 190pC/N) and high temperature stability (~160°C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180° domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectric materials. PMID:25716551
Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K₀̣₅Bi₀̣₅TiO₃-BaTiO₃-Na₀̣₅Bi₀̣₅TiO₃ piezoelectric materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maurya, Deepam; Zhou, Yuan; Wang, Yaojin

2015-02-26

We synthesized grain-oriented lead-free piezoelectric materials in (K₀̣₅Bi₀̣₅TiO₃-BaTiO₃-xNa₀̣₅Bi₀̣₅TiO₃ (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d₃₃ ~ 190pC/N) and high temperature stability (~160°C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180° domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectricmore » materials.« less
Giant Piezoelectricity and High Curie Temperature in Nanostructured Alkali Niobate Lead-Free Piezoceramics through Phase Coexistence.

PubMed

Wu, Bo; Wu, Haijun; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo; Pennycook, Stephen J

2016-11-30

Because of growing environmental concerns, the development of lead-free piezoelectric materials with enhanced properties has become of great interest. Here, we report a giant piezoelectric coefficient (d 33 ) of 550 pC/N and a high Curie temperature (T C ) of 237 °C in (1-x-y)K 1-w Na w Nb 1-z Sb z O 3- xBiFeO 3- yBi 0.5 Na 0.5 ZrO 3 (KN w NS z -xBF-yBNZ) ceramics by optimizing x, y, z, and w. Atomic-resolution polarization mapping by Z-contrast imaging reveals the intimate coexistence of rhombohedral (R) and tetragonal (T) phases inside nanodomains, that is, a structural origin for the R-T phase boundary in the present KNN system. Hence, the physical origin of high piezoelectric performance can be attributed to a nearly vanishing polarization anisotropy and thus low domain wall energy, facilitating easy polarization rotation between different states under an external field.
Self-assembled graphene/azo polyelectrolyte multilayer film and its application in electrochemical energy storage device.

PubMed

Wang, Dongrui; Wang, Xiaogong

2011-03-01

Graphene/azo polyelectrolyte multilayer films were fabricated through electrostatic layer-by-layer (LbL) self-assembly, and their performance as electrochemical capacitor electrode was investigated. Cationic azo polyelectrolyte (QP4VP-co-PCN) was synthesized through radical polymerization, postpolymerization azo coupling reaction, and quaternization. Negatively charged graphene nanosheets were prepared by a chemically modified method. The LbL films were obtained by alternately dipping a piece of the pretreated substrates in the QP4VP-co-PCN and nanosheet solutions. The processes were repeated until the films with required numbers of bilayers were obtained. The self-assembly and multilayer surface morphology were characterized by UV-vis spectroscopy, AFM, SEM, and TEM. The performance of the LbL films as electrochemical capacitor electrode was estimated using cyclic voltammetry. Results show that the graphene nanosheets are densely packed in the multilayers and form random graphene network. The azo polyelectrolyte cohesively interacts with the nanosheets in the multilayer structure, which prevents agglomeration of graphene nanosheets. The sheet resistance of the LbL films decreases with the increase of the layer numbers and reaches the stationary value of 1.0 × 10(6) Ω/square for the film with 15 bilayers. At a scanning rate of 50 mV/s, the LbL film with 9 bilayers shows a gravimetric specific capacitance of 49 F/g in 1.0 M Na(2)SO(4) solution. The LbL films developed in this work could be a promising type of the electrode materials for electric energy storage devices.
Molecular variability and evolution of the pectate lyase (pel-2) parasitism gene in cyst nematodes parasitizing different solanaceous plants.

PubMed

Geric Stare, Barbara; Fouville, Didier; Širca, Saša; Gallot, Aurore; Urek, Gregor; Grenier, Eric

2011-02-01

While pectate lyases are major parasitism factors in plant-parasitic nematodes, there is little information on the variability of these genes within species and their utility as pathotype or host range molecular markers. We have analysed polymorphisms of pectate lyase 2 (pel-2) gene, which degrades the unesterified polygalacturonate (pectate) of the host cell-wall, in the genus Globodera. Molecular variability of the pel-2 gene and the predicted protein was evaluated in populations of G. rostochiensis, G. pallida, G. "mexicana" and G. tabacum. Seventy eight pel-2 sequences were obtained and aligned. Point mutations were observed at 373 positions, 57% of these affect the coding part of the gene and produce 129 aa replacements. The observed polymorphism does not correlate either to the pathotypes proposed in potato cyst nematodes (PCN) or the subspecies described in tobacco cyst nematodes. The trees reveal a topology different from the admitted species topology as G. rostochiensis and G. pallida sequences are more similar to each other than to G. tabacum. Species-specific sites, potentially applicable for identification, and sites distinguishing PCN from tobacco cyst nematodes, were identified. As both G. rostochiensis and G. pallida display the same host range, but distinct from G. tabacum, which cannot parasitize potato plants, it is tempting to speculate that pel-2 genes polymorphism may be implicated in this adaptation, a view supported by the fact that no active pectate lyase 2 was found in G. "mexicana", a close relative of G. pallida that is unable to develop on cultivated potato varieties.
Geometric MCMC for infinite-dimensional inverse problems

NASA Astrophysics Data System (ADS)

Beskos, Alexandros; Girolami, Mark; Lan, Shiwei; Farrell, Patrick E.; Stuart, Andrew M.

2017-04-01

Bayesian inverse problems often involve sampling posterior distributions on infinite-dimensional function spaces. Traditional Markov chain Monte Carlo (MCMC) algorithms are characterized by deteriorating mixing times upon mesh-refinement, when the finite-dimensional approximations become more accurate. Such methods are typically forced to reduce step-sizes as the discretization gets finer, and thus are expensive as a function of dimension. Recently, a new class of MCMC methods with mesh-independent convergence times has emerged. However, few of them take into account the geometry of the posterior informed by the data. At the same time, recently developed geometric MCMC algorithms have been found to be powerful in exploring complicated distributions that deviate significantly from elliptic Gaussian laws, but are in general computationally intractable for models defined in infinite dimensions. In this work, we combine geometric methods on a finite-dimensional subspace with mesh-independent infinite-dimensional approaches. Our objective is to speed up MCMC mixing times, without significantly increasing the computational cost per step (for instance, in comparison with the vanilla preconditioned Crank-Nicolson (pCN) method). This is achieved by using ideas from geometric MCMC to probe the complex structure of an intrinsic finite-dimensional subspace where most data information concentrates, while retaining robust mixing times as the dimension grows by using pCN-like methods in the complementary subspace. The resulting algorithms are demonstrated in the context of three challenging inverse problems arising in subsurface flow, heat conduction and incompressible flow control. The algorithms exhibit up to two orders of magnitude improvement in sampling efficiency when compared with the pCN method.

Is the 10th and 11th Intercostal Space a Safe Approach for Percutaneous Nephrostomy and Nephrolithotomy?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muzrakchi, Ahmed Al; Szmigielski, W., E-mail: wojszmi@qatar.net.qa; Omar, Ahmed J.S.

2004-09-15

The aim of this study was to determine the rate of complications in percutaneous nephrostomy (PCN) and nephrolithotomy (PCNL) performed through the 11th and 10th intercostal spaces using our monitoring technique and to discuss the safety of the procedure. Out of 398 PCNs and PCNLs carried out during a 3-year period, 56 patients had 57 such procedures performed using an intercostal approach. The 11th intercostal route was used in 42 and the 10th in 15 cases. One patient had two separate nephrostomies performed through the 10th and 11th intercostal spaces. The technique utilizes bi-planar fluoroscopy with a combination of amore » conventional angiographic machine to provide anterior-posterior fluoroscopy and a C-arm mobile fluoroscopy machine to give a lateral view, displayed on two separate monitors. None of the patients had clinically significant thoracic or abdominal complications. Two patients had minor chest complications. Only one developed changes (plate atelectasis, elevation of the hemi-diaphragm) directly related to the nephrostomy (2%). The second patient had bilateral plate atelectasis and unilateral congestive lung changes after PCNL. These changes were not necessarily related to the procedure but rather to general anesthesia during nephrolithotomy. The authors consider PCN or PCNL through the intercostal approach a safe procedure with a negligible complication rate, provided that it is performed under bi-planar fluoroscopy, which allows determination of the skin entry point just below the level of pleural reflection and provides three-dimensional monitoring of advancement of the puncturing needle toward the target entry point.« less
Proceedings of the Workshop on Advanced Network and Technology Concepts for Mobile, Micro, and Personal Communications

NASA Technical Reports Server (NTRS)

Paul, Lori (Editor)

1991-01-01

The Workshop on Advanced Network and Technology Concepts for Mobile, Micro, and Personal Communications was held at NASA's JPL Laboratory on 30-31 May 1991. It provided a forum for reviewing the development of advanced network and technology concepts for turn-of-the-century telecommunications. The workshop was organized into three main categories: (1) Satellite-Based Networks (L-band, C-band, Ku-band, and Ka-band); (2) Terrestrial-Based Networks (cellular, CT2, PCN, GSM, and other networks); and (3) Hybrid Satellite/Terrestrial Networks. The proceedings contain presentation papers from each of the above categories.
The Preparation of an Ultrastable Mesoporous Cr(III)-MOF via Reductive Labilization

DTIC Science & Technology

2015-09-02

of metal clusters from a template MOF with a known structure. Fe(III)-MOFs can serve as practical structural templates because iron resembles chromium ...clusters in PCN-333 are able to accommodate both di- and trivalent metal ions by varying the charges of the terminal ligands, the bridging oxygen atoms, and...molecules in trivalent aqua complexes27 Inert complexes Labile complexes M(OH2) Cr(OH2)6 3+ Ir(OH2)6 3+ V(OH2)6 3+ Fe(OH2)6 3+ Ti(OH2)6 3+ k (s1) 2.4 10
Antimicrobial susceptibility of clinically isolated anaerobic bacteria in a University Hospital Centre Split, Croatia in 2013.

PubMed

Novak, Anita; Rubic, Zana; Dogas, Varja; Goic-Barisic, Ivana; Radic, Marina; Tonkic, Marija

2015-02-01

Anaerobic bacteria play a significant role in many endogenous polymicrobial infections. Since antimicrobial resistance among anaerobes has increased worldwide, it is useful to provide local susceptibility data to guide empirical therapy. The present study reports recent data on the susceptibility of clinically relevant anaerobes in a University Hospital Centre (UHC) Split, Croatia. A total of 63 Gram-negative and 59 Gram-positive anaerobic clinical isolates from various body sites were consecutively collected from January to December 2013. Antimicrobial susceptibility testing was performed using standardized methods and interpreted using EUCAST criteria. Patient's clinical and demographic data were recorded by clinical microbiologist. Among 35 isolates of Bacteroides spp., 97.1% were resistant to penicillin (PCN), 5.7% to amoxicillin/clavulanic acid (AMC), 8.6% to piperacillin/tazobactam (TZP), 29.0% to clindamycin (CLI) and 2.9% to metronidazole (MZ). Percentages of susceptible strains to imipenem (IPM), meropenem (MEM) and ertapenem (ETP) were 94.3. Resistance of other Gram-negative bacilli was 76.0% to PCN, 8.0% to AMC, 12.0% to TZP, 28.0% to CLI and 8% to MZ. All other Gram-negative strains were fully susceptible to MEM and ETP, while 96.0% were susceptible to IPM. Clostridium spp. isolates were 100% susceptible to all tested antibiotics except to CLI (two of four tested isolates were resistant). Propionibacterium spp. showed resistance to CLI in 4.3%, while 100% were resistant to MZ. Among other Gram-positive bacilli, 18.2% were resistant to PCN, 9.1% to CLI and 54.5% to MZ, while 81.8% of isolates were susceptible to carbapenems. Gram-positive cocci were 100% susceptible to all tested antimicrobials except to MZ, where 28.6% of resistant strains were recorded. Abdomen was the most common source of isolates (82.5%). The most prevalent types of infection were abscess (22.1%), sepsis (14.8%), appendicitis (13.9%) and peritonitis (6.6%). Twenty four patients (19.7%) received empiric antimicrobial therapy. One hundred and one patients (82.8%) had polymicrobial aerobic/anaerobic isolates cultivated from the same specimens. Almost all aerobic bacteria were of endogenous origin and showed fully susceptible antimicrobial profile; only 8.7% (9/104) were multiresistant and considered as hospital acquired. Based on our findings, β-lactam/β-lactamase inhibitor combinations and metronidazole remain useful antimicrobials for empiric treatment of anaerobic infections, while carbapenems should be reserved for situations were multidrug resistant, aerobic or facultative Gram-negative bacteria are expected. However, a certain percentage of resistant isolates were observed for each of these agents. Therefore, periodic resistance surveillance in anaerobes is highly recommended in order to guide empirical therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.
Long-Term Percutaneous Nephrostomy Management of Malignant Urinary Obstruction: Estimation of Optimal Exchange Frequency and Estimation of the Financial Impact of Patient Compliance.

PubMed

McDevitt, Joseph L; Acosta-Torres, Stefany; Zhang, Ning; Hu, Tianshen; Odu, Ayobami; Wang, Jijia; Xi, Yin; Lamus, Daniel; Miller, David S; Pillai, Anil K

2017-07-01

To estimate the least costly routine exchange frequency for percutaneous nephrostomies (PCNs) placed for malignant urinary obstruction, as measured by annual hospital charges, and to estimate the financial impact of patient compliance. Patients with PCNs placed for malignant urinary obstruction were studied from 2011 to 2013. Exchanges were classified as routine or due to 1 of 3 complication types: mechanical (tube dislodgment), obstruction, or infection. Representative cases were identified, and median representative charges were used as inputs for the model. Accelerated failure time and Markov chain Monte Carlo models were used to estimate distribution of exchange types and annual hospital charges under different routine exchange frequency and compliance scenarios. Long-term PCN management was required in 57 patients, with 87 total exchange encounters. Median representative hospital charges for pyelonephritis and obstruction were 11.8 and 9.3 times greater, respectively, than a routine exchange. The projected proportion of routine exchanges increased and the projected proportion of infection-related exchanges decreased when moving from a 90-day exchange with 50% compliance to a 60-day exchange with 75% compliance, and this was associated with a projected reduction in annual charges. Projected cost reductions resulting from increased compliance were generally greater than reductions resulting from changes in exchange frequency. This simulation model suggests that the optimal routine exchange interval for PCN exchange in patients with malignant urinary obstruction is approximately 60 days and that the degree of reduction in charges likely depends more on patient compliance than exact exchange interval. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.
Short-term temperature-dependent air-surface exchange and atmospheric concentrations of polychlorinated naphthalenes and organochlorine pesticides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, R.G.M.; Burnett, V.; Harner, T.

2000-02-01

Atmospheric concentrations of five organochlorine (OC) pesticides, some of which have been banned for a number of years, and polychlorinated naphthalenes (PCNs) were measured at a U.K. site over periods of 6 h for 7 days resulting in 28 samples. Mean concentrations of the pesticides were {alpha}-HCH 90 pg m{sup {minus}3}, {gamma}-HCH 500, {rho},{rho}{prime}-DDE 8, dieldrin 63, endrin 22, and HCB 39. PCN mean homologue concentrations were {sub 3}CNs 67 pg m{sup {minus}3}, {sub 4}CNs 78, {sub 5}CNs 5, {sub 6}CNs 0.6, {sub 7}CNs 0.6, and {Sigma}PCNs 152. TEQ concentrations for those PCNs ascribed TEF values ranged between 0.36 andmore » 3.6 fg m{sup {minus}3} which corresponds to {approximately}3.0--30% of the TEQ concentrations of PCDD/Fs at the same site. All the compounds measured, except HCB, exhibited a strong temperature-dependent diurnal cycling. Results from Clausius-Clapeyron plots show that pesticide concentrations were controlled by temperature-driven air-surface recycling throughout the first 5 days when stable atmospheric conditions were dominant, while during the last 2 days advection became more influential as more unstable and cooler weather started to influence the site. PCN concentrations were controlled primarily by a mixture of recycling and advection throughout the first 5 days and then by advection in the final 2 days, suggesting that there are ongoing emissions from diffuse point sources of PCNs into the U.K. atmosphere. This study provides further evidence of the rapid air-surface exchange of semivolatile organic compounds (SOCs) and shows how different factors alone or in combination can produce rapid changes in the atmospheric concentrations of past and present SOCs.« less
Analysis of phytochelatin complexes in the lead tolerant vetiver grass [Vetiveria zizanioides (L.)] using liquid chromatography and mass spectrometry.

PubMed

Andra, Syam S; Datta, Rupali; Sarkar, Dibyendu; Saminathan, Sumathi K M; Mullens, Conor P; Bach, Stephan B H

2009-07-01

Ethylenediamene tetraacetic acid (EDTA) has been used to mobilize soil lead (Pb) and enhance plant uptake for phytoremediation. Chelant bound Pb is considered less toxic compared to free Pb ions and hence might induce less stress on plants. Characterization of possible Pb complexes with phytochelatins (PCn, metal-binding peptides) and EDTA in plant tissues will enhance our understanding of Pb tolerance mechanisms. In a previous study, we showed that vetiver grass (Vetiveria zizanioides L.) can accumulate up to 19,800 and 3350 mg Pb kg(-1) dry weight in root and shoot tissues, respectively; in a hydroponics set-up. Following the basic incubation study, a greenhouse experiment was conducted to elucidate the efficiency of vetiver grass (with or without EDTA) in remediating Pb-contaminated soils from actual residential sites where Pb-based paints were used. The levels of total thiols, PCn, and catalase (an antioxidant enzyme) were measured in vetiver root and shoot following chelant-assisted phytostabilization. In the presence of 15 mM kg (-1) EDTA, vetiver accumulated 4460 and 480 mg Pb kg(-1) dry root and shoot tissue, respectively; that are 15- and 24-fold higher compared to those in untreated controls. Despite higher Pb concentrations in the plant tissues, the amount of total thiols and catalase activity in EDTA treated vetiver tissues was comparable to chelant unamended controls, indicating lowered Pb toxicity by chelation with EDTA. The identification of glutathione (referred as PC1) (m/z 308.2), along with chelated complexes like Pb-EDTA (m/z 498.8) and PC(1)-Pb-EDTA (m/z 805.3) in vetiver root tissue using electrospray tandem mass spectrometry (ES-MS) highlights the possible role of such species towards Pb tolerance in vetiver grass.
Symmetrical and unsymmetrical pincer complexes with group 10 metals: synthesis via aryl C-H activation and some catalytic applications.

PubMed

Niu, Jun-Long; Hao, Xin-Qi; Gong, Jun-Fang; Song, Mao-Ping

2011-05-21

Aryl-based pincer metal complexes with anionic terdentate ligands have been widely applied in organic synthesis, organometallic catalysis and other related areas. Synthetically, the most simple and convenient method for the construction of these complexes is the direct metal-induced C(aryl)-H bond activation, which can be fulfilled by choosing the appropriate functional donor groups in the two side arms of the aryl-based pincer preligands. In this perspective, we wish to summarize some results achieved by our group in this context. Successful examples include symmetrical chiral bis(imidazoline) NCN pincer complexes with Ni(II), Pd(II) and Pt(II), bis(phosphinite) and bis(phosphoramidite) PCP pincer Pd(II) complexes, unsymmetrical (pyrazolyl)phosphinite, (amino)phosphinite and (imino)phosphinite PCN pincer Pd(II) complexes, chiral (imidazolinyl)phosphinite and (imidazolinyl)phosphoramidite PCN pincer complexes with Ni(II) and Pd(II) as well as unsymmetrical (oxazolinyl)amine and (oxazolinyl)pyrazole NCN' pincer Pd(II) complexes. Among them, the P-donor containing complexes are efficiently synthesized by the "one-pot phosphorylation/metalation" method. The obtained symmetrical and unsymmetrical pincer complexes have been used as catalysts in Suzuki-Miyaura reaction (Pd), asymmetric Friedel-Crafts alkylation of indole with trans-β-nitrostyrene (Pt) as well as in asymmetric allylation of aldehyde and sulfonimine (Pd). In the Suzuki couplings conducted at 40-50 °C, some unsymmetrical Pd complexes exhibit much higher activity than the related symmetrical ones which can be attributed to their faster release of active Pd(0) species resulting from the hemilabile coordination of the ligands. Literature results on the synthesis of some related pincer complexes as well as their activities in the above catalytic reactions are also presented.
Comparative face-shear piezoelectric properties of soft and hard PZT ceramics

NASA Astrophysics Data System (ADS)

Miao, Hongchen; Chen, Xi; Cai, Hairong; Li, Faxin

2015-12-01

The face-shear ( d 36 ) mode may be the most practical shear mode in piezoelectrics, while theoretically this mode cannot appear in piezoelectric ceramics because of its transversally isotropic symmetry. Recently, we realized piezoelectric coefficient d 36 up to 206pC/N in soft PbZr1-xTixO3 (PZT) ceramics via ferroelastic domain engineering [H. C. Miao and F. X. Li, Appl. Phys. Lett. 107, 122902 (2015)]. In this work, we further realized the face-shear mode in both hard and soft PZT ceramics including PZT-4 (hard), PZT-51(soft), and PZT-5H (soft) and investigated the electric properties systematically. The resonance methods are derived to measure the d 36 coefficients using both square patches and narrow bar samples, and the obtained values are consistent with that measured by a modified d 33 meter previously. For all samples, the pure d 36 mode can only appear near the resonance frequency, and the coupled d 36 - d 31 mode dominates off resonance. It is found that both the piezoelectric coefficient d 36 and the electromechanical coupling factor k 36 of soft PZT ceramics (PZT-5H and PZT-51) are considerably larger than those of the hard PZT ceramics (PZT-4). The obtained d 36 of 160-275pC/N, k 36 ˜ 0.24, and the mechanical quality factor Q 36 of 60-90 in soft PZT ceramics are comparable with the corresponding properties of the d 31 mode sample. Therefore, the d 36 mode in modified soft PZT ceramics is more promising for industrial applications such as face-shear resonators and shear horizontal wave generators.
Change in the plasmid copy number in acetic acid bacteria in response to growth phase and acetic acid concentration.

PubMed

Akasaka, Naoki; Astuti, Wiwik; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

2015-06-01

Plasmids pGE1 (2.5 kb), pGE2 (7.2 kb), and pGE3 (5.5 kb) were isolated from Gluconacetobacter europaeus KGMA0119, and sequence analyses revealed they harbored 3, 8, and 4 genes, respectively. Plasmid copy numbers (PCNs) were determined by real-time quantitative PCR at different stages of bacterial growth. When KGMA0119 was cultured in medium containing 0.4% ethanol and 0.5% acetic acid, PCN of pGE1 increased from 7 copies/genome in the logarithmic phase to a maximum of 12 copies/genome at the beginning of the stationary phase, before decreasing to 4 copies/genome in the late stationary phase. PCNs for pGE2 and pGE3 were maintained at 1-3 copies/genome during all phases of growth. Under a higher concentration of ethanol (3.2%) the PCN for pGE1 was slightly lower in all the growth stages, and those of pGE2 and pGE3 were unchanged. In the presence of 1.0% acetic acid, PCNs were higher for pGE1 (10 copies/genome) and pGE3 (6 copies/genome) during the logarithmic phase. Numbers for pGE2 did not change, indicating that pGE1 and pGE3 increase their PCNs in response to acetic acid. Plasmids pBE2 and pBE3 were constructed by ligating linearized pGE2 and pGE3 into pBR322. Both plasmids were replicable in Escherichia coli, Acetobacter pasteurianus and G. europaeus, highlighting their suitability as vectors for acetic acid bacteria. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
Thermal dechlorination of PCB-209 over Ca species-doped Fe₂O₃.

PubMed

Su, Guijin; Huang, Linyan; Shi, Ruifang; Liu, Yexuan; Lu, Huijie; Zhao, Yuyang; Yang, Fan; Gao, Lirong; Zheng, Minghui

2016-02-01

Degradation reaction of decachlorobiphenyl (PCB-209) was investigated over the synthesized Ca species-doped Fe2O3 at 300 °C. The 1%Ca-Fe2O3 exhibited the highest activity among the four catalysts prepared with the pseudo-first order reaction at k(obs) = 0.103 min(-1). PCB-207, PCB-197, PCB-176, PCB-184, PCB-150, PCB-136, PCB-148, PCB-104, PCB-96, PCB-54, PCB-19, PCB-4 and PCB-1 were identified as the dominant isomers in their respective nonachlorobiphenyl (NonaCB) to monochlorobiphenyl (MonoCB) homologue groups. Analysis of the hydrodechlorination products indicated that dechlorination was much more favored on meta- and para-than on ortho-positions. The formation of significantly predominant NonaCB and octachlorobiphenyl (OctaCB) isomers was attributed to lower energy principles and to the 90° dihedral angles of two aromatic rings which prevented the hydrodechlorination at ortho-positions. When the number of chlorine atoms is not more than 7, the steric effect supports the formation of predominant PCB isomers having chlorines at four ortho-positions. During the dechlorination of tetrachlorobiphenyl (TetraCB) formed to generate monochlorobiphenyl (MonoCB) isomers, the chlorine atoms fully substituted at the ortho-positions have to be successively removed, with the first two dechlorinations preferentially occurring at the two different benzene rings. This is dissimilar to that of octachloronaphthalene (PCN-75) in which the hydrodechlorination reaction happened preferentially at ortho-position due to the existence of steric effects. The opposite roles of the steric effect in ortho-position between PCB-209 and PCN-75 might be due to the difference of the π-conjugated plane caused by the dihedral angle of 90° and 0° of the two aromatic rings. Copyright © 2015 Elsevier Ltd. All rights reserved.
Dynamical Cluster-decay Model (DCM) applied to 9Li+208Pb reaction

NASA Astrophysics Data System (ADS)

Kaur, Arshdeep; Hemdeep; Kaushal, Pooja; Behera, Bivash R.; Gupta, Raj K.

2017-10-01

The decay mechanism of 217At* formed in 9Li+208Pb reaction is studied within the dynamical cluster-decay model (DCM) at various center-of-mass energies. The aim is to see the behavior of a light neutron-rich radioactive beam on a doubly-magic target nucleus for the (total) fusion cross section σfus and the individual decay channel cross sections. Experimentally, only the isotopic yield of heavy mass residues * 211- 214At [equivalently, the light-particles (LPs) evaporation residue cross sections σxn for x = 3- 6 neutrons emission] are measured, with the fusion-fission (ff) component σff taken zero. For a fixed neck-length parameter ΔR, the only parameter in the DCM, we are able to fit σfus =∑x=16σxn almost exactly for 9Li on 208Pb at all E c . m .'s. However, the observed individual decay channels (3n-6n) are very poorly fitted, with unobserved channels (1n, 2n) and σff strongly over-estimated. Different ΔR values, meaning thereby different reaction time scales, are required to fit individually both the observed and unobserved evaporation residue channels (1n-6n) and σff, but then the compound nucleus (CN) contribution σCN is very small (< 1%), and the non-compound nucleus (nCN) decay cross section σnCN contributes the most towards total σfus (=σCN +σnCN). Thus, the 9Li induced reaction on doubly-magic 208Pb is more of a quasi-fission-like nCN decay, which is further analyzed in terms of the statistical CN formation probability PCN and CN survival probability Psurv. For the reaction under study, PCN < < 1 and Psurv → 1, in particular at above barrier energies.
Challenges in Identifying Patients with Type 2 Diabetes for Quality-Improvement Interventions in Primary Care Settings and the Importance of Valid Disease Registries.

PubMed

Wozniak, Lisa; Soprovich, Allison; Rees, Sandra; Johnson, Steven T; Majumdar, Sumit R; Johnson, Jeffrey A

2015-10-01

Patient registries are considered an important foundation of chronic disease management, and diabetes patient registries are associated with better processes and outcomes of care. The purpose of this article is to describe the development and use of registries in the Alberta's Caring for Diabetes (ABCD) project to identify and reach target populations for quality-improvement interventions in the primary care setting. We applied the reach, effectiveness, adoption, implementation and maintenance (RE-AIM) framework and expanded the definition of reach beyond the individual (i.e. patient) level to include the ability to identify target populations at an organizational level. To characterize reach and the implementation of registries, semistructured interviews were conducted with key informants, and a usual-care checklist was compiled for each participating Primary Care Network (PCN). Content analysis was used to analyze qualitative data. Using registries to identify and recruit participants for the ABCD interventions proved challenging. The quality of the registries depended on whether physicians granted PCN access to patient lists, the strategies used in development, the reliability of diagnostic information and the data elements collected. In addition, once a diabetes registry was developed, there was limited ability to update it. Proactive management of chronic diseases like diabetes requires the ability to reach targeted patients at the population level. We observed several challenges to the development and application of patient registries. Given the importance of valid registries, strong collaborations and novel strategies that involve policy-makers, PCNs and providers are needed to help find solutions to improve registry quality and resolve maintenance issues. Copyright © 2015 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.
Contractors Road Heavy Equipment Area SWMU 055 Corrective Measures Implementation Progress Report

NASA Technical Reports Server (NTRS)

Dorman, Lane

2015-01-01

This Corrective Measures Implementation (CMI) Progress Report, Revision 1, for Contractor's Road Heavy Equipment (CRHE) Area Solid Waste Management Unit (SWMU) Number 055 was prepared by Geosyntec Consultants (Geosyntec) for the National Aeronautics and Space Administration (NASA) under contract number NNK09CA02B, Delivery Order NNK09CA62D and Project Number PCN ENV-2324. This CMI Progress Report documents: (i) activities conducted as part of supplemental assessment activities completed from June 2009 through November 2014; (ii) Engineering Evaluation (EE) Advanced Data Packages (ADPs); and (iii) recommendations for future activities related to corrective measures at the Site.
Texture and anisotropy in the bismuth sodium titanate system

NASA Astrophysics Data System (ADS)

Fancher, Christoher M.

Bi0.5Na0.5TiO3 has received interest as a potential replacement for lead containing ferroelectrics. However, the piezoelectric response of pure Bi0.5Na0.5TiO 3 does not compare to the strong piezoelectric response of lead based piezoelectrics. To increase the piezoelectric response, Bi0.5Na 0.5TiO3 has been alloyed with BaTiO3 and K 0.5Na0.5NbO3. Another route to enhance the response is to take advantage of the anisotropic properties by inducing a preferred crystallographic orientation. Both routes were used to investigate the effect a crystallographic texture has on the strain response of Bi0.5Na 0.5TiO3-based ceramics. A crystallographic texture was induced by templated grain growth of pure phase Bi0.5Na0.5TiO3 templates using the tape casting method to orient template particles relative to the tape cast normal. Sintered Bi0.5Na0.5TiO3-based materials developed a strong (00l)pc fiber texture relative to the tape cast normal, with no preferential alignment relative to the tape cast plane. Textured Bi0.5Na0.5TiO3-(5)BaTiO3 showed a piezoelectric response of 245 pC/N, a better than 50% enhancement from the 150 pC/N response of randomly oriented samples. The Bi0.5Na0.5TiO3-(5)BaTiO3-(2)K 0.5Na0.5NbO3 (x,y) system has been shown to undergo electric-field-induced phase transformation from a pseudocubic to polar phase. For (7,2) a strong 8.7 multiples of a random distribution (MRD) crystallographic texture increased the macroscopic strain response by 50%. Applying the electric field perpendicular to the fiber texture axis reduces the macroscopic strain response of textured (7,2) by 17%. The affect field direction has on the electric-field-induced phase transformations of textured (7,2) was investigated using in situ electric field dependent diffraction. In situ diffraction data showed the high strain response of textured (7,2) can be attributed to a reversible pseudocubic to tetragonal transformation. The field-induced tetragonal phase nucleates preferentially with a strong c-axis alignment in the electric field direction, ferroelastic domain texture. In situ diffraction data suggests the origin of the reduction in strain associated with a field applied perpendicular to the fiber texture axis is the result of a shorter induced lattice spacing and lower domain texture.
Cellular-foam polypropylene ferroelectrets with increased film thickness and reduced resonance frequency

NASA Astrophysics Data System (ADS)

Sborikas, Martynas; Wegener, Michael

2013-12-01

Ferroelectrets are piezoelectric materials suitable for acoustic applications such as airborne ultrasonic transducers. Typical ferroelectrets exhibit resonance frequencies in the high kHz to low MHz range. In order to decrease the transducer resonance frequencies to the low kHz range, processes such as gas-diffusion expansion and electric charging were adjusted to cellular films which are initially twice as thick as in earlier studies. The demonstrated film expansion and electric charging lead to mechanically soft cellular structures which show high piezoelectric activities with coefficients up to 130 pC/N. Due to the simultaneously increased film thicknesses, the resonance frequencies are lowered down to about 233 kHz.
Operation bandwidth optimization of photonic differentiators.

PubMed

Yan, Siqi; Zhang, Yong; Dong, Jianji; Zheng, Aoling; Liao, Shasha; Zhou, Hailong; Wu, Zhao; Xia, Jinsong; Zhang, Xinliang

2015-07-27

We theoretically investigate the operation bandwidth limitation of the photonic differentiator including the upper limitation, which is restrained by the device operation bandwidth and the lower limitation, which is restrained by the energy efficiency (EE) and detecting noise level. Taking the silicon photonic crystal L3 nano-cavity (PCN) as an example, for the first time, we experimentally demonstrate that the lower limitation of the operation bandwidth does exist and differentiators with different bandwidths have significantly different acceptable pulse width range of input signals, which are consistent to the theoretical prediction. Furthermore, we put forward a novel photonic differentiator scheme employing cascaded PCNs with different Q factors, which is likely to expand the operation bandwidth range of photonic differentiator dramatically.
The Science Teachers and Their way of Thinking about Astronomy. (Spanish Title: Los Profesores de Ciencias y Sus Formas de Pensar la Astronomía.) Os Professores de Ciências e Suas Formas de Pensar a Astronomia

NASA Astrophysics Data System (ADS)

Leite, Cristina; Hosoume, Yassuko

2007-12-01

The research presented in this article is about the way science teachers from Elementary School think about astronomical elements. Its methodology is based on semi-structured interviews, which were video recorded. The research is centered in a three-dimensional perspective of astronomical Earth, the Sun, the Moon, the planets and the stars, and also the conceptions about sky and Universe. The esults indicate a Universe that contains: Sun, stars, planets and Moon; where the Solar System is a little part of the whole. Sometimes they think that the Solar System is the Universe. The objects are in the sky or in the Universe, which, for many of them, is only the space above the Earth. The flat shape of astronomical objects and the spatial structure of the Universe are striking features. Many of them think that Sun and stars are different: the Sun is a hot object and the stars are cold ones. These results worry us and they certainly indicate how urgent it is to plan Professional Development in Astronomy for teachers, after all the PCN's emphasize that this subject is important to be taught. El objeto de investigación de este artículo es la manera de pensar sobre los elementos de la Astronomía de los profesores de Ciencias en la enseñanza fundamental. La metodología consiste en entrevistas semi-estructuradas, filmadas en video y centradas en la tridimensionalidad de los elementos astronómicos, para posibilitar un mapeamiento de las concepciones sobre las formas y dimensiones de la Tierra, del Sol, de la Luna, de los planetas y de las estrellas, como también de la concepción de cielo y de Universo en su totalidad. Los resultados indican un Universo conteniendo: Sol, estrellas, planetas y Luna, donde el Sistema Solar se ubica como parte. Algunas veces, el Universo es concebido como el propio Sistema Solar. Los objetos están en el cielo o en el Universo, que, para muchos, se restringe al espacio que está arriba de la Tierra. La forma plana de los objetos astronómicos y la estructura espacial del montaje del Universo son características fundamentales. Muchos indican Sol y estrellas como cosas distintas: el Sol es un objeto caliente y las estrellas son frías. Esos resultados nos preocupan y ciertamente señalan una urgencia de programas de formación continuada para profesores en el contenido de astronomía, pues los PCN's (Parámetros Curriculares Nacionales) recomiendan con énfasis la enseñanza de este contenido. O modo de pensar dos professores de Ciências do ensino fundamental sobre os elementos da Astronomia é o objeto de pesquisa presente neste artigo, cuja metodologia consiste em entrevistas semiestruturadas, filmadas em vídeo e centradas numa perspectiva tridimensional dos elementos astronômicos, possibilitando um mapeamento das concepções das formas e das dimensões da Terra, do Sol, da Lua, dos planetas e das estrelas, bem como da concepção de céu e de Universo como um todo. Os resultados indicam um Universo contendo: Sol, estrelas, planetas e Lua, onde o Sistema Solar é parte do todo. Algumas vezes o Universo é concebido como o próprio Sistema Solar. Os objetos estão no céu ou no Universo o qual, para muitos, se restringe ao espaço que está acima da Terra. A forma plana dos objetos astronômicos e a estrutura espacial da montagem do Universo são características marcantes. Muitos indicam Sol e estrelas como coisas diferentes: Sol é um objeto quente e as estrelas são frias. Esses resultados nos preocupam e certamente sinalizam uma urgência de programas de formação continuada para professores no conteúdo de astronomia, uma vez que os PCN's indicam fortemente o ensino desse conteúdo.
Motivational Didactics Activities for Education of Astronomy in Basic Education

NASA Astrophysics Data System (ADS)

Melo, J.

