The study investigated the low-temperature preparation of belite (β-C2S) from a mixture of lime and white sand using hydrothermal treatment and calcination. Sodium hydroxide was added at concentrations of 0.5M, 2M, and 5M to influence the reaction. The addition of NaOH changed the composition of products, with different amounts of β-C2S and other calcium and sodium silicate phases produced depending on the NaOH concentration. The optimum condition for producing belite cement rich in β-C2S (77.7%) was hydrothermal treatment with 2M NaOH followed by calcination.
A topic of organotransition metal chemistry which is a part of course taught in university of Sargodha in BS chemistry 8th Smester in Inorganic Chemistry Minor
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A topic of organotransition metal chemistry which is a part of course taught in university of Sargodha in BS chemistry 8th Smester in Inorganic Chemistry Minor
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Concrete is one of the reliable, durable, economical and acceptable construction materials among the building and construction stakeholders worldwide. Performance of concrete could be threatened especially reinforced concrete by some processes such as corrosion, sulfate attack among others. Corrosion of reinforcement in reinforced concrete can be induced by carbonation process. Even though carbonation initiates corrosion, it has been gathered that carbonation could still be of immense benefits to building and construction industries if its mechanism of operation is understudied. This research work has therefore investigated the effect of carbonation on some selected mechanical properties of concrete such as compressive strength, flexural strength, water absorption and weight changes. Concrete cubes and beams of M15 grade with 0.5 % water-cement ratio were prepared and subjected to accelerated carbonation. Their compressive strength, flexural strength, water absorption and weight changes were determined in accordance with the relevant standards. The outcomes show that carbonation improves all the mechanical properties investigated. The use of carbonation can be positively explored in reinforced concrete provided there is adequate nominal cover.
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us: http://www.infomaticaacademy.com/
torm water normally refers to any precipitation that occurs during a rainstorm. At times, the term is used to specifically identify snowmelt or any other type of water that is not readily absorbed into the ground. In cities, this type of water is sometimes known as runoff water, referring to rain that is routed into sewage systems by way of drains. One of the major concerns with storm water today is the potential for polluting bodies of water as the runoff makes its ways to rivers, streams, and lakes.
Mechanism of different chemical attacks in a concrete like chloride attack, sulfate attack , which causes corrosion and spalling. Other reactions are alkali aggregate reaction , alkali silica reaction in concrete etc.
Recycling of hydrated Portland cement paste into new clinkershivakumar m naidu
The recycling of concrete is essential because it reduces the environmental impact of concrete construction
and demolition waste. For recycling, concrete waste is crushed and the coarse fraction of crushed
material can be recycled as a coarse aggregate. Concrete waste fines, which are a mix of fine aggregates,
coarse aggregate debris, and the hydrated cement paste, are currently not a part of the recycling process.
Since hydrated cement paste has all the necessary chemical elements for clinker production but without
heavy carbon dioxide emissions associated with traditional clinker raw material, it would be beneficial to
recycle concrete fines for the production of clinker. However, the data available in the literature about the
transformations of hydrated cement paste upon heating are contradictory. It is not clear whether
hydrated cement paste can be converted back to clinker. In this research, the phase transformations in
hydrated cement paste upon heating in the temperature range from 600 to 1450 C were investigated
using thermal analysis and X-ray diffractometry. The results show that hydrated Portland cement paste
can be completely recovered into a new clinker using a thermal treatment. The main phase transformations
during heating are described and compared to the literature data. The results indicate a great potential
for the complete recycling of concrete fines for the production of cement with a low carbon footprint
Concrete is one of the reliable, durable, economical and acceptable construction materials among the building and construction stakeholders worldwide. Performance of concrete could be threatened especially reinforced concrete by some processes such as corrosion, sulfate attack among others. Corrosion of reinforcement in reinforced concrete can be induced by carbonation process. Even though carbonation initiates corrosion, it has been gathered that carbonation could still be of immense benefits to building and construction industries if its mechanism of operation is understudied. This research work has therefore investigated the effect of carbonation on some selected mechanical properties of concrete such as compressive strength, flexural strength, water absorption and weight changes. Concrete cubes and beams of M15 grade with 0.5 % water-cement ratio were prepared and subjected to accelerated carbonation. Their compressive strength, flexural strength, water absorption and weight changes were determined in accordance with the relevant standards. The outcomes show that carbonation improves all the mechanical properties investigated. The use of carbonation can be positively explored in reinforced concrete provided there is adequate nominal cover.
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us: http://www.infomaticaacademy.com/
torm water normally refers to any precipitation that occurs during a rainstorm. At times, the term is used to specifically identify snowmelt or any other type of water that is not readily absorbed into the ground. In cities, this type of water is sometimes known as runoff water, referring to rain that is routed into sewage systems by way of drains. One of the major concerns with storm water today is the potential for polluting bodies of water as the runoff makes its ways to rivers, streams, and lakes.
Mechanism of different chemical attacks in a concrete like chloride attack, sulfate attack , which causes corrosion and spalling. Other reactions are alkali aggregate reaction , alkali silica reaction in concrete etc.
