scholarly journals Sustainable Ecocements: Chemical and Morphological Analysis of Granite Sawdust Waste as Pozzolan Material

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4941
Author(s):  
Santiago Yagüe ◽  
Cristina González Gaya ◽  
Victor Rosales Prieto ◽  
Alberto Sánchez Lite

The processes focused on stone cutting generate a large volume of waste. Small size waste, silt/clay, is not used and goes to landfill. However, the composition of these wastes makes them useful for adding to cements and for use in construction. In the present paper, 10% Ordinary Portland cement is replaced by 10% waste from granite sawmill, which is studied to obtain sustainable ecological cement. This replacement provides advantages from the morphological and chemical point of view at the cements. The waste has a particle size that does not exceed 15 µm and that when replacing in the cement, after the hydration reaction, generates structures where Calcium Silicate Hydrate (C-S-H) gels and double layered hydroxide compounds (LDH) are reaction products formed in high concentration. These products develop stable phases in the structures over long time periods such one year, which was the time frame used in this study.

2012 ◽  
pp. 66-80
Author(s):  
Michał Mrozowicki

Michel Butor, born in 1926, one of the leaders of the French New Novel movement, has written only four novels between 1954 and 1960. The most famous of them is La Modification (Second thoughts), published in 1957. The author of the paper analyzes two other Butor’s novels: L’Emploi du temps (Passing time) – 1956, and Degrés (Degrees) – 1960. The theme of absence is crucial in both of them. In the former, the novel, presented as the diary of Jacques Revel, a young Frenchman spending a year in Bleston (a fictitious English city vaguely similar to Manchester), describes the narrator’s struggle to survive in a double – spatial and temporal – labyrinth. The first of them, formed by Bleston’s streets, squares and parks, is symbolized by the City plan. During his one year sojourn in the city, using its plan, Revel learns patiently how to move in its different districts, and in its strange labyrinth – strange because devoid any centre – that at the end stops annoying him. The other, the temporal one, symbolized by the diary itself, the labyrinth of the human memory, discovered by the narrator rather lately, somewhere in the middle of the year passed in Bleston, becomes, by contrast, more and more dense and complex, which is reflected by an increasinly complex narration used to describe the past. However, at the moment Revel is leaving the city, he is still unable to recall and to describe the events of the 29th of February 1952. This gap, this absence, symbolizes his defeat as the narrator, and, in the same time, the human memory’s limits. In Degrees temporal and spatial structures are also very important. This time round, however, the problems of the narration itself, become predominant. Considered from this point of view, the novel announces Gerard Genette’s work Narrative Discourse and his theoretical discussion of two narratological categories: narrative voice and narrative mode. Having transgressed his narrative competences, Pierre Vernier, the narrator of the first and the second parts of the novel, who, taking as a starting point, a complete account of one hour at school, tries to describe the whole world and various aspects of the human civilization for the benefit of his nephew, Pierre Eller, must fail and disappear, as the narrator, from the third part, which is narrated by another narrator, less audacious and more credible.


2014 ◽  
pp. 156-163
Author(s):  
Simona Jişa

Jean Echenoz’s text presents Victoria’s story who runs away from Paris, believing that she has killed her lover. Her straying (that embraces the form of a relative deterritorialization in a Deleuzian sense) lasts one year and it is built up geographically upon a descent (more or less symbolical) to the South of France and, after that, she comes back to Paris and encloses the spatial and textual curl. From a spatial point of view, she turns into a heterotopia (Foucault) every place where she is located, fact that reflects her incapability of constituting a personal, intimate space. The railway stations, the trains, the hotels, the improvised houses of those with no fixed abode are turning, according to Marc Augé’s terminology, into a « non-lieux » that excludes human being. Her vagrancy is characterized through a continuous flight from police and people and through a continuous decrease of her standard of living and dignity. It’s not about a quest of oneself, but about a loss of oneself. Urged by a strong feeling of culpability, her vagrancy is a self-punishment that comes to an end when the concerns of her problems disappear and she finds out that her lover is alive.


2014 ◽  
Vol 29 (2) ◽  
pp. 271-279 ◽  
Author(s):  
Mikko Tuominen ◽  
Hannu Teisala ◽  
Janne Haapanen ◽  
Mikko Aromaa ◽  
Jyrki M. Mäkelä ◽  
...  

