Some Insights on the Role of Relative Humidity and Compaction on the Carbonation Rate of CaO/SiO2 (50/50) Clinker

2016 ◽  
Vol 711 ◽  
pp. 837-843
Author(s):  
Marco Agnelli ◽  
Bruno Huet ◽  
Vincent Briaud ◽  
Elodie André ◽  
Alexander Pisch
Keyword(s):  
Relative Humidity ◽  
Reaction Rate ◽  
Mass Gain ◽  
Testing Procedure ◽  
Phase Assemblage ◽  
Carbonation Reaction ◽  
Curing Conditions ◽  
The Relationship ◽  
Mineralogical Assemblage

This paper focuses on the carbonation of non-hydraulic binders based primarily on wollastonite (CaSiO3) in order to study the relationship between clinker composition, curing conditions and compaction on carbonation reaction rate. Decoupled carbonation and drying experiments are carried out using cements at different CaO/SiO2 ratio, at 60 °C, 1 bar of CO2 and multiple RH (relative humidity) and compaction degrees. Solid analysis include mass gain or loss, TGA, XRF and Carbon/Hydrogen (CH) to determine respectively the bound H2O content, CO2 content and the mineralogical assemblage. Relative humidity strongly influences carbonation intrinsic reaction rate, while compaction seems to be a second order mechanism. Testing procedure can be used to discriminate the reactivity of clinkers with various initial phase assemblage.

The Role of the Kaolinite-Mullite Reaction Sequence in Moisture Mass Gain in Fired Kaolinite

2010 ◽  
Vol 68 ◽  
pp. 38-43 ◽  
Author(s):  
Hesham Mesbah ◽  
Moira A. Wilson ◽  
Margaret A. Carter
Keyword(s):  
Relative Humidity ◽  
Mass Gain ◽  
High Accuracy ◽  
Atmospheric Moisture ◽  
Reaction Sequence ◽  
Fourth Root ◽  
Aluminosilicate Mineral ◽  
Mass Increase ◽  
Traditional Ceramics

Kaolinite (2SiO2.Al2O3.2H¬¬¬¬2O), an aluminosilicate mineral, is the most common constituent mineral in clay used in manufacturing traditional ceramics such as whitewares, some refractories and structural clay products. On firing, kaolin (mainly kaolinite) undergoes several phase transformations. Immediately following firing, kaolin starts to chemically combine with atmospheric moisture. This reaction causes a mass increase that is proportional to the fourth root of time. The consequence of this mass gain is an accompanying expansive strain. Kaolinite transformations following firing at a range of temperatures between 700 and 1200 oC were examined by XRD. Following firing, high accuracy mass gain measurements were carried out using a microbalance under precisely controlled conditions of temperature and relative humidity. It was found that the formation and development of crystalline phases increases with increasing firing temperature. This causes a reduction in the amorphous phase which, in turn, leads to reduced mass gain. Kaolin fired at 1200 oC exhibited the least reactivity with moisture and mullite was found to be the dominant crystalline phase after firing at that temperature. SEM was used to examine microstructural changes in the fired specimens. The reactivity of the ceramic with moisture is shown to be directly related to the crystallinity of the fired clay.

scholarly journals Speciation of Organic Aerosols in the Tropical Mid-Pacific and Their Relationship to Light Scattering

2004 ◽  
Vol 61 (21) ◽  
pp. 2544-2558 ◽  
Author(s):  
Kathleen K. Crahan ◽  
Dean A. Hegg ◽  
David S. Covert ◽  
Haflidi Jonsson ◽  
Jeffrey S. Reid ◽  
...  
Keyword(s):  
Light Scattering ◽  
Principal Component ◽  
Mass Gain ◽  
Organic Component ◽  
Research Platform ◽  
Marine Air ◽  
The Relationship ◽  
Aerosol Hygroscopicity