2010-03-01

The present research was carried through with 234 pupils of the State school of Basic Education Mayor Rinaldo Poli located in the city of Guarulhos. In this project it was aspired to use topics of Astronomy with the following objectives: to motivate the pupils in the lessons of Sciences; to search ways so that the learning process would become more significant and also to help to spread out Astronomy in the level of basic education. Although being recommended in the "Parametros Curriculares Nacionais (PCN)", in the "Orientacoes Complementares aos Parametros (PCN+)" and more recently in the "Proposta Curricular do Estado de Sao Paulo", Astronomy is little imparted in the Basic Education. Initially a questionnaire was applied with the intention to verify the previous knowledge of the pupils, which evidenced that, among other things, 18.5% of the pupils of 5th grades knew what Astronomy investigates, whereas only 3.8% of the pupils of 6th grades knew what a planet is, and still 25.5% of the pupils of 8th grades knew how to define the Moon. The intervention work was conducted in the following form: first some Astronomy-related subjects were chosen which the pupils researched and afterwards presented in groups; then they built mockups, using Conceptual Maps to explain this subject and making a work with scales of the stars. After the intervention work the same questionnaire was applied and the index of rightness reached, respectively, the percentages of 63.0%, 39.2% and 68.1%, showing that the learning became significant. It is supposed that Astronomy is important in the process of Education Learning for being the oldest of the sciences, for having a character to multidiscipline, allowing the quarrel of fascinating and interesting subjects as, for example, the space origin of the universe, trips, the existence or non-existence of life in other planets, beyond current subjects as the new technologies.
P(VDF-TrFE) Polymer-Based Thin Films Deposited on Stainless Steel Substrates Treated Using Water Dissociation for Flexible Tactile Sensor Development

PubMed Central

Tseng, Hong-Jie; Tian, Wei-Cheng; Wu, Wen-Jong

2013-01-01

In this work, deionized (DI) water dissociation was used to treat and change the contact angle of the surface of stainless steel substrates followed by the spin coating of P(VDF-TrFE) material for the fabrication of tactile sensors. The contact angle of the stainless steel surface decreased 14° at −30 V treatment; thus, the adhesion strength between the P(VDF-TrFE) thin film and the stainless steel substrate increased by 90%. Although the adhesion strength was increased at negative voltage treatment, it is observed that the crystallinity value of the P(VDF-TrFE) thin film declined to 37% at −60 V. In addition, the remanent polarization value of the P(VDF-TrFE) thin film declined from 5.6 μC/cm2 to 4.61 μC/cm2 for treatment voltages between −5 V and −60 V. A maximum value of approximately 1000 KV/cm of the coercive field value was obtained with the treatment at −15 V. The d33 value was approximately −10.7 pC/N for the substrate treated at 0 V and reached a minimum of −5 pC/N for treatment at −60 V. By using the P(VDF-TrFE) thin-film as the sensing material for tactile sensors, human pulse measurements were obtained from areas including the carotid, brachial, ankle, radial artery, and apical regions. In addition, the tactile sensor is suitable for monitoring the Cun, Guan, and Chi acupoints located at the radial artery region in Traditional Chinese Medicine (TCM). Waveform measurements of the Cun, Guan, and Chi acupoints are crucial because, in TCM, the various waveforms provided information regarding the health conditions of organs. PMID:24177729

Thermostability of In Vitro Evolved Bacillus subtilis Lipase A: A Network and Dynamics Perspective

PubMed Central

Srivastava, Ashutosh; Sinha, Somdatta

2014-01-01

Proteins in thermophilic organisms remain stable and function optimally at high temperatures. Owing to their important applicability in many industrial processes, such thermostable proteins have been studied extensively, and several structural factors attributed to their enhanced stability. How these factors render the emergent property of thermostability to proteins, even in situations where no significant changes occur in their three-dimensional structures in comparison to their mesophilic counter-parts, has remained an intriguing question. In this study we treat Lipase A from Bacillus subtilis and its six thermostable mutants in a unified manner and address the problem with a combined complex network-based analysis and molecular dynamic studies to find commonality in their properties. The Protein Contact Networks (PCN) of the wild-type and six mutant Lipase A structures developed at a mesoscopic scale were analyzed at global network and local node (residue) level using network parameters and community structure analysis. The comparative PCN analysis of all proteins pointed towards important role of specific residues in the enhanced thermostability. Network analysis results were corroborated with finer-scale molecular dynamics simulations at both room and high temperatures. Our results show that this combined approach at two scales can uncover small but important changes in the local conformations that add up to stabilize the protein structure in thermostable mutants, even when overall conformation differences among them are negligible. Our analysis not only supports the experimentally determined stabilizing factors, but also unveils the important role of contacts, distributed throughout the protein, that lead to thermostability. We propose that this combined mesoscopic-network and fine-grained molecular dynamics approach is a convenient and useful scheme not only to study allosteric changes leading to protein stability in the face of negligible over-all conformational changes due to mutations, but also in other molecular networks where change in function does not accompany significant change in the network structure. PMID:25122499
Pregnane X receptor agonists enhance intestinal epithelial wound healing and repair of the intestinal barrier following the induction of experimental colitis.

PubMed

Terc, Joshua; Hansen, Ashleigh; Alston, Laurie; Hirota, Simon A

2014-05-13

The intestinal epithelial barrier plays a key role in the maintenance of homeostasis within the gastrointestinal tract. Barrier dysfunction leading to increased epithelial permeability is associated with a number of gastrointestinal disorders including the inflammatory bowel diseases (IBD) - Crohn's disease and ulcerative colitis. It is thought that the increased permeability in patients with IBD may be driven by alterations in the epithelial wound healing response. To this end considerable study has been undertaken to identify signaling pathways that may accelerate intestinal epithelial wound healing and normalize the barrier dysfunction observed in IBD. In the current study we examined the role of the pregnane X receptor (PXR) in modulating the intestinal epithelial wound healing response. Mutations and reduced mucosal expression of the PXR are associated with IBD, and others have reported that PXR agonists can dampen intestinal inflammation. Furthermore, stimulation of the PXR has been associated with increased cell migration and proliferation, two of the key processes involved in wound healing. We hypothesized that PXR agonists would enhance intestinal epithelial repair. Stimulation of Caco-2 intestinal epithelial cells with rifaximin, rifampicin and SR12813, all potent agonists of the PXR, significantly increased wound closure. This effect was driven by p38 MAP kinase-dependent cell migration, and occurred in the absence of cell proliferation. Treating mice with a rodent specific PXR agonist, pregnenolone 16α-carbonitrile (PCN), attenuated the intestinal barrier dysfunction observed in the dextran sulphate sodium (DSS) model of experimental colitis, an effect that occurred independent of the known anti-inflammatory effects of PCN. Taken together our data indicate that the activation of the PXR can enhance intestinal epithelial repair and suggest that targeting the PXR may help to normalize intestinal barrier dysfunction observed in patients with IBD. Furthermore, our data provide additional insight into the potential mechanisms through which rifaximin elicits its clinical efficacy in the treatment of IBD. Copyright © 2014 Elsevier B.V. All rights reserved.
Enhanced temperature stability and quality factor with Hf substitution for Sn and MnO2 doping of (Ba0.97Ca0.03)(Ti0.96Sn0.04)O3 lead-free piezoelectric ceramics with high Curie temperature

NASA Astrophysics Data System (ADS)

Tsai, Cheng-Che; Chao, Wei-Hsiang; Chu, Sheng-Yuan; Hong, Cheng-Shong; Weng, Chung-Ming; Su, Hsiu-Hsien

2016-12-01

In this work, the process of two-stage modifications for (Ba0.97Ca0.03)(Ti0.96Sn0.04-xHfx)O3 (BCTS4-100xH100x) ceramics was studied. The trade-off composition was obtained by Hf substitution for Sn and MnO2 doping (two-stage modification) which improves the temperature stability and piezoelectric properties. The phase structure ratio, microstructure, and dielectric, piezoelectric, ferroelectric, and temperature stability properties were systematically investigated. Results showed that BCTS4-100xH100x piezoelectric ceramics with x=0.035 had a relatively high Curie temperature (TC) of about 112 °C, a piezoelectric charge constant (d33) of 313 pC/N, an electromechanical coupling factor (kp) of 0.49, a mechanical quality factor (Qm) of 122, and a remnant polarization (Pr) of 19 μ C /cm2 . In addition, the temperature stability of the resonant frequency (fr), kp, and aging d33 could be tuned via Hf content. Good piezoelectric temperature stability (up to 110 °C) was found with x =0.035. BCTS0.5H3.5 + a mol% Mn (BCTSH + a Mn) piezoelectric ceramics with a = 2 had a high TC of about 123 °C, kp ˜ 0.39, d33 ˜ 230 pC/N, Qm ˜ 341, and high temperature stability due to the produced oxygen vacancies. This mechanism can be depicted using the complex impedance analysis associated with a valence compensation model on electric properties. Two-stage modification for lead-free (Ba0.97Ca0.03)(Ti0.96Sn0.04)O3 ceramics suitably adjusts the compositions for applications in piezoelectric motors and actuators.
Ferroelectric and Piezoelectric Properties of KNbO3 Ceramics Containing Small Amounts of LaFeO3

NASA Astrophysics Data System (ADS)

Kakimoto, Ken-ichi; Masuda, Izumi; Ohsato, Hitoshi

2003-09-01

Dense KNbO3 ceramics have been successfully synthesized by pressure-less sintering under optimized heat-treatment conditions using a small amount of La2O3 and Fe2O3 additives. KNbO3 forms (K1-xLax)(Nb1-xFex)O3 solid solutions and changes in the crystal system, depending on the additive content, from orthorhombic to tetragonal at x of 0.020, and from tetragonal to cubic at x of 0.200 or higher. When only 0.002 mol of La2O3 and Fe2O3 (x=0.002) was added into KNbO3, the highest value (98.8%) of the theoretical density was obtained. This specimen showed orthorhombic symmetry with a high Curie temperature of 420°C, and demonstrated a well-saturated ferroelectric hysteresis loop with large remanent polarization (Pr) of 18 μC/cm2, which is comparable to the value reported for pure KNbO3 ceramics fabricated by hot pressing. Furthermore, the x=0.002 specimen showed a planar electromechanical coupling ratio (kp) of 0.17 and piezoelectric d33 constant of 98 pC/N, regardless of the unsaturated poling state.
Processes in massive nuclei reactions and the way to complete fusion of reactants. What perspectives for the synthesis of heavier superheavy elements?

NASA Astrophysics Data System (ADS)

Mandaglio, G.; Nasirov, A. K.; Curciarello, F.; De Leo, V.; Romaniuk, M.; Fazio, G.; Giardina, G.

2012-12-01

By using the dinuclear system (DNS) model we determine the capture of reactants at the first stage of reaction, the competition between the DNS decay by the quasifission (QF) and the complete fusion (CF) process up to formation of the compound nucleus (CN) having compact shape. Further evolution of the CN is considered as its fission into two fragments or formation of evaporation residues (ER) by its cooling after emission of neutrons or/and charged light particles. Disappearance of the CN fission barrier due to its fast rotation leads to the fast fission (FF) by formation of fissionlike fragments. The results of calculations for the mass symmetric 136Xe+136Xe reaction, almost mass symmetric 108Mo+144Ba reaction, and mass asymmetric like 24Mg+238U and 34S+248Cm reactions are discussed. The fusion probability PCN calculated for many massive nuclei reactions leading to formation of superheavy nuclei have been analyzed. The reactions which can lead in perspective to the synthesis of superheavy elements in the Z = 120 - 126 range and, eventually, also to heaviest nuclei, are discussed.
Enhanced piezoelectricity and high temperature poling effect in (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 ceramics via an ethylene glycol route

NASA Astrophysics Data System (ADS)

Tailor, H. N.; Ye, Z.-G.

2010-05-01

A solution chemical method utilizing ethylene glycol as solvent has been developed to prepare the ceramics of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3[(1-x)PMN-xPT] from a precursor powder that can be pressed and fired in one step to produce high quality ceramics with excellent piezoelectric properties. The ceramics reach a relative density of up to 97% of the theoretical value after direct calcinations. This high density is achieved without the need of additional sintering after calcination which is usually required in conventional solid state syntheses to produce ceramics. The ceramics exhibit a unipolar piezoelectric coefficient d33 of 848 pC/N, which is one of the highest values for any unmodified/untextured binary systems reported to date. Since the piezoelectric properties depend on composition and electric field, the effect of poling conditions was investigated. A critical temperature limit has been found, above which poling can dramatically impair the piezoelectric properties due to a field-induced increase in the monoclinic phase component around the morphotropic phase boundary.
Numerical Analysis of Ginzburg-Landau Models for Superconductivity.

NASA Astrophysics Data System (ADS)

Coskun, Erhan

Thin film conventional, as well as High T _{c} superconductors of various geometric shapes placed under both uniform and variable strength magnetic field are studied using the universially accepted macroscopic Ginzburg-Landau model. A series of new theoretical results concerning the properties of solution is presented using the semi -discrete time-dependent Ginzburg-Landau equations, staggered grid setup and natural boundary conditions. Efficient serial algorithms including a novel adaptive algorithm is developed and successfully implemented for solving the governing highly nonlinear parabolic system of equations. Refinement technique used in the adaptive algorithm is based on modified forward Euler method which was also developed by us to ease the restriction on time step size for stability considerations. Stability and convergence properties of forward and modified forward Euler schemes are studied. Numerical simulations of various recent physical experiments of technological importance such as vortes motion and pinning are performed. The numerical code for solving time-dependent Ginzburg-Landau equations is parallelized using BlockComm -Chameleon and PCN. The parallel code was run on the distributed memory multiprocessors intel iPSC/860, IBM-SP1 and cluster of Sun Sparc workstations, all located at Mathematics and Computer Science Division, Argonne National Laboratory.
Enhanced piezoelectricity in A B O3 ferroelectrics via intrinsic stress-driven flattening of the free-energy profile

NASA Astrophysics Data System (ADS)

Feng, Yu; Li, Wei-Li; Yu, Yang; Jia, He-Nan; Qiao, Yu-Long; Fei, Wei-Dong

2017-11-01

An approach to greatly enhance the piezoelectric properties (˜4 00 pC/N) of the tetragonal BaTi O3 polycrystal using a small number of A -site acceptor-donor substitutions [D. Xu et al., Acta Mater. 79, 84 (2014), 10.1016/j.actamat.2014.07.023] has been proposed. In this study, Pb (ZrTi ) O3 (PZT) based polycrystals with various crystal symmetries (tetragonal, rhombohedral, and so on) were chosen to investigate the piezoelectricity enhancement mechanism. X-ray diffraction results show that doping generates an intrinsic uniaxial compressive stress along the [001] pc direction in the A B O3 lattices. Piezoelectric maps in the parameter space of temperature and Ti concentration in the PZT and doped system show a more significant enhancement effect of L i+-A l3 + codoping in tetragonal PZT than in the rhombohedral phase. Phenomenological thermodynamic analysis indicates that the compressive stress results in more serious flattening of the free-energy profile in tetragonal PZT, compared with that in the rhombohedral phase. The chemical stress obtained by this acceptor-donor codoping can be utilized to optimize the piezoelectric performance on the tetragonal-phase site of the morphotropic phase boundary in the PZT system. The present study provides a promising route to the large piezoelectric effect induced by chemical-stress-driven flattening of the free-energy profile.
Bismuth Titanate Fabricated by Spray-on Deposition and Microwave Sintering For High-Temperature Ultrasonic Transducers.

PubMed

Searfass, Clifford T; Pheil, C; Sinding, K; Tittmann, B R; Baba, A; Agrawal, D K

2016-01-01

Thick films of ferroelectric bismuth titanate (Bi4Ti3O12) have been fabricated by spray-on deposition in conjunction with microwave sintering for use as high-temperature ultrasonic transducers. The elastic modulus, density, permittivity, and conductivity of the films were characterized. Electro-mechanical properties of the films were estimated with a commercial d33 meter which gave 16 pC/N. This value is higher than typically reported for bulk bismuth titanate; however, these films withstand higher field strengths during poling which is correlated with higher d33 values. Films were capable of operating at 650 °C for roughly 5 min before depoling and can operate at 600 °C for at least 7 days.
Micro-particle manipulation by single beam acoustic tweezers based on hydrothermal PZT thick film.

PubMed

Zhu, Benpeng; Xu, Jiong; Li, Ying; Wang, Tian; Xiong, Ke; Lee, Changyang; Yang, Xiaofei; Shiiba, Michihisa; Takeuchi, Shinichi; Zhou, Qifa; Shung, K Kirk

2016-03-01

Single-beam acoustic tweezers (SBAT), used in laboratory-on-a-chip (LOC) device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d 33 = 270pC/N and k t = 0.51) was employed for SBAT applications and a press-focusing technology was introduced. The obtained SBAT, acting at an operational frequency of 50MHz, a low f-number (∼0.9), demonstrated the capability to trap and manipulate a micro-particle sized 10μm in the distilled water. These results suggest that such a device has great potential as a manipulator for a wide range of biomedical and chemical science applications.
Domain disruption and defect accumulation during unipolar electric fatigue in a BZT-BCT ceramic

NASA Astrophysics Data System (ADS)

Fan, Zhongming; Zhou, Chao; Ren, Xiaobing; Tan, Xiaoli

2017-12-01

0.5Ba(Zr0.2Ti0.8)O30.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) is a promising lead-free piezoelectric ceramic with excellent piezoelectric properties (e.g., d33 > 600 pC/N). As potential device applications are considered, the electric fatigue resistance of the ceramic must be evaluated. In this Letter, electric-field in situ transmission electron microscopy is employed to study the microstructural evolution in the BZT-BCT polycrystalline ceramic during unipolar cycling. It is shown that the large ferroelectric domains are disrupted and replaced with accumulated defect clusters and fragmented domains after 5 × 104 unipolar cycles. In this fatigued state, the grain becomes nonresponsive to applied voltages.
Piezoelectric Characteristics of Chiral Polymer Composite Films Obtained under Strong Magnetic Field

NASA Astrophysics Data System (ADS)

Nakiri, Takuo; Okuno, Masaki; Maki, Nobuyuki; Kanasaki, Masayoshi; Morimoto, Yu; Okamoto, Satoshi; Ishizuka, Masayuki; Fukuda, Kazuyuki; Takaki, Toshihiko; Tajitsu, Yoshiro

2005-09-01

It is difficult to obtain a drawn chiral polymer/inorganic material composite membrane with shear piezoelectricity by the conventional method because the chiral polymer/inorganic material composite membrane breaks during the drawing process by which shear piezoelectricity is realized. Using a strong magnetic field, we propose to manufacture a drawn composite membrane of poly-l-lactic acid (PLLA), a chiral polymer, and hydroxyapatite (Hap), an inoroganic material (PLLA/Hap composite membrane). The manufacturing method used here is effective for obtaining a drawn PLLA/Hap composite membrane with a large uniform area. Also, the shear piezoelectric constant of the drawn PLLA/Hap composite membrane is about 20 pC/N. This value is large for piezoelectric polymers.
High-piezoelectric behavior of c-axis-oriented lead zirconate titanate thin films with composition near the morphotropic phase boundary

NASA Astrophysics Data System (ADS)

Fu, Desheng; Suzuki, Hisao; Ogawa, Takeshi; Ishikawa, Kenji

2002-05-01

The piezoelectric responses of c-axis-oriented Pb(Zr0.53Ti0.47)O3 (PZT) thin films have been studied by measuring the stress-induced charge with an accurate charge integrator. These measurements reveal that the c-axis-oriented PZT films have high values of d33, which are several times those of ceramic materials. The intrinsic d33 values of poled films are about 680 and 800 pC/N for the c-axis-oriented films on Si and MgO single-crystal substrates, respectively. It shows that the thin-film deposition technique opens an approach for exploring the potential superior properties of PZT near the morphotropic phase boundary.
A Piezoelectric Shear Stress Sensor

NASA Technical Reports Server (NTRS)

Kim, Taeyang; Saini, Aditya; Kim, Jinwook; Gopalarathnam, Ashok; Zhu, Yong; Palmieri, Frank L.; Wohl, Christopher J.; Jiang, Xiaoning

2016-01-01

In this paper, a piezoelectric sensor with a floating element was developed for shear stress measurement. The piezoelectric sensor was designed to detect the pure shear stress suppressing effects of normal stress generated from the vortex lift-up by applying opposite poling vectors to the: piezoelectric elements. The sensor was first calibrated in the lab by applying shear forces and it showed high sensitivity to shear stress (=91.3 +/- 2.1 pC/Pa) due to the high piezoelectric coefficients of PMN-33%PT (d31=-1330 pC/N). The sensor also showed almost no sensitivity to normal stress (less than 1.2 pC/Pa) because of the electromechanical symmetry of the device. The usable frequency range of the sensor is 0-800 Hz. Keywords: Piezoelectric sensor, shear stress, floating element, electromechanical symmetry
Large piezoelectric properties in KNN-based lead-free single crystals grown by a seed-free solid-state crystal growth method

NASA Astrophysics Data System (ADS)

Yang, Jie; Zhang, Faqiang; Yang, Qunbao; Liu, Zhifu; Li, Yongxiang; Liu, Yun; Zhang, Qiming

2016-05-01

We report lead-free single crystals with a nominal formula of (K0.45Na0.55)0.96Li0.04NbO3 grown using a simple low-cost seed-free solid-state crystal growth method (SFSSCG). The crystals thus prepared can reach maximum dimensions of 6 mm × 5 mm × 2 mm and exhibit a large piezoelectric coefficient d33 of 689 pC/N. Moreover, the effective piezoelectric coefficient d33 * , obtained under a unipolar electric field of 30 kV/cm, can reach 967 pm/V. The large piezoelectric response plus the high Curie temperature (TC) of 432 °C indicate that SFSSCG is an effective approach to synthesize high-performance lead-free piezoelectric single crystals.
Physical properties of inorganic PMW-PNN-PZT ceramics

NASA Astrophysics Data System (ADS)

Sin, Sang-Hoon; Yoo, Ju-hyun; Kim, Yong-Jin; Baek, Sam-ki; Ha, Jun-Soo; No, Chung-Han; Song, Hyun-Seon; Shin, Dong-Chan

2015-07-01

In this work, inorganic Pb(Mg1/2W1/2)0.03(Ni1/3Nb2/3)x(Zr0.5Ti0.5)0.97-xO3 (x = 0.02 ∼ 0.12) composition ceramics were fabricated by the conventional solid state reaction method. And then their micro structure and ferroelectric properties were investigated according to the amount of PNN substitution. Small amounts of Li2CO3 and CaCO3 were used in order to decrease the sintering temperature of the ceramics. The 0.10 mol PNN-substituted PMW-PNN- PZT ceramics sintered at 920°C showed the excellent physical properties of piezoelectric constant (d33), electromechanical coupling factor (kp), mechanical quality coefficient (Qm), and dielectric constant of 566 pC/N, 0.61, 73, and 2183, respectively.
High performance Aurivillius phase sodium-potassium bismuth titanate lead-free piezoelectric ceramics with lithium and cerium modification

NASA Astrophysics Data System (ADS)

Wang, Chun-Ming; Wang, Jin-Feng

2006-11-01

The piezoelectric properties of the lithium and cerium modified A-site vacancies sodium-potassium bismuth titanate (NKBT) lead-free piezoceramics are investigated. The piezoelectric activity of NKBT ceramics is significantly improved by the modification of lithium and cerium. The Curie temperature TC, piezoelectric coefficient d33, and mechanical quality factor Qm for the NKBT ceramics modified with 0.10mol% (LiCe) are found to be 660°C, 25pC/N, and 3135, respectively. The Curie temperature gradually decreases from 675to650°C with the increase of (LiCe) modification. The dielectric spectroscopy shows that all the samples possess stable piezoelectric properties, demonstrating that the (LiCe) modified NKBT-based ceramics are the promising candidates for high temperature applications.
Texturing of sodium bismuth titanate-barium titanate ceramics by templated grain growth

NASA Astrophysics Data System (ADS)

Yilmaz, Huseyin

2002-01-01

Sodium bismuth titanate modified with barium titanate, (Na1/2Bi 1/2)TiO3-BaTiO3 (NBT-BT), is a candidate lead-free piezoelectric material which has been shown to have comparatively high piezoelectric response. In this work, textured (Na1/2Bi1/2)TiO 3-BaTiO3 (5.5mol% BaTiO3) ceramics with <100> pc (where pc denotes the pseudocubic perovskite cell) orientation were fabricated by Templated Grain Growth (TGG) or Reactive Templated Grain Growth (RTGG) using anisotropically shaped template particles. In the case of TGG, molten salt synthesized SrTiO3 platelets were tape cast with a (Na1/2Bi1/2)TiO3-5.5mol%BaTiO3 powder and sintered at 1200°C for up to 12 hours. For the RTGG approach, Bi4Ti3O12 (BiT) platelets were tape cast with a Na2CO3, Bi2O3, TiO 2, and BaCO3 powder mixture and reactively sintered. The TGG approach using SrTiO3 templates gave stronger texture along [001] compared to the RTGG approach using BiT templates. The textured ceramics were characterized by X-ray and electron backscatter diffraction for the quality of texture. The texture function was quantified by the Lotgering factor, rocking curve, pole figures, inverse pole figures, and orientation imaging microscopy. Electrical and electromechanical property characterization of randomly oriented and <001>pc textured (Na1/2Bi1/2)TiO 3-5.5 mol% BaTiO3 rhombohedral ceramics showed 0.26% strain at 70 kV/cm, d33 coefficients over 500 pC/N have been obtained for highly textured samples (f ˜ 90%). The piezoelectric coefficient from Berlincourt was d33 ˜ 200 pC/N. The materials show considerable hysteresis. The presence of hysteresis in the unipolar-electric field curve is probably linked to the ferroelastic phase transition seen in the (Na 1/2Bi1/2)TiO3 system on cooling from high temperature at ˜520°C. The macroscopic physical properties (remanent polarization, dielectric constant, and piezoelectric coefficient) of random and textured ([001] pc) rhombohedral perovskites were estimated by linear averaging of single crystal data. However, the complete polarization, dielectric, and piezoelectric tensors are not available for NBT-BT single crystals. Therefore, the properties of lead based (PZT, 52/48) rhombohedral ferroelectric single domain-single crystals, whose properties (polarization, dielectric and piezoelectric) were computed using Landau-Ginsburg-Devonshire phenomenological theory (by Haun et. al.), were used in the calculations for random and textured cases. (Abstract shortened by UMI.)
Piezoelectric ceramics with high dielectric constants for ultrasonic medical transducers.

PubMed

Hosono, Yasuharu; Yamashita, Yohachi

2005-10-01

Complex system ceramics Pb(Sc(1/2)Nb(1/2))O3-Pb(Mg(1/3)Nb(2/3))O3-Pb(Ni(1/2)Nb(1/2))O3-(Pb0.965,Sr0.035) (Zr,Ti)O3 (PSN-PMN-PNN-PSZT abbreviated PSMNZT) have been synthesized by the conventional technique, and dielectric and piezoelectric properties of the ceramics have been investigated for ultrasonic medical transducers. High capacitances of the transducers are desired in order to match the electrical impedance between the transducers and the coaxial cable in array probes. Although piezoelectric ceramics that have high dielectric constants (epsilon33t/epsilon0 > 5000, k'33 < 70%) are produced in many foundries, the dielectric constants are insufficient. However, we have reported that low molecular mass B-site ions in the lead-perovskite structures are important in realizing better dielectric and piezoelectric properties. We focused on the complex system ceramics PSMNZT that consists of light B-site elements. The maximum dielectric constant, epsilon33T/epsilon0 = 7, 200, was confirmed in the ceramics, where k'33 = 69%, d33 = 940 pC/N, and T(c) = 135 degrees C were obtained. Moreover, pulse-echo characteristics were simulated using the Mason model. The PSMNZT ceramic probe showed echo amplitude about 5.5 dB higher than that of the conventional PZT ceramic probe (PZT-5H type). In this paper, the electrical properties of the PSMNZT ceramics and the simulation results for pulse-echo characteristics of the phased-array probes are introduced.
Measuring horizontal integration among health care providers in the community: an examination of a collaborative process within a palliative care network.

PubMed

Bainbridge, Daryl; Brazil, Kevin; Krueger, Paul; Ploeg, Jenny; Taniguchi, Alan; Darnay, Julie

2015-05-01

In many countries formal or informal palliative care networks (PCNs) have evolved to better integrate community-based services for individuals with a life-limiting illness. We conducted a cross-sectional survey using a customized tool to determine the perceptions of the processes of palliative care delivery reflective of horizontal integration from the perspective of nurses, physicians and allied health professionals working in a PCN, as well as to assess the utility of this tool. The process elements examined were part of a conceptual framework for evaluating integration of a system of care and centred on interprofessional collaboration. We used the Index of Interdisciplinary Collaboration (IIC) as a basis of measurement. The 86 respondents (85% response rate) placed high value on working collaboratively and most reported being part of an interprofessional team. The survey tool showed utility in identifying strengths and gaps in integration across the network and in detecting variability in some factors according to respondent agency affiliation and profession. Specifically, support for interprofessional communication and evaluative activities were viewed as insufficient. Impediments to these aspects of horizontal integration may be reflective of workload constraints, differences in agency operations or an absence of key structural features.

The 5As team intervention: bridging the knowledge gap in obesity management among primary care practitioners.

PubMed

Ogunleye, Ayodele; Osunlana, Adedayo; Asselin, Jodie; Cave, Andrew; Sharma, Arya Mitra; Campbell-Scherer, Denise Lynn

2015-12-22

Despite opportunities for didactic education on obesity management, we still observe low rates of weight management visits in our primary care setting. This paper describes the co-creation by front-line interdisciplinary health care providers and researchers of the 5As Team intervention to improve obesity prevention and management in primary care. We describe the theoretical foundations, design, and core elements of the 5AsT intervention, and the process of eliciting practitioners' self-identified knowledge gaps to inform the curricula for the 5AsT intervention. Themes and topics were identified through facilitated group discussion and a curriculum relevant to this group of practitioners was developed and delivered in a series of 12 workshops. The research question and approach were co-created with the clinical leadership of the PCN; the PCN committed internal resources and a practice facilitator to the effort. Practice facilitation and learning collaboratives were used in the intervention For the content, front-line providers identified 43 topics, related to 13 themes around obesity assessment and management for which they felt the need for further education and training. These needs included: cultural identity and body image, emotional and mental health, motivation, setting goals, managing expectations, weight-bias, caregiver fatigue, clinic dynamics and team-based care, greater understanding of physiology and the use of a systematic framework for obesity assessment (the "4Ms" of obesity). The content of the 12 intervention sessions were designed based on these themes. There was a strong innovation values fit with the 5AsT intervention, and providers were more comfortable with obesity management following the intervention. The 5AsT intervention, including videos, resources and tools, has been compiled for use by clinical teams and is available online at http://www.obesitynetwork.ca/5As_Team . Primary care interdisciplinary practitioners perceive important knowledge gaps across a wide range of topics relevant to obesity assessment and management. This description of the intervention provides important information for trial replication. The 5AsT intervention may be a useful aid for primary care teams interested to improve their knowledge of obesity prevention and management. Clinical Trials.gov (NCT01967797).
New Insights into the Electroreduction of Ethylene Sulfite as Electrolyte Additive for Facilitating Solid Electrolyte Interphase of Lithium Ion Battery

PubMed Central

Sun, Youmin; Wang, Yixuan

2017-01-01

To help understand the solid electrolyte interphase (SEI) formation facilitated by electrolyte additives of lithium-ion batteries (LIB) the supermolecular clusters [(ES)Li+(PC)m](PC)n (m=1–2; n=0, 6, and 9) were used to investigate the electroreductive decompositions of the electrolyte additive, ethylene sulfite (ES), as well as the solvent, propylene carbonate (PC) with density functional theory. The results show that ES can be reduced prior to PC, resulting in a reduction precursor that will then undergo a ring opening decomposition to yield a radical anion. A new concerted pathway (path B) was located for the ring opening of the reduced ES, which has much lower energy barrier than the previously reported stepwise pathway (path A). The transition state for the ring opening of PC induced by the reduced ES (path C, indirect path) is closer to that of path A than path B in energy. The direct ring opening of the reduced PC (path D) has lower energy barrier than those of paths A, B and C, yet it is less favorable than the latter paths in terms of thermodynamics (vertical electron affinity or the reduction potential dissociation energy). The overall rate constant including the initial reduction and the subsequent ring opening for path B is the largest among the four paths, followed by paths A>C>D, which further signifies the importance of the concerted new path in facilitating the SEI. The hybrid models, the supermolecular cluster augmented by polarized continuum model, PCM-[(ES)Li+(PC)2](PC)n (n=0,6, and 9), were used to further estimate the reduction potential by taking into account both explicit and implicit solvent effects. The second solvation shell of Li+ in [(ES)Li+(PC)2](PC)n (n=6, and 9) partially compensates the overestimation of solvent effects arising from the PCM model for the naked (ES)Li+(PC)2, and the theoretical reduction potential with PCM-[(ES)Li+(PC)2](PC)6 (1.90–1.93V) agrees very well with the experimental one (1.8–2.0V). PMID:28220165
Análise sobre o Conhecimento de um Grupo de Alunos do Ensino Médio da Rede Estadual de São Paulo sobre Termos e Fenômenos Astronômicos do Cotidiano

NASA Astrophysics Data System (ADS)

de Oliveira, E. F.; Voelzke, M. R.; Amaral, L. H.

2007-08-01

Embora os Parâmetros Curriculares Nacionais do Ensino Médio (PCN-EM) e as orientações complementares a esses Parâmetros (PCN+) apontem a importância de uma abordagem significativa de conceitos relacionados à astronomia nas aulas de Física, muitos estudantes terminam o Ensino Médio (EM) sem compreender a razão de certos acontecimentos de origem celeste, ainda que estes façam parte de seu cotidiano. Este trabalho tem por objetivo analisar os conhecimentos básicos em astronomia dos alunos de EM da escola estadual Batista Renzi, bem como investigar os meios através dos quais estes conhecimentos foram adquiridos. Para tanto foi elaborado um questionário de múltipla escolha aplicado a 310 alunos distribuídos entre as três séries do EM dos períodos matutino e noturno. Dessa forma, observou-se que apenas 34,5% relacionaram as estações do ano à inclinação do eixo de rotação da Terra, 21,3% indicaram a influência gravitacional da Lua e do Sol como responsáveis pelo fenômeno das marés, 24,5% indicaram corretamente quais são os objetos celestes mais próximos da Terra, 36,1% identificaram ano-luz como uma medida de distância e 34,2% reconheceram uma estrela cadente como meteoro. Em contrapartida, 67,1% compreendiam a sucessão entre dia e noite, 73,9% identificaram o Sol como estrela e 52,3% relacionaram o Big Bang à origem do Universo. Além disso, foram comparadas as respostas de alunos de diferentes séries e períodos, observando-se, dentre outras coisas, que os estudantes do terceiro ano apresentam um percentual de acertos semelhante ao dos alunos do primeiro, caracterizando que a abordagem de tópicos relacionados à astronomia no EM não tem contribuído para uma maior compreensão dos fenômenos e conceitos.
Enhanced electrical properties of SrBi4Ti4O15 ceramic with addition of ZrO2

NASA Astrophysics Data System (ADS)

Mamatha, B.; Rani, G. Neeraja; Shankar, J.

2018-04-01

Polycrystalline SrBi4Ti3.95Zr0.05O15 (SBZT) ceramic was prepared by solid-state double sintering method. It was characterized by X-Ray Diffraction (XRD) and Scanning Electron Micrograph (SEM). With the increased addition of ZrO2, the electrical properties as dielectric, ferroelectric and piezoelectric were studied. From XRD, single-phase formation with orthorhombic structure was identified by the increase of ZrO2. The remnant polarization (Pr) and dielectric constant was found to be increased with the increase of ZrO2. With the increase of ZrO2, Curie temperature (Tc) was found to be decreased. The planar electromechanical coupling coefficient (Kp = 0.57) and Piezoelectric coefficient (d33 = 18 pC/N) was found to be increased with the increase of ZrO2.
Fbis report. Science and technology: China, October 18, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-10-18

;Partial Contents: Nanomaterials Fabrication, Applications Research Advances Noted; CAST Announces World`s First Space-Grown Large-Diameter GaAs Monocrystal; Assay of Antiviral Activity of Antisense Phosphorothioate Oligodeoxynucleotide Against Dengue Virus; Expression and Antigenicity of Chimeric Proteins of Cholera Toxin B Subunit With Hepatitis C Virus; CNCOFIEC Signs Agreement With IBM for New Intelligent Building; Latest Reports on Optical Computing, Memory; BIDC To Introduce S3 Company`s Multimedia Accelerator Chipset; Virtual Private PCN Ring Network Based on ATM VP Cross-Connection; Beijing Gets Nation`s First Frame Relay Network; Situation of Power Industry Development and International Cooperation; Diagrams of China`s Nuclear Waste Containment Vessels; Chinese-Developed Containment Vesselmore » Material Reaches World Standards; Second Fuel Elements for Qinshan Plant Passes Inspection; and Geothermal Deep-Well Electric Pump Technology Developed.« less
Piezoelectric Properties of LiSbO3-Modified (K0.48Na0.52)NbO3 Lead-Free Ceramics

NASA Astrophysics Data System (ADS)

Wu, Jiagang; Wang, Yuanyu; Xiao, Dingquan; Zhu, Jianguo; Yu, Ping; Wu, Lang; Wu, Wenjuan

2007-11-01

Lead-free piezoelectric (1-x)(K0.48Na0.52)NbO3-xLiSbO3 [(1-x)KNN-xLS] ceramics were prepared by conventional sintering. A morphotropic phase boundary (MPB) between the orthorhombic and tetragonal phases was identified in the composition range of 0.04
Perfect absorption in 1D photonic crystal nanobeam embedded with graphene/Al2O3 multilayer stack

NASA Astrophysics Data System (ADS)

Liu, Hanqing; Zha, Song; Liu, Peiguo; Zhou, Xiaotian; Bian, Li-an

2018-05-01

We exploit the concept of critical coupling to graphene based chip-integrated applications and numerically demonstrate that a perfect absorption (PA) absorber in the near-infrared can be obtained by graphene/Al2O3 multilayer stack (GAMS) critical coupling with a resonant cavity in the 1D photonic crystal nanobeam (PCN). The key point is dynamically matching the coupling rate of incident light wave to the cavity with the absorbing rate of GAMS via electrically modulating the chemical potential of graphene. Simulation results show that the radius of GAMS as well as the thickness of Al2O3 layer are closely connected with the performance of perfect absorption. These results may provide potential applications in the high-density integrated optical devices, photolectric transducers, and laser pulse limiters.
Piezoelectric characterization of Sc0.26Al0.74N layers on Si (001) substrates

NASA Astrophysics Data System (ADS)

Sinusía Lozano, M.; Pérez-Campos, A.; Reusch, M.; Kirste, L.; Fuchs, Th; Žukauskaitė, A.; Chen, Z.; Iriarte, G. F.

2018-03-01

Scandium aluminum nitride (ScAlN) films have been synthesized by pulsed-DC reactive magnetron sputtering. The degree of c-axis orientation as well as piezoelectric characteristics of the Sc0.26Al0.74N thin films grown on Si (001) at various discharge powers and processing pressures values have been investigated. According to x-ray diffraction (XRD) measurements, the texture of the as-grown Sc0.26Al0.74N thin films becomes more prominent in the [0001]-direction at the highest target power (700 W) and at the lowest processing pressure (4 mTorr). The piezoelectric response, as determined by measuring the d33 piezoelectric constant, shows a maximum value of -12 pC/N also at 4 mTorr and 700 W, confirming a direct correlation between the d33 piezoelectric constant and the degree of orientation in the [0001]-direction. The atomic concentration of Sc and Al in the synthesized ScAlN thin film, determined by secondary ion mass spectroscopy (SIMS), reveals a Sc concentration lower than in the ScAl alloy target. The piezoresponse force microscopy (PFM) shows homogeneous polarity distribution with no inversion domains. The piezoelectric layers have been used to fabricate and measure surface acoustic wave (SAW) resonators on a Sc0.26Al0.74N/Si (001) bilayer system with resonance frequency of 1.4 GHz and coupling coefficient of 0.567. Such characteristic in the frequency response reveals the potential of these materials for advanced SAW devices in applications such as next generation (5 G) wireless communication systems.
Pore-Environment Engineering with Multiple Metal Sites in Rare-Earth Porphyrinic Metal-Organic Frameworks.

