Evaluation of clogging effects on nonwoven geotextile filters by negative-ion treatment

2008 ◽  
Vol 9 (3) ◽  
pp. 365-373 ◽  
Author(s):  
Kwangyeol Lee ◽  
Hanyong Jeon
Keyword(s):  
Negative Ion ◽  
Geotextile Filters ◽  
Nonwoven Geotextile ◽  
Ion Treatment

Negative ion treatment increases positive emotional processing in seasonal affective disorder

2011 ◽  
Vol 42 (8) ◽  
pp. 1605-1612 ◽  
Author(s):  
C. J. Harmer ◽  
M. Charles ◽  
S. McTavish ◽  
E. Favaron ◽  
P. J. Cowen
Keyword(s):  
Recognition Memory ◽  
Affective Disorder ◽  
Emotional Processing ◽  
Seasonal Affective Disorder ◽  
Negative Ion ◽  
Treatment Modalities ◽  
Common Mechanism ◽  
Healthy Controls ◽  
Seasonal Depression ◽  
Ion Treatment

BackgroundAntidepressant drug treatments increase the processing of positive compared to negative affective information early in treatment. Such effects have been hypothesized to play a key role in the development of later therapeutic responses to treatment. However, it is unknown whether these effects are a common mechanism of action for different treatment modalities. High-density negative ion (HDNI) treatment is an environmental manipulation that has efficacy in randomized clinical trials in seasonal affective disorder (SAD).MethodThe current study investigated whether a single session of HDNI treatment could reverse negative affective biases seen in seasonal depression using a battery of emotional processing tasks in a double-blind, placebo-controlled randomized study.ResultsUnder placebo conditions, participants with seasonal mood disturbance showed reduced recognition of happy facial expressions, increased recognition memory for negative personality characteristics and increased vigilance to masked presentation of negative words in a dot-probe task compared to matched healthy controls. Negative ion treatment increased the recognition of positive compared to negative facial expression and improved vigilance to unmasked stimuli across participants with seasonal depression and healthy controls. Negative ion treatment also improved recognition memory for positive information in the SAD group alone. These effects were seen in the absence of changes in subjective state or mood.ConclusionsThese results are consistent with the hypothesis that early change in emotional processing may be an important mechanism for treatment action in depression and suggest that these effects are also apparent with negative ion treatment in seasonal depression.

scholarly journals Effect of the Number of Constrictions on the Filtration Behaviour of a Soil-Geotextile System

2020 ◽  
Vol 28 (1(139)) ◽  
pp. 87-92
Author(s):  
Anna Miszkowska ◽  
Anna Miszkowska ◽  
Eugeniusz Koda ◽  
Zygmunt Krzywosz
Keyword(s):  
Selection Criteria ◽  
Fine Particles ◽  
Filter Design ◽  
Ratio Test ◽  
Flow Through ◽  
Gradient Ratio ◽  
Geotextile Filters ◽  
Nonwoven Geotextile ◽  
Geotextile Filter ◽  
Base Soil

Nonwoven geotextile filters have been used in geo-environmental engineering for decades to prevent the movement of base soil fine particles, allowing adequate seepage to flow through the geotextile plane. Most of the design criteria developed for nonwoven geotextiles are based only on the comparison between their characteristic opening size and the indicative diameter of the soil to be filtered. In the meantime, the nonwoven geotextile fibrous structure has an influence on the filtration of the soil-geotextile system. In this paper the numbers of constrictions of nonwoven geotextile samples were determined to verify the existence of a correlation between the geotextile structure and the filtration behaviour of soil-geotextile systems. The compatibility between an internally unstable soil and a nonwoven geotextile filter was evaluated using the gradient ratio test. The results obtained can also be the basis for modifying the geotextile filter design and selection criteria.

Influence of polyurethane foam on chemical clogging of nonwoven geotextile and tailings caused by ferrous iron

2020 ◽  
pp. 004051752097345
Author(s):  
Sheng Liu ◽  
Yuan Wang ◽  
Di Feng
Keyword(s):  
Polyurethane Foam ◽  
Ferrous Iron ◽  
Water Saturation ◽  
High Water ◽  
Hydraulic Gradient ◽  
Column Tests ◽  
Hydraulic Gradients ◽  
Geotextile Filters ◽  
Nonwoven Geotextile ◽  
Engineering Projects

The chemical clogging of geotextiles filters is a common issue, which threatens the safety of engineering projects. To reduce the chemical clogging of nonwoven geotextiles and enhance their drainage capability, a polyurethane foam was innovatively placed under the nonwoven geotextiles in this paper. A series of column tests were conducted to study the mechanism of the polyurethane foam to reduce the chemical clogging of the nonwoven geotextile filters in tailings caused by ferrous iron. In addition, the influence of the concentration of Fe2+, hydraulic gradient and thickness of the tailings specimen on the chemical clogging of the polyurethane foam and nonwoven geotextiles was examined. Less chemical clogging of geotextiles caused by polyurethane foam was observed and the related mechanism was firstly explained. The polyurethane foam under the geotextile reduced the contact between the geotextile and air. As a result, the chemical clogging of the geotextile was alleviated, which increased the drainage capability of the geotextiles. A high water saturation of the polyurethane foam would help to a reduce the extent of the chemical clogging of the geotextile. The chemical clogging characteristics of geotextiles and polyurethane foam under different concentrations of Fe2+ and hydraulic gradients were observed.

scholarly journals Research Letter: High-density negative ion treatment increases positive affective memory

2009 ◽  
Vol 39 (11) ◽  
pp. 1930-1932 ◽  
Author(s):  
C. P. MALCOLM ◽  
P. J. COWEN ◽  
C. J. HARMER
Keyword(s):  
High Density ◽  
Negative Ion ◽  
Ion Treatment

Confounding contaminants in mass spectrometric reaction monitoring

2018 ◽  
Author(s):  
Gilian T. Thomas ◽  
Landon MacGillivray ◽  
Natalie L. Dean ◽  
Rhonda L. Stoddard ◽  
Lars Yunker ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Reaction Monitoring ◽  
Schlenk Flask ◽  
Dynamic Analyses ◽  
Rubber Septa ◽  
Negative Ion Mode ◽  
Mode A

<p>Reactions carried out in the presence of rubber septa run the risk of additives being leached out by the solvent. Normally, such species are present at low enough levels that they do not interfere with the reaction significantly. However, when studying reactions using sensitive methods such as mass spectrometry, the appearance of even trace amounts of material can confuse dynamic analyses of reactions. A wide variety of additives are present in rubber along with the polymer: antioxidants, dyes, detergent, and vulcanization agents, and these are all especially problematic in negative ion mode. A redesigned Schlenk flask for pressurized sample infusion (PSI) is presented as a means of practically eliminating the presence of contaminants during reaction analyses.</p>

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