Abstract Superhydrophobic nanoparticle coating was created on the surface of board using liquid flame spray (LFS). The LFS coating was carried out continuously in ambient conditions without any additional hydrophobization steps. The contact angle of water (CAW) of ZrO2, Al2O3 and TiO2 coating was adjusted reversibly from >150° down to ~10−20° using different stimulation methods. From industrial point of view, the controlled surface wetting has been in focus for a long time because it defines the liquid-solid contact area, and furthermore can enhance the mechanical and chemical bonding on the interface between the liquid and the solid. The used stimulation methods included batch-type methods: artificial daylight illumination and heat treatment and roll-to-roll methods: corona, argon plasma, IR (infra red)- and UV (ultra violet)-treatments. On the contrary to batch-type methods, the adjustment and switching of wetting was done only in seconds or fraction of seconds using roll-to-roll stimulation methods. This is significant in the converting processes of board since they are usually continuous, high volume operations. In addition, the creation of microfluidic patterns on the surface of TiO2 coated board using simple photomasking and surface stimulation was demonstrated. This provides new advantages and possibilities, especially in the field of intelligent printing. Limited durability and poor repellency against low surface tension liquids are presently the main limitations of LFS coatings.


2020 ◽  
Vol 1 (1) ◽  
pp. 32-37
Author(s):  
I. Naydenova

As a research area, interior design took shape in the 20s of the last century, despite the fact that the practice of decorating living spaces dates back many hundreds of years. However, the "self-sufficiency" of design and its connection with architecture to this day is the subject of scientific discussions of urban specialists, historians, art historians, and anthropologists. The article discusses the leading artistic styles and trends that prevailed in architecture and design from the point of view of their mutual influence on each other. Time frame of the research: from the middle of XIX century to the first half of XX century. As a result of the research of foreign experience in the formation of interior design, the main stages of the movement development and its relationship with architecture in two formations were identified: activities directly dependent on architectural decisions, activities that determine the entire design process to a large extent: from the functional zoning of the premises to the features of the placement of utilities in the building. Entering the information era in art as a whole is characterized by the rejection of slogans that clearly delineate stylistic boundaries and determine the role of a designer in creating the living space. The determining factor influencing the integrity of the building’s appearance in a modern view is the harmony of the facade and the internal content, which was made possible thanks to the equal interaction of the architect and designer, starting from the first half of the 20th century.


2020 ◽  
Vol 13 (1) ◽  
pp. 31
Author(s):  
Enrico Creaco ◽  
Giacomo Galuppini ◽  
Alberto Campisano ◽  
Marco Franchini

This paper presents a two-step methodology for the stochastic generation of snapshot peak demand scenarios in water distribution networks (WDNs), each of which is based on a single combination of demand values at WDN nodes. The methodology describes the hourly demand at both nodal and WDN scales through a beta probabilistic model, which is flexible enough to suit both small and large demand aggregations in terms of mean, standard deviation, and skewness. The first step of the methodology enables generating separately the peak demand samples at WDN nodes. Then, in the second step, the nodal demand samples are consistently reordered to build snapshot demand scenarios for the WDN, while respecting the rank cross-correlations at lag 0. The applications concerned the one-year long dataset of about 1000 user demand values from the district of Soccavo, Naples (Italy). Best-fit scaling equations were constructed to express the main statistics of peak demand as a function of the average demand value on a long-time horizon, i.e., one year. The results of applications to four case studies proved the methodology effective and robust for various numbers and sizes of users.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 152
Author(s):  
Hernan Vanegas ◽  
Fredman González ◽  
Yaoska Reyes ◽  
Edwing Centeno ◽  
Jayrintzina Palacios ◽  
...  

Zika virus (ZIKV) RNA has been found to remain in human semen for up to one year after infection, but the presence of Flavivirus antigens in the different compartments of semen has been largely unexplored. Following the introduction of ZIKV in Nicaragua (2016), a prospective study of patients with clinical symptoms consistent with ZIKV was conducted in León to investigate virus shedding in different fluids. ZIKV infection was confirmed in 16 male subjects (≥18 years of age) by RT-qPCR in either blood, saliva or urine. Of these, three provided semen samples at 7, 14, 21, 28, 60 and 180 days postsymptom onset (DPSO) for Flavivirus antigens and RNA studies. These cases were compared with 19 asymptomatic controls. Flavivirus antigens were examined by immunofluorescence (IF) using the 4G2 Mabs, and confocal microscopy was used to explore fluorescence patterns. The three (100%) symptomatic subjects and 3 (16%) of the 19 asymptomatic subjects had Flavivirus antigens and viral RNA in the spermatozoa fraction. The percentage of IF Flavivirus-positive spermatozoa cells ranged from 1.9% to 25% in specimens from symptomatic subjects, as compared with 0.8% to 3.8% in specimens from asymptomatic controls. A marked IF-pattern in the cytoplasmic droplets and tail of the spermatozoa was observed. The sperm concentrations (45 × 106/mL vs. 63.5 × 106/mL, p = 0.041) and the total motility percentage (54% vs. 75%, p = 0.009) were significantly lower in specimens from ZIKV-positive than in those of ZIKV-negative. In conclusion, this study demonstrated the presence of Flavivirus antigens and RNA within a time frame of 28 DPSO in sperm cells of symptomatic and asymptomatic subjects during the ZIKV epidemic. These findings have implications for public health, in terms of nonarthropod-born, silent transmission facilitated by sperm cells and potential transmission from asymptomatic males to pregnant women, with consequences to the fetus.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1823
Author(s):  
Won-Kyung Kim ◽  
Young-Ho Kim ◽  
Gigwon Hong ◽  
Jong-Min Kim ◽  
Jung-Geun Han ◽  
...  