PubMed

Zhang, Liangliang; Yuan, Shuai; Feng, Liang; Guo, Bingbing; Qin, Jun-Sheng; Xu, Ben; Lollar, Christina; Sun, Daofeng; Zhou, Hong-Cai

2018-04-23

Multi-component metal-organic frameworks (MOFs) with precisely controlled pore environments are highly desired owing to their potential applications in gas adsorption, separation, cooperative catalysis, and biomimetics. A series of multi-component MOFs, namely PCN-900(RE), were constructed from a combination of tetratopic porphyrinic linkers, linear linkers, and rare-earth hexanuclear clusters (RE 6 ) under the guidance of thermodynamics. These MOFs exhibit high surface areas (up to 2523 cm 2 g -1 ) and unlimited tunability by modification of metal nodes and/or linker components. Post-synthetic exchange of linear linkers and metalation of two organic linkers were realized, allowing the incorporation of a wide range of functional moieties. Two different metal sites were sequentially placed on the linear linker and the tetratopic porphyrinic linker, respectively, giving rise to an ideal platform for heterogeneous catalysis. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Piezoelectric nanoparticle-polymer composite foams.

PubMed

McCall, William R; Kim, Kanguk; Heath, Cory; La Pierre, Gina; Sirbuly, Donald J

2014-11-26

Piezoelectric polymer composite foams are synthesized using different sugar-templating strategies. By incorporating sugar grains directly into polydimethylsiloxane mixtures containing barium titanate nanoparticles and carbon nanotubes, followed by removal of the sugar after polymer curing, highly compliant materials with excellent piezoelectric properties can be fabricated. Porosities and elasticity are tuned by simply adjusting the sugar/polymer mass ratio which gave an upper bound on the porosity of 73% and a lower bound on the elastic coefficient of 32 kPa. The electrical performance of the foams showed a direct relationship between porosity and the piezoelectric outputs, giving piezoelectric coefficient values of ∼112 pC/N and a power output of ∼18 mW/cm3 under a load of 10 N for the highest porosity samples. These novel materials should find exciting use in a variety of applications including energy scavenging platforms, biosensors, and acoustic actuators.
Summary of Synoptic Meteorological Observations. Indonesian Coastal Marine Areas. Volume 2. Area 8 - West Borneo, Area 9 - Karimata Strait, Area 10 - Southwest Java Sea, Area 11 - South Central Java, Area 12 - Southeast Java, Area 13 - Southeast Java Sea, Area 14 - Northeast Java Sea

DTIC Science & Technology

1975-04-01

5 ’ :00 0 1’.20 2. 219 39 : .:0 :00 .0 A.. AP99 120 , ~ ~ ~ ~ ~ -y- ,M -.7yT ,, T , . , .,77M III II P~ kID : (¢E(’Ll) 9•3-977AREA 0009 KARIMATA STRAIT...TYPE OTHER WEATHER PHENOMENA kNO 01D RAIN PAIN VAIL RAIG SNOW OTHER HAI. PORN AT PCPN PAST ?HOR FOG FOG WO SMOKE SPRAY NO SHoR PON FRZN 06 TIME HOUR LTNG...NAONO DIR RAIN RAIN ORIL RCZG SNOW OTHER HAIL PCORN A? FCN PAST THOR OTOH HAZE SPRy NOUST SI ? R G PUG W SMOK SPRAY No PHft PCN PRN OPTM OR LTNG Wa PORN
Gas-particle distributions, sources and health effects of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in Venice aerosols.

PubMed

Gregoris, Elena; Argiriadis, Elena; Vecchiato, Marco; Zambon, Stefano; De Pieri, Silvia; Donateo, Antonio; Contini, Daniele; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

2014-04-01

Air samples were collected in Venice during summer 2009 and 2012 to measure gas and particulate concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). PCB-11, considered a marker for non-Aroclor contamination of the environment, was found for the first time in the Venetian lagoon and in Europe. An investigation on sources has been conducted, evidencing traffic as the major source of PAHs, whereas PCBs have a similar composition to Aroclor 1248 and 1254; in 2009 a release of PCN-42 has been hypothesized. Toxicological evaluation by TCA and TEQ methods, conducted for the first time in Venice air samples, identified BaP, PCB-126 and PCB-169 as the most important contributors to the total carcinogenic activity of PAHs and the total dioxin-like activity of PCBs and PCNs. Copyright © 2014 Elsevier B.V. All rights reserved.
High temperature (NaBi)0.48□0.04Bi2Nb2O9-based piezoelectric ceramics

NASA Astrophysics Data System (ADS)

Gai, Zhi-Gang; Wang, Jin-Feng; Zhao, Ming-Lei; Wang, Chun-Ming; Zang, Guo-Zhong; Ming, Bao-Quan; Qi, Peng; Zhang, Shujun; Shrout, Thomas R.

2006-07-01

The effect of (LiCe) substitution for A site on the properties of (NaBi)0.48◻0.04Bi2Nb2O9 (NB◻N)-based ceramics was investigated. The coercive fields (EC) of NB◻N)-based ceramics were significantly decreased from 61.0to32.5kV/cm and the Curie temperature (TC) gradually decreases from 820to803°C with increasing the (LiCe) modification. The piezoelectric coefficient d33, planar coupling factor kp, and mechanical quality factor Q of (NaBi)0.38(LiCe)0.05◻0.14Bi2Nb2O9 ceramic were found to be 27pC/N, 11.2%, and 2600, respectively, together with the high TC (˜809°C) and stable piezoelectric properties, demonstrating that the (LiCe) modified NB◻N-based material a promising candidate for high temperature applications.
Porous polymer composite membrane based nanogenerator: A realization of self-powered wireless green energy source for smart electronics applications

NASA Astrophysics Data System (ADS)

Ghosh, Sujoy Kumar; Sinha, Tridib Kumar; Mahanty, Biswajit; Jana, Santanu; Mandal, Dipankar

2016-11-01

An efficient, flexible and unvaryingly porous polymer composite membrane based nanogenerator (PPCNG) without any electrical poling treatment has been realised as wireless green energy source to power up smart electronic gadgets. Owing to self-polarized piezo- and ferro-electretic phenomenon of in situ platinum nanoparticles (Pt-NPs) doped porous poly(vinylidenefluoride-co-hexafluoropropylene)-membrane, a simple, inexpensive and scalable PPCNG fabrication is highlighted. The molecular orientations of the -CH2/-CF2 dipoles that cause self-polarization phenomenon has been realized by angular dependent near edge X-ray absorption fine structure spectroscopy. The square-like hysteresis loop with giant remnant polarization, Pr ˜ 68 μC/cm2 and exceptionally high piezoelectric charge coefficient, d33 ˜ - 836 pC/N promises a best suited ferro- and piezo-electretic membrane. The PPCNG exhibits a high electrical throughput such as, ranging from 2.7 V to 23 V of open-circuit voltage (Voc) and 2.9 μA to 24.7 μA of short-circuit current (Isc) under 0.5 MPa to 4.3 MPa of imparted stress amplitude by periodic human finger motion. The harvested mechanical and subsequent electrical energy by PPCNG is shown to transfer wirelessly via visible and infrared transmitter-receiver systems, where 17% and 49% of wireless power transfer efficiency, respectively, has been realized to power up several consumer electronics.
Significantly enhanced piezoelectricity in low-temperature sintered Aurivillius-type ceramics with ultrahigh Curie temperature of 800 °C

NASA Astrophysics Data System (ADS)

Cai, Kai; Huang, Chengcheng; Guo, Dong

2017-04-01

We report an Aurivillius-type piezoelectric ceramic (Ca1-2x (LiCe) x Bi4Ti3.99Zn0.01O15) that has an ultrahigh Curie temperature (T c) around 800 °C and a significantly enhanced piezoelectric coefficient (d 33), comparable to that of textured ceramics fabricated using the complicated templating method. Surprisingly, the highest d 33 of 26 pC/N was achieved at an unexpectedly low sintering temperature (T s) of only 920 °C (~200 °C lower than usual) despite the non-ideal density. Study of different synthesized samples indicates that a relatively low T s is crucial for suppressing Bi evaporation and abnormal grain growth, which are indispensable for high resistivity and effective poling due to decreased carrier density and restricted anisotropic conduction. Because the layered structure is sensitive to lattice defects, controlled Bi loss is considered to be crucial for maintaining structural order and spontaneous polarization. This low-T s system is very promising for practical applications due to its high piezoelectricity, low cost and high reproducibility. Contrary to our usual understanding, the results reveal that a delicate balance of density, Bi loss and grain morphology achieved by adjusting the sintering temperature is crucial for the enhancing performance in Aurivillius-type high-T c ceramics.
The effects of IL-1β, IL-8, G-CSF and TNF-α as molecular adjuvant on the immune response to an E. tarda subunit vaccine in flounder (Paralichthys olivaceus).

PubMed

Guo, Ming; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

2018-06-01

Cytokines play vital roles in mounting immune responses and activating host defense network. In this study, the expression plasmid pcDNA3.1 (pcN3) encoding four flounder (Paralichthys olivaceus) cytokines including IL-1β, TNF-α, IL-8 or G-CSF (pcIL-1β, pcTNF-α, pcIL-8 and pcG-CSF) were successfully constructed, and their adjuvant potential on an Edwardsiella tarda (E. tarda) subunit vaccine OmpV (rOmpV) were comparatively analyzed in vaccinated flounder model. Results revealed that flounder vaccinated with rOmpV plus pcIL-1β, pcIL-8 or pcG-CSF produced the relative percent survivals (RPS) of 71%, 65% and 49% respectively, which were higher than that in flounder vaccinated with rOmpV plus pcTNF-α (39%) or pcN3 (36%, the control group). Immunological analysis showed that: (1) except pcTNF-α, higher levels of anti-E. tarda serum antibodies and sIg + lymphocytes in spleen, head kidney and peripheral blood were significantly enhanced by pcIL-1β, pcIL-8 or pcG-CSF, however, pcIL-8 and pcIL-1β enhanced higher levels of sIg + lymphocytes and anti-E. tarda antibodies than pcG-CSF; (2) pcTNF-α could promote the up-regulation of genes participated in cellular immunity (MHCIα, IFN-γ, CD8α and CD8β), pcIL-1β could enhance the expression of genes related to humoral immunity (CD4-1, CD4-2, MHCIIα and IgM), and all the detected genes were augmented by pcIL-8 and pcG-CSF; Among the four cytokines, pcIL-8 and pcIL-1β could strengthen the highest levels of genes participated in cellular immunity and humoral immunity, respectively. These results demonstrated that pcIL-8 and pcIL-1β could enhance stronger cellular and/or humoral immunity induced by rOmpV than pcG-CSF and pcTNF-α, and evoked higher RPS against E. tarda challenge in flounder, which indicated that pcIL-8 and pcIL-1β are promising adjuvants of vaccines in controlling E. tarda infection. Copyright © 2018 Elsevier Ltd. All rights reserved.
ColE1-Plasmid Production in Escherichia coli: Mathematical Simulation and Experimental Validation.

PubMed

Freudenau, Inga; Lutter, Petra; Baier, Ruth; Schleef, Martin; Bednarz, Hanna; Lara, Alvaro R; Niehaus, Karsten

2015-01-01

Plasmids have become very important as pharmaceutical gene vectors in the fields of gene therapy and genetic vaccination in the past years. In this study, we present a dynamic model to simulate the ColE1-like plasmid replication control, once for a DH5α-strain carrying a low copy plasmid (DH5α-pSUP 201-3) and once for a DH5α-strain carrying a high copy plasmid (DH5α-pCMV-lacZ) by using ordinary differential equations and the MATLAB software. The model includes the plasmid replication control by two regulatory RNA molecules (RNAI and RNAII) as well as the replication control by uncharged tRNA molecules. To validate the model, experimental data like RNAI- and RNAII concentration, plasmid copy number (PCN), and growth rate for three different time points in the exponential phase were determined. Depending on the sampled time point, the measured RNAI- and RNAII concentrations for DH5α-pSUP 201-3 reside between 6 ± 0.7 and 34 ± 7 RNAI molecules per cell and 0.44 ± 0.1 and 3 ± 0.9 RNAII molecules per cell. The determined PCNs averaged between 46 ± 26 and 48 ± 30 plasmids per cell. The experimentally determined data for DH5α-pCMV-lacZ reside between 345 ± 203 and 1086 ± 298 RNAI molecules per cell and 22 ± 2 and 75 ± 10 RNAII molecules per cell with an averaged PCN of 1514 ± 1301 and 5806 ± 4828 depending on the measured time point. As the model was shown to be consistent with the experimentally determined data, measured at three different time points within the growth of the same strain, we performed predictive simulations concerning the effect of uncharged tRNA molecules on the ColE1-like plasmid replication control. The hypothesis is that these tRNA molecules would have an enhancing effect on the plasmid production. The in silico analysis predicts that uncharged tRNA molecules would indeed increase the plasmid DNA production.
Bulk Crystal Growth of Piezoelectric PMN-PT Crystals Using Gradient Freeze Technique for Improved SHM Sensors

NASA Technical Reports Server (NTRS)

Aggarwal, Mohan D.; Kochary, F.; Penn, Benjamin G.; Miller, Jim

2007-01-01

There has been a growing interest in recent years in lead based perovskite ferroelectric and relaxor ferroelectric solid solutions because of their excellent dielectric, piezoelectric and electrostrictive properties that make them very attractive for various sensing, actuating and structural health monitoring (SHM) applications. We are interested in the development of highly sensitive and efficient PMN-PT sensors based on large single crystals for the structural health monitoring of composite materials that may be used in future spacecrafts. Highly sensitive sensors are needed for detection of defects in these materials because they often tend to fail by distributed and interacting damage modes and much of the damage occurs beneath the top surface of the laminate and not detectable by visual inspection. Research is being carried out for various combinations of solid solutions for PMN-PT piezoelectric materials and bigger size crystals are being sought for improved sensor applications. Single crystals of this material are of interest for sensor applications because of their high piezoelectric coefficient (d33 greater than 1700 pC/N) and electromechanical coefficients (k33 greater than 0.90). For comparison, the commonly used piezoelectric ceramic lead zirconate titanate (PZT) has a d33 of about 600 pC/N and electromechanical coefficients k33 of about 0.75. At the present time, these piezoelectric relaxor crystals are grown by high temperature flux growth method and the size of these crystals are rather small (3x4x5 mm(exp 3). In the present paper, we have attempted to grow bulk single crystals of PMN-PT in a 2 inch diameter platinum crucible and successfully grown a large size crystal of 67%PMN-33%PT using the vertical gradient freeze technique with no flux. Piezoelectric properties of the grown crystals are investigated. PMN-PT plates show excellent piezoelectric properties. Samples were poled under an applied electric field of 5 kV/cm. Dielectric properties at a frequency of 1 kHz are examined. The grown PMN-PT crystals show typical relaxor dielectric properties. Additionally, the thermal properties of the sample are tested. The results are in good agreement with those found in the literature and some are reported for the first time.
Piezo-/dielectric properties of perovskite-structure high-temperature relaxor ferroelectrics: The Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ternary ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tao; University of Chinese Academy of Sciences, Beijing 100049; Long, Xifa, E-mail: lxf@fjirsm.ac.cn

2014-03-01

Graphical abstract: - Highlights: • Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-based ternary ferroelectric ceramics were prepared by solid-state synthesis method. • Morphotropic phase boundary region has been determined by XRD, di-/piezoelectric properties. • The compositions near MPB region exhibit excellent piezoelectric properties. - Abstract: A new compositional system of relaxor ferroelectrics was investigated based on the high piezoelectricity Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ferroelectric perovskite family. Compositions were fabricated near an estimated morphotropic phase boundary (MPB) of the Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} (PLZNT) ternary system by a two-step synthetic process. Their structures have been analyzed by means ofmore » X-ray diffraction technique. On the basis of X-ray powder diffraction, the morphotropic phase boundary (MPB) region for the ternary system was obtained. The Curie temperature T{sub C} of ternary system varied from 240 °C to 330 °C and the coercive fields E{sub c}s > 10 kV/cm. The values of piezoelectric coefficients d{sub 33} vary in the range of 260–450 pC/N with different PZN contents. It is worth noting that the optimum compositions were located at MPB region but near the tetragonal phase. The new PLZNT ceramics exhibit wider range of T{sub C}s and E{sub c}s, making it a promising material for high-powder ultrasound transducers using in a large temperature range.« less
Study on stimulus-responsive cellulose-based polymeric materials

NASA Astrophysics Data System (ADS)

Luo, Hongsheng

Stimulus-responsive cellulose-based polymeric materials were developed by physical and chemical approaches. The thermal, structural, mechanical and morphological properties of the samples were comprehensively investigated by multiple tools. Shape memory effect (SME), programming-structure-property relationship and underling mechanisms were emphasized in this study. Some new concepts, such as heterogeneous-twin-switch, path-dependent multi-shape, rapidly switchable water-sensitive SME were established. The samples were divided into two categories. For the first category, cellulose nano-whiskers (CNWs) were incorporated into crystalline shape memory polyurethane (SMPU) and thermal plastic polyurethane (TPU). The CNW-SMPU nano-composites had heterogeneous switches. Triple- and multi-shape effects were achieved for the CNW-SMPU nano-composites by applying into appropriate thermal-aqueous-mechanical programming. Furthermore, the thermally triggered shape recovery of the composites was found to be tuneable, depending on the PCN content. Theoretical prediction along with numerical analysis was conducted, providing evidence on the possible microstructure of the CNW-SMPU nano-composites. Rapidly switchable water-sensitive SME of the CNW-TPU nano-composites was unprecedentedly studied, which originated from the reversible regulation of hydrogen bonding by water. The samples in the second category consisted of cellulose-polyurethane (PU) blends, cellulose-poly(acrylic acid) (PAA) composites and modified cellulose with supramolecular switches, featuring the requirement of homogeneous cellulose solution in the synthesis process. The reversible behaviours of the cellulose-PU blends in wet-dry cycles as well as the underlying shape memory mechanism were characterized and disclosed. The micro-patterns of the blends were found to be self-similar in fractal dimensions. Cellulose-PAA semi-interpenetrating networks exhibited mechanical adaptability in wet-dry cycles. A type of thermally reversible quadruple hydrogen bonding units, ureidopyrimidinone (UPy), reacted with the cellulose as pendent side-groups, which may impart the modified cellulose with thermal sensitivity. It is the first attempt to explore the natural cellulose as smart polymeric materials systematically and comprehensively. The concepts originally created in the study provided new viewpoints and routes for the development of novel shape memory polymers. The findings significantly benefits extension of the potential application of the cellulose in smart polymeric materials field.

Factors influencing pharmacists’ adoption of prescribing: qualitative application of the diffusion of innovations theory

PubMed Central

2013-01-01

Background In 2007, Alberta became the first Canadian jurisdiction to grant pharmacists a wide range of prescribing privileges. Our objective was to understand what factors influence pharmacists’ adoption of prescribing using a model for the Diffusion of Innovations in healthcare services. Methods Pharmacists participated in semi-structured telephone interviews to discuss their prescribing practices and explore the facilitators and barriers to implementation. Pharmacists working in community, hospital, PCN, or other settings were selected using a mix of random and purposive sampling. Two investigators independently analyzed each transcript using an Interpretive Description approach to identify themes. Analyses were informed by a model explaining the Diffusion of Innovations in health service organizations. Results Thirty-eight participants were interviewed. Prescribing behaviours varied from non-adoption through to product, disease, and patient focused use of prescribing. Pharmacists’ adoption of prescribing was dependent on the innovation itself, adopter, system readiness, and communication and influence. Adopting pharmacists viewed prescribing as a legitimization of previous practice and advantageous to instrumental daily tasks. The complexity of knowledge required for prescribing increased respectively in product, disease and patient focused prescribing scenarios. Individual adopters had higher levels of self-efficacy toward prescribing skills. At a system level, pharmacists who were in practice settings that were patient focused were more likely to adopt advanced prescribing practices, over those in product-focused settings. All pharmacists stated that physician relationships impacted their prescribing behaviours and individual pharmacists’ decisions to apply for independent prescribing privileges. Conclusions Diffusion of Innovations theory was helpful in understanding the multifaceted nature of pharmacists’ adoption of prescribing. The characteristics of the prescribing model itself which legitimized prior practices, the model of practice in a pharmacy setting, and relationships with physicians were prominent influences on pharmacists’ prescribing behaviours. PMID:24034176
Stable Ferroelectric Behavior of Nb-Modified Bi0.5K0.5TiO3-Bi(Mg0.5Ti0.5)O3 Lead-Free Relaxor Ferroelectric Ceramics

NASA Astrophysics Data System (ADS)

Zaman, Arif; Malik, Rizwan Ahmed; Maqbool, Adnan; Hussain, Ali; Ahmed, Tanveer; Song, Tae Kwon; Kim, Won-Jeong; Kim, Myong-Ho

2018-03-01

Crystal structure, dielectric, ferroelectric, piezoelectric, and electric field-induced strain properties of lead-free Nb-modified 0.96Bi0.5K0.5TiO3-0.04Bi(Mg0.5Ti0.5)O3 (BKT-BMT) piezoelectric ceramics were investigated. Crystal structure analysis showed a gradual phase transition from tetragonal to pseudocubic phase with increasing Nb content. The optimal piezoelectric property of small-signal d 33 was enhanced up to ˜ 68 pC/N with a lower coercive field ( E c) of ˜ 22 kV/cm and an improved remnant polarization ( P r) of ˜ 13 μC/cm2 for x = 0.020. A relaxor-like behavior with a frequency-dependent Curie temperature T m was observed, and a high T m around 320°C was obtained in the investigated system. This study suggests that the ferroelectric properties of BKT-BMT was significantly improved by means of Nb substitution. The possible shift of depolarization temperature T d toward high temperature T m may have triggered the spontaneous relaxor to ferroelectric phase transition with long-range ferroelectric order without any traces of a nonergodic relaxor state in contradiction with Bi0.5Na0.5TiO3-based systems. The possible enhancement in ferroelectric and piezoelectric properties near the critical composition x = 0.020 may be attributed to the increased anharmonicity of lattice vibrations which may facilitate the observed phase transition from a low-symmetry tetragonal to a high-symmetry cubic phase with a decrease in the lattice anisotropy of an undoped sample. This highly flexible (at a unit cell level) narrow compositional range triggers the enhancement of d 33 and P r values.
Systematic study of probable projectile-target combinations for the synthesis of the superheavy nucleus 302120

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Safoora, V.

2016-08-01

Probable projectile-target combinations for the synthesis of the superheavy element 302120 have been studied taking the Coulomb and proximity potential as the interaction barrier. The probabilities of the compound nucleus formation PCN for the projectile-target combinations found in the cold reaction valley of 302120 are estimated. At energies near and above the Coulomb barrier, we have calculated the capture, fusion, and evaporation residue cross sections for the reactions of all probable projectile-target combinations so as to predict the most promising projectile-target combinations for the synthesis of the superheavy element 302120 in heavy-ion fusion reactions. The calculated fusion and evaporation cross sections for the more asymmetric ("hotter") projectile-target combination is found to be higher than the less asymmetric ("colder") combination. It can be seen from the nature of the quasifission barrier height, mass asymmetry, the probability of compound nucleus formation, survival probability, and excitation energy, the systems 44Ar+258No , 46Ar+256No , 48Ca+254Fm , 50Ca+252Fm , 54Ti+248Cf , and 58Cr+244Cm in deep region I of the cold reaction valley and the systems 62Fe+240Pu , 64Fe+238Pu , 68Ni+234U , 70Ni+232U , 72Ni+230U , and 74Zn+228Th in the other cold valleys are identified as the better projectile-target combinations for the synthesis of 302120. Our predictions on the synthesis of 302120 superheavy nuclei using the combinations 54Cr+248Cm , 58Fe+244Pu , 64Ni+238U , and 50Ti+249Cf are compared with available experimental data and other theoretical predictions.
New Pb(Mg1/3Nb2/3)O3-Pb(In1/2Nb1/2)O3-PbZrO3-PbTiO3 Quaternary Ceramics: Morphotropic Phase Boundary Design and Electrical Properties.

PubMed

Luo, Nengneng; Zhang, Shujun; Li, Qiang; Xu, Chao; Yang, Zhanlue; Yan, Qingfeng; Zhang, Yiling; Shrout, Thomas R

2016-06-22

Four series of Pb(Mg1/3Nb2/3)O3-Pb(In1/2Nb1/2)O3-PbZrO3-PbTiO3 (PMN-PIN-PZ-PT) quaternary ceramics with compositions located at the morphotropic phase boundary (MPB) regions were prepared. The MPBs of the multicomponent system were predicted using a linear combination rule and experimentally confirmed by X-ray powder diffraction and electrical measurement. The positions of MPBs in multicomponent systems were found in linear correlation with the tolerance factor and ionic radii of non-PT end-members. The phase structure, piezoelectric coefficient, electromechanical coupling coefficient, unipolar strains, and dielectric properties of as-prepared ceramics were systematically investigated. The largest d33s were obtained at S36.8, L37.4, M39.6, and N35.8, with the corresponding values of 580, 450, 420, and 530 pC/N, respectively, while the largest kps were found at S34.8, L37.4, M39.6, and N35.8, with the respective values of 0.54, 0.50, 0.47, and 0.53. The largest unipolar strain Smax and high-field piezoelectric strain coefficients d33* were also observed around the respective MPB regions. The rhombohedral-to-tetragonal phase transition temperature Trt increased with increasing PIN and PZ contents. Of particular importance is that high Trt of 140-197 °C was achieved in the M series with PZ and PIN contents being around 0.208 and 0.158, which will broaden the temperature usage range.
Factors influencing pharmacists' adoption of prescribing: qualitative application of the diffusion of innovations theory.

PubMed

Makowsky, Mark J; Guirguis, Lisa M; Hughes, Christine A; Sadowski, Cheryl A; Yuksel, Nese

2013-09-14

In 2007, Alberta became the first Canadian jurisdiction to grant pharmacists a wide range of prescribing privileges. Our objective was to understand what factors influence pharmacists' adoption of prescribing using a model for the Diffusion of Innovations in healthcare services. Pharmacists participated in semi-structured telephone interviews to discuss their prescribing practices and explore the facilitators and barriers to implementation. Pharmacists working in community, hospital, PCN, or other settings were selected using a mix of random and purposive sampling. Two investigators independently analyzed each transcript using an Interpretive Description approach to identify themes. Analyses were informed by a model explaining the Diffusion of Innovations in health service organizations. Thirty-eight participants were interviewed. Prescribing behaviours varied from non-adoption through to product, disease, and patient focused use of prescribing. Pharmacists' adoption of prescribing was dependent on the innovation itself, adopter, system readiness, and communication and influence. Adopting pharmacists viewed prescribing as a legitimization of previous practice and advantageous to instrumental daily tasks. The complexity of knowledge required for prescribing increased respectively in product, disease and patient focused prescribing scenarios. Individual adopters had higher levels of self-efficacy toward prescribing skills. At a system level, pharmacists who were in practice settings that were patient focused were more likely to adopt advanced prescribing practices, over those in product-focused settings. All pharmacists stated that physician relationships impacted their prescribing behaviours and individual pharmacists' decisions to apply for independent prescribing privileges. Diffusion of Innovations theory was helpful in understanding the multifaceted nature of pharmacists' adoption of prescribing. The characteristics of the prescribing model itself which legitimized prior practices, the model of practice in a pharmacy setting, and relationships with physicians were prominent influences on pharmacists' prescribing behaviours.
Hardening of electromechanical properties in piezoceramics using a composite approach

NASA Astrophysics Data System (ADS)

K. V., Lalitha; Riemer, Lukas M.; Koruza, Jurij; Rödel, Jürgen

2017-07-01

Piezoelectric applications such as ultrasonic motors, transformers and therapeutic ultrasonics demand high power generation with low losses, which is facilitated by "hard" ferroelectrics. Hardening of piezoelectric properties, characterized by high mechanical quality factor (Qm), is usually achieved by doping with lower valence elements, thereby tailoring the domain wall dynamics. In the present study, we demonstrate a hardening mechanism by developing composites of 0.94(Na1/2Bi1/2)TiO3-0.06BaTiO3 (NBT-6BT) with ZnO inclusions, as an alternative to chemical modifications. A decrease in the saturation polarization and total strain, higher internal bias fields, lower hysteretic losses and a two-fold increase in Qm are observed in comparison to NBT-6BT. The composite with 0.1 mole ratio of ZnO exhibits the highest Qm of 320 with d33 = 125 pC/N and Kp = 0.29. A one-to-one correspondence between the increase in Qm and the decrease in the domain wall mobility is established from the ac field dependence of permittivity, in the framework of the Rayleigh law. A further increase in ZnO content beyond a mole ratio of 0.1 reduces Qm, but retains it at a higher level, as compared to NBT-6BT. The results are explained based on the poling-induced strain incompatibility between the matrix and the hard ZnO phase. This composite approach is therefore considered a generic hardening concept and can be extended to other ferroelectric systems.
Computational evaluation of metal-organic frameworks for carbon dioxide capture

NASA Astrophysics Data System (ADS)

Yu, Jiamei

Metal-organic frameworks (MOFs), a new class of porous solids comprised of metal-containing nodes linked by organic ligands, have become promising materials for gas separations. In particular, their flexible chemistry makes them attractive for CO2 capture from flue gas streams in post-combustion plants. Although numerous efforts have been exerted on the investigation of MOFs for CO2 capture, the exploration of the effects from coexisting components present in very dilute proportions in flue gases is limited because of the experimental difficulty to determine the coadsorption of CO2 with trace components. In this regard, molecular simulations show superiority. In this study, molecular simulations are used to estimate the influence of impurities: water, O2, and SO2 on post-combustion CO2 capture in MOFs. Firstly, two MOFs with coordinatively unsaturated metal sites (CUMs), HKUST-1 and Mg-MOF-74 are explored. Increase of CO 2 adsorption is observed for hydrated HKUST-1; on the contrary, the opposite water adsorption behavior is observed in hydrated Mg-MOF-74, leading to decrease of CO2 adsorption. Further, water effects on CO 2 capture in M-HKUST1 (M = Mg, Zn, Co, Ni) are evaluated to test whether comparing the binding energy could be a general method to evaluate water effects in MOFs with CUMs. It is found that the method works well for Zn-, Co-, and Ni-HKUST1 but partially for Mg-HKUST1. In addition, the effects of O2 and SO2 on CO2 capture in MOFs are also investigated for the first time, showing that the effects of O2 may be negligible but SO2 has negative effects in the CO 2 capture process in HKUST-1 systems. Secondly, the influences of water on CO2 capture in three UiO-66 MOFs with functional groups, --NH2, --OH and --Br are explored, respectively. For UiO-66-NH2 and -OH, the presence of water lowers CO2 adsorption significantly; in contrast, water shows much smaller effects in UiO-66-Br. Moreover, the presence of SO 2 decreases water adsorption but enhances CO2 uptakes slightly in both UiO-66-NH2 and -Br. Finally, the effects of impurities on CO2 capture in a MOF with suitable pore size (PCN-200) are analyzed. The adsorption of both CO 2 and N2 decrease substantially even with 1% water present in the mixture. In addition, the presence of low SO2 does not show obvious effect in PCN-200. However, a lower CO2 adsorption is observed for a mixture with a high SO2 content. In collaboration with experimental groups, the performances of three new MOFs in CO2 capture are evaluated using molecular simulations. The computational results demonstrate the feasibility of precisely designing single-molecule traps (SMT) for CO2 capture. Also, a multi-functional MOF with micro-porosity, open Cu2+ sites and amine groups has also proved computationally the selective adsorption of CO2 over CH4 and N2. Last, we demonstrate that charge separation is an effective strategy for improving CO2 capture in MOFs.
Effect of vanadium doping on the properties of high Curie point ferroelectric strontium niobate ceramic

NASA Astrophysics Data System (ADS)

Ning, Huanpo

2017-10-01

Different levels of isovalent dopant vanadium were doped on the B site of Sr2Nb2O7 to explore the doping effect on its dielectric and ferroelectric properties. A second phase could be detected with above 1 mol% V2O5 doping. The grains after doping remained anisotropic and plate-like. The samples are not dense, as there are pores present at the grain boundaries. The corrected dielectric constant for 0.1 mol%, 0.2 mol%, and 0.3 mol% V doped SNO at 1 MHz is around 46, 48 and 49, respectively, which indicates the effect of V doping on the increase of dielectric constant of SNO (ɛr is about 40 at 1 MHz). The Curie point Tc increased with the increase in the V doping level. The relatively high d33 (2.3 pC/N) measured from the non-dense and untextured samples indicates the potential effect of V2O5 doping on the improvement of piezoelectricity of SNO.
Pigment-cellulose nanofibril composite and its application as a separator-substrate in printed supercapacitors

NASA Astrophysics Data System (ADS)

Torvinen, Katariina; Lehtimäki, Suvi; Keränen, Janne T.; Sievänen, Jenni; Vartiainen, Jari; Hellén, Erkki; Lupo, Donald; Tuukkanen, Sampo

2015-11-01

Pigment-cellulose nanofibril (PCN) composites were manufactured in a pilot line and used as a separator-substrate in printed graphene and carbon nanotube supercapacitors. The composites consisted typically of 80% pigment and 20% cellulose nanofibrils (CNF). This composition makes them a cost-effective alternative as a substrate for printed electronics at high temperatures that only very special plastic films can nowadays stand. The properties of these substrates can be varied within a relatively large range by the selection of raw materials and their relative proportions. A semi-industrial scale pilot line was successfully used to produce smooth, flexible, and nanoporous composites, and their performance was tested in a double functional separator-substrate element in supercapacitors. The nanostructural carbon films printed on the composite worked simultaneously as high surface area active electrodes and current collectors. Low-cost supercapacitors made from environmentally friendly materials have significant potential for use in flexible, wearable, and disposable low-end products. [Figure not available: see fulltext.
Dielectric and ferroelectric properties of Ba0.87Ca0.10La0.03Ti1-xSnxO3 lead-free ceramics

NASA Astrophysics Data System (ADS)

Chen, Zhi-hui; Li, Zhi-wei; Fang, Chang; Qiu, Jian-hua; Ding, Jian-ning; Zhu, Wei-qin; Xu, Jiu-jun

2017-12-01

Ba0.87Ca0.10La0.03Ti1-xSnxO3 (BCLTS) piezoelectric lead-free ceramics were fabricated by conventional solid-state sintering process at 1480 °C. The effects of Sn4+ substitution on microstructure and electrical properties of the ceramics were researched. All samples show a pure perovskite structure with no secondary phase, and the coexistence of orthorhombic phase and tetragonal phase in the composition range of x = 0.06-0.10 is identified in the XRD pattern. Average grain size decreases with the increase of Sn content in the BCLTS samples. The BCLTS ceramics exhibit excellent piezoelectric properties and ferroelectric properties with d33 = 501pC/N and kp = 45.6% at x = 0.10, and Pr = 9.87 μC/cm2 at x = 0.06. The analysis on the temperature dependence of dielectric permittivity approved the diffuse relaxor ferroelectric feature for all the BCLTS samples.
Piezoelectric Flexible LCP-PZT Composites for Sensor Applications at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Tolvanen, Jarkko; Hannu, Jari; Juuti, Jari; Jantunen, Heli

2018-03-01

In this paper fabrication of piezoelectric ceramic-polymer composites is demonstrated via filament extrusion enabling cost-efficient large-scale production of highly bendable pressure sensors feasible for elevated temperatures. These composites are fabricated by utilizing environmentally resistant and stable liquid crystal polymer matrix with addition of lead zirconate titanate at loading levels of 30 vol%. These composites, of approximately 0.99 mm thick and length of > 50 cm, achieved excellent bendability with minimum bending radius of 6.6 cm. The maximum piezoelectric coefficients d33 and g33 of the composites were > 14 pC/N and > 108 mVm/N at pressure < 10 kPa. In all cases, the piezoelectric charge coefficient (d33) of the composites decreased as a function of pressure. Also, piezoelectric coefficient (d33) further decreased in the case of increased frequency press-release cycle sand pre-stress levels by approximately 37-50%. However, the obtained results provide tools for fabricating novel piezoelectric sensors in highly efficient way for environments with elevated temperatures.
Realization of face-shear piezoelectric coefficient d36 in PZT ceramics via ferroelastic domain engineering

NASA Astrophysics Data System (ADS)

Miao, Hongchen; Li, Faxin

2015-09-01

The piezoelectric face-shear ( d36 ) mode may be the most useful shear mode in piezoelectrics, while currently this mode can only exist in single crystals of specific point groups and cut directions. Theoretically, the d36 coefficient vanishes in piezoelectric ceramics because of its transversally isotropic symmetry. In this work, we modified the symmetry of poled PZT ceramics from transversally isotropic to orthogonal through ferroelastic domain switching by applying a high lateral stress along the "2" direction and holding the stress for several hours. After removing the compression, the piezoelectric coefficient d31 is found much larger than d32 . Then, by cutting the compressed sample along the Z x t ±45 ° direction, we realized d36 coefficients up to 206 pC/N , which is measured by using a modified d33 meter. The obtained large d36 coefficients in PZT ceramics could be very promising for face-shear mode resonators and shear horizontal wave generation in nondestructive testing.
Novel bioassay demonstrates attraction of the white potato cyst nematode Globodera pallida (Stone) to non-volatile and volatile host plant cues.

PubMed

Farnier, Kevin; Bengtsson, Marie; Becher, Paul G; Witzell, Johanna; Witzgall, Peter; Manduríc, Sanja

2012-06-01

Potato cyst nematodes (PCNs) are a major pest of solanaceous crops such as potatoes, tomatoes, and eggplants and have been widely studied over the last 30 years, with the majority of earlier studies focusing on the identification of natural hatching factors. As a novel approach, we focused instead on chemicals involved in nematode orientation towards its host plant. A new dual choice sand bioassay was designed to study nematode responses to potato root exudates (PRE). This bioassay, conducted together with a traditional hatching bioassay, showed that biologically active compounds that induce both hatching and attraction of PCNs can be collected by water extraction of incised potato roots. Furthermore, our results demonstrated that PCN also were attracted by potato root volatiles. Further work is needed to fully understand how PCNs use host plant chemical cues to orientate towards hosts. Nevertheless, the simple attraction assay used in this study provides an important tool for the identification of host-emitted attractants.
An in vitro study of electrically active hydroxyapatite-barium titanate ceramics using Saos-2 cells.

