Selection of Herbicide Alternatives Based on Probable Leaching to Groundwater

1994 ◽  
Vol 8 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Ralph E. Franklin ◽  
Virgil L. Quisenberry ◽  
Billy J. Gossett ◽  
Edward C. Murdock
Keyword(s):  
Coastal Plain ◽  
Partition Coefficients ◽  
Degradation Rate ◽  
Soil Surface ◽  
Computer Code ◽  
First Order ◽  
Degradation Rate Constant ◽  
And Migration ◽  
Herbicide Alternatives ◽  
Selection Of

Extension workers are sensing pressure to use soils information and chemical characteristics data to guide farmers in selecting pesticides least prone to leach into groundwater. Our objective was to estimate differences in herbicide migration to groundwater under conditions typical for the Southeast Coastal Plain, and to consider how a farmer might be advised to use such knowledge in selecting herbicides. We used a simple computer code for microcomputers to predict persistence and migration of 17 herbicides through a hypothetical, coarse-textured soil typical of the Southeast Coastal Plain. Appropriate herbicides were selected for several common crop-weed problems, such as sicklepod in soybean and Palmer amaranth in corn. Groundwater was assumed to be 3.15 m below the soil surface. Herbicides selected covered a broad range of half-lives and organic carbon partition coefficients. Only after the first-order degradation rate constant was reduced by a factor of five did predicted soil water concentrations of several herbicides at the groundwater interface reach normal detection limits. Still, predicted concentrations were below the level established for health effects advisory purposes. Due to the large number of uncertainties and the inability to estimate practical benefits, we conclude that data relating to soil and herbicide characteristics cannot be used at this time to override cost effectiveness, efficacy, and other factors normally considered by farmers and Extension professionals in herbicides for weed control.

Impact of transverse and longitudinal dispersion on first-order degradation rate constant estimation

2004 ◽  
Vol 73 (1-4) ◽  
pp. 3-14 ◽  
Author(s):  
Greg A. Stenback ◽  
Say Kee Ong ◽  
Shane W. Rogers ◽  
Bruce H. Kjartanson
Keyword(s):  
Rate Constant ◽  
Degradation Rate ◽  
Longitudinal Dispersion ◽  
First Order ◽  
Degradation Rate Constant

Protein metabolism and beta-myosin heavy-chain mRNA in unweighted soleus muscle

1989 ◽  
Vol 257 (2) ◽  
pp. R300-R305 ◽  
Author(s):  
D. B. Thomason ◽  
R. B. Biggs ◽  
F. W. Booth
Keyword(s):  
Protein Synthesis ◽  
Soleus Muscle ◽  
Time Course ◽  
Degradation Rate ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Hindlimb Unweighting ◽  
First Order ◽  
Degradation Rate Constant ◽  
Myofibril Protein

To investigate the relative influence of protein synthetic and degradative control mechanisms in vivo during skeletal muscle atrophy, we measured myofibril and total mixed protein synthesis rates in muscles of rats prevented from hindlimb weight-bearing for 5 h and 7 days. Protein synthesis rates were determined by infusing the animals with [3H]Leu for 5 h and measuring the specific activity of [3H]Leu in the aminoacyl-tRNA precursor and protein product fractions of the muscles. In the soleus muscle, myofibril protein synthesis rates decreased from a control value of 5.9 to 4.6%/day during 5 h of hindlimb unweighting and to 2.4%/day after 7 days of hindlimb unweighting. The relatively more phasic muscles (plantaris, medial gastrocnemius, quadriceps) showed a tendency for increased myofibril protein synthesis rates (117-127% of control) during the first 5 h followed by a decrease (46-62% of control) at 7 days of hindlimb unweighting. A predicted time course of soleus muscle myofibril protein degradation rate was obtained from a numerical model of the decrease in soleus myofibril protein synthesis rate as a first-order process [half-time (t1/2) = 0.3 day by least-squares fit] and the time course of soleus muscle myofibril protein previously observed with hindlimb unweighting (Thomason et al., J. Appl. Physiol. 63: 130-137, 1987). The degradation rate model makes specific, testable predictions for the mechanism of myofibril protein degradation during soleus muscle atrophy: 1) the first-order degradation rate constant does not obtain a fixed value over a 24-day period but is continuously changing throughout atrophy, and 2) the first-order degradation rate constant changes on a time scale slower than protein synthesis rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Photo-catalytic degradation of gaseous pollutants in paper mills of southern China

