scholarly journals Stress in Salminus brasiliensis fingerlings due to different densities and times of transportation

2008 ◽  
Vol 60 (3) ◽  
pp. 755-761 ◽  
Author(s):  
W.B. Adamante ◽  
A.P.O. Nuñer ◽  
L.J.G. Barcellos ◽  
A.B. Soso ◽  
J.A. Finco
Keyword(s):  
Electrical Conductivity ◽  
Pure Oxygen ◽  
Transportation Time ◽  
Plastic Bags ◽  
Salminus Brasiliensis

The stress in dorado fingerlings (Salminus brasiliensis) caused by transportation at densities of 5, 10, and 15g/l after 4, 8, and 12h was evaluated by the concentration of tissue cortisol measured by ELISA. The conditions of transportation were simulated on an orbital table shaker with horizontal movements, inside 15 litres plastic bags filled with 4 litres of water and pure oxygen. Cortisol concentrations increased in all densities after 4h of transportation converging to a common concentration at the end of the tested times. Electrical conductivity of water increased with density and transportation time. The transportation caused stress on fish, but the increase on density and in times of transportation did not cause mortality to fingerlings. The transportation of S. brasiliensis fingerlings can be done without mortality or apparent injuries to animals until the maximum analyzed density of 15g/l and up to 12h.

Ceramic composite membranes based on Bi3Ru3O11 – Bi1,6Er0,4O3 for obtaining of oxygen

2021 ◽  
Vol 6 ◽  
pp. 22-28
Author(s):  
P. E. Dergacheva ◽  
◽  
I. V. Kulbakin ◽  
S. V. Fedorov ◽  
A. S. Lysenkov ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ceramic Composite ◽  
Oxygen Permeability ◽  
Total Porosity ◽  
Composite Membranes ◽  
Ceramic Composites ◽  
Argon Atmosphere ◽  
Pure Oxygen ◽  
Total Conductivity ◽  
Temperature Dependence Of Conductivity

Using hot uniaxial pressing in an argon atmosphere with a stress of 35 MPa and with a holding at 800 °C for 1 hour, ceramic composites of Bi3Ru3O11 – 50, 65 wt % Bi1,6Er0,4O3 were obtained. It was found that phase composition of the composites does not change during gas chromatographic testing at 800 °C and well corresponds to the specified one. Microstructure of the obtained composites was tested and the formation of dense composites with a total porosity of less than 1% and with a uniform distribution of the Bi3Ru3O11 and Bi1,6Er0,4O3 components in bulk of material was demonstrated. Transport properties (total conductivity, oxygen fluxes and selectivity of separating oxygen over nitrogen) of the obtained composites at 600 – 800 °C had been investigated. Thus, at 800 °C the electrical conductivity of Bi3Ru3O11 – 50, 65 wt % Bi1,6Er0,4O3 was about 200 and 50 Ohm–1∙cm–1, respectively, while the metallic nature of their temperature dependence of conductivity is correlated to that for the Bi3Ru3O11. The value of oxygen permeability for the obtained ceramic composites of about 7∙10–9 mol·cm–1·s–1 at 800 °C, which is compared to other membrane materials based on bismuth oxide, demonstrated the potential of their further use in the tasks for obtaining of pure oxygen from air.

scholarly journals Fabrication and Cold Drawing of Copper Covetic Nanostructured Carbon Composites/ Otrzymywanie Oraz Ciągnienia Kompozytów Miedzianych Typu Covetic O Strukturze Nanometrycznej

2014 ◽  
Vol 59 (4) ◽  
pp. 1283-1286 ◽  
Author(s):  
T. Knych ◽  
G. Kiesiewicz ◽  
P. Kwasniewski ◽  
A. Mamala ◽  
B. Smyrak ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Secondary Ion Mass Spectrometry ◽  
Cold Drawing ◽  
Production Method ◽  
Pure Oxygen ◽  
Cast Material ◽  
Mechanical And Electrical Properties ◽  
Type Device ◽  
Bridge Type ◽  
Composite Production

Abstract This paper presents the research results of copper Covetic metallurgical synthesis along with the characterization of cast material and the processing of casts into wires. The Cu-C composite production method was based on patent applications of Third Millennium Metals. Obtained materials were tested for their chemical composition (including Secondary Ion Mass Spectrometry (SIMS) analysis for carbon presence), mechanical properties and electrical conductivity. Measurements were also performed for wires which were first cut from obtained casts and next cold drawn into final wire form. Produced wires were tested for their mechanical and electrical properties. Electrical conductivity of wires was measured with the use of high precision Thompson’s- Kelvin’s bridge type device. A key objective of the research was to determine if Covetic copper has higher electrical conductivity than pure oxygen free copper.