PubMed

Baxter, Frances R; Turner, Irene G; Bowen, Christopher R; Gittings, Jonathan P; Chaudhuri, Julian B

2009-08-01

Electrically active ceramics are of interest as bone graft substitute materials. This study investigated the ferroelectric properties of hydroxyapatite-barium titanate (HABT) composites and the behaviour of osteoblast-like cells seeded on their surfaces. A piezoelectric coefficient (d(33)) of 57.8 pCN(-1) was observed in HABT discs prepared for cell culture. The attachment, proliferation, viability, morphology and metabolic activity of cells cultured on unpoled HABT were comparable to those observed on commercially available hydroxyapatite at all time points. No indication of the cytotoxicity of HABT was detected. At one day after seeding, cell attachment was modified on both the positive and negative surfaces of poled HABT. After longer incubations, all parameters observed were comparable on poled and unpoled ceramics. The results indicate that HABT ceramics are biocompatible in the short term in vitro and that further investigation of cell responses to these materials under mechanical load and at longer incubation times is warranted.
Large piezoelectricity in electric-field modified single crystals of SrTiO3

NASA Astrophysics Data System (ADS)

Khanbabaee, B.; Mehner, E.; Richter, C.; Hanzig, J.; Zschornak, M.; Pietsch, U.; Stöcker, H.; Leisegang, T.; Meyer, D. C.; Gorfman, S.

2016-11-01

Defect engineering is an effective and powerful tool to control the existing material properties and produce completely new ones, which are symmetry-forbidden in a defect-free crystal. For example, the application of a static electric field to a single crystal of SrTiO3 forms a strained near-surface layer through the migration of oxygen vacancies out of the area beneath the positively charged electrode. While it was previously shown that this near-surface phase holds pyroelectric properties, which are symmetry-forbidden in centrosymmetric bulk SrTiO3, this paper reports that the same phase is strongly piezoelectric. We demonstrate the piezoelectricity of this phase through stroboscopic time-resolved X-ray diffraction under alternating electric field and show that the effective piezoelectric coefficient d33 ranges between 60 and 100 pC/N. The possible atomistic origins of the piezoelectric activity are discussed as a coupling between the electrostrictive effect and spontaneous polarization of this near-surface phase.
Phase-Change Nanoparticles Using Highly Volatile Perfluorocarbons: Toward a Platform for Extravascular Ultrasound Imaging

PubMed Central

Matsunaga, Terry O.; Sheeran, Paul S.; Luois, Samantha; Streeter, Jason E.; Mullin, Lee B.; Banerjee, Bhaskar; Dayton, Paul A.

2012-01-01

Recent efforts using perfluorocarbon (PFC) nanoparticles in conjunction with acoustic droplet vaporization has introduced the possibility of expanding the diagnostic and therapeutic capability of ultrasound contrast agents to beyond the vascular space. Our laboratories have developed phase-change nanoparticles (PCNs) from the highly volatile PFCs decafluorobutane (DFB, bp =-2 °C) and octafluoropropane (OFP, bp =-37 °C ) for acoustic droplet vaporization. Studies with commonly used clinical ultrasound scanners have demonstrated the ability to vaporize PCN emulsions with frequencies and mechanical indices that may significantly decrease tissue bioeffects. In addition, these contrast agents can be formulated to be stable at physiological temperatures and the perfluorocarbons can be mixed to modulate the balance between sensitivity to ultrasound and general stability. We herein discuss our recent efforts to develop finely-tuned diagnostic/molecular imaging agents for tissue interrogation. We discuss studies currently under investigation as well as potential diagnostic and therapeutic paradigms that may emerge as a result of formulating PCNs with low boiling point PFCs. PMID:23382775
Effects of (LiCe) co-substitution on the structural and electrical properties of CaBi2Nb2O9 ceramics

NASA Astrophysics Data System (ADS)

Tian, Xiao-Xia; Qu, Shao-Bo; Du, Hong-Liang; Li, Ye; Xu, Zhuo

2012-03-01

The piezoelectric, dielectric, and ferroelectric properties of the (LiCe) co-substituted calcium bismuth niobate (CaBi2Nb2O9, CBNO) are investigated. The piezoelectric properties of CBNO ceramics are significantly enhanced and the dielectric loss tan δ decreased. This makes poling using (LiCe) co-substitution easier. The ceramics (where □ represents A-site Ca2+ vacancies, possess a pure layered structure phase and no other phases can be found. The Ca0.88(LiCe)0.04□0.04Bi2Nb2O9 ceramics possess optimal piezoelectric properties, with piezoelectric coefficient (d33) and Curie temperature (TC) found to be 13.3 pC/N and 960 °C, respectively. The dielectric and piezoelectric properties of the (LiCe) co-substituted CBNO ceramics exhibit very stable temperature behaviours. This demonstrates that the CBNO ceramics are a promising candidate for ultrahigh temperature applications.
Origin and plasticity of the subdivisions of the inferior olivary complex.

PubMed

Hidalgo-Sánchez, Matías; Backer, Stéphanie; Puelles, Luis; Bloch-Gallego, Evelyne

2012-11-15

The precerebellar nuclei (PCN) originate from the rhombic lip, a germinal neuroepithelium adjacent to the roof plate of the fourth ventricle. We first report here that, in chicken, the Brn3a-expressing postmitotic medullary cells that produce the inferior olive (ION, the source of cerebellar climbing fibres) originate from a dorso-ventral domain roughly coinciding with the hindbrain vestibular column. Whereas Foxd3 expression labels the whole mature ION but is only detected in a subpopulation of ION neuroblasts initiating their migration, we report that Brn3a allows the visualization of the whole population of ION neurons from the very beginning of their migration. We show that Brn3a-positive neurons migrate tangentially ventralwards through a characteristic dorso-ventral double submarginal stream. Cath1 expressing progenitors lying just dorsal to the ION origin correlated dorso-ventral topography with the prospective cochlear column (caudal to it) and generate precerebellar nuclei emitting mossy-fiber cerebellar afferents. We used the chick-quail chimaera technique with homotopic grafts at HH10 to determine the precise fate map of ION precursors across the caudal cryptorhombomeric subdivisions of the medullary hindbrain (r8-r11). We demonstrate that each crypto-rhombomere contributes to two lamellae of the ION, while each ION sub-nucleus originates from at least two contiguous crypto-rhombomeres. We then questioned how rhombomere identity is related to the plasticity of cell type specification in the dorsal hindbrain. The potential plasticity of ectopically HH10 grafted ION progenitors to change their original fate in alternative rostrocaudal environments was examined. Heterotopic grafts from the presumptive ION territory to the pontine region (r4-r5) caused a change of fate, since the migrated derivatives adopted a pontine phenotype. The reverse experiment caused pontine progenitors to produce derivatives appropriately integrated into the ION complex. Grafts of ION progenitor domains to myelomeres (my) 2-3 also showed complete fate regulation, reproducing spinal cord-like structures, whereas the reverse experiment revealed the inability of my2-3 to generate ION cell types. This was not the case with more caudal, relatively less specified myelomeres (my5-6). Interestingly, when heterotopically grafted cells are integrated dorsally, they do not change their phenotype. Our results support the hypothesis that positional information present in the hindbrain and spinal cord at early neural tube stages controls the specific fates of ventrally migrating PCN precursors. Copyright © 2012 Elsevier Inc. All rights reserved.
The influence of A-site strontium ion in controlling the microstructure and electrical properties of P{sub 1−x}S{sub x}ZNZT ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Mupeng; Hou, Yudong, E-mail: ydhou@bjut.edu.cn; Yue, Yunge

2016-04-28

A Pb{sub 1−x}Sr{sub x}(Zn{sub 1/3}Nb{sub 2/3}){sub 0.2}(Zr{sub 0.5}Ti{sub 0.5}){sub 0.8}O{sub 3} (P{sub 1−x}S{sub x}ZNZT, 0.00 ≤ x ≤ 0.10) system was prepared through a conventional solid oxide process. Increasing addition of Sr{sup 2+} was found to induce a continuous decrease in grain size from 2.46 μm to 1.14 μm, accompanied by a phase transformation from coexisting rhombohedral and tetragonal phases to tetragonal phase only. The underlying mechanism of the evolution of dielectric and ferroelectric behavior in the P{sub 1−x}S{sub x}ZNZT ferroelectric ceramics was ascribed to the synergy between the grain size effect and the dilution of Pb-O covalency. Additionally, the grain sizemore » effect on domain wall displacement was found to be the main origin of the superior permittivity and piezoelectricity of the ceramics at intermediate grain size. The optimal electrical properties achieved for the P{sub 0.95}S{sub 0.05}ZNZT specimen at a grain size of about 1.79 μm, d{sub 33} = 465 pC/N, d{sub 33} × g{sub 33} = 11 047 × 10{sup −15} m{sup 2}/N make this material promising for multilayer energy harvesting device applications.« less
Comparison of Two Types of Double-J Ureteral Stents that Differ in Diameter and the Existence of Multiple Side Holes along the Straight Portion in Malignant Ureteral Strictures.

PubMed

Song, Myung Gyu; Seo, Tae-Seok; Lee, Chang Hee; Kim, Kyeong Ah; Kim, Jun Suk; Oh, Sang Cheul; Lee, Jae-Kwan

2015-06-01

This study was decided to evaluate the impact of diameter and the existences of multiple side holes along the straight portion of double-J ureteral stents (DJUS) on early dysfunction of stents placed for malignant ureteral strictures. Between April 2007 and December 2011, 141 DJUSs were placed via a percutaneous nephrostomy (PCN) tract in 110 consecutive patients with malignant ureteral strictures. 7F DJUSs with multiple side holes in the straight portion were placed in 58 ureters of 43 patients (Group 1). 8F DJUSs with three side holes in the proximal 2-cm of the straight portion were placed in 83 ureters of 67 patients (Group 2). The incidence of early DJUS dysfunction was compared between the two groups, and nephrostographic findings were evaluated in the cases of early dysfunction. Early dysfunction of the DJUS was noted in 14 of 58 patients (24.1 %) in Group 1, which was significantly higher (p = 0.001) than in Group 2 in which only 1 of 83 patients (1.2 %) had early dysfunction of the DJUS. Nephrostographic findings of early dysfunction included dilatation of the pelvicalyceal system, filling defects in the ureteral stent, and no passage of contrast media into the urinary bladder. In malignant ureteral strictures, multiple side holes in the straight portion of the 7-F DJUS seem to cause early dysfunction. The 8F DJUSs with three side holes in the proximal 2-cm of the straight portion may be superior at preventing early dysfunction.

Dynamics of Db isotopes formed in reactions induced by 238U, 248Cm, and 249Bk across the Coulomb barrier

NASA Astrophysics Data System (ADS)

Kaur, Gurjit; Sandhu, Kirandeep; Kaur, Amandeep; Sharma, Manoj K.

2018-05-01

The dynamical cluster decay model is employed to investigate the decay of *265Db and *267Db nuclei, formed in the 27Al+238U , 18O+249Bk , and 19F+248Cm hot fusion reactions at energies around the Coulomb barrier. First, the fission dynamics of the 27Al+238U reaction is explored by investigating the fragmentation and preformation yield of the reaction. The symmetric mass distribution of the fission fragments is observed for *265Db nucleus, when static β2 i deformations are used within hot optimum orientation approach. However, the mass split gets broaden for the use of β2 i-dynamical hot configuration of the fragments and becomes clearly asymmetric for the cold-static-deformed approach. Within the application of cold orientations of fragments, a new fission channel is observed at mass asymmetry η =0.29 . In addition to 238U-induced reaction, the work is carried out to address the fission and neutron evaporation cross sections of *267Db nucleus formed via 19F+248Cm and 18O+249Bk reactions, besides a comprehensive analysis of fusion and capture processes. Higher fusion cross sections and compound nucleus formation probabilities (PCN) are obtained for the 18O+249Bk reaction, as larger mass asymmetry in the entrance channel leads to reduced Coulomb factor. Finally, the role of sticking (IS) and nonsticking (INS) moments of inertia is analyzed for the 4 n and 5 n channels of *267Db nuclear system.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuoka, T., E-mail: ta-matsuoka@mg.ngkntk.co.jp; Kozuka, H.; Kitamura, K.

A (K,Na)NbO₃-based lead-free piezoelectric ceramic was successfully densified. It exhibited an enhanced electromechanical coupling factor of kₚ=0.52, a piezoelectric constant d₃₃=252 pC/N, and a frequency constant Nₚ=3170 Hz m because of the incorporation of an elaborate secondary phase composed primarily of KTiNbO₅. The ceramic's nominal composition was 0.92K₀.₄₂Na₀.₄₄Ca₀.₀₄Li₀.₀₂Nb₀.₈₅O₃–0.047K₀.₈₅Ti₀.₈₅Nb₁.₁₅O₅–0.023BaZrO₃ –0.0017Co₃O₄–0.002Fe₂O₃–0.005ZnO, abbreviated herein as KNN–NTK composite. The KNN–NTK ceramic exhibited a dense microstructure with few microvoids which significantly degraded its piezoelectric properties. Elemental maps recorded using transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM–EDS) revealed regions of high concentrations of Co and Zn inside the NTK phase. In addition, X-ray diffraction patternsmore » confirmed that a small portion of the NTK phase was converted into K₂(Ti,Nb,Co,Zn)₆O₁₃ or CoZnTiO₄ by a possible reaction between Co and Zn solutes and the NTK phase during a programmed sintering schedule. TEM studies also clarified a distortion around the KNN/NTK interfaces. Such an NTK phase filled voids between KNN particles, resulting in an improved chemical stability of the KNN ceramic. The manufacturing process was subsequently scaled to 100 kg per batch for granulated ceramic powder using a spray-drying technique. The properties of the KNN–NTK composite ceramic produced using the scaled-up method were confirmed to be identical to those of the ceramic prepared by conventional solid-state reaction sintering. Consequently, slight changes in the NTK phase composition and the distortion around the KNN/NTK interfaces affected the KNN–NTK composite ceramic's piezoelectric characteristics.« less
Compositional inhomogeneityand segregation in (K 0.5Na 0.5)NbO 3 ceramics

DOE PAGES

Chen, Kepi; Tang, Jing; Chen, Yan

2016-03-11

The effects of the calcination temperature of (K 0.5Na 0.5)NbO 3 (KNN) powder on the sintering and piezoelectric properties of KNN ceramics have been investigated in this report. KNN powders are synthesized via the solid-state approach. Scanning electron microscopy and X-ray diffraction characterizations indicate that the incomplete reaction at 700 °C and 750 °C calcination results in the compositional inhomogeneity of the K-rich and Na-rich phases while the orthorhombic single phase is obtained after calcination at 900 °C. During the sintering, the presence of the liquid K-rich phase due to the lower melting point has a significant impact on themore » densification, the abnormal grain growth and the deteriorated piezoelectric properties. From the standpoint of piezoelectric properties, the optimal calcination temperature obtained for KNN ceramics calcined at this temperature is determined to be 800 °C, with piezoelectric constant d 33=128.3 pC/N, planar electromechanical coupling coefficient k p=32.2%, mechanical quality factor Q m=88, and dielectric loss tan δ=2.1%.« less
Dielectric and electromechanical properties of rare earth calcium oxyborate piezoelectric crystals at high temperatures.

PubMed

Yu, Fapeng; Zhang, Shujun; Zhao, Xian; Yuan, Duorong; Qin, Lifeng; Wang, Qing-Ming; Shrout, Thomas R

2011-04-01

The electrical resistivity, dielectric, and electromechanical properties of ReCa(4)O(BO(3))(3) (ReCOB; Re = Er, Y, Gd, Sm, Nd, Pr, and La) piezoelectric crystals were investigated as a function of temperature up to 1000 °C. Of the studied crystals, ErCOB and YCOB were found to possess extremely high resistivity (p): p > 3 × 10(7) ω.cm at 1000 °C. The property variation in ReCOB crystals is discussed with respect to their disordered structure. The highest electromechanical coupling factor κ(26) and piezoelectric coefficient d(26) at 1000°C, were achieved in PrCOB crystals, with values being on the order of 24.7% and 13.1 pC/N, respectively. The high thermal stability of the electromechanical properties, with variation less than 25%, together with the low dielectric loss (<46%) and high mechanical quality factor (>1500) at elevated temperatures of 1000 °C, make ErCOB, YCOB, and GdCOB crystals promising for ultrahigh temperature electromechanical applications. © 2011 IEEE
Blood Perfusion in Microfluidic Models of Pulmonary Capillary Networks: Role of Geometry and Hematocrit

NASA Astrophysics Data System (ADS)

Stauber, Hagit; Waisman, Dan; Sznitman, Josue; Technion-IIT Team; Department of Neonatology Carmel Medical Center; Faculty of Medicine-Technion IIT Collaboration

2015-11-01

Microfluidic platforms are increasingly used to study blood microflows at true physiological scale due to their ability to overcome manufacturing obstacle of complex anatomical morphologies, such as the organ-specific architectures of the microcirculation. In the present work, we utilize microfluidic platforms to devise in vitro models of the underlying pulmonary capillary networks (PCN), where capillary lengths and diameters are similar to the size of RBCs (~ 5-10 μm). To better understand flow characteristics and dispersion of red blood cells (RBCs) in PCNs, we have designed microfluidic models of alveolar capillary beds inspired by the seminal ``sheet flow'' model of Fung and Sobin (1969). Our microfluidic PCNs feature confined arrays of staggered pillars with diameters of ~ 5,7 and 10 μm, mimicking the dense structure of pulmonary capillary meshes. The devices are perfused with suspensions of RBCs at varying hematocrit levels under different flow rates. Whole-field velocity patterns using micro-PIV and single-cell tracking using PTV are obtained with fluorescently-labelled RBCs and discussed. Our experiments deliver a real-scale quantitative description of RBC perfusion characteristics across the pulmonary capillary microcirculation.
Geoeffectiveness of Stream Interaction Regions during 2007-2008

NASA Astrophysics Data System (ADS)

Sanchez-Garcia, Elsa; Aguilar-Rodriguez, Ernesto; Ontiveros, Veronica

2016-07-01

The Stream Interaction Regions (SIRs) are generated in the interplanetary medium when a fast solar wind stream overtakes a slower one. If these large-scale phenomena interact with the Earth's magnetosphere they can give rise to geomagnetic storms (GSs). In this study we analyze the degree of geoeffectiveness of 20 events that were generated by SIRs. The events were observed during the 2007-2008 period that comprising the extended downward phase of solar cycle 23. The degree of geoeffectivity is measured using magnetic indices from different latitudes: PCN (Polar cap north), PCS (polar cap south), AA (antipodal amplitude), AE (Auroral Electrojet), Kp (estimated global index) and Dst (Disturbance storm time). We discuss some results on the correlation of these magnetic indices with the characteristics of shocks associated with the SIRs observed by STEREO-A/B, WIND and ACE spacecraft. All the 20 SIRs events generated GSs with Dst values in ranging from -86 nT up to -12 nT. Moreover, 6 out of the 20 events presented storm sudden commencement (SSC). We also discuss on the characteristics of the SIR-associated shocks and the intensity of the GSs.
Latitudinal features of Total Electron Content over the African and European longitude sector following the St. Patrick's day storm of 2015

NASA Astrophysics Data System (ADS)

Paul, A.; Kascheyev, A.; Rodriguez-Bouza, M.; Pathak, K.; Ferreira, A. A.; Shetti, D.; Yao, J. N.

2018-04-01

GNSS TEC values have been obtained from 18 stations distributed from the magnetic equator to nearly 80°N magnetic dip in the African and west-European longitude sector corresponding to the March 17-18, 2015 geomagnetic storm. Significantly depleted ionosphere have been observed at stations north of 50°N geographic on March 18, 2015 following the above storm over a longitude swath 11.9°-21°E covering the Eastern Africa and Western European longitude sector. High ROTI values were noted on March 17th at locations around 80°N magnetic dip. Two prominent peaks in PCN were noted around 09:00 UT and 14:00 UT on March 17, 2015 and around 15:00 UT on March 18, 2015. Daytime thermospheric (O/N2) ratio was markedly less on March 18th at latitudes above 60°N geographic which is suggested to be the major driver behind depleted high latitude ionosphere during the recovery phase of the storm on March 18, 2015.
Facile synthesis high nitrogen-doped porous carbon nanosheet from pomelo peel and as catalyst support for nitrobenzene hydrogenation

NASA Astrophysics Data System (ADS)

Zuo, Pingping; Duan, Jiaqi; Fan, Huailin; Qu, Shijie; Shen, Wenzhong

2018-03-01

Nitrogen-doping porous carbon-based nanosheets were fabricated from pemole peel and melamine through hydrothermal route and carbonization. The pomelo peel with sponge-like natural structure was employed as carbon source, and melamine was used both as nitrogen precursors and as nanosheet structure directing. The morphology and chemical composition of the obtained porous carbon nanosheet carbon materials were characterized by scanning electron microscopy, thermogravimetric analyzer, Fourier transform infrared spectra, transmission electron microscopy, BET surface area measurement, X-ray photoelectron spectroscopy and X-ray powder diffraction. The result indicated that the nanosheet thickness, nitrogen-doped amount and surface area were determined by the ratio of pomelo peel to melamine and carbonization temperature. The catalytic nitrobenzene hydrogenation was evaluated after Pd was loaded on nitrogen-doping porous carbon-based nanosheet. The results showed Pd@PCN had almost 100% conversion and good cycling performance towards the hydrogenation of nitrobenzene due to the developed pore structure, high nitrogen-doping and well dispersed less Pd particle; it was superior to other nanomaterial supports and demonstrated great potential application.
Radiation tolerance of piezoelectric bulk single-crystal aluminum nitride

DOE Office of Scientific and Technical Information (OSTI.GOV)

David A. Parks; Bernhard R. Tittmann

2014-07-01

For practical use in harsh radiation environments, we pose selection criteria for piezoelectric materials for nondestructive evaluation (NDE) and material characterization. Using these criteria, piezoelectric aluminum nitride is shown to be an excellent candidate. The results of tests on an aluminumnitride-based transducer operating in a nuclear reactor are also presented. We demonstrate the tolerance of single-crystal piezoelectric aluminum nitride after fast and thermal neutron fluences of 1.85 × 1018 neutron/cm2 and 5.8 × 1018 neutron/cm2, respectively, and a gamma dose of 26.8 MGy. The radiation hardness of AlN is most evident from the unaltered piezoelectric coefficient d33, which measured 5.5more » pC/N after a fast and thermal neutron exposure in a nuclear reactor core for over 120 MWh, in agreement with the published literature value. The results offer potential for improving reactor safety and furthering the understanding of radiation effects on materials by enabling structural health monitoring and NDE in spite of the high levels of radiation and high temperatures, which are known to destroy typical commercial ultrasonic transducers.« less
Tetragonal (K, Na)NbO3 based lead-free single crystal: Growth, full tensor properties, and their orientation dependence

NASA Astrophysics Data System (ADS)

Zheng, Limei; Wang, Junjun; Liu, Xuedong; Yang, Liya; Lu, Xiaoyan; Li, Yanran; Huo, Da; Lü, Weiming; Yang, Bin; Cao, Wenwu

2017-10-01

A Li and Ta modified (K, Na)NbO3 lead-free single crystal with a large size (13 × 10 × 20 mm3) has been grown by using the top-seeded solution growth method. The large size allows us to carry out an extensive study on this tetragonal crystal. We have measured a complete set of elastic, dielectric, and piezoelectric constants for the [001]C poled crystal with the single domain state. The crystal exhibits high shear piezoelectricity with d15 = 518 pC/N and k15 = 0.733, showing excellent potential in shear electro-sonic energy transformation devices. It is found that the high shear piezoelectricity originates from the vicinity of orthorhombic-tetragonal phase transition, which favors polarization rotation greatly. The orientation dependence of longitudinal dielectric, piezoelectric, and elastic constants and electromechanical coupling factor in the 3-dimentional space were calculated based on the single domain dataset. We believe that this work is of great importance for both fundamental studies and device designs for lead-free materials.
Origin of high piezoelectric activity in ferroelectric (K0.44Na0.52Li0.04)-(Nb0.84Ta0.1Sb0.06)O3 ceramics

NASA Astrophysics Data System (ADS)

Akdoǧan, E. K.; Kerman, K.; Abazari, M.; Safari, A.

2008-03-01

We study the temperature dependence of dielectric constant (K) and spontaneous polarization (Ps) in the range of -95-200°C. Cubic (C)-tetragonal (T) and T-orthorhombic (O) transitions are observed at 264 and 25°C, respectively. The Curie-Weiss temperature of C-T transition is 249°C, indicating it is first order. X-ray data indicate T-O phase coexistence at 25°C. A singularity in Ps at 25°C and a T-O phase coexistence spanning 25-31°C was observed, wherein Ps increases from 17×10-2C /m2 at 31°Cto23×10-2C/m2 25°C. The transition at 25°C appears diffusionless and polymorphic with martensite start and finish temperatures of 31 and 25°C, respectively. The maximum in d33 is 345pC/N and is attributed to the instability at 25°C, where Ps and K show singularity.
Development of a 20-MHz wide-bandwidth PMN-PT single crystal phased-array ultrasound transducer.

PubMed

Wong, Chi-Man; Chen, Yan; Luo, Haosu; Dai, Jiyan; Lam, Kwok-Ho; Chan, Helen Lai-Wa

2017-01-01

In this study, a 20-MHz 64-element phased-array ultrasound transducer with a one-wavelength pitch is developed using a PMN-30%PT single crystal and double-matching layer scheme. High piezoelectric (d 33 >1000pC/N) and electromechanical coupling (k 33 >0.8) properties of the single crystal with an optimized fabrication process involving the photolithography technique have been demonstrated to be suitable for wide-bandwidth (⩾70%) and high-sensitivity (insertion loss ⩽30dB) phased-array transducer application. A -6dBbandwidth of 91% and an insertion loss of 29dBfor the 20-MHz 64-element phased-array transducer were achieved. This result shows that the bandwidth is improved comparing with the investigated high-frequency (⩾20MHz) ultrasound transducers using piezoelectric ceramic and single crystal materials. It shows that this phased-array transducer has potential to improve the resolution of biomedical imaging, theoretically. Based on the hypothesis of resolution improvement, this phased-array transducer is capable for small animal (i.e. mouse and zebrafish) studies. Copyright © 2016 Elsevier B.V. All rights reserved.
The effect of polychlorinated naphthalenes and tributyltin on the occurrence of aberrant nuclei in erythroid cells of medaka

USGS Publications Warehouse

Talykina, Melaniya G.; Papoulias, Diana M.; Allert, J. Alan; Izyuov, Y.U.; Villalobos, Sergio A.; Giesy, John P.; Tillitt, Donald E.

2003-01-01

The micronucleus test using erythrocytes of the peripheral blood of fish is often conducted to evaluate the genotoxic effects of pollutants under experimental and natural conditions. This report presents information on the production of micronuclei and other nuclear anomalies in erythrocytes of medaka (Oryzias latipes) exposed to three polychlorinated naphthalene (PCN) formulations (Halowaxes 1014, 1031 and 1051) or tributyltin (TBT). Three types of deviation in the morphology of interphase nuclei were observed in medaka erythrocytes: micronuclei, nuclei fragmented into two equal or unequal parts, and nuclei at different stages of invagination. The number of erythrocytes with nuclear anomalies typically increased after chemical exposure. However, differential dose-response patterns were observed with exposures to PCNs or TBT. Polychlorinated naphthalenes caused genotoxicity, while TBT caused an amitotic effect. Gender did not influence the frequency of nuclear anomalies. This is the first report on the application of the piscine micronuclear test with medaka and is the first study that investigated the potential for detecting micronuclei in erythrocytes from adult medaka exposed in ovo to mutagens.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Kepi; Tang, Jing; Chen, Yan

The effects of the calcination temperature of (K 0.5Na 0.5)NbO 3 (KNN) powder on the sintering and piezoelectric properties of KNN ceramics have been investigated in this report. KNN powders are synthesized via the solid-state approach. Scanning electron microscopy and X-ray diffraction characterizations indicate that the incomplete reaction at 700 °C and 750 °C calcination results in the compositional inhomogeneity of the K-rich and Na-rich phases while the orthorhombic single phase is obtained after calcination at 900 °C. During the sintering, the presence of the liquid K-rich phase due to the lower melting point has a significant impact on themore » densification, the abnormal grain growth and the deteriorated piezoelectric properties. From the standpoint of piezoelectric properties, the optimal calcination temperature obtained for KNN ceramics calcined at this temperature is determined to be 800 °C, with piezoelectric constant d 33=128.3 pC/N, planar electromechanical coupling coefficient k p=32.2%, mechanical quality factor Q m=88, and dielectric loss tan δ=2.1%.« less
Comparison of Two Types of Double-J Ureteral Stents that Differ in Diameter and the Existence of Multiple Side Holes along the Straight Portion in Malignant Ureteral Strictures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Myung Gyu, E-mail: acube808@naver.com; Seo, Tae-Seok, E-mail: g1q1papa@korea.ac.kr; Lee, Chang Hee, E-mail: chlee86@korea.ac.kr

PurposeThis study was decided to evaluate the impact of diameter and the existences of multiple side holes along the straight portion of double-J ureteral stents (DJUS) on early dysfunction of stents placed for malignant ureteral strictures.MethodsBetween April 2007 and December 2011, 141 DJUSs were placed via a percutaneous nephrostomy (PCN) tract in 110 consecutive patients with malignant ureteral strictures. 7F DJUSs with multiple side holes in the straight portion were placed in 58 ureters of 43 patients (Group 1). 8F DJUSs with three side holes in the proximal 2-cm of the straight portion were placed in 83 ureters of 67more » patients (Group 2). The incidence of early DJUS dysfunction was compared between the two groups, and nephrostographic findings were evaluated in the cases of early dysfunction.ResultsEarly dysfunction of the DJUS was noted in 14 of 58 patients (24.1 %) in Group 1, which was significantly higher (p = 0.001) than in Group 2 in which only 1 of 83 patients (1.2 %) had early dysfunction of the DJUS. Nephrostographic findings of early dysfunction included dilatation of the pelvicalyceal system, filling defects in the ureteral stent, and no passage of contrast media into the urinary bladder.ConclusionsIn malignant ureteral strictures, multiple side holes in the straight portion of the 7-F DJUS seem to cause early dysfunction. The 8F DJUSs with three side holes in the proximal 2-cm of the straight portion may be superior at preventing early dysfunction.« less
A modified barbell-shaped PNN-PZT-PIN piezoelectric ceramic energy harvester

NASA Astrophysics Data System (ADS)

Gao, Xiangyu; Wu, Jingen; Yu, Yang; Dong, Shuxiang

2017-11-01

The quaternary system of relaxor-ferroelectric based Pb(Ni1/3Nb2/3)O3-Pb(ZrxTi1-x)O3-Pb(In0.5Nb0.5)O3 (PNN-PZT-PIN) piezoelectric ceramic at the morphotropic phase boundary was investigated via the solid reaction method. The optimized ceramic with excellent electric properties of ɛr = 8084, d33 = 977 pC/N, kp = 0.61, and Ec = 3.0 kV/cm was fabricated into d33-mode discs with separated surface electrodes, which were arranged in a series connection and, then as a piezo-stack, assembled into a barbell-shaped energy harvester that could bear a strong mechanical vibration. It is found that under a vibration mass-induced bending moment, the energy harvester produces an open circuit voltage of 26.4 Vp-p at the acceleration of 2.5 g at a load of 1.56 MΩ, which is two times higher in comparison to one without surface electrode separation. Its power output is 30 μW at the acceleration of 1 g and 104 μW at 2.5 g, which are even six times higher than that of a previously reported barbell-shaped energy harvester at room-temperature with the same acceleration. The enhanced power output can be attributed to (i) the excellent piezoelectric response of PNN-PZT-PIN ceramic and (ii) harvesting positive and negative charges from the separated surface electrodes other than a full surface electrode on piezoelectric discs under bending moment. Furthermore, the practical test was performed within a car engine, which shows that the PNN-PZT-PIN piezoelectric ceramic is a promising candidate for vibration energy harvesting.
Dielectric, Piezoelectric, and Vibration Properties of the LiF-Doped (Ba0.95Ca0.05)(Ti0.93Sn0.07)O₃ Lead-Free Piezoceramic Sheets.

PubMed

Cheng, Chien-Min; Chen, Kai-Huang; Lee, Da-Huei; Jong, Fuh-Cheng; Chen, Mei-Li; Chang, Jhih-Kai

2018-01-24

By the conventional solid state reaction method, a small amount of lithium fluoride (LiF) was used as the sintering promoter to improve the sintering and piezoelectric characteristics of (Ba 0.95 Ca 0.05 )(Ti 0.93 Sn 0.07 )O₃ (BCTS) lead-free piezoceramic sheets. Using X-ray diffraction (XRD) and a scanning electron microscope (SEM), the inferences of the crystalline and surface microstructures were obtained and analyzed. Then, the impedance analyzer and d 33 -meter were used to measure the dielectric and piezoelectric characteristics. In this study, the optimum sintering temperature of the BCTS sheets decreased from 1450 °C to 1390 °C due to LiF doping. For the 0.07 wt % LiF-doped BCTS sheets sintered at 1390 °C, the piezoelectric constant (d 33 ) is 413 pC/N, the electric-mechanical coupling coefficient (k p ) is 47.5%, the dielectric loss (tan δ) is 3.9%, and the dielectric constant (ε r ) is 8100, which are all close to or even better than that of the pure undoped BCTS ceramics. The Curie temperature also improved, from 85 °C for pure BCTS to 140 °C for BCTS-0.07 LiF sheets. Furthermore, by using the vibration system and fixing 1.5 g tip mass at the end of the sheets, as the vibration frequency is 20 Hz, the proposed piezoelectric ceramic sheets also reveal a good energy harvesting performance at the maximum output peak voltage of 4.6 V, which is large enough and can be applied in modern low-power electronic products.
Synchrotron microtomographic quantification of geometrical soil pore characteristics affected by compaction

NASA Astrophysics Data System (ADS)

Udawatta, Ranjith P.; Gantzer, Clark J.; Anderson, Stephen H.; Assouline, Shmuel

2016-05-01

Soil compaction degrades soil structure and affects water, heat, and gas exchange as well as root penetration and crop production. The objective of this study was to use X-ray computed microtomography (CMT) techniques to compare differences in geometrical soil pore parameters as influenced by compaction of two different aggregate size classes. Sieved (diameter < 2 mm and < 0.5 mm) and repacked (1.51 and 1.72 Mg m-3) Hamra soil cores of 5 by 5 mm (average porosities were 0.44 and 0.35) were imaged at 9.6 μm resolution at the Argonne Advanced Photon Source (synchrotron facility) using X-ray CMT. Images of 58.9 mm3 volume were analyzed using 3-Dimensional Medial Axis (3-DMA) software. Geometrical characteristics of the spatial distributions of pore structures (pore radii, volume, connectivity, path length, and tortuosity) were numerically investigated. Results show that the coordination number (CN) distribution and path length (PL) measured from the medial axis were reasonably fit by exponential relationships P(CN) = 10-CN/Co and P(PL) = 10-PL/PLo, respectively, where Co and PLo are the corresponding characteristic constants. Compaction reduced porosity, average pore size, number of pores, and characteristic constants. The average pore radii (63.7 and 61 µm; p < 0.04), largest pore volume (1.58 and 0.58 mm3; p = 0.06), number of pores (55 and 50; p = 0.09), and characteristic coordination number (3.74 and 3.94; p = 0.02) were significantly different between the low-density than the high-density treatment. Aggregate size also influenced measured geometrical pore parameters. This analytical technique provides a tool for assessing changes in soil pores that affect hydraulic properties and thereby provides information to assist in assessment of soil management systems.
Purification and characterization of antifungal phenazines from a fluorescent Pseudomonas strain FPO4 against medically important fungi.

PubMed

Gorantla, J N; Kumar, S Nishanth; Nisha, G V; Sumandu, A S; Dileep, C; Sudaresan, A; Kumar, M M Sree; Lankalapalli, R S; Kumar, B S Dileep

2014-09-01

The strain FPO4 was isolated from the rhizoplane of rice plant root and identified as a fluorescent Pseudomonas aeruginosa on the basis of 16S rDNA sequences and BLAST analysis. The extracellular metabolites produced by this strain were purified by silica gel column chromatography and isolated four pure compounds. Based on the spectral data the four compounds were identified as phenazin-1-ol, phenazine-1-carboxylic acid (PCA), 2-heptyl-3-hydroxyl-4(1H)-quinolone (PQS), and phenazine-1-carboxamide (PCN), respectively. Phenazin-1-ol and PCA were active against all the eight fungi tested. The highest activity of 4 μg/mL by PCA was recorded against Trichophyton rubrum, a human pathogen responsible for causing athlete's foot, jock itch, ringworm and fingernail fungus infections, followed by Candida albicans and Candida tropicalis. The activity of phenazin-1-ol, PCA against Candida spp. was found to be better than the standard antifungal agent amphotericin B. Furthermore, the present study reports the antimicrobial activity of the purified phenazines on major human pathogen, T. rubrum for the first time. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Piezoelectric Behaviour of Sputtered Aluminium Nitride Thin Film for High Frequency Ultrasonic Sensors

NASA Astrophysics Data System (ADS)

Herzog, T.; Walter, S.; Bartzsch, H.; Gittner, M.; Gloess, D.; Heuer, H.

2011-06-01

Many new materials and processes require non destructive evaluation in higher resolutions by phased array ultrasonic techniques in a frequency range up to 250 MHz. This paper presents aluminium nitride, a promising material for the use as a piezoelectric sensor material in the considered frequency range, which contains the potential for high frequency phased array application in the future. This work represents the fundamental development of piezoelectric aluminium nitride films with a thickness of up to 10 μm. We have investigated and optimized the deposition process of the aluminium nitride thin film layers regarding their piezoelectric behavior. Therefore a specific test setup and a measuring station were created to determine the piezoelectric charge constant (d33) and the electro acoustic behavior of the sensor. Single element transducers were deposited on silicon substrates with aluminium electrodes for top and bottom, using different parameters for the magnetron sputter process, like pressure and bias voltage. Afterwards acoustical measurements up to 500 MHz in pulse echo mode have been carried out and the electrical and electromechanical properties were qualified. In two different parameter sets for the sputtering process excellent piezoelectric charge constant of about 8.0 pC/N maximum were obtained.