Recycling of hydrated Portland cement paste into new clinkershivakumar m naidu
The recycling of concrete is essential because it reduces the environmental impact of concrete construction
and demolition waste. For recycling, concrete waste is crushed and the coarse fraction of crushed
material can be recycled as a coarse aggregate. Concrete waste fines, which are a mix of fine aggregates,
coarse aggregate debris, and the hydrated cement paste, are currently not a part of the recycling process.
Since hydrated cement paste has all the necessary chemical elements for clinker production but without
heavy carbon dioxide emissions associated with traditional clinker raw material, it would be beneficial to
recycle concrete fines for the production of clinker. However, the data available in the literature about the
transformations of hydrated cement paste upon heating are contradictory. It is not clear whether
hydrated cement paste can be converted back to clinker. In this research, the phase transformations in
hydrated cement paste upon heating in the temperature range from 600 to 1450 C were investigated
using thermal analysis and X-ray diffractometry. The results show that hydrated Portland cement paste
can be completely recovered into a new clinker using a thermal treatment. The main phase transformations
during heating are described and compared to the literature data. The results indicate a great potential
for the complete recycling of concrete fines for the production of cement with a low carbon footprint
Concrete Construction: Batching of mixes; casting process, compaction and curing;
requirement of mix design and casting of test cubes – removing cubes from moulds and
curing for strength tests; bar-bending equipments and preparation of reinforcement for
R C C works
Chemical Design, Synthesis and Bio-efficacy Screening of New Growth Inhibitor...CrimsonPublishersACSR
The present work aimed to find new growth inhibitors agents spodoptera littoralis (Boisd.), several
inhibitors structurally relevant to the insect growth regulator, Fenoxycarb and the naturally transpiring
juvenile hormone of insects were chemically designed, prepared and evaluated as anti-proliferative agents.
Epihalohydrins derivatives have been synthesized and their agricultural bio-efficacy as insecticides
against spodoptera littoralis (Boisd.). Insecticidal bio-efficacy data showed that that some compounds are
very active against spodoptera littoralis (Boisd.)
Recent cases of casualty of workers in rubber latex factories due to hydrogen sulfide call for urgent
attention to better understanding, prevention of damages in working and living in risky environments,
and promotion of public and labor awareness. Specific responsible organization here is the subcontractor
of latex factories. H2
S characteristics, sources and symptoms from exposure are emphasized. Proper
practice should be followed strictly along with better cooperation among experts for the main objective
in saving lives and greater safety in living and working.
Design, Synthesis and Structural Inspection of Some Novel Di- And Tri-Azometh...CrimsonPublishersACSR
In this study, NBA imine compound was synthesized via an easy one-pot condensation of 3-nitro-benzaldyhide with 2-amino benzoic acid in 1:1 ratio and DAPH imine compound derived from 2,6-diacetyl pyridine and phenyl hydrazine hydrochloride. Consequences of the newly synthesized compounds
hooked up with the aid of FT-IR, elemental analyses, 13C-NMR ,1H-NMR and digital spectral research.
Experiments had been consistent with their chemical structures. Theoretical DFT calculations had been
implemented to confirm the molecular geometry of the investigated chemo-sensors. The sensor property
of all organized imines had been tested upon addition of the metal ions, consisting of Cr(III) ,Fe(II) ,Co(II) ,
Ni(II) ,Cu(II) ,Zn(II) ,Mn(II), VO(II) and Pd(II) .The interactions among receptors and ions are effortlessly
monitored with the aid of UV-visible spectroscopy. DAPH receptor confirmed color modification from
blood red to excessive deep green color to Co(II) ,a yellow color to Cu(II) and different colors to different
ions. Where the NBA receptor showed color modification from light yellow to excessive deep orange color
to Fe(II), pale orange to Pd(II) and different colors for other ions.
Azomethine Metal Chelates as an Efficient Catalyst for Oxidation of Organic C...CrimsonPublishersACSR
Azomethine ligands and their metal chelates are flexible compounds synthesized from the condensation
of an amino compound with carbonyl compounds and extensively used for industrial purposes and also
show a broad range of biological efficiencies including antibacterial, antifungal, antiviral, antimalarial,
antiproliferative, anti-inflammatory, anticancer, anti-HIV, anthelminthic and antipyretic properties.
Azomethine metal chelates show excellent catalytic activity in diversity reactions. Over the past few
years, there have been many reports on their applications in homogeneous and heterogeneous catalysis.
The high thermal and moisture stabilities of many azomethine metal chelates were useful attributes for
their application as catalysts in reactions involving at high temperatures. Recent researches in oxidation
catalysis have focused on how to employ the metal-catalyzed oxidation of organic substrates. This review
concerns with the current developments for the oxidations of organic compounds.
With the objective of analyzing metal ions simultaneously in several samples which can be applied in
various areas, electrochemical methods based on anodic stripping voltammetry are prominent due to
the fact that their analytical performance can be increased by electrode modifications. The development
of electrodes and methods together with the availability of small and low cost instrument would be
beneficial for onsite analysis and makes it much more practical.