scholarly journals Transport of Pirarucu Arapaima gigas juveniles in plastic bag

2003 ◽  
Vol 33 (4) ◽  
pp. 637-642 ◽  
Author(s):  
Levy de Carvalho Gomes ◽  
Rodrigo Roubach ◽  
Bruno Adan Sagratzki Cavero ◽  
Manoel Pereira-Filho ◽  
Elisabeth Criscuolo Urbinati
Keyword(s):  
Fish Species ◽  
Pure Oxygen ◽  
Fish Feeding ◽  
Atmospheric Air ◽  
Plastic Bags ◽  
Arapaima Gigas ◽  
Plastic Bag ◽  
Response To Stress ◽  
Normal Feeding ◽  
Polyethylene Bags

This study examined the stress response of pirarucu juveniles in a closed system transport. Pirarucu (Arapaima gigas) is a native Amazonian fish species from the Osteoglossidae family and an obligated air breather. A short duration transport trial (6h) was undertaken comparing closed polyethylene bags filled with atmospheric air (Air group) and bags filled with pure oxygen (Oxi group). Dissolved oxygen was the only water parameter that presented a difference between fish groups, and was saturated in the oxi group as expected. There was no mortality in either group after transport. Fish feeding was observed 36 h after transport for all fish, and normal feeding consumption was observed at 72 h. In both groups physiological responses were similar. Cortisol did not show any significant alteration during the sampled period. Unlike most fish species, cortisol values were unaltered in both groups during sampling, while glucose presented a significant change up to 12 h after transport. The results showed that pirarucu transport in plastic bags could be made with either atmospheric air or pure oxygen, since physiological response to stress, water quality and feeding behavior after 36 h were similar in both groups.

scholarly journals An Evaluation of Sedatives for Use in Transport of Juvenile Endangered Fishes in Plastic Bags

2019 ◽  
Vol 10 (2) ◽  
pp. 532-543
Author(s):  
Laura A. Tennant ◽  
Ben M. Vaage ◽  
David L. Ward
Keyword(s):  
Logistic Regression ◽  
Field Trial ◽  
Grand Canyon ◽  
Pure Oxygen ◽  
Remote Locations ◽  
Plastic Bags ◽  
Conservation Actions ◽  
Humpback Chub ◽  
Helicopter Transportation ◽  
Tricaine Methanesulfonate

Abstract Trucks and aircraft typically transport rare or endangered fishes in large unsealed tanks containing large volumes of water (typically hundreds of liters) during conservation efforts. However, to reduce weight and overall shipping costs, fish breeders commonly send ornamental fishes by mail in small sealed plastic bags filled with oxygen, minimal water, and a small amount of sedative. Our goal was to evaluate if we could also use these “minimal-water” methods used for shipping ornamental fishes to safely transport endangered Humpback Chub Gila cypha into remote locations within Grand Canyon on foot to eliminate helicopter transportation costs associated with conservation actions. In the laboratory, we placed 20 (mean = 193.9 g of fish/L, SD = 37.8) juvenile Bonytail Gila elegans or Humpback Chub in plastic bags containing 1 L of water and pure oxygen for 4, 8, and 12 h. Treatments contained either no sedative or one of three sedatives—AquaCalm (metomidate hydrochloride), Tricaine-S (tricaine methanesulfonate or MS-222), or Aqui-S 20E (eugenol)—to evaluate the effectiveness of minimal-water methods for use in fish transport. Aqui-S 20E and the control without sedatives exhibited the highest survival (logistic regression, Aqui-S 20E, p = 0.994, 95% CI [0.978, 0.998]; control, p = 0.995, 95% CI [0.981, 0.998]), followed by Tricaine-S (p = 0.933, 95% CI [0.902, 0.955]) and AquaCalm (p = 0.355, 95% CI [0.307, 0.406]). We also conducted a field trial in which we placed 240 juvenile Humpback Chub in shipping bags (n = 20 fish/bag/L of water; mean = 143.2 g of fish/L, SD = 9.72) with no sedative or 10.0 mg/L of Aqui-S 20E and transported them by vehicle and on foot. No fish perished during transport, indicating fisheries personnel can use these minimal-water methods to safely, and at little expense, transport endangered Humpback Chub into remote locations.

scholarly journals Hydrogen peroxide on acclimation of soursop seedlings under irrigation water salinity

2019 ◽  
Vol 40 (4) ◽  
pp. 1441 ◽  
Author(s):  
André Alisson Rodrigues da Silva ◽  
Geovani Soares de Lima ◽  
Luana Lucas de Sá Almeida Veloso ◽  
Carlos Alberto Vieira de Azevedo ◽  
Hans Raj Gheyi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Peroxide ◽  
Leaf Area ◽  
Salt Concentration ◽  
Irrigation Water ◽  
Sandy Loam ◽  
Water Salinity ◽  
Limiting Factor ◽  
Exogenous Application ◽  
Plastic Bags