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 167-178 ◽  
Author(s):  
Xin Tong ◽  
Jiao Li ◽  
Jun Ma ◽  
Xiaoquan Chen ◽  
Wenhao Shen
Keyword(s):  
Degradation Rate ◽  
Southern China ◽  
Catalytic Degradation ◽  
Pulp And Paper ◽  
Gaseous Pollutants ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Initial Concentration ◽  
First Order ◽  
First Order Kinetics

Studies were undertaken to evaluate gaseous pollutants in workplace air within pulp and paper mills and to consider the effectiveness of photo-catalytic treatment of this air. Ambient air at 30 sampling sites in five pulp and paper mills of southern China were sampled and analyzed. The results revealed that formaldehyde and various benzene-based molecules were the main gaseous pollutants at these five mills. A photo-catalytic reactor system with titanium dioxide (TiO2) was developed and evaluated for degradation of formaldehyde, benzene and their mixtures. The experimental results demonstrated that both formaldehyde and benzene in their pure forms could be completely photo-catalytic degraded, though the degradation of benzene was much more difficult than that for formaldehyde. Study of the photo-catalytic degradation kinetics revealed that the degradation rate of formaldehyde increased with initial concentration fitting a first-order kinetics reaction. In contrast, the degradation rate of benzene had no relationship with initial concentration and degradation did not conform to first-order kinetics. The photo-catalytic degradation of formaldehyde-benzene mixtures indicated that formaldehyde behaved differently than when treated in its pure form. The degradation time was two times longer and the kinetics did not reflect a first-order reaction. The degradation of benzene was similar in both pure form and when mixed with formaldehyde.

scholarly journals Ozone Application for Tofu Waste Water Treatment and Its Utilisation for Growth Medium of Microalgae Spirulina sp

2018 ◽  
Vol 31 ◽  
pp. 03002 ◽  
Author(s):  
Hadiyanto Hadiyanto
Keyword(s):  
Waste Water ◽  
Waste Water Treatment ◽  
Oxygen Demand ◽  
Ozone Treatment ◽  
Order Kinetic ◽  
Pollution Load ◽  
First Order ◽  
Degradation Rate Constant ◽  
Nitrogen Contents ◽  
Microalgae Growth

Tofu industries produce waste water containing high organic contents and suspendid solid which is harmful if directly discharged to the environment. This waste can lead to disruption of water quality and lowering the environmental carrying capacity of waters around the tofu industries. Besides, the tofu waste water still contains high nitrogen contents which can be used for microalgae growth. This study was aimed to reduce the pollution load (chemical oxygen demand-COD) of tofue wastewater by using ozone treatments and to utilize nutrients in treated tofu waste water as medium growth of microalgae. The result showed that the reduction of COD by implementation of ozone treatment followed first order kinetic. Under variation of waste concentrations between 10-40%, the degradation rate constant was in the range of 0.00237-0.0149 min-1. The microalgae was able to grow in the tofue waste medium by the growth rate constants of 0.15-0.29 day-1. This study concluded that tofu waste was highly potent for microalgae growth.

Drowning Not Waving: The ‘Children Overboard’ Event and Australia's Fear of the other

2003 ◽  
Vol 109 (1) ◽  
pp. 93-108 ◽  
Author(s):  
Kate Slattery
Keyword(s):  
Media Coverage ◽  
Asylum Seekers ◽  
News Coverage ◽  
National Identities ◽  
Global Village ◽  
Print News ◽  
The People ◽  
Identity Based ◽  
And Migration ◽  
Selection Of

The last few years have been an awakening time for the people, communities and governments of the global village. Escalating problems in the Middle East, global economic uncertainty and an increase in asylum seekers, refugees and migration worldwide have reignited tensions involving boundaries and borders, both geographical and cognitive. One event which highlighted these tensions in Australia, and which was given much media coverage, was the ‘children overboard’ event in October 2001. Utilising a selection of print news coverage of the event, this paper explores how the ‘children overboard’ event demarcated national identities and spaces through the construction and representation of ‘good’ Australian citizens and ‘bad’ asylum seeker ‘others’. Specifically referring to ‘children overboard’ as an ‘event’, I seek to highlight the constructed and representational nature of ‘children overboard’ as a media story and political tool, one which promoted a continuing threat of ‘others’ to the nation in order to gain support for government policy and legitimize national security, and in so doing creating a model of Australian citizenship and identity based upon fear.