Study of Temporal Trends of Pollution in the Russian Coastal Areas of the Bla...CrimsonPublishersACSR
Study of Temporal Trends of Pollution in the Russian Coastal Areas of the Black Sea by Nuclear and Related Analytical Techniques by Frontasyeva MV in Annals of Chemical Science Research
Botanic, Phytochemistry and Pharmacological Aspects of Phyllanthus Amarus Sch...CrimsonPublishersACSR
Botanic, Phytochemistry and Pharmacological Aspects of Phyllanthus Amarus Schum & Thorn as Powerful Tools to Improve its Biotechnological Studies by Maria Aparecida MM in Annals of Chemical Science Research
Properties of Zinc Phosphate Coatings on Carbon Steel Using a Thermostatic Ce...CrimsonPublishersACSR
Properties of Zinc Phosphate Coatings on Carbon Steel Using a Thermostatic Cell and a Mobile System by Reyes Astivia MJE, Torres JV*, Barrera GM and Díaz CB in Annals of Chemical Science Research
Characterization of Rubber Seed Shell and Kernel (Hevea brasiliensis) as Raw ...CrimsonPublishersACSR
Characterization of Rubber Seed Shell and Kernel
(Hevea brasiliensis) as Raw Materials for Coliquefaction with Low Rank Coal by Mohd Azlan Mohd Ishak*, Siti Nur Ain Mohd Hassan, Ali H Jawad and Khudzir Ismail in Annals of Chemical Science Research
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
Low-Temperature Preparation of β-C2S from Sand/Lime Mixture: Influence of Sodium Hydroxide_Crimson Publishers
1. Low-Temperature Preparation of β-C2
S from
Sand/Lime Mixture: Influence of Sodium
Hydroxide
Tantawy MA*
Chemistry Department, Egypt
The Common Phases that Appeared in the study and their Formula
Phase Formula
Afwillite Ca3
Si2
O8
(OH)2
(H2
O)2
Alite, C3
S Ca3
SiO5
Belite (β-C2
S) Ca2
SiO4
Calcite CaCO3
Combeite Na4
Ca4
(Si6
O18
)
Dellaite Ca6
(SiO4
) (Si2
O7
) (SiO4
) (OH)2
α-Dicalcium silicate hydrate Ca2
(HSiO4
) (OH)
Gehlenite Ca2
Al [AlSiO7
]
Hillebrandite (dicalcium silicate hydrate) Ca2
(SiO3
) (OH)2
Kaolinite Al2
Si2
O5
(OH)4
Lime CaO
Mayenite Ca12
Al14
O33
Portlandite Ca (OH)2
Quartz SiO2
Rankinite Ca3
Si2
O7
Sodium-calcium silicate Na2
Ca3
(Si3
O10
)
Sodium-hydrogen silicate hydrate Na2
(H2
SiO4
).7H2
O
Xonotlite Ca6
Si6
O17
(OH)2
Crimson Publishers
Wings to the Research
Research Article
*Corresponding author: Tantawy MA,
Chemistry Department, Egypt
Submission: May 11 2019
Published: May 28, 2019
Volume 1 - Issue 3
How to cite this article: Tantawy MA.
Low-Temperature Preparation of β-C2
S
from Sand/Lime Mixture: Influence of
Sodium Hydroxide. Ann Chem Sci Res.
1(2).ACSR.000512.2019.
Copyright@ Tantawy MA, This article is
distributed under the terms of the Creative
Commons Attribution 4.0 International
License, which permits unrestricted use
and redistribution provided that the
original author and source are credited.
1Annals of Chemical Science Research
Abstract
The low-temperature preparation of belite (β-C2S) from a mixture of lime and white sand (Ca/Si=2)
in presence of 0.5-5 M NaOH solution was investigated by hydrothermal treatment in a stainless steel
capsule at 135 ̊C for 3 hours followed by calcination at 1000 ˚C for 3 hours. All materials were analyzed
by FTIR, SEM-EDX, and XRD with semi-quantitative phase analysis calculation. The addition of NaOH
changed the composition of the hydrothermal and calcination products. Different percent of β-C2S and
other calcium and sodium silicate phases were produced with increasing the concentration of NaOH.
In presence of 0.5M NaOH, 32.6% of β-C2S formed with the formation of calcium silicate with mole
ratio CaO/SiO2=1.5 (rankinite, 30.9%) and sodium-calcium silicate (combeite, 8.6%). Whereas, in the
presence of 5M NaOH, the hydrothermal reaction between lime and silica was effectively deactivated i.e.
32.9% of β-C2S formed. The formation of sodium silicate (31%), rankinite (15.4%) and sodium-calcium
silicate (16.7%) phases were encouraged. The optimum condition for preparation of low-temperature
β-C2S rich cement from lime and sand under these conditions can be achieved by the addition of 2M
NaOH were, 77.7% of β-C2S formed and 12.4% combeite.
Keywords: White sand; Lime; Hydrothermal treatment; Calcination