Abstract Although the importance of the aerosol contribution to the global radiative budget has been recognized, the forcings of aerosols in general, and specifically the role of the organic component in these forcings, still contain large uncertainties. In an attempt to better understand the relationship between the background forcings of aerosols and their chemical speciation, marine air samples were collected off the windward coast of Oahu, Hawaii, during the Rough Evaporation Duct project (RED) using filters mounted on both the Twin Otter aircraft and the Floating Instrument Platform (FLIP) research platform. Laboratory analysis revealed a total of 17 species, including 4 carboxylic acids and 2 carbohydrates that accounted for 74% ± 20% of the mass gain observed on the shipboard filters, suggesting a possible significant unresolved organic component. The results were correlated with in situ measurements of particle light scattering (σsp) at 550 nm and with aerosol hygroscopicities. Principal component analysis revealed a small but ubiquitous pollution component affecting the σsp and aerosol hygroscopicity of the remote marine air. The Princeton Organic-Electrolyte Model (POEM) was used to predict the growth factor of the aerosols based upon the chemical composition. This output, coupled with measured aerosol size distributions, was used to attempt to reproduce the observed σsp. It was found that while the POEM model was able to reproduce the expected trends when the organic component of the aerosol was varied, due to large uncertainties especially in the aerosol sizing measurements, the σsp predicted by the POEM model was consistently higher than observed.

scholarly journals The influence of relative humidity on fires in forests of Central Poland

2018 ◽  
Vol 79 (3) ◽  
pp. 269-279
Author(s):  
Krystyna Konca-Kędzierska ◽  
Krystyna Pianko-Kluczyńska
Keyword(s):  
Relative Humidity ◽  
Forest Fires ◽  
Cross Correlation ◽  
Fire Risk ◽  
Low Humidity ◽  
Cross Tabulation ◽  
The Relationship ◽  
Fire Information

Abstract The purpose of the present work was to answer the question of how and to what extent information about low air humidity in a selected area can be used in determining the fire risk. The central region as defined in the Classification of Territorial Units for Statistics (NUTS) was selected for the study, because this classification is also used in the National Fire Information System, which provides data on the number of forest fires. Data on humidity for a given region were taken from the synoptic or climatic station of The Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB) located in the region. Two independent experiments were conducted based on various methodological assumptions. In experiment A, the main focus was on humidity deficit, as defined by nine different indicators. Using the relative risk and the Jaccard index, their connection to fire cases of third class or higher was studied. A class reconstruction of the number of fires was also carried out using the fuzzy analogues method, and the obtained reconstructions were evaluated using cross-correlation indicators in contingency tables. In experiment B, correlation relationships between the number of fires and the annual characteristics of relative humidity were studied. In order to use the association measures in the cross-tabulation tables, the number of fires and humidity characteristics were categorised using quantiles. The relationship between the number of fires and the percentage share of low-humidity (<40%) days in the year was tested using the Mann–Whitney test. The obtained values of the examined correlation indices and the analysis of correlation relationships emphasise the important role of relative humidity dynamics in determining the fire risk.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Staring Down Death

Crisis ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Thomas E. Joiner ◽  
Melanie A. Hom ◽  
Megan L. Rogers ◽  
Carol Chu ◽  
Ian H. Stanley ◽  
...  
Keyword(s):  
Suicide Risk ◽  
Clinical Utility ◽  
Blink Rate ◽  
Specific Task ◽  
Careful Planning ◽  
Eye Blink ◽  
Eye Blinks ◽  
Potential Clinical Utility ◽  
The Relationship

Abstract. Background: Lowered eye blink rate may be a clinically useful indicator of acute, imminent, and severe suicide risk. Diminished eye blink rates are often seen among individuals engaged in heightened concentration on a specific task that requires careful planning and attention. Indeed, overcoming one’s biological instinct for survival through suicide necessitates premeditation and concentration; thus, a diminished eye blink rate may signal imminent suicidality. Aims: This article aims to spur research and clinical inquiry into the role of eye blinks as an indicator of acute suicide risk. Method: Literature relevant to the potential connection between eye blink rate and suicidality was reviewed and synthesized. Results: Anecdotal, cognitive, neurological, and conceptual support for the relationship between decreased blink rate and suicide risk is outlined. Conclusion: Given that eye blinks are a highly observable behavior, the potential clinical utility of using eye blink rate as a marker of suicide risk is immense. Research is warranted to explore the association between eye blink rate and acute suicide risk.

