Generalized differential specific rate equation for microbial growth

1979 ◽  
Vol 21 (10) ◽  
pp. 1871-1875 ◽  
Author(s):  
F. Kargi ◽  
M. L. Shuler
Keyword(s):  
Rate Equation ◽  
Microbial Growth ◽  
Specific Rate ◽  
Generalized Differential

Degradation biokinetics of used and fresh lube oils in contaminated soil environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Microbial Growth ◽  
Equilibrium Constants ◽  
Culture Method ◽  
Petroleum Products ◽  
Specific Rate ◽  
Phenol Content ◽  
Soil Environment ◽  
Degradation Pattern ◽  
Rate Maximum ◽  
Maximum Specific Rate

In order to solve the problems of the soil environment caused by the discharge of petroleum products especially oils used for lubrication, investigations were carried out to assess the degradation of fresh and used lube oil in soil environment using bacteria degraders present in the soil. This was done by introducing some quantities of the pollutant (fresh and used lubricating oils) into some soil samples obtained from the environment. The degradation pattern was studied by estimating the level of the microbial growth using culture method and the phenol content. This was done before the introduction of the pollutant and at two weekly intervals for 42days. Results show that the phenol content, microbial and micro species present in the soil rapidly increased to maximum and then declined. The specific rate, maximum specific rate and equilibrium constants were determined using Line-Weaver Burk Plots. Results obtained show that the bacteria which degraded the fresh and used lube oil were inhibited by the presence of phenol which was informed during the biodegradation reaction. Empirical equation for microbial growth rate using the data from the experiment was obtained. The degradation of the fresh lube oil occurred faster than the used lube oil. The equation is useful in monitoring and predicting the performance of microorganisms in bioreactor and predicting the performance of microorganisms in bioreactor containing used or fresh lube oil.

Suicidal Behavior in Four Ethnic Groups in The Hague, 2002–2004

Crisis ◽  
2009 ◽  
Vol 30 (2) ◽  
pp. 63-67 ◽  
Author(s):  
Irene Burger ◽  
Albert M. van Hemert ◽  
Willem J. Schudel ◽  
Barend J.C. Middelkoop
Keyword(s):  
Suicide Attempt ◽  
Ethnic Groups ◽  
Suicidal Behavior ◽  
Emergency Service ◽  
Attempted Suicide ◽  
Public Health Problem ◽  
Specific Rate ◽  
Completed Suicide ◽  
The Hague ◽  
Psychiatric Department

Background: Suicidal behavior is a severe public health problem. Aims: To determine the rates of attempted and completed suicide among ethnic groups in The Hague, The Netherlands (2002–2004). Methods: By analyzing data on attempted and completed suicide (from the psychiatric department of general medical hospitals; the psychiatric emergency service and the municipal coroners). Results: Turkish and Surinamese females aged 15–24 years were at highest risk for attempted suicide (age-specific rate 545 / 100,000 and 421 / 100,000 person-years, respectively). Both rates were significantly higher than in the same age group of Dutch females (246 / 100,000 person-years). Turkish (2%) and Surinamese (7%) had lower repeat suicide-attempt rates than did Dutch (16%) females aged 15–24. Significantly lower suicide-attempt rates were found for Surinamese than for Dutch females aged 35–54 years. Differences were not explained by socioeconomic living conditions. The ratio fatal/nonfatal events was 4.5 times higher in males than in females and varied across age, gender, and ethnicity strata. Completed suicide was rare among migrant females. No completed suicides were observed in the Turkish and Surinamese females aged 15–24 years. Conclusions: The study demonstrates a high risk of attempted suicide and a low risk of completed suicide among young Turkish and Surinamese females.

