Acute toxicity of ammonia in Meagre (Argyrosomus regiusAsso, 1801) at different temperatures

2015 ◽  
Vol 47 (11) ◽  
pp. 3593-3598 ◽  
Author(s):  
Mehmet Kir ◽  
Mustafa Topuz ◽  
Murat Can Sunar ◽  
Havva Topuz
Keyword(s):  
Acute Toxicity ◽  
Different Temperatures

Acute Toxicity of Arsenic under Different Temperatures and Salinity Conditions on the White Shrimp Litopenaeus vannamei

2013 ◽  
Vol 152 (3) ◽  
pp. 350-357 ◽  
Author(s):  
Jesús Alberto Valentino-Álvarez ◽  
Gabriel Núñez-Nogueira ◽  
Laura Fernández-Bringas
Keyword(s):  
Acute Toxicity ◽  
Litopenaeus Vannamei ◽  
White Shrimp ◽  
Different Temperatures

scholarly journals Effects of Fe3+ on Acute Toxicity and Regeneration of Planarian (Dugesia japonica) at Different Temperatures

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xue Ding ◽  
Linxia Song ◽  
Yahong Han ◽  
Yingbo Wang ◽  
Xiaowang Tang ◽  
...  
Keyword(s):  
Water Pollution ◽  
Acute Toxicity ◽  
Toxic Effects ◽  
Regeneration Rate ◽  
Planarian Regeneration ◽  
Suitable Temperature ◽  
Different Temperatures ◽  
Dugesia Japonica ◽  
The Difference ◽  
Head Regeneration

Objective. To investigate the effects of different concentrations of Fe3+ on the acute toxicity and regeneration of planarian at different temperatures. Method. The planarians were treated with 40 mg/l, 50 mg/l, 60 mg/l, and 70 mg/l Fe3+ solution and placed in 15°C, 20°C, and 25°C, respectively, to observe the mortality and the poisoning pattern of the planarian. In addition, the planarians were cut into three parts of head, trunk, and tail, then placed in Fe3+ solution at concentrations of 10 mg/l, 15 mg/l, 20 mg/l, and 30 mg/l, and placed in 15°C, 20°C, and 25°C respectively, and the regeneration rate of the planarian was investigated. Results. At the same temperature, in the concentration of Fe3+ from 40 mg/l to 70 mg/l, the mortality of the planarian increased with the increasing of the concentration of Fe3+; at the same concentration and different temperatures, the death speed of the planarian is the fastest at 20°C, the next at 25°C, and the lowest at 15°C, indicating that the toxic effect of Fe3+ can be accelerated at a suitable temperature of 20°C. At the same temperature, in the low concentration of Fe3+ from 10 mg/l to 30 mg/l, the regeneration rate of the planarian gradually decreased with the increasing of the concentration of Fe3+; at the same concentration and different temperature, the regeneration rate of planarian was faster at 20°C and 25°C, but the difference between 20°C and 25°C was small, and the slowest at 15°C, indicating that the low temperature significantly affects the planarian regeneration speed. The study also found the regeneration rates of the head, trunk, and tail of the planarian were different; the head regeneration was the fastest, the trunk was the second, and the tail was the slowest. Conclusion. Fe3+ had obvious toxic effects on the survival and regeneration of planarian; the planarian is sensitive to Fe3+ and may be used to detect Fe3+ water pollution; in addition, temperature can affect the toxic effects of Fe3+ and thus affect the survival and regeneration of the planarian. Therefore, the temperature should be taken into consideration when detecting water Fe3+ pollution.

scholarly journals Acute Effects of Ammoniac Nitrogen on Marine Copepod Acartia pacifica When Exposed to Different Temperature Conditions

2018 ◽  
Vol 6 (2) ◽  
pp. 6
Author(s):  
Jiagen Shang ◽  
Qi Yu ◽  
Mengxue Lu
Keyword(s):  
Acute Toxicity ◽  
Temperature Gradients ◽  
Acute Effects ◽  
Marine Copepod ◽  
Temperature Conditions ◽  
Different Temperatures ◽  
Observation Results ◽  
Changing Tendency

Acute toxicity of ammoniac nitrogen on marine copepod Acartia pacifica when exposed to different temperatures of 10℃~25℃were performed under controlled lab conditions. The changing tendency of mortality was evaluated and the 48h LC50 was determined according to the observation. Results showed that the 48h LC50 in different temperature gradients were for Pacific spindle daphnia 48 h - LC50 is 65.889 mg/L for 25 ℃, 134.214 mg/L for 20 ℃, 71.247 mg/L for 15 ℃ and 27.318 mg/L for 10 ℃, respectively. Temperature seemed to exert impacts on the stress induced by ammoniac nitrogen, and the peak of 48h LC50 appeared in between 15 ℃ and 20 ℃. The toxicity of ammonia showed a tendency to decrease with the increase of temperature before the peak while the was significantly enhanced with temperature increasing thereafter. 

