Picloram Absorption by Broom Snakeweed (Gutierrezia sarothrae) Leaf Tissue

Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 390-394 ◽  
Author(s):  
Tracy M. Sterling ◽  
Norman K. Lownds
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Leaf Tissue ◽  
Axillary Bud ◽  
Solution Ph ◽  
Simple Diffusion ◽  
Foliar Absorption ◽  
Ph Dependent ◽  
Gutierrezia Sarothrae ◽  
Diffusion Absorption

Foliar absorption of picloram by broom snakeweed, a rangeland shrub, was investigated. Picloram uptake into leaf, axillary bud, and stem tissues was similar. In addition, picloram uptake by leaf tissue from greenhouse- and field-grown broom snakeweed did not differ. Picloram accumulated rapidly and absorption saturated between 15 min and 1 h of application; no further absorption occurred through 72 h with maximum uptake ca. 15% of applied picloram. Picloram content increased linearly with increasing external picloram concentration, implying that movement of the herbicide across the cuticle is via diffusion. Absorption was dependent on relative humidity and temperature with the greatest uptake at 94% relative humidity and 35 C, respectively. Absorption was pH dependent; picloram absorption was greatest at pH 4 and least at pH 8. In addition, picloram absorption was less at pH 3 compared to pH 4. These results provide evidence that picloram is absorbed across the cuticle via simple diffusion and absorption is dependent on environmental conditions and solution pH at and following application.

scholarly journals Environment and Spray Additive Effects on Picloram Absorption and Translocation in Leafy Spurge (Euphorbia esula)

Weed Science ◽  
1989 ◽  
Vol 37 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Kevin D. Moxness ◽  
Rodney G. Lym
Keyword(s):  
Relative Humidity ◽  
Trisodium Citrate ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Additive Effects ◽  
Buffer Concentration ◽  
Solution Ph ◽  
Citrate Buffer ◽  
Foliar Absorption ◽  
Spray Solution

Relative humidity after application, spray additives, and solution pH affected both foliar absorption and translocation of14C-picloram to leafy spurge roots.14C-picloram absorption increased from 11 to 34% and translocation increased from 5 to 21% as time at posttreatment humidity increased from 0 to 48 h. Absorption and translocation were not different when pre- or posttreatment temperatures were 30/18 or 18/10 C (day/night).14C-picloram absorption and translocation to the roots were 18 and 6%, respectively, when applied alone, and increased to 46 and 12%, respectively, when applied with ammonium sulfate at 2.5 kg/ha. Absorption and translocation were unaffected by ammonium nitrate. Foliar absorption and translocation of14C-picloram in leafy spurge were unaffected by pH of unbuffered spray solution but increased at least 50% when applied in a solution buffered at pH 4.8 with trisodium citrate. Foliar absorption in detached leafy spurge leaves increased from 26 to 51% of applied14C as the citrate buffer concentration increased from 0.01 to 0.1 mM, respectively.

Factors Affecting Toxicity and Translocation of Metriflufen in Cotton (Gossypium hirsutum)

Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 308-313 ◽  
Author(s):  
G. D. Wills ◽  
P. M. Jordan
Keyword(s):  
Relative Humidity ◽  
Gossypium Hirsutum ◽  
Environmental Conditions ◽  
Leaf Tissue ◽  
Propanoic Acid ◽  
Stem Tissue ◽  
Differential Absorption ◽  
Herbicide Application ◽  
Factors Affecting ◽  
Treated Area

Toxicity of nonradiolabeled and translocation of14C-labeled metriflufen3{2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoic acid} in cotton (Gossypium hirsutumL. ‘Stoneville 213’) were evaluated under different environmental conditions as affected by surfactant and by the maturity of stem or leaf tissue at the place of herbicide application. Cotton was very tolerant to metriflufen, with the greatest tolerance at high temperatures. The herbicide entered the plant quite rapidly and autoradiographs indicated that radioactivity from the herbicide moved freely throughout the plant. Relative humidity (RH) between 40 and 100% had little effect on metriflufen toxicity. Two weeks after treatment with metriflufen at 0.5 kg/ha, cotton was essentially free of injury symptoms at 35 C, but injury was as great as 41 and 13% at 18 and 25 C, respectively. All plants recovered fully after 6 additional weeks in the greenhouse. When surfactant was added to the spray solutions, cotton injury was frequently increased during the first 2 weeks but not after 8 weeks. Accumulation of14C at the site of14C-metriflufen application was 31 to 65% after 48 h. Between 16 and 51% of the applied14C moved from the treated area by translocation into other parts of the plant, or by volatilization into the atmosphere. Movement was greatest from stem tissue at 35 C and 100% RH. There was no correlation between14C movement and herbicide toxicity within the plant. The selectivity of metriflufen to cotton probably results from deactivation by, or tolerance within, the plant rather than from differential absorption and translocation of the herbicide.