The digital divide in individual e-commerce utilization in China

2012 ◽  
Vol 29 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Shizhan Zhu ◽  
Juan Chen
Keyword(s):  
Digital Divide ◽  
The Internet ◽  
Digital Inequality ◽  
Urban Inequality ◽  
First Order ◽  
Gender Education ◽  
Residency Status ◽  
Logistic Regressions ◽  
Using Data ◽  
And Migration

Using data from a national survey with 1,288 respondents, this study investigates the socio-demographic determinants of the first-order digital divide (access to the Internet) and the second-order digital divide (e-commerce use) in China. The survey employed spatial probability sampling technology so it would encompass migrants as well as registered residents. Multiple logistic regressions were applied to model the associations between access to the Internet/e-commerce use and demographic characteristics, socio-economic attributes, and migration and residency status. The results demonstrate the significant effects of rural-urban inequality and socio-economic divisions in Internet access. Age, gender, education, and residency were identified as significant predictors for individual e-commerce use. The findings provide helpful information for enterprises wishing to broaden their business horizons. The research can also be used in designing effective policies to reduce China’s digital inequality.

Variable Contributions of Mercury from Groundwater to a First-Order Urban Coastal Plain Stream in New Jersey, USA

2013 ◽  
Vol 224 (4) ◽  
Author(s):  
Julia L. Barringer ◽  
Zoltan Szabo ◽  
Pamela A. Reilly ◽  
Melissa L. Riskin
Keyword(s):  
New Jersey ◽  
Coastal Plain ◽  
First Order

scholarly journals Enhanced photocatalytic activity of wool-ball-like TiO2 microspheres on carbon fabric and FTO substrates

2018 ◽  
Vol 38 ◽  
pp. 02014
Author(s):  
Yu Zhang ◽  
Jian Gu ◽  
Mengqi Zhang
Keyword(s):  
Hydrothermal Method ◽  
Order Kinetic ◽  
Carbon Fabric ◽  
Facile Hydrothermal Method ◽  
Sem Images ◽  
First Order ◽  
Good Crystallinity ◽  
Degradation Rate Constant ◽  
Order Kinetic Model ◽  
Pseudo First Order

The wool-ball-like TiO2 microspheres on carbon fabric (TiO2-CF) and FTO substrates (TiO2-FTO) have been synthesized by a facile hydrothermal method in alkali environment, using commercial TiO2 (P25) as precursors. The XRD results indicate that the as-prepared TiO2 have good crystallinity. And the SEM images show that the wool-ball-like TiO2 microspheres with a diameter of 2-3 μm are composed of TiO2 nanowires, which have a diameter of ~50 nm. The photocatalytic behavior of the wool-ball-like TiO2 microspheres, TiO2-CF and TiO2-FTO under ultraviolet light was investigated by a pseudo first-order kinetic model, using methyl orange (MO) as pollutant. The wool-ball-like TiO2 microspheres obtained a degradation rate constant (Kap) of 6.91×10-3 min-1 . The Kap values of TiO2-FTO and TiO2-CF reach 13.97×10-3 min-1 and 11.80×10-3 min-1, which are 2.0 and 1.7 times higher than that of pristine wool-ball-like TiO2 microspheres due to the “sum effect” between TiO2 and substrates. This study offers a facile hydrothermal method to prepare wool-ball-like TiO2 microspheres on CF and FTO substrates, which will improve the recyclability of phtocatalysts and can be extended to other fields.

scholarly journals Analysis of measured and calculated counterpart test data in PWR and VVER 1000 simulators

2005 ◽  
Vol 20 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Francesco d’Auria ◽  
Marco Cherubini ◽  
Maria Galassi ◽  
Nikolaus Muellner
Keyword(s):  
Nuclear Power ◽  
Computer Code ◽  
Scaling Analysis ◽  
Behavior Prediction ◽  
Plant Behavior ◽  
Test Methodology ◽  
Qualitative Level ◽  
Reactor Type ◽  
New Phenomena ◽  
Selection Of

This paper presents an over view of the "scaling strategy", in particular the role played by the counter part test methodology. The recent studies dealing with a scaling analysis in light water reactor with special regard to the VVER 1000 Russian reactor type are presented to demonstrate the phenomena important for scaling. The adopted scaling approach is based on the selection of a few characteristic parameters chosen by taking into account their relevance in the behavior of the transient. The adopted computer code used is RELAP5/Mod3.3 and its accuracy has been demonstrated by qualitative and quantitative evaluation. Comparing experimental data, it was found that the investigated facilities showed similar behavior concerning the time trends, and that the same thermal hydraulic phenomena on a qualitative level could be predicted. The main results are: PSB and LOBI main parameters have similar trends. This fact is the confirmation of the validity of the adopted scaling approach and it shows that PWR and VVER reactor type behavior is very similar. No new phenomena occurred during the counter part test, despite the fact that the two facilities had a different lay out, and the already known phenomena were predicted correctly by the code. The code capability and accuracy are scale-independent. Both character is tics are necessary to permit the full scale calculation with the aim of nuclear power plant behavior prediction. .

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