scholarly journals Variations in the Toxic Effects of Petroleum Hydrocarbons to Isochrysis galbana under Different Environmental Factors

2015 ◽  
Vol 3 (2) ◽  
pp. 1
Author(s):  
Jianming Chen ◽  
Yongqian Li ◽  
Xuexi Tang ◽  
Hui Xiao
Keyword(s):  
Environmental Factors ◽  
Population Growth ◽  
Stationary Phase ◽  
Growth Rates ◽  
Petroleum Hydrocarbons ◽  
Petroleum Hydrocarbon ◽  
Stationary Phases ◽  
Isochrysis Galbana ◽  
Low Ph ◽  
Marine Phytoplankton

<p><span style="font-family: Times New Roman;">In order to study the toxic effect of petroleum hydrocarbons on marine phytoplankton, <em>Isochrysis galbana</em> was investigated by using the index of 96 h-EC50 and population growth. The results showed that the 96 h-EC50 increased significantly (P</span>＜<span style="font-family: Times New Roman;">0.05) when temperature rising from 15</span>℃<span style="font-family: Times New Roman;"> to 25</span>℃<span style="font-family: Times New Roman;">. The intrinsic growth rates (r) increased but the time to enter into the stationary phase shortened from 15</span>℃<span style="font-family: Times New Roman;"> to 25</span>℃<span style="font-family: Times New Roman;">, and the carrying capability (K) reached highest at 20</span>℃<span style="font-family: Times New Roman;">. In addition, the 96 h-EC50 in the salinity of 31 is higher than that in other salinities and the carrying capability reached the highest level. Moreover, the 96 h-EC50 increased when the pH changing from 6.5 to 8.1, but decreased when the pH more than 8.1. The results also show that the maximum (K) and (r), and the shortest time into stationary phases in the natural pH of seawater. It shows the minimum (K) in the low pH of 6.5. There is no significant (P</span>＞<span style="font-family: Times New Roman;">0.05) between pH7.5 and pH 8.5. In conclusion, temperature, pH and salinity did influence the toxicity of petroleum hydrocarbon to the microalgae (<em>I. galbana</em>).</span></p>

scholarly journals Estimates of regional annual abundance and population growth rates of white sharks off central California

2021 ◽  
Vol 257 ◽  
pp. 109104
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Taylor K. Chapple ◽  
Scot D. Anderson ◽  
Timothy D. White ◽  
...  
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Central California ◽  
Population Growth Rates

Carboxylated cyclofructan 6 as a hydrolytically stable high efficiency stationary phase for hydrophilic interaction liquid chromatography and mixed mode separations

2016 ◽  
Vol 8 (31) ◽  
pp. 6038-6045 ◽  
Author(s):  
Yadi Wang ◽  
M. Farooq Wahab ◽  
Zachary S. Breitbach ◽  
Daniel W. Armstrong
Keyword(s):  
Liquid Chromatography ◽  
Benzoic Acid ◽  
Stationary Phase ◽  
Mixed Mode ◽  
High Efficiency ◽  
Stationary Phases ◽  
Hydrophilic Interaction Liquid Chromatography ◽  
Hydrophilic Interaction

Stationary phases composed of native cyclofructan 6 (CF6) and benzoic acid modified CF6 were synthesized and evaluated for hydrophilic interaction liquid chromatography (HILIC).

scholarly journals Bacterial Cellulose as a Substrate for Microbial Cell Culture

2014 ◽  
Vol 80 (6) ◽  
pp. 1926-1932 ◽  
Author(s):  
Na Yin ◽  
Thiago M. A. Santos ◽  
George K. Auer ◽  
John A. Crooks ◽  
Piercen M. Oliver ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Growth ◽  
Physicochemical Properties ◽  
Stationary Phase ◽  
Bacterial Cellulose ◽  
Growth Rates ◽  
Bacterial Cell ◽  
Acetobacter Xylinum ◽  
Primary Factor ◽  
Nutrient Diffusion

ABSTRACTBacterial cellulose (BC) has a range of structural and physicochemical properties that make it a particularly useful material for the culture of bacteria. We studied the growth of 14 genera of bacteria on BC substrates produced byAcetobacter xylinumand compared the results to growth on the commercially available biopolymers agar, gellan, and xanthan. We demonstrate that BC produces rates of bacterial cell growth that typically exceed those on the commercial biopolymers and yields cultures with higher titers of cells at stationary phase. The morphology of the cells did not change during growth on BC. The rates of nutrient diffusion in BC being higher than those in other biopolymers is likely a primary factor that leads to higher growth rates. Collectively, our results suggest that the use of BC may open new avenues in microbiology by facilitating bacterial cell culture and isolation.