The Brazilian Northeast region provides favorable conditions for the exploitation of several crops, but the high salt concentration in irrigation water constitutes a limiting factor for production in most cases. In this context, this study aimed to evaluate the emergence, growth and partition of photoassimilates in soursop seedlings, cv. ‘Morada Nova’, subjected to irrigation with water of increasing salinity levels and to exogenous application of hydrogen peroxide. The study was carried out in plastic bags under greenhouse conditions, using a sandy loam Regolithic Neosol, in the municipality of Campina Grande, PB, Brazil. Treatments were distributed in randomized blocks, in a 5 x 5 factorial arrangement, relative to five levels of irrigation water electrical conductivity - ECw (0.7, 1.4, 2.1, 2.8 and 3.5 dS m-1) and five concentrations of hydrogen peroxide - H2O2 (0, 25, 50, 75 and 100 µM), with four replicates and three plants per plot. Increasing salt concentration compromised all variables analyzed and leaf area was most sensitive. As irrigation water electrical conductivity increased, the deleterious effects of water salinity on the emergence percentage, emergence speed index, stem diameter and leaf area were attenuated by the exogenous application of hydrogen peroxide, with highest efficiency at the concentration of 50 µM. Hydrogen peroxide concentrations above 38 µM inhibited the specific leaf area of soursop, cv. ‘Morada Nova’.

Electrical Conductivity and Phase Transition of Solid Oxide Fuel Cell Electrolyte La2Mo2-xTixO9-δ Ceramics

2012 ◽  
Vol 557-559 ◽  
pp. 1223-1227
Author(s):  
Ju Mei Yu ◽  
Ming Ju Chao ◽  
De Chuan Li ◽  
Ming Yu Li ◽  
Hua Wu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Solid State Reaction Method ◽  
Pure Oxygen ◽  
Transport Numbers ◽  
Structure Transition ◽  
Ion Conductor ◽  
Oxygen Ion ◽  
Oxygen Ion Conductor ◽  
Electrical Conductivities ◽  
Ion Transport Numbers

A novel series of ceramic samples La2Mo2-xTixO9-δ (x = 0, 0.025, 0.05, 0.075) were prepared by solid-state reaction method. Their structures and phase transitions were studied by XRD, DSC and CTE. Their Electrical conductivities and oxygen ion transport numbers were measured by AC impedance spectroscopy at 773~1073 K and EMF at 673~1073 K, respectively. Results showed that even when x=0.075, the sample was almost pure oxygen ion conductor under the oxygen partial pressure gradient of 1.0 atm/0.21 atm, and though all the Ti-doped samples still underwent α/β structure transition, no abrupt change in the electrical conductivity was observed accompanying with the transition. They exhibited considerably higher electrical conductivity than La2Mo2O9, especially at 773~873 K and the conductivity increased with increasing x value. The value of conductivity for La2Mo1.925Ti0.075O9-δ reached 8.5×10-3 S•cm-1 at 773 K and 0.08 S•cm-1 at 1,073 K.

scholarly journals Irrigação com águas salinas e adubação nitrogenada na produção de mudas mamoeiro “Formosa”

2017 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
Francisco Wesley Alves Pinheiro ◽  
Reginaldo Gomes Nobre ◽  
Leandro de Pádua Souza ◽  
Sabrina Gomes de Oliveira ◽  
Jonathan Estievns Soares Araújo ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Irrigation Water ◽  
Saline Water ◽  
Block Design ◽  
Stem Biomass ◽  
Plastic Bags ◽  
Randomized Block Design ◽  
Affected Plant ◽  
Semi Arid Region ◽  
Nitrogen Rates

<p>A ocorrência de longos períodos de estiagem e a irregularidade anual das precipitações no Semiárido do Nordeste brasileiro torna a prática da irrigação imprescindível para garantir a produção agrícola com segurança, no entanto, as fontes hídricas disponíveis nem sempre são de boa qualidade. Desta forma, objetivou-se avaliar os efeitos da irrigação com águas de distintos níveis salinos associado a doses de nitrogênio sobre o crescimento de mudas de mamoeiro 'Formosa' em condições de semiárido nordestino. O experimento foi conduzido em sacolas plásticas sob condições de ambiente protegido no Centro de Ciências e Tecnologia Agroalimentar da Universidade Federal da Campina Grande, campus Pombal- PB. Utilizou-se o delineamento experimental de blocos casualizados, em esquema fatorial 5 x 4, com 4 repetições, sendo os tratamentos compostos de cinco níveis de condutividade elétrica da água – CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m<sup>-1</sup>) e quatro doses de nitrogênio (70, 100, 130 e 160% de N recomendada). A condutividade elétrica da água de irrigação a partir de 0,3 dS m<sup>-1</sup> afetou negativamente altura da planta e fitomassa seca de caule. Observa-se que a dose de 70% de N e de 100% proporcionou respectivamente, maior produção de fitomassa seca de raiz e número de folhas. Não foi verificado efeito significativo para as variáveis diâmetro do caule e fitomassa seca do caule submetida a distintas CEa e adubação nitrogenada; assim como, não houve interação entre os fatores (CEa x Adubação com N) sobre o crescimento das mudas, As variáveis NF, FFF, FSF, FSR apresentaram tolerância ao aumento da condutividade elétrica da água de irrigação.</p><p align="center"><strong><em>Irrigation with saline water and nitrogen in seedlings papaya production "Formosa" </em></strong></p><pre><strong>Abstract:</strong> The occurrence of long periods of drought and the annual irregularity of precipitation in the semi-arid region of the Brazilian Northeast make irrigation practice essential to ensure safe agricultural production, however, the available water sources are not always of good quality. In this way, the objective of this work was to evaluate the effects of irrigation with waters of different saline levels associated with nitrogen rates on the growth of 'Formosa' papaya seedlings under northeastern semiarid conditions. The experiment was carried out in plastic bags under protected environment conditions at the Center of Science and Technology Agrifood of the Federal University of Campina Grande, Pombal - PB campus. The experimental design was a randomized block design, in a 5 x 4 factorial scheme, with four replications, being the treatments composed of five levels of electrical conductivity of the water (EC, 0.3, 1.1, 1.9, 7 and 3.5 dS m-1) and four nitrogen doses (70, 100, 130 and 160% N recommended). The electrical conductivity of irrigation water from 0.3 dS m-1 negatively affected plant height and dry stem biomass. It is observed that the dose of 70% of N and of 100% provided, respectively, greater dry matter production of root and number of leaves. No significant effect was observed for the variables stem diameter and dry stem biomass submitted to different CEa and nitrogen fertilization; As well as, there was no interaction between the factors (CEa x Fertilization with N) on the growth of the seedlings. The variables NF, FFF, FSF, FSR presented tolerance to the increase of electrical conductivity of irrigation water. </pre>

A High Voltage Electron Microscopy Study of Sub-Oxide Formation in Vanadium

1971 ◽  
Vol 29 ◽  
pp. 212-213
Author(s):  
R. H. Geiss ◽  
R. L. Ladd ◽  
K. R. Lawless
Keyword(s):  
High Vacuum ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Ultra High Vacuum ◽  
Pure Oxygen ◽  
Pressure Oxidation ◽  
High Voltage Electron Microscopy ◽  
Oxidation Study ◽  
Voltage Electron ◽  
Good Agreement

Detailed electron microscope and diffraction studies of the sub-oxides of vanadium have been reported by Cambini and co-workers, and an oxidation study, possibly complicated by carbon and/or nitrogen, has been published by Edington and Smallman. The results reported by these different authors are not in good agreement. For this study, high purity polycrystalline vanadium samples were electrochemically thinned in a dual jet polisher using a solution of 20% H2SO4, 80% CH3OH, and then oxidized in an ion-pumped ultra-high vacuum reactor system using spectroscopically pure oxygen. Samples were oxidized at 350°C and 100μ oxygen pressure for periods of 30,60,90 and 160 minutes. Since our primary interest is in the mechanism of the low pressure oxidation process, the oxidized samples were cooled rapidly and not homogenized. The specimens were then examined in the HVEM at voltages up to 500 kV, the higher voltages being necessary to examine thick sections for which the oxidation behavior was more characteristic of the bulk.

Removing Substrate Background in TEM Microanalysis

1974 ◽  
Vol 32 ◽  
pp. 568-569
Author(s):  
John C. Russ ◽  
Nicholas C. Barbi
Keyword(s):  
Electrical Conductivity ◽  
Rapid Growth ◽  
Organic Film ◽  
Absolute Concentration ◽  
Background Signal ◽  
X Ray ◽  
Elemental Concentrations ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
The Continuum

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

1983 ◽  
Vol 41 ◽  
pp. 606-607
Author(s):  
Klaus-Ruediger Peters ◽  
Samuel A. Green
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Critical Point ◽  
Metal Films ◽  
High Magnification ◽  
Osmium Impregnation ◽  
Instrumental Resolution ◽  
20 Nm ◽  
Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

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