A polyethylene glycol-assisted route to synthesize Pb(Ni 1/3Nb 2/3)O 3-PbTiO 3with improved electric properties

NASA Astrophysics Data System (ADS)

Ye, Yin; Yu, Shuhui; Huang, Haitao; Zhou, Limin

2007-07-01

Polyethylene glycol (PEG)-assisted solid state reaction route is employed to prepare the relaxor-type ferroelectric powders and ceramics of (1-x)Pb(Ni 1/3Nb 2/3)O 3-xPbTiO 3 (PNN-PT) with the morphotropic phase boundary (MPB) composition at x=0.36 (0.64PNN-0.36PT). PEG additive with the molecular weight of 200 is introduced into PNN-PT oxide precursors in order to obtain the perovskite phase. The XRD and TG/DSC results demonstrate that the interactions between PbO and PEG favor the transformation from the lead-rich pyrochlore to the lead-deficient pyrochlore, thus facilitating the formation of the perovskite. Consequently, nearly pure perovskite 0.64PNN-0.36PT powders are synthesized at a relatively low temperature of 850 °C. A significant improvement of electric properties of the ceramics sintered at 1200 °C is achieved by PEG modification. The dielectric constant at room temperature and the maximum dielectric constant at T c reach 4987 and 24307, respectively, at a frequency of 1 kHz. The piezoelectric constant d 33 is 460 pC/N.
Dielectric Dispersion, Diffuse Phase Transition, and Electrical Properties of BCT-BZT Ceramics Sintered at a Low-Temperature

NASA Astrophysics Data System (ADS)

Tian, Yongshang; Gong, Yansheng; Meng, Dawei; Li, Yuanjian; Kuang, Boya

2015-08-01

Lead-free ceramics 0.50Ba0.9Ca0.1TiO3-0.50BaTi1- x Zr x O3 (BCT-BZT) were prepared via sintering BCT and BZT nanoparticles, which were synthesized using a modified Pechini polymeric precursor method, at a low temperature of 1260°C. The relative densities of the ceramics prepared with different zirconium contents ( x) were all above 95.3%, reaching a maximum of 97% when x = 0.08. X-ray diffraction results confirmed the onset of phase transformation from orthorhombic to rhombohedral symmetry with increasing zirconium contents, and the polymorphic phase transition was observed at x = 0.10. The dielectric dispersion, diffuse phase transition (DPT), and relaxor-like ferroelectric characteristics as a function of zirconium content were thoroughly studied. Optimum physical properties, remnant polarization ( P r) = 16.4 μC/cm2, piezoelectric constant ( d 33) = ~240 pC/N, and electromechanical coupling factor ( k p) = 0.22, were obtained at x = 0.10. The findings of the current DPT behavior study of BCT-BZT ceramics are believed to be insightful to the development of ferroelectric materials.
Processing research and development of 'green' polymer nanoclay composites containing a polyhydroxybutyrate, vinyl acetates, and modified montmorillonite clay

NASA Astrophysics Data System (ADS)

McKirahan, James N., Jr.

The purpose of this research was to determine the feasibility of direct melt-blending (intercalation) montmorillonite nanoclay to polyhydroxybutyrate along with vinyl acetate, at different weight percentages, to enhance plasticization using typical plastic processing equipment and typical processing methodology. The purpose was to determine and compare the specific mechanical properties of tensile strength and flexural strength developed as a result from this processing. Single screw and twin screw extrusion, Banbury mixer compounding, and compression molding were used to intercalate montmorillonite, and for sample preparation purposes, to test tensile and flexural strength of the resultant polymer clay nanocomposites (PCN). Results indicate Polyhydroxybutyrate and Ethylene vinyl acetate, and weight percentages of 70%, 65% and 60% PHB, and 15%, 20%, and 25% of EVA, respectively, influenced mechanical properties. The resultant materials remained in a mostly amorphous state. The nanoclay, at specific weight percentage of 10%, acted as an antimicrobial and preservative for the materials produced during the research. The intention of the research was to promote knowledge and understanding concerning these materials and processes so technology transfer regarding the use, mechanical properties, manufacture, and process ability of these bio-friendly materials to academia, industry, and society can occur.
A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback: The PCN Incubation-Panarctic Thermal (PInc-PanTher) Scaling Approach

NASA Astrophysics Data System (ADS)

Koven, C. D.; Schuur, E.; Schaedel, C.; Bohn, T. J.; Burke, E.; Chen, G.; Chen, X.; Ciais, P.; Grosse, G.; Harden, J. W.; Hayes, D. J.; Hugelius, G.; Jafarov, E. E.; Krinner, G.; Kuhry, P.; Lawrence, D. M.; MacDougall, A.; Marchenko, S. S.; McGuire, A. D.; Natali, S.; Nicolsky, D.; Olefeldt, D.; Peng, S.; Romanovsky, V. E.; Schaefer, K. M.; Strauss, J.; Treat, C. C.; Turetsky, M. R.

2015-12-01

We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a 3-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100.
Laboratory Studies Of Astrophysically-interesting Phosphorus-bearing Molecules

NASA Astrophysics Data System (ADS)

Ziurys, Lucy M.; Halfen, D. T.; Sun, M.; Clouthier, D. J.

2009-05-01

Over the past year, there has been a renewed interest in the presence of phosphorus-containing molecules in the interstellar medium. Recent observations have increased the number of known interstellar phosphorus-bearing species from two (PN, CP) to six with the identification of HCP, CCP, and PH3 in the carbon-rich circumstellar shell of IRC+10216 and PO in the oxygen-rich envelope of VY Canis Majoris. More species of this type may be present in the ISM, but laboratory rest frequencies, necessary for such detections, are not generally known for many potential molecules. To fill in this gap, we have been conducting measurements of the pure rotational spectra of phosphorus-containing molecules of astrophysical interest, using both millimeter/submm direct absorption and Fourier transform microwave (FTMW) spectroscopy. We have developed a new phosphorus source for this purpose. These methods cover the frequency ranges 65-850 GHz and 4-40 GHz, respectively. Our recent study of the CCP radical (X2Πr) using both of these techniques has resulted in its identification in IRC+10216. Rotational spectra of other molecules such as PCN, HPS, and CH3PH2 have been recorded. We will report on these species and additional new laboratory developments
Low-Temperature Co-Fired Unipoled Multilayer Piezoelectric Transformers.

PubMed

Gao, Xiangyu; Yan, Yongke; Carazo, Alfredo Vazquez; Dong, Shuxiang; Priya, Shashank

2018-03-01

The reliability of piezoelectric transformers (PTs) is dependent upon the quality of fabrication technique as any heterogeneity, prestress, or misalignment can lead to spurious response. In this paper, unipoled multilayer PTs were investigated focusing on high-power composition and co-firing profile in order to provide low-temperature synthesized high-quality device measured in terms of efficiency and power density. The addition of 0.2 wt% CuO into Pb 0.98 Sr 0.02 (Mg 1/3 Nb 2/3 ) 0.06 (Mn 1/3 Nb 2/3 ) 0.06 (Zr 0.48 Ti 0.52 ) 0.88 O 3 (PMMnN-PZT) reduces the co-firing temperature from 1240 °C to 930 °C, which allows the use of Ag/Pd inner electrode instead of noble Pt inner electrode. Low-temperature synthesized material was found to exhibit excellent piezoelectric properties ( , , %, pC/N, and °C). The performance of the PT co-fired with Ag/Pd electrode at 930 °C was similar to that co-fired at 1240 °C with Pt electrode (25% reduction in sintering temperature). Both high- and low-temperature synthesized PTs demonstrated 5-W output power with >90% efficiency and 11.5 W/cm 3 power density.
Characterization of polychlorinated dibenzo-p-dioxins and dibenzofurans, dioxin-like polychlorinated biphenyls, and polychlorinated naphthalenes in the environment surrounding secondary copper and aluminum metallurgical facilities in China.

PubMed

Hu, Jicheng; Zheng, Minghui; Liu, Wenbin; Nie, Zhiqiang; Li, Changliang; Liu, Guorui; Xiao, Ke

2014-10-01

Unintentionally produced persistent organic pollutants (UP-POPs) were determined in ambient air from around five secondary non-ferrous metal processing plants in China, to investigate the potential impacts of the emissions of these plants on their surrounding environments. The target compounds were polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs). The PCDD/F, dl-PCB, and PCN concentrations in the ambient air downwind of the plants were 4.70-178, 8.23-7520 and 152-4190 pg/m(3), respectively, and the concentrations upwind of the plants were lower. Clear correlations were found between ambient air and stack gas concentrations of the PCDD/Fs, dl-PCBs, and PCNs among the five plants, respectively. Furthermore, the UP-POPs homolog and congener patterns in the ambient air were similar to the patterns in the stack gas samples. These results indicate that UP-POPs emissions from the plants investigated have obvious impacts on the environments surrounding the plants. Copyright © 2014 Elsevier Ltd. All rights reserved.
Aligned porous barium titanate/hydroxyapatite composites with high piezoelectric coefficients for bone tissue engineering.

PubMed

Zhang, Yan; Chen, Liangjian; Zeng, Jing; Zhou, Kechao; Zhang, Dou

2014-06-01

It was proposed that the piezoelectric effect played an important physiological role in bone growth, remodelling and fracture healing. An aligned porous piezoelectric composite scaffold was fabricated by freeze casting hydroxyapatite/barium titanate (HA/BT) suspensions. The highest compressive strength and lowest porosity of 14.5MPa and 57.4% with the best parallelism of the pore channels were achieved in the HA10/BT90 composite. HA30/BT70 and HA10/BT90 composites exhibited piezoelectric coefficient d33 of 1.2 and 2.8pC/N, respectively, both of which were higher than the piezoelectric coefficient of natural bone. Increase of the solid loading of the suspension and solidification velocity led to the improvement of piezoelectric coefficient d33. Meanwhile, double-templates resulted in the coexistence of lamellar pores and aligned macro-pores, exhibiting the ability to produce an oriented long-range ordered architecture. The manipulation flexibility of this method indicated the potential for customized needs in the application of bone substitute. An MTT assay indicated that the obtained scaffolds had no cytotoxic effects on L929 cells. Copyright © 2014 Elsevier B.V. All rights reserved.
Effect of Ca2+ Ions on Electrical Properties of Ba1-x Ca x Ti0.90Sn0.10O3-0.05Y2O3 Ceramics

NASA Astrophysics Data System (ADS)

Chen, Zhi-hui; Li, Zhi-wei; Ding, Jian-ning; Zhao, Tian-xiang; Qiu, Jian-hua; Zhu, Ke-qian; Xu, Jiu-jun; Zhang, Bing

2018-03-01

Ba1-x Ca x Ti0.90Sn0.10O3-0.05Y2O3 (BCTSY) lead-free piezoceramics with x = 0.02 to 0.10 have been fabricated by solid-state sintering method at 1420°C. The effects of Ca2+ ions on the microstructure and electrical properties of the samples were studied. X-ray diffraction analysis showed that all samples possessed pure perovskite structure with Ca2+ ions diffused into the matrix lattice. The rhombohedral phase and tetragonal phase coexisted in the composition range of 0.02 < x < 0.06. The microstructure of BCTSY ceramic became more homogeneous with addition of Ca2+ ions, and the average grain size of the samples decreased from 97 μm (x = 0.02) to 18 μm (x = 0.10). Addition of Ca2+ remarkably improved the piezoelectric properties, enhanced the dielectric frequency dispersion, and increased the Curie temperature of the ceramics. The piezoelectric properties of the ceramics were optimized at x = 0.04 with d 33 and K p values of 579 pC/N and 52.7%, respectively.
High-performance bio-piezoelectric nanogenerator made with fish scale

NASA Astrophysics Data System (ADS)

Ghosh, Sujoy Kumar; Mandal, Dipankar

2016-09-01

Energy harvesting performance of an efficient flexible bio-piezoelectric nanogenerator (BPNG) is demonstrated, where "bio-waste" transparent fish scale (FSC), composed of self-assembled and ordered collagen nano-fibrils, serves as a self-poled piezoelectric active component, exhibiting intrinsic piezoelectric strength of -5.0 pC/N. The dipolar orientation (˜19%) of the self-polarized FSC collagen is confirmed by the angular dependent near edge X-ray absorption fine structure spectroscopy. The BPNG is able to scavenge several types of ambient mechanical energies such as body movements, machine and sound vibrations, and wind flow which are abundant in living environment. Furthermore, as a power source, it generates the output voltage of 4 V, the short circuit current of 1.5 μA, and the maximum output power density of 1.14 μW/cm2 under repeated compressive normal stress of 0.17 MPa. In addition, serially integrated four BPNGs are able to produce enhanced output voltage of 14 V that turn on more than 50 blue light emitting diodes instantly, proving its essentiality as a sustainable green power source for next generation self-powered implantable medical devices as well as for personal portable electronics with reduced e-waste elements.
Effect of hydrated salts on the microstructure and phase transformation of poly(vinylidenefluoride-hexafluoropropylene) composites

NASA Astrophysics Data System (ADS)

Yuennan, Jureeporn; Sukwisute, Pisan; Muensit, Nantakan

2018-05-01

The present work has investigated a means of fabricating porous, β phase P(VDF-HFP) film by adding two kinds of hydrated metal salts. Without the use of mechanical stretching or electrical poling treatments, MgCl2 · 6H2O and AlCl3 · 6H2O are found to induce the formation of β phase crystals in porous film derived from the solution casting method. Trivalent Al ions have been found to effectively promote the self-oriented β phase of the P(VDF-HFP) film greater than divalent Mg ions. The overall β content is achieved about 38% and 42% for adding 0.25 wt% Mg- and Al-salts, respectively. The average pore sizes and surface roughness of porous P(VDF-HFP) films are increased with increasing salt concentration. The dielectric constant of about 5 for pure P(VDF-HFP) film (at 100 Hz) has been boosted up to 13–19 when adding the salts. In addition, the P(VDF-HFP) films filled with Al-salt exhibit the largest piezoelectric coefficient of 20 pC/N. Thus, the modified polymers are one of candidate materials for using in dielectric and piezoelectric applications.
Direct Ink Writing of Three-Dimensional (K, Na)NbO3-Based Piezoelectric Ceramics

PubMed Central

Li, Yayun; Li, Longtu; Li, Bo

2015-01-01

A kind of piezoelectric ink was prepared with Li, Ta, Sb co-doped (K, Na)NbO3 (KNN) powders. Piezoelectric scaffolds with diameters at micrometer scale were constructed from this ink by using direct ink writing method. According to the micro-morphology and density test, the samples sintered at 1100 °C for 2 h have formed ceramics completely with a high relative density of 98%. X-ray diffraction (XRD) test shows that the main phase of sintered samples is orthogonal (Na0.52K0.4425Li0.0375)(Nb0.87Sb0.07Ta0.06)O3. The piezoelectric constant d33 of 280 pC/N, dielectric constant ε of 1775, remanent polarization Pr of 18.8 μC/cm2 and coercive field Ec of 8.5 kV/cm prove that the sintered samples exhibit good electrical properties. The direct ink writing method allows one to design and rapidly fabricate piezoelectric structures in complex three-dimensional (3D) shapes without the need for any dies or lithographic masks, which will simplify the process of material preparation and offer new ideas for the design and application of piezoelectric devices. PMID:28788028
Study of the structure, dielectric and ferroelectric behavior of BaBi4+δTi4O15 ceramics

NASA Astrophysics Data System (ADS)

Khokhar, Anita; Goyal, Parveen K.; Thakur, O. P.; Sreenivas, K.

2016-05-01

The structure and ferroelectric properties of excess bismuth doped barium bismuth titanate BaBi4+δTi4O15 (δ = 2 - 10 wt.%)) ceramics prepared by solid-state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of a single phase material with a change in the orthorhombic distortion with varying excess of bismuth content. There is no change in the phase transition temperature (Tm) while the relaxor behaviour has been modified significantly with excess of bismuth doping. Saturated hysteresis loops with high remnant polarization (Pr ~ 12.5 µC/cm2), low coercive fields (Ec ~ 26 kV/cm) are measured and a high piezoelectric coefficient (d33 ~ 29 pC/N) is achieved in poled BaBi4Ti4O15 ceramics prepared with up to 8 wt.% of excess bismuth oxide. The improvement in the ferroelectric properties with increase in the excess bismuth content in BaBi4Ti4O15 ceramics has been explained in terms of changing oxygen vacancy concentration and structural relaxation. Tunable ferroelectric materials can be obtained by manipulating the doping amount of excess bismuth.
Molecular cloning and expression in Saccharomyces cerevisiae and Neurospora crassa of the invertase gene from Neurospora crassa.

PubMed

Carú, M; Cifuentes, V; Pincheira, G; Jiménez, A

1989-10-01

A plasmid (named pCN2) carrying a 7.6 kb BamHI DNA insert was isolated from a Neurospora crassa genomic library raised in the yeast vector YRp7. Saccharomyces cerevisiae suco and N. crassa inv strains transformed with pNC2 were able to grow on sucrose-based media and expressed invertase activity. Saccharomyces cerevisiae suco (pNC2) expressed a product which immunoreacted with antibody raised against purified invertase from wild type N. crassa, although S. cerevisiae suc+ did not. The cloned DNA hybridized with a 7.6 kb DNA fragment from BamHI-restricted wild type N. crassa DNA. Plasmid pNC2 transformed N. crassa Inv- to Inv+ by integration either near to the endogenous inv locus (40% events) or at other genomic sites (60% events). It appears therefore that the cloned DNA piece encodes the N. crassa invertase enzyme. A 3.8 kb XhoI DNA fragment, derived from pNC2, inserted in YRp7, in both orientation, was able to express invertase activity in yeast, suggesting that it contains an intact invertase gene which is not expressed from a vector promoter.
Post-activation of in situ Bsbnd F codoped g-C3N4 for enhanced photocatalytic H2 evolution

NASA Astrophysics Data System (ADS)

Cui, Yanjuan; Wang, Hao; Yang, Chuanfeng; Li, Ming; Zhao, Yimeng; Chen, Fangyan

2018-05-01

Porous graphitic carbon nitride polymer (p-CN-BF) with enhanced photoproduction of H2 from water was prepared by a two-step treatment process including in-situ Boron and fluorine codoping using [Emim]BF4 as dopants followed by post-calcination in air. Several techniques were employed to characterize the modified structure and elucidate the doping state of B and F. It was shown that in-situ doping method is necessary for efficient doping of heteroatoms into the molecular composition of CN. The difference of doping state of B and F was that B doping primary existing in the inside skeleton of CN, but F doping merely presents in the surface layer. The inside doped B made for the enhanced visible light absorption and the production of uniform porous structure during post-sintering process. By the synergistic effect of Bsbnd F codoping and post-activation, p-CN-BF showed much enhanced photoelectron generation, transmission and separation, therefore, it performs high photocatalytic activity for H2 evolution (351 μmol h-1), which was 13 and 5 times higher than samples only modified by Bsbnd F codoping (CN-BF) or post-annealing (P-CN).
Enhanced electrical properties of textured NBBT ceramics derived from the screen printing technique.

PubMed

Wu, Mengjia; Wang, Youliang; Wang, Dong; Li, Yongxiang

2011-10-01

(001)(pc)-oriented (Na(0.5)Bi(0.5))(0.94)Ba(0.06)TiO(3) (NBBT) lead-free piezoelectric ceramics were fabricated by the screen printing technique using Na(0.5)Bi(0.5)TiO(3) (NBT) templates. The plate-like NBT template particles were synthesized from bismuth layer-structured ferroelectric Bi(4)Ti(3)O(12) (BiT) precursors by the topochemical method. The screen printed NBBT ceramics with 20 wt% NBT templates contained a large fraction of grains aligned with their c-axis normal to the sample surface, giving a Lotgering factor of 0.486. The dielectric and ferroelectric properties of textured NBBT ceramics were anisotropic. Compared with the non-textured NBBT ceramics, the dielectric, ferroelectric, and piezoelectric properties of the textured NBBT ceramics were improved, giving a dielectric constant ϵ(T)(33)/ϵ(0) of 910, a remnant polarization P(r) of 29.2 μC/cm(2), a coercive field E(c) of 23.5 kV/cm, a piezoelectric coefficient d(33) of 180 pC/N, and a thickness-mode electromechanical coupling coefficient k(t) of 0.485.
Screening metal-organic frameworks for selective noble gas adsorption in air: effect of pore size and framework topology.

PubMed

Parkes, Marie V; Staiger, Chad L; Perry, John J; Allendorf, Mark D; Greathouse, Jeffery A

2013-06-21

The adsorption of noble gases and nitrogen by sixteen metal-organic frameworks (MOFs) was investigated using grand canonical Monte Carlo simulation. The MOFs were chosen to represent a variety of net topologies, pore dimensions, and metal centers. Three commercially available MOFs (HKUST-1, AlMIL-53, and ZIF-8) and PCN-14 were also included for comparison. Experimental adsorption isotherms, obtained from volumetric and gravimetric methods, were used to compare krypton, argon, and nitrogen uptake with the simulation results. Simulated trends in gas adsorption and predicted selectivities among the commercially available MOFs are in good agreement with experiment. In the low pressure regime, the expected trend of increasing adsorption with increasing noble gas polarizabilty is seen. For each noble gas, low pressure adsorption correlates with several MOF properties, including free volume, topology, and metal center. Additionally, a strong correlation exists between the Henry's constant and the isosteric heat of adsorption for all gases and MOFs considered. Finally, we note that the simulated and experimental gas selectivities demonstrated by this small set of MOFs show improved performance compared to similar values reported for zeolites.
Fabrication and Piezoelectric Properties of Textured (Bi1/2K1/2)TiO3 Ferroelectric Ceramics

NASA Astrophysics Data System (ADS)

Nagata, Hajime; Saitoh, Masahiro; Hiruma, Yuji; Takenaka, Tadashi

2010-09-01

Textured (Bi1/2K1/2)TiO3 (BKT) ceramics were prepared by a reactive templated grain growth (RTGG) method to improve their piezoelectric properties. Also, a hot-pressing (HP) method was modified on the basis of RTGG method to obtain dense ceramics and promote the grain orientation. The textured BKT ceramics prepared by the RTGG and HP methods exhibited a relatively high orientation factor F of 0.82 and a high density ratio of 95-99%. Scanning electron microscopy (SEM) micrographs of the textured HP-BKT indicated a textured and poreless microstructure. In addition, the resistivity of the textured HP-BKT was 1.73×1013 Ω·cm. The piezoelectric strain constant d33 determined by means of resonance and antiresonance method was 125 pC/N for the direction parallel to the sheet-stacking direction of the RTGG process. From the measurement of field-induced stain, the normalized d33* (=Smax/Emax) at 80 kV/cm were 127 and 238 pm/V on the randomly oriented and textured samples (F=0.82) for the (∥) direction, respectively.
An uncommon case of antegrade stent causing serious persistent haematuria

PubMed Central

Ejikeme, Chidozie M.

2015-01-01

Introduction Transient minor bleeding after nephrostomy tube placement is very common, occurring in up to 95% of cases. Often this is due to small vessel or venous bleeding. Severe post procedure bleeding requiring transfusion or other intervention is RARE. Presentation of case A case of a 79 year old man, who had antegrade stent insertion for 10 mm left upper ureteric stone. He was alright for up to one week but developed severe haemturia requiring three way catheter. Catheter was blocking regularly and needed to go to theatre for bladder washout. No source of bleeding was found in bladder. CT renal angiogram revealed his stent has migrated into the nephrostomy tract. He was taken to theatre and had his stent changed. His haematuria settled. Discussion The severe bleeding recorded in this case could not have been attributed to the stent, though the initial bleeding following the procedure has settled it seemed likely to blame vascular injury following PCN as the cause of bleeding. Subsequent CT scan was able to point at the right source of bleeding. Conclusion All possibilities should be considered when presented with a case severe bleeding following antegrade stent insertion. PMID:25797353
An uncommon case of antegrade stent causing serious persistent haematuria.

PubMed

Ejikeme, Chidozie M

2015-01-01

Transient minor bleeding after nephrostomy tube placement is very common, occurring in up to 95% of cases. Often this is due to small vessel or venous bleeding. Severe post procedure bleeding requiring transfusion or other intervention is RARE. A case of a 79 year old man, who had antegrade stent insertion for 10mm left upper ureteric stone. He was alright for up to one week but developed severe haemturia requiring three way catheter. Catheter was blocking regularly and needed to go to theatre for bladder washout. No source of bleeding was found in bladder. CT renal angiogram revealed his stent has migrated into the nephrostomy tract. He was taken to theatre and had his stent changed. His haematuria settled. The severe bleeding recorded in this case could not have been attributed to the stent, though the initial bleeding following the procedure has settled it seemed likely to blame vascular injury following PCN as the cause of bleeding. Subsequent CT scan was able to point at the right source of bleeding. All possibilities should be considered when presented with a case severe bleeding following antegrade stent insertion. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

Enhanced electrical properties, color-tunable up-conversion luminescence, and temperature sensing behaviour in Er-doped Bi3Ti1.5W0.5O9 multifunctional ferroelectric ceramics

NASA Astrophysics Data System (ADS)

Zhang, Ying; Li, Jun; Chai, Xiaona; Wang, Xusheng; Li, Yongxiang; Yao, Xi

2017-03-01

Er-doped Bi3Ti1.5W0.5O9 (BTW-x) ferroelectric ceramics were prepared by a conventional solid-state reaction synthesis method, and their structure, electrical properties, up-conversion (UC) luminescence, and temperature sensing behaviour were investigated. A high piezoelectric coefficient d33 (9.6 pC/N), a large remnant polarization Pr (12.75 μC/cm2), a high Curie temperature Tc (730.2 °C), and the optimal luminescent intensity are obtained for the samples at x = 0.05. By changing the Er doped concentration, the BTW-x ceramics are capable of generating various UC spectra and the color could be tunable from green to yellow. According to the fluorescence intensity ratio of green emissions at 532.6 nm and 549.2 nm in the temperature range from 83 K to 423 K, optical temperature sensing properties are investigated and the maximum sensing sensitivity is found to be 0.00314 K-1 at 423 K. The results conclude that BTW-x would be a candidate in high temperature sensor, fluorescence thermometry, and opto-electronic integration applications.
Effect of Ca2+ Ions on Electrical Properties of Ba1- x Ca x Ti0.90Sn0.10O3-0.05Y2O3 Ceramics

NASA Astrophysics Data System (ADS)

Chen, Zhi-hui; Li, Zhi-wei; Ding, Jian-ning; Zhao, Tian-xiang; Qiu, Jian-hua; Zhu, Ke-qian; Xu, Jiu-jun; Zhang, Bing

2018-07-01

Ba1- x Ca x Ti0.90Sn0.10O3-0.05Y2O3 (BCTSY) lead-free piezoceramics with x = 0.02 to 0.10 have been fabricated by solid-state sintering method at 1420°C. The effects of Ca2+ ions on the microstructure and electrical properties of the samples were studied. X-ray diffraction analysis showed that all samples possessed pure perovskite structure with Ca2+ ions diffused into the matrix lattice. The rhombohedral phase and tetragonal phase coexisted in the composition range of 0.02 < x < 0.06. The microstructure of BCTSY ceramic became more homogeneous with addition of Ca2+ ions, and the average grain size of the samples decreased from 97 μm ( x = 0.02) to 18 μm ( x = 0.10). Addition of Ca2+ remarkably improved the piezoelectric properties, enhanced the dielectric frequency dispersion, and increased the Curie temperature of the ceramics. The piezoelectric properties of the ceramics were optimized at x = 0.04 with d 33 and K p values of 579 pC/N and 52.7%, respectively.
Reaction of singlet-excited 2,3-diazabicyclo[2.2.2]oct-2-ene and tert-butoxyl radicals with aryl-substituted benzofuranones.

PubMed

Lundgren, Cecilia Vannesjö; Koner, Apurba L; Tinkl, Michael; Pischel, Uwe; Nau, Werner M

2006-03-03

5,7-Di-tert-butyl-3-aryl-3H-benzofuran-2-ones are lactones with potential antioxidant activity, owing to their abstractable benzylic C-H hydrogens. The fluorescence quenching of the azoalkane 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO), an established probe for the hydrogen-donor propensity of chain-breaking antioxidants, was investigated for 16 aryl-substituted benzofuranone derivatives [m,m-(CF3)2, p-CN, m-CN, p-CF3, p-COOCH3, m-CF3, p-Cl, p-F, H, m-CH3, p-CH3, m,p-(CH3)2, p-OCH3, o-CH3, o-CF3, o,m-(CH3)2]. Analysis of the rate data in terms of a linear free energy relationship yielded a reaction constant of rho = +0.35. This implies that n,pi*-excited DBO acts as nucleophilic species. In contrast, hydrogen abstraction of tert-butoxyl radicals from the benzofuranones was accelerated by electron-donating substituents (rho = -0.23), in conformity with the electrophilic character of oxygen-centered alkoxyl radicals. Possible implications for the optimization of the hydrogen-donor propensity of antioxidants through structural variation are discussed.
Self-Poling of BiFeO3 Thick Films.

PubMed

Khomyakova, Evgeniya; Sadl, Matej; Ursic, Hana; Daniels, John; Malic, Barbara; Bencan, Andreja; Damjanovic, Dragan; Rojac, Tadej

2016-08-03

Bismuth ferrite (BiFeO3) is difficult to pole because of the combination of its high coercive field and high electrical conductivity. This problem is particularly pronounced in thick films. The poling, however, must be performed to achieve a large macroscopic piezoelectric response. This study presents evidence of a prominent and reproducible self-poling effect in few-tens-of-micrometer-thick BiFeO3 films. Direct and converse piezoelectric measurements confirmed that the as-sintered BiFeO3 thick films yield d33 values of up to ∼20 pC/N. It was observed that a significant self-poling effect only appears in cases when the films are heated and cooled through the ferroelectric-paraelectric phase transition (Curie temperature TC ∼ 820 °C). These self-poled films exhibit a microstructure with randomly oriented columnar grains. The presence of a compressive strain gradient across the film thickness cooled from above the TC was experimentally confirmed and is suggested to be responsible for the self-poling effect. Finally, the macroscopic d33 response of the self-poled BiFeO3 film was characterized as a function of the driving-field frequency and amplitude.
Glutathione peroxidases of the potato cyst nematode Globodera Rostochiensis.

PubMed

Jones, J T; Reavy, B; Smant, G; Prior, A E

2004-01-07

We report the cloning and characterisation of full-length DNAs complementary to RNA (cDNAs) encoding two glutathione peroxidases (GpXs) from a plant parasitic nematode, the potato cyst nematode (PCN) Globodera rostochiensis. One protein has a functional signal peptide that targets the protein for secretion from animal cells while the other is predicted to be intracellular. Both genes are expressed in all parasite stages tested. The mRNA encoding the intracellular GpX is present throughout the nematode second stage juvenile and is particularly abundant in metabolically active tissues including the genital primordia. The mRNA encoding the secreted GpX is restricted to the hypodermis, the outermost cellular layer of the nematode, a location from which it is likely to be secreted to the parasite surface. Biochemical studies confirmed the secreted protein as a functional GpX and showed that, like secreted GpXs of other parasitic nematodes, it does not metabolise hydrogen peroxide but has a preference for larger hydroperoxide substrates. The intracellular protein is likely to have a role in metabolism of active oxygen species derived from internal body metabolism while the secreted protein may protect the parasite from host defences. Other functional roles for this protein are discussed.
Percepção astronómica de um grupo de alunos do ensino médio de uma escola da rede estadual de São Paulo

NASA Astrophysics Data System (ADS)

de Oliveria, E. F.; Voelzke, M. R.

2009-03-01

Sendo a Astronomia uma das cièncias mais antigas da humanidade, e considerando sua importáncia histórica e cultural, é de extrema releváncia que tópicos relacionados a ela sejam tratados nas escolas. Embora os Parámetros Curriculares Nacionais do Ensino Médio (PCN-EM) e as Orientaçiacute;es Complementares aos Parámetros (PCN+) apontem a importáncia de uma abordagem significativa de conceitos relacionados à Astronomia nas aulas de Física, muitos estudantes terminam o Ensino Médio (EM) sem compreender a razão de certos acontecimentos de origem celeste, ainda que estes façam parte de seu cotidiano e sejam alvos da curiosidade natural dos jovens. Da observação dessa curiosidade em alunos de uma escola pública paulista, na cidade de Suzano, surgiu o interesse em investigar os conhecimentos básicos em Astronomia dos alunos do Ensino Médio desta escola, constituindo-se este como principal objetivo desta pesquisa. Para tanto foi elaborado um questionário de múltipla escolha aplicado inicialmente a 34 alunos do primeiro ano e, posteriormente, a mais 310, distribuídos entre as très séries do Ensino Médio dos períodos matutino e noturno. Dessa forma, observou-se que 73,9% dos estudantes identificaram o Sol como sendo uma estrela, 67,1% mostraram compreender a sucessão entre dia e noite e 52,3% relacionaram o Big Bang à origem do Universo. Em contrapartida, apenas 34,5% relacionaram as estaçíes do ano à inclinação do eixo de rotação da Terra, 21,3% indicaram a influència gravitacional simultánea da Lua e do Sol como responsável pelo fenòmeno das marés, 24,5% indicaram corretamente quais são os objetos celestes mais próximos da Terra, 36,1% identificaram ano-luz como uma medida de distáncia e 34,2% reconheceram as estrelas cadentes como meteoros, evidenciando-se assim o pequeno discernimento dos estudantes quanto aos fenòmenos e termos astronòmicos do cotidiano. Além disso, foram comparadas as respostas de alun! os de diferentes séries e períodos, observando-se, dentre ou tras coi sas, que os estudantes do terceiro ano apresentam um percentual de acertos semelhante ao dos alunos do primeiro, caracterizando que a abordagem de tópicos relacionados à astronomia no Ensino Médio não tem contribuído de forma significativa para uma maior compreensão dos fenòmenos e conceitos.
Using online database for landslide susceptibility assessment with an example from the Veneto Region (north-eastern Italy).

NASA Astrophysics Data System (ADS)

Floris, Mario; Squarzoni, Cristina; Zorzi, Luca; D'Alpaos, Andrea; Iafelice, Maria

2010-05-01

Landslide susceptibility maps describe landslide-prone areas by the spatial correlation between landslides and related factors, derived from different kinds of datasets: geological, geotechnical and geomechanical maps, hydrogeological maps, landslides maps, vector and raster terrain data, real-time inclinometer and pore pressure data. In the last decade, thanks to the increasing use of web-based tools for management, sharing and communication of territorial information, many Web-based Geographical Information Systems (WebGIS) were created by local governments or nations, University and Research Centres. Nowadays there is a strong proliferation of geological WebGIS or GeoBrowser, allowing free download of spatial information. There are global Cartographical Portals that provide a free download of DTM and other vector data related to the whole planet (http://www.webgis.com). At major scale, there are WebGIS regarding entire nation (http://www.agiweb.org), or specific region of a country (http://www.mrt.tas.gov.au), or single municipality (http://sitn.ne.ch/). Moreover, portals managed by local government and academic government (http://turtle.ags.gov.ab.ca/Peace_River/Site/) or by a private agency (http://www.bbt-se.com) are noteworthy. In Italy, the first national projects for the creation of WebGIS and web-based databases begun during the 1980s, and evolved, through years, to the present number of different WebGIS, which have different territorial extensions: national (Italian National Cartographical Portal, http://www.pcn.minambiente.it; E-GEO Project, http://www.egeo.unisi.it), interregional (River Tiber Basin Authority, www.abtevere.it ), and regional (Veneto Region, www.regione.veneto.it). In this way we investigated most of the Italian WebGIS in order to verify their geographic range and the availability and quality of data useful for landslide hazard analyses. We noticed a large variability of the accessing information among the different browsers. In particular, the Trento and Bolzano Provinces Geobrowsers (http://www.provincia.bz.it; http://www.territorio.provincia.tn.it) provide a large availability of data respect to the other regional and interregional WebGIS, which generally allow only the download of topographic data. Recently, the Italian Institute for Environmental Protection and Research, ISPRA (Istituto Superiore per la Protezione e la ricerca Ambientale), makes available and free usable the Italian Inventory of Landslides (IFFI Project). The inventory contains information derived from the census of all the instability phenomena in Italy, offering a base-cognitive instrument for the landslide hazard evaluation. For the landslide hazard assessment it is essential to evaluate the real effectiveness of the available data. Hence, we test the effectiveness of the web databases to evaluate the landslides susceptibility in the Euganean Hill Regional Park (185.5 km2), located at SE of Padua (Veneto Region, Italy). We used data available from three online spatial databases: Veneto Region Cartographic Portal (http://www.regione.veneto.it), for vector terrain data at 1:5000 scale; the IFFI archive (http://www.sinanet.apat.it), for information concerning landslides; and the National Cartographic Portal of the Italian Ministry of Environment (http://www.pcn.minambiente.it), for the multi-temporal orthophotos. The landslide susceptibility was evaluated using a simple probabilistic analysis considering the relationships between landslides and DEM-derived factors, such as slope, curvature and aspect. For the validation of the analysis, we made a spatial test by subdividing the study area in two sectors: training area and test area. The obtained results show that the actual no-completeness of online available spatial databases related to the Veneto Region allows only regional and medium scale (>1:25,000) susceptibility analysis. Data about lithology, land use, groundwater and others relevant factors are absent. In addition, the lack of data on the temporal evolution of the landslides permits only a spatial analysis, impeding a complete evaluation of the landslide hazard.
Study of xCo0.8Ni0.2Fe2O4+(1-x) Pb0.99625 La0.0025Zr0.55Ti0.45O3 magnetoelectric composites

NASA Astrophysics Data System (ADS)

Dipti; Singh, Sangeeta; Juneja, J. K.; Raina, K. K.; Kotnala, R. K.; Prakash, Chandra

2016-06-01

We are reporting here, the studies of the structural, dielectric, ferroelectric and magnetic properties of magnetoelectric composites of La modified lead zirconate titanate (PLZT) and Ni modified cobalt ferrite (CNFO) with compositional formula xCo0.8Ni0.2Fe2O4+(1-x) Pb0.99625La0.0025Zr0.55Ti0.45O3 (x=0.00, 0.05, 0.10, 0.15 and 1.00 by weight) prepared by the solid state reaction method. Coexistence of both the phases in composites was confirmed by X-Ray diffraction technique. The microstructure and average grain size were determined from Scanning Electron Micrograph (SEM) in backscattered mode. Both the phases could be observed clearly. The variations of dielectric properties with frequency and temperature were also studied. P-E and M-H hysteresis measurements were carried. Magnetoelectric coupling (ME) coefficient for samples with x=0.05 and 0.10 were measured as a function of DC magnetic field. Maximum value of ME coefficient (1.2 mV/cm Oe) and piezoelectric coefficient (96 pC/N) for x=0.05 were observed.
Analysis of survival and hatching transcriptomes from potato cyst nematodes, Globodera rostochiensis and G. pallida.