This study analyzed the effects of applying highly concentrated hydrogen nanobubble water (HNBW) on the workability, durability, watertightness, and microstructure of cement mixtures. The number of hydrogen nanobubbles was concentrated twofold to a more stable state using osmosis. The compressive strength of the cement mortar for each curing day was improved by about 3.7–15.79%, compared to the specimen that used general water, when two concentrations of HNBW were used as the mixing water. The results of mercury intrusion porosimetry and a scanning electron microscope analysis of the cement paste showed that the pore volume of the specimen decreased by about 4.38–10.26%, thereby improving the watertightness when high-concentration HNBW was used. The improvement in strength and watertightness is a result of the reduction of the microbubbles’ particle size, and the increase in the zeta potential and surface tension, which activated the hydration reaction of the cement and accelerated the pozzolanic reaction.


2021 ◽  
Vol 13 (15) ◽  
pp. 8499
Author(s):  
Monika Blišťanová ◽  
Michaela Tirpáková ◽  
Ľubomíra Brůnová

The year 2020 was very challenging for the whole world, given the outbreak of the ongoing coronavirus-related pandemic, and was marked in particular by overcoming new hitherto unknown obstacles. For air transport, in particular, airlines stopped flying altogether and were forced to ground hundreds of planes worldwide involuntarily. Airports had to close their terminals for a long time, wholly suspend operations, and its resumption required significant organizational changes. This article summarizes the measures related to the COVID-19 pandemic adopted by airports to minimize the risk of spreading the disease. The article focuses on countermeasures and their implementation at selected airports in a specific time frame and airports’ behavior during a pandemic which varies depending on country and time of the year. The results demonstrated that steps being taken at airports include the use of face coverings or masks, social distance, enhanced cleaning and disinfection, or temperature checks and/or symptoms (fever, loss of smell, chills, cough, shortness of breath), RT-PCR (reverse transcription-polymerase chain reaction) screening and data collection with health declaration. These measures have now become an essential standard for the operation of airports and can, therefore, be used to assess the level of airport safety achieved. In the final phase, the article evaluates the level of achieved airport safety based on the proposed scoring method.


2017 ◽  
Vol 14 (3) ◽  
pp. 228-240 ◽  
Author(s):  
Riana Rahmawati ◽  
Beata Bajorek

Objectives This study aimed to explore perspectives about hypertension from patients who do not take anti-hypertensive medications. Factors that shape their perspectives as well as patients’ expectations were also canvassed. Method Individual, face-to-face interviews were conducted with 30 people (≥45 years old) living in rural villages, diagnosed with hypertension, who had not taken any anti-hypertensive medications for at least one year. Interviews were audiotaped, transcribed verbatim and thematically analysed. Results Four themes emerged: (1) alternative medicines for managing high blood pressure; (2) accessing health care services; (3) the need for anti-hypertensive medications; and (4) existing support and patients’ expectations. Reluctance to take anti-hypertensive medications was influenced by patients’ beliefs in personal health threats and the effectiveness of anti-hypertensive medications, high self-efficacy for taking alternative medicines, the lack of recommendation regarding hypertension treatment, and barriers to accessing supplies of medicines. Conclusion Despite their awareness of being diagnosed with hypertension, patients undervalued visiting a health professional to control their high blood pressure. Health strategies need to consider patients’ beliefs, concerns and expectations. Providing an accessible, affordable and adequate supply of hypertension medication is also key to any programs designed to optimise hypertension management.


2014 ◽  
Vol 28 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Thomas E. Lovejoy

One of the fundamental challenges of climate change is that we contribute to it increment by increment, and experience it increment by increment after a considerable time lag. As a consequence, it is very difficult to see what we are doing to ourselves, to future generations, and to the living planet as a whole. There are monumental ethical issues involved, but they are obscured by the incremental nature of the process and the long time frame before reaching the concentration of greenhouse gases and the ensuing accumulation of radiant heat—and consequent climate change—that ensues.


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