Retardation and Recovery of Growth in Brook Trout Fry (Salvelinus fontinalis) Exposed for Various Durations to Acidified Water

1986 ◽  
Vol 43 (10) ◽  
pp. 2048-2050 ◽  
Author(s):  
W. H. Tam ◽  
P. D. Payson ◽  
R. J. J. Roy
Keyword(s):  
Growth Inhibition ◽  
Growth Rates ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Fish Growth ◽  
Control Fish ◽  
Treated Fish ◽  
Test Fish ◽  
Neutral Water

Brook trout fry (Salvelinus fontinalis) were exposed to pH 4.66 for various durations up to 141 d and then returned to neutral water. Growth of test fish was in general significantly lower than that of control fish for exposures up to days 45–78. In four of six groups of acid-treated fish, growth eventually recovered and the growth rates were not different from that of control fish. The results suggested that growth inhibition was induced early in the exposure to sublethally low pH and that recovery in the latter phase of the experiment occurred whether pH remained acidic or was readjusted to neutral.

scholarly journals ATIVIDADE ACARICIDA DE ÓLEOS ESSENCIAIS SOBRE Tetranychus ludeni (Zacher) (Acari: Tetranychidae) EM DUAS CULTIVARES DE ALGODOEIRO

Nativa ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 469
Author(s):  
Yasmin Bruna de Siqueira Bezerra ◽  
José Vargas de Oliveira ◽  
Taciana Keila dos Anjos Ramalho ◽  
Douglas Rafael e Silva Barbosa ◽  
Carlos Romero Ferreira de Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Essential Oils ◽  
Growth Rates ◽  
Ocimum Basilicum ◽  
Alternative Control ◽  
Population Growth Rates ◽  
Colored Cotton ◽  
Potential Alternative ◽  
Tetranychus Ludeni ◽  
Corymbia Citriodora

O presente trabalho teve como objetivo avaliar os efeitos repelentes e as taxas de crescimento populacional de óleos essenciais de Corymbia citriodora, Ocimum basilicum e Myracroduon urundeuva sobre o ácaro vermelho Tetranychus ludeni (Zacher) em algodoeiro de fibra colorida. Para o teste de repelência, óleos de Corymbia citriodora, Ocimum basilicum e Myracroduon urundeuva foram testados em diferentes concentrações sobre fêmeas adultas de T. ludeni, assim como para o teste de crescimento populacional, onde as cultivares foram tratadas com óleos essenciais.  O efeito repelente foi verificado para todos os óleos testados nas duas cultivares de algodão colorida. As taxas instantâneas de crescimento populacional para T. ludeni nas cultivares de algodoeiro BRS Verde e BRS Rubi foram todas positivas (ri> 0), indicando que a população está em estado ascendente, no entanto, a população cresceu a uma taxa menor quando comparada ao controle. Os óleos essenciais de C. citriodora, O. basilicum e M. urundeuva apresentam efeito acaricida e potencial controle alternativo de T. ludeni em algodoeiro de fibras coloridas sem causar danos ao algodoeiro.Palavras-chave: ácaro vermelho; algodão colorido; controle alternativo; taxa instantânea de crescimento; repelência. ACARICIDAL ACTIVITY OF ESSENTIAL OILS ON RED MITETetranychus ludeni (Zacher) (Acari: Tetranychidae) IN TWO COTTON CULTIVARS ABSTRACT: The objective of this work was to evaluate the repellent and population growth rates of essential oils of Corymbia citriodora, Ocimum basilicum and Myracroduon urundeuva on the red mite Tetranychus ludeni (Zacher) in cotton fiber. For the repellency test, oils of Corymbia citriodora, Ocimum basilicum and Myracroduon urundeuva were tested in different concentrations on adult females of T. ludeni, as well as for the population growth test, where the cultivars were treated with essential oils. The repellent effect was verified for all tested oils the two cultivars of colored cotton. The instant population growth rates for T. ludeni in the cultivars BRS Verde and BRS Rubi were all positive (ri> 0), indicating that the population is in an upward, however, the population grew at a lower rate when compared to the control. The essential oils of C. citriodora, O. basilicum and M. urundeuva have an acaricidal effect and potential alternative control of T. ludeni in cotton from colored fibers without causing damage to the cotton.Keywords: Red mite; colored cotton; essential oils; instant growth rate; repellency.

scholarly journals Biodegradation Potentials of Aspergillus sydowii and Fusarium lichenicola on Total Petroleum Hydrocarbon in an Oilfield Wastewater in Rivers State

2020 ◽  
pp. 1-7
Author(s):  
Williams, Janet Olufunmilayo ◽  
Aleruchi Owhonka
Keyword(s):  
Mixed Culture ◽  
Contaminated Soils ◽  
Petroleum Hydrocarbons ◽  
Petroleum Hydrocarbon ◽  
Total Petroleum Hydrocarbon ◽  
Total Petroleum Hydrocarbons ◽  
Aspergillus Sydowii ◽  
Significant Difference ◽  
Set Up ◽  
Rivers State