PubMed

Duceppe, Marc-Olivier; Lafond-Lapalme, Joël; Palomares-Rius, Juan Emilio; Sabeh, Michaël; Blok, Vivian; Moffett, Peter; Mimee, Benjamin

2017-06-20

Potato cyst nematodes (PCNs), Globodera rostochiensis and G. pallida, cause important economic losses. They are hard to manage because of their ability to remain dormant in soil for many years. Although general knowledge about these plant parasitic nematodes has considerably increased over the past decades, very little is known about molecular events involved in cyst dormancy and hatching, two key steps of their development. Here, we have studied the progression of PCN transcriptomes from dry cysts to hatched juveniles using RNA-Seq. We found that several cell detoxification-related genes were highly active in the dry cysts. Many genes linked to an increase of calcium and water uptake were up-regulated during transition from dormancy to hydration. Exposure of hydrated cysts to host plant root exudates resulted in different transcriptional response between species. After 48 h of exposure, G. pallida cysts showed no significant modulation of gene expression while G. rostochiensis had 278 differentially expressed genes. The first G. rostochiensis significantly up-regulated gene was observed after 8 h and was coding for a transmembrane metalloprotease. This enzyme is able to activate/inactivate peptide hormones and could be involved in a cascade of events leading to hatching. Several known effector genes were also up-regulated during hatching.
Atomic Iron Catalysis of Polysulfide Conversion in Lithium-Sulfur Batteries.

PubMed

Liu, Zhenzhen; Zhou, Lei; Ge, Qi; Chen, Renjie; Ni, Mei; Utetiwabo, Wellars; Zhang, Xiaoling; Yang, Wen

2018-06-13

Lithium-sulfur batteries have been regarded as promising candidates for energy storage because of their high energy density and low cost. It is a main challenge to develop long-term cycling stability battery. Here, a catalytic strategy is presented to accelerate reversible transformation of sulfur and its discharge products in lithium-sulfur batteries. This is achieved with single-atomic iron active sites in porous nitrogen-doped carbon, prepared by polymerizing and carbonizing diphenylamine in the presence of iron phthalocyanine and a hard template. The Fe-PNC/S composite electrode exhibited a high discharge capacity (427 mAh g -1 ) at a 0.1 C rate after 300 cycles with the Columbic efficiency of above 95.6%. Besides, the electrode delivers much higher capacity of 557.4 mAh g -1 at 0.5 C over 300 cycles. Importantly, the Fe-PCN/S has a smaller phase nucleation overpotential of polysulfides than nitrogen-doped carbon alone for the formation of nanoscale of Li 2 S as revealed by ex situ SEM, which enhance lithium-ion diffusion in Li 2 S, and therefore a high rate performance and remarkable cycle life of Li-sulfur batteries were achieved. Our strategy paves a new way for polysulfide conversion with atomic iron catalysis to exploit high-performance lithium-sulfur batteries.
Investigation of structural, ferroelectric, piezoelectric and dielectric properties of Ba0.92Ca0.08TiO3-BaTi0.96Zr0.04O3 lead-free electroceramics

NASA Astrophysics Data System (ADS)

Keswani, Bhavna C.; Patil, S. I.; Kolekar, Y. D.

2018-04-01

Lead free ferroelectric with composition 0.55Ba0.92Ca0.08TiO3-0.45BaTi0.96Zr0.04O3 (BCT8-BZT4) was synthesized by solid state reaction method and investigated their structural, ferroelectric, piezoelectric and dielectric properties. X-ray diffraction analysis shows that BCT8-BZT4 ceramic possess both tetragonal (space group P4mm) and orthorhombic (space group Amm2) crystal structure which was further confirmed from Raman spectra spectroscopy. The micronized grains were observed from scanning electron micrographs while the presence of polarization-electric field hysteresis loop confirms ferroelectric nature of BCT8-BZT4 ceramic. Higher values of maximum polarization (Pmax = 22.27 μC/cm2), remnant polarization (Pr = 11.61 μC/cm2), coercive electric field (Ec = 4.77 kV/cm) and direct piezoelectric coefficient (d33) approximately 185 pC/N were observed. The real part of dielectric constant with frequency shows the usual dielectric dispersion behaviour at RT. The observed properties show that the lead free BCT8-BZT4 ceramic is suitable for ferroelectric memory device, piezoelectric sensor, capacitor, etc. applications.
Influence of Europium Doping on Various Electrical Properties of Low-Temperature Sintered 0.5Ba0.90Ca0.10TiO3-0.5BaTi0.88Zr0.12O3-0.1%CuO- xEu Lead-Free Ceramics

NASA Astrophysics Data System (ADS)

Tian, Yongshang; Li, Shuiyun; Sun, Shulin; Gong, Yansheng; Li, Tiantian; Yu, Yongshang; Jing, Qiangshan

2018-01-01

0.5Ba0.90Ca0.10TiO3-0.5BaTi0.88Zr0.12O3-0.1%CuO- xEu (BCT-BZT-Cu- xEu; x = 0-0.90%) lead-free ceramics were sintered at 1220°C with as-synthesized nanoparticles by a modified Pechini method. The structural characteristics and electrical properties of the ceramics that were influenced by varying europium-doping were investigated. All the ceramics featured high densification (relative density: ˜ 96%). X-ray powder diffraction results indicated the samples possessed pure orthorhombic phase. The maximum relative permittivity ( ɛ r, 10869) was found at x around 0.30%. Europium ions could dope on different substitution sites in the ABO3 lattice, which evidently influenced electrical properties with various volumes of oxygen vacancy. Moreover, the formation mechanisms of oxygen vacancy and defect electron complexes were stated. The piezoelectric properties were impacted by defect electron complexes, internal stress, ionic electronegativity, etc. The optimal electrical properties, i.e., d 33 = 384 pC/N, Q m = 92, and k p = 0.36, were detected at x = 0.45%.
Structure and electrical properties of intergrowth bismuth layer-structured Bi4Ti3O12-CaBi4Ti4O15 ferroelectric ceramics

NASA Astrophysics Data System (ADS)

Choi, Gi Ppeum; Cho, Sam Yeon; Bu, Sang Don

2016-09-01

Pb-free ferroelectric Bi4Ti3O12-CaBi4Ti4O15 (BIT-CBT) ceramics were manufactured using a solid-state reaction method. Structural analysis by using X-ray diffraction confirmed the presence of a second phase of Bi2Ti2O7, and the surface depth X-ray diffraction analysis revealed that this phase existed only on the surface. This second phase appears to have been caused by the volatilization of Bi ions at high sintering temperatures. For resolution of the issue of volatilization of Bi ions and manufacture of BIT-CBT ceramics with a single phase, Bi2O3 powder was added to the BIT-CBT mixture, and a powder-bed method, in which pellets were covered with BIT-CBT powder, was used to manufacture the ceramic. The piezoelectric coefficient of the single-phase BIT-CBT ceramics was 12.4 pC/N while the residual polarization and the coercive electric field were 11.3 μC/cm2, and 125 kV/cm, respectively. The results suggest that single-phase BIT-CBT ceramics are suitable for the manufacture of elements incorporating these electrical characteristics.
A primary care based healthy-eating and active living education session for weight reduction in the pre-diabetic population.

PubMed

Weir, Daniala L; Johnson, Steven T; Mundt, Clark; Bray, Dianne; Taylor, Lorian; Eurich, Dean T; Johnson, Jeffrey A

2014-12-01

Many studies have demonstrated the effectiveness of primary prevention strategies in type 2 diabetes, however, questions remain around the feasibility of high resource, intensive interventions within a healthcare setting. We report the results of a dietitian-led pre-diabetes education session targeting healthy eating and active living as strategies for weight reduction. Participants were asked to complete a baseline questionnaire prior to completing the pre-diabetes education session and were sent follow-up questionnaires at 3 and 6 months. Differences between participants at baseline, 3 and 6 months were determined using χ(2), t-tests and ANOVA. Of the 211 participants asked to fill out baseline questionnaires, 45 participants completed questionnaires at baseline, 3 months and 6 months. Although we observed general trends towards improvements in diet, physical activity and weight related behaviours among the 45 completers, no significant changes were observed among participants between questionnaire periods. A "one-off", theory-guided group education session may be insufficient to support lifestyle modifications in the context of weight management in a pre-diabetic population. Further evaluation of the efficacy and feasibility of the PCN as a setting for lifestyle intervention is required. Copyright © 2014 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.
Emissions of Selected Semivolatile Organic Chemicals from Forest and Savannah Fires.

PubMed

Wang, Xianyu; Thai, Phong K; Mallet, Marc; Desservettaz, Maximilien; Hawker, Darryl W; Keywood, Melita; Miljevic, Branka; Paton-Walsh, Clare; Gallen, Michael; Mueller, Jochen F

2017-02-07

The emission factors (EFs) for a broad range of semivolatile organic chemicals (SVOCs) from subtropical eucalypt forest and tropical savannah fires were determined for the first time from in situ investigations. Significantly higher (t test, P < 0.01) EFs (μg kg -1 dry fuel, gas + particle-associated) for polycyclic aromatic hydrocarbons (∑ 13 PAHs) were determined from the subtropical forest fire (7,000 ± 170) compared to the tropical savannah fires (1,600 ± 110), due to the approximately 60-fold higher EFs for 3-ring PAHs from the former. EF data for many PAHs from the eucalypt forest fire were comparable with those previously reported from pine and fir forest combustion events. EFs for other SVOCs including polychlorinated biphenyl (PCB), polychlorinated naphthalene (PCN), and polybrominated diphenyl ether (PBDE) congeners as well as some pesticides (e.g., permethrin) were determined from the subtropical eucalypt forest fire. The highest concentrations of total suspended particles, PAHs, PCBs, PCNs, and PBDEs, were typically observed in the flaming phase of combustion. However, concentrations of levoglucosan and some pesticides such as permethrin peaked during the smoldering phase. Along a transect (10-150-350 m) from the forest fire, concentration decrease for PCBs during flaming was faster compared to PAHs, while levoglucosan concentrations increased.
Temperature characteristics of SAW resonators on Sc0.26Al0.74N/polycrystalline diamond heterostructures

NASA Astrophysics Data System (ADS)

Sinusía Lozano, M.; Chen, Z.; Williams, Oliver A.; Iriarte, G. F.

2018-07-01

Surface acoustic wave (SAW) resonators have been fabricated on a 2 μm scandium aluminium nitride (ScAlN) film deposited by means of pulsed-DC reactive magnetron sputtering on a 5.8 μm polycrystalline diamond substrate. Thin film characterization comprised of the assessment of the thin film texture by means of x-ray diffraction (XRD) measurements, reporting highly c-axis oriented ScAlN thin films with a full width at half maximum (FWHM) of the ω-θ scans below 2°. Compositional and piezoelectric analyses of the thin films synthesized with the sputtering parameters used in this work, namely a sputtering power of 700 W and a synthesis pressure of 0.53 Pa, have reported a thin film composition of Sc0.26Al0.74N together with a piezoelectric d33 constant of ‑11 pC/N. Finally, a SAW resonator has been characterized using a vector network analyser (VNA) under various substrate temperature conditions with two iterations. The resulting temperature coefficient of frequency (TCF) values show a highly linear behaviour within two temperature ranges, namely from 20 K to room temperature (300 K) (‑12.5 ppm/K) as well as from 300 K up to 450 K (‑34.6 ppm/K).
Enhancement of piezoelectric constants induced by cation-substitution and two-dimensional strain effects on ZnO predicted by density functional perturbation theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, Kaoru, E-mail: n-kaoru@criepi.denken.or.jp; Higuchi, Sadao; Ohnuma, Toshiharu

2016-03-21

Using density functional perturbation theory, we investigated the effect of various substitutional dopant elements and in-plane strain on the piezoelectric properties of ZnO. The piezoelectric stress constant e{sub 33} of doped ZnO was found to depend on the formal charge of the substitutional dopant. By decomposing the piezoelectric stress constant e{sub 33} into the individual atomic contributions, the change in the piezoelectric properties was found to originate from a change in the coupling between the atomic displacement and the strain. Furthermore, we found that in-plane tensile strain along the a axis, which is specific to the thin film, can enhancemore » the piezoelectric constant of ZnO. A phase transition from wurtzite to h-BN-type structure was found to occur with increasing in-plane tensile. The piezoelectric strain constant d{sub 33} was predicted to reach ∼200 pC/N for 2.78 at. % V-substituted ZnO at 5.5% in-plane strain, just before the phase transition. These theoretical results suggest that the piezoelectric constant of ZnO can be enhanced by controlling the in-plane strain via selection of the substrate material and dopant element.« less
Cold sintering and electrical characterization of lead zirconate titanate piezoelectric ceramics

NASA Astrophysics Data System (ADS)

Wang, Dixiong; Guo, Hanzheng; Morandi, Carl S.; Randall, Clive A.; Trolier-McKinstry, Susan

2018-01-01

This paper describes a cold sintering process for Pb(Zr,Ti)O3 ceramics and the associated processing-property relations. Pb(Zr,Ti)O3 has a very small, incongruent solubility that is a challenge during cold sintering. To circumvent this, a Pb(NO3)2 solution was used as the transient liquid phase. A bimodal lead zirconate titanate powder was densified to a relative density of 89% by cold sintering at 300 °C and 500 MPa. After the cold sintering step, the permittivity was 200, and the dielectric loss was 2.0%. A second heat-treatment involving a 3 h anneal at 900 °C increased the relative density to 99%; the resulting relative dielectric permittivity was 1300 at room temperature and 100 kHz. The samples showed well-defined ferroelectric hysteresis loops, having a remanent polarization of 28 μC/cm2. On poling, the piezoelectric coefficient d33 was ˜200 pC/N. With a 700 °C 3 h post-annealing, samples show a lower room temperature relative permittivity (950 at 100 kHz), but a 24 h hold time at 700 °C produces ceramics where there is an improved relative dielectric constant (1050 at 100 kHz).
Investigation to synthesis more isotopes of superheavy nuclei Z = 118

NASA Astrophysics Data System (ADS)

Manjunatha, H. C.; Sridhar, K. N.

2018-07-01

We have studied the α-decay properties of superheavy nuclei Z = 118 in the range 275 ≤ A ≤ 325. Most of the predicted, unknown nuclei in the range 291 ≤ A ≤ 301 were found to have α-decay chains. Of these the nuclei 293-301118 were found to have long half-lives and hence could be sufficient to detect them if synthesized in a laboratory. Fusion barries for different projectile-target combinations to synthesis superheavy nuclei Z = 118 are studied and are also represented in simple relations. We have also studied the evaporation residue cross section, compound nucleus formation probability (PCN) and survival probability (PSurv) of different projectile-target combinations to synthesis superheavy element Z = 118. The selected most probable projectile-target combinations are Ca+Cf, Ti+Cm, Sc+Bk, V+Am, Cr+Pu, Fe+U, Mn+Np, Ni+Th and Kr+Pb. We have formulated simple relations for maximum evaporation residue cross sections and its corresponding energies. This helps to identify the projectile-target combinations quickly. Hence, we have identified the most probable projectile-target combinations to synthesis these superheavy nuclei. We hope that our predictions may be a guide for the future experiments in the synthesis of more isotopes of superheavy nuclei Z = 118.
Unleashing the Full Sustainable Potential of Thick Films of Lead-Free Potassium Sodium Niobate (K0.5Na0.5NbO3) by Aqueous Electrophoretic Deposition.

PubMed

Mahajan, Amit; Pinho, Rui; Dolhen, Morgane; Costa, M Elisabete; Vilarinho, Paula M

2016-05-31

A current challenge for the fabrication of functional oxide-based devices is related with the need of environmental and sustainable materials and processes. By considering both lead-free ferroelectrics of potassium sodium niobate (K0.5Na0.5NbO3, KNN) and aqueous-based electrophoretic deposition here we demonstrate that an eco-friendly aqueous solution-based process can be used to produce KNN thick coatings with improved electromechanical performance. KNN thick films on platinum substrates with thickness varying between 10 and 15 μm have a dielectric permittivity of 495, dielectric losses of 0.08 at 1 MHz, and a piezoelectric coefficient d33 of ∼70 pC/N. At TC these films display a relative permittivity of 2166 and loss tangent of 0.11 at 1 MHz. A comparison of the physical properties between these films and their bulk ceramics counterparts demonstrates the impact of the aqueous-based electrophoretic deposition (EPD) technique for the preparation of lead-free ferroelectric thick films. This opens the door to the possible development of high-performance, lead-free piezoelectric thick films by a sustainable low-cost process, expanding the applicability of lead-free piezoelectrics.

Nanoscale insight of high piezoelectricity in high-TC PMN-PH-PT ceramics

NASA Astrophysics Data System (ADS)

Zhu, Rongfeng; Zhang, Qihui; Fang, Bijun; Zhang, Shuai; Zhao, Xiangyong; Ding, Jianning

2018-03-01

The piezoelectric properties of the high-Curie temperature (high-TC) 0.15Pb(Mg1/3Nb2/3)O3-0.38PbHfO3-0.47PbTiO3 (0.15PMN-0.38PH-0.47PT) ceramics prepared by three different methods were compared. The 0.15PMN-0.38PH-0.47PT ceramics synthesized by the partial oxalate route exhibit the optimum properties, in which d33* = 845.3 pm/V, d33 = 456.2 pC/N, Kp = 67.2%, and TC = 291 °C. The nanoscale origin of the high piezoelectric response of the 0.15PMN-0.38PH-0.47PT ceramics was investigated by piezoresponse force microscopy (PFM) using the ceramics synthesized by the partial oxalate route. Large quantities of fine stripe submicron ferroelectric domains are observed, which form large island domains. In order to give further insights into the piezoelectric properties of the 0.15PMN-0.38PH-0.47PT ceramics from a microscopic point of view, the local poling experiments and local switching spectroscopy piezoresponse force microscopy (SS-PFM) were investigated, from which the local converse piezoelectric coefficient d33*(l) is calculated as 220 pm/V.
Dielectric, Piezoelectric and Variable Range Hopping Conductivity Studies of Bi0.5(Na, K)0.5TiO3 Ceramics

NASA Astrophysics Data System (ADS)

Pattipaka, Srinivas; James, A. R.; Dobbidi, Pamu

2018-04-01

We report a detailed study on the structural, microstructural, piezoelectric, dielectric and AC conductivity of Bi0.5(Na1-x K x )0.5TiO3 (BNKT; x = 0, 0.1, 0.2 and 0.3) ceramics fabricated by a conventional solid-state reaction method. XRD and Raman analysis revealed that Bi0.5(Na0.8K0.2)0.5TiO3 and Bi0.5(Na0.7K0.3)0.5TiO3 ceramics exhibit a mixture of rhombohedral and tetragonal structures. The segregation of K at the grain boundary was confirmed by transmission electron microscopy and is related to typical microstructural local compositional mapping analysis. Two transitions, at ˜ 330°C and 150°C, observed from the ɛ' versus T curve in pure BNT are associated with the ferroelectric tetragonal to paraelectric cubic phase (T C) and ferroelectric rhombohedral to ferroelectric tetragonal phase (T d), respectively. Further, the T C and T d shifted towards the lower temperature with a rise in K concentration. Frequency dispersion of T d and T C suggest that BNKT ceramics exhibit a weak relaxor behavior with diffuse phase transition, which is confirmed by Uchino-Nomura criteria and the Vogel-Fulcher law. The AC resistivity ρ ac(T) follows the Mott variable range hopping conduction mechanism. A significant enhancement of dielectric and piezoelectric properties were observed for x = 0.2 system: dielectric constant (ɛ' = 1273), dielectric loss (tanδ = 0.047) at 1 kHz, electromechanical coupling coefficients (k ij : k 33, k t ˜ 60%, k 31 ˜ 62% and k p ˜ 46%), elastic coupling coefficients ( S_{33}D = 6.40 × 10-13 m2/N and S_{33}E = 10.06 × 10-13 m2/N) and piezoelectric constants (d 33 = 64.23 pC/N and g 33 = 5.69 × 10-3 Vm/N).
Dielectric, Piezoelectric and Variable Range Hopping Conductivity Studies of Bi0.5(Na, K)0.5TiO3 Ceramics

NASA Astrophysics Data System (ADS)

Pattipaka, Srinivas; James, A. R.; Dobbidi, Pamu

2018-07-01

We report a detailed study on the structural, microstructural, piezoelectric, dielectric and AC conductivity of Bi0.5(Na1- x K x )0.5TiO3 (BNKT; x = 0, 0.1, 0.2 and 0.3) ceramics fabricated by a conventional solid-state reaction method. XRD and Raman analysis revealed that Bi0.5(Na0.8K0.2)0.5TiO3 and Bi0.5(Na0.7K0.3)0.5TiO3 ceramics exhibit a mixture of rhombohedral and tetragonal structures. The segregation of K at the grain boundary was confirmed by transmission electron microscopy and is related to typical microstructural local compositional mapping analysis. Two transitions, at ˜ 330°C and 150°C, observed from the ɛ' versus T curve in pure BNT are associated with the ferroelectric tetragonal to paraelectric cubic phase ( T C) and ferroelectric rhombohedral to ferroelectric tetragonal phase ( T d), respectively. Further, the T C and T d shifted towards the lower temperature with a rise in K concentration. Frequency dispersion of T d and T C suggest that BNKT ceramics exhibit a weak relaxor behavior with diffuse phase transition, which is confirmed by Uchino-Nomura criteria and the Vogel-Fulcher law. The AC resistivity ρ ac( T) follows the Mott variable range hopping conduction mechanism. A significant enhancement of dielectric and piezoelectric properties were observed for x = 0.2 system: dielectric constant ( ɛ' = 1273), dielectric loss (tan δ = 0.047) at 1 kHz, electromechanical coupling coefficients ( k ij : k 33, k t ˜ 60%, k 31 ˜ 62% and k p ˜ 46%), elastic coupling coefficients ( S_{33}D = 6.40 × 10-13 m2/N and S_{33}E = 10.06 × 10-13 m2/N) and piezoelectric constants ( d 33 = 64.23 pC/N and g 33 = 5.69 × 10-3 Vm/N).
Synchrotron Microtomographic Quantification of Geometrical Soil Pore Characteristics Affected by Compaction

NASA Astrophysics Data System (ADS)

Udawatta, Ranjith; Gantzer, Clark; Anderson, Stephen; Assouline, Shmuel

2015-04-01

Soil compaction degrades soil structure and affects water, heat, and gas exchange as well as root penetration and crop production. The objective of this study was to use X-ray computed microtomography (CMT) techniques to compare differences in geometrical soil pore parameters as influenced by compaction of two different aggregate size classes. Sieved (diam. < 2mm and < 0.5mm) and repacked (1.51 and 1.72 Mg m-3) Hamra soil cores of 5- by 5-mm (average porosities were 0.44 and 0.35) were imaged at 9.6-micrometer resolution at the Argonne Advanced Photon Source (synchrotron facility) using X-ray computed microtomography. Images of 58.9 mm3 volume were analyzed using 3-Dimensional Medial Axis (3DMA) software. Geometrical characteristics of the spatial distributions of pore structures (pore radii, volume, connectivity, path length, and tortuosity) were numerically investigated. Results show that the coordination number (CN) distribution and path length (PL) measured from the medial axis were reasonably fit by exponential relationships P(CN)=10-CN/Co and P(PL)=10-PL/PLo, respectively, where Co and PLo are the corresponding characteristic constants. Compaction reduced porosity, average pore size, number of pores, and characteristic constants. The average pore radii (64 and 61 μm; p<0.04), largest pore volume (1.6 and 0.6 mm3; p=0.06), number of pores (55 and 50; p=0.09), characteristic coordination number (6.3 and 6.0; p=0.09), and characteristic path length number (116 and 105; p=0.001) were significantly greater in the low density than the high density treatment. Aggregate size also influenced measured geometrical pore parameters. This analytical technique provides a tool for assessing changes in soil pores that affect hydraulic properties and thereby provides information to assist in assessment of soil management systems.
Synchrotron microtomographic quantification of geometrical soil pore characteristics affected by compaction

NASA Astrophysics Data System (ADS)

Udawatta, R. P.; Gantzer, C. J.; Anderson, S. H.; Assouline, S.

2015-07-01

Soil compaction degrades soil structure and affects water, heat, and gas exchange as well as root penetration and crop production. The objective of this study was to use X-ray computed microtomography (CMT) techniques to compare differences in geometrical soil pore parameters as influenced by compaction of two different aggregate size classes. Sieved (diam. < 2 mm and < 0.5 mm) and repacked (1.51 and 1.72 Mg m-3) Hamra soil cores of 5- by 5 mm (average porosities were 0.44 and 0.35) were imaged at 9.6-micrometer resolution at the Argonne Advanced Photon Source (synchrotron facility) using X-ray computed microtomography. Images of 58.9 mm3 volume were analyzed using 3-Dimensional Medial Axis (3DMA) software. Geometrical characteristics of the spatial distributions of pore structures (pore radii, volume, connectivity, path length, and tortuosity) were numerically investigated. Results show that the coordination number (CN) distribution and path length (PL) measured from the medial axis were reasonably fit by exponential relationships P(CN) = 10-CN/Co and P(PL) = 10-PL/PLo, respectively, where Co and PLo are the corresponding characteristic constants. Compaction reduced porosity, average pore size, number of pores, and characteristic constants. The average pore radii (63.7 and 61 μm; p < 0.04), largest pore volume (1.58 and 0.58 mm3; p = 0.06), number of pores (55 and 50; p = 0.09), characteristic coordination number (6.32 and 5.94; p = 0.09), and characteristic path length number (116 and 105; p = 0.001) were significantly greater in the low density than the high density treatment. Aggregate size also influenced measured geometrical pore parameters. This analytical technique provides a tool for assessing changes in soil pores that affect hydraulic properties and thereby provides information to assist in assessment of soil management systems.
Determining change of bathymetry with GPR method in Ordu-Giresun, a sea-filled airport in the Black Sea, Turkey

NASA Astrophysics Data System (ADS)

Kadioglu, Selma; Kagan Kadioglu, Yusuf

2016-04-01

Ordu-Giresun (OGU) is a newly-constructed airport, the first sea-filled airport in Turkey and in Europe, and the second airport in the world after Osaca-Japan. The airport is between Gulyalı district in Ordu city and Piraziz district in Giresun city in Black Sea -Turkey. A protection breakwater has been constructed by filling a rock approximately 7.435-m long and with an average height of 5.5 m. Then, the Black Sea has been filled until 1 m over the sea level, approximately the area is 1.770.000 m2 wide and includes a runway, aprons and taxiway covered by breakwater. The runway has a 1-m thickness, 3-km length and 45-m width, PCN84 strength, and stone mastic asphalt surface. The aprons has a 240 x 110 m length and PCN110 strength, the taxiway is 250 x 24 m wide. The airport was started to be constructed in July 2011 and it began to serve on 22th May 2015. The aim of this study was to determine the depth of the rock-filled layer and the amount of sinking of the bathymetry which has been determined before filling processing. In addition, before bathymetry determination, unconsolidated sediments had been removed from the bottom of the sea. There were four drilling points to control the sinking of the bathymetry. Therefore, six suitable Ground Penetrating Radar (GPR) profiles were measured, crossing these points with runway and aprons, using 250-MHz and 100-MHz shielded antennas. Starting points of the profiles were in the middle of the runway to merge between depth and thickness changing of the filled layer and bathymetry along the profiles. Surface topography changing was measured spaced 1 m apart with 1 cm sensitivity on each profile. At the same time, similarly the topography changing, bathymetry coordinates was re-arranged along the each profile. Topography corrections were applied to the processed radargrams and then the bottom boundary lines of the rock-filled layer were determined. The maximum height was 3.5 m according to the sea level, which was on the middle point of the runway, representing zero depth of the radargrams of the profiles. To determine the amount of the sinking of the rock filled layer, the first sea level were lined at 3.5 m in depth on the right side depth axes of the radargrams. The second, bathymetry changing lines were placed on the interested radargrams. Finally, differences between the bottom boundary lines of the filled layer and bathymetry lines were compared. The results showed that GPR method could be applied successfully to determine the depth of the rock filled layer in Black Sea and the small amount of the sinking of the bathymetry. Acknowledgement This project has been supported by Cengiz - Içtaş Joint Venture-Turkey. This study is a contribution to the EU funded COST action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" (www.GPRadar.eu, www.cost.eu).
Program (systems) engineering

NASA Technical Reports Server (NTRS)

Baroff, Lynn E.; Easter, Robert W.; Pomphrey, Richard B.

2004-01-01

Program Systems Engineering applies the principles of Systems Engineering at the program level. Space programs are composed of interrelated elements which can include collections of projects, advanced technologies, information systems, etc. Some program elements are outside traditional engineering's physical systems, such as education and public outreach, public relations, resource flow, and interactions within the political environments.
Evidences of extracellular abiotic degradation of hexadecane through free radical mechanism induced by the secreted phenazine compounds of P. aeruginosa NY3.

PubMed

Nie, Hongyun; Nie, Maiqian; Wang, Lei; Diwu, Zhenjun; Xiao, Ting; Qiao, Qi; Wang, Yan; Jiang, Xin

2018-03-02

The aim of this work was to investigate the effects of secreted extracellular phenazine compounds (PHCs) on the degradation efficiency of alkanes by P. aeruginosa NY3. Under aerobic conditions, the PHCs secreted by P. aeruginosa NY3 initiate the oxidation of alkanes outside cells, in coupling with some reducing agents, such as β-Nicotinamide adenine dinucleotide, reduced disodium salt (NADH) or reduced glutathione (GSH). This reaction might be via free radical reactions similar to Fenton Oxidation Reaction (FOR). P. aeruginosa NY3 secretes pyocyanin (Pyo), 1-hydroxyphenazine (HPE), phenazine-1-carboxylic acid (PCA), and phenazine-1-amide (PCN) simultaneously. The cell-free extracellular fluid containing these four PHCs degrades hexadecane effectively. The observation of Electron Spin Resonance (EPR) signals of superoxide anion radical (O 2 - ), hydroxyl radical (OH) and/or carbon free radicals (R) both in vivo and in vitro suggested the degradation of hexadecane could be via a free radical pathway. Secretion of PHCs has been found to be characteristic of Pseudomonas which is often involved in or related to the degradation of organic pollutants. Our work suggested that certain organic contaminants may be oxidized through ubiquitously extracellular abiotic degradation by the free radicals produced during bio-remediation and bio-treatment. Copyright © 2018. Published by Elsevier Ltd.
The fabrication and characterization of barium titanate/akermanite nano-bio-ceramic with a suitable piezoelectric coefficient for bone defect recovery.

PubMed

Shokrollahi, H; Salimi, F; Doostmohammadi, A

2017-10-01

In recent years, due to the controllable mechanical properties and degradation rate, calcium silicates such as akermanite (Ca 2 MgSi 2 O 7 ) with Ca-Mg and Si- containing bio-ceramics have received much more attention. In addition, the piezoelectric effect plays an important role in bone growth, remodeling and defect healing. To achieve our objective, the porous bioactive nano-composite with a suitable piezoelectric coefficient was fabricated by the freeze-casting technique from the barium titanate and nano-akermanite (BT/nAK) suspension. The highest d 33 of 4pC/N was obtained for BT90/nAK10. The compressive strength and porosity were for BT75/nAK25 and BT60/nAK40 at the highest level, respectively. The average pore channel diameter was 41 for BT75/nAK25. Interestingly enough, the inter-connected pore channel was observed in the SEM images. There was no detectable transformation phase in the XRD pattern for the BT/nAK composites. The manipulation flexibility of this method indicated the potential for the customized needs in the application of bone substitutes. An ((3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide)) MTT assay indicated that the obtained scaffolds have no cytotoxic effects on the human bone marrow mesenchymal stem cells. Copyright © 2017 Elsevier Ltd. All rights reserved.
Understanding the role of A-site and B-site cations on piezoelectric instability in lead--free (1-x) BaTiO3 -- xA(Cu1/3Nb2/3)O3 (A = Sr, Ca, Ba) solid solutions

NASA Astrophysics Data System (ADS)

Maurya, Deepam; Zhou, Yuan; Priya, Shashank

2013-03-01

This study provides fundamental understanding of the enhanced piezoelectric instability in lead-free piezoelectric (1-x) BaTiO3-xA(Cu1/3Nb2/3) O3(A: Sr, Ba and Ca and x = 0.0-0.03) solid solutions. These compositions were found to exhibit large longitudinal piezoelectric constant (d33) of ~330 pC/N and electromechanical planar coupling constant (kp) ~ 46% at room temperature. The X-ray diffraction coupled with atomic pair distribution functions (PDF)s indicated increase in local polarization. Raman scattering and electron paramagnetic resonance (EPR) analysis revealed that substitutions on A and B-site both substantially perturbed the local octahedral dynamics and resulted in localized nano polar regions with lower symmetry. The presence of nano domains and local structural distortions smears the Curie peak resulting in diffuse order-disorder type phase transitions. The effect of these distortions on the variations in physical property was modeled and analyzed within the context of nanodomains and phase transitions. *spriya@vt.edu The financial support from National Science Foundation and Office of Basic Energy Science, Department of Energy (Microscopy analysis) is gratefully acknowledged. The authors would also like to acknowledge the support from KIMS (new piezoelectric)
Compositional dependence of phase structure and electrical properties in (K0.42Na0.58)NbO3-LiSbO3 lead-free ceramics

NASA Astrophysics Data System (ADS)

Wu, Jiagang; Xiao, Dingquan; Wang, Yuanyu; Zhu, Jianguo; Yu, Ping; Jiang, Yihang

2007-12-01

(1-x)(K0.42Na0.58)NbO3-xLiSbO3 [(1-x)KNN-xLS] lead-free piezoelectric ceramics were prepared by the conventional mixed oxide method. The compositional dependence of the phase structure and the electrical properties of the ceramics were studied. A morphotropic phase boundary (MPB) between the orthorhombic and tetragonal phases was identified in the composition range of 0.04
Effects of PbO-B2O3 Glass Doping on the Sintering Temperature and Piezoelectric Properties of 0.35Pb (Ni1/3Nb2/3)O3-0.65Pb(Zr0.41Ti0.59)O3 Ceramics

NASA Astrophysics Data System (ADS)

Yi, Jinqiao; Shen, Meng; Liu, Sisi; Jiang, Shenglin

2015-12-01

0.35Pb(Ni1/3Nb2/3)O3-0.65Pb(Zr0.41Ti0.59)O3 (PNN-PZT) ceramics doped with 0.5PbO-0.5B2O3 glass have been synthesized by the conventional solid-state sintering technique. The effects of 0.5PbO-0.5B2O3 glass on the sintering temperature and piezoelectric properties of PNN-PZT ceramics were studied. The results indicated that the sintering temperature of PNN-PZT was significantly reduced due to the incorporation of 0.5PbO-0.5B2O3 glass dopant. When the content of 0.5PbO-0.5B2O3 glass was 0.5 wt.%, the sintering temperature of PNN-PZT was observed to reduce from above 1200°C to 920°C while the samples maintained high density (7.91 g/cm3), excellent piezoelectric constant ( d 33 = 479 pC/N), large electromechanical coupling coefficient ( K p = 0.55), and relatively low electromechanical quality factor ( Q m = 79). Moreover, large dielectric constant ( ɛ 33 T / ɛ 0 = 2904) and low dielectric loss (tan δ = 0.0166) were obtained in this work.
A characteristic scale for cold gas

NASA Astrophysics Data System (ADS)

McCourt, Michael; Oh, S. Peng; O'Leary, Ryan; Madigan, Ann-Marie

2018-02-01

We find that clouds of optically thin, pressure-confined gas are prone to fragmentation as they cool below ∼106 K. This fragmentation follows the lengthscale ∼cstcool, ultimately reaching very small scales (∼0.1 pc/n), as they reach the temperature ∼104 K at which hydrogen recombines. While this lengthscale depends on the ambient pressure confining the clouds, we find that the column density through an individual fragment Ncloudlet ∼ 1017 cm-2 is essentially independent of environment; this column density represents a characteristic scale for atomic gas at 104 K. We therefore suggest that 'clouds' of cold, atomic gas may, in fact, have the structure of a mist or a fog, composed of tiny fragments dispersed throughout the ambient medium. We show that this scale emerges in hydrodynamic simulations, and that the corresponding increase in the surface area may imply rapid entrainment of cold gas. We also apply it to a number of observational puzzles, including the large covering fraction of diffuse gas in galaxy haloes, the broad-line widths seen in quasar and AGN spectra and the entrainment of cold gas in galactic winds. While our simulations make a number of assumptions and thus have associated uncertainties, we show that this characteristic scale is consistent with a number of observations, across a wide range of astrophysical environments. We discuss future steps for testing, improving and extending our model.
Study of the structure, dielectric and ferroelectric behavior of BaBi{sub 4+δ}Ti{sub 4}O{sub 15} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khokhar, Anita, E-mail: mails4anita@gmail.com, E-mail: goyalphy@gmail.com; Goyal, Parveen K., E-mail: mails4anita@gmail.com, E-mail: goyalphy@gmail.com; Sreenivas, K.

2016-05-23

The structure and ferroelectric properties of excess bismuth doped barium bismuth titanate BaBi{sub 4+δ}Ti{sub 4}O{sub 15} (δ = 2 - 10 wt.%)) ceramics prepared by solid-state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of a single phase material with a change in the orthorhombic distortion with varying excess of bismuth content. There is no change in the phase transition temperature (T{sub m}) while the relaxor behaviour has been modified significantly with excess of bismuth doping. Saturated hysteresis loops with high remnant polarization (P{sub r} ~ 12.5 µC/cm{sup 2}), low coercive fields (E{sub c} ~ 26 kV/cm) aremore » measured and a high piezoelectric coefficient (d{sub 33} ~ 29 pC/N) is achieved in poled BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics prepared with up to 8 wt.% of excess bismuth oxide. The improvement in the ferroelectric properties with increase in the excess bismuth content in BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics has been explained in terms of changing oxygen vacancy concentration and structural relaxation. Tunable ferroelectric materials can be obtained by manipulating the doping amount of excess bismuth.« less
Piezoelectric and dielectric characterization of corona and contact poled PZT-epoxy-MWCNT bulk composites

NASA Astrophysics Data System (ADS)

Banerjee, S.; Cook-Chennault, K. A.; Du, W.; Sundar, U.; Halim, H.; Tang, A.