An Experimental Investigation of the Effects of the Environmental Conditions and the Channel Depth for an Air-Breathing Polymer Electrolyte Membrane Fuel Cell

2008 ◽  
Vol 5 (4) ◽  
Author(s):  
Yong Hun Park ◽  
Jerald A. Caton
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Flow Field ◽  
Current Density ◽  
Environmental Conditions ◽  
Polymer Electrolyte Membrane ◽  
Channel Depth ◽  
Air Breathing ◽  
Fuel Cell Performance ◽  
Electrolyte Membrane

The effects of the environmental conditions and the channel depth for an air-breathing polymer electrolyte membrane fuel cell were investigated experimentally. The fuel cell used in this work included a membrane and electrode assembly, which possessed an active area of 25 cm2 with Nafion® 117 membrane. Triple serpentine designs for the flow fields with two different flow depths were used in this research. The experimental results indicated that the relative humidity and temperature play an important role with respect to fuel cell performance. The fuel cell needs to be operated at least 20 min to obtain stable performance. When the shallow flow field was used, the performance increased dramatically for low humidity and slightly for high humidity. The current density was obtained around only 120 mA/cm2 at 30°C with an 80% relative humidity, which was nearly double the performance for the deep flow field. The minimum operating temperature for an air-breathing fuel cell would be 20°C. When it was 10°C at 60% relative humidity, the open circuit voltage dropped to around 0.65 V. The fuel cell performance improved with increasing relative humidity from 80% to 100% at high current density.

EFFECT OF PRE-FREEZING HAMS ON QUALITY ATTRIBUTES OF DRY-CURED PRODUCT

1972 ◽  
Vol 35 (2) ◽  
pp. 98-101 ◽  
Author(s):  
P. P. Graham ◽  
T. N. Blumer
Keyword(s):  
Weight Loss ◽  
Relative Humidity ◽  
Environmental Conditions ◽  
Water Loss ◽  
Moisture Loss ◽  
Internal Tissue ◽  
Surface Ph ◽  
Aging Period ◽  
Acceptable Quality ◽  
Fresh State

Hams were frozen, stored, and thawed before dry-curing to study the profiles of quality as related to environmental conditions. Quality appraisals and sampling were done after thawing, after curing, and after 30 days aging in an atmosphere where temperature and relative humidity were controlled at about 34.5 C and 62.5%, respectively. The pH, water, NaCl, and fat contents were determined. Surface pH of hams increased from the thawed fresh state to the unstored cured state, but decreased generally after the aging period (stored cured ham). The pH was higher on the surface than that of corresponding internal areas. The pH of the internal tissue was lower for thawed product than cured or aged product. The average percent water decreased during curing and aging periods. Water loss after curing and after aging in the prefrozen hams was greater than that reported for unfrozen hams. The quantity of water, NaCl, and fat varied among the several muscle areas and reasons for variation are discussed. All hams were of acceptable quality at each appraisal period. Decreasing moisture levels of hams were reflected by decreases in conformation scores throughout the processing periods. Increased firmness was accompanied by weight loss, moisture loss, and increased NaCl percentage.

Complex coacervation of Mg(ii) phospho-polymethacrylate, a synthetic analog of sandcastle worm adhesive phosphoproteins

Soft Matter ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 379-386 ◽  
Author(s):  
In Taek Song ◽  
Russell J. Stewart
Keyword(s):  
Environmental Conditions ◽  
Outer Shell ◽  
Synthetic Analog ◽  
Complex Coacervation ◽  
Ph Dependent

A phospho-methacrylate analog of sandcastle worm adhesive phosphoproteins forms temperature and pH dependent complex coacervates with Mg(ii) ions through outer shell H-bonds and inner shell coordinate bonds in natural environmental conditions of the sandcastle worm.

scholarly journals Isolated individuals and groups show opposite preferences toward humidity

2018 ◽  
Author(s):  
Mariano Calvo Martín ◽  
Stamatios C. Nicolis ◽  
Isaac Planas-Sitjà ◽  
Jean-Christophe de Biseau ◽  
Jean-Louis Deneubourg
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Group Level ◽  
Individual Level ◽  
Negative Effect ◽  
Multi Level ◽  
The Individual ◽  
Shed Light ◽  
Selection Of