Acute Toxicity of Cyanide to Rainbow Trout (Salmo gairdneri) Acclimated at Different Temperatures

1982 ◽  
Vol 39 (10) ◽  
pp. 1426-1429 ◽  
Author(s):  
Tibor G. Kovacs ◽  
Gérard Leduc
Keyword(s):  
Rainbow Trout ◽  
Acute Toxicity ◽  
Temperature Effect ◽  
Salmo Gairdneri ◽  
Cyanide Concentration ◽  
Cyanide Toxicity ◽  
Juvenile Rainbow Trout ◽  
Different Temperatures ◽  
Median Lethal Concentrations ◽  
Flow Through

The toxicity of cyanide (HCN) to juvenile rainbow trout (Salmo gairdneri) acclimated for 3 wk at 6, 12, and 18 °C was determined at these temperatures by flow-through bioassays, in the cyanide concentration range of 0.018–0.087 mg∙L−1. The 96-h median lethal concentrations (LC50) were 0.028 ± 0.004 mg∙L−1 at 6 °C, 0.042 ± 0.004 mg∙L−1 at 12 °C, and 0.068 ± 0.004 mg∙L−1 at 18 °C. Warm acclimated rainbow trout survived longer in lethal concentrations of cyanide. Toxicity curves clearly showed the temperature effect on the acute toxicity of cyanide is concentration dependent. At slowly lethal concentrations, cyanide is more toxic at lower temperatures, whereas at rapidly lethal levels the reverse occurs; the reversal takes place at 0.10 mg∙L−1 HCN.Key words: cyanide, acute toxicity, temperature, rainbow trout

Observations oh Nucleation and Growth of Voids in Nickel

1970 ◽  
Vol 28 ◽  
pp. 414-415
Author(s):  
J. L. Brimhall ◽  
H. E. Kissinger ◽  
B. Mastel
Keyword(s):  
High Purity ◽  
Growth Stage ◽  
Elevated Temperatures ◽  
Early Growth ◽  
Nucleation And Growth ◽  
Pure Nickel ◽  
Different Temperatures ◽  
Total Fluence ◽  
Neutron Exposure ◽  
Growth Of Voids

Some information on the size and density of voids that develop in several high purity metals and alloys during irradiation with neutrons at elevated temperatures has been reported as a function of irradiation parameters. An area of particular interest is the nucleation and early growth stage of voids. It is the purpose of this paper to describe the microstructure in high purity nickel after irradiation to a very low but constant neutron exposure at three different temperatures.Annealed specimens of 99-997% pure nickel in the form of foils 75μ thick were irradiated in a capsule to a total fluence of 2.2 × 1019 n/cm2 (E > 1.0 MeV). The capsule consisted of three temperature zones maintained by heaters and monitored by thermocouples at 350, 400, and 450°C, respectively. The temperature was automatically dropped to 60°C while the reactor was down.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

Microstructure of sputter deposited Ni-Sb ohmic contacts on GaAs

1989 ◽  
Vol 47 ◽  
pp. 450-451
Author(s):  
S. Yegnasubramanian ◽  
V.C. Kannan ◽  
R. Dutto ◽  
P.J. Sakach
Keyword(s):  
High Performance ◽  
Ohmic Contacts ◽  
Surface Defects ◽  
Pure Metal ◽  
Device Fabrication ◽  
Native Oxide ◽  
Metal Thin Films ◽  
Recent Developments ◽  
Different Temperatures ◽  
Sputter Deposited

Recent developments in the fabrication of high performance GaAs devices impose crucial requirements of low resistance ohmic contacts with excellent contact properties such as, thermal stability, contact resistivity, contact depth, Schottky barrier height etc. The nature of the interface plays an important role in the stability of the contacts due to problems associated with interdiffusion and compound formation at the interface during device fabrication. Contacts of pure metal thin films on GaAs are not desirable due to the presence of the native oxide and surface defects at the interface. Nickel has been used as a contact metal on GaAs and has been found to be reactive at low temperatures. Formation Of Ni2 GaAs at 200 - 350C is reported and is found to grow epitaxially on (001) and on (111) GaAs, but is shown to be unstable at 450C. This paper reports the investigations carried out to understand the microstructure, nature of the interface and composition of sputter deposited and annealed (at different temperatures) Ni-Sb ohmic contacts on GaAs by TEM. Attempts were made to correlate the electrical properties of the films such as the sheet resistance and contact resistance, with the microstructure. The observations are corroborated by Scanning Auger Microprobe (SAM) investigations.

Sign in / Sign up

Export Citation Format

Share Document