Prediction of Tread Pattern Wear by an Explicit Finite Element Model3

2007 ◽  
Vol 35 (4) ◽  
pp. 276-299 ◽  
Author(s):  
J. C. Cho ◽  
B. C. Jung
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Tangential Stress ◽  
Rate Equation ◽  
Constitutive Equations ◽  
Slip Velocity ◽  
Test Results ◽  
Explicit Finite Element ◽  
Driving Condition ◽  
Driving Conditions

Abstract Tread pattern wear is predicted by using an explicit finite element model (FEM) and compared with the indoor drum test results under a set of actual driving conditions. One pattern is used to determine the wear rate equation, which is composed of slip velocity and tangential stress under a single driving condition. Two other patterns with the same size (225/45ZR17) and profile are used to be simulated and compared with the indoor wear test results under the actual driving conditions. As a study on the rubber wear rate equation, trial wear rates are assumed by several constitutive equations and each trial wear rate is integrated along time to yield the total accumulated wear under a selected single cornering condition. The trial constitutive equations are defined by independently varying each exponent of slip velocity and tangential stress. The integrated results are compared with the indoor test results, and the best matching constitutive equation for wear is selected for the following wear simulation of two other patterns under actual driving conditions. Tens of thousands of driving conditions of a tire are categorized into a small number of simplified conditions by a suggested simplification procedure which considers the driving condition frequency and weighting function. Both of these simplified conditions and the original actual conditions are tested on the indoor drum test machines. The two results can be regarded to be in good agreement if the deviation that exists in the data is mainly due to the difference in the test velocity. Therefore, the simplification procedure is justified. By applying the selected wear rate equation and the simplified driving conditions to the explicit FEM simulation, the simulated wear results for the two patterns show good match with the actual indoor wear results.

Density matrix and rate equation analyses for picosecond pump/probe combustion diagnostics

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 723-731
Author(s):  
Thomas Settersten ◽  
Mark Linne ◽  
James Gord ◽  
Gregory Feichtner
Keyword(s):  
Density Matrix ◽  
Rate Equation ◽  
Pump Probe ◽  
Combustion Diagnostics

A New Adsorption Rate Equation in Batch Systems

2018 ◽  
Author(s):  
yongson hong ◽  
Kye-Ryong Sin ◽  
Jong-Su Pak ◽  
Chol-Min Pak
Keyword(s):  
Experimental Data ◽  
Kinetic Analysis ◽  
Adsorption Kinetics ◽  
Rate Equation ◽  
Kinetic Models ◽  
Adsorption Kinetic ◽  
Adsorption Rate ◽  
Batch Systems ◽  
New View

<p><b>In this paper, the deficiencies and cause of previous adsorption kinetic models were revealed, new adsorption rate equation has been proposed and its validities were verified by kinetic analysis of various experimental data.</b> <b>This work is a new view on the adsorption kinetics rather than a comment on the previous adsorption papers.</b></p>

THE FEATURES OF BIODESTRUCTION PROCESSES OF THE SURFACES OF HYDRAULIC ENGINEERING CONSTRUCTIONS

2017 ◽  
Author(s):  
Marina Vasilenko ◽  
Marina Vasilenko ◽  
Elena Goncharova ◽  
Elena Goncharova ◽  
Yury Rubanov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Environmental Factors ◽  
Food Chain ◽  
Building Materials ◽  
Microbial Growth ◽  
Mineralogical Composition ◽  
Mechanical Action ◽  
Chemical Processes ◽  
Hydraulic Engineering ◽  
Optimal Conditions

The surfaces of building materials of hydrotechnical constructions undergo the process of algae biofouling. The degree of damage depends on the environmental factors that are affect-ed by the level of anthropogenic load areas. Modeling the biofouling process of concrete with algae under laboratory conditions has allowed determining their impact on the building ma-terial, accompanied by changes in chemical and mineralogical composition of the surface of products. The microscopic examination of sample’s surfaces and evaluation of the effective-ness of various ions leaching from building materials shows the results of "algal attack" relat-ed to the acceleration of biodegradation of materials under the influence of aggressive meta-bolic products, mechanical action neoplasms, creating optimal conditions for the development of subsequent aerobic microbial decomposers. To clarify the nature of chemical processes in the system “algocenosis – concrete” the changes of chemical and phase (mineralogical) com-position of the surface layer of concrete sample were studied. The effect that algae produce on hydraulic engineering constructions is due to the fact that these organisms, belonging to phototrophs and standing at the beginning of the food chain, initiate new microbial growth.

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