AbstractCockroaches, like most social arthropods, are led to choose collectively among different alternative resting places. These decisions are modulated by different factors, such as environmental conditions (temperature, relative humidity) and sociality (groups size, nature of communications). The aim of this study is to establish the interplay between environmental conditions and the modulation of the interactions between individuals within a group leading to an inversion of preferences. We show that the preferences of isolated cockroaches and groups of 16 individuals, on the selection of the relative humidity of a shelter are inversed and shed light on the mechanisms involved. We suggest that the relative humidity has a multi-level influence on cockroaches, manifested as an attractant effect at the individual level and as a negative effect at the group level, modulating the interactions.

scholarly journals Development of gypsy moth (Lymantria dispar L) on the foliage of Quercus cerris L., Q. Petraea (matt) Liebl. and Q. Robur L. in the controlled conditions

2007 ◽  
pp. 55-67 ◽  
Author(s):  
Slobodan Milanovic
Keyword(s):  
Relative Humidity ◽  
Host Plant ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Environmental Conditions ◽  
Quercus Robur ◽  
Quercus Petraea ◽  
The Other ◽  
Study Results ◽  
Quercus Cerris

The development of Gypsy moth (Lymantria dispar L) was monitored in laboratory conditions, on the foliage of the species Quercus cerris L. Quercus petraea (Matt) Liebl. and Quercus robur L. The experiment was established in the controlled environmental conditions, at the temperature of 25?C, photoperiod 14:10 (day: night) and relative humidity 70%. The objective of the research was to determine the suitability of the study host plant species for gypsy moth development. The study results show that Gypsy moth caterpillars cultivated on Q. petraea foliage had a lower survival, higher number of moultings, longer preadult development and lower fecundity, which makes this species less suitable compared to the other two. Gypsy moth caterpillars cultivated on Q. cerris foliage had the highest survival degree the lowest number of moultings, the shortest preadult development and the highest fecundity, which makes this species the most favourable for gypsy moth development. Q. robur was between the former two species in this respect.

scholarly journals The pH dependent reactions of graphene oxide with small molecule thiols

RSC Advances ◽  
2018 ◽  
Vol 8 (33) ◽  
pp. 18388-18395 ◽  
Author(s):  
Al de Leon ◽  
Michael Mellon ◽  
Joey Mangadlao ◽  
Rigoberto Advincula ◽  
Emily Pentzer
Keyword(s):  
Graphene Oxide ◽  
Small Molecule ◽  
Solution Ph ◽  
Ph Dependent ◽  
Carbon Based

Graphene oxide (GO), a heterogenous 2D carbon-based material, is functionalized or reduced with ethane thiol depending on solution pH.

Effect of the Environmental Conditions of Tropical Climates on the Performance Parameters of a Gas Turbine Power Generation Plant

2020 ◽  
Author(s):  
J. Fajardo ◽  
D. Barreto ◽  
T. Castro ◽  
I. Baldiris
Keyword(s):  
Power Plant ◽  
Relative Humidity ◽  
Gas Turbine ◽  
Output Power ◽  
High Temperatures ◽  
Environmental Conditions ◽  
Thermal Efficiency ◽  
Specific Work ◽  
Atmospheric Conditions ◽  
Compressor Inlet

Abstract It is known that high temperatures adversely affect the performance of gas turbines, but the effect of the combination of atmospheric conditions (temperature and relative humidity -RH-) on the operation of this type of system is unknown. In this work the effects of atmospheric conditions on the energy and exergy indicators of a power plant with gas turbine were studied. The indicators studied were the mass flow, the specific work consumed by the compressor, specific work produced by the turbine, the combustion gas temperature, the NO concentration, the net output power, the thermal efficiency, the heat rate, the specific consumption of fuel, the destruction of exergy and exergy efficiency. Among the results, it is noted that for each degree celsius that reduces the temperature of the air at the compressor inlet at constant relative humidity on average, the mass flow of dry air increases by 0.27 kg/s, the specific work consumed by the compressors decreases by 0.45%, the output power increases by 1.17% and the thermal efficiency increases by 0.8%, the exergy destruction increases by 0.72% and the exergy efficiency increases by 0.81%. In addition, humidity changes relative to high temperatures are detected more significantly than at low temperatures. The power plant studied is installed in Cartagena, Colombia and since it is not operating in the design environmental conditions (15 °C and 60% relative humidity) it experiences a loss of output power of 6140 kW and a drop in thermal efficiency of 5.12 %. These results allow considering the implementation of air cooling technologies at the compressor inlet to compensate for the loss of power at atmospheric air conditions.

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