2016-11-01

Three-phase lead zirconate titanate (PZT, PbZr0.52Ti0.48O3)-epoxy-multi-walled carbon nanotube (MWCNT) bulk composites were prepared, where the volume fraction of PZT was held constant at 30%, while the volume fraction of the MWCNTs was varied from 1.0%-10%. The samples were poled using either a parallel plate contact or contactless (corona) poling technique. The piezoelectric strain coefficient (d33), dielectric constant (ɛ), and dielectric loss tangent (tan δ) of the samples were measured at 110 Hz, and compared as a function of poling technique and volume fraction of MWCNTs. The highest values for dielectric constant and piezoelectric strain coefficients were 465.82 and 18.87 pC/N for MWCNT volume fractions of 10% and 6%, respectively. These values were obtained for samples that were poled using the corona contactless method. The impedance and dielectric spectra of the composites were recorded over a frequency range of 100 Hz-20 MHz. The impedance values observed for parallel-plate contact poled samples are higher than that of corona poled composites. The fractured surface morphology and distribution of the PZT particles and MWCNTs were observed with the aid of electron dispersion spectroscopy and a scanning electron microscope. The surface morphology of the MWCNTs was observed with the aid of a field emission transmission electron microscope.
Dielectric and piezoelectric properties of lead-free Ba0.85Ca0.15Ti0.9-xZr0.1CuxO3 ceramics synthesized by a hydrothermal method

NASA Astrophysics Data System (ADS)

Hunpratub, Sitchai; Phokha, Sumalin; Maensiri, Santi; Chindaprasirt, Prinya

2016-04-01

Ba0.85Ca0.15Ti0.9Zr0.1-xCuxO3 (BCTZC) nanopowders were synthesized using a hydrothermal method after which they were pressed into discs and sintered in air at 1300 °C for 3 h to form ceramic samples. The phase and microstructure of the powder and ceramic samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results indicated that the ceramic samples exhibited a tetragonal structure and that CuO, BaZrO3 or CaTiO3 impurity phases, which had been present in the powder samples, were not observed. The average grain sizes in the ceramic samples were found to be 17.0, 16.1, 20.0, 18.1 and 19.6 μm for Cu mole fractions x of 0.002, 0.004, 0.006, 0.008 and 0.01, respectively. The dielectric constants, ferroelectric hysteresis loops and piezoelectric charge coefficients of the BCZTC ceramic samples were also investigated. Optimum values for the relative dielectric constant (ɛ‧), tan δ and piezoelectric charge coefficient (d33) of the samples were 3830, 0.03 and 306 pC/N, respectively, in the Cu mole fraction samples with x = 0.002.
Influence of sintering temperature on properties of BNKLLT-6 wt% BCTZ binary lead-free piezoelectric ceramic prepared through the solid-state combustion technique

NASA Astrophysics Data System (ADS)

Kornphom, Chittakorn; Laowanidwatana, Artid; Bongkarn, Theerachai

2017-03-01

In this work, a new binary 94 wt%[Bi0.5(Na0.68K0.22Li0.1)0.5TiO3 + 0.10 wt% of La2O3]-6 wt% [(Ba0.85Ca0.15)(Ti0.90Zr0.10)O3] [BNKLLT-6 wt% BCTZ] ceramic was fabricated by the solid-state combustion technique and glycine was used as the fuel. The effect of sintering temperature in the range of 1075-1175 °C for 2 h on phase evolution, microstructure and electrical properties was investigated. The phase formation exhibited a coexistence structure between rhombohedral and tetragonal at low sintering temperature. As the sintering temperature increased, the phase formation changed to pseudo-cubic phase. The average grain size of the ceramics was increased with the increasing sintering temperature. Density, ɛr, ɛSA and TFA of BNKLLT-6 wt% BCTZ ceramics increased while the TSA decreased when the sintering temperature increased up to 1125 °C, while after this temperature the opposite trends occurred. At a sintering temperature of 1125 °C, the BNKLLT-6 wt% BCTZ sample showed the highest theoretical density (95.8%), maximum dielectric constant ɛSA (5278), highest d33 (227 pC/N) and fair ferroelectric properties (Pr = 24.5 µC/cm2 and Ec = 15.45 kV/cm).
High-Temperature Properties of Piezoelectric Langatate Single Crystals

NASA Technical Reports Server (NTRS)

Sehirlioglu, Alp; Sayir, Ali; Klemenz, Christine

2007-01-01

Langasite type crystals belong to non-polar point group of 32 and do not show any phase transformations up to the melting temperature. Langatate (La3Ga(5.5)Ta(0.5)O14) demonstrates piezoelectric activity better than quartz and possesses attractive properties for high temperature sensors, resonators and filter applications. High-quality and colorless langatate crystals were grown by the Czochralski technique. The electromechanical and electrical properties of langatate crystals in different crystallographic directions were characterized at elevated temperature. The piezoelectric coefficient along x-axis was 7 pC/N as measured by a Berlincourt meter for a plate geometry with an aspect ratio of 10:1. The dielectric constant did not exhibit any significant temperature dependence (K33 approx. 21 at 30 C and K33 approx. 23 at 600 C). Loss tangent at 100 kHz remained <0.003 up to 300 C and <0.65 at 600 C. The dielectric properties along the y-axis were similar and its temperature dependence was analogous to the x-axis. Electromechanically, the inactive z-axis exhibited no resonance with K33 approx. 84 at room temperature, decreasing down to approx. 49 at 600 C. Resistivity of these crystals along x-axis decreased from approx. 6x10(exp 11) omega-cm at room temperature, to approx. 1.6x10(exp 6) omega-cm at 600 C.
PBDEs, PBBs, and PCNs in three communities of free-ranging killer whales (Orcinus orca) from the northeastern Pacific Ocean.

PubMed

Rayne, Sierra; Ikonomou, Michael G; Ross, Peter S; Ellis, Graeme M; Barrett-Lennard, Lance G

2004-08-15

Polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and polychlorinated naphthalenes (PCNs) were quantified in blubber biopsy samples collected from free-ranging male and female killer whales (Orcinus orca) belonging to three distinct communities (southern residents, northern residents, and transients) from the northeastern Pacific Ocean. High concentrations of sigmaPBDE were observed in male southern residents (942+/-582 ng/g Iw), male and female transients (1015+/-605 and 885+/-706 ng/g Iw, respectively), and male and female northern residents (203+/-116 and 415+/-676 ng/g Iw, respectively). Because of large variation within sample groups, sigmaPBDE levels generally did not differ statistically with the exception of male northern residents, which had lower sigmaPBDE concentrations than male southern residents, male transients, and female transients, perhaps reflecting the consumption of less contaminated prey items. Male transient killer whales, which consume high trophic level prey including other cetaceans and occasionally spend time near populated areas, had sigmaPBDE concentrations approximately equal to southern residents. No significant age-related relationships were observed for sigmaPBDE concentrations. sigmaPBDE concentrations were approximately 1-3 orders of magnitude greater than those of sigmaPBB (3.0-31 ng/g Iw) and sigmaPCN (20-167 ng/g Iw) measured in a subset of samples, suggesting that PBDEs may represent a contaminant class of concern in these marine mammals.
High Performance Relaxor-Based Ferroelectric Single Crystals for Ultrasonic Transducer Applications

PubMed Central

Chen, Yan; Lam, Kwok-Ho; Zhou, Dan; Yue, Qingwen; Yu, Yanxiong; Wu, Jinchuan; Qiu, Weibao; Sun, Lei; Zhang, Chao; Luo, Haosu; Chan, Helen L. W.; Dai, Jiyan

2014-01-01

Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) have drawn much attention in the ferroelectric field because of their excellent piezoelectric properties and high electromechanical coupling coefficients (d33∼2000 pC/N, kt∼60%) near the morphotropic phase boundary (MPB). Ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals also possess outstanding performance comparable with PMN-PT single crystals, but have higher phase transition temperatures (rhombohedral to tetragonal Trt, and tetragonal to cubic Tc) and larger coercive field Ec. Therefore, these relaxor-based single crystals have been extensively employed for ultrasonic transducer applications. In this paper, an overview of our work and perspectives on using PMN-PT and PIN-PMN-PT single crystals for ultrasonic transducer applications is presented. Various types of single-element ultrasonic transducers, including endoscopic transducers, intravascular transducers, high-frequency and high-temperature transducers fabricated using the PMN-PT and PIN-PMN-PT crystals and their 2-2 and 1-3 composites are reported. Besides, the fabrication and characterization of the array transducers, such as phased array, cylindrical shaped linear array, high-temperature linear array, radial endoscopic array, and annular array, are also addressed. PMID:25076222

Flexible Pb(Zr0.52Ti0.48)O3 Films for a Hybrid Piezoelectric-Pyroelectric Nanogenerator under Harsh Environments.

PubMed

Ko, Young Joon; Kim, Dong Yeong; Won, Sung Sik; Ahn, Chang Won; Kim, Ill Won; Kingon, Angus I; Kim, Seung-Hyun; Ko, Jae-Hyeon; Jung, Jong Hoon

2016-03-01

In spite of extremely high piezoelectric and pyroelectric coefficients, there are few reports on flexible ferroelectric perovskite film based nanogenerators (NGs). Here, we report the successful growth of a flexible Pb(Zr0.52Ti0.48)O3 (PZT) film and its application to hybrid piezoelectric-pyroelectric NG. A highly flexible Ni-Cr metal foil substrate with a conductive LaNiO3 bottom electrode enables the growth of flexible PZT film having high piezoelectric (140 pC/N) and pyroelectric (50 nC/cm(2)K) coefficients at room temperature. The flexible PZT-based NG effectively scavenges mechanical vibration and thermal fluctuation from sources ranging from the human body to the surroundings such as wind. Furthermore, it stably generates electric current even at elevated temperatures of 100 °C, relative humidity of 70%, and pH of 13 by virtue of its high Curie temperature and strong resistance for water and base. As proof of power generation under harsh environments, we demonstrate the generation of extremely high current at the exhaust pipe of a car, where hot CO and CO2 gases are rapidly expelled to air. This work expands the application of flexible PZT film-based NG for the scavenging mechanical vibration and thermal fluctuation energies even at extreme conditions.
Cavity turnover and equilibrium cavity densities in a cottonwood bottomland

USGS Publications Warehouse

Sedgwick, James A.; Knopf, Fritz L.

1992-01-01

A fundamental factor regulating the numbers of secondary cavity nesting (SCN) birds is the number of extant cavities available for nesting. The number of available cavities may be thought of as being in an approximate equilibrium maintained by a very rough balance between recruitment and loss of cavities. Based on estimates of cavity recruitment and loss, we ascertained equilibrium cavity densities in a mature plains cottonwood (Populus sargentii) bottomland along the South Platte River in northeastern Colorado. Annual cavity recruitment, derived from density estimates of primary cavity nesting (PCN) birds and cavity excavation rates, was estimated to be 71-86 new cavities excavated/100 ha. Of 180 active cavities of 11 species of cavity-nesting birds found in 1985 and 1986, 83 were no longer usable by 1990, giving an average instantaneous rate of cavity loss of r = -0.230. From these values of cavity recruitment and cavity loss, equilibrium cavity density along the South Platte is 238-289 cavities/100 ha. This range of equilibrium cavity density is only slightly above the minimum of 205 cavities/100 ha required by SCN's and suggests that cavity availability may be limiting SCN densities along the South Platte River. We submit that snag management alone does not adequately address SCN habitat needs, and that cavity management, expressed in terms of cavity turnover and cavity densities, may be more useful.
Extracorporeal shockwave lithotripsy, endourology and open surgery: the management and follow-up of 200 patients with urinary calculi.

PubMed Central

Webb, D. R.; McNicholas, T. A.; Whitfield, H. N.; Wickham, J. E.

1985-01-01

The management and follow up of 200 consecutive patients with renal and ureteric calculi are presented. The primary treatment of 185 (92.5%) was by extracorporeal shockwave lithotripsy (ESWL), of whom three (1.6)%) with large calculi underwent percutaneous nephrolithotripsy (PCNL) prior to ESWL as a planned combined procedure. Twelve (6%) were treated by PCNL or ureterorenoscopy (URS) as their definitive treatment and three (1.5%) by conventional open renal and ureteric surgery. The average in-patient stay was 3.8 days and most returned to normal activity within one day of discharge. Of the 185 patients 102 (55%) required no analgesia after treatment by ESWL, 29 (15.6%) required parenteral analgesia and the rest were comfortable with oral non-narcotic medication. Thirty (16%) required auxillary treatment by percutaneous nephrostomy (PCN), PCNL and URS following ESWL for obstructive complications from stone particles. Two required further ESWL and one PCNL at three months for large fragments. Overall, open surgery was required for only 1% of renal calculi and 13% of ureteric stones. These results are consistant with the extensive West German experience confirming that most urinary calculi are now best managed by ESWL and endoscopic techniques. Where these facilities are available open surgery should only be necessary for less than 5% of upper urinary tract stones. PMID:4073760
Computer program system for dynamic simulation and stability analysis of passive and actively controlled spacecraft. Volume 1. Theory

NASA Technical Reports Server (NTRS)

Bodley, C. S.; Devers, D. A.; Park, C. A.

1975-01-01

A theoretical development and associated digital computer program system is presented. The dynamic system (spacecraft) is modeled as an assembly of rigid and/or flexible bodies not necessarily in a topological tree configuration. The computer program system may be used to investigate total system dynamic characteristics including interaction effects between rigid and/or flexible bodies, control systems, and a wide range of environmental loadings. Additionally, the program system may be used for design of attitude control systems and for evaluation of total dynamic system performance including time domain response and frequency domain stability analyses. Volume 1 presents the theoretical developments including a description of the physical system, the equations of dynamic equilibrium, discussion of kinematics and system topology, a complete treatment of momentum wheel coupling, and a discussion of gravity gradient and environmental effects. Volume 2, is a program users' guide and includes a description of the overall digital program code, individual subroutines and a description of required program input and generated program output. Volume 3 presents the results of selected demonstration problems that illustrate all program system capabilities.
20 CFR 632.76 - Program management systems.

Code of Federal Regulations, 2010 CFR

2010-04-01

... NATIVE AMERICAN EMPLOYMENT AND TRAINING PROGRAMS Program Design and Management § 632.76 Program management systems. (a) All Native American grantees shall establish management information systems to... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Program management systems. 632.76 Section...
Terminal-area STOL operating systems experiments program

NASA Technical Reports Server (NTRS)

Smith, D. W.; Watson, D.; Christensen, J. V.

1973-01-01

Information which will aid in the choice by the U.S. Government and industry of system concepts, design criteria, operating procedures for STOL aircraft and STOL ports, STOL landing guidance systems, air traffic control systems, and airborne avionics and flight control systems. Ames has developed a terminal-area STOL operating systems experiments program which is a part of the joint DOT/NASA effort is discussed. The Ames operating systems experiments program, its objectives, the program approach, the program schedule, typical experiments, the research facilities to be used, and the program status are described.
Mississippi Curriculum Framework for Computer Information Systems Technology. Computer Information Systems Technology (Program CIP: 52.1201--Management Information Systems & Business Data). Computer Programming (Program CIP: 52.1201). Network Support (Program CIP: 52.1290--Computer Network Support Technology). Postsecondary Programs.

ERIC Educational Resources Information Center

Mississippi Research and Curriculum Unit for Vocational and Technical Education, State College.

This document, which is intended for use by community and junior colleges throughout Mississippi, contains curriculum frameworks for two programs in the state's postsecondary-level computer information systems technology cluster: computer programming and network support. Presented in the introduction are program descriptions and suggested course…
Human operator identification model and related computer programs

NASA Technical Reports Server (NTRS)

Kessler, K. M.; Mohr, J. N.

1978-01-01

Four computer programs which provide computational assistance in the analysis of man/machine systems are reported. The programs are: (1) Modified Transfer Function Program (TF); (2) Time Varying Response Program (TVSR); (3) Optimal Simulation Program (TVOPT); and (4) Linear Identification Program (SCIDNT). The TV program converts the time domain state variable system representative to frequency domain transfer function system representation. The TVSR program computes time histories of the input/output responses of the human operator model. The TVOPT program is an optimal simulation program and is similar to TVSR in that it produces time histories of system states associated with an operator in the loop system. The differences between the two programs are presented. The SCIDNT program is an open loop identification code which operates on the simulated data from TVOPT (or TVSR) or real operator data from motion simulators.
Afghanistan: U.S. Rule of Law and Justice Sector Assistance

DTIC Science & Technology

2010-11-09

Sector Support Program ( JSSP ) and Corrections System Support Program (CSSP); • U.S. Agency for International Development’s (USAID’s) formal and informal...Sector Support Program ( JSSP )........................................................................ 28 Corrections System Support Program (CSSP...programs are the Judicial Sector Support Program ( JSSP ), the Corrections System Support Program (CSSP), the ROL Stabilization (RLS) Program, and the
Terminal-area STOL operating systems experiments program

NASA Technical Reports Server (NTRS)

Smith, D. W.; Watson, D.; Christensen, J. V.

1972-01-01

A system study to determine the application of short takeoff aircraft for a high speed, short haul air transportation service was conducted. The study focused on developing information which will aid in choosing system concepts, design criteria, operating procedures, landing guidance systems, air traffic control systems, and airborne avionics and flight control systems. A terminal area STOL operating system experiments program was developed. The objectives, program approach, program schedule, typical experiments, research facilities to be used, and program status are discussed.
Integrating computer programs for engineering analysis and design

NASA Technical Reports Server (NTRS)

Wilhite, A. W.; Crisp, V. K.; Johnson, S. C.

1983-01-01

The design of a third-generation system for integrating computer programs for engineering and design has been developed for the Aerospace Vehicle Interactive Design (AVID) system. This system consists of an engineering data management system, program interface software, a user interface, and a geometry system. A relational information system (ARIS) was developed specifically for the computer-aided engineering system. It is used for a repository of design data that are communicated between analysis programs, for a dictionary that describes these design data, for a directory that describes the analysis programs, and for other system functions. A method is described for interfacing independent analysis programs into a loosely-coupled design system. This method emphasizes an interactive extension of analysis techniques and manipulation of design data. Also, integrity mechanisms exist to maintain database correctness for multidisciplinary design tasks by an individual or a team of specialists. Finally, a prototype user interface program has been developed to aid in system utilization.
Porting a Mental Expert System to a Mainstream Programming Environment

PubMed Central

Jao, Chiang S.; Hier, Daniel B.; Dollear, Winifred; Fu, Wenying

2001-01-01

Expert systems are increasingly being applied to problems in medical diagnosis and treatment. Initial medical expert systems were programmed in specialized “expert system” shell programming environments. As the power of mainstream programming languages has increased, it has become possible to implement medical expert systems within these mainstream languages. We originally implemented an expert system to record and score the mental status examination utilizing a specialized expert system programming environment. We have now ported that application to a mainstream programming environment without losing any functionality of an accurate and comprehensive diagnostic tool. New system supplements the need of normative consultation report and offline reference library to the traditional patient care system.
NASA pyrotechnically actuated systems program

NASA Technical Reports Server (NTRS)

Schulze, Norman R.

1993-01-01

The Office of Safety and Mission Quality initiated a Pyrotechnically Actuated Systems (PAS) Program in FY-92 to address problems experienced with pyrotechnically actuated systems and devices used both on the ground and in flight. The PAS Program will provide the technical basis for NASA's projects to incorporate new technological developments in operational systems. The program will accomplish that objective by developing/testing current and new hardware designs for flight applications and by providing a pyrotechnic data base. This marks the first applied pyrotechnic technology program funded by NASA to address pyrotechnic issues. The PAS Program has been structured to address the results of a survey of pyrotechnic device and system problems with the goal of alleviating or minimizing their risks. Major program initiatives include the development of a Laser Initiated Ordnance System, a pyrotechnic systems data base, NASA Standard Initiator model, a NASA Standard Linear Separation System and a NASA Standard Gas Generator. The PAS Program sponsors annual aerospace pyrotechnic systems workshops.
Automatic system for computer program documentation

NASA Technical Reports Server (NTRS)

Simmons, D. B.; Elliott, R. W.; Arseven, S.; Colunga, D.

1972-01-01

Work done on a project to design an automatic system for computer program documentation aids was made to determine what existing programs could be used effectively to document computer programs. Results of the study are included in the form of an extensive bibliography and working papers on appropriate operating systems, text editors, program editors, data structures, standards, decision tables, flowchart systems, and proprietary documentation aids. The preliminary design for an automated documentation system is also included. An actual program has been documented in detail to demonstrate the types of output that can be produced by the proposed system.
A Review of Generic Program Visualization Systems for Introductory Programming Education

ERIC Educational Resources Information Center

Sorva, Juha; Karavirta, Ville; Malmi, Lauri

2013-01-01

This article is a survey of program visualization systems intended for teaching beginners about the runtime behavior of computer programs. Our focus is on generic systems that are capable of illustrating many kinds of programs and behaviors. We inclusively describe such systems from the last three decades and review findings from their empirical…
Regional Aquifer-System Analysis Program of the US Geological Survey; bibliography, 1978-86

USGS Publications Warehouse

Weeks, J.B.; Sun, Ren Jen

1987-01-01

The Regional Aquifer-System Analysis Program of the U.S. Geological Survey was initiated in 1978. The purpose of this program is to define the regional geohydrology and establish a framework of background information on geology, hydrology, and geochemistry of the Nation 's important aquifer systems. This information is needed to develop an understanding of the Nation 's major groundwater flow systems and to support better groundwater resources management. As of 1986, investigations of 28 regional aquifer systems were planned, investigations of 9 regional aquifer systems were completed, and 11 regional aquifer systems were being studied. This report is a bibliography of reports completed under the Regional Aquifer-System Analysis Program from 1978 through 1986. The reports resulting from each regional aquifer-system study are listed after an introduction to the study. During 1978-86, 488 reports were completed under the Regional Aquifer-System Analysis Program, and 168 reports which were partially funded by the Regional Aquifer-System Analysis Program were completed under the National Research Program. (Author 's abstract)
75 FR 68418 - Real-Time System Management Information Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

...-Time System Management Information Program AGENCY: Federal Highway Administration (FHWA), DOT. ACTION...) to establish a Real-Time System Management Information Program that provides, in all States, the... traveler information. The purposes of the Real-Time System Management Information Program are to: (1...
76 FR 42536 - Real-Time System Management Information Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

...-Time System Management Information Program AGENCY: Federal Highway Administration (FHWA), DOT. ACTION... Real-Time System Management Information Program and general information about current and planned... establishing requirements for the Real-Time System Management Information Program on November 8, 2010, at 75 FR...
75 FR 6250 - ITS Joint Program Office; Intelligent Transportation Systems Program Advisory Committee; Notice...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-08

... DEPARTMENT OF TRANSPORTATION ITS Joint Program Office; Intelligent Transportation Systems Program... the Intelligent Transportation Systems (ITS) Program Advisory Committee (ITSPAC). The Web conference... Transportation on all matters relating to the study, development, and implementation of intelligent...
Linear systems analysis program, L224(QR). Volume 2: Supplemental system design and maintenance document

NASA Technical Reports Server (NTRS)

Heidergott, K. W.

1979-01-01

The computer program known as QR is described. Classical control systems analysis and synthesis (root locus, time response, and frequency response) can be performed using this program. Programming details of the QR program are presented.

Composition-microstructure-property relationships in dual phase bulk magnetoelectric composite

NASA Astrophysics Data System (ADS)

Islam, Rashed Adnan

The coexistence of coupled electrical and magnetic properties in the "magnetoelectric" material has led to the possibility of developing smarter and smaller electronic components. In order to make this possibility a reality, significant efforts are required to understand the science of magnetoelectric (ME) behavior and apply this understanding to develop higher sensitivity material. The primary aims of this thesis are to identify the role of composition, microstructural variables, composite geometry, texturing, post sintering heat treatment, and nanoscale assembly on ME coefficient. The overall objective is to synthesize, characterize and utilize a high ME coefficient composite. The desired range of ME coefficient in the sintered composite is more than 1.5 V/cm.Oe. At first, a piezoelectric composition in the system of Pb(Zr,Ti)O 3 - Pb[(Zn,Ni)1/3Nb2/3]O3 was designed and synthesized which has high energy density (d.g) parameter of 18456.2 x 10-15m2/N and high g constant of 83.1 V-m/N in order to use it as the matrix in piezoelectric---magnetostrictive composite. Secondly it was found that soft piezoelectric phase shows much better magnetoelectric response. The magnetoelectric coefficient for Pb(Zr 0.52Ti0.48)O3 - 15% Pb(Zn1/3Nb 2/3)O3 [PZT - 15 PZN] - 20% Ni0.8Zn 0.2Fe2O4 was found to be around 186 mV/cm.Oe. Thridly, soft magnetic phase with lower coercivity and higher magnetization was found to be suitable for high ME coefficient. Zinc doped Ni-ferrite has higher resistivity, permeability, magnetization and it was found that with increasing Zn concentration the ME coefficient increases exhibiting maxima near 30 at% Zn (138 mV/cm.Oe). Fourthly, if the connectivity was changed from (0-3) to (2-2) which is a bilayer geometry, improved piezoelectric (d33 ˜ 80 pC/N), ferroelectric (polarization = 60 muC/cm2), magnetization (25 emu/gm) and lower coercive field (2.8 Oe) were measured. The bilayer shows an enhancement of 67% increase in ME coefficient compared to bulk composite. Finally it was found that the electrical, magnetic and magnetoelectric properties of (1-x) Pb(Zr0.52Ti0.48)O3 - xNiFe 1.9Mn0.1O4 (PZT-NFM) composites were enhanced after post-sinter annealing and aging. The thermal treatment relaxed the strain in the matrix as observed by change in PZT lattice constant from (a = 3.87A, c = 4.07 A) to (a = 4.07A, c = 4.09 A). This signifies that strain relaxation helps to enhance the ME coefficient by ˜ 50%. A trilayer composite was synthesized using pressure assisted sintering with soft phase [0.9PZT - 0.1 PZN] having grain size larger than 1mum and soft ferromagnetic phase of composition Ni0.8Cu0.2Zn 0.2Fe2O4 [NCZF]. The composite showed a high ME coefficient of 412 and 494mV/cm.Oe after sintering and annealing respectively. Optimized ferrite to PZT thickness ratio was found to be 5.33, providing ME coefficient of 525mV/cm.Oe. The ME coefficient exhibited orientation dependence with respect to applied magnetic field. Multilayering the PZT layer increased the magnitude of ME coefficient to 782mV/cm.Oe. Piezoelectric grain texturing and nano-particulate assembly techniques were incorporated with the layered geometry. It was found that with moderate texturing, d33 and ME coefficient reached up to 325 pC/N and 878 mV/cm.Oe respectively. Nano-particulate core shell assembly shows the promise for achieving large ME coefficient in the sintered composites. A systematic relationship between composition, microstructure, geometry and properties is presented which will lead towards development of high performance magnetoelectric materials. Using the particulate type ME composite developed in thesis, a high sensitivity magnetic field sensor based on piezoelectric transformer principle was fabricated and characterized. This application demonstrates the advantages of ME composites for magnetic field sensing.
Conservation and solar energy program: congressional budget request, FY 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1981-01-01

Funding summaries are presented for the Conservation and Solar Energy Program funding information and program overview on energy conservation (Volume 7 of 7, DOE/CR-0011/2) are included for the Buildings and Community Systems, Industrial, Transportation; State and Local, Multi-Sector, Energy Impact Assistance, and Residential/Commercial retrofit programs. Funding information and program overviews on solar technology (Volume 2 of 7, DOE/CR-011/2) are included for Active and Passive Solar Heating and Cooling, Photovoltaics Energy Systems, Solar Thermal Power Systems, Biomass Energy Systems, Wind Energy Conversion Systems, Ocean Systems, Solar International Activities, Solar Information Systems, SERI Facility, MX-RES, Program Direction, and Alcohol Fuels programs. Informationmore » and overviews on energy production, demonstration, and distribution (Volume 6 of 7, DOE/CR-0011/2) are given for the solar program. A funding summary and a program overview are included for electrochemical and physical and chemical storage systems as appearing in DOE/CR-0011/2, Volume 3 of 7. Relevant tabulated data from the FY 1981. Request to the Congress are presented for Supplementals, Rescissions, and Deferrals. (MCW)« less
Computer Assistance for Writing Interactive Programs: TICS.

ERIC Educational Resources Information Center

Kaplow, Roy; And Others

1973-01-01

Investigators developed an on-line, interactive programing system--the Teacher-Interactive Computer System (TICS)--to provide assistance to those who were not programers, but nevertheless wished to write interactive instructional programs. TICS had two components: an author system and a delivery system. Underlying assumptions were that…
Army Contract Writing System (ACWS)

DTIC Science & Technology

2016-03-01

2016 Major Automated Information System Annual Report Army Contract Writing System (ACWS) Defense Acquisition Management Information Retrieval...Program Information Program Name Army Contract Writing System (ACWS) DoD Component Army Responsible Office Program Manager References MAIS...UNCLASSIFIED 4 Program Description The Army Contract Writing System (ACWS) will be the Army’s single, next-generation, enterprise-wide contract writing
75 FR 41798 - Solicitation of Letters of Interest to Participate in Biotechnology Quality Management System...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-19

...] Solicitation of Letters of Interest to Participate in Biotechnology Quality Management System Program AGENCY... participate in the APHIS Biotechnology Quality Management System Program. The Biotechnology Quality Management..., audit-based compliance assistance program known as the Biotechnology Quality Management System Program...
On the writing of programming systems for spacecraft computers.

NASA Technical Reports Server (NTRS)

Mathur, F. P.; Rohr, J. A.

1972-01-01

Consideration of the systems designed to generate programs for the increasingly complex digital computers being used on board unmanned deep-space probes. Such programming systems must accommodate the special-purpose features incorporated in the hardware. The use of higher-level language facilities in the programming system can significantly simplify the task. Computers for Mariner and for the Outer Planets Grand Tour are briefly described, as well as their programming systems. Aspects of the higher level languages are considered.
Evaluation of a data dictionary system. [information dissemination and computer systems programs

NASA Technical Reports Server (NTRS)

Driggers, W. G.

1975-01-01

The usefulness was investigated of a data dictionary/directory system for achieving optimum benefits from existing and planned investments in computer data files in the Data Systems Development Branch and the Institutional Data Systems Division. Potential applications of the data catalogue system are discussed along with an evaluation of the system. Other topics discussed include data description, data structure, programming aids, programming languages, program networks, and test data.
78 FR 12259 - Unmanned Aircraft System Test Site Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-22

...-0061] Unmanned Aircraft System Test Site Program AGENCY: Federal Aviation Administration (FAA), DOT... Defense, develop a test site program for the integration of unmanned aircraft systems in to the National Airspace System. The overall purpose of this test site program is to develop a body of data and operational...
Difficulties of First Years Elementary School Teachers with the Teaching of Astronomy. (Breton Title: Dificuldades de Professores dos Anos Iniciais do Ensino Fundamental em Relação ao Ensino da Astronomia. ) Dificultades de LOS Profesores de los Primeros Años de la Escuela Primaria en Relación a la Enseñanza de la Astronomía

NASA Astrophysics Data System (ADS)

Langhi, Rodolfo; Nardi, Roberto

2005-12-01

This paper reports Primary School teachers' discourses analysis about their difficulties related to the teaching of Astronomy. It reports partial data of a master's level research carried out in the last two years, named "An exploratory study for inserting Astronomy in primary school teachers' education" (LANGHI, 2004). The study took into consideration students' and teachers' common sense conceptions about astronomical phenomena, conceptual mistakes in textbooks, and Astronomy's suggestions given by the PCN (Parâmetros Curriculares Nacionais - The Brazilian National Curriculum Standards). The paper aims to characterize teachers' difficulties, in order to provide subsides to the implementation of an initial or continuing education program. This study is justified by the fact that courses plans like these only will be adapted to the teacher's (and students') reality, if there is a primary investigation about what the teachers really need to know about Astronomy. This fact was possible here by the enunciations interpretation of a teachers' sample using semi-structured interviews, according to discourse analysis procedures. The research outcomes show difficulties related to factors like: those of personal order, methodological, on teacher's formation, educational infrastructure and other related to information sources for educators. Este artigo, que relata as dificuldades de professores em relação ao ensino da Astronomia, faz parte de um estudo exploratório para a inserção da Astronomia na formação de professores dos anos iniciais do Ensino Fundamental. Esse estudo leva em consideração as concepções alternativas de alunos e professores sobre fenômenos astronômicos, os erros conceituais em livros didáticos e as sugestões de conteúdos de Astronomia constantes nos PCN (Parâmetros Curriculares Nacionais). Caracterizar as dificuldades dos professores é a questão central deste texto, apontando para o objetivo de contribuir com subsídios para um futuro programa de formação continuada neste tema. O estudo se justifica mediante o fato de que planejamentos de cursos como estes só se adequarão à realidade do professor (e do aluno) se houver uma investigação antecipada sobre o que os docentes precisam saber e saber fazer a respeito da Astronomia, o que se concretizou em nosso caso pela interpretação dos discursos de uma amostra de professores coletados através de entrevistas semi-estruturadas, utilizando para interpretação os princípios e métodos da análise do discurso em sua linha francesa. Os resultados da pesquisa indicaram dificuldades de ordem pessoal, metodológica, de formação, de infra-estrutura e outras relacionadas às fontes de informações para docentes. Este artículo que relata las dificultades de los profesores en relación a la enseñanza da laAstronomía es parte de un estudio preliminar para la implantación dela Astrnomía enla formación de profesores de ls primeros años del ciclo primario.El estudio considera las concepciones alternativas de alumnos y profesores respecto a los fenómenos astronómicos, los errores conceptuales en los libros didácticos y las sugerencias de contenidos de Astronomía que constan en los Parámetros Curriculares Nacionales del Brasil. Caracterizar las dificultades de los profesores constituye la cuestión central de este texto, apuntando para el objetivo de contribuir para un futuro programa de educación contínua en este tema. El estudio se justifica mediante el hecho que la planificación de cursos de este tipo solo se adecuarán a la realidade del profesor (y del alumno) si existe una investigación anterior a respecto de lo que los docentes precisan saber y saber realizar en Astronomía, lo cual se concretó en nuestro caso por medio de la interpretación de los discursos de una muestra de profesores obtenidos através de entrevistas semiestructuradas, utilizand para esta interpretación los principios y métodos de análisis del discurso en su línea francesa. Los resultados mostraron dificultades de orden personal, metodológica, formativa, de infraestructura y otras relacionadas a las fuentes de información para los docentes.
Feedback Improvement in Automatic Program Evaluation Systems

ERIC Educational Resources Information Center

Skupas, Bronius

2010-01-01

Automatic program evaluation is a way to assess source program files. These techniques are used in learning management environments, programming exams and contest systems. However, use of automated program evaluation encounters problems: some evaluations are not clear for the students and the system messages do not show reasons for lost points.…
Applied Information Systems Research Program Workshop

NASA Technical Reports Server (NTRS)

Bredekamp, Joe

1991-01-01

Viewgraphs on Applied Information Systems Research Program Workshop are presented. Topics covered include: the Earth Observing System Data and Information System; the planetary data system; Astrophysics Data System project review; OAET Computer Science and Data Systems Programs; the Center of Excellence in Space Data and Information Sciences; and CASIS background.
Elementary Education Program for Engineering by Dual System of Workshop and Teaching Program with Practical Subject

NASA Astrophysics Data System (ADS)

Hara, Toshitsugu

Elementary education program for engineering by the dual system combined with workshop program and teaching program with practical subject was discussed. The dual system which consists of several workshop programs and fundamental subjects (such as mathematics, English and physics) with practical material has been performed for the freshmen. The elementary workshop program (primary course) has four workshops and the related lectures. Fundamental subjects are taught with the practical or engineering texts. English subjects are taught by specified teachers who have ever worked in engineering field with English. The dual system was supported by such systems as the center for success initiative and the English education center.
An implementation of the programming structural synthesis system (PROSSS)

NASA Technical Reports Server (NTRS)

Rogers, J. L., Jr.; Sobieszczanski-Sobieski, J.; Bhat, R. B.

1981-01-01

A particular implementation of the programming structural synthesis system (PROSSS) is described. This software system combines a state of the art optimization program, a production level structural analysis program, and user supplied, problem dependent interface programs. These programs are combined using standard command language features existing in modern computer operating systems. PROSSS is explained in general with respect to this implementation along with the steps for the preparation of the programs and input data. Each component of the system is described in detail with annotated listings for clarification. The components include options, procedures, programs and subroutines, and data files as they pertain to this implementation. An example exercising each option in this implementation to allow the user to anticipate the type of results that might be expected is presented.
Overview of Advanced Turbine Systems Program

NASA Astrophysics Data System (ADS)

Webb, H. A.; Bajura, R. A.

The US Department of Energy initiated a program to develop advanced gas turbine systems to serve both central power and industrial power generation markets. The Advanced Turbine Systems (ATS) Program will lead to commercial offerings by the private sector by 2002. ATS will be developed to fire natural gas but will be adaptable to coal and biomass firing. The systems will be: highly efficient (15 percent improvement over today's best systems); environmentally superior (10 percent reduction in nitrogen oxides over today's best systems); and cost competitive (10 percent reduction in cost of electricity). The ATS Program has five elements. Innovative cycle development will lead to the demonstration of systems with advanced gas turbine cycles using current gas turbine technology. High temperature development will lead to the increased firing temperatures needed to achieve ATS Program efficiency goals. Ceramic component development/demonstration will expand the current DOE/CE program to demonstrate industrial-scale turbines with ceramic components. Technology base will support the overall program by conducting research and development (R&D) on generic technology issues. Coal application studies will adapt technology developed in the ATS program to coal-fired systems being developed in other DOE programs.
Reuniting the Solar System: Integrated Education and Public Outreach Projects for Solar System Exploration Missions and Programs

NASA Technical Reports Server (NTRS)

Lowes, Leslie; Lindstrom, Marilyn; Stockman, Stephanie; Scalice, Daniela; Klug, Sheri

2003-01-01

The Solar System Exploration Education Forum has worked for five years to foster Education and Public Outreach (E/PO) cooperation among missions and programs in order to leverage resources and better meet the needs of educators and the public. These efforts are coming together in a number of programs and products and in '2004 - The Year of the Solar System.' NASA's practice of having independent E/PO programs for each mission and its public affairs emphasis on uniqueness has led to a public perception of a fragmented solar system exploration program. By working to integrate solar system E/PO, the breadth and depth of the solar system exploration program is revealed. When emphasis is put on what missions have in common, as well as their differences, each mission is seen in the context of the whole program.
45 CFR 1304.51 - Management systems and procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... control program quality, maintain program accountability, and advise governing bodies, policy groups, and... DELEGATE AGENCIES Program Design and Management § 1304.51 Management systems and procedures. (a) Program... program planning that includes consultation with the program's governing body, policy groups, and program...
School District Program Cost Accounting: An Alternative Approach

ERIC Educational Resources Information Center

Hentschke, Guilbert C.