Parenting Behaviors and Anxiety in Young Adults

2015 ◽  
Vol 36 (3) ◽  
pp. 170-176 ◽  
Author(s):  
Erin N. Stevens ◽  
Joseph R. Bardeen ◽  
Kyle W. Murdock
Keyword(s):  
Effortful Control ◽  
Parenting Behaviors ◽  
Protective Role ◽  
Anxiety Symptoms ◽  
Interactive Effects ◽  
Parental Overprotection ◽  
High Control ◽  
Development Of Anxiety ◽  
The Relationship

Parenting behaviors – specifically behaviors characterized by high control, intrusiveness, rejection, and overprotection – and effortful control have each been implicated in the development of anxiety pathology. However, little research has examined the protective role of effortful control in the relation between parenting and anxiety symptoms, specifically among adults. Thus, we sought to explore the unique and interactive effects of parenting and effortful control on anxiety among adults (N = 162). Results suggest that effortful control uniquely contributes to anxiety symptoms above and beyond that of any parenting behavior. Furthermore, effortful control acted as a moderator of the relationship between parental overprotection and anxiety, such that overprotection is associated with anxiety only in individuals with lower levels of effortful control. Implications for potential prevention and intervention efforts which specifically target effortful control are discussed. These findings underscore the importance of considering individual differences in self-regulatory abilities when examining associations between putative early-life risk factors, such as parenting, and anxiety symptoms.

Social Support, Emotional Intelligence, and Posttraumatic Stress Disorder Symptoms

2016 ◽  
Vol 37 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Nicole L. Hofman ◽  
Austin M. Hahn ◽  
Christine K. Tirabassi ◽  
Raluca M. Gaher
Keyword(s):  
Social Support ◽  
Posttraumatic Stress Disorder ◽  
Emotional Intelligence ◽  
Protective Factors ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Traumatic Events ◽  
Ptsd Symptoms ◽  
The Relationship

Abstract. Exposure to traumatic events and the associated risk of developing Posttraumatic stress disorder (PTSD) symptoms is a significant and overlooked concern in the college population. It is important for current research to identify potential protective factors associated with the development and maintenance of PTSD symptoms unique to this population. Emotional intelligence and perceived social support are two identified protective factors that influence the association between exposure to traumatic events and PTSD symptomology. The current study examined the mediating role of social support in the relationship between emotional intelligence and PTSD symptoms. Participants included 443 trauma-exposed university students who completed online questionnaires. The results of this study indicated that social support mediates the relationship between emotional intelligence and reported PTSD symptoms. Thus, emotional intelligence is significantly associated with PTSD symptoms and social support may play an integral role in the relationship between emotional intelligence and PTSD. The current study is the first to investigate the role of social support in the relationship between emotional intelligence and PTSD symptoms. These findings have important treatment and prevention implications with regard to PTSD.

Coping Humor as a Mediator Between Emotional Intelligence and Job Satisfaction

2017 ◽  
Vol 16 (3) ◽  
pp. 155-159 ◽  
Author(s):  
Peizhen Sun ◽  
Jennifer J. Chen ◽  
Hongyan Jiang
Keyword(s):  
Job Satisfaction ◽  
Emotional Intelligence ◽  
Future Research ◽  
Satisfaction Scale ◽  
Primary School Teachers ◽  
Mediating Role ◽  
Regulation Of Emotion ◽  
The Relationship ◽  
Overall Job Satisfaction

Abstract. This study investigated the mediating role of coping humor in the relationship between emotional intelligence (EI) and job satisfaction. Participants were 398 primary school teachers in China, who completed the Wong Law Emotional Intelligence Scale, Coping Humor Scale, and Overall Job Satisfaction Scale. Results showed that coping humor was a significant mediator between EI and job satisfaction. A further examination revealed, however, that coping humor only mediated two sub-dimensions of EI (use of emotion and regulation of emotion) and job satisfaction. Implications for future research and limitations of the study are discussed.

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