scholarly journals Physiological Effects of Physical Postharvest Treatments on Insects

2003 ◽  
Vol 13 (2) ◽  
pp. 272-275 ◽  
Author(s):  
Lisa G. Neven
Keyword(s):  
Carbon Dioxide ◽  
Temperature Extremes ◽  
Physiological Effects ◽  
X Rays ◽  
Low Oxygen ◽  
Agricultural Chemicals ◽  
Modified Atmospheres ◽  
Insect Mortality ◽  
Physical Treatments ◽  
The Impact

As concerns about the safety of our food supply increase along with concerns about the impact of agricultural chemicals on our environment, the development of nonchemical quarantine treatments to meet export requirements become increasingly necessary. The types of physical treatments used have been largely determined by commodity tolerances and processing practices. The most common physical treatments use temperature extremes such as heat [>40 °C (104.0 °F)] and cold [<10 °C (50.0 °F)]. Other physical treatments commonly include the use of controlled or modified atmospheres (low oxygen, elevated carbon dioxide). Current technology has led to investigations in the application of energy to control infesting insects. These treatments include ionizing radiation, microwaves, ultraviolet radiation, infrared radiation, radio frequency, electron beam, X-rays, and electricity. Although the effects of these physical treatments can impact commodity quality, the goal of the treatments is to kill infesting (real or in certain instances, potential) insects to meet quarantine requirements. The effects of physical treatments on insect mortality and fecundity are discussed.

Impact of Internal Entrainment on High Intensity Distributed Combustion

2015 ◽  
Author(s):  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Carbon Dioxide ◽  
Gas Turbine ◽  
Oxygen Concentration ◽  
High Intensity ◽  
Flame Structure ◽  
Flame Stabilization ◽  
Low Oxygen ◽  
Gas Turbine Combustors ◽  
Reactive Gases ◽  
The Impact

Colorless Distributed Combustion (also referred to as CDC) has been shown to provide ultra-low emissions and enhanced performance of high intensity gas turbine combustors. To achieve distributed combustion, the flowfield needs to be tailored for adequate mixing between reactants and hot reactive species from within the combustor to result in high temperature low oxygen concentration environment prior to ignition. Such reaction distribution results in uniform thermal field and also eliminates any hot spots for mitigating NOx emission. Though CDC have been extensively studied using a variety of geometries, heat release intensities, and fuels, the role of internally recirculated hot reactive gases needs to be further investigated and quantified. In this paper, the impact of internal entrainment of reactive gases on flame structure and behavior is investigated with focus on fostering distributed combustion and providing guidelines for designing future gas turbine combustors operating in distributed combustion mode. To simulate the recirculated gases from within the combustor, a mixture of nitrogen and carbon dioxide is introduced to the air stream prior to mixing with fuel and subsequent combustion. Increase in the amounts of nitrogen and carbon dioxide (simulating increased entrainment), led to volume distributed reaction over a larger volume in the combustor with enhanced and uniform distribution of the OH* chemiluminescence intensity. At the same time, the bluish flame stabilized by the swirler is replaced with a more uniform almost invisible bluish flame. The increased recirculation also reflected on the pollutants emission, where NO emissions were significantly decreased for the same amount of fuel burned. Lowering oxygen concentration from 21% to 15% (due to increased recirculation) resulted in 80∼90% reduction in NO with no impact on CO emission with sub PPM NO emission achieved at an equivalence ratio of 0.7. Flame stabilization at excess recirculation can be achieved using preheated nitrogen and carbon dioxide, achieving true distributed conditions with oxygen concentration below 13%.

Balancing Unbalanced Breathing: The Clinical Use of Capnographic Biofeedback

Biofeedback ◽  
2013 ◽  
Vol 41 (4) ◽  
pp. 183-187
Author(s):  
Andrea Meckley
Keyword(s):  
Carbon Dioxide ◽  
Biofeedback Training ◽  
Physiological Effects ◽  
Clinical Use ◽  
Breathing Patterns ◽  
Panic Disorders ◽  
Panic Symptoms ◽  
Carbon Dioxide Levels ◽  
Dysfunctional Breathing ◽  
The Impact

Dysfunctional breathing, primarily in the form of overbreathing or hyperventilation, has been reported to play a major role for some individuals with anxiety and panic disorders. This is due to the decrease in carbon dioxide, a state called hypocapnia, which results from hyperventilation. The author reviews the physiological effects of hypocapnia and describes how carbon dioxide levels are measured with capnography. In addition, she introduces the use of capnography as a form of biofeedback and outlines ways to incorporate capnography into a clinical setting. Capnographic biofeedback enables individuals to become aware of the impact dysfunctional breathing has on their symptoms and assists them in learning more balanced, healthy breathing patterns. Use of this type of biofeedback training has been found to decrease panic symptoms and may be useful in improving physiological functioning in other medical and psychiatric disorders as well.