This study investigated the potential of Aspergillus sydowii and Fusarium lichenicola as mixed cultures in the biodegradation of Total Petroleum Hydrocarbons TPHs in oilfield wastewater. Oilfield wastewater was collected from an onshore oil producing platform and biodegradation of total petroleum hydrocarbons was investigated using standard methods. Fungi were isolated from oilfield wastewater contaminated soils obtained from the vicinity of the oil producing platform. Experimental control set-up and treatment with mixed culture of fungal isolates were periodically analyzed on days 7 and 21 intervals for total petroleum hydrocarbon degradation using Gas Chromatography (GC). The total amount of TPHs on day 1 recorded 381. 871 mg/l.  The amount of TPHs on days 7 and 21 in the mixed culture of fungi was 108.975 mg/l and 21.105 mg/l respectively while TPHs in control was 342.891 mg/l and 240.749 mg/l respectively. There was a significant difference between the mixed culture and the control on days 7 and 21 at p≤0.05. The results therefore revealed actual and significant reduction of TPHs in the mixed culture. In addition, there was clearance of n-alkanes by the mixed culture. This suggests that fungi have great potentials in biodegradation of TPHs and in remediation of TPH contaminated environments.

scholarly journals Kovats retention index-boiling point relationship of 2-phenyl-2-alkyl-acetonitriles on stationary phases of different polarity

2005 ◽  
Vol 11 (2) ◽  
pp. 55-58 ◽  
Author(s):  
Dusan Mijin ◽  
Dusan Antonovic
Keyword(s):  
Stationary Phase ◽  
Retention Index ◽  
Boiling Point ◽  
Chemical Potential ◽  
Stationary Phases ◽  
Kovats Retention Index ◽  
Standard Chemical Potential ◽  
Relationship Of ◽  
Kováts Retention Index ◽  
Methylene Group

Linear and reciprocial Kovats retention index-boiling point relationships known from the literature were used to study the Kovats retention index-boiling point dependence of 2-phenyl-2-alkylacetonitriles on stationary phases of different polarity (OV-17, OV-210 and OV-225). The standard chemical potential of the partitioning of one methylene group of an n-alkane for the stationary phase was calculated and compared with available literature data.

scholarly journals OIL SPILL INCIDENTS AND DISPERSANT APPLICATIONS IN KUWAIT

1987 ◽  
Vol 1987 (1) ◽  
pp. 247-253
Author(s):  
Salah M. Al-Mazidi ◽  
Omar Samhan
Keyword(s):  
Oil Spill ◽  
Marine Environment ◽  
Petroleum Hydrocarbons ◽  
Petroleum Hydrocarbon ◽  
Oil Spills ◽  
Petroleum Products ◽  
Coastal Environment ◽  
Industrial Activities ◽  
Oil Refineries ◽  
North And South

ABSTRACT Since the discovery of oil in Kuwait, most oil-related activities have been located along the coastline 50 km south of Kuwait City. Other related industrial activities have been developed in this area apart from oil and petroleum products export in order to diversify the national sources of income. For these reasons, the potential for large oil spills in Kuwait's marine environment is highest along the south coast, where oil refineries and exporting facilities are located. An average of 219 barrels of oil were spilled annually between 1979 and 1985, and 2,100 gallons of dispersants were used in cleanup operations. The majority of incidents involved less than 5 barrels of oil and 500 gallons of dispersants. Incidents involving more than 100 barrels of oil and 5,000 gallons of dispersants were confined to the Sea Island and Mina Al-Ahmadi North and South Piers. This distribution undoubtedly affects the concentration of petroleum residues in various components of the marine environment, resulting in an increase in tar ball density along this coast, reaching a maximum at Ras Az-Zor, and significantly higher levels of vanadium and petroleum hydrocarbons in sediments and oysters collected south of Mina Al-Ahmadi. The objective of this paper is to report on the number, volume, and frequency distribution of oil spill incidents in Kuwait and the usage of dispersants in cleanup operations. Vanadium and petroleum hydrocarbon concentrations also are described as is the sensitivity of the southern coastal environment to oil spills. Recommendations have been made on how to conduct cleanup operations for any future oil spill incidents along the southern shoreline of Kuwait.

scholarly journals La población rural en España: un enfoque a escala municipal

2011 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
Ignacio Atance ◽  
María Teresa Martínez Jávega ◽  
Rogelio Pujol ◽  
Julio Urruela
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Rural Areas ◽  
Rural Population ◽  
Population Data ◽  
Demographic Variables ◽  
Rural Depopulation ◽  
Demographic Growth

Population in Spain has grown significantly during the last decade; however, population growth has not increased evenly across the country. High demographic growth rates in costal and urbaninfluenced rural areas can lead to errors when considering added rural population data. This research depicts Spanish rural population’s evolution using a municipal scale approach and analyzes classic demographic variables and their explanatory capacity on rural population’s evolution. Results show that rural depopulation is still increasing in wide areas of the country. Classical demographic variables have been tested significant although they are not deciding factors in explaining rural population’s evolution

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