1975-01-01

Discusses the value for school districts of a program cost accounting system and examines different approaches to generating program cost data, with particular emphasis on the "cost allocation to program system" (CAPS) and the traditional "transaction-based system." (JG)
Satellite broadcasting system study

NASA Technical Reports Server (NTRS)

1972-01-01

The study to develop a system model and computer program representative of broadcasting satellite systems employing community-type receiving terminals is reported. The program provides a user-oriented tool for evaluating performance/cost tradeoffs, synthesizing minimum cost systems for a given set of system requirements, and performing sensitivity analyses to identify critical parameters and technology. The performance/ costing philosophy and what is meant by a minimum cost system is shown graphically. Topics discussed include: main line control program, ground segment model, space segment model, cost models and launch vehicle selection. Several examples of minimum cost systems resulting from the computer program are presented. A listing of the computer program is also included.
Distributed Pair Programming Using Collaboration Scripts: An Educational System and Initial Results

ERIC Educational Resources Information Center

Tsompanoudi, Despina; Satratzemi, Maya; Xinogalos, Stelios

2015-01-01

Since pair programming appeared in the literature as an effective method of teaching computer programming, many systems were developed to cover the application of pair programming over distance. Today's systems serve personal, professional and educational purposes allowing distributed teams to work together on the same programming project. The…
An expert system for the design of heating, ventilating, and air-conditioning systems

NASA Astrophysics Data System (ADS)

Camejo, Pedro Jose

1989-12-01

Expert systems are computer programs that seek to mimic human reason. An expert system shelf, a software program commonly used for developing expert systems in a relatively short time, was used to develop a prototypical expert system for the design of heating, ventilating, and air-conditioning (HVAC) systems in buildings. Because HVAC design involves several related knowledge domains, developing an expert system for HVAC design requires the integration of several smaller expert systems known as knowledge bases. A menu program and several auxiliary programs for gathering data, completing calculations, printing project reports, and passing data between the knowledge bases are needed and have been developed to join the separate knowledge bases into one simple-to-use program unit.

Energy Systems Training Programs and Certifications Survey White Paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cox, Daryl; Nimbalkar, Sachin U.; Wenning, Thomas J.

2017-02-01

Compressed air system, industrial refrigeration system, chilled water system, pump system, fan system, steam system, process heating system, and combined heat and power system are the major industrial energy systems. By helping enhance knowledge and skills of workforce, training and certification programs on these systems are essential to improve energy efficiency of manufacturing facilities. A literature survey of currently available training and certification programs on these systems was conducted.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Hao, Jigong; Xu, Zhijun, E-mail: zhjxu@lcu.edu.cn; Chu, Ruiqing

Reddish orange-emitting 0.948(K{sub 0.5}Na{sub 0.5})NbO{sub 3}-0.052LiSbO{sub 3}-xmol%Sm{sub 2}O{sub 3} (KNN-5.2LS-xSm{sub 2}O{sub 3}) lead-free piezoelectric ceramics with good piezoelectric properties were fabricated in this study, and the photoluminescence and electrical properties of the ceramics were systematically studied. Results showed that Sm{sub 2}O{sub 3} substitution into KNN-5.2LS induces a phase transition from the coexistence of orthorhombic and tetragonal phases to a pseudocubic phase and shifts the polymorphic phase transition (PPT) to below room temperature. The temperature stability and fatigue resistance of the modified ceramics were significantly improved by Sm{sub 2}O{sub 3} substitution. The KNN-5.2LS ceramic with 0.4 mol. % Sm{sub 2}O{sub 3} exhibitedmore » temperature-independent properties (25–150 °C), fatigue-free behavior (up to 10{sup 6} cycles), and good piezoelectric properties (d{sub 33}{sup * }= 230 pm/V, d{sub 33} = 176 pC/N, k{sub p} = 35%). Studies on the photoluminescence properties of the samples showed strong reddish-orange emission upon blue light excitation; these emission intensities were strongly dependent on the doping concentration and sintering temperature. The 0.4 mol. % Sm{sub 2}O{sub 3}-modified sample exhibited temperature responses over a wide temperature range of 10–443 K. The maximum sensing sensitivity of the sample was 7.5 × 10{sup −4} K at 293 K, at which point PPT occurred. A relatively long decay lifetime τ of 1.27–1.40 ms and a large quantum yield η of 0.17–0.19 were obtained from the Sm-modified samples. These results suggest that the KNN-5.2LS-xSm{sub 2}O{sub 3} system presents multifunctional properties and significant technological potential in novel multifunctional devices.« less
Systems theory as a framework for examining a college campus-based support program for the former foster youth.

PubMed

Schelbe, Lisa; Randolph, Karen A; Yelick, Anna; Cheatham, Leah P; Groton, Danielle B

2018-01-01

Increased attention to former foster youth pursuing post-secondary education has resulted in the creation of college campus based support programs to address their need. However, limited empirical evidence and theoretical knowledge exist about these programs. This study seeks to describe the application of systems theory as a framework for examining a college campus based support program for former foster youth. In-depth semi-structured interviews were conducted with 32 program stakeholders including students, mentors, collaborative members, and independent living program staff. Using qualitative data analysis software, holistic coding techniques were employed to analyze interview transcripts. Then applying principles of extended case method using systems theory, data were analyzed. Findings suggest systems theory serves as a framework for understanding the functioning of a college campus based support program. The theory's concepts help delineate program components and roles of stakeholders; outline boundaries between and interactions among stakeholders; and identify program strengths and weakness. Systems theory plays an important role in identifying intervention components and providing a structure through which to identify and understand program elements as a part of the planning process. This study highlights the utility of systems theory as a framework for program planning and evaluation.
Hydraulic dynamic analysis

NASA Technical Reports Server (NTRS)

Gale, R. L.; Nease, A. W.; Nelson, D. J.

1978-01-01

Computer program mathematically describes complete hydraulic systems to study their dynamic performance. Program employs subroutines that simulate components of hydraulic system, which are then controlled by main program. Program is useful to engineers working with detailed performance results of aircraft, spacecraft, or similar hydraulic systems.
Steady-state simulation program for attitude control propulsion systems

NASA Technical Reports Server (NTRS)

Heinmiller, P. J.

1973-01-01

The formulation and the engineering equations employed in the steady state attitude control propulsion system simulation program are presented. The objective of this program is to aid in the preliminary design and development of propulsion systems used for spacecraft attitude control. The program simulates the integrated operation of the many interdependent components typically comprising an attitude control propulsion system. Flexibility, generality, ease of operation, and speed consistent with adequate accuracy were overriding considerations during the development of this program. Simulation modules were developed representing the various types of fluid components typically encountered in an attitude control propulsion system. These modules are basically self-contained and may be arranged by the program user into desired configuration through the program input data.
20 CFR 632.76 - Program management systems.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Program management systems. 632.76 Section... management systems. (a) All Native American grantees shall establish management information systems to... for the overall management of all programs including: (1) Eligibility verification systems as...
75 FR 70654 - Approval and Promulgation of Air Quality Implementation Plans; Texas; System Cap Trading Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-18

... Promulgation of Air Quality Implementation Plans; Texas; System Cap Trading Program AGENCY: Environmental..., 2001, and August 16, 2007, that create and amend the System Cap Trading (SCT) Program at Title 30 of.... What action is EPA proposing? II. What did Texas submit? III. What is the System Cap Trading Program...
47 CFR 63.02 - Exemptions for extensions of lines and for systems for the delivery of video programming.

Code of Federal Regulations, 2011 CFR

2011-10-01

... systems for the delivery of video programming. 63.02 Section 63.02 Telecommunication FEDERAL... systems for the delivery of video programming. (a) Any common carrier is exempt from the requirements of... with respect to the establishment or operation of a system for the delivery of video programming. [64...
47 CFR 63.02 - Exemptions for extensions of lines and for systems for the delivery of video programming.

Code of Federal Regulations, 2010 CFR

2010-10-01

... systems for the delivery of video programming. 63.02 Section 63.02 Telecommunication FEDERAL... systems for the delivery of video programming. (a) Any common carrier is exempt from the requirements of... with respect to the establishment or operation of a system for the delivery of video programming. [64...
47 CFR 63.02 - Exemptions for extensions of lines and for systems for the delivery of video programming.

Code of Federal Regulations, 2013 CFR

2013-10-01

... systems for the delivery of video programming. 63.02 Section 63.02 Telecommunication FEDERAL... systems for the delivery of video programming. (a) Any common carrier is exempt from the requirements of... with respect to the establishment or operation of a system for the delivery of video programming. [64...
47 CFR 63.02 - Exemptions for extensions of lines and for systems for the delivery of video programming.

Code of Federal Regulations, 2014 CFR

2014-10-01

... systems for the delivery of video programming. 63.02 Section 63.02 Telecommunication FEDERAL... systems for the delivery of video programming. (a) Any common carrier is exempt from the requirements of... with respect to the establishment or operation of a system for the delivery of video programming. [64...
47 CFR 63.02 - Exemptions for extensions of lines and for systems for the delivery of video programming.

Code of Federal Regulations, 2012 CFR

2012-10-01

... systems for the delivery of video programming. 63.02 Section 63.02 Telecommunication FEDERAL... systems for the delivery of video programming. (a) Any common carrier is exempt from the requirements of... with respect to the establishment or operation of a system for the delivery of video programming. [64...
Computer Program and User Documentation Medical Data Input System

NASA Technical Reports Server (NTRS)

Anderson, J.

1971-01-01

Several levels of documentation are presented for the program module of the NASA medical directorate minicomputer storage and retrieval system. The biomedical information system overview gives reasons for the development of the minicomputer storage and retrieval system. It briefly describes all of the program modules which constitute the system. A technical discussion oriented to the programmer is given. Each subroutine is described in enough detail to permit in-depth understanding of the routines and to facilitate program modifications. The program utilization section may be used as a users guide.
Advancing Systems Engineering Excellence: The Marshall Systems Engineering Leadership Development Program

NASA Technical Reports Server (NTRS)

Hall, Philip; Whitfield, Susan

2011-01-01

As NASA undertakes increasingly complex projects, the need for expert systems engineers and leaders in systems engineering is becoming more pronounced. As a result of this issue, the Agency has undertaken an initiative to develop more systems engineering leaders through its Systems Engineering Leadership Development Program; however, the NASA Office of the Chief Engineer has also called on the field Centers to develop mechanisms to strengthen their expertise in systems engineering locally. In response to this call, Marshall Space Flight Center (MSFC) has developed a comprehensive development program for aspiring systems engineers and systems engineering leaders. This presentation will summarize the two-level program, which consists of a combination of training courses and on-the-job, developmental training assignments at the Center to help develop stronger expertise in systems engineering and technical leadership. In addition, it will focus on the success the program has had in its pilot year. The program hosted a formal kickoff event for Level I on October 13, 2009. The first class includes 42 participants from across MSFC and Michoud Assembly Facility (MAF). A formal call for Level II is forthcoming. With the new Agency focus on research and development of new technologies, having a strong pool of well-trained systems engineers is becoming increasingly more critical. Programs such as the Marshall Systems Engineering Leadership Development Program, as well as those developed at other Centers, help ensure that there is an upcoming generation of trained systems engineers and systems engineering leaders to meet future design challenges.
Flexible High-Performance Lead-Free Na0.47K0.47Li0.06NbO3 Microcube-Structure-Based Piezoelectric Energy Harvester.

PubMed

Gupta, Manoj Kumar; Kim, Sang-Woo; Kumar, Binay

2016-01-27

Lead-free piezoelectric nano- and microstructure-based generators have recently attracted much attention due to the continuous demand of self-powered body implantable devices. We report the fabrication of a high-performance flexible piezoelectric microgenerator based on lead-free inorganic piezoelectric Na0.47K0.47Li0.06NbO3 (NKLN) microcubes for the first time. The composite generator is fabricated using NKLN microcubes and polydimethylsiloxane (PDMS) polymer on a flexible substrate. The flexible device exhibits excellent performance with a large recordable piezoelectric output voltage of 48 V and output current density of 0.43 μA/cm(2) under vertical compressive force of 2 kgf, for which an energy conversion efficiency of about 11% has been achieved. Piezoresponse and ferroelectric studies reveal that NKLN microcubes exhibited high piezoelectric charge coefficient (d33) as high as 460 pC/N and a well-defined hysteresis loops with remnant polarization and coercive field of 13.66 μC/cm(2) and 19.45 kV/cm, respectively. The piezoelectric charge generation mechanism from NKLN microgenerator are discussed in the light of the high d33 and alignment of electric dipoles in polymer matrix and dielectric constant of NKLN microcubes. It has been demonstrated that the developed power generator has the potential to generate high electric output power under mechanical vibration for powering biomedical devices in the near future.
The enhancing performance of (Ba{sub 0.85}Ca{sub 0.15}Ti{sub 0.90}Zr{sub 0.10})O{sub 3} ceramics by tuning anatase–rutile phase structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Xiaolian, E-mail: chaoxl@snnu.edu.cn; Wang, Juanjuan; Wang, Zhongming

2016-04-15

Graphical abstract: Titanium dioxide (TiO{sub 2}) with different phase structure had interesting influence on the crystal structure, microstructure, the sintering temperature and electrical properties. - Highlights: • BCZT ceramics were prepared using either anatase or rutile structures as Ti source. • Orthorhombic and tetragonal mixture structure was exhibited by adjusting Ti source. • The optimal properties were observed in BCZT ceramics with rutile titanium dioxide. - Abstract: To research effect of raw materials TiO{sub 2} with the phase structures on the crystal structure, microstructure and electrical properties of lead-free (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.90}Zr{sub 0.10})O{sub 3} (BCZT) ceramics, BCZT ceramics usingmore » either anatase or rutile as Ti source were synthesized by solid-state reaction. Titanium dioxide (TiO{sub 2}) with anatase/rutile phase structures had interesting influence on the crystal structure, microstructure and the sintering temperature by the X-ray diffraction and SEM, which also played an important role in improved electrical properties. The BCZT ceramics with rutile titanium dioxide demonstrated optimal piezoelectric and dielectric properties: d{sub 33} = 590 pC/N, k{sub p} = 0.46, ε{sub r} = 2810, tanδ = 0.014 and T{sub c} = 91 °C, which was obviously superior to BCZT ceramics with anatase titanium dioxide.« less
Comparative study of 2mol% Li- and Mn-substituted lead-free potassium sodium niobate ceramics

NASA Astrophysics Data System (ADS)

Dahiya, Asha; Thakur, O. P.; Juneja, J. K.; Singh, Sangeeta; Dipti

2014-12-01

The effect of Li and Mn substitution on the dielectric, ferroelectric and piezoelectric properties of lead free K0.5Na0.5NbO3 (KNN) was investigated. Samples were prepared using a conventional solid state reaction method. The sintering temperature for all the samples was 1050°C. The optimum doping concentration for the enhancement of different properties without the introduction of any other co-dopants such as Ti, Sb, and La was investigated. X-ray diffraction analysis confirmed that all the samples crystallize in a single phase perovskite structure. The dielectric properties were investigated as a function of temperature and applied electric field frequency. Compared with Li-substituted KNN (KLNN), Mn-substituted KNN (KMNN) exhibited a higher dielectric constant ɛ max (i.e., 4840) at its critical transition temperature T c (i.e., 421°C) along with a lower value of tangent loss at 10 kHz and greater values of saturation polarisation P s (i.e., 20.14 μC/cm2) and remnant polarisation P r (i.e., 15.48 μC/cm2). The piezoelectric constant ( d 33) of KMNN was 178 pC/N, which is comparable to that of lead-based hard ceramics. The results presented herein suggest that B-site or Mn substitution at the optimum concentration results in good enhancement of different properties required for materials used in memory devices and other applications.
Three dysconnectivity patterns in treatment-resistant schizophrenia patients and their unaffected siblings.

PubMed

Wang, Jicai; Cao, Hongbao; Liao, Yanhui; Liu, Weiqing; Tan, Liwen; Tang, Yanqing; Chen, Jindong; Xu, Xiufeng; Li, Haijun; Luo, Chunrong; Liu, Chunyu; Ries Merikangas, Kathleen; Calhoun, Vince; Tang, Jinsong; Shugart, Yin Yao; Chen, Xiaogang

2015-01-01

Among individuals diagnosed with schizophrenia, approximately 20%-33% are recognized as treatment-resistant schizophrenia (TRS) patients. These TRS patients suffer more severely from the disease but struggle to benefit from existing antipsychotic treatments. A few recent studies suggested that schizophrenia may be caused by impaired synaptic plasticity that manifests as functional dysconnectivity in the brain, however, few of those studies focused on the functional connectivity changes in the brains of TRS groups. In this study, we compared the whole brain connectivity variations in TRS patients, their unaffected siblings, and healthy controls. Connectivity network features between and within the 116 automated anatomical labeling (AAL) brain regions were calculated and compared using maps created with three contrasts: patient vs. control, patient vs. sibling, and sibling vs. To evaluate the predictive power of the selected features, we performed a multivariate classification approach. We also evaluated the influence of six important clinical measures (e.g. age, education level) on the connectivity features. This study identified abnormal significant connectivity changes of three patterns in TRS patients and their unaffected siblings: 1) 69 patient-specific connectivity (PCN); 2) 102 shared connectivity (SCN); and 3) 457 unshared connectivity (UCN). While the first two patterns were widely reported by previous non-TRS specific studies, we were among the first to report widespread significant connectivity differences between TRS patient groups and their healthy sibling groups. Observations of this study may provide new insights for the understanding of the neurophysiological mechanisms of TRS.
Three-dimensional ceramic molding process based on microstereolithography for the production of piezoelectric energy harvesters

NASA Astrophysics Data System (ADS)

Maruo, Shoji; Sugiyama, Kenji; Daicho, Yuya; Monri, Kensaku

2014-03-01

A three-dimensional (3-D) molding process using a master polymer mold produced by microstereolithography has been developed for the production of piezoelectric ceramic elements. In this method, ceramic slurry is injected into a 3-D polymer mold via a centrifugal casting process. The polymer master mold is thermally decomposed so that complex 3-D piezoelectric ceramic elements can be produced. As an example of 3-D piezoelectric ceramic elements, we produced a spiral piezoelectric element that can convert multidirectional loads into a voltage. It was confirmed that a prototype of the spiral piezoelectric element could generate a voltage by applying a load in both parallel and lateral directions in relation to the helical axis. The power output of 123 pW was obtained by applying the maximum load of 2.8N at 2 Hz along the helical axis. In addition, to improve the performance of power generation, we utilized a two-step sintering process to obtain dense piezoelectric elements. As a result, we obtained a sintering body with relative density of 92.8%. Piezoelectric constant d31 of the sintered body attained to -40.0 pC/N. Furthermore we analyzed the open-circuit voltage of the spiral piezoelectric element using COMSOL multiphysics. As a result, it was found that use of patterned electrodes according to the surface potential distribution of the spiral piezoelectric element had a potential to provide high output voltage that was 20 times larger than that of uniform electrodes.
PtII diimine chromophores with perfluorinated thiolate ligands: nature and dynamics of the charge-transfer-to-diimine lowest excited state.

PubMed

Weinstein, Julia A; Blake, Alexander J; Davies, E Stephen; Davis, Adrienne L; George, Michael W; Grills, David C; Lileev, Igor V; Maksimov, Alexander M; Matousek, Pavel; Mel'nikov, Mikhail Ya; Parker, Anthony W; Platonov, Vyacheslav E; Towrie, Michael; Wilson, Claire; Zheligovskaya, Natalia N

2003-11-03

The synthesis of new Pt(II) diimine complexes bearing perfluorinated thiolate ligands, Pt(II)(NN)(4-X-C(6)F(4)-S)(2), where NN = 2,2'-bipyridine or 1,10-phenanthroline and X = F or CN, is reported, together with an investigation of the nature and dynamics of their lowest excited states. A combined UV-vis, (spectro)electrochemical, resonance Raman, and time-resolved infrared (TRIR) study has suggested that the HOMO is mainly composed of thiolate(pi)/S(p)/Pt(d) orbitals and that the LUMO is largely localized on the pi*(diimine) orbital, thus revealing the [charge-transfer-to-diimine] nature of the lowest excited state. An enhancement of the thiolate ring vibrations, C-F vibrations, and the vibration of the CN-substituent on the thiolate moiety was observed in the resonance Raman spectra, whereas no such enhancement was seen for the nonfluorinated analogues. Thus, the introduction of fluorine substituents on the thiolate moiety probably leads to a more pronounced contribution of the intrathiolate modes to the HOMO compared to the analogous complexes with nonfluorinated thiolates. Furthermore, the introduction of the p-CN group into the thiolate moiety has allowed the dynamics of the lowest excited state of Pt(bpy)(4-CN-C(6)F(4)-S)(2) to be monitored by picosecond TRIR spectroscopy. The dynamics of the lowest [charge-transfer-to-diimine] excited state are governed by ca. 2-ps vibrational cooling and 35-ps back electron transfer.

Fabrication of lead-free piezoelectric Li2CO3-added (Ba,Ca)(Ti,Sn)O3 ceramics under controlled low oxygen partial pressure and their properties

NASA Astrophysics Data System (ADS)

Noritake, Kouta; Sakamoto, Wataru; Yuitoo, Isamu; Takeuchi, Teruaki; Hayashi, Koichiro; Yogo, Toshinobu

2018-02-01

Reduction-resistant lead-free (Ba,Ca)(Ti,Sn)O3 piezoceramics with high piezoelectric constants were fabricated by optimizing the amount of Li2CO3 added. Oxygen partial pressure was controlled during the sintering of (Ba,Ca)(Ti,Sn)O3 ceramics in a reducing atmosphere using H2-CO2 gas. Enhanced grain growth and a high-polarization state after poling treatment were achieved by adding Li2CO3. Optimizing the amount of Li2CO3 added to (Ba0.95Ca0.05)(Ti0.95Sn0.05)O3 ceramics sintered under a low oxygen partial pressure resulted in improved piezoelectric properties while maintaining the high sintered density. The prepared Li2CO3-added ceramic samples had homogeneous microstructures with a uniform dispersion of each major constituent element. However, the residual Li content in the 3 mol % Li2CO3-added (Ba0.95Ca0.05)(Ti0.95Sn0.05)O3 ceramics after sintering was less than 0.3 mol %. Sintered bodies of this ceramic prepared in a CO2 (1.5%)-H2 (0.3%)/Ar reducing atmosphere (PO2 = 10-8 atm at 1350 °C), exhibited sufficient electrical resistivity and a piezoelectric constant (d 33) exceeding 500 pC/N. The piezoelectric properties of this nonreducible ceramic were comparable or superior to those of the same ceramic sintered in air.
Microstructure, Piezoelectric, and Ferroelectric Properties of BZT-Modified BiFeO3-BaTiO3 Multiferroic Ceramics with MnO2 and CuO Addition

NASA Astrophysics Data System (ADS)

Guan, Shibo; Yang, Huabin; Chen, Guangcong; Zhang, Rui

2018-02-01

A new lead-free piezoelectric ceramic, 0.67BiFeO3-0.33BaTiO3-xBi(Zn0.5Ti0.5) O3 + 0.0035MnO2 + 0.004CuO, was prepared through the solid-state reaction route. The ceramic was sintered in the 950-990°C range. In this paper, the crystal structure of the sample is pure perovskite structure with a pseudo-cubic structure in the range of x = 0-0.05, and does not change greatly with the increase of x. The grain size increases first and then decreases with the increase of x. The addition of Bi(Zn0.5Ti0.5) O3(BZT) promoted the grain growth of the sample. The piezoelectric constant reached the maximum value of d 33 = 188 pC/N, electromechanical coupling coefficient k p = 0.301 and the remanent polarization P r = 61.20 μC/cm2 at x = 0.03. It has a high Curie temperature of T c = 420°C. On the other hand, the depolarization temperature reaches the maximum value, T d = 426°C, at x = 0. A small amount of BZT doping can improve the piezoelectric, dielectric, and ferroelectric properties of the samples. Therefore, this material can be considered as a promising lead-free piezoelectric ceramic material in the application field of high-temperature materials.
Piezoelectric properties and temperature stability of Mn-doped Pb(Mg1/3Nb2/3)-PbZrO3-PbTiO3 textured ceramics

NASA Astrophysics Data System (ADS)

Yan, Yongke; Cho, Kyung-Hoon; Priya, Shashank

2012-03-01

In this letter, we report the electromechanical properties of textured 0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 (PMN-PZT) composition which has relatively high rhombohedral to tetragonal (R-T) transition temperature (TR-T of 160 °C) and Curie temperature (TC of 234 °C) and explore the effect of Mn-doping on this composition. It was found that MnO2-doped textured PMN-PZT ceramics with 5 vol. % BaTiO3 template (T-5BT) exhibited inferior temperature stability. The coupling factor (k31) of T-5BT ceramic started to degrade from 75 °C while the random counterpart showed a very stable tendency up to 180 °C. This degradation was associated with the "interface region" formed in the vicinity of BT template. MnO2 doped PMN-PZT ceramics textured with 3 vol. % BT and subsequently poled at 140 °C (T-3BT140) exhibited very stable and high k31 (>0.53) in a wide temperature range from room temperature to 130 °C through reduction in the interface region volume. Further, the T-3BT140 ceramic exhibited excellent hard and soft combinatory piezoelectric properties of d33 = 720 pC/N, k31 = 0.53, Qm = 403, tan δ = 0.3% which are very promising for high power and magnetoelectric applications.
Synthesis and piezoelectric properties of (1 - x)Bi0.5(Na0.8K0.2)0.5TiO3-xSr2ZrTiO6 ceramics

NASA Astrophysics Data System (ADS)

Onishi, Ryo; Ogawa, Hirotaka; Iida, Daiki; Kan, Akinori

2017-10-01

The effects of Sr2ZrTiO6 (SZT) addition on the piezoelectric properties of (1 - x)Bi0.5(Na0.8K0.2)0.5TiO3 (BNKT)-xSZT ceramics were characterized in this study. The X-ray powder diffraction (XRPD) profiles and Raman spectra of the ceramics in the composition range of 0-0.02 implies the presence of morphotropic phase boundary (MPB) which consists of the rhombohedral and tetragonal phases. Moreover, the temperature dependence of dielectric loss indicated a presence of the ferroelectric-relaxor transition temperature (T F-R) of around 75 °C for x = 0.005 and the temperature dependence shifted to a lower temperature at x = 0.01. The temperature dependence of the P-E hysteresis loop of the ceramics at the compositions of x = 0.005-0.02 showed pinched hysteresis loops above T F-R. Regarding the piezoelectric constant (d 33), it was increased by SZT addition in the MPB region (x = 0-0.01) and the highest d 33 of 202 pC/N was obtained at the composition of x = 0.0025. The S-E unipolar loop was also evaluated, the strain of the ceramic increased up to x = 0.02; and the highest d33* = 436 pm/V was obtained at the composition of x = 0.02.
Unintentional production of persistent chlorinated and brominated organic pollutants during iron ore sintering processes.

PubMed

Li, Sumei; Liu, Guorui; Zheng, Minghui; Liu, Wenbin; Li, Jinhui; Wang, Mei; Li, Changliang; Chen, Yuan

2017-06-05

Iron ore sintering (SNT) processes are major sources of unintentionally produced chlorinated persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). However, few studies of emissions of brominated POPs, such as polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs), during SNT have been performed. Stack gas and fly ash samples from six typical SNT plants in China were collected and analyzed to determine the concentrations and profiles of PCDD/Fs, PCBs, PCNs, PBDD/Fs, and PBDEs, as well as any correlations among these compounds. The PCDD/F, PCB, PCN, PBDD/F, and PBDE emission factors were 2.47, 0.61, 552, 0.32, and 107μgt -1 , respectively (109, 4.07, 10.4, 4.41 and 0.02ng toxic equivalents t -1 , respectively). PCBs were the most abundant compounds by mass, while PCNs were the next most abundant, contributing 51% and 42% to the total POP concentration, respectively. However, PCDD/Fs were the dominant contributors to the chlorinated and brominated POP toxic equivalent concentrations, contributing 89% to the total toxic equivalent concentration. The PCDD/F and other chlorinated and brominated POP concentrations were positively correlated, indicating that chlorinated and brominated POP emissions could be synergistically decreased using the best available technologies/best environmental practices already developed for PCDD/Fs. Copyright © 2017 Elsevier B.V. All rights reserved.
Systems Engineering Education Development(SEED)Case Study

NASA Technical Reports Server (NTRS)

Bagg, Thomas C., III; Brumfield, Mark D.; Jamison, Donald E.; Granata, Raymond L.; Casey, Carolyn A.

2003-01-01

The Systems Engineering Development Program (SEED) was initiated to help Goddard resolve a Systems Engineering skill shortage. The chronology of events and the experiences of the pilot program are outlined to describe the development of the present program. The program goals are included in order to give a focus on what the developers saw as the program drivers. Lessons learned from a pilot program were incorporated into the present program. This program is constantly learning from its past efforts and looks for continuous improvement. We list several future ideas for improvement and change.
Programming distributed memory architectures using Kali

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Vanrosendale, John

1990-01-01

Programming nonshared memory systems is more difficult than programming shared memory systems, in part because of the relatively low level of current programming environments for such machines. A new programming environment is presented, Kali, which provides a global name space and allows direct access to remote data values. In order to retain efficiency, Kali provides a system on annotations, allowing the user to control those aspects of the program critical to performance, such as data distribution and load balancing. The primitives and constructs provided by the language is described, and some of the issues raised in translating a Kali program for execution on distributed memory systems are also discussed.
Formulation of advanced consumables management models: Environmental control and electrical power system performance models requirements

NASA Technical Reports Server (NTRS)

Daly, J. K.; Torian, J. G.

1979-01-01

Software design specifications for developing environmental control and life support system (ECLSS) and electrical power system (EPS) programs into interactive computer programs are presented. Specifications for the ECLSS program are at the detail design level with respect to modification of an existing batch mode program. The FORTRAN environmental analysis routines (FEAR) are the subject batch mode program. The characteristics of the FEAR program are included for use in modifying batch mode programs to form interactive programs. The EPS program specifications are at the preliminary design level. Emphasis is on top-down structuring in the development of an interactive program.
Involving Scientists in the NASA / JPL Solar System Educators Program

NASA Astrophysics Data System (ADS)

Brunsell, E.; Hill, J.

2001-11-01

The NASA / JPL Solar System Educators Program (SSEP) is a professional development program with the goal of inspiring America's students, creating learning opportunities, and enlightening inquisitive minds by engaging them in the Solar System exploration efforts conducted by the Jet Propulsion Laboratory (JPL). SSEP is a Jet Propulsion Laboratory program managed by Space Explorers, Inc. (Green Bay, WI) and the Virginia Space Grant Consortium (Hampton, VA). The heart of the program is a large nationwide network of highly motivated educators. These Solar System Educators, representing more than 40 states, lead workshops around the country that show teachers how to successfully incorporate NASA materials into their teaching. During FY2001, more than 9500 educators were impacted through nearly 300 workshops conducted in 43 states. Solar System Educators attend annual training institutes at the Jet Propulsion Laboratory during their first two years in the program. All Solar System Educators receive additional online training, materials and support. The JPL missions and programs involved in SSEP include: Cassini Mission to Saturn, Galileo Mission to Jupiter, STARDUST Comet Sample Return Mission, Deep Impact Mission to a Comet, Mars Exploration Program, Outer Planets Program, Deep Space Network, JPL Space and Earth Science Directorate, and the NASA Office of Space Science Solar System Exploration Education and Public Outreach Forum. Scientists can get involved with this program by cooperatively presenting at workshops conducted in their area, acting as a content resource or by actively mentoring Solar System Educators. Additionally, SSEP will expand this year to include other missions and programs related to the Solar System and the Sun.
DIALOG: An executive computer program for linking independent programs

NASA Technical Reports Server (NTRS)

Glatt, C. R.; Hague, D. S.; Watson, D. A.

1973-01-01

A very large scale computer programming procedure called the DIALOG Executive System has been developed for the Univac 1100 series computers. The executive computer program, DIALOG, controls the sequence of execution and data management function for a library of independent computer programs. Communication of common information is accomplished by DIALOG through a dynamically constructed and maintained data base of common information. The unique feature of the DIALOG Executive System is the manner in which computer programs are linked. Each program maintains its individual identity and as such is unaware of its contribution to the large scale program. This feature makes any computer program a candidate for use with the DIALOG Executive System. The installation and use of the DIALOG Executive System are described at Johnson Space Center.
Computer program for design and performance analysis of navigation-aid power systems. Program documentation. Volume 1: Software requirements document

NASA Technical Reports Server (NTRS)

Goltz, G.; Kaiser, L. M.; Weiner, H.

1977-01-01

A computer program has been developed for designing and analyzing the performance of solar array/battery power systems for the U.S. Coast Guard Navigational Aids. This program is called the Design Synthesis/Performance Analysis (DSPA) Computer Program. The basic function of the Design Synthesis portion of the DSPA program is to evaluate functional and economic criteria to provide specifications for viable solar array/battery power systems. The basic function of the Performance Analysis portion of the DSPA program is to simulate the operation of solar array/battery power systems under specific loads and environmental conditions. This document establishes the software requirements for the DSPA computer program, discusses the processing that occurs within the program, and defines the necessary interfaces for operation.
Expert system for the design of heating, ventilating, and air-conditioning systems. Master's thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Camejo, P.J.

1989-12-01

Expert systems are computer programs that seek to mimic human reason. An expert system shelf, a software program commonly used for developing expert systems in a relatively short time, was used to develop a prototypical expert system for the design of heating, ventilating, and air-conditioning (HVAC) systems in buildings. Because HVAC design involves several related knowledge domains, developing an expert system for HVAC design requires the integration of several smaller expert systems known as knowledge bases. A menu program and several auxiliary programs for gathering data, completing calculations, printing project reports, and passing data between the knowledge bases are neededmore » and have been developed to join the separate knowledge bases into one simple-to-use program unit.« less
System Analysis in Instructional Programming: The Initial Phases of the Program Construction Process.

ERIC Educational Resources Information Center

Bjerstedt, Ake

A three-volume series describes the construction of a self-instructional system as a work process with three main phases: system analysis, system synthesis, and system modification and evaluation. After an introductory discussion of some basic principles of instructional programing, this first volume focuses on the system analysis phase,…
Programs for Testing Processor-in-Memory Computing Systems

NASA Technical Reports Server (NTRS)

Katz, Daniel S.

2006-01-01

The Multithreaded Microbenchmarks for Processor-In-Memory (PIM) Compilers, Simulators, and Hardware are computer programs arranged in a series for use in testing the performances of PIM computing systems, including compilers, simulators, and hardware. The programs at the beginning of the series test basic functionality; the programs at subsequent positions in the series test increasingly complex functionality. The programs are intended to be used while designing a PIM system, and can be used to verify that compilers, simulators, and hardware work correctly. The programs can also be used to enable designers of these system components to examine tradeoffs in implementation. Finally, these programs can be run on non-PIM hardware (either single-threaded or multithreaded) using the POSIX pthreads standard to verify that the benchmarks themselves operate correctly. [POSIX (Portable Operating System Interface for UNIX) is a set of standards that define how programs and operating systems interact with each other. pthreads is a library of pre-emptive thread routines that comply with one of the POSIX standards.
Space shuttle atmospheric revitalization subsystem/active thermal control subsystem computer program (users manual)

NASA Technical Reports Server (NTRS)

1973-01-01

A shuttle (ARS) atmosphere revitalization subsystem active thermal control subsystem (ATCS) performance routine was developed. This computer program is adapted from the Shuttle EC/LSS Design Computer Program. The program was upgraded in three noteworthy areas: (1) The functional ARS/ATCS schematic has been revised to accurately synthesize the shuttle baseline system definition. (2) The program logic has been improved to provide a more accurate prediction of the integrated ARS/ATCS system performance. Additionally, the logic has been expanded to model all components and thermal loads in the ARS/ATCS system. (3) The program is designed to be used on the NASA JSC crew system division's programmable calculator system. As written the new computer routine has an average running time of five minutes. The use of desk top type calculation equipment, and the rapid response of the program provides the NASA with an analytical tool for trade studies to refine the system definition, and for test support of the RSECS or integrated Shuttle ARS/ATCS test programs.
23 CFR 637.207 - Quality assurance program.

Code of Federal Regulations, 2012 CFR

2012-04-01

... program. (a) Each STD's quality assurance program shall provide for an acceptance program and an independent assurance (IA) program consisting of the following: (1) Acceptance program. (i) Each STD's... STD shall establish a dispute resolution system. The dispute resolution system shall address the...
23 CFR 637.207 - Quality assurance program.

Code of Federal Regulations, 2014 CFR

2014-04-01

... program. (a) Each STD's quality assurance program shall provide for an acceptance program and an independent assurance (IA) program consisting of the following: (1) Acceptance program. (i) Each STD's... STD shall establish a dispute resolution system. The dispute resolution system shall address the...
23 CFR 637.207 - Quality assurance program.

Code of Federal Regulations, 2013 CFR

2013-04-01

... program. (a) Each STD's quality assurance program shall provide for an acceptance program and an independent assurance (IA) program consisting of the following: (1) Acceptance program. (i) Each STD's... STD shall establish a dispute resolution system. The dispute resolution system shall address the...
Status of the NASA YF-12 Propulsion Research Program

NASA Technical Reports Server (NTRS)

Albers, J. A.

1976-01-01

The YF-12 research program was initiated to establish a technology base for the design of an efficient propulsion system for supersonic cruise aircraft. The major technology areas under investigation in this program are inlet design analysis, propulsion system steady-state performance, propulsion system dynamic performance, inlet and engine control systems, and airframe/propulsion system interactions. The objectives, technical approach, and status of the YF-12 propulsion program are discussed. Also discussed are the results obtained to date by the NASA Ames, Lewis, and Dryden research centers. The expected technical results and proposed future programs are also given. Propulsion system configurations are shown.
77 FR 51845 - Intelligent Transportation Systems Program Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-27

... DEPARTMENT OF TRANSPORTATION Intelligent Transportation Systems Program Advisory Committee; Notice.... Department of Transportation. ACTION: Notice. The Intelligent Transportation Systems (ITS) Program Advisory..., development, and implementation of intelligent transportation systems. Through its sponsor, the ITS Joint...

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