Physiological Effects at Low Oxygen Tensions of Replacing Oxygen with Carbon dioxide.

1943 ◽  
Vol 52 (4) ◽  
pp. 320-322
Author(s):  
W. B. Youmans ◽  
M. Pennington ◽  
H. E. Griswold ◽  
J. A. Gius
Keyword(s):  
Carbon Dioxide ◽  
Physiological Effects ◽  
Low Oxygen ◽  
Oxygen Tensions

Internal Entrainment Effects on Distributed Combustion

2015 ◽  
Author(s):  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Concentration ◽  
High Intensity ◽  
Flame Structure ◽  
Low Oxygen ◽  
Air Stream ◽  
Pollutants Emission ◽  
Reactive Gases ◽  
Colorless Distributed Combustion ◽  
The Impact

Colorless Distributed Combustion (CDC) has been shown to provide ultra-low emissions and enhanced combustion performance of high intensity gas turbine combustors in terms of efficiency and stability. To achieve distributed combustion, the flowfield needs to be carefully tailored for adequate mixing between reactants and hot reactive species from within the combustor to result in high temperature low oxygen concentration environment prior to ignition. Such distributed reactions result in uniform thermal field and also eliminates any hot spots for mitigating NOx emission. Though Distributed Combustion have been extensively studied using a variety of geometries, injection velocities, heat release intensities, and fuels, the role of hot reactive internally recirculated gases requires further examination. In this paper, the impact of internal entrainment of reactive gases on flame structure and behavior is investigated with focus on fostering distributed combustion and providing guidelines for designing high intensity combustors operating in distributed combustion mode. A mixture of nitrogen and carbon dioxide, used to simulate the recirculated gases, is introduced to the air stream prior to mixing with the fuel and subsequent combustion. Increase in the amounts of nitrogen and carbon dioxide (simulating increased entrainment), led to volume distributed reaction over a larger volume in the combustor with enhanced and uniform distribution of the OH* chemiluminescence intensity. At the same time, the bluish flame stabilized by the swirler is replaced with a more uniform almost invisible bluish flame. The increased recirculation also reflected on the pollutants emission, where NO emissions were significantly decreased for the same amount of fuel burned. Lowering oxygen concentration from 21% to 15% (due to increased entrainment) resulted in 80∼90% reduction in NO with no impact on CO emission with sub PPM NO emission achieved at an equivalence ratio of 0.7. The same trend was seen at higher diluents injection temperature as well, with significant pollutants emission reduction down to an oxygen concentration of 10%.

Climate-forced changes of bio-productivity of Belorussian terrestrial ecosystems

2019 ◽  
pp. 77-88
Author(s):  
S. A. Lysenko
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Vegetation Index ◽  
Precipitation Amount ◽  
Terrestrial Ecosystems ◽  
Vegetation Period ◽  
Climatic Trend ◽  
Vegetation Growth ◽  
Current Century ◽  
The Impact

The spatial and temporal particularities of Normalized Differential Vegetation Index (NDVI) changes over territory of Belarus in the current century and their relationship with climate change were investigated. The rise of NDVI is observed at approximately 84% of the Belarus area. The statistically significant growth of NDVI has exhibited at nearly 35% of the studied area (t-test at 95% confidence interval), which are mainly forests and undeveloped areas. Croplands vegetation index is largely descending. The main factor of croplands bio-productivity interannual variability is precipitation amount in vegetation period. This factor determines more than 60% of the croplands NDVI dispersion. The long-term changes of NDVI could be explained by combination of two factors: photosynthesis intensifying action of carbon dioxide and vegetation growth suppressing action of air warming with almost unchanged precipitation amount. If the observed climatic trend continues the croplands bio-productivity in many Belarus regions could be decreased at more than 20% in comparison with 2000 year. The impact of climate change on the bio-productivity of undeveloped lands is only slightly noticed on the background of its growth in conditions of rising level of carbon dioxide in the atmosphere.

