Effect of Environmental Pollutant Mixtures on Acid DNase Activity in Mussel Mytilus galloprovincialis: Ex Situ and In Situ Study

2017 ◽  
Vol 99 (4) ◽  
pp. 433-437
Author(s):  
Ines Kovačić ◽  
Maja Fafanđel ◽  
Lorena Perić ◽  
Iris Batel
Keyword(s):  
Mytilus Galloprovincialis ◽  
Environmental Pollutant ◽  
Ex Situ ◽  
Dnase Activity ◽  
In Situ Study ◽  
Acid Dnase ◽  
Pollutant Mixtures

scholarly journals Macroinvertebrates and fishes in the part of the Danube flowing through the Iron Gate national park and possibilities of their protection under in situ and ex situ conditions

2004 ◽  
Vol 56 (1-2) ◽  
pp. 53-57 ◽  
Author(s):  
Vladica Simic ◽  
Snezana Simic
Keyword(s):  
National Park ◽  
Stress Factors ◽  
Ex Situ ◽  
Legal Regulations ◽  
Medium Term ◽  
Natural Conditions ◽  
In Situ Study ◽  
Iron Gate ◽  
Comparison Of The Results

Comparison of the results of later investigations of the Danube in the part flowing through in the Iron Gate (Djerdap) National Park with those of research conducted earlier (20 to 40 years ago) shows that changes have occurred in regard to the presence and especially the abundance of certain hydrobionts on this sector of the river, a finding that applies to all groups examined. The paper discusses the potential and results of conservation measures realized through both legal regulations and medium-term plans for the advancement of fishing in this region. In addition to in situ study during the period from 1999 to 2003, a large number of species (especially of macroinvertebrates and fish) were also investigated under artificial conditions (in the Kragujevac Aquarium) in order to gain a better understanding of their ecological characteristics, especially their sensitivity to various environmental stress factors. The presented results indicate that weight of specimens and success of culturing under ex situ conditions are correlated with their sensitivity under natural conditions.

Plasma Passivation Scheme for III–V Compound Semiconductor Surfaces

1984 ◽  
Vol 38 ◽  
Author(s):  
J. B. Theeten ◽  
S. Gourrier ◽  
P. Friedel ◽  
M. Taillepied ◽  
D. Arnoult ◽  
...  
Keyword(s):  
Auger Spectroscopy ◽  
Ex Situ ◽  
Leakage Currents ◽  
In Situ Study ◽  
Gaas Devices ◽  
Deposition Yield ◽  
Plasma Passivation ◽  
Electrical Analysis ◽  
Recombination Velocity

AbstractPassivation of III-V compounds, especially GaAs, is still a major problem. Surface mechanisms related to stoichiometry defects (free As formation, vacancies) play an important role in the detrimental effects observed on GaAs devices (interface traps, leakage currents, parasitic transients …).We first analyze the phenomena occuring at GaAs (100) surfaces exposed to several (H2,N2 ) multipolar plasmas, with the following methods : - in situ study of the surface morphology and roughness using ellipsometry and electron diffraction - chemical analysis using photoemission and Auger spectroscopy - electrical analysis in situ (Fermi level position deduced from photoemission, work function measurements) or ex situ (device characterization, C(V) analysis).Using H2 based plasma treatments, a complete cleaning (oxide and contamination removal) can be obtained at moderate (below 200 °C) temperatures. This process, associated with surface nitridation and dielectric deposition, yield improved surface properties (lower recombination velocity and reduction of devices parasitic effects).The case of Ga1−xInxAs (100) surfaces (with x varying from 0 to 0.53)is then discussed and a comparative study is given, indicating that native nitridation may also be a good solution,in this case.

scholarly journals Walleye Responses to Barotrauma Relief Treatments for Catch-and-Release Angling: Short-Term Changes to Condition and Behavior

2018 ◽  
Vol 9 (2) ◽  
pp. 415-430 ◽  
Author(s):  
Rebecca L. Eberts ◽  
Megan A. Zak ◽  
Richard G. Manzon ◽  
Christopher M. Somers
Keyword(s):  
Deep Water ◽  
Sublethal Effects ◽  
Ex Situ ◽  
Control Fish ◽  
Swim Bladder ◽  
Short Term ◽  
Catch And Release ◽  
In Situ Study ◽  
And Behavior

Abstract Barotrauma causes stress and impairment in fish and can cause mortality after catch and release. Relief of barotrauma symptoms is necessary to reduce mortality, but we currently know little about sublethal effects associated with relief methods. Here, we assess the condition and behavior of tournament-caught Walleye Sander vitreus with barotrauma by using three popular relief methods: 1) swim bladder venting, 2) deep-water release (descending), and 3) livewell reorientation with fin weights. In a short-term ex situ experiment, 50% of untreated fish with barotrauma did not recover sufficiently to be released after 20 h. Fin weighting immediately improved condition by enabling fish to regain correct orientation; however, only 53% of fin-weighted fish recovered sufficiently to be released. All vented fish were negatively buoyant, but 73% were releasable after the holding period. In a concurrent in situ study, acoustic telemetry showed that Walleye without barotrauma (controls) made variable postrelease movements (total distance: 5.1–27.6 km), descended fish behaved similarly to controls (4.7–28.6 km), and vented fish made the shortest movements (2.6–16.7 km). However, there were no statistically significant differences in distance metrics among groups. Control and descended fish used larger areas and volumes of the lake than vented fish. Descended fish also used significantly deeper depths than vented fish, and control fish were intermediate in the depth used. Telemetry did not indicate mortality of any fish in the in situ study. Our data suggest that without treatment, mortality of Walleye with barotrauma could be as high as 50%. Fin weighting is not an effective catch-and-release aid for Walleye with moderate-to-severe barotrauma, and swim bladder venting may alter short-term, postrelease movements and habitat use. The consequences of these short-term changes to Walleye behavior from a fisheries management perspective are unclear. Eliminating catch-and-release angling in deep water is the best means of managing barotrauma in Walleye. If deep-water angling cannot be avoided, we recommend noninvasive descending over venting.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Atomic Layer Deposition of LiF and Lithium Ion Conducting (AlF3)(LiF)x Alloys Using Trimethylaluminum, Lithium Hexamethyldisilazide and Hydrogen Fluoride

2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Atomic Layer ◽  
Mass Gain ◽  
Alloy Film ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Ion Conducting ◽  
Good Agreement

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>

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