Extremes of Temperature

2017 ◽  
Author(s):  
Ann M. Krake
Keyword(s):  
Control Measures ◽  
Temperature Extremes ◽  
Physiological Effects ◽  
Assessment And Evaluation ◽  
The Public ◽  
Adverse Health Effects ◽  
Extreme Cold ◽  
Prevention And Control Measures ◽  
And Control ◽  
Extremes Of Temperature

This chapter covers extremes of temperature conditions, physiological effects, and prevention. All deaths caused by exposure to hot and cold temperature extremes are preventable when proper measures are taken. Described in this chapter are the effects of extreme heat and extreme cold on the health of members of the public, particularly older people and young people, and workers employed in various workplace settings. The differences between heat stress and heat strain are also discussed, as are various regulations governing exposure to temperature extremes. The nature and magnitude of heat- and cold-related conditions and symptoms are described in detail. Final sections of the chapter address various assessment and evaluation tools as well as prevention and control measures. In addition, an appendix describes the hazards related to hyperbaric and hypobaric environments and adverse health effects.

scholarly journals X-ray Shielding, Mechanical, Physical, and Water Absorption Properties of Wood/PVC Composites Containing Bismuth Oxide

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2212
Author(s):  
Worawat Poltabtim ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Vichai Rosarpitak ◽  
...  
Keyword(s):  
Impact Strength ◽  
Water Absorption ◽  
Attenuation Coefficient ◽  
Bismuth Oxide ◽  
Morphological Properties ◽  
Linear Attenuation Coefficient ◽  
X Rays ◽  
Equivalent Thickness ◽  
X Ray ◽  
The Impact

The potential utilization of wood/polyvinyl chloride (WPVC) composites containing an X-ray protective filler, namely bismuth oxide (Bi2O3) particles, was investigated as novel, safe, and environmentally friendly X-ray shielding materials. The wood and Bi2O3 contents used in this work varied from 20 to 40 parts per hundred parts of PVC by weight (pph) and from 0 to 25, 50, 75, and 100 pph, respectively. The study considered X-ray shielding, mechanical, density, water absorption, and morphological properties. The results showed that the overall X-ray shielding parameters, namely the linear attenuation coefficient (µ), mass attenuation coefficient (µm), and lead equivalent thickness (Pbeq), of the WPVC composites increased with increasing Bi2O3 contents but slightly decreased at higher wood contents (40 pph). Furthermore, comparative Pbeq values between the wood/PVC composites and similar commercial X-ray shielding boards indicated that the recommended Bi2O3 contents for the 20 pph (40 ph) wood/PVC composites were 35, 85, and 40 pph (40, 100, and 45 pph) for the attenuation of 60, 100, and 150-kV X-rays, respectively. In addition, the increased Bi2O3 contents in the WPVC composites enhanced the Izod impact strength, hardness (Shore D), and density, but reduced water absorption. On the other hand, the increased wood contents increased the impact strength, hardness (Shore D), and water absorption but lowered the density of the composites. The overall results suggested that the developed WPVC composites had great potential to be used as effective X-ray shielding materials with Bi2O3 acting as a suitable X-ray protective filler.

scholarly journals Imaging with Coherent X-rays: From the Early Synchrotron Tests to SYNAPSE

2021 ◽  
Vol 7 (8) ◽  
pp. 132
Author(s):  
Giorgio Margaritondo ◽  
Yeukuang Hwu
Keyword(s):  
Human Brain ◽  
International Collaboration ◽  
Phase Contrast ◽  
Asia Pacific ◽  
X Rays ◽  
New Techniques ◽  
Simple Description ◽  
Contrast Radiography ◽  
The Impact ◽  
Extract Information

The high longitudinal and lateral coherence of synchrotron X-rays sources radically transformed radiography. Before them, the image contrast was almost only based on absorption. Coherent synchrotron sources transformed radiography into a multi-faceted tool that can extract information also from “phase” effects. Here, we report a very simple description of the new techniques, presenting them to potential new users without requiring a sophisticated background in advanced physics. We then illustrate the impact of such techniques with a number of examples. Finally, we present the international collaboration SYNAPSE (Synchrotrons for Neuroscience—an Asia-Pacific Strategic Enterprise), which targets the use of phase-contrast radiography to map one full human brain in a few years.

scholarly journals Breathing space: deoxygenation of aquatic environments can drive differential ecological impacts across biological invasion stages

2021 ◽  
Author(s):  
James W. E. Dickey ◽  
Neil E. Coughlan ◽  
Jaimie T. A. Dick ◽  
Vincent Médoc ◽  
Monica McCard ◽  
...  
Keyword(s):  
Climate Change ◽  
Oxygen Saturation ◽  
Ecological Impacts ◽  
Neogobius Melanostomus ◽  
Aquatic Environments ◽  
Relative Impact ◽  
Low Oxygen ◽  
Per Capita ◽  
The Impact ◽  
Prey Populations

AbstractThe influence of climate change on the ecological impacts of invasive alien species (IAS) remains understudied, with deoxygenation of aquatic environments often-overlooked as a consequence of climate change. Here, we therefore assessed how oxygen saturation affects the ecological impact of a predatory invasive fish, the Ponto-Caspian round goby (Neogobius melanostomus), relative to a co-occurring endangered European native analogue, the bullhead (Cottus gobio) experiencing decline in the presence of the IAS. In individual trials and mesocosms, we assessed the effect of high, medium and low (90%, 60% and 30%) oxygen saturation on: (1) functional responses (FRs) of the IAS and native, i.e. per capita feeding rates; (2) the impact on prey populations exerted; and (3) how combined impacts of both fishes change over invasion stages (Pre-invasion, Arrival, Replacement, Proliferation). Both species showed Type II potentially destabilising FRs, but at low oxygen saturation, the invader had a significantly higher feeding rate than the native. Relative Impact Potential, combining fish per capita effects and population abundances, revealed that low oxygen saturation exacerbates the high relative impact of the invader. The Relative Total Impact Potential (RTIP), modelling both consumer species’ impacts on prey populations in a system, was consistently higher at low oxygen saturation and especially high during invader Proliferation. In the mesocosm experiment, low oxygen lowered RTIP where both species were present, but again the IAS retained high relative impact during Replacement and Proliferation stages at low oxygen. We also found evidence of multiple predator effects, principally antagonism. We highlight the threat posed to native communities by IAS alongside climate-related stressors, but note that solutions may be available to remedy hypoxia and potentially mitigate impacts across invasion stages.

scholarly journals An Examination of Green Credit Promoting Carbon Dioxide Emissions Reduction: A Provincial Panel Analysis of China

2021 ◽  
Vol 13 (13) ◽  
pp. 7148
Author(s):  
Wenjie Zhang ◽  
Mingyong Hong ◽  
Juan Li ◽  
Fuhong Li
Keyword(s):  
Carbon Dioxide ◽  
Carbon Emissions ◽  
Carbon Dioxide Emissions ◽  
Industrial Structure ◽  
Emissions Reduction ◽  
Green Finance ◽  
Carbon Emissions Reduction ◽  
Negative Effect ◽  
Emissions Intensity ◽  
The Impact

The implementation of green finance is a powerful measure to promote global carbon emissions reduction that has been highly valued by academic circles in recent years. However, the role of green credit in carbon emissions reduction in China is still lacking testing. Using a set of panel data including 30 provinces and cities, this study focused on the impact of green credit on carbon dioxide emissions in China from 2006 to 2016. The empirical results indicated that green credit has a significantly negative effect on carbon dioxide emissions intensity. Furthermore, after the mechanism examination, we found that the promotion impacts of green credit on industrial structure upgrading and technological innovation are two effective channels to help reduce carbon dioxide emissions. Heterogeneity analysis found that there are regional differences in the effect of green credit. In the western and northeastern regions, the effect of green credit is invalid. Quantile regression results implied that the greater the carbon emissions intensity, the better the effect of green credit. Finally, a further discussion revealed there exists a nonlinear correlation between green credit and carbon dioxide emissions intensity. These findings suggest that the core measures to promote carbon emission reduction in China are to continue to expand the scale of green credit, increase the technology R&D investment of enterprises, and to vigorously develop